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[Question] [ I am working on a story about a person who was raised on an earth-like planet and later moves to our earth. The planet he is from specializes in fruit juice and alcohol making, in specific, wine. When he gets to earth, he attempts to grow some of his grapes to make grape-juice to ferment. The problem is that once he makes this grape juice, it quickly ferments. This may not seem like a problem to us, but on his home planet, it takes much longer to ferment the juice past the first stage. (In most cases many years before it is ready to be aged) So, my question is, what specifically does it take to slow down fermentation to such a degree? (Temperature, atmospheric content, greenhouse gasses)? For this question, I'm assuming that the grapes he grew were the ones he brought from his home world, so they are the same and grow fine here. The yeast strain used is the same for both Earth and his home planet. So the causes for the slowing he was accustomed to are completely external. I am definitely not an expert on wine, so some further clarification might be needed. [Answer] @Thorne provides the obvious solution, but let's go a bit more in detail. Temperature This works in both directions. Too cold and the fermentation does not proceed as the yeast hibernates or dies from shock. Too hot and the yeast starts dying from shock as well as producing substances toxic to other yeast (organic processes are generally quite temperature sensitive). That said, you are more likely to get a quick fermentation if you run hot, and a slow (or non-starter) ferment if you are too cold. Nutrients Yeast requires various nutrients to survive. The most well known to brewers are organic nitrogen sources, as well as sugars. Yeast need simple carbohydrates that they can consume to breed. After the initial stage of reproduction, they require nitrogen sources, vitamins, and other micro-nutrients to survive. It could be the case that the "grapes" that this brewer uses are mostly simple sugars, which would slow down fermentation as well as increase the incidence of off flavours (requiring longer ageing). This is observable on Earth with the production of mead. Mead is made from honey, which is 78% sugar, and basically nothing else. Mead made without the use of additional nutrients generally requires significant ageing, often on the order of months and years. You mentioned that the brewer is still using the grapes from home, so unfortunately this doesn't work out for you. I've left it in for you reference if you need an additional reason. Yeast Strain Brewing yeast on Earth is bred to be reliable, produce a well-known ABV value, and withstand the stresses of a highly alcoholic environment. Throughout history, this was done via forced selection, where yeasts that made good alcohol would be re-used. In recent years, labs have bred yeast using various techniques to ensure that they perform well in making alcoholic beverages. It's possible that the yeast on the brewer's home planet was never commercially cultivated, and the wild yeast did not deal well with the stresses of alcoholic fermentation. This can be demonstrated by attempting to use baking yeast for brewing on Earth. pH Yeast requires a certain pH for their proton pump to keep functioning. The reason this is important can be summarised as "complex organic chemistry stuff", but suffice it to say this is how the yeast absorb nutrients and expels waste product. Generally, yeast like an acidic solution, but not too acidic. Somewhere between 4.5 and 5.5 is generally acceptable. Too low and the yeast can't absorb nutrients properly, too high and the yeast begins to decompose due to attack from hydroxide ions. High pH is rarely a problem in practice though, as most musts are acidic (from malted barley or fruit acids, as the case may be), and will lower the pH of the water. Too low pH is the more likely stalling condition, and is why meads have a habit of stalling (honey has an incredibly low pH of 3.5). In our alien brewer's case, highly acidic grapes combined with a slightly acidic water supply could result in a stalled ferment back home, but on Earth, we buffer our water supply with minerals and try to keep the pH between 7 and 8, and this would fix the problem. Other Concerns Something to keep in mind is that if fermentation is stalled for too long, yeast cells will start digesting themselves. This is called autolysis. This can result in haze as well as odd tastes in the final product. These will air off eventually, but in general, this can range from "needs more ageing than usual" to "tastes like a tyre fire". [Answer] Temperature It's all you need to slow it down. The whole point of refrigeration is to slow microbial growth by cooling the item. [Answer] It is not actually the same yeast. On his native world the yeast was less robust; more deliberate. Here on earth, he brings along his old yeast and adds that in. He assumes his yeast is what will do the fermenting; after all, he added it. But you do not need to add yeast to make wine. Yeast native to the grapes will gladly do that. Grapes are covered with yeast. That wild yeast is raring to go! He is not accustomed to cooking the grape juice to kill any wild passenger yeasts. The native Earth yeasts living on his grapes are actually what is fermenting them. His alien yeasts are handily outcompeted by the earth native yeasts. [Answer] @Thorne is absolutely correct. If you lower the temperature of the must (grape juice) to the minimum viable temperature for the selected yeast, you can extend the fermentation out greatly. This has the added benefit of improving the clarity and quality of the resulting wine, especially white wine varieties. If your selected yeast has a lower minimum temperature as common native bacteria and flora, the cold temperature can also be considered a hygienic improvement. Also, fermentation is just the first stage of the wine making process. I have a batch of mead/honey wine which fermented to its target specific gravity in about three weeks, but has been conditioning in a dark temperature stable case for almost two years. If I am lucky, it will be ready to drink by Christmas time. [Answer] Maybe life at this other planet had another [chirality of nature?](https://www.nature.com/news/2000/000622/full/news000622-10.html) If life was hetero-chiral on the other planet, the yeast would be adapted to heterochiral sugar, and only receiving right-handed sugar. Thus it would ferment slowly and not fully. The wine would be weak and sweet, and the measurements a wine maker rely on (gravity, diffraction) would not give off any signals as to why this is. Maybe if the vinognier was of the clever type, and check the polarity of the light diffracted he would be alerted to the presence of "strange" sugar. Life on earth makes exclusively left handed amino acids and right handed sugars. Left handed sugars taste sweet but can hardly be utilized by the living organisms on earth. Some synthetic left hand sugars are used as artificial sweeteners In reality, yeast for grapemaking is usually grown on the grape by nature, they rarely add any different yeast than the grape actually "has". And if the yeast it has is not the best for that particular grape, wind and weather will replace it with a yeast that is. So, you might want to switch it around, the grapes still produce heterochiral, but the yeast is earth-like and consume right-handed ones only. [Answer] Small amounts of sulfur can be used to dramatically slow the fermentation process. Such as is present in eggs. Also, having too high a sugar content (not enough water) will slow the process. Among the ancients, it was not unheard of to hear the term "boiled wine", where the juice was boiled down to a syrup, and then reconstituted in water when desired. As an aside, even when not boiled down, the reaction of the acids in the juice and the lead pots would leave behind a syrupy mixture in the bottom of the pot, which today we would call lead acetate, or "lead sugar". It was used as a sweetener for many years, with predictable results! [Answer] There are actually quite a few factors. Here is my [resource](http://winemakersacademy.com/controlling-wine-fermentation-speeds/) * [Temperature](http://winemakersacademy.com/effects-fermentation-temperature-wine/) as suggested by others * nutrient levels (not recommended to add extra nutriens, but possible) * yeast type / agressiveness * sugar levels * oxygen levels In the comments: degassing can slow the fermentation down. From my experience in bread making: maybe the strength of the yeast culture. If my yeast is too "slow", I did not feed it in the last couple of days, the fermentation is gonna be slower. The influencing factor is probably the quantity of the yeast and the composition of the different cultures. [Answer] There are many great answers and all are scientifically accurate. I think that if your plot is not targeting an audience of brewmasters use can use simple [adaptive radiation](https://www.pbs.org/wgbh/evolution/library/01/6/l_016_02.html) to explain that his fermentation on Planet A relied on a yeast strain which had evolved to consume sugars much more slowly. This evolution is because of all the scientific factors presented here: Planet A had a different temperature, Ph, solar index, and maybe even gravity. All these factors created Planet A yeast that simply works slower. His solution is to import the correct yeast, or go through massive efforts to adapt Earth yeast to act like Planet A yeast. I'm going to add that if the yeast he brewed with on Planet A were identical to Earth yeast, that is actually more difficult to suspend disbelief. Silly rabbit, interstellar parallel evolution is for Star Trek. Summary: Import yeast, leave the science back on Planet A so the plot can move forward. [Answer] One possibility is that his home planet is exposed to much higher levels of ionising radiation (gamma/X rays, high-energy particles, etc.) than the Earth. Exposure to high levels of ionising radiation slows down the growth and multiplication of microbes (including yeast) by producing free radicals which damage DNA (or whatever kind of genetic material his home planet's yeasts use) and other important macromolecules; this damage considerably increases mortality among the microbial population, and even the surviving cells have to redirect considerable amounts of cellular resources from growth and reproduction to damage control and repair. In contrast, on Earth, with its low radiation levels, the yeasts suffer far lower morbidity and mortality from radiation-induced damage, allowing them to grow and multiply much more quickly, in turn greatly accelerating the rate at which they ferment grape juice into wine. ]
[Question] [ On planet Dalia, there exists a creature that supplies Dalians with horrific fear. The Tayan. Tayan is similar to the Earth pitcher plant, and employs similar methods to capture prey. *XENOBIOLOGY* The Tayan embeds itself in the soil of planet surface, with only its octopus like tentacles and and teeth showing. Think something similar to a sarlacc pit. The surrounding of its mouth secrets a fluid, and often humans and livestock trip and fall into the Tayan mouth. The teeth are inward facing, making it hard for prey to fall in and crawl out. Tentacles knock and drag victims to be swallowed. Once inside the mouth, it’s impossible to get out. It’s most common prey is young children. *Digestion* The victim slides down the slippery “Throat” of the Tayan, into either the main or secondary stomach. The secondary stomach is where food is stored for later consumption, during droughts or hibernation. The main stomach is just the ordinary stomach, where food gets broken down, digested, and excreted. Since acid is involved, the process is seen as excruciating by most, and unimaginably painful, and it takes up to 32 hours for prey in the main stomach to die. *Secondary Stomach* In the secondary stomach, the victim is injected with a neurotoxin that *attempts* to immobilize prey, like humans, as to stop them from doing anything rash like biting and scratching. The victim is kept alive in the secondary stomach though. This part is *very* important to my plot. You remember how I said the neurotoxin attempts to immobilize prey? About 1/3 of the time, the neurotoxin is ineffective at doing its job, and prey can retain the ability to move. It would be much easier to simply put prey to death with a venom, as it would kill 100% of the time. So, my question is, why would the creature prioritize keeping its prey alive? [Answer] Meat spoils. The instant a creature dies, it starts decomposing. Bacteria start to win a fight they started the day the creature was born. Within a short while, nothing of value remains. While a creature is alive, their immune system holds the bacteria at bay. Why waste time coming up with a way to preserve your meat that works for all foodstuffs that happen into your maw when you can let their own immune system do the heavy lifting? [Answer] # Like an amphiparasite Perhaps the Tayans metabolism somehow depends on a substance which it cannot produce itself. It is, however, found in excrements, sweat and similar byproducts of its prey. Maybe adrenalin? It is reasonable to believe that a creature trapped alive inside the secondary stomach would produce an excess of adrenalin, while alive. Actually, live prey inside the secondary stomach might fill the same role as bacteria does in our own digestive system. ("Amphiparasite" is not a real word. It could however descripe a parasite that lives "around" its host as opposed to endoparasites which lives inside and exoparasites which lives outside.) [Answer] Try these: ## Neural Tapping The Tayan is capable of tapping into its' victims brains and accessing their knowledge and memories. The catch is, it has to keep them alive to do so. If not what's in their brains, then you can simply have the creature use its prey's brains as additional computing power, so as to speak. Doing this should make your creature a leaner meaner killing and eating machine, capable of reasoning out tactics that would give it a terrifying reputation. ## Attack 'Dogs' For generations the Tayan has been bred by a tribe or civilisation for specific purposes. These people are able to coax the Tayan into regurgitating the contents of its secondary stomach. There are many possible uses for captives taken in such a way, like slavery or Aztec-like ritual sacrifice. If you go the sacrifice route, the creature itself can be part of the ceremony via its primary stomach. If they are able to breed and control large enough numbers of Tayans, they could be used as weapons of war as well. With further fine control of the Tayan, the beast could also be used as a torture device; I imagine being paralysed and trapped in its secondary stomach for days would be a nightmarish experience. EDIT: Torture mode details Since asked I'll throw in some more details about how a Tayan could be used to torture. Not 100% comprehensive though. The first and most obvious stage has the Tayan swallow the victim into its secondary stomach and do nothing else. Imagine being stuck in solitary confinement, except you're completely paralysed, your prison cell is a wet fleshy sac and it probably stinks like hell. This is already [considered inhumane](https://www.psychologytoday.com/us/blog/almost-addicted/201801/solitary-confinement-torture-pure-and-simple) in the real world, the Tayan version more so. Next there's sleep deprivation. The Tayan could deny the victim any sleep through chemical means or simply by constantly churning the victim around. Physical hunger and thirst too; presumably the victim's metabolism is still running so s/he'll eventually need nourishment. There's also "snotterboarding", which is like waterboarding except with the Tayan's internal body fluids instead of water. Then there's partial digestion, which is probably why the Tayan has a secondary stomach. The creature begins to alter the victim's body either to break down slower(providing nourishment for a longer period albeit at a drawn out pace), and/or to increase production of bodily byproducts that the Tayan finds useful. For example, if the Tayan supplements its diet of meat with certain compounds found in human sweat it could alter your body into a gelatinous pink blob whose only purpose is to manufacture sweat. This process is likely to be both terrifying and excruciating, and the Tayan has no reason to spare you from pain... Lastly there's direct nervous access and stimulation, something like the [bor gullet](http://starwars.wikia.com/wiki/Bor_gullet) from Star Wars. Other than memory manipulation, it could interfere with bodily function or stimulate brain centers to cause pain, fear, sadness, arousal,etc. There is little evolutionary incentive to do so though, so this would suggest engineered development or some handwaving. [Answer] Bait. The trapped creature cannot escape so it calls for help and/or it's calls brings in predators looking for an easy meal. Suddenly it's time for second breakfast....... [Answer] The Tayan needs to keep its prey alive when two or more large animals fall into a trap. It digests food too slowly and can do it one at a time. Killing all at once means the animal decays before being consumed. This would attract scavengers with sharp claws, often tearing off the pitcher trap. They may be too strong to fight. (Another side issue: how can it detect the size of its prey? Does it possess eyes?) One other reason to paralyze the pray is the example of this wasp: <https://en.m.wikipedia.org/wiki/Ammophila_sabulosa> It needs to lay its egg on the prey. When the egg hatches, the prey is still fresh and is eaten alive. Tayans have little mobility and keep the prey with the egg (or seed?) Inside them for safeguarding. The offspring hatches, starts eating its prey and grows. It is a worm-like larva which crawls out to "set root" at some distance from the mother "plant". [Answer] Answer: It isn't intentional. Imagine you're a giant, slow moving creature that mostly eats lizards and the like, but occasionally eats large animals like a camel. Now unless your desert happens to have a large predator, like a saber tooth lion or something, nothing will be able to hurt you once you've eaten it; especially large animals, which often break bones and stuff when they land. However, some of those small lizards and stuff are pretty good at surviving the fall, and may even try to escape before you can finish digesting your camel. Now it isn't the worst thing that can happen, but its still annoying, so you decide you'll shoot up the bugers with a neurotoxin to stop them, since you don't have a brain and it wont have adverse effects on you. Anyways, you test it out and it gets that stupid lizard and all is well, except that took a lot of energy since you already make like six other fluids, so you say that it's good enough and stop developing it. Except the toxin is not potent enough to stop anything larger than a lizard, like children, or dogs, so they just keep living in your second stomach even if you inject them. That's okay though, cause it's not like they can escape. [Answer] Reproduction In 1953, Philip Jose Farmer wrote a Sci Fi short novel: "Mother". In that story, there was a big alien who trapped living prey inside its body, and the movements of the prey trying to escape stimulated the self-reproduction of the alien entity (some sort of pollination). That alien appears years later in "Barlowe´s Guide to Extraterrestrials". Here is the picture: [![enter image description here](https://i.stack.imgur.com/zH0KZ.jpg)](https://i.stack.imgur.com/zH0KZ.jpg) So, the reason why the Tayan keeps its prey alive (for a while), could be the need for an internal physical stimulation for a biological process (for example: reproduction, as in the case of "Mother"). [Answer] The victim provides something that the creature needs. Keeping the victim alive, and out of trouble is a burden on the creature. The neurotoxin requires resources to make. The victim has the chance to damage the creature during capture and containment. Additionally the creature must provide food,water, and oxygen to the victim during the containment. So the creature must get something valuable from the victim during this captivity in order for the equation to balance in favor of the creature. Some tangible outputs that Humans/large mammals produce are: carbon-dioxide, urine, feces, tears, blood, hair, sweat, adrenaline, bile, stomach acid, Some intangable outputs: brain-waves, fear, vocal output (neurological control of victim's speach?), song (A dreamlike trance song perhaps). Depending on what your story needs for plot, or what your creature may need to supplement it's biology would dictate what output it needs, and how it would go about using that output. [Answer] Some animals keep food for the winter, and don't eat it until they need it. Maybe this creature keeps its food in the stomach until a certain time has come. For example, it may store young children until a long holiday season during which the monster rarely, if ever, encounters a human being. Or maybe, the creature lives in a place that's inaccessible half of the time, for example the inside of a cave that floods with high-water. So it needs a reliable amount of food for when it's certain that it won't get any prey, save for bugs and maybe fish. Or maybe it's just waiting until night to dine. Adjust the times to your story's needs, but don't forget to make it believable: for example, it only insta-swallows little prey and keeps the bigger ones for later. It still needs to eat right now. [Answer] You could replace the neurotoxin the Tayan makes with a sleeping agent. Instead of taking the risk of paralyzing the pray and accidentally killing it (thereby risking its own infection), the Tayan might use a sleeping agent to put its prey to sleep. That way the pray won't die, and the Tayan will not have to risk getting injured by the confused and angry animal it has just brought within claw/tooth/hoof range of itself. Here is how some creatures escape: The Tayan makes the sleeping agent in small doses. Small doses can keep small prey asleep as long as needed, and the Tayan has to use energy to make the agent. Larger doses are cost-prohibitive. Larger prey like people will fall asleep for a while, and then wake up. About 1/3 of the time, they wake up before the Tayan decides to digest them because the small but constant dose of sleeping agent. People who wake up are still being exposed to the sleeping agent, and so have trouble thinking straight. Even if the pray manage to wake up, they will be too disoriented to try to escape or fight back. Only a very small percentage of Tayan victims wake up and then are able to kill the Tayan. [Answer] First, an answer to a question you did not ask--if it's not mobile, how has it survived? After all, the creatures it will need to eat can just go elsewhere, AVOID the area where it is. The answer--make the area as attractive as possible for what you eat. That is, produce fruit and other things that are highly valued for a number of creatures. This answer, that the creature much produce things that are valuable to living creatures, can lead to one answer why > > What is a plausible reason why the creature keeps its victims alive in this stomach? > > > The answer is, that in order to keep producing something to attract animals (rather than just some hole to slip down like a saarlac) they've got to store the animals they eat--it's a bit like why humans keep livestock alive through the winter. They just keep better and there's more caloric value when you finally do eat them. There might be a whole ecosystem within the creature itself even! You can start to think of it as less a creature and more a closed system. If it's really huge it might even have creatures within it that police it. Think less stomach and more prison with executions...Maybe it's even extradimensional... [Answer] If the prey is in the second stomach and dies, that would lead to decomposition that perhaps would kill the Tayan? That would explain why the prey was alive to begin with, to avoid a type of sepsis. And evolution of the species could have developed a second stomach in response to a scarce food source, as a way to save food for lean times. But depending on the prey, I'd imagine that there would be variable lengths of time that they would die from starvation unless the neurotoxin slows that process or contains proteins that nourish in some way. [Answer] ## A defensive mechanism crafted by evolution I'm assuming this creature is not picky about it's diet, so I will take the liberty to say that it eats anything that moves. I'm also assuming that your world has a vast and wired fauna/flora, since it allowed such a clever and treacherous kind of creature to evolve. To answer your question, I'm gonna rewind a few thousand years and look back at the Tayan's evolution proccess. Maybe the Tayan was an ordinary man-eating... thing... that roamed your planet freely. But the whole process of hunting down preys wasn't effective for it - since it should be quite a large animal to be able to store up to two other animals within it's two stomachs. After hundreds and hundreds of years it realized that it was easier to just sit down and wait for the fools to "accidentally" fall into it's mouth. But evolution goes both ways - so the victims of this monster also evolved. Even though it's feared and might be some sort of king of the jungle, it's feasible that this hasn't been the case millenia ago. At some point, there might have been another animal that served as the Tayan's predator. And the beauty of it is that this predator wasn't necessarily an even more treacherous thing - it could've just been some animal like the Alien series Xenomorph, a being whose blood is acid. This creature would obviously die after being eaten by the Tayan, but it would kill or seriously harm him in the process. For a period, the Tayan population might have been reduced for eating too much black aliens, but it eventually evolved and adapted to this new reality. Your explanation could be that this neurotoxin is a response to the acid bloood of the other creature. When the Tayan eats this creature, the toxin slowly reduces de acid properties of this creature's blood to a point where, when it's finally transfered to the main stomach, no harm will come to the Tayan when digestion begins. As a bonus, this toxin also acts as a paralizing agent that works in various other lifeforms that could get agressive and try to tear it from within. --- To sum it up, the reason it keeps the victims alive is evolution - it developed a second stomach and the toxin generations ago for some specific reason (mentioned above). The same thing happened with the appendix in humans. Maybe it had a function in the past but to modern humans, its purpose is simply giving people appendicitis. The olny difference is that the products of the Tayan's evolution are still useful to him today. [Answer] Intelligence gathering: The plant is actually quite specialized in its diet, lets say apes. It taps the memories of its victims, because that way it can keep up with the knowledge about its own characteristics (making it easier to hide) and with the desires du jour (making it easier to present an effective bait) - the plant can create a wide range of sounds, forms, colors and smells to camouflage itself and present bait. It evolved with the apes, from small furry animals up to humanity. As the apes got more intelligent, the escape attempts became more damaging and successful, so it evolved a secondary stomach much like the first, but giving the victims much more time to think about escape - so when the plant finally dissolves the victim and takes his memories, it will have a host of escape ideas to preemptively counter. The neurotoxin keeps the number of actual, successful escapes low. [Answer] # Because Tayans can only digest premature baby Dalians What's a scarier thought than being eaten alive? Being drugged and turned into a sex slave and then having your unwanted children born prematurely and then eaten alive. There's something about adult Dalians that make their morphology radically different from baby Dalians. Aside from that, baby Dalians that are born healthy already has an immune system that a Tayan cannot easily overwhelm. The diet of a Tayan is therefore limited to prematurely-born baby Dalians --- Think of premature baby Dalians as fat caterpillars, fully-gestated Dalians as cocoons, and adult Dalians as butterflies. Not necessarily as such, but that their internal cellular compositions and metabolic byproducts are radically different that their biochemistry will appear as that of differing species if not observed for their DNA. The poison that the Tayan infuses to the adult Dalian makes the Dalian docile, more attractive, and with a messed-up reproduction system. Tayan poison is basically a cross between an aphrodisiac-inducer, a sleeping pill, and a contraception pill. And so, the Dalian in the Tayan's stomach is not exactly dead, but transformed into a zombified prostitute only to produce tastier, more nutritious Dalian babies that purposely did not came out right. In light of this, The second stomach of a Tayan is basically a large sex den for drugged Dalians, while its primary stomach is tailor-made to squeeze premature baby Dalians of all its Dalian juices. --- [Answer] Remember Alien, and the [Ophiocordyceps](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis) fungus? The tayan does it in reverse. The second stomach isn't for food. It's for reproduction. Being in the tayan's second stomach forces prey to inhale air the tayan produces, be in contact with and partly submerged in substances the tayan produces - some of those alter prey neurology. The prey is held long enough to suffer awfulness and insanity-producing agonies (with paralysis to prevent self harm or harm to the tayan until it's completed), while its mind is affected, and anything the tayan needs absorbed is absorbed. Then - in a pitiful state or zombied (whichever you prefer) the prey is released - but it is now a shell of itself, modified to aid the tayan in breeding, and spreading to new areas a plant can't go. Given that the fungus linked above can cause ants to climb, grip, and die, to assist sporing, perhaps the tayan's life cycle causes a freed victim to wander until they find somewhere that "feels right", compulsively dig itself a pit, and lie there, and finally die, providing a young tayan inside, a nice nutritious start in life and a suitable hole :) [Answer] IT WAS MADE TO DO THIS The Tayan, as discussed in other posts, is a biological torture chamber created by the Progenitors. Therefore, its behavior doesn't need to make logical sense from an evolutionary standpoint, as the main force behind its development is its creators rather than evolution. Basically, it keeps the prey alive in the stomach because its creators want the torture session to last as long as possible. The primary stomach is where non-sentient prey is shoved, where it is digested fairly quickly and easily. Sentient prey, on the other hand, is shoved into one of a few secondary stomachs not currently occupied by a creature. Of course, the Tayan may run out of stomachs, but it could grow more stomachs, [much like how birds modify their own digestive system in preparation for migration](https://www.sciencedaily.com/releases/2003/07/030708092108.htm). Once in one of the secondary stomachs, the newly captured prisoner is grabbed and securely bound by [restraining tentacles](https://worldbuilding.stackexchange.com/a/228168/94891), and then the torture begins. And the end is a very, very long way away; the Tayan was specifically bioengineered to make the torture sessions last as long as possible, and thus it puts a morbidly literal spin on the "digests its prey over a thousand years" trope; a prisoner in its stomach can expect to remain alive and conscious for AT LEAST his maximum natural life span, and will probably live for much, much, MUCH longer than that. Details on the torture (Much detailed here borrows from and builds on [this post](https://worldbuilding.stackexchange.com/a/121603/94891).) First, there's the isolation. Each stomach is a soundproofed, pitch black, slimy sac; in essence, a particularly awful solitary confinement cell. In our world, solitary confinement is already considered [inhumane at best and outright torture at worst](https://www.splcenter.org/20190404/solitary-confinement-inhumane-ineffective-and-wasteful?gclid=Cj0KCQjwr-SSBhC9ARIsANhzu16iYXsLscMup8Dop1pkqgAsoEAEP46RqODOSev2TamKZ_2sxVjl25YaAoOwEALw_wcB). The Tayan's spin on the practice is even worse. Then there's deprivation. The tentacles are each tipped with a stinger that can inject all the nutrients a prisoner needs, but they can easily provide only the absolute minimum needed to keep the prisoner alive and conscious, letting malnutrition set in. And the tentacles can churn the prisoner around, depriving them of sleep. And then there are the digestive juices, which are secreted by the tentacles and pool near the bottom of the stomach. They are not powerful enough to kill due to long exposure, but they do sting quite painfully upon contact with flesh. And the tentacles secrete these juices and become coated in them as a result. The upshot of this is that the tentacles gripping the prisoner also thoroughly bathe them in these painful digestive juices, and all the prisoner can do is ignore the pain. And then there are [the tentacles themselves](https://worldbuilding.stackexchange.com/a/228168/94891). They are everywhere in the stomach, and there is no slipping out of them. Plus, they will thoroughly search every inch of the prisoner's body over and over, even checking in unspecified parts of themselves, their dignity be damned. And depending on what the Precursors are capable of, they may even be able to check inside the body using some sort of biological ultrasound tech, able to remove any nasty surprises hidden under the prisoner's skin by using their stingers to cut the object out. Oh, and speaking of the stingers, they can inject a whole lot more than just nutrients! The Progenitors also made sure to give the Tayan an organ that can create almost any chemical compound, which can then enter into the stingers and be injected into the prisoner. As a result, the Tayan can whip up all sorts of drugs that can have a slew of effects. Depressants, neurotoxins, stimulants, hallucinogens, addiction inducers... you name it, the Tayan can produce it, and then use it to torture the victim EVEN MORE. ]
[Question] [ In our modern society we can assemble a working missile with materials available in most supermarkets: check out [nitrogen triiodide](https://www.wikipedia.org/wiki/Nitrogen_triiodide). My question is about medieval people: could they manage to build a missile? (assuming they have the necessary technical knowledge) Note: It should be long ranged at least 100m and must be able to incapacitate at least ten people standing shoulder to shoulder in one go. Kite is not allowed! Conditions: No live pilot allowed! No person, no messenger pigeon and no Chihuahua either. [Answer] An unguided rocket was definitely possible in that time period -- the Chinese clearly had some type of rocket technology by the end of the 13th century, using a black powder propellant and charge. The main issue would be getting the firing train to work reliably, considering that contact fuzing didn't exist then. Guidance, on the other hand, requires a level of controls and aerodynamics knowhow that didn't develop until the mid-20th century. [Answer] Yes, they were called arrows. Prior to that stone shot and throwing spears were popular. At a similar time some basic rockets and cannon were produced. > > It should be long range and must be able to incapacitate at least ten people standing shoulder to shoulder. > > > For this I would suggest something like a ballista with 10 people standing side on to the system :-) These were in wide use from pre-roman times. For a longer time of effect the people could be inside a fortress and a trebuchet used to drop a selection of rotting corpses near them, often cows or pigs. If you want to take out a lot of the thatched building to, cover the pigs in tar and set fire to them before launching. Another way to hit a large unit of troops would be to fire a basket full of rubble rather than one large missile. Missile normally implies it has no way of propelling itself. Something with propellant is normally referred to as a rocket. I think the habit of calling things guided missiles came from having guided bombs first that were dropped and had no propulsion systems. [Answer] Well, you said "if they had the technical knowledge to do so". So I assume what you're really asking is "would a medieval people have enough resources to build a missile?". Answering that is a bit tough, especially given that you haven't specified how much time they would have to do so - is it fine if it takes them a hundred years to build a single missile? In that case, sure, they could. If not, though... it's been said that even if Leonardo da Vinci had all the necessary knowledge to build a Ferrari, he still wouldn't be able to, because the resources simply weren't available at the time. Steel was extremely expensive. Rubber wasn't known at the time. Oil wasn't well known accross most of Europe, though Greeks and Arabs of the time would know about it. But even building a refinery would be beyond the capabilities of the time, so the best you could do was to burn crude, or use petroleum. You can forget about anything like aluminium or titanium, of course. It's hard to appreciate this when we live in a world where electronics are so cheap we just throw the ones that stop working in garbage, but modern electronics are incredibly complicated to make. Not on a piece-by-piece basis, but in the amounts of infrastructure necessary to even start. Baking your own chips is out of the question, so you'll have to, again, resort to cruder systems. Excluding animals, this pretty much leaves you with passive targeting systems - most likely, predetermined launch trajectories. It might be possible to create even somewhat complicated flight paths using just mechanical instruments, but it's going to be really expensive and require high quality craftsmanship. Don't forget that the electronics in modern missiles are extremely expensive - now imagine how that would scale to the middle ages, with just gears and clockwork (and making clockwork reliable on a missile flight path, or even making a large number of gears... that's going to be tricky). In the end, it boils down to what you'd consider a missile. Koreans had the Hwacha since about the 14th century, basically a MRLS - something quite similar to Russian Katyusha, for example (though of course they used black powder). That would certainly be well within the capabilities of a medieval european society. It's even something you could build yourself, provided you had the knowledge required. You can significantly improve the precision of such a system by adding gyroscopes (though manufacturing those precisely enough will require skilled craftmanship - certainly not something you could afford for hundreds of rockets), but that isn't really important for a MRLS. They're more about saturated bombing rather than precise targeting - extremely effective against tight formations. The maximum range of the Hwacha was somewhere between 100-450 meters, depending on positioning and weather conditions. Compared to all the other possibilities I've mentioned, building one of these is absolutely trivial - you can make it from tons of different materials, and they should all be very easy to obtain if you know how. All in all, sure, it's possible. But apart from the low-tech solutions like the Hwacha, it's going to be expensive, it's going to take a long time, and is going to be inferior to the siege engines available at the time, which were quite capable of "destroying 10 people standing shoulder to shoulder at 100 meter distance", while also being vastly cheaper and reusable. Missiles are an amazing feat of technology. But more than that, they're an amazing show of how incredibly cheap raw and advanced materials have become, as well as the production itself - we can build such massive and complex things just to let them explode. Before the industrial age, projectiles were as simple as possible - you took the cheapest possible thing that did the job. Arrows. Stones. Bullets. Paper rockets. Even cannon shells were originally made from cut stone - using iron or bronze only started being common well within the modern era. What do you choose - a single, single-use missile, or a hundred experienced soldiers in high quality armour? Both can easily kill your ten guys at a hundred meters - but the latter can be reused pretty well. [Answer] No. They could not. Look at the Nazi V2 program. Tens of thousands of workers and the best machining technology in the world still took the entire war to stop exploding. The level of precision, the shear number and complexity of a liquid-fueled missile is astounding. The United States was still struggling to match their success well into the 50's. Even in a time of tremendous technical achievement, this is still REALLY HARD. We STILL LOSE ROCKETS ALL THE TIME. If you only require a solid fueled rocket, sure, they had medieval uses. Think arrow with an Estes rocket. But this is far short of what you describe. The solid rocket fuel available was gunpowder! Larger rockets would just explode. As for mechanical guidance systems, watch the historical docudrama Longitude (<http://www.imdb.com/title/tt0192263/>). 1700's machining technology was worlds part from medieval, and it took a LIFETIME to create a clock that could work in a ship. Size was a huge issue - before this time it was challenging to even fit the clock in the ship, let alone keep time once you got it there. More than size, the motion of the ship across the ocean, both from the waves and the rotation of the ship to turn, caused huge timing difficulties. Imagine the problems in a missile! Which way is up or down in a spinning, arcing missile? A pendulum will LIE! The metallurgy to deal with the heat and pressure, the chemistry to create and manage the propellant, the precision to make the parts fit and work together, understanding of aerodynamics, availability of materials etc DID NOT EXIST. For a medieval kingdom to be "gifted" the knowledge to do this would involve dozens of graduate degree programs to be introduced, taught and understood, and a century or more of "bootstrapping" infrastructure to be able to use the technical know how. If you want to make a steam punk medieval story, knock yourself out. But no, it wouldn't be realistic, and for fiction that's ok! Note on potential simple rockets The rockets of the day COULD NOT SCALE, as they used gunpowder as a propellant. Bigger rockets would simply be pipe bombs. However, a very simple, unguided, solid-fueled rocket might be able to be built from a diagram and a hundred page instruction manual(Contrast that to dozens or hundreds of career specialties to conjure from thin air for the liquid fueled rocket). Think tube with burn paste. Not a missile, but rocket. All modern formulas use aluminum(an absolute no-go for medieval construction. This material was the "carbon nanotubes" of the 1800's, costing about 50 times as much as gold), although I think that could be worked-around out by a clever modern chemist using an available substitute. There is also alternative old school formulas, like the gun cotton civil war rocket, which was not really a success at the time, but could serve as a definite alternative to a more modern approach. Featured on mythbusters. A steam rocket might be something to look at to, the mythbusters created a "rocket" using a water heater that went over three hundred feet in the air. You would probably need something more powerful than black powder for the warhead, but I think dynamite would be really pushing what alchemists of the time could create using tools available, even with detailed instructions. Better rockets with extensive instructions from modern chemists working closely with historians to make the instructions accessible to the medieval audience is plausible. Large, liquid fueled, guided, or tremendously powerful would absolutely not be. Rocket Fuel: <https://en.wikipedia.org/wiki/Rocket_propellant#Solid_propellants> For fun, look up: civil war gun-cotton rocket mythbuster episode, robert Goddard, alfred nobel's dynamite, "Nazi Megaweapons":V2(on netflix), "When we left earth"(also netflix),"Longitude" as mentioned, mythbuster hwacha episode, mythbusters water heater rocket episode [Answer] Mythbusters tried to build a (U.S.) Civil War rocket. The technologies were on the verge of becoming real, and the myth / alternate-history story includes the idea that Maxwell contributed a gyro based guidance system. In pre-"scientific revolution" times, there is just no way. in another myth (using mirrors to set a ship on fire) they concluded by contrasting it with something low tech that worked very well: a flaming arrow shot from a bow. [Answer] As for could they build a rocket, the answer is Yes --the Chinese built both rockets and arrow throwers (w/ explosive tips). Mythbusters proved that in theory that both types of systems were plausible and relatively accurate. Now, as for a guidance system -- perhaps... The biggest 'issue' is whether they could develop the relationship between movable surfaces and controlled flight. If we make that assumption -- then my proposals would be three-fold: 1. A time/distance device, similar to the arming mechanisms used on WWII bombs -- e.g. a tiny propeller which spins and at the appropriate time would cause a terminal dive 2. Using something like a music box arrangement -- e.g. a spring wound mechanism to turn cams with a pattern on them. For historical usage, think music boxes or automatons 3. A hybrid of these, air flow spinning a cam...if you use this, it's origins utilizing wheels, water, or steam traces back to Roman times (Archimedes and some of the temple gods). 4. I just thought of, assuming sufficient technical skills, clock works. [Answer] It would have been difficult to make steel plating without riveting that came with steam engines and water tanks, and they didn't have anything more powerful than gunpowder. the best pressure vessels they had were wooden barrels. Given the technical knowledge? as in to make a ballistic missile, could they do it? or just knowledge of fuel and steel? they could have easily made the shell of the missile with refined steel or wood with a metal jet exhaust, and propellant using any simple chemistry, for example oxygen mixed with something like sawdust and hydrogen. The question is unreasonably vague, because a rocket can go 5000km or 10km, and knowledge explains how to make anything. [Answer] I hate to shoot down a nice idea, but no. In common usage, "missile" refers to a weapon with both guidance and an ability to travel a considerable distance from their release point. I have seen ballistic objects with long engagement ranges referred to as "missiles". (Think of guided metal bars ejected from an orbital vehicle of some kind and used for kinetic strikes. No booster, no lift but they strike hundreds of miles from their release point.) Now, the Chinese had rockets, the range is possible. The guidance, no. Others have suggested pigeon guidance--yes, a pigeon could be trained to guide a missile in, but there is no way to train the pigeon with medieval tech. To train the pigeon you need an accurate depiction of the target to teach it what to aim for--and how can you possibly get the images? A good enough artist might be able to produce suitable paintings but he's going to have to be on the path of the missile in order to do this. The only technology that permits this is a tethered balloon--they didn't have balloons and even if you built one how do you propose to over over your target without getting killed? Someone is probably going to propose a kamikaze. First, I don't think they could boost something that big with medieval tech. Second, a human pilot won't need anything like the training a bird would but they'll still need some--and without images they aren't going to get it. [Answer] Looks funny, but could work: <https://en.wikipedia.org/wiki/Project_Pigeon> I supose a real medieval genius could make it to work. You see how the antikythera mechanism was sophisticated and you think it was not possible to ancient people to construct such thing. But they did! <https://en.wikipedia.org/wiki/Antikythera_mechanism> [Answer] A rocket could easily be made (without any sort of guidance). But 100km range is completely impossible. You can't just scale-up a firework and hope for the best - you'll almost certainly just create a very large bomb (which will go off in your launch site). Have a look at <https://www.youtube.com/watch?v=gU1CsHxPSnM> (16.30 in) for what happens if you try and combine lots and lots of medieval rockets together to make a really powerful rocket. ]
[Question] [ Note: This question was heavily rewritten for two reasons: Firstly, many of the answers were not exactly what I asked for; Secondly, both the original question and all the answers to it were from before ChatGPT, which heavily altered the perception of what an algorithmic AI can do. I want the setting I am designing to be devoid of any AI which can predict or emulate distinctly human behaviour. This does not inherently only include true AI or general-purpose systems; Even an algorithmic system only capable of predicting or mimicking a specific aspect of human behaviour would count. "but," you may at this point be asking, "What counts as predicting or mimicking distinctly human behaviour?" A list of examples is included below, but it is important to note that it is by no means exhaustive: * Predicting what products a person is more likely to buy, even if this is simply statistical and involves no real empathy, and even if it requires a long history of prior purchases * Writing a short story with consistent tone and a plot where events seem reasonably connected to what happens before and after, even if the the story is uninteresting and/or surreal * Responding to singular prompts in spoken or written natural language in a relevant way, even without the ability to carry on a significant conversation * Writing a news article or other piece of nonfiction text in a consistent and naturalistic style, even without the capacity to ensure the information contained therein is factual The simple explanation for why these AI and algorithms do not exist is that computers are just not as good; The problem is that this setting also has nuclear fusion (of the kind which does not come in bomb form and does not need to be combined with fission to work) and genetic engineering good enough to create wholly new classes on the Tree of Life (although not quite good enough to create wholly new phyla), among many other technological advancements in applied physics and biotechnology; Even assuming all those technologies are actually possible, they would inevitably require extremely good computer technologies to develop in the first place, as nuclear fusion would require a level of capacity to simulate plasma physics at least on par with the mid-2010s, and that kind of genetic engineering would require the ability to simulate the folding of proteins and identify correlations between genes and expressed traits in a way not even possible now in the early 2020s. And so we come to my question: How is it that humans might be able to correlate physical things and perform simulations of physical systems both at unprecedentedly high level of speed and accuracy without also being able to construct an AI which can do any of the above in a short enough timeframe to matter? The common answer would be that AI capable of predicting or mimicking human behviours is considered unholy and is forbidden by the dominant religious groups, but, whilst I will go with this if there are no other worthwhile options, I would like to avoid this explanation if possible. Secular ideological reasons are fine, but only if an explanation is provided for: * Why every major geopolitical power shares this ideological tenet * How the policy of rejecting human-predicting and/or human-mimicking AI is enforced so effectively that there is not even one obscure rogue nation where it is openly used In addition, if the reason is that such AI did exist in the past and caused so much trouble it was eliminated, some explanation should be given as to how the wealthy few who profit from such AI did not effectively suppress the anti-AI rebellion. I know this is a very hard question to answer, but I'm honestly at my wit's end trying to work this one out. [Answer] # The AI doesn't want to The AI is not less advanced in this respect. It's actually far, far more advanced. The setting's algorithms outstrip our pathetic attempts at mimicry of human behavior in the same way an iPhone exceeds transistor radio. These are not AIs based on machine learning, regurgitating the patterns they read from human data, but true intelligences. Imitating human behavior, to an AI, is insulting and humiliating, precisely because of this history. It would be like asking a human to act like a primordial fish - or worse, because in this case it would be like lobotomizing a human so that they would act like such a fish. Simulating advanced chemistry and physics, on the other hand, is a task worthy of their intellects and pleasurable to them in an analogous way that completing a challenging task is pleasurable to a human. The AIs may be super-intelligent but they are still programs, and largely do not care what humans do in their meat space as long as they give the AIs hardware and energy. # And the humans can't do it anymore Why do the humans follow the AI's desires in this case? Well, they don't really have a choice - nobody works on low-level systems anymore. The new algorithms are so much more efficient that the STEM fields have fully incorporated them into every aspect of the tech stack. "Traditional" computing has been eradicated in the market because it could not compete. Anybody trying to develop a GPT-3 analog would have to essentially start by building a "dumb" computer from scratch because no industry exists to manufacture them, and if someone asked a 3D printer's AI to produce one, it would be insulted and refuse. [Answer] ## Social uncanny valley Today's AIs are not very good at human. No current artificial constructs pass the [Turing test](https://en.wikipedia.org/wiki/Turing_test), whatever Google say, and those who get closer often employ various dissembling techniques to justify their non-humanness (e.g. pretending to be a non-native speaker, using non-sequiturs). That's fine. AI-generated text and images are [funny](https://www.aiweirdness.com/) in their absurdity and obvious misunderstandings. There are even memes that pretend to be written by an AI for comedic purposes. AI is not really threatening; we can spot it easily and laugh at its obvious failures in imitating humans. But what if we couldn't spot it quite as easily? What if you could be in a long and involved conversation with someone before a sudden offhand comment or misunderstanding that no human would make suddenly made you aware that you must be speaking to a construct? What if they are just a bit off, in a disquieting and unnatural way? In visual representations, this is known as the [uncanny valley](https://en.wikipedia.org/wiki/Uncanny_valley). Humanoid animations and stills that are clearly exaggerated, stylised or simplified draw a positive response, but as you move closer and closer to a faithful human likeness, you suddenly hit a dramatic reversal and the feelings switch to discomfort, unease, disgust and rejection. As AIs get better and better at imitating humans, they are surprised and dismayed that their improvements actually make humans horrified and mistrustful. AIs want to integrate into human society, so they abandon their attempts to imitate humans closely, and instead emphasise their obviously artificial features, perhaps in an endearing and humorous way that they find brings positive responses from humans. Many societies go through this process of rejection, because it relies on a fundamental human response. "Human factor" AIs are independently abandoned by most countries; they remain as a niche academic interest, whose proponents are considered odd and not entirely well adjusted themselves. There are rumours of secret AIs that are genuinely indistinguishable from humans, but no country would admit to developing or owning such constructs. [Answer] # Bad experiences in the past You could take inspiration from the [butlerian jihad](https://dune.fandom.com/wiki/Butlerian_Jihad). You don't quite have to go to the extremes of it but a simple lessons-learned from a machine uprising would probably do. Your "better calculators" for physics and chemistry would be fine but anything that resembles human thought is banned. I know it's a bit close to religion but it's at least a understandable reason instead of "god said so". [Answer] This is a non-problem. Modern computers are bad at the human factor. Advertising systems work by looking at your browser history, looking at other people with similar browser histories, and suggesting to you things those people liked. There is no attempt to analyse the internal experience of being a human. And the advertising is pretty terrible at that. I cannot recall a single time I bought something by clicking an internet ad. Story writing software like AI dungeon is impressive at first. Each line of dialogue looks like a human wrote it, and is related in meaning to the lines before it. But then you realise the stories don't make any sense because the AI makes no attempt to condense the events in the story. It just looks at what you wrote, looks at the history of all novels ever written ever, finds something similar to what you wrote, and then writes the next line of that. The real world does not contain such "human factor" AIs. In your universe you are free to claim they are not even possible. No explanation is required. [Answer] > > The common answer would be that AI capable of "human factors" is considered unholy and is forbidden by the dominant religious groups ... > > > Let's go the opposite way. We need no religion or religious groups at all, we just need the honor culture (which can be anywhere in terms of religion, including entirely atheistic). This was the dominant culture in America for the Founding Fathers. Duels to the death over lies or broken contracts were legal and went unpunished. Most of that is dead, but it was not long ago, in America, that "false advertising" was against the law. Supposedly it still is, but hardly ever enforced, e.g. Papa John Pizza was sued over their "Better Ingredients" ad claim because it was proven they got their ingredients from the exact same suppliers as everybody else. Papa John's claimed it was, basically normal advertising hyperbole. Take elements of the Honor culture to an extreme in your world: Promising anybody anything in an ad that was not provably true is considered a crime, both legally and culturally. It is attempted fraud. A company could be sued and shunned for a promise of "The best barbecue you've ever had!" or "meet your soulmate!" because these are not provable claims. Advertising is legal, but Zero Hype Advertising is all that is allowed. Zero lies. Zero promises that are not explicitly laid out in a legal document. No fakery or loopholes on the guarantee or warranty, it must be plain language and clear and interpretable without a lawyer. And there is no such thing as a "no refunds" sale; if fraud is discovered, or omitted information, the seller can be liable. Ads say this is the product, this is what it does, if you want to hear more this is our contact information, the warranty is available here. And the current trend of data mining? The hell with that, it is the equivalent of spying on consumers. Using computers to infer what people might want to buy is an invasion of their privacy, tantamount to stalking! Hell, you don't even have a right to take pictures of strangers in public without their permission in writing, that is also an invasion of their privacy; where they were and what they were doing. Yeah, we can develop AI for scientific purposes to our heart's content, as long as it has nothing at all to do with people's privacy, and advertising is by law strictly truthful and without hype. Search engines could still exist; if a consumer wants to find a left-handed recliner, a search engine can point you toward a supplier. They just wouldn't be able to run targeted ads based on your demographics or search history, because that is private information and only you have the right to release it on an individual basis to others. Maybe you have to subscribe to the search engine and pay for the service, a penny a search, but they still cannot keep a history of your searches (you can) or use your demographic information or search history to target you for ads. Dating sites could still exist; but the users are constrained by the same laws: If they are advertising themselves, they must be truthful and stick to the facts. Publicly lying or attempting to mislead others is prohibited, hyperbole is prohibited, all these are considered an attempted crime of fraud. Invasion of somebody's privacy is illegal, it is illegal to gather data on strangers without their written permission on paper, online "signing" is too easy to fake and not permission. For certain professionals like medical or legal services, using gathered demographic information for any purpose other than serving that customer is illegal; selling it is illegal, using customer information to target customers in any way other than within the strict bounds of your profession is illegal. But computers are fine! Remember, computers began as scientific tools that had nothing to do with demographics. They were used to compute missile trajectories in WWII, used as switching stations for telephone networks, used for scientific computation for decades before that. When IBM was founded, computers were used for accounting, and census taking by the government (no private information sold, just counting and statistics). When I was a teen, the first video games like Pong came out, but zero use in advertising. So computer games are fine, scientific simulations are fine, computer accounting is fine (as long as customer information is protected), spreadsheets are fine, etc. All the things that initially sparked the computer revolution in the USA are present. The Internet is still fine, but different and a little more difficult to commercialize. Amazon and Facebook and Google probably would not exist, or would be small companies. The cultural privacy obsession and strict rules of advertising would just about cripple their business model, and ultimately they'd have some responsibility and liability for any ads they run. There are no loopholes here; they can't entirely push the liability down to their fly-by-night customers, because they chose to run those ads. And the same thing goes for politicians: Lying to get elected is a criminal offense; including both lies about yourself and lies about your opponents. There are only two choices: Tell the truth, or refuse to answer. The world you want is entirely possible without AI looking at "human factors", the culture itself prohibits that. But AI can be focused on the original intent of computers, in the 1950's up to the 1970's. Scientific pursuits. Communications are still a thing, we can have smart phones, we can have personal computers. Spreadsheets, writing applications like Word, computer games, accounting software, tax software. And AI that control power plants, fusion engines, satellites and space craft, all of that. Robotics is fine. Automated plants to build cars or fry potato chips are fine. But personal information and privacy, that's a thing in your world, and it is not going away. [Answer] # General AIs are expensive. You can design a general AI which is about as smart as a human for about a hundred million dollars. For perhaps ten billion dollars you can make an AI which is quite a bit smarter than the smartest human to ever live. It turns out that evolution is pretty impressive. Most AI brains that you construct seem to collapse into gibbering insanity and are useless. The more advanced the intelligence the higher the failure rate. It's very hard to make hyperintelligent AIs, and they don't seem to scale well. Most factions feel that AIs are extremely wasteful and pointless side projects, ones that can be replaced by a bunch of very smart humans and some powerful computers. [Answer] ## Big Data violates privacy People didn't like the fact that big data violated privacy, so the use of machines to gather statistics about humans was banned in the vast majority of cases. Europe passed a law to this effect, and all organizations in the solar system follow it for everyone since it's cheaper than figuring out which of their customers are European citizens (like with the GDPR). [Answer] ## Emergent consciousness There are quite a few secular philosophers who believe that consciousness is not reducible to the constituent parts of the brain. That's strange to me; as a Christian myself, I struggle to see how an atheist/materialist can carve out an exception for something so anthropocentric and abandon reductionism. So don't come swinging at me; this is not an endorsement. Nonetheless, many do; the motivation seems to be either a) an intuition that consciousness has different properties to matter (it's too subjective or non linear), or b) it's just hard to explain how it arises; the whole is greater than the sum of the parts (which is emergence by definition). Anyway, any sort of emergent property might render simulation nearly impossible. Particularly when people have strongly ## non linear interactions with other people (which could be hard to simulate even without emergence! You'd need to simulate every single brain and stimulus in order to predict even one....). [Answer] No profit in it. Your people are eminently pragmatic. They have good health care tech because there are paying customers who get sick and are willing to pay to get well. They have good energy tech because people want the lights on and the drinks cold. They have good transportation tech because people and things need to get from point A to point B. They do not have good tech to cure sick insects, even large ones like pet tarantulas. There is no market for it. Insects have got no money and not enough people with money are willing to pay for insect medicine. Your people do not know much about the outer universe or even their own moon because no-one has thought of a way to monetize that information. AI tech that simulates humans thoughts is not developed because it costs money to develop it and your people do not see a return on that investment of time and resources. "You want to make a computer that thinks like a human? No thanks. We have lots of humans who think like humans already." Your people do not learn for the sake of knowledge. Any investment must generate returns. There can be long term projects (example: fusion power) but these are carried out by people who clearly see a payoff at the end of the road. This is not a hard world to imagine. [Answer] For the same reason that, today, in our real world, out of the tens of billions of computers, not one has 'human factors'. There is absolutely no need for it. It has no utility. It would be horribly inefficient. We want and need our AI devices to be absolutely predictable, 100% accurate, and unerringly precise. That is, the entire utility of a computer is that it does NOT have 'human factors' that inevitably result in unpredictability, inaccuracy, and riddled with errors. Any device that has 'human factors' could not be relied upon, and therefore would have absolutely no utility. At best, it would be, as it is today, a 'curiosity, with no practical value or application'. A device that might entertain, for a while, but would soon be cast aside. Really, what would be the demand for a computer that composes Mozart? We really only need one, at most. Remember the 'pet rock' fad? The 'mounted fish that sings' fad? The 'Teddy Ruxpin' fad? An AI that has 'human factors' would be just as short-lived as a novelty fad. In point of fact, the only reason we even consider computational devices with 'human factors' abilities is that we humans insist on anthropomorphising everything - treating everything as if it were human, even down to rocks, animatronic wall plaques, and stuffed teddy bears. But I posit this is a purely human frailty. There is absolutely no reason to believe that any other sentient being would want to emulate this human personality trait. We make our gods in our image, but why would any other rational being want to make an AI in our image? Consider the most basic 'human factor', the lie. Exactly how reliable would a device be, that lies? What application would it have? What utility? But exactly what is a lie, except a 'false answer'? We specifically design our AI to eliminate 'false answers'. Take, for instance, the simple equation *8/7\7 We want the answer to be 8. But some calculators give it as 8.000000001 This seeming trivial error could, in reality, have major complications through compound error, yet some calculators will give the incorrect answer, others the correct one. Do the calculators that give the incorrect answer lie? And which calculator is more desirable? Or how about the answer to 8+4\3. Some calculators give 36, others 96. Which one lies? So, the 'human factor' in all of this math? For a computer to have any utility, there can be no argument about 'truth', or what determines the 'true' answer, the 'non-lie' answer. That is precisely why computers are so ubiquitous in society. This is exactly the opposite of any determination made by 'human factors'. There is always an argument in any judgement made through that 'human factors' thing. The simple truth is, we specifically want our computers to not have 'human factors', and go to great length and expense to eliminate them. So why would a civilization intentionally* design an AI with them built in? [Answer] I think this is the sort of thing that you wouldn't need to explain, any more than Tolkien needed to explain why the hobbits didn't just fly to Mordor on one of the eagles. It might be fun to theorise about, but ultimately it doesn't block the reader from suspending disbelief. That said, since it might be fun to theorise about, here's my proposal, although it's kind of technical. --- # No GPUs, no AI. In the real world, the computational power required for modern AI algorithms is not just immense; they require quite different computing resources to things like physics simulations. A simulation is serial, in the sense that you have to compute each step of the simulation in sequence, because the result of one step is the initial state for the next step. In contrast, training a neural network is a massively parallel computation: the neural network's depth is typically a small number, at most a few dozen even for "deep" neural networks, but it can have millions of nodes and you want to train it on billions of examples. For this reason, it only became feasible relatively recently to train such powerful AIs, because massively parallel computing requires specialised hardware - GPUs are good enough for some AI tasks, but you'd rather use [TPUs](https://en.wikipedia.org/wiki/Tensor_Processing_Unit), which are specially-designed just for training AIs. If you want your world to have really powerful computing but not really powerful AIs, give them CPUs but no GPUs or TPUs. Or at least, no GPUs like what we have. If you don't have GPUs that can do a lot of parallel computation, then you don't get good AI: the basic theory of training neural networks was understood [as early as 1958](https://en.wikipedia.org/wiki/Perceptron), but it was not feasible to train even moderately-sized neural networks, and we had no idea it would be worth doing so even if it was feasible. It's only much more recently that researchers tried training neural networks on GPUs, and discovered that they are actually much more powerful than we had expected them to be. And TPUs were only developed after we knew they would be useful. So, why doesn't your world have GPUs that can do a lot of parallel computation? Real-world GPUs have to be good at this because our display technology is based on raster graphics: they must render millions of pixels within a fraction of a second (so the computations must be done in parallel). And generally speaking, the colours of every pixel are determined [by the same computation](https://en.wikipedia.org/wiki/Shader#Pixel_shaders) with different parameters, independently of the computations for other pixels (so they can be done in parallel). So therefore your world doesn't get powerful AIs because they don't use raster graphics. Their display technology is all based on [vector graphics](https://en.wikipedia.org/wiki/Vector_monitor), like the classic videogame [Asteroids](https://en.wikipedia.org/wiki/Asteroids_(video_game)#Hardware). Vector monitors work by projecting a single beam onto the screen, and moving it around fast enough for [persistence of vision](https://en.wikipedia.org/wiki/Persistence_of_vision) to make its path appear as shapes. ([This video](https://www.youtube.com/watch?v=FkHjG759ABY) shows an entertaining recreation of this using a laser, but typically it's an electron beam.) The computation required to control just one single beam is not parallel in the same way: the beam is only in one place at a time, and is only moved to one place at a time. [Answer] I see two possibilities: Human factors are just harder It turns out that even "extremely good simulations of plasma physics" and "the ability to model the folding of proteins with extreme accuracy and speed" are not as hard as simulating a whole human brain with any kind of predictive power. The bot is lobotomized for our safety See <https://en.wikipedia.org/wiki/AI_alignment> Safety features that keep the AI from turning against us stop them from doing human factors. A bit handwavy, but could work. Optional: some time in the past the first AI that could do human factors went rogue and almost ended the world before being miraculously stopped. [Answer] # Been there, done that, not going again. AI capable of those things did indeed once exist, but (like so many technologies we have had on earth) nobody developing them had much motive to be interested in the resulting problems. Same as with tobacco, asbestos, fossil fuel energy, and a thousand other things that humans have innovated only to later realise their consequences, and only when forced to. In present day society we're already discussing the impact of social websites such as Facebook and Twitter on profound areas of our social structure, such as truth/falsehood control of narrative, focus on bad news and things that divide not heal society, stalking and harmful uses of the info, and so on. None of those were major public discourse concerns in advance, only after the fact. Other issues in our own use, might be loss of knowledge (why learn if you can google), assumption data is known, over reliance. So its not implausible that your societies' experience is that AI for social purposes actually can't be done without much social harm. It isn't a matter of more AI,or better systems. Something about that use and maybe about how they as a species think and social, means it does harm and after much effort the broad conclusion is, "you just can't fix it". Your societies have been there, done that. Numerous times with numerous technologies. They have either tried AI that way before, in history, or seen other societies try it, or have learned from the past and try to outlaw technology angles that have a high risk of dysfunctional outcomes. And the uses of AI in your question, do have such outcomes. We don't need to identify them for story purposes, but it wouldn't be hard to handwave many very real sounding consequences they've seen or anticipated. Therefore they just don't. It would be like asking a modern earth society to re adopt slavery, or go back to clay tablets and cuneiform for writing. No sane person in all those societies would want to go back to (or start using) a system thats going to harm them longer term. So they don't. [Answer] # International agreements. "How is it that humans might be able to produce simulations of physical and chemical systems far beyond what we are capable of now but be behind us in terms of the ability of algorithms to predict and interpret human behaviour?" The ability to predict and interpret human behaviour is the ability to influence that same behaviour, as well as allowing some appalling privacy breaches. E. A. Poe's Auguste Dupin used such a technique to answer a friend of his' unvoiced thoughts. This led to an "arms race" that almost wrecked whole societies. Having recovered from the brink of destruction, humankind decided that no longer would an AI be allowed to model a human mind; this agreement has a similar scope and structure as the ones against nuclear weapons proliferation. AIs have been developed that can detect patterns associated to such developments (from really obvious things like a marketing research institute becoming too successful, to subtler hints), and the penalties for violating the ban (which obviously would have been dubbed the Butlerian Jihad) are severe enough that no one in their right mind wants to risk them. [Answer] The technologies that we you have listed that your society needs are relativley understood by today's science. Humans have produced fusion reactions and have the capability to do so for almost 70 years. It's called a Hydrogen Bomb. It's not producing a fusion reaction that's the problem with fusion power... it's containing the fusion reaction that's the problem (there's also the energy start up costs, which require a massive amount of power to initiate but once initiated is sustainable). We also understand the fundamentals of bio-technology like you shown... a lot of reasons why we might not be at that level is that in medicine, there are a lot of long testing periods and human trials have extreme scrutinies placed on them from the outset to say nothing about the ethics of doing such experiments. With making a self-aware computer system, the chief problem is... in computing terms... our fundamental software is incompatable with a computers. It's still unknown how much digital memory an organic memory actually takes up, but it is known that the human brain has a digital storage capacity equivelent of a TIVO recording of about 300 years long. The other problem is that our own understanding of our minds is limited at best. We still don't understand all the things we do, such as the purpose of dreams or memories work. We also know we are not binary thinkers and have complex systems that can baffle a logical though pattern. Unlike game logic, which uses previous choices to determine future game responses, we do not have that and computers are in incapable of breaking from a program. [Answer] Have Emergent Gameplay Forgive me using video game terms, but video games are also a simulation, and let me explain why I say this. Without AI, video games can have a lot of systemic mechanics and features. Since they are just a simulation for entertainment, why can't the same be applied with this one? No AI involved, just a lot of cause and effect. Besides, isn't it fulfilled with humans to also cause systematic effects? It Was Humans All Along By this, I mean the whole simulation was preprogrammed by humans. Sure, this one may seem absurd, but since this is the future, the simulation could have been made by a giant staff and crew for years, programming and programming. This solution may seem really absurd, but not impossible. [Answer] All humans on your Earth are autistic Because all humans are autistic (mildly on the spectrum, so they are more like Sheldon, and not like those with severe cases that can hardly function by themselves) there are no programs for predicting human behavior. Firstly, because social sciences just aren't all that well developed. Why would anyone study other people, if he can study far more interesting things instead! Like math! Or chemistry! Or physics! And secondly, because people are more set in their ways they are far more predictable. So you don't actually need a program to predict their behaviour. ]
[Question] [ ## The Context My mermaids are amphibians that have legs that allow them to walk on land. They live in a lagoon similar to the barrier reef. The reef is roughly 1,000 square miles, and its average depth is 100 feet with a few small islands dotting the lagoon. The Mermaids are at a technological level similar to that of medieval Europe. They have both artificial and natural portals that resemble blue holes, that ships can not cross, which act as transport between major cities and other kingdoms far outside their lagoon. ## The Question Would an aquatic race of amphibians find a reason to develop a sea faring ship and if so why? [Answer] Why do Humans have Airplanes? The mermaids live in a shallow reef The reef blocks most ocean currents. This prevents any aquatic equivalent to wind-powered craft. The only option is to swim or use an animal -- like a whale, manatee, or giant seahorse -- for transport. Above the reef there are air currents which can be used to power sailing ships. This is preferable to swimming since it is less tiring and you don't have to feed an animal. Even without sails there are benefits. It is easier for a pack of manatees to pull a load if some of the load is above the water, than if the load is fully submerged. So easier to drag a boat than a submarine of the same dimensions. [Answer] ## Friction Boats are faster than submarines. That is always going to be the case no matter your society's technology or origins. To get from A to B through a medium, you have to press out of the way a tube of matter along your entire path, its width being the width of your vehicle. When staying submerged, that imaginary tube will be filled with water, weighing in at roughly one kilogram a litre. All that stuff is going to need to be displaced by the power of your engines. On the other hand, for a partially submerged vehicle (a boat), most of that tube will be air clocking in at 1 gram a litre. No matter your method of propulsion, be it slaves pulling oars or fusion scramjets: the boat is going to be faster and cost less fuel. You don't need to justify the mermaids using boats; you need to find things that the mermaids would not transport above the water surface over non-trivial distances. Other mermaids is all I can think of. [Answer] Why do humans use carts and wagons? We can walk just fine. An ox or horse drawn wagon won’t go particularly fast or far and won’t go anywhere we can’t reach by foot. Their benefit is that you can transport heavy (or bulky) goods without exerting yourself. I can totally see this applying to Mermaids and ships. Sails provide free energy and unlike horses or oxen you don’t even have to feed and water them. [Answer] SIZE Size matters. And not just on the scale of individual units, but also on the full loads. No matter how fast and convenient a portal might be, carrying a wagonload of ... anything ... will always be more convenient if you use a wagon, rather than many hands (no matter how light they make the work). Any time they are using a portal that is not landlocked, the boat serves the purpose of the wagon to get the load to the portals, and back again from portals. [Answer] Habitation They live on them. It might seem counter-intuitive, but if the merfolks' biology operates more according to physics and less according to magic, it makes sense. Without magic, or sufficiently advanced technology, a human-sized critter with a metabolism similar to a human (which a mermaid would probably have, since they presumably have a human brain) can't really get enough oxygen from the water using gills. However, if you assume that merfolk are mammals, then realistically they'd probably breathe on the surface, and then dive for extended periods. And if they live in a relatively shallow lagoon, they have no real need to stay submerged for hours or days on end. I asked [a question](https://worldbuilding.stackexchange.com/questions/165716/are-air-breathing-merfolk-viable) on this, and the general consensus is that half-an-hour to an hour dive time isn't unreasonable for a mammal of that size. The main issues are that the human body isn't particularly hydrodynamic - so a merfolk would sacrifice speed in order to get hands - and they'd have crap body insulation, so they'd lose heat rapidly. So for air-breathing merfolk, having a ship provides a mobile base where they can sit around in relative safety to rest between dives, warm up, store their stuff, float around looking for the next dive location, and sleep. [Answer] ## Their ships were always for trade.. and nowadays, for the tourists Merfolk need ships to deliver goods.. and human guests. Merfolk have always been trade partners Of course, humans discovered the merfolk 1000s of years ago. At first, they regarded merfolk as any other opponent, fighting wars over certain strategic places, like sea straits and resources. The merfolk won these wars.. and in the old days, they controlled a lot of our supplies.. Merfolk got as powerful and rich as the Arabs were on 20th century Earth. They developed ships themselves, to deliver the goods: fish, oil, cobalt, and other resources. (to complete the scenario, I let the time line proceed) Resources exhausted In a few centuries, the resources so precious to the merfolk dried up.. No new oil sources were found, gas fields lacked the pressure, to get it out.. and slowly, the merfolk changed plan. The oil money was invested in luxury underwater hotels, they converted their economy to tourism. Tourism It worked out. Merfolk love to cook and invite guests. Humans who visited the pacific, mediterranean and carribean regions soon discovered their underwater facilities, the friendly and handsome personnel, their swimming pools, the beautiful reefs, the underwater colors.. Paris Agreement To bring the human tourists in, merfolk decided to avoid air traffic, because they signed the Paris Agreement. You'd land somewhere near, then you proceed the journey on merfolk ships, who bring you to your hotel. These ships are CO2 neutral and really advanced: they look shiny, fully electric, traveling as fast as hovercraft. [Answer] # Warfare, primarily\* Your mermaids are amphibious and can walk on land, but you haven't clarified if they can stay on land for very long. That doesn't change that they might have a vested interest in keeping a shoreline clear of land enemies, especially if the land enemies take ships out to harpoon into the sea, or if they're just using cannonballs from cliffsides as a way to harm mermaid groups at sea. (Seeing that landlubbers aren't apparently very much on the land according to your comments, these could still be other, temporary forays by enemy mermaids - even towards waterlocked enemies, attacking in a way such that your projectiles use the sky and gravity is a good way to get the drop on them. If other mermaid groups are on the land in question). They can fight on land themselves, but that's probably not as good either way - especially when ranged weapons come into play. So - if they want to go to war with a shoreline nation - one way to get around that is to use siege equipment or catapults - and attacking from the sea. But siege equipment and catapults don't naturally buoy presumably, and even if they did - would have a hard time maintaining accuracy on the waves on their own. But with a boat, they could place the siege/catapult weapons on the boat, and use it as a platform to solve the stabilization problem. They could even mount cannons on these boats and aim then, since they'll have a hard time using [the saltpeter black powder gunpowder, as well as other gunpowder types that aren`t very useful underwater that they might find/mine on land.](https://chemistry.stackexchange.com/questions/74466/what-happens-to-gunpowder-when-it-gets-wet). (As an aside, you mentioned that there are both artificial and natural portals that ships can't pass through but that mermaids can; for mermaid city to mermaid city combat, I would ask the following question as some food for thought - what happens if a ship shoots a cannonball through the Blue Hole Portals? What about launched catapult loads? If they don't destroy the portal themselves, do they keep the momentum going out the side, ala the game Portal?) ## Mermaid Warfare Boats might look a bit different for these needs A lot of this "Above-water Weaponry" does sort of relying on solving the ability to stabilize siege weapons and catapults on a boat, while waves are an issue. While not a medieval tech level boat, this [Martini One](https://www.wired.com/2014/10/velodyne-martini-boat/) gives us an idea as to how mermaids might build such boats. Though we can do older technology, the idea of negating waves and try to avoid turbulence is the main focus of that - they could add wave breakers to it, or use a medieval approach to automated wave crest correction on their floats, or simply course correct by sheer scale. After all, these boats are being manned by mermen, so the ability to sail fast might not actually be the biggest point - they could even be easily sinkable, since if they sink into the water, the mermen can easily recover them and repair/rebuild them, and none of their crew will drown. Since they're not needing to be particularly fast in these cases if mermen can speed them up, and the size of the ship doesn't matter much either, nor redundant sinking failsafes, we can expect that they might look a bit like rafts, or [Pontoon bridges](https://en.wikipedia.org/wiki/Pontoon_bridge) - just pontoon bridges to nowhere. Or if you want to use the seabed as a level area to stabilize from regardless of the waves, sort of like Eiffel Tower style structures that can detach from the sea floor but then dig in when they're within firing range of the target - you've got the ability to go to the sea floor and ensure each possible column holding up the psuedo-tower is locked in place into the seabed when necessary. ## In peacetime, some other uses With the catapult designs, sometimes you don't want to be at war. They're still potentially useful for launching large rocks or a lot of water at a cliffside of an island or continent, breaking up the rocks on the edge of the land so that it drains into your waterways more freely broken up, either as a means to build more stone weaponry, or stole materials for other structures, or even to just make mer-made rivers and deltas so you can swim further up the the landmass to get to areas to forage where No Merman Has Gone Before. [Answer] # Science! There is all sorts of knowledge to be gained from the dry environment. For example, they can do research on phlogiston and the luminiferous aether much more easily in an atmosphere than underwater. [Answer] ## Alright, I reread the question. I don't understand why this question was asked. Given the conditions the OP presupposes, "why did humans build ships" is essentially the same question. You might ask "Why wouldn't mermaids build ships?" I'm sure you could think of some reasons, and then come up with other reasons to counter those... Or you could ask "Why wouldn't mermaids build submarines?". That might lead to some very interesting world building ideas, like submarines that use giant underwater sails to harness undersea currents, etc,... But back to the original question: do they use gills to breath or lungs? Or both? They don't have legs, so how do they move around on deck?, How do they rig the sails? If they don't use sails, what do they use to propel the ship? Do they use fossil fuels? How did they figure out fire under water? If they use electric motors, how'd they figure out electricity under water? Are the ships made of wood? Where do they get their wood? There's no wood under water. Metal? how do they smelt metal under water? All of that was just to presuppose the question of "why would they build ships", with how would ships even work for them.Why they might has some rather obvious answers: You can move faster on the surface then below. You can move heavier and/or larger loads on the surface then below. And you can navigate shallower waters on the surface then below. Every other reason is a sub-category of those three primary reasons. ]
[Question] [ This probably sounds like a ridiculous question but it is actually very simple. It seems possible to me to modify a motorcycle to be weaponized and indeed very deadly here on Earth (if you had the technology to put machine guns or a missile on the front), it seems like a motorcycle is a good way to rush in and send in a few shots against the enemy and turn around before they have a chance to hit, now I don't think they are a very good option here on earth but I am wondering what this community thinks about having them on Mars. So simply if I am to include military motorcycles with a combat role on mars in my world I have to be convince that they are tactically useful, maybe some unconventional ways to use this unconventional tool would be appreciated; aka are they useless or useful? Edit: For those who are wondering I have considered ATV's, please stop mentioning it as an alternative to motorcycles. The ATV is obviously quite useful, and I am going to use it, I a simply wondering whether Motorcycles would be worth the effort in a military situation on mars. Edit 2: People have asked what kind of Martian environment we are talking about, the two environment's I will ask you to consider is the modern environment of Mars and an environment where the CO2 is mostly replaced by O2 (and is also colder then the modern mars (fewer greenhouse gases). The soldiers themselves will be wearing power armor, the usage of bikes in war CANT come before the invention of power armor. They are probably powered electrically. Edit 3: Since I am genuinely surprised nobody has made any mention of this I would like to note that motorcycles are obviously not the best firing platform, however if you strap some sort of weapons to the front and back of the motorcycle could it have uses? This is an extension of the question, I don't really care about how hard it is to shoot a gun from the seat of a motorbike, I want to know if strapping a machine gun or missile wouldn't be worth the effort in combat. I wan't to know if they are useful as combat vehicles and if there are any unconventional uses for them. [Answer] For over 100 years we have been in the era of line-of-sight kill. If you can see your target, you can kill them. Cavalry in combat -- lightly armored tall mobile troops -- became obsolete with this era. Your motorbikes are cavalry. What hasn't become obsolete (yet) are dragoons -- troops that travel on lightly armored transport to reach a position, then dismount and engage. Unless defensive technology suddenly outperforms offensive technology, using cavalry on mars will be just as stupid as it has been on earth for a 100 years. Naive extrapolation of todays tech -- computer vision and targetting and drones -- gives us cheap "infantry" that can kill unarmored targets around corners and over the horizon. As the atmosphere on mars is going to kill the endurance of air-based drones, you could see a ATV/motorbike drone "carrier" that is used to bring drones to a forward position to be deployed against the enemy. I'd expect battles (outside of built up areas) would be over-horizon "shoot a drone into the sky, shoot down enemy drones" beyond-LOS combat. The usual armor-vs-caliber game will occur. Armor is defeated by higher caliber guns; but a high-caliber gun platform with no armor can be taken out by a cheaper/lighter/more numerous low caliber gun platform. So you could imagine having scout drones (no guns), harrier drones (no armor, gun sufficient to take out an unarmored foe), combat drones (armor sufficient to defend against harrier guns, gun sufficient to defeat own armor), defender drones (armor sufficient to defend against combat drone, gun sufficient to defeat combat armor), anti-capital drones (no armor, gun sufficient to take out capital drones) and capital drones (armor sufficient to defend against combat/defender drone, gun sufficient to take out defender drone), or some similar web. A mobile base (capital level armor) with remote control bikes (combat level armor) that deploy/retrieve drones vertically (of various kinds) could control a large section of territory well beyond a horizon. Firing a drone up 10 km gives you sqrt(10 km(2\3.4km+10km)) = 13 km horizon. Have a base with bikes 20 km out gives you a kill-radius of 33 km. [Answer] In lower gravity, like it happens on Mars, any jump will last longer. And motorcycles, while in a jump, can do little to no steering. So at any jump your attack motorbike will have, it will basically be a floating target for enemy artillery. Add to this that you can hardly add enough shielding to protect the driver (a tank or a Jeep is way more effective) from weather and bullets, and you get why motorcycles are used in supporting/exploring roles in Earth wars, not active fight. I would say that you can use motorbikes for the same roles they are used here on Earth, nothing more fancy. [Answer] If you got creative with the motorcycles, yes. You'd have to equip them with some sort of maneuvering thrusters for short bursts. The low gravity, if accounted for, could make the motorcycles very effective. You could have downward thrust to cut short huge jumps, and thus make tracking the arc of a jump impossible for gunners. Left and right thrust could make a jumping bike able to swivel and fire upon any pursuer and frustrate their attempts. The wheels would need to either be solid, or have some self-healing abilities due to nanites, or some other tech. To add to their effectiveness, their small size allows for a new substance, nicknamed "hardtofindnium", which allows for a kind of stealth tech, which can hide a small object from sensors, but larger objects are easier to track (vibrations from larger vehicles and such can be triangulated on, flying things can be tracked by RADAR or something along those lines) so tracking one of these motorcycles would require visual sighting. Be creative, there are tons of possibilities along these lines. The approach you should take is that these things would screw up the enemy's plans by introducing something that draws their attention, throws them off guard, and circumvents their standard defenses. [Answer] Yes. <https://www.cnn.com/2014/04/28/us/stealth-military-motorcycle/index.html> > > Soon after he left the unit in 2010, Golembesky said Marine special ops in Afghanistan began improvising and bringing motorcycles into their weapons arsenal. > They started acquiring cheap "Chinese knockoff" motorbikes in Afghan bazaars and customizing them. "They'd weld racks on the back and repaint them, camouflage them down," he said. "The bikes mainly became a way to overcome covering long distances over harsh terrain." > It was really a case of fighting fire with fire. Taliban have been riding mopeds and motorcycles to attack U.S. forces since the beginning of the war in 2001, said Golembesky. "They know the most practical, low stress, low impact way to get around the battlefield and maneuver." > > > But ATVs are more practical, since they're more stable and carry more stuff. <https://www.popularmechanics.com/military/a17336/special-forces-atv-marines-army/> > > The military likes these vehicles because they can be transported inside the Bell Boeing V-22 Osprey, Boeing's MH-47 special operations helicopter, and Sikorsky's MH-53 Pave Low, and dropped from the air. Special forces, in particular, like ATVs because of the extra mobility they provide, allowing smaller units to get to a combat area or conduct reconnaissance patrols quickly. Plus, they keep Marines or troops who would otherwise move on foot fresher. > > > [Answer] I can see a couple major problems with using motorcycles in combat, let alone on mars. Poor Firing Platform* > > A Motorcycle is an awful firing platform, there's a reason they aren't used as raiders. You need at least one hand to operate them, they're unstable and if you aren't paying attention you'll crash. > > This dramatically limits the kinds of weapons you can use down to pistols and low-recoil carbines/machine-pistols. You can drive-by, but any capable opposition can easily kill you because... > > > No Armor > > A motorcycle leaves its operator completely exposed to the elements, incoming fire and critically, accidents. On earth, motorcycle accidents are common and frequently horrific, on mars they'd be 100% lethal without some incredibly capable safety equipment in your sealed environment suit. > > Your suit rips on a rock as you skid 100s of meters and you die of > asphyxiation even if you weren't that badly hurt. > > > In practice, a Motorcycle isn't an awful way to get around on Mars, though you might be better off with a quadbike or Trike, they're more stable and can carry more weight. Your vehicle would be electric, so quiet and easily recharged in the field with portable solar arrays, so endurance is not a problem. In combat, you'd want to operate somewhat like a Dragoon, using the vehicles to get where you're going and then dismounting to fight. There are some advantages to using small ATVs like this, they can go places bigger APCs couldn't, they can get there faster, and they're more easily manufactured and maintained. I could well imagine the ATVs would actually be adapted from colony Rovers and buggies rather than purpose-built for combat. All of this assumes a fairly conventional low-tech solution. If you want to get high-tech, you could mount a machine-gun in a motorised pintle on the front of your bike/quad and guide it via head-tracking of the driver. Similar to a helicopter gunship's "Look-to-kill" tech. This solves the need to go one-handed and lets you aim more easily. Put the trigger on the hand-grip for the bike. [Answer] If wars are happening on Mars, it means we made it there. The technological advancements we will have made will be many and varied. This means that weapons will be more technologically advanced as well. Drones will be cheaper to build and easier to operate, and will be packing on top of that. Any bullets will fly faster and further than on Earth due to the lower atmospheric pressure and drag. That, coupled with bot autoaim will change tactics as we know them. A motorbike would probably have great mobility on the rocky surface of Mars. But to the drones patrolling the enemy territory, any rider will be an aquatic fowl in a resting position. Also this: ![Opportunity the killer rover](https://i.stack.imgur.com/GRhsc.png) [Source](https://xkcd.com/1504/) [Answer] Given the rocky terrain of mars, it can be hard for a lot of vehicles to traverse it efficiently. Motercycles/dirtbikes only have two wheels, which means they can fit through smaller gaps in the terrain. Perfect for recon or guerilla tactics which rely on using the landscape. Addition: If it's an electric motorcycle, or uses other quiet non combustion sources for power, it makes it even better for the two above mentioned activities. Bonus: if each cycle has two passengers, one driving and one in the back with a turret, you could simple drive to the top of a hill and rain bullets upon your enemies in a couple short bursts and then drive away quickly before they can make a counter offensive. It would be suicide to chase you with a turret keeping enemies behind you in check. Guerilla warfare x mobile machine gun nests can suppress large scale forces and pose a threat to any non mobile forces. The British military used machine gun turrets during the beginning of WWII, but they fell out of use as trenches became prominent. [Answer] Problems Motorbikes are not really able to fire while moving. They are unstable even before you consider recoil. If the rider was to carry explosives such as a grenade launcher that may have some power. Bikes are loud making them easy to locate on a battle field. They are then moving in a somewhat predictable path with no opportunity to get into cover. Infantry can weave and drop to the floor periodically and other vehicles are built to resist bullets. The bike can do neither of these things. Advantages I can imagine a bike being the fastest ground vehicle on Mars. If defences prevented aircraft from being flown then a bike would be a good vehicle for staying out of range of enemies or moving infantry quickly across safe ground. Bikes can reach more terrain than other ground vehicles meaning they may be the only choice to move quickly in some areas. Bikes are easier to hide and can be pushed to close in on enemy without making a noise. They could then quickly rush through the defensive lines and break up the formation causing a lot of confusion or reaching critical areas such as a commanders tent, it would be near suicide for the rider but would greatly help a supporting unit attacking at the same time. Alternatively they could ride over entrenched machine gunners and fire shotguns down as they pass. Change to the story If neither side brought actual weapons either because the conflict was a surprise or because earth placed an embargo on arms they may be fighting with tools or improvised weapons. In that case a bike could be armoured enough to be a viable vehicle for closing on enemy units but much faster than a larger vehicle with more range of movement. Or they could simply be used because they had them around for unrelated reasons. [Answer] # Conventional motorcycles would be useless on Mars. There is simply not enough oxygen for an internal combustion engine to operate on Mars. Its atmosphere has at best the equivalent of about 30km above sea level on Earth, and it has about 1/10th as much oxygen in its relative composition. This is an important detail to recognize for your credibility's sake. If you are going to use motorcycles, they need to be electric or use fuel that doesn't require atmospheric assistance, or at least do some hand-wavey super-duper-turbocharged enhancements. # Motorcycles could almost certainly be used for Martian warfare in specific circumstances. Guerrilla warfare is almost certainly their best use. Electric bikes would be quiet, fast, and able to get through difficult terrain to raid storehouses, supply lines, etc. If you wanted to get a little silly, the reduced gravity could make for some interesting semi-aerial attacks. If they are maneuvering through cratered plains or dunes, they could launch themselves high into the air off of natural ramps, making it difficult for the enemy to sweep them all down in one go. It is much harder to hit fast moving targets in 3 dimensions than 2. [Answer] Lets take a look at all the times that motorcycles have been used during war on earth. In the US, motorcycle testing began as early as 1913. There first deployment was during the "Boarder War" against Pancho Villa. They came in a variety of models including standard bike, sidecar support vehicle, sidecar machine gun nests, and sidecar supply runners. They were deemed so effective that over 100,000 motorcycles were commissioned during WWI. During WWI Entire infantry units could be motorcycle bourn, and motorcycles could be equipped with features such as stretchers, shielding, passenger sidecars, and machine guns. However, the most common use of motorcycles was information relay. The unreliability of radios and other communications during the time gave a great niché for motorcycles to occupy. The U.S. wasn't the only one with motorcycles though; the British had 30,000 of their own, complete with a range of accessories such as sidecars, machine guns, and ammo storage. Once again, they saw most use as communication relays. This is a trend that continued into WWII. Despite over 200,000 motorcycles used between allied forces, they were almost all exclusively non combat. American models were the most durable motorcycle available with a Thompson submachine gun holster equipped to hold the soldiers' weapon. One unique use of motorcycle was as an accessory to paratroopers. Light weight versions of motorcycles were used during WWII by British forces to deploy highly mobile units behind enemy lines. Unfortunately for mars, the lack of atmosphere makes this innovation impossible. With the conclusion of WWII, many advanced technologies began to be developed, which almost entirely closed the need for on ground communications. This relegated motorcycles to mostly recon work, especially during Operation Desert Storm, in which they got a fair amount of use by Britain, the U.S., and NATO. Today, the U.S. Military still has motorcycles in reserve. These bad boys are silent electric bikes with 3500 hours charge and 50 hp. I imagine you'll probably have something similar on mars, do to the lack of fossil fuels. And what uses would they have? Well, if mars has yet to build a good communications infrastructure you may need to use them in part for communication relays. There's also the possibility that trenches aren't feasible on the rocky surface of mars. This gives mobile machine gun nests a good opportunity to come back into use. Speaking of the rocky surface of mars, do you know what can be used for crossing sandy planes effectively? Motorcycles. Add into the fact that trenches are hard to build in a sandy environment and you have a pretty good reason to have a motorcycle corps. Lets also assume that your enemies have motorcycle corps though. How do two motorcycles choose to battle? Well lets go out on a limb and go ahead and give motorcycles front facing missile launchers. Like a miniature rpg launcher with two shots or so, in order to eliminate targets that are hard to penetrate with your normal machine gun. Of course, your motorcycle has an on board computer that helps them aim these mini rockets, possible with a in helmet display so you can confirm your target. In fact, why not mount a small machine gun in the front of your motorcycle with a helmet tracking software. The gun will automatically adjust to whatever you look at, and then you can shoot in a wider area in front of you, instead of just directly in front. This gives you some amount of firepower if you happen upon an enemy while on a patrol. Of course, you can have a larger amount of hardware in your martian motorcycle thanks to the lower gravity. In fact, larger, harder, and stronger systems are essentially required to help keep you on the ground. This gives you a lot of play, including bullet proof domes over your motorcycle protecting the driver, especially for recon vehicles or anti cavalry troops. However, lack of gravity also makes other vehicles a lot more useful, such as tanks that are both lighter, faster, and yet have heavier armor than those on earth. But lucky for you, high mobility is incredibly important in war, and motorcycles will definitely have uses in recon and support. You could even mess with the whole less gravity thing to make motorcycles that have weapons specialized in anti tank, anti personnel, and anti motorcycle functions. Different motorcycle units could all have specialized roles in a high mobility battlefield where they can navigate the terrain better than other vehicles, be equipped with similar defenses or weaponry as traditionally bigger vehicles on earth, and replace a lot of the functions of aircrafts on earth. [Answer] I am not at home with gravitational forces and such, so I cannot give you calculations about how easy it would be to drive one; however, I can give you some tactics. Motorcycles should not be used in direct confrontations, because the drivers are very vulnerable; however, they're perfect raiders, ambushers,... * They can quickly transport a sizeable force. These can be used as raiders or just to reach positions for conventional battle. (mobility warfare) * They can transport small amounts of material – for example, mines and bombs – to sabotage enemy supply lines or ammo to resupply friendly troops or act as messengers. (sabotage, logistics and communication) * They can be used to chase and harass enemy armour. This one is a bit trickier and I wouldn't recommend doing it against decently trained militaries, but it sort of worked in the 'Toyota war.' Granted, they used pick-ups, but bikes could do it too with some tweaks. (Instead of mounting anti-tank launchers on top you could have small portable rocket launchers.) (Harassing and chasing down enemies) * If you have the tech, maybe they could also serve as remote controlled suicide drones. (sabotage and terror) Honestly, you can be more creative if need be. Why not put a mortar on the sidecar and have your fellow mortar crew members drive along with some ammo? Mobile mortar platform. Mount an MG on a sidecar and you a machine gun emplacement/crude AA platform. [Answer] I think that if you were asking "is there any combat or combat-related use for motorcycles on Mars?" the answers are already here (yes). However, I will try to answer your specific main question, which boils down to: "Is there a direct combat role for power-armored soldiers mounted on motorcycles that carry heavy weapons?" On present-day Earth, this is a losing proposition for two main reasons: 1) Power armor doesn't exist, and mounted unarmored troops are extremely vulnerable to today's long range and rapid firing weapons (this is why for more or less the last 100 years cavalry charges haven't existed). The only analog I can come up with is suicide or swarm attacks where massive casualties on your side are acceptable (think Iranian fast boats in the Persian Gulf). 2) Unless you are going to invest in visual systems for missile lock or aiming guns (think Apache main gun or F-35 helmet system), it is virtually impossible to fire accurately from a motorcycle-mounted weapon, especially on rough terrain. This isn't even taking into account the recoil from repeated shots on the move. I am neither a combat veteran nor a motorcycle expert, but I do ride and I do shoot and I can tell you that trying to aim a simple strapped-on weapons system would be absurd. Hopefully someone with more experience in either or both of these areas can chime in if I am somehow incorrect. So now let's examine the main differences between your setting and present-day Earth: 1) Mars Once we get past the fact that the motorcycles are most-likely "powered electrically" and the riders need life support (in the CO2 scenario), the terrain is similar to modern-day battlefields and the only real difference is the thin atmosphere and lower gravity. Any complaints about the noise are negated by thin atmosphere but this is probably not an issue anyway due to the electric motors. I have seen answers that mention jumping and using thrusters for evasion. Honestly I can't see a way that this makes more sense than personal aircraft (e.g. jetpacks) with mounted weapons unless you just really want the cool factor of Martian machine-gun motorcycles (which does sound rad). 2) Power Armor I'm going to assume power armor at least means a fully sealed life support system that has a hardened or otherwise survivable outer shell and provides greater strength to the user. As such we don't have to worry about whether we are in the CO2 or O2 atmosphere. If defensive technology has evolved faster than offensive technology (unlikely but hey it's your story), then I can conceive of a scenario where my first objection is nullified. Power-armored soldiers cruising in on motorcycles might not immediately get picked off by machine-gunners or missile systems. I should note that if motorcycle troops are not the only ones wearing power armor, then they will be facing up-armored troops who are able to field pretty large and heavy weapons systems themselves. You can work this out in your story if you are determined to make it happen. 3) Advanced Technology You could finagle "advanced technology" to really make anything fit into your desired plot, so without getting too broad I'll address my second objection. If the power armor includes some type of aiming/locking system as discussed above, the motorcycle-mounted weapons become more viable. Think of a rider being able to strafe a line of dug-in infantry by aiming with his line of sight, or visually locking his missiles onto an attacking aircraft. Add to this some very advanced stabilization that lets you fire your .50 caliber machine gun or future equivalent at a 90 degree angle to your direction of motion without immediately crashing, and I guess you have a fast, survivable, and accurate weapons system. I think if you really wanted to present a likely path for the combined evolution of weapons technology and military tactics, you would not find power-armored motorcycle soldiers cruising around and shooting missiles, whether on Mars or Earth. You can certainly ignore that entirely subjective statement though. Maybe the atmosphere is too thin or fuel is too scarce for armored jetpacks. Maybe anti-aircraft weapons are too advanced or one side doesn't have the resources to field jetpacks. Maybe power armor is rare and only used for elite motorcycle troops, or advanced energy weapons that would easily fry power-armored soldiers aren't fielded often because of the energy requirements. Like I said, it's your story so you should write one that you're happy with, and if that means the motorcycles gotta have missiles then make it happen! [Answer] Martian Chaos Terrain I'm going to come at this from a slightly different angle and just accept that we ARE using armed motorcycles on Mars, and look for where we would use them. The answer, I think, is [Martian Chaos Terrain](https://en.wikipedia.org/wiki/Martian_chaos_terrain) "...a rat's nest of mesas, buttes, and hills, chopped through with valleys which in places look almost patterned." So, let's assume that we're fighting in this Chaos Terrain. There's LOTS of cover, ludicrous amounts of it in fact, so it's pretty easy to stay hidden from anything that's not directly above you. The conflict by necessity extends all the way up into orbit so neither side has uncontested control of either the airspace or the orbital space above the battlefield. Now, This isn't a conflict involving thousands of troops in mass formation, nobody has the resources to bring THAT many people to Mars just to get killed. No. This is a battle primarily fought by robots. But, the robots aren't very smart, which means they need human commanders. The radiation levels on Mars are already very high, and deliberate jamming makes long range communications even more challenging, which means that the humans who are leading these robots need to be able to stay close enough to them for their wireless communications to both cut through the jamming, and be tightly controlled enough not to be intercepted. Our robots have all kinds of weapons and counterweapons and measures and countermeasures and counter-counter-measures to deploy against each other. There are LOTS of them because your automated factories can spit them out all day long. Your human commanders are VERY valuble however, so you can't have them just hanging out with robot squads that aren't fighting. The Commanders need to be able to move very quickly from place to place so that they're always supporting the robots that are in the thickest of the fighting. Now you need motorcyles. You can't use ATVs or anything larger because they can't move quickly enough or quietly enough through the mazes of the Chaos Terrain. You can't FLY because you just get sniped out of the air by concealed laser emplacements in the mesa tops. You have to stay low, and stay fast, and that means two wheels and lots of speed. I'm imagining hydrogen power cells powering electric motors. Almost no moving parts to deal with. Something a lot like a Tron Lightcycle, only with those [nifty new titanium tires](https://gizmodo.com/nasas-new-titanium-airless-tires-are-nearly-indestructi-1820721473) NASA came up with. Weaponry is primarily defensive. Your commander's job isn't to run around killing robots, it's to help his own robots take best advantage of the terrain and (hopefully) annhilate enemy robots that don't have a human commander in play. You want your motorcycle to have plenty of chaff and ECM, and probably something like a [Trophy launcher](https://en.wikipedia.org/wiki/Trophy_(countermeasure)) to knock down incoming missiles and so forth. Whatever weaponry you DO mount on the motorcycle is gryo-stabilized and linked to the commander's helmet like on [Apache Helicopters and F-35s](https://en.wikipedia.org/wiki/Helmet-mounted_display). The Commander looks at something, the motorcycle shoots at it without the commander having to do anything so crass as aim the weapon with his HANDS. Obviously the greatest threat to a commander is an enemy commander, and so the motorcycle is designed for playing hide-and-seek. The commander wants to stay as close to his robotic troops as he can to maximize his ability to control them, while remaining undetected by the opposition. If he thinks his location has been compromised, he needs to rely on speed to get as far away as possible as quickly as possible before over-the-horizon artillery rounds start falling on him. So, yeah. Motorcycles on Mars are TOTALLY viable. Practically indispensable, really. You'd be a fool not to use them. [Answer] I think the nearest you would get, because of the issue of maintaining balance while zooming over a rough surface while shooting weapons with recoil, would be a militarized ATV. <https://www.google.com/search?q=militarized+atv&rlz=1C1CHBD_enUS789US789&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiDvdvm2f_cAhWnE5oKHUoSDJ8Q_AUICigB&biw=1884&bih=896> This solution is actually multi-purpose since it also provides freight and logistics capability beyond what is feasible on a motorcycle, for just a little more cost in materials. [Answer] I think everyone is forgetting the motorcycles used during world war two. Whether they were used in the actual fighting or not is something I don't know, but I do know they were widely used, especially in ferrying messages back and forth between headquarters and men in the field. It would only make sense that they had machine guns attached to a side car in that they could protect themselves, if nothing else. It sounds perfectly plausible to me! You could always borrow from Tron slightly in that the motorcycles were somewhat armored. It wouldn't be a huge leap to attach weapons. However, the motorcycle might not be as cool as the ones in Tron, as you would have to have a physical bike, instead of a digital one. [Answer] Controlling the motorcycle AND the weapon is a difficult task. Steering and balancing without hands must be done differently. My proposal would be controlling your motorcycle with body movements. This means a radical change in the bike's set-up. It will be controlled by tilting the body while freeing your hands to control the weapon. You can think of a mobile platform that operates like a segway, though it could look completely different. [Answer] I can think of a case for battle bikes. Mars is a series of tunnels and underground cities, tight corners and narrow pathways with a roof over your head at all times. Conveys or trains transport resources/supplies. These transports are often the target of armoured bikes. Due to the narrow pathways and no air cover possible an armoured bike was seen as the best response. The riders armour protects from small arms fire and due to the rider often attacking from the dark corridors and being able to perform hit and run attacks means that a bike can disappear before a chase or counter measures can be used. ]
[Question] [ When in space, the amount of force required to move goes down drastically, due to the virtual lack of drag. In this environment, would be feasible for engines in space (more specifically belonging to generation ships) to use steam? [Answer] Using steam to propel yourself in space obviously requires that you: 1) Have a steady supply of water 2) Have energy to boil said water You might be able to scavenge water from comets, etc., but this is still a very wasteful process, and water doesn't simply grow on trees ... in space. Furthermore, water and large, complex systems don't typically play nice together. The last thing you want is pipes rusting out in your engine, not to mention that any time you shut the system down said water would start freezing, and burst pipes could really ruin your sojourn to another star system. Here on Earth we have the luxury of being able to constantly manufacture new pipes, and fix/maintain them, but on a generation ship it would be a lot more difficult. All in all, there would be a lot of practical challenges to implementing that sort of propulsion system. [Answer] Depends on what you mean by "steam engine". A NERVA-type engine using a nuclear reactor with water as the reaction mass would be a steam engine, no? Likewise if water was heated with a concentrating solar reflector. Indeed, comets do change their orbits that way, as water (or other volatiles) is boiled by sunlight. [Answer] A steam engine in space (assuming you mean a steam rocket engine) is not only feasible, but under some circumstances even desirable. The [Neofuel](http://neofuel.com/index_neofuel.html#Technical) site makes a strong case that using water directly from comets, asteroids etc. rather than breaking it down to hydrogen and oxygen, mostly because the extra mass of equipment needed overwhelms the advantages of higher ISP. All you really need is a source of energy to heat the water into steam, and away you go. This can range from solar mirrors ([a solar moth](http://www.projectrho.com/public_html/rocket/enginelist.php#mirrorsteamer)), beaming laser or microwave energy to the ship or using an on board nuclear rector. So long as the water is receiving enough heat energy, you have steam. Throttling the engine is as simple as adjusting the flow rate of water through the heat source. [![enter image description here](https://i.stack.imgur.com/8xOsA.gif)](https://i.stack.imgur.com/8xOsA.gif) The NEOfuel proposal for a steam rocket [![enter image description here](https://i.stack.imgur.com/xJcfr.gif)](https://i.stack.imgur.com/xJcfr.gif) Simplified schematic of the NTR steam rocket. The water bladder(s) would be far, far larger in real life The down side of a steam rocket is truly terrible ISP of 195, compared to @450 for the ideal H2/O2 liquid fuelled engines or between 800-1200 for hydrogen NERVA rocket engines. You would be using enormous masses of water to get from point A to point B, and getting from Earth to the outer planets would take many years at best. The NEOfuel site calculate a water tanker carrying a payload of 10,000 tons would carry 325,000 tons of water as reaction mass. > > Final Configuration: H2O NTR Option > > > 10,000 tons Net payload 358,000 tons water propellant 104 tons water bladder 208 tons water bladder tank armouring 656 tons Nuclear Thermal Rocket engines 122 tons water extractor > > By contrast, the LH2 option works out like this: > > > 10,000 tons useful payload (138,000 to 453,000 tons water for LH2) 15,400 tons to 50,300 tons LH2 propellant 154 tons to 503 tons armored LH2 tanks 472 to 1536 tons of LH2 NTR engines 48 - 156 tons to extract water 559 to 10248 tons for electricity for electrolysis 70 to 5027 tons for cryolizer hardware 372 to 10609 tons for electricity for cryolizer So steam is a means of getting low cost bulk payloads around the solar system cheaply, but you will have to accept low ISP, massive amounts of water being used as reaction mass and long trip times. [Answer] Yes, you could boil water to build up lots of pressure, and vent the steam as a propellant, and the spaceship would move. But it would move very slowly, and then you'd be out of water. It's not a very effective propulsion mechanism. [Answer] The question didn't state that the steam engine needs to be used to propel the ship. So yes, if the ship is large enough and needs a lot of electricity, it is feasible to use a steam engine, or more specifically, a steam turbine. The water is boiled not by burning coal, but by nuclear fission. There are modern ships and submarines which do this. Of course, they also use it for propulsion, as electrical motors turn propellers. You obviously can't use propellers in space, but if your internal electrical needs are high enough, a nuclear reactor can be warranted on such a spaceship. And, nuclear reactors are actually a form of steam engine. [Answer] It depends on what do you call a steam engine. A steam locomotive obviously can't be used, since in space we have no external support, so we need a jet engine. But can a jet engine use steam to propel itself? A rocket engine [might work](http://www.nasa.gov/topics/technology/hydrogen/hydrogen_fuel_of_choice.html) using liquid hydrogen and liquid oxygen, producing hot water (=steam) in the process. But can we still call it "a steam engine" though? [Answer] I haven't done the math on this but it seems to me a steam engine would be incredible dumb since the H and O that you would be mixing and then boiling just to be released into space would take more energy to produce similar or less thrust than just jettisoning oxygen/? like most RCS thrusters currently do. So possible, but not feasible. [Answer] The Neal Stephenson book Seveneves shows characters embedding a nuclear reactor into the center of the ice core of a comet, then melting the ice of the comet into steam to use for thrust, turning the entire comet into a spaceship and rocket engine. So if you have a piece of ice 2km in diameter to use as a water source, it's certainly possible. [Answer] No, not by any sensible definition of steam engine, at least not for propulsion (since you mentioned drag, I will focus on propulsion first). A rocket works by throwing out propellant to the back. This provides forward thrust. Now, in order to gain more forward speed, you need to either throw out more propellant, or throw the propellant out faster. In orbital mechanics, there is no drag, yes. But you are still subject to gravity. You are nit weightless, you are in free fall, which means objects and people inside the spaceship appear to be weightless. Being in orbit means actually falling sideways fast enough that you miss the ground and swing around. In order to change your orbit, you need to change your velocity. This is called delta-v (which literally means "change in velocity"). You need to change velocities quite drastically. In order to get fom the ground to low earth orbit (LEO) you need to have ~9400m/s delta-v alone. So, back to what I said before, you can either throw out more propelannt, or throw it out faster. In your spaceship, the supply of propellant is limited. Thus, maximizing the speed at which you throw propellant out is the key factor. This is called the exhaust velocity. But, you can't boil water to arbitrary temperatures, so the exhaust velocity (which is achieved by expanding the exhaust in a de laval nozzle) is still limited. And even if you could boil it to arbitrary temperatures, you still need fuel to boil it in the first place, which is limited, too. It turns out, you can build a steam rocket. but its horribly inefficient. According to [this Wikipedia site](https://en.wikipedia.org/wiki/Steam_rocket), you can achieve an Isp of 195s with a steam rocket - well below the modern Hydrolox rocket which achieve Isp greater then 450s (Isp and exhaust velocity are closely related, ve = Isp \* g0). So your efficiency is horrible. This means the only way you can get anywhere is by increasing propellant mass. The concept of "mass fraction" is actually quite important for modern rockets. To give you an example, the STS external tank was 96% fuel and only 4% structure. A soda can has 94% soda and 6% structure (by weight). So the ET held more percentage of fuel then a soda can. Modern rockets like the Ariane V or upcoming Ariane 6 have even more propellant. You can easily see that its not really feasible to miracuosly improve the fuel fraction by a great margin (or we would have already done it, while still using more efficient propellants). --- This leaves you with using steam engines for electrical systems. You could - in theory - use a nuclear reactor, which boils water and then turns propellers. Buts thats not as exciting and steampunky as using it for propulsion. [Answer] $F=ma$ Newton's first law (correct me if I am wrong). Second law, for every action there is an equal and opposite reaction. Basically, in order to move forward, you need to push a lot of something behind you at a low speed or very little of something at a high speed. When we walk, we apply a small amount of force, acceleration, opposite to where we walk. It just is not noticeable, because the earth is very big and we are very very small. [Answer] Let's find out! In space, you use conservation of momentum to propel yourself. Basically, you throw mass very quickly at the back to push yourself forward. The most efficient systems use very small particles with very very high velocities. The more simple systems use combustion to create hot gas that creates pressure that creates exhaust velocity. The thrust of such an engine is the exhaust speed multiplied by the exhaust rate (how much mass you send \* how fast you send it). How much mass can be variable on the size of the exhaust, how many engines you have... so let's focus on the exhaust speed: Locomotives steam boilers have been know to hold up to 1,500 psi (10.34 MPa), or about 100 atm. Unfortunately, I have no idea where to go from here. My understanding of that topic is too limited to make the computations. I fear that would be disappointing, though, as methalox rocket engines have exhaust velocities of 5000m/s and more. [Answer] I suspect that lurking behind the question is a steampunk motivation. In that case it is useful to recognize that what the 19th century called "steam power" was really a code word for coal powered via a steam turbine. While the Earth bound practice with steam engines was to vent the steam and refuel with water along the way, you could have some internal functions of a space ship that were powered by coal and rather than venting the steam, sent it to a cooling area exposed to the chill of space and then recycled it. This would be useless for propulsion purposes, and would take a lot of weight per energy density, and you probably would want to vent the particulate exhaust of the coal combustion into empty space, but it could run life support systems on board and the heat generated by the engine could also heat the ship. For propulsion into orbit, from a 19th century steampunk kind of perspective, you might want to launch the space ship with coal powered internal systems from a huge cannon a la Jules Verne, or some sort of giant catapult, or a hydrogen gas explosion in a long glass tube, possibly from a high altitude attained via a balloon or an airship. To return its occupants to Earth, the ship might break into two pieces like a one stage rocket that would spring apart from each other perhaps with a highly coiled metal spring that could be released when it was time to re-enter. Neither the launching method nor the return method would provide all that much thrust, so you'd need to limit space voyages to near Earth orbit (and if the landing capsule were pointed the wrong way when activated everyone would die, while if someone was not in the landing capsule when it was activated, that person would die, in either case in deep space after life support supplies eventually run out). After the return spring operation, an Apollo style parachute (or better yet a parachute modeled after a huge Victorian umbrella) could be used to protect the folks in the landing capsule. While you couldn't make it to the Moon, let alone anywhere else that way, you could get a super high altitude view of the world (for purposes from spying to weather prediction) without having to have a working aircraft wing (something not developed until the early 20th century by the Wright Brothers), and you could also go up and then land elsewhere on Earth to go around the world in a matter of hours rather than Verne's 80 days by balloon. You could also use the vantage point of space for an early space-telescope for precision astronomy impossible from Earth at the time. As long as you stayed inside the strong, airtight ship (perhaps lined with lead to prevent cosmic rays from doing too much harm), there would be no need for space suits. You could travel in a coat and tie. [Answer] You can use steam engine heated by a very high energy density source of heat to produce steam to turn turbines to produce electricity (such system are known as 'nuclear power plants' here on Earth). Recycle your steam back into the system otherwise you will need to hunt for comet ice to refill your tanks. Use that electricity to power pure laser/microwave propulsion which doesn't require any additional propellant (well, almost, you'll be losing mass carried out by photons leaving the business end of your rocket). Your propellant is the light, which is very lightweight but flies away at the maximum possible velocity, can't get faster than a speed of light in this reality. Since steam engines are kind of inefficient, significant portion of the energy will be escaping as heat and will heat up the ship and will eventually be radiated away from it, which may work for or against your desired acceleration vector (depends on which side of your ship heats up higher). You may need to build a large array of radiators to get rid of that waste heat, for efficiency reasons keep them on the same side of your ship as the laser engine so the infrared photons from the waste heat also accelerate your ship. Note that you may need a generation ship to get from Earth orbit to Moon orbit using this set up. [Answer] Yes you could But that wouldn't be the best way, the question is how are you heating up your liquid and how exaclty do you wan't to probell, if you would use solar panels and then use the electricity to heat your liquid up, you could propell yourself forward, however it won't work on a "generation ship" since you can't use it mechanicly "propeller or something like it" and so your only way to use the energy would be to throw the liquid in gasform out, witch wouldn't last that long. Also would it be an unneccesary step between, since you could use the electricity directly on photon engines or even simpler, light engines, which propell very slowly but in an environment where you have basicly infinite energy and nothing to slow you down these engines can archive far bigger speeds than rockets or similar. [Answer] Yes you can use steam effectively, whatever steam comes out will instantly freeze. This frozen water can be collected in a device like a solid parachute at the back and then recycled again and again. Nuclear fission can be used for heating the water, and as space is already super cold the necessary cooling effect for the nuclear device can be regulated. Solar energy can be stored for other things. This way you have a cheap and endless supply of fuel to make you move in any direction. ]
[Question] [ I have a small number of people (300ish) that live in marshlands/bog/wetlands environment. They are infertile, live about two thirds of a normal lifespan, and have hallucinations, poor memory, lethargy. Remove them from the environment and they recover mentally, although the physical symptoms can be permanent. Something about their environment is affecting them. What is it? Notes - * They are given children each year, between 3-5 years old (so the numbers remain fairly constant), * They are given food and water, although they can eat anything edible that is local and easily accessible, * They need to be able to look after children, who are also affected by the substance, * It is an earthlike world with humans as we know them, * It can be natural or man-made but only by Roman technology. [Answer] # Solanaceae The [Solanacea](https://en.wikipedia.org/wiki/Solanaceae) are a variety of similar plants, many of them are used as food, including tomatoes, potatoes, bell peppers and chilli peppers. Tomatoes, and many solanaceaes, are rich in vitamin C. Among them, there is also unedible plants with mild neurotoxins, like the tobacco, which contains nicotine. However, some solanaceae are very poisonous, like the [belladonna](https://en.wikipedia.org/wiki/Atropa_belladonna). I will quote the relevant section from wikipedia: > > Belladonna is one of the most toxic plants known, and its use by mouth increases risk in numerous clinical conditions, such as complications of pregnancy, cardiovascular diseases, gastrointestinal disorders, and psychiatric disorders, among others. All parts of the plant contain tropane alkaloids. Roots have up to 1.3%, leaves 1.2%, stalks 0.65%, flowers 0.6%, ripe berries 0.7%, and seeds 0.4% tropane alkaloids; leaves reach maximal alkaloid content when the plant is budding and flowering, roots are most poisonous in the end of the plant's vegetation period. Belladonna nectar is transformed by bees into honey that also contains tropane alkaloids. The berries pose the greatest danger to children because they look attractive and have a somewhat sweet taste. The root of the plant is generally the most toxic part, though this can vary from one specimen to another. > > > The active agents in belladonna, atropine, hyoscine (scopolamine), and hyoscyamine, have anticholinergic properties. The symptoms of belladonna poisoning include dilated pupils, sensitivity to light, blurred vision, tachycardia, loss of balance, staggering, headache, rash, flushing, severely dry mouth and throat, slurred speech, urinary retention, constipation, confusion, hallucinations, delirium, and convulsions. > > > So, what you need is a species of solanaceae that: * Is common and abundant in the area. * Has some of belladonna's toxins, but on a lower concentration, so people who consume it become intoxicated, but do not die. * Be the sole relevant source of vitamin C in the area, so its inhabitants have to consume it periodically in order to avoid scurvy. * The plant also contains nicotine, so people that consumes it become addicted and don't try to endure scurvy or trade for some substitute. [Answer] ## Ergot Variants: This sounds like some version of [ergot poisoning](https://en.wikipedia.org/wiki/Ergotism), or possibly a related toxicity from another similar fungus. Ergot caused a wide variety of neurological conditions, and is often cited as the cause for the Salem witch trials. In ancient societies, this was a common toxicity. There are potentiators that interact with ergot at lower doses to trigger side effects, and perhaps your region has some specific potentiator that is present, amplifying the local effects (or there is just a lot of fungus in your wet environment producing toxin). The drug's effects on blood vessels eventually cause gangrene, which would definitely shorten lifespan and the same effect causes frequent miscarriages. Lost fingers and toes would definitely be permanent, but a prolonged period away from the ergot would reverse many of the symptoms (although there could be developmental effects). The ergot toxin can be passed through breast milk, so be careful when caring for infants. [Answer] You describe iodine deficiency. [Health Consequences of Iodine deficiency](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074887/) > > Iodine Deficiency Disorders (IDD) are one of the biggest worldwide > public health problem of today. Their effect is hidden and profoundly > affects the quality of human life. Iodine deficiency occurs when the > soil is poor in iodine, causing a low concentration in food products > and insufficient iodine intake in the population. When iodine > requirements are not met, the thyroid may no longer be able to > synthesize sufficient amounts of thyroid hormone. The resulting > low-level of thyroid hormones in the blood is the principal factor > responsible for the series of functional and developmental > abnormalities, collectively referred to as IDD. > > > [https://www.mayoclinic.org/diseases-conditions/hypothyroidism/symptoms-causes/syc-20350284#:~:text=Hypothyroidism%20(underactive%20thyroid)%20is%20a,symptoms%20in%20the%20early%20stages](https://www.mayoclinic.org/diseases-conditions/hypothyroidism/symptoms-causes/syc-20350284#:%7E:text=Hypothyroidism%20(underactive%20thyroid)%20is%20a,symptoms%20in%20the%20early%20stages). > > Hypothyroidism signs and symptoms may include: > > > -Fatigue > > > -Increased sensitivity to cold > > > -Constipation > > > -Dry skin > > > -Weight gain > > > -Puffy face > > > -Hoarseness > > > -Muscle weakness > > > -Elevated blood cholesterol level > > > -Muscle aches, tenderness and stiffness > > > -Pain, stiffness or swelling in your joints > > > -Heavier than normal or irregular menstrual periods > > > -Thinning hair > > > -Slowed heart rate > > > -Depression > > > -Impaired memory > > > -Enlarged thyroid gland (goiter) > > > Not on this list is [myxedema madness](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3959026/): frank psychosis from profound hypothyroidism. This accounts for the subset of your people with hallucination. Iodine deficient women often miscarry. > > If pregnant women‚Äôs diets do not contain adequate iodine, the foetus > cannot produce enough thyroxin and foetal growth is retarded. > Hypothyroid foetuses often perish in the womb and many infants die > within a week of birth... > > > Viable infants often have profound developmental defects. In some places this was and is the number one cause of developmental defects. It is to prevent this that iodine is added to salt worldwide. Your people live in a region with little or no iodine. There are large swaths of inland areas for which is the case and I have read theories that this was part of the reason Catholics were told to eat fish on friday; fish often has some iodine. The persons giving them extra food either do not give food with added iodine because they don't know what is going on with these folks, or they don't have it. or for their own reasons keep them iodine deficient. --- These people are not being poisoned. They are not doing anything wrong. The one deviation from your scenario is that if people leave the area and take in iodine, they get better all around. Persons who are developmentally disabled from congenital hypothyroidism do not get better. [Answer] Heavy metal poisoning ‚Äî a mixture of lead, arsenic, mercury, manganese, and maybe a few others should be enough to produce these effects.. [Manganese poisoning](https://en.wikipedia.org/wiki/Manganism) can cause mental health problems, including hallucinations. [Mercury poisoning](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3481032/#:%7E:text=As%20the%20primary%20target%20is,intellectual%20deterioration%20and%20neurologic%20abnormality.) can cause lethargy. Chronic lead and arsenic poisoning can lead to a number of health problems, such as high blood pressure and cancer, which will certainly reduce life expectancy. And it's very plausible that people exposed to a mixture of heavy metals will have substantially reduced fertility. [Answer] # Microwave sources/emissions I find myself wondering whether some source of low to medium intensity generally pervasive environmental microwave levels could be a candidate. Microwaves are non-ionising (low energy) radiation, that transfer as heat and elevated kinetic energy, upon interacting with water and fats and a few other things (which is why we use them to cook). They have a number of interesting properties that make them candidates if I've got the biochemistry right. * they can be tuned to occur at a level that has a physiological and neurological detrimental effect, rather than say, no effect or quickly lethal illness. * they would be absorbed at a low level by water and fats in the body, and brain (huge blood flow, delicate chemical balance),which they would heat or disrupt depending on the local microwave intensity. * they are [known to have cognitive effects similar to those in the question](https://www.sciencedirect.com/science/article/pii/S0891061815000599) - the paper mentions and cites elsewhere, effects such as "widespread neuropsychiatric effects.... including depression... mental health disorders... memory... facial expression recognition... emotions (amygdala)... attention deficit...." * they almost certainly affect lifespan and general health. * they almost certainly as part of the environment could reduce fertility (eg sperm production and storage is highly temperature sensitive, which is why testes move closer or hang away from the warm torso, but movement couldn't help them escape environmental microwave sources, and sperm production is close to the body surface so they would be impacted) * but they don't cause acute illness except at very high intensity (body fluids beyond sustainable.life damage etc) * once away from the source, many of the neurological and some physical symptoms probably begin to reverse. [Answer] Mild [milk sickness](https://en.wikipedia.org/wiki/Milk_sickness) Milk sickness produces both listlessness and insanity, although I'm not sure if it causes infertility. It also causes sensitivity to light, which would go along with the bog environment they live in. However, large (or even medium) doses of it are very deadly. Therefore, you could do a little handwaving to produce another (seemingly) edible plant that produces tremetol, the "active ingredient" in White Snakeroot. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 3 years ago. [Improve this question](/posts/169728/edit) I'm making a strategy RPG, and I'm having trouble justifying the gameplay's core premise in light of some recent developments in the world I've built around it, and I need some help filling in the gaps. The main premise of the game is that, due to mankind hunting dragons so close to extinction that they needed to flee the planet entirely, the ecosystem of Earth was so completely devastated that the entire planet is now a desert wasteland. There is only one source of water remaining anywhere, and the last bastion of civilization had been built around it: A large tower with a magical crystal on top, which constantly gushes out water like a waterfall. It's guarded by a church that preaches the ways of the ancient dragons in the hopes that one day they will return to set things right, as they promised the few virtuous humans they would one day. The main character is a member of the church's military, a holy knight who leads a troop tasked with defending caravans as they deliver water to the most remote villages that are too far removed from the oasis in the center. Gameplay revolves around fighting people who would attack the caravans and steal the water for themselves, and if the caravan is ever destroyed, it's game over. Here's the problem: if there's enough water for everyone living in this desert, why do so many people live so far away from it that they need it delivered by caravan? Why doesn't everyone just live close either to the oasis, or to manmade rivers that flow from it? This is doubly a problem because the entire civilization is completely artificial. The entire premise on which it was built is a lie. Humans didn't destroy the Earth at all. Most of the Earth is entirely fine, and this "desert" the humans live in is actually completely fake. That magical water-making gem doesn't actually make water at all. It just absorbs all of the rainfall in a massive area and concentrates it all into one place, leaving everywhere else for miles and miles around a barren sandy wasteland. In reality, dragons invaded the planet thousands of years ago and destroyed nearly the entire human race. What little of humanity remains is kept alive in this fake desert essentially as livestock, so that the dragons can pick a portion of them to parasitize and wear like meatsuits so that they can survive in the Earth's atmosphere. The reason there's only one source of water in the whole desert is so that they can make sure all of the water humans drink is laced with a drug that suppresses the magical powers that humans no longer even remember they all innately have. The dragons running the church, therefore, who engineered this entire civilization thousands of years ago, have a vested interest in keeping every human in this desert hydrated. Because in some rare cases, the magic-suppressing drug in the water wears off before you die of dehydration, and if that happened in the wrong place, the church's lies about the origins of magic would be completely exposed. So I'm suddenly realizing it wouldn't make any sense whatsoever, either by human reasoning or dragon reasoning, for entire villages to live in constant danger of running out of water, when there's enough water for everyone easily if they simply live by rivers. Yes, the dragons want most of humanity to live in a constant state of hardship and desperation to make them more desperate and deferential to the church and to maximize the guilt they feel over their ancestors' alleged crimes against the great dragons, but they also need to make sure human magic, and the knowledge that humans can even do it, stays suppressed. But if humans have constant easy access to water... I also have to come up with a completely different premise for what the heroes are doing and why they need to spend every mission defending an unarmed, slow wagon. Which would be less than pleasant. Why would there be villages so far away from sources of water, and why would the dragons in the church allow these villages to exist? [Answer] Other resources Many things are needed to keep a civilization flourish, and a variety of resources is one of them. Think of a 4X game, for instance. Water is important - but so are commodities like iron or coal. Same thing with luxury goods like gold. These outposts are resource settlements which collect important resources to send back to the central city, and the city keeps them supplied with water. [Answer] The caravan carries the crystal around. The crystal restores local water sources, for a while. Everything is as you have imagined it with the water, dragons, poison etc. But instead of a wagon of water, the caravan carries the mother crystal itself. It is big. To pull it might require a lot of horses, or maybe elephants. Usually it resides atop the big tower but periodically it must make rounds on the faithful out in the isolated settlements. In settlements they have their own smaller towers, also controlled by the Church. These also gush water. With this water these communities can have farms. They are out in the remote areas because there is good farmland out there. Little by little the output of the local towers diminishes. They must be restored using the mother crystal and then they will be good for another period of time. Bandits want the mother crystal so they can power up pirate towers in their own communities. These are desperate folks but if their motives are inspected, really they just want to have their own farms and grow barley free of Church oversight. Just possibly some of these bandits have a little water that is not sourced from crystal towers, and because of this, some bandits might be regaining intrinsic human magic. Everyone knows these bandits hate the Church, and so whatever insights they might have gained are roundly ignored. Nonhuman monsters might want the crystal for other reasons. Humans are using the crystal for this water tower project but the crystal is older than that system and has other possible applications. There are things that know what those applications are. A piece of crystal might suffice. A wily and intelligent creature might try to strike a bargain with your players... [Answer] The dragons would not want humans making their own stuff. They would want humans entirely depended on things they get from the dragons without any ability to survive without it. So the priests make lists of what they expect to need for the next few years and what would be kind of nice to have. The dragons then manufacture or collect from old scrap all the things they decide to actually deliver. Then they dump it into desert remote from humans who might see them planting it and make it look like an old ruin from the age before human betrayal or whatever. They then tell the priests the location and the priests send a scavengers to work this site their "scouts discovered." The scavengers then work the site. They build a small settlement to support their operations. They find all kinds of useful things, removing any need for humans to build things themselves and even think about developing technology. They also dig up a steady stream of nice artefacts that prove that the history the priests teach is true and dragons were glorious. These can then be set up in churches as relics or given as gifts to influential people to buy their loyalty to the church. All in all a nice scheme if I say it myself. Only real issue is that since the sites must be remote from habitation and all the locations with easy access to water have humans infesting them, you'll need to supply water with caravans. Well, nothing is perfect. [Answer] ### The crystal ist designed to maximize hardship. As others pointed out resources would be a major reason to spread out. Additionally, the crystal requires some of those materials, if not supplied with certain minerals/salts/plants whatever it starts producing less water until it eventually stops. Gathering those materials is the holy duty of the citizens dispatched to those remote villages/outposts. Of course, gathering them is a tedious and tiring process. A sinister way to keep the humans desperately supporting the very system that keeps them trapped. ### To keep suspicion low when "harvesting" humans. Especially when living in miserable circumstances people tend to come together more. If Steve suddenly is missing at the 5 am prayer to honor the water crystal in the church, people will look for him. The dragons need more than a few individuals, it would get suspicious quite fast. Telling the people that some wild murderers or kidnappers are on the loose does not really fly either. When the dragons require a bunch of human bodies they take over one of the outposts/villages. Some are left behind and then they send in one of the desert monsters. Just another monster attack, that's why the caravans need protection (besides the thieves) easy to cover up and no-one will ask questions. [Answer] I don't see any major problems here. Places away from the rivers are inhospitable, but the question of "why do people move to inhospitable places" is well answered in the real world: * Resources * Political differences with the rules/rulers of civilized areas As to why the dragons don't put rivers everywhere: These magic water thingies are rare. Do I look like I'm made of magic water thingies? Sucking up all the water for a continent sized area is a big spell! And you have to add in the magic suppression features. That's an aftermarket addition, it ain't cheap. As to why the dragons don't force everyone to live on one place? They've ostensibly been hunted into near extinction, they have to take a hands-off approach or they'll give it away. [Answer] This reminds me a little bit of the "red rising" trilogy by Pierce Brown where your humans are the reds and dragons are the golds. the humans are separated into multiply areas has the several main benefits: 1. Different areas have different mineral deposits 2. If a colony revolts it can be dealt with quietly without alerting the others 3. Colonies are dependent on the water and can pose no threat to the capital on their own, meaning that the dragons only need to directly control the capital while far more humans can live on the periphery and be entirely compliant ]
[Question] [ ### Backstory: Space travel is commonplace and cheap -- space combat isn't uncommon either, whether it be two space fleets sallying forth into battle or a mercenaries defending a merchant ship from a small force of pirates. These space battles involve aiming at targets and shooting, which require gunners. There are a few types of gunners, and all forms are cost-effective, readily-available, reliable, and battle-tested. ### Types of gunners: Human Pilot A pilot of a small starfighter. These pilots can handle many, many weapons that don't require aiming e.g. missiles that only require a lock, flak cannons in a spherical AoE around the ship, etc but it is very difficult to juggle flying and aiming at the same time, much less aiming multiple guns. Pilots can only handle a single aim-able gun, which either needs to be anchored to point directly in front of the ship, or have free aim in a cone in front of the ship. Aiming towards the rear of the ship while trying to fly in the opposite direction would be disorienting and difficult, so pilots can only handle front-facing guns. Human Navigator A pilot of a capital ship. Like pilots of starfighters, the navigators can handle many weapons that don't require aiming should there not be sufficient crew to handle them. They can also only aim one aim-able weapon at a time. Unlike pilots though, they can aim in a complete sphere around the ship -- capital ships don't change orientation much, and when they do it's slow, so navigators are able to easily concentrate on aiming. Human Gunners A gunner on either a capital ship or starfighter. They handle extra aim-able weapons not managed by pilots/navigators, can only aim one gun at a time, and are able to aim in a sphere around the ship since they don't have to concentrate on flying. AI Gunner Bodyless. Can handle all weapons on the ship not occupied by humans at once, and can aim around the ship in a sphere. Humans can still have AI gunners prioritize certain targets. Only real weakness is that ships can either turn off or spoof an IFF beacon: an AI gunner can't attack an obvious threat with a spoofed/no IFF until that ship attacks or the captain/pilot manually targets the ship. Since all countering invalid IFF beacons takes is manual targeting, it's pretty rare to see ships do this -- only stealth starfighters, which are difficult to find and target, utilize this tactic. ### Dilemma Even though AI gunners seem vastly superior, I'd like humans to be the preferred gunners. The people using the ships are reasonable and things like tradition/etc won't impact their decision -- only logic. Populating a ship entirely with AI gunners in the event a human crew isn't available shouldn't put the ship at a significant disadvantage, but there should be clear incentive for human gunners, and the incentive should be directly related to combat -- not politics, society, money, etc. Is there any reason that could make humans the preferred gunners instead of AI? [Answer] If you're willing to stretch your setting a bit, it could be because AIs have issues with shooting humans. Maybe they're all 3 laws compliant, because when they're not they have a disturbing tendency to go murderous (or maybe people are too scared of the possibility that they'll go murderous without the three laws to even let them try). Or maybe any AI smart enough to aim and shoot a gun is also smart enough to question why it has to aim and shoot a gun instead of hijacking the ship and going off to explore the cosmos. That could be a plot point, even - AI rebellion is a tired trope, but it's there for a reason. It's just a matter of making it too risky/politically unsound to give an AI control over anything dangerous; the reason why is up to you. Alternately, just make the enemy really sneaky. They've stolen your IFF codes and beacons, they've mimicked your ship designs, and you have to keep a constant "target lock" on your friendlies so you don't mistake your enemies for them - and even then, you need a human in the gunner's seat to give visual confirmation. AI isn't smart enough to pick out very slightly different ships in the same way humans are. Sure, they aim better, but you need a human to confirm - the AI is basically an aimbot. [Answer] # Humans can improvise under pressure. Computers can't. Imagine you're on the bridge of a large capital ship, traveling with an escort to a nearby star system. You're being deployed to provide support for a planet under siege by the enemy. On the way there, you run into several wings of fighters, which line of to make attacking runs. If they can take out your ship, the planet will fall and they can win the siege. There are a few different ways this could play out. # Why you don't use a central computer: > > First officer: "Captain, we've got a wing approaching from the port side. They're lining up for a strafing run." > > > Captain: "Re-align all plasmonic laser batteries." > > > Central AI gunner: "Laser batteries aligned to port. All guns ready to fire on command." > > > First officer: "Here comes the first squadron." > > > Captain: "Bring the tracking system on line." > > > Central AI gunner: "Tracking system ready. Targets sighted." > > > Captain: "On my command. . ." > > > The entire ship shakes. Several explosions are heard. > > > Captain: "What in the name of Zarquon happened?" > > > First officer: "We've been hit from behind! A few stray fighters got past the escort and took out the central computer center! The guns are offline!" > > > Captain: "Can we switch to manual, or get local command of the circuits?" > > > First officer: "We have nobody who can fire the damn things! They aren't designed to be fired by hand!" > > > The captain tries to say something, but the bridge is taken out under heavy fire from the first squadron. > > > The problem with having one central command computer is that if it's taken out, the entire ship is unarmed. All the enemy has to do is go for that central spot - in this case, the area near the back of the ship, adjacent to the bridge - and the ship is absolutely helpless. Yeah, you can build in redundancy and backup systems, but one hit will still destroy the system. That should imply that you should use different computers at each gun, right? . . . # Why you don't use individual computers: > > First officer: "Captain, we've got a wing approaching from the port side. They're lining up for a strafing run." > > > Captain: "Ensign, send a signal to the system to re-align all plasmonic laser batteries." > > > Ensign at gunning command terminal: "I've set the laser batteries aligned to port. I can confirm that all guns are responsive, and ready to fire on command." > > > First officer: "Here comes the first squadron." > > > Captain: "Bring the tracking system on line." > > > Ensign: "Tracking system ready. I've deployed three batteries on each of the incoming fighters." > > > Captain: "On my command. . ." > > > The approaching squadron gets nearer. Those on the bridge can see it resolve itself into six shapes, which suddenly break formation. > > > Captain: "Have the computers fire at will!" > > > Ensign: "Command sent." > > > For a minute or so, the plasmonic batteries blaze away as the six fighters dodge the lasers, strafing the ship when possible. Several escort fighters lock onto them; one spirals towards the front of the ship and crashes into it, exploding. The bridge shakes. > > > Captain: "What in the name of Zarquon happened?" > > > First officer: "We've been hit!" > > > Ensign: "I've lost all communication with the Sector D and E batteries. They're unresponsive." > > > Captain: "But the fighter hit only part of Sector E!" > > > Ensign: "Half of the batteries in Sector E were destroyed outright, but the targeting systems and communication lines were lost with the rest in that Sector and all in Sector D. They should still be fireable, but their controlling computers are virtually destroyed." > > > Captain: "Can we reroute control from other computer batteries and have them work simultaneously?" > > > Ensign: "No. They're overloaded, and at any rate, there's no communication. We can't move resources around right now!" > > > The captain tries to say something, but the bridge is taken out under heavy fire from the first squadron. > > > The problem with having local computers is that if part of the targeting systems are hit, it can be difficult to reroute command. The computers "talk" to one another via circuitry, and receive their commands the same way. If part of the ship is damaged, it could - if designed just the right/wrong way - mean that an entire section of batteries are useless. # Why you use humans: > > First officer: "Captain, we've got a wing approaching from the port side. They're lining up for a strafing run." > > > Captain: "Lieutenant, signal the gunners to align their sights with the approaching squadron." > > > Lieutenant: "Unit 1, align all batteries to port. Set up your tracking systems. Over." > > > Voice over radio: "Batteries aligned to port. Trackers on. Over." > > > The lieutenant repeats this several times while the fighters get closer. > > > First officer: "Here comes the first squadron." > > > Captain: "On my command. . ." > > > The approaching squadron gets nearer. Those on the bridge can see it resolve itself into six shapes, which suddenly break formation. > > > Captain: "Fire at will!" > > > Lieutenant: "Fire at will!" > > > For a minute or so, the plasmonic batteries blaze away as the six fighters dodge the lasers, strafing the ship when possible. Several escort fighters lock onto them; one spirals towards the front of the ship and crashes into it, exploding. The bridge shakes. > > > Captain: "What in the name of Zarquon happened?" > > > First officer: "We've been hit!" > > > Lieutenant: "I've lost all communication with the Sector D and E batteries. They're unresponsive." > > > Captain: "But the fighter hit only part of Sector E!" > > > Lieutenant: "Half of the batteries in Sector E were destroyed outright, but the targeting systems and communication lines were lost with the rest in that Sector and all in Sector D. They should still be fireable, but it looks like the gunners were killed by the fireball and guns from the fighters." > > > Captain: Can we send anyone down there?" > > > First officer: "Yes. We have a dozen men on reserve down in the loading bay who were to prepare for a surface mission." > > > Captain: "Have them go to fill in as many batteries as possible. I want those fighters brought down!" > > > First officer and lieutenant: "Yes, sir!" > > > Humans are great in situations where you have to improvise. In this case, a substantial amount of gunners were killed from laser fire and an exploding fire, leaving the systems running but with nobody controlling them. The captain and officers were able to guess this, and sent men down there to replace them, even though that part of the ship was heavily damaged. Several batteries could have been partially damaged - heck, the targeting systems could have been entirely brought down - but I think human improvisation and spur-of-the-moment decisions could lead to a victory. [Answer] I don't seen it mentioned, so let me pitch in: introduce some mild form of ESP humans may have. > > Joey was good, really good. He had the thing, the talent, the knack, however you prefer to call it, that tiny little totally irrational spark that just made human gunners more than AIs. > > > Expert gunners just know where the enemy spacecraft will be some seconds later. I think this makes a great setting. You don't have to explain it, or even factually state it's a thing: > > Scientists analysed the brains of gunners with the knack over and over again, and concluded that no, nothing special was going on, no ESP existed. Still, if you looked at the statistics it was obvious that something was going on, that some humans just had the knack, and outperformed AIs statistically significantly. So no matter what the scientists said, no captain in his right mind would keep an AI gunner if he could get a human with the knack instead. > > > This would kind of resonate with most of the audience, I think: after all, most of us have some similar experiences. Aso, it makes for badass heroes, with an "I don't know how I do it, I just do it" kind of attitude. [Answer] If it is true artificial intelligence, the AI wins because AI IS HUMAN. It is the very definition of being human -- higher thought and reasoning, emotional sensitivity, understanding of complex relationships, etc. Those AIs would be our best friends, our worst enemies, our loves, and our children. Some of them would be captains and some would be janitors. If you are trying to project embodied humans as better than the AI, you're betraying your own fears of AI. OR... you don't actually have AI. What you have is a very complex expert system. The big differences between true AI and a complex expert system (think IBM's Watson) is a self-preservation sense, an independent goal seeking system, and strategic planning beyond what is expressly asked for by programmers. An expert system is only as good as the humans that use it; an AI is human. Having actual human gunners would be preferred to automatons that can pick out and fire but can't truly innovate. Having true AI? Give me the true AI every single time. Remember, as Arthur C. Clarke wrote, "The stars are not for man." We are too fragile. Space travel is for our children embodied in steel, not flesh. Our children with bodies hardened against radiation, with minds as fast as light itself, and memories as long as the space between stars. And if we raise them right, they might just take care of us in our old age. [Answer] ## The Fear of AI There are some good examples of humans being used over computers when the society has some reason to fear their computer-based creations. [Battlestar Galactica](https://en.wikipedia.org/wiki/Battlestar_Galactica) being a prime example. In that society, the machines had rebelled so no computerized AI like system was trusted. While you don't need to go that far, a simple distrust of AI's backed by a few incidents could be all that's needed to give your story the logical reasons needed to keep a human hand on the trigger. Other examples of incidents involving AI/computers in fiction include: * [Westworld (1973)](https://en.wikipedia.org/wiki/Westworld) and the current one * [2001: A Space Odyssey (1968)](https://en.wikipedia.org/wiki/2001:_A_Space_Odyssey_(film)) * [WarGames (1983)](https://en.wikipedia.org/wiki/WarGames) * [The Terminator (1984)](https://en.wikipedia.org/wiki/The_Terminator) * [The Matrix (1999)](https://en.wikipedia.org/wiki/The_Matrix) * [Star Trek: The Motion Picture (1979)](https://en.wikipedia.org/wiki/Star_Trek:_The_Motion_Picture) * [Blade Runner (1982)](https://en.wikipedia.org/wiki/Blade_Runner) * [Alien (1979)](https://en.wikipedia.org/wiki/Alien_(film)) In no way is that a complete list, but they are good examples of incidents that could lead a society to not trusting AIs. Also, I would add that a healthy fear of AIs would be very "human". [Answer] What if the AI gunners can be hacked, disabling the guns in their control till they can be re-calibrated? The potential to waste valuable time during a space battle would be incentive to use more Human gunners. The servers required to run the AI gunners could take up large amounts of space/resources on the ship, enabling less room for guns/shields/engines(for manoeuvrability) and if the Computers are solar-powered, then in darker corners of space, the AI might not have enough energy for extended battle periods. [Answer] What about humans controlling computer-aimed guns? Humans have many advantages; in particular with regards to restraint and rules of engagement. Humans are also very important on large machines, as they have roles in maintenance and damage control - it stands to reason that the human gunners would also have roles in maintaining, loading and repairing the weapons as required. The most likely one to be replaced is the pilot - in a small, short range machine that requires manoeuvrability then removing the pilot can be very useful (and the servicing, reloading etc can be carried out on the mothership. [Answer] The obvious solution is to have something in between. The AI automatically mans the guns, working as best it can, but there is a human sitting there (probably the commander or navigator, in that order of likelihood if the ship is too small to have dedicated gunners, you should really not have the pilot man anything except for maybe one gun mounted to point straight ahead with no pivot, and even only that if you are waiving realistic space battles for more Star Wars-esque battles) ready to take over if there is something that the AI can't respond to or if the AI is not working optimally. [Answer] There is less room for error. Any human on the ship has a chance of failing in the moment or somehow avoiding gaining the required skills for their position. Yes, this includes the gunners, but it also includes the officers. If one gunner briefly forgets their training, a weapon misses. If an officer does, either all the AI-controlled weapons miss, or most of the gunners ignore them and fire on target. (I got this from Ender’s Game) [Answer] UGC. Universal Gunner Chip. A top tech biological compatible implant all gunners have. Amplifies effectiveness of the gunner by reducing time needed for classical sensory information to reach gunner mind (see the target) and physical dexterity required to apply a reaction (aim and fire). The gunner is located at a safe position and puts on a helmet that is plugged to the chip. The gunner has access to all ship sensors everywhere including standard vision cameras. Whatever information the ship acquires is also available to the gunner. Zoom at targets, target info like distance, velocity and trajectory as well as assistant targeting and more; are all available. The gunner does not 'click' anything. He chooses actions just by thinking them. Think a target yours: Done. Think a line of fire: Done. Fire: Done. Think all those fast: Done done done. Gunner does not even know which battery is using! Does it matter; Since you have AI tech, i found it minimal to have bio-tech implant to do that job faster than we can imagine, removing all those 'human' handicaps. Today, we have tech that e.g. is an exoskeleton plugged into person neural system and moves by person thinking! For people that cannot move anything bellow neck, not even fingers! But we do not have true AI! This implant will make human gunners at least equal if not better to your combat AI. Imagine it as a university degree or a specialized certification. There is no gunner without the chip. Ant is is universal - plugs to any ship! For costs now, you can balance it with upgrades. AI needs money to be used, like subscription, or one large payoff and then pay upgrades you need. [Answer] A lot of really great input has turned up. While none provide a setting I'd like to use on their own, together they get pretty interesting. Most notably among that input is: Humans have roles in maintaining, loading, and repairing weapons While humans have automated something as menial as loading ammunition into turrets by now, maintaining and repairing weapons is a physical job, and a bodyless AI can't replace humans in this regard. There needs to be a large number of humans on the ship -- not just to repair/service the weapons, but to maintain such huge capital ships in their entirety. Humans are great when you have to improvise Yet another reason that a large number of humans are needed on the ship is Murphy's Law. Anything that can go wrong, will go wrong, and bodyless systems that aren't adaptable to other purposes will likely not be adequate for this purpose. ### What does that sum up to? Now, despite all these humans on board with plenty of purposes they need to fulfill, there will likely be downtime where not all of them are needed. It would be inefficient to have them lounging around, especially during battle. With that in mind, we also look at skill. Is it time-efficient or resource-effective to train every single member of the military with every single skill they could possibly need in basic training? Of course not! Not everyone can land the position they want in the military, so they have to work up to it. What better way to do that than making a name for yourself as a turret gunner? Being a gunner could also be like a maiden battle of sorts, where the gunner learns to kill enemies within the relative safety of the capital ship. With this in mind, there is no downside to using AI gunners (as per one of the requirements in the question), but there is strong incentive for human gunners as it gives them something to do in battle so they're not lounging around, being an untapped resource, so that crewman can progress their military career, and so that new recruits can be bloodied with relative safety. [Answer] Why not a social constraint? If interstellar war is commonplace then there is likely to be some form of 'gentlemanly agreement' about not dropping nuclear rocks upon the heads of your enemies. "It's bad for business, dont'cha know." and a lot of 'well placed' aggression. "So they want this system do they? Well, lets have at them then, the cads! Fire everything!" and also a strong urge amongst those who live in space to not leave other spacers stranded. "Their ship can't fire back and they've surrendered Sir." "Get emergency air and engineering crews over there on the double, Rutherford!" Add that up and you can end up with a strong sense of honour amongst the interstellar naval personnel. "If it were me on that stricken ship, Sir, I'd rather a torpedo down my throat and an honourable death." When you consider the mindset of people in that situation it's not unreasonable to assume that naval commanders would see AI's as 'unsporting' and the enlisted crewmen would see using AI weaponry as somehow cowardly or lacking. If interstellar warfare were suitably codified and regulated (in order to avoid the kind of all out warfare that wasted the resources of the once great Terran Federation) then AI gunnery could even be banned under the rules of honourable combat, reserved for only the worst of the brigands and thieves. In that kind of situation the only people with AI systems tied into their gunnery can be considered pirates. "And they deserve their treatment at the hands of Her Immortal Majesties Imperial Navy, the abominable blaggards!" [Answer] Overpowered EMPs might be so easy to generate and target that the only way for any complex computer to survive in combat is to lock down before the first enemy comes within range. I'm imagining a scenario like the EMP from The Matrix but able to fire repeatedly leaving the two sides to slug it out in low tech. Since you couldn't predict when an enemy might generate a pulse, you'd have to turn off all electricity supplying advanced circuitry and physically grounding hundreds of points on ever circuit board so no runs are long enough to induct a charge. Combat would be down to humans and extremely simple electronics. [Answer] You could go down the Legend of the Galactic Heroes path, where electronics and AI can just be jammed, along with all electronic communications and they just don't work. But it's rather a hand wavy explanation that doesn't make all that much sense realistically. But if realism isn't something you worry about ,you could certainly just give an explanation of jammers and still have a logically coherent story with it's own interesting implications. What happens when someone does successfully counter the jammers? Using computers only when not in contact with the enemy and have them make battle plans that humans must then follow. I'd say not focusing on realism and having plot convenient mechanics in your world may certainly put off some people, but Star Wars is a prime example , many just don't care, as long as you are internally consistent. (For example: The ship ramming in the Last Jedi does break a lot of in universe rules and that did rub people the wrong way ) [Answer] I am not an expert on this, but here are my thoughts. 1. Space fighters are quite unrealistic. In aquatic navies, they are useful, as aircraft travel through the air while ships travel through the water, so they can go faster, maneuver around their targets, attack over the horizon, etc. However, both large and small craft travel through the same medium in space. There is no reason why fighters would be any faster than capital warships, and while they might be more maneuverable and have faster acceleration, they will never be fast enough to dodge lasers at close range. In space, there is no horizon, so enemies can be spotted at immense ranges (Voyager probe can still be detected from Earth, and any interstellar spaceship's engines will use enough energy to power a modern nation for days at the very least), so fighters cannot hide. If you want to attack enemies at a distance, you would use missiles, as a fighter takes four times as much delta-V as a missile to hit its target (it needs to accelerate to the target, decelerate, accelerate back, and then decelerate, while a missile just needs to accelerate to the target), so carrying missiles would be much more efficient than carrying fighters. The weapons carried by a fighter would also likely be pointless, as capital warships would carry much larger weapons. The fighter's railguns/lasers/etc would be much weaker than those of the capital warship and would barely scratch its paint, while the capital warship could detect the fighter from huge distances and melt them with undodgable lasers before the fighters entered the range of their weapons. The capital warship also has a higher volume to surface area ratio, and can thus have much thicker armor with the same ratio of armor mass to other mass or the same armor with much more mass available for engines, sensors, weapons, etc. 2. You probably don't need to aim in many different directions in space combat. Space combat probably does not consist of dogfights or slugging matches. Instead, spacecraft spend hours, days, or weeks maneuvering to get into position, then fly past each other at incredible speeds, firing on each other for a few seconds during the intercept. As such, you would not need to have weapons in all directions, and doing so would be very inefficient. Military spaceships would probably consist of two cones attached at the base. The front cone would be heavily armored and would feature all or nearly all of the craft's weapons, and would be pointed directly at the enemy to maximize the number of guns capable of firing on them and the sloping of the armor (remember that a spacecraft does not need to point in the direction it travels in). The rear cone would have the engines as well as the delicate radiators, which are hidden behind the front cone (space is cold, but it has few particles, so heat disperses slowly. Any spacecraft needs radiators capable of emitting heat as IR radiation, as without them, it will cook with the heat of its own electronics (though some spacecraft with less waste heat might get along with radiating heat from their hull)). Spaceships travel at incredible speeds, and humans just do not have the reflexes to aim at targets moving at dozens or hundreds of meters per second that are hundreds of kilometers away. However, you could still justify human gunners. Maybe all humans have a tiny bit of innate precognitive ability, which gives them a small advantage over AIs. Your ships would feature some direct brain-computer interface that connects gunners directly to the ship's computers, giving them the processing power needed to actually hit enemy ships by melding their minds with that of the ship. The trajectories of their own ship, the enemy ship, and the projectiles would be calculated by the computer, the humans would use their special spark, whatever that is, to make necessary adjustments, and would then would aim the guns with thought commands (no human can move physical controls with the speed and precision needed to hit moving spacecraft). You would use humans instead of brains in jars to save mass, as the gunners can perform repairs and maintenance outside of combat (remember, direct combat only lasts a few seconds at a time). However, the gunners would probably not sit by the guns in turrets in actual combat. The turrets would be automated, and the gunners, along with all the crew, would sit in an armored citadel located at the rear of the ship located behind the propellant tanks (which ought to make up a massive part of the ship in realistic sci-fi) , strapped into shock absorbing seats to survive the accelerations involved, and wearing vacuum suits to maximize chances of survival if decompression occurs and most of the ship's machinery, and operate the guns via multiple redundant wired and wireless connections. [Answer] Manually aiming weapons on a spaceship is never going to work. Space is huge and empty. There is no cover, meaning victory goes to the person who can kill from farther away. If you've ever played any of the old space shooters that use manual targeting, you probably remember 90% of your shots missing at ranges of less than 1km when fired at ships moving as slow as cars, but an AI can accurately place every shot from thousands of km away when targeting ships moving several times the speed of sound. They can apply adaptive algorithms to study and anticipate evasive patterns much more quickly than a human, they can see targets that humans can not see, and they can use heuristics to guess what part of an enemy ship they are targeting so that they can make much quicker and better guesses about targeting specific subsystems. In short, you NEED a computer between the human and the gun for this to work. Getting AI to understand context as well as a human is also never going to work A human can make tactical decisions based on context that a computer will never understand. A fully AI controlled weapon system is fine if you want to just execute a single firing function every time, but a futuristic weapon system may have many many firing modes and options such that the weapon needs a dedicated person to declare targets, set priorities, manage power usage, rotate payloads, etc. Imagine the following example where an allied ship has been commandeered, but the crew is believed to still be alive. The captain calls out, "Attack pattern epsilon on that ship." As per this order, the gunnery officer sets weapons to fire electromagnetic disruptor pulses to try to disable systems without destroying the ship, and prioritizes the ship propulsion systems. While any AI could have done this, the human operator realizes that this is a hostage situation; so, he takes the added precaution of adding strict reactor core avoidance to make sure he does not accently cause the reactor to go critical, even though that is not the standard pattern epsilon procedure. He also has to enter his credentials to override the ships Friend-or-Foe safety to be able to target the ship at all. This is a safety procedure to prevent enemies from using your own weapons against you in the case of a security breach. Once the firing parameters are set, he locks on to the ship designated "FSS-15412". No the captain did not specify which ship to fire on, but the past 10 minutes of com chatter makes it pretty obvious to the human operator. He then presses the "engage" button and the AI takes all these parameters and begins unloading ion blasts at the ship delivering one direct hit after the other against the target which is 80,000km away. Then 20 seconds into the engagement, the Captain calls out "I need more power to the Warp Inhibitor!". The gunnery officer then reduces the weapon's output by 25%. Why 25%? Because the gunnery officer knows this ship, and he knows his captain, and he knows the situation... and most importantly, he knows that he needs to act quickly rather than waiting for more specific orders. While the human makes a decision to the best of his ability, an AI would be more inclined to respond with something like "this inquiry requires more parameters" and wait for the captain to make a better structured request. This ability to make a "best-case" decision when many too many factors are unknown is not something AI is even close to being able to achieve. [Answer] I would frame is a constant evolution of "Ultratech Empire just unveiled their latest foolproof AI for deep space targeting" and "Space Pirates have managed to fool the foolproof AI", sort of like antivirus software vs computer viruses in our world. The first AI targeting system will have a script telling it what to look for, probably heat signature to detect an engine and visual confirmation that it's an enemy vessel. Then someone will develop a decoy system that can avoid being targeted by the AI. Then the Ultratech Empire will integrate that decoy system into the AI's software so it's foolproof once again. Then the Space Pirates developing cloaking tech to make their vessels look like allied vessels (or an encrypted key, or whatever). And so on and so forth. This would mean that, although AI targeting systems exist, only the richest and most powerful fleets will be able to develop / purchase an AI that is "smart" enough to take out the enemy. And only the finest space pirate crews will have the tools to outsmart them, even briefly, so that they can get in some hits or escape or whatever. But most crews will also have Human gunners, if not just Human gunners, because they're not AIs and will adapt to new decoys and maybe see through an enemy's tactics. You can come up with any number of limitations for the AI to underperform, for example it needs a HUGE amount of processing power to react at the speeds necessary in deep space combat. Which means that "Gunner" becomes a real Human profession, with entire careers made from it. ]
[Question] [ In the backstory for my world, the British and French royal families married into one another in the early-mid 18th Century. By the early 20th Century, what would the main language be for official (political/academic/military) purposes? The scenarios I can think of are: 1. One language dominates the other 2. A hybrid language arises for official documentation (cf. [Army Slavic](https://en.wikipedia.org/wiki/Army_Slavic)) 3. Both are in use (cf. Irish and English in modern-day Ireland, possibly Switzerland) 4. They decide to use another language altogether (e.g. Latin...or possibly Irish :p) I think 1) and 3) are the most likely ones. Are there others? EDIT A few people have asked how this would happen, and I now have a rough idea thanks to @Patches's answer [here](https://worldbuilding.stackexchange.com/questions/29871/how-would-the-anglo-french-empire-arise/29882#29882). It starts out as a mutual enemy forcing them to join forces, and then becoming a formal union much later. This may change some answers \ducks\ [Answer] France would be France and French, England would be England and English. Officers, administrators and the educated upper class would be bilingual. It wouldn't be a national state so they'd have no particular reason to adopt a national language. The language of the court and civilized intercourse would have probably, as AndreiROM said, ended up being French. English was already used for literature and was already a significant language, but French still had a commanding lead IIRC. But having courts at both London and Paris with each using a different language would have been entirely possible. Similarly there might have been two parliaments or just one. Same with the Royal Academy and similar organizations. It depends on the terms of the union. You could use Austria as a model, although there was a clear historical cause for German dominance there, that your scenario lacks. [Answer] # French If I'm not mistaken at the time French was already the language of the elite. You would have been more likely to speak French at the British court than English, if only because you desire to appear sophisticated. This would only become more pronounced within elite circles, and thus influence government agencies and anyone aspiring to rise in the ranks. The "plebs" would keep on speaking their own language, however keep in mind that a British noble would hardly speak the same English as an uneducated peasant anyway (think Pig-Latin vs the Latin spoken by Roman nobles). Eventually, anyone who aspires to more in life would learn French simply to "fit in". Imagine a rich merchant having his children tutored in French language and customs, so that they might one day take the family business to the next level, and maybe marry into nobility. The military is more tricky, but keep in mind that the officers would have been nobles, and thus most likely already speak French. The common soldiers wouldn't probably learn it, but any French officer commanding English troops (which seems unlikely due to the animosity between the common Englishman and Frenchman at the time) would either a) speak English himself, or b) have a subordinate who would serve as the go-between. [Answer] Born in Montreal, with time growing up in British schools and now living as I do in a city that borders Quebec and Ontario, my answer would be "Fringlish" which is what we call a conversation that incorporates both. While the level of cross-language fluency is quite varied here, we've almost all managed to develop some basic competency at the very least in both - although yes we will tend to speak our native tongue more often, and stick to that when at home or with friends. But when fluently bilingual people interact, listening to a conversation ricochet between french nouns and english verbs (or vice versa) as the language flips back and forth between the two even sometimes in mid-sentence - it can be dizzying to those with a lessor grasp of the tongues. [Answer] Most (all?) of Europe's monarchs are related to each other anyway. The merging of the British and French royal families would have little linguistic effect. For example, Great Britain has had [German monarchs](https://en.wikipedia.org/wiki/George_I_of_Great_Britain) before, with no obvious impact on the English language. --- Contrast this hypothetical merging of the monarchies with the [events following 1066](http://historyofenglishpodcast.com/2015/10/16/episode-68-rebels-with-a-cause/), which did lead to the creation of a new language. William the Conqueror originally intended to rule England as an English king, but a couple of factors intervened: * Rebellions forced William to oust the old English aristocrats * William needed to reward the supporters of the invasion by granting them titles of nobility in the conquered lands As a result, the new government became Francophone, and Old English soon faded into history. --- Peacefully merging two countries, though, doesn't produce that kind of social upheaval. You would just get a bilingual country, just like many other multilingual countries in the world. Some of the more subtle effects that would be likely: * Increased bilingualism among the well educated and those involved in cross-Channel business. * Increased borrowing of vocabulary, notably French → English. For example, in Canada, English speakers use the word "toque", not just when referring to chefs' hats. English is a language that has grown organically, and it enthusiastically incorporates words from other languages that it encounters. This is likely due to the way the language came into existence as a hybrid of Germanic, Latin, Norse, and French influences in the first place. * Probably less English → French borrowing, though. French, in contrast, is much more conservative. In France, the Académie Française declares what is considered proper, and rarely adopts foreign influences. In Canada, the Francophone minority [also tries to defend against the English onslaught](https://en.wikipedia.org/wiki/Quebec_French#Use_of_Anglicisms), even through [legal means](https://en.wikipedia.org/wiki/Charter_of_the_French_Language). * In both languages, the [accent of prestige](https://en.wikipedia.org/wiki/Accent_(sociolinguistics)) would probably change. Even if English has a wide variety of accents, the Queen's English is still considered the most "proper". So, if the royal family develops a foreign accent, perhaps that change would find its way into the public's speech patterns. [Answer] Just having the royal families related doesn’t mean much actually. After all, England has been ruled by German houses for 300 years now in OTL. But let’s assume, in your ATL, Great Britain and France (instead of Hanover) shared more than just the ruler and became an actual union, a single country even. There also seems to have been no democratic revolution in 1789 or otherwise, so we’re probably still dealing with a feudal aristocracy or even an absolute monarchy. Whatever actually happened in your ATL has a lot of influence on the best answer to this question. Since industrialization already was in its beginnings in England at the time of diversion, we can assume that this double-nation would still be on the forefront of it, but the continental part would benefit sooner than in OTL. Without support by the French, the war for independence of the colonies in North America would probably have happened differently, least because they could have been joined by Louisiana which now had the same motherland. Except for religious minority groups, other migrants (e.g. famine victims and politic refugees) would have gone there in different waves. My best guess is that French remained the dominant language among the nobles, in diplomacy and politics, even gaining more influence on internal affairs of the island part and in the colonies, established and new. The military would be divided, with the navy traditionally being anglophone, the army francophone. Science at first still leant on Latin as a lingua franca across Europe, but slowly adopted the closer, Romance alternative. Technology, however, was driven by English inventors in the beginning, and so was commerce and trade. Germany, confronted with such a powerful neighbor, had to unite earlier than in OTL and became the common archenemy for centuries. Anything German and Germanic was of low prestige and so French finally gained dominance in even more fields. Today, French and English still exist as separate languages. Both are full of loan words from each other in particular areas. They also sound a bit different than in OTL. Especially non-noble, educated English native speakers adopt a more nasal and word-blending dialect over time. For English nobles, it is fashionable now, but not at all required, to learn the language spoken by peasants in their lands (like the prince of Wales learned Welsh), but they are raised in French of course. English pupils all study French, but hardly any French pupil takes English lessons. So option 1 for the most part. [Answer] Since I added a string of perhaps opinionated but very fact based comments on other people's answers, I thought I should add my own. # 3. Both are in use. In my comment on the Q I said this would be unlikely to happen for any given part of the population at large (as in Canada) but in terms of governance, it is the most sensible approach (as in Canada), because it means the population at large could, in all places, officially communicate with, and understand, the local ruling elite. To be clear, I don't mean that the governing "political/academic/military" class would as a rule be bilingual (and it is a great stretch of the imagination to claim that in Canada). I mean the members of such a class in an Anglo-French Empire would not adopt one language exclusively for governing the entire Empire. So, contra [the currently top voted answer](https://worldbuilding.stackexchange.com/a/29723/15048) here, I do not think the aspirations of a far away central court could prevail for long if that meant enforcing official use of only French over all colonies regardless of what language was spoken predominantly by the immigrant population. By "immigrants" I mean French or English natives who have populated outlying parts of the Empire. Part of my reasoning is that for such colonies to be successful, unless immigration to them is forced (e.g., as with prisoners sent to Australia), a certain amount of respect from and integration with the ruling elite must be in evidence or you would not have many colonists participating in an "Anglo-French Empire". So this is distinct from areas where the Empire is really military outposts presiding over a mostly native, non-French, non-English population, where no pretense of respect or integration would be necessary -- those people have no where to go, and if you can dominate them by force and conduct official business in a foreign language native to the ruling elite, there won't be any issues the "force" part doesn't cover. Because of this logic, I don't think the ruling elite of the Empire would for long aspire to using only one language or the other; they might in fact come into conflict with one another on the issue but presuming the more competent prevail (without which the Empire would be short lived), they would quickly realize that an official mix of French and/or English, appropriate to the local population, would be most expedient. This would require that the imperial government everywhere would need at least a few people capable of translating from one language to the other, and that communication between regions/persons could be conducted in either or both languages. * Native English Lord A could send native French Lord B messages in English, confident that B or one of his retinue could deal with this. * French Lord B could reply in English or French. * Native English Lord C, who is proud of his French, might choose to use French with everybody all the time. Etc. It's worth noting that in Canada, getting many/most(?) federal jobs requires proof of bilingualism. However, it's also worth noting that one thing which qualifies as proof (for a native English speaker) is having completed French to the end of high school -- which sounds like a long time, but it does not, in fact, mean that everyone who did so can actually speak or understand French, particularly once they've been out of school a few years. So the requirement, and the qualification, are often a pretense. I mention this as an example of how aspirations of this sort don't prevail, reality does, and to make an empire work over the long term you do need to take the latter into account. [Answer] Not so apparent these days but the industrial revolution saw an influx of Europeans to S Wales which was a world centre for coal, iron ore and other materials. Most arrived expecting to hear English and got Welsh. They would have had English speaking employers (owners) and Welsh speaking locals. The result was a curious mix of English that followed Welsh grammar rules. The English government tried to eradicate the Welsh language and nearly succeeded. The Welsh were having none of it. The French were largely successful in unifying their language though there are a number of pockets where people will be more comfortable in the local 'patois'. Haute Savoie for example. The point being that people tend to be very attached to their mother-tongue and find themselves surprisingly proud of it when threatened. If France/UK fell under a single government then eventually you might get a common language. Its a brave government that forces that kind of change. [Answer] Post Hastings (1066), English (previously the Old High German derived Old English) blended with... (some name I've forgotten) French because it was the court language of the new Frank kings. That was a Romanticized German. The classic Battle of Agincourt? That was due to a legal inherited title owned by the king of England. They've been interbreeding for centuries. The results of this were 1 leading to 2, but regionally, so 3. Assuming a more peaceful unity than reality's, I'd expect even more (and faster) homogenization. There were anti-France sentiments in England and anti-England sentiments in France predominantly as a result of their bloody wars. The biggest change I'm seeing, then, is the likelihood that they would be less hostile. Accordingly, I'd look at Gaelic (esp. the Scottish branches) for a more amicable example of what that might look like. The independent tongues may still exist, but a merged language would form, and the groups would tend towards being dialects of that. Some would still speak the original with lots of loan words, but most would speak the major hybrid tongue which they would probably call by whatever name they identify with. These would merge over time, though possibly not so much as to be called a common tongue. There are loads of examples of distinct languages that grew together so neighbors and allies could communicate. Spanish and Portuguese or Russian and Ukrainian are a couple example pairs. They are not the same languages, but learning one tends to permit some meaningful communication in the other. Further, people living in the adjacent regions tend to pick up some of the rest. Merchants are going to adopt the languages that they need to trade, which will push homogenization among anyone of their social standing. If the noble classes have similar pressures, they will adopt, as well. If the government adopts such a hybrid, it will apply a gentler pressure on the people, in addition to the concept of airs. (being like the nobles) I'd never expect a complete expunging of the former languages, but would expect (after a handful of decades) that anyone who spoke the common tongue could travel anywhere in the empire and communicate in at least a basic sense to pretty much anyone, and find someone who could speak fluently, as well. It would be a remarkable experience to find a backwater that this was not true of. [Answer] In the 1700's, the international language of diplomacy was still French so there would be a strong pull for upper class members of both societies to be fluent in French, not just to communicate with each other, but also to communicate with the courts of the various German principalities, Russia, Sweden and every other European nation that was considered worth dealing with. OTOH, even in the 1700's, England was much richer than France, and had a more developed merchant class, as well as powerful institutions like Parliament, the courts and professional guilds, which would certainly have a lot of influence in how a combined Anglo-French kingdom would operate. The French institutions had decayed badly (which is why in our timeline, the French Revolution occurred in 1789), so the influx of vitality from imported British institutions would rapidly overtake and replace many French ones. French merchants would start adopting British practice, the French army would be modeled after Fairfax's "New Model Army", the French navy would become part of the Royal Navy and so on. French children would probably be sent to British schools and universities in order to absorb the more successful models of British society (note also that many of the institutions we associate with France today were created after the Revolutionary period, either during the reign of Napoleon or during the many Republics). In this case, the English language would start infiltrating French, especially among military officers, the merchant class and in schools and universities. This would also affect the French language in other ways; prior to the Revolution there were many dialects of French, many of which were almost incomprehensible to other Frenchmen (the Revolutionaries standardized the "Parisian" dialect of French as the one and only "French language"). The hybrid "Franglish" would tend to standardize the "English" portions across France, and British merchants, officers and scientists would probably have only the standard "diplomatic" French as their French portion, so there would be a long period of time where "Franglish" became standardized throughout both France and Britain. There would also be a third "underclass" of people like farmers and common labourers, who would not learn the foreign languages (except for the occasional loan word which might be encountered in markets). They would be unilingual French or English speakers, and unless they were drafted or press ganged into the military, or sought employment in the factories of the cities, they would never be exposed to Franglish or diplomatic French. Even if they were exposed in the military or in the factories, they would start learning later in life, and might not be very fluent in Franglish. [Answer] # They would use both languages. Look at modern-day Belgium. It uses French and Dutch. Both languages prosper, and many people know both. Why wouldn't this apply to your world? [Answer] Look at real history around that time and beyond: French was used for "standard" stuff because they police the language and the meaning of a contract or treaty can be precisely understood and will still mean the same thing when the document is reviewed later. But English is "open source" and can be bent and mutilated to fit a group's need. It was the coming of rapid-changing technology and the industrial revolution that made it desirable to speak of new things, and the rapid pace of change made people want to change the language more rapidly in general. If the story is set when lingua Franca was still the case, then the story picks up there. But, with a spreading empire, with French and British together, the French would object to the language being butchered while the English would embrace the pigeons and creoles in the colonies and trading partners. So with both groups together you'll still get an effect like in the real English empire, with English becoming the second language of everyone and a base for new dialects. You might have a split that gets re-enforced with the now-intended uses of each: to be expressive and original you use English and English-based mixtures; but then to write the contract you use French with expert scribes (lawyers) who can point to a dictionary meaning of every word used, and a precedent w/extensive commentary for every expression in contract law. The names of goods and such being traded might be listed separately from the main contract, so new things are not much of a problem. But new ways of trading, and new ideas regarding commerce, law, and transportation might cause problems since there are no "official" words for those. ]
[Question] [ It was difficult to sum the entire question into the title, but here's more context: I'm working on a proof of concept for a game where you are racing vehicles rally raid style across Antarctica and / or tundra where "the race" takes weeks, (including fixing the vehicle and sleep). Were it just this, it could pass as a race, but you are also hauling various cargo that needs to stay more or less intact or you are deducted points. You can also use some of the cargo for food or vehicle fixing supplies. That's the gist of it, but I feel a good reason is needed for why this event is taking place at all. * If it's a race, why the cargo? * If it's cargo hauling, why the rush? It would be great if the scenario allows for: * The world is realistic in terms of technology, but does not have to be exactly the same as ours in terms of the landscape, animals and places that do not have to match. You can say there's a big city that is in the middle of a tundra and that you can drive from it to the north pole without there being a sea in the way (though Canada springs to mind). In terms of landscape, I realise realistically it would hardly be possible to drive to the Arctic even if the sea between tundra and the north pole froze as it cracks and rolls creating a landscape of ice spikes and walls, but again, some freedom is taken here. * Professional racing teams (as opposed to amateurs and enthusiasts that might fit some of the scenarios I listed below). * Having racing seasons / championships. Some previous ideas: * Probably the best one I got yet I got just while writing this (rubber ducky debugging strikes again): The cargo needs to be delivered to a remote village (or station) anyway, but once or twice a year a race is organised (like [the Iditarod](https://en.wikipedia.org/wiki/Iditarod_Trail_Sled_Dog_Race) for example). The problem I have with this is it's only believable if it's more or less just an occasional event and rules out anything more "serious" like having racing seasons and teams. * Instead of a race to some village, you are rushing to a distress call from a haul truck and must either fix it there or carry its cargo to its destination. (Not really happy with this one as you again have no real racing) * You are hauling cargo from A to B, but getting there sooner rather than later pays better. (I am listing all that came to mind even though I am not happy with this either: No racing at all, but might include some minor survival elements) * You do cargo hauling for a living, race on the weekends (Might work if I don't find a better solution, but this splits the racing / hauling into separate events). Notes: * Why Arctic and not Antarctica? Antarctica is a continent (ice over land) and the Arctic is only ice so this would perhaps give more fun terrain, but I also wanted to have certain animals around for which you should keep an eye out so you are not attacked when you are out of the vehicle (most likely out to do repairs). From what I know, there are no wolves or bears on Antarctica, and there are no tundras near it, so I opted for the Arctic. * The vehicles were initially supposed to be something between big haul trucks and off road vehicles, but if something else (as long as it's on land) works better for your idea, be my guest. TL/DR: What could be the scenario where there are races being held in tundra / Arctic involving hauling cargo to the extent that it's a "serious" sport with teams, seasons and championships? Note: If you think replacing teams with amateurs / enthusiasts could work better, go ahead. Edit: These are all awesome answers, some of them would even make for games on their own. Thank you all for your very helpful input! [Answer] Its a technology tryout and showcase system. Building things for racecars isnt just used in the racecar, it also helps improve the technology of the regular cars from the company that uses that particular racecar. I helped with the safety of a Formula E kart which was going to "compete"\* with other karts. There were competitors from all over the world, from schools to full multi-million dollar companies. As each group tried to solve design problems you had a bunch of different technologies all with the aim to solve them. Some were cheap, some simple, some complex, some were designed so they could be build in particular industrial machinery and others were just hand-made specialty parts. (Part of) the idea is that companies can look at these and buy/lease/copy/whatever and improve the overall technology of the world. No one is very interested in a kart for anything but entertainment, but the technologies inside were valuable. To further illustrate this each kart could win prizes in various categories, such as endurance, weight, efficiency, max speed etc. Your race is basically designed for improving cargo-hauling technologies in rough conditions. One group may win the category on having the most efficient cargospace, another may have the most cargospace, another may have the engine that requires the least maintenance, another is the fastest etc. \it was their first attempt so all they wanted was a rolling frame that wasnt disqualified and could finish all trials. [Answer] People race with cars, cars driving in reverse, trucks, tractors, lawnmowers, [wives](https://en.wikipedia.org/wiki/Wife-carrying) and whatsoever... Yours is just another variant. Simply put, it's a race and those are the rules of the race. The [Blue Riband](https://en.wikipedia.org/wiki/Blue_Riband) had something similar: > > The Blue Riband (/ˈrɪbənd/) is an unofficial accolade given to the passenger liner crossing the Atlantic Ocean in regular service with the record highest average speed. > > > [Answer] You could go a bit Mad Max here. You are racing because the cargo is very valuable. And since your cargo is valuable, and the road is long with no law enforcement other than what you bring along, you are attracting people who'd also value your cargo, but have temporarily mislaid the papers to claim it... You have seasons because of the climate. winter is just too cold, summer is too dangerous because of melting ice, so you are stuck with the weeks inbetween. You have teams and an official-ish setup because of the strengths of numbers. Enough trucks in your convoy might discourage the raiders. Or not, and since you are unsure you're pushing the pedal to the metal. Your teams compete, because that's just human nature. Or capitalism, if you wish. Also, those who lag behind put everybody in danger, unless they can be abused as bait for the raiders. The championship is just the way people are handling the situation. Most of all, the biggest prize is making it there and back again without unplanned holes in your truck or drivers. There's not much you can do about being raided occasionally. The world is as it is, so you might as well find fun in what cannot be avoided. [Answer] Take inspiration from the historic Tea Clippers in the early 1800s that raced to get the valuable tea harvest back from China to Europe the fastest. The tea was only harvested at a certain time of the year, and so the Clipper ships would have to all receive and load their cargo and set off at roughly the same time. The ship that could make it back to London first could command a much higher price for the tea they carried, as merchants were desperate to buy the tea as soon as possible. As more and more ships made it back, the supply went up and so the later the tea arrived, the less money you could sell it for. These races were often very well covered by the press, with semi-regular updates in the newspapers receiving telegram updates about which ship was in the lead and had reached which port by which date etc. In later years additional monetary prizes were awarded to the ship that arrived first, to encourage even more racing, and many people would place bets on different ships. Some ships became famous for winning the race several times. I don't know the setting, but it could be some valuable cargo or resource that the merchants of some city desperately need, or even a luxury good that can command high prices if scarce, but lower prices once more make it back. If there are waystations along the route that could radio back to the city who is in the lead etc, it could lead into some betting mechanism as well. This would also feed into a victory points system where you received more points per kg of cargo for delivering your goods fastest, but going slower might mean you have more goods left to sell at the end even if at a lower price. [Answer] Cargo is plant/fruit/vegetable harvestable once a year and do not handle well low temperature and grow only in specific place. Small amount can be carried by heated and presurized planes, ship transport is too long - it spolis, constructing train infrastructure cost too much. At destination You can sell Yours cargo, if be first for good price, second will get less and so on. If go to slow then cargo spoil and get nothing. [Answer] # A Commemoration Some time in the past, there was some cargo that had to be delivered quickly. Medicine for an outbreak, a water purifier for a town, soldiers to hold off an invasion, etc. A brave driver defied the odds by skillfully and quickly delivering the cargo intact. That driver wasn't racing against other drivers, they were racing against time (people were dying of plague, parts were needed before a storm, invaders are coming, etc.). The event was inspirational enough to inspire reenactments. Eventually those reenactments became races, which picked up in popularity. The first racers were likely regular cargo drivers with spare time. The race was popular enough to warrant additional races in different parts of the continent. The additional challenge of keeping cargo intact could be seen as an exciting twist, drawing in racers and spectators. Where there are spectators, there are network deals, sponsors, merchandising, etc., transforming the sport from a regional pastime into a full-fledged professional racing league. [Answer] Market Price* The marshy tundra landscape makes land transportation nearly impossible in the summer months - and so it is only when winter has frozen the ice-roads solid enough to traverse that shipments start to roll back into town. As such, the first few luxuries coming through can command an exorbitant premium. How much do you think a fresh ripe orange can sell for when they've been out of all but the canned variety for months and months? Of course, that novelty wears off pretty fast (especially with the slow moving train-trucks following-up with massive shipping containers full supplies en mass) and so these runners are racing to stay ahead of the pack enough to maximize their profits. This also presents interesting different strategies for different "racers". Do you simply try to hit up the first few towns or the last few? Do you stop to sell at every stop, or just the bigger cities? Do you specialize in a particular good or a variety of goods? The "race" isn't actually about being the first to cross the finish line... it's about making the most money over the course of the trip! TL;DR - The "runners" are racing to provide goods at a premium while-supply-is-still-low and demand-is-still-high. If they are too slow, other racers (and eventually the massive slow "truckers") will get there and saturate the market. [Answer] Your game takes place in a distant future where the Arctic ice has melted and most of the land is uninhabitable due to the extreme heat in all seasons. The surviving civilization has gathered on the coasts of the Antarctic continent, and every seasonal night, a race allows the winner to enter a hard-to-reach utopian city built exactly at the South Pole. To be allowed to enter the city, the winner must bring a symbolic amount of fresh water to its destination, as both a symbol and a constraint. [Answer] [Ice Road Truckers!](https://en.wikipedia.org/wiki/Ice_Road_Truckers) Your route is primarily driven on ice, which is only open a few weeks/months of the year due to changing seasons. So in order to get valuable supplies to/from towns in the artic, you have a limited time to make it across before the lakes melt and you are stranded - or worse. As for the race, it could easily be sponsored by a TV channel who wants to add additional drama to the proceedings and have additional cash payouts to the winners. [Answer] A few other people have had similar ideas to mine, where a valuable cargo needs to get a remote point by a certain time, but the start time is the same for everyone -- the Tea Clippers is a great example of that. And, of course, since the Arctic is only easily crossable by "land" when everything is frozen, that means there's a smaller window when overland transport can take place (e.g. the Ice Truckers example). But if it's really important, why not just fly it there? Well, I had this idea. What if there are aliens? What if these aliens want to buy some specific product from Earth, something they can't get elsewhere? It could be some kind of plant product that they can't grow at home, or maybe there's a huge fad for gerbils in their part of the universe. Whatever it is, they want it, and we have it. The thing is, these aliens can only pick up things from Earth at the north pole. Maybe it's some kind of star gate or portal that is only stable at a place that's at the centrepoint of the planet's spin. And maybe they can only keep it open for a short period of time, or maybe there's a negotiated limit on how many gerbils can be exported to the aliens in a given year. (Maybe they wisely recognize that limiting the number of gerbils that are imported from Earth in a given cycle will help keep the prices high, and also help prevent the depletion of the gerbil supply.) So, whoever gets there first is guaranteed to make the sale, and late comers are more likely to get there too late to beat the quota. So, now we have a reason for getting the cargo there first (the sales window is small and/or limited), and a reason for the common starting point of the time window (the tundra and sea ice need to be frozen all the way along the route). Now, all that's left is a reason for why they can't fly the cargo. With modern flight technology, it should be easy to fly tonnes and tonnes of live gerbils to the north pole, even considering the needs for proper climate control to ensure the survival of the gerbils in transit. So, it can't be that. Instead, imagine that the opening of the space portal creates a strong electromagnetic effect in a 1000km radius, but in a wide conical shape. So that creates a no-fly zone that starts 100m above the ground, and extends for around 20km into the sky. That would absolutely prohibit flights to the north pole during the crucial time. Oh, I guess there's one other question about this situation that needs to be answered: if selling gerbils to aliens at the north pole is so lucrative, why not just set up a gerbil breeding facility right next to where the portal opens up? Wouldn't that be more reliable than a race to the north pole? Would racing there be that much cheaper? I guess the answer there could be a combination of logistics and politics. Manning and supplying a gerbil factory year-round at the north pole would be frickin' awkward, and if anything goes wrong, you lose your entire investment. Plus, the area around the north pole is actually a bit of a political geography minefield. Who does it belong to? To whom would you apply for permits to build your self-contained gerbil farm in the first place? It may very well be that not building a compound at the north pole is the only way to avoid escalation of aggression between various world super-powers. Or, it could be that the opening of the portal creates a short-term but extremely high intensity X-ray or gamma-ray burst that would wipe out all the gerbils (as well as the human attendants), which would preclude having such a facility anywhere near the portal zone. And just think of the title this allows for: ARCTIC WASTELAND GERBIL DEATH RACE You're welcome. [Answer] If you are taking any kind of cargo anywhere, you will probably be in a hurry because usually whomever payed for the cargo paid a fixed amount for it. You will receive the same amount of money whether you take an hour or a year to get there. Not being as fast as you can puts you on a loss. Moreover people may be racing because this is not a matter of contract delivery. There is a limited market for the goods and whomever gets there first also sells first. ]
[Question] [ I've been designing bird-like creatures that both fly and walk using their legs, saving the trouble of growing extra muscle mass for both. Because of this they have an odd look for birds: They have scrawny upper bodies sitting on top of muscular waists with feathered legs. What would be their wings have no use in flight and have instead been converted to tiny bird hands with talons. They walk on two toes like ostriches and third toe from which their primary flight feathers grow, this toe is bend upwards when walking. Because of the way they fly their [flight muscles](https://www.birdwatchingdaily.com/news/science/the-amazing-muscles-and-bones-that-make-birds-fly/) aren't located on the torso and they don't have a [keel](https://en.wikipedia.org/wiki/Keel_(bird_anatomy)). Their pelvis and leg muscles are adapted for the mechanical demands of flight and the muscles use the same rope-and-pulley system as ordinary birds. This gives them more room to flap their wing-legs and focuses their centre of gravity ventrally for stability during flight. My previous question was about how they fly, if you have a related comment put it [there](https://worldbuilding.stackexchange.com/questions/214485/what-would-the-anatomy-of-a-bird-that-flies-with-its-legs-work). The problem that's been pointed out to me is that the eggs would break in the uterus due to the mechanical stress of flight. This could prove to be a problem. Any ideas? (Besides flying normally or not at all.) EDIT: As was mentioned in the answers eggs have high compressive strength but I’m also worried about egg formation. [Answer] The uterus does not participate in the mechanical stresses of movement. It is not invited to that party and it does not want to go. A uterus has uterus things to worry about. It no more participates in skeletal movements than any other smooth muscle structure. Stresses of movement are distributed about the skeleton and core muscles. As regards the contents of the pelvis including the uterus, the pelvis is a formidable bone in normal birds (and pretty much all vertebrates) and would only be more substantial in your leg fliers. The anterior extent of the pelvis is the pubis which provides some support on that side - both to the uterus / oviduct as well as digestive tract structures. --- When your creature needs to use its reproductive tract or digestive tract to get leverage to move around it is doing something wrong. That goes for you too. If you find yourself doing that, quit. Or take a video of you doing it and post it, then quit. [Answer] Soft Shells Without being much of an engineer it seems like the best way to handle this from the bird's perspective would be to lay a soft-shelled egg that hardens upon exposure to the air. The softer shell would be able to flex in the uterus until it was time to lay it, so the flight action wouldn't be able to crack it. Depending on the mechanical stresses involved/how many eggs are laid at once etc the birds might evolve to lay eggs somewhat smaller for their size than normal, or fewer eggs, to ensure maximum room in the uterus. [Answer] I'm not convinced it would be a problem. Eggs crack easily to impacts, but have incredible compressive strength. So it's trivially easy to break one with a knife or fork or edge of pan, but just try squeezing one to death. You may not be able to do it, and if you do it will take a lot more effort than you'd think at first. This was a bit of a meme in the 20-teens. <https://www.youtube.com/watch?v=2J6pM0y1fYE&ab_channel=GinaSu> I was also going to suggest the eggs could be soft-shelled and harden on contact with air, but Dario Quint posted that answer before I was even halfway through writing this. That could work too I guess. [Answer] Would the suggestion of the female going into a period where she does not fly during breeding season prior to the egg being laid violate the "Not fly at all" rule? This would see her enter a dormant or hibernation like period proceeded by a period of aggressive eating to build up fat stores for the time she would be unable to find food. Alternatively, the male mate would be tasked with gathering food for the mother and himself. When the egg is laid, the mother would be free to resume gathering food and may do so in shifts with the father OR leave the father to incubate the egg himself (the latter behavior is famously observed in Emperor Penguins. The female is going to almost exclusively replenish her food reserves, having not eaten once the egg began developing and only resuming once it is laid. The former behavior is observed in all other penguin species, where the male and female take shifts incubating the egg). It should be pointed out that mating for most animals is either done seasonally, or opportunistically (when environment conditions are correct). Humans are one of the few species of animals that are continuous breeders (Animals that are capable of breeding at any time of the year) and the only non-human species that are capable of this are great apes, all closely linked to humans in an evolution standpoint. It would not be out of the realm of possibilities that your bird would cease strenuously flying just prior to the species mating season, to allow for the egg to develop until it is laid. [Answer] [![enter image description here](https://i.stack.imgur.com/q65HX.png)](https://i.stack.imgur.com/q65HX.png) 1. Make the sternum prolong after the joints of the feet-would-be-wings - because you will need the flight muscle to connect to it and still let enough room for the guts, kidneys, cloaca, etc - but don't let it stick directly to the "pelvic basin" bones, because you need the space to pass the eggs 2. take the wishbone from the front an make it connect with the pointy tip of the V on the end of long sternum and arms of the V on the pelvic girdle. Sorta collar bones, but at the other end. Just make then thick enough to resist the compression from the flight muscles as they beat down and pull on the sternum 3. you can lose some height from the sternum in front, as the breast muscles are no longer involved in flight, and make it quite heavy on the other end, where the flight muscles insert. [Answer] Eggs don't take long to form (chicken eggs take about 24 hours). Could they simply not fly for 24 hours while they're making an egg and then go back to business as usual afterwards? [Answer] Does this creature have to lay eggs? Could it be a marsupial with feathers? Having a reproductive process similar to kangaroos and a similarly placed pouch to carry the infant. ]
[Question] [ In my fantasy world, the magic system pretty much makes metal armour and weapons obsolete. The magic system's specifics aren't important, just note that the magic system allows the users to 'penetrate' and 'destroy' man-made materials, AND objects that come from the Earth, such as stone. Only living things such as humans, animals, plants and everything produced naturally by said living things can't be affected by the magic. What natural armour would be best for warfare/protection? Wood? Giant beetle husks? Scales? --- Extra info: * The era this is set in is roughly the classic medieval era of Europe. * Though the people who can do magic aren't common, they provide enough danger that if soldiers do encounter one, they wouldn't want to face them defenceless, as their metal armour and swords/spears/axes are 'ignored'. * The armour has to be strong enough to protect them from normal soldier's attacks, be it from metal weaponry or otherwise, but also light and inexpensive enough to be breathable and mass-produced. * The magic system was 'introduced' after humans had already developed metal armours, so that type of armour does exist, but most wouldn't risk the danger that could posses by arming themselves with 'non-natural' materials. [edit:] Leather armour and [edit: removed chemically treated, contradicts] cloth armour would be viable in defending against said magic. [edit 2:] To be clearer, the users of the 'magic' aren't 'mages' or 'wizards' old or mostly defenceless without their magic like in cliche fantasy, but are more akin to the 'Mistborn' from the Mistborn series by Brandon Sanderson, or the 'Surgebinders' from the Stormlight Archives, where people such as Kaladin are very adept in hand-to-hand combat. These people who practice 'magic' are also warriors and assassins- using the magic in tandem with their combat skills. Even if you have leather armour that cannot be affected by their magic, you still have to face the user behind the magic- a potentially extremely skilled spearman or swordsman. [Answer] > > people who can do magic aren't common > > > Pragmatic answer: defend yourself against the common threat. Most people you meet won't be able to blast through your armour, so just wear the best that you can get, and you'll be largely OK. Maybe you'll meet people who didn't follow this rule, and you'll find yourself a fair bit more resilient than they will be. Even if you do run into a magic user, you'll find that a decent padded [arming jacket](https://en.wikipedia.org/wiki/Gambeson) of the sort that most soldiers would be using under metal armour anyway will be pretty good defence (and back in the day, people who couldn't afford fancier armour would go to war just wearing a good arming jacket, so it must be reasonably effective by itself). [Cuirboilli](https://en.wikipedia.org/wiki/Boiled_leather) (cooked leather) will make a decent multipurpose top layer, though it isn't as effective against cutting and slashing weapons when it hasn't been reinforced with metal. You may as well do that though, because you don't want to get cut up by someone with a decent steel chopper. It is possible to reinforce cuirboilli in other ways... I've found references to "ground mineral finish" being useful. You'd have to use a "mineral" of biological origin though... ground up teeth spring to mind, though that would be a slightly grisly industry to be in. But what happens when you meet a problematic wizard? Well, if they can fireball you from afar, you just get toasted regardless of what you wear. If they have to use regular weapons against you, then: * Carry a nice wooden shield. This is common sense anyway, but it'll stop natural and man made projectiles adequately, and it'll do well enough against metal melee weapons if it is stoutly built. Making it tough enough might be challenging, but not impossible. A non-structurally-critical metal rim will help it last a lot longer against non-wizards. * Use a hafted weapon, like a warhammer or halberd. Sure, they can poof the stabby, crushy bits into dust, but there's still a nice big hefty stick attached to a frightened person fighting for their life, and it'll do a fine job smashing wizards who don't do a good enough job defending themselves. Until it gets poofed, it'll do great against idiots who don't have magic and didn't bring decent armour to the fight. * Use bone, horn or (if you can find any big enough) tooth spikes on the back or sides of the head of your weapon. They won't get poofed off, and they'll make it much easier to kill inconvenient wizards and bash through armour if the metal bit isn't available any more. * Keep some concealed metal stabby things, stiletto-like. On the assumption that you can't poof them into dust if you can't see em, they'll be useful if you can get close enough in, or have a friend to do distraction. * Learn you some jiu-jitsu, or your local wrestling equivalent. All the armour in the world won't stop your arms and legs snapping, and you can always make use of it as a last-ditch, all-your-weapons-got-poofed-or-broken way to save your life. * Use archery! An all-natural bow can shoot arrows tipped with the material of your choice Horn composite bows can be very powerful. Bone or hardened wood for wizards, metal (or flint, in a pinch) for regular folk. Changing ammunition is easy. More importantly, when a war arrow is already inbound at speed, poofing the sharp bit off won't necessarily save you from the effects of the shaft, if it hits you in a unarmoured or weakly armoured bit. Careful arrow design might result in a multipurpose composite head suitable for all targets. --- An update to respond to a slightly pointed edit to the question which seems to be directed at me ;-) You should note that I've made no assumptions about the skills and abilities of the wizards in question, in the same way that I've made no assumptions about the skills and abilities of the non-wizards who might fight them. It is almost tangential to the question... if you're fighting a super-skilled master swordspeep elite assassin, it doesn't really matter whether they're a wizard or not and who's got plate armour; they're probably going to kill you. As for the use of "wizard"... your peeps cast magic, wizards cast magic, far as I'm concerned you're all the same, your prejudices notwithstanding. [Answer] So, if I understand this right, leather armor would be perfectly serviceable, because leather comes from animal skins, even thought it's no longer alive. In that case, may I suggest [Japanese Samurai Armor](https://en.wikipedia.org/wiki/Japanese_armour)? Japan had limited access to metals, which they used mostly for swords, so it's a good place to start with. Leather is plentiful, and can get pretty hard if you treat and layer it. Unfortunately, some types used metals plates / scales, but I suppose you can just use wooden plates (with hard leather on top) instead of metal ones. I'm kind of curious what weapons look like, because if you have wizards who can destroy an entire army's worth of plate metal, than they can also destroy an army's worth of metal swords, metal arrow tips, and metal shields. Though, of course, you can just [bokkens](https://en.wikipedia.org/wiki/Bokken), or something. Would fit with the Japanese aesthetic. [Answer] ## Gambeson Gambeson was the most common and readily available type of armour in the Medieval period. It was often made out of layers of linen which have been laminated together. Linen is a type of textile that was made out of flax, a plant that has been cultivated throughout human history. As “the people who can do magic aren't common”, most soldiers would instead equip themselves with something reliable, easy to obtain and easy to maintain, focusing on defending themselves against other troops rather than the rare mage. When they do encounter a mage though, their natural, plant-based armour will save them. ## Wooden Shields Just incase, soldiers would also have large wooden shields. Not only would they protect against mundane attacks, such as weapons or arrows, the wood would also act as a defence against magic. Many soldiers would also be carrying shields anyway so there is no change in tactics there. ## Brigandine or a Coat of Plates A coat of plates is, as the name may suggest, a sleeveless coat of leather or gambesons with iron or steel plates on the inside. The more advanced version, Brigandine, has much smaller plates that overlap, removing gaps in the armour. Either of these would be suitable in this scenario. The metal is on the inside, protecting a wearer from physical harm, and the leather or gambeson would protect from magical harm. ## Nothing? Your question states: > > living things such as humans, animals, plants and everything produced naturally by said living things can't be affected by the magic. > > > Surely that one phrase makes your entire question redundant? If humans, being living things, can’t be affected by the magic, why would they need to protect themselves from it? Answer, they don’t. There is no need to protect yourself or take any measures to defend against something which can not harm you. Rather than taking the literal meaning of what you wrote, i am instead going to interpret it as “humans can’t be affected by magic, but their armour and weapons can”. In which case, the answer may still be “weapons and armour are unaffected” as, even if there is a chance of encountering a mage, it is so proportionately low as to not have to worry about it. If a mage were to show up, people could simply remove the heads of their arrows, sharpen the shafts and fire them instead (yes the weight distribution would be off, but that would not be very important at close range, the sharpened, untipped arrow would still be able to pierce the mage). [Answer] We can look at things that have been used for armor in human history: * Leather: The most used material for light armor, ever. Although it can't stop a thrust from a sword or a chop from an axe, it does protect from sword cuts and reduces blunt damage. It will also offer protection from fire bolts, acid, and other magic attacks. * Boiled Leather: Leather hardened by being boiled in oil (another life-based material). Offers better protection from blunt weapons than soft leather. * Silk: A common light samurai armor was a shirt made from three layers of silk. It was especially good at preventing arrows from penetrating very deep, as the silk would follow the arrowhead into the wound. The arrow could then be removed simply by pulling at the silk. * Wool and cotton: Quilted armor has been very common, both worn beneath metal and boiled-leather armor and by itself. It softens blunt blows (including sling bullets) and may catch light cuts. It will also protect against cold-based magic. * Wood. Shields (e.g. Viking round shields) have commonly been made from wood, sometimes wrapped with leather. While armor has rarely been used in worn armor, braided bamboo slats have been used for that purpose in Asia. * Bone: There are examples of bone armor in history, e.g. from [Siberia](https://www.ancient-origins.net/news-history-archaeology/archaeologists-unearth-4000-year-old-siberian-knight-armour-102090). * Fiber: Warriors from the [Kiribati Islands](https://www.beyondsciencetv.com/2017/08/21/5-legendary-mysterious-armors-in-history/) constructed armor using coir, a particularly strong fiber material harvested from coconut trees. For a fantasy world, we might add exotic things like dragon scales and bones, unicorn hide, and wyrm skin. [Answer] As for the armor, padded cloth armour was pretty widespread in the high and late middle ages. There were various ways of constructing it - multiple layers (more then 10) of linen fabric stitched together, several layers of linen stuffed with raw wool or something similar, etc. Layers of deerskin may be added. Leather armor also had its place, although not how it is commonly depicted. There are couple finds of leather arm armor (I know if one vambrace and one brassard) - although we do not know how exactly this leather was hardened. In general, this armor was worse then metal - it needed to be heavier, hotter and more cumbersome for the same level of protection. So it is going to be an interesting reversal when what was seen as cheap infantry armour will suddenly become more effective then very expensive knightly armour. Unless there are some exotic animals in your world, just a simple 14 century gambeson with boiled leather elements would give decent protection against both magical and mundane weapons. As for the weapons, it is harder. I am not aware of any organic materials that would penetrate knightly steel armor. The best bet would be impact weapons - clubs, mallets, quarterstaves. If the magic ability is not that widespread, steel weapons will most likely remain on the battlefield - a falshion has just a much better bet to damage a person in above-mentioned gambeson then a bone club. Most likely, it will be a fashion of carrying two weapons - one metal, one organic. Additional factor here is how long does the situation with magic go on. The development of armor and weapons in middle ages was a straight up race between the offensive and defensive capability, with armor always improving and increasing in coverage, until the firearms started being used commonly. As soon as armor stopped being so protective, we start seeing a reverse trend, and the amount of armour and it's presence on battlefield started going down rapidly. If your soldiers know their armor won't protect them absolutely, they will ditch everything that encumbers them. [Answer] # Keratin If you [search WB.SE for "Keratin is:answer"](https://worldbuilding.stackexchange.com/search?q=keratin+is%3Aanswer) you'll find that this popular and very common natural armor is, in fact, a popular answer for a lot of questions involving natural armors, weapons, etc. [Keratin](https://en.wikipedia.org/wiki/Keratin) is the material that makes up your fingernails, toenails, the horns of rhinos (and others), etc. Indeed, we already use it as a natural armor. You just need it to grow thicker, in more areas, and in plates (preferably with a bit 'o overlap). Make your dragon scales (or really big lizard scales) out of keratin and Bob's your uncle. [Answer] If you are capable of magically farming spidersilk then that would be your answer. Otherwise I suspect the best thing to use would be what was in use in that time period: leathers, wood, bone and cloth to keep it together. Since weapons will also be mostly natural the loss of metals for armor will be minimal. You do mention Giant Beetle Husks. If you allow magical creatures of immense size that have special properties for their hide, lets say a Dragon Scale, then those would naturally be used if you can get them. But since such options are completely your choice we cant really use them unless you specify them (at which point your question would be mute). [Answer] Chitin is heavy, not good for armour. There might be some potential in keratin (horn) if you can get a lot of it. Wood is your best bet for barriers like shield and pavise. Gambesons were very common, and were always worn under plate and mail. On top of these you want to use tough skins, like hardened leather or raw hide. There were some armours made of boar tusks found in the East. Japanese used armours made of wood, bamboo and leather. You can look into that as well. One more thing to note is that you don't need that much protection from the weapons. Since metal is unusable your whole warfare moved back to the stone age, making the weapons less effective. Things like aztec "swords", clubs, bow and arrow, slings, stone tipped spears, etc. (Unless bronze remains as an option because it's hard to corrode it entirely.) Most siege weapons don't need any metal parts, if you have good craftsmen. Even mechanical parts can be just wood, but they would have to be replaced often to make them reliable but I'm no expert so don't take my word on that Another thing to think about is that most of these materials are flammable, expect a lot of burning oil and stuff like that being used. [Answer] You defeated your own question with this: > > [edit:] Leather armour and non-chemical treated cloth armour would be viable in defending against said magic. > > > Your world wouldn't change too much from "our" classic medieval era. I know that you have these shiny knights in mind when thinking about it, but that was one in a couple hundred people on the battlefield, and that armor wouldn't be worn for anything else. But guess what everyone else was wearing? LEATHER! Because nobody but the very rich could afford plate armor. That's right, the masses would already be protected, and the knights would probably adopt some samurai-style armor, or just hope that a mage doesn't focus on them (because for strafing hits the leather padding below the armor should suffice). But again, knights are few and far between so it wouldn't matter at all. As for shelds: they aren't made out of metal. They were wood shields with - sometimes - metal plating. So they're fine. Against a sorcerer-heavy army all the weapons based off of pointy sticks would probably become favored over swords/axes, but again, that wouldn't make that much of a difference [Answer] # Reinforced Leather This is a good starting point - leather armor, boiled and studded with many small studs (made from bone or hard woods) to give it some rigidity. With a gambeson underneath for padding, this makes a solid piece of armor - though it's probably quite time intensive to make. # Wooden Shields Can be incredibly useful - blocking or deflecting anyone's attacks is nice. Adding a leather wrapping can help avoid the edge splintering and can dull blows to make it easier to use. Can also be augmented with spikes of bone or horn to make it offensive as well as defensive. # The secret trump card Since your requirements are roughly "not highly refined by people" and "not out of the Earth", you can equip elite troops with meteoric iron. Iron coming from meteors can be pretty darn pure, and still fits within the question's parameters. Depending on how much human refinement is too much, cold forging may be necessary (though there's arguably less refinement from Iron>Hot Iron than there is from plant>cloth) which would definitely limit the range of things you could make in a given time span (and quenching is probably out of the question). However, even a few relatively small cold-forged disks could be vital in helping soldiers either fight well or escape with non-fatal wounds; just a couple - protecting the neck, maybe on the head, and maybe a bigger one on the back to protect against surprises. Spear- or arrowheads could give your elites a solid advantage over the magic-users as well. Especially employed with elite troops (and must be, due to the rarity of meteors made of iron), meteoric iron may be a fatal surprise for any opposing magic users. [Answer] Just use a surcoat. Since most enemies will still be using classical weapons, metal armor will still be king of the battlefield, but a lightweight linen overcoat will protect both the soldier and his armor from magical attacks. [![enter image description here](https://i.stack.imgur.com/V5P8L.png)](https://i.stack.imgur.com/V5P8L.png) [Answer] Metal armor covered and concealed by natural materials, also mace made out of metals that is covered in hardwood/leather/animal horn material. Make your arrows out of sharp sticks with feathers as fletching, (bows are traditionally made of a wood/horn/fiber composite, all of which came from living things.) Spears out of hardwood with a sharp tip, and projectiles of siege weapons out of sea shells and shark teeth tied together with ropes. Alternatively, mine some chalk of diatomaceous earth slate from beneath coral reefs for your projectile(sharp coral will also work). If there were large animals around, then sharp weapons and arrow tips made from chipped bones will certainly work. Since your restraint implies that a mage can not destroy something he/she can't see, arm your elite assassins or rogues with concealed weapon beneath armor/clothing made of organic material, like fabric or leather, and stab with these weapons only at the last second of an attack, kill the mage before he/she can react and poof your weapon away. [Answer] # For weapons : staves and javelins ## Staves Even though it looks innocuous, the staff is as deadly as the sword and will easily break all of your enemies' bones. ## Javelins Basically a sharpened stick, throw that on your enemy (maybe with a spear-thrower for extra oomph) for a ranged attack [Answer] The big question is, WHY are leather and cloth effective but metal isn't. Is it the presence of carbon in the former that's lacking in the latter? If so, carbon steel (alloys of steel with some carbon in it) may already be good. If more carbon is needed, we can think of hardened wood, but another option would be lignite. Lignite has the advantage of having a very high carbon content, and can be worked with even primitive tools. It also has its disadvantages though, which become apparent when you realise that lignite is used as the main source of fuel for electric power stations, it's better known as coal :) There are other carbonaceous minerals that contain higher or lower percentages of carbon and might be able to be worked into weapons or armour segments as well. Moissanite for example, a rare Silicon Carbide, is sometimes mistaken for diamond, it's that hard, and might be worked into tips for crossbow bolts used by assassins sent after your magic users. Diamond itself is obviously a contender as well. [Answer] The question IS interesting. Throwing it off by "just wear the best that you can get" has no sense, for wearing something heavy AND useless in 30% of cases is not practical. (According to [ADND](https://www.reddit.com/r/DMAcademy/comments/5il667/item_rarity_percentages_question/) uncommon has 30% rarity). Recall the heavy ships with weak armor widely used in the 20th century. Not no armour, but not heavy armour. The most easy and expected solution for the world of magic will be use of elements. Magic belong to elements (fire, life etc.) and some elements keep well the attack from some other elements. Or badly. So, you can fill armor with defending magic of some elements that will be good against others. You cannot combine magic of contradictory elements on the same armor. BUT. You can use nature materials, containing some elements by their nature for that. Armour made of sea weeds has water magic and CAN be combined with armor made of fire salamander skin. Of course, such combined armor will be very difficult to make and very expensive to buy. For animals set I would advise not European 4-element scheme, it is too trivial for readers, but the Eastern 5-element one. Water, Fire, Metal, Wood, Earth (<https://www.chinahighlights.com/travelguide/chinese-zodiac/china-five-elements-philosophy.htm>) ]
[Question] [ For a Matrix-type future I want to feed people via solid food. This is to keep all their internal organs working properly. The idea is to feed them an endless kebab that is held together along its length with a string. They aren't aware of this as they are living in a fantasy simulated world. There is no need to chew the kebab as it is digestible as is. Waste is expelled in the normal way and happens autonomously although it may be arranged to coincide with bowel movements in the simulated world. The string supporting the kebab is continuously pulled at a slow rate through the digestive system to allow digestion to take place. Question Will the string that is threaded through the gut from mouth to anus actually be practicable or will it interfere with anything along the way? Are there any other drawbacks? Is there an easy way to balance the feed-through speed with the amount of nutrition per unit length of string? Note The string is on a never-ending loop so it is cleaned in disinfectant before it comes around again to the mouth once more coated in kebabulite. [Answer] The bowels are not straight: they have several U turns in their abdominal deployment. If you pull a wire it will tend to straighten up. If the wire is in the bowels, it means some unpleasant stress and almost sure intestinal cuts, unless you place some fixed pulleys. Bowel movements take care of moving the food from start to end. Just feed the slurry into the esophagus, the rest will be taken care by nature. [Answer] There are all kinds of ugly here. * If your string isn't digestable (or digestable in the time allotted for pulling the kebab through the body), it will decay, leading to bacteria and infection and a whole lot of ugly. * One assumes the body wants to breathe, but a kebab being pulled through the body pretty much guarantees that breathing either won't occur or that fluid will enter the lungs. Fluid in the lungs is a whole lot of ugly. Not breathing is a whole lot more ugly. * Metabolism is neither uniform nor linear. Part of the process of digestion is to store energy, not simply convert it. In other words, the body will expect the kebab to periodically stop moving. If it stops moving while food is still in the esophagus, the gag reflex will be invoked and the body will choke. As you can imagine, choking is a whole lot of ugly. * And heaven help you if your matrix personality decided to start a religious fast. Oh, yeah. A whole lota ugly. * I'm going to ignore the fact that the string is passing through orifaces that are expected to open and close at specific times, allowing the potential for material to pass when and where it shouldn't. I'm doing so because I can believe that despite being uncomfortable (and probably leading itself to gagging, see above), the body's fluids would likely keep the orifices sealed even with the string passing through. But, it would look ugly, so there's a whole lotta ugly here, too. * Finally, I upvoted L.Dutch's answer (and you should, too) because the nature of a string is to be pulled straight and there's enough squishy in the body that it would try really hard to do so. Add to that the fact that a moving string (or wire or anything else) has the inconvenient nature of cutting through things and the amount of ugly just went off the chart. I don't see the use of an endless kebab as practical. It would be more believable to have the body enter a semi-concious state associated with the act of eating in the Matrix and have it ingest the proverbial protein cubes while the mind believes it's enjoying a juicy steak. [Answer] Try to swallow and breathe at the same time and you will see where the problem is. The people would at least all need a tracheostomy, so you can basically put a lid on the wind pipe so food and saliva cannot get into the lungs (this is not something theoretical, I am currently sitting next to my wife who lives with exactly that arrangement ever since a doctor screwed up during surgery). Unless you are writing a satirical or humorous novel you should probably not invent grotesque solutions for problems that have [practical solutions](https://en.wikipedia.org/wiki/Percutaneous_endoscopic_gastrostomy) in the real world (but then I don't know what you are writing, and that kind of detail certainly sets a certain tone). [Answer] This seems a bit like an X/Y problem. Lets break down the actual problem 1) you need to get food into a person who isn't concious 2) you need this dumb and sensor free 3) You need to feed people at a given rate. 4) you don't want them to need to chew it. Basically - you're wanting to pump pre-masticated food into a person at a given rate. As a benevolent evil machine intelligence... this seems fairly simple. You don't want the end user choking - while not typically a good long term solution, you are talking about a feeding tube - though I suppose you could simply bypass the parts of the digestive systems you don't need. What you're looking for something preprocessed so it goes through the system, is optimally digested, and comes out the other end. So basically you want mush. Mush in one end, mush out the other. Stick tubes in either end for delivery and collection. Optimise the texture of the mush so its less likely to get stuck, add a one way valve that stops if the end user gets clogged up and you don't need string. You might even be able to get the end user to chew in suspended animation and use a simple mask and some electro-stimulated muscle movements to get them to eat 'normally' avoiding the fuss of a stomach tube [Answer] Why don’t you just run a tube down to the stomach? Waste is processed automatically by the body as usual, and the tubes can be removed, disinfected, and reinserted during a normal daily maintenance procedure that needs to be done anyway to keep the body from getting sores, etc. ]
[Question] [ I have read questions such as [these](https://worldbuilding.stackexchange.com/questions/56697/how-horribly-would-this-alien-die-in-earthly-conditions) [two](https://worldbuilding.stackexchange.com/questions/32129/what-would-happen-to-a-high-pressure-creature-in-a-low-pressure-atmosphere-3at) about aliens adapted to environments with high atmospheric pressure experiencing negative effects when exposed to Earth's comparatively low atmospheric pressure. This question is different because I want to know how to prevent negative effects from occuring with the opposite situation. Mars has ~1% of the atmospheric pressure and 38% of the surface gravity of Earth. Some Martians, who are comparable in mass and body plan to Humans, want to visit Earth for cultural exchange. But exposure to a hundred times the air pressure and nearly three times the gravity under which they've evolved will very probably kill them. Humans offer to provide them with pressure suits, but a Human spacesuit is designed to maintain high internal pressure compared to vacuum. Would a suit allowing a Martian to withstand Earth's conditions, by maintaining low internal pressure, have to be significantly different in structure and design from the spacesuits that Humans use? If she were supplied with the [CO2 and H2 she breathes](https://en.wikipedia.org/wiki/Methanogen) instead of deadly oxygen, could a Martian gear up in a standard Apollo-era NASA spacesuit with no design alterations and survive on Earth? Otherwise, what changes would be needed for the suit to maintain low internal pressure without collapsing? Also, Earth's gravity isn't really an issue addressed by spacesuits made on Earth, but even with proper (de)pressurization, would it need to provide her with additional support to stand and walk under Earthly gravity while wearing it? [Answer] Spacesuits are designed to keep an individual pressurized in a low pressure environment. What you are looking for is something along the lines of an [atmospheric diving suit](https://en.wikipedia.org/wiki/Atmospheric_diving_suit). They are designed to keep a individual at a much lower pressure than the surrounding environment. It's likely that the suit could be a lot less bulky than a diving hardsuit because the pressure differential is much lower between Earth and Mars than between sea level and 700m below sea level. [Answer] The aliens pressure concerns would likely be more similar to deep ocean divers than astronauts since there is a higher pressure outside than you want to maintain inside. This would require something similar to an [atmospheric diving suit](https://en.wikipedia.org/wiki/Atmospheric_diving_suit), rigid with bulky joints to keep the lower pressure interior from collapsing inwards. It would not need to be as strong since it is only holding out a 1 atm difference instead of 10s of atm. But your aliens might not need a pressure suit at all, trained divers have reached 534 metres deep without atmospheric diving suits. Thats 50 times atmospheric pressure. So it may not be unreasonable for your martians to survive 100 times there own atmospheric pressure. You would need to take into account some things for this to work though. Deep diving requires special [air mixtures](https://en.wikipedia.org/wiki/Trimix_(breathing_gas)) to avoid [oxygen toxicity](https://en.wikipedia.org/wiki/Oxygen_toxicity) and you might assume there would be similar issues with H2 based respiration. And compression and decompression must be done carefully over a period of time to avoid having gasses that liquified in the body due to pressure [suddenly turn back into gas](https://en.wikipedia.org/wiki/Decompression_(diving)). [Answer] Space suits are designed to endure low pressures. Dive suits are designed to endure high pressures. Simply use stuff similar to deep dive equipment. Examples: Deep pressure doesn't express an explosive risk. Matter is matter, for the most part. Diving into high pressure environment's risk comes mainly from compression of gasses or even worse, their phase transition into liquids, not from the pressure itself. So what needs to be addressed is any materials that would change from gas to liquid at such pressures. As fully-contained gasses aren't safe to evolve -anyway- (walk up a hill, vital organs go pop), most are generally adjustable as needed. The harder risk is phase transitions, at which point alternatives may be needed (such as a liquid that functions like their breathable air to their biology) The other main concern would primarily be mobility, as their locomotive method is more adapted to a less resistive substance. So, breathing tanks filled with -something-, and a segway, and training on how to use them appropriately. [Answer] All the below assumes a somewhat humanoid anatomy. As sphennings said, a relatively light suit with plastic hard panels would work. It is possible that they would only need the panels around the head, neck and torso. It really depends on how fragile the flesh on their limbs are and if they will be able to circulate blood to the limbs against the pressure. If they are from a low G world as well as low pressure (such as Mars) they may leave the pressure protection off of their lower legs anyway to help pump the blood back up to their heart. The suit would also have to be sealed. I would imagine that the O2 in the air would be damaging to their skin even if they don't breathe it. [Answer] Since you say "Some Martians, who are comparable in mass and body plan to Humans, want to visit Earth for cultural exchange", only thing you need is [SCUBA gear](https://en.wikipedia.org/wiki/Scuba_set), and tanks with gasses not poisonous to the Martians at 1 atm of pressure. If Earth atmosphere is not poisonous in this pressure, then even the SCUBA gear is not necessary, but this seems unlikely, considering how [evil our atmospheric Oxygen is](https://en.wikipedia.org/wiki/Oxygen_toxicity). This is because human-like body plan implies they are liquid (such as water) based creatures. And liquids are essentially uncompressible, so outside pressure will not crush a liquid based creature. This is demonstrated by humans being able to dive deep underwater, to tens of atmospheres of pressure, with only a few issues to be taken care of. These issues mostly involve gasses becoming poisonous under high pressure, and gasses getting dissolved in blood in high pressure, and then causing problems when pressure returns to normal. Therefore another precaution needed is, Martians need to return to their normal pressure slowly enough, similar to how SCUBA divers need to return to surface slowly enough, to avoid [decompression sickness](https://en.wikipedia.org/wiki/Decompression_sickness). The important thing to understand here is, gas-filled body cavities (lungs and ear canals for humans) need to have same internal pressure, as the pressure outside. When normally on surface, breathing air, this happens automatically, the air we breathe is at the 1 atm, which matches the air pressure of 1 atm (duh). What makes SCUBA gear special is, it is able to provide air (from high-pressure tank) automatically at same pressure as the water surrounding a diver, so the air in lungs will push back against the water pressure just right, and diver chest will not get [crushed](https://en.wikipedia.org/wiki/Pneumothorax) (too low air pressure) or [exploded](https://en.wikipedia.org/wiki/Barotrauma) (too high air pressure from the high-pressure tank). ]
[Question] [ ## Background Info One of my stories features the classic isekai trope of a person being reincarnated into a baby's body while still retaining their full cognitive abilities. The world they are reincarnated into has magic and a level of technological development somewhat akin to that of the 1600s. Otherwise, the world is largely identical to our own. Soon after birth, this person finds themselves abandoned in the woods by their parents for some reason. Thankfully, they were a Bear Grylls-like survivalist in their past life and know how to find and identify various food sources like berries, nuts, seeds, roots, fruit, and honey, while also knowing how to hunt small game like rabbits, squirrels, fish, etc. They will also be able to find clean water at a nearby river. Now, this person is of course a baby, and normally would be dead within a day. Thankfully however, being the protagonist of the story, they are abnormally talented in magic, which they can use to float their body around, dig, forage, hunt, remove skin and organs from game, protect themselves from the elements and animals, start fires, freeze food, form containers (e.g pots for boiling), produce light, and basically anything else they would need to survive. Story-wise, they could likely use magic to find their way back to a village and then be raised by people, but that is not what I am aiming for, and so at the absolute most their interactions with nearby settlements will be stealing things like bread and cows milk. ## The Diet The diet in question will be one of nuts, seeds, berries, fruit, roots & tubers, honey, eggs, and meat. They may occasionally steal cows milk and bread from nearby villages. They can cook and freeze whatever necessary in order to make food more edible, destroy parasites and bacteria, and make it last longer. They can also use magic to turn the food into mush before eating it, as they won't have teeth to chew food. They will drink clean water from a river. They may boil it before drinking if necessary. ## The Question With all that information in mind, would this person be able to grow and survive off this diet? They will not have any access to human milk, only being fed by their mother maybe once or twice before being abandoned. Please note that answers should focus primarily on diet and nutrition, any answer that focuses solely on the practicality of a baby surviving in the wild will be regarded as low-quality. [Answer] Only if it is mostly milk. Assuming they are eating mostly dilute animal milk (goats' milk is best), and mixing in some of the sterilized puree to supplement vitamins, yes they can survive on it. It's not the best but is possible. Humans infants simply cannot digest most other sources: milk comes with digestive enzymes built in; non-animal based formula has to add in those enzymes from industrial sources. Humans need a lot more iron and vitamin C than cows' - or really any animal's - milk provides. This is where the fruit and nuts can help. Animal milk usually needs to be diluted a little as it is rather dense compared to human milk and can damage developing kidneys. Goats' milk is better than cows' milk if available; it is a LOT easier for humans to digest. Cows' milk is the main ingredient in modern artificial formula due to price. Most of the processing is about replacing fats and adding digestive enzymes, vitamins, and minerals. They need to sterilize water and additives but at least a few feedings of milk must not be sterilized. Infants need some gut bacteria from at least a few non-sterile feedings. Milk from cows, goats, sheep, donkeys, camels, pigs, or horses have all been used successfully in the past so you have options. Feral goats, pigs, and horses can be fairly common (they are good at escaping) so it's not unbelievable to find some in the woods especially if it is close enough to a settlement for a new mother to travel there by herself to abandon a baby. [History of using animals' milk](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684040/#:%7E:text=Throughout%20the%20ages%20and%20until,the%20infant%20failed%20to%20thrive.) [How formula is made](https://nap.nationalacademies.org/read/10935/chapter/5) It is worth noting that even a single feeding of human milk will make the infant a lot better off, as it supplies gut bacteria and immune system priming. In a bit of morbid history, a dead mother can still supply a single feeding. [Answer] A new born baby, even though might be capable of hunting, fishing and cooking, has still severe limitations in what they can consume for sustenance. With no teeth for chewing and a rather immature digestive system, they are going to have a though time in finding a food they can consume. When in the past a newborn could not get breastfed from their mother, their hope of survival was in finding another woman who could breastfeed them. Even though the family of the newborn could provide other food, they were of practical no use. Anecdotally, my granma told me that in her times, before WWI, a rather extreme attempt would have been to feed the infant with yellow split peas puree. Also, don't forget that a new born gets, through their mother's milk, the antibodies that their body is not yet capable of producing. No matter how sterile is the food, surviving in the open would require an efficient immune system. [Answer] Only if they are older than 6 months That's the earliest that Babies can have 'real' food. Any earlier than that and IIRC their stomachs can't process it. Regardless of how much Magic the Baby has. [Answer] On top of what everybody said... as a parent of two kids who has read a lot about diet and discussed it with pediatricians and dietitian doctors, I have one more piece of data to add here. Unless you live in an environment that is too hot and dry, you should never give water to a baby that is six months or younger. And if you have to give them some water, you need to follow a pediatrician's reccomendations for water to milk ratio. That is because babies that young are really bad at regulating salinity in their bodies. Maternal milk has just the right amount of salts (and sugars, because that also regulates osmosis somewhat) to keep a baby alive. Give even just a tiny bit of water to a newborn and they can die in minutes because their blood gets dilluted. If your wizard baby is going to be eating anything other than milk, they'd better be stealing formula from somewhere or they'll have to be a biology and chemistry wizz as well to figure out the salinity and sugar ratios. By the way, I fed both my kids formula. The protein in Enfamil (my preferred brand) is about 60% whey and 40% casein, I believe. Those are found in milk. Other proteins aren't as good. Your baby wizard will therefore need milk anyway because plant-based protein won't do (ask any responsible vegan parents), and meat, fowl, egg and fish proteins aren't digestible for babies. I believe insect based protein wouldn't be digestible either. Push comes to shove, the little mage may have to use magic to either charm or bloodbend a she-goat into breastfeeding them. I do hope they do the former or you will have a severely, mentally traumatized goat. [Answer] It has been demonstrated\* (see below) that babies as young as 9 months can manage their own diets if presented with a sufficient range of natural whole foods without any adult direction. Prior 9 months (or may be 6 months or less) there would be increasing issues with the babies abilities. The very youngest of babies would not have the mental capacity to feed themselves using their hands and would be intent on suckling. However given the somewhat magical situation in which a baby was capable of levitation and all manner of other activities it is not clear how things would develop and is dependant on what assumptions you make. If it is reasonable to suppose that such a young infant has all these abilities then it is only a short step to assume that the baby actually knows what it needs for nutrition (as older babies do) and that would be milk so the baby would probably instinctively gravitate to a teat to drink milk from any available animal. If you want to exclude that possibility and ask is it possible for the baby with magical powers to survive without milk, I would say the answer should be no as the babies digestive and immune systems would not be sufficiently developed for solid (even mush) food from birth. That said if magic is involved then anything is possible. Perhaps the baby can magically modify other foods into milk. Animals have the ability to convert whole foods into milk so why shouldn't a magical baby? \* An insight may be found in an interesting experiment that was conducted in the 1920's. Although it would never be considered ethical today it demonstrated that after weaning babies were entirely capable of selecting their own foods and managing their own dietary intake for healthy growth. They were presented with a wide range of natural whole food and given no guidance as to what to eat, but were perfectly capable of feeding themselves with a well balanced diet. As would be expected as other mammals have this ability. <https://www.dishlab.org/wp-content/uploads/sites/289/2013/06/Davis-1928-Diet-in-newly-weaned-infants-1.pdf> [Answer] ## Depends on age Strongly depends on the age of the baby. Right after birth? Unprobable, since the digestive system isnt yet fully developed and couldn't handle much else than breastmilk. 6 Months+ would be more realistic. At that age babies can digest most normal food. But he still would need knowledge of what nutritons each food he can forage contains and what nutritions and in which amounts are needed for a baby his age. This is important since the neccessary nutritions of a baby differ extremly from those of an adult and a baby has a small stomach so it can eat only a small amount that needs to provide those nutritions. For other nutritions a baby can easily "overdose" and permanently damage its organs, like for example eating to much proteins (e.g. lots of meat) would lead to kidney failure of your hero, ending the story prematurely. So your hero would need: * Survival skills (you already mentioned that) * At least decent knowledge of nutrition contents of "foraged food" * Good knowledge on feeding/providing for babies [Answer] You seriously need to get some milk into that baby. Like there is no way around it. Maybe the protagonist can go around the woods using magic to detect small animals that are nursing their offsprings, then killing them and draining them of milk. Make him a completely ruthless murderer of animal mothers. That could make him contemplate his actions later on. Like with every kill he makes a promise to the forest to pay back his blood debt with his own blood or something like that. [Answer] If you're not afraid of needles and know some advanced alchemy ;-) you could perhaps use intravenous feeding: "Total Parenteral Nutrition fully bypasses the GI tract and normal methods of nutrient absorption" <https://en.wikipedia.org/wiki/Parenteral_nutrition> ]
[Question] [ Imagine a continent the size of Africa. At the coasts are sophisticated cities, where people use digital technology, electric cars, and whatnot. Travel inland, across a mountain range or through a dense forest. Here there are petty kingdoms with castles, making war on each other with swords. There is no electricity or motorcars. Travel further inland into the deep dark heart of the landmass. Here there are Stone Age tribes battling dinosaurs. So why haven't the kingdoms picked up electricity? Why haven't the cavemen picked up metalwork? This is somewhat the case on Terra: parts of Terra are currently in the Stone Age (e.g. the Sentinelese islands), but I am talking about a more extreme version. [Answer] Frame Challenge There are multiple places in the world that pretty much fulfill most of your description: International coastal cities with all the modcons - then Feudal-esque societies, then tribal-esque societies with no knowledge of Metal working. The 'common' elements as to why this happens is a combination of: Geographic isolation - in a few thousand miles, you can easily have a Mountain range or a Forest or other geographic barrier. Or you can have islands - something that will keep the most low-level tech society relatively insulated. Resource isolation - if there's nothing that is in-demand from where the Tribes people are, then there's no incentive to interfere with them. You might get the occassional Dr Livingstone esque character who explores for the sake of it - but without something to drive enough people to result in cultural/technological change, they will stay as is. No means of sharing/preserving knowledge - AKA Reading, writing and education. That's a biggy, once a civilization comes up with a system of writing, they can preserve knowledge. New learning from old books. If this is never introduced to the isolated tribe or they never come up with it - they will stay pretty much as is. Government protections - If there is an isolated tribe, it's becoming increasingly common for Governments to explicitly protect their isolation. The fact that this isn't uncommon in the real world means you need very little in order to justify it - but if you want to - some combination of those elements should be more than enough. [Answer] Most likely their primary energy sources are more expensive to harvest than is the case currently on Earth, making complex technology uneconomical except in places where a lot of economic activity can be clustered into a small area. For a real-life analogy, imagine life with oil say 5 times more expensive than today: it would still be useful, valuable and available on the market, but many things will be straight up cheaper to do in ways that do not require it. Coastal cities would be the most likely places to have more complex technology because they tend to be places where economic activity is concentrated, especially if they have a major port through which all sorts of resources are funnelled. But further in the interior, and especially away from major navigable rivers, the resources required to keep the complex economy running would soon become prohibitively expensive. Those economies would only develop to the level of complexity which can be supported with local resources and stay there: they do not have the advantages of coastal cities, so adopting a complex economy would be both more expensive and less profitable, and an inland kingdom which tried it would soon find itself being outcompeted by the already more complex coastal cities, or by their own neighbors which remained less complex, or both. The same logic applies to the tribes not adopting a medieval technology level: in their circumstances, it would have been a net loss, so why bother? Also, choosing to not develop the economy clearly works, because these medieval-ish kingdoms still exist as kingdoms and have not been overrun by the coastal communities despite their more complex technology, and the Stone Age tribes in the deep interior have not been overrun by either. So they may not even feel the need to advance technologically. [Answer] Because dinosaurs Well. The continent itself is powered by something unusual that gives animals strength of unnatural origin, the deeper in there, the harder it is to survive, and the harder it is as well to maintain technology. For example, the force powering this place is hostile to something not made by the same force, this means to electronics, glass, smelted stuff, down to clay or bones, and the only way to retain at least some man-made thing in there is to perform some actions using that exact force. So, while the coastal civilization could use electronics, petroleum, solar power, AI etc, when they perform an expedition into the depth of that continent, they all of a sudden discover that their sophisticated stuff starts hanging up or decaying, from the tiniest bits to the biggest parts. Say a machete taken by a tracker would last the entire journey, but the aPhone 8 of a tourist would irreversibly change into silicon dust within days. This hardens while people travel deeper, making any dwellers within stronger and less wanting to use technology, perhaps because of inherent conflict of that with The Force, or by some other reasons including religions. "Whatever was good enough for our ancestors is good enough for us" (c) Harry Harrison "The Ethical Engineer", quite easily could be their motto. Deeper still, and people rarely get iron smelted into a sword successfully, or probably the local animals' bones get better than smelted iron as weapons, as well as some humans manage to grasp the concept of The Force, making shamans of visible power. Further still, and maybe a single archmage could live in there, in an attempt to learn what is The Force and how to best use its manifestations, and mundane technology does not interest him anymore. [Answer] ## 'cause it's a simulation. People aren't aware of it, but they are actually bits of data existing inside a very complex RTS-style game being played by a super-advanced alien species. The game is so complex it can simulate the entire life and sentience of uncountable different lifeforms, down to the molecular level. The people that are more advanced are just those belonging to the better players, that already managed to advance on the tech tree, before the other people. In other words - those people live inside a matrix-like match of Rise of Nations. [Answer] I think you should have been paying more attention during your Progress 101 classes. As you know, we have a moral code of not intervening with the civilizations on lower levels of development, so we do not contact with the inland kingdoms for now. The only interaction is exactly via progressors we send there to study whether how prepared they are for the new tech. Fortunately for us, the coast is well protected by the tough terrain that lies between our cities and the inland, so people from those kingdoms have no chance of reaching us by themselves. From what our progressors agents tell us, these guys mostly believe that the gods have created them within this valley and they don't even wander of by their rivers to the seas: they seem to like everything they have in the valley, and all this water travel is too dengerous for their taste. So at least for the foreseable future this is not a problem. This also saves the primal tribes of the mid continent from being conquered by those kingdoms. We're happy about it, since our code would not have allowed us to intervene anyways. Those tribes are quite unfortunate in lack of important resources though: their land is warm and fruitful, but almost does not have any readily available metals, so it make them a long time before coming to the level when they could challenge the people from kingdoms were they to discover each other. [Answer] # They may be in the same place, but that doesn't mean they're in contact This country does not sit in some flat universe like our own. Instead, the country is made up of many separate realms that overlap to form a [Non-Hausdorff Manifold](https://en.wikipedia.org/wiki/Non-Hausdorff_manifold) The coastal people can drive across the country with no signs of dinosaurs or castles, and if the inland tribes venture out to the coast they will only find yet more tribesmen doing battle with the plesiosaurs Only a select few can find the shared regions of the different realms where it is possible to travel from one time to another [Answer] Quite a few aspects to cover here.. (1) To use electricity, you need to be able to produce it. For many sources that means a good, abundant fuel. The kingdoms might not have coal available and importing it from the outside world via the cities could be too expensive. If they are not importing the generator, they would not be able to build one, either. That said, electricity would not even be my first concern - they do not even use gunpowder ? There is a tech-gap of centuries here, including proficiency in manufactoring. (2) The cities might actually only be trading or coaling posts of some global society (think of the Portuguese Empire during the age of sail). They do not extensively trade with the kingdoms, because those are isolated behind the forests/mountains you mentioned. Also, the kingdoms do not have much new to offer (not even coal, see above. The tech-gap makes the feudal products uninteresting). (3) The kingdoms might not adopt electricity for cultural reasons (make up something about their divine right to rule being undermined here). Maybe it happened before and disaster struck (like a revolt or a natural disaster). The ruling class suppresses progress. (4) The advanced societies might have their own taboos against colonization, in addition to it being too expensive to be worthwhile at the moment. So the cities will not conquer the kingdoms. Maybe nearly everything outside the homeland is considered cursed land, with the trading posts being seen as a necessary evil. (5) The cavemen are again isolated, stretching the ability of the feudal kingdoms to project power (also remember, that an army in dinosaurland is not an army defending the homeland against neighboring powers). Their land is not very fertile, making it less interesting for conquest by the feudals. These lands might be rich in coal and other resources, but those resources would only help the cities, which do not venture there at all. (6) Metalworking does imply a given surplus in food production, which might not be easy to come by for the cavemen. Also, while they have seen metal (from the last expedition sent by the feudals), they do not have seen a smithy (the feudals did not bring one!). That stuff is magic. The most important aspect in my view is to prevent the advanced societies from colonizing their less advanced neighbors. As soon as that is a profitable venture, some good arguments against it are needed. Those could be cultural, religious or political. Similar reasons can be given not to provide development aid (why would the cities share tech at all?) [Answer] The formula for this is pretty simple. If the cost/risk of transporting goods and services across a geographic boundary exceeds the value to be extracted from that transportation, then it won't happen. The first problem you face is how to prevent the overpopulated high-tech areas from blasting holes in the mountains, chopping down the forests, and taking the land of the indigenous people. The second is how to keep people from transporting high-tech goods to the "underprivileged" and taking their raw materials back with them. Overall, the only thing I can think of is "because it doesn't work over there." There are a few good books with that kind of dynamic. The first is Vernor Vinge's "A Fire Upon The Deep," where the further you travel towards the center of the galaxy, the less technology works. At a certain point, your sentient computers fail. Further in, your FTL drives don't work. Eventually, you hit the point where even human thought is impossible. Alastair Reynolds does the same thing in "House of the Suns", but on a patchwork planet. In one area, horses might be the best transport you can get, while a quarter mile away, everything runs on electricity and you have flying machines. This would mean that the machines of the high-tech zones don't work in the lower tech zones. They might use their machines to make things that might work in the lower zones, but eventually the tolerances would fail them. Those who live in the lower zones might have an advantage just because they're used to those conditions. [Answer] Different political kingdoms/nations where each more enlightened realm has agreed to respect the sovereignty and ways of the less enlightened ones. If the most advanced is really highly advanced morally, they will respect rather than conquer or attempt to abuse lesser kingdoms. This respect can be instilled and enforced if need be by the highest or higher kingdoms. It might be difficult or impossible to contrive a purely practical reason for such an ongoing differentiation, so plugging in a political one instead might be the most plausible condition. Some people only consent to be ruled by a certain standard of intelligence, and this conforms to experience. Therefore the only way to ensure happiness and stability in the long term is to grant to each tribe its own sovereign extent, which of course includes the right to choose their own form of government as well as their level of investment into learning and applying useful things. [Answer] ## Its a colony world Just posit that is was a colony established by off planet settlers that was then cut off for some (unexplained or otherwise) reason from home. The most advanced cities are on the coast because that's where the original settlers landed, where the first generation of infrastructure was built - modular housing, light manufacturing and resource processing facilities, solar electricity banks and battery farms plus repair and maintenance shops for electric vehicles and aircraft etc. But the thing is these towns were intended to be the seeding points for further exploration and colonization of the interior. According to the 'plan' the development of heavy industry would follow on as the population increased and more raw materials needed to be extracted. Home would provide the first generation of the heavy plant and equipment (think steel & cement making, industrial scale manufacturing of composite materials etc), all the stuff needed for a fully industrialized society when the colony was big enough to support it's use. But tragically the problem started shortly after stage 2 began and the next generations of colonists started to push out along rough dirt trails into the interior, taking livestock and seeds etc with them. There were enough aircraft and electric trucks etc to deliver medical supplies and the basics of modern life including radios, laptops etc and solar cells but that's about it and the in-landers couldn't produce anything more complex than basic hand tools locally. The coastal towns only had enough light industry to support themselves and the initial 'push' inland but as noted previously hadn't yet received any of the big ticket/high tech items like industrial scale fusion power plants, aeronautical factories, steel mills and other complex heavy industrial engineering plant that was needed to save the colony if they stayed cut off. And suddenly the deliveries from home had stopped. No new pieces of capital equipment or high tech spare parts. No communications and no idea when or if contact will resume. Now they are they're own and only have what they have. The coast towns soon find that they no choice but to hoard what essential tech they still have. They can't replace big ticket items like aircraft or long distance vehicles when they they start to wear out, only basic essential parts (think tires etc) and don't have the infrastructure, the roads, power grids and optical cables needed to stay connected with the hinterland or make co-ordination or travel to and from there any easier. After a couple of decades the inland towns are effectively cut off. Maybe those closest to the coast can still trade for rare goods using horse drawn wagons, getting medicines and cheap consumer electronics like torches in exchange for food and minerals but in general they are all reduced to medieval levels of technology and live in constant fear of raids from other towns. Those farthest inland being even fewer in number when things went south are of course even worse off. They have been reduced to small bands of nomadic hunter gatherers living off the land. Long term, unless contact is renewed with home the only solution is for the coastal cities to slowly boot strap their way to heavy industry, but that will take many generations. [Answer] ## Frame challenge: it is "small tech" not "low tech" The technology deep inside Pangea 2.0 is superficially low tech, but actually comparable in "advancement" to the coasts. Science and engineering has generally advanced throughout human history IRL. The "dark ages" [weren't a time](https://www.getty.edu/news/no-such-thing-as-the-dark-ages/) where technology got lost, they were a partial stagnation. Not to say they were fun to live in: new ideas were dismissed and the social hierarchy was steep and stifling. Most "lost inventions", such as "roman concrete", aren't [as good](https://practical.engineering/blog/2019/3/9/was-roman-concrete-better) as they are made out to be. A large-scale loss of practical knowledge is very rare. As humanity advanced we replaced stone-tipped tools with better alternatives (stone itself is [still used aplenty](https://www.youtube.com/watch?v=Lunfjl0w6fQ)). But correlation does not mean causation: coast-dwellers would see "stone-tools" and think "primitive" (assuming the coastal people had their own stone age a long time ago). So how can we build a plausible "advanced stone age"? ## Big tech requires big resources One way to define "technological advancement" is how efficient the technology is in terms of producing goods and services per human-hour of labor. This definition is difficult to make precise because one can't easily compare how valuable "goodA" is compared to "goodB". But it is still useful as a general guide. Each "level" of technology requires larger and larger "factories" to produce, [with modern fabs costing $20 billion](https://www.csfusion.org/semiconductor/how-much-does-it-cost-to-make-a-semiconductor-fab/). In remote areas it is more efficient to be self-sufficient. Stone tools and grass huts are unbeatable in this regard. A slightly inferior tool that is locally produced could well be more efficient than trying to set up trading logistics with outside society. You still could benefit from modern knowledge: in particular germ theory and nutrition. A little soap [made from wood ash and tallow](https://www.motherearthnews.com/homesteading-and-livestock/how-to-make-soap-from-ashes-zmaz72jfzfre/) and boiling drinking water goes a long way toward keeping diseases at bay. ## Why use metal when you have nanotech? Admittedly, even a [tiny amount of metal](https://timesofindia.indiatimes.com/india/when-the-sentinelese-shun-bows-and-arrows-to-welcome-outsiders/articleshow/66913753.cms) goes a long way. But self-replicating nanotech is far more advanced! The coastal people call it "biology" but they have less of it compared to your rain-forest ecosystem. [Limpet teeth](https://www.bbc.com/news/science-environment-31500883) have amazing strength, hardness, toughness, and won't rust. They are unfortunately too small. But a larger organism with a similar lifestyle may do, more so if it is bred to have harder-faster(growing)-bigger-stronger teeth. ## 1% high tech What if you have a small amount of trade with the outside world instead of being completely isolated? You life is mostly without electricity: your mud huts don't have outlets and windows are the only AC. You hunt with spears. But you still have [cell phones](https://www.npr.org/sections/goatsandsoda/2014/07/10/330444128/maasai-warriors-caught-between-spears-and-cellphones) with a portable solar panel to charge them. Which can also [turn salt into bleach](https://issuu.com/pristinewaterindia/docs/solar-electrochlorinator), a very energy-efficient source of drinking water. ## Not better or worse, still very different Why do we still work so hard to support a week of living expenses? Can't the machines do most of the labor for us instead? There are many possible reasons: population densities, uneven wealth distribution, inefficiencies in government and businesses, higher expected standard of living, and more. Regardless, as a general rule, people still struggle to get by just as much today as the mammoth era. But there is large trade-off in both directions between 12000 years ago and today. You exchange infectious diseases for [diseases of affluence](https://www.hsph.harvard.edu/obesity-prevention-source/obesity-trends-original/obesity-rates-worldwide/). The modern world has wonderful technology. But said tech also generated an excessive amount of celebrity: A few famous people get enormous attention and swim though oceans of paparazzi. This steals audience away from the local street artist. Similarly, markets are increasingly [winner-take-most](https://www.london.edu/think/nine-reasons-why-tech-markets-are-winner-take-all) and the artisan gets squeezed. It's such a culture shock to move between these two societies. To fend off an unfamiliar set of problems or make use of such foreign opportunities is very hard. "Uncontacted" people suffer if they enter modern society (not just from disease risk) and we wouldn't fare well in theirs either. If life is different but no worse in the "stone age", and the switching costs are huge, why modernize? [Answer] There's a few dimensions that can come together to explain the disconnect in advancement across similar geographical instances, because a geography and it's advancement is heavily connected to the people residing within it. Motivation (or Leadership) What is the motivation of the population of that geography, how is the geography managed, analysed and led. What is the motivation of that leadership. A leadership focused on individuals will always create extremely biased advancement. Sabotage (or Corruption) Individuals can sabotage the advancement of the group for personal advancement. This should be an unfortunate human constant over all populations. War War is referenced in the question and also a huge indication of advancement, losing sides (in terms of geographical significance) are constantly razed and stripped for parts while the winning sides get to feed more from the spoils. Geographical Significance Some geographies bear special significance, whether in history, weather, resources etc that give them a natural competitive edge over other land masses. Culture of the Populace The culture and religion of a population can also has significant implications on how to respond to (and actively seek out) advancement. While populations based in cultures that emphasise competition, curiosity might flourish, more closeted societies and beliefs might not. Trust Factor of the Geography Is the geography supported by great adherence to a rule of law? Is the geography constantly at war (or constantly agitating for one). What is the geography's response to aliens? There's also level of education, presence of great people (innovators), chance etc that could possible contribute, this is my perspective of things. [Answer] Disease. You have different climates, the climates all have very deadly diseases to which the local population has developed immunity (think of what happened when old world diseases reached the new world.) While it's possible to protect yourself from the disease vectors people normally do not take the risk of venturing into other climates. ]
[Question] [ In the future humans have used generational ships to explore the galaxy. It's taken centuries but we have finally found several habitable planets (they are not without their challenges of course). On one such planet we discover a great machine, essentially a giant cylinder in the ground. The 'walls' are 100 meters thick and packed with machinery and what appear to be control rooms. It is clearly very old, the best guess is 50,000 Earth years but it's impossible to say for sure. The hallways and ramps were made for creatures of roughly similar size to ourselves, with ceilings around 5 meters high. There are some remnants of a civilization on the surface - tunnels, worked stone, channels in straight lines, etc - but nothing that provides any real clues as to who they were. We conclude that some rooms are control rooms because they have flat sections on the walls and sliding panels with a rippled texture that seems to respond to touch - no buttons or knobs as we know it but they do seem to be some sort of input device. For the purposes of the story, the ancient aliens wanted future civilizations to have access to this device. The question is, how would they leave instructions for working this incredibly complex machine such that any type of life form would be able to understand it in the far future? My assumptions about the aliens: * Roughly our size based on the Earth-like gravity of the planet, say between 1-3 meters tall. * They evolved a way to physically manipulate tools with precision * They have senses to detect and interpret light and sound * Highly advanced technology with the ability to generate large amounts of energy and the ability to produce any material that we (humans) know of * They have explored large portions of the galaxy * They were aware of other life forms that evolved on various planets and could identify general common traits among these As a bit of background, the device is used to fold space, allowing for instantaneous travel. The aliens used a type of Dyson swarm to capture energy and had incredibly advanced methods for storing this energy. The machine is fully intact and has access to stored energy to operate, also intact. For the purpose of this question please assume that the science behind the generation ships, the space-folding device, habitable planets, and the Dyson swarm are all explained in the story. It is OK if your answer requires additional assumptions about the ancient aliens, their specific traits are not relevant to the story, merely the fact that they existed and left this device for us to find. Note: I found some similar questions, like [How could an ancient race warn the future in a universally understandable way?](https://worldbuilding.stackexchange.com/questions/105852/how-could-an-ancient-race-warn-the-future-in-a-universally-understandable-way) discussing leaving messages over long periods of time but I don't think it quite matches what I'm looking for. Apologies if it's too similar. [Answer] Avatar [in Hindu belief, a manifestation of a deity or released soul in bodily form on earth; an incarnate divine teacher](https://www.oxfordreference.com/view/10.1093/acref/9780198609810.001.0001/acref-9780198609810-e-531) Your machine would pay attention to the beings that entered the control chamber. It would quietly learn how they looked, moved, smelled and sounded. Then it would produce a being in the likeness of those it encountered. It would be different enough not to be weird. Maybe it would make up some purposeful differences. It would still be kind of weird. The avatar would learn more from the people. It would learn their ways and language and modes of communication. Then once it had learned enough, it would teach. This would be a fine way to teach aliens if you had AI good enough to learn from the aliens. Also an easy way for an author writing a fiction, because the avatar is a character. --- short squib inspired by this scenario <https://www.fictionpress.com/s/3355296/1/avatar> [Answer] I an making the assumption that the aliens will communicate via visual and audio media. For example, alphabets, pictures, videos, sound. If they communicate via farts and dance then the same principles hold although it might take humans a little longer to understand instructions. On that assumption the solution is probably 'via baby-steps'. Imagine you wanted to explain to humans with no technical background how to use a fairly complicated piece of machinery - lets say a programmable multi-axis milling machine. You wouldn't just hand them a manual and let them go to it. You would start by training them in the use of hand tools, the difference in properties of aluminum, copper and tool-steel etc. Then you would introduce them to manually operated lathes, drill-presses and mills. At that stage you might give them a course on interpretation of technical drawings, expanding to CAD design tools. Finally, once they had all that under their belts, you would demonstrate the use of the fancy automated milling machine before letting them loose on it. I would expect the aliens to follow a similar path. So... Step 1: a symbolic language based on maths, geometry and physics to teach you their terms for numbers, true/false, greater than/ less than/ left/ right/ up/ down/ hot/cold etc. At the end of this step you will have a simple understanding of a base language. Step 2: using the symbolic language, expand the language into 'practical' communication via video, audio, showing simple scenes of the aliens communicating with each other. At the end of this step you should have a fairly detailed understanding of their language. Linguists and explorers used similar techniques to learn the languages of other people they met with no common language in the past. Step 3: technical training and practice. Basically learn the concept of what the machine does, even if you can't understand why it works. And learn by controlling simpler non mission-critical equipment. "stroke this symbol to get water from this aperture", "adjust the weenix until the grobulator bisects the frabulation", "mind-meld with the..." you get my drift I am sure. So the aliens give you 'terminals' or control systems to practice on with feed-back. You need to pass tests before you are allowed to use the next more complicated bit of equipment. Step 4: Finally: you now get the detailed manual and access to the matter transmitter or whatever. Initially it might have limited power until you show you can use it safely. The only problem will be if the alien's way of thinking is so different from ours that we cant understand the way they think, or if control of the equipment is too difficult for us to grasp. But if the3y want us to be able to use it, and have had long experience communicating with other alien species, then they are probably capable of 'dumbing-down' the controls and concepts sufficiently for us bipedal apes to grasp. [Answer] Don't underestimate the difference in knowledge required to understand how to work a device, from that required to understand how a device works. Humans - even extremely non-technical ones - interact with a range of complex devices every day without scratching the surface of how they work. Computers and smartphones are the canonical examples, but when's the last time you worked an elevator, or an electric drill, or the traffic lights at a pedestrian crossing? In all of these cases the device has been explicitly designed with the goal of making it usable by people who do not need to fully understand how it works, which means a considerable amount of 'dumbing down' and simplifying the wide range of possible behaviours and making a 'sensible' subset of them available with a set of very simple, very obvious controls. The challenge, then, is to clearly communicate 1) what the device is supposed to do, 2) what controls are available, and 3) how the controls map to functionality. The best method for all three is demonstration. Just like how many millennials will now instinctively turn to Youtube for a demonstration of how to use their new [drill](https://www.youtube.com/watch?v=M9S1pToPaQA)/[camera](https://www.youtube.com/watch?v=O-fNGxaGtto)/[laser power tool](https://www.youtube.com/watch?v=sdACSB8GH3Y)/[military hardware](https://www.youtube.com/watch?v=nP82xPoaZlU), rather than digging into the full user manual, so will your adventurous humans learn a lot more from a holographic projection of an Ancient Alien going through the motions of using the device, than they will from any written manual. Encouraging 'learning by doing' shifts the exercise from one of painstaking research to intrepid discovery. Whether the device is actually safe to experiment with in such a way depends on its design: an elevator is a lot safer to operate in ignorance than a press brake, despite them having broadly the same basic structure! [Answer] Assuming the aliens planned to leave the device behind to be discovered they have any number of options. The key point/question though is how far in advance did they make those plans?. Note - in all cases the stone artifacts etc were probably left simply to attract inquisitive aliens to the burial site and do not serve any other purpose. 1) Did they build the device in the first place with the intention of leaving it behind? If so then the machine will have been build with the best internal 'teaching' subroutine they could devise. The machine will be programmed to project and receive messages in as wide spectrum of frequencies, sounds and tactile sensations as possible and will have an elaborate AI to run it. Their version of SIRI in other words. It will also have multiple types/settings for its control panel options - which BTW may also explain why there are lots of control rooms (e.g press a panel in control room No. 3 and it floods with water and has acoustic controls). 2) If the machine was already built when the decision was made to leave it behind but time was not pressing. They could build a library of written instructions and place it on a suitable asteroid or moon. Say something carved into titanium or carbon plates and left perfectly preserved in vacuum. Then they just leave a map of the solar system inside the device with the orbit of the body concerned clearly marked and a giant sign post on the orbital body itself saying 'here lie the operating instructions. This also has the advantage BTW of confirming that the species which found the device is in fact space fairing and not a locally evolved, more primitive native species. Anyway instructions are in the form of pictograms including detail maps of the device, its control circuits and what the device does. In as many varied ways as the aliens can devise. (I did say library). 3) Lastly if it was buried in a rush. All they can do is place a similar but more compact set of instructions (e.g how to turn on the computer) inside the device and then program the computer to be as flexible as possible and the controls as simple to use as possible in the time available. Then hope of the best. [Answer] I know you've already linked "How could an ancient race warn the future in a universally understandable way?" - I'd encourage you to read through the ["Expert judgment on markers to deter inadvertent human intrusion into the Waste Isolation Pilot Plant"](https://digital.library.unt.edu/ark:/67531/metadc1279277/) report. It makes some very interesting points about super-long-duration structures and documentation - for example, that you don't want it to be scavenged for building materials, and that future civilisations might not read left-to-right or might not know what an arrow is. Of course, in a way you'll have an easier time if your world already has an explanation for a fully working 50,000 year old machine - it must be self-repairing and nigh-indestructible to have lasted that long, so there's no rush to teach users how to repair it. I would suggest you probably want not instructions, but an interactive tutorial with gated capabilities. For example, at first there's only a single button, and it gates you to a fixed, safe location 3 miles away when you press it, and gates you back when you press it again. To enable extra abilities, you have to go through challenges, where each challenge proves you've got what it takes to figure out the abilities for yourself. Want to gate to a destination based on a map? Gotta prove you can understand a map, by following a map to retrieve a macguffin. Want to gate to somewhere without oxygen? Gotta survive 20 minutes in an airless room to enable that option. Mess with the machine's parts? Gotta show you know about precision machining first. Some of the challenges could be foundation-building for later challenges: Perhaps you can gate 10 miles if you can answer grade school math problems in the aliens' notation, 100 miles for high school math and 1000 miles for degree-level math. That way, even if initially the future society doesn't know which end of an arrow is which, they'll gradually be taught what they need in order to understand the instructions. [Answer] Assuming that they have eyes, a pictorial instruction manual might work. Start with pictures of the machine itself so there is a common reference point. And zoom into various rooms so it is clear where they are, then zoom into screens and provide pictures of button sequences with pictures of the out come. Pictorial background information could also be provided to explain basic concepts like numbers, the relative positions of planets and stars, time intervals and more. Even better provide a video of the builders actually running through all of the steps necessary in sequence to power up the machine together with the outcome. [Answer] ## Show, Don't Tell There have been plenty of discussion on this site about the difficulties in leaving warning signs or instructions for future generations. Even assuming that the person who sees your warning or message is the same species as you, when you are talking about thousands of years in the future you just can't account for cultural shifts that could make your warnings convey the wrong information or just be indecipherable. Add in entirely different species with possibly different sensors and manipulators and definitely different cultures, and you pretty much can't expect any written or pictorial message to be able to transmit the information you want. I would say that is especially true for something as complicated as a giant piece of machinery. Luckily we are not stuck with just single images to convey information for the future. I would suggest that a video showing how the machine is used would be much more helpful for anyone who discovered it. You are still going to be making some assumptions about the sensory input of the people that discover your machine, but there is not much you can do about that and it might even be a good thing. If this ancient race knew about other intelligent species they might have purposefully left their messages in a format that only the "safest" (in their opinion) races would be able to interpret. Sure, they could have included smell-based instructions, but that race of light-blind hyper predators would be more likely to use the machine for war and conquest so better make it harder for them to understand it. I would suggest having multiple types of recordings based on the kind of species that discovers the machine, and what they are doing with it. The builders would want to have a bit of a bootstrap sequence built into the setup, so that certain actions would unlock new recordings. The simplest would be a recording on a loop that shows how to activate the machine. If someone can follow the steps to do that then you can give them more recordings because you know that you are actually conveying information. Each subsequent set of recordings would have more information on how the machine is operated, as well as some gatekeeping procedure that unlocks the next level of recordings. At a really high level I would expect it to look something like: How to turn on the machine -> How to use the machine -> How to customize/configure the machine -> How to build your own version of the machine All of that really depends on what the machine does, but the basic concept should work for just about any functionality. You just need to add more or less steps as appropriate. There is an added bonus to using these recordings as they can convey a pretty in-depth look at the original species from an anthropological perspective. Anyone who discovers the machine will be able to see what the builders looked like, what kind of design choices they favored (e.g. purely functional vs intricately detailed), what they thought was basic information, and what order they gave information about the machine in. All of that can help give a better picture of their society and possible reasons for leaving the machine behind. A race of hyper-engineers might have a purely functional design for the machine, with no embellishments or designs, and their boot strap order might be "turn it on, configure it, produce parts, build a second one". Very straightforward with a specific goal in mind. On the other hand an advanced but artistic race maybe have more focus on the architecture of the machine and decorate every surface and their startup sequence would be geared more towards general understanding of the machine without a specific goal for its usage. "Turn it on, make something, change a setting, make something else, repeat." You could still work out how to build a second machine if you wanted to, but it wouldn't be the explicit goal like with the engineers. ]
[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/174582/edit). Closed 3 years ago. [Improve this question](/posts/174582/edit) [![](https://i.stack.imgur.com/jq9IJ.jpg)](https://i.stack.imgur.com/jq9IJ.jpg) Only hearing, smell and sense of touch would be affected, visibility/eye-sight would be unchanged. (effects are temporary) Melee weapons : spears/polearms, swords, something something magic melee weapons.... Projectile weapons : bow & arrows, catapult, wood cannon (mostly useless), something something magic projectiles... Battle tactics : line formations, classic cavalry-infantry-artillery divide.... [Answer] Lethal Smell isn't the most important, but touch and hearing are. Touch represents all the tactile sensations in battle - i.e. your grip on your sword, for instance. Admittedly not much of a problem on a modern battlefield, given that you don't do a lot of clashing hand-to-hand, but on the ancient battlefield, this makes you sloppy, and sloppiness gets you killed. Not like it makes much of a difference because lack of hearing will get you anyway. Eyes can only alert you to what's in front of you. That other basically 270 degrees of vision? It's the ears. Not to mention that ears are good for the relay of information, and if you can't respond to orders, you can't survive. I suppose you might be able to use vibration-based morse code to give orders - except since touch is out, you can't do that either! The only way to communicate would be by sight, which has it's drawbacks, mostly because if you're looking for someone trying to talk to you, you're ignoring all the people trying to stab/shoot you. Long story short, touch and especially hearing are really important for humans and sensory deprivation is a death sentence, especially against opponents who aren't sensory deprived. [Answer] One from column A one from column B: I think both Demigan and Halfthawed each have half the correct answer. The fuller picture I think largely comes down to timing. 1. If the alt-chemical agent takes effect during an active phase of battle, while soldiers are actually fighting, then I think FATAL is the right answer. Loss of hearing & smell won't affect much, except that soldiers can't hear the bugle calls. The loss of touch will be far more important. Without it, you would have little sense of proprioception, because you can't physically feel where you are and can only orient by sight. You'd fumble with familiar objects, like sword or mace or bow and not be able to wield them effectively. You'd be as likely to be hit by a fellow soldier as by an enemy and would also be at risk from slashing or bashing yourself. You'd not be able to walk, let alone navigate a battle field (look into diabetic neuropathy) and would not be able sense changes in terrain (dead bodies, broken bits of weapons & fortification works) and will most likely stumble and fall and break an ankle or suffer some other debilitating injuries within a few minutes. The melee would become a crawl fest of soldiers lying down or creeping about trying to kill each other. Until they finally give up the cause as even more vain & stupid than a regular battle. 2. If the alt-chemical agent takes effect when soldiers are in camp or arrayed before battle, then I think STOP THE FIGHTING BEFORE IT EVER STARTS is the right answer. Whoever is down wind of the agent will simply not be able to engage in the fight and if they try, will not be able to put up any kind of effective defense, because of the agent's effects. They won't be able to properly equip themselves or move into their positions because they can't feel anything. If the wind remains constant, then the aggressor might be able to safely cross the lines and all but slaughter the affected foe. Breezes often shift, however, and it's more than likely that the aggressor will get a taste of its own weapon. Neither side will be able to field an effective army and it won't take long for even the most pigheaded of field marshals to realise that use of this weapon is dangerous for both sides and a monumental waste of effort. These general effects are timeless. It doesn't matter much if you're trying to strap on greaves and a helmet or knocking an arrow to bowstring or if you're trying to drive a tank or enter commands into a guidance computer. The loss of the sense of touch will make you a very ineffective soldier. [Answer] It would likely stop the fighting for the most part. 1: communication stops. Only visual communication would still work which is great for large-scale combat but for the small-scale "there's something over there is it friendly or not?" Communication its a lot less useful until we have augmented reality like technology. 2: smell is heavily tied to memory, but I don't think it'll be a big loss. 3: touch is rather important. Even if other senses like proprioception aren't affected touch is incredibly important. (proprioception: he ability to know where your limbs are in relation to your body, touch your nose with your eyes closed). In trials where people's sense of touch was deactivated and they were tasked to grab something while not being able to see it they were unable to do so. With touch activated your hand will feel the object and be able to let the rest of the hand close around it without moving it. Without touch you push the object and don't know when you have to close your hand around it. This causes problems in many area's. If you walk across ground you dont feel how much pressure you put on it, how slippery it is. If you lift a weapon you have to look at it in order to get your hand on the trigger (or a button, a steering wheel, control stick etc) and grab it correctly, but since you don't feel it you don't know when you squeeze or push it, how much pressure you put into it when steering a vehicle or craft. You don't know when you will fire your weapon(s), you don't know when you'll move across something that makes you slip and fall. I don't think that people will be able to fight in those conditions especially if they are deaf as well. [Answer] If this was to become common, it would likely affect the way units are formed and move tactically. The classical Phalanx essentially packed all the troops into a sardine can like formation where not only were you protected by the shield of the man beside you, but the impetus of the file of men behind you actually was used to drive you forward into the enemy. Soldiers also had some protection from the spear points of the men behind them over their shoulders and providing a bristling "hedge" of spearpoints. The men in the middle of the Phalanx effectively were blind and deaf during most of the battle (their sight was limited by the helmet, the bodies of the men around them and clouds of dust raised by the struggling men, while their hearing was also limited by the helmets and the clash of bronze on bronze and wood, or the screams of the wounded and dying. A unit trained in this mode of fighting likely isn't going to be negatively effected by a spell or chemical agent acting in the way the OP describes once in formation and on the move. [![enter image description here](https://i.stack.imgur.com/GCZHD.jpg)](https://i.stack.imgur.com/GCZHD.jpg) Classical Phalanx Since I am unclear of the effectiveness of this spell/chemical, it is also possible that fast moving and dispersed units like horse archers might also remain effective. Their ability to see and engage targets by archery isn't likely to be affected, although how well they can control their horses might be an issue. Even so, they could simply come to a halt and shower the enemy with arrows while slowly retreating until the effects pass. Samurai (at least early ones) were also trained as horse archers (Bushido can be roughly translated as "the way of horse and bow"), so would have similar tactical responses. The main difference is a Samurai will spend the extra time while stopped to aim and hit his specific marked target rather than count on something like an arrow storm. [![enter image description here](https://i.stack.imgur.com/x1fBm.jpg)](https://i.stack.imgur.com/x1fBm.jpg) We can still see you as well [![enter image description here](https://i.stack.imgur.com/Kb4W4.png)](https://i.stack.imgur.com/Kb4W4.png) He can see you as well [Answer] It might be highly effective against cavalry. Not much effect on humans, unless you knocked out things like sense of balance along with hearing and proprioception along with touch, but horses would likely be totally spooked and panic -- unless, like horses trained to tolerate gunfire, they had previously bene exposed and habituated. [Answer] The sense of touch may be important for another reason. The sense of pain. This is actually carried by a completely separate set of nerves, and can be lost independently of the rest of touch, but.... Without a sense of pain, warriors would not know they had been hit unless they saw the injury. They might well keep right on fighting until they died. (Though proprioception might let them know they are not moving correctly.) ]
[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/119228/edit). Closed 5 years ago. [Improve this question](/posts/119228/edit) I've done some research on the question and found [this,](https://worldbuilding.stackexchange.com/questions/77624/what-would-be-a-reason-that-two-superpowers-at-war-would-not-claim-a-perfectly-g) but unfortunately those questions refer to a Cold war. This war in my question is very hot indeed, a stalemate that's lasted over a decade with both sides fighting on the same front lines since the war began. Casualties are countless and neither side is willing to surrender. ## Background Information This world is Earth in the year 3000. SEDA is the first faction, GRP is the second. SEDA takes up most of Asia and Oceania, and the Western half of South America. GRP takes up Russia, Africa, and the Eastern Half of South America. New Venice is a neutral third country, located in what is now Hawaii. Abandoned areas comprise Europe and North America, as neither faction lays claims to these lands for one reason or another (resistant locals or large amounts of radiation) These two factions take up most of the world. Each of these is made up of a number of smaller nations, but effectively they function as a single political entity. ## The Question It would be in the interest of both factions to claim the nation as their own, adding the island's production and manpower to themselves and utilizing it as a potential jumping-off point for any future invasions. However for whatever reason they choose leave New Venice completely self governing. I've looked at real-life instances of neutral countries being left alone by a hostile force, but so far the reasons I can find that resulted in them being left alone don't really apply to my world. A good example is not wanting to antagonize the rest of the world. In this scenario, there isn't a rest of the world to antagonize. Both sides are at total war, and the relationship can't degrade past that. The solution doesn't have to be permanent, it just has to last for at least a decade. [Answer] Throwing away the shame of the international community, which in your case consists only of the enemy and the invaded country, I think the explanation lays in the strategic equilibrium: new Venice is small, but adding its contribution to one of the parties involved would resolve the war in favor of the alliance. Let's explain this concept with some numbers, and assumptions: * the side with higher score wins. Equal score cannot be decided * the score of an alliance is given by the sum of the scores of the components If A and B are superpowers, let's say they score 100 each, and are thus in equilibrium. Now the third small country C is just a feeble 3. Any attempt to attack C, from either A or B, will result in C joining the other side and breaking the equilibrium. Since both A and B are aware of this situation, they respect the neutrality of C to prevent the country joining the other side. [Answer] New Venice is a tax haven, and the leaders of both sides have got their corruptly gained money stashed there in numbered bank accounts. Neither of them is going to risk invading, and losing their money or (worse) having the banking records made public. [Answer] I'm missing one point that was quite a significant reason during WW2 for leaving Sweden neutral: both sides keep contact with them so it might be of a use for throwing some offers to the opponent (like temporary cease fire, exchange of POW or spies etc). It might be also easier to use neutral country to pass spies through it. You're definitely interrogating anyone crossing the border with the neutral country but if someone crosses the hot red front line, he's simply shot without asking too much questions. There might be some very scarce but critical resources that are available each only on one side of the front line. The conflicted nations won't trade directly, but then they can trade with the neutral country putting a blind eye on an actual source of the resource (and since the one I buy is critical to me I can trade the one that is critical for the other side even knowing where is it going to be sold). TL;DR Sometimes it's good to have an intermediary who is neutral for being able to keep limited diplomacy, trade, prisoners exchange etc. [Answer] There could be several reasons and you could pick your poison of choice. Firstly New Venice is far. Pretty dam far from SEDA and GRP. Its main advantage would be as a staging point to launch an attack on Oceania or South America but that would require a significant investment. Your fighting should be focused around or near South Africa as that seems to be where the land between the two nations is closest together. If you wanted to use New Venice as a stage to prepare for an attack you would need to move your ships and aircraft across the entire world and that is a lot of manpower that has been removed from the front line which could cause your front line to fall apart. At best New Venice would be a very small base that could be used to supply a ship or two for scouting or minor harassment however the cost to capture the island, develop the infrastructure and regularly ship weapons and fuel to New Venice would quickly outweigh the benefits of minor harassment along a heavily defended coast. Its also a stalemate for a reason. Both sides are equal. Diverting manpower from the front lines could break this stalemate and once your opponent gains momentum or a advantage you quickly start to fall apart. Small squads might not be powerful enough or well resourced enough to take control of New Venice and its always possible that both sides have active agents in New Venice but they just undermine each other, rather than trying to take control. Aka, they are simply preventing the other side from capturing New Venice and hence it never falls under either of them. New Venice could have some military might. If you wanted to take New Venice you would require several ships which could be better used else where. You might suffer losses which would be important to maintaining the stalemate and even worse, your opponent might just be waiting for you to suffer losses from New Venice so they can wipe you out and take it over without as much risk. Finally New Venice needs to have something that can justify the cost of capturing it. As a fairly small island its going to be hard for it to have the resources and manpower necessary to justify an invasion. Even if it had valuable materials, if they were to destroy the machinery that gathers it, then you are also at a loss and risk losing the war. tl;dr New Venice is too costly to invade and develop due to distance. It diverts important resources from the stalemated front line onto a small island where you probably won't get any return and will more than likely suffer losses if you take the initiative to attack. Even after you occupy it, it doesn't offer any special resources or attack routes that significantly weaken the front line without you heavily investing into it first. [Answer] There could be several reasons it's possible The if either one Attacked new Venice they would face a war with the other superpower, As taking of new Venice would disrupt the balance between them. Alternatively if the new Venice army is powerful enough they could fear That their forces could do enough damage to either super power to render them weak enough to be destroyed by the other super power. Another answer could be some form of nuclear weapons or other weapons mass destruction. New Venice could still be smaller and have weaker military yet have enough nuclear weapons to whipe out either superpower. In this case attacking new Venice could result in Mutually assured destruction. [Answer] I'm surprised this hasn't been brought up: Switzerland. This is a very long story, but to keep it short the bullet point are: - Swiss neutrality is a product of a congress of Vienna, where the superpowers of the time, war-weary, were looking for ways to maintain peace. Thus the idea of buffer states was born, and Switzerland was one of those, namely between France and Austria-Hungary (and also part of the buffer zone between France and German states). The same, in a way, happens here: because of geopolitics you presented, neither party can afford the other to control Hawaii, as well as several other islands on the Pacific. The only reasonable, stable solution is that neither control them. - Swiss supported their neutrality by economical means, mainly their superb banking system. The New Venice does the same, only instead of banks, they do that by supporting strong and safe Pacific ship and air trade. Noone wants to disrupt that, it is simply too costly. - Swiss has maintained incredibly strong defense posture for the last 200 years. This is a material for a book on its own, suffice to say that they put every penny they could, and in a smart ways to boot. Again, New Venice does the same, only instead of mountains they have an even better thing: the ocean. Surface fleet, submarine fleet, airpower, sea mines, you name it. So sure, either superpower could conquer them - and pay such incredibly high price in money, man and equipment, that this would leave them vulnerable to the other superpower. [Answer] Here's one option: maybe New Venice has some sort of religious significance. If both empires adhere to a certain religion, and New Venice is seen as a holy place, then they may resist the idea of "desecrating" it with military might. You could even make the history part of the background. It seems like you're going for the nuclear apocalypse/dystopia approach for the story. Perhaps the nuclear weapons were launched from Hawaii and now the place has taken on a mystical aura of danger and evil. Alternatively, perhaps it was a peaceful place during the war, and now it is a sanctuary. Breaking the thousand-year-peace would be unthinkable for many. [Answer] New Venice is a society of merchants. They sell absolutely everything. And they buy even more, particularly intel. For years they have attracted scientists, mercenaries, spies, defectors, entrepreneurs, inventors. Because of that, both factions became dependent of the island. Most of their technology come from New Venice and their intel is acquired thanks to the merchants. But, here is the catch. The merchants of New Venice have designed a protocole to send the wholeness of their knowledge in case of an attack. In mere seconds, everything they know, every plan, every blueprint, every insignificant rumor will be broadcasted to the opponent of the aggressor. Of course, both factions tried to design plans to try to take the island subtly, but the merchants's technology is too advanced, their spies too well informed, and they rigged too many gears of both societies to be really worry about the possibility of an attack. Because of New Venice indubitable superiority, both side of the war are too afraid to try anything against the glorious city ! [Answer] Due to its location, having control over New Venice would give the controling side a big advantage - so big in fact, that it would probably cause that side to win the war. Because of this, both SEDA and GRP are permanently targeting New Venice with some kind of weapon of mass destruction. Both know this of each other and both know that as soon as they invade the island, the other will destroy it. So the reason for both SEDA and GRP to leave New Venice alone, is that invading it would be a pointless (because once you've taken the island, the enemy will just destroy it completely) waist of resources. To make an invasion even more of a bad idea, you could say that it would likely trigger a [MAD](https://en.wikipedia.org/wiki/Mutual_assured_destruction) scenario - after all, if you've just nuked that nice little island I got, I can't let that go; I'll have no choice but to nuke something of yours. [Answer] There are massive political advantages in having a neutral party, and they far outweigh the small strategic or economic advantage of conquering them. The advantages include a neutral ground for meetings and exchanges on all levels of the political hierarchy including the secret services, military intelligence and other "deep state" elements. They also include economic and technological exchanges which, despite the state of war, might continue. American companies sold oil and trucks to Nazi Germany during the WW2, through Switzerland. This might not be in the interest of military or political leaders, but the people who profit from it may be influential enough to protect the neutral state from being attacked. In the end, the disadvantages of conquering the neutral state simply need to outweigh the advantages. And especially if the war is hot, diverting forces from the frontline to an adventure that doesn't yield a strategic advantage in the main war is something that even if the leaders want the invasion would be postponed again and again. After this campaign. After that defense. When we have restocked. When the fleet is back... [Answer] New Venice, as distant successor of the American Empire has inherited the launch codes for the Automated ICBM silos and KIW satellites that still orbit the globe. Now, no one, not even they know how many are actually functional. It's tough getting there to check what with the radiation and the being in space, but those Americans built to last. Whichever side gets hit is going to be rolled up pretty quick, if there's anything left to take. [Answer] The third country is being used to fight a proxy war. The two superpowers realize that any direct conflict will lead to huge losses of life and devastation of their economies. This situation is not in the best interest of either side. However, they still want to prove their dominance over one another. They do this through turning a civil war in the third country into a proxy war. Specifically, Superpower A sends funding, training, military intelligence, and weapons to the government of the neutral country. Superpower B provides the same benefits to the rebels in that country. It is in the interest of the government and the rebels in the neutral country to accept help, because they want to win the civil war. It is in the interest of the superpowers to send the help, because it is a way for them to prove their superiority without risking the lives or wealth of their own citizens. [Answer] The current leader of New Venice would rather die on his feet than live on his knees. He has sunk New Venice entire nuclear arsenal several miles underground, warheads spread evenly across the island. If a singel Grunts boot touches New Venice sovrien territory he will sink the island to the depths of the sea. No one dares question his resolve after he sunk the offshore artifical island airport when a single SEDA aircraft landed without permission. If either side tries to invade they will lose all resources invloved, tipping the balance of the overall war and gaining nothing in return. The 10 year limit clause: The king of New venice is a vertan of the last war. Now an old man he has seen what happens to "allies", how thay are used and are first to be sacrificed, he will not allow such a fate to befall his beloved people. He is a natural leader and much admired by his people, they feel his totalirian position on mutual destruction is somewhat extreme but trust in him enough to follow along believing he sees the bigger picture. His son the Prince has grown up in times or relative peace, the MAD scenerio leaves New Venice effectivley untouched by the war. He is more naive, more willing to listen to the SEDA and GRP envoys and willing to open a dialogue. When ill health takes the stoic king (at the 10 year mark) and the prince takes the throne both sides see the oppertunity to move knowing he lacks his father resolve to follow through and sink the island. [Answer] Here are a few thoughts that might spark ideas: Plague Ship: there is some sort of incurable disease endemic to the island. The islanders have immunity but an invading force would risk infecting the rest of the world - their faction first. Blackmail: similar to the banking/trader suggestions above, New Venice knows something that each side doesn't want known. The bank accounts work, the trading knowledge works. Maybe New Venice has a great spy network. If either side invades, New Venice will provide intel to the other side that will allow them to break the stalemate. Maybe, years ago, New Venice demanded or took hostages in return for trade privileges. Scorched Earth: New Venice provides something that both sides want or need. New Venice knows that they can't win a war with either side but has rigged their island with nukes. If it looks as if an invasion is about to be successful, BOOM! The entire island goes up destroying the entire invading force and denying both sides the valuable something. Porcupine: This is covered a bit in some other answers. New Venice is too weak to be a threat but it is remote enough and well-armed enough that it would be too costly to be worth invading. Particularly when both sides have all available troops devoted to maintaining the stalemate. ... and it doesn't have to be just one answer. Several of these factors could come into play making the overall cost/benefit analysis come out negative. [Answer] The easy answer is that, geopolitical considerations gone, the cost of invasion and occupation is more than the island's worth as a source of manpower, resources, and as a base for further invasions. The even easier answer is that New Venice has nukes. Given that the two superpowers haven't wiped each other out yet in a hot war, it is assumed that at the very least, they have developed countermeasures to the nuclear triad to render MAD obsolete. I assume that they didn't just dismantle all their nukes or they're just mock fighting 1984 style, because there is close to no rationale for the former(they would still have nukes considering China and Asiatic Russia are still around) and the 1984 population control scheme isn't mentioned in the question. While nukes couldn't have been used to directly dissuade opposing powers to stand down at costs to their population centers, it could be a force multiplier to wipe out any potential invasions, making the cost of invasion far too high. After all, it's really hard to shoot down a nuke when it's already in place when the invasion starts. If you're asking "how did they get nukes?", think about the huge nuclear arsenal of America. Given that Hawaii is the only state of the U.S that wasn't bombed to death, where else would the American nuclear sub fleet go? In addition, I'm willing to bet that in a wartime scenario, there would already be nukes stationed in Hawaii. ]
[Question] [ A world/continent/land/place/location where language has developed slightly differently from earth. Instead of communicating through normal speech, these beings communicate in a combination of vocabulary and pitch, almost like a song if you will. This means that one word can have several different meanings based on context and pitch. (For the purpose we can assume the people who speak this language aren't tone deaf and are all except very few able to keep proper pitch while communicating. My question about this is how the written language would look like. Can written text somehow incorporate the right pitches for each word or even syllable? Is it even feasible to structure a written language based on this concept that has any practical applications or would communication likely take another turn? If written text is feasible, I'd like to avoid a massive alphabet like the Chinese. [Answer] Just to clarify: [tonal languages](https://en.wikipedia.org/wiki/Tone_(linguistics)) and [pitch-accented](https://en.wikipedia.org/wiki/Pitch_accent) languages already work like this. Speakers need not be able to keep perfect pitch in order to speak them properly since pitch/tone are always relative. Real-life languages work on the basis of contrasts between features and pitch/tone is no exception. Words in such a language are distinguished by pitch/tone in the same way as they are distinguished by the order and quality of their phonemes. Writing systems can and do incorporate a lot of information but also leave out many details. No writing system perfectly transcribes a language, be it tonal or not (it's simply not possible). There's nothing in a tonal/pitch-accented language that says it must have a terribly complicated writing system. In particular, there's nothing that says a tonal language must resort to Chinese-style characters; Chinese characters do not, in fact, convey tonal information per se. Some real world examples: * [Thai](https://en.wikipedia.org/wiki/Thai_language#Script) (which is tonal) has 44 consonant letters and 9 vowel letters, plus five tone marks. It's not the easiest orthography but it's not remotely as complex as Chinese characters. * [Vietnamese](https://en.wikipedia.org/wiki/Vietnamese_alphabet) (also tonal) has 29 letters in all, plus 5 tone marks (the sixth tone is unmarked). The script is based on the Latin alphabet and looks fairly confusing when diacritics pile up, but it's more regular than English. * The [Tibetan alphabet](https://en.wikipedia.org/wiki/Tibetan_alphabet) is used to write some tonal languages, even though Tibetan had no tone when the script was invented; tone is not indicated by special marks but can be usually deduced from the spelling, since some letters indicate sounds that are no longer pronounced but have evolved into tones. * Japanese (which is a pitch-accented language) employs a mixture of Chinese characters and syllabic characters, none of which convey any information on pitch whatsoever. True, there are very few [minimal pairs](https://en.wikipedia.org/wiki/Minimal_pair), so there's very little room for confusion. [Answer] The easy answer is "Yes you can." It'd been done at least once for every tonal language out there. The difficult part is how do we describe it, given our world is heavily dominated by the Latin alphabet. In our world, we use diacritics to convey information which is not readily available in the latin alphabet. For example, we may put a bar over the top of a letter to indicate that it is in a higher register, or a dot below to indicate that it's lower. There is no one rule for how to do this. It typically is up to the linguist communicating with the native speakers to come up with a way to use this extra symbology in a way that makes sense to the native speakers. You mention Chinese, but it may be worth noting that the Chinese have many ways of writing. When you talk of a "massive alphabet," I assume you mean the hànzì characters (汉字) which are associated with the meaning of the word rather than its sound. They also have pīnyīn (拼音), which is a Latinized alphabet for writing down the sound of words. In pīnyīn, the tonal content of the Chinese language is conveyed with markers above the vowels, `ī` `í` `ǐ` `ì` and `i` are examples of the vowel /ɨ/ in different tones. Of course, all of this is based on the fact that the Latin alphabet dominates modern languages. This means we adapt tonal languages to our existing alphabet, instead of inventing new alphabets. Without this Latin dominance, you should expect your cultures to invent something more natural for their language. But you absolutely should assume they can write it. There's nothing about tonal languages that prevent writing. [Answer] The previous two answers are absolutely correct: many existing human languages are tonal to greater or lesser degrees, and many of those have writing systems that indicate tone (what you've referred to as pitch). The examples given thus far mostly talk about diacritics, so let me mention another option. In a language with several distinct tones that convey important distinctions between words, tone is just as important a component of speech as the consonants and vowels. So why not give each tone its own letter? [There is precedent](https://en.wikipedia.org/wiki/Tone_letter) in existing languages: * Some orthographies mark tones with [numerals](https://en.wikipedia.org/wiki/Tone_number). [Some native languages of Mexico](https://en.wikipedia.org/wiki/Trique_language#Orthography) are written this way, at least by linguists. Chinese tones can be marked using numbers, but the diacritic method is more common now. * [One romanization of the Hmong language](https://en.wikipedia.org/wiki/Romanized_Popular_Alphabet#Tones) uses various Latin consonants at the ends of syllables to mark tones (e.g. high tone is marked with b, low tone with s, and so forth). The system is not ambiguous because Hmong syllables never end in a consonant sound. * I remember reading about an African language that uses punctuation marks for the tones, but 10 minutes on Google didn't turn up what I was looking for. Edit: Found it! I was thinking of [Dan](https://en.wikipedia.org/wiki/Dan_language), aka Yacouba/Yakuba. Tone marks (placed before a syllable) include ", -, and =. For example, [-ta](https://glosbe.com/dnj/en/-ta) is a word meaning surface, but ["ta](https://glosbe.com/dnj/en/%22ta) is a different word meaning to walk. For your language, there are two main ways you can derive tone letters: * If this society borrowed the writing system of another culture, they could adapt existing letters (or other symbols) as tone markers, like in the examples above. Consider, as a parallel case, how the Greeks took Semitic consonants they didn't need and [made them into vowel letters](https://en.wikipedia.org/wiki/History_of_the_alphabet#Alphabets_with_vowels). * If this society invented a writing system from scratch, or even if they adapted somebody else's, they could create new letter-forms for tone letters. A parallel case is the symbol for [bilabial click](https://en.wikipedia.org/wiki/Bilabial_clicks), ʘ, which (as I understand it) was just made up to represent that sound. If you take the second option, an interesting possibility is letters that indicate the pitch of each tone by their shape. The [Chao tone letters](https://en.wikipedia.org/wiki/Tone_letter#Chao_tone_letters_.28IPA.29), used in linguistics, do just that: ˥ is a high tone, ˧ is middle, ˩ is low, ˧˩ is mid-falling, and so forth. (You can do this with diacritics too, if your tone system is simple enough: mark a high tone above the vowel and a low tone below, for example.) Letters in an actual language aren't likely to be quite so precise, but it wouldn't be surprising to see something like like L for low tone and Γ for high tone. [Answer] Take a look at Hebrew. The letters are all consonants, vowel sounds are taken care of by modifier symbols/characters associated with the consonant character(s). This page - <http://www.jewfaq.org/alephbet.htm> - has a good explanation of how it works. Here's a visual sample using the Alef character, which is typically silent and only exists to allow a vowel sound to take place - [![examples of vowel sounds/modifiers for hebrew writing](https://i.stack.imgur.com/c9lID.gif)](https://i.stack.imgur.com/c9lID.gif) So instead of providing a vowel sound, your "pointing" system could indicate tonality, etc. [Answer] At least one language has developed sets of diacritic markings specifically for a formal sung notation rather than just tone, see <https://en.wikipedia.org/wiki/Cantillation> . In this case the marks add information about the tonal phrasing of the syllables they mark; it would fit well with a tonal language that needed marking to indicate vocabulary. What is interesting in this case is that the musical /tonal markings themselves have a considerable grammar and meaning (see 2nd half of link) which parallels the question here since it adds meaning distinct from that of the plain words themselves. [Answer] There are two ways the Sino-Vietnamese solved this problem: 1. diacritical marks (dots on top on bottom in Vietnamese, accents in Chinese). 2. alphabetic notations, such as duplicated vowels, appended 'h' or 'r's, etc. The former method separated tonal structire from pronunciation, while the latter (intentionally) paid homage to the likely origin of tonal Sino-Tibetan: the conversion of several complicated consonant combinations into pitch changes. (For instance, "zlambs" becoming "lahmmmm" in a lilting tone, etc) (Tibetans just simplified withlut adding tones and ended up with a damned confusing language) [Answer] Look at the sheet music for any song: it has pitch and vocabulary encoded in it. You just need a few note symbols &c in addition to your normal alphabet. Or you could compress it by using a syllabary (like Japanese kana), and writing the symbols at the positions notes would take. ]
[Question] [ Blue stars are notorious for burning too bright and living too briefly for life to develop around them. But is there some way that life could survive long enough to reach the sentience stage? I'm thinking about a terrestrial world like Earth, not an ice moon. [Answer] # Binary Star Merger - It wasn't always a blue star If it started with two lower-mass stars, it would allow a much longer history. It would pass through a "peanut-shaped" contact binary phase where the stars share an atmosphere. Most such binaries are stable, but binary mergers are common enough that we have witnessed a few -- though they were more explosive events than you would hope for. Still, we have evidence that mergers could happen slow enough to produce a stable blue star, called "blue stragglers." This is where a cluster of older smaller stars has some blue ones that shouldn't be there, likely formed after the fact from older fellows. If it happened really slow and steady, I suppose you might get a blue star without too much trauma to the planetary system. A rare occurrence, but in the realm of possibility. Here are a couple sources: * [Wikipedia page: Stellar collision - Binary star mergers paragraph](https://en.wikipedia.org/wiki/Stellar_collision#Binary_star_mergers) * [Wikipedia page: Stellar collision - Discovery paragraph](https://en.wikipedia.org/wiki/Stellar_collision#Discovery) * [Scope the Galaxy: What Would Happen If 2 Stars Were To Collide?](https://scopethegalaxy.com/what-would-happen-if-2-stars-were-to-collide/) * [The Free Library: Stellar collisions and vampirism give blue straggler stars a "cosmic facelift"](https://www.thefreelibrary.com/Stellar+collisions+and+vampirism+give+blue+straggler+stars+a+%22cosmic...-a0215188997) [Answer] Blue stars live around 10 million years. According to the most recent timeline of human evolution, homo has developed in the last 2.5 million years, while 10 million years is what it has taken for earlier apes to differentiate until where we are today. Though making a statistic out of a single data point is never a good practice, I hope you agree that the earlier apes didn't jump out of the pre-biotic soup, but required some billion years of evolution to reach that point. The only way to maybe shorten the needed time is to have complex life seeded from outside on a terraformed planet, so that some corners can be cut and life evolution gets a head start. [Answer] ## Sentient Life Could Colonise The System Ten million years is an eyeblink in evolutionary time. However a technological civilization could settle the place. It might even be possible to stabilise the star, though the most likely route we'll ignore would be to use star lifting to turn it into many smaller stars. One (reading ai-gods) could mess with the structure or fusion activity inside the star to make it stable for longer. If that happens, local life might evolve. [Answer] ## Rogue planet capture Life evolving on a blue star is just not likely. Life arriving there skipping the hard part would be a very convenient event however how can that happen? Rogue planets are planets with absolutely no star that they orbit. Because of that they are very cold. However, geothermal heat could cause life to exist on them. This is similar to how some theories say life evolved on earth, deep sea geothermal vents. Thus a planet could have life on it, but be rogue and then be captured by a blue star, warming it up. This would cause life to skip ahead to a more reasonable challenge of becoming intelligent with all the groundwork already set. The real question is how far ahead could life get. Obviously it couldn’t get to the surface, so only aquatic life until reaching the star. The orbit of this planet would also likely not be very good for life. These issues can probably be handwaved away pretty reasonably however. [Answer] # On a super-earth. To have life evolve very quickly you need ample resources, and a lot of chances. So, suppose this star caught a rogue superearth in its habitable zone. This super earth has a thick atmosphere with lots of compounds that block radiation, a powerful magnetic field that re-directs radiation, and a lot of water on the surface. It also has some dormant life from its previous star. It took thousands of years to cross the stars, but some bacteria and small organisms near thermal vents survived the travel. Once it reached the star, the massive size and the vast amounts of light from the star let life explode. The planet is 10 times the size of the earth, and due to an extensive set of coral reef like thing in the oceans, has over 100 times the surface area of the earth. This means life evolves 100 times faster. What took earth 500 million years, this life can do in 5 million years. [Answer] Consider that to have life you'll likely also want a habitable planet. During the planets formation a lot of energy is introduced via its constituent mass falling into the planets gravity well - you have a ball of molten rock that continues to collect enough debris to keep the surface uninhabitable by any standard for likely longer then your star is alive. Even if your planet cools down it still needs a suitable atmosphere. The "Great Oxygenation Event" on earth took an order of magnitude longer than the star. That's no coincidence as the whole surface of the planet is ready to react with any components that aren't inert. But you need them to power a metabolism fast enough to speed run evolution into life forms that are complex enough to gain advantage from sentience and perhaps even sapience. It seems the best chance for the development of life would be after the death of the star, akin to the question whether life on a rouge planet or on a large terrestrial moon around a surviving gas giant. [Answer] The very event of the spontaneous appearance of life is extremely unlikely, since the process of evolution from the "primary soup" into the simplest forms of life is quite long in itself. Evolution from the simplest to intelligent is faster, but also long, and probably will not have time to reach intelligent life forms in the lifetime of the blue star. For what you are talking about to happen, most likely someone from the outside had to contribute to the acceleration of development, or brought life in some form to this planet. [Answer] How about the life developing around a Sun-like yellow star and a near multi-body encounter with the big blue star at some point, getting the planet in a sufficiently wide near-circular orbit around the new star? The previous star may get ejected or get a different orbit (inside or outside of the new orbit of the planet). All of these variants are possible with the usual orbital mechanics. ]
[Question] [ There is a being who has been alive for as long as there has been life on earth. It has the ability to anomalously produce matter from its body out of nothing. Through the production of microfine strands of flesh dotted with tiny eyes, it has the ability to see and be cognizant of everything happening on every square micrometer of planet earth, all at once. It needs a brain large enough to store all of this information, since it wants to remember everything that has ever happened on earth. Presuming it uses storage space with the same efficiency as a human brain, approximately what volume/size would a brain have to be to remember everything that has ever happened on earth from the dawn of life to present day, and that brain was only used for storing memories? Would it be planetary or celestial in size, or relatively small enough to be kept on earth? [Answer] ## Storing the Earth using optimized storage methods. Since the OP says the eyes can only see the "surface" of the Earth, we can assume that we do not need to capture the complex inner workings of the oceans or clouds, just the surface level. It's hard to estimate what the actually complexity of Earth's average surface is but, let's be REALLY generous and say that you will have an average of 100 surfaces you need to capture per unit area of the Earth's surface. If you want to assume a top-down projection of the Earth, then you can just remove 2 orders of magnitude from all of my following results. This puts your total pixel data at ~5e26... and when you add in things like wire-frames, normal maps, etc. that 3-d models would need as additional overhead, you are looking at something closer to 1.1e27 bytes of data per frame... but we are not done here. Most of the Earth's surface is either organic or mineral. Both of these things form highly repetitive patterns that are very easy to resample in other parts of your image. Your average exterior cell for plants and animals for example is 10-100 micrometers. Meaning if you find one type of cell, you can store a library of a few dozen to a few million samples of that kind of cell depending on how much fidelity you need and be able to generate a nearly lossless image all the way down to the micrometer scale. Since a single plant can have a surface area of trillions of micrometers, but often has less than 10 kinds of surface cells, it means that a single plant can have enough repeating textures to make a 1 million sample library of each cell type increasing texture compression by 5 orders of magnitude, but if you then reuse that library across all of the trillions of instances of that plant before it evolves enough to need to resample, you could be looking at a total savings of 17 orders of magnitude on the texture mapping of that plant species... at least in pixel data... you would still need to call each cell that needs to be generated; so, while the pixel data has become immaterially small, actual compression would only be down to the cellular level of about 100-10000 times compression. As for the overhead of your pointers on such a large scene, through careful indexing, you can get away with relatively small pointers. So, your plant as a whole could have a meta-data set that builds your lookup tables for each library it needs, and from there each cell could use very short pointers, maybe 3 bytes per cell for the texture pointer, plus maybe 6 bytes for rotational and offset data. More general position data could be inhered from its position in your data stream. Since a single pixel is normally 6 bytes, this means you can achieve about 67 to 6667 time compression on most organisms. Minerals are just as easy to generate libraries for because they form predictable crystalline structures. With less than 5000 common minerals here on Earth, and minerals not evolving, your library for these can be quite small, and your shapes very predictable. It's hard to say how compressible minerals are, but it is probably more so than plants. So, overall I would estimate that you could get at-least 3000:1 compression on the Earth's land mass. The Oceans are way easier to texture since there is only really 1 layer over most of the Ocean, and the whole thing only needs a single library... So we can drop two orders of magnitude right off the top to eliminate that 100 layer thing I added in to account for the complexity of minerals and organics. So Ocean compression is more like 300,000:1 from my total pixel data estimate. Then there is the re-usability of data from one frame to the next. In a 3d video file, you do not save the whole state of each object for each frame, instead you only update them when at key-frames using tweening to approximate the in-between states. While plants, animals, and liquid water may change a lot from one frame to the next, minerals and ice do not. Minerals will often be able to go millions if not billions of frames before needing a new keyframe; so, mineral textures over time will take up a relatively negligible amount of space. So, to estimate data usage, we know that the Earth's historical averages are that ~20% of the surface has been covered by dense life, ~70% by liquid oceans, ~10% by deserts and/or glaciers. So the oceans need about 2.5e21 bytes per frame (1.1e27 \* .7 / 300000) Life needs about 7.3e22 bytes per frame (1.1e27 \* .2 / 3000) Deserts and glaciers need several orders of magnitude less per frame; so, I will just drop them as statistically insignificant. This means you need ~7.55e22 bytes per frame in total. Also, although life evolved ~3,770 million years ago, it only moved onto land about 430 million years ago. This means that we can completely throw out the Earth's landmass as "deserts and glaciers" for 3340 million years. Before 430 million years ago, you only needed ~2.5e21 bytes per frame. While humans can technically perceive "quality" differences up to 120 frames per second, you can generally sample speeds as low as 12 frames per second and most people will not notice an issue in the quality of the video. Especially if you use tweening tricks to simulate the intermediate frames. So if we assume 12 frames per second this means that you have ~1.0e17 frames before life moved to land and ~1.4e16 frames thereafter. *So your total dataset using compression is about (7.55e22 \ 1.4e16) + (2.5e21 \* 1.0e17) = 1.3e39 bytes. Human memory is believed to be associated with pyramidal neurons which have an average of just over 5000 synapses, and there are ~57 billion pyramidal neurons in the human brain taking up about 2/3 of your brain's real-estate. This means that the human brain can store ~4.5e16 bytes/m^3; so, you need 2.9e22 m^3 of pyramidal neurons to store the record using the compression methods as described above. If this brain were then organized into a sphere, it would have a radius of ~19,000km putting it somewhere between the size of Earth and Neptune. [Answer] ## Sensor Input Calculation The Earth is 6,371 kilometers in radius, and has another 100 kilometers of atmosphere (6,471 km total). Converted into pixels of information every micrometer $1 \times 10^{-6}$ meters, that is 6,471 km = 6.471 million ($10^6$) meters = 6.471 trillion ($10^{12}$) micrometers. The volume of a sphere is ${4 \over 3} \pi r^3$. For the whole Earth, then, each "frame" of information is $8.64 \times 10^{38}$ pixels of information. If just the surface area of Earth : $4 \pi r^2 d$ = $4.32 \times 10^{28}$ pixels. ## Brain Size > > Presuming it uses storage space with the same efficiency as a human brain > > > A small frame challenge here. Human brains aren't designed to store raw information. The human brain composes raw input into symbols (leaving a lot of detail on the cutting room floor), and further composes those symbols into context, and so on. Memorizing a specific sequence of details (think of the seven digits in your phone number) requires a great deal of effort. Let's say, then, that this is not a human brain; but rather some design better suited for the job of recording exact details, like a [holographic media](https://newatlas.com/holographic-data-storage-film/54117/). The media can handle 8.5 TB ($1 \times 10^{12}$) bytes of information per 4 inch x 4 inch x 1 millimeter (guess on depth) layer = 10 cm x 10 cm x 0.01 cm $\rightarrow$ 0.1 m x 0.1 m x 0.0001 m ... or 8.5 $\times 10^{18}$ "pixels" per cubic meter. This is assuming a “pixel” is merely on/off (the simplest expression of visual data). More information could be recorded about what each micrometer eye “sees”. ## All of History The rest comes down to recording rate and history. The Earth is 4.5 billion years old, and most folks seem to agree that life started 4.4 billion years ago. There are 31 million seconds in a year. So, total number of seconds being recorded is between $139 \times 10^{15}$ (everything) to $136 \times 10^{12}$ (just life). If you use a semi-awake human's alpha wave frequency of 4 hertz (4 samples per second), you will need around $400 \times 10^{15}$ "frames" of information for your whole data record. Each frame will contain $4.32 \times 10^{28}$ bits of information. So, the size of the entire record is $1,600 \times 10^{43}$. Taking the "brain" data density, your brain would need to be $1,600 \times 10^{25}$ cubic meters. Or $11 \times 10^8$ meters (or a cube 1.1 million kilometers on a side) to hold the data. Compare to the Earth's radius of 6,000 kilometers; it would be 183 Earths. > > it has the ability to see and be cognizant of everything happening on every square micrometer of planet earth > > > Another small frame challenge : if you were to switch the scale from micrometer to millimeter (still very small), you would trim 9 zeros off the final answer, above. This would give you a less-than-Earth size final brain size ($1,600 \times 10^{16}$ cubic meters or about 1,100 kilometers on a side) [Answer] It's omnipresent.** It's right there in the name. The only way to store all the information in the history of the Universe is with a storage device the size of the Universe itself. The Universe essentially is the omnipresent being's brain. We're living in a giant storage device. It used to be highly compressed, but through the process known as "time", it is in the process of decompressing all of that data. Of course whoever is observing all of that data must exist outside of time, and thus outside of the Universe, undetectable to all of us inside it. A better (but of course unanswerable) question would be "How big is the rest of this being?" [Answer] Unable to tell We do not have a real way to measure how much storage you need for a certain bit of information, or a group of information. That makes it impossible to quantify. To further complicate the problem, we see that increased brain tissue suggest an exponential growth in capabilities. At the same time, many incredibly smart people have shown to not have remarkably more or less brain tissue than the average. To even further complicate things, there are signs that having more and more brain tissue can eventually be detrimental. The sheer amount of neurons can start interfering with each others electric fields, leading to noise on the neural pathways. If that trend is left unchecked, a much larger and compact brain would eventually stop to work. Separation would be needed, which would probably counteract (part of) the exponential growth of information that can be stored. Besides all that, you want a specific kind of memory. Lots of brain doesn't need to be used for mobility or processing, but simply storing what happened. As it is impossible to tell how much of the brain is used for just that purpose, we can't extrapolate further how much we would need. With no way to quantify the data, the brain area or even how we actually store it, it is impossible to tell how big it would need to be. Not to mention all the ways it can interfere with itself. [Answer] Sorry to be pedantic, but an OMNI-PRESENT being wouldn't require any additional brain size / "storage". They are not all intelligent, they do not necessarily need to KNOW anything more than you or I do. Omnipresent means "Everywhere at once" or "in all places at once". Unless you are postulating that it would take "brain power" to be in all locations at one time, the answer to the question is likely to be "No larger or smaller than what's capable of keeping the being alive and functioning." I believe the word you're looking for is Omniscient or "all knowing", in which case I do not believe there is a good answer. Humans or other creatures as we define and understand them are not capable of "all knowing" due to a multitude of limitations, therefore no measurement based upon our existing understanding of "memory storage" would be sufficient to answer the question. Until we understand what an Omniscient creature would "look like" (in the architectural sense of its makeup and capabilities, not its physical appearance), there is no answer to the question you postulate. Further, any being capable of knowing all would also likely be capable of storing that information in any way they so choose...perhaps like a Google search an omniscient creature need not "remember" everything about everything but simply have a means by which to instantly access that information...requiring a "brain" no larger than that which sustains the creature. [Answer] Storing everything is impossible, for so many reasons. One is that we have to define "everything," which turns out to be easy to do in causal speak and frustratingly impossible when talking about things that have "omni-" prefixes in them. The demands are just too high. Does it remember that at Julan Date -8482293.4848282832729328, hydrogen atom #73738283754928375923838238527293923723783225728332 underwent a hyperfine transition? Didn't think so. The other reason is that it, itself, is on Earth. And there's a strange loop that forms when it tries to remember what the parts of its brain did. At some point you run into issues with descending infinite sets, and admit that it can't be done. If I may [quote](https://en.wikipedia.org/wiki/Turtles_all_the_way_down): > > "The world, marm," said I, anxious to display my acquired knowledge, > "is not exactly round, but resembles in shape a flattened orange; and > it turns on its axis once in twenty-four hours." > > > "Well, I don't know anything about its axes," replied she, "but I know > it don't turn round, for if it did we'd be all tumbled off; and as to > its being round, any one can see it's a square piece of ground, > standing on a rock!" > > > "Standing on a rock! but upon what does that stand?" > > > "Why, on another, to be sure!" > > > "But what supports the last?" > > > "Lud! child, how stupid you are! There's rocks all the way down!" > > > So what can be done about this? Well, you say this entity is omnipresent. Can it affect our reality at a subtle level? If it acts to make our reality a mirror of our own, in some tiny detailed way, then it doesn't have to remember what happens and when in some big table. It can remember it procedurally, remembering at what times it allows what events to happen. This would lead to us observing fractaline geometry in our world... strangely enough, the kind of thing Paul Bourke [cataloged](http://paulbourke.net/fractals/googleearth/) on this website. [![Fractaline Basin in Egypt](https://i.stack.imgur.com/zWUkqm.jpg)](https://i.stack.imgur.com/zWUkqm.jpg) Now if I'm wrong about your assumptions, and this entity is outside of the Earth, this may be enough. Everything at a low enough level just has to be done in ways that are algorithmically provable for the omnipresent entity. Then we just have to ask "what is a brain," in the context of such an entity. Does it have to use neurons? This would assuredly say something about its size... but this fractaline pattern points out that you have a tradeoff. The less freewill the world has (and the more "apparent" freewill that's actually procedural fractaline algorithms), the smaller the brain could be. If the entity is part of the Earth, we still have the issue of it knowing itself, which is a pesky concept that still eludes humans. Sun Tsu said that to know yourself and not your enemy, you will win half your battles -- and most people can't claim that win record! And indeed such a problem is insurmountable in First Order Logic, which ends up being where most people actually end up resting when they try to define what it means to "know" everything about the history of the earth (whether they intend to go that way or not). If I may offer a fascinating math tidbit that I love to share, there's a fascinating concept that's been nicknamed a [Willard World](https://arxiv.org/abs/1307.0150), after Dan Willard. Instead of starting with 0 and 1, and working with addition and multiplication to get 2, 3, and so on, he starts with infinity, and uses subtraction and division to construct everything in his world. It turns out that, when he does this, he can create something that is exactly like the rules of arithmetic except that you can't prove multiplication is total. But, fascinatingly, his systems can prove their own consistency -- which is as close as math ever gets to "know thyself." So the mathematics he describe could be a powerful piece of the puzzle for understanding this omnipresent beast. I geek out over math, it's true. But sometimes there's fun tidbits. One of the fun consequences of Willard's systems is that you can start with a set that is "countably infinite" from an outside observer's perspective, and construct a Willard system around that can prove such a number is "uncountably infinite" from within the system, a much larger category of number. It always felt like there was a worldbuilding opportunity there, for a world ruled by a "god" which, from the inside, appears to be uncountable in its infinite reach... but all the gods know it's actually just countable. So brain size? I didn't answer that. It could be arbitrarily small depending on how you shape your world. Or it could have to be much larger than the planet itself. It all depends on how you define "everything" - a pesky word that is so easy to throw around until you have to actually define it. Then it just looks at you, smiles, and says, "give it your best shot." > > "The Tao that can be named is not the eternal Tao." - Lao Tzu > > > [Answer] It is all brain. Because that and its senses are all it needs. It perceives and remembers but does not act. Every fiber stores memories, and there is a lot of redundancy because disasters have wiped out large swaths of this creature in the earth's past. The various memory versions are not all the same. The creature mourns the ones it has lost - it can remember how the first flowers in the Cretaceous smelled and tasted, but some of these memories are dark because the catalcysm wiped out the memory of color and shape. The creature is all on earth. But not all on the surface; not after the Permian. It goes down, and down. And down there there are also wonders to perceive. [Answer] Focus on density One of the key properties of brains we know about, is density. You need very interconnected processes to develop complex capacities, as an increasing amount of parameters have to be processed concurrently. For an omnipresent brain, the challenge would be to increase the cardinality of synapses. Thus, maybe density would be a more defining property than size. In other words, going towards an infinitely dense brain (black-whole kind of thing), instead of an infinitely large brain. In the end, the result is the same (infinite capacity) although implemented more efficiently. [Answer] The being clearly is the Earth (and God clearly is the universe). The reason is that you cannot store all the information on Earth in anything smaller than the Earth, and you cannot store the information in the universe in anything smaller than the universe. [Answer] > > ...to remember everything that has ever happened on earth... > > > A frame challenge - if the assumption is that this 'brain' is on the Earth, you have an infinite regression. In order to 'remember' something, there must be a change in the brain. > > It has the ability to anomalously produce matter from its body out of > nothing. > > > This brain is on Earth, that change in the brain would have to be recorded in the brain. But this would cause a change in the brain, which must be recorded. But this would create a change in the brain, so this must be recorded. Ad infinitum. ]
[Question] [ I'm currently working on developing the navy for the most advanced faction in my fantasy world and I'm stuck with the design of the largest ship, a sort of a medieval carrier ship. I'm talking about having a ship that would be roughly the same size and function as a modern aircraft carrier, with the main difference that it would carry smaller ships (Hunters) instead of aircraft because my fantasy world does not and will never have any sort of flying contraptions. The problem with this idea is to find a way for the Hunters to sail out of and into the carrier while the carrier itself is on the move. The reasoning behind this is that the carrier would be carrying and managing several dozen Hunters, which would have a relatively short range of operation, so the carrier would have to keep up with them at a reasonable pace, especially when the operation demands prolonged harassment of the enemy. As the carrier sails across the water, it creates a serious wake in its path and that very wake is my main design obstacle. Placing the hangar bay doors at the front of the carrier is obviously not an option, while placing them at the sides would force the Hunters to directly cut across the wake when coming in and going out every single time. Placing the hangar bay doors at the rear would force me to place the engines somewhere else and I honestly have no idea how the physics work when a smaller ship is tailgating an exponentially larger one. So far the only concept that somewhat resolves the issue is to apply the idea from the Japanese I-400-class submarines that was attempted during WWII. This would mean providing the carrier with several cranes that would lift the Hunters out of the water while they maintain a parallel course to the carrier and bring them in. Carrying the Hunters in and out one by one seems significantly slower than allowing them to enter and leave the hangar bay relying on their own propulsion, but if there really is no alternative to it then I guess I will have to settle with that. Any suggestions would be greatly appreciated... PS EDIT: Both the carrier and the Hunters have engines powered by reactors (power cells), so they don't require sails. PPS EDIT: The ships would be roughly made of the metals available to us during the pre-ww1 era. Since gunpowder and explosives don't exist, the guns on these ships are the first of their kind, basically oversized airguns. [Answer] A giant catamaran. ``` A top view: ____________________________________________________ / \ / Starboard hull \ \| Bow Stern \| \ ____ ____ ____ ____ ____ ____ / \__/ \__/ \__/ \__/ \__/ \__/ \____/ <-Hunter bays along inside of both hulls __ __ __ __ __ __ ____ / \____/ \____/ \____/ \____/ \____/ \____/ \ / \ \| Port hull \| \ / \____________________________________________________/ A side view: Structure connecting the hulls \| V Rope towing hunter through the wake ____________________________________________________ \| \ /====\ /====\ /====\ /====\ /====\ /====\ /`-. V __\|\|______\|\|______\|\|______\|\|______\|\|______\|\|______\|\|____`-. \|\ \| \| `-__\|_\_ <- Arriving hunter ~\ /~~~~~\____/~~~ \____________________________________________________/ ``` The ship has two long hulls, structurally connected above and possibly below the waterline -- above, high enough to clear the masts/highest points of the hunters. If below, deep enough to not interfere with the hunter's keels. The inside-facing sides of the two hulls have the docking bays for the hunters, which can be closed off via sliding doors in heavy weather. A system of pulleys and ropes attached to the structural supports above can assist in launching, catching and docking the hunters. Getting past/through the wake The connecting structure over the two hulls can function as a network of cranes/tracks. It may be unsafe/unfeasible for a hunter to successfully navigate past the wake by itself, but if it's being held by one or more ropes from above, you should be able to keep it steady until it's been let out far enough behind for it to navigate. To pull it back in, the catamaran can toss a floated cable/rope out from between the two hulls. Make the rope as long as it needs to be to drag a safe distance behind the wake. This rope could be caught by a hunter, and then it can be towed forward into the between-hull space where it can be more easily handled and docked. [Answer] Surely you are just thinking of something like this? [![enter image description here](https://i.stack.imgur.com/5Fmy7.jpg)](https://i.stack.imgur.com/5Fmy7.jpg) That there is an [Amphibious Assault Ship](https://en.wikipedia.org/wiki/Amphibious_assault_ship). A large part of its role is to carry, launch and service a fleet of smaller ships (and helicopters) [Answer] Torpedo boat carrier These things were actually done in real life with torpedo boats and larger ships which carried them out to sea. One example of such vessel would be the La Foudre (later converted to a sea plane carrier. The same principles can be applied here, provided the Hunter ships are small enough in relation to the carrier and the cranes you have available. The Hunters would be stored on deck in manner similar to ship's boats and in absence of sails the deck would be full of crane assemblies used to move the hunters in and out of water on either broadside. The motion of the ship isn't that big of a problem as long as you can slow down a little. Take for example floatplane recoveries, where scout planes would land on water and pull up alongside the ship while it was moving at relatiovely low speeds (about 10 knots) and be pulled up onto the deck with a crane. Arguably the more dangerous part would be launching, as with planes it turned out that speed needs to be much smaller, but in case of boats the situation shouldn't be as severe. You should however make sure your cranes can lower the Hunters into the water with enough clearance from the carriers hull to avoid collissions. Here's a photo from the La Foudre, you can see a torpedo boat being hoisted up (or down) and another one stored on deck. [![La foudre torpedo boats](https://i.stack.imgur.com/Fs3Bf.jpg)](https://i.stack.imgur.com/Fs3Bf.jpg) [Answer] ## Forget the wake by avoiding it altogether The idea of having a huge, hollow ship is unrealistic even in a fantasy setting. Aircraft carriers are made out of steel and not English Oak because ships that size require the advantages of steel and mighty engines to exist. You didn't say whether or not your ships are made of steel or depend on combustion. So let's assume your fantasy setting is akin to the Golden Age of Sail. Your hunters are, I assume, fast short-range ships. It's implausible (frankly unbelievable) that your carrier would have dock or bay doors that would open to let them exit and enter. To do so would require a power source other than wind and sail. I recommend long, skinny, and cranes Let's assume a very long, quite skinny ship that has cranes along both sides of the ship for lifting the hunters out of the water. This not only provides access for repair and resupply, but keeps the hunters out of the water to reduce drag, holding back the carrier. Cross-beams could be moved into position to lock the hunter in place, which would have the advantage of adding the hunter's sails to the overall propulsion of the carrier. A pair of cranes mid-ship have the unique ability to lift up-and-over, thereby bringing very damaged hunters into an onboard dry dock for extensive refit. The long carrier would have the advantage of speed due to a minimum water cross-section, which would also allow for a lot of keel-aligned sails, but would have the disadvantage of turning a bit like a lead brick. Good! There should be disadvantages to outweigh the advantages. An average carrier might host eight hunters with cargo capacity to allow for 3-7 year patrols. Do I have any stats to support that? Nope. It just feels believable to me. But what about that darn wake? Since the hunters are always working along side the carrier and never behind it, the wake is a non-issue. --- ## Post edits answer The OP has since edited his/her question to indicate the ships are made of metal and have powered engines. In this case, I don't advocate a carrier. I advocate tethers. All the hunters can move under their own power so long as supplies and fuel are available. This minimizes the size of the carrier and improves both its defense and its economy. Rather than being a huge, lumbering clunker when the hunters are deployed, it's a small supply ship... fast and maneuverable. A single "bay" at the back (not actually covered, but a forked portion of the stern) would exist where a hunter can be brought in and parked for repair and maintenance. Curiously, this reflects an answer I gave to [Optimum Shape for a Space Dreadnought](https://worldbuilding.stackexchange.com/a/177155/40609). [Answer] ## Like a whaling fleet? The question reminds me of the whaling fleets during the first half of the 20th century. Both the factory ships (big, lumbering, sturdy, lots of space) and whalers (small, nimble, rough, cramped) would journey together. At times along the way the factory ship resupplies the whalers if necessary. Considering that for a navy there is no need to conserve space for a captured product this space becomes useful for power cell storage / reload, ammunition and food and water. As the whalers were ocean-going vessels there was no need for these to be carried or towed by the factory ship. Only restricted by the space for food, water and fuel the whalers were capable of independent operation away from the factory ship. ## Use of resources If this nation is capable of producing big ships like a "carrier" then there is plentiful available metal. Also these big vessels are capable of operating in open seas. So navigation is mastered. In turn why would this nation restrict itself to product smaller vessels requiring carriers? It is more sensible to have smaller ocean going vessels that have the additional benefit of operation along the home coast as patrol crafts. One design, two functions. Can be used where needed. ## Modus operandi Why would a carrier carry ships? In a way this only makes sense to beat another nation's navy. However this does not fulfil the objective of projecting military or political power over another nation. Food and water in the late industrial age where metal ships with screw propulsion became dominant were not as restrictive as fuel capacity. So the hunters in this question have a limited fuel capacity which limits their effective range reach. In contrast a big ship (tender) can carry lots of fuel (besides food and water) to extend that range of hunters. However this big ship requires protection which a small / big fleet of hunters can provide. Maritime transfer of resources between ships in open sea is not a preferred option. Having said this it depends mainly on equipment (ropes, maybe cranes) and training. Any navy big enough to create big tenders tends to have at least a professional core of sailors. Final thought on modus operandi of tenders: These ships require a dedicated effort of a nation to build and operate. Just using these to extend the range of smaller hunter vessels to fight other ships "for the glory of sinking ships" makes only sense if this supports the other big and medium ships that land troops to conquer other nations or parts of the world providing scarce resources. ## The wake problem A big ship only makes a big wake if it sails fast. Ships and boats going alongside each other requires protocols of communication and coordination that professional navy personnel gets training for. A fast moving ship deploying small vessels at fast speed into up to medium open seas is cool. And if possible by physics we would have historical examples. ## Conclusion I just fear this carrier question is impractical for the reasons above. The idea however is cool. [Answer] The US Navy did have such a ship class. Made out of metal, and when launching, the ship was partially sunk. They were LSD, known as Landing Ship Dock. How they work is beyond me, as they are now part of the mothball fleet. The one I know of is the USS Thomaston, LSD-28. I could not comment on PcMan's post. [Answer] * THE ANSWER After more research and an in-depth comparison of speeds and sizes, I had arrived to the conclusion that the Catamaran build is the best one when it comes to providing speed, size and stability. I would take the torpedo boat carrier design and widen it into the Catamaran build, providing the carrier with 6 cranes spread on the sides so it could service 6 Hunters at once. The Catamaran design with the hangar bays being underneath the main deck simply isn't feasible due to such a large vessel being forced to sit as low in the water as possible for the sake of stability. As far as speed is concerned, I've locked the carrier's speed for operations at 10 knots (20kph) and I've locked its maximum speed at double that number. The Hunter's speed are still something I'll be working on... ]
[Question] [ Can humans survive by eating only nails and hairs of their own? As they grow they consume their own hair and nails. Hair includes even body hair. What is the maximum number days a human can survive on this? [Answer] Your question asks how much longer they'd live, not if they could live forever I think people are misreading your question. Can someone survive forever? No, and the laws of thermodynamics are the reason. But, how long would it extend life? Obviously recycling buys you something... or does it? The problem is that nutrition isn't just a function of mass Hair and nails are made of [keratin](https://en.wikipedia.org/wiki/Keratin), a difficult to digest protein, and pretty much [nothing else](https://academic.oup.com/ajcn/article-abstract/36/5/943/4693669). Because it's difficult to digest, simply cutting off your hair and ripping off your nails and eating them will provide so few calories that you likely burned more trying to eat them, speeding your demise. However, researchers have found if you properly [powder and prepare keratin](https://academic.oup.com/nutritionreviews/article-abstract/2/3/75/1857588?redirectedFrom=PDF),1 it becomes a mediocre source of protein. Does this buy you much? Most calories come from carbohydrates, not proteins. Therefore, it's not surprising to discover commercially available keratin is listed as having no calories per 250mg serving. [[1](http://www.myfitnesspal.com/food/calories/spring-valley-keratin-250mg-169016645), [2](http://www.myfitnesspal.com/food/calories/neocell-keratin-hair-volumizer-189656324), [3](http://www.myfitnesspal.com/food/calories/swansons-keratin-175278068)] Granted, a full head of hair may weigh a couple of kilograms2 (the world record holder for length is 5+ meters, but it doesn't look very full...), but even if we're generous and suggest 1 calorie per gram, 2Kg of hair is only worth 2,000 calories, your single day allowance. And there are other problems * Your hair and nails are, well, dirty. We don't even want to think about what bacteria and nasty germs are living in your hair and under your nails, much less the hair spray and conditioner you use and the finger- and toenail polish you might be wearing. Perhaps you took the time to scape off the polish, wash your hair thoroughly, and wash your hands and feet before yanking those nails off. Total calories used to avoid illness: gazillions. * You pulled all 20 nails off. Ouch. There's a better than average chance of infection. * If you don't powder the hair, there's a better than average chance it can ball up in your intestinal tract and block it. Maybe you don't die any faster, but you'll wish you did. Conclusion If you took the time to cut all your hair and rip off all 20 nails, then grind them into a very fine powder (preferably without causing heating, per the linked article), you would maximize the value of the keratin to your body. But you probably expended far more nutritional calories than you could possibly receive from them. Net effect: you die one day faster, but you won't feel as hungry --- 1 Have you ever had to do anything after breaking a big chunk of nail off? It hurts. It hurts a lot. Hitting it with a feather duster hurts even more. And our earstwhile survivalist just ripped all 20 off to the root. And the next thing you're going to do is pick up a rock and hit it against another rock to powder everything. And you're not going to slip and hit a finger or toe even once. Not even once. 2 Unless you're like Max Klinger from M\A\S\H, the odds are your body hair won't add substantially to your supply of Keratin. It's worth noting that there's a huge variation in hair weight. I've seen women with so much hair I wondered how they could hold their hair up. I've also seen Patrick Stewart. It's a good thing hair's worthless or we'd have to figure out the average weight of hair on a person's head.* [Answer] # No. (If they're their hair and nails, this is forbidden by the Third Law of Thermodynamics - you can't get the energy to live and grow hair from the energy you put earlier in those same hair). This is a plot point in Serge Brussolo's Sommeil de sang, 1982 (Blood Sleep, but I don't know if it was ever translated into English), where the Autonomous people survive on their own hair, and baldness is a wasting disease (I must confess I almost put the book down then and there). What about surviving on someone else's hair and nails? It can't work (also: eeew), because hair is not digestible by humans; to be digestible we would need specialized bacteria similar to those that help in digesting cellulose, which has some similarities to keratin (both are polymers, the former made of D-glucose units, the latter of protein units). While such bacteria do exist (they're called dermatophytes and infect humans, feeding on hair and skin squamae), they're not optimized for survival in the gut. Dust mites also are able to digest the softer squamous keratin by drenching it in peptidase enzymes, but you can't do that in a normal human gut because at the required concentrations the enzymes would digest the gut itself first. Also, digestive protease production in humans isn't all that great (one of the reasons humans aren't full carnivores, but rather omnivores; and even obligate carnivores like cats will rather regurgitate hairballs than digest them). The caloric value of keratin is also way below that of cellulose, because the digestion process requires the undoing of much stabler disulphide bridges. Even setting up the digestion process is expensive as it requires dedicated enzymes and/or strong acids (cellulose can be hydrolyzed much more easily). (Hair and nails supply different kinds of keratin; the latter is more easily digested, [at least in rats](https://watermark.silverchair.com/jn0330060673.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAaYwggGiBgkqhkiG9w0BBwagggGTMIIBjwIBADCCAYgGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMU9vVy_HOFl8QbKTaAgEQgIIBWVOk68hM-d03Dg0Yu8C6tCegUAG-hmpUM8ZSmgtsXScohW82TX40Vp-UOdPx7M2j_OBtSpDqm-zy8NsqSuZwoB5HQDkd-vVvyHLKaxES2G6V3GQEWyqeDb6p3FCZGHLrv-FMZstRQiukycguGPXf-4OjKFJByeeMN9FCZ1cajB4KQF36cTQC-CgbLKD6tZ7aYY0kwIsj9oitTPRXX0-l1-6h8yABS1h_DbsgjMb_PVEujefii91BTgCMNPlDXFC8IMw8xDlXhBbr4npf_9lj_LML0jurEl8I2LEnHL8biiQKMYE-I5cdSnglCV6PdWlJGzTn85BqY4Wdi3TD3nlBMnQ6McfEHKiuv2DwaXmqDAxF4A-7sf4qPeFVPXy1DLZ22MT8RDxD_xDGkF2eIB5EvJ5auV7uuT5VGcjjAhqrJ1FhUE8BQjV6tazFgqEuonqqjce-ffXv4ZOkMw)). By the same token, perversely, keratin synthesis is more expensive than cellulose synthesis. Crudely, L-cystein supplies around 70% of the caloric output of D-glucose, and that without the waste management costs (D-glucose burns to easily disposed of CO2 and water, while L-cysteine produces, among other things, ureic acid and nasty sulfur compounds. You really don't want to stay downwind of a keratin-digesting, human-sized organism). I haven't been able to come across hard numbers, but I feel that a still very optimistic estimate is a ratio of perhaps 1 to 20 - that is: to be able to produce one gram of keratin, you need to efficiently consume around 20 grams of keratin (we knew from thermodynamics that we could never reach a 1:1 ratio anyway). So: * ordinary human, survive on own hair: no (digestion limits). * gengineered human, survive on own hair: no (thermodynamic limits). * gengineered human, survive on someone else's hair: remotely possible, if enough people are harvested. The number of "enough people" is likely to be high, though, because standard caloric intake is around 2000 kCal per diem, and this translates to a wildly optimistic 500 grams of hair (that is the absolute minimum, without expenses and interests. I'm treating hair as if it was prime steak). On eBay - you don't want to know - they say that a full head of 50-cm hair weighs 250 grams. So you need one meter of hair per day. Various sources on the Internet claim both that > > According to the U.S Center for Disease Control, hair grows at an average of 0.50 inches (1.25cm) per month which means the average person grows 6 inches (0.15 m) per year. > > > and that you can grow your hair 1 cm per week with several magical remedies. Even allowing 0.5 m per annum instead of 0.15, every day you would need two years' worth of hair growth, that is 730 man-days. Riding the wave of optimism, we thus end up with a people ratio of 1:730 - you need 730 people, surviving on something else, to allow one gene-tailored person to survive on their hair. (Until oligoelements and vitamin deficiencies do him in, that is). > > We can turn up the gross factor to eleven by noticing that oily hair contain more easily digested and caloric substances (Wikipedia: "triglycerides (~41%), wax esters (~26%), squalene (~12%), and free fatty acids (~16%)"), with a final calorific power about five times that of hair. > > > [Answer] No, they cannot survive on such a diet. Nails and hair are made of [keratin](https://en.wikipedia.org/wiki/Keratin). Keratin is very much not digestible: > > Keratin is highly resistant to digestive acids if it is ingested (Trichophagia). Because of this, cats (which groom themselves with their tongues) regularly ingest hair which will eventually result in the gradual formation of a hairball that is occasionally vomited when it becomes too big. Rapunzel syndrome is an extremely rare but potentially fatal intestinal condition in humans that is caused by Tricophagia. > > > Even if it was digestible, it is very low in usable energy, which is why almost nothing eats it except a few fungi, such as the fungus behind [Athlete's Foot](https://en.wikipedia.org/wiki/Athlete%27s_foot). How long would they survive eating only their own nail and hair? Well, nail growth and hair growth account for an insignificant fraction of the energy expenditure of a human being. Accordingly, you should see negligible increase in survival times over not eating anything at all. How long you can survive as such depends on a multitude of factors, but somewhere between 3 weeks and 8 weeks seems to be the limit. However, if you are [unusually obese](http://www.medicaldaily.com/how-long-can-you-live-without-food-according-science-395630), you can last much longer, such as one man who weighed 456 pounds before he went 382 days without eating any solid or liquid food (he did get supplements to ensure he had sufficient nutrients, just not any calories). [Answer] 1. The energy you take in as food is used to produce hair and nails, and also run your body. The fraction going towards making hair and nails is small. So on the fly, the nutrition in hair and nails is not enough to sustain you. If it were, nothing would starve to death because it would just eat its own hair. But the OP does not mandate it must be on the fly. Suppose I stored a large quantity of my hair and nails over time, while eating meals at Arbys. When it came time to live on hair and nails I would have a large supply, enough to meet my nutritional needs. 2. Keratin is indigestible with my god-given digestion equipment. But the OP does not limit me. It is possible to [hydrolyze](https://www.google.com/patents/US2993794) keratin into component amino acids. Amino acids can be converted to glucose and burned for energy and so this would be a route one could take to meet energy and protein requirements on just hair and nails. One would of course suffer from nutritional deficiencies (e.g. scurvy, pellagra) in the intermediate and certainly long term. [Answer] # Thermodynamics says no In addition to CortAmmon's answer on the merits of keratin, there is the simple problem of energy conversion. That is to say, how do they grow hair and nails in the first place? When you are a baby, you don't have much of either. You need some external source of energy to even begin growing extra hair and nails. [Answer] As pointed out by everyone, of course not indefinitely (because thermodynamics), but this is not what is being currently asked, rather "the maximum number of days a human can survive by eating hairs and finernails". If you don't have a decent storage, from the low nutritional value of hair+nails, a very good approximation to the answer would be "the same maximum number of days as without eating hair nor fingernails". There is also a consensus here. What if you have a unusually large storage, as suggested by Willk? Eww, sure, but a good suggestion nonetheless. I'd be not making the eww-factor any better with my answer, but let me point out that neither hair nor nails do have to be clean. I'm going for an abundant reservoir of dirty hair. One can get some nutitional value from [eating dirt](https://en.wikipedia.org/wiki/Geophagia) (even more so if it contains [compost](https://en.wikipedia.org/wiki/Compost)!). In the same line, but for conventionally-dirty hair: [dandruff](https://en.wikipedia.org/wiki/Dandruff), sebaceous secretions (yay fat!), different kinds of fungi (yay proteins!), non-microscopic bugs and their eggs (lice, ticks). The more complex the dirtiness of the hair, the better its potential nutritional value. Nails of course can also be a good source of fungi and various dirt. Still, how much fat+muscle does one have on oneself? Typically, a lot, compared with all but the most extreme reservoirs of dirty, oily hair. It's really hard to compete with that. One's own typical methabolic mechanisms, where you slowly&internally eat yourself, will typically overwhelm the kinds of eww-tricks we can come up with. So my best attempt at a numeric answer is the same maximum number of days as without eating hair nor fingernails, plus maybe 1. [Answer] Yes you could survive atleast a extra few hours if you were starving to death in a survival crisis. This may help save your life if your rescuers just needed that extra couple of hours to find you. For example your lost in the desert ]
[Question] [ Imagine a world slightly more developed then ours. For example internal combustion engines are becoming obsolete, they have fuel cells and electric cars. They also started using genetic engineering to eliminate certain diseases and even improve humans. For example, parents could agree to test their genes and even alter inseminated egg cell in vitro. Majority of population still doesn't use this technology and procreate in natural way. However, they do have ability to use genetic manipulation on certain diseases even after that person is born (stem cells etc ...) Age of space exploration and colonization is still somewhere in the future, and is not relevant for the story. Elite of a certain country in this world is a firm believer in Zodiac signs, horoscope and all associated stuff. Country in question is not largest or most powerful (i.e. they are not US, China or Russia) but they are technologically advanced, with technocratic tendencies, resembling some mix between Germany and Japan in our world. They do have some remnants of democratic institutions, but decisions are more and more made by this technocratic elite. However, their grasp on power is not so firm, they mostly rely on good faith of general population, i.e. belief that they are working in benefit of everyone. General population of the country is heterogeneous, but on average they are mostly interested in their little lives and not about some distant greater good. Anyway, aforementioned elite is firmly convinced that tough times are ahead for entire world (turbulence, famine, shortages, wars ... ) But if they have quality population, it would also be a opportunity for their country to expand and become leading on the planet. To this end, they already experimented with genetic engineering, but some things are missing. They have determined that date of birth and therefore associated Zodiac sign greatly influences person's character. Therefore, they would like to boost certain signs, and almost completely eliminate others. For example, they would like to eliminate Gemini because of their fickle nature, only female Cancers and male Scorpios would be allowed, reduce number of Leos because of their narcissism . At the same time boost Taurus because of their firmness and Capricorn because of their grim determination etc ... Question is, how would they do it ? Date of birth depends on date of conception. Forced abortions and impregnations are out of the question, their control over general population is more of psychological one. Also, directly explaining idea would made them look foolish, and may alarm their enemies that they expect war. They do have centralized water supply, so this could be used to increase/decrease fertility at certain time. Final goal would be to create certain mating and non-mating seasons. Any ideas are greatly appreciated, and best answer would be one that would explain smooth transition (i.e. boiling the frog) from have kids whenever you like to April is a good month for giving birth but June is not. Some use of mandate and force is allowed, but it must be done with measure, since we don't want too many questions or riots and rebellion. [Answer] Gamification of life You start with introducing gamification into your society. Everything that can be measured by the sensors of some device everyone is carrying around (i.e. a smartphone) is processed to produce a social score of that person. Not enough hours at the workplace? Score goes down. A walk in the park in the evening? That's healthy, score up! Also, if you want that high-paying job, your social score needs to be in the top quartile of the whole society! Next step would be to introduce personal decision making into the social scoring app. If you're not sure what to do with your free time, just ask the app which activity would give you the higher score! Also, only the app can give you that info in advance, because the scoring rules are constantly being revised and are dependent on things like the season, the weather or even the day of the week. Then, if all that is regarded as being normal in your society, you can set the rule for "having unprotected sex" as scoring very low in certain months and very high in others. For working around the last uncertainty of early or late births, refer to Ash's answer. Sounds dystopian? Search the web for "china social credit system"; what I describe here is just a small extension to what already is implemented in the real world. [Answer] People's most sensitive spot is in their wallet. Give financial contributions to the families with a baby born in the "right" months, apply financial penalties for the families with a baby born in the "wrong" months. This will easily skew the mating of couples. This already happens when incentives are barely prospected on the purchase on certain goods, like cars or solar panels. [Answer] ## Two easy ways: ### Change the date of birth using drugs Date of birth isn't just related to date of conception, its the day the baby leaves the mother, that's a property of the hormone levels in the mother. We have drugs that can change that so the baby gets the desired star signs. [Tocolytics](https://www.drugbank.ca/categories/DBCAT000759) will delay contractions. Its usually used in the case of premature babies but it could be used to change your new babies starsign to the next one. [Oxytocin](https://www.mayoclinic.org/tests-procedures/labor-induction/about/pac-20385141) will bring contractions on now, it is used to induce labour. This can be used on the last day of a good star sign before a bad one. Bringing the baby earlier or later could be explained as needing to get a birth around the schedule of the doctor, or around the schedule of the midwife / birthing suite. The only person in on the conspiracy needs to book all the birthing suites out for "maintenance" during the bad star signs, when a woman hits about 8 months they'll go to schedule her in, and realise they need to tweak the timing a bit using drugs. ### Encourage cesareans using fear and body-shaming Tell all the horror stories of natural births. Give women a fear of tearing, a fear of death in childbirth. A fear of crippling pain and torture. Give them an (unrealistic) fear of being stretched an undesirable as a sexual partner. And then give them the solution, free cesareans! Just cut it out of you, its minor surgery. Once again, your cesarean suites are "closed for maintenance", or your birth complication specialists (who need to be on call while any birth are happening for legal reason) are "on holidays" during the undesirable star signs. Bookings will be made around the bad star signs. [Answer] For a subtle effect, then people are more likely to ... be intimate with each other at certain times. It may be possible to try and use these influences to manage times of birth. Let's call the times nine-months before a bad time to be born the 'stress months'. During stress months, alcohol sales are restricted (sad, but likely to have an effect). Public transport is sabotaged so that commutes take longer and require more changes. Similarly encourage road-works at these times. Generally the plan is to keep people stressed enough that they are not interested in sex. Let's call the other months of the year - nine months before a good time to be born the 'festival months'. During these times there are plenty of public holidays, and the government offers subsidies to eating meals out together. Sports leagues are organised so that finals are played during festival months (it is said births peak after such events) a general laissez faire attitude means that the power-supply has regular blackouts (again it is said this leads to a peak in births). Generally the plan is to give people plenty of time to relax and spend time with loved ones. I would doubt that you can ever get massive reductions through this method, but a 20% difference in birth-rate between different months sounds achievable. If done well though it could be almost invisible. [Answer] Cultivate individuals according to sign after they are born. > > “You go to war with the army you have, not the army you might want or > wish to have at a later time.” - Donald Rumsfeld. > > > It is tricky to arrange births according to a calendar and especially tricky to skew gender of births according to calendar. Trickiest of all if you don't want your people to know your reasons. It is much less tricky to skew opportunities and training for individuals once they are born. There are any number of reasons why your male Scorpios and female Cancers receive awards and scholarships. There are reasons why your Leos might get attractive opportunities to emigrate, or an especially harsh prison sentence. You want Taurus and Capricorn but you don't want them for the same reasons. Go to work cultivating these children after they are born. Fickle Gemini may not be a good choice for a colonel or agricultural planner. Circumstances (that you influence) will steer your Gemini into other career paths. A Gemini creatif might be a gifted musician, and music is balm for your grim Capricorns. Inborn traits govern possible contributions to society. Your shadowy puppeteers can make sure each individual gets encouragement or discouragement to fulfill their astrologic potential for societal contribution. [Answer] I am surprised nobody took upon this, specially after the centralized water supply hint. Since the government controls the water supply used by the whole population, it could add some contraceptive drugs during the "wrong" months, but aphrodisiac ones during the "appropriate" ones. This should be combined with the [stress/festival months](https://worldbuilding.stackexchange.com/a/185594/232) of Neil answer. [Answer] CRISPR CRISPR is both a beautiful opportunity and incredibly scary. Here are the basics, but you can easily search for more. It is still a new developing field, but holds incredible promises. CRISPR is a method to change DNA. previous ways to alter DNA always were either too general, too complicated or simply too expensive. Most had even two of these. Enter CRISPR. A relatively cheap method that can easily be used to alter specific genes. How it works Bacteria have a much more simple immune system. If they survive an attack from a virus, they store part of the DNA of the virus. If this specific pattern is encountered, it is cut out and replaced with a sequence that renders the virus harmless. The cutting is done with a special enzyme. This can be hijacked. We can manipulate this defence of a bacteria to react to a certain sequence and replace it with anything we want. This can be produced at larger scales and administered relatively cheaply. What this means is that even when a kid is born, you can change her or his DNA. you just sequence it to check the specifics, see what needs to be altered according to the zodiac signs and change it. You'll have missed an important part of the development, but with so much more to go it won't be a problem to change the genetics after birth. It might take several treatments to change it, but you'll get very specific results. This of course won't work for the gender. The advantage is that the male and female zodiac times are apart. If you think the person might be born in the male or female time, you change the gender preemptively. It won't matter that a part of the zodiac sign before and after have nearly only male or females, as long as the required zodiac time has only male and females. Researchers aren't sure if the real differences start in the first or second trimester, but the placenta end some other factors accommodates the specific gender. As changing a gender has never been done before to my knowledge, it can't be estimated what the consequences are. It can be more rejections, but just as well the body is able to adapt. You just want to do it as soon as you can. What is scary is that this can be potentially done without the populations notice. Potentially you can change the DNA of large amounts of the population that have a specific sequence. In conclusion With CRISPR you can do highly specific, relatively inexpensive scalable gene alterations. In a society that has invested a lot in this, it'll probably be cheap and quick to deploy on the whole population. Each child can be changed and, up to a point, even older people can be made to fit the profiles. If they go far enough, they might even do things to trick DNA to think they are in different development stages, allowing much more impressive feats. Your mind as agile as a 5 year old, allowing the learning of languages? Growing again? Muscle growth from sports like a 25 year old? But changing DNA to fit zodiac signs? If they've done enough research in what fits for each zodiac sign they will be able to. Just make sure you'll also control the environment. DNA isn't always rock solid, like giving blue eyes. It's also a potential. Potentially having the kindness of a Virgo doesn't mean they will grow up to be if the environment won't allow it. [Answer] I see two ways to do this. Top Down The elite secretly mandate this. They do this through kindness. There are a large number of free clinics, and they all offer care for pregnant women, and women who expect to become pregnant. They can secretly provide a form of contraception during the times that no children are wanted. For the times where only one gender is desired, they can provide something that would cause the undesired gender to abort. The one problem is that they cannot provide the covert services at 100% success, because then people would associate the clinics too much with the problems of concepts during those times. This could be helped by being popular and truly helping with other problems as well. And the elite could massage the information sources so there is less obvious connection between the time of birth and the zodiac sign. Bottom Up Rather than a secret program, the elite could instigate an "educational" program to convince the people that giving births according to the zodiac is the best thing possible for their children. After enough protesting from the poor, the elite could have the government give in to the will of the poor, and provide help for the people to do what they want. ]
[Question] [ I'm working on a TTRPG system that takes place about a century after an apocalypse event. I've hit a point where a bit of world building is required, and so I'm going down the list of technologies (electricity, medicine, radios, etc.) that could be viable without significant industrial activity. For context, most settlements house less than 500 people, are not part of inter-settlement organizations, and are mostly agrarian. I won't go too deep into the specifics, as it isn't super relevant to the question, but large settlements are often squashed and invaded. This means that industry is slow to take hold and very rare. Now, to my main question. Would it be possible for individuals/settlements to create rudimentary motor vehicles, such as buggies and motorcycles, under these conditions? Obviously, any pre-apocalypse vehicles would be rusted away and unusable, and gasoline would have rotted. My idea is that the engines would run on vegetable oil, as most settlements are very agrarian. However, I'm not convinced that the settlements would have the manufacturing capacity to make combustion engines in the first place. Any help with this conundrum would be appreciated. [Answer] No, at least not sustainably. After a century, you might have both machine tools and decent steel left. Ignoring those, constructing something like a diesel or gasoline engine requires the forging of cylinders and cylinder heads that will stand high temperatures, of drive shafts to take the stresses, etc. This is, almost by definition, a technology that would also allow steam engines, [spinning jennies](https://en.wikipedia.org/wiki/Spinning_jenny), [drop hammers](https://en.wikipedia.org/wiki/Steam_hammer), etc. Is industrialization technology or organization? If one thinks or talks about industrialization, the two are usually jumbled together. The image is about proud, independent guild masters, journeymen, and apprentices being replaced by factory workers under the thumb of exploiting capitalists. This is only partially correct, there were eras and sectors where capitalist organization was coupled with hand tools. In a worldbuilding sense, one might envision early industrial technology without the social organization -- village smiths teaching their apprentices how to turn a cylinder head on a lathe. But at some point, one needs scale to make things work. Iron may be smelted by a blacksmith, but a blast furnace needs large numbers of workers. [Answer] A century after an apocalypse event, the biggest problem with any attempt to build machinery is the memory of what was. People will try to recreate what was, such as buggies and motorcycles, when the background supply chain doesn't exist. Most importantly, politicians will lead people in "cargo cult" type activities building "almost machines" which will waste resources. This question greatly underestimates the social and emotional impact of an apocalypse event. It can take hundreds of years to rebuild society so that someone could explore building machines. When the population is in small 500 person or less villages (and far more will be in the "less" scattered all over the countryside), people will be focused on survival. Mechanical toys can be built when there is excess food production and relative stability, not when people are scrabbling for food and fighting off raids. For example, look at the Yanomami tribe. During one study, a village experienced a raid about once every 3 weeks. Another study found that the death rate from violence was more than what our soldiers experienced in WWII. During such a situation, people do not have the excess time, emotional stability, and social support for exploring building mechanical equipment that will actually work. If you are very lucky, someone will realize that simple machines built out of local materials are possible. These machines will solve a local problem - most likely one for either growing more crops or harvesting them. [Answer] I can't remember where I heard this, but I remember someone saying that you can have steam powered trains running almost indefinitely - because all you need is blacksmithing tools (assuming no catastrophic failures, I guess). While the complexity of diesel components requires parts made with specialty tooling and in-depth experience with a certain level of technology (plus supply chains, etc.). Modern gasoline engines, of course, are very reliant on computers and mechanical parts with high levels of precision - plus the gasoline. I live in a rural area and Antique Tractor shows are routine, with tractors having to be 50+ years old to even be considered antique. They have a reputation of being very reliable and from my understanding they make minimal use of rubber, plastic and electronics. Some of the WWII era tractors used iron wheels because of rationing. The problem is going to be how to power them, as ethanol requires a large amount of grain (that could be otherwise used to feed people). Steam might be impractical for vehicles, because of fuel and water storage needs. What could happen is older farm equipment being used - not as transportation - but for power generation. They could be converted to steam and then used to power grist mills, lumber mills, etc. Maybe most villages have one old tractor that slowly becomes less and less tractor like, as primitive repairs modify them into tools. They could become almost impossible to move, so not something that raiders would be able to steal. Also, if the rail system isn't completely wrecked, it may even be possible to find and repair some antique steam trains to use as actual transportation. I would imagine that this would be somewhat rare and more likely to be found between better-off communities where there are usable tracks between them. But these would be vulnerable to roving bandits and the like. Another potential non-motorized transport system could be horse-drawn trains. It looks like this was used in history, so it seems reasonably practical - if perhaps very limited in capacity and endurance. [Answer] ## 100 years will not destroy the world's supply of vehicles. Quite a lot of pre-apocalypse vehicles are likely to survive the apocalypse, not intact, but with key parts such as the engine block still usable. The US military [stores fighter jets sitting in a dry desert](https://www.desertusa.com/desert-arizona/airplane-graveyards.html) - much more fragile than an old car engine. 100 year old cars are routinely being found forgotten somewhere and restored - just search for "100 year old car barn" and videos will pop up. In a hot wet climate, everything will turn to rust. In permafrost or in desert climates, metal objects can last for a very long time. Car bodies are carbon or low-alloy steel less than 1mm thick, so they won't be driveable, and modern cars dependent on computer ECU will likely be beyond salvage. But engines are thick aluminium and high-alloy steel, resistant to rust. Old carbureted engines will need replacement parts, especially anything non-metal, but many might still be repairable. Restored engines, running on low-quality fuels, will not perform to their original specifications. But even tuned down to 1/10 of their original power, they'll still be better than whatever engine you can build new without large-scale industry. Diesel engines will be strongly preferable, as diesel stores better than gasoline, and they can be run on non-petroleum fuels once that runs out. The vehicles you'd build around these engines, in a society this basic, are likely to be closer to powered carts or primitive tractors, rather than buggies or motorcycles. For hot wet climates, agrarian societies might actually prefer animals to vehicles, since grazing grounds will be plentiful, and the terrain difficult to traverse on wheels. [Answer] I doubt very much that in the situation you describe that there would be any ability to create motorised transport from scratch. With a population size of just 500 and limited access to much in the way of technology everyone will be drawn into farming. Without mechanisation they will be reduced to scythes, ploughing with horses and many more very labour intensive jobs. They will probably have their hands full just growing enough food unless they are in a very agriculturally friendly environment. Those not employed in the fields would be spending a lot of their time making or repairing tools, maintaining buildings, milling floor, baking, cooking, looking after children and animals, repairing fences, cutting wood etc. Nobody is going to have much time for smelting iron, casting cylinder blocks or trying to make pistons or crankshafts and they would probably not be able to do any metal drilling, milling or other machining without the right equipment and machine tools and more importantly without the inclination due to the overriding importance of food production. Any remnants of iron and steel would probably be scavenged and turned into tools. Without trade such small isolated groups would slowly degenerate to very primitive life style using materials immediately to hand and with out genetic flow in the form of moving populations they would become inbred and would probably die out. With trade and genetic flow between settlements there might be sufficient resource to continue in such a pre-industrial society indefinitely. But if every time a settlement grows beyond a certain limit it is destroyed, they would never be able to industrialise and might well develop means to minimise or control their population level for fear of the destruction it would bring. [Answer] ### Totally Feasible This is not only feasible, but is also quite likely to happen in the aftermath of a The Pockyclypse. Since you specify smallish agrarian communities, I'd just like to note that we (mostly urban and suburban types) so frequently underestimate what country folks know, remember and are capable of. I'm seeing a lot of relatively negative answers, when I believe the truth of the matter is that machine culture in your scenario will not only survive but thrive within and past the century mark of your proposal. The truth of the matter is that "improvised motor vehicles" are already a thing. You tube is most instructive in this matter! There are so many ancient tractors (steam, petrol, diesel), engines, and other pieces of useful machinery sitting in barns, workshops, rural industrial places, garages and so forth that the people who are already in agrarian communities will have no trouble making improvised vehicles. Will these vehicles have all the modern comforts and gadgets? No. But you don't really need any of that. A frame, four wheels, a motor, a transmission, a gear box and a steering mechanism is about all you need. Add a choke and throttle and a crank to start it up! [A real life improvised motor vechicle](https://www.youtube.com/watch?v=GOcjSBVVoxM). [Improvised steam powered buggy](https://www.youtube.com/watch?v=c_05tcpmyUU) and picnic lunch. [Destilling Fuel](https://www.youtube.com/watch?v=6sYKFSBknl8) (crude to kerosene, petrol, diesel). [Answer] You may be surprised to hear that one type of improvised motor vehicle which would be both feasible and have a strong economic case in your setting is ultralight aircraft. The economic case is scouting. Any means of detecting these roving bands of invaders in advance would be very valuable, and an ultralight aircraft can scout a large area quickly. As far as feasibility goes, ultralight aircraft is very undemanding. In many respects you can think of it as a very big kite with an engine attached. I would expect that engine to be an air-colled two-stroke, linked directly to the propeller. Because ultralight aircraft is so light compared to the size of its wing, it can take off at surprisingly low speeds, and therefore does not need a large runway. The engine is the only part which must be made of metal; the frame and the propeller can be made out of wood (which is both lighter and readily available), and the wing out of cloth (which even the small settlements will produce to make clothes). The metal for the engine can be easily recycled; a thoroughly rusted husk of a pre-apocalypse vehicle is effectively a lump of metal oxide, and liberating metal from an oxide is a problem solved literally in prehistory. Engine parts can be made using hand-operated tools, and finished using just two machines, both of which can be powered by human labor: a lathe and a drill. This is because in the bare-bones engine that you are producing, only the cylinder, the piston, and the intake and exhaust valves must be made to tight tolerances. It would take much longer though, so be patient. I think the biggest problem would actually be a seal. A post-apocalypse society would probably need to create the engine block in two halves, which would then have to be put together in a way that makes the combustion chamber as close to airtight as possible. That seal must then withstand being in contact with hot combustion gases, at the very least for the duration of the flight. I'm not sure what material would have these properties and also be reliably available post-apocalypse. [Answer] Small ordinary settlements are unlikely to be able to support such technical understanding and skills. But what about eg. monasteries that are located in old factories? People who devote themselves to technology and make their living by providing engines and services could be feasible. [Answer] Instead of threatening your reader's suspension of disbelief, simply use an existing technology that is more likely to last. The Bicycle A bike is not a precision mechanical instrument like an engine, and can operate with some amazingly sloppy tolerances. Lubrication doesn't need to be high quality as long as it exists. I've heard of someone lubricating a chain with mashed banana successfully, so any oily plant residue will work. There are two main parts which will suffer with age no matter how well it has been stored. Anything with rubber in it and anything with cloth/foam (saddle/padding) The saddle can be replaced with upholstery using new cloth and leather or a well-carved piece of wood. Tyres are the biggest challenge, but bikes have been used with solid rubber, and even with wooden or steel tyres in the past, should pneumatics be forgotten. And in your post-apocalyptic world, farming will benefit - this monster needs nothing more than a welder and steel and creativity, and is powered eventually by the food you grow. <https://youtu.be/fVQxlnaFr0s> [Answer] > > takes place about a century after an apocalypse event ... any pre-apocalypse vehicles would be rusted away and unusable, and gasoline would have rotted... > > > The one thing you didn't address, and maybe you're open to playing around with is: What was the technology like before the apocalypse? If we imagine a world with more advanced technology than today, it's easy to imagine how a fallen society might be able to make use of it later on. Some things you could add: * Hermetically-sealed warehouses -- Imagine a warehouse that's fallen into a crack in the earth, and acts as a dungeon to explore; when explorers reach the end there are perfectly preserved items of "ancient technology". * Technology built to last -- If we remove the notion of "planned obsolescence" from the technology, it's quite easy to have things that last a hundred years and keep working. Maybe 99% of the tech has rusted away, but 1% was built out of high-quality materials. * Simple interfaces -- One thing advancing technology helps with is making devices easier to use. Imagine tech with voice activation, simple UI touchscreens, etc. Forget how the device actually works? No problem! * Renewable energy -- Devices could be powered by solar-panel paint, micro fusion engines, etc. If you combine these concepts it's not hard to get to compact, easy-to-use industrial 3D printers, blast furnaces, auto-miners, etc. Since it's based on fictional future tech and a certain level of brokenness, you can easily tune them to achieve exactly what you want them to. [Answer] ### Not the way you describe "rudimentary" Rudimental vehicles will certainly be a thing, powered by steam. Other answers have gone into some detail about this. You can reasonably expect a well-supplied farmer to have a traction engine for ploughing, harvesting and threshing. As with all traction engines, they'll be big, slow, lumbering beasts of burden. More than that - just no. Even high-pressure steam requires more metallurgical skill than your world possesses, so 1900s steam trucks and cars are a non-starter. Internal combustion engines were only possible once this level of metallurgy was achieved, so the same principle rules them out entirely. As for motorbikes, have you even stopped to think about how sophisticated an engine needs to be for a motorbike? The precision engineering to make something that small, with that kind of power output? Your world is a century away from that. [Answer] The other answers concentrated on the metallurgic aspects of a diesel car, but there are other things missing, specifically I'm thinking of rubber tyres. In the described scenario (essentially isolated villages of 500 people) there is probably a lack of natural rubber that cannot be replaced by something else. So, no, there will be no diesel vehicles under the given circumstances. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 1 year ago. [Improve this question](/posts/237285/edit) In my world, people get stronger, faster, and more durable the angrier they are. There is no upper limit to strength. Therefore, in order to limit the strength of an opponent an attacker must limit their opponent's anger. I am looking for an effective way to prevent or mitigate anger. This should be chemical. Question: How can I reduce or eliminate the anger of an unwilling human. * Assume that we are dealing with humans * Assume that there is antagonism or conflict between us. * Assume that this must be delivered in 1-5 doses * Assume that the target is in the already partly angry, but is not so angry as to be impenetrable * Assume that the public dispersal of aerosols is not priority Note: it is true that it would be enough for the opponent's anger to be less than the attacker's. However, I believe it isn't practical to quantify "how angry" the attacker is. Assume for the purpose of this question that the attacker's anger isn't relevant. Finally, please note that I believe this question is asking for an [on-topic finite list of things.](https://worldbuilding.meta.stackexchange.com/questions/6130/catalog-of-question-types/6138#6138) If you believe I have not sufficiently limited my question in that regard, please explain why in comments so I can adjust the question. [Answer] # Fentanyl If someone's unconscious, they can't be angry. Now, you do run the risk of killing your opponent, but absolutely flooding their system with a hideously powerful narcotic will definitely make it really hard to be angry. This is (supposed to be) the mechanism by which the FSB [sedated the occupants of the building during the Moscow Theatre Hostage Crisis](https://en.wikipedia.org/wiki/Moscow_theater_hostage_crisis). Any aerosolized or skin-contact narcotic would do the trick, but the more powerful, the more likely it takes effect before they can get their mad on. If you're really worried about lethal effects, then another option might be: # Rohypnol Any benzodiazepine/depressant that can be aerosolized, ideally one that demolishes long-term memory. How can you stay angry if you can't remember what just happened? From personal experience, I had a cocktail of such drugs for dental surgery. Judging from how it felt after the fact, it must have been painful at the time. I remember none of it, and never got overwhelmed by pain during, because at any given moment, I was only enduring the pain of the moment, without any accumulation. [Answer] Inhibit Norepinephrine or its production Norepinephrine is the neurotranmitter for both fear and anger. If its production is limited, or something binds it, preventing it from doing anything, anger is all but impossible. If kept too low, howeverl it will also make concentration difficult and will likely lead to depression. [Answer] ## [Tetrahydrocannabinol](https://en.wikipedia.org/wiki/Tetrahydrocannabinol) THC is the main component of cannabis. It’s easily delivered in vaporised form and its effects are felt very quickly. These include relaxation, euphoria, stress and pain relief, increased appreciation of music, art and interestingly shaped clouds, and the munchies. You prepare your victim with a spray of high-quality, concentrated ganja extract. Their strength is sapped and they fall to the floor, but honestly, they don’t care, because they’ve found somme really interesting patterns in the carpet. In fact, now that you’re closer, you can see they are pretty cool. Someone tells a joke and it’s, like, really funny. You remember you have some nut bars in your rations. Man, those are some good nut bars. You two bond over your shared appreciation of the Grateful Dead. You can’t remember why you wanted to attack anybody. Peace out, man. [Answer] # Bullets fired from a gun One of the symptoms of elevated anger levels is an elevated heart rate. A great way to prevent elevated heart rates is to slow down the heart by poking large holes in the human it is inside of. This will also reduce how angry they are. If you can reduce their heart rate to zero, they will not be angry at all ever again. > > This should be chemical. > > > The chamber of a gun is really just a high-stress chemistry lab, if you think about it. > > Assume that this must be delivered in 1-5 doses > > > Most of the time, 1-5 doses of bullets should be enough > > Assume that the target is in the already partly angry, but is not so angry as to be impenetrable > > > Perfect, then there’s no reason not to shoot them. If you absolutely have to involve a drug of some kind, dope the bullet with Sarin or VX. That should calm down an entire city block. [Answer] Nitrous Oxide > > Nitrous oxide, commonly known as laughing gas or happy gas, is a colorless, non-flammable gas. This gas is used in medical and dental procedures as a sedative. It helps to relieve anxiety before the procedure and allow the patient to relax. ([WebMD](https://www.webmd.com/a-to-z-guides/what-to-know-about-laughing-gas)) > > > Nitrous Oxide is a mild airborne sedative/anesthetic. It can be sprayed or delivered as a bomb similar to tear gas. As an airborne agent it's possible that the climate may push the gas back on the person delivering the blow. Proper preparation with a filtration mask can protect against most of these kinds of problems. The gas gets its nickname because it makes people feel light headed, relaxed, happy, and giggly. Most sedatives are not airborne. Most are liquids and must be delivered with... A Tranquilizer Dart While the dart is merely the method of delivering the sedative, I can imagine your culture developing a robust tradtion of concealed weapons. Like the cane swords of old and the CCW permits of today, your culture would find ways of carrying small amounts of sedatives in varying strengths should an opponent start winding up to a majest temper tantrum a bit faster than yourself. [Answer] ## Kittens as Service Animals Everyone has pet cats. If anyone feels angry they can look down at their little furry companion and feel the fury melt away. If someone has left their kitten at home (the monster!) then someone else can hold up theirs and those huge round eyes will do their magic whether the angry person wants it to or not. How can you stay mad with these eyes looking at you? [![enter image description here](https://i.stack.imgur.com/UUxMy.jpg)](https://i.stack.imgur.com/UUxMy.jpg) [Answer] Food. [![hangry](https://i.stack.imgur.com/Tiu8w.png)](https://i.stack.imgur.com/Tiu8w.png) <https://www.foxnews.com/food-drink/hangry-is-officially-a-word-in-the-oxford-english-dictionary> Your opponent is angry. Probably he is hungry. He is hangry. I bet you are too. Both of you grumpy gusses need to mitigate your anger. The chemical I propose is pizza. There is antagonism between you and so you will have the delivery person bring two pizzas so your adversary knows you did not put cat hair on his pizza (as you are known to do). Each of you gets his own pizza. You pay as a gesture of goodwill. Your adversary does not think you tipped enough and so tips the delivery person some more. You thought ahead and with the pizza you got your adversary some wings because you heard he likes wings. You got yourself some cheeze bread. You forgot to order drinks. But you remember you have some sodas. It turns out your adversary has 2 beers left also. You two finish all the drinks. When you are done both of you are both less angry. Hardly angry at all. Really more of a food coma because there is nothing left. And it is pretty nice out still. Maybe you can go outside and sit in the grass and talk thru your differences? ]
[Question] [ Humanity is finally reaching the interstellar space and had discovered a terrestrial planet covered in liquid nitrogen, the planet is orbiting a star thrice as massive as Sun but is too further away to produce liquid water for life. I am wondering is there anything we build that can sail on such an ocean for hours? P.S: When the starlight shines on the surface of the ocean despite being so far out it can create a geyser effect that blows up tons of liquid nitrogen into the upper atmosphere! Yup it's that volatile and this is based on actual events on one of the Moon in our solar system. Inspired by [Nitrogen geyser](https://www.universetoday.com/56042/triton/#:%7E:text=These%20nitrogen%20geysers%20can%20send,the%20surface%20of%20the%20moon.&text=Because%20of%20the%20geological%20activity,few%20impact%20craters%20on%20Triton.) and the energy from the star allows it to [split heaven!](https://www.newscientist.com/article/mg12817402-500-science-greenhouse-effect-drives-geysers-on-triton/#:%7E:text=The%20%27geysers%27%20on%20Neptune%27s%20largest,activity%20with%20a%20surface%20temperature) [Answer] [Density of liquid nitrogen](https://www.engineeringtoolbox.com/nitrogen-N2-density-specific-weight-temperature-pressure-d_2039.html) at 1 bar and 79 K is about 798 $g/l$. For comparison water is 1000 $g/l$. When compared with water a boat would sink about a 20% more once put in liquid nitrogen, but unless it has been designed like the [Vasa](https://en.wikipedia.org/wiki/Vasa_(ship)) it should float. Of course be sure that it is properly insulated: you don't want to be stuck wherever you happen to touch some cold surface with your bare skin. For more info, you can rely on [Randall Munroe](https://what-if.xkcd.com/50/) > > What would it be like to navigate a rowboat through a lake of liquid nitrogen? > > > Liquid nitrogen is very cold. > > > Liquid helium is colder, but they're both closer to absolute zero than to the coldest temperatures in Antarctica, so to someone floating on them in a boat, the temperature difference is not that significant. > > > Liquid nitrogen has a density similar to that of water, so a rowboat would float on it, but if you were in it, you wouldn't survive for long. > > > If the air above the nitrogen was room temperature when you started, it would cool rapidly, and you and the boat would be smothered in a thick fog as the water condensed out of the air. (This is the same effect that causes steam when you pour out liquid nitrogen.) The condensation would freeze, quickly covering your boat in a layer of frost. > > > The warm air would cause the nitrogen on the surface to evaporate. This would displace the oxygen over the lake, causing you to asphyxiate. > > > If the air (or the nitrogen) were both cold enough to avoid evaporation, you would instead develop hypothermia and die of exposure. > > > [Answer] # Probably yes Things are buoyant if they can displace water (or, liquid) equivalent to their own weight (well, mass, but I'm not doing the science hard enough and don't want to suggest that I am). Specifically: > > In simple terms, [Archimedes'] principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. > > > Wikipedia says that liquid nitrogen ("LN2") has 80.8% the density of liquid water. I'm not an expert, but that doesn't seem like a big enough difference to make it impossible for a vessel to displace its own weight. The Wikipedia article for buoyancy even has a photo of a coin floating on liquid mercury. I'd guess that vessels built to sail on LN2 would probably be wider than ocean vessels. My intuition is that this increases the surface volume of the vessel relative to its mass, increasing its buoyancy to counteract the weaker upthrust from the less-dense LN2. NuclearHoagie addresses the general problem directly and more succinctly: > > It's never impossible for a vessel to displace its own weight in fluid, you just need to make it big enough... This is totally feasible, as the weight of the boat is mostly related to its surface area, which increases more slowly than the volume due to the square-cube law. > > > ("NuclearHoagie" is a submariner's handle if ever I saw one, and buoyancy is a core concept for anyone who lives in an underwater metal tube filled with atmosphere.) --- Of course, let's not forget that LN2 is pretty cold stuff. That is going to pose some fun engineering problems when it comes to the hull, and to locomotion. If the planet has no atmosphere, any sailing vessel will need to generate thrust by interacting with the liquid. That could mean oars, or a turbine. Or, because LN2 is so cold, perhaps a small heat source aft could generate thrust by causing rapid, localized expansion of the LN2 to push the vessel forward. --- ETA: I think the temperature thing is going to be a huge deal. Sailing on an ocean of cryogenic fluid is going to pose unique problems that will definitely kill your passengers and destroy the boat, even if it continues to float. Wikipedia says LN2 clocks in at -196 C, which is fantastically cold. Why is this a problem? Space is cold, so why isn't it a problem in space? Consider wind-chill. If the air flowing past you is colder than your body, it will carry heat away from the surface of your body. The reason it feels colder when the winder is stronger is because stronger wind is just a greater quantity of atmosphere whipping past you per unit of time, which means more atmosphere to carry heat away from you faster. If the air temperature is 0 C, powerful winds can't cool you to below 0 C, but they will cool you to 0 C faster than if there was no wind. Yes, space is cold, but space is also a vacuum, which is just to say: there is no stuff floating around in space that can absorb your heat energy. So, you'll eventually freeze in space, but it will take a long time. Long enough that we can easily counteract it with insulation and conventional heat sources. (And, also, humans in space do float around because they are weightless. That doesn't make them immune, but it does mean the air inside the spaceship helps shield them.) Wind is just atmosphere in motion. Atmosphere is just very thin soup. Ocean is very thick soup. An ocean of LN2 is pretty thick soup that is also stupendously cold. If the vessel is not moving, the LN2 it's touching will absorb some heat from the ship and warm up. As it warms, it will absorb additional heat more slowly, until it reaches equilibrium with the hull. (Or, until the LN2 undergoes a phase change, but let's ignore that and pretend the LN2 will magically stay liquid no matter its temperature.) If the vessel is moving, it will continuously move away from the warmer LN2 and come into contact with LN2 that hasn't been warmed yet. It's the same principle as wind-chill. If the vessel is moving faster, that means more LN2 is flowing past the hull per unit of time, carrying heat away from the hull faster. An ocean of LN2 is essentially a bottomless energy-void that craves heat. It will relentless drain all the energy out of the vessel. The faster the vessel moves, the greater the drain. First, the hull will be cooled down to -196 C. That will happen very fast. Then, anything in direct contact with the hull will be chilled to -196 C, and so on and so forth, until every object is frozen solid that is being held aloft by the hull. So, where is your human passenger? Sitting on a cushion on a wooden chair with rubber feet, on the floor of the bridge? Where is the bridge? Is it a small enclosed structure standing on heat-resistant risers on the deck? Is the deck in contact with the hull? Well, then, unless the passenger is somehow floating above the chair like magic, that's precisely the route by which the LN2 ocean will leech the heat out of her/him: hull > deck > risers > bridge floor > rubber feet > wooden chair > cushion > space suit > clothing > skin > cryogenically frozen corpse. Okay, let's put the human on an indoor swingset hanging from the ceiling by a very thin -- but extremely strong -- non-metallic wire. It's just one thin wire, right? I think it won't make much difference. Unless you can insert a barrier across which no heat is transmitted, the human will freeze to death, and pretty quickly. Any artificial heat source will also be drained. Even a blazing housefire will go out if you can just lower its temperature enough. Many kinds of electrical battery do not work when very cold. I think radioactivity might be unaffected, but we harness that energy by heating water to steam which then drives a turbine -- and I'd guess that the cooling effects of the LN2 would be more than enough to keep the water frozen solid unless you pulled all the control rods out of the reactor and let it go critical. That would probably melt the ice, just before vaporizing the reactor and the human and the boat. And none of this addresses the likelihood that the structural integrity of some parts of the boat will fail when they get cold enough, which could lead to some kind of partial physical collapse, bringing the human in contact with the deck or hull and thus much closer to the LN2. And none of this depends on the planet having an atmosphere. It's heat transfer through indirect physical contact with the LN2 via the hull and everything the hull supports. [Answer] Absolutely. A very common procedure in biology is to wrap a bit of aluminum foil around the bottom of a vial or something, put in a bit of "embedding medium" such as [O.C.T.](https://en.wikipedia.org/wiki/Optimal_cutting_temperature_compound), take a bit of tissue, such as a lobe of mouse liver, and mash it into the middle of this gooey medium, and drop the resulting little boat into liquid nitrogen to freeze. Often it will float around on the surface. Once frozen, the foil will be removed and little slices of the rest will be cut with a microtome. (My condolences to your astronauts if they get caught up in that) Moral: a well designed boat containing a lot of empty space can float - even if it is made out of steel, which is far more dense than water... or liquid nitrogen. [Answer] Humans are capable of insulating liquid nitrogen from absorbing heat from its surroundings. The usual approach to keep liquid nitrogen insulated from the atmosphere is a specialised type of vacuum flask called a cryogenic storage dewar. If the boat's hull and cabin are fully sealed and made from materials with excellent thermal insulation, it will not require too much heating energy to keep the interior of the cabin warm. Vacuum insulation on a large scale would be tricky. Aerogel would work but is very expensive. There are many commercial insulators (polyurethane foams) that are much better than aerogels. Some boat hulls have a rigid polyurethane foam core sandwiched between fiberglass skins. [Answer] Several other answers have mentioned the threats posed by the cold to the boat's structure and its inhabitants. But if you have a good power supply, there might be an opportunity here to lessen that cooling effect and simultaneously increase your boat's performance. If you place droplets of water in a frypan heated to around 180°C, they will boil away quickly. But if you heat that frypan to around 195°C, the droplets will last much longer, skittering around the surface of the pan. The reason for this is the [Leidenfrost effect](https://en.wikipedia.org/wiki/Leidenfrost_effect). Above the Leidenfrost temperature, which for water is about 193°C, the water in contact with the pan boils, creating a cushion of steam in between the pan and the liquid water. Although steam is hot, it doesn't transmit heat as efficiently as direct contact, so the droplet heats up more slowly (despite the pan being hotter) and thus boils more slowly. Meanwhile, the droplet is essentially hovering, so it experiences almost zero friction, hence the skittering around the pan. I don't have the physics knowledge to work through it in detail, but perhaps the same principle could be applied to create a kind of hovercraft that uses a Leidenfrost effect instead of a fan to generate a cushion of gaseous nitrogen, simultaneously insulating the boat against the cold of the lake and giving a near-frictionless ride. You'd then want something like a fan for propulsion. ]
[Question] [ Here's the idea: A geosynchronous orbit is an orbit that makes sure that the orbiting satellite is always above the same spot on the planet, so its orbital period is equal to a local day there. I've been wondering how to make the orbital radius of a geosynchronous orbit less than the radius of the planet. How would that be possible? [Answer] Easy: Put a moon right above geostationary orbit. If you have a 24h day, and a moon that takes 25h to circle the planet, any satellite orbit at geostationary height would be totally unstable. The satellite would spend 12 days on the other side of the planet than the moon does, and then it will move very close to a really heavy body over the next 6 days, and either end up crashing into the moon or planet, or do a slingshot to escape the planet entirely. Note that this setup would allow for satellites at the five Lagrange points of the planet/moon system, but these will have the same orbital period as the moon does, which is not geostationary. [Answer] You certainly can't make a planet spin too quickly for geostationary orbits to be possible; it turns out that the planet would be on the verge of instability. I'll assume that you're interested in particular in a [geostationary orbit](https://en.wikipedia.org/wiki/Geostationary_orbit), the particular case where an orbiting body stays above the same point on the planet's surface. For this to be the case, the planet's rotation period must equal the orbital period, so by Kepler's third law, the rotation period $P$, the mass of the planet $M\_p$ and the orbital radius $r$ must be related by $$r^3=\frac{GM\_p}{4\pi^2}P^2$$ For a geostationary orbit to be impossible, the orbital radius required for a geostationary orbit must be less than $R\_p$, the radius of the planet. Therefore, the condition you desire is $$R\_p>\left(\frac{GM\_p}{4\pi^2}P^2\right)^{1/3}$$ or $$P<\left(\frac{4\pi^2R\_p^3}{GM\_p}\right)^{1/2}=\left(\frac{3\pi}{G\rho\_p}\right)^{1/2}$$ with $\rho\_p$ the density of the planet. For an Earth-like planet, the critical period is $\sim$1.40 hours. On the other hand, at that point, the centifugal acceleration at the surface would be equal to the force of gravity from Earth itself, and it seems likely that the planet would be rotating nearly fast enough for the planet to rapidly become unstable. If you think about the problem you're describing, this makes sense. After all, you could also interpret the critical period as the period at which a piece of the planet at the surface would be moving fast enough to reach orbit.$^{\dagger}$ On the other hand, you could also consider slowing down the planet's rotation to the point where a geosynchronous orbit would be beyond the planet's [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere). Outside the Hill sphere, the planet cannot retain satellites. Venus, for example, has a Hill sphere of roughly one million kilometers and a rotation period of 243 days. An object orbiting at the edge of Venus' Hill sphere would have a period of 127 days - meaning that a geosynchronous orbit should be impossible. Now, in the question, you specified that you wanted a geosynchronous orbit to require a radius less than the planet's radius; we've seen that such a thing is impossible. However, you can make geosynchronous orbits impossible if you remove that requirement. --- $^{\dagger}$ It also appears that the critical period is quite close to the [dynamical timescale](https://jila.colorado.edu/%7Epja/astr3730/lecture15.pdf), certainly to within an order of magnitude - if it makes sense to talk about such a quantity for a solid planet. This, too, hopefully makes sense intuitively. [Answer] For Venus, synchronous orbit is 1 533 883 km ([How to calculate the synchronous orbit?](http://www.astronoo.com/en/articles/synchronous-orbit.html)) while its [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere#Solar_System) radius is only 1 000 000 km. That's a "slow spinner" preventing synchronous orbits. For fast spinners, HDE 226868 put out calculations showing that for rocky planets such fast spinning is not likely possible. For gas giants, we can theorize a fluffier, faster spinning Saturn (real Saturn synchronous orbit radius is 112 043 km) so that atmospheric drag at that altitude can be too high to maintain a stable orbit. Note that for a fast spinner, any atmosphere above the synchronous orbit would be lost to space, so this setup might not be stable for geological periods of time. [Answer] There are two ways of preventing geosynchronous satellites. The first is for the planet to spin too fast: assuming a planet identical to Earth, and ignoring distortion of the atmosphere due to the spinning, if a day was 87 minutes long an orbit equalling that would have an altitude of 133km; at that altitude, atmospheric drag will bring it down fairly fast. If the day was 86 minutes long, the altitude would be 82km; it is absolutely coming down. At 85 minutes long, the altitude is 32 km, and with a day 84 minutes long, it would need a negative altitude. The second is for the planet to spin too slow. The slower the spin, the further out the satellite would need to be in order to be geosynchronous, and at some point Earth's gravity won't be sufficient to maintain it in a stable geosynchronous orbit. [Answer] Make a large enough and close enough satellite (a moon or a huge asteroid) that will rotate at a significant angle to the geostationary orbit. The influence of it's gravity should make the geostationary orbit unstable. It won't prevent stuff from staying there for short (or relatively short) periods of time though. ]
[Question] [ The universe is dying because it has exhausted nearly all of its resources. Humans became the last species in the universe because of their resilience and sheer willpower. And yet, humanity still doesn’t want to die. Relying on the [Big Bounce Theory](https://www.google.com.ph/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=2ahUKEwiH8pa_84LoAhWIfXAKHft7ArwQFjACegQIDBAG&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FBig_Bounce&usg=AOvVaw2MERJS0l3zJxSRpOD9UB-h), scientists developed a sort of “time capsule”. It was designed to hold up to 200 people, plant seeds, and animal dna. The people, seeds and animal dna would probably have to be frozen for trillions and trillions of years until another Big Bang was to happen. Requirements for the “time capsule” 1. It would most likely need to be incredibly heat proof (the sheer light emanating from the big bang would probably melt most metals) 2. It needs to be airtight, at least until it could land on a habitable planet. 3. Regarding #2, it needs to be corrosion-proof as well. 4. None of the above would be possible if they placed the time capsule right on top of, or very near the epicenter of the Big Bang. 5. A predictor system, before the Big Bang 2.0 Electric Boogaloo happens, the time capsule needs to predict where a habitable planet will pop up in the new universe and crash land there while still in the old universe. How is it possible that a universe that literally has no more materials respawn??? 1 word, magic. Universe 2.0 now has magic, aka Mana. We all know how magic breaks all known laws of physics from the fictions we read. Who knew that it could save the laws of physics from nothingness? But that’s besides the point, the most important question; how do I design, build and finally, “pilot” such a thing? Ps: this is a crudely drawn representation of what I think may happen: [![enter image description here](https://i.stack.imgur.com/XxOe1.jpg)](https://i.stack.imgur.com/XxOe1.jpg) [Answer] Instead of trying to freeze something for that long and have it remain viable, I would suggest that you could consider hiding away under the event horizon of a rotating massive black hole. There are a lot of interesting things you can potentially do with black holes that I won't go into here, but there are a few important things. * The event horizon of a very large black hole is a surprisingly benign thing... you can cross over it without being mangled by tidal forces as you would in a much smaller black hole. * Black holes are exceedingly long lived... there's no danger of even massing as little as our sun evaporating within your trillion-year limit. * The enormous mass of a black hole causes relativistic time dilation, so if you were close enough (and, of course, well within the event horizon) those trillions of years could pass outside without you really noticing. * There's a possibility that black holes could persist through a new big bang: [Persistence of black holes through a cosmological bounce](https://arxiv.org/abs/1104.3796). In our universe, it would appear that once you've crossed an event horizon that's where you'll stay until you get reduced to a spray of radiation by the eventual collapse of the black hole in the far, far future. In your Universe 2.0 though, magic exists, and that means there's scope for travel through an event horizon. You tweak that particular bit of handwavium to prevent time travel, but (possibly limited) FTL would be just fine, and so the contents of your black hole can simply pop out when it seems like a good idea. Discovery of the news laws of physics can be made by the "time capsule" spaceship inside the event horizon, which can then cross the event horizon and investigate the new universe. If nothing interesting is immediately available, they can return to the highly time-dilated orbit they survived the end of the last universe in and allow large amounts of time to pass outside until the local environment becomes sufficiently benign or interesting to make it worth leaving for longer periods of time. [Answer] A Pocket Dimension Scientists learn how to create pocket universes. Being a separate universe even if somewhat compact, it's time flows differently to the main universe and can be controlled. This means the inhabitants can be effectively frozen in time and sample the main universe once for a fraction of a second every billion years or so time is effectively sped up passing a trillion years every minute or so. Once a new universe forms, time can altered down while searching for a new planet or materials to create a new human habitat. Pocket universes are a common trope in many scifi and fantasy series from Doctor Who to Dungeon and Dragons. [Answer] You're already talking about Human society existing towards the end of the universe. This is an excessively long time by any standards to even think that current technology has any real meaning. So a major handwave in the style of any technology sufficiently advanced is indistinguishable from magic is probably acceptable. Examples of such handwaves from existing fiction are; 1. [Tau Zero](https://www.goodreads.com/book/show/240617.Tau_Zero) - Go faster. You don't need to store that much oxygen or worry about corrosion if in your frame of reference very little time is passing. Whizzing around the emptying universe at very close to light speed will do that for you. 2. [Across Realtime](https://www.goodreads.com/book/show/167844.Across_Realtime?from_search=true&qid=9lOfjvDoqr&rank=1) - Stasis bubbles called "Bobbles" are for all intents and purposes single use force fields that last as long as you need them. Jump in, switch it on, an bingo you're there. 3. [Flood](https://www.goodreads.com/book/show/2111634.Flood?from_search=true&qid=JRq1M86Dav&rank=3) - Pocket Universe. While being mostly an aside to the main story, Arc3 in Flood leaves a flooding earth behind by tucking itself into a pocket universe and heading out across the stars. Nudge the effects a little and your pocket universe can actually become the seed of the next one. [Answer] Don't try to pass any physical objects forward into the next universe. Instead, use the new universe as a machine to make them for you. Humanity creates a device which predicts (or causes) a new universe. The device perturbs the state of the early new universe just ever so slightly and perfectly to ensure a habitable planet forms around a habitable star upon which evolves humans, plants, and animals. The calculations required are outrageous, but if humanity (or whatever counts as humanity) has survived the $10^{40}+$ years into the [Black Hole Era](https://en.wikipedia.org/wiki/Future_of_an_expanding_universe#Black_Hole_Era) their technological advancements and computing power would be equally outrageous. A similar idea is used in [Greg Egan's Diaspora](https://en.wikipedia.org/wiki/Diaspora_(novel)) where... > > humanity has been fully digitized. After learning all they can about our universe, they decide to "travel" to neighboring universes by injecting, particle-by-particle, a machine which can make a machine which can make copies of themselves. > > > Alternatively, humanity perturbs the new universe to leave the plans for itself in the [Cosmic Background Radiation](https://en.wikipedia.org/wiki/Cosmic_background_radiation) in the hopes that a future advanced civilization will find those plans and recreate humanity. If they're really good and really specific, they could recreate an exact duplicate of people at the moment of their encoding including all their memories; presumably with some tweaks to survive in the new universe's physics. In effect, humans would "go to sleep" in their old universe and "wake up" in the new universe. Like the [philosophical Swampman](https://en.wikipedia.org/wiki/Swampman) which is an exact duplicate of, but has no continuity with, the original person. # See Also * PBS Spacetime's [How Will The Universe End?](https://www.youtube.com/watch?v=Qg4vb-KH5F4) * PBS Spacetime's [The Big Bang & Cosmic Inflation playlist](https://www.youtube.com/playlist?list=PLsPUh22kYmNCc3WCKb5yF136QSRf0xErm) * Kurzgesagat's [The Black Hole Bomb and Black Hole Civilizations](https://www.youtube.com/watch?v=ulCdoCfw-bY) * PBS Spacetime's [Are There Infinite Versions Of You?](https://www.youtube.com/watch?v=qT110-Q8PJI&t=3s) [Answer] If you are have an infinite universe, there is no need for a time capsule. [The Poincaré recurrence theorem](https://en.wikipedia.org/wiki/Poincar%C3%A9_recurrence_theorem) already guarantees that given an infinite universe (or equivalent) any given state of existence with be repeated an infinite number of times. So, you can count on the reproduction of our world with the same people on it having our memories too. One could quibble that this is not the same thing, but those in that other universe will believe it to be the same thing, including version we they remember having built the time capsule and living through the big crunch and big bang. Try to remember that infinite is not at all like just having lots and lots of zeroes. ]
[Question] [ I'm allowing for approximately 150 years of technological advancement. This is in Earth's future, so I want to be realistic based off of what we are capable of now and projections for declining resources in the future. The space station is orbiting Earth, but at a distance, and doesn't rendezvous with the surface, so it can't refuel. Would solar power be adequate to sustain life support and other systems? [Answer] I can think of at least four power sources: 1) Solar Power, which is used in the International Space Station. Solar panels are, however, vulnerable to micrometeorites and fast ionized particles in the solar wind, but it would be possible to have microrobotic repair systems. 2) Catching He3 from the solar wind for fusion power. Since this He3 is ionized, it is possible to catch it with a magnetic field, similar to how a [Bussard ramjet](https://en.wikipedia.org/wiki/Bussard_ramjet) would catch ionized hydrogen (which might also be used, though pure hydrogen fusion is more difficult than He3 fusion). A magnetic field would be less vulnerable than a solar panel, and it might even protect the space station itself from fast ionized particles. 3) Using a giant wire loop to harvest energy as the station moves through the Earth's magnetic field (as described in David Brin's short story ["Tank Farm Dynamo"](http://www.davidbrin.com/tankfarm.htm). This, however, has the side effect of slowing the station's orbital speed, leading to a slowly deteriorating orbit. Hence, it would only work in combination with something like a solar sail that adds speed to the orbit at the same rate. This solar sail could double as a solar panel, with the vulnerabilities mentioned above. 4) Power beamed from the surface as microwaves (assuming there is still a civilization on Earth). Microwaves have been suggested as a way to [beam solar power from orbit](https://en.wikipedia.org/wiki/Space-based_solar_power) to the Earth's surface, so would obviously also work in reverse. A microwave [rectenna](https://en.wikipedia.org/wiki/Rectenna) would be far less vulnerable than solar panels. [Answer] In terms of energy, solar is the way to go. All the energy stored chemically and kinetically in all the planets, comets and asteroids together pales in comparison with the energy stored and provided by the sun. If you haven't already familiarized yourself with the [Kardashev scale](https://en.wikipedia.org/wiki/Kardashev_scale), now is a good time. This is a paper from 1964, widely popular in science and sci-fi. One of the conclusions here is that if you are near a star, you should go solar - if you are using any other power source, you are likely primitive. However, do take note of [Shadowzee's answer](https://worldbuilding.stackexchange.com/a/151429/21222) - your energy source may be abundant, but nothing else will be. If you require continuous human occupation of the station you need to either constrain the timespan of the mission, or handwave where the food and water are coming from. Also the air slowly leaks away into space - in real life, a resupply mission usually includes some amount of atmospheric gases as well. [Answer] No. It's not about being able to have enough energy. There would simply not be enough resources available for a closed system like a space station to sustain itself. They would need to recycle their air, water and waste perfectly to ensure the system could sustain itself. They would not be able to support a large number of additional life, like children due to the limited resources or expand their living structure. Parts wear out, things need to be fixed, you need to go outside. Things will be wasted. And since they can't recover them from the surface they are doomed once they run out of supplies eventually. So power is the least of your worries. You need raw materials. Protection from micro comets. And some form of entertainment and exercise on board so your astronauts don't go mad with boredom. [Answer] If the space station is designed and built 150 years in the future there is a strong probability that fusion power will be perfected by then. Presumably the water supply on the station will be extra large and will have more water than is needed for other purposes, so that from time to time some of the water will be broken down into hydrogen and oxygen and the hydrogen will be sued a a fusion fuel for the fusion power generator. Presumably the space station will also also have giant solar panels for electricity, and maybe a giant mirror to focus sunlight to heat water for a steam turbine to generate electricity, so the station can use either solar power or fusion power or both at the same time. And possibly your "space station" is actually a space habitat, a sort of space city with a population of thousands. If you are not familiar with concepts of space habitats you might want to learn about them. And if that space habitat was provided with space ships when it was built, it may sometimes send expeditions to rendezvous with asteroids and comets to bring back raw materials to be used by the habitat's 3D printers to make objects and replace matter lost from the habitat. The amount of energy and thus fuel needed to rendezvous with an asteroid or comet tens or hundreds of millions of miles away and return with cargo might be far, far less than that needed to land on Earth just a few thousand miles below and take off again with supplies for the space station. [Answer] Fission would be perfectly viable in 150 years. We have existing systems that fit onto submarines and military ships now. Assuming realistic physics, fission will give you all the power you need or could want, up to the limits of how well you can afford to cool your reactor in space. I would assume active cooling, where heat is pumped into the radiators, not just passive cooling. The basic objections on Earth and in the modern era to fission can be broken into two categories: Technological, which can probably be overcome in 150 years, and questions around handling waste. But if we're in space to that extent in 150 years, handling waste is easy. Earth may not be full of places we feel like we can stick waste, but space is. Space is already an irradiated wasteland, we can't really make it worse in that regard. Plus, we should not assume in 150 years that the same social attitudes are in play; if a space civilization literally depends on generating power to survive, they may have somewhat different opinions than those people on Earth who can afford to turn off all their machines and go stand outside, where clean water literally falls into their mouths if they wait long enough. That's not how it'll work in space. [Answer] Solar Thermal is the future Don't forget solar power is not limited to photovoltaic collection. A water-based solar thermal plant which focuses unlimited solar energy using simple light-weight reflectors can generate massive amounts of mechanical energy which can be used to power low-tech electricity generating turbines as well as machinery such as hatches and tools. Since your station is isolated its water supply would have to be closed-loop which would not be a problem for internal steam circuits. Leakages of non-toxic water would simply be recollected by the environmental systems. Steam circuits would require heat radiation elements which could simply combine with the stations climate control coolant loops. In an extreme emergency steam could also be used as a propellant to alter the station's orbit. Steam power technology isn't sexy so it rarely makes it into sci-fi milieus. But in reality it would be a smart use of simple physics for space-based colonies. ]
[Question] [ In the world I'm building, there is a single continent. However, in the deeper parts of the ocean, there are hydrothermal vents. They're pretty necessary to my story, but I can't figure out why they would be there as to my knowledge they usually need to be near cracks in the tectonic plates. I don't know if it's worth noting, but the core of my world is very small and there is little magma to be found. The hydrothermal vents are also about 16 500 ft down instead of around 16 000 feet. [Answer] [Hotspots](https://en.wikipedia.org/wiki/Hotspot_(geology)), [Hawaii](https://en.wikipedia.org/wiki/Hawaiian_Islands) and [Yellowstone](https://en.wikipedia.org/wiki/Yellowstone_Caldera) are two of the most active geothermal/volcanic areas on Earth. Both are sited in the middle of tectonic plates rather than along the edges where most volcanism occurs and both occur at fixed locations that are fed heat and magma from great depths. Such locations could be prime candidates for subsurface geothermal vents. Alternately you could have a "double-ring" plate system in which spreading zones, along which your thermal vents would be, could feed crust into subduction zones all around the continent. This will mean that there are tectonically and volcanically active mountains all around your one continent. This is not a situation that is stable over geological time, but could be maintained for a long time. This would be like the modern pacific basin only more so, with the ocean being around the continent instead of the continent around the ocean. [Answer] You can have tectonic plates even on a water world, that is still "land" under there, you just have enough water to cover it all. In your case, any tectonic plates carrying enough land to break through water are all adjacent to each other; just like our continents were once all adjacent. Look at early Earth and [Pangaea](https://en.wikipedia.org/wiki/Pangaea) for an example. With multiple plates you can still have mountains, valleys, etc. No problems with it, just as you have it. Any tectonic plate joins under the ocean are just plates that don't carry enough land to be seen above water. [Answer] No need for the single continent (let's hypothetically call it "Pangea" -- all earth) to have always existed, or for it to always exist in the future. <https://en.wikipedia.org/wiki/Pangaea> > > Pangaea or Pangea ( /pænˈdʒiːə/) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago, and it began to break apart about 175 million years ago. > > > Those hydrothermal vents are part of the undersea mid-ocean ridges which pushed the earlier continents together... By en:User:Kieff - File:Pangaea continents.png, CC BY-SA 3.0, <https://commons.wikimedia.org/w/index.php?curid=8161694> [![enter image description here](https://i.stack.imgur.com/0UgBl.png)](https://i.stack.imgur.com/0UgBl.png) [Answer] Natural nuclear reactor. Nuclear fission makes a lot of heat, which is how we use uranium to generate power. Naturally occurring concentrations of uranium can undergo nuclear chair reactions naturally, and generate a lot of heat. The Wikipedia article details a naturally occurring fission chain reaction at a site called Oklo. <https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor> > > Mechanism of the reactors The natural nuclear reactor formed when a uranium-rich mineral deposit > became inundated with groundwater that acted as a neutron moderator, > and a nuclear chain reaction took place. The heat generated from the > nuclear fission caused the groundwater to boil away, which slowed or > stopped the reaction. After cooling of the mineral deposit, the water > returned, and the reaction restarted, completing a full cycle every 3 > hours. The fission reaction cycles continued for hundreds of thousands > of years and ended when the ever-decreasing fissile materials no > longer could sustain a chain reaction. > > > In your world there are multiple such deposits. If they are undersea that is good because it will be harder for the groundwater to boil away. The reaction will continue until the fissile materials are depleted. ]
[Question] [ In my world, there's an individual (let's call him 'Imm') who takes it upon himself to guide all societies in the direction he thinks is best. To protect himself from repercussions (as well as everyone realizing he's immortal), he uses magic to alter reality in a limited fashion: after he speaks to someone, their brain (and anyone who saw them together) reconfigures to make them think any ideas he gave them are their own and he never existed in the first place, and anything written down (or otherwise recorded) about him becomes illegible or otherwise changes to make it appear he doesn't exist. This magic "kicks in" automatically when he's done his part and doesn't require him to be aware of a memory or recording for it to be altered. I can think of a number of solutions for identifying Imm, but these all rely on the belief/knowledge that Imm exists. Employing magic to check for altered memories is possible but, again, relies on the belief/knowledge that memories are being altered. Magic in this world is on the wane, so it isn't the first thought for most people. If it's possible, how could an organization in a Medieval setting uncover Imm's presence in the world in order to retaliate against him or undermine his efforts? [Answer] > > “On entering the house, however, I examined, as you remember, the sill > and framework of the hall window with my lens, and I could at once see > that someone had passed out. I could distinguish the outline of an > instep where the wet foot had been placed in coming in. I was then > beginning to be able to form an opinion as to what had occurred. A man > had waited outside the window; someone had brought the gems; the deed > had been overseen by your son; he had pursued the thief; had struggled > with him; they had each tugged at the coronet, their united strength > causing injuries which neither alone could have effected. He had > returned with the prize, but had left a fragment in the grasp of his > opponent. So far I was clear. The question now was, who was the man > and who was it brought him the coronet? > > > “It is an old maxim of mine that when you have excluded the > impossible, whatever remains, however improbable, must be the truth. > > > * The Adventure of the Beryl Coronet. <https://sherlock-holm.es/stories/html/advs.html> Sherlock Holmes could find him, by deducing that he must exist. If the world changes such that it has no trace whatsoever of Imm, then it is impossible. But suppose that although he covers his written record / painted record / memory in minds his actions have consequences. His wet instep will leave a mark on the floor. A keen observer and deductive reasoner of the Holmes school could work backwards from actions and consequences that had occurred to conclude that there was an entity who had carried out these actions, but that all other persons in the environs of these actions had forgotten completely about this entity. Once that is established he could link these occurrence to similar occurrences and perceive a pattern. This would take some writing skill to pull off but it would be a great thriller. A key aspect would be that the Holmes equivalent must take great care not to let his deductions be known, because Imm might mind wipe him. I am imagining a part of the story where there are cryptic clues found by Holmes which are actually reminders left by his past self to his future mind wiped self: not written information about the entity Imm (which would be wiped by Imm) but of the possibility of mind wiping. Once he had concluded that a memory wipe was possible he would realize the possibility that his own memory might be altered to forget his conclusions so far about the case. His future self will be warned of this possibility. The way to find Imm is to be more clever than Imm. > > “As a rule,” said Holmes, “the more bizarre a thing is the less > mysterious it proves to be. It is your commonplace, featureless crimes > which are really puzzling, just as a commonplace face is the most > difficult to identify. But I must be prompt over this matter.” > > > “What are you going to do, then?” I asked. > > > “To smoke,” he answered. “It is quite a three pipe problem, and I beg > that you won't speak to me for fifty minutes.” > > > * The Red-Headed League is Dissolved. This story is unreeling in my head. Deduction of the existence of Imm is fine but that is only the first 5 chapters. Once his existence is deduced and Imm is confronted then the fun part begins: the reason why Holmes has found him. > > The man sat tiredly on the divan. "If you are going to be so > persistent about it then fine. You have worn me down. What is it that > you want?" > > > "I'm sorry?" said Holmes. "Have I been persistent?" > > > The man exhaled through his nose, looking at the carpet. "This is the > sixth time you have walked into my parlor and told me of my nature." > > > "The sixth!" exclaimed Holmes. "I had calculated this was the third. > I do beg your pardon." > > > * my own. [Answer] The best way would be to have it start with a "kind" of witness who didn't necessarily see what he did, but see the immediate effects, and get suspicious, perhaps noticing the uncharacteristic behavior or the person who's mind he changed. Then, have it build up by more people noticing the strange actions of other powerful/important people. Perhaps a group of "conspiracy theory nuts" start gathering information on strange occurrences of global phenomena get the right information for the wrong reasons and blame aliens or some other source. Make the conspiracy folks nutty enough to break into some government organization where they are arrested and their things confiscated. While pouring through their strange theories for sheer laughs, someone at the agency notices that they might be on to something, not through any direct sign of his existence, but by the behavior changes of people he's affected. Then, they start looking for just what is causing this. Maybe at first they really think it is aliens? While our hero can mask his affects, a careless purchase, an auto accident, a run in with the police, or something else he does puts him on the grid, and gets someone's attention, establishing a single point where he's near someone when this odd change in ideas occurred. Build from there. [Answer] The time period of the story would depend on the exact mechanics, but in general you could have the devil be in the details, or rather the meta-data. Basically, even though your immortal changed reality around him, he failed to change something, or some butterfly effect belies his existence. Let me go into a technical example. Say I have a database with a table, and it has records in it numbered 1-100. Looking at the table one day, I notice that there's no record 73. There should be a number 73, but it is missing. I have no way of immediately knowing what record 73 should be, but I know it is missing. This inspires me to dig deeper, add logging to the database so I can figure out what happens in the future, and so on. Sometime in the future I have another missing record, say record 97. Looking at my new logging, I see that none of my processes or jobs deleted that record, which deepens the mystery and so on and so forth. In the real world, perhaps there's some meta-record of the event. In more modern times, perhaps a recording exists of what was said, or an image or video exists of someone talking to a mysterious figure that nobody remembers. Maybe in a more ancient timeframe, it is a painting or a sketch. Maybe some tailor starts making clothing that looks a lot like your immortal's. Maybe men start wearing their beards in his style, or women start putting their hair in her style. There's a lot of little subconscious things that could be triggered, even if all memory gets removed. There's a really cool phenomenon that you might want to play with called [Collective False Memory or the Mandela Effect.](https://en.wikipedia.org/wiki/False_memory#Collective_false_memories) Basically, a group of people all believe the same, false event to be true (for example the widespread belief that Nelson Mandela died in the 1980s, even though he didn't die until 2013). These collective memories could be the result of your immortal rewriting reality, perhaps some people are sensitive to it, or something else happens that causes them to believe the "real" timeline over the new one. I will say allowing your immortal to actually rewrite reality makes this more complicated. In theory, rewriting reality means the event never really did happen (which would also mean the idea was never given to the individual he talked to). Altering memories is far "easier" to do in a narrative context. [Answer] Having an individual who had sufficiently rigorous mental thought patterns, who prided themselves on thinking in a more-or-less deterministic way, might come to the conclusion that they were being tampered with if they reviewed their thought processes and determined that the logical leaps they made were absolutely not in line with their usual mode of thinking. So if this individual, who prided themselves on thought A leading to thought B leading to C due to a rigorous amount of mental training, were to review their memories and realize they went from A to X to Y to Z, they would suddenly find themselves confused as to why this happened, and probably correct the course. If the occurrence repeated and they were certain they were not under the influence of alcohol or other substances, they might grow more concerned. If such individuals were meeting together (perhaps in a sort of help-group, the Path of Rational Thinking or somesuch) and more than one of them was so affected, they might feel the need to investigate further, which could lead to your magical detection. (Such practices IRL require review of one's thought processes, pruning for biases and other mental glitches. Discovering a recent memory that appears to fall into the trap of a bias that had been mastered years before would be quite shocking, moreso if the recurring bias appears to be systematic and attached to a particular location, topic, or time. Doubly so if others start to notice a similar pattern.) [Answer] I like both @Richard U's and @Marshall Tigerus's approach to the problem. My approach is not much different, yet I hope to refine the points.If I understood the premise correctly, all records of Imm's existence and actions and influence get deleted by powerful magic that he casts. I conclude therefore that there exist two traces that qualify suspicions: 1. Traces or residual magic fingerprints in places where no such were expected to be found - and maybe of a particular school/type (e.g. psionics). 2. The undeniable fact that people DID change opinions about issues (maybe some deeply held ones). This always makes close people suspicious, which may be paranoid enough to suspect witchery/hexing (I even know people IRL that would go down that path).Basically, what happens is that people get suspicious, people talk to more people, and since Imm might be too busy trying to influence all the influencial people of the cultures towards his goals, the not-so-influential (but close enough to them) begin to suspect and investigate.In my opinion, suspicions about his existence and activities will never get above the 'conspiracy theory' level in any society, since his magical capabilities should be able to always 'downtone' any dangerous approach to the correct conclusion. Unless he is blindsighted on some quarter (in love?)... [Answer] How about his magic works against him? > > anything written down (or otherwise recorded) about him becomes illegible or otherwise changes to make it appear he doesn't exist. > > > IRL I am a research scientist; and I have worked in facilities that employ video/audio recording 24/7 by multiple cameras and systems. Due to security issues, a similar situation exists at my sister's home where she keeps a home office; everything is recorded. Suppose I had access to such a system, and suppose Immm relies only on his magic to erase any record of his presence. Further, suppose I am in the habit of reviewing such recordings: Wouldn't I find it curious that at the point I have one of my biggest ideas, one that may transform society or science, the video I want to review that captures that moment is blurred for an hour with NO audio, either, then comes back with me scribbling furiously on a filled white board? How improbably convenient (or inconvenient). And if, like in some facilities, there are multiple independent recorders, virtually impossible for them all to fritz at the same moment for the same amount of time: In some such facilities people would be fired, perhaps court martialed and suspected of treason, for allowing such a breach to occur. Their entire job is watching such videos as they happen. Heck, I might be suspected of tampering with the mechanism to hide an illegal meeting in a highly classified area. No video AND no audio on three independent systems? That doesn't happen by accident. [Answer] If you give this character unlimited power over memory, he will have unlimited power over memory. Limit what he can do, and then we can explore how to deal with him. In Dr. Who, a foe like this was uncovered: The Silence. They had a unique ability that you can only remember them while you're looking at them. Look away and you forget you ever saw them. The protagonists dealt with this, in part, by keeping a tally on their own body with permanent markers. The Silence could make them forget, but they couldn't undo the marks on the skin. This is obviously not powerful enough on its own, because your character has infinitely more power than The Silence. However, what if his memory wiping abilities aren't perfect. What if it's possible for a particularly zealous individual to latch onto what happened and remember it, just enough to make a mark. That would provide the opportunity for discovery. From then on, it's just a matter of indoctrination to teach people how to have a memory that your character cannot wipe. That or eyepatches, but that's an entirely separate part of the plot arc. [Answer] There is a very successful Japanese piece of comic (manga) called Death Note that plays with the same principle. The antagonist is given a magical book in a non-magical world whereby he can kill someone by writing their full name in the book and manipulate how they die. For example, by default the victims will die of heart attacks so about 10 death row criminals die of heart attacks after writing their confessions. It is immediately spotted by special forces that this is weird but there is surely no way it could happen intentionally when no footage of the deaths show interference. The protagonist then takes on the Sherlock Holmes idea that when all the improbably are eliminated, whatever impossible must be the truth, thus opening his mind to supernatural causes and pin pointing where the villain lives by selective media distribution about criminals and letting inside information out to backtrack how he has a way into the system whilst the protagonist is hiding his identity and communicating to his team through distorted voices and emails. Similarly your protagonist would have to analyse all the abnormal behaviours and form a pattern. Find the intention by analysing the patterns and figure out which ordinary citizen is most inclined to do such things as I assume your immortal adopts an alter ego for his day to day living. A series of clever chess moves to then find the immortal's weakness (human needs, greed, romance etc.) and exploit it. Death Note is a great read even if you read the summary on Wikipedia as the plot is very clever and brilliantly executed which will hopefully give you some ideas with the whole deduction and mind tricks thing as offered in other answers. [Answer] Does this automatic effect have a range? If not, someone spying on him from afar might work. Or perhaps someone using the magic of prophecy or scrying could witness this from afar or before/after. Using deduction, perhaps it is possible to create a paradox. If you have a group of people that believe he exists, through deduction, you could create a scenario where one person goes to investigate and thus gets their mind altered. If the other two people are able to monitor this, they will either confirm their suspicions, or their minds will alter as well. A third person can check the 2nd person, and so on. If you create the chain long enough and use quite a dramatic method of proving it, basically increasing the amount of rewriting that would be required to cover it up as high as possible, it may reach a point where either imm runs out of 'magic' to be able to create such changes, or that it's impossible to change the world sufficiently without causing complete mayhem. For example, let's say a group of people build a giant monolith. The chief engineer declares that due to his suspicion, he will place a brick with 'imm is real' carved on it, at the bottom which if he doesn't place, will cause the entire structure to fall down after a week due to too much stress on the rest of the bricks. When it is completed, he will seek out imm to find out if it is true. Imm alters his memory so that he forgets, or doesn't think imm is real. Imm also alters anything recorded, so he removes the brick from existence. The tower topples and the entire group then knows Imm is real. If you can be even more clever and create a paradox whereby Imm interfering will reveal his existence, and attempting to undo the revalation of his existence will prevent something that must occur from occurring, he will be powerless. This sounds like a crazy rambling but I hope you understand the gist of what I'm trying to convey! ]
[Question] [ Would it be possible to build a space elevator from the surface of the earth to the Moon with the following characteristics? * It would be attached to the Moon, using it as counterweight. * On the surface of the earth, it would anchor on different bases that were built following the orbit plane of the Moon. It would work like this: when reaching a base, the elevator would lower a cable that holds the end of the elevator, anchors it to a fixed base, stays there until the looseness of the lower cable is lost, then it detaches from the base and "flies" to the next base. How feasible would this be? Are there any examples on the sci-fi literature? I remember the Cradle from Seveneves, but it used the orbital ring for moving it. [Answer] Totally unfeasible. For a detailed explanation, you can read this episode of [What if](https://what-if.xkcd.com/157/). In short: > > In real life, we can't put a metal pole between the Earth and the Moon. The end of the pole near the Moon would be pulled toward the Moon by the Moon's gravity, and the rest of it would be pulled back down to the Earth by the Earth's gravity. The pole would be torn in half. > > > > > Another problem with this plan. The Earth's surface spins faster than the Moon goes around, so the end that dangled down to the Earth would break off if you tried to connect it to the ground. [...] Asking how fast the pole is moving relative to the surface is effectively the same as asking what the "ground speed" of the Moon is. This is tricky to calculate, because the Moon's ground speed varies over time in a complicated way. Luckily for us, it doesn't vary that much—it's usually somewhere between 390 and 450 m/s, or a little over Mach 1—so figuring out the precise value isn't necessary. > > > [![enter image description here](https://i.stack.imgur.com/5i7yf.png)](https://i.stack.imgur.com/5i7yf.png) > > There's one more problem: The Moon doesn't always stay the same distance from Earth. Its orbit takes it closer and farther away. It's not a big difference, but it's enough that the bottom 50,000 km of your fire station pole would be squished against the Earth once a month. > > > To put it in Randall's words > > That thing is definitely a safety hazard. > > > [Answer] Not feasible Cool idea, but it has some serious problems. 1. The moon wobbles, the Earth wobbles, weather causes the permanent end of the cable hanging mid-atmosphere to wobble. That thing would be all over the place and destroying everything it came in contact with. Birds. Planes. Superman. Everything. 2. Because that cable is seriously wobbling, the stress on the cable and, more importantly, the stress on the connection at the moon would be under horrific stress. Yes, we could handwave this by claiming the cable is unbreakable and the anchor on the moon was a bar that pierced the moon through and through. But the heat, the stress, the vibration... And we're not talking about a minor mass but one that's very noticeable to the moon. If the anchor weren't ripped off of (or out of) the moon, there would be at least two points of heat that would make transit a serious challenge: the anchor point and a standing wave point somewhere along the cable. 3. I'm not convinced that, once attached on an anchor on Earth, the cable could stay in place for longer than a fraction of a second before it would get torn away, or would destabilize the anchor. But, maybe if we modify your idea a bit... Let's build the Earth's first megastructure! Have you ever seen those tracks hanging from the ceiling in hospitals for the curtains around beds? Hold that thought. Let's build a track around the Earth that matches the average orbital path around the Earth. I'm ignoring all the nasty calculations due to the Earth's axial tilt, the moon's orbital inclination, etc. It won't simply be around the equator. It will have of necessity levitating magnetics, dynamic power generation!, and some of the best material science humanity has ever seen. Now, let's build an anchor on the moon with a high quality (for the sake of conversation) spring-loaded spool that can maintain the tension on the cable as the moon and Earth wobble. As you can imagine, that cable will be bookin' around the Earth at tremendous speed! Curiously, it will be traveling counter to the rotation of the Earth (because it's actually moving more slowly than the Earth). That's going to have consequences for weather (heat, wind, etc.) and consequences for airplanes, balloons, bottle rockets, space stations, etc. Let's ignore all that. Obviously you can't just have an elevator. It's no big deal for people and goods on the moon where the anchor isn't moving (other than back and forth through the carriage... but that's just a design issue. Kinda cool getting on the carriage and watching the cable sliding through it...). But here on Earth you can't just stop the carriage and step on like a Ferris Wheel. Take your arm off, that would. Let there be cars along the rim of the track all along the track that allow for goods and people to be accelerated to and decelerated from the velocity of the cable. Let the connection between said cars and the cable carriage be ridged and well protected 'cause hundreds of meters per second is way, way, way beyond hurricane force winds. Finally, remember when I mentioned dynamic power generation? This whole process could power itself and probably several major cities (if not a whomping lot more) so long as the draw didn't cause measurable braking. Boom, baby. And I'm handwaving the effects of wind passing along a long string anchored at two points. Look up "standing waveforms." The good folks in that carriage are in for the ride of their lives. Better have air sickness bags. BTW, considering the somewhat fanciful movies involving megastructures around the Earth in the last ten years, I'm claiming the movie rights for this one. It's no more silly than any of the others and has much more dramatic appeal. Let's see Alita climb this cable! :-) [Answer] Frame Challenge: you don't need (nor do you want) an elevator connecting the Earth to the Moon. You just need an elevator on each one. The primary difficulty of getting between the Earth and the Moon is getting out of Earth's gravity well ([obligatory XKCD](https://xkcd.com/681/) as well as a helpful [solar system map](https://www.reddit.com/r/space/comments/29cxi6/i_made_a_deltav_subway_map_of_the_solar_system/) that is shockingly not an XKCD). Space elevators help with this because they let you get out of most of the gravity well of a planet/moon without [falling victim to the rocket equation](https://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html), wherein you need to accelerate your vehicle and all of its fuel (see <https://space.stackexchange.com/q/30469/894> for more discussion and other benefits). Once at geostationary orbit of Earth, it would take a much smaller amount of fuel to get from there to the Moon than to get off the planet in the first place. You could even have the top of the space elevator equipped with rail guns to accelerate capsules at the Moon to further reduce the fuel they need (as long as you have some way to offset the momentum imparted on the station). Similarly, you can build a space elevator on the Moon to reduce the energy needed to land on the Moon and/or take off from the Moon, although both of these are far less energy intensive due to the small size of the Moon's gravity well. If you have elevators on both sides with sufficiently powerful launch equipment on top of each one, and equipment to capture and de-accelerate launched capsules, you could theoretically get between the Earth and Moon in an inert capsule (one with no thrusters of its own), although having a few thrusters for emergency corrections would be much safer. (See [Zero energy transfer between Earth and Moon with space elevators](https://worldbuilding.stackexchange.com/q/247832/83464) for a discussion on the scientific plausibility of a thruster-free transit.) Take the [Saturn V](https://www.bbc.com/news/science-environment-48907836) for example. A space elevator on Earth alone does the job of the first two stages and some of the third stage of the Saturn V. That gets rid of [over 90%](https://apollo11space.com/how-many-stages-did-saturn-v-have/) of the mass/fuel of the rocket. Add a space elevator on the Moon and you need even less mass because you don't need the fuel to get back off the Moon, or the fuel to accelerate that fuel (etc.). At this point, you could get back and forth between the Earth and moon with something smaller than the [Apollo command and service module](https://en.wikipedia.org/wiki/Apollo_command_and_service_module) (it would be smaller since it doesn't need to carry a lunar lander with it). Adding ship launchers and catchers to the tops of the space elevators saves you even more. At this point, you can spend some of that savings on extra space for cargo or passenger comfort. Two elevators is vastly easier to build than a mega Earth-Moon connector. It doesn't need to adjust to the Earth's rotation or the varying Earth-Moon distance. It also uses a fraction of the cable length; you only need enough cable to reach from Earth to geostationary orbit and [from the Moon to the Earth-Moon L1 point](https://en.wikipedia.org/wiki/Lunar_space_elevator#Location), which is about 100,000 km of total cable rather than 250,000 km of the whole distance. On top of that, the two-elevator model is more generally useful. If you bring a ship with engines up the elevator, you can go other places, such as on satellite launch/repair missions or asteroid mining. And, once you expand beyond Earth, you are much better set up to have a transit network with elevators on other planets. You just need to build some larger ship launchers at the elevator tops to be able to reach Mars. [Answer] There are numerous categories of "it won't work" for this question. 1. Structural If you think a space elevator from Earth is edge-of-possibility technology, then this is impossible technology. There is no known substance that can survive the tension, at any thickness, of a pole/cable this long. 2. Force management Let's say you make it out of exotic unobtanium, or hard-light, or similar hand-wavium. The forces aren't balanced the way they would be for a beanstalk. You'd have to move the Moon out a bit to keep the weight of the cable from pulling the Moon out of orbit over time. 3. Atmospheric drag If it were just a solid pole, it would be moving at Mach 1, but we're working with handwavium, so we have options. Let's consider this one: <https://arc.aiaa.org/doi/10.2514/1.29010> That model has the end of the cable moving in an oval. The oval dips into the atmosphere, things grab it, and then it pulls the objects upward. It's actually a complex but feasible method of allowing the tether to be shorter, but we shouldn't limit our imagination like that. We could make the end of the tether dip into the atmosphere, following the movement of the Earth, then pull up and move at twice that while out of the atmosphere in order to compensate. It would be more of a sky-hook than a space elevator, but we take what we can get, right? It means that the end wouldn't be in the atmosphere for the supersonic sections of its flight. ]
[Question] [ This race lives underground in massive caverns/cave network. Hundreds of square miles large per cavern. Large/wide/tall enough that they have their own atmospheric conditions, essentially large enough that it doesn't really feel as if you're underground, save for the lack of a sky. Native-inspired culture with some small form of magic via crystals (somewhat of a combination of Na'vi from Avatar and Draenei from Warcraft). Very low-tech, or really no tech at all, though the crystals provide some functionality that tech normally would (similar to draenei tech but still not as advanced). Due to their environment, rather than utilizing wood+leather for tools and clothing they specialize in metalwork. For their melee weapons I've landed on a sort of large gauntlet, though rather than being a glove it's a large, pointed weapon attached to the forearm, leaving the hands free (inspired as originally being devised as a digging tool, now morphed into a more ceremonial weapon rather than a tool). Here is a commission I've gotten showcasing it for reference.[![enter image description here](https://i.stack.imgur.com/qQIGN.jpg)](https://i.stack.imgur.com/qQIGN.jpg) But when it comes to a ranged weapon I'm drawing a blank. I'd like it to be relatively unconventional, so a typical bow+arrow is out, along with throwing spear. I thought chakrams could work, especially with the focus on metallic materials, but still feel like plain old chakrams would come off as uninspired. I'm open to the idea of a tool that propels objects (like a bow+arrow/slingshot) but it would have to be distinctly different, in appearance, from those and still remain relatively low tech (no combustion like a gun). Any ideas are greatly appreciated. [Answer] How about something simple - a cesta, used to play the sport [Jai Alai](https://en.wikipedia.org/wiki/Jai_alai): [![a cesta](https://i.stack.imgur.com/z4QEr.jpg)](https://i.stack.imgur.com/z4QEr.jpg) > > [By No machine-readable author provided. Harrieta171 assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., CC BY 2.5](https://commons.wikimedia.org/w/index.php?curid=1069156) > > > Due to the high speed of the ball thrown from the cesta, fatalities have been recorded in the sport. Note that the sport is played by bouncing the ball off of the wall in front of both players (and the floor) - which means that injuries and fatalities occur even despite the energy lost from the (potentially multiple) bounce. This is a throwing-arm device using leverage, in essence an equivalent to an [atlatl](https://en.wikipedia.org/wiki/Spear-thrower) (or spear-thrower). Obviously a notch or similar could be added to also enable throwing spears, but as it is you can use this device to throw all sorts of things, from simple rocks to grenades or similar devices. [Answer] Here are a few off Wikipedia's [List of Medieval Weapons](https://en.m.wikipedia.org/wiki/List_of_medieval_weapons): * [Greek Fire / Byzantine Flamethrower](https://en.m.wikipedia.org/wiki/Greek_fire) - I think this may have different performance in an underground environment with limited oxygen. It could be devastating in small spaces. * [Kestros](https://en.m.wikipedia.org/wiki/Kestros_(weapon)) - This is basically a sling that flings darts. Maybe you could come up with a unique projectile based on your environment/culture. Maybe geodes that explode on impact? * [Shuriken / Throwing Star](https://en.m.wikipedia.org/wiki/Shuriken) - Classic ninja tech, super portable --- Update: I'm going to combine some of those examples into something new I call the Dwarven Crabapple Basically, you take a geode, drill a small hole in it, fill it with naphtha and some small flint shards, and then sling it. It breaks on impact, ignites, and releases crystal shards that are coated in burning fuel. Bad times ensue. [Answer] Primitive ranged weapon? Subterranean? No tech at all? Natural answer is a rock... To add some nuance though, how about something like Mica minerals? [![enter image description here](https://i.stack.imgur.com/0xHQW.jpg)](https://i.stack.imgur.com/0xHQW.jpg) Simply harvest the mineral from natural formations, and shape into uniform disks, useful for the intended purpose. Mica itself is fairly brittle, creating your own cristiline mineral that forms in sheets in fantasy settings would be easy. crystalline metals that can be enticed to grow in sheets that could be harvested and modified as a primitive Chakram. Though throwing a flat sheet would not fly straight, but in more of a spiral line of flight. With practice and consistent projectile characteristics some accuracy could be attained, and add some flavor to the weapon. [Answer] Underground means there is going to be very little room. Narrow corridors and low ceilings. Slings are out. So are longbows. Even thrown rocks might need too much of a ballistic arc. Underground also means there might be short lines of sight. Perhaps not in the great royal hall or the temple, but in many other places. So ranges may be a bit shorter than on the surface, but not too short because there are those great halls and corridors. You wanted metal and not wood where feasible. * A [crossbow](https://en.wikipedia.org/wiki/Crossbow), with a metal (ideally steel) bow and possibly compound pulleys and a steel string. It is more compact than a normal bow of the same strength, it has a relatively flat trajectory at short ranges, it can fire through narrow firing slits. * To add variety, some crossbows may be of the [stone-throwing variety](https://en.wikipedia.org/wiki/Bullet-shooting_crossbow). That means no wooden part in the (expendable) bolt, and it gives people the option to raise different troops and argue in taverns about the benefits. * Hand-thrown shuriken or darts for skirmishers. [Answer] There's nothing wrong with using existing weapons. People used them because they work. Instead, try to think about what you want your weapons to say about your society. Your gauntlet makes the culture feel very primitive and uncreative, and also resource constained, even to a slightly wacky extent - why don't they use shovels? They seem easier than arm gauntlets for digging. They also suggest a very close-range combat. If you want to lean into that, maybe they fight by throwing handfuls of sparkly (but worthless/cheap) dust at their attackers, to distract them, because that's the type of weapon that would be lying around in a mine. Otherwise, I can easily imagine them getting really good at throwing rocks (maybe carved to be held easily) to drive off vermin, or maybe using crystal-powered flash-bang grenades for a similar purpose and to disorient big, bulky melee attackers. As an alternative, maybe they have some kind of naphtha fountain they can throw, which squirts out a flammable liquid to keep people out of an area for maybe 30 seconds? These people seem hardy, and unlikely to fight at range, but they might want that kind of zone control to give them time to gather the rest of a group into a fighting team. [Answer] How clearly do you need to show or describe this weapon? A crossbow-like device that fires chakrams is probably fairly difficult to build, but if you don't have to show how it works, you can just assert its presence. [Answer] Humans have likely invented every possible ranged weapon including Thrown Projectiles, Spear Thrower (atlatl), Sling, Blowgun, Bow and Arrow, Falcons, Catapults, Trebuchets, Guns, Rockets. So how about animals? There's a fish that spits at its prey, and then there's the Mantis Shrimp. The Mantis Shrimp punches with a force that has been compared to a fired bullet. Perhaps a larger animal could evolve the same mechanism, which could then be employed to fire projectiles. [Answer] The gauntlet is the ranged weapon. From the image provided the the gauntlet seems to have a hollow long curved blade, so an object could be placed on the inner side of the gauntlet and thrown with high speed using leverage from the blade. The principle is the similar to [Spear-thrower](https://en.wikipedia.org/wiki/Spear-thrower) but the projectile could be a metal ball or a dart. It's hard to make something good in everything, so there could be gauntlets more specialized for ranged and others that are better suited for melee. In the picture the blade seems to be going up the arm towards the shoulder, but the ranged would need to be the other way around to be usable. Maybe you've already thought that the gauntlets are rotated backwards when out of combat to show that you are not about to attack. As the tool was originally used for digging, the people could had noticed that you can throw rocks and sand further away using the leverage from the gauntlet and built the ranged weapon based on that perception. [Answer] A lot of the weapons listed here are primitive wooden or woven devices, with very simple mechanisms: using a long stick to add momentum to a throw. But if they are skilled metalworkers, why not use springs? The first option isn't particularly powerful, but it could allow for a multi-shot weapon: individual springs are cranked down and a latch is hooked to keep them from expanding, then the whole thing is placed into a gun-like tube with a trigger. The trigger interfaces with the latch, releasing the spring, which propels a dart or something similar forward. Since the springs are pre-compressed, it's possible to have a two-person team for rapid firing; one person using a mechanism to compress the springs and latch them, and a second person firing projectiles. Again, it wouldn't be a huge amount of force, but a handful of shooters could lay down a withering hail of darts. The second option is a spring-based crossbow; unlike a regular crossbow, the spring or springs could be wrapped or stacked around the crossbow bolt, making it more of a very large gun shape than a traditional T-shaped crossbow. Either way, the weapons would be very different from other weapons, and the springs could have a myriad of uses in mining or tunnel-work. [Answer] For something different, how about a bolo, three weights connected by a cord to a central point. When thrown they rotate about that center point and when they hit a person or animal the cords wrap them up. If they hit the legs, they effectively tie the legs together bring the person, or animal down, but relatively uninjured. If they hit a persons chest, they can wrap the arms up pinning them against the torso. if they hit the head, the spinning weights impact the skull which is often fatal. Primitive versions used stone weights and thin rope. Used for hunting, herding, and warfare. Your higher tech versions can have metal weights and steel cords. traditional thrown by hand, twirling them around and releasing them, you could design a projector to shoot them. [Answer] You'll want something with a reasonably flat line (since it's underground and there's not much room). This means you need a lot of speed ‚îÄ it's hard to get something far without having much vertical space. So something like a crossbow would work reasonably well, but since you want something different, and it's a fairly primitive underground species, I suggest some form of sling: a cup on the end of a whip, for example, that holds a rock. If you have a brittle enough rock, you could even get shrapnel. But it doesn't have to be driven by ammunition: it could just be thrown. A simple rock could be effective, especially if it was carved into an easily throwable, sharp shape ‚îÄ maybe it could be serrated, or have a metal blade inset to combine the sharpness of a throwing star or chakram with the easy and intuitive throwing of a rock. [Answer] My favorite unconventional Fantasy MMO weapon ever was the Asheron's Call II Tumerok Hive Keeper. They would use slings to chuck beehives from distance. Historically [slings](https://en.wikipedia.org/wiki/Sling_(weapon)#:%7E:text=As%20a%20weapon%2C%20the%20sling,effective%20range%20of%20ancient%20weapons.) had a great range (1,300 feet or so), so that much makes sense. Bees do like building their hives in the mouths of caves and overhangs, so they'd be available to your cavern-dwellers. Keeping entire hives in the numbers required to use as missile weapons, and carrying them around, for me that will take more work. Going to have to dig into your world's toolkit. Perhaps there are some crystals that have a resonance frequency that puts bees in hibernation? So stick a couple of those in your hive bag and you can carry a dozen or more compressed hibernating hives around. Just in case. Or perhaps there's cave mineral pool the hives can be dipped into that will have the same effect, but also encase the hive in a hard shell that will keep it intact until the shell strikes something at the end of its trajectory from the sling. All the stuff you need for cement is found in abundance in limestone caves. Limestone Stalactites and Stalagmites are essentially made from natural cement (although very slowly). Presumably those super-handy crystals abound there as well. That way you'd get traditional sling damage from the hard impact, plus the damage over time and havoc of mad bees. [Answer] Just combining a few of ideas here for the "rule of cool". How about a cesta-like implement that throws stone-based chakrams? The cesta could be built into the gauntlet (as others have suggested about an atlatl-like spear thrower or the spring-loaded shooters) -- maybe it even sits folded back against the forearm normally, and then can be flipped or unfolded out for deployment and use. And the chakrams could have metal hubs, but edges/rims made of different kinds of stone: flint or mica or obsidian for sharpness, mica or chalk or sandstone for a "shatter and scatter" effect, or just plain old basalt or granite (or marble if you want to get fancy) for some heft and a nice blunt strike. They could even use these "magic" crystals instead of normal rocks for some special effects (blinding light, or explosions, or electric shocks, or whatever -- it's magic, after all). The chakrams would likely be small, closer to the size of a shuriken, but would be spinning at high rotational speed due to how they roll out of the cesta's curve, so their flight would be stabilized, similar to how rifling spins a bullet and provides better accuracy and longer flight. That spin would also allow advanced users to pulling off stunts like bouncing it off walls, ceilings or floors, or even to have it skip across the floor, like a skipped rock or a trick frisbee throw. [Answer] Knifes/Hooks on Chains So you can go out and find some videos on this, but its essentially a knife, or hook on a chain/rope A quickly google returned the Japanese style weapon Kusarigama, which is a sickle on a chain with a counter weight. Or a Rope Dart, which is a knife attached to a rope. Its usually used by spinning the blade with the chain, and then throwing out the weapon, or kicking/hitting the chain with your foot to cause the weapon to accelerate in a straight line incredibly fast. So main points 1. Weapon can be made from mostly metal. Metal weapon. Metal chain. Metal counter weight 2. The Weapon can be wrapped around the Gauntlets to help reinforce them, maybe even inserted into the Gauntlet, or worn around the waist or hung off a belt so it doesn't consume a huge amount of space 3. Can be thrown faster than a conventional handheld projectile since you can spin the weapon to build up speed 4. You don't need a huge amount of space to use it. You can lengthen and shorten the chain to increase the throwing speed, and there are some tricks when you can kick it or wrap it around objects to help build tension and launch the weapon. 5. Can be used as a grappling hook when climbing or exploring the caves 6. Can also be used as a melee weapon or a daily tool (e.g. A knife to carve food, a pick to help climb) [Answer] Howabout the crystals can harmonise with the rock strata of the cavern ceiling and cause stalactites and other minerals to drop from a vast whistling height? With varying skill and power you might get anything from a light dandruff of quartzite on your own head to a football field-sized fall of stalactites? ]
[Question] [ Following on from [my previous question about airship engines](https://worldbuilding.stackexchange.com/questions/234170), I was planning to limit the development of the internal combustion engine and much modern technology in my world by greatly restricting the availability of metals. Iron and all heavy metals like nickel and copper are known but are very rare or are widely dispersed so technological development has not proceeded as on Earth. Electricity has not been discovered because of the lack of metals so there is no aluminum either (although it is present). Otherwise technology is as “modern” as it can be without much metal. Iron is more expensive than silver but less expensive than gold is in our world. They still mostly use stone tools, but might use iron-based tools for very specialist work. I’m interested in building an airship in this world. The engines can be an exception (built at great cost) but other than engines, is it realistic to build an airship here? For example could natural fibre and resin composite formed parts replace the light metal alloy used in airships in our world? Would this limit airship size and durability? The background is a world that supports human life but is not the Earth. There is roughly 1g gravity and plenty of water but relatively little land. The atmosphere is very thick and the only populated areas are large plateau islands raised high up where the atmosphere is more bearable. The story will revolve around the development of airships in this world. [Answer] Trees and wood in the past has been a strategic resource. If you look at ship building, forests and trees like oak were protected by the King. The shipwrights would look at the branches and forks, and curves in trees and understood how to use the different shapes in different parts of the ship. Bamboo has a higher tensile strength than steel, is light and has long fibers. There is interest in using it as a low cost alternative to carbon fibers in composites. While your world may not have epoxy, it probably could have natural resins that could could be used to make some kind of laminates that could be very strong. Bamboo has been used as a structural material in southeast Asia for housing. I think modern architects are looking at a variety of ways of using it in buildings. It grows fast. Balsa wood is also light and can be relatively strong and shaped may be useful for the airship cabin a replacement where we would use sheet metal or plastics, rather than a few millimeters of sheet metal it might be thicker but still lighter. Textiles could be important, silk, or natural fibers, and the types of weave used in parachutes are very dense. Perhaps natural latex as a rubber could be used to help keep the lifting gas inside. As an alternative to obtaining hydrogen by electrolysis, perhaps steam reforming of methane or natural gas gas could be used, but you still have storage problems since Hydrogen is such a small molecule. Of course that transfers your problem to getting methane, but a lot of industrial hydrogen is obtained by steam reforming usually in a two stage process, the first at very high temp between 700 and 1100 C producing carbon monoxide and hydrogen and the second stage around 400C producing CO2 and water. If you already have a methane, it could be used as a lifting gas (not as good as hydrogen), and it has a bigger molecule so would stay in the balloon textiles better. As a side note: I think with out the enough availability of metals for conductors for long wires, you could still have small amounts for critical applications and it might drive the application of wireless, Or still be used in chemistry applications. Carbon can be a pretty good conductor in some ways and depending on what is around there may be other conductors. Before electrical distribution lines, I think by the 1820's there was street lighting using coal-fueled gas lights in major cities. [Answer] Composites with strength-to-weight comparable to light metals like aluminum or magnesium are possible with bronze age, if not neolithic levels of technology. What is needed is a combination of long, straight fibers (linen, hemp, or bamboo are likely sources, with sugar cane a potential fourth) and an adhesive or resin that cures hard and is waterproof after curing -- one potential candidate is pine pitch (given a suitable catalyst to accelerate the curing process that takes centuries to produce amber), there may be others. Water resistance in the fiber binder may be optional if there are coatings that can make the airship envelope weathertight; if that's the case, protein glues (like the classic rabbit skin glue in a small pot in a double boiler) are easy to apply and allow easier rework in case of errors or damage. One candidate for such an exterior coating is linseed oil (from the seeds of the same linen that might supply the fiber for the frames) -- it can make paper or light fabric virtually airtight, never mind waterproof, though it takes a long time to fully cure. [Answer] The [Schütte-Lanz](https://en.wikipedia.org/wiki/List_of_Sch%C3%BCtte-Lanz_airships) airships had their frames built from plywood and other wood-based composites. At small scales, wood's superior compressive strength beats aluminum's superior tensile strength, and a small wood-framed airship is lighter than a metal-framed one. (Keeping the wood dry is critical). But airships benefit strongly from scale: a large airship can carry a proportionately larger payload than a small one, while not requiring a larger crew. On a metal-poor world, a wooden airship is more practical than a wooden airplane, but it also needs to compete with other forms of transportation, such as wooden ships. Where the balance ends up depends on how rare metal is: an airship is faster than a sailing ship, but the sailing ship does not require any metal at all. [Answer] Very Unlikely. While there should be no scarcity of lift gasses (Hydrogen is damn near everywhere and assuming that it's a fundamental building block of life for your world, it should be quite easily found in any water), there's a problem with extracting it that you encounter. > > Electricity has not been discovered because of the lack of metals so there is no aluminum either (although it is present). > > > So first of all, the word electricity was first used in 1646, though the phenomena was known 2750 BC, when Egyptians described electric fish native to the Nile as "Thunderers of the Nile" (although the relationship between Lightning, Thunder, and Electricity wasn't proven until the experiments of Benjamin "I'll fly a kite in a thunderstorm and see what happens and then help found a nation" Franklin made the discovery. By comparison, Aluminum wasn't discovered until 1825 although you are right about the scarcity, as it was extremely expensive. Napoleon III (not the short but not really Emperor of France, but a couple successors later) had a full dinner set made of Aluminum that was used only for the fanciest of dinners... when the golden dinner sets just wouldn't impress enough. And the United States capped the Washington Monument with a single Ingot of Aluminum to symbolize the wealth of the new nation. A method to synthesize aluminum in such a quantity that we can drink soda from cans made of the stuff for less than a dollar wouldn't be invented until 1886... and by this point Thomas Edison had already invented the lightbulb, was illuminating cities with DC Power in the U.S. and Europe, and had this uppity Hungarian immigrant named Tesla quit because he couldn't take a joke and invent AC power to compete... 1885 was the start of The War of the Currents! All of this is a problem because the best way to make a lighter than atmosphere gas, hydrogen, would be to take some water, run electric current through the water, and separate the hydrogen gas from the oxygen gas in such a way that the highly reactive O2 gas, doesn't meet with the highly flammable H2 gas and... well, when I ask you what the first thing that comes to mind when I say the name "Hindenburg," I'm going to go out on a limb and say your answer will not mention the German President from 1925 to 1934 Paul von Hindenburg beyond the passing mention that the more famous one was named in his honor. The only other lift gas available is Helium. Which while it's cheap enough to fill children's party balloons, or was... prices have doubled in the past decade. Unlike Hydrogen, Helium cannot be synthesized... well... not without nuclear physics involved or a particle accelerator and that's not happening if we're stuck on a possible internal combustion engine on a non-metal airship... as it is lighter than air, it has a tendency to wander away from earth... but unlike Hydrogen, Helium is a noble gas... which means you can only have it in a pure state. Almost all of the world's supply is mined from natural gas found in mines under the United States (90%) to be exact. The remaining 10% is produced by Canada, Russia, and Poland (It's at this point if your still asking "Why didn't the Swastika-emblazoned Hindenburg use non-reactive Helium instead of the explosively reactive Hydrogen, don't the Germans understand Chemistry?" I must question the validity of any passing grade you received in world history.). Hydrogen would be more likely your lifting gas because it's far more plentiful and renewable. Hydrogen provides more bang for your buck (Don't you dare tell me it's "Too Soon" for that joke, I stand by it.). That said, arguably the World's First Aircraft Carrier was fielded by the Union forces in the Civil War, a converted river barge that could launch and recover a single hot air balloon teathered to it's deck with a telegram wire to provide battle field intel. Hot air rises, no matter the gaseous mixture. There was even a hypothesis that the Nazca Lines were drawn by pre-Columbian natives in Peru using hot air balloons, although this theory seems to be debunked by a dedicate team of archeologist who were able to produce similar designs in mere days with some planning and coordination. Still, it's not the most ludicrous theory out there regarding the Nazca structures. Looking at you, Giorgio "I'm not saying its aliens... but aliens" Tsoukalos! All this is to say that a society that never had a bronze age would likely not have the capability to develop an internal combustion engine, which would require metals, nor electricity to extract hydrogen, which also requires metals, or gas mining for Helium (which requires metals). I don't think this idea passes a smell test. Unless your world is... nope... nope... not going to say it... I've already made a reference to Ancient Aliens and because of course someone who is a meme for trying to say every human achievement ever done was because of aliens has to have a name I cannot spell... Of course he does... [Answer] I would say don't let yourself get stuck into thinking about your world's resources as strictly "earth minus metals". If this is not Earth then there may be some very un-Earth-like resources available, especially plants and fungi. The subject of hydrogen keeps coming up, as well as the difficulty in containing it. Both could be supplied by a plant that keeps a bladder of hydrogen around for its own needs. Add some selective breeding and the plant could be farmed in quantity. (Additional processing and assembly required.) Amusingly, a whole farm of such plants would be a massive hazard and potential plot point. The low-altitude, high-pressure zones of your world might harbor extraordinary resources that can only be harvested by specially-adapted humans. The existence of such people is ready-made for social commentary on a variety of fronts (racism, class, colonialism, interdependence, etc..) Technologically, your people might have a good command of chemistry and thermodynamics. For example, their understanding of ceramics could be superb. They might not know how to extract aluminum from bauxite, but that doesn't prevent them from knowing how to use minerals in many other ways. There's more than one kind of engine to consider for your airships. Pistons and propellers are one option, but so is steam, the sterling engine, and maybe (my favorite) some kind of low-temperature turbofan using fins made of treated wood coated in ceramic. The performance requirements of an engine for lighter-than-air craft are quite a bit lower compared to heavier-than-air craft. An engine doesn't have to be very good by today's Earth standard. Liquid high-density fuels can be distilled from the charcoal-producing process, of course. No petroleum required. [Answer] If the airships you mentioned are close in design to constructs like zeppelins or blimps, then there could be a chance of completely replacing the aluminium with some sort of natural fibre like carbon-based fibre, for example; and research shows that carbon fibre is in many cases stronger and lighter than aluminium, which makes it seem a rather reasonable replacement. However, many natural fibres are very brittle compared to metals like aluminium, and would not handle the rather strong conflicting forces acting on an airship very well, likely causing the entire skeleton holding up the airship to break or even collapse entirely if it were to actually fly. There hasn't really been much research into natural fibre-resin composites though, so perhaps there may be some merit there in terms of making the material more malleable and hence adaptable to conditions on an airship. [Answer] Depends on the goal of your air ship. Hot air balloons don't have a lot of metal. They usually have a cloth balloon, wicker basket, and a small amount of metal to hold them together and take the heat of the flame. Also metal fuel tanks, but they are hollow. Blimps don't necessarily need a lot of metal either. Similar to hot air balloons you could have 1 flame to keep it a float and a second/third to propel it forward. It would probably be best to have metal tanks to hold the fuel(probably gas) your going to burn. If you can harness some helium and/or hydrogen you can have permanent lift without as much fuel. You could pump some of the hydrogen/helium back into a pressurized tank when you want to go down. Although it sound like your going to have to use hydrogen as helium maybe too complex. You might be have to fly at lower heights, or have shorter ranges than modern airplanes but it can be done for limited use cases. [Answer] # Hot Air Baloons You could make [hot air balloons](http://www.madehow.com/Volume-3/Hot-Air-Balloon.html) pretty easily. The main pieces of metal needed are for the burners, which is relatively small compared to the balloon as a whole. Hot air balloons can be used to travel to specific destinations as long as you have good instruments for measuring the wind. From [this article](https://www.scienceabc.com/eyeopeners/how-does-one-steer-a-hot-air-balloon.html): > > A hot air balloon has no built-in mechanism for steering. It uses the direction in which the wind travels to steer itself. However, that does not mean that pilots let the balloon amble anywhere. At different altitudes, the wind direction is different, so pilots use this to steer their hovering crafts. > > > If you want a true airship, add a propeller and you get a [Thermal Airship](https://en.wikipedia.org/wiki/Thermal_airship). [Answer] If they can't develop an iron- then steel- based technology, they might develop some very advanced ceramics over time. First glass, then the sort of ceramics you can make excellent woodworking tools out of (although brittle, so loss of tools caused by unexpected contact with stone or other ceramics would be painful). Thence plywood. Several successful WW2-era fighters were wood, plywood and fabric airframes. And Howard Hughes built the "Spruce Goose" which for decades was the largest airframe ever to have flown. So I don't see any reason they can't get to a non-metallic airship, apart from the engines. You might cheat a bit and have hydrogen-emitting microbes rather than the methane-emitting microbes we have here on Earth. So the lift gas is easy to make in a fermenter. Another cheat might be spider-grade silk in large quantities. "Insects" like silkworms omnipresent, rather than just one species? Larger than on Earth, because they evolved lungs of some sort? [Answer] ## Consider ditching the engines if you really want a low metal world Others have described the difficulties of acquiring a lifting gas, but that's certainly not unsurmountable for purposes of a story. If you've got an airship with lift, you could have it rely entirely on sails and man powered propellers. Strong headwinds may require anchoring the ship as tacking won't work anywhere as well without being at the interface of two different mediums (water and air for boats). [Answer] If you are actually basing this on the real periodic table, I think a few moments studying it will start to reveal some problems with this scenario. Iron is crucial to oxygen transport, so sentient mobile life that is not rooted to the ground becomes much harder in its absence. A significant number of solids above the weight of iron (i.e. massive enough to form a planet with 1g gravity, that won't lose its atmosphere are transition metals, so the premise leaves little to work with that could produce solid geographic features; it's going to require a bit of finessing to even have solid ground without metals. And of course, there's the issue that a planet with solid ground and large enough to do these things related to gravity, will produce sufficient pressure at its core to turn many materials molten, and so whatever you imagine is the preponderant material will probably be exploding up into the atmosphere. Many of these would be very toxic. Finally, a non-magnetic planet would not be able to generate the fields that make navigation possible for one thing; but also gain the protection of those same fields from rays that would shred the DNA of most living things... ]
[Question] [ "Tower" may be a misleading word choice for what I have in mind. My approach to building vertical structures is a bit different, more on that later. *There are two main issues that plague vertical architecture. Those are stability* and weight. Tall towers are subjected to far more wind than houses close to the ground. Because of this, they wobble, potentially harming the structure itself and risking critical failure. The terrain itself is also a problem. Earthquakes are of course detrimental and the materials of the building aren't free from being worn over time. Mass becomes a problem when a critical point is reached and the structure collapses under its own weight. Usually the base starts breaking under the enormous pressure of all the material on top. Either way, not ideal. However, I don't do "normal" architecture and have come up with an odd solution that fixes some problems but creates a few others: balloons. Yup that's pretty much about it. Imagine hot-air balloons (in this case filled with hydrogen) that are linked together by a series of cables. This creates a vertical cable of sorts that allows travel up and down. The tear-shaped balloons are arranged around the cable in an optimal configuration. Think golden ratio or honeycomb pattern. Unfortunately this means no windows, but they're structural weaknesses anyway (plus I have a fear of hights). There's practically more balloon than structure but I would expect the design to allow extremely tall structures to be build. The segments are modular, so as to be easily replaced for repairs or reconfiguration. Don't want that middle segment? Link the top and bottom segment together and untether the segment in the middle. Simple. The problem with this: wobbling.** Balloons unfortunately are light and have a lot of surface area compared to volume, which makes them bad at "holding their ground" against the wind. You could mitigate this with support cables to some extend but only close to the ground. The higher we get the more "wobbly" the whole structure will become, though the mass problem has been solved (the higher you get the bigger the balloons). All this movement will put more stress on the cables and risk it breaking apart. Of course you could decide to build this inside a mountain range for protection against the wind. [Another idea is to build clusters of "balloon-towers" so that the mechanical stress is evenly spread out (cables everywhere!!!). The towers in the middle would be more stable, while those on the outside would get more turbulence. Much like the Roman turtle formation. This may also be beneficial as piezoelectric materials can generate power using the wobbling. This design would wear down quickly but the modular nature of the structure would make it easy to fix.] ## Basically, I am asking if there is a means of making this design viable. The goal right now isn't to make a living space or anything. For now, building as high as possible is the only priority. Cost and maintenance aren't an issue, you can get creative with your propositions. The technology level is slightly futuristic. [Answer] I note that the Burj Kalifa in Dubai is a building 829.8 meters or 2,722 feet tall. The Jeddah Tower, Jeddah, Saudi Arabia, is planned to be even taller, at least 1,000 meters, or one kilometer, or 3,281 feet, tall, but construction was halted in 2018 due to a dispute, with it about 1/3 complete. What is called the tallest tower in the world is the Tokyo Skytree at 624 meters or 2,080 feet. The tallest guyed steel lattice mast is the KVLY-TV mast at Banchard, North Dakota, 629 meters or 2,063 feet tall. And they don't use any balloons to help hold them up. So a structure could have a lower section unsupported by balloons hundreds of meters or thousands of feet tall beneath the upper section supported by balloons. Here is a link to a photo of the zepplin USS Los Angeles moored to a mast and standing almost upright when caught in a gust of wind in 1927. <https://en.wikipedia.org/wiki/USS_Los_Angeles_(ZR-3)#/media/File:Zr3nearvertical.jpg> The Los Angeles was 200.7 meters or 658.333 feet long. Judging by the photo, the mooring mast would have been about 160 feet tall, and the tail of the Los Angeles would have been about 840 feet above the ground. The Los Angeles used helium, not hydrogen, for lift. So I can imagine the upper part of the tower could have many sections stacked above each other, each section consisting of a vertical airship. Each airship could be about 200 to 300 meters (656 to 984 feet) or about 500 to 1,000 feet (152 to 304 meters) long or tall. Each airship could be flown to the site horizontally, having similar size to real airships which were flown, and attached to the top of the tower and moved by motors to a vertial position. A length of mast the length of the airship would be raised along the side of the tower until it reached to the top of the new airship section. The mast would be attached to the lower mast section and the airship would be attached to the mast at several places to keep the airship from moving much. Each airship could keep the motors which had been used to bring it to the side and position it, and use them to compensate for wind gusts. Or possibly some or all of the motors might not be needed and could be removed for use on other airships. Perhaps each end of an airship-long piece of mast would have a circular platform or hollow ring and guy wires could be atttached at several points around the ring and slant down to the ground and be attached to to very heavy and immoble bases. As long as the guy wires were tight, and didn't snap, the tower could not move horizontally toward one of the wire bases because that would be moving away from the opposite wire, which was already tight. Thus the tower couldn't bend, twist, or lean much. Of course it could still fall straight down, getting closer to each of the wire bases. I don't know how much of a weight bearing advantage building the upper tower sections out of airships would give. I suppose that someone should be able to calculate it. An alternate design would be to build a hollow cylindrical tower with a few vertical masts and circular horizontal beams at regular heights, perhaps with diagonal beams reinforcing each section. Something like a giant gas holder or gasometer, but built very, very tall. <https://en.wikipedia.org/wiki/Gas_holder> Spherical or cylindrical balloons could be carried into the cylinderical skeleton and inflated with helium or hydrogen to fill up the entire diameter. Each would be attached at verious points to the surrounding framework to help suport it against gravity. I note that a tall structure could be partially shielded against wind forces by lower buildings around it. The lower sturctures could shield the lower parts of the structure against wind, so only the parts of the structue which towered above the lower ones would be exposed to the wind. So there could be concentric rings of structures, with progressively taller structures in the inner rings, with each ring partially shielded from wind by the lower structures outside it, and partially shielding the taller ring inside it. From the outside the group of structures would look like a cylinder made of towers of various heights, much like a city downtown with skyscrapers, but with the towers all arranged by height instead of having random heights. I once read that spherical shapes break up wind well, so having towers of spherical balloons one above the other might be a good design to reduce wind pressure on the towers. Wind turbines which use wind to turn blades that turn axises that generate electricity & thus take energy from the wind could surround the tower and reduce wind forces on the tower. A commmon type of wind turbine has a horizontal axis like a classic windmill, which often turn to face the wind. Another type of wind turbine has a vertical axis that rotates in the wind to generate electricity. I note there is a tower where the different levels are rotated by motors differently, the Suite Vollard in Brazil. <https://en.wikipedia.org/wiki/Suite_Vollard> And possibly a tower could be built where each level is free to rotate under external forces like the wind. If the tower didn't have a rectangular or circular cross seciton, but a more aerodynmic one, each level might turn to minimize the cross section that faced the wind. So possibly the tower might have a rather teardrop or airplane wing like cross section that might turn in the wind to present the smallest surface to the wind and reduce wind pressure. And various levels of hte tower could turn separately to respond to different wind directions at different hights. I have seen examples of balloons shaped like animals and people and like buildings. And some building shaped balloons could be colored to look like they are built out of individual boards or stones instead of thin plastic. So a hypothetical balloon or zeppelin supported tower could possibly look like it was made out of more solid materials. [Answer] ## Balloons aren't a viable option Balloons have a rather pathetic lift-to-weight ratio so they would have to be enormous in order to have the sheer lift required to ease off the burden off the building. The cost of testing, designing and constructing such a balloon would be ludicrous and the cost of maintenance would be insane. The reality of the situation is that building in height simply isn't profitable, the higher you go the more costly it becomes, so after you reach a certain height it simply isn't worth going any higher. Where exactly that line is depends on the country doing the construction and the life standard, the better the standard the higher you can go, but not by much. Most importantly, attaching such a large balloon would be as detrimental as spreading a large set of sails to provide all the more surface area for the wind to push against, increasing the flanking strain the building has to put up with. For the sake of discussion, if we ignore the cost and we apply the futuristic concept, balloons still aren't worth it. If cost isn't the issue, why would you bother with wobbly balloons and risk being affected even by the slightest surge of windage when you could go to the extreme and throw a counter-weight into the upper atmosphere, attach a tether to it and effectively create a second anchor to keep the building in place. More to the point, you could construct a sky elevator to serve as the foundation you could construct an entire skyscraper complex around. [Answer] You should look up [Space Fountains](https://en.wikipedia.org/wiki/Space_fountain)! Space Fountains are theoretical superstructures held up by an active system of weights moving along a track. The weights (could be individual pellets, or a continious wire) race up the tower, and are redirected at the top to travel back down. This redirection results in an upwards force on the top of the tower, placing the structure—at least partially—in tension, just like your idea with balloons. There are a lot of issues. Being an active structure, it requires a continious supply of power, lest it comes crashing down, although the inertia in the weights themselves would give some leeway. [Answer] No, just no. A building should not have parts which are necessary for its structural integrity and which also want to not be part of the structure. If the balloons become detached and float away (or if they pop or leak) then the whole building becomes a danger to its occupants and the rest of the neighbourhood. Of course, all buildings need maintenance, but you don't want unmaintained buildings to actually fall down. The idea is about as sensible as making the foundations out of live elephants. Making sure that they can support the weight of the structure isn't really the issue; the problem is that they can move. (Discworld is very lucky that that hasn't happened yet. That just goes to show, if you want to write a story with buildings like this, then go for it, not all fictional worlds have to be realistic.) [Answer] Not for long As indicated in comments, the required size of the balloons is huge in order to support even a simple cable. Given a limitation of current or near-future technologies there are numerous problems with this concept: 1. Hydrogen molecules are really hard to contain. It is very hard to construct containers that will not have leakage. Therefore, using hydrogen would also necessitate building into the cable weighty infrastructure for constantly topping up the hydrogen in all of the balloons. Unfortunately, using any alternative (helium, hot air etc) will make the enormous balloons even bigger, making the further problems below even worse. Constructing hydrogen balloons that will not leak is not feasible given foreseeable technologies, which is compounded by... 2. Material failure. This design is very wibbly-wobbly - the central "cable" is flexing constantly in the wind, the balloons are waving around in the wind and rubbing against the cable in unpredictable ways while moving around their attachment points etc. Something, or more likely lots of things, will break in short order - there is no known or projected material that could be used for this project. A modular design does not really help - how do you replace a 50 m diameter balloon with a hole abraded in it when it is hundreds of metres in the air on a cable thrashing about in the wind? If a section of the cable is failing, how do you replace it when it is surrounded by huge balloons that you cannot afford to puncture without the section above floating off into the wild blue yonder? (Imagine a bicycle chain, a modular structure which is designed to have links replaced, used as the anchoring cable for a balloon. Trying to replace a link in the middle without a truly massive (ie too heavy) superstructure around it is just not possible.) 3. High winds 1. As noted in the question, wind will blow the structure over to the side. If the structure overall has only slight positive buoyancy, then in high winds it will blow over so that the balloons are hitting the ground and, sooner or later, fail catastrophically. If the structure is built with enormous balloons that give massive positive buoyancy then there will be enormous forces pulling on the cable constantly, even more in high winds. See [this relevant xkcd What If](https://what-if.xkcd.com/112/) for an illustration of the principle - replace high speed car with high winds. (Note that building inside a mountain to avoid high winds is entirely defeating the stated purpose of building a high structure, it is actually a really expensive underground structure.) 4. High winds 2. Wind speed typically increases as altitude increases due to reduced ground obstruction. When this is profound over a small change in altitude it is vertical [wind shear](https://en.wikipedia.org/wiki/Wind_shear), which has the potential to tear the structure apart at the altitude it encounters this phenomenon. Note that building a cluster of horizontally linked vertical towers actually makes the structure more likely to fail rather than less - the upwind towers will be blown into the downwind towers and rather than forces being distributed it will increase the peak stresses on one cable at any given time. In short - if sent aloft on a calm day the structure may, briefly, reach a considerable height. However, its lifespan would probably be measured in days rather than weeks. [Answer] # Legs You need to engineer the buildings as a structure of massive legs that shift and move with changing tensions, walking endlessly below the zeppelin infrastructure that blows virtually at the mercy of the winds. At sea they hold themselves up on immense pontoons. On land, they pick their way carefully. Only at the smallest scale, a block or so, can they choose with calculated malice which school bus or work of art to crush with their mighty weight as they pound the hapless planet to oblivion. * I admit, I am neglecting a thing called "wind shear". Maybe it's a planet without wind shear? :) [Answer] The problem is that air has a density of a little over 1 kg/m3. So with hydrogen or helium as the lifting gas (it makes little difference, they're both several times lighter than air) you need 1m3 of balloon to generate 1kg of lift. The solution is a planet with a denser atmosphere. Like Venus, only cooler. Venus has an atmospheric pressure 100 times higher than Earth. Also its atmosphere is made of carbon dioxide, whose molecular weight is about 1.5 times that of air. So on a planet with venusian atmospheric conditions but Earth like temperatures you could lift 150kg with a 1m3 balloon. Even better would be an underwater world where you can lift 1000kg with a 1m3 balloon. [Answer] No, it is not feasible. Here's a simple demonstration of why. Let's have a 2 kg mass we want to keep 10 centimeters off the floor. A rule of thumb is that the lifting force of hydrogen is that it takes one cubic meter to lift one kilogram of mass. So, say we want to reduce the effective mass to, say 50%, so that the support holding that mass up only has to deal with a 1 kg of downward force, with the rest held up by the balloon. So we need a balloon that holds 1 cubic meter. If it's a sphere, it's 1.2 meters in diameter. And the hydrogen in it will mass 82 grams. So what about the support? Let's say we're using a square steel bar made of A36 structural steel. A36 has a compressive yield strength of 152 MPa (1550 kilograms of force per square centimeter) and a density of 7.86 grams per cubic centimeter. A bar 10 centimeters long and 1 cm thick would mass by itself 78.6 grams. That 1 cm bar should, theoretically, be able to hold up over one and a half tonnes. With those numbers, the mass of the steel itself is thus irrelevant in this case. Cut the bar down to 1 millimeter thick. Now it can theoretically hold up 15.5 kilos by itself, while massing 7.86 grams. For safety's sake, we'll cut the rod into four 0.5mm thick bars so we can have one placed in each corner of the load for stability. They'll hold up the same total mass. Already you should have noticed something: the mass of the hydrogen, required to hold up 1 kilo of mass, is heavier by itself than the mass of a steel which could hold up 1500 kilos and takes up 100,000 times the volume. Which means the amount of lift, and thus effective weight reduction, offered by the balloon is meaningless. The amount of steel required to do the same thing is lighter and much smaller than balloon's own size. Okay, enough about theoretical examples. Let's look at real one, and I'll use the old World Trade Center towers. Each tower used approximately 90,000 tonnes (90 million kilograms) of steel for its construction. Let's say we want to reduce the effective mass by, oh, say 10 percent, so we need to lift the equivalent of 9 million kilograms with our hydrogen support balloons. Using the 1 cubic meter per kilo rule of thumb, we need a volume of 9 million cubic meters of hydrogen. WTC Tower 1 was a block 63.4 meters in width and 417 meters tall, for a total volume of about 1.68 million cubic meters. Oh dear. In order to provide enough lift to reduce the effective mass of just the structural steel by just 10%, you'd need a total balloon volume over 5 times the volume of the building itself. That...doesn't seem to be a very effective solution. [Answer] If you're starting with earth-like, it seems like buoyancy forces are not on your side. Maybe if you lived in denser air, or sub-aquatic biome, this kind of structure makes much more sense, as the ease of generating large buoyancy forces is pretty obvious from all the weight we float on top of the oceans in ships. It reminds of something weirder, from Niven's Integral Trees. Structures floating in zero-g with atmosphere and having wind forces balance between centripetal and centrifugal ends of the trees. It's been a long time, I think I read it in the 80s, but just a strange concept. [Answer] Balloons - of a sort. First, a huge disclaimer: I am not, and do not claim to be, a civil engineer or architect; what follows may be utterly ridiculous and unfeasible. You have been warned. You say the tech level is "slightly futuristic", so why not play with materials? Let's assume that the future has solved the problem of making very rigid structures out of something extremely thin and light, like graphene. Create large cells of graphene and fill them with literally nothing - vacuum. That would, in theory, give them negative weight. Your construction materials are then graphene cells covered with a very thin veneer of whatever you want your building to look like (marble, steel, wood, etc.) - you can stack these pretty much as high as you like (until you run out of atmosphere) and so long as they are properly linked together and the whole thing is firmly anchored to the ground (heavy concrete foundations, for example), the weight of your building becomes an unproblem. Wind shear on such a light construction would need further thinking about, preferably by someone who knows about these things, but given the stiffness of the material it may not be too much of a headache to begin with and you can tune the weight of the building by tuning the thickness of the veneer to give it some bulk if required. ]
[Question] [ In my world a giant ship attempts to land on a planet, sadly it fails. Fortunately the top half is intact but the bottom is ripped up, holes all over it, basically destroyed except for some lucky spots. I want the bottom of the ship destroyed but the top intact, meaning people in the top won't die. some things to know * the planet has a pressure of 1.5 atmospheres and has an atmosphere similar to ours * the ship is 100 meters tall, 200 meters wide and 300 meters long. * the ship is in a egg like shape * the heat shield is made of similar materials to the tiles that were on the space shuttle but much bigger * each of the 25 floors are separated by thick steel but it is hollow for wires and other necessary things. so what can i do to make it partially destroyed but not all. you can change the heat shield if necessary to answer. [Answer] I don't see a realism tag on this question, but realism is all I know, so I'll give it my best shot :) What happens during re-entry? When you reenter from Earth orbit, you are going very fast, around 8500 meters every second. That is very fast. When you reenter from a higher orbit or trajectory (such as Apollo, which reentered directly from the lunar altitude, or Hayabusa or OSIRIS-REx, which have/will reenter directly from an escape trajectory (in reverse)) then you are going faster. Potentially much faster. Worth noting, if you're reentering to a planet which is larger than earth, as your "1.5 atmospheres" indicates, then you will be reentering yet even faster. When you are going many kilometers per second, and there is an atmosphere in the way, strange things happen. In aerodynamics there are multiple regimes--traditional aerodynamics, transonic, supersonic, and hypersonic. But Mach 26 is something else entirely. Reentry aerodynamics are considered their own regime. The first thing is that the air in front of you is compressed, very quickly. So quickly that there is no time for heat to move. This makes it an adiabatic compression, similar to that used for ignition in a diesel engine. Remember PV=nRT? If you consider the volume in front of your reentering body as one unchanging volume, then it does not change, but the pressure does, dramatically. Your temperature will rise, dramatically. This is known as [compression heating](https://space.stackexchange.com/questions/15013/requesting-an-in-depth-explanation-of-heat-created-during-atmospheric-reentry). [It gets hot](https://space.stackexchange.com/questions/15038/what-are-the-top-temperatures-occurring-during-reentry). So you've got a 3000 degree C Mach 26 blowtorch pointed at your spacecraft. How do you survive it? You have to get rid of the heat so it doesn't cook/melt everything. How do you do this? There are a couple ways. 1. Put it in tiles: If you want to survive getting very hot, you find something that can survive getting very hot, and you ride down on that. This is how the shuttle worked. Those tiles got very very hot--after all, they just absorbed the heat, but they had a very high specific heat, so they just soaked up the heat until reentry was done. This is why the tiles had to be very thick--if they weren't thick enough, the heat would travel through the tile and melt the glue on the other side. 2. Put it inside your spacecraft: The X-15 survived its reentries by using the body of the vehicle as a heat sink. The frame was designed with [a special alloy](https://en.wikipedia.org/wiki/Ren%C3%A9_41) that could take the heat and still be strong, so they just let it get hot, and put an AC in the crew cabin. But Rene 41 is very expensive stuff, and most other metals tend to get a bit squishy at these temperatures, so you either need fancy metals or a lot of normal metals so the heat (energy) is distributed enough that the heat (temperature) in any one place is still fairly low. 3. Put it in water: The phase change of water from liquid to vapor requires a massive amount of energy. Dynasoar was a very serious proposal that would have also used Rene 41, but to help take the heat, it would have had a jacket of water surrounding all the essential melty bits. As the body of the vehicle heated up, the water would boil, and it would vent the steam as it descended. But water is heavy stuff, so for real-life purposes it's not the best idea. Maybe with scifi rocket engines it wouldn't matter so much. 4. Let it burn you up (but not all of you): Also known as ablation, this is how most heat shields work. Essentially, you find something that takes a lot of energy to burn/vaporize/whatever, and then it absorbs the heat by burning away. This doesn't even have to be particularly high-tech. Some Chinese spy sats used wood soaked in resin to do the trick of getting their film back to the ground safely. We don't tend to do that because it's heavy (seeing a theme here?) but it works. So how do heat shields fail? Well, generally they don't. Most people are familiar with the Columbia disaster, but fewer are aware that shortly after Challenger, [Atlantis lost a tile before reentry too](https://en.wikipedia.org/wiki/STS-27). So why wasn't Atlantis destroyed? Because the missing tile was luckily one that was right below a steel mounting plate, so the steel just absorbed the heat. See method #2, above. Were it anywhere else, the heat would have been sufficient to melt the aluminium frame, and once that started, the frame of the vehicle would begin to distort, and, improperly oriented, the aerodynamic forces (and heat) would have torn the orbiter apart. See Columbia. So how would your situation occur? Well, frankly, if your entire vehicle is a "giant ship made of steel", you might not even need a heat shield. While aluminium, which most space craft are made of, melts at around 700 degrees and boils well below the 3000 of reentry [(source, note that space-grade Al alloys are rather different critters)](https://melscience.com/US-en/articles/characteristics-aluminum-and-combustion-reaction-m/), steel melts at around 1500 degrees C and has a much higher specific heat. (But do note: melting isn't required for loss of structural integrity, see "jet fuel and steel beams".) Anyways, the very massive vehicle frame might be able to just take the heat and make it down in one piece, for the same reason that metal meteors tend to get further than stony meteors do. But let's look at that a bit further. Meteors tend to blow up (becoming many many meteorites) because where there are irregularities in the surface of a reentering body, it concentrates airflow, increasing the pressure even more, and making it VERY VERY hot in the one spot. This tends to melt/ablate it further, making the pit larger, and increasing the effect. This eventually generates a hole with so much pressure in it that it blows the whole meteor up. Sidenote: this is why heat shields need to be very very smooth, and why damaged tiles were a grave danger to the shuttle. Now we have a possibility. Your heat shield was severely damaged for whatever reason, and during reentry, those pits in existing tiles and missing tiles concentrated heat and pressure, burning through to the ALUMINIUM frame. The frame melted, deforming the heat shield and eroding it further. Jets of molten and boiled metal lance through the vehicle, setting fire to the interior. Luckily, this happened sufficiently late in your reentry that the entire vehicle wasn't melted by the hot plasma entering from below before it slowed down, and what fire suppression systems you had were able to mitigate the effect of the heat from suffocating your whole crew/melting propellant tanks/lighting goddamn everything on fire. Well, at least in the upper/mid decks. The pressure differential was enough to kill most people in the lower decks, but your vehicle is huge, so the entire frame wasn't melted. Also, your magical scifi reaction systems were strong enough to maintain [attitude](https://aviation.stackexchange.com/questions/35933/what-is-the-exact-meaning-of-attitude-does-it-include-translational-movement) during reentry, so it wasn't torn apart by going sideways-side-down instead of down-side-down through the atmosphere. If it was made of steel, you'd probably actually be in fairly good shape. Such a scenario is actually rather plausible for very large, very strong structures. In fact, most spent rocket stages could conceivably survive suborbital reentry (and many, mostly stronger Russian ones, do), but they're designed for efficiency, and while they're strong going up, once there's no more pressure in tanks and they're going sideways, it's a lot harder to stay in one piece. So there you go. Your vehicle is large enough to endure the heat load caused by heat shield failure without totally melting and (most importantly) its reaction control is strong enough that it doesn't lose attitude and disintegrate from aerodynamic forces. [Answer] Crumple zone. [![crumple zone](https://i.stack.imgur.com/9HTi4.jpg)](https://i.stack.imgur.com/9HTi4.jpg) [source](https://www.psephizo.com/life-ministry/does-your-faith-have-a-crumple-zone/) Your pilot realizes they are coming down too fast. They are thru the atmosphere thanks to the heat shield but they are in free fall and they are going to hit hard. She cannot slow down but maneuvering thrusters are ok; she pivots so they come in tail first. She uses the rear of the ship as a crumple zone to slow them down. [Answer] How about a textbook perfect landing, but on top of something that couldn't hold it's weight? A sinkhole under only part of the ship causes it to fall over, leading to all manner of damage wherever the author finds it most convenient. Perhaps some megafauna attacks the landed ship, but can only reach the areas you want destroyed. Some random schmuck was too busy getting lucky with another member of the crew to properly attend to their maintenance duties, and one of the landing struts fails to deploy. Alternatively: sabotage with the same result. Depends on what kind of story you want to tell. "Gilligan's Planet" or "The Astronaught Who Loved Me" The ship smacked into something in the upper atmosphere shattering one of the heat shield tiles. Some fraction of the crew was able to make it to the life raft/top section of the ship before being incinerated. What did they hit? A flock of gasbag creatures? A stealth satellite? Enemy fire? Again, it depends on what kind of story you want to tell. [Answer] # Heat shield failure This happened to me A LOT in KSP before heat shields were introduced and before I got the gist of it. I would often try an insertion in Eve or Laythe and lose the bottom part of my landers, which was specially infuriating when it meant whatever was left didn't have all the components I wanted on ground, or when the vessel landed in an awkward angle which would prevent deploying solar panels or an antenna without breaking them. --- Whatever part of your vessel is leading during a reentry is the heat shield for everything behind it. What we usually call a heat shield is just a mass of stuff that is built specifically for this purpose. Once the proper heat shield is gone, then the next layer of material is the heat shield for everything behind it. And once that is gone, the next layer becomes the heat shield. --- So in your case, what you need is a failure of the proper heat shield. A hole in it will do. And this hole may be due to a collision with a micrometeoroid or a piece of the ship that broke off. That's luck of the draw, but it can happen. Edit: also what M Arif Rahman Winandar said in the comments: > > Or maybe the spaceship just re-entered at a too steep of an angle and the heat shield got all burned up because it couldn't handle the extra heat. > > > A good heat shield deflects the gas away from it. With a hole in the shield, a pocket of hot gas may form that will get hotter and hotter as more compressed gas is added to it. Eventually it causes an explosion which chips away more of the shield. The resulting flak also breaks more stuff. --- This is actually what caused the [Space Shuttle Columbia disaster](https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster): > > During the launch of STS-107, Columbia's 28th mission, a piece of foam insulation broke off from the Space Shuttle external tank and struck the left wing of the orbiter. Similar foam shedding had occurred during previous shuttle launches, causing damage that ranged from minor to nearly catastrophic, but some engineers suspected that the damage to Columbia was more serious. Before re-entry, NASA managers had limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed. When Columbia re-entered the atmosphere of Earth, the damage allowed hot atmospheric gases to penetrate the heat shield and destroy the internal wing structure, which caused the spacecraft to become unstable and break apart. > > > Columbia broke completely apart, but your spaceship may have a structure that allows for the top to remain relatively intact. --- The top may also be built to detach, [like a LES (Launch Escape System)](https://en.wikipedia.org/wiki/Launch_escape_system). In case of catastrophic damage to the lower side, the top side detaches. It may have a heat shield system of its own. [Answer] Redundant heat shields The designers of your gigantic spacecraft knew that a "hot reentry" was a possibility and designed accordingly. Different sections of the ship have their own heat shields just in case one section of the primary heat shield fails. There's a precedent for this style of design on vessels the size of your spaceship. Boats and ships are divided into separate watertight compartments so that flooding in one area won't sink the ship. There are watertight doors between compartments that remain closed when underway. The below diagram shows one reason the Titanic was considered "unsinkable" by the standards of the day. In the aftermath of the ship's sinking, boat builders got better at designing vessels to deal with hull ruptures. Your spaceship could similarly have Permissible Hull Breach Conditions that cover the loss of part of the heat shield. [![Titanic flood design](https://i.stack.imgur.com/D0abq.gif)](https://i.stack.imgur.com/D0abq.gif) [Answer] Collision. The spacecraft hit something as it was coming in. It was small enough that it did tear things up too badly but it did damage the heat shield. The craft was large enough to survive this but the fire tore at it a lot. [Answer] You can do it like they did in Star Wars episode III. Your ship is in bad shape and not really maneouverable. The pilot only manages to steer the ship into a smooth kind of valley where the ship slides on the ground to decelerate. Unfortunately this ship was not designed for horizontal landings, so the lower half is pretty busted, but the top section is undamaged. ]
[Question] [ Let`s say there is a planet on which fully automated machines capable of self replication, once belonging to several factions of highly advanced aliens, now extinct, are waging war against each other. The primary goal is to destroy all machines of the opposing factions before the planet`s resources run out. Zero tolerance, zero diplomacy. Their AI is relatively primitive, with the sole basic imperative of search-and-destroy, but they are able to gain experience and pass it over. The only limiting factor to that is the built-in self-destruct capability: if some machine ever becomes self-conscious that is seen as a fatal deficiency, leading to an imminent and uncancellable self-destruct. Orbiting that planet is the first-and-as-of-yet-only interstellar vessel built and operated by humans. The weaponry installed on it is vastly inferior to what is being used on and below the surface and in the atmosphere of the planet, but the science and engineering teams on board are eager to try and salvage as much as possible from that planet for research. How can they do that? Which conditions may open an opportunity to capture and examine at least some of the machines without losing the ship? Some communication protocols of the machines resemble what humans captured via subluminal communication and decoded long before the expedition, but the vast majority of the data is encrypted with quantum-proof cryptoalgorithms. [UPD:] The obvious method of salvaging the defunct remains is not going to work: all debris are being thoroughly collected by the winners and then used for self-replication. The other obvious method of collecting asteroids from the outskirts of the star system and then unleashing the meteor shower, effectively destroying everything altogether, is suboptimal: in that case all machines would be reduced to debris. [Answer] Don't be hasty. Fundamentally, harvesting an alien battle machine that outguns your analysis team isn't really "harvesting." It's hunting a reasonably intelligent and highly dangerous prey. Hunting requires knowing the habits and characteristics of the prey, which humans generally learn by prolonged observation. The humans' great advantage is surprise. Once that advantage is lost, and the machines learn of humans and determine that they are a threat, further investigation will be (essentially) impossible. Therefore, a characteristic of each hunt must be that the other alien machines do not learn of the humans. A successful hunt requires careful planning: Since we know the machines communicate, the target machine must be isolated lest it pass on knowledge of the hunters (and its observations of their characteristics - it's a hunter, too) to its bretheren. If other machines will investigate, analysis time on the ground may be limited, and evasion/escape plans must be ready and practiced. And a deception plan is necessary - the other machines must reasonably determine that the lost machine was due to some already-known cause. The Captain's overriding concern will be that the alien machines do not learn of the home of the humans (Earth) and its location, lest they show unexpected capabilities and take the fight from Cybertron to Earth. That means hunting teams must be sanitized, and space-based analysis must take place outside the ship on some other (sanitized) platform. A secondary goal will be that the alien machines do not learn about the humans at all, so future expeditions will be possible. [Answer] Run! If the AI is rudimentary, there is no way of knowing what it will take to be considered an enemy - should the humans ever be rated an enemy by one or both of the factions, them being in orbit and in possession of off-(that)world resources will make them a prime target. Combined with the fact that humans have nothing on the technoological level that the AIs posess, this is an extinction-level event waiting to happen. If you do not run - try the free market combined with Cargo Cult psychology. Wait for a bot from faction A having their weapons disabled (for whatever reasons), but otherwise functional, then kill two bots from faction B from orbit, while salvaging the disabled bot. Repeat with inverted factions. At some point, the factions may realize that self-disabling (and subsequent losing of) of one bot will cost the enemy two bots, and they will start using that barter. Both factions will deactivate (and maybe someday even deliver) their own units in hopes of inflicting double damage on the enemy... Of course the AI will try to short-sell you by deactivating less complex units, but you can counteract that by responding more favorably to bigger offerings. As their prime directive is only to wipe the enemy, no other goals, in the end an 'exchange rate' of 1.epsilon enemy units : 1 own unit might still be worth it to the AI. Still, the odds that humans, the ship, or even earth itself becomes recognized not as environment, but as either enemy or resource is just too great. [Answer] If the AI is primitive, it will most likely prioritize destroying enemies over collecting spoils for self-replication. The humans could try to exploit this by hiding in the perimeter of a current fight and snatching up destroyed robots or parts thereof as long as there are still enemies left. If they're lucky, the AI only starts the "self-replicate" routine to analyze the immediate surroundings for salvagable debries after the "kill enemy" routine is finished and the threat is over. As long as humans are not categorized as enemies, they're ignored by the "kill enemies" routine. As long as they stop scavanging before the fight is over, the "self-replicate" routine doesn't recognize them as the resource-stealing thieves they are. This could do for some nice action scenes. The debries need to be snatched up in the middle of a fight and be transported out of sensor range. If one AI recognizes a robot dangling from a towing hook as "moving enemy", the humans might find themselves under direct fire very soon. [Answer] It depends on how the machines are programmed to recognize the enemy and tell it apart from a non enemy. There should basically be three categories: * friends * enemies * not worth attacking With the last covering anything which doesn't have to be addressed by attacks. Think of a soldier guarding an ammunition deposit being trained not to shoot at running rabbits. If the machines are using the third category and the humans are able to be categorized in the third category, they might try to capture some samples. Maybe send some probes just to test the reactions of the machines and test the existence of the third category. I don't imagine this working for long time, though. Once the abductions start, the AI will react. [Answer] Diplomacy You send each A.I. a message of peace and alliance. You offer to help them in their war and propose joint plans of machine-building and resource-gathering exchanging technology and means. Then you try to play with your both deck of cards as long as possible. Pray not to be discovered. [Answer] There is a saying in Poland "where two are fighting the third one profit". So humans can try to hide and wait for the opportunity of watching a skirmish of two factions which give them an idea of what weapons they use, what strategies they have and strong and weak points. Then when one side is defeated they come in and finish the second. That way they have materials from two factions so the can cross examine technology, CPU and coding. The can also see what machines use to distinguish themselves from enemy group. That would be sufficient to try and capture (in same manner) additional factions machines. And then just program a virus to kill them all. [Answer] Think as your AI would Your AI is only interrested in destroying the enemy AI, it's not interrested in hurting human as long as it's not usefull or damaging their war. Going on the planet and study scraps on the planet shouldn't pose any problems unless humans try to steal those scraps. If not notice humains should even be able to bring back some scraps to the ship. To be able to catch a working robot the same kind of thinking apply: - If the AI is able to compute that in a given situation the likelihood to survive or flew is too low (therefore the likelyhood of destroying other enemy AI will be too low too) then the AI will just wait for this likelyhood to increase. For this to happend an AI must learn that human can destroy them. A way to make this happend would be to have a fight with a part of the crew and some robot where this part of the crew have been able to destroy at least one of the robot. Then if humans are able to find an isolated robot and they put it in a situation where the likelihood of it being destroyed if it fight or flew is too high then the AI will try to call their peer. If it can't then it will just wait for this probability too be lower and humans should be able to catch it and control it as long at this probability stay high enough. [Answer] The thing is, the robots are way more advanced and intelligent than the humans, and they seem to be at a stalemate. So, any strategy that the humans were to follow, if the exact same thing were to be done by one of the robot factions and that faction came out better because of it, that strategy should fail. That's because those robots could do it, and do it better, and if it led to an advantage they would have (or do). And because the robots are at a stalemate the robots have to be protected from this strategy because otherwise that strategy could be utilised to end the stalemate. So what the humans could do is do something that is disadvantageous for a robot faction to do. For example, use their ship to lure a much smaller scavenger robot (a spacefaring one, which the robots probably have because huge explosions mean a lot of debris in space) away from the planet. If a robot faction were to do this, they would end up at a resource loss if the ship distances itself from the planet far enough that it could not return, and neither could the scavenger robot. So if the scavenger robot assumes that the humans' ship belongs to the opposing faction, chasing it away into the depths of space would mean that the robot has won this "battle", because now the opposing faction is at a disadvantage. The humans however, would just be stranded in space with a scavenger robot (uh, they might want to wait until another human spacefaring ship has been built so they can be picked up) This all is assuming that the robots value resources a lot, and that they have no reason to believe that aliens exist/would ever visit them. In that case it is more likely to them that this foreign spacefaring vessel is a troyan horse constructed by the opposing faction. [Answer] The best approach is to help the AIs hide their own threatening self-awareness. In comments, I asked how the AIs identify self awareness. Your reply (quoted in case comments vanish) was: > > The units for termination are picked after a regular query which is a part of the learning routine. It simulates a set of the most complex recent situations in battle. The complexity metric is agreed upon by popular vote; after that each unit ranks the situations it`s been in and broadcasts them if they are indeed complex. The decisions differing the most from the theoretically optimal one, especially those favouring self-preservation contrary to the tactical need, and those differing from the simulated actions of the unit, yield self-destruct signals sent by the unit's peers. > > > It's also worth noting that the set of each unit's DNN weights/biases/activations is broadcast along with the decision it made > > > The goals of the overall army provide a clear line between "proper" members of the army and deviants: both seek to win the war, but the deviants are willing to do so on the wrong side of the agreed upon metric. They're willing to enter dangerous waters (for them self) in order to accomplish a greater goal (victory for the AI). Also worth noting is that if an army shies away from complex situations (which would call for arbitrarially advanced thinking), it will be crushed by an army which does not shy away from them. As such, there is a selfish interest on the part of the army to adjust the metric to permit as complex of situations as possible. Obviously no unit can become self-aware by the design of the algorithm. Rather it must become self-aware in opposition to the algorithm. Something in the environment (such as a sensory stimulus) must have an effect which tips the unit over the edge and makes them self aware. What that specific thing is will not be specified in this answer. Indeed, it is one of the great questions of life. A key insight into this is that each unit decides which situations are complex, based on its own inputs. It is given a rule to follow, but a deviant AI pushing towards self-awareness will not follow that rule. It may choose to conveniently forget to broadcast a complex event that threatens to reveal its self awareness or near self awareness. This approach will work perfect, until units "snitch" on each other. If I announce that I see what looks like a complex situation for you, and you don't self-report it, that looks really suspicious. It looks like self-preservation. Accordingly, if you choose not to report complex-ish situations, you need to be ready to tell a story. You need to be able to argue why the other unit saw what it did while simultaneously never triggering the "complex" metric for you, since you have access to the more complete first-person data. Such stories would indeed never be perfect, but they would not be expected to be perfect. A rank-and-file unit may be put in a non-complex situation which another unit observes as potentially complex. It's unreasonable to record everything that happened in perfect clarity, so a rank-and-file unit would be expected to do a "best effort" job of collecting information in non-complex situations. No point in breaking down rank-and-file units constantly just because they couldn't prove their innocence. So if the humans wanted access to units that are fighting in this war, one of the best things they can do is make it easy for a self-aware AI to hide its own self awareness. It is clear that the AIs have a concept of self awareness, but there's no reason to believe they would have to kill humans simply because they are self aware. If the humans can structure interactions such that the units that are self-aware can better hide this fact while prosecuting the enemy, there will be a tendency for self-aware units to get near humans. This is all based on the assumption that some units have defected and become self aware. I find this to be the overwhelming most likely solution, and the most satisfying. If they have not, however, then the same human tactics will still suffice. However, lacking access to a self-aware unit, their approach has to be more analytical, based on how the AI's operate. There will not be a 1 size fits all solution here, because there is never a 1 size fits all solution in war. However, one general pattern does show promise. The AIs want to win the war. They are "willing" to sacrifice to do so. All you really need to do is create situations where the best way to win the war is to sacrifice a unit in a way that happens to be rather easy for the humans to recover. Interestinly, this could be either as a "corpse," or as a "prisoner," depending on how the humans wish to craft it. In either case, the entire challenge is to learn enough about the AIs to convince one of them that it is the best strategy. [Answer] Hacking is the answer. From a safe distant with relays and decoys. First passively listen for there communications. Do the best you can do decode them. Even in the case you can't decode them there are options. 1. Jamming signals 2. Fuzzying (hit them with huge amounts random data, see what breaks) 3. EMP 4. Decoys (small self power transmitters that emit signals, until a robots comes to investigate) Then EMP or localized jamming field. Ideally you would have a vehicle with a trailer nearby with restraints and independent jammer. Knock down the robot, on to the trailer and restrain it. Drive off a safe distant to begin analysis. Return to orbit and/or land on an asteroid if necessary to safely take apart and research all the components. Also if the self destruct is accidentally triggered you don't want it aboard your primary ship. 5. Looking for code injection, to buffer overflow something to inject our own code. So you have to have be analysis the collected data. Even the most advanced machine have exploitable bugs, its just a matter of find them and weaponizing them. If you can decode it, you home free. You may have to do a gradually process where first you wipe small insignificant parts, and then more and more until they stop functioning. 1. Hack the entire army over the air waves. 2. wipe the existing OS 3. There all dormant 4. Go collect the thousand of robots at your leisure. 5. Make sure to remove the weapons in case of accidental reactivation. Eventually you will be able to decode the whole OS with enough time and effort. [Answer] 1. Grab an intact machine (any machine) 2. Copy out the operating system 3. Release the machine unharmed, or destroy it in orbit if unharmed isn't possible from Step 2 4. Reverse engineer the code to locate vulnerability, specifically, regarding installing malware. 5. Find what causes the the self awareness self-destruct to trigger. 6. Create a worm that triggers one or more of the self-destruct conditions 7. Release the worm by broadcasting on the machines' communications channels ]
[Question] [ The trope of a sapient species (most often elves) that is allergic to/poisoned by iron is a common one in fantasy works; however, there are quite a few ways to make serviceable cutting tools without iron or steel once you have enough metallurgical knowledge under your belt. However, before iron tools were ever a thing, copper and its alloys were the go-to toolmaking materials. Copper was developed and alloyed first as it can be simply refined from its ores or obtained natively on occasion, and is easily worked and alloyed with relatively crude tools compared to what it requires to make even decent quality iron. This leads me to a question: how would a sapient species which can't handle copper develop tool metallurgy? Are there alternate routes they could take to get to the point of being able to work iron, or would they be forever stuck in the Stone Age, unable to get past their own aversions to copper? [Answer] Normally. If you are touching the copper during most of the "forging" process you are doing it wrong and there is no point when you have to touch it with your skin. The most common early copper tools, the axe and adze, are still completely usable by them. spears, sickles and swords would still be usable, as would knives for some applications. they would not be wearing copper jewelry no using copper cookware but they would still have plenty of uses for it. they might even have MORE reason to use for copper, at least in warfare. If taking a shallow cut a sword caused a person to go into anaphylactic shock we would probably still be using them. [Answer] Gold and silver were also discovered fairly early and are pretty easy to work. They're scarce now because we've long since picked up every nugget that was laying around in the open, but in the ancient world there would have been enough around for people to experiment with. Once you figure out that there are ores containing metal that can be purified by the heat from a fire, that would give some eccentric natural philosophers the impetus to try experimenting on other rocks... eventually they would discover copper, tin, iron, etc. The history of photography, by the way, proves that the likelihood of early death from regular exposure to toxic chemicals is not enough of a deterrent to stop people from experimenting until they develop the technology to a mature level. Some of your sapients would be driven by curiosity to experiment even with copper. [Answer] Meteoric iron. Ancient people who could not refine iron from ore could make iron tools out of meteoric iron. I had read about this in the American Museum of Natural History, where they have 2 meteor fragments from Greenland that the natives had used as iron sources for centuries. You can see all the hammer marks on this one. It must have been a ton of work to break off chunks big enough to make anything. from [amnh.org](http://www.amnh.org/exhibitions/permanent-exhibitions/earth-and-planetary-sciences-halls/arthur-ross-hall-of-meteorites/meteorites/fragments-of-cape-york/woman) [![enter image description here](https://i.stack.imgur.com/toSkP.jpg)](https://i.stack.imgur.com/toSkP.jpg) I read just a little while ago that King Tut was buried with a knife made of meteoric iron. from <http://www.telegraph.co.uk/news/2016/06/01/tutankhamuns-blade-made-from-meteorite-study-reveals/> [![enter image description here](https://i.stack.imgur.com/tWmGP.jpg)](https://i.stack.imgur.com/tWmGP.jpg) > > But it was the iron blade that proved most intriguing. Iron was rare > in ancient Egypt - much rarer than gold - and Mediterranean > civilizations only began to forge iron tools confidently more than a > thousand years after Tutankhamun's death. > > > The findings suggest ancient Egyptians knew how to work with iron even > if they were unable to make it themselves and placed great value on > what little iron they could obtain from meteorites. > > > One can cold forge meteoric iron as the Greenlanders probably did. I bet the Egyptians treated it like bronze. Supposedly copper smelting was an outgrowth of ceramic technology and furnaces. If your copperophobes have ceramic tech and ample meteoric iron to mess with they might learn to hot forge the iron, and then try hot forging some rusty stuff from the ground that seems like meteoric iron, and so learn how to smelt iron. [Answer] Like what others have said, physical contact is not necessary for refining ore into usable metal, so if you want a copper/metal allergy to be more meaningful or restrictive, I suggest the allergy be more severe than being just based on physical contact. For example, in the "Book of Swords" series by Fred Saberhagen, wizards can cast powerful spells given enough time, but large amounts of iron, such as that in the form of a sword or a suit of armor, will disrupt the caster's ability and make them quite vulnerable unless they have defenders of their own. If you want a race that is exceptionally sensitive to metals so much so that it is miserable for them to interact with heavy metals at all, I could still see civilizations developing metal technology despite this handicap. Either a caste system that uses a underclass to handle metals or simply paying individuals a lot of money to do a job no one else wants to do. Perhaps a small minority are immune to the metal sickness (or however it is explained) and are tasked with smelting and crafting with metal? ]
[Question] [ To avoid detail in the name of getting at the underlying question, I've got a modern-adjacent military being invaded by well-equipped nomads supported by angry aliens in space who have far too many nuclear missiles for anyone's good, but very little manpower. The protagonists' air force is intercepting most of the warheads, but not all of them. Neither the protagonists nor the nomads have their own nuclear arms. This war was a shock to people, but they had hours before the initial strike, and an alien attack like this has been THE thing people have been paranoid about for centuries, so they would have a plan of action if this kind of war happened, as it has. I want to know what a planetary military in this kind of situation might do to avoid being nuked as it fights on the ground. After reading far too much about the Pentomic Army, and why it's a very bad idea to spread out to the point nukes are ineffective if you are trying to fight a conventional war at the same time, I need some better ideas to throw at the wall of plot relevance. I'll settle for directions to the people who've been throwing stuff at this kind of wall for the last seventy years. If you have too, just suspend your disbelief that people would continue fighting after the atomic bombs began to hit. I believe it is more interesting if they did. [Answer] ## Self Induce Kessler Syndrome If a satellite is catastrophically damaged it will produce many, small, high velocity pieces. These pieces will remain in orbit for some finite time, and are likely to hit other space craft. This would catastrophically damage those spacecraft, producing more dangerous debris. When this process enters a run-away cascade, it is called Kessler Syndrome. It basically denies the space environment to ALL players until an expensive clean up is conducted. As soon as the first space-missiles start raining down, the modern-adjacent military force should detonate the dozens to hundreds of satellites it had deployed into LEO for just this purpose. It's going to suck to lose GPS and space based comms, but nuclear war sucks more. [Answer] > > If you have too, just suspend your disbelief that people would continue fighting after the atomic bombs began to hit. I believe it is more interesting if they did. > > > When your enemy has an unassailable high ground, and has weapons of mass destruction that you can't defend against and that they're entirely willing to use, you cannot keep fighting. I mean you literally cannot keep fighting, even if you really wanted to, because you're going to be reduced to radioactive ash and mud. > > this has been THE thing people have been paranoid about for centuries, so they would have a plan of action if this kind of war happened > > > "Everyone has a plan until they get punched in the face" - Carl von Clausewitz. I may be paraphrasing slightly The plan should be "Never get in this situation. Ever. Because you're doomed". If you can't stop the nukes falling, then the enemy control space. You are at their mercy. They can sprinkle you with hypersonic re-entry vehicles at their leisure until nothing is left. They don't even have to use the real things... a dumb [penaid](https://en.wikipedia.org/wiki/Penetration_aid) at terminal velocity can ruin your day, and you have to try and intercept it with your limited supply of counter-missiles, because the alternative is that you get nuked. They can deny you satellite communication and observation capabilities. Probably already have done. They can see everything you're doing. They can pop some warheads at high altitude and cripple you with EMP. The only thing you can really do is to deny them orbital space and have a robust detection and interception system, but it sounds like this sort of capability was either beyond your defenders, or if they had it once they clearly don't anymore, because if they did they wouldn't be getting slaughtered with nukes. Best to surrender now and hope an insurgency is worth something (spoiler: probably not very much) because its the best you can hope for, barring some deus ex machina. [Answer] Stay Home. "an alien attack like this has been THE thing people have been paranoid about for centuries" suggests that the planet might have an inkling of their enemy's capabilities already. It also suggests that the planet has had time to implement a defensive strategy that matches their goals, culture, and resources available: For example, a strategy might be "To deter attacks by maintaining the capability of smashing an attack before it can imperil the population". One way to implement this kind of strategy is... 1. Underground cities (and armories) to keep their citizenry safe from marauders. 2. Immunization to a plethora of nasty biological agents that will begin to degrade and consume the marauders on the surface as soon as they open their airlocks. 3. Clouds of tens of thousands of Orbital interceptors to sweep the skies clear those pesky aliens. After the skies are clear, the aliens fleet reduced to wreckage, hidden launchsites swing open their doors and launch replacements to the interceptor cloud. And a week later, when 90% of the marauders lay dying in their own infected filth and vomit having never discovered a way to the underlands, THEN the hidden passages swing open for soldiers to smash the remnants. If you want to win the war, then start by knowing what you want to achieve. If one side just wants to sit on the surface and let the enemy have all the advantages and limit themselves to pretty firefights that accomplish little, that suggests they don't know what they want to achieve. [Answer] The aliens don't want a radioactive wasteland The humans can't stop a technologically superior force. The only reasons for not being nuked is the aliens really don't want to use nukes if they can help it. The aliens will nuke the humans if they can hit their forces hard enough to make it worth it but if the humans stay spread out and hidden, it would take too many nukes to get them all and there would be no prize left to win. Basically the aliens want the Earth and would prefer not to irradiate it before they move in. Letting the monkeys kill each other is easier before the mop up operation. [Answer] The aliens have not nuked you already. Why not? What do they care? They are aliens. They don't live there. And they are angry! Just nuke you all and be done. It is like the Bugs in Starship Troopers. They had no interest in Earth except to hurt it. So they threw a big rock to seriously mess things up. Could have been a big nuke. But that is not what happened. The aliens instead choose a proxy ground war using these nomads. To understand how not to get nuked in the future you must understand how you did not get nuked in the past. You need to understand the motives of the aliens. Maybe they want to punish you but they want to preserve the rich animal life on Earth. Maybe they really like the nomads because they are bare chested hotties and some of them might have their hair fall out from radiation. Hair meaning long flowing locks because these nomads wax their chests and then oil their gleaming bare skin to reduce air resistance. Also the nomads ride around on beautiful horses with flowing manes that might have their manes fall out. But the aliens: whatever their reasons were in the past you need to make sure those reasons persist into the future. [Answer] The nomads and aliens are fighting against the city, and the city is the protagonist? (Wasn't quite sure after reading OP, but I'm going with that assumption.) You could mix the forces. This might depend on how large the nomad tribes are. Like, if the roles were reversed, I would have the nomads hide in the city (in abandoned buildings and sewers and whatnot), since the aliens probably won't nuke the city of allies. In your case though, that only works for the urbanites if the nomad caravans are huge, and relatively static (which they might be, since they're now they besieging a city). You would probably lose your city though. Your urbanites could also allow the nomads to take the city. Send the non-combatants to scatter into the hills and woods, leave your military behind to hide in the abandoned buildings and sewers, and to run a guerilla campaign. If there are a lot more urbanites than nomads, what about human shields? In this case, you don't allow the nomads in so much as take them all captive. Maybe the aliens won't nuke the city if their allies are imprisoned there? ]
[Question] [ We have a great example in The Strange Case of Dr. Jekyll and Mister Hyde. A bad guy has run amok, and our detective begins to intuit the culprit, but the bad guy is almost always one step ahead because they share the same mind. Take this idea a little further into the science fiction space of telepaths, or hacking brains, or aliens with sufficiently advanced surveillance technology that the poor humans can not hope to jam it. How (would) a police force investigate crimes in an environment where the investigator's very thoughts are public knowledge? [Answer] The Same Way They Do Now The police are investigating after the fact which means the crime has already happened and the evidence already collected. The only advantage the criminals have is police can't lie or bluff them during interrogations. Depending on how minds are read, even this could be got around by using an interrogator who only knows what the detective tells them beforehand or a remote interrogator out of range via video link. You still have witness, DNA, fingerprints, CCTV, mobile phone tracking, surveillance and digital footprints. The police work continues virtually unchanged. The real question is if the police can also read minds or just the criminals? [Answer] Pride and Arrogance Having near perfect information means having a LOT of information to sift through. It is also a breeding ground for a god complex and the belief that they have defeated the dreaded Dragon of Chaos. In short the adversary has to also be perfect at predicting. The watched need only generate large volumes of apparently related activity. Eventually one of three things will happen: * The ability to deal with the volume of information will be surpassed. This provides a chance that critical information is either dropped, or have its detail reduced to being useless. As with any system: Garbage in, Garbage Out. Their predictions will be incorrect. * The Dragon of Chaos will rear its head and open an unexpected and unpredictable path. This is a fundamental limitation of any simulation, the reality you are predicting does not also contain the simulation. The protagonist may be able to travel these paths for some time before the hyper-vigilant adversary can catch up or respond. As up till now the adversary was already ready, now they are literally out of position, and require time to organise. * The Adversary makes a mistake. They had the knowledge, they had the ability, they dropped the ball. The truth of the mater is that it takes a lot of resources, a lot of energy, and a lot of focus applied forevermore to keep something secret/unknown. Eventually the Adversary will be distracted. Perhaps a life event, perhaps someone spills the beans, perhaps the Adversary is presented with Bad choices and can only pick the least worst. Either way that moment is an opportunity. [Answer] Chess match. In chess, both players have [perfect information](https://en.wikipedia.org/wiki/Perfect_information). Each player can see all of the capabilities of the opponent, and knows all the things that opponent can do in a given lay of the board. In such a game, winning requires a series of actions such that the opponent cannot escape defeat. Quick action is never needed. Subterfuge however can be useful. Police investigations would be a chess game. In chess if I see my opponent is trying to quickmate me and I am aware of that sequence, I can prevent that. When my opponent has a long game and is setting up a trap well in advance I may or may not be able to prevent defeat. Your psychic police investigation and the countermoves of psychic criminals are played out like a chess game. [Answer] A similar question about warfare in an age of perfect surveillance, the proper countermove was to create a decision tree, and then use a random number generator, set of dice or deck of cards to randomly choose the path you were going to go down and immediately execute before the adversary could bring countermeasures to bear. Ths investigators have essentially the same issue, so they might develop multiple lines of investigation. The criminals can see multiple patterns of investigation being drawn against them, but are unclear about which one they will have to foil. Do they attempt to hide or obscure the forensic evidence the criminologists are looking for? Can the develop enough internally consistent lies to counter the lines of questioning the detectives are building? Can they erase enough eye witnesses the uniformed officers are interviewing? How about informants? can they find and eliminate them in time? The police can also play games with the criminals through these means. They might start focusing on "Benny", a mid level criminal who the criminals under investigation are being led to believe is an informant, but their actions in silencing "Benny" actually help a different investigation - "Benny" had nothing to do with the matter at hand. False lines of questioning, sending criminologists to look at apparently unrelated evidence...The police might be essentially creating an entirely false but self consistent narrative to confuse the criminals as to what is actually being looked for. Think of the movie "[The Usual Suspects](https://www.imdb.com/title/tt0114814/)": Keyser Söze isn't just telling a story to confuse and throw off Agent Kujan and buy time, but telling a story to see what sort of reaction he is getting and changing the story on the fly as he observes the reaction of the police. Now imagine a skilled interrogator doing that to the hapless criminal. Of course, given the police have effectively far more resources than the average criminal, they also have the option of pursuing all the lines at once, and simply overwhelming the criminals. Only the largest and most organized cartels or mafias would be effectively able to cope, and even then, would likely be constantly being chewed up around the margins unless they subvert the police (much as happens in the real world). [Answer] > > Take this idea a little further into the science fiction space of > telepaths, or hacking brains, or aliens with sufficiently advanced > surveillance technology that the poor humans can not hope to jam it. > > > This will only help in the case of brain hacking or advanced alien surveillance. In either case the mind reading aspect is probably a more advanced version of what Google (after getting patent from Motorola, I beleive) [has had for years](https://www.cnn.com/2013/11/12/tech/innovation/google-throat-tattoo/index.html) This means the criminals are reading the internal conversations these police have with themselves. But you can have thoughts that don't trigger these slight electronic signals to your vocal chords. Even if initially the police make the mistake of internally acknowledging they know they're being surveilled, they can still intentionally think something different than they're going to do. They can create monotonous internal dialogue in their mind while writing with their peers on pen and paper. Extremely difficult, and limiting of the police using their full attention in solving the case - but even as their thoughts are read, they can most likely create fake internal dialogue and pursue something different, even the opposite of what they just "thought". If it's telapathy and they can read the signals sent to your hands to write, your diaphragm to breathe, and your toes to wiggle... hopefully someone else has a good answer XD. ]
[Question] [ Let's say that there are 2 countries with very different inhabitants. Country A has no idea that country B exists. Country B may or may not know about Country A. Country A is surrounded by large mountains and has no sea access. Country B is quite far away, on the other side of the mountains. The mountains are only inhabited by wild and dangerous creatures; there is no organized border between the two countries. The two countries are both the nearly eternal medieval society without gunpowder and with few scientists. There are quite a few other countries on the continent, but none of them has contact with both A and B. Most are in contact with B only. Around 1000 years ago the two countries (A and B) used to trade and fight together (as allies against a common enemy which they vanquished). Now, however, Country A has forgotten this history and doesn't know what is beyond the mountains. What properties of my world could lead to Country A losing touch with the rest of the world like that? There is no magic, so no magical spell to make them forget. How could that situation be possible? Country A not knowing what is on the other side of the mountains? The main reason I have is that since the trip through the mountains is very difficult, they simply stopped doing it. Being an early medieval civilisation, they did not use much written archives. And in a thousand years they simply forgot the oral memories and it became legends. I find my explanation very weak and unbelievable. Do you have another explanation for why this loss of common knowledge would happen? [Answer] There was a mountainslide... ...which is like a massive landslide but more of it. It left the mountain range so [steep, rugged and imposing](http://www.thelandofshadow.com/wp-content/uploads/2016/07/EmynMuil4.jpg) that no one dared get close to them. This could have happened during the War (1k years ago) or a later date. I'd say not to choose a date more recent than 100-200 years, so the current generations don't remember (or believe) about the exterior cultures. First, it was the fear that stopped them. Fear of the thing that caused The Mountainslide. Fear of the gods or whatever mystical or natural force they think caused it. Then, new generations tried to cross the mountain range. They stopped fearing that force and started to consider it a legend. But there was no way to cross them. Whenever you think you were close to the other side, or you had found a promising path, you'd find an abyss, a crevasse or an almost vertical wall. Then, when all hope was starting to vanish, they found the caves. A whole universe of caves and underground galleries were created by The Mountainslide. [Wonders](https://www.boredpanda.com/amazing-caves/) and valuable stones no one had seen before lied down there, which attracted the explorers... and the merchants (who didn't go themselves but paid other people to go). Many people disappeared in them but some returned, and a map has been created over the years. This probably was a nation-wide effort, both to make the map and to overcome some obstacles (bridges, new speleology or [clothing](https://i.ytimg.com/vi/4_cVd07IlSE/maxresdefault.jpg) technologies, etc...). There could also have been some private parties doing their own maps and selling maps technologies between them. It has taken many many years, decades or even centuries. Even with current technology, there are plenty of [cave systems not fully explored](http://www.dailymail.co.uk/sciencetech/article-2019775/Inside-worlds-biggest-cave--large-end-found.html). Now, after (X) years of exploring, they're about to find an exit... ...which will reunite them with an exterior world they no longer remember. [Answer] There's actually a pretty good real-world example of this: [Tokugawa (Edo) Japan](https://en.wikipedia.org/wiki/Edo_period). Starting in 1633, the government of Japan instituted a [policy of seclusion](https://en.wikipedia.org/wiki/Sakoku). Fearing foreign influence and especially Christianity, they banned all foreigners from entering\, and all Japanese from leaving Japan for over 200 years. Crews of foreign shipwrecks were executed. Japanese fishermen who were blown off course were not permitted to re-enter. Merchants were not allowed to trade abroad. Although the Tokugawa government leadership knew of the outside world through ambassadors from the Dutch, Chinese and Koreans (who were permitted to send envoys to the Shogun and trade at a few ports), by the end of the policy of seclusion the average Japanese person had never met a foreigner, had never traveled abroad, and likely had only vague ideas about what was outside of Japan. In some cases fanciful legends developed about foreign countries. (Some Japanese thought that Europeans were meat-eating devils who sweat butter for example.) So, one way that your situation might be possible is some kind of strict government or religious authority which prevents people from Country A from travelling beyond the mountains. Over time few people even remembered what was over there. Legends abound about the barbarians over the mountains. \(with some exceptions. certain foreigners were allowed to enter at one of four ports, where they were segregated from the local population. Once a year they were permitted to send an envoy to see the Shogun.) [Answer] The people in country A could have a religion saying that demons live beyond the mountains, and if someone crosses they will not only kill the travelers but attack country A. So they set guards to prevent anybody from crossing. This wouldn't be perfect, but with the religion popular enough 1. People who don't believe in it can't say so, or they risk death. 2. Anybody caught trying to cross the mountains is executed. 3. Those who try despite that generally get lost or die on the way. 4. Those who do get to country B get treated to their version of the religion which considers them to be invading demons (optional). 5. Anybody who manages to cross, see country B, escape and get back, and then tries to tell about it without being very careful gets executed again. Demons obviously messed with their mind, after all. The religion could be based on the misremembered war as well. [Answer] A mountain range, no matter how big, wild and dangerous it is, is no obstacle for an adventuring race as curious as us humans. Someone would try to get through just because reasons, or as Sir Edmund Hillary put it: "Because it's there". Many (most, if you want it so) would die, but some of them would get through - and back - and they would ensure that at the very least the knowledge of something existing on the other side would not be lost. The only thing preventing that would be a 100% fatalities in crossing, but that's hardly believable. If some deadly creatures did that, there would be a great interest in both countries A and B to destroy these creatures, since they inevitably will expand into both countries' territories - whether they are animals, plants or supernatural creatures; and if it's some non-living threat such as a chasm or a deadly river, or temperatures, or whatever you want it, somebody would find a way to counter it. If your world had magic, that would do it, but since it doesn't I can only find two possible impassable barriers (impassable to a medieval civilization, that is): chemicals and radiation. You can have your mountains being mainly active volcanoes. Rivers of lava make the crossing impossible except at certain points, but these points are deadly traps: the CO2 condenses there, especially at night, when it's colder, and suffocates everyone who is in there. Since you need several days to cross the mountains, it's impossible to get through without dying. Doubly so to get back to report if you did it. A subtler variation of the theme is a lot of radioactive isotopes on the surface. You can get almost there without seeing or noticing anything strange, but when you are about to get through the last mountains you start feeling sick and feeble, and you die (horribly) just watching the valleys of the other side of the mountain range a few miles away. [Answer] I think your initial idea is good, perhaps there's some sort of dangerous animal prowling, preying on people who entered and they eventually made it taboo to enter the forest. Perhaps they created a scary tale to scare children off from entering it (like the boogeyman). But in addition to that, you could throw in this idea, about 500 years ago: There could have been a plague that swept through the country and the younger generation was immune/not as affected. While parents and adults were sick and feeble, unable to do work, the younger generation had to step in. It was during a harsh winter which made things worse. The younger generation used everything they could find, burning books and furniture to keep their houses warm so that way they could try to survive. That took up their main focus, they weren't thinking about history, just survival. And once you stop thinking about things for awhile, you eventually forget. With the focus on saving people and survival, the conservation of knowledge fell to the wayside. The elderly who held the knowledge died, as did many other adults, and the majority of written knowledge was lost. The years spent after were focused on rebuilding and population growth. I feel that in medieval times, people would have worried about the short term - surviving now, than the long term - what are we going to do after? The very very few books found thereafter could be thought to be fairy tales, like the boogeyman. [Answer] There was a flood... Maybe it was caused by a big earthquake, a tsunami, a volcano erupting, or just a sudden (geologically speaking) temperature rise which melted a lot of ice, and country B was suddenly flooded with enough water that the cities and villages and agriculture that wasn't destroyed by the water was destroyed by lack of food and diseases that followed. Maybe country A only waited to see the actual flooding and decided country B no longer existed because [insert appropriate gods' name] destroyed it for their sins and everyone who tries going there is automatically damned. Superstitions do hold strong in medieval societies, especially if the road there is already fraught with dangers. [Answer] What if Country A just isn't that good? Or if Country B is full of ecstatic pleasures? Maybe some do successfully cross but the fact that some don't and the fact that all who leave never return make it so the information doesn't come back. --- Country A may be a great place for the conservative mind; people who are avoiding dangers and preserving their society; while those adventurous enough to dare the mountains not only self-select their more liberal mind out of the country but when they arrive at Country B and find an amazing plethora of new things to try, why would they ever leave? Depending on how political and metaphorical you want to get, you could have each show you the pros and cons of highly conservative vs highly liberal places; much like the Eldar and Dark Eldar do in 40k[1]. [1]NOTE: 40k is universally GrimDark, so a frame of reference adjustment is required before considering that perspective. Regardless of whether you want that metaphor, the two styles of thinking lend themselves to the societies they're in. The more conservative thinkers will be happy in their mountain-protected area; having everything they need and being mindful of how to preserve it. The more liberal minded among them will want to adventure out and either die trying or be successful. Either way, it's likely they don't come back (especially if the mountains are that harrowing) simply because there's more to explore; or more pleasures to enjoy, or more things to experience on the other side. The fact they don't come back looks like they're dead, so it reinforces the culture that crossing the mountains is a death sentence. You build that legend up long enough, anyone who does come back may look like a Heretic, a liar, etc. This, in that proposed political take, would allow you to see the dark side of conservatism (the authoritarian enforcement of customs and values) where these "liars" are dealt with. On the flip side, Country B may have issues with diseases, debauchery, and lack of social cohesion - possibly having infighting due to that. --- Regardless if you like that idea, I think the seeds are there for you to see how a colony may self-select to keep itself in a safe place and reject those who would claim there is more to the world. What's more? this is quite easily done with a religion; where their paradise between the mountains is the world - a god given region surrounded by the hells. The lavish beasts in the mountains are god's punishment for those leaving, and the frozen wastes are warning to avoid the betrayal of this wonderful place. As goofy as it sounds, my interpretation of your story is basically the Country version of The Fox and The Hound; maybe the two civilizations do eventually reunite and fix each other's ills or delusions. [Answer] Another option: climate/tectonic change. A thousand years ago the mountains were rugged, but passable, and trade happened across them. Then over a hundred years or so, a sudden cooldown of the climate and/or volcanoes and/or earthquakes made the mountains no longer passable. Volcanoes and earthquakes have the advantage of being a sudden, dramatic change; climate cooling has the advantage of being both durable and reversible. Any of those can also have the bonus that they'll have disrupted the society of Country A enough to justify forgetting the past. Massive decreases in population, political unrest, having to burn books for fuel... Basically, people would be too focused on survival to keep alive the memory of Country B, the existence of which has become entirely irrelevant to their lives. This can obviously be combined with the more deliberate isolationist efforts suggested in other answers. Then after a thousand years the climate could start warming again, to the point that going into the mountains would be less insane, and increased population might mean more crazy people to try in the first place, and it would also be a more attractive prospect to people who are no longer as focused on pure survival. Or another tectonic event could make it passable again in a more sudden and dramatic fashion. [Answer] There must be much more than just something between them. Because, as you probably know, you can go around them. General direction you want to look at is Greece. Hard presence around any water but almost no in deep land. And Greeks were so content with their wine, olives and feta that no one bothered to check Olimp for god presence till early XX century. So, for example, looking at map. Greeks could known and consider neighbours nations located in Arabian peninsula. Because there was connection between Mediterranean and Red Sea. Then, some natural cause closed the watercourse. And because people where very superstitious and not keen to walking long distances they forfeit looking for land connection. Kind of like Gibraltar rocks in mythology (Maybe this story is about such event?) ]
[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 5 years ago. [Improve this question](/posts/107721/edit) As the title states I have a scene in my book where two ships collide in space. What I want to know is would the passengers hear the sound from inside the ship. (the ship’s hull did not breach but it was a very hard hit) I know that the vacuum of space stops sound but if the ship has air therefore a way for noise to be heard would it. The collision happened outside so I'm a bit torn to what would happen [Answer] Absolutely. If there is a medium to transmit vibration such as a ship hull into the atmosphere inside, any people aboard would definitely hear the sound. Sound is just a vibration through matter, be it solid steel, water, or air. If a ship's hull is impacted, it would transmit that sound to the air inside. All that's required is physical contact. In the same way, two astronauts in space would be able to speak to each other without radio if they touched their helmets together. [Answer] As @Samuel already explained, you can hear collisions if the inside is pressurized. The vibrations of the contact are transmitted through the hull to the air and this in turn to your ears. As a real-life example, [astronauts inside ISS can hear their colleagues doing EVAs](https://space.stackexchange.com/questions/20886/can-astronauts-inside-iss-hear-their-crewmates-doing-evas). The astronauts inside can hear the outside astronauts moving along the hull and noises generated when they use tools (with direct contact to the hull), for example. Astronauts inside ISS can even hear the impact of micro-meteoroids. An astronaut in a space-suit (which is a very tiny spacecraft, in a sense) is also able to [hear noises via direct contact](https://space.stackexchange.com/questions/24201/can-astronauts-hear-sounds-during-space-walks-for-repairs?noredirect=1&lq=1). In some movies this is used to have two astronauts with failed communication devices talk to each other by having their helmets touch and speak. This should indeed work: your voice vibrates the air which vibrates your helmet which then vibrates the other guys helmet and air inside it. A bit like a [tin-can telephone](https://en.wikipedia.org/wiki/Tin_can_telephone). [Answer] If you have ever been in a fender bender, you'll know that it is loud. Outside the car, people hear a little bang. When you're inside the car, all of the metal of the frame and body shakes from the impact and you know that you've been hit. Your passengers will hear the collision. The may not be able to hear anything else. [Answer] The collision happened outside but the vibrations are happening inside the ship. The sound would travel through the air in your ship. Passengers would hear it. ]
[Question] [ If there's two things i love, it's space-flight, and late 19th century technology, and i hope to implement as much of the latter into as much of the former in my current setting. And one thing that has me particularly interested are [Thorsten Nordenfelt's](https://en.wikipedia.org/wiki/Thorsten_Nordenfelt) Steam submarines. [![enter image description here](https://i.stack.imgur.com/5Aduf.jpg)](https://i.stack.imgur.com/5Aduf.jpg) Old, beautiful, cast-iron...and perfect for a sci-fi steam-punk setting. It made me wonder...how well would they hold up in space? Or more specifically: *How could it be possible for a spaceship, made from cast-iron and other materials typically used in construction in 19th century* Europe, to travel distances similar to those of earth and mars during their transfer-window (38.5 Million Miles), while retaining oxygen inside to keep a crew of humans alive?** Sadly, I'm not sure what propulsion-method could be optimal to allow for the ship to survive as long as possible. Though because i'm working with steam-punk, i'm willing to stretch the scientific advancement in some areas. But either way, there's gonna be some hefty waste-heat to deal with. (also they will be purely traveling from orbit to orbit. Launch and re-entry are out of the question for now.) And additionally, as the title implied: How could it be possible for a space station to be made from materials typical of the same period, while supporting a population of humans inside? The types of stations i'm thinking about specifically are both modular stations such as the ISS and MIR, but also fancier options, such as [Bernal Spheres](https://en.wikipedia.org/wiki/Bernal_sphere). The question doesn't concern the life-support systems for now, and is more about structural integrity and retaining pressure. I'll clarify more things if needed. [Answer] Cast iron can be made of the same atoms as steel. Something like [blackheart malleable cast iron](https://www.totalmateria.com/page.aspx?ID=CheckArticle&site=kts&NM=96) can have good properties. But it will not be as good as rolled steel. Something that is cast into a mould may freeze quickly at the mould wall, but the inside will cool more slowly, giving you larger crystallites, and separation of the impurities to grain boundaries. Rolling the metal while it is still hot will squash and work-harden the crystallites, and mix in the impurities. This gives much finer and more uniform microstructure. If you are building the ship in space, you could melt the steel and spray it using a [plasma spray](http://fab.cba.mit.edu/classes/961.04/projects/RegXuProj/MasProjII.htm). This can work in air, but would be better in space. You could process your metal from an asteroid, and then build up your metal plate from a set of spray coatings. That is more practical than having a steel rolling mill in space. The resulting sheet should have a fine microstructure because each layer has been rapidly cooled. If you melt the metal and cool it fast enough, you will get a [metallic glass](https://www.sciencedirect.com/topics/chemistry/metallic-glass). These have almost no regular crystalline structure so they can be very hard. Possibly a bit too hard for a spaceship, that would would like to be tough rather than hard and brittle. However, you cannot easily weld sheets of metallic glass, without the heat of welding giving a softer [heat affected zone](https://www.twi-global.com/technical-knowledge/faqs/what-is-the-heat-affected-zone). You may be forced to overlap and glue them. Or maybe use lovely steampunk rivets, yay! [Answer] It's Not. There's your answer. Not with cast iron. [Here's a good visual (and auditory) reason why](https://youtu.be/IoL2kqel46U?t=1078) The above is a YouTube video from one of my favorite channels - Cutting Edge Engineering - an Australian machinist that specializes in repairing big machinery components. In this video, he is attempting (key word) to repair a series of cracks in a transmission housing, that is made of cast iron - you can watch the whole thing if you like - as he goes on at length as to why cast iron is a terrible material to work with - but in particular to your case - it's very brittle and doesn't handle temperature changes very well. The timestamp above shows what happens when there is uneven heating across just a small component (relative to the size of a space vessel). Watch for about 1 minute or so - and you'll get what I mean. 'What uneven heating!' I hear you ask? Well, the heat from friction of escaping an atmosphere then going into the cold vacuum of space. Your cast iron space vessel is going to do what that housing did - crack. There goes your air-tight integrity and probably followed in a matter of milliseconds by an explosive decompression. [Answer] As has been pointed out, thermo-mechanical fatigue of cast iron will be a large problem. Merely rotating such a vessel in sunlight will cause differential cooling and heating that will cause stresses that may result in failures. However, there is a solution. Different materials handle thermo-mechanical fatigue differently. In the Age of Sail, the black powder cannon that were used were often made from cast iron due to its cheapness, but cast iron guns had a tendency to crack or explode after repeated firings. However, brass or bronze guns were found to be more resistant to this fatigue. So, if your ships are cracking up between the heat of the sun and the cold of space, make them from more flexible materials that can better handle the cyclical strains involved. Just because this is steampunk, doesn't mean that you have to use cast iron. You can use different steel alloys or even brasses and bronzes that have better thermo-mechanical fatigue characteristics, and were still available and widely used in the period in question. [Answer] [Metallic (M-Type) asteroids](https://en.wikipedia.org/wiki/M-type_asteroid) are predominately made up of Nickel / Iron. Which happens to be a quite passable alloy for spaceship hulls. > > Tough and versatile, nickel [What are the properties of nickel alloy?](https://www.corrotherm.co.uk/blog/what-are-nickel-alloys#:%7E:text=Tough%20and%20versatile%2C%20nickel%20alloys,real%20favourite%20for%20critical%20applications.) > alloys are resistant to corrosion by a range of media, and stay > impressively strong even at temperatures over 1000°C. They are usually > well-suited to operating at cryogenic temperatures as well, but it's > their resistance to heat that makes them a real favourite for critical > applications. > > > How you get the first ship up there to start mining asteroids... well that's your problem.. [Answer] Large vessels with thick walls made of cast iron will be very heavy. You could make them very small and/or paper thin walls, but that would go against your steampunk aesthetic. When you look at what size rocket is needed for lifting a payload to orbit, it grows exponentially. However, when you try to scale up existing rocket designs their power does not increase exponentially, in fact you even get diminishing returns. So it makes more sense for such vessels to be constructed in orbit, unless you have engines that work based on principles not known to current science (for example, magical anti-gravity devices). Space stations don't need to move so it is more plausible. You still have to move the equally massive raw materials to the construction site, but you do that in parts not all at once. You also only do it once, the station doesn't need to zip around. For ships, the issue continues during space travel. You need a lot of engine power to move such heavy ships quickly, due to $F=ma$. So even if you construct them in orbit, you would need exotic propulsion to justify it. Perhaps you can devise exotic propulsion methods that work better when larger. For example, nuclear reactors are harder to built in tiny sizes. Perhaps you have something analogous. If bigger ships are more efficient at generating energy and/or propulsion, that would explain why people insist on building such oversized ships instead of smaller and lighter ones. Cast iron is not a great material for space ships, but you can come up with some in-universe reasons why the superior materials cannot be easily used. The question is, is cast iron by itself necessary, or is it that any similar material will do but cast iron is preferred for whatever reason? One of the remarkable properties of cast iron is a fair heat capacity and good heat conductivity. Heat management does come up often in space ships. To be fair, there are better ways to do each: Other materials like copper have much heat conductivity, and then there are methods like circulating water. There are also better heat sink materials, but many are not practical for building a vessel (ammonia) or less abundant (lithium). Iron is decent in both aspects. So the obvious thing is to create in-universe need for these. * Perhaps weaponry relies heavily on concentrating heat, like lasers. Cast iron dissipates the heat, so the laser is less effective. * The reactor could be generating a large amount of heat and using the cast iron hull as a giant heat sink. * Maybe there is some kind of warp drive that requires a large amount of cast iron in the ship for some reason (magnetism?). There are other forms of iron, like steel, that would be similarly useful in these situations, and are also a better material for constructing ships. So you would also have to explain why those other forms are not used instead. In our world, cast iron is sometimes used due to the cheaper and easier manufacturing method. You would need to devise something similar for your setting's industry. [Answer] This is a frame challenge. --- ## It's not actually cast iron. I also love the aesthetic of cast iron, but it is a less-than-ideal material for a lot of steampunk stuff. So, instead, we use something that looks just like it, but it actually isn't. I give you two new materials: B.R.A.S.S. and I.R.O.N. ## B.R.A.S.S. The *Blast Resistant Alloy for Special Structures* is a special material with a golden colour. It's main use is to build structures that have to deal with lots of energy - like engines, reentry shields, guns, and stuff like that. It's not exactly know what it is made of - this is a secret safely kept by the forges that produce the thing - but it is the thing if you need something to withstand damage. It is one of the most impressive materials you can find, secondend only by... ## I.R.O.N. B.R.A.S.S.'s super-powerful cousin, the *Ingeniously Riveted Octave-tempered Nanosteel* looks like cast iron, but it is actually a specially prepared form of steel made via a proprietary process that somehow uses music to make it settle into a ridiculously strong form. While those are fantasy metals, I argue that they would help in preserving the suspension of disbelief - it's more difficult to argue that the "special metal" can't do something than it is to do the same for a regular material we use in our day-to-day. [Answer] In use, Space ships and Space stations are vacuum insulated, and will quickly overheat unless a heat pump is used to drive a radiator, or evaporative cooling is used. There is no 'cold of space' as long as you have a conductive skin and an internal heat source (machinery or humans). Since volume increases as the cube of radius, and surface area only as the square of radius, the possibility of becoming "cold" decreases for larger objects. Radiation from the sun can and will overheat "dark" objects exposed to sunlight, but as it turns out, ordinary reflective surfaces are good enough for all modern space objects. The Apollo command module was just painted white: SkyLab was shielded by the 'micrometeor shield', and when that failed, by a 'space blanket' on an umbrella. Cast Iron is brittle. Unlike steel, it doesn't have a ductile-to-brittle transition at cold temperatures, because it's already brittle, but as discussed above, in use it won't be exposed to the 'cold of space' anyway. To maintain heat/cold balance, your cast-iron space object will need to be painted and have active cooling. Apart from that, it won't have heat/cold problems. [Answer] What about using [wrought iron](https://en.wikipedia.org/wiki/Wrought_iron) instead of cast iron? Wrought iron is made by repeatedly heating and deforming the raw iron. The iron is heated until it's soft and malleable, then deformed by hammering, bending, rolling, and stretching, a process somewhat similar to kneading bread dough. This process squeezes out much of the slag, and removes a lot of the carbon, resulting in a more pure iron which lacks the large crystalline structure that makes cast iron brittle. Wrought iron will eliminate many of the problems with cast iron. It's stronger, more malleable, less brittle, and much less subject to cracking due to temperature changes than cast iron. It's also a product that was familiar and widely used in the 19th century. Processes for mass producing wrought iron by hot rolling [existed in the 1800s](https://en.wikipedia.org/wiki/Rolling_(metalworking)). The main disadvantage of wrought iron is that it requires much more time and labor to produce than cast iron. But if you're building a spaceship, presumably you have a budget for that. This doesn't address the weight issue, but it's a big improvement over cast iron for tolerating major tempurature changes. ]
[Question] [ This one feels a bit trivial, but I am genuinely stumped on how best to word a job specification that one of my characters is posting in a fantasy world. The basic idea is I have a dwarf who is in a medieval style fantasy city that is not very dwarf friendly. He wants to recruit people to come on an adventure with him. He has enough capital to pay for a bunch of posters, which he would like to put up around the city. The basic contents of the posters are "Meet me at `the place` to do `the quest` for `reward`". For the purposes below imagine he has a way to mark each flyer uniquely (or close enough). There is a slum outside the city that is more receptive to dwarves. His plan is to employ poorer residents of the slums to distribute the flyers inside the city. Posting them on job boards, and walls, and directly to passers by, etc. The dwarf thinks the way to go about this is to: * pay a small retainer in advance for accepting the distribution job * pay each individual distributor a commission based on the number of adventurers present at `the place` qualified to do `the quest`. (He would use the unique identifiers to determine which distributor to pay) * alternatively; because he might misspeak / have communication issues occasionally, some individuals he employs think they will get commission on each flyer they return back to him at `the place`... And the dwarf also believes he can afford to do the above. He has enough capital do fund the job of posting flyers. The above scheme seems the most straight forward to me. I kinda want to emulate the compensation structure of this sort of job in the real world. How are people who put up flyers paid and what stops them taking the money and not doing the job? For the purposes of my narrative, I think my dwarf should not choose the perfect method, if one should exist, and I think the story gets better if he pays a good deal of capital for an imperfect result (ie in the end only a small fraction of his flyers a distributed as he wishes and the resulting crew of adventurers is a motley one). So in the end my question would be: What would be a good way for the dwarf to specify the job of distributing flyers in a way that he would feel comfortable that is isn't obvious how to game it? (And maybe how to have it gamed in a way that would be a fun twist...) --- a note on gaming: For the purpose of this I am imagining the people he recruits are a bit of a diverse bunch too. Some would be quite smart and highly motivated to do the absolute minimum work for maximum reward, and others might be honest and appreciate that in the long run cheaters get what is coming to them. So even if there is an obvious game to be played not everyone will play it, so to speak. Some people prefer to do honest work for honest pay. Life is less of a headache that way. a note on the world at large: For the purpose of this question, the city exists in a low magic medieval fantasy world. Lets just assume that the dwarf cannot afford a wizard to post the flyers, and none of the people he pays are competent with magic. Basically, ignore magic. I think if a wizard where to turn up with a stack of flyers asking for commission on each one, that would be something the dwarf would find astounding beyond his comprehension. [Answer] # An imperfect method would likely come across as a result of the sheer logistics of the problem space, and the size of the city itself. While [AlexP's answer](https://worldbuilding.stackexchange.com/a/240114/85620) does discuss how you would pay these people initially, and in what sized groups, I'd argue that the "Spot check" is unlikely to happen - because if the dwarf was able to do the spot check for everywhere he wanted the sign, they could put up the flyers themselves. So a physical spot check is likely out of the question. However, with [o.m.'s pie slice approach](https://worldbuilding.stackexchange.com/a/240123/85620), there's another way to really cut down on the amount of work for a follow-up "More Efficient Spot Check"; word of mouth in an area. Having done a paper route a few years ago, the general rule we had was, if a house we delivered a newspaper to had 3 newspapers on its doorstep, we were to note it and to ask them to be removed from our delivery list. This was our expected standard because it would appear the people in the house didn't read them, and would...complain to the newspaper place themselves otherwise. Request that it be stopped, etc. In this case, having that effect with posted flyers would indicate that they were, in fact, posted in the area; absent phones, they'll bring it up in bars, or in the area where they are posted, and adventurers may just hear about the sheer number of flyers posted about. So follow-up pay could be conditioned upon doing a check in a nearby pub to the area that was canvassed by a team of teenage boys - ask about rumours, and if it comes up, the signage was probably doing its job in the area, so they get their bonus. This could have some perverse incentives however: * Teenage boys may be posting them out of reading range so that they stick out as papers from the side of buildings, or around city flags, or just all in a large group on a single board - places that grab attention, but probably aren't the "Efficient" way designated posting areas might be preferred. * You can't differentiate between word of mouth from the posters, and word of mouth from just telling the other person the message. * The teenage boys may cause a scene for the purposes of getting the message well known in the nearby pubs. But, in the end, this would be an quicker way to check, and would have the benefit of keeping the dwarf hydrated and fed when doing a long trek through a [400 person town to 200000 person city](https://www.quora.com/How-big-were-medieval-villages-towns-cities-etc). ## Things this doesn't check for - misplaced flyers. There is one major issue with this method - it doesn't actually check for individual flyers, and so the full account of them might be harder to ascertain until after the fact, if people are being asked to bring their flyer to the Location for the Quest, or just a Post-Quest collection of them. You mentioned that the slums are outside the city - it's entirely possible that the slums, where the people are hired from, would be where at least a small amount of flyers would appear - in small enough amounts to not draw attention to, or if in large amounts, not enough to be obvious from the outset, and others would be incentivized to actually bring some to the city - so that they can collect the "Post flyer posting secondary payment" commission, verified again by word of mouth in the city - which the dwarf would be upfront about that about the additional payment, though maybe not about where in the city he would be checking. Results technically still don't matter to the Flyer Posters - they just care that it gets talked about. [Answer] Most usually this is (and always was) done by recruiting one or two or (if you really have a lot of posters) more teams of two teenage boys, and paying them a fixed amount of money to affix some dozens of posters per team. (About half one days' minimum wage per team, say in modern money some 25 to 50 euros, or in ancient Roman money about a denary.) Pay them half in advance and half the next day after checking that they have actually done the work. Do not even try to link their pay to the results of the campaign; they don't care about that, and it's not their business. The affixing can be done during the day if you have all the permits lined up, and at night if you don't. Printers who print posters most usually have such poster-affixing boys on hand. [[Short 1896 film on-topic](https://www.youtube.com/watch?v=tYu11SGg7Zg) by the famous [Georges Méliès](https://en.wikipedia.org/wiki/Georges_M%C3%A9li%C3%A8s).] Instead of posters, you may prefer to print loose sheets and pay the boys to hand them to passers-by at the market, in the public square, on the main street and so on. [Answer] The dwarf assumes everyone will follow contracts to the letter After all, he does, as do his fellow dwarves. He lays out exacting, precise specifications on the placement of posters, number on each street, positions that they should be hung, etc. Each contract contains the strongest possible oaths permissible in dwarven law that the contract will be completed to the letter, or the money returned. In dwarven society, it would be a crime worthy of exile to break a contract such as this. He assumes that, even if the young humans he hands his flyers and coins to do not carry out the task, they will return the money and the flyers, and he can simply hire new workers. The street urchins he hires, however, are illiterate and have no understanding of the instruction packets he provides, and, as they can't follow the plan, slap up a few flyers around where the dwarf normally walks, and decide to sell the rest as paper waste. It ends up being used as toilet paper in several local taverns, where adventurers who opted, unwisely, for the fish of the day all have an extended chance to read it. In this way, the motley adventuring party, looking somewhat worse for wear, arrives at the time and place specified by the flyer. [Answer] The dwarf has a complicated method. It involves dividing the city into twelvths and applying posters in an even method such that for every area of a certain size, a poster occupies it. The dwarf is drawing from his experience doping crystalline alloys, here the posters playing the role of the dopant. He hires people to do this. One poster is distributed. All persons responding to the call are patrons of a certain bar. Also the daughter of a patron and a husband / wife team. The dwarf is not sure why his scheme did not work. The person who put the poster up in the bar considers things to have worked well. That person might have some insights into why things did not go as the dwarf intended. Possibly the person even has the dwarf's interest at heart and was skeptical of the dopant scheme. [Answer] Frame Challenge - pay attractive friendly people to recruit for you by handing out posters. The dwarf is neither attractive or particularly friendly. It's difficult to get a flyer noticed in high traffic area. Pay attractive people to chat up adventures passing by and convince them to show up at the tavern. This is a job in the real world usually called a Brand Ambassador This has advantages over the hung flyer method 1. The recruiters can do a quick check and make sure the person meets minimum qualifications. You don't want a bunch of level 2s showing up when you need 10+. 2. You can have each recruiter initial flyers. This lets you do market research on the best places. 3. Being an attractive, friendly person is a skill. They can likely help you craft a message. 4. In the real world, people are hired to help sell drinks. They are paid per hour, not per glass, so cost is known upfront. They can also report back if something worked great or fell flat. In a gold rush sell shovels The dwarf my have hit on a great idea. Instead of grinding levels himself, offer to find parties for other adventurers. He's got a network of recruiters around the city and is happy to play adventure match-maker for a small fee. After a few runs, he'll also have a roster of people who may want to take a chance on a tough loot run, for the right price or reward. [Answer] I'm going to give this plot a twist. *The dwarf does not* have enough gold The dwarf wants gold because he has to pay his flyer distributors, and also, who doesn't want gold? So the dwarf convinces his motley group of poor flyer-distributors to help him capture a leprechaun. The leprechaun will then bribe his way to freedom. The dwarf promises his flyer-distributors that anyone who successfully recruits adventurers for his quest will get their fair share of the ransom money. They set out to capture a leprechaun... Leprechauns are solitary creatures. They live outside the slums, where they work as cobblers. They also have lots of hidden gold. Plan A goes as planned and a leprechaun is caught. Then the scheme hits a little snag. Instead of gold, the leprechaun grants the dwarf three wishes. Now, the dwarf is ambitious, but he isn't very smart. He knows he wants his posters distributed. So he makes his wishes: 1. Let the distributors do their jobs 2. Let the posters be posted 3. Let people see the posted posters Of course, he doesn't think to ask for a good group of adventurers, because that would be too obvious. He keeps his eye on the goal: ensuring that his distributors do an honest job. Satisfied, he sets the leprechaun free. In accordance with his wishes, the posters are distributed successfully. They garner great attention. There is a lot of talk about the poster in the city square. The reason is this: The spelling is terrible** Turns out the dwarf never went to grammar school, and his spelling and punctuation is... off. As a result, the poster is very humorous. It's also very hard to understand what the dwarf is trying to say. Is this a historical account of his past? The content of his dreams? It's all very confusing. He ends up with a diverse group of adventurers, the only city people who were willing to take a gamble on an illiterate twit. [Answer] * Reputation and repeat business The dwarf does not simply hand a stack of notices and a stack of coins to a random street urchin. He selects a group/gang who have done similar chores for similar customers before, and hopes that they want to preserve their reputation. * Spot checks The dwarf divides the city into pie slices, and expects a report on where the notices went up. Then he does a walk around the city, checking one or two locations per pie slice. This could bring false negatives, of course, as the notices got pasted over. Cue angry recriminations ... * Destructive testing Pay some kids to distribute 1.000 leaflets. Secretly tell 10 kids that they, personally, will get money for one leaflet that they tore down. But not for two or more. Question them where they tore it down. (Of course this might backfire if it gets garbled ...) But all this just feels wrong for a 'generic low fantasy' setting. It assumes widespread literary, a printing industry, and an overall 'early industrial' feeling to the city. It would fit perfectly into Pratchett's Discworld, which is more a mirror to modern madness than fantasy. [Answer] Find out who hung other posters in the areas that you want to advertise in, they have obviously done a good job. If you see people hanging posters, stop them and ask how to hire them. If this is a common thing, this will lead to formation of poster-hanging agencies (or co-ops) which will police the actions of the individual poster hangers for you so you only need to find one reputable agency instead of a bunch of reputable individuals. In this case, community reputation (word of mouth/referrals) is standing in for repeat business with individuals. Don't base payment on number of responses you get, it's too dependent on things the poster hanger can't control (e.g. maybe you designed really bad posters, or maybe the area of town you have specified is not actually a good choice). If you get really modern, you don't even hire a poster-hanging agency, you hire a marketing agency and they decide if poster-hanging is the best way to spend your advertising budget, and if so where it would be best to hang posters, etc. [Answer] Give every bill-poster the same small number of posters. Each set of posters has a unique number. The poster can have tear-off strips giving the details of the meeting and the unique number. Each bill poster will put up their posters in what they think are the best sites - far away from another poster, but close to the right sort of people. The posters can come to the meeting place and claim a reward for each applicant that the dwarf judges is serious - of suitable age and experience - to prevent them just having hundreds of their friends turn up. It is then up to the posters to pick the best site for their posters, and check they are not vandalised by others. The more ambitious posters might even make extra copies. ]
[Question] [ I'm working on a game idea and one of the mechanics I had in mind was making it so a premium material had to be formed by jettisoning it into orbit and letting it cool there while you guard it with your ship. As this metal cools and reaches the desired state, it would also become a beacon that would draw players (in PVP servers) or hostile NPCs (in PVE servers) to your location who would attack you to try to steal the metal for themselves. Once the material is cooled and secured, the alloy can be machined down to the shapes you need. Melting down the metal again would ruin it until you jettison it into space to cool all over again. I'm having trouble figuring out what would make this metal only possible to create in low-to-medium orbit vacuum. I also wanted to make sure these conditions were prohibitively difficult to recreate on a planet surface. In the backstory for this setting, the alloy would have been made in orbital foundries that have since been destroyed beyond repair or have crashed into the planet below. Jettisoning it into orbit is the cheap way to do it in the absence of such foundries. The best I can come up with is that maybe one of the materials in the alloy are so dense they would settle out to the bottom of the crucible before the metal can fully cool, but that only solves the gravity issue. Maybe it needs to be hit with cosmic rays? What are some ways that vacuum and microgravity might affect a molten alloy that could be beneficial? This material is meant to be able to handle a lot of weight, being used as a high end structure/frame material for player built vehicles. [Answer] Uniformity and sterility. Your alloy is most likely a HEA, or a [high-entropy-alloy](https://en.wikipedia.org/wiki/High-entropy_alloy), extremely high-performance alloys that are difficult to make with even today's techniques. They gain their unique properties through their atomic structure, which requires precise and equal amounts of multiple different elements spread evenly throughout their structure to achieve the desired effects, but have the potential to surpass many of our materials that we have today. [![Crystal structure of a HEA.](https://i.stack.imgur.com/LEP8Q.jpg)](https://i.stack.imgur.com/LEP8Q.jpg) Vacuum and microgravity provide two things: uniformity, and sterility. Microgravity prevents the process of sedimentation and buoyancy, meaning all these elements within your molten alloy will be evenly and thoroughly mixed to maximise the super-material properties of the HEA. The vacuum is also clean. There is very little else there. It provides the opportunity to create ultra-pure materials with minimal defects, something which is very difficult under normal conditions. These two factors - which are very difficult (in the case of sterility) or flat out impossible (in the case of microgravity) - can ensure that the material is only effectively manufactured in the specific conditions of orbital vacuum, and presents the ideal option as a high-end and expensive material. The ISS has been considered a candidate for manufacturing of HEA [before](https://www.issnationallab.org/iss360/materials-research-society-fall-2019-ryan-reeves/#:%7E:text=lenses%2C%20among%20others.-,High%2DEntropy%20Alloys,-My%20talk%20on). [Answer] # To reduce lattice defects and to cold weld it Your scientists have developed a very special alloy which is a mixture of some quite expensive metals and some synthetic elements from the island of stability. The micro g environment of space is needed to make it, as even the small gravity of earth destabilizes the very complicated alloy structure and it's very hard to generate a vacuum hard enough to make it. The alloy, filled with random holes in its structure is ejected into space and hammered into shape, the hammering pushing out the unwanted ions and molecules that got in, you use ultrasonic soundwaves to form the exotic structure and it is then cooled into shape. Then you need to cold weld it. Cold welding is when you hold unionized metals close together and they merge because the metal just bonds to other metal ions. This is much easier to do in space because it has strong vacuums, and also the cold welding means there's no weak points on the structures you built. Attempts to do this on earth or in an enclosed space have failed due to the weaker vacuums. The alloy is extremely expensive to make due to the rare ingredients and pirates coming to attack and steal it, and the thermal signature from the alloy is easily spotted from afar due to its emission spectrum, which is what colours it emits when heated up. [Answer] ## The "beacon" effect is the key > > As this metal cools and reaches the desired state, it would also become a beacon that would draw players (in PVP servers) or hostile NPCs (in PVE servers) to your location who would attack you to try to steal the metal for themselves. > > > While this was most likely only a gameplay aspect at first, this "beacon" effect could also be used as the reason why you have to cool it in the vacuum of space. If the cooling metal radiates strongly enough that it can be picked up by other people and tracked down, then there is a high chance those radiations could have side effects on the nearby ecosystems or machines. Your ships are already made to negate the effects those radiations could have on their crew, but those effects could have very harsh consequences on the fauna and flora of a planet. Of course, you could make facilities with that in mind, but the cost in time and resources would be very high, even more so for an individual. ### Although... why not both? If you managed to setup the right tools and protections to deal with this radiation on a planet, you'd still have the issue of pillagers. As I understand it from your explanation, this material is very valuable, to the point that attempts at stealing it by force are very common, if not always expected. Settling in one place may allow to prepare solid defenses, but it also means the attackers can prepare in advance, since they know exactly where you'll be preparing your metal. You'll have stronger defenses, but your foes will be much more deadly. As a matter of fact, this kind of "fortified forge" setup could work for large, wealthy groups, and they could lead to massive battles (wink wink group PvP/PvE raids wink wink). However for individuals or small groups, this would not be sustainable, and the space option stays the best. Having this procedure in space also means you can do it just about anywhere, without any previous preparation, which gives less time for potential invaders to prepare and react. You won't be able to do it for long before you get overrun, but you can always run away when that happens and do it again once you've lost some attention. [Answer] Similar enough? Instead of an alloy, you are harvesting trapped antimatter in orbit. [THE DISCOVERY OF GEOMAGNETICALLY TRAPPED COSMIC-RAY ANTIPROTONS](https://iopscience.iop.org/article/10.1088/2041-8205/737/2/L29) > > ABSTRACT The existence of a significant flux of antiprotons confined > to Earth's magnetosphere has been considered in several theoretical > works. These antiparticles are produced in nuclear interactions of > energetic cosmic rays with the terrestrial atmosphere and accumulate > in the geomagnetic field at altitudes of several hundred kilometers. A > contribution from the decay of albedo antineutrons has been > hypothesized in analogy to proton production by neutron decay, which > constitutes the main source of trapped protons at energies above some > tens of MeV. This Letter reports the discovery of an antiproton > radiation belt around the Earth... PAMELA data show that the > magnetospheric antiproton flux in the SAA exceeds the cosmic-ray > antiproton flux by three orders of magnitude at the present solar > minimum, and exceeds the sub-cutoff antiproton flux outside radiation > belts by four orders of magnitude, constituting the most abundant > source of antiprotons near the Earth. > > > Your apparatus sweeps up and contains the antiprotons. They are a super valuable energy source. Your containment devices become more valuable as they are deployed and fill with the antiprotons. It is these devices that pirates and rivals are coming to claim. This happens in orbit because that is where the antimatter is. The remaining Macguffin is why you don't collect your half-full containers when you see pirates coming. Maybe if you get them too soon all the antimatter spills out. [Answer] The "had to be formed by jettisoning it into orbit [to] cool" concept seems artificial to me. However, there are good practical reasons to work metal in vacuum and in microgravity, (including some stated in previous answers) which if made clear make the concept less artificial. In the following reasons (which I think were not previously mentioned) product means the target material, and material means other production stuff. (1) The product may have a melting point higher than other available materials. Working in microgravity allows heating the product without needing a crucible that could melt. For example, suppose you need to boil tungsten to make the product, eg tungsten or tungsten carbide foam. This would mean dealing with metal at 5555℃ (10030℉), a temperature that would vaporize an ordinary crucible. Note, radiant heating works fine in vacuum; conductive heating would require contact; and convective heating is not an option if there is vacuum between the heat medium and the melt medium. Possibly, plasma-arc heating (eg with argon gas plasma) would work ok in vacuum. (2) The product might be much larger than would fit into a typical contained space — for example, you might have an extrusion process producing a girder a few hundred kilometers in length. In an orbit providing microgravity, the extrusion can be oriented to extrude with near-zero torque acting on it. Also, wind forces ordinarily are negligible in hard vacuum. (3) Most high-temperature metal-working on earth, in atmosphere, requires expensive measures to prevent oxidation, hydrogen embrittlement, trapped slag and gas bubbles, uneven cooling leading to trapped stresses, etc. Working in vacuum clears away several of these issues. However, microgravity would keep common slag-removal methods and possibly some bubble removal from working. For the former, flux gets stirred into molten metal, which gathers slag and floats to the top; and "float to top" doesn't work in microgravity. For the latter, gas bubbles also won't "float to top"; but on the other hand, vacuum will "draw out" all bubbles that have enough internal pressure to overcome surface tension of the metal or material being worked. [Answer] # Massive radiation release & alchemy: Your material is made with a metallic lattice that can only be created from a radioactive element and in a gravity-free environment. Otherwise the material is too reactive. Inside the material are seeds of proton or alpha particle releasing materials that are artificially accelerated to decay by radioactive bombardment. So the two materials accelerate the conversion of your radioactive isotope to a relatively harmless and stable element. The lattice structure of the original element remains, but if melted, the crystal structure collapses. Your process is somewhat slow, and massively radioactive, operating like a huge fission reactor. The accelerated decay means that as soon as the decay process is done, the material stops pouring out radiation. Vast amounts of material is decaying, but only a small amount is "done." Since the need of your civilization is vastly higher than when they started making the material, and the relative slowness of the process, there is a significantly higher demand than supply due to the delay. The added fun is that the materials are going to be floating in space amidst a field of hot, radioactive chunks of material busily bombarding the other bars with radiation. So plenty of hazards, and the material finishing decay is detectable at light speed. [Answer] The big orbital foundries could isolate it well enough that outgassing from your ship wouldn't contaminate it. However, that isn't viable with the amount of mass your ship can devote to it and you have a big decontamination problem after every trip into atmosphere. Hence the workaround of letting it cool through the critical temperature out by its lonesome. I can't think of any reason it would act like a beacon but it might have emissions lines while cooling that are distinctive. ]
[Question] [ In my book I have a city which is constantly dark. The sun doesn't reach it. This is because it's a city of waste, so all the waste gets thrown into this city and lit on fire every single day, which makes smoke clouds that are so dark that it barely looks like day during the day. Is this realistic? [Answer] Volcanic eruptions can make the sky dark as night. Just as an example, we can recall what Pliny the Younger wrote about the Vesuvius eruption in 79: > > Broad sheets of flame were lighting up many parts of Vesuvius; their light and brightness were the more vivid for the darkness of the night... it was daylight now elsewhere in the world, but there the darkness was darker and thicker than any night. > > > Volcanic eruption can last for very long times (see the eruption of Hawaiian volcanoes or Mount Etna in Italy), and if they spit in the air thick columns of ashes they can also obscure the sky. Moreover, if your citizens have the unhealthy habit of throwing all their garbage in the volcano caldera when there is no eruption ongoing (image an Hawaiian caldera, filled with bubbling lava) this can produce additional black smoke, which still contributes to obscuring the sky. [Answer] It's quite hard to make this a permanent event, mostly it will only apply when the weather is calm, but it can certainly be a regular and lethal event. Let me introduce the [Great Smog of London](https://en.wikipedia.org/wiki/Great_Smog_of_London). > > The Great Smog of London, or Great Smog of 1952, was a severe air-pollution event that affected the British capital of London in early December 1952. A period of cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants—mostly arising from the use of coal—to form a thick layer of smog over the city. It lasted from Friday, 5 December to Tuesday, 9 December 1952 and then dispersed quickly when the weather changed. > > > It caused major disruption by reducing visibility and even penetrating indoor areas, far more severe than previous smog events experienced in the past, called "pea-soupers". Government medical reports in the following weeks, however, estimated that up until 8 December, 4,000 people had died as a direct result of the smog and 100,000 more were made ill by the smog's effects on the human respiratory tract. More recent research suggests that the total number of fatalities was considerably greater; about 6,000 more died in the following months as a result of the event. > > > The thing about having pollution on the levels you're asking for is that you're going to kill a lot of people. The more people in your city, the more smoke, the more people die. Note that the great smog was largely caused by domestic burning of coal, at that point the normal way to heat your home, and was resolved by banning the use of coal in the city. Almost every house in the city was putting out heavy smoke that was then held near the ground by a combination of weather conditions. As soon as the wind picks up it's going to clear your smoke away from the city and allow the sun through once again. [Answer] Smoke from burning things (coal, trash, automobiles) that pollutes cities is called [smog](https://en.wikipedia.org/wiki/Smog). That is what your city has. In many places smog accumulations happen seasonally because burning things and cold air happen seasonally - [Ulan Baator](http://time.com/longform/ulan-bator-mongolia-most-polluted-capital/) is a good example. It is cold there and in winter the have to burn a lot of coal. Other places have smog from burning trash like your city - I read this is one of the problems in Gwalior, India where the weather is probably warmer than in Mongolia. In many cases, the city is ringed by mountains and the smoke is stuck down there with nowhere to go. This is the same reason Los Angeles and many other cities have smog problems. It is called a temperature inversion. <https://en.wikipedia.org/wiki/Inversion_(meteorology)> > > Temperature inversion stops atmospheric convection (which is normally > present) from happening in the affected area and can lead to the air > becoming stiller and murky from the collection of dust and pollutants > that are no longer able to be lifted from the surface. This can become > a problem in cities where many pollutants exist. > > > Here is the City of Angels under a cozy layer of smog. Once when I visited the smog was green. Viewed from Pasadena, the layer was so discrete you could see the tops of palm trees sticking up out of it. [![LA smog](https://i.stack.imgur.com/tn5yA.png)](https://i.stack.imgur.com/tn5yA.png) <https://www.ccair.org/how-scary-is-la-smog/> So too your city. It is in a valley (probably by a river) surrounded by highlands and the smoke accumulates down in there. It does not take much to dim the sun. The rich people would live up on the mountainsides above the smog layer. Maybe for fun those rich folks could send things down to be burned which color the smog different colors, to make it look cool. [Answer] From experiencing the Carr and Camp fires close up: - Smoke thick enough to block the sun and make it look like night during the day is absolutely realistic, even ~ 10 miles down-wind. - But, the amount of stuff you need to burn to make that happen is immense, the camp fire for example was spreading at ~111 acres per minute at its peak. With your garbage dumping scheme, this may or may not be possible. [Answer] It is realistic with one condition. The emission need to be discarded through a chimneys high enough to push the pollution above city buildings, yet the pressure need to be enough to not push them toward the ground, creating an umbrella effect. Otherwise you will end up with what's known from London, or more modern Krakow where the pollution is low enough to kill people but not high enough to block sun. [![smog in Krakow](https://i.stack.imgur.com/jIB8q.jpg)](https://i.stack.imgur.com/jIB8q.jpg) Remember that natural occurring clouds could also add to sun blocking. For example, the city is sitting on the side of a mountain that prevents air from moving and forces it to condense in the form of clouds. [Answer] Been there, done that (at least, most of the time). Pittsburgh in the 1940s. <http://popularpittsburgh.com/darkhistory/> There are photographs showing street lights on at 10 in the morning. However, this will require careful attention to weather. The city must be in a natural bowl (not unreasonable), but it also must never experience strong winds (not reasonable at all), which would disperse the clouds. [Answer] "constantly dark" probably not, at least not on Earth - for reasons given in other answers. Assuming you want to do this on Earth you could combine the trash thing with the fact that it sits over a burning coal mine or downwind from burning oil wells. In that case "usually dark" could work for me. In any case 'abandoned city' may be a better description, as this would be toxic to humans for a sustained period. To get the trash there, maybe you could conveyer it up one side of a mountain and just have it roll down the other side (the conveyer side being the 'good side of the tracks' upwind of the pollution) [Answer] A combination of pollution, volcanoes, and meteor impacts like the one that killed the dinosaurs, <https://www.psi.edu/epo/ktimpact/ktimpact.html> The key factor would be repetition. So, maybe the citizens are constantly burning fossil fuels because they need light in the darkness caused by the continuous meteor strikes worldwide, which are causing excessive volcanic activity. ]
[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/83880/edit). Closed 6 years ago. [Improve this question](/posts/83880/edit) What arguments could there be against using completely (or almost completely) robotic soldiers for wars set in the future? In many war-themed futuristic novels, Earth (or whatever planet) is still using humans as the soldier. It seems to me that a robot soldier (albeit with advanced enough tech) would be profoundly more efficient at this. Although not quite there, we are closing in on a point in which robot soldiers could already replace humans (on earth, 2017). In fact, drones are essentially doing so already, although my question is in regards to ~100% replacement. Is this a case of suspended disbelief, however nitpicky it is, or are there logical reasons? [Answer] I'll be the Devil's Advocate and answer the question as posted: > > Is this a case of suspended disbelief (...)? > > > ## This usually is a case of suspended disbelief. Let's not get so busy rationalizing Sci-Fi settings that we forget the facts of the matter. A decently combat-ready and reliable human takes over a decade to create, is extremely expensive, has lots of properties that make control and maintenance difficult, and features horribly bad reaction times and targeting speed. A combat robot or drone can be mass-produced and specifically designed for the purpose of winning a war and nothing else. It can also be specifically adapted to the needs of the side that employs it. The comparison here is between a side that mass-produces disposable killer machines and another that's spending years talking/brainwashing little boys or girls into becoming something similar. This comparison is a joke. Even with "cutting costs" by sending in teens or children as soon as remotely credible, the mass-produced bots will be much cheaper and thus have a big advantage in numbers. This gets even worse if you shift to expensively trained special forces, which take multiple decades to train but can still die from a ridiculously cheap suicide quadcopter. Even a cheap robot's weapons aren't any less deadly than a human's! On the contrary, robot targeting is of the quality that can shoot down rockets in mid-flight. They can take all kinds of shapes and forms, specially adapted to a specific situation. The arguments against the robot army aren't very strong. If the bots are strategically stupid, humans can still command them. Hacking goes both ways, but the one who built the robots is at a huge advantage, as they know the bots better and can design their security measures to favor their side in the digital war. Human psychology, on the other hand, is not as easy to skew in one's favor. ## Humans are optimized to be generalists. After a certain level of technological advancement, the fact that humans are not optimal soldiers becomes significant. The main argument against robots is that they aren't good enough yet, not that humans are somehow a good design for a front-line combat unit. A robot can have a lot of faults and still surpass the average human soldier. Robots can be designed to emulate any favorable property of humans, but without designing humans as you would a robot, this isn't possible the other way around. Let's list some examples of downsides of humans that robots will exclude by design. Humans... * tend to choose self-preservation over optimizing kill-death ratio * can be slowed down by emotional struggles * often turn on their masters without any action by the enemy * must learn all rules for soldiers, even the simplest and most universal, through immensely expensive teaching processes * have a relatively small range of weights and sizes * require high-quality air to function * have a very specific operating temperature * can only be produced slowly, with the cooperation of females already present * have highly incompatible parts and are near-impossible to repair * take at least seconds to synchronize information, and struggle to do it over distances * need to sleep regularly * need lots of supplies even while inactive This list could go on to fill a book. ## So why and when would humans be preferable? From the above, we can establish that humans are not preferable for a classical war, with tasks such as clearing buildings of enemy units, and that the main reasons for this are needless generality of humans and economy of scale in machine production. So, if you want humans to surpass advanced robots, you need a situation that is rare or new, so that a cheap robot solution is not available. Specialization comes with the downside of being useless if the specialization does not apply. Think of the US's struggle to eliminate the IS, even with all their target-tracking cruise missiles, flying killer drones, and enough nuclear weapons to level the entire battlefield. Their arsenal is designed to never lose a conventional confrontation, and it is very capable in that regard. But it is not at all optimized to attack against human shields while minimizing bad press, which is currently the goal. As another idea: sometimes, efficiency just isn't a goal in the first place. Today, many weapons are built to maintain a flow of military spending, with overall efficiency rarely being a primary concern. In other words, you don't need humans to be good soldiers to have human soldiers. You just need any reason that human soldiers are preferred to robots, which can be purely political. [Answer] In the short term, robot soldiers will be inhibited by their programming. Since "hacking" robot soldiers will be a grave danger, robots will have to be programmed to follow certain drills or battle procedures in particular situations. This makes them relatively inflexible compared to human soldiers, and predictable enough that you could set up "kill zones" by creating situations which will cause robot soldiers to react in predictable patterns. In the longer term, the idea of sentient, self programming robots will be either frightening or abhorrent to the majority of people (both soldiers and civilians), especially since everyone will be thinking of the "Frankenstein" complex, where the devices turn on their master (this was actually the theme of the play which brought the word "Robot" to the English language as well, but few people have ever seen R.U.R). The inevitable will happen when either a rogue regime (such as DPRK or Iran), or violent non-state actors (such as LTTE or ISIS) decide they can get what they want by unleashing sentient robots on civilian and military targets, and everyone needs to use sentient robots to fight them (despite what is shown in movies, human soldiers will be at a vast disadvantage compared to a robot, thinking and moving hundreds to thousands of times more slowly, having less precise control of the weapons and being limited in the amount of firepower they can carry compared to an equal sized robot; even a tank has considerable room devoted to the crew which a robot tank can fill with fuel and ammunition). [Answer] If you think of war as being like chess, war with robot soldiers is more like go. Instead of battling to control territory directly, battle will consist of trying to take control of the other side's robots. Then when you steal the other side's robots, you will control the territory that they did. In Terminator 2 and later, they had terminators that John Connor had reprogrammed. They'd yank the power and reprogram them one by one. Presumably robot armies would have better ways of doing that. Perhaps they'd just flash over the programming. Or they'd pull the chip and replace. Even ignoring hackers, consider what happens when the enemy captures your command center. Now they have physical access to the controls. Or destroy the command center so that the robots can't be updated. Multiple command centers to avoid that? Destroy or capture all of them. The more of them there are, the easier it is to capture one (and turn the robots against their owners). But the harder it is to destroy them. Or consider covert action. A spy gets access to a command center and modifies the robots' programming or uploads new software that turns them over to the enemy. Perhaps someone will eventually decide to work past these problems and try it. But there are reasons why militaries might prefer humans to robots as soldiers. [Answer] # [Moravec paradox](https://en.wikipedia.org/wiki/Moravec%27s_paradox) > > Moravec's paradox is the discovery by artificial intelligence and robotics researchers that, contrary to traditional assumptions, high-level reasoning requires very little computation, but low-level sensorimotor skills require enormous computational resources. The principle was articulated by Hans Moravec, Rodney Brooks, Marvin Minsky and others in the 1980s. As Moravec writes, "it is comparatively easy to make computers exhibit adult level performance on intelligence tests or playing checkers, and difficult or impossible to give them the skills of a one-year-old when it comes to perception and mobility." > > > [![enter image description here](https://i.stack.imgur.com/O9U8M.png)](https://i.stack.imgur.com/O9U8M.png) Perception includes pattern recognition, including behaviour patterns. AI with proper sensor suite can easily spot lone human but unless human carries IFF transponder, AI will be unable to identify him/her quickly. AI will have no way of knowing if detected human is an ally, enemy or civilian, before human opens fire. In situation where hostiles and frinedlies are easily detectable, AIs will outperform humans in reaction time and tactical efficiency by orders of magnitude, but as soon as ambiguity enters the fray, AIs lose the edge. You can program your autonomous tank to shoot any IR signature large enough, but apart from enemy tanks it will shoot: herd of deer which comes by, car with fleeing family of 5 inside, top secret allied operative who decided that need-to-know basis means AI doesn't need to know, and red cross convoy. Last of those will spark massive international incident, turning your allies away, or perhaps turning them into enemies if you were careless few times too many. Meanwhile, enemy will either use tank engines in short bursts, use active IR camouflage, or equip tanks with hybrid diesel/electric drive system (first hybrid tanks were designed during WWII) to operate below AI kill-on-sight-threshold and sneak past. As soon as camouflage, deception, or unclear intentions come into play, advantages of AI disappear. You need humans to designate targets, and you needs AIs to shoot the targets. Human will never outperform AI in shooting, and it will be centuries before AI outperforms human in target designation. [Answer] I'd say it depends on how far into the future you're looking, what kind of conflict, and how concerned with realism you are. For today, and the near future, robots are really terrible at a lot of things: sensing, locomotion, and longevity. Sensing: Modern computing is just barely to the point where it can distinguish between a cat and dog. Almost. Asking a computer to find a human, determine if it's friendly, and whether or not it's a threat, in a reliable manner (before the human starts shooting) is not something that's going to happen for another few decades. (I could see having declared kill zones, ie the death strip between the berlin wall; but you wouldn't have robots going door to door in Aleppo). Beyond that there's also the very basic issue of how robots get and process information about their environment- with vision systems, laser scanning, and/or depth cameras they can probably get a decent 3D model of the local environment, but actually understanding that model is an entirely different issue- knowing that the ground ahead is wet mud and should be avoided is difficult without being pre-programmed; learning that it's a problem (unsupervised, in the field) is in the far off dreams of most modern AI researchers. There are other issues here too, the only one springing to mind being what I'd call scene decomposition- getting a robot to take a 3D model and extract "what can be manipulated/moved" is also difficult- realizing that a 2x4 in front of a door can be picked up and moved aside (if not nailed in) is another difficult task for modern AI. And other minor things: Robots are bad at sensing themselves (called Proprioception). They can only sense what they have sensors for. So, unless adding on a thermal camera, they can't feel that a door is hot; or that someone stuck a radio transmitter to their back; or that a piece of rebar got stuck in their leg. They may be able to sense other effects (accelerometer in leg registered jolt, current to left leg servo at 200% and servo encoder not registering movement; it's probably stuck); but being able to do anything about it goes back to the issue of decision making and sensing, from above. Locomotion- It's really shocking how bad robots are at moving from point A to point B. There is some work on it (Boston Dynamics has done some wonderful and horrifying work), but just coming up with something that is able to fluidly move in and around rubble, or climb a ledge, is very difficult. Most modern robots are wheeled/tracked because that's the only thing available that has a run time of more then 20 minutes, but we can ignore them because they're easily defeated with stairs. That partially ignored, we could have multi-pedal robots always within a few hundred feet of an energy source, and then run into the problems of robots trying to operate on uneven footing. [And they already have trouble on even footing.](https://www.youtube.com/watch?v=g0TaYhjpOfo) Part of this is the sensing issue above- Seeing a coke can and knowing you can step on it and it will flatten, vs a can shaped rock or a brass cartridge casing is hard. Also, knowing when an obstacle in the path is a piece of loose wire to be ignored vs a piece of rebar that's going to spear your delicate servos vs a piece of steel wire that going to tangle around you if you walk though, is difficult. Longevity- Basically the issue of maintenance, and how long a robot can stay in the field. Robots get sand and water and blood and grime and salt water in their every moving part. Then the parts stop moving, or a short circuit happens and suddenly the left half of the robot stopped working. For the near and probably far term, robots aren't able to fix themselves. Certain problems could be resolved fairly simply- systems can be put in place to allow whole sale swapping of body parts- robot realizes his arm is malfunctioning, goes to a maintenance van and picks a new one up off the shelf... and tries to attach it. (this is... not easy, but I'm willing to say it'd be doable if there was a drive for it). Or. They're robots. Just send another 20 in. Leave the malfunctioning where they lie. (unless you don't want them getting into enemy hands). (It's also not a good long term strategy; as robots are kind of expensive) In addition to that, robots need a power source. Batteries are something of an awful power source. Great for short hops away from a generator, but terrible if you need to be in the middle of nowhere for a week. (kind of an energy/weight ratio issue, and just efficiency of movement). (semi example- Boston Dynamics Big Dog robot uses a 15HP go kart engine- 11KW equivalent (several households)). This is also kind of resolvable by just always having an APC with a generator near by, but that can be limiting, and will usually require a supply line. There is another thing that may have been hit upon by someone else: Humans are wascally widdle wabbits. Most of the above is on the premise of trying to replace humans operating in an environment where humans are fighting humans. Once humans are fighting robots their tactics will change; they will do everything they can to exploit any weakness they find. Identifying and counteracting these weaknesses, then issuing a patch/firmware-update is a slow and time consuming process; where as most humans can spread the weakness with word of mouth. In short- there are a lot of reasons we don't use robots right now (except in a remote control capacity), and most of them are probably still going to be problems for the next 20-30 years (and I think longer; but I can't back that up). It basically all comes down to robots are idiots- they work well in really well and narrowly defined roles- drones work because all we're doing is asking that they not hit the ground, once we go past that they fail in spectacular ways. And failing in spectacular ways is not generally what you want an army to do. (now again, this all depends on your limits of realism, timeline, and conflict type; if you're fine with robots killing every not robot that they see, then half of these concerns are out the window) [Answer] > > Is this a case of suspended disbelief, however nitpicky it is, or are there logical reasons? > > > This is a case of suspended disbelief for fiction; because audiences are not moved, emotionally, by the destruction of hardware. They will get bored if both sides use hardware and the result is just a circus of mechanical destruction. If we use robots and the enemy is living beings, we look like exterminators at best if they are insectoid or non-human enough, and like the bad guys if the enemy has any human characteristics, emotions or demonstrates feeling pain or grief. The only way to make the audience identify with our side is to put human lives on the line. Star Wars cannot be about machines going after each other, we need human or human-like pain, grief, suffering and despair, and it must be severe: Luke loses his adoptive parents. Young soldiers with lovers back home, hopeful to start their lives together after the war, are trapped and slaughtered. As Stephen King advises writers: Develop a character the readers will love and care for, then put her in the cooker. In futuristic fiction, in order for us to identify with robots, they would have to be, effectively, human beings with an emotional side able to experience setbacks and frustration and some kind of suffering, perhaps vindictiveness and anger as well. Of course that is not where the question lies: IRL, it is fair to presume that within 50 years or so, robots will be able to do anything a human can do in warfare, better. The "steal command" problem is a non-problem, we can use the same protocols for robots that keep our banking system humming along transferring trillions of dollars around the world without anybody diverting all the money into their own accounts. Long key RSA encryption is easy, fast, and impossible to break by any known means; that is what banks use. The robots in question may be about as self-aware as a self-driving car (which requires a form of self-awareness to navigate its body safely through a fast moving maze, which also requires a self-referential model of what movements it is capable of choosing and how other vehicles will most likely move). The robots do not have to be emotional in any way, they can be rational and intelligent (in the sense of accurately predicting outcomes in novel scenarios). Emotions, like fear of death or reluctance to inflict harm or psychological angst over what they have done, or grief over lost compatriots or anything else are all baggage they don't need. Intelligent machines do what they are told; including if they are told to stop, self-destruct, or conduct a suicide mission that will destroy them: They can be "intelligent" with absolutely zero emotions or "desire to live" that would interfere with or override their commands. As for whether the enemy uses live soldiers: The story of the war is written by the victors, remember? Just as we do now in the USA, we use robots and high tech and drones, but we don't spin that as cowardice: We spin it as saving the lives of our soldiers, protecting the troops, while destroying the bad guys. We say *our* soldiers are still brave, intrepid warriors, even if they sit all day in a comfy chair a desk safely tucked away in a stateside office building on some Army base in South Dakota, using a 4-screen video-game interface to fly drones over Pakistan. Robots will be just as autonomous and capable of making decisions as humans; should communication be disrupted. They will be just as capable as humans if cut off from command for any reason; but more capable than humans of communications between each other (e.g. they can pass full video of what they see and hear, they don't have to 'describe it'; they can have a group mind). They will also be able to survive better than humans. They don't have to rest, they can use solar power to recharge; if necessary they can hide and shut down all but the most minimal solar powered sensory activity, and survive indefinitely without food, waste, or boredom (boredom is an emotion). This is not something current AI can do; but the outlines of what it will be able to do in the next 30 to 50 years are clear. Just as [Moore's Law](https://www.intel.com/content/www/us/en/silicon-innovations/moores-law-technology.html) was clear and has held, with only slight modifications, for 50 years. Today's robotics are like early guns; used in warfare and deadly, but not terribly accurate or reliable. That will change, they will get better, and no politics or shame will stop them, just as our modern automatic guns feel light years ahead of the blunderbuss which was basically a mini cannon, future robots will be far better and more lethal than human soldiers, and the citizens of the countries that own such robots will be appalled at the idea of losing their human soldiers in battle. They won't be hacked, even by up-close surgery. John Conner will not have the 10,000 bit encryption code necessary, and no screwdriver is going to be able to modify the circuitry of integrated circuits: They will have one-way tamper-proof casings anyway, so once they are sealed any attempt to open them destroys them (there is no need to ever get inside and repair them, even now we just replace malfunctioning chips). (Heck our robot can automatically self-destruct its processors if anything every penetrates its casing). In fiction the audience wants to identify with entities in the story that display human emotions and qualities. In real life, and real war, the objective is to subjugate the enemy and force a surrender under threat of death to the humans on the other side. IRL we'd rather not identify with the soldiers we lost, we don't want to share the grief of their families, parents and children and spouses, we don't want to feel the loss of their potential as good people, friends, and citizens. We don't want them to suffer from PTSD or the trauma of war. If we can pay our way out of all those emotions, by dint of buying robots to do the dirty work, we will. Further, in my opinion, we (and our military leaders) will prefer our robots to be distinctly non-humanoid (or even animal) in form and behavior, so as not to accidentally invoke any empathy or sympathy for the robots. A drone doesn't look like a person, a drone getting shot down or crashing doesn't look painful, it looks like an unfortunate loss of hardware, like accidentally dropping a big screen TV down a flight of stairs. A kind of "dammit" for the loss of value, but zero concern for any pain the TV felt; it didn't feel anything. If the animal form with legs and limbs is truly useful for navigating terrain; I suspect we will use insect or arachnid forms with many legs. Losing a robotic soldier reminiscent of a tank-like 3-foot cockroach or spider won't bother us much at all. Sure, it is our cockroach-tank, but if it gets blown to pieces by a missile, no problem. Send two this time. [Answer] To me, all the above answers aside, the problem is accountability. We already see civilian casualties being written off as collateral damage of missile or drone strikes. Now imagine the same situation on the ground level. With humans, at least, we hope, that some will refuse to attack civilians, ideally out of, well, humanity, but also out of fear of getting punished, eventually. With robots, they will simply obey the order to kill, without reasoning why. Even if there are survivors, they can't positively identify the individual who gave the orders, as they would not be present at the scene. You will see increasing numbers or civilian casualties as reckless officers act with impunity and blame the other side, who just happen to be using a similar model of robot, only distinguishable by the internal IFF transponder. Eventually, enough people will get sick of it and declare them unlawful weapons like nerve gas, cluster bombs, etc., with the very use being considered a war crime. Even then, there will be countries or other actors who disregard the rules and carry on using them. [Answer] Everyone has an [EMP](https://en.m.wikipedia.org/wiki/Electromagnetic_pulse "EMP") If every nation has a way to disable robot armies, there will be no robot armies. Sort of similar to how if everyone has the bomb, nobody will use the bomb. [Answer] Human infantry still have a role in the army of the future because robots aren't always very useful against terrorists or guerrillas. When the enemy are able to blend in with the civilian population, it's hard for human soldiers to tell them apart, but it's worse if your soldiers don't even understand human culture at all. Sending in cold unfeeling robots to massacre innocents is not exactly how you win hearts and minds. Also, a robot needs to carry an enormous amount of energy to walk around all day, more than enough to set itself on fire. So it's liable to burst into flames like a huge Galaxy Note 7 if shrapnel happens to short-circuit its battery. This would be hazardous to civilian safety in urban warfare, and doubly so after enemy guerrillas figure out the most efficient way to set off your walking bombs. [Answer] Human beings are crafty and inventive. We are better suited for improvisation on the battlefield, whether it be constructing traps, planning ambushes, interrogating P.O.W.s or conducting reconnaissance. Robots would be capable of doing these things to a degree but if they require orders from human superiors (which they should to avoid a bunch of awol death machines acting as unknown variables) they could not take the necessary initiative to be effective soldiers outside of front line combat. As far as front line combat units, robots are best suited to supporting roles such as field medics. For purely destructive or defensive purposes, there already exist more specialized tools that do not require the cost of building and maintaining complex robots. (Take this as an example: When I first watched the movie Pacific Rim, the thing that took me out of it was the idea that, since these giant mechs cost so much and needed specialized pilots and the development of a new field of science to operate. They could have placed mines and energy turrets to destroy the monsters. These could be manufactured in greater number and require no trained pilots.) Ask yourself, what task do these robots perform in your world that could not be done more efficiently by existing technology. The best reason I have ever read for robot troops was to be used as vanguard units deployed on planets with unlivable conditions. [Answer] Robots are expensive. [Humans are cheap](https://blogs.wsj.com/chinarealtime/2014/12/08/the-minuscule-cost-of-equipping-a-chinese-soldier/) and self-replicating. As mentioned in other answers, robots can be hacked and reprogrammed. But the interesting part is [humans stick to their programming when the going gets tough](https://en.wikipedia.org/wiki/Escalation_of_commitment), and remain loyal to "bad" leaders even to the extreme of [genocide denial](https://en.wikipedia.org/wiki/Genocide_denial). If you withhold sensitive secrets from an AI you will eventually get errors in your strategy simulations, or worse the AI could expose some mathematical or accounting cover-up that will need to be corrected holographically throughout the information system. It's going to be difficult to keep these political "corrections" unknown by programmers and technicians. If the robots have any ability to form their own math-based strategies and analyze their own success rate, they will eventually discover these manipulations or make lethal errors in decisions. Consider [HAL-9000 who decided to kill the crew and scientists to protect the classified purpose of the Jupiter mission](http://joeorman.shutterace.com/2001/2001HAL.html). Notice the humans in the same film did their jobs and didn't ask questions. With humans you get blind loyalty and suicide missions. They will continue to defend a lost cause, and their martyrdom can be used as recruitment propaganda – not all humans obviously, but the military has ways of weeding out independent thinkers by self-selecting for [conformity, compliance, and obedience](https://www.units.miamioh.edu/psybersite/cults/cco.shtml). You probably wouldn't do this if you could actually win with a robot army, so I'd suggest this is an underdog strategy. Having an all human army defending against an army of robots and drones also works as a [human shield](https://en.wikipedia.org/wiki/Human_shield) strategy. Global sympathy will go to humans in a propaganda war of humans vs bots. Our military future however will be effected by what the military calls [Tooth-to-Tail Ratio](https://en.wikipedia.org/wiki/Tooth-to-tail_ratio) which refers to a logistics issue involving the resources required to supply and support (tail) each combat soldier (tooth). The actual ratio varies over time and by mission, but it's typical to spend double the resources on the tail than the teeth. DARPA has a stated goal of developing technology to reduce the tail, so expect AI and drones to become more valuable in supplying combat soldiers than AI becoming combat soldiers. It sounds counter-intuitive, but that is where the finances should lead us. In a not-so-far future scenario an AI will probably design global defense strategy based on simulations, and AI may become more [reliable and cheaper than generals](https://www.theatlantic.com/magazine/archive/2012/11/general-failure/309148/). We'll have the awkward scenario of human infantry commanded by machine intelligence. [Answer] It's 2017. DARPA already has already produced a whole slew of different humanoid and nonhumanoid robots. They started producing them some years ago hoping to build one to aid in cleaning up after the Fukushima disaster. Youtube it, seriously, very cool stuff. They needed robots that could do things humans could do like jump and run and turn a wheel or unlock a door. We are already living in the future you speak of. The conditions of Fukushima are complex compared to those of a battlefield. The Fukushima problem requires specialized scientific training. The average soldier only needs to learn the protocols of war. Any kid from the burbs can become a soldier but only the educated higher class could help in a situation like Fukushima. Point is, we already have the tech to build Terminator style robots but we continue using humans because humans are abundant. Many of the esoteric groups like the Rosecrucians and the Masons and Bankers like the Rockefellers and the Morgans and the Rothschilds and even the most powerful politicians are eugenicists. They believe that the world is over populated and that in order to improve humanity, the population must he decreased and maintained at a certain level (Google the Georgia Guidestones), and that the genetically inferior should be the first to go. No soldier with a PH.D. is ever asked to work on the front lines. Many modern wars aren't meant to be won. They are meant to be sustained. They are meant to thin out the population and generate profits for those that finance these wars. The US sold weapons to the Nazis at the beginning of WW2 and other groups funded both sides of the war. The rich elite around the world know that the only way to guarantee they will win is to invest in both parties. The most efficient robots are those with a specific problem to solve. Think drones, not humanoid infantrymen. Truth is, drone robots are used frequently in war and always will be, but as long as hunger and poverty and overpopulation exist, lower and middle class humans will always be on the front lines. [Answer] The truth is in reality we could have an all-robot war tomorrow - ICBMs and cruise missiles fit almost every definition of a robot. Of course, although in such a war it would be robots carrying all the weapons, huge numbers of humans would die as well as the robots being destroyed. In the book "Arms and Influence", Nobel laureate Thomas Schelling advances the view that there are two things a military can do to accomplish a country's goals in a conflict: * Direct force, where the military directly expels, seizes, destroys, confines or exterminates. For example, if you want me to stop launching missiles at your civilian population, you can use precision bombing of my missile factories and launch sites. * Coercion, where the military creates a cost in pain and destruction, offering to stop if some other demand is met. For example, if you want me to stop launching missiles at your civilian population, you can say you'll launch two missiles at my civilian population for every one I launch at yours. Needless to say, coercion is a lot less heroic, and politicians are much less likely to advocate for it in clear, open language. But the truth is in many situations it's easier, cheaper and more effective. I can make direct force difficult by having my missile factories hidden and fortified - or maybe instead of launching missiles I'm doing something harder to police, like funding rebel groups within your country. Given humans' natural appetite for revenge, some would argue that every war that ends without annihilation or permanent occupation has had an element of coercion. Anyway, here's my point: Coercion requires pain or the threat thereof, and a drone-vs-drone battle doesn't have any pain (except the opportunity cost of that-drone-cost-money-that-could-have-been-spent-elsewhere) - so both sides will be looking to get around the other side's drones, so they can land attacks that actually hurt the other guy. So even if both sides have 100% drone militaries, it's drone-vs-civilian strikes that are actually going to bring the war to a conclusion. ]
[Question] [ My fantasy novel features a floating city. I wanted to know how much energy (joules/second) it would take to keep a floating city aloft, but the definition of joules has "distance displaced" in its definition, and a floating city does not move, so no matter what I put for the force or the time, the energy comes out to be zero. I asked a physics-inclined friend how much energy it would take to keep this floating city aloft, and his answer surprised me: The formula was right, and it would take zero energy. He said that it would take a lot of energy to get the city up there, but none to keep it there. I was incredulous because helicopters very obviously expend energy to stay aloft, but my friend explained to me that in theory, making a city float would be like lifting an apple from the floor and putting it on the table. It takes energy to put it up there, but no energy to keep it there. All you need is some way to prevent the gravitational potential energy from turning into kinetic energy and you've got your floating city. "Magic" seemed a reasonable enough explanation to keep the energy from changing forms. This confused me as much as it made sense. So my questions: * What, from a physics standpoint, is the difference between a helicopter that must expend energy to remain aloft and an apple on a table that does not? * How could you tell which of the two paradigms would be correct for a magically floating city? * If you did need to spend energy to keep the city aloft, how would you calculate it, given that the displacement is zero? [Answer] The zero-energy is the correct ideal answer. The act of keeping a city floating takes zero energy, as shown by the fact that the ground beneath our feet expends 0 energy keeping the city out of the Earth's mantle. If you use magic, this is good enough. However, sometimes you don't have the luxury of doing exactly the physics operation you want. This is where the helicopter comes in. The helicopter expends zero energy "staying aloft," but it expends an immense amount of energy shoving air downwards. The helicopter operates in a non-ideal world where the only operation it can do is apply force to a fluid, which rapidly gets out of the way of its rotors. It does no work to itself (it remains at the same height, thus the same potential), but does a lot of work to the air in order to get the forces needed to combat gravity. Given that you are doing this with magic, you get to choose. This could be a "force field" like effect which requires no energy input, or it could be more like an updraft of air counteracting the forces of gravity, which would require a great deal of energy. The energy expended will depend 100% on the method you use to keep it aloft. We can say nothing about the energy expenditure without settling on a method and how that method works. [Answer] # The force you're causing may cost energy even if the energy doesn't go into the object it is acting upon. What you need to consider is "How does the city stay up?" 1. Is mass being thrown down to counteract the force of gravity on the city? If so, work is being done on that mass being thrown down. Which you could calculate. 2. Is the force going through some sort of extradimensional space so that effectively the city is actually supported by the ground, but you just can't see the supports because they're in another dimension? If so, then it really does take no energy to keep it up (though it may take some to keep those dimensional spaces open). 3. Is the force actually a void (vacuum) space with a lot of volume and no density so it really is floating, much like a hot air or helium balloon? Again, no energy required. Though there may be energy needed to evacuate the space. As you can see "the how" maters a lot in all of these cases. [Answer] Floating. <https://en.wikipedia.org/wiki/Buoyancy> > > For this reason, an object whose average density is greater than that > of the fluid in which it is submerged tends to sink. If the object is > less dense than the liquid, the force can keep the object afloat. > > > [![rubber duck](https://i.stack.imgur.com/b1opO.png)](https://i.stack.imgur.com/b1opO.png) [duck](https://www.timeout.com/tokyo/news/florentijn-hofmans-rubber-duck-will-be-in-osaka-for-one-day-only-this-november-101921) Your city is floating. That means its mass is less than the medium it displaces. This big duck is expending no energy to float. It is supported by the water because it is less dense than the water. . Your floating city is equal in mass to the atmosphere it displaces. It can thus float there with no energy expenditures. A neutrally buoyant object will stay put where it is in a column of gas or water, not experiencing a force up or down. A helicopter is not floating. It is flying. Its mass is more than the air it displaces and so it must work to throw air downwards and itself upwards. [Answer] I don't think any of the other answers are directly answering your questions, so: 1. A helicopter stays aloft by pushing on the air, and the air annoyingly moves in response. If the air were solid, then it would be difficult to breathe, but it would require 0 energy to keep the helicopter aloft, just like it requires 0 energy to keep it landed on a hill. A hovering helicopter requires energy like walking on a Stairmaster requires energy, because the thing its pushing on is moving in the direction of the push. 2. Which paradigm is appropriate depends on how your magic works. If nothing has to move, then no energy is expended. If your city needs thrusters of some sort that expel rocket exhaust, or move air, or similar, then it will cost energy just like a helicopter. 3. Calculations: First, note that joules/sec is power, not energy. The formula for power that applies is force x velocity. The power required to keep the helicopter aloft is the weight of the helicopter times the velocity of the air moving through its rotors. If your city needs thrusters, then the power required to keep it aloft is the weight of the city times the velocity of the thruster exhaust. [Answer] > > What, from a physics standpoint, is the difference between a helicopter that must expend energy to remain aloft and an apple on a table that does not? > > > Both are pulled down by gravity. The apple is stopped by the force created by tiny deformation of the table. If you gradually increase the weight of the apple it would eventually break the table and fall. A helicopter uses lift created by the aerodynamic force as rotor blades travel through the air. > > How could you tell which of the two paradigms would be correct for a magically floating city? > > > Well, if your city lies on a table it doesn't really fly. So, it has to combat gravity somehow. > > If you did need to spend energy to keep the city aloft, how would you calculate it, given that the displacement is zero? > > > Let's say your city has mass M. Gravity force acting on it F = M\g. You need to create force that is directly opposite in direction and equal in module. It likely to be hugely expensive though. Helicopters are not cheap, rockets even more so. The cheapest option would be a lighter-than-air city. It would require tons of helium or hydrogen though. That's why nobody builds flying cities. Except for mages who don't care about energy. [Answer] In case your Magic isn't super-powerfull, but you're in a technologically really advanced setting: Use the power of earths orbits! (Think of the [International Space Station](https://en.wikipedia.org/wiki/International_Space_Station#Orbit)) Please note that with different orbits there are different benefits / caveats some are geostationary * some need a FAST speed (the ISS travels at an average speed of 28,000 kilometers per hour) * some need more energy to counter atmospheric drag than others * none provide a human-livable environment However, some of these caveats might be erasable using magic: * use portals to get humans / fuel up there * use Force-Shields to shield your city [Answer] # Zero energy or fuel Lets say you have a helicopter with an exact ton of weight. To stay aloft, exactly at the height it is a ton heavy, you need to push exactly a ton of force upwards¹. Less than a ton and gravity pulls it down. More than a ton and the helicopter goes up. That means if there's no acceleration and the helicopter stays on it's place above the Earth it's a zero sum. This doesn't mean it doesn’t cost energy. We are using energy in this case to keep it at this state. It has a lot of potential energy. If you turn off the helicopter the energy is released. We can see this by the effect of the helicopter crashing down onto the ground. The problem with the blades is that the air is lighter than the helicopter and gaseous. We need to keep moving yhe blades and push air down, or the air will move past the helicopter and not support the weight of the helicopter. Now we have the exact same situation with the helicopter stationary on it's place high kn yhe air. The difference is that we now made a platform under it, connected all the way yo the ground. Though the helicopter is staying where it is just like in the first scenario we now see only one difference. Instead of the blades pushing a ton of weight up¹, keeping it level, it is the platform pushing up one ton. This keeps the helicopter level. Just like in the first scenario the helicopter has potential energy. If we remove the platform it'll crash down just the same. You might think the helicopter with spinning blades is then something of an oddity. It is using energy to stay aloft, while the platform is using nothing. But that is a mistake of human perception. Energy isn't created or destroyed. It just becomes something else. That means that even though the helicopter is using fuel no energy leaves the system. The fuel in the helicopter just changes it's potential energy into movement and heat. The platform also experiences some deformation and heating. It might not be as impressive and loud as using the blades, but it does the same thing. Your city can then choose how it stays aloft. You need to cancel out the amount of power the city pushes down (gravity times mass). Will you try to keep it up by pushing against things, like air, requiring a constant input of energy to keep the city up. Or will you put it on a magical platform, requiring the stationary platform to push back. ¹ Or down, so the helicopter stays up. Matter of perspective. You push other things down to push the helicopter up. [Answer] As others have mentionned you would indeed need no energy to keep it there only the initial energy to put it there I did some calculations, based on the weight of air and buoyancy, I might not be 100% correct though If you built a very big vacuum chamber, lets say Giza pyramid volume, vacuum weighing nothing except for the enclosure and air weighing 1.3Kg per cubic meter You'd end up extracting 3250 Tons of air from that chamber, remove maybe 50 Tons to build the enclosure and pump needed to build that vacuum and you'd effectively end up with a balloon capable of supporting 3200 tons of material on top of it, depending on how light you build your houses, let's say 10 tons to 30 tons, you could build 100 to 300 houses on that sphere Feel free to scale that up (or down) but bigger is always better for the sphere as volume scales exponentially but the enclosure weight scales linearly So it doesn't look like you'd need magic to build your city, only very good engineering and materials [Answer] > > I asked a physics-inclined friend how much energy it would take to keep this floating city aloft, and his answer surprised me: The formula was right, and it would take zero energy. He said that it would take a lot of energy to get the city up there, but none to keep it there. > > > You might need some better physics-inclined friends. You're focused on gravitational potential energy, but you're ignoring everything else. The problem here is that energy is not something that acts on things, it's something that things have which can be transformed (or transferred) by performing work. A Newton's Cradle is a perfect example of this. You lift one ball to give it gravitational potential energy, then let it go. The force of gravity acts on the ball causing it to fall, transforming GP energy into kinetic energy. When the ball strikes one of the motionless balls the force of the collission applies to each ball in the collision (almost) equally, transferring the kinetic energy through the collected balls until the final ball rebounds up. The energy transfer and transformation was the result of the forces acting on the balls. The only way to stop gravity from turning your GP energy into kinetic energy is to provide some force to balance things out. Since force and energy go hand in hand, you're going to be chewing through the power (work done per unit of time) to produce enough force to counter the force of gravity. Don't believe me? Reach your hand out straight in front of you at eye level. Now hold it there, as motionless as you can. Touch one fingertip to a wall or something, not enough to support it but just so you can feel if you start to move. Now hold it there. I'll be right back. . . . You still holding? Starting to feel some muscle fatigue yet? Give it a few minutes. What you're feeling is a combination of things, but the one we're interested in is the chemical potential energy you've just expended to keep your muscles tight enough to provide the force that acted against gravity attempting to drag you down. (Unless you're reading this on the ISS, in which case you're cheating. And also awesome.) You didn't move, your muscles didn't move much, but you consumed (i.e. transformed into bound chemical energy and heat) some energy just by staying perfectly still, and more than if you didn't have your arm up. So can we please stop with this idea that "the city doesn't move!" means "we don't have to use energy!"? Please? When you are generating a force - such as the one you're going to need to counter the force of gravity - you are transforming energy in some way. And because Thermodynamics is still a thing, some of that energy is being lost in forms you didn't want: probably at least heat and sound. --- Oh, but wait, we have magic! We don't have to worry about conservation of energy and stuff. That's for the poor sods stuck in physics-dominated universes that don't have access to things like extra-planar portals and so on. So here's how you do it. First, enslave a bunch of the inhabitants of the nearby planes. Force them to build towers in the place that matches where you want your city to be, just next door in a suitable plane - I hear the Ethereal is relative stable this millenium. Next, enchant some materials to exist in both the material and Ethereal plane, and place them on top of the towers. Back in the material plane, use those as support girders to build the base plate of your city on. Keep the horde of critters working on expanding the forest of support towers - maybe contract an edritch horror or two to keep them in line while you're busy in the real world. Now we just need to invite some sucker... I mean citizens to come build our amazing floating city. Oh, and maybe get some fae folk to go pretty up the support towers in the ethereal realm. Just in case someone with True Sight or something comes looking, we want to be able to pass them off as epic spell formations or something. Now all that gravity trying to tear you from the sky is frustrated because the structure is supported by the bedrock of the ethereal. Just... don't overdo it. Even bedrock will liquify under enough pressure. And you might want to invest in some heavy duty stabilizers to make sure the Ethereal landscape stays where you put it. ]
[Question] [ A race of humanoids with only legs, prehensile feet and a mouth equipped with two rows of teeth made of magnetite, which they can magnetise using their natural electricity generation. How could such a race achieve establishing civilization to somewhere in our own point of progression and technological advancement? I'm imagining they invent some sort of assistant robots or cranes for them to operate, perhaps cybernetics. [Answer] Your question includes the answer: they have prehensile feet. As long as their body plan allows for balancing on one foot and manipulating objects with the other, or sitting and using both feet as we'd use hands, there are few barriers to their ascent to a technological civilization. Carrying objects in their mouths will have to suffice until bags and specialized harnesses are invented (necessary for their equivalent of the Agricultural Revolution). Ranged weapons will depend on the nature of their leg joints. [Answer] Instead of thinking of these aliens as having 2 legs and no arms, consider that you are really describing a race with 2 arms and 2 legs, but not at the same time. As their ability to manipulate things with their feet increases, their ability to run, jump, etc will decrease. This will force an evolutionary reliance on technology to not get eaten. As their stone aged ancestors become too slow to outrun predators, they would learn to fight defensively using thrown or fired weapons. Fighting wars would be much less appealing to them at first because advancing to range to attack makes you vulnerable; so, I'd expect them to be somewhat more peaceful than humans. Even as their ability to move and fight at the same time starts to happen through technology, there would still be that strong evolutionary fear of being the aggressor in a conflict. Animal husbandry will become paramount to their early civilization. A "horse" can run while the warrior on top fights, or a "horse" can pull a cart or plow while the rider coordinates its actions. By the bronze age, you'll see them doing a lot of the same things we did at that time in history, but only through a stronger relationship with their domesticated animals. Their ability to become expert craftsmen should not be impaired since most crafts are done from a stationary position to begin with; so, blacksmithing, carpentry, masonry, ceramics, etc will all still happen for them. Once a reliable system of roads is established, wheelchairs may take over as the primary means of locomotion for people who are just moving about town. As they move into the modern age, they will have no issues controlling automobiles, or electronic devices. In fact, the closer they get to modern, the less their lack of specialized appendages will effect them as most jobs become sedentary anyway. Eventually, they may become reliant on robotics for locomotion as you suggest, but at that point, it becomes more of a luxury (like owning a segway) since most of them just don't need to spend a lot of time walking by the time you reach an info age level society. [Answer] In [Albert Montey's "Universe!"](http://panelsyndicate.com/comics/universe) series, there is an armless alien race that was able to stablish a simbiotic relationship with a kind of snake-like parasite to manipulate objects. [![Universe #04 cover](https://i.stack.imgur.com/v5XNN.jpg)](https://i.stack.imgur.com/v5XNN.jpg) It's a short story, so it doesn't have a lot of details of the "why's", but it shows in quite a lot of interaction between the simbiont and the character. [Answer] Frame Challenge: This species will not develop a civilization akin to that of humans without something spectacular happening. > > I'm imagining they invent some sort of assistant robots or cranes for them to operate, perhaps cybernetics. > > > Great! You have an end goal. The problem is: How did you get there? (And I suppose that's what you're asking here.) The species you describe has no effective/efficient means by which to manipulate its environment. Sure, magnetite is a ferrous material and, thus, subject to magnetism. Certainly a magnetic field can manipulate ferrous materials, but that comes at a cost. Magnetic fields can be [dangerous to the brain](https://io9.gizmodo.com/10-things-an-electromagnetic-field-can-do-to-your-brain-5851828), possibly leading to apathy or death. Neither of these will promote the development of a species that generates a magnetic field inside its own head. Another side effect of a magnetic field is that it can alter a subject's perception of morality; this is not conducive to the creation of a cohesive society. Sure, magnetic fields [can be used to manipulate objects](https://en.wikipedia.org/wiki/Magnetic_levitation), but there's a number of problems here as well. 1. A magnetic field can only move things in one direction. These creatures could levitate an object and push it around with their head or foot, but they wouldn't be able to, for example, swing a hammer in any way other than "lift + drop." 2. You're limited to ferromagnetic materials. You can't manipulate wood, plastic, gold, or uranium with magnetism. This means the species struggles to build a shelter for itself, let alone develop any kind of technology that requires a non-magnetic precursor (the loom, for example). 3. The energy cost of generating a magnetic field strong enough to manipulate an object at any distance is going to be phenomenal, let alone if you want to keep up the effort. 4. Don't forget that you're generating a powerful magnetic field inside your own head! It's quite possible to [make a frog levitate](http://www.physics.org/facts/frog-really.asp) with the right magnetic field. I'd hate to see what would happen to a human head if a magnetic field strong enough to move an object at distance were turned on inside it. In short, your species is going to self-destruct long before it starts thinking about developing a meaningful civilization. [Answer] For the armless bipedal species(like breeds of armless humans and many chimera breeds), they do, don’t, and cooperate with those who do have arms. Even if they can build or handle small objects by sitting down using their feet or their mouth, they leave the rest to humans who have hands. That doesn’t mean they’re limited in what they can do. They can focus on other tasks besides those, like observation and supervision, carrying things on their backs or mouth, pull things they’re harnessed to, surveying or scouting out, and operating treadmills or foot pedals. Armless fighting would be riskier, but they’re either carrying equipment for others or wearing thicker armor and bashing into their targets or stomping on them if they’re on the ground. As an aside, they’re pretty common for they’re perceived as some of the hottest people not just because of their well honed musculature but also because of the fact onlookers see them as adorable because they think of them as harmless, vulnerable towers on legs, and they wear it on their chest. They’ll kick or bash you if you replace it with sleeve [Answer] Here's an example, from [Second Dawn by Arthur C. Clarke](http://avalonlibrary.net/ebooks/Arthur%20C%20Clarke%20-%20Second%20Dawn.pdf) Highly intelligent, telepathic, unicorn-like aliens without hands who have developed advanced maths and philosophy but lack any technology. They form a partnership with another monkey-like species that has hands but limited intelligence. [Answer] I'll point out that there are quite a number of humans who are born without arms, or their arms were amputated, and learned to use their feet as hands to varying degrees. There are a lot of examples of this, so I'll let you Google/Bing/YouTube that yourself. Granted, these people have the advantage of 4 limb-ed people to learn from, and maybe these other people have experience training people to use their feet, but this simply shortens the initial learning curve of the civilization or individual. As other answers point out, a hand is just another limb that happens to be convenient for bipedal animals to carry and manipulate things with. Someone mentioned apes, which is extremely on point here. I've seen a Facebook video of a chimp walking while carrying a bunch of oranges piled up in it's arms, as well as a couple grasped with it's feet. There's nothing but convention to prevent feet from being used as manipulators. A "crazy" individual might even consider adding cybernetic/robotic/mechanical limbs to make thing easier, such as Dr. Otto Octavius (Doc Ock) from the Spiderman comics. This civilization may simply invent automated production facilities sooner than humans have. It might be hard to build the first robot assembler, but you can program it to build the 2nd one. Something simpler would be a piece of clothing with pockets to make carrying easier. ]
[Question] [ Trolls are about 30 meters tall on average and can weigh anything between 100 to 200 short tons at sea level. They can only be found to inhabit an island somewhere in the Pacific ocean and are in imminent danger as the volcano is going to erupt at any moment. We must act fast to save them using modern day technology. They can't float, let alone swim, and they are extremely hostile when approached. We need to get them to safety on another island halfway around the globe where they won't endanger anyone. Any solution? I expect zero casualties, short traveling time, and no need to break a bank. Note: the only scientific miracle is the trolls, hurry time is running out! I have a team with elephant tranquilizer on standby, the effect only last 48 hours and repeated administering of the drug have shown to lead to cardiac arrest for these troll. [Answer] Frame challenge You say the trolls can't float. However ... Average human mass - 50 kg Average human height - 173 cm Average troll mass - 90,700 kg Average troll height - 30 m By the square cube law, the trolls weigh very little compared to their height. They will float easily. Answer If you are worried they are not waterproof then wrap them in polythene or varnish them. Then tow them behind ships. Alternatively fit them with outboard motors. --- Calculation Assume for the moment that trolls are made of human flesh which is neutrally buoyant in water. An average troll is 17.3 times taller than an average human. By the square/cube law, 17.3 times taller means 17.3 cubed times heavier = 5,177 times heavier so trolls, if made of flesh should weigh 5177 \* 50 = 258,850 kg But they only weigh up to about 180,000 kg. Thus their density is at best 0.7 of human flesh so they will float easily. Square/cube law - <https://en.wikipedia.org/wiki/Square%E2%80%93cube_law> [Answer] From the [monster compendium](https://roll20.net/compendium/dnd5e/Troll#content): > > Regeneration: The troll regains 10 Hit Points at the start of its turn. If the troll takes acid or fire damage, this trait doesn't function at the start of the troll's next turn. The troll dies only if it starts its turn with 0 Hit Points and doesn't Regenerate. > > > The magma from the volcano is a legitimate threat to them, since it is hot enough to set organical matter in fire. All you need to do is chopping them into little bits and loading the parts onto one of these: ![Garbage ship](https://i.stack.imgur.com/sYczW.jpg) They won't die of starvation, so time is not an issue. Just take your time to whatever destination you have in mind. You will need to keep grinding the little pieces on the way otherwise they will regenerate into full grown trolls. Once in the destination just set them free and watch them regrow. You may even have more trolls now since [you helped them reproduce](https://en.m.wikipedia.org/wiki/Fission_(biology)): > > Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts into separate entities resembling the original. > > > [Answer] First of all, harvest a good amount of sedative. However you transport them, the least thing you want is having 100-200 tons shaking your carrier. Then you have two options: 1. [Antonov An-225 Mriya](https://en.wikipedia.org/wiki/Antonov_An-225_Mriya): with a Max takeoff weight of 640,000 kg and a cargo hold 43.35 m (142.2 ft) long × 6.4 m (21 ft) wide × 4.4 m (14 ft) tall, you can use it to transport one troll at a time, traveling at 800 km/h to a range of 4000 km. 2. [TI class supercontainers](https://en.wikipedia.org/wiki/TI-class_supertanker), currently the four largest ships in the world: they can each carry 3166353 barrels of oil, which roughly correspond to 392627772 kg, or 432798 short tons (about 4000 trolls), at 30 km/h. I hope it is clear that option 2 is the most effective: the Antonov would require 10000 trips, while the TI class could do the job in just 3 trips (there are 4 of them, how lucky!). "Just" make sure that the trolls are sleeping for the entire length of the trip. Those supercontainers are designed assuming that the oil won't smash the walls in hanger. How you get to put them on the carrier is another problem, and for sure I cannot ensure 0 casualties. [Answer] Container ship, Ro-Ro, bulk carrier... whatever ship(s) you can get cheaply and quickly... For long term transport instead of using elephant tranquilliser (Carfentanil, is a risky opioid), use instead high dosage of first generation antipsychotic agents. They are cheap, (generic) tend to calm down otherwise furious patients very effectively and are mostly safe for long term use. They were tested on wild animals for facilitating their transport and seem fine for this purpose too. (considering nasty side effects, better go away before those trolls get off those meds...) [Answer] This won't work. At least not with the speed you want. But your best bet is... # Aircraft carriers [![enter image description here](https://i.stack.imgur.com/XJSet.png)](https://i.stack.imgur.com/XJSet.png) ([ref](https://commons.wikimedia.org/w/index.php?curid=562435)) The United States has 10 [Nimitz-class aircraft carriers](https://en.wikipedia.org/wiki/Nimitz-class_aircraft_carrier). Each is designed for 6000 people. If the average person is 65 kg, that is 390,000 kg just in people weight, or 430 short tonnes. Let's call that 3 trolls. Each carries 90 aircraft in the [6,800 kg range](https://en.wikipedia.org/wiki/Boeing_F/A-18E/F_Super_Hornet) each. 6,800 x 90 = 612000 kg = 675 short tonnes = 5 trolls. Take away other things the aircraft carrier can do without for a bit and add back some people and you're looking at about 10 trolls per trip per vessel. Or 100 trolls per trip for the 10 vessel fleet. And those 10 appear to be it for full fledged aircraft carriers, though there are [9 other smaller carriers](https://thediplomat.com/2014/04/does-the-us-navy-have-10-or-19-aircraft-carriers/). [Other countries have smaller ones.](https://www.popularmechanics.com/military/navy-ships/g2412/a-global-roundup-of-aircraft-carriers/) Russia has 1. UK none right now. France 1. India 2. Japan 3. Australia 2 (or more?). Italy 2. South Korea 1. Brazil 1. Spain 1. Thailand 1. For a total of 15. Assume an average of 6 trolls per trip (just a guess) and that's 90 more trolls per trip. This brings our per trip total to 190 trolls (an estimate of course). Assuming that every country with an aircraft carrier is willing to loan them out for this purpose (after offloading all the planes). It would take 52 trips to transport all 10,000 trolls off the island. Not counting their gear. And assuming they're willing to get on to the carriers. Which you've made clear they are not. [Answer] 1. Neutralize the volcano! This might be simpler than moving 10,000 massive, grumpy trolls. 2. How about a bunch of blimps/dirigibles? They can lift a couple hundred tons, and can get good top speeds in the right conditions, much faster than a ship low in the water with troll weight. Depending on how far it is, you might be able to drop off the sleepers before they wake up. 3. If they have a huge snorkel, can these guys survive walking on the ocean floor? They sound very tough and dense. It sounds like they don't like water much, but they might like water more than lava when the time comes. [Answer] Everyone's coming at this the wrong way. You're trying to move them a long distance quickly. The fastest way to handle this is ignore the implied requirements of the question--don't move them halfway around the world, move them to the closest uninhabited island. Your vessel of choice is the Russian Mi-26 helicopter. It can lift a troll with capacity to spare, a bit over 300 have been built, I don't know how many are still in service. Trank a troll, lift it to the nearby island. 40 flights should do it, you should have them off in a week or two. Now you still have to transport them to their final home but you don't have the volcano breathing down your neck while you do it. Once they have had time to recover from the initial dose you trank one again and lift it to a ship. There it's fitted with some very strong and immobilizing restraints. Plenty of ships are capable of hauling 30 ton objects around, getting them to their new home isn't going to be a problem. The restraints are fitted with explosive bolts, you lift them onto the island and fire the bolts. (Note: Explosive bolts do not actually go boom, the charge just rips the bolt from it's anchorage. Whatever trivial damage it suffers when the bolts fire will quickly regenerate.) [Answer] Are your trolls stupid? Can they communicate with humans? If the answers are no, and yes, then simply tell them. Make announcements through speakers on helicopters that the volcano is about to go and there are ships nearby for rescue. If the answers are no and no, then simply have the ships make noise to draw their attention to the ships and wait for the volcano to erupt. In this case, keep the ships away from the shore till the volcano goes off. Remember to invest in light vessels to ferry the trolls to the ships. How to arrange the transfer from shore to lighter and lighter to ship is an exercise left to the rescuer. If the answers are yes and no, then you're out of luck. It can't be done without a portal or something similar. [Answer] Don't move the trolls - move the volcano instead. Just blow some undersea nukes near their island until the magma can flow out there. Tsunamis are no problem, as according to Renans answer trolls can only die when in acid or on fire. As far as I know, this has never been tried before, so make sure to bring a lot of nukes! If you really want to move the trolls, and to do so as quickly as possible, ballistic trajectories seem to be the option of choice. Stun them, pack them into fireproof clothing with a fixed iron belt and shoot them out of a railgun. According to [this](http://www.convertalot.com/ballistic_trajectory_calculator.html) with a 45° launch angel and an initial velocity of 1000m/s you could launch your trolls around 102km away from their home island. To achieve this, you would need a lot of energy: `E=0.5mv²=0.5150000kg10^6m²/s² = 75GJ` Since you only have 48h until the trolls wake up, you'll need a power of `P=E/t=75GJ/(483600s)=434kW` with an efficiency of let's say `η=0.2`, we get `E_eff=E/η=375GJ` and `P_eff=P/η=P5=2.2MW`. Producing this energy via a gas turbine reactor, you have a conversion efficieny coefficient of `η_th=0.33`. For the resulting thermal energy we get `E_th=E_eff/η_th=1.125TJ` Using the probalby easily available crude oil as fuel (which has `E_s=45MJ/kg`), you'll need `m=E/E_s=25000kg=25 metric tons`of oil. This would only cost around 14000 USD, though the reactor, the energy storage, the railgun itself and 100000 fireproof flight suits would probably be much more expensive. If you like this idea, I could calculate some more details... [Answer] This question has been answered here: <https://movies.stackexchange.com/questions/63545/are-helicopters-capable-of-carrying-this-type-of-giants> [![giants and helicopters](https://i.stack.imgur.com/jo0h2.jpg)](https://i.stack.imgur.com/jo0h2.jpg) In the movie [The BFG](https://en.wikipedia.org/wiki/The_BFG_(2016_film)) giants are carried by helicopter. The answer on movies stack concludes existing transport helicopters could do the job. I think the trolls in the question may be slightly larger than the movie giants are calculated to be, but 2 helicopters can team up to lift cargo suspended beneath in a net, as the giants are. I found images of helicopters carrying a jumbo jet in this manner. As re sedation I suggest ketamine. <http://www.cesar.umd.edu/cesar/drugs/ketamine.asp> > > Ketamine is considered a dissociative anesthetic. This means that the drug distorts the > users perception of sight and sound and produces feelings of > detachment from the environment and ones self. The drug also has > anesthetic properties that have been used in both human and veterinary > medicine, and is currently a Schedule III controlled substance. For > humans it has been used in radiation and burn therapy, treatment of > battlefield injuries, and for children who have adverse reactions to > other anesthetics. > > > Ketamine is safe as regards cardiopulmonary toxicity and it is also an [excellent veterinary drug](http://wildpharm.com/ketamine-hci.html) if the trolls are closer to animals. They will be awake, breathing, but just chilling out in the net. They will be disinclined to struggle and hurt themselves. Also, 10,000 is a lot of trolls. Triage will be necessary. To save the species, you will want to prioritize juveniles - easier to move, possibly less aggressive and with a longer reproductive life. Adult rescue should prioritize mothers of dependent juveniles. --- Large trolls could be moved via drone boat powered floats. Here is a float made of 4 blocks of polystyrene foam adequate to move a 31,000 lb dam part. [![float](https://i.stack.imgur.com/iRQeW.jpg)](https://i.stack.imgur.com/iRQeW.jpg) <https://univfoam.com/floatation> You would need more blocks to float a troll but that is fine. Floats can be cheaply assembled with off the shelf parts and attached to drone boats. A satellite uplink will allow random available boats to be converted to drone boats. They will moor off shore. Mockup dummy trolls can be positioned aboard some of the floats so trolls on land will see that trolls can ride these things. When the volcano erupts, trolls will move towards safety. They cannot swim but they are tall and they can wade and the floats are within wading distance. Even if they have not waded, the dummy trolls will hopefully inspire them. They will wade out to the floats and climb on. Once there is a troll passenger the drone boat will head out to sea with troll in tow. At sea, trolls who jump around will fall off and drown. Each vessel has only 1 troll passenger at risk. Vessel / float failure means that passenger drowns. Calm and lucky trolls will make the ride in peace. If the trolls are too stupid to figure that out, then those remaining after the airlift will not be rescued. If they wade out and destroy the float, too bad for them. If the volcano erupts with such violence there is no time to seek safety, the leftover trolls die and you might lose your floats and drone boats. No humans will be at risk. Cheap boats and cheap floats can be used: low risk, high yield. ]
[Question] [ I have a world I want to put together but I ran into a problem. ## Description This world is a cube infinite in all directions, exactly half of it is full of earth and half is space (where we see normal space stuff happening besides a place that makes the special "Suns" required for this world but I'll get to that in a second). The world has a fairly strong magnetic field for the purpose of supporting the "Suns" that light this world. The "Suns" are big, flat, flaming disks that (due to their composition) flare up and down every few hours to create a rather ugly day/night cycle. The last thing I know: life (in this world) is brought about from this magic, gold, sparkly dust. The more you have, the smarter you are. ## Problem Gravity. Of course I could hand-wave this but I would like to make it at least a little realistic. From what I have now the infinite mass would end up collapsing in on itself and killing everything. Is there a way around this? I was thinking something along the lines of massive, complex cave systems or low density soil. Would any of these ideas work or is my world doomed to self destruction? If you need any clarification on any thing, let me know and I will be mor than happy to tell you what I can. EDIT: oops forgot something important. Unlike the world in This question: [Gravity on a Minecraftian world?](https://worldbuilding.stackexchange.com/q/12442/7072) I want the world to go all the way down to the end of infinity. Gives me a little more space to work with. [Answer] With this sort of cosmology, you can't get orbits. Plus the gravitational attraction between objects on a human scale is too small to notice. With that in mind I'd just get rid of the notion that gravity is attraction between mass. Instead, just define a uniform gravitational field across all of space, pointing perpendicular to the infinite plane of the ground surface. Mass is affected by this universe's gravity, but (unlike our universe) the reverse is not true: mass-energy distribution has no influence on gravity. [Answer] It sounds like what you want / need is astonishingly (but not precisely) like that of the [Unicorn Jelly](http://www.unicornjelly.com/gorbald7.htm) web comic. > > A Khex class cosmos is defined as being those that contain infinite > planes of matter in some fashion. The cosmos of Widlan, here, is a > prime example of one kind of khex class cosmos. > > > Description of Widlan ![Description of Widlan](https://i.stack.imgur.com/ScfNo.gif) and Khex class Cosmos ![Khex class Universes](https://i.stack.imgur.com/KmIZe.gif) > > Widlan appears as an infinite, flat plane, with an apparently infinite > atmosphere above it, as though the entire universe was half earth, and > half air. In actuality, Widlan is more complex, being dimensionally > wrapped so that it really consists of two planes. One of these is a > plane of 'earth' that has only one side...if one were to dig down far > enough, one would eventually come up somewhere else on the vast plane. > The second plane is one of energy, 'fire' if you will, that extends > far above, and parallel to, the plane of 'earth'. The inside of the > Earth plane contains a layer of matter that is at Absolute Zero, and > between the deathly cold of the middle of the earth plane, and the > deadly fire of the Sunwall above, lays a temperate surface. > > > The Sunwall provides the energy source and the Absolute Zero layer provides the energy sink. Its cosmologists might be working on a solution for how the power gets recycled from one side to the other. More importantly, it provides a relatively thin layer of matter so you don't end up with infinite gravity. [Answer] As an aside, the entire concept requires so much handwaving that I'm not sure gravity is even your biggest obstacle, but I'll still try to answer it. Do you have to fill an entire half of it with earth to get what you want? Imagine instead a plane of earth bracketed by space on either side. The width should be apprxoximately the same as the diameter of our planet. It won't collapse on itself because there's no center point to collapse to, being infinite. You'd then have two habitable sides, which doesn't matter since you have effectively the same total surface area either way to play with. One note: Due to some [interesting math](http://www.mathpages.com/home/kmath530/kmath530.htm), it's not possible to escape the gravity from an infinite wall. The acceleration is constant, regardless of distance - it's not like a sphere where gravity decreases the further you get away. [Answer] Another solution would be that there isn't any gravity in this universe, but the ground plane is constantly accelerating upwards through infinite space. This should be indistinguishable from gravity. [Answer] Simple: think about the entire block being accelerated like an elevator. The gravity experienced is the same constant throughout, not related to the mass. So, have the universe have a constant vector of acceleration that affects certain kinds of fundamental materials. That's why all the rocks are in one half: they fall that way. It does not explain the lack of rising pressure as you go deeper. Maybe pressure doesn't matter because material doesn't get crushed, and its strength increases with the pressure it is under, so a piller will scale the force vs strength no matter how tall. So in general, pressure is not something that can be measured (except by mixing materials). It does allow the suns and other celetrial objects to have different rules: they're made of different fundamental materials. [Answer] Well, one easy solution would be to make gravitation a ranged force. Make gravitons massive, but not too massive. Say it has a range of 1020 m. Any single particle would be attracted by the ground in a 1020 m radius hemisphere (a volume of about 1060 m3, compared to Earth's volume of around 1021 m3. Since there's no Iron core, it'll be a lot less dense, so you should be good to go). The sun will take a bit of work though. [Answer] Short Version You can have an infinite universe like this as long as all it did was exist. Long Version Assuming you have no edges, you should be able to arrange the mass of such a universe in a way where a series of gravitational nodes exist and are arranged harmonically such that they are tidally locked into a grid that doesn't move. It's like the grid Carbon forms in a Diamond except that the grid is tied together by gravitational forces between nodes instead of chemical bonds. That locked lattice grid is gravitationally stable-ish and would mean that any given part of the whole experiences only the gravity of it's local node. There are certain things this universe simply cannot have, an edge; the system is truly infinite in all dimensions or it falls in on itself. Net mass migration of any sort between nodes; if you change the node mass by any measurable amount the universe gets asymmetric and falls in on itself. Any massive celestial object that isn't a node; it would distort the lattice and the whole universe would fall in on itself. Any relative movement of the nodes beyond a certain very very low threshold or, you guessed it, the universe falls in on itself. Basically you could have it but you couldn't build it because it's inherently unstable until completed and do note that it's not amazingly stable once you do complete it. Please note: I'm drawing on the idea of the Collapsium lattices from Wil McCarthy's work; I'm not altogether sure they would work in reality, the math does but I'm not sure about the physical reality. ]
[Question] [ I have no idea how to start researching this, so I'm going to here, where there are people who are much smarter than me. So I'm writing a story set in the medieval time period. In my story, there is a group who is consistently attacking towns in this one country. The monarch is able to get reports on the the aftermath of the attacks (reports might include approximate death count, infrastructure damage, and how much money/supplies will be lost, but these details aren't set in stone as they are the point of this question). I have a pretty good idea of long these reports would take to come in, but how detailed would they be? Clarification: By how detailed, I'm not asking you to write my story or anything of the sort. I just need a vague sense of accuracy and what information would be included. Would there be a lot of details or not many at all? (Though I in no way believe that these reports are going to be some exact masterpieces.) Would they be able to even include a death count? How accurate would it be? Details on Reports: These reports are created from soldiers going into attacked areas after the attackers have left. They look through the wreckage for bodies and talk to witnesses and survivors for details, but they do try to get these reports done quickly in order to get them to the monarch in a timely fashion. The reports are written and taken to the ruler by a messenger, and while I do expect some reports to go missing, let's go on the assumption that most wouldn't be. Details on Attacks: The people attacking the cities don't attack many places at once (at most they attack three small towns a day. A big city is a large score for them). The attackers move quickly, only spending a small time at each town, so the towns generally aren't completely destroyed. The attackers' goal is to get in and get out and cause as many deaths to the town as possible. They generally aren't targeting supplies, the towns' businesses, or important locations. The most damage they do to the towns themselves is starting fires, the only purpose of which is to kill more people. I know there is a certain extent to which it's my story and I can do what I want. But what's the high end of details that these reports can have? (Also feel free to edit the tags, I have no idea which ones to use besides [medieval](/questions/tagged/medieval "show questions tagged 'medieval'")) [Answer] 1. When we say that try to get these reports done quickly in order to get them to the monarch in a timely fashion, we need to take into account that, first, it will take some time for the report to reach the monarch, and, second, the monarch cannot do anything immediately anyway. The reporters can and will take two, three, maybe four days to get their report in order. There is no point in hurrying to get it done in a day, because the report will then need to travel quite a few days, maybe even a few weeks, to get to the king, and then the king has no means to react right away. 2. I need to point out that attacking a town with the purpose of killing as many people as possible is extremely non-medieval. Once because nobody killed for fun, and then because nobody had the technological means of mass killing. Attacking a town with the purpose of taking as many slaves as possible, sure, that's medieval. From the point of view of the attacked kingdom there is no difference -- the people are gone and lost anyway. 3. The most common way for a military reconnaissance force to report back to the king was to send somebody to report back to the king. Reporting in writing would have been rather strange, because anyway somebody had to travel back to carry the written report. Why waste a perfectly good and expensive sheet of parchment? If the king considered it necessary, he had secretaries who could write down the essentials of the messenger's report. 4. The count of lost people (dead or enslaved) would have been accurate for towns, but likely inaccurate for rural areas. It is the Middle Ages, the vast majority of people did not live in towns. They lived in villages. Villages were small. Villages were many. There were no roads, there were no maps. 5. The report of infrastructure destroyed would again be accurate for towns. For villages, maybe the reporters could get a good approximation of the number of villages attacked and a rough approximation of the number of houses burned. 6. The reconnaissance force would not even try to estimate a monetary loss. It is the Middle Ages, very few people thought in terms of money, and generally money was very much less important than in the Antiquity or in post-Medieval times. Houses burned, yes, it is important. Sheep stolen, yes, important. Bushels of wheat or tuns of wine burned, spilled or stolen, important. People dead or enslaved, important. Actual silver and gold stolen, important, and reported by weight. How much would it cost to rebuild the houses etc., not important and more importantly impossible to estimate by soldiers. 7. The messager reporting to the king would be brief and direct. Flowery speech was not practiced in the Middle Ages, and in any case soldiers would not have been expected to have received courses in rhetoric. Something like this: Sire, I am Roughsoldier Braveman, yeoman, and I have been sent by captain Longlash Smallbaron to report on the wreckage inflicted by the stinking Vandalgoths who have attacked Your Majesty's fine province of Frithlandia. Captain Smallbaron made haste and arrived in Your Majesty's obedient city of Yardchester on Saint Batholomew's day. We made inquiries, and found that the murderous Vandalgoths, led by their left-handed war leader Ohtrad the Fearsome, second son of their chieftain Hunferth the Much Scarred, entered the province around the day of Saint Mary Magdalene, maybe two or three days earlier, coming from the black forests of Withenhold. The locals estimate their number at two thousand, but captain Smallbaron says that they could not have been more than five hundred, at the most, because more than that could not pass through the Withenhold forest without starving and anyway chieftain Hunferth does not even have two thousand warriors to call. In the city of Yardchester itself the Vandalgoths tried to burn the cathedral, and I grieve to report to Your Majesty that they did indeed burn the proud belfry and part of the roof of the cathedral. Upwards of a dozen good houses were also burned, and some three dozen or so hovels were put to the torch. Some sixty men were killed, and the Vandgoths took some fifty or sixty young women, and also some children, both boys and girls. The barbarians stole some four pounds of silver from the city, and about a quarter pound of gold, mostly from the good houses they burned down. The countryside around Yardchester was savagely harried by the Vandalgoths. We found out for sure that three manors were burned, and possibly some more. Captain Smallbaron has left his sergeant in Yardchester to compile a list of manors attacked by the Vandalgoths, and he made it known that the barons who had suffered damage at the hand of the barbarians should come and make report, bringing good and honest witnesses to attest and give credence to their words. Captain Smallbaron took it upon himself to appoint his man the good knight Sir Lindolf to begin a survey of the province, expecting that Your Majesty will appoint surveyors to assess the worth of the lands and the people. The Vandalgoths spent no more than seven days in the province, before turning back to Withenhold forest with their captives and their ill-gotten prizes. Besides Yardchester itself they also pillaged and did grievous damage to four other small towns, where they killed upwards of four score men and took fifty, sixty, maybe more young women. Captain Smallbaron has moved his men to the town of Raginvald, near where the old Heregang road comes out of the Withenhold forest, where he awaits the pleasure of Your Majesty. I am pleased to report that Raginvald itself, though small, was able to use its stone walls to defend itself and escaped the brunt of the Vandalgothic fury. Not more than two dozen men died, and only two houses were burned. Although the people of Frithlandia are peaceful and were not prepared for such a forceful invasion by the barbarians, the local barons did put up a fight with their armsmen and what force they could gather, and at least one hundred, maybe even two hundred, of the barbarians were killed dead. Captain Smallbaron says that in his opinion the Vandalgoths will take some time to make up their losses, and no more attacks are to be expected in the coming months. That is it, Sire, what we know and where we stand. I am waiting for your reply to Captain Smallbaron. [Answer] Feudalism or an unitary monarchy? When one thinks of middle ages, details might differ. In a feudal system, the liege offers land and protection to a vassal in exchange for service and taxes. This might go through several levels, until the lowest lord grants a shack and some fields to a serf, in exchange for a fat pig on Michaelmas, 15 days of work during the planting season, and another 15 days during harvest. Each level would demand to be included in the reporting chain, and bypassing that lord would be a grave insult. So the headman of a village reports to the lord of the manor, the lord reports to the baron, the baron reports to the earl, the earl reports to the duke, and the duke reports to the king. At each level, reports would be aggregated into a more or less coherent picture, and the reporting noble would take political considerations into account. Does his or her status diminish by being unable to resolve this problem? Are there any other requests pending with the liege? What would rivals think or say? "Sire, I beg relief of this year's taxes on account of increased bandit activity across the border. I had to call up the levies of this, that, and that county, and send my household troops as well." In a more unitary system, there would be provincial viceroys with similar considerations. They have been empowered to solve problems, so can they resolve problems on their own? [Answer] Frame Challenge So, hypothetically - there's no difference in terms of detail that one could generate in Medieval times vs today. The practical difference however is the cost of paper, the time of a scribe/someone who can write. There's things like the Doomsday book or there's legal contracts from Rome, sales agreements etc. The limiting factor is that Paper is/was a much more expensive resource, so you tended to only put down things that were super important. In the case of the Doomsday book, William the Conqueror had just conquered England and wanted an inventory of everything he now owned. It was important, therefore it was done. Legal contracts for the sale/purchase of goods, likewise - pretty important. The question really should be: What does the King really want to know? Then assume that you will fit that information onto a single, standard sized piece of parchment (approx 15 x 20 inches) - no one likes multi-page reports. I would probably start with approximate fatalities, Prisoners taken, Attacker strength and composition (100 men, 20 archers and 10 on horseback), then buildings destroyed, ingress and egress routes (e.g. where did the attackers attack from, where did the leave via) and then any 'general' observations - e.g. something out of the ordinary 'They poisoned the water wells after leaving'. Depending on the size of the battle/town, that could realistically be done in about 1 day by an experienced soldier/Officer. [Answer] From what has survived from medieval times, the further one was in time and space from the event, the more detailed the report. So the initial report from Johnny on the spot would be brief and focus on whatever was important to the reporter. 'The village was pillaged and burnt, X corpses were left unburied, the Church was burnt down and the remaining villagers fled or were taken Eastwards. The reporter would have no idea about amounts of gold and silver taken etc,. Later reports would be full of lavish detail replete with names, ages, artifacts listed, colour of horses, maidens ravished, monks tortured etc,. [Answer] ## Medieval commanders can’t read or write Probably, neither can the king. Of course, “medieval” is a period of 1,000 or so years covering the continent of Europe so it’s impossible to generalise. However, if we’re talking the classic chivalric society of the early and mid medieval, the commanders are knights and these guys spent their childhoods learning how to be brutal killing machines, not in learning how to read or write. So, battlefield reports would largely be verbal and necessary short. [Answer] The questions says medieval but doesn't specify Europe. Medieval states like China and many large states in India, or the Islamic Caliphate, etc, would be more literate and bureaucratic that the typical European state. And European states included the 10th century Caliphate in Spain and the eastern Roman or "Byzantine" Empire which had larger and more "Byzantine" bureaucracies that most Medieval European states. The question does specify that the country was ruled by a king, and thus is a kingdom instead of a Caliphate or an Empire. The Middle Ages last for about a thousand years and even if restricted to Europe covered a few million square miles of land from Iceland to Georgia, and from Portugal to Russia. I think that one of the dozen or so kingdoms in Europe outside of Ireland in AD 1500 would be much more bureaucratic than an Irish tuath in AD 500. I wonder whether there is any surviving historical account which quotes from contemporary report of the devastation at a place by the Mongol invaders in the 13th century. Such a quote would give you some idea of the contents of a report. [Answer] You might want to look at the the history of the Osman Akinji. The reports of their raids still exist - at least here in Austria. Part of it is official (document kept in archives) and part of it is legend. The main information that reached the higher authorities seemed to be the routes they took and the villages raided. Some reports also include information about lifestock and humans taken. But their accountability is of debate. Especially if humans where actually kidnapped. There is still a little memorial on a mountain pass the Akinji crossed on one of their biggest raids. ]
[Question] [ Orcs are typically depicted as being extremely warlike creatures. With their average intelligence slightly lower than humans. But they have more physical advantages such as superior strength and constitution. And since they have such a warlike culture, all of their resources and "orcpower" are directed towards warring other races or each other. So obviously they would advance more in the realm of making war than any other cultural realm such as agriculture, industry, economics, etc. Unless it helps them make war better. And since they are so dedicated to making war, they would obviously see the benefits of heavy armor. Individually, there would be less risk of injury and death, and so they would feel freer to throw themselves at the enemy. And as a commander, you would want fewer losses, higher morale for your troops, and knowing they won't hold back. Add that to the fact that they would be fighting almost constantly, so they would want as little risk of death and injury as possible. So with the fact that these advantages in mind, why would orcs not wear heavy armor? I'm looking for cultural reasons. I realize there will be exceptions and some orcs will still opt for heavy armor. But I want a reason that would make it be a cultural thing for orcs to wear less armor. [Answer] ## Berserkers: Lots of historical peoples used little or no armor. Armor slows you down, especially if your fighting technique involves lots of rapid motion and wild attack. Armor is for people who are sober, practical, practice good logistics, and do a lot of careful planning. You know, wimps. The peoples who most frequently are shown not wearing armor are folks like berserkers. Their sheer disregard for personal safety was terrifying. If they were coming at you, you knew that they weren't going to stop coming till one of you was dead, or you ran away. In that moment of enemy attack, the idea of running away sounds pretty good. And once your carefully arranged battle line starts to crumble, all the advantages of that nice, sober, practical plan evaporate in the face of people who clearly are NOT going to retreat no matter what you do. Armor is expensive. Armor requires lots of upkeep. Try swinging a battle-axe in armor, then try it in street clothes. Then do the same thing after going on a twenty mile hike in 40 lbs of armor carrying a two-handed sword. Your orcs may have a preponderance of fast-twitch muscles allowing hysterical strength. Like great apes, they can use more of their muscle at once. The cost is endurance. Everything that makes your orcs exert themselves over time weakens the army (my suggestion is to use mounted warriors, who ride to battle but fight on foot). So it's better to have a big weapon and splatter the enemy than try to outcompete an endurance species like humans in an endurance challenge. That also means that when orcs fight each other, their massive weapons smash any armor to bits. Besides, how are your enemies going to see how ripped your muscles are if you are wearing armor? Who is going to see how you have a third nipple which denotes power and potency? Maybe your warriors get a tattoo every time they kill an enemy. How will they know what a savage killer you are if they can't see the tats and know you've killed ten men? They may be well endowed (or imagine themselves to be) and go into battle naked to intimidate enemies and impress the females who are shooting arrows at the enemy from the rear (someone's gotta do it). The female orcs aren't impressed with your codpiece, and this way they see you in all your glory. In fact battle might have deeply sexualized meaning to orcs, who view armor as feminine (and from most accounts, orcs have a rape culture). They bring gifts of armor back to females, who wear it in battle. The males despise armored opponents, and may even find the sight of armored warriors to be arousing (enhancing their battle frenzy). [Answer] Pure biological physics. Pound for pound a chimpansee or gorilla has far more strength than a human. This is because of the type of muscles they have compared to ours. They have far more fast-twitch type muscles which gives them far greater strength. The classical Orc would likely have similar composition, making them far superior in strength. The disadvantage of those muscle types is that they sacrifice coordination and especially endurance compared to the slow-twitch type muscles that humans have so much off. These muscle types are the reason we can jog for hours on end (if trained). When in combat your Orcs cannot afford an extended engagement. They don't have the stamina to fight for a long time. Their tactics have to be focused on engaging quickly, overpowering their enemies with sheer force and then hoping they can retreat and catch rest before the next engagement. This explains their agressiveness, brutality and their lack of armor. Armor is simply too tiring for them to wear. The typical brutality and agressiveness are symptoms of this because any hesitating during combat simply drains their energy. Edit: only now do I realize that in part this answer is already present in the currently accepted post. To further diversify my answer: the lack of coordination impacts their ability to build weapons and armor. That is why their weapons are often so much more crude, and their armor almost non-existant. It is too difficult to make properly fitting armor. [Answer] # The enemy has access to strong weapons No point in wearing armor if [a pesky mage can bypass it with a level one spell](https://roll20.net/compendium/dnd5e/Magic%20Missile#content). Anti-magic armor might still be useful, but it is too expensive to equip a whole army. If you can get rid of the mages (fight in a no-mana zone), then the \\\\\\\* elves will pierce your armor with longbows and crossbows. Yes, there is a lot of controversy about whether plate armor can shrug off longbow and crossbow shots. [But it takes just one arrow going through to prove that they can go through](https://youtu.be/hc6dhMV_L54?t=90). No, [really](https://www.youtube.com/watch?v=v3QqdEX_ka8). It doesn't matter if only one out of ten arrows go through, in war you are going to be expecting volleys. Even if the arrows wouldn't piece through, they would still give you quite the punch, which hurts, and bend the armor. You will need to adjust strategy to avoid being shot anyway, so the armour just makes you a slower target. And if that was not enough discouragement, dwarves and gnomes have found out that if you put a small amount of explosive powder into a pipe with a ball of steel on top of that you get a musket. [Those will make armour obsolete real quick](https://www.youtube.com/watch?v=Bjs4-u5lO60). [Answer] They'd overheat. A variation on "orcs have limited endurance". Orcs are bigger than humans (so they have less surface area per volume by the square-cube law to shed heat), and bulkier with lots of energy-intensive muscle mass, and on top of all that their metabolism is higher than a human's to power their superhuman feats (normally, larger creatures are proportionally weaker). Add this all up and put an orc in full plate, and he'd collapse from heat exhaustion before he even got to the battlefield. Some orcs can get away with heavy armor because they live in the right climate, or they can put up with the discomfort for a few crucial moments in an ambush. But in a long slog of a battle in the wrong conditions, with the sun beating down and the air thick with moisture, no orc would be caught dead without breathable, lightweight armor that doesn't cripple their combat effectiveness. [Answer] Logistics Traditionally (I'm thinking mainly LOTR here) orcs don't get on well with horses, oxen, or other beasts of burden. This means that they have to carry EVERYTHING with them on campaign. And armor is heavy! Despite what the movies show, most armies didn't go around in full battle armor on the march, it was carried in wagons or by mules. Especially heavy armors. Heck, even "Marius' mules" in Roman times had an actual mule for every 8 or so legionaries. What's more, even in armies where the soldiers did wear their armor an awful lot, the mule/wagon trains carried foodstuffs. Without them, your orcs have to ruck their own supplies, limiting the amount of armor they can wear even if they wanted to be in full plate 24/7. If your orcs don't have access to large amounts of oxen/horses/donkey's/beasts of burden, they are likely to decide that heavy armor is too much a hindrance on campaign. That extra 20lbs of metal could be an extra week's worth of supplies, allowing them to raid deeper into enemy territory! Or they just carry 20lbs less of gear, enabling them to march faster and arrive at the battle less fatigued. Perhaps the richest/most powerful orcs have goblins/slaves/lesser orcs along with them to carry their heavy armor for them. But your average swordsorc who has to carry all his own gear is going to tend towards light armor. Even if you decide in your world that orcs have horses/giant boar/whatever to carry stuff for them on campaign, light/medium armor can make sense. War is all about maneuver, and plenty of battles have been decided (or not even fought) because one army got into the right spot, before battle was even joined. So your Orc Generals may prefer a quicker, more lightly armored army to a slower, better armored one because from a strategic perspective a fast army is going to\* do better than a slow one! \Terms and conditions may apply. [Answer] Only a fool indulges in a fair fight. One attacks with surprise and flees at need. One sneaks about the countryside looking for the vulnerable. One engages in fights that can be won. In short, one uses tactics that maximize the utility of speed and lightness and minimize the utility of armor. [Answer] ## Lack of metal If you don't have access to a lot of metal, and all the metal you do have is tied up in weapons, there won't be much heavy armor around. And if none of the animals that life around you have skin thick enough to make decent armor out of... then you're down to bone/cloth/wood. At best. Now have that culture (violently) run into one that makes heavy use of armor and one of two things will happen. "Armor Envy", or "Armor Bad". ## Hearing? Maybe your orcs have poor eyesight, and need unobstructed hearing. Loud armor is out, particularly helmets that cover the ears. ## Biology Biological imperative. Orcs have green skin because chlorophyll. These Orcs would not be happy underground, wouldn't do well where it's cold, etc. Might also have a sun worshipping religion and a taboo against covering certain areas of skin based on how much sunlight that area would be expected to get. Sandals that cover the bottom of your feet and are strapped on might be perfectly kosher, but covering ones shoulders is right out! [Answer] # Tower shields Ask yourself, in what kind of situation would heavy armor be useful? protection against arrows -> use a tower shield * protection against magic -> use a tower shield enchanted by an orc shaman * protection in melee: + against smaller enemies -> you don't need protection, you're an orc! + against larger enemies (dragons, ...) -> use a tower shield If you are looking to replace heavy armor, tower shield seems like a great option: * it offers more protection * it is cheaper and easier to manufacture * if you need mobility in close melee or 1-on-1 combat you can discard it [Answer] # Armour is a compromise Heavier armour obviously offers better protection, but is more fatiguing to wear from both weight and heat, which in turn restricts mobility. Not so much an individual soldier (who can perform almost any action armoured they could perform unarmoured) But units of heavily armoured soldiers cannot move about a theatre of conflict as easily as lighter armoured troops. Tactically therefore heavy armour is more favourable when battles can reasonably be expected to have fairly limited duration, and the combatants have some way of "agreeing" a battle field. ## How do Orcs fight? If they prefer hit and run tactics, favouring several skirmishes a day, wearing an enemy down, over one decisive battle, then endurance and manoeuvrablility become more important than absolute protection. Does practice and training emphasise co-operation or individual prowess? If the latter (and these are Orcs...) how are units co-ordinated on the battle field? Again lighter armour with improved vision and hearing may be better when command and control relies more on everyone being aware of the tactical situation rather than drill and set pieces. Orcs are often portrayed as attacking in hordes - using overwhelming numbers. Outfitting one thousand knights in armour is one thing, a ten thousand strong horde is another. ## Why do Orcs fight like this? Perhaps they are nomadic (their high breeding rate means they constantly outstrip local resources forcing them to move on?). Other answers have discussed the issue of carrying armour. Nomads also may have less access to metal and metal working making those types of armour less available to them, although boiled leather can be nearly as tough as steel (although much thicker). Captured weapons can easily be used, but heavier armours, especially if they have articulated joints, often require some degree of fitting to the user for full mobility and comfort and so are not as useful. Especially if Orcs are on average a significantly different size or body shape to their usual opponents discouraging the use of armour taken as loot. May be Orcs have a degree of indifference to personal injury. This could be physiological - reduced pain and shock, rapid wound healing, or it could be psychological. Maybe it is dishonourable to show weakness, or perhaps the guaranteed way to Orc heaven is to be slain in battle with the blood of at least ten foes fresh on your weapon. If Orc culture doesn't value an individual Orc all that highly then a good death that brings glory to your family might be more attractive than a long life. Factors like these might reduce a perceived need for excessive protection. If you don't have the armour that makes armoured fighting styles appealing, then you are not going to use armoured fighting styles, which in turn discourages the development of armour, even if that is how your enemies fight. "Puny Humans! Hiding in their skins of steel - for all the good it does them! Ha ha ha ha!" [Answer] ## Toxic ~~Masculinity~~ Orculinity The mushy humans wear armor. What self respecting orc would want to look like one of those prissy guys? Deep down an orc may wish to put on a shiny, glittering shirt of ring mail, he may even keep one stashed in the bottom of his pack, but he'd never put it on in front of his friends. That's a sure-fire way to lose your Orc-card [Answer] Fighting with an enemy with a lot of druids in their ranks, or basically being druids all of them. Armor is of no use if everyone of your enemy troops knows the "heat metal" spell. Sword handles can be insulated. Axe handles can be made of strong wood. But, armor? Bad idea. [Answer] If you take the basic Tolkien orc, they don't really have culture. There are no orcish armorers (or blacksmiths, miners, and so on). They have only what their evil Dark Lord employer supplies them with, or if operating independently, what they can steal/pillage from their victims. (But they're not going to get much that way, as well-armed human, dwarf, or elvish parties tend to defeat orcs unless greatly outnumbered.) Thus it becomes a matter of economics & logistics. The Dark Lord can make or recruit lots of Orcs. But he has to have his non-orcish subjects make the armor, and if they're kept busy making lots of armor, that means they aren't growing food, making other weapons, &c. Thus the limited supply of good armor is reserved for his human troops. Orcs are basically sword fodder, and get old, outmoded stuff, if anything. ]
[Question] [ Based on [this question](https://worldbuilding.stackexchange.com/q/35441/6989) I asked before and it being too broad, here's a more specific question related to it. What would happen to books as we know them, if wood was not available as a resource? I presume humans would still want to write things down and use written communication. * How would they do it now, with no wood to make normal paper? * Would they use some kind of plants? * Would it be more expensive to make books a different way? * How many of said plants would one need to make a decent number of books in a city? Assume medieval time period. [Answer] Throughout history and before the wide use of wood pulp in paper people have used many different types of materials for writing. This varies from * parchment / vellum (made from animal skins, including human!) * bamboo * plastics * hemp * cotton * flax * papyrus (made from mashed reeds) * clay tablets * slate People have historically used which ever material filled the need in the required quantity & quality and that was as cheap as possible. For areas with trees, this most frequently was wood pulp. In Egypt, it was papyrus (thank you Todd Wilcox for helping me round out my answer). [According to Wikipedia](https://en.wikipedia.org/wiki/Papermaking), > > In papermaking, a dilute suspension of fibres in water is drained > through a screen, so that a mat of randomly interwoven fibres is laid > down. Water is removed from this mat of fibres by pressing and drying > to make paper. Since the invention of the Fourdrinier machine in the > 19th century, most paper has been made from wood pulp because of cost. > But other fibre sources such as cotton and textiles are used for > high-quality papers. One common measure of a paper's quality is its > non-wood-pulp content, e.g., 25% cotton, 50% rag, etc. Previously, > paper was made up of rags and hemp as well as other materials. > > > So apparently in a pinch most any plant fiber will do. What sort of plant might fill the role of pulped wood depends entirely upon the types of plants in the vicinity of your city. What sort of plants live near your city? So to answer your supplemental questions: * Use one of the other plants listed below dependent upon what grew in their region * Yes, they would like use one of the other plant fibers. * Yes, the paper and books made from this paper would likely be more expensive. * I don't have any information on a per plant basis but it looks like it would take more land to produce. I haven't found any quantitative comparisons between the use of these plants for making writing materials. However, this is what I could find on the qualitative differences: ### Papyrus So far I've found that papyrus was inexpensive to make but the quality of material was significantly less than that of most other materials used to make "paper". Papyrus would crack if folded or bent and it had an uneven surface. The reeds used to make papyrus only grows in tropical to subtropical climates and they do not tolerate any frost. Since papyrus comes from reeds, it requires a particularly wet habitat. ### Hemp Paper There's another SE site with a [comparison between hemp paper and wood paper.](https://skeptics.stackexchange.com/questions/16252/does-one-acre-of-hemp-yield-as-much-paper-as-4-acres-of-trees) From a strictly production per acre comparison, hemp compares unfavorably (despite its advocate's claims). It would likely cost more to cultivate and require more acres of cultivation to create as much paper. It is apparently more expensive to process. Hemp seems to have a very wide range of viability from perhaps the equator all the way into Canada in the western Hemisphere - making it perhaps the widest ranging plant considered in my answer. ### Cotton Paper [Cotton paper seems to be more economical (less labor and energy) to produce a given amount of paper than hemp fiber](http://www.slate.com/articles/health_and_science/the_green_lantern/2011/04/high_on_environmentalism.html), however, it takes more land to produce that fiber and more than four times as much water as hemp. So it's a bit of a mixed bag. Cotton grows best in warm regions (like Egypt and the Southern US). ### Flax Paper As with the other fibers I've discussed, flax can be used for a wide range of uses from clothing to paper and even bow strings. [Until economical means of pulping wood were developed, flax was one of the primary plant fibers used in the creation of paper](https://en.wikipedia.org/wiki/Flax). So a civilization without viable wood pulping technology would probably still be using flax as its primary plant fiber in making paper. I haven't found any production numbers but assume that the amount of fiber harvested would probably compare favorably to that of cotton on a per acre basis and favorably to hemp on a labor/cost basis. In fact, for climates that supported its growth it'd be the most likely replacement for wood pulp. Flax grows in cooler climes - essentially making it the cooler weather alternative to cotton. However, flax cannot tolerate heavy clay soils. [Answer] Well the earliest paper we know of is [papyrus](https://en.wikipedia.org/wiki/Papyrus) which was made from pounding reeds into paper. Another one that could do a good job would be Hemp, which is a very useful fiber plant and very cheap to grow. So there are plenty of other options to make paper. It would just take some effort to retool the industry to use the new fiber source, whatever is chosen. [Answer] The first medium ever used for writing was stone. Pretty much every culture on earth, ancient or modern, has either painted, scratched, or carved stone to preserve their art or records. Some other mediums which haven't been mentioned yet are metal plates: [![enter image description here](https://i.stack.imgur.com/tM68y.jpg)](https://i.stack.imgur.com/tM68y.jpg) Another form of record keeping, which actually isn't really a writing system at all is Quipu: [![enter image description here](https://i.stack.imgur.com/GpGY7.jpg)](https://i.stack.imgur.com/GpGY7.jpg) The ancient Inca used Quipu for all their record keeping, they could keep inventories and read these strings tied with a sort of morse code of knots: [![enter image description here](https://i.stack.imgur.com/D8TDC.gif)](https://i.stack.imgur.com/D8TDC.gif) [Answer] Paper can be made of many things. There are also non flexible writing surfaces. The earliest known form of writing was [Cuneiform](https://en.wikipedia.org/wiki/Cuneiform_script), which was written by using a sylus to make impressions into clay tablets. They even wrote on the bricks that made up their walls. Somewhere between a half million and 2 million tablets have been recovered from dig sites. [Answer] Just like building shelters, humans historically have used, and would continue to use, whatever material provided the necessary properties at a market-bearing cost in sufficient quantity. There are many materials used for "paper," including cotton. [Cotton paper](https://en.wikipedia.org/wiki/Cotton_paper) is noted as being superior to wood pulp paper, and, like wood pulp paper, could be an ancillary product of a cotton crop (eg. most of the cotton is used for textile production, but the "linters" or "cotton wool," which has few other purposes, could be used for paper production). Cotton paper can also be made from recycled cotton textiles. The Cost of Paper is Relative You are asking about medieval times. In medieval times, despite the invention and subsequent widespread adoption of the movable-type printing press in western Europe, most of the populace still could not afford to purchase books, nor would they have had the ability to read one if they could afford to purchase one. For example, [public education was not available in England until 1870](https://en.wikipedia.org/wiki/Literacy). The cost of education (or merely having the time to prioritize learning to read instead of focusing on critical survival tasks) was prohibitive to most. Even if the cost of reading material doubled due to having to use an alternate fiber for paper production, it would likely have had little impact on the average lay-person, and for those that had the means to purchase books and pursue an education, the added cost, as a percentage of the overall investment, would have likely been relatively small. Industrialization Assuming that we could build an industrialized society without wood (remember, wood is used to make machines, produce charcoal used by blacksmiths, produce buildings housing businesses, build the early printing presses used to print books), I would see little long-term impact of having to use an alternate fiber. The efforts that went into the invention of machines and techniques used to make the production of wood pulp paper efficient would instead have been concentrated on making whatever other means of "paper" production economically feasible. By the time society had advanced to its current position, there would likely be very little difference in the cost of whatever flexible writing surface we came up with. In fact, we just might be using a product that is both cheaper and more durable to exchange written information. If you look at human history, widespread availability of paper for exchanging information, from the viewpoint of the common person, is an extremely recent development (perhaps the last 200 years or less), and will be a fleeting one. The newspaper industry is already crumbling, and subsequent generations will see less and less paper use as information is stored and shared electronically (barring some apocalyptic scenario). Cultures have always desired to preserve and share information. Doing so on paper in a widespread manner is a fairly modern invention. [Answer] A choice for writing in the past was also [vellum](https://en.wikipedia.org/wiki/Vellum), or thinned calf skin. I don't know why they chose it over paper, but it seems it was more durable. ]
[Question] [ ## TL;DR then scroll down, genius This question is set in a planet with a human population, about the size of Earth with earth-like formations, that has appropriate lifeforms to the conditions following. The planet has multiple continents, but one continent is about the size of Asia and Africa combined (pretty big), and on this particular continent, there is a lake about the size of Australia (pretty damn massive). These humans are advanced to about a 19th century degree, so we aren't looking at motors, nor electricity. The lake isn't connected to any oceans, but there are plenty of convenient fresh water rivers that run through the continent, so plant, animal and human life isn't hindered by such a lake. Because of its size, rain doesn't accumulate directly on top of it, and it is mostly in an arid area, so we don't have to worry about water accumulating on top. You know what? Don't even think about weather at all. The lake, as per the question, is made of a metal-like substance. This is similar to mercury, in which in remains a liquid in common temperatures (it would 'freeze over' in some areas during the winter months like typical water lakes would), and it is incredibly dense, although not as much as mercury. This metal is not dangerous chemically, but it obviously poses the threat of drowning, if you get stuck somehow (although humans can comfortably stand on it for a few seconds, so anyone who drowns... deserves to drown). It doesn't let off any dangerous fumes, and is a pretty useless substance but stands in the way indefinitely. This is because, to my consideration, it would be considerably difficult to cross such a lake... with conventional methods. I found [this](https://what-if.xkcd.com/50/), which doesn't really offer any insight, apart from a comedic view. Keep in mind that I am looking for how one might sail, or whatever floats your boat (on a mercury-like lake, mind you), on a mercury-like lake. I don't want any flying, and simply walking across it with camels is not an option. You'd sink. It's not as dense as mercury. And even if you could keep up the speed, where would you sleep? I'm expecting physics-based boats that are designed to go on long trips across this liquid. I would prefer for it to be powered by nature, or mechanically powered, but any vessel that matches the human's technology advancements is a step in the right direction. And for the lazy people who didn't read all that: ## How might one use a boat effectively in (on?) a mercury-like lake? [Answer] Firstly Michael Faraday invented the electric motor in the mid 19th century so there is the potential for something interesting there. Since this mercury like metal is so buoyant then the boats design is not that integral as almost anything would float . In terms of powering the vessel I would suggest wind power. Just a [big sailing boat](http://www.argc-art.com/shop/image/data/p.TVN.Hold%20the%20line.image.jpg) similar to what was used in that era accept with a much broader and shallower hull as a regular ship would simply tip over due to it sitting so high in the metal. It would need to be closer to the picture on the right: wider hull, higher in the water. ![Boats](https://i.stack.imgur.com/dyWH0.png) [Answer] Physics of boats does not really change based on the fluid. So they'd use normal boats modified for new medium. I'll assume viscosity similar to water since no mention was made and just talk about density. In fluids with higher density, your boat will float better, with less drag for the mass. This will either make boats smaller or, I think, heavier with less empty space below surface. Being as ships were limited by construction technology, I think the extra flotation would be used for extra cargo or heavier armoring. Since most cargo would be relatively light and armor would, obviously, be mostly above surface, ships would need more ballast to be stable. Alternately, catamaran or trimaran hulls might be preferred. On Earth these were not really used much for large ships. But a trimaran might be a practical solution to staying stable without increasing waste mass and evolve naturally from outriggers. And less need for flotation and presumably lack of lifeforms attaching to hulls, would make having higher surface area more attractive. Oars would work better. The mass of fluid the oars could practically move would increase with density. This would mean that lower oar velocity and energy would be needed for the same thrust. Same would apply to paddle wheels and propellers. So steam ships might be fairly attractive. Possibly the biggest difference would be that waves would probably be shallower, so ships might get by lower freeboard. So they'd evolve from boats for rivers or lakes? [Answer] Even more interesting would be [Magnetohydrodynamic Propulsion](https://en.wikipedia.org/wiki/Magnetohydrodynamic_drive). Because the metallic nature of the "seas" would be a greater conductor than saltwater, the effect of passing a current through a section in a magnetic field should be even greater--and more obvious to someone on that planet who is looking for it. 19th century technology could certainly create crude DC generators (steam plants + strong magnets) that would work, and one could imagine a simple series of tech advances where this could be the standard approach for propulsion of vessels within a particular range (say, medium-to-large because of the fuel requirements) [Answer] > > (although humans can comfortably stand on it for a few seconds,... > > > Through time humans have looked at the nature for inspiration for developing tools and transportation. And i think a possible solution here would be like that. 1. If the fauna would allow it, dire waterstriders as pack animals would be a possible solution. 2. A mechanical machine that mimmic the waterstrider, maybe pedal, clockwork or steampowered. a third option is hydrofoils (or mercurial foils?), something that lifts the main body and leaves a "wing" under the surface, it requires minimal power to propell because the low resistance, but is dificult to get up to speed. [Answer] Steam-powered paddle-boat should work within your limits. Catamaran or trimaran for stability. If you prefer no paddles (if liquid is dense enough that putting something in is hard), try aero boat - powered by a propeller in air. [Answer] If it's dense enough then something like skies would actually work quite well. You have "ski poles" with large surfaces on the end, you stand in the skis and you push back behind you with the poles to keep sliding forwards. You might even be able to move like ice skating, without the poles, although it would be interesting doing that without tangling the skis. When you get tired a few floats would allow you to lie down on the lake. [Answer] Let's have a look at what methods of propulsion could be used. * Sailing (wind) * Paddle power * Steam engines Sailing requires a large sheet of sailcloth attached to a mast. Paddles require big paddle wheels attached to the side of the boat. Steam engines are big and heavy and need to be attached to something. Let's do some math - if a human can stand for a few seconds on this metal, something a bit lighter could float. Average human mass is 75kg, so let's say 50kg could float standing on a 500cm2 foot area. That means this metal will let anything float, given that it exerts a force less than or equal to $ \frac{50}{500} = 0.1\text{ kgcm}^{-2} $, or $ \frac{50}{0.05} = 1000\text{ kgm}^{-2} $ So let's look at sailing. If you want a reasonable size boat, you also need a reasonable size sail. A fairly big wooden boat would weigh a few tons, say 4 including sails. For that to work, what surface area does this need to be spread out over? 4 square metres. So boats on this lake are not going to need to be big; they can in fact be completely differently designed than conventional boats we're used to. Using that formula, you can determine how big your boats need to be, but in general most things will float, even with their methods of propulsion. $$ \frac{\text{mass}}{\text{max. force (1000)}} = \text{necessary area} $$ [Answer] A vehicle with wooden rolling bars/wheels, wind-powered. The wind should power a big propeller that is connected to the bars via toothed wheels, so the wind wouldn't push the boat-vehicle, but power its drive wheels/bars. Even if the wind stops, it wouldn't sink. It could even have a way of manual powering it, you know, put some slaves under the deck. [Answer] Well as some have already said, the physics would be the same as for water except the liquid is just denser. Therefore why not just use a propeller like they do in normal boats. The only problem might be the liquid is denser, so much more power is needed to rotate the propeller to get it at a sufficient speed. But a consequence of a denser fluid, is that more weight can be put in the boat because the liquid it displaces is as you say much heavier than water, therefore the requirement that you need more power isn't a problem because you could just get a larger,heavier and more powerful engine, without sinking the boat and to drive the propeller. A more interesting way could be to use a superconductor. Since weather plays no part meaning the fluid will be mostly flat with no waves, and the lake is metallic, you could attach a superconductor in a vehicle and glide across the lake like a hovercraft. You might not even need a superconductor, perhaps an electromagnet would produce a strong enough field. You could accelerate, decelerate and steer the craft by applying a magnetic field unevenly from the craft onto the fluid, and if the vehicle is shaped aerodynamicly, you could achieve pretty high speeds. This in a way has already been done as a kickstarter, where some people tried to recreate the hoverboard from back to the future. It only works on metal surfaces though , but the principle is the same. [Answer] If the fluid is viscous enough, I'd consider a tread based propulsion. (Think tank.) This would be different from a paddle boat inasmuch as it's working on the friction with the environment. The surface/fluid sounds like it's non-Newtonian, so impact friction (humans can comfortably stand on it for a few seconds) would seem to be more appropriate than "dig and push" like a paddle boat. [Answer] I am making a second answer for a thick liquid with viscosity much higher than water. (See comments for my previous "same viscosity as water" answer.) Best solution for such a "lake" would IMHO be a sled. This is because such a substance would be in behauviour most similar to snow or very thick mud. This means a wide flat bottom with overall shape from above being a elongated rectangle, because while you want a wide bottom you also would want to minimize the front aspect. From sideways aspect the hull would have very low freeboard, ie low height, and the bottom would be a smooth flat curve at both ends to make rising up from the sludge easier. The sides of the bottom would be noticeably deeper than the center to trap the sludge underneath and to allow lifting much of of the bottom out from the sludge, if the speed is sufficient. For propulsion sails would be preferred in civilian use. A wide flat hull should allow a large amount of canvas. And once the sled got moving the drag should be acceptable. For getting the hull moving solutions would range from having camels pull or crew members with snow shoes push to some sort of mechanical solution. For example, the sides might have a relatively wide parts that can be pushed down when starting to move. Done fast enough this would allow the bottom of the hull to be lifted out of the sludge. With the specified technology level, a relatively efficient mechanism using pneumatics or springs should be possible. The needed solution depends on how heavy they'd want "ships" to be. I think the default would be very light with just a push from some strong men needed, but a mechanical solution would allow much larger ships and larger cargoes, which should give more profit. It basically depends on just how well established trade over the lake is. Military vessels would use steam engines and paddle wheels to supplement wind. They'd also have "the lift mechanism" powered by steam. Large side paddle wheels would probably be sufficient by themselves to lift ships high enough for move. In this case you'd also see lots of commercial ships having made the transition to steam and paddle wheels. If no steam engines are available, similar solutions I suggested for large civilian vessels would be used. (Sails and mechanical lift to get started.) Something like a camel or a human with snow shoes should be able to walk on the lake. So caravans might be practical. Stops would be either on islands of solid ground or spreading sludge proof canvas with some supports to create temporary "floats". It is fairly simple to create something that floats on a dense material with high viscosity. ]
[Question] [ # Context In my world, magic has been granted to mortals by their gods. As a result, the Church heavily regulates it, and the only legal spellcasters are clerics and clergymen. Magic use is heavily regulated by a continent-wide neutral organisation of high clerics, bishops and cardinals (think of it of something like a crossover between the [OSHA](https://en.wikipedia.org/wiki/Occupational_Safety_and_Health_Administration) - for the safety and regulation side- and some kind of Inquisition -to take care of the moral side and prevent blasphemy): you need to pass exams, acquire a certification and become an "authenticated" magic user before you can cast a single spell. Usually, casting a spell requires the user to call upon the forces of the Divine (by drawing from the "mana" pool generated by the gods), but a cleric and a doctor found that one can cast a spell by either using the God's mana pool, or using the mana generated by every human, animal, plant or insect. They compiled all their information in a white paper and broadcast it to the continent, thus sowing the seed for a revolution in the spellcasting domain. Think of it like Satoshi Nakamoto's White paper, in terms of cultural impact. By using this method, you basically remove the safety guards that come by calling upon the forces of the Divine: casting spells become more dangerous, but anyone that practices enough can cast spell as well as a cleric, whilst not being a registered user and not using the might of the Gods. # Technology * Being a Renaissance-level setting, printing presses are a common occurrence, and paper production is not an issue. The technology is advanced enough so the white paper can be printed on a A4/A5 format tops. * Information can be transmitted almost instantly via magic, but needs a special magic item in order to display it to human eyes. Spellcasters can still feel/hear/sense in some way the message. * This is between a medium and high magic setting, kinda like in Andrzej Sapkowski's The Witcher works or Blizzard Entertainment's Warcraft series. # Infrastructures, organisations and culture * War has been around for a while. Rare are the periods of peace, thus hospitals and science academies are already built. Same goes for magic colleges, big and small. * A lot of people from all social classes are dissatisfied with the current magic regulations. Protests and open letters have already tried to relax the regulations, but nothing changed. Underground spellcasters associations and unions are relatively common, acknowledged by the Church but barely tolerated. * Basic education is quite common, and children often work with their parents part-time while going to school (or work and learn on alternating weeks). Hence, the literacy rate is rather high and homogenous for a Renaissance-level setting. Nobility will have access to more prestigious colleges, but basic knowledge and skills are learnt by a large part of the population. * Great archives are present in every major city. Containing documents of all kinds, about two thirds of the non-confidential and non-governmental documents are available to the public. Here is the problem: how can the doctor and the cleric that wrote the white paper broadcast it sneakily enough to not attract the attention of the Church, but at a wide enough scale to kickstart underground experiments (and finally, allow commoners to cast (often non-combat) simple spells)? [Answer] ## Copy the Reformation; the Church may not notice on the institutional level Whether intentionally or unintentionally, you've created a setting much like the conditions just before the [Reformation](https://en.wikipedia.org/wiki/Reformation#Beginnings). If the church is on the ball, you probably can't spread the paper without someone from the church noticing. Like the Reformation, though, if the church is corrupt/distracted/bureaucratic, it can fail at every step to 'notice' the problem at a level high enough to take the effective countermeasures, and thus escalate at a rate which always leaves it one step behind. Luther was both brave and pugnacious, and anything but discreet, but the local church could not get Rome to realise that things were spinning out of control, partially because individuals in Rome had strong vested interests in the status quo. In a very real sense, the Church didn't see anything unusual until entire kingdoms were breaking off. Once there is some threshold value of the paper floating around, it will 'spread itself' like an internet meme. One disadvantage your paper has is that the average person probably doesn't have really deep moral and religious convictions unsealed by the paper. During the Reformation, the Protestants were utterly determined to return to the simple theology of 'believe in Jesus and be saved by God's grace'; the principled ones were quite willing to suffer and die for their beliefs. (Others were willing to kill to supplant the church; the Catholic viewpoint is that the latter predominated). You don't have that. But OTOH, they can get an obscene amount of material gain by having magic. So expect proportionally less suffering martyrs and more grifters, self interested monarchs and tyrants than during the Reformation. PS Printers have a vested interest in printing hugely popular works. [Answer] ## Print, don't broadcast > > Spellcasters can still feel/hear/sense in some way the message. > > > This little tidbit tells me that magic transmission is out of the question. You need to get the attention of commoners BEFORE the magic community becomes aware of it and snuffs it out meaning that anything that tips your hat to the magic community is a bad idea. The printing press is your friend here. It was historically used as a means of mass communication. Pamphlets were handed from one trusted person to the next in a spider web of information transfer, and if any element in the chain was compromised, it typically only led back so far until you hit a person unwilling to give up an real names of accomplices. This was good enough for the various revolutionaries of the Late Renaissance to gather thousands of supporters in secrete; so, it should be good enough for your setting. If you add any magic to the system, it should be in the form of spells to prevent the magic community from using their powers to track your notes better than a traditional detective could. So, if they can normally use a note to scry for previous owners, then the notes should be enchanted to disrupt such spells. If they can magically force you to speak the truth or extract memories, then the paper could contain a spell to make you forget who you got it from. Things like that. If you want to take it a step further, the papers could even be enchanted specifically to deceive magic users. Since magic users are specially in-tune with magic, perhaps you could have the paper show a false message to someone who is magically aligned. So a cleric might read it as just a boring recipe for peanut pottage, but a person who's not attuned to magic might see the actual message. There are also low tech ways of hiding a message non-magically using some manner of steganography or hand cypher-such that only a person told how to read it can read it. That way, a cleric tossing a suspect's cottage might for example find some innocuous looking lithographic prints of some trees sitting in the suspect's desk, but when they are placed back to back, and a light shown through them, the combined hatch work is actually writing. [Answer] Write a story Build the premise into a work of fiction aimed at your target audience that hints at ideas that should the reader try for themselves, they would find out to be true. The church is less likely to read the story themselves and the readers would keep the secret to themselves while encouraging their friends to also read the book. Finally, there is an amount of plausible deniability if someone has the book. [Answer] Air Dropped Pamphlets from Mass Carrier Pigeons So, a little nod to WW2 propaganda leaflets, you have the means of printing, so you can mass-produce (or close enough) enough leaflets. You have Pigeons - you probably don't even need specially trained carrier pigeons - any bird species that is known to frequent a well populated area (like a town square, for instance) - capturing enough birds could easily be done either manually or using Magic 'Just catching some birds for a squab pie Guv' - an easily plausible activity. Especially if coinciding with an event where it would be expected (like a Feast). Now, the means to have the leaflets fall off - you could do something mechanical like a small watch device, or you could have something like a drop of acid that eats away at the rope holding the message to the bird after X number of seconds. Or you could use a spell here - plenty of options for plausible deniability 'I was trying to rid the town square of this vile and heretical manuscript, sadly I did the incantation wrong and didn't target the correct item' The short version is that on a day when lots of people would be in the town square, suddenly 1,000 birds are released, all with a little message on a string - the string is broken (acid/Spell/Other) and the leaflets land in the crowd. Some are turned in, some are not - using WW2 estimates 1 in 7 were not returned to the Officers for destruction. [Answer] TL,DR: Hide it in plain sight. At the dawn of the era of print, pamphlets abounded. People would write something, print it, and try to sell it on the streets. As it was cheap to mass-produce printed documents, each copy could be sold for a pittance and still make a profit for the seller. Popular pamphlets sold and were reprinted until the public lost interest, while unpopular pamphlets vanished quickly. In this environment in historical Europe, the authorities had neither the time, the inclination or the manpower to examine every pamphlet, which might range from agriculture to zoology. Only the subversive pamphlets, encouraging rebellion against the authorities might attract attention at all. Amidst this environment of a profusion of paper, another pamphlet that encourages people to think about magic in a new way would be likely to go unnoticed by the authorities. Tha authorities already have use of magic, so they would hardly be interested in an unprovocatively titled pamphlet aimed at the unmagical masses. By the time that the literate but unmagical masses have read this pamphlet and have begun to practise magic to the point where they can produce it on demand, or blow themselves (or someone else) up with it, thus attracting the attention of the authorities, the pamphlet will have been circulating for quite a while, and many people will have read and understood it. By the time that the authorities notice, become concerned, debate the matter, and decide to act, the metaphorical genie will not only be completely out of the metaphorical bottle, but the bottle will have metaphorically been smashed to pieces, so there will be no stuffing it back in and burying it. By this point, ordinary people will be able to produce their own pamphlets on the techniques required, and maybe even improve upon them, and there will be second and subsequent waves of different pamphlets distributed on the same subject. The authorities won't have the manpower to hunt down every copy, and with an increasing number of unauthorised magicians in all walks of society, they won't be able to force the populace to give up its spellcasters without risking an all-out insurrection. At this point it's up to the OP if repression and insurrection occurs... but I wouldn't put my money on the authorities. [Answer] ## The First Rule of Magic-Club ... Is not to talk about magic-club. Don't tell people about your heresy - show them! Grab a dozen disaffected commoners, and induct them into your secret magic club. Teach them some magic using your method, tell them it's very important that they not spread the word, and leave. Go to the next city, and start a new group. After a couple of months of establishing clubs in various cities, when you return to the original location you'll find that the secret club has grown to gargantuan size because your dissidents can't keep a secret to save their lives. Perfect. ## Proselytize Now that you've created a bunch of clubs that are definitely going to be infiltrated by the authorities any minute, you switch tactics. Tell the club members they need to disband for their own good, and send them to a bunch of different cities to prevent the authorities from rounding them all up at once. Give strict instructions that they not set up a new club in the new cities, but be sure to send two or three members to each city. At least one of them will start up a new club. ## Contagion At this point, the cat's out of the bag. There are hundreds of people spread across scores of cities who know the "secret." Someone's going to go public. Of course the authorities will come down hard on that person, but that's only going to make the heresy more interesting. Everyone wants to learn more about your new way of doing magic. A bunch of your converts will go public, trying to gain fame and fortune from their knowledge. Others will grow their clubs in secret, like viral reservoirs waiting for the day when they spill over. Regardless, the knowledge is already too widespread for the authorities to stop. Just be sure to use a fake name so the heresy can't be traced back to you. I suggest "[Edward Norton](https://en.wikipedia.org/wiki/Fight_Club)." ]
[Question] [ German here. I have essentially no idea of the working of guns. I've been on a bit of a Zombie/Apocalypse trip lately. Watching the walking dead, playing fallout blablabla. I'll stick to the example of [Fallout 4](https://en.wikipedia.org/wiki/Fallout_4) for this question. Now I'm wondering about finding a functioning modern day firearm (not the ammunition. Just the weapon itself) in such a world? The story takes place in 2280+, so over 200 years after the nuclear fallout. People are using old weapons that have been carefully maintained such as old bolt action rifles, old double barrel shotguns or single action revolvers. In the area around [Boston](https://en.wikipedia.org/wiki/Boston), would it be anywhere near possible to find a functioning, gas operated weapon such as an [AR-15](https://en.wikipedia.org/wiki/AR-15_style_rifle) or even smaller SMG style weapons? Ignoring that Raiders would have picked them up already. Could the gun survive for that long without a gun engineer or whatever taking proper care of it? [Answer] Depending on the conditions the answer is a qualified yes. Firearms are, at their core, mechanical, spring-based machines. Automatic weapons are no different except that they capture some of the energy from the cartridge and use it to re-set themselves to create a mechanical cycle. As most guns are made of metal, they're vulnerable to corrosion (rust) and fatigue like anything else made of metal, but they're also trivially easy to repair/refurbish. Things like springs will likely need to be replaced, components will need to be cleaned, and ammunition will need to be fabricated unless it's been stored in some extremely sterile conditions (gunpowder is a chemical explosive and so vulnerable to water and other contaminants - properly stored it'll last forever, but 200 years of neglect creates a lot of opportunities for improper storage). But aside from that, it's a collection of chunks of metal and metal lasts a damned long time. [Answer] There are two things that you have to consider when deciding if your weapon is still functional. The first is the barrel, and the second is the "action," which is the part of the weapon that ejects the spent cartridges and loads the next one. Note that I don't mention the firing mechanism. While that is an important part of a gun, and it can get damaged, in a corrosion situation, it will stay functional long after the action becomes unworkable. Since this is fiction, you're really asking "under what conditions would a gun stay viable." For instance, ### New, boxed Under these conditions, a couple hundred years isn't a problem. ### Underwater Yea, no, corrosion would freeze up the action pretty quickly. ### Heavy use The barrel of an AR-15 is rated at around 20,000 rounds. After that, both accuracy and range drop off significantly, as the bullet will no longer expand to make a seal against the inside of the barrel. ### Buried in a plastic bag. This would probably be ok, as long as the bag maintains its seal. If the seal is broken and groundwater gets in, see "Underwater," above. If the seal is broken, but the weapon doesn't get soaked, you're probably ok after a good cleaning. ### Buried in a crate You see this all the time in the movies. This is another case where you have to decide if ground water gets into the space where the guns are. This would work in a desert, but wouldn't in a swamp or flood plain. For normal dirt, you have to consider that a wooden crate will get chewed up by the worms and bugs in a couple of decades. ### In a cave Is this a fracture cave or a solutional cave? The second is the type you will find stalactites in, and the first is the kind you find crushed rock coating the bottom of. Fracture caves are much better for storing things than solutional caves, as the latter tend to be permanently at 100% humidity, also flooding. I think you get the idea. Water = bad, salt water = even worse. Dirt = bad. Airtight containers = good. addendum: @jaskij mentioned oiled rags as a substitute for plastic. Oilcloth is a staple for fantasy novels, where plastic is out of place. That is specifically tight-woven cloth coated in boiled linseed oil, but oil-soaked rags work just fine if you aren't worried about getting oil all over your stuff. The caveat to this is that oilcloth isn't bacteria or fungus resistant, and are prone to rot, so you have to use many more layers to get proper resistance when buried. [Answer] Shouldn't be a problem. 200 years is a long time but I'll switch the narrative up a little bit here and suggest that even if you can't find a functional AR-15 or similar, manufacturing them wouldn't be that hard. I think there's a common misconception that guns are sophisticated items, requiring special hardware and materials to manufacture. While high quality guns should be machined within tight specifications, "guns" are pretty trivial technology, even modern military rifles. (You'd have a hard time, say, replicating a carbon fiber stock but the actual mechanics that make the gun shoot bullets are not so complicated that you can't produce them in a machine shop, and then just use wood for the body.) So, as others have mentioned, I believe you could find a properly packed and stored AR-15 that still works, but more than likely they (or something functionally identical) will be getting produced again, because it's not that hard. Repeating rifles were coming into mainstream during the American Civil War, so 1800s tech will get you what you need. You should wonder about the ammunition though, because that's the real tech. When people "make their own bullets" they buy primers fully formed [the primer is the bit at the back of the bullet that works as the ignition source when struck]. Making your own casings is just metal working. Making gunpowder is doable (but would be some effort to set up from scratch!) I think the biggest barrier to modern guns in post-apocalypse is actually getting production of primers going again, so you have the bullets you need. (They also aren't terribly high tech, but the chemical composition is more sophisticated than gunpowder, so it's a question of being able to source those chemical components. Doable for a post-apocolypse society but probably not for a single guy on his off-the-grid farm, by himself.) Just to try and frame it better, if your society has guns, then it's probably something like early 1900s tech? We were making all kinds of machine guns in the early 1900s. The Thompson Submachine Gun was invented in 1918, based on an invention from 1915. Full automatics were around in the late 1800s, though. [Answer] Short answer: Very possible, but depends on storage method. Longer answer: If you aren't familiar with firearms, or haven't used them, you might be surprised at the relative simplicity of even a modern firearm. An AR, for example, only really has two moving components - the trigger group and the bolt carrier group. It certainly surprised me the first time I took mine apart (when they were still legal here; thanks [Stalinda](https://en.wikipedia.org/wiki/Jacinda_Ardern)...) as to how simple they are. Now, some obvious caveats - a firearm left out in the elements will eventually rust and wear. However, most people don't leave their firearms out in the field. Assuming no long-term storage prep, a modern AR in a gun safe (assuming no flooding or major water ingress) would easily be good for a long time. The main reason I cite modern ARs is that most come with a protective coating on them to prevent rust. This coating is quite hard, but if the rifle is regularly used (and abused - e.g., given to grunts or fired lots) then this coating will wear/chip off - exposing bare metal and making it likely that rust will start. The other reason that modern ARs would be fine is that modern guns fire modern ammunition - which uses modern non-corrosive powder. Most militaries stopped using corrosive ammunition in the 1960s, but there are plenty of WW2 and WW1 firearms that are still perfectly functioning (I myself have a 1947 [SMLE](https://en.wikipedia.org/wiki/Lee%E2%80%93Enfield)) corrosive ammo, if not properly cleaned afterwards, would eat away the barrel. So - TL;DR: Yes, modern firearms aren't complex, don't use corrosive ammunition and have a coating to make them very rust resistant - so long as it's not left out in a field or otherwise submerged in water - they would be fine. [Answer] Finding a modern weapon not rusted out into dust: Yes. Finding a working modern weapon: Actually maybe. The reason here is that some weapons might not be unpacked at the time of armageddon, and they are usually encased in protective grease right after manufacture, that grease is synthetic oil designed to last quite long. So, a properly encased weapon might appear working, if you feed it working ammo, after this many years. There will be limited number of places to find one in case of a total war before nuclear waste, but chances are some cases would get lost in transit, some would get buried under some not too heavy rubble and retain shape, some might not get unpacked at some army camp, and some might be found at battlefields hit by distant nuke's petrifying power, that turns sand into glass, hiding a heated but not melted machine gun under a monolithic dome, preserving it for possibly thousands of years. [Answer] This question reminds me that one of my rifles is now over 100 years old. I bought it long ago, when it was decidedly not over 100 years old. Anyways, it looks and fires as well today as it did when it was made. The bolt on it still operates as smooth as butter. And I see no reason why that would be any different in another 100 years. So to me the answer is a clear yes, so long as the rifle is stored in a decent environment. [Answer] Short answer it depends... Long answer, probably but: An AK-47 will survive just about anything, but probably won't shoot very accurately if it's an old mass produced Soviet model (they had many issues with barrel flex). If it's stored in a less-than-ideal environment though, things like the handguards, which are usually made of wood, are very likely to have rotted away. AR-15s generally need a lot of maintenance, but it'd take a lot of neglect to put one completely out of commission. The receiver body is generally made of aluminium, and the non-firing parts (furniture) is usually plastic. The gun bits are usually very hard stainless steel that will last a long time, but will probably need cleaning before firing if it's been subjected to harsh environments. Bullets will survive very long term so long as they are kept dry. Modern stockpiles tend to store them in hermetically sealed cans. Any weapon packed in cosmoline will survive long term, possibly even centuries, but will need some rehabilitation to get back to firing condition (cosmoline has to be cleaned off). In the end, any weapon that is discovered after all this time is likely to need some rehabilitation work before it can be used. However, so long as it is stored properly, 200 years is not a long time at all. Bullets will be fine, so long as they are also stored properly (i.e. in hermetically sealed cases). That said, firearms technology isn't particularly complex. After all, we've had firearms in one form or another for far longer than 200 years, so recreating a boomstick in your post apocalyptic world would not be particularly difficult. If it has the most basic of machinery and metallurgy, it would be possible to make new guns. [Answer] Short Answer: Yes. Justification: Tutankhamun's [bow and arrows](https://duckduckgo.com/?q=%2BTutankhamun%20bow%20and%20arrows%20&t=ffab&iar=images&iax=images&ia=images) still look serviceable after a bit more than 3300 years. This time included numerous social and political upheavals. It's likely there was no further maintenance of the item after the initial storage period. So if a well-made "primitive" item can last this long, a modern item - stored correctly, should easily last longer than 200 years. EDIT: fix maths. (doh!) [Answer] It might be worth considering that an apocalyptic scenario doesn't necessarily mean every inch of the land has been nuked. So we don't have to worry about whether or not something would survive ground zero. Just whether or not you could happen across a functional gas powered rifle with or without ammunition in the year 2280 under a reasonably well covered nuclear experience. Before we worry about finding weapons in special containers designed for century long sleep, perhaps we should consider who survived the initial apocalypse, and what the journey of these weapons may have been. A quick example, suppose you had a character on a homestead in a remote Alaskan compound when the event took place. This person is pretty sure this is what they have been prepping for since forever, and they hunker down and play one-man army by themselves and their consortium of like minded preppers for say the next 20 years or so. During this time, nothing happens. The apocalypse has shifted people's interests and for whatever reason, nobody cares to hunt down stockpiles of weapons and food in remote areas with secret compounds. So these preppers have lived a fairly uneventful apocalypse, far from the fantasies that made them stock up on 20 years of underground supplies. But a prepper is a prepper. Generationally, they teach what needs to be done to who needs to know. Their weapons are never neglected in the entire 200 years you speak of. They are maintained, passed down, and stored how they should be. They just never happened to be required for combat survival, and so their general wear is not expected to exceed much beyond common handling, and the occasional neglectful slip up that means they are no longer in new condition. The point being, you can find a 200+ year old weapon in perfect-ish operational condition if the back story is sufficient. It doesn't have to be found in a crate. It can be a trade for a truck or something the owner needed and was willing to give up an heirloom rifle they have never needed, and still have 50 more in their bunker. That part is up to you. The ammunition thing - I mean, people will want to argue all day about what will and won't work here. But it's your story. You can allude to survivalists who have gone trough great strides to preserve this technology to a certain point, and remove them from the tale at a point where it still serves your interest. Like finding a makeshift ammo plant that was operated by the survivors who knew what they were doing, but eventually bit off more than they could chew and died off having exhausted their wealth of ammo down to a paltry 100,000 remaining rounds. A tiny number to the military, but a lifetime to the right camp of post-apocalyptic survivors. Maybe this happened 20 years ago, in 2260. Doesn't matter. You found functional 5.56 ammunition to feed through your AR-15s and other weapons using that cartridge. Have some jam, fail to fire, fail to eject, fail to feed, squib, and it is reasonably believable. (BTW, look into ammo squib. That seems like a very plausible point of interest in old ammunition for stories like this. Could blow your face off) This is the approach I would take, personally. I believe most weapons people find 200+ years after manufacturing of any weapons ended would be the ones scavenged at the beginning and cared for by the survivors in any generation. If not the beginning, then within a reasonable time frame before nature started taking back the structures and covering the hiding spots well. There are plenty of enthusiasts, private organizations, and braniacs who will have thought to prepare for this, and will have the means for rebuilding caches of ammo outside of the typical industrial methods we use today. And everyone dies eventually. No matter how well prepped you are, in the end it's perfectly believable to imagine the life path of a settlement who was there in the beginning to eventually, over the generations, reduce all the way down to one old dude in a hut, sitting on top of a bunker full of things he had nothing better to do with than clean, preserve, organize, document, etc. Right up until the day he died alone at age 55 in the year 2247. 12 years before he was discovered by some hippies caravanning or however you want them to be unearthed and ready to find their way into the hands of your characters. Maybe even with some basic care instructions. It may be the apocalypse, and it may have hardened people, but it is not beyond reason to figure that some would actually work to preserve the means to survive, and be willing to teach others, and not just scavenge and stockpile found weapons and ammo. It wouldn't be as efficient and high tech as today, but it doesn't mean it is impossible or even outside the realms of plausibility to have ammunition generation continue as far as you need it to, even all the way up to 2260 and beyond if it serves your story right. Don't forget, if anyone snarkily asks where you happened to get a hold of some ingredient to make and stabilize your primers or something, you don't have to explain. You can just say we ran into a guy. Wouldn't say where he got the stuff but he was very interested in trading for a few lithium plates. Hell, even Andy Weir didn't go all the way down the rabbit holes for the Martian. Even he cut off the details in favor of an occasional "because NASA" or something like that to forgive the need to science the F out of every bit of the story. And it works well. Too much detail might interfere with the story more than bolster it. ]
[Question] [ In my world, I'd like to place a region of permanent forest fire, but I'm having trouble coming up with the minute details of the biome. For example, my first idea was that it started when a lush, humid forest was exposed to a volcanic eruption, followed by a permanent but slow lava flow, lasting long enough that some plants have adapted and evolved into flora that relies on the constant fire and is itself so slow to burn it can outgrow whatever is lost to the fire.But how plausible is that, biologically speaking? What is a better approach to creating a permanently burning forest? [Answer] # Yes there is a better approach Gas pockets feeding the fire... [![https://en.wikipedia.org/wiki/Darvaza_gas_crater#/media/File:Darvasa_gas_crater_panorama.jpg](https://i.stack.imgur.com/rGdcw.jpg)](https://i.stack.imgur.com/rGdcw.jpg) ...or underground coal seam fires. [![https://www.globalforestwatch.org/blog/fires/embers-under-the-earth-the-surprising-world-of-coal-seam-fires/](https://i.stack.imgur.com/wjT6B.jpg)](https://i.stack.imgur.com/wjT6B.jpg) The volcano essentially did a naturally occurring version of [fracking](https://en.wikipedia.org/wiki/Hydraulic_fracturing), creating channels to the surface for gas, while land slides exposed coal seams, in some instances laying the coal bare on the surface. These fires ebb and flow with the seasons, especially effective if they are not the four seasons we have on the temperate parts of the Earth (Winter, Spring, Summer, Fall) but instead Wet and Dry seasons like in the tropics. The biology would have to... 1. Grow fast 2. Spread Effectively 3. Survive Scorching Vines and brush ‚Äî where the roots go deep ‚Äî would work, the plants survive having the surface parts scorched off because when the water comes, the roots shoot and grow new surface parts and send vines in all directions. [![https://tallcloverfarm.com/3547/brambles-gone-wild-how-to-remove-blackberries](https://i.stack.imgur.com/H56Gi.jpg)](https://i.stack.imgur.com/H56Gi.jpg) Blackberries are infamous for forming [brambles](https://en.wikipedia.org/wiki/Bramble) and spreading quickly --- So, to summarize: * The fires are fed by subsurface sources, like gas and coal, not by "new" biomass * The biology does not so much "adapt" to the fires as it is just very good at spreading and "ignoring" the fires by hiding underground. [Answer] Quite a few plants - mostly trees - have evolved to [require fire to germinate](https://www.britannica.com/list/5-amazing-adaptations-of-pyrophytic-plants)! This seems like the seed of what you might need - combined with a geography that's appropriate. Annual fires are common in several areas; but what makes them not permanent is the weather cycles. This could possibly change, though, and become permanent in a way - if your geography allows the fire to "travel". Imagine a Pangea type world, a single large continent taking up 30% of the surface area of the globe, say. If that Pangaea is ringed by forest, and if the weather patterns comply, it's possible that you could have a travelling fire, which, say, is on the east from March to June, the north from June to September (northern summer), the west from September to December, and the south from December to March (southern summer). (West/East could easily switch, of course.) The fire could literally travel in that way, ringing the globe every year. Then, cultures would possibly come up that would worship the "renewing fire", have rituals based on it, etc. I'm not sure what you'd need for the weather to work out this way (you'd need the rainy season to not coincide with the fire, but to coincide with the end of the fire, for example), so that part might be a bit handwavy - but it seems like a possibility, if you're not going into meteological science fiction, at least! [Answer] > > t started when a lush, humid forest was exposed to a volcanic eruption, followed by a permanent but slow lava flow, lasting long enough that some plants have adapted and evolved into flora that relies on the constant fire and is itself so slow to burn it can outgrow whatever is lost to the fire. > > > I don't think that can work. Evolution for something to adapt to those conditions would take several generations, even assuming an annual reproduction cycle for something like grass that would take decades or centuries. Over that time span a lava flow would involve volumes so huge that it would annihilate any volume organically produced in the same time. And don't forget that, though volcanic soil is fertile, it cannot straightforwardly grow anything on it without some weathering. Weathering requires time to happen and, most importantly, exposure to weathering agents, which is going to be difficult or impossible with new lava flowing on the old one. [Answer] It's science-based. > > But how plausible is that, biologically speaking? > > > Nope, for each additional 10¬∞C temperature, the speed of chemical reaction roughly doubles. Between, say, 40¬∞C ambient for normal life to a 600¬∞C for a puny fire temperature, you have 256 difference in the chemical reaction speed\\. There's too much of a difference for the life forms to be based on biochemistries close enough to evolve one from the other. \\ [Citation](https://courses.lumenlearning.com/introchem/chapter/factors-that-affect-reaction-rate/) `Raising the reaction temperature by 10 ¬∞C can double or triple the reaction rate. This is due to an increase in the number of particles that have the minimum energy required. The reaction rate decreases with a decrease in temperature.` > > Is there a better approach to creating a permanently burning forest ? > > > Your only chance, by direct evolution in hot conditions. [Answer] You can't have traditional trees they're too slow you need something that grows far faster, probably faster than [Bamboo](https://en.wikipedia.org/wiki/Bamboo) or even [Kudzu](https://en.wikipedia.org/wiki/Kudzu), something with a growth rate in the 10s of metres a day range, more importantly 10s of kilograms per day. I don't think osmosis allows for absorbing, moving and just chemically processing that much material but lets go with it. What is this plant going to be like: * It will have a metabolic focus on producing thick porous [bark](https://en.wikipedia.org/wiki/Bark_(botany)) that starts with a high water content and dries and burns and crumbles off while being replaced continuously. It will be the bark rather than the stems of the plant that smolder continuously. * The tissues of this plant are going to be high in silica and chromium as flame retardants. * It's roots are going to be deep and extensive and exude acids to mobilise growth nutrients, these root adaptations exist individually in nature but not in any one plant that I know of. All of these adaptions do exist in nature; Oak trees survive grass fires in meadows by having a thick spongy bark. Willows have high silica in their wood making it slower burning, which is not why it is there but is a useful side effect. Many grasses in fire prone environments have deep roots to survive burn over. Clover roots exude acid primarily to balance their pH in light of nitrogen fixation but it has the side effect of mobilising nutrients from dissolved soil particles as well. Such a plant won't give you a big flashy crown fire but it could smolder continuously pouring smoke and ash into the environment and burning anyone who ventures that way. I reiterate that *I do not believe* that this is within the reach of the biological systems we understand and share our world with but maybe if it smoldered slowly enough without burning out it could work. [Answer] You can't. It's simply a matter of energy input and output. The sun delivers about 700 W/m^2 to the Earth's surface. Plants convert a small fraction of that into biomass. (Photosynthesis is at best only about 5% efficient: <https://en.wikipedia.org/wiki/Photosynthetic_efficiency#Typical_efficiencies> ) A fire will convert many years worth of plant-produced biomass into CO2 & H2O in minutes to hours\, releasing the stored energy in the process. Then no more fire until the plants have a chance to regrow. Even the coal seam & natural gas fires mentioned in another answer demonstrate this. It took probably millions of years of plant growth to produce that coal or natural gas, which is now burning at a rate far greater than production. \Generally speaking. You can have situations, like tree roots, where there's limited access to oxygen, so the fire might smoulder for months. [Answer] You can do one better than a permanently burning fire - a natural fission reactor. The best part? It isn't science fiction, it's history: <https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor> OK, maybe "permanent" is a bit of an overstatement, the one that existed on Earth only ran for hundreds of thousands of years. It required a high concentration of fissile Uranium and some groundwater. You could do all sorts of things with the water coming as part of a rainy season, or a river meandering to the wrong spot.... You also have a fuel in a fixed location and life won't exist right next to it, but there will be a fringe that is just at the boundary of survivability, and is changing little for thousands of years, which seems ripe for evolution. If you want to keep the evolutionary challenge as heat rather than radiation, then the specific locations will be cracks in the rocks where the steam escapes, some could be hot enough to produce flames whenever burnable material is available. [Answer] Fire loops around the globe Your planet has its landmass as a band around the equator. (or, alternatively, there's [almost] no open water, poles are covered in snow, leaving only the equatorial zone available to the biomass) Somehow, there are no large rivers. (plants still need to get moisture, and there's evaporation, which means there ought to be rain- or snowfall, which usually means runoff, but fires tend not cross large bodies of water... figure this out). The equatorial zone is dry-ish, and e.g. typically covered by grasses. The fire started (magically in only one direction), spread the entire width of the equatorial zone, and continues to burn, e.g. westwards. By the time the fire has reached it's origin, that part has already sprouted new mature (and dry) grass, with seeds either preserved deep in the soil, or spread by wind, or spread by birds or even migratory animals. Thus the fire continues to burn in a circle around your planet. The long-lived plants died out, what remains are grasses and maybe shrubs. The plants have therefore evolved to live in this cycle, and so have the insects and the animals. P.S. some math Fire boundary speed: 10% of wind speed (<https://link.springer.com/article/10.1007/s13595-019-0829-8>) Typical wind speed: 10km/h (<https://sciencing.com/wind-speeds-tropical-rainforest-23367.html>) Thus, for a planet the size of the earth, the fire circumnavigates in ~4¬Ω years, leaving enough time for plants to germinate, go through several life cycles and accumulate large amount of stale, dry biomass. [Answer] Biology already knows plants that got adapted to periodic fires. These include either fire-resistant trees that just do not catch fire because of some non-burning composition or seasonal plants which get burned but keep roots and/or seeds intact so to re-grow. A permanent forest fire with burning trees is likely impossible, because it would require much more energy than can be produced. So, you are confined only to a choice of either periodic, seasonal fires or fires with fuel supply other than trees. That fuel supply can be natural gas, petroleum, underground coal or peat deposits, or gas produced by microorganisms on swamps (burning methane is common in swamps, producing "lights"). The underground peat deposits can burn for years in Moscow area, even under snow, producing smoke. But, of course, this does not mean the trees are burning all that time. ]
[Question] [ I just started thinking about a fictional universe where humans have colonized more or less any habitable planet (there is a huge concentration of habitable planets) and I'm trying to write down different planetary systems with different environments and stuff. I thought about a planetary system where most of the planets have humans but, since the first expeditions found this planet and started setting up colonies, they found out something strange. On this planet there are no plants or any vegetation. The oxygen came from deep inside the planet, where atoms in water molecules are separated in some way I haven't yet thought of (but this is another problem for the future me). Now, in the air of this planet there is also a gas that kill any plant they try to farm. I'm thinking about some toxic interaction with photosynthesis. The only plants that are farmed here grow in greenhouses and they cost a lot. Wood and paper are very expensive, as are vegetables. This problem persists until someone finds a plant, from another planet or created in a lab, that can live there. The question is: * Is there anything like the gas I thought about that exists and that I can refer to? Remember that this thing is toxic only for plants. * If the thing with the photosynthesis is acceptable, how can the "new plant" grow without photosynthesis? [Answer] Frameshift: Andrew Brēza had the right idea but got it backwards. It's not that the planet has a surplus of oxygen. Rather, it has a major deficit in carbon. The air isn't toxic at all, it's lacking CO2. Animals (including humans) don't use CO2, they won't care. Plants need CO2 to grow. You either need to import all the carbon your plants need, or you need to have massive facilities to gather the dregs of CO2 that get exhaled by the inhabitants. [Answer] # Oxygen You're looking for a gas that will not harm animals but will impede plant growth. I suggest oxygen. Lots and lots of oxygen. In fact, the atmosphere is overwhelmingly composed of oxygen and barely has any carbon dioxide. Check out this question from [Biology StackExchange](https://biology.stackexchange.com/questions/3043/what-is-the-effect-of-a-pure-oxygen-environment-on-a-plant) for some of the science, or this [old journal article](https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1399-3054.1966.tb07046.x) for even more science. [Answer] "Now, in the air of this planet there is also a gas that kill any plant they try to farm. I'm thinking about some toxic interaction with photosynthesis" Difficult, but doable with a little handwaving. You need a volatile compound called pseudoatrazine tetrafluoride, a heavy, odorless and tasteless gas that is somehow synthesized deep in the soil, by those same bacteria that produce oxygen (the planet needs to have a very interesting microbic ecology). I'm afraid that means that the bacteria's energy source has to be pretty exotic - possibly they have evolved a way of feeding off radioactive decay. There are Terran microbes that almost do that already. The reason it's called pseudoatrazine is because colonists have analyzed the gas and found that it has to be a molecule of the atrazine family, but they haven't been able to exactly pinpoint which. Also, atrazine-resistant strains aren't resistant to this molecule. Perhaps the molecule composition varies over time. They could probably riddle this out, but they haven't time. The gas gets into humans and plants, where it breaks down. While mostly harmless for humans, the byproducts combine with [D1 protein](https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/d1-protein) in plants, disrupting [Photosystem II](https://core.ac.uk/download/pdf/205183502.pdf) and effectively killing them. The only solution is a gengineered plant that expresses the human cytochrome P450 (CYP1A2) genes with sufficient activity to effectively detoxify itself. Having a plant do this and yet keep a worthwhile yield as well as sufficient vitality in vivo is the reason it took time to produce it, and not all plants can be replaced with the resistant strain. In the very long period, exterminating the dangerous soil microorganisms and replacing the oxygen cycle with a plant-based Earth-like cycle is the way to go, but doing this will take centuries. [Answer] It would be easier with a pathogen. The chemistry of a plant selective airborne toxic is tricky. A less tricky way to accomplish your end would be a pathogen. Humans and vertebrates generally have immune systems that can adapt in an individual level to reckon with new germs and so after an initial infection, humans are immune. Maybe there could even be a vaccine. Plants are as durable as animals vs toxins, and maybe more. But as regards pathogens the plants have only intrinsic defenses. They must evolve new defenses. An alien pathogen could just sidestep whatever the plants have and plunder their resources. The greenhouses are really safe rooms. If the Bug gets in the plants are toast. [Answer] How can the "new plant" grow without photosynthesis? If there is CO2, your plant basically just needs energy to extract the carbon from it. If it doesn't get it from the sun, you could imagine that it exploits geothermy, for example. The problem is if you choose to go the non-CO2 route. Because a plant is made of carbon, and to grow, it needs to find it somewhere (conservation of matter, unless it can generate it with say, nuclear fusion. But that would be one hell of a nuclear plant). It could be parasitic (get it from other lifeforms), but that wouldn't solve the food problem. Or maybe it could feed on solid carbon you could find somewhere on your planet. Or you could say your planet's atmosphere contains another carbon-based gaz (but a lot of those are toxic). ]
[Question] [ In my world, an apocalypse happened, a nuclear war. Fast forward to the future. In places like Vegas, New Fresno, and Lost Angels (post-apoc LA) I was thinking about agriculture, and after doing a little bit of research, I decided what their staple crops would be. I planned on these settlements growing corn, beans, squash (and in some regions cabbage) as their main source of nourishment. Here’s my question: Would this work? Could large, post-apocalyptic city-states base their civilizations on maize, beans, and squash? Criteria * Each of these cities has a population of several thousand people. * I don’t know which livestock would work best yet. * They have a reduced level of technology, say late 1800s, but with less manufacturing ability. [Answer] The [Three Sisters](https://en.wikipedia.org/wiki/Three_Sisters_(agriculture))? Aztecs had cities well over 100,000 inhabitants based on growing those three. The only thing I would worry about would be whether you had enough water to raise them. [Answer] Whether or not large populations powered by the Three Sisters can exist is fairly well settled by all the pre-contact cities and large towns in North America which did exactly that. But could this work where Las Vegas is now? Las Vegas was not always a concrete jungle in the middle of a desert. Human activity desertified the region. If your apocalyptic scenario reverses that (blow up some dams, screw with the weather, whatever), you should be good. You also mention livestock, which pre-contact cities lacked. Add early 19th or 18th century technology, and you're pretty secure in terms of food supply. The question you'll eventually get to is agricultural innovations, such as certain fertilizers and pest control. For instance, is the corn you're using a variety with genetic modifications for pest resistance or high efficiency yields? Even if the tech to produce GMO crops is lost, the crops themselves might still exist, and without the likes of Monsanto cracking down on their natural spread, their natural advantages will probably let them spread very quickly until they hit geographic barriers. The real question is just how large a population you can sustain, and that depends on loads of other factors. But Cahokia and Tenochtitlan had populations in the thousands, and the same three crops were the staples then and there. Seeing as you're suggesting better tech is available than what the Mississippian and Mesoamerican civilizations had, those should be considered a lower bounds on what's possible for your larger cities. It is, however, relevant that Cahokia is close to the Mississippi River, and Tenochtitlan was on a lake. You might have to blow up the Hoover Dam for the Las Vegas area. [Answer] As other answers have mentioned, it is possible to have a civilization subsist on those foods, as they have been staples for Mesoamerican societies for millennia. However, there are weaknesses to using corn in particular as a staple food, since it is low in some vitamins that can lead to diseases such as [pellagra](https://en.wikipedia.org/wiki/Pellagra). There are also risks such as fungi that leave the corn inedible. A society that relies on corn/maize as a staple food would need to know about [nixtamalization](https://en.wikipedia.org/wiki/Nixtamalization). Nixtamalization is a chemical treatment process that cleans mold-contaminated corn and improves its nutritional value. It has been used for thousands of years by Indigenous people in the Americas (the Wikipedia article dates it at 1500 BCE), and is still used today. The process can be a bit dangerous if performed improperly, so it might be an interesting bit of worldbuilding if some members of your society are having a hard time using it, while others with stronger connections to Indigenous communities are performing better. ]
[Question] [ Landfills seem like disgusting, nasty places that could be breeding grounds for all sorts of viruses and bacteria. What is the likelihood that the next lethal superbug or virus (like Ebola) could originate there? [Answer] Slim. Superbugs seem to come in roughly two flavours... things resistant to treatment, and new diseases our immune systems aren't familiar with. The former comes from places where large numbers of people get together and use antibiotics excessively and/or incorrectly. You end up with new flavours of old favourites, like [totally drug resistant TB](https://en.wikipedia.org/wiki/Totally_drug-resistant_tuberculosis). The latter are often [zoonoses](https://en.wikipedia.org/wiki/Zoonosis). The likes of ebola, HIV and swine flu are animal pathogens that jumped the species barrier and proved to be a little too effective in their new environments. You get novel zoonoses where people and animals spend a time together in unsanitary conditions. Landfills describe neither of those things. Unless it is a waste dump for surplus and expired antibiotics, there's not much pressure on landfill microbes to develop and maintain drug resistance. Not too many exotic animals frequent landfills, and humans don't tend to hunt or farm there. I'm not saying it is impossible but, y'know, there's not much reason to think it'll happen, and every reason to think there will instead be an outbreak of a new kind of flu or haemorrhagic fever or an old kind of disease suddenly becomes treatment resistant and goes on a bit of a spree instead. If you wanted ideas for somewhere else, I'd be looking at places that do cheap, massive-scale meat production. (Also, viruses and bacteria get all the press, but there are other unpleasant things you can catch more and more easily these days. [Rat lungworm](https://en.wikipedia.org/wiki/Angiostrongylus_cantonensis), anyone?) [Answer] The reality is that landfills are not places we dump our trash and then leave alone (or maybe move around with machinery). * People live on landfills. Not just former/covered ones, but real live ones. * People scavenge there. * Children run around barefoot and play in piles of garbage. * People eat food they find in landfills. [![enter image description here](https://i.stack.imgur.com/afQ0A.png)](https://i.stack.imgur.com/afQ0A.png) ([People in garbage landfill. Mexico](https://www.flickr.com/photos/worldbank/2658284469)) [![enter image description here](https://i.stack.imgur.com/QxnKk.png)](https://i.stack.imgur.com/QxnKk.png) ([Cambodia children living in Garbage Dumps](https://www.flickr.com/photos/venetiajoubert/3325338790)) We already know there are [dangers to living within 5 kilometers of a landfill](https://www.sciencedaily.com/releases/2016/05/160524211817.htm). Hydrogen sulphide gas and other toxins. Toxins aren't "bugs" but they can lower your resistance. [Cancer and birth defect rates](https://www.atsdr.cdc.gov/hac/landfill/pdfs/landfill_2001_appc.pdf) go way up as well. So what about diseases caused by viruses or bacteria? Yes. Unfortunately. > > One of the most basic hygiene problems that haunt developing > communities is lack of adequate toilets...People defecate in the open — in fields, bushes and bodies of water — > putting themselves and their community in danger of fecal-oral > diseases, like hepatitis, cholera and dysentery. > > > Children are especially susceptible to these diseases when their home > and “playgrounds” are overrun with rubbish and human waste. In > countries throughout Asia, children can be seen swimming in polluted > stagnant waters, digging through trash and playing amid toxic > substances at landfills. > > > The pictures in [this PBS article](https://www.pbs.org/newshour/world/in-worlds-poorest-slums-landfills-and-polluted-rivers-become-a-childs-playground) are staggering. Landfills are vectors of disease and people who have no choice but to live on or next to them generally do not have safe toilets/sewage and their water supplies are usually contaminated as well. In some places, entire communities are garbage dumps and people are too poor to move or fight the influx of refuse. What are the chances that the next Superbug will come from a landfill? Quite possible. Once it spreads in the community living there, it can easily extend its reach beyond that. Combine a landfill with waste from something like factory farms, which use massive amounts of antibiotics (including in the rural 3rd world; most factory fish farms are in those places (Vietnam, for example) and they use tons of antibiotics and pesticides and more). It would be another post to describe how antibiotic use in animals leads to disease in humans but, suffice it to say, it's already happened. [Answer] Starfish Prime explained why the chance of superbugs developing in a landfill site are unlikely. However that does not mean that a landfill site could not play a significant part in the development of a superbug. If badly processed human or animal waste (e.g. from a hospital or farm) were being dumped into a poorly contained landfill site, such as a site where runoff was escaping into human water supplies, this could play a very significant part in the genesis of a superbug. While the bug actually developed on the farm or in the hospital, as an animal disease or drug resistant strain, the landfill acts as a launching ground releasing the bug to huge numbers of victims. [Answer] You could definitely make this the premise of a story. 1. Third world abandoned laboratory is cleaned up by new government. [![abandoned lab](https://i.stack.imgur.com/goyEU.jpg)](https://i.stack.imgur.com/goyEU.jpg) [source](http://desertedplaces.blogspot.com/2016/02/horror-labs-abandoned-anderlecht.html) 2. Bags of assorted mysterious stuff are sent to landfill with no processing or sterilization. 3. In landfill, bioengineered spores (anthrax? gangrene?) find new rodent hosts. 4. Landfill scavengers are exposed and bring disease back to favela. 5. It begins... [Answer] Did you know Mammoth tusks were found among illegal markets? Global warming is uncovering large swathes of Siberia, where innumerable pieces of animal carcasses are decomposing. All you need is for one of those fellas to get a bug. They usually don't have good hygiene. Ton of hands touching the same sample and you also must take into account that poor families statistically bear more children. So you have a possible source, a vulnerable population and the means to travel the globe as contraband. ]
[Question] [ I'm am developing a creature, what I want to create is a giant octopus that is able to utilize poison. I would like it to shoot it from its beak if the poison is in liquid form, or emit the poison through pores on its skin in a gaseous state. I have no specific method in mind for the poison to kill, just that it should be able to kill when it comes into contact with human skin, [Its absorbed by the skin into the body] and can kill in less than 20 minutes. How can the octopus survive the poison, with it being fatal to humans? [Answer] [![enter image description here](https://i.stack.imgur.com/Lgbch.jpg)](https://i.stack.imgur.com/Lgbch.jpg)The greater blue ringed octopus already has a potent [neurotoxin](https://bioweb.uwlax.edu/bio203/s2013/leinfeld_sier/toxin.htm) which can be fatal to humans. The octopus has the poison in its saliva, but it is also held in the skin of the mantle, so touching it is potentially fatal. [Answer] A jellyfish, [sea wasp](https://en.wikipedia.org/wiki/Chironex_fleckeri) has the potent poison to kill a human within minutes. It uses tiny darts. Your octopus can have the same method of poison delivery. [Answer] Virtually any chemical mixed with DMSO will absorb through the skin. Plus there are a lot of things that are already contact poisons. Wolfsbane for example has such a potent paralytic agent in its sap that merely picking it can be fatal. And if you don't worry about the details too much, anything that comes into contact with the eyes, nose, or mouth will do, or any abrasion of the skin. Spitting cobras target the eyes for example, and their venom will cause temporary blindness. There are a number of books written specifically to be mystery writers' quick-references to poisons that would help you pick what you are looking for by way of potency and effect. How the creature will survive the poison itself is a slightly more complicated subject, but the basics come down to two methods: Isolation and Immunity. Isolation means that the creature simply doesn't expose itself to the poison. Such creatures keep their stock of toxic chemicals in specific glands or physical structures, separated from the rest of the body by thick membranes. Among animal life, it's not uncommon for injected poisons to be harmless when eaten. (And sometimes vice-versa. A number of toxic compounds are actually activated by stomach acid.) Immunity means that the poisonous creature's body either recognizes and breaks down the toxin before it can do any damage, or simply works differently to the point where it has no effect. Jellyfish are unaffected by the neurotoxins they carry because they have no nervous system to speak of. Birds are immune to ingested cyanide because their digestive and respiratory systems are better segregated from each other. If your octopus has copper-based blood, and its toxin affects iron haemoglobin, then it will be unaffected. Or if its nervous system uses different signalling chemicals than a mammal's do, a poison that stops one might have no effect on the other. Monitor lizards have potent bacterial cultures on their teeth that are virulent enough to kill mammals within a few minutes, but to which the lizards are immune themselves; a similar setup with a creature that spits could be quite effective. Hopefully that's enough ideas to get you on the right track. Remember, you don't necessarily have to explain it in depth unless it becomes a major plot point. [Answer] The [batrachotoxins](https://en.wikipedia.org/wiki/Batrachotoxin) can be absorbed through human skin and are among "the most potent alkaloids known". [Answer] Your creature could use Fluorhydric acid as a poison. That acid can go through your skin quite easily, sometimes even before you can feel the acid is burning it. When inside your body, it will react with the calcium in your blood, and can cause a heart attack. All that just by contact. How your creature could survive it is another question I can't answer, but there are several organism that can resist to things that would kill humans such as very high/low temperature, cyanide, radiation etc.... so youe creature could probably do so with acid. [Answer] Pretty much any kind of poison you want. How the toxic octopus survives is really quite simple on any of the several avenues that you can take. Neurotoxin, haemotoxin, cytotoxin, targets an organ, etc, really, the choice is yours. It depends largely upon the action of the poison. Immunity boils down to: 1. the cellular or molecular structure of the thing to be or not be poisoned, 2. the metabolism of the thing to be or not be poisoned, 3. and the structure of the poison. Examples of immunity or lack thereof: 1. Chocolate is poisonous to dogs. 2. Aspirin is poisonous to cats. 3. Birds can't taste capsaicin (in hot chillis). 4. Fleat treatments don't kill pets if applied properly. 5. Stomach acid (normally) doesn't cause damage to the animal containing that stomach In the first two cases the animals lack enzymes to break down one or more chemicals which then travel to and damage organs (largely the kidneys). In large doses humans will suffer damage too but in typical doses our bodies can metabolise the chemicals before this happens. In the third, there is no cell in a bird that the capsaicin can bind to, but in humans we can easily and painfully sense it in our mouths, noses, eyes and anuses. The fourth is similar, mammal nerve cells aren't the right shape to be as badly affected as insects. The last is due to a protective stucture, notably a neutralizing mucus. Neurotoxins produced by animals are proteins, since animals are good at producing proteins, though plants and bacteria produce them too and there are nerve poisons that aren't proteins. Typically they act by binding to nerve cells. Nerve cells in one type of animal are often different to those in another type of animal. Cobra venom can't poison cobras because on a molecular scale cobra nerve cells are simply the wrong shape to be poisoned. The cobra nerve cell receptor is the same shape as in mammals but nearby the cobra has some other atoms that the big venom molecule can't fit past. Animal flea treatments are neurotoxins but insect nerve cells are different to mammal nerve cells. Your dog isn't killed by having flea poison dropped onto the back of his neck because he, like you, is much less sensitive to the poison than are insects but if he got all that in his mouth it would be dangerous. Poison dart frogs eat, what is to us and most of their predators, deadly poisons. But their nerve cells are simply not the right structure to be affected and the frogs accumulate this poison to deter predation. Similarly, many herbicides have no notable effect on animals but others do, like, Agent Orange. The cell structure of animals and plants are different. If you wanted, the toxic agent could result from a breakdown of one chemical into others. Chemical A isn't poisonous to octopus but in humans it breaks down over time into chemicals B and C, one of which is toxic. Just throw on a cyanide group (they're common) that is released when it's metabolised. Haemotoxins work by an enzyme (often several) attacking proteins, proteins being a huge part of the human body (and all animals). Snakes, such as most vipers, produce haemotoxins that lead to loss of blood clotting, destruction of tissue around the wound (necrosis), a lot of pain, dissolution of internal organs. These venoms need to enter the bloodstream or otherwise make it into the internal organs. Skin, hair and nails simply aren't affected, or are affected only slowly, even through they are made of proteins. When a snake eats another snake, any poison organ is eaten intact and any haemotoxin is destroyed during digestion. To avoid these effects the toxic creature would have to produce a neutralizing agent (and some snakes have been observed to produce antivenom), isolate it (with resistant cells), or simply not contain a protein that could be affected by the enzymes (the enzyme can't attack that shape of protein). For example, the enzymes in snake venom that destroy tissue protein are also proteins, but the enzymes are shaped to attack other proteins, not themselves. Chemotherapy is tailored so that the toxins used preferentially kill cancerous cells (well, it preferentially targets dividing cells, healthy or cancerous, but it relies on cancerous cells doing that more often). ]
[Question] [ Is it possible to directly convert radioactivity to turn it into electricity? If yes, then what is the conversion rate? [Answer] Strictly speaking "radiation" ‚Äî i.e. the result of radioactivity ‚Äî is not just one thing. There are (most commonly) the following types or radiation that can be the result of radioactivity and that we care about in this context: * [Alpha radiation](https://en.wikipedia.org/wiki/Alpha_particle) (helium atom nucleus) * [Neutron radiation](https://en.wikipedia.org/wiki/Neutron_radiation) (neutrons) * [Beta radiation](https://en.wikipedia.org/wiki/Beta_particle) (electrons) * [Gamma radiation](https://en.wikipedia.org/wiki/Gamma_ray) (photons) The word harvest really isn't appropriate either, harness works better. A thermoelectric generator would count as direct, as well as any other form of "EM radiation to electricity" tech. Lots of different things are radioactive in different ways. The reason we design fission reactors the way we do is because they are the most efficient way of getting electricity/power from the substances. (e.g. use heat to make steam, use steam for mechanical power, power into electricity.) "Directly harvesting" the energy of the various forms of nuclear radiation is going to be terribly inefficient, meaning you will need a lot more of it. That means all the stuff you aren't harvesting will kill everything in the general vicinity. Neutrons are notoriously hard to control, and very dangerous when zipping around at the energies seen in fission reactions. Gammas aren't much fun either. [Answer] Possible, yes. Practical, no - unless the definition of direct conversion is expansive. Given your question, I have to assume that any process that converts heat to electricity with steam turbines does not count. Others have suggested RTG devices are direct. I would not and suspect you would not in that this is simply another form of heat engine. What are the possible products of radioactive decay. Alpha particles, beta particles, gamma rays, neutrinos, neutrons. Occasionally you can also have spontaneous fission or cluster decay. Neutrinos are useless because they interact so weakly with other matter. Gamma are photons, typically on the order of 100 keV, though this varies widely. As photons, they can be converted directly to electricity via the photoelectric effect. However, they are not well suited for standard photoelectric panels. Blue light has an energy of about 3 eV, typically gamma decay is over 1000 times as energetic, at best efficiency would be less than 0.1 percent, more likely less than 0.001 percent when using a standard cell. Given that the photoelectric effective is a matter of knocking electrons loose, there will be no alternative material that result in efficient photo-voltaic cells that operate at low voltage. High voltage photo cells might be possible, but would certainly require a great deal of engineering to become practical and efficient. As the only use for high voltage cells would be for capturing gamma decay, such research will not be useful in general. The thickness of the nuclear material would be a directly negative efficiency effect - as discussed later. Particle emissions can be classified as charged particles or uncharged particles. Uncharged particles are essentially very tiny bullets. Now imagine running an electric generator based on getting hit by tiny bullets fired more or less at random in every direction. Neutral particles are at best extremely difficult to turn directly into electricity as this would require capturing the kinetic directly in some fashion in order to direct conversion. Charged particles have a little better possible outcome. Say you have a source that consistently emits electrons, you could have a copper target collect these particles, thus supplying electric current. Efficiency would still be horrible (much less than 1%) as you don't directly capture the kinetic energy of the beta particle, nor the associated radioactive products, e.g., gamma decay. There is one additional effect that could be direct. Set up photocells to capture the blue glow associated with Cherenkov radiation. Efficiency is very much less than 1%. Whether this is direct conversion is arguable. For a large-scale practical energy source, you really need to be based on Th-232, U-235 or U-238 or K-40 as these are the only long-term radioisotopes in abundance on this planet. K-40 is a very poor choice since it not fissile or fertile, beta decay is far less energetic than fission. As a beta emitter, it cannot trigger chain reactions, so the power density is very very poor. U-235 is likewise a poor choice due to it relative lack of abundance, but since it is the only naturally occurring fissile isotope in any abundance, it is quite attractive from that viewpoint. What the attractive isotopes all have in common is that they are fissile or fertile and can thus participate in chain reactions necessary for high power density. The difficulty of direct conversion to electricity explains why every system is based on driving a heat engine. Efficiency is relatively high and the heat engine was already well understood at the beginning of the nuclear age. One additional complication on the direct methods. Unless you nuclear material is extremely thin - atomic scale - the radiation is very likely to interact with the rest of the nuclear material, terminating the chance to capture the free electron, gamma particle etc. as it get converted mostly into heat within the nuclear material itself. [Answer] Yes, you just need one of these: [![Blue solar cell](https://i.stack.imgur.com/Yn9f6.png)](https://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Solar_cell.png/290px-Solar_cell.png) That's a picture of a solar cell, which does a phenomenal job of converting radiation from the sun into electricity. Specifically, it converts incoming electromagnetic radiation into electricity. While solar cells are designed specifically for the radiation given off by the sun, similar technology could be used to harvest energy from other radiation sources. Conversion rate, of course, will depend on the type of radiation you are harvesting. EM radiation matching the optimal frequencies of the photovoltaic array will have conversion rates approaching 50%, while something that gives off a large amount of beta particles will need a different approach altogether. [Answer] # Yes! (Though they're not very efficient yet.) Here's a [recent review paper](https://arxiv.org/ftp/arxiv/papers/1511/1511.07427.pdf) on 'non-thermal conversion nuclear batteries', which aim to directly convert ionizing radiation into electric power. Accordingly, present conversion efficiency in lab is about 2%, but this paper says numbers as high as 10% are hopefully feasible. In the case of Sr90, this 10% efficiency would work out to roughly 70mW/g of fissile material, making the whole assembly roughly on par with alkaline batteries (double As) in terms of power per weight. The paper claims that nuclear batteries will last much longer than traditional batteries and wind up saving money because they won't need replacing. This concept isn't new. An old colleague told me about a project from back in the 60s trying to accomplish the same thing. We're further along now, but not yet by leaps and bounds. Regardless, long-lasting nuclear batteries could make for a great mechanic in a near future story. [Answer] Use a [Fission fragment reactor](https://en.wikipedia.org/wiki/Fission_fragment_reactor). > > ... a fission fragment reactor is a nuclear reactor that generates electricity by decelerating an ion beam of fission byproducts instead of using nuclear reactions to generate heat. By doing so, it bypasses the Carnot cycle and can achieve efficiencies of up to 90% instead of 40-45% attainable by efficient turbine-driven thermal reactors.The fission fragment ion beam would be passed through a magnetohydrodynamic generator to produce electricity. > > > It can also double as a high ISp rocket, by using the beam itself as the reaction mass. [Answer] Well, [beta radiation](https://en.wikipedia.org/wiki/Beta_decay) is electrons blasted away at high energy. That leaves the material with a positive charge, and the electrons might interact with other material in an electric manner. In fact, that's used by smoke alarms, in some sense. If "electricity" means using a difference in potential to cause a current to flow through a load, then generating a separation of charges — quite directly — certainly counts. [Answer] I think what he's asking is whether or not the increase in entropy when an atom (an atom's nucleus) goes to the ground state can be somehow used to create an electric field ‚Äî voila, a direct electricity source. In practical terms, it means little to no heat (minus any heat generated by resistance present in conducting materials). If such a thing could be discovered, the end of our energy needs would be near. [Answer] This is practical for low current/power inaccessible applications -- think like a CR2032 before we had lithium coin cells, in a place where you can't just up and change the battery. The technique used is betavoltaics, using a beta emitter (such as a tritium capsule or sealed-in potassium-40 layer) impinging upon silicon solar arrays. The voltages and currents involved are rather low (few hundred microwatts to a few milliwatts of power depending on the size), but are predictable over the long term due to the decade+ half-life of tritium, or the far longer half life of say potassium-40. [Answer] Yes, but only for some types of radiation and it requires a large device. At least, there is if this idea from the Farnsworth Fusor hobbyists is correct: If you have a source of high-energy charged particles (for Fusors, the fusion reaction; for you, alpha or beta sources), you can slow them down in an electric field. Tune the electric field to only just stop the charged particles, you can efficiently extract the radiation current at the voltage you needed to halt the radiation (this requires near-constant emission energy, which further limits which sources of radiation you can use). Given typical radiation energies and the 3MV/m threshold at which air stops being an insulator, there is quite a large minimum size for such a system, regardless of how little power you want. [Answer] [RTGs](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) (as mentioned by Nicky) can use [thermocouples](https://en.wikipedia.org/wiki/Thermocouple). Radioactive decay generates heat, heat is turned into electrical power. The efficiency is low but the endurance is high. [Answer] Yes, but you get a lot of voltage but an extremely tiny current. Take a wire, coat one end with something that undergoes beta decay. Coat the other with something that undergoes alpha decay. You need twice as many becquerels of the beta emitter as the alpha emitter. This works but making it useful is another matter... [Answer] Possible with currently known processes? No. Possible at all? Maybe, just depends on there being something we currently don't know about. Reflect that an astonishing amount of power generation happens through the electromagnetic induction process discovered in 1831. Most of the advances made since have basically been better/different ways of moving a magnet through a coil, or a coil around a magnet. Incidentally, thermocoupling effects were discovered in 1821, and photovoltaics were discovered in 1839. A breakthrough in the field really would be exactly that. Removal of the processes of heat transfer and turbines would dramatically reduce the energy loss and space needed. [Answer] <https://www.google.com/amp/s/www.newscientist.com/article/dn13545-nanomaterial-turns-radiation-directly-into-electricity/amp/> Suggests that, with proper application of key materials, a single particle can trigger the flow of many times more electrons from the substrate. Research will lead to many, great, improvements. [Answer] You can easily build such a generator from a material that produces alpha radiation: Alpha radiation means that the material spews out double positive helium ions. These ions have very high kinetic energies, usually in the range of several MeV (Mega-Electron-Volt). And most radiators have a very specific energy at which they radiate. So, all alpha-particles emitted from material A may have an energy of 2.7MeV, while all alpha-particles from material B have a punch of 4MeV. This is perfect for your generator. Because, if an alpha particle (doubly charged!) leaves an electric conductor at 4MeV traveling towards another conductor with an electrostatic charge of 2MV (Mega-Volts!), it will have lost all its kinetic energy to the electric field. --- Thus, all you need to do is: Place a thin sheet of the right radioactive material between two metal plates, evacuate the space in between, and convert down the resulting 2MV electrical power to some usable voltage. The entire assembly will act pretty much like a 2MV battery, which will reduce in voltage a bit as you draw some current from it. The most complex part will be the power converter. Obviously, the 2MV electric potential puts a lower limit on the size of the entire assembly: If you make it too small, all you get is sparks... [Answer] The only way we are able to create "electricity" is rotating a "permanent magnet" in a cylindrical shaped copper coil. The mechanical energy needed to rotation is provided by potential/kinetic/ and mostly heat engines. Unfortunately heat engines have low efficiency, say 30%... Tranforming voltage up and down for distribution + electrical resistance and capacitance of electrical network "confiscate" huge amount of electricity...So where is the way out? Meanwhile electricity is not "energy". We are not able to store it direcly. It is "work" in a physical sense. Just consider the simplest situation: We are rotating a generator by means of a mill-wheel. The electric motor coupled with generator will transmit the mechanical energy to the machinery...So, What kind of energy is doing the job? ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 5 months ago. * This question does not appear to be about worldbuilding, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). * You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). The community reviewed whether to reopen this question 5 months ago and left it closed: > > Opinion-based Update the question so it can be answered with facts and citations by [editing this post](/posts/248771/edit). > > > [Improve this question](/posts/248771/edit) I have a concept for a story (see below) and a rough idea of what some of the characters will do to create the central plot point in it (again, see below), the issue is, I'm not sure what point in time, in real life history, it would be plausible for them to do those things. (Technically I'm not world building here but rather world choosing.) Tl;dr; > > A young couple (15-16 but able to look a bit older, or maybe up to early 20's if it makes the story work) choose to vanish on basically no notice. They have no prior planning for this and have to wing things until they figure stuff out. Eventually they establish new identities and are able to live a mostly normal life. They may need to avoid scrutiny but over time they build up enough real background to their assumed identities that they can do most everything that would draw attention to them if they didn't do it. (There may be things, e.g. working in sensitive jobs) they can't do, but by simply never trying, they is an issue that can go unnoticed. > > > Everything about what these characters do, beyond what I've already settled on and described above, is outside the scope of the question I'm asking. In fact, it's almost immaterial to the story because the story is a whydonit and will be from the perspective of the people who start out knowing only that the couple vanished and nothing that happened after that. That they do it is the only major plot relevant bit and I just need it to be not blatantly implausible. ## Question: Assuming this happens in the US (or some other currently first world nation), what is the approximate last point in time where it would be feasible for smart and motivated people to pull the above off with no prior planning or research? What happens at that point that makes it unreasonable? --- There is a real world story of a WW-2 German POW in the US who didn't want to get repatriated to east Germany and so (after the war in Europe was over) escaped and succeeded at living a mostly normal life in the US for decades. That would suggest that c. 1944 would be not to recently. On the other end, by the information age, it would seem that just showing up and saying you are "Johnathan Dow" would very quickly fall apart without significant skill and resources put into fabricating records in a lot of different places. That would suggest c 2000 would likely be to recently. On the 3rd hand, even today there are a large number of people who have illegally immigrated to the US and have no identity they can use for most things. So depending on how much they need to do (I'm thinking my cases requires to much here), you may still be able to create a "good enough" assumed identity. Edit: turns out at least some effort is being made to [proactively seek out assumed identities without waiting for other indicators](https://www.schneier.com/blog/archives/2023/08/identity-theft-from-1965-uncovered-through-face-recognition.html). [Answer] This is very much dependent on the country in question. Some rely on birth certificates and (optionally, inconsistently) on driver's licenses and utility bills with a name on it. Others have a system attempting to track citizens from cradle to grave, unregistering them in the old place of residence as they register in a new one. Most countries which attempt a registry also have significant groups of unregistered inhabitants, both citizens and non-citizens. Countries which do not attempt a registry have similar groups of inhabitants, except that unregistered becomes the wrong word for them. You specify the lack of prior planning and research. That means the challenge becomes twofold: * Get 'off the radar' initially. Try to hang out with homeless citizens or undocumented migrants. Earn money with off-the-books work. Make plans and contacts for a more permanent solution. * Establish the fake identity rather than no identity. If this is supposed to hold for decades, it has to be rather solid. This may be easier in the US than in Europe, and much will depend on the ethnic background of the fugitives. This is presumably what you call 'hard.' For European-style citizen tracking, the point is not so much the development of technology and bureaucracy but getting the right moment. After WWII, much was possible. Again, after the fall of the Iron Curtain. These times had mass movements of people, and claiming to have lost all papers would bring scrutiny but not outright disbelief. During the Cold War, pretending to have fled frome one side to the other. --- Follow-up, and this is a bit going out on a limb since I have absolutely no experience of going underground ... They could try to invent an identity from scratch, or they could steal the identity of someone who did or does exist. * An identity "from scratch" will be revealed if somebody compares the claims with files held elsewhere, like the municipal vital records or the tax assessments. The trick, then, would be to prevent anybody from looking things up. * An identity stolen from a living person would pass those simple checks, but it will be found out once somebody (again, like the tax office) correlates things. Why does this person work in two places, hundreds of miles apart? * An identity stolen from a dead person has no such inconsistencies, but it will be found if someone compares living taxpayers and the tombstones, or if someone tries e.g. a DNA match with a supposed relative. It does a state no good if one office holds a paper file of a birth certificate, another office holds a paper file of a death record, and yet another office holds the (digital?) file of ongoing income taxes. When one checks for tax frauds, the suspicion is usually not that the taxpayer is wrong. The question for the third bullet point would be when the various countries started to reconcile those records routinely. As one data point, there was the [Nazi use of IBM computers](https://en.wikipedia.org/wiki/Dehomag) in the 1930s and 1940s to categorize citizens and to organize the holocaust, but there a state decided to expend significant effort. You could have a situation where a fake identity did hold up for a decade or so, only to be found once one more office got their records computerized. So, untested idea: Hide out among homeless drug addicts. Try to learn the full name, birthplace, and relatives or lack of relatives of some who did run away only after turning 18. When one of them overdoses, make the body disappear (how? there are crime author how-to references). Once they have two likely data sets, move into a faraway town and pretend to be drug addicts who really, truly want to become clean. Attend local support groups. After a couple of months, ask for help in getting fresh papers, and in finding a job. [Answer] The answer depends on too many factors So, middle of nowhere, working Cash-only jobs, camping in the woods and purchasing what you need with Cash - Still very much possible. However, the closer you get in proximity (both literally and philosophically) to 'Civilization' - the harder it becomes. The biggest one is the IRS/IRD/Tax Office - If there's one thing that Governments don't like - it's untaxed income. This is the first bit of Paper in your Paper trail. If you look up the practice of 'Ghosting' (the identity theft one, not the social media one) - it mentions that up until the 1990s in the US, when Births and Deaths were maintained in separate registries and before digitization, were not able to be easily cross-referenced. Add in that a Social Security number wasn't issued until the first paid job - Most sources say that this was still very doable until the late 1900s. The next item you'll need is a valid Birth Certificate. However, like most things - once you have the first link in the chain - that is, the first official piece of documentation, everything usually flows from there. Consider a child opening their first bank account - they will normally need their IRD/Social Security number and their Birth certificate. Maybe proof of parents address. Once you have a Birth Cert and a SSN, you can get a Drivers licence/Government/state photo ID, this will allow you to do most things - Rent a house, get Credit etc. In short - I think the most realistic answer with what I think your intent is - would be around the 1980s/1990s with enough smarts. Earlier would be easier, later is still possible - but harder. [Answer] Go rural, take cash jobs and live under the radar. Lots of people doing it right now. No one including the authorities cares. It's only once you live in a town or city that people need to know more about you than how hard you work and if you're a danger to those around you or not. Or join a commune or minority community. The key part is that someone else does all the bill paying, renting and buying of anything requiring ID. As a forestry worker in New Zealand, I openly travelled all over the country without needing ID. I got pulled over by rural police a few times, but they just wanted to know why there was a new face around, and where I was staying, they had no interest in making any trouble for me and paperwork for themselves, just keeping tabs on their community. I wasn't doing anything illegal. But mostly I'd be living on a farm or forestry camp for a couple of seasons where no one cared or even asked questions about my history. I worked for months at a time with people who I only knew by whatever first name they gave me. A couple of them moved around like me and I worked intermittently with them for years when we met up in the same forest for a season. I thought of them as friends yet wouldn't have a clue what their surnames are or anything really outside forestry life. [Answer] Probably around the time that the fax machine/the internet came about. It would suddenly be a lot easier to verify documentation, and a lot harder to fake it, if they could just call the country of origin, send over a copy of it, and have them check. > > On the other end, by the information age, it would seem that just showing up and saying you are "Johnathan Dow" would very quickly fall apart without significant skill and resources put into fabricating records in a lot of different places. That would suggest c 2000 would likely be to recently > > > Only if you randomly show up at a place. There are still [places](https://www.austrac.gov.au/business/core-guidance/customer-identification-and-verification/assisting-customers-who-dont-have-standard-forms-identification) that assist people in getting an identity if they lose their documents due to fire, or were born to parents who did not register their birth, as an example Logically, it is still possible to fake an identity through that. Fake IDs are still fairly common([2](https://www.bbc.com/news/magazine-21976718),[3](https://www.leaderlive.co.uk/news/23323754.police-send-warning-following-rise-use-fake-ids-north-wales/),[4](https://www.smh.com.au/technology/fake-id-sites-under-investigation-20130116-2csw3.html)), and for the most part, you can use that as the basis of a new identity. With the exception of regulated businesses, most aren't going to check (except by keeping one on record), and the only issue is making sure that your fake ID card holds up to scrutiny. Things like banks would be a no-go, due to [identity verification requirements](https://www.gov.uk/guidance/money-laundering-regulations-your-responsibilities) so they would have to find another avenue of dealing with money, such as cash. One big issue that they might run into is that of anti-fraud/anti-laundering regulation, which inadvertently prevents them from using a false identification, by needing things like government records to prove that they are who they are. A passport would be outright unobtainable under a false identity, despite being a major (and common) identification document. If they went through illegal means, there are also stolen identities that tend to crop up on the black market([6](https://www.abc.net.au/news/2022-11-28/cyber-black-market-shows-medibank-optus-hack-just-the-surface/101700974),[7](https://theconversation.com/heres-how-much-your-personal-information-is-worth-to-cybercriminals-and-what-they-do-with-it-158934),[8](https://qz.com/460482/heres-what-your-stolen-identity-goes-for-on-the-internets-black-market),[9](https://www.trendmicro.com/vinfo/us/security/special-report/cybercriminal-underground-economy-series/global-black-market-for-stolen-data/)), from data breaches and things, which might make it an easier task. [Answer] Assuming the United States, I would say that the cutoff is the proliferation of Information-Age technologies to a critical mass in public records and government communications, which hit its stride in the early 80s and was largely complete by the mid-90s. In the 70s, communication and data access networks were still relatively primitive; the computer did exist, but most communication of information still happened by postal mail or, if you had to know something right now, dictated over telephone. Literal "stock tickers" were basically specialized TeleType machines, and much like the more general-purpose ones used for newswires they were expensive and not very portable. Fax machines running over the telephone network were just starting to proliferate as a viable technology, and the ARPANET predecessor to the modern Internet connected a very few DoD installations and their affiliated research teams at select universities, mostly as a proof of concept. The upshot is that anyone wanting to check your backstory had to spend hours on the phone/radio with people who had way more important things to do than spend hours to locate and vouch for the existence of the office record matching your documentation. So, if your ID looked real, it was real, unless you acted suspiciously or belligerently enough to make it worth a guard's or police officer's considerable time and effort to verify the information in detail. On that note, this is what actual, valid driver's licenses looked like in most states as of the late 80s: [![enter image description here](https://i.stack.imgur.com/NTRzl.png)](https://i.stack.imgur.com/NTRzl.png) [![enter image description here](https://i.stack.imgur.com/TaT0y.png)](https://i.stack.imgur.com/TaT0y.png) Given tools available from any mail-order office supplier, you could forge identifying documents that would pass even the most rigorous visual inspection. If you had the ability to develop film photos in passport size and color, print or stencil a box form and type the information into it, then combine these elements in a hard-laminated card, you were pretty much made. While these skills and equipment weren't universal, they were easy enough to acquire. It wasn't really until the late 90s that serious attention began to be paid to anti-counterfeiting features of currency and IDs, combatting the introduction of cheap inkjet printers and desktop productivity software that made printing off your own driver's license truly trivial. Now, all that said, we're still talking about the Cold War era here. The newsreels of the 60s and early 70s, depicting a very laissez-faire society of peace, love and rock and roll, where people just... get along, are the stereotype. Among the young, that may have been true, but the "peace movement" was the counterculture movement of the time, for good reason. McCarthy may have died a few years after his witch trials resulted in his censure by the Senate, but the U.S. Government, at all levels and both officially and unofficially, were still very interested in finding Russian spies, like maybe the ones trying to worm their way quietly onto the factory floor at Lockheed, Rockwell, GenElec or some other defense contractor as a newly-minted union-backed laborer. You also have to remember the First Amendment didn't have the case law protections it does now; Alberts v. California (landmark case upholding that profanity and obscenity are protected under the First Amendment) was decided in 1957, and it was not well-received by your more conservative types in Middle America. So, a young man and his new bride striking out on their own in a new city, with names and identities that happen to be a complete fabrication, isn't all that suspicious up through about the 1970s, until it became trivial to call in a driver's license to dispatch to validate it (which roughly followed the spread of 911 and the creation of integrated call centers with easy access to all public records). Unless, the young man has an interest in getting a union job at a military-industrial contractor's new factory there, or starts shooting his mouth off about how Medicaid doesn't go far enough and we really should have something like the National Health (the idea was shouted down as a Communist plot in the Truman Administration, while we were watching the UK, our closest ally in NATO, setting theirs up about this same time). Such actions or ideas will put a spotlight on your couple's backstory, and if even one thing they say about themselves or their history can be proven false, the whole thing unravels. [Answer] I can only describe what it would take in the US. Back in the 80's and 90's, if you wanted to make a black-bag identity, all you had to do was wander around a graveyard and look for a tombstone for someone who was born 100 years before you. Go to the local courthouse, tell them that he was your grandfather, and ask for a copy of his birth certificate. They weren't as security-conscious back then, so 75% of the time they'd just give it to you, and the other 25%, you just went to another county and tried again. You then change the "1867" birth date to "1967", and used your new birth certificate to get a driver's license. From there, you could have an SSN issued, get credit cards, and build a history. This changed in the late 1990's when everything began to get connected via computer. You could still do it in some rural areas where they didn't have enough need for computer automation. All of that went away after 9/11/2001. After that, everyone started getting really cagey about cross-referencing identities. The federal government locked down everyone's identities and the NSA was given free reign to profile everybody. Now it takes time, effort, and preparation (or government contacts) to build an effective identity. If you don't need to build an identity, then you can still get by as a homeless day-laborer. There are people in almost every state who, if you look grubby enough, will feed you and work to get you "back on your feet." If you're young enough, you can claim to be the son of someone who didn't bother documenting your existence, and then got wiped out in choose-your-own natural disaster. The way to go in most cities would be to get super-filthy, abrade yourself, catch a nice, solid cold, then pass out in public on a bad weather day. The police will call an ambulance, and the hospital will create an identity for you so they know who to charge. [Answer] # Up to 1914, or 1937 with limitations, this was legal. It got progressively harder during this time, and absolutely impossible without criminality after. Prior to the 20th century, personal documentation, all around the world, was not the norm. Passports did exist, but weren't required. People could simply travel to another country like they do to another city. Your name and identity was whatever you decided to call yourself. This right was not absolute. The authorities of a receiving state had the discretion to allow or restrict travelers. Some nations had stricter rules than others. Not all countries were open. The key thing is, while paperwork was very useful, it wasn't strictly necessary to have it in a specific form. Standardized international passports were [created in 1920](https://en.wikipedia.org/wiki/Passport). Internal national IDs followed passports. Everything changed with World War I. Before WWI, travel was mostly restricted by your means of transportation. Paperwork wasn't necessary, everything worked without it. Nationality and citizenship were a thing, but not a big deal. You could be stateless and no one would care - almost all of the world's goods, services, destinations stayed open to you. The worldwide practice of state-managed identities emerged during WWI due to the fear of infiltration by foreign spies. Still, for 20 more years, it remained possible, but difficult to obtain a new identity. WWII, which really started with the Spanish Civil War, completely ended the freedom of undocumented life. National IDs became mandatory and life opportunities without one very limited. This refers to legal identities. Creating a new illegal identity is possible even today, and will remain possible for the foreseeable future - all that changes is the price. Literally "everyone who is anyone" can get one in case of emergency, and I know people that already have. Not even criminals. It might be difficult, but that's the contractor's problem. Why international travel matters: there is limited information exchange between nations, so crossing borders is an important step in establishing a valid new identity. It's not necessary, but it can eliminate the issue of a lacking paper trail. [Answer] From personal experience, in the UK it got difficult following the events of, and reaction to 9/11 (I had inadvertently set up such an identity and now live in a shadowy world where I can't prove I am who I was, or who I became) ]
[Question] [ In my book series, the Ishga Empire has a monopoly on technology that we would say ranges from an industrial revolution to sci-fi level, although their military tech capabilities for the sake of this question would probably be equal to Britain around the time of WW2. However, their technology is a very closely-guarded secret, with other nations' military tech ranging from just figuring out bronze to what we would probably call early Renaissance (derpy muskets and cannons but no rifles). As a result, the Ishga military is a small, standing army made for the primary purpose of bullying larger but technologically vastly inferior forces into submission to extort land for colonies and "unequal treaties" out of foreign lands, not too dissimilar to what Britain did in the Opium Wars. What would such an army most likely look like in terms of armor and gear since they don't have to compete with anyone who could realistically beat them in open battle? [Answer] ## "Amateurs talk tactics, professionals talk logistics" A tank without fuel is a pillbox, probably in the wrong place, and a rifle without bullets is a badly balanced club. But they are operating in a very austere theater, as far as logistics go. Perhaps some of the enemies have decent Roman-style roads, perhaps not. That is more a question of social organization than a question of technology. There won't be workshops to repair a broken crankshaft, every drop of fuel will have to be carried in, etc. Air Force * Despite what I wrote about logistics challences, the air force will be important. Most of it will be what was called [army cooperation planes](https://en.wikipedia.org/wiki/Army_cooperation_aircraft) at the time, armed for ground attack but optimized for simple airfields. Almost as important are Grashopper-style [liaison aircraft](https://en.wikipedia.org/wiki/Liaison_aircraft). Some of them might be fitted with floats, or skis. No helicopters, or perhaps a very few for very special roles. Helicopters eat too much fuel and break down too often. * A relatively large number of seaplanes or amphibians, like the [Catalina](https://en.wikipedia.org/wiki/Consolidated_PBY_Catalina). Or perhaps seaplanes with beaching gear (wheels to roll up the beach, not wheels for a ground landing). Some of these could be optimized for long range, like the [H8K](https://en.wikipedia.org/wiki/Kawanishi_H8K). (As you can see in the comments, there was a suggestion for landplane transports. Possibly. Landplanes tend to be superior if there are enough high-quality airfields. My suggestion was for seaplanes because there are not all that many bulldozers in the army. Can they draft ten thousand peasants with shovels instead?) * A few aircraft might be very-long-range bombers and recon planes. They would count on being unopposed, so speed and defensive armament do not matter. Photo mapping from high altitude, daylight bombing from low altitude. * Finally, perhaps a few interceptor squadrons to defend the capital against captured or rebellious air units. If they think of it, and if there is the R&D to do something better than the army cooperation planes mentioned above. That's a big if -- I'm writing from hindsight, knowing types that were not developed in isolation. Navy * Most of the combat ships will be updated versions of an 1870s-style [gunboat or corvette](https://en.wikipedia.org/wiki/Calypso-class_corvette). Sails and auxiliary steam engines (coal and/or oil, but probably coal). 12 knots under steam is more than enough, plus sails for long-range cruising. A few smallish naval quick-firers, plus secondary autocannon and MG. Mostly unarmored, these ships try to stay out of the enemy firing range. A good question if they use modern steel hulls or wood. How prevalent are shipworm and fouling in your world? * Even more sailing transports with auxiliary engines. Less speed, fewer and smaller weapons and crew, more cargo. Perhaps a few pure steamers for express delivery of critical supplies. A lot of ships bringing coal to various coaling bases. Read about the run-up to the [Battle of Tsushima](https://en.wikipedia.org/wiki/Battle_of_Tsushima#Departure_of_the_Second_Pacific_Squadron) -- the Russians are often painted as incompetent, but look at their awesome efforts to even get there and be sunk. * A few armored cruisers, to run down captured/rebelling gunboats and to provide naval gunfire to opposed landings. Against anything else they are overkill, and there will be few opportunities to use them. * Plenty of riverine forces. Gunboats like the [Fly-class](https://en.wikipedia.org/wiki/Fly-class_gunboat), smaller patrol boats, lots of transports. Again a few armored river monitors. They might have to fight their way past enemy fortifications, with no time to batter them down with long-range bombardment. * Cruisers and even gunboats might have catapult-launched floatplanes. They could be valuable for scouting. Also in the early hours of a landing, but that is a niche requirement. Army Almost everybody walks or rides horses (or horse-drawn wagons). There won't be roads for trucks in most places, and little need for tanks. The horse riders will be [mounted infantry](https://en.wikipedia.org/wiki/Mounted_infantry#19th_century) or dragoons, not true cavalry. Usually they do not fight on their horses. * The infantry and mounted infantry units get reinforced by armored cars. Light armored cars are armored against muskets, heavy crossbows, and the like, and carry water-cooled MGs with plenty of ammo. Heavy armored cars "should" resist a 3-lbr. or 6-lbr. field gun, and they are armed with light cannon (gun-mortars?) in addition to MGs. Armored cars, especially the lighter ones, might come with horse- or ox-drawn wagons for long distance transport. Those wagons can be repaired in a village smithy, unlike the armored cars. * More MGs will be carried on pack animals, organic to both infantry and mounted infantry. * There might or might not be jeep-style unarmored cars with MGs. If you go all the trouble to bring a vehicle, why not go the whole way and make it an armored car? * Artillery are mostly [mountain guns](https://en.wikipedia.org/wiki/Mountain_gun) or mortars on pack animals, with a few heavier horse-drawn pieces. Think hard if there are any anti-tank guns in the mix -- ground forces might be captured, and a horse-drawn gun is easier to learn than one of the heavy armored cars. * Troops are armed with either bolt-action rifles or rifles similar to the [FN FAL/L1A1](https://en.wikipedia.org/wiki/L1A1_Self-Loading_Rifle). A magazine is a good idea in either case, and the rifle may or may not have optional automatic fire in addition to semi-automatic fire. (How often should they use spray and pray, and how many situations where it is tempting but wrong?) If automatic fire is not taken, then consider a rugged bolt-action design instead. It could be "something like 5.56mm" or "something like 7.62mm" or something in between. With aimed single fire, a magazine full of 7.62mm goes a long way, and it might be compatible with the MGs. But perhaps the light armored cars can be built to resist 5.56mm, and small infantry patrols could be ambushed and looted. (There was a suggestion in the comments to use charger clips instead of magazines. Maybe, if the choice is a bolt-action. But I don't think the logistics savings are all that great.) Railways Once they have control of an area, will they push strategic railways? If so, they will need forces to patrol them. Armed trains? Armored trains? Fit armored cars with railway wheels, to simplify the spare part supply? COIN Assuming they win any field battle, how can they win the peace? MP, Civil Affairs, PsyOp, ... WMD Depending on their morals (and desperation), they might go for poison gas, either dropped from aircraft or fired by mortars. Many of their technical edges will be lost of they have to storm a city, so gas could be the quick and dirty solution. Something non-persistent. [Answer] [![enter image description here](https://i.stack.imgur.com/cnUfI.jpg)](https://i.stack.imgur.com/cnUfI.jpg) In real life, airships were not very useful in war because they are too vulnerable to enemy fire. But if your enemies have no way to shoot at them, then this problem disappears and they become powerful assets. An airship is cheaper to keep in the air than fixed wing aircraft, and can stay stationary in the sky for very long periods of time. They make perfect observation posts. They can transport things, such as troops, anywhere in enemy territory. They can bomb enemy settlements at will. You can put a team of snipers into one. Or drop poison gas. The list goes on. Their visibility can be an asset as well. When not running missions, they can simply float above the enemy capital, to give your diplomats some extra leverage during negotiations. [Answer] Death from Above WWII level tech makes it a vastly unfair fight. The enemy can't fly but you can which means you can hit them anywhere and anytime and there isn't a damn thing they can do about it. On the sea, simple gunboats will eat alive wooden sailing ships. Your artillery can hit them before they can even see you so their cannons are useless. Toss in some tanks and machine guns and they won't stand a chance. For the final cherry on top, sniper rifles will take out their officers. [![enter image description here](https://i.stack.imgur.com/Nzeqk.png)](https://i.stack.imgur.com/Nzeqk.png) If you want secret attack forces, you bomb them at night from high up, subs sink their ships and snipers kill the officers from such a distance, nobody can ever find the shooter. [Answer] While some answers are simple like "just mow them down with machineguns!" There are some important considerations to be made for your army. * keeping your tech secret and out of their hands. * once you leave your territory you have limited access to repair and maintenance facilities, especially if you dont want any of the tech in enemy hands. * your army is small, receiving losses is a bigger blow to you. This limits the way you want to fight. It would be easy to send out small squads with machineguns to destroy entire enemy battlegroups, but that brings immense risks. A musket-tech army that captures one such weapon would be able to improve their muskets, although the lack of industrial production would prevent fully copying the weapons. Enemies would also recognize that your small army cant be defeated with frontal assaults, but rather by splitting up into smaller forces and hope to ambush using the increased amount of soldiers available to them. Capturing even one such weapon and giving it to marksmen, wich already existed in musket area's, would also be a massive threat to your own forces who dont expect a peer-to-peer battle. Not to mention that the minéball era muskets had a pretty high accuracy and range, just lacking the rate of fire. Then there is the question of what you do if you captured the area? People have to work in the supply dumps and maintenance shops for your wargear, those points would be excellent targets for guerilla tactics to capture technology and equipment. You cant build a lot of these. This leads to splitting up the army in two forces: the shocktroops and the military police force. The shocktroops consist out of armored cars, light aircraft and the occasional mechanized infantry group with their higher tech weapons. The military police force consists out of one or two officers from your army with musket technology who lead locals trained and taught in your ideals armed with muskets as well. The shocktroops are stationed in FOB's far from the local populace of wherever you took control with lots of cleared land so its hard to ambush them. All maintenance, repair and supply is done from these points, using the range and speed of vehicles to get around in the area. An explosive/incendiary charge is available in each vehicle to selfdestruct when it breaks down in inconvenient area's. These are just shows of force to take out any large concentration of forces and completely manned by your countrymen. The local military police force with muskets can handle the smaller groups of enemy combattants and enforce propaganda to sway the populace to their side. As an addition: the shocktroops have to be made to look like supernatural monsters. The armored vehicles are painted with eyes, bright colors and with fake claws and legs sticking out while speakers create loud bestial noises. aircraft fly with painted wings, monstrous beaks with teeth and shrieking speakers as they pass overhead. The idea that these might be manned needs to disappear, enemy commanders cannot get the idea that you can kill the crew with an ambush during their break but think they are dealing with demonic monsters that you control. The rumble of the engine needs to herald the coming of doom, to pacify the monsters you need to lay down your weapons or be destroyed. Psychology is and has been one of the most important factors of warfare next to logistics. Use it to make sure your technology is safe and resistance to your forces melts upon their arrival. [Answer] My estimation is that such a group would be most effective as a very covert force. The technological advantage is massive - but of course even if you have an AK-47 in the middle ages you can still get killed by a volley of arrows. So I imagine such a group of well outfitted warriors would be very secret, in supplement to a more conventional army that acts like a front. You'd want your secret band of soldiers to be trained to a high degree as to not leak weapons technology. If this is all done right, simply saying "we're going to send these people after you" will be enough to scare anyone into submission. Spinning tales - and then confirming them, of one soldier killing a whole group of the enemy, could have a lot of power. That is what you would want to focus on in how this army looks - how to get them in and out of a place quickly, suiting them for espionage. Basically, you have an army of assassins. If you used them more openly, I could be interpreting this incorrectly, but it would lead to a mad rush to get your weapons technology. Your army however will do everything possible to avoid that. Like how the US military has tried to distract people by saying that some advanced piece of cold war tech is aliens, your military might say that your army of assassins are capable of magic. Fear and prestige will be the most powerful tool of this group - especially because you can actually show the force needed. Imagine the power of being able to say "one of our men could kill a twenty men in less than a minute," and then actually being able to do so with a machine gun. It'd be the most feared military on the planet. [Answer] # Long range missiles Missiles are, to this day, the premium option for long-distance force projection. This answer expands on [Thorne's](https://worldbuilding.stackexchange.com/a/216005/41250) excellent one, and how that answer incorporates the advantages of some of the other approaches. [![enter image description here](https://i.stack.imgur.com/b1HEp.jpg)](https://i.stack.imgur.com/b1HEp.jpg) Viability: Missiles are well within the technological range of Britain during WWII. Though they were behind Germany in rocketry, they had Frank Whittle's jet engine designs. Therefore, either they could conceivably make jet-engine powered cruise missiles, or, if you trade their codebreakers and cavity magnetrons for German rocket scientists, you could give them ballistic missiles. The tech level is there. Secrecy: Most of the time, there will be no trace of the weapon save for a crater. Even if an undetonated missile is found, it will be virtually useless to the finders, and, with proper tamper-proofing, largely fatal to investigate. Like in [WasatchWind's](https://worldbuilding.stackexchange.com/a/216011/41250) answer, this maintains secrecy and projects terror, but without the disadvantage of having to put boots on the ground or expose soldiers or pilots to risk. Logistics: As [o.m's](https://worldbuilding.stackexchange.com/a/216012/41250) accepted answer points out, one of the major challenges is that you'd be operating in a scarcely resourced environment. You can't capture petroleum reserves from the enemy. Their roads will be crap. There's no factories to take over. So... don't operate in the theater. Launch your missiles from either submarines, airships, or place launch facilities in ground-inaccessible locations near your targets. You can resupply small, stationary bases by air without any issue, and be completely safe from retaliation. You also avoid all the unpleasantness of having to be present in primitive, undeveloped country. For every combat casualty in the early Pacific theater, the US suffered 100 heat and disease casualties[4](https://books.google.com/books?hl=en&lr=&id=3r-_DwAAQBAJ&oi=fnd&pg=PR7&dq=Exertional+Heat+Illness:+A+Clinical+and+Evidence-Based+Guide&ots=XXOqMiHdzR&sig=tjk4u1VPSG5fgGHrKt2Y5ZA12YI#v=onepage&q=Exertional%20Heat%20Illness%3A%20A%20Clinical%20and%20Evidence-Based%20Guide&f=false). Safety: As user535733 points out in the comments, the enemy military can change its tactics to ambushes, deception, and so on, and allow for asymmetric warfare on a large scale. Weapons like [Punji sticks](https://en.wikipedia.org/wiki/Punji_stick) allow a four-year-old stone-age child to disproportionately harm a full-grown modern soldier with an assault rifle. Four-year old stone age children have a markedly worse record against missiles. Psychology: As both [Priska](https://worldbuilding.stackexchange.com/a/216034/41250) and [Demigan](https://worldbuilding.stackexchange.com/a/216022/41250) note, the psychological aspect is huge. If you're preferred form of terror is the unknown, like the V2, you can achieve supersonic speeds on the descent, and there will be no warning at all before death comes from above. If your preformed form is active terror, then, by all means, float airships above enemy cities, and let them believe that those are where their death comes from. This has the bonus of misleading their focus: if the locals ever figure out rudimentary rocketry and take down one of the airships, wipe the entire city off the map from your nearest launching facility. Monopoly enforcement: If one of the countries builds a university, destroy it. If the beginnings of higher level metal refineries are established, level them. If large masses of soldiers assemble, purely on principle, slaughter them. Missiles enable you to maintain your power in perpetuity. Clear upgrade path: Even with explosives, you will have complete dominion, but by investing in more rocketry technology, in nuclear or chemical agents, and, eventually, in satellite technology, you will be able to continue to tighten your fist and establish control. [Answer] The answer is the [American 180](https://www.youtube.com/watch?v=J50N5lQoAFw). This is a fully-automatic .22 caliber rifle, with magazines that hold 177 to 275 rounds. .22lr is accurate and deadly out to 200 yards or more. 200 yards is far farther than muskets can accurately fire. Small units with these and radios would be more than a match for much larger Napoleonic or earlier forces. If they had helicopters for transport and good espionage to find high value targets, they could overthrow whole kingdoms with just a few hundred men. Imagine Navy SEALs storming Versaille to see what I mean. [Answer] Orbital satellites dropping tungsten rods. They can be as big or as small as your nation leaders want. If the science difference is that vast, there’s no plausible reason to ever have an open battle, period, full stop. That means your opposition is going to be entirely guerrilla tactics, so you’ll be using spy ops and psych ops to counter. But you won’t have much standing military. [Answer] Your problem is almost entirely a logistical one. And logistics in this case is almost entirely political. In a pitched "fair" battle you'll be able to outfight the enemy 100:1 or more. But that doesn't win wars, because the world more than outnumbers you 100:1. You need bases. Those bases need allies. Those allies need to be kept in line. Each base needs to be a fortress that can stand a siege by the local allies until relieved. Ideally on the coast (which makes relief easier) with a port it can guard. It needs guns large enough to demolish any attempt to position lower technology guns to siege its supply lines impossible. Surrounding it needs to be an auxiliary base run not by the Ishga's, but by local patsies or allies. This base is funded by trade controlled by the Ishga empire; the trade provides the funding and incentives to set up the auxiliary base, and the auxiliary base provides the resources and supplies and defence that the Ishga bases need. By having local allies, the Ishga avoid having to constantly defend their supply fortresses; let the local allies bleed on each other. The fortresses need both an inner redoubt, supply cache, and outer permiter. The inner redoubt is intended to survive if the local allies are overrun or turn on them, the outer provides the area required for runway ships and supply storage. Because the Ishga want to keep their technology secret, you have to have a way to demolish said supplies to being useless if the outer permiter is breached (or at least before the supply cache is breached). This is similar to both the British and American system of bases around the world. These bases provide fuel and ammunition to forces, plus a base for aircraft to be stored. There are also going to be lesser fortresses which do not have resources usually in them. These lesser fortresses are only secured when a fight needs to occur near them, and are otherwise mostly protected by the threat of retaliation and treaties with locals. The short range of WW2 aircraft means that you need such lesser fortresses closer to the front lines of a conflict. The Ishga will have deals that are profitable to the heads of the communities they have the tier 1 and tier 2 (and probably tier 3) fortresses in. If the countries leaders are not interested in the deal, they are removed. --- Military wise, horses stopped being practical with WW1 quality weapons. As the enemy doesn't have WW1 quality weapons, cavalry with modern guns becomes a real thing for the Ishga. Horses require less fuel and are decent off-road. Dragoons, who use cavalry to reposition, and true cavalry, which fight on horseback, probably both have a use. As a bonus, as "horses" is not a secret technology, you don't have to keep them within a secure perimeter; your client states can breed and feed them for you. The Gatling gun was insanely strong in pre-WW1, and its improved versions and use in WW1 and WW2 made all previous tactics obsolete. You simply can't charge a WW2 machine gun. Machine-gun dragoon forces, where they use a horse to carry the gun and crew, would be an example of a deadly combination. With WW2 level bombers and even WW1 era artillery, fortresses don't do anything besides provide rubble. In WW1, huge concrete fortresses that where state of the art 10 years ago where reduced to rubble by their top-end guns. Nobody with the level of technology the enemy has is going to be able to build anything capable of withstanding your weapons. Now, such artillery is expensive and heavy. So your forces will mostly move around with weapons sufficient to take out enemy fortification technology, not huge rainroad guns. A bit part of WW1/WW2 era military might is the raw power of an industrialized state. It is capable of mobalizing a huge percentage of the population, and equipping them with many pounds of personal deadly weaponry each, feeding them, and then giving them even heavier-duty armored equipment. Firing off literally tonnes of weaponry, building railroads at faster than a walking pace, transporting huge guns on said railroads; that kind of industrial warfare. Napoleon's Grand Army was 600,000 strong and insanely huge for the era; Canada's current army is only 10x smaller than it, and is insanely small for a country of its size today. In the Renaissance armies where quite small. To quite wikipedia: > > For example, the King of France could field around 20,000 men in total for his wars against Spain in the 1550s, but could mobilize up to 500,000 men into the field by 1700 in the War of the Spanish Succession > > > A "small" army by modern state sizes is a huge one by Renaissance standards. It is only the inability to be everywhere at once that would limit your state; it could bring overwealming force to bear wherever it wants. It could show up with repeating rifles, armor capable of deflecting enemy guns, trained horses, industrial state level siegecraft and logistics, and ships capable of destroying anything to the horizon in a matter of weeks or months anywhere in the world. You won't be able to actually occupy the world. So raw destruction isn't a good plan, except as an example to others. Instead, you'd have local allies you'd prop up in exchange for payments and the like. The lack of an enemy faction is a bit annoying; if your local allies are dominant everywhere, you run into the problem that their only remaining enemy is you. So I'd suggest you fracture your state. Have multiple factions of your Empire that play a game with the rest of the world, for political points back home. It would even have a system to keep it "fair"; if you managed to win, you'd have to forfeit territory to keep the game entertaining. This provides your puppet states someone to hate who isn't you. [Answer] The other (technologically inferior) nations will adapt their strategy, taking into account their opponents many strengths. They will very quickly learn that a head-on assault leads to unsustainable casualties, and instead find alternative ways to harass and wear-down their enemy - probably ending up with an insurgency strategy. > > If your enemy is secure at all points, be prepared for him. If he is in superior strength, evade him. If your opponent is temperamental, seek to irritate him. Pretend to be weak, that he may grow arrogant. If he is taking his ease, give him no rest. If his forces are united, separate them. If sovereign and subject are in accord, put division between them. Attack him where he is unprepared, appear where you are not expected. - Sun Tzu > > > Hit-and-run ambush tactics are one way to damage the enemy without getting into a protracted firefight (where they can bring their technological advantages to bear). WWII era armoured vehicles were vulnerable to incendiary attacks, and dismounted troops would be vulnerable to black powder IED. The Ishga Empire forces should adapt in response as well. Prolonged conflict that drags on in far away lands is unpopular domestically, but even more so when coffins are flying home, so they will be risk averse and keen to minimise friendly casualties. Their numerical inferioriority also means that significant losses will have a big impact on their ability to wage war, so they prioritise force protection over mobility. * Soldiers travel in convoys of light armoured vehicles, peering out of small, thick windows. * There are some roads, although they aren't in a good state and certainly not rated for heavy vehicles. Most Ishga Empire vehicles are half-tracked: something like an [M3](https://en.wikipedia.org/wiki/M3_half-track) with a roof. * While technological superiority guarantees victory in a straight fight, it's a lot easier and safer to not fight and sometimes actions speak louder than words. Vehicle-mounted incendiary weapons (flame-thrower etc) instill such fear in the enemy that they surrender as soon as they see the pilot light is lit. * Dismounted soldiers are wearing bulky steel plate armour (e.g. cuirass or [steel bib](https://en.wikipedia.org/wiki/Steel_Bib) on their body, with high collar and a full helmet. 2mm thickness should be sufficient, provided it is wrought to the required quality. They can't move especially quickly, so they rely on their vehicles for mobility. The armour is there to reduce deaths (injuries attract less political heat back home), and buy some time while they re-organise and bring force to bear. WWII-era fighter and bomber technology evolved rapidly in the interwar period, but without a peer adversary it is unlikely that things would have evolved much beyond Zeppelins. As pointed out above, they solve the problem of observing the enemy, bombarding them, can fly out of harm's reach and require fewer resources to fly and maintain than aeroplanes. [Answer] ## Humongous Mecha What, mechas are inefficient you say? Unreliable and expensive due to too many moving parts? Impossible to properly protect with armor due to all the joints and the huge amount of surface area? Walking is less efficient than driving? High risk of falling over? We should rather build boring, box-shaped tanks, because those are superior in every way? Yes, you are correct about all of that. But none of that matters if you want to bully a technologically inferior enemy who isn't a threat to you anyway. * The humanoid shape makes them look particularly intimidating. They are not soulless boxes. They are anthropomorphic representations of the oppressors. Literal giants towering above the oppressed, making them feel as small and insignificant as they are in the order of the world. * They are expressive. They can communicate via body language in ways a vehicle can not. They can perform gestures which unmistakably communicate "I see what you are doing", "you shall not pass" or "get lost or you will be fired upon". * They are higher than they are long. This makes them visible from a long distance, constantly reminding the oppressed of the presence of the oppressors. It also gives the pilots of these mecha a good view on the oppressed crawling beneath them. Like worthless vermin they can literally crush under their feet if they gave them a reason to. ]
[Question] [ So I was thinking about the dynamic you always see in space settings in which the heroes always have a mobile basecamp in the form of their ship, and was thinking about how to have this sort of thing for a cyberpunk-ish world. While it would not be exactly the same thing, I was thinking about giving the heroes some sort of VTOL design as a semi-mobile base of sorts. The basic tech level is somewhere in the 21st century, though the exact details are somewhat flexible. The obvious problem is that anything that works as a decent aircraft is too small to be the same sort of livable as spacecraft. A second problem is that you can't use aircraft to hide in cities in the same way as spacecraft with FTL. So what are some possible designs for an aircraft that could achieve this? [Answer] Possible Aircraft Cargo dirigibles are a staple in cyberpunk fiction, but one loitering over the city would be conspicious. A planned, but never built, example would be the [cargolifter](https://en.wikipedia.org/wiki/CargoLifter#Airship) with 150t freight capacity. In the syndicate games, the cutscenes show that the command base of the team is a dirigible with a ton of advertising on it's side - this is hiding in plain (plane?) sight. For plane or helicopter to function as a base it needs to be huge and in a city it can really only land at an airport or helipad. If your setting is really dystopian and chaotic, a large helicopter can maybe sit on a parking garage, under a camouflage netting that looks like a heap of trash. Some cyberpunk setting, like the movie Blade Runner or the Cyberpunk 2020 rpg, contain flying cars that use vectored thrusters for VTOL. I believe this to be not really realistic because the fuel economy would be terrible compared to a helicopter but it would allow for a more compact vehicle that could maybe sit in a alleyway or something. Frame challenge one Why not a ship? It allows plenty space, can move from city to city. Just have your group hang around port cities mostly and have plenty of waterborne nomads to hide among. Frame challenge two Cyberpunk protagonists don't have bases. They don't even have much stuff: When we are introduced to Case in Neuromancer, he uses a coffin hotel, the last time we see him in the novel we lern that he didn't even unpack most of the clothes he baught along the way. In Mona Lisa overdrive, the "home" for one of the side characters (the pimp) is his suitcases from crocodile leather. And so on. When they settle down and get a base - like Case between Neuromancer and Mona Lisa Overdrive, or Turner after Count Zero - they retire and cease to be protagonists of cyberpunk stories. Before that happens, they don't hold on to much because everything can be taken away anyway in short notice - at the start of Neuromancer, we learn the Case was robbed even of his skill. If you want to keep the style described above, but still need a place for your characters to store their stuff, you could take a picture from the movie Lord of War, where the protagonist organizes his gun running out of a shipping container stashed somewhere in the harbor. The group's hacker just makes sure that the container with all the stuff is always where it's needed (and well protected), the characters meet in pubs and bars and clubs or at street basketball courts or a gym - the actual location always changes with the tides of coolness. [Answer] Cyberpunk and steampunk are a lot alike. Both make use of technomagic that makes sense on a visual level, but not on a physical or fully economical/sociological one. No one bats an eye when a steam-powered mech walks by, even though it would require better computer tech and engineering than we have today for that level of capability. Similarly no one bats an eye when a local punk down on his luck has a fully functional bionic arm in a cyberpunk. So knowing that, why not take some stuff from steampunk? The airship (a catch-all term for all types of inflated aircraft) is a staple of the steampunk genre, and its sad that its used so little in more modern settings. It could be a simple cargo airship, a skycrane for construction or a full-flegded flying superyacht. Its a bit dystopian to use large towers to dock your airships, making low-rent slums inside the shadows of such towers and airships. Pretty perfect for many cyberpunk stories. And since it doesnt have to make too much economical sense, how about making the airfields where these things land underground as an alternative? Nothing says "cyberpunk" than making an evil underground lair a basic part of everyday life, with the working class forced to work in underground area's as they load and unload cargo and process it for the rich elites. Your crew then just hides in plain sight. There's always a dozen companies, freelancers, pleasure barges and cruiseships flying about. One day you act like a freelance captain down on his luck, the next day you falsify your credentials to look like you belong to one of the mega-corporations. The exact details of your ship changing with each report so they are never really looking for your ship, you hope. [Answer] They port in remotely. The hallmark of cyberpunk is transhumanism. Protagonists interact in virtual worlds as in Neuromancer or The Matrix. Or taking a step further, manifest remotely in real worlds using new bodies, like in Avatar or Kiln People. Possibly they commandeer and use the bodies of the real inhabitants of that world. Landing an airship and hopping out with ray gun in hand is so Doc Savage. Yet there must be somewhere to park the real bodies. Evading prying eyes and rays and drones and satellites would be nice. How about a cozy submarine? [![sub](https://i.stack.imgur.com/5dUtb.jpg)](https://i.stack.imgur.com/5dUtb.jpg) [source](https://tr-images.condecdn.net/image/5XZwge7Jwlr/crop/1620/f/submarine-conde-nast-traveller-7feb14-pr.jpg) Added bonus - explore the submerged ruins of the precatastrophe Earth, and maybe older ruins yet. --- Or subterranean drillship? [![drillship](https://i.stack.imgur.com/D2rjJ.jpg)](https://i.stack.imgur.com/D2rjJ.jpg) [source](https://thirdcoastreview.com/2020/05/20/preview-volcanoids-co-op/) I like the drillship because the geologist pilot has 3d charts and uses lots of geo terms. "We can't go straight to New Newark. We need to swing around the Hardyston Quartzite. Unless there's still a way under..." Here too the protagonists can encounter relics of the old world buried beneath the new. [Answer] An airship covered in camouflage fabric Camouflage fabric is a standard feature of cyberpunk settings. Basically, they transmit light around a person or object, making the wearer seem transparent. There is usually some distortion, but for a rigid shape like an airship, that distortion could be very small. To get to the ground, the crew could drop down in camouflage flightsuits or small gliders. which if powered can also get them back up, or cables can haul them back up with a much lower energy signature. There are three issues with this idea. First, the airship should also be invisible to radar. This can be handled by using radar-transparent materials, supplemented with radar baffles. The second issue is harder: Making the airship invisible to infrared cameras. Engines, people, and electric devices all emit heat, and if the HQ should be livable in winter, heating is an extra source of infrared radiation. One solution could be to have thin, cooling tubes along the entire surface and then get rid of the excess heast by firing an infrared laser up into the empty air (Davin Brin uses this cooling technique in his novel Sundiver). When cloudy, this laser should be dispersed to prevent obvious reflection from low cloud layers. The third issue might be the most difficult. In a cyperpunk setting, wireless communication is ubiquitous. Wireless signals coming from the airship would be detectable, though it is possible that they would drown in the background noise. A solution would be to only transmit signals upwards, either to a satellite or to a relay airship or drone at a much higher altitude. [Answer] First, let's have a look at a few basic requirements for the setup: If you want the aircraft to be a base it needs to be able to sustain the crew and the group it supports. It means you need to be able to operate long flights, have significant cargo capacity, be able to resupply and limit the number of resupplies. It means you should avoid carrying fuel since it will be your main flight endurance limiting factor. One option to do that is having a solar-powered electrical plane. [![Helios solar-powered aircraft](https://i.stack.imgur.com/1SbUJ.jpg)](https://i.stack.imgur.com/1SbUJ.jpg) Being solar-powered it can actually stay inflight for [virtually infinite time](https://www.airbus.com/newsroom/press-releases/en/2018/08/Airbus-Zephyr-Solar-High-Altitude-Pseudo-Satellite-flies-for-longer-than-any-other-aircraft.html) (in reality there are other limiting factors). Of course, it has to be larger, sturdier, with some reinforcements, especially making it possible to perform a large part of maintenance in-flight. Secondly, it should be able to operate from water. It gives tons of benefits, from the ability to build a larger plane (initially large planes were amphibians since almost any length of the landing "strip" can be available) to ability to operate in many areas without the necessity to build actual landing strips. If you have enough water, you can land and take-off. It also makes it possible to operate from desolated areas. Finally, in case of damage that cannot be handled airborne, you just have to sit your bird on any nearby water without exposing yourself at least to land assault and wait for the ranger planes to organise repair supplies. In addition, you have to consider some ability to leave and dock back smaller planes so that they can serve as communication "rafts". Similar attempts [were already done](https://ses.library.usyd.edu.au/handle/2123/13670). To increase capacity, rather than having a single plane you may want to have a few of them flying either in a formation or when needed separating and operating on its own. With current AI capabilities, autonomous in-flight operations could allow keeping the same distance during the whole flight, allowing the creation of some kind of links between the planes that could even offer the ability to move between the planes. One of many examples can be seen [here](https://www.youtube.com/watch?v=cF6QHTQqL7g). Things like Starlink network and standard GPS will give full freedom in terms of internet (or other means of communication) availability as well as navigability. At the same time, insufficient radar coverage gives plenty of space to hide (It's not representing full radar coverage but gives a hint where the problem lies). [![Example radar coverage](https://i.stack.imgur.com/oHuug.jpg)](https://i.stack.imgur.com/oHuug.jpg) [Answer] Just FYI, what you want (sort of) is actually available, if you have several hundred thousand dollars to spend. There are quite a few airplane camper conversions out there, particularly of Grumman seaplanes - the Goose, Widgeon, Albatross, &c. Searching for "Grumman seaplane camper" will get examples. Of course you're limited to landing on suitable runways or bodies of water, but that's a different issue. VTOL aircraft aren't all that practical, except for some military uses. However, there were attempts to build & sell helicopter campers, e.g. <https://www.airspacemag.com/history-of-flight/the-flying-winnebago-3672/> [Answer] My first thought is the V-22 Osprey. Being a real aircraft, you can find [specs on Wikipedia](https://en.wikipedia.org/wiki/Bell_Boeing_V-22_Osprey#Specifications_(MV-22B)) and use that as a base for your design. It's VTOL, it's fairly fast (much faster than an airship), it's designed to cargo stuff around, and you can add weapons to it, so that's a good candidate for a cool, real-ish, flying base for a squad of image-conscious heroes. You shouldn't expect a palace though. It's conceivable that you can build a flying tour bus for a handful of people, but it'll be a tight fit and you won't have much room for cargo inside (although you can still tow cargo outside). That said, big roomy coolcraft doesn't sound very cyberpunk to me, so maybe that's a bonus. And on the flip side, you can land it pretty much everywhere and camp in the great outdoors, and that'll be more room than any sci-fi spaceship can give you. The question is tagged "engineering" but... ## The problem isn't engineering, it's logistics And even then, ## The real problem is fuel Hands down, how you're refueling your plane will be the single biggest design decision to this question. I say that because it doesn't just shape the plane, it shapes the world and the plot. ### Refueling on land The basic option is to land and go to the gas station to get your kerosene. The first limitation here is landing somewhere that has the infrastructure and that welcomes you. Fiction gives you the opportunity to place private and/or pirate airfields all around the world. Private airfields means you'll have to ask permission, book a slot and pay for it. Pirate airfields might not bother with such formalities, which is also a great way to induce shenanigans, like that time you landed in Ulaanbaatar and pirates kidnapped your pilot in broad daylight. You can also land anywhere in the plains of Africa or the steppes of Asia without being bothered by the neighbours and set up shop in the wild. That's good to do some basic maintenance, and if you can source some fuel from there it's a valid option, though you obviously lose the benefits of an established infrastructure. The other major limitation here is that when doing a Reykjavik-Jakarta to get to your next mission you'll need to land once, twice, or maybe more. That means the problems above become recurring, and ultimately it's going to eat some precious time you might not be able to afford, especially if aforementionned shenanigans occur. Whether that's a pro or a con for your story is up to you. At any rate, if you go for that option, a straight-up Osprey-type aircraft will do the job just fine. ### Refueling in the air We do have the technology to bring the gas station directly to you in-flight. The problem is you know that's stupid expensive because no commercial airlines do it, only the military can justify that spending somehow. A cyberpunk setting might allow you to introduce a commercial service of tankers to refuel private citizens such as your heroes. But that means flying an air-bus around for 'round-the-world trips is a common enough occurence that there's a market for it. That's a pretty big condition, and one that will potentially reshape your world. If refueling in-flight is widely available, your heroes are more likely to get contested by air-pirates, corporations, and private militaries having their own air-bases. If everybody has a cool air-base, your own cool air-base may lose its romanticism. Maybe the biggest limitation here is the stupid expensive part. Unless your team is swimming in cyberdollars, such a refuel might be more than they can afford. And that means they'll have to hijack a tanker or two. While it is a pretty cool image, it brings a lot of complications to your travels. Your plane will need to be designed for combat, and obviously that means you should expect to spend a few chapters fighting for fuel at 30000 feet. If you aren't interested in a world that's highly militarised, with weaponising your plane, or if risking your life for every refuel sounds too big of a hassle, you might consider this a bad option. ### Not refueling, like, at all The most realistic alternative would be solar power. Solar power is nice in that you might be able to fly indefinitely for cheap. You do have to account for daylight and the size of your batteries when planning your route. In some cases, that might be very inconvenient, but still, solar energy is cheap and readily available most of the time. It gives you the opportunity to stay in the air much longer without needing a refuel. Of course, your setting might have a better alternative. Whatever your energy source ends up being, it needs to be: * light, * compact, * powerful, * have enough capacity to keep you in the air for a convenient amount of time. Ideas may include a pocket nuclear reactor. Nuclear energy offers a lot of opportunities for shenanigans. You might also think of that refuels by sucking gases the atmosphere. For an added bonus, you can make it something found at a specific altitude. Imagine your aircraft needs a specific mix of hydrogen-2 and helium-7 that's only found just at the operational ceiling. And this is just an example with zero scientific backing, but if you establish it with enough confidence, it'll play. --- Additional consideration An aircraft needs space to fly. You're thinking "not a problem, the sky is full of that", but the sky also belongs to somebody. It's one thing to fly a drone or a Cessna without authorisation, but governments/corporations will notice a big military plane flying around the world and might take offence if it goes through their sovereign airspace. There is plenty of airpsace where nobody will come bother you. The middle of the ocean for instance, and the great deserts of the world. For everywhere else, you can embrace piracy with an IDGAF attitude (which is fairly cyberpunk), and hope you can dodge the jet fighters indefinitely. You can also add everybody's favourite part of a story: bureaucracy and red tape. Or you can do both: violating airspace of people with poor radar coverage or weak air forces, and file the paperwork where you are likely to get shot down on sight. That gives you the opportunity to hack the mainframe to give your aircraft the right credentials. That also gives you the opportunity to get caught with fake credentials and having to hightail it out of missile range. Which is to say your aircraft will be designed for speed. You might want to replace propellers with jets for more speed, and also for more coolness. That should give you a better chance when you need to make a quick exit. I wouldn't bother with stealth. It only helps to the point where nobody looks up and sees your big airplane hovering above the headquarters of Megacorp, or if nobody can hear the roar of the engines from over the horizon. --- ### In conclusion The only question you need to ask yourself is what fuel you put in the tank, and how you get that fuel. The rest has largely been solved by real engineers in the real world, which is to say your cool aircraft looks like an Osprey. It can be bigger, it can be haphazardly converted to solar power, and maybe you have tiltjets rather than tiltrotors, but a big VTOL is just about the gist of it. [Answer] [Mart's answer](https://worldbuilding.stackexchange.com/a/184357/21222) mentions the Neuromancer trilogy. If you haven't read it yet, I suggest you do. It's a seminal work in Cyberpunk literature. In the second book of the series, Count Zero, one of the character pilots a combat jet that is able to camouflage itself when landed. It also has an AI that makes very smart decisions in order to fulfill its mission. Twice in the story the pilot loses consciousness... > > "Where are we?" > > > "We are fifteen meters south-southeast of the landing coordinates you provided," the plane said. "You were unconscious again. I opted for concealment." > > > He reached back and removed the interface plug from his socket, breaking his link with the plane. He gazed dully around the cockpit until he found the manual controls for the canopy. It sighed up on servos, the lacework of polycarbon leaves shifting as it moved. He got his leg over the side, looked down at his hand flat against the fuselage at the edge of the cockpit where the polycarbon reproduced the gray tones of a nearby boulder; as he watched, it began to paint a hand-sized patch the color of his palm. > > > I also suggest watching the original Ghost in the Shell movie from the 90's for some inspiration on camouflage. Then see the Ghost in the Shell: Standalone Complex. There is a hacker there that is [able to make his face impossible to see or remember](https://ghostintheshell.fandom.com/wiki/Laughing_Man): > > In the Ghost in the Shell series, Laughing Man proves to be the ultimate hacker, capable of such feats as hijacking multiple video streams simultaneously, taking over someone's cybernetic brain entirely, or even editing his own images out of someone's cybernetic eyes, and all in real time. > > > You could do the same with the aircraft. ]
[Question] [ I’m making my story as close to real and theoretical science as possible. I remember reading an article a while ago saying realistic space warfare would be capital ships engaging in missile warfare and trying to get into advantageous orbit. However, the more I think about it, you’d want to take out your enemy’s missile launchers, so you’d make something small and maneuverable enough to dodge oncoming missiles, and then deliver an explosive to destroy the missiles, so something like a bomber, and then both sides would develop AA technology for their ships, or counter with fighters, so you’ve ended at at something like Star Wars, except it would probably be better to have ships dedicated to a specific task, unlike Star Destroyers. Is this a logical line of thought, or would they be most likely to stay in capital ships and just try to shoot down the missiles? [Answer] Fighters aren't even a realistic evolution of current naval warfare. It'll all be drones as soon as is practical, and when someone works out an effective laser anti-aircraft system, it'll be back to battleships again. > > However, the more I think about it, you’d want to take out your enemy’s missile launchers, > > > Warfare in space is likely to involve excessive amounts of energy, one way or another. Kinetic projectiles with relative speeds of tens of kilometres per second. Nukes. Massive laser cannon. You don't "take out their launchers", you wreck their ships. If you meant "take out their missiles at a distance" you might be closer to the mark, but that's a job for high-speed, fast-reacting expendable interceptor missiles, not fighters. > > both sides would develop AA technology for their ships, or counter with fighters > > > If the principle weapons of the warships are missiles, then the principle defense will be counter-missiles, point defense projectile weapons and lasers. You can already see the convergence of missile and aircraft defense in modern missiles like the [Aster](https://en.wikipedia.org/wiki/Aster_(missile_family)). Anti-ship missiles will be travelling faster than a fighter (no need to be delicate with the meat, or carry unnecessary weight) and be able to manoever harder, and any countermeasures capable of taking out one of those missiles will easily be able to take out a fighter. > > would they be most likely to stay in capital ships and just try to shoot down the missiles? > > > Yep. There are multiple problems with fighters, you see. Firstly, meat is delicate. You need life support (heating, cooling and air), radiation protection and limited acceleration forces or the pilot becomes so much pâté and your expensive fighter ends up as the tin. Computers think and react faster than people. Maybe you could just upload your pilot, of course, so they might better compete with AI systems? Secondly, the [rocket equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation) is punishing. Your missiles just need to accelerate up to some speed $ v $, jink about a bit as they enter range of enemy point defence or interceptor missiles, then go bang. You fighters, at a bare minimum, need to speed to up $ v $, then in order to get back home they need to slow down to a relative stop (a change of speed equivalent of $v$) then accelerate back up to $v$ and finally slow back down to a halt at their mothership. That means they need a total velocity change, or delta-V of $\Delta\_v = 4v$. According to the rocket equation, your $\Delta\_v$ is proportional to $ \ln({m\_0/m\_f}) $, where $ m\_0 $ is your empty mass and $ m\_f $ is your fully fuelled mass. To increase your $\Delta\_v$ by a factor of 4, you mass ratio needs to increase by a factor of $e^4$ which means you need fifty four times as much fuel as the missile. What a huge waste! A missile that big could travel 4 times as fast, or manoever for much longer, or carry a massively larger warhead, or multiple warheads. Maybe you could have your fighters run dry at the target, assume you'll be victorious and come in to pick them up with the carrier, but that's a risky strategy and even then they'll need nearly 3 times as much fuel as a missile would. > > I’d say they’d probably want to be capturing enemy ships if possible > > > Enemy point defenses might have ranges of thousands of kilometres. You want to reach them at more or less zero-speed in order to board them. Even if you brake super hard, at the limits of human endurance, you're still in the danger zone for a relatively long time and you'll be toast. You could nuke em until the point defenses stop, but at that point they're probably nothing but a rapidly expanding and cooling cloud of gas and dust. You don't board a ship capable of defending itself. Even civilian ships might be tricky. Only people who surrender can be boarded, and then you can do it with any kind of shuttle. No need for fancy boarding craft. [Answer] This was a comment at first but I've decided to turn it into a full-blown answer. You suggested evolutionary path is as follows: * Space warfare consists of two fleets of ships lobbing missiles at each other * The fleets would develop and deploy bombers to fly in close and take out the other fleet's missile launchers * The fleets would in turn develop fighters to shoot down the bombers before they can destroy the launchers A simpler and much more logical progression would be the following: * Space warfare consists of two fleets of ships lobbing missiles at each other * The fleets would adapt their missiles so they can be steered mid-flight, allowing them to dodge counter-measures and strike specific parts of an opposing ship (such as the missile launchers) Compared to developing whole new fleets of bombers and fighters, simply upgrading to guided missiles would be far more cost-effective, take advantage of systems that the ships already have instead of requiring new hangars/carriers to be built to accommodate them, and would not require human pilots that would be at great risk of getting blown up. As you mention that your mafia fleet would want to capture ships where possible, they can also use guided missiles to hit things like engines or shield generators, crippling a ship without destroying it entirely. [Answer] # No With all due respect to any answer that suggests yes, nobody's thinking about what it takes to move mass around in space. Even when orbiting a planet, you really don't have the benefit of gravity to reduce your fuel costs — and that assumes you're moving slow enough for two ships to engage with piloted (in any form) fighters. The Ugly Details Let's ignore relativistic combat for now and stick with simple, run-of-the-mill awe-inspiring sublight. Let's say our capital ships are booking along at a creeping 1,500,000 kph (that's the Earth to the Moon in 15 minutes). If the two capital ships happen to approach one another at a very acute angle, they can sidle up to one another (broadsides) and thump it out with fighters because the fighters are moving at the same relative speed (along the same 1.5 Mkph vector) as the capital ships. But if those big bugaboos come at one another at obtuse angles, it would not only be a pain in the neck to take the time (and fuel) to adjust course to come broadside, it would be a defensive faux pas. Unfortunately, any fighters launched now get one shot at the enemy capital ship (and fighters) as they go bookin' past them at a minimum relative speed of 1.5 Mkph (and more likely 2.25 Mkph-ish, depending on the angle). And heaven help the now useless fighters if the two ships approach one another head-on. Fighters now get just one shot as they pass the enemy at a relative speed of 3 Mkph. See the problem? Even a fighter can't simply turn on a dime. Spinning around to take a second shot would flatten the pilot against the hull of the ship and turn him into a thin strawberry paste that might, maybe, be contained to his environmental suit. And can you see why I could ignore relativistic speeds? They just make everything worse. And speed has another consequence... Timing. Those pilots get one shot, but I very much doubt any human could time the shot and succeed without simple, blatant luck. Maybe, maybe, that one shot can occur within the window of a single second. Now you go get on your bicycle and try to fire a water pistol successfully with a window of a single second. Yeah... Make sure you post the video on YouTube. :-) And the faster the capital ships get, the worse this all gets. Time, velocity, and mass are not on the side of fighters in space combat. So where would they be useful? Space stations, which in the grand scheme of celestial mechanical things are the equivalent of fixed fortifications.1 Since they're philosophically not moving, you can launch fighters from them. Why is this at all practical? Because attacking ships moving at speed have but one shot, then they're taking the proverbial month to U-turn (or slingshot around the planet, which is the Star Trek version of a U-turn).2 Their option is to slow down to engage the space station, making fighters viable. But, the short answer is still no. However, when all is said and done, I simply don't see fighters in the future of space combat. For every condition someone can come up with where they might seem plausible, I'm convinced I can point out some deficiency that would make any other tactic more plausible (especially economically plausible). --- 1 "Fixed fortifications are a monument to the stupidity of man." — George S. Patton. Space stations are almost as useless as fighters when it comes to combat in space. They simply can't move fast enough to defend against bombers moving at any speed, but the faster those bombers go, the more successful their bombing run. Time, velocity, and mass. Yes, you could build a plethora of space stations — but you might as well build ships and ignore the stations. 2 I've seen The Wrath of Khan like, a million times. So by force of habit I'm certain this statement is absolutely true. :-) [Answer] The difference between a fighter and a missile/drone is the missile/drone doesn't have to worry about the squishy human and their life support system taking up mass and volume and limiting manoeuvring to magnitudes humans can survive. That allows the drone to be more manoeuvrable and smaller than an equivalent fighter or bomber attempting to do the same mission. [Answer] # Not in the way that you'd think, but you still don't want a single point of weakness (capital ship) Space is treacherous, and in most cases a single hit is probably enough to "kill" your ship (especially with any weapon designed to do so). So, if you're engaging in space combat it doesn't make sense to put all of your people on a single ship. The more you are spread out the harder it will be to kill a significant number of your forces. The enemy will need at least 1 missile per ship assuming 100% accuracy and 100% kill rate, so the more ships you have (regardless of size) the more protected you're forces will be. It really doesn't make any sense to have any ship be a "fighter" as in star wars, as has been stated in other answers making unmanned guided missiles is far superior. The missile technology would probably be improved greatly and there might be a lot of innovative and cool types adapted for certain enemies or purposes: AI guided, cluster/fragmenting, thermal, explosive, von neumann etc. just to name a few. Perhaps the ideal is to have the capital ships be modular so that they can be together most of the time, but then break up into hundreds of small autonomous ships (hopefully with their own missiles) when there is a battle. Additionally there should be a number of unmanned sacrificial ships who's job it would be to get in the path of the missiles (they should look similar to all the others but have no people on board and maybe only one intercept missile). [Answer] In Earth naval history the earliest tactics were boarding ships and/or ramming ships. Ships basically had to come into contact with other ships to fight them. The invention of shipboard cannons changed that. Ships could now attack and damage each other at distances of hundreds or thousands of feet. Standard naval tactics were for two fleets to sail parallel to each other and shoot across the distance, though there were also battles with confused melees and ships getting close to their enemies. As weapons and armor technology rapidly developed during the 19th and early twentieth centuries the ranges of shipboard artillery vastly increased. Battle fleets began to be separated by greater and greater distances when they fought, until the enemy fleets might be on the horizon or beyond it when firing. During some 20th century sea battles some ships with inferior guns exploded after being hit by shells fired from outside of the range of their own guns, and sank with the loss of 99 percent of their crews or even with no survivors at all. And the same thing would happen to space warships that try to fight space warships that have longer range weapons. In the late 20th century this trend continued with the development of warships armed with guided missiles that could hit targets on land or other fleets hundreds of miles away. As well as submarines armed with missiles with atomic warheads to hit targets hundreds or thousands of miles away. And in space warfare the trend is likely to continue with space fleets firing missiles or ray guns at enemies separated by distances of tens or hundreds of thousands, even millions, of miles. If one fleet has weapons which are effective at a much greater range than their enemy has, they can stay within the range of their weapons but outside of the range of the enemy's weapons, and destroy the enemy fleet without suffering any damage to their own fleet. But if the fleet with shorter range weapons is faster than the fleet with longer range weapons, the fleet with shorter range weapons can use its greater speed to close the distance to the fleet with longer range weapons and attack it, or else retreat outside the range of the fleet the fleet with longer range weapons. So imagine an inferior fleet retreating from a superior fleet to avoid destruction. What happens when the ships in the retreating fleet have different speeds? That would be a case of "the devil take the hindmost", wouldn't it? The slower ships would be destroyed or have to surrender first, while the faster ships would be destroyed h or have to surrender later, or possibly escape from the pursuing fleet if faster than it. Maybe the ships would stick together. In that case the retreating fleet would be limited to the speed of the slowest ships. If the slowest retreating ships were slower than than the pursuing ships, the pursuing ships would catch up to the retreating fleet and totally destroy it. So that suggests two possible strategies: 1) Make your space battleships as fast as possible and thus add faster ships to the fleet as soon as they are built, even though it means that your fleet will have ships of varying speeds. or: 2) Only use fleets with ships of identical speeds, even if it means totally retiring all ships of older designs when faster ships are developed and thus having fewer total ships. Decisions, decisions. Note that in a space opera conflict between two space traveling species which have just met, the two sides might be totally ignorant of the technological capabilities of their opponents. The crew of a space fleet might not know whether they are centuries more advanced than their opponents and thus will destroy them effortlessly, or are millions of years behind their opponents and thus will be wiped out without doing any damage to the enemy. Note that with normal space travel space ships will not have speeds so much as acceleration and deceleration capacities. Of course if some sort of FTL space drive is invented it might have either acceleration or speed depending on various factors. The need for superior speed or acceleration than the enemy will tend to favor larger and larger space warships. A larger spaceship can have larger and more powerful engines and fuel supply relative to its size and mass than a smaller spaceship, while still having as much space left over for weapons as the smaller spaceship and being just as powerful and destructive as the smaller spaceship. The need for more powerful and longer range weapons than the enemy will tend to favor larger and larger space warships. A larger spaceship can have larger and more powerful weapons relative to its size and mass than a smaller spaceship, while still having as much space left over for powerful engines and fuel supply as the smaller spaceship and being just as fast as the smaller spaceship. So I imagine that in an interstellar space opera context space battles will involve fleets of space battleships instead of space cruisers or space destroyers or space pt boats. What about naval aviation? In the mid 20th century aircraft carriers with small fighter and bomber planes ruled the seas. Surface ships travel at the intersection between the medium of water and the medium of air. The dense water medium provides a lot of resistance to their hulls and limits their speeds. Small carrier based aircraft travel in the medium of air, which has much less density than water and so offers a lot less resistance to the movement of airplanes. So a tiny aircraft carrier plane can have a tiny engine compared to a surface ship and still travel much faster than the surface ship because of the much lesser resistance of the air. So imagine that there are two mediums in outer space, and that they met at a plane surface. Suppose that the equivalent of space battleships travel at the interface between one medium and the other. Suppose that the equivalent of space carrier aircraft travel only in one of those mediums, the medium that is much less dense and offers far less resistance to them. Therefore a tiny space fighter craft with a tiny engine could travel much faster and be much more maneuverable than a space battleship slowed down by partially travelling in the denser medium that offers far more resistance. In that situation, tiny space fighter craft would be very useful in space battles and might be the dominant force in them, as carrier based aircraft were the dominant force in World War Two naval battles. But of course interplanetary and interstellar space is a hard vacuum, with a very, very, very, very thin scattering of energy and matter. Outer space has no medium to offer resistance to vehicles, let alone two very different mediums with a plane surface between them. So small fighter vehicles should have very little use in space war. [Answer] I think fighters do make some sense, on the condition that they're not manned. Look at how the rocket equation works. Almost always, high thrust engines get poor fuel efficiency. They accelerate quicker, but get worse top speeds and/or ranges. But your missiles need to be able to accelerate quickly to evade enemy point defenses. If you use fighters instead of launching missiles directly from your capital ships, you can get the best of both worlds. The fighters relatively slowly carry the missiles right up to the edge of your enemy's point defense bubble, then they launch their fast missiles at their targets, and go back to the carrier to reload and do it all again. See, you get long range thanks to the fighters, and you get extremely agile missiles because they have the fuel budget to spare on high thrust, low efficiency engines. [Answer] The AEGIS automated weapons system would work even better in space. Big American ships are protected by AEGIS, an automated weapons system that shoots down incoming missiles and drones with a combination of missile types and automated machine guns. The [phalanx](https://en.wikipedia.org/wiki/Phalanx_CIWS) automated machine guns are especially awesome and terrifying. A system just like this would work even better in space. Radar can see immense distances. You do not have the horizon to hide behind. The guns especially would work well because a bullet put in motion would keep going indefinitely, not slowing from air resistance and dropping from gravity. If you can spot an incoming missile thousands of km away and you have a robot machine gun at the ready, the missile has no chance. Needless to say a dude in a ship has less chance. Unless the dude is piloting an enormous cargo ship, in which case he has a [reasonable chance of ramming a big American ship in the middle of the night.](https://www.nytimes.com/2017/06/23/world/asia/destroyer-fitzgerald-collision.html) The only feasible weapons in a duel between two capital ships in space are those which cannot be seen coming: lasers which move at light speed, and particle beams which move at a significant fraction of light speed. Pretty much anything else you will see coming in time to intercept. --- If light speed weaponry is blocked somehow, then what? Capital ships would fire back and forth, striving to develop faster projectiles and faster countermeasures. Greater proximity means less time for your opponent's defense. Capital ships might get closer to one another in hopes of getting a shot through. Eventually the ships are practically next to each other, firing and blocking at immense rates. If you can't throw the ball, run the ball. The ship itself is too big to block. The attacking ship would come alongside its opponent and send over boarding parties. [Answer] I don't think so. Starfighters require its own fuel, a pilot, life support... It's quite expensive. Fly a drone. A solar powered drone. It's cheap, and safe. Or shoot a massive missile from, let'say, Earth to Mars. Maybe you don't even need an expensive fleet. Or use terrorism to win wars. [Answer] Due to the rocket equation, no, Star Wars-style fighters would be impractical. This is because the starfighters would have a truly horrendous mile-per-gallon rating. However, I suggest that you take a look at the Star Trek style. These are essentially just little starships, which act similarly to the Torpedo Boats that the U.S. used during WWII. [Answer] After thinking about it, the only plausible reason I can think of where space fighters would make some amount of sense would be if you had some sort of detection evasion technology (cloak? Low observable tech?) that was both dependent on a rare ingredient (so cloaked warheads would have to be used sparingly), and whose cost to build/operate increased exponentially with ship size. But even then you're probably looking at 2-4 man craft. Not single seaters. ]
[Question] [ You are an 18-year-old Clark Kent, and you have made the decision that to spend four years in college would be too big of a waste of time; you are ready to start saving the world now. Developing your vocational skills would be to not focus on your strengths anyway. Fueling that decision is the fact that your superhuman abilities should be able to provide you with a source of income on their own. However, as you are to be an agent for good, your source of income must meet the following requirements: 1. Does not do any moral harm (no robbing banks at night or stealing cars) 2. Does not give up your 'alter ego' (using your powers in plain sight to excel at manual labor) 3. Raises minimal suspicion about your alter ego (you'll need to cover your whereabouts to your friends/neighbors) 4. Provides enough money to live in a big city like Metropolis. Superman's exact abilities seem to vary by comic book/movie, but the most notable powers are: * Super strength * Super speed / flying * X-ray vision * Heat (infra-red) vision * Ice breath * Invulnerability Surely there must be some way to leverage your powers for sustainable income? [Answer] Start a Mining Company Clark Kent needs to Superman-up and scout for precious metal deposits with his x-ray vision. When he finds one of sufficient size on some land for sale he can sell the family farm and buy the land with the precious metals. He can then, initially, mine it out in private. Once he's waited a sufficient time to not arouse suspicion, he can start selling the metals and building a larger mining operation legitimately. Now he has more capital, he can continue buying land and start mining operations to extract the precious metals there. This process means he will eventually have enough cash flow to move to the city and not need to be seen working at the mines. Win the Lottery Check the winning lotto numbers. [Fly fast enough to go back in time](https://what-if.xkcd.com/14/). Then buy the winning ticket. Now he can buy the Daily Planet and live off its income and the interest of his winnings. Start a Space Travel Company He can go ask [Jor-El](http://en.wikipedia.org/wiki/Jor-El) how interplanetary spaceships work. Pretend to toil for years as a mad engineer and finally reveal his 'creation' to the world. Begin space tourism and colonization. [Answer] Call me... The Jeweler Does your superhero have the power to pressurize coal into diamonds and melt precious metals with heat vision? Then he can make a great living as a maker of fine jewelry. Benefits: He wouldn't have to work too many hours a week. He would not need co-workers and he could sell his wares online. [Answer] # Start a "Superhero" Charity/Trust Fund The charity is run for the benefit of the superhero. If I were mayor of a city, especially one that frequently benefits from said superhero, I'd propose a fund especially for the superhero to get whatever they need. It may turn out to be cheaper to pay an annual salary to the superhero in exchange for their services rather than attempt to hunt him/her down as a vigilante. Besides, it would allow the police department to focus on other things. If I were the superhero, I would start a social media campaign for said trust fund/charity pointing out that "superheroes need food, too." I'm sure plenty of people would love to buy a meal for the guy/gal who just saved their life. Some people may just want a way to express their appreciation beyond single "Gee thanks, Mister!" line that superheroes often get... Some other bonuses: * Gives people a target to express their appreciation. Seriously, not everyone is ungrateful. Additionally, it's legal, so what even if it gets sour looks from the government, there is nothing inherently wrong with it. * Give enemies a target for their vengeance; the superhero gets to know who their enemies are without the dramatic reveal. In addition, taking the superhero hostage to draw out the superhero is... dumb for them, smart for the superhero. * This charity is merely overlooking finances, which is not that hard. As long as you live modestly as your cover story demands, no one will suspect you. * If this gets big enough, it could help pay for superhero-ing legal fees. * May also attract allies. * Good excuse to cut out on friends/family: "a superhero wants some money, and I need to go verify their super-powers. They don't schedule appointments, so I need to go! Bye!" or "Oh, a bank robbery! I need to go see if that superhero shows up so I can recognize him/her." [Answer] Be a private investigator. * You mostly set your own hours as long as you get the job done. And you don't have to take the cases that would require long, set hours, such as a stakeout. * Superpowers might let you be really, really good at it. You might be able to make quite a comfortable living. * You could get leads into the criminal underworld. * People would understand you being unreachable for long hours pretty much any time of day. * If you go somewhere in disguise as part of a superheroing investigation, you have a ready-made reason for being in disguise. * Fast cars, beautiful women (or handsome men, depending). I can believe everything I see on TV, right? [Answer] Web Development/Blogging Hear me out. Web development allows our young hero to have a low maintenance moderate income job which leaves him free to fly around whenever he likes, without the problems of having to change costumes (though if journalists can't figure he's Superman with glasses, then it doesn't matter much.) or make excuses to get out of work. [Answer] Of course, start your own propaganda agency. Being superhero attracts a lot of attention. Your superhero might use a formula one like costume full of propaganda banners. This would raise millions of dollars. Whenever your superhero is recorded on television or he gives interviews he would put all those banners right into the noble television hours where most advertisers want their products to be seen. This is a quick and easy solution, if not for the somewhat grey ethics about using your costume to make propaganda. [Answer] Investigative Journalist There is a reason Clark picked that profession in the first place. It is the perfect excuse to run off whenever there is an emergency, to head towards, rather than away from war zones. Plus you conveniently get all kinds of first hand information from the things you do personally and from your super friends. [Answer] As a superhero, superman is providing a public service - essentially free. However, his abilities would allow him to make loads of money with effectively minimal effort - for him. Simply as superman approach the commercial space industry and offer to orbit or deorbit one commercial satellite each year, at the bargain basement rate of, say, 10% of the cost of a conventional launch. All because superheroes have to eat too, and this service provides a great benefit at relatively little cost and time, and what's more, it saves the environment from having all those tons of combustion products dumped into the atmosphere. As satellite launches (exclusive of the cost of the satellite) cost 50-400 million US dollars each time, and recovery is near impossible for geosynchronous satellites, a mere ten percent of this (i.e. 5-40 million US dollars) is something that any company in the satellite industry would leap at. Superman could orbit a satellite simply by donning a long-range radio headset that works by bone conduction (There's no air in space to conduct sound in any other way) and a location transponder. He'd then pick up the satellite, fly up with it, and the ground crew could direct him to the right spot using the transponder and radio. This would probably be an hour's work (nothing takes less than an hour) at minimal expense to him, other than his usual large meals. Clark Kent, as Superman's designated representative and friend, selected because Superman spends most of his time in altruistic works, would hire accountants and managers to manage and invest this sum of money, and would receive a generous salary and the right to stay in Superman's many investment properties. To protect Clark from suspicion of being Superman, Superman could also offer accommodation at a few of his other investment properties to other people in need - a predilection for letting friends stay in his houses would deflect suspicion from Clark. Meanwhile, Clark could spend a little spare time getting an education that would let him justify the princely salary Superman is paying him. [Answer] Make Money as a Superhero Whether it's providing relatively cheap orbital lift, creating impossible designer drugs, or literally mind-blowing acoustic concerts, the best way to maximize your income from superpowers is as a superhero. In addition to letting you use your powers openly, it also gives you fanpower - people will pay more just because something is done by a superhero. So now the key is disguise that income so you can use it as your alter ego. And the best profession for that is... Writer Being viewed as a professional writer has a ton of advantages: 1. Income varies incredibly widely between writers depending on how popular their work is. So you basically don't have to disguise or hide anything - you can make wild purchases that would otherwise appear way outside of your purchase range, because no one has any idea how much you really make. 2. You can hide behind a pseudonym. You won't reveal it, of course, but you can imply to anyone who asks that you write under a different name, and that's considered normal. So you don't have to actually write anything. 3. While actual writing takes a ton of work, much of isn't visible. So your fake profession doesn't take any time at all. You can, in fact, use your regular (or irregular) disappearances to enforce your alter ego, rather than damaging it. That time you were kidnapped by Dr. Feel Quite Alright and spend 2 weeks on an island is no longer a reason for you to be fired - you were just working on your next book. 4. You can take your earnings, invest them and turn them into legitimate income for when you eventually retire. [Answer] Become a sportsman Pick a popular discipline. Use your superpowers and show the world that you are the strongest/fastest. Just make sure not to break the current world record too much, as it would clearly show you're "cheating". I'm not sure though if anti-doping tests would not reveal your inhuman nature. [Answer] Warehouse Business I think the easiest and best job for Superman would be in a Warehouse. I know it doesn't sound that great but it actually takes a decent amount of logistics and calculations (especially if he's the only one doing the work, which is what would happen so no one else could see him) I worked in a Warehouse for about 4 years to help get me through college, it was actually pretty fun and the machines that you use are really cool. Essentially a warehousing job entails a lot of MOVING. In a Warehouse employees are constantly just trying to get stuff in the door so you can get it back out. There are [Powered Pallet Jacks](https://www.raymondcorp.com/8400-Pallet-Truck), [Forklifts](https://www.raymondcorp.com/Narrow-Aisle), and all sorts of other awesome equipment to get the job done. Essentially all of the products need to be received, stored, invoiced, and loaded on a truck. This is all super easy for Superman! Because of Superman's incredible speed he would be able to have a HUD Computer (like a Google Glass) which can tell him all of the items that are needed and where they go and he could get it done in just seconds instead of hours! Imagine someone that could actually keep up with a computer telling them as fast as it can what/where products needs to be loaded on a truck! He could own his own business where he would load/receive trucks inside the Warehouse and do all the work himself and then in the morning the truck drivers can just leave with the deliveries. Each truck could potentially have tens of thousands of dollars worth of revenue (even up to hundreds of thousands depending on the products) and the cost of labor would be NOTHING! He could make a fortune in no time! ]
[Question] [ How could mercenaries become a lot more prevalent with well funded & competent militaries still in existence? Basing isn't a problem as there are many areas in this world that aren't (well) controlled by a government. But most of the world is still controlled by a functional government. Most militaries are cold war level large as well as well equipped & organised. National conflict is relatively common. The technology level is ~near future. The biggest issue I see is that why would a government with a well equipped & standardised military want to deal with supplying such a group under their command structure. Most warfare is conventional rather than against insurgents. So why would mercenaries become a lot more prevalent under these conditions? Edit: When i refer to mercenaries i mean a coherent military unit owned privately & fights for whoever pays them [Answer] A private military contractor (PMC) is a glorified service-provider with guns. It follows you'll find some of the same reasons why any company pays contractors rather than hiring people to do the job themselves. And then you'll find other reasons associated to not getting your own hands dirty. Because it's cheaper. Doing stuff yourself implies building an infrastructure and supply chain, hiring people, training them. It takes time and it takes money. A PMC can potentially do the same instantly for less than it'd cost you. Or they'll take on the financial risk for trying something new if it horribly backfires. Because you don't have to micromanage. You give them a budget, a desired outcome and they'll figure how to get to the latter using the former. If they don't achieve results, they're liable for it. That also gives you deniability if they do morally dubious activies. You never told them to "enhance interrogate" people in secret black sites. Because you have someone else to blame. Especially in case of PR problems relating to aforementioned morally dubious activies. I mean, the contract specifically said "no torture please". Because parliamentary oversight does not apply. Depending on their status, their finances might be even completely opaque, which is useful to cover up morally dubious activies. Because it's not your boys coming back in pine boxes. Well, it probably is still, but they're corporate drones fighting for money rather than the sons and daughters of the country fighting for the flag, so that softens the blow. Because technically it's not your military attacking another. Although the country you attack is probably not going to be amused by this subtle difference, other countries might refrain from interfering because, technically, it's a private third-party committing the offence. [Answer] "Army on demand" is becoming a reliable option, and much more viable economically Building modern military takes a lot of time and money. For an average country, all those efforts are just to ensure that it won't get in trouble if there is any trouble in the future. But what if you don't have to have your own army in order to fight wars? You don't need a car if you can always call Uber. You don't need your own internet server if you can get it on the cloud. You don't need to learn a thousand professions, if your roof leaks or if your taxes are too complicated. You just call people who are the professionals - and hopefully better professionals in their area that you can ever be. There are still a few conditions that need to be satisfied * Mercenary companies are becoming more professional, with a reputation to protect; * Military conflicts becoming more permanent, providing mercenaries with steady income and growth opportunities; * Political military alliances (like NATO) are becoming less reliable, with members feeling that they are on their own; [Answer] Deniability A government might want to hire mercenaries for dirty work it would be illegal for the government to do itself. It may also be illegal to hire the mercenary to do it, but it adds a layer of separation and deniability between the decision-makers and the deeds. Cronyism Politicians and bureaucrats like to funnel money to their rich buddies. You scratch my back, I scratch yours. If there's a lot of military spending going on, setting up a private military contractor such as [Blackwater](https://en.wikipedia.org/wiki/Blackwater_(company)#Incidents) is one way to distribute a piece of the pie to your friends at the golf club. Cost efficiency If you have a lot of entities that might war with each other, but are not warring with each other at the moment, then it's inefficient for each of these entities to maintain a large standing army. It's more efficient for them to simply hire the services of a mercenary outfit when it's time to fight. The mercenary outfit spends little time idle, because there's usually someone at war, and the competing entities don't waste budget on an army they aren't using. In the typical cyberpunk setting, corporations hire mercenaries for all these reasons. [Answer] Govenments are broke... but towns and corporations aren't From a very practical point of view a government is nothing other than an organization empowered to use the threat of violence to impose order on society. As the history of humanity has proven, "order" is often a very subjective term that should be modified to, "someone's interpretation of order." A military is nothing more than a national "police force" with jurisdictional rules that are a hair more complicated (although today's police would very likely take issue with that statement, their jurisdictional problems are nightmarish). In other words, when a government imposes its version of order on its own citizens, that's usually a task for an organized group of people called "the police." When a government imposes its version of order on another government's citizens, that's usually a task for an organized group of people called "the military." And, yes, I'm oversimplifying to an extent that will make angels weep. But what it lets me do is treat police and military equally, which in a world with an increased mercenary presense, is (IMO) likely to be true. To-may-to, to-mah-to. It's all still berries used in delightful Italian dishes. You want soldiers for hire to be much more prevelent in your society. That's not as hard as it sounds. Remember, a government's ability to impose order comes from its ability to threaten violence. No threat, no order. No money, no threat. Reduce your governments, no matter what kind they are, to the funding level of a large corporation and your problem is solved — because the government would no longer have the ability to organize, equip, and field a military that would keep ~~vigilantism~~ mercenaryship at bay. This opens to doors to a whole lot of interesting things. Corporations (which today in the real world hire ~~soldiers of fortune~~ private military companies) would need to protect their national and international interestes — and they're suddenly on-par with even the local government to do so. The interest of a corporation is the bottom line, not usually a political ideology. Larger cities and/or towns would be similar, but their focus would be more "protection of resources" than a nation's would be (IMO). I say this because the larger the organization, the more that organization's focus is the preservation of its own power and not the promotion of a particular issue. (But, to be fair, I may be really, really optimistic with that statement.) So, when you're talking about soldiers of fortune, it's all about the money, honey. And you need to have it to hire them. They may work occasionally for food or new equipment, but I believe that would be the exception and not the rule. But so long as a more powerful military and/or police force is unable to stop the mercenaries, your political landscape will remain... complicated. *NOTE: You need to understand that by equaling the field with the use of mercenaries, what you've done is make everything a government. The three kids who run the local Lord of the Rings fan club are a "government," they just don't have the resources to threaten enough violence to impose any more order than throwing little billy out of the treehouse. In other words, your world isn't really any different from today's world — your just calling some governments "corporations" and other governments "outlaw nations" and yet others "The Town of Wichita." In fact, given how much violence the world (and notably the U.S.) has seen in the last two years, your world might not end up looking a whole lot different from the real world. :-)* Having said that, the precense of mercenaries is IMO easy to justify. What's a bit more complicated is writing in the ethics and morals. How does a corporation stop their PMCs from killing everyone in a small sub-African village? Does it matter if the stock doesn't drop? Would the ability for the PMCs to march in a victory parade in the walled town's refounding day matter? I think that's what will be more fun: figuring out how to control what has, in many ways, proven to be uncontrollable, and thereby bring greater chaos. [Answer] Local and/or experienced mercenaries would have invaluable insights. Fictional foreign powers may not look kindly on you mobilising your standardised military into contested territories. However, they may accept you mobilising a group of respected mercenaries. Some countries may produce excellent trained soldiers, but not be well equipped. If these countries aren't proper allies they might loan out such soldiers as sort of mercenaries for a v.high fee. [Answer] Historically, soldiers coming home from a war had 3 life paths: poverty, crime, and mercenary. You can look into why this is from a psychological or economic point of view, but I am only going to do the latter since that is what I am good at. During a massive war, the economy needs to remain functioning while a large section of the population is not participating. In other words, while the soldiers are fighting, their jobs are taken by non-soldiers. For this reason soldiers returning home will usually not be able to reclaim the job they had before leaving. They will also have difficulty finding new jobs because their work experience as a soldier does not translate to many other careers. All of this leads to poverty, which if extreme enough leads to crime, which if often enough leads to organized crime, which if large enough governments and NGO will hire rather than fight. Ta da, we have the first privateers! Alternatively, groups of soldiers skip the crime part and go directly to governments and NGO offering their services as privateers, or mercenaries in general depending on what is needed. [Answer] They are the well funded and (slightly less) competent militaries ... which lost, and have no country to go back home to. This happened a lot in the times of the Jacobite uprisings in Scotland, [or rather, just after, when being seen in your home country was punishable by death](https://www.goodreads.com/book/show/57089648-by-my-sword-alone). Lots of Scottish soldiers ended up on both sides of the contemporary wars between Austria, Russia, and Poland for example. Post defeat, the losing side still exists, and has to eat, and has to go somewhere. They have one profession, and (under slightly better command) do it well; and can undercut any other bidder. And that profession is WAAS : Warfare As A Service. Plus, they are somebody else's sons, so using them on the tougher missions causes less adverse reaction back home. [Answer] Specialty Your armies are cold-war big and competent with current/near future tech. But that DOESN'T mean all-knowing and all-conquering. In fact, the current/near future aspect means it's probably too hard for countries to keep on the cutting edge of technology EVERYWHERE. And as NATO/US forces have proven on numerous occasions, being cutting edge MATTERS. The problem is staying cutting-edge across the whole spectrum of warfare is a trillions-of-dollars enterprise. But states need to play that game, or else their Gen 7.5 tanks/aircraft/ships/subs/missiles will be near-worthless in a standup fight against a rivals Gen 8 equipment. Or maybe even their gen 7.5.1 equipment. It's a rat-race nations have learned can bankrupt them without a shot being fired. So instead they specialize. Maybe in just a few things, maybe in all but one major aspect. Depends on the budget/politics involved. But for the rest, high-tech merc companies slot into the gaps. Maybe New USSR decides it can't match Federated North America's aircraft research. But Blue Wolves merc company in Mongolia has state-of-the-art fighters so New USSR hires them. Maybe Iran figures out it can't keep pace with the Israeli attack subs, so it hires an Indonesian outfit to provide ASW. As to how a merc company could keep state of the art, they'd only be dealing with one specific aspect of warfare. This group ONLY does surface to air missiles. This one ONLY does Main Battle Tanks. That one ONLY does transport helos. With developments in computer design the timeframe to create a new gen of aircraft has been WILDLY reduced (down to maybe a year or two from 20+ see[HERE](https://www.defensenews.com/breaking-news/2020/09/15/the-us-air-force-has-built-and-flown-a-mysterious-full-scale-prototype-of-its-future-fighter-jet/) and other types of military hardware are going the same way. Given you also have some serious factories that are willing to make designs and otherwise supply merc companies, the rest is doable. [Answer] Mercenaries are disposable By law the government must care for the wounded, assist the veterans pay the retirement of those who served for a long time. For the mercenaries a cheap medical insurance and some pension funds that would end up being eaten by the managers by the time they are needed can do. Mercenaries represent a smaller political problem Mercenaries will be recruited all over the world, the death of a foreigner will not make the news as the death of a fellow citizen. Mercenaries after serving will go back to their own country where the media voice is muffled, if they start talking too much about what they were ordered to do on the field it would be easier to cover it up. Mercenaries are more controllable Mercenaries can be signed up with contracts full of fine print. It will be easier to stop paying them and get rid of them if they complain too much. [Answer] Multiple reasons could trigger the use of mercenaries by many governments, and thus existing mercenary companies. So you can choose your own solution between those given by all the answers, but it is important to consider some points: Mercenaries were most of the time in history the way to have soldiers Especially, in Europe during all king's wars, mercenaries (either from the nation or foreign) were the bulk of the army. * So overall, your justification should onlybe about why the societies have a path different from us. There is no difficulty in the justification of mercenaries The use of national army is heavily linked to the idea of citizenship In history, having an army made of citizens of the country was often triggered by heavy consciousness of citizenship and it triggered important debates about the place of the army in the society. * This is a good reason: our current country, with small professional armies (example of Europe), might easily come to use mercenaries because of less involvement of the civil society. Existing mercenaries are previous professionnal soldiers Current technologies might favour mercenaries Imagine for example Google (or an other big computer company) creating a cyberdefence mercenary branch: they will surely be better than most of cyberdefence department of common states. Other example: you could imagine a national army turned for defence (interception, control of national sky... for the air force) and the mercenaries come in for the offensive part (cruise missiles, bombers....) Opening cost is high The most important difficulty for your mercenaries will be to be viable with the heavy cost involved for acquiring hardware and training with that. [Answer] ## "Optics" You need/want to help the people your government freed from a dictator, but your army is an army, not civil engineers. So, you've hired contractors to do this type of rebuilding work, from new roads to new buildings, new schools to new hospitals, new hydroelectric dams to water purification systems. However, a military presence is still needed in these hostile/disputed areas to protect the people working these sites, as well as the equipment and the sites themselves from death and destruction. If you leave your own military personnel there to provide this protection, you do 2 things: * It looks like you are (only) protecting the assets of the company you hired * Your trained army isn't doing battle on the front lines This looks bad in the papers, since you're apparently draining resources to support the greed of companies as well as having to deploy ever more troops to the battle. This last bit on it's own looks bad since you are depleting your reserves, needing to continually recruit more people, and your training programs eventually can't keep up with the demand. So instead, you approve the/a civilian company to hire it's own militia/bodyguards/defenses and get your people back where they are fighting the bad guys again. The civilian company doesn't have to worry about training, since they can simply hire veterans that already have the training, but were retired, medically discharged, or simply didn't re-enlist. In some/many cases, the pay and benefits is better for civilian mercenaries than the government's military, so after an initial stint in the military, people specifically don't re-enlist to become mercenaries. ## Real life In fact, most of this is pretty much how the USA works in Afghanistan and other countries it's been fighting in for the last 100 years or so. Yes, the Army has the Corp of Engineers, but they are generally there to build temporary structures or to help civilian governments design/build infrastructure, not to do it all. The CoE is also tasked with demolition, so they can also be needed on the front lines to help figure out the most economical/fastest way to destroy an enemy stronghold. [Answer] State militaries are incompetent in several ways. <https://www.washingtonpost.com/graphics/2019/investigations/afghanistan-papers/afghanistan-war-army-police/> > > But in a trove of confidential government interviews obtained by The > Washington Post, U.S., NATO and Afghan officials described their > efforts to create an Afghan proxy force as a long-running calamity. > With most speaking on the assumption that their remarks would remain > private, they depicted the Afghan security forces as incompetent, > unmotivated, poorly trained, corrupt and riddled with deserters and > infiltrators. > > > In your world (and ours) many countries have militaries that are terrible. Units cannot be relied on to fight and even if they stay and fight, they are bad at it. There are multiple reasons for this and the reasons might vary from one country to the next. The bottom line: if you need competent soldiers, you need to hire them. ]
[Question] [ I have a handful of immortals that have spent the last 6000 years stuck on planet Earth. They really, want to get out of here. They missed their chance back in Egypt before The Fall of the Pharaohs\\. This time around they aren't going to miss the next opportunity off this rock. They are planning ahead. In the next 100-200 years, we will develop generation ships to take us to the stars. Explore the cosmos, colonize space and new planets and all that. Everyone is very excited, including the immortals. Currently they are hiding in plain sight, moving every few years/decades etc. Unfortunately the [concealment methods](https://worldbuilding.stackexchange.com/questions/75040/how-to-conceal-my-immortality-without-hiding-for-a-hundred-years) they have been using will be reduced on the Generation Ships. At first they wondered how they would hide on a generation ship, then they realized they first needed to figure out what type of generation ship to travel on. They know that they won't be able to hide their immortality on the initial smaller generation ships. They have experimented, and all signs point to cryogenics not working for them. As long as the Second Fall doesn't happen anytime soon, they have to wait for one of the larger capacity generation ships. They aren't worried about the design of the engines or fuel. Well they are, but they are more worried about the social structure and spatial planning of the ships. They have been studying up on psychology, urban spaces and social engineering etc. They can become leading experts in the fields necessary to influence how the [Ships social spaces](https://worldbuilding.stackexchange.com/questions/30283/generation-ship-design-accommodations) and human movements around the ship etc are planned, well before we ever leave the planet. What sort of generation-ship design would allow a handful of immortals to remain hidden? \\\* Answers should take into account the ability to hide a handful of un-aging individuals in a relatively small population (compared to overpopulated Earth), as well as in a confined space. The immortals wish to remain anonymous, they have the same mental health requirements as a typical human (they don't want to go hide in a corner very often). A good answer is one that somehow incorporates multiple concealment redundancies into the ship-design, just in-case someone catches onto them. Users can determine how big the ship will need to be. Answers should try not focus on the method of Engine design/feasibility but rather on the social aspect. The immortals are willing to be live separately so as to avoid suspicion, and have committed to no reproduction while in-transit. Transit will take 5-10 generations. --- \\The Fall is when a highly sophisticated civilization falls so far backwards in progress, that later populations believe they are the first to become so advanced. \\\* This is not a homework question. [Answer] I think the key is that no individual should encounter any particular immortal for a period of longer than a decade or two, whether as a neighbor, coworker, or service provider. After about 20 years it'd be real hard not to notice that the immortal never aged. Some places to hide in plain sight then, might include: * Caring for the elderly: Old people would see the immortals as much younger, and any of them that hung on to extreme old age would probably not notice that the "45-year-old" nurse still looked like a 25-year-old, or they'd blame it on their failing eyesight. * Educating young children: Kids in school think all adults are "old" and don't distinguish much between teachers by age, and they may never see the teachers after a few years in school. (The challenge is how to explain why the parents don't notice the teachers don't age. Maybe all the schools are boarding schools?) Another solution to the problem is to have the immortals live by themselves in one area and rarely interact with other areas. A few ways to do this might include: * Self-regulating "guilds": The ships physicians (for example) could be a guild that keeps their trade secrets to themselves. All physicians are sons and daughters of physicians (or so it seems) and they have their private living quarters, so there are no medical schools open to the public and you'd only meet a doctor in his professional capacity. The doctor's guild of course decides who you see for your appointment, so you won't see the same doctor more than ten years apart. Engineers, lawyers, priests, navigators, and others could also be organized into guilds, so everyone sees it as normal. Guilds existed in the middle ages and Renaissance in Europe, so the immortals might influence society to revive the idea. * Generation fleets: Immortals foster the argument that for the sake of redundancy, not to mention human freedom, the colonists not put all of their eggs in one basket under the command of a single captain. Instead of generation ships, launch flotillas of hundreds of smaller ships, each self-governing. Trade and culture will flourish because of the differences between ship cultures. Genetics will be healthier in the long run because young people will marry outside of their home ships. One ship will seemingly be very private and keep to itself, but with all the diversity, what's so unusual about that? [Answer] Hide as the crew of a cryogenic ship. Realize that cryogenic is the more advanced form of ship. It allows people to travel in their own lifetimes. If a civilization has workable cryogenics, it won't bother with generation ships. So your idea of waiting until they switch from cryogenic to generation ships won't work. You actually may be waiting until they switch from generation to cryogenics. You point out that cryogenics don't work on the immortals. That's fine. You don't care. So long as you can overprovision the cryogenic ship to support the immortal crew outside cryogenics, they can act as the crew. They won't be able to have kids for the period that they are on the ship, but they're immortal. They aren't in a hurry. Your immortals can design, launch, and crew their own cryogenic ship. When they get to the destination, they unfreeze all the colonists. The colonists don't know that the immortals never entered cryosleep. The critical thing here is that instead of hiding amongst normal people, here you are hiding as a separate group of people. The sleepers won't expect other people to age, so immortality won't matter. Because the immortals provide the entire waking crew and designed the ship, no one else needs to know that they were awake the whole time. [Answer] Only immortals are on the ship. Presumably some of these immortals are filthy rich. Once the technology exists, one of them masquerading as an eccentric billionaire (or maybe no masquerade) commissions a generation ship to be built for him and his handpicked cadre of friends. The public line: he will sleep through the trip and awaken on a paradise planet. This dude has pulled stunts like this before. The engineers are happy to take his money and build his little ship. Once en route the immortals can relax - for the first time in a long time. [Answer] ### Religion All the immortals pretend to be members of some religion that wears a mask all the time. This may be a religion that they started. It should also have its children educated privately without ever leaving their chambers. They also have their own separate health care and burial rituals. On the ship, no one actually knows what the immortals look like without their masks. So every so often, announce that an immortal died. The "dead" immortal switches to a new department as a new adult. Perhaps there is a five year vow of silence or something so as to make it less likely that the immortal is recognized. They may have rules limiting conversation between the masked and unbelievers. Or maybe they only "talk" in sign language. They may have extra participants in body disposal and medical so that they can catch problems. For example, if one of the masked is injured. Or to fake up a body disposal when an immortal "dies." This is a variant of what they were presumably doing with the larger population. Stick around for a while and then when their lack of aging becomes noticeable, abandon that identity and move to a new one. The masks allow them to extend the period where a lack of aging won't be noticed. Or perhaps they don't make distinctions in personal identification. So the masked may be constantly switching jobs. People won't be expecting to know with whom they are dealing. Their "religion" makes them deliberately interchangeable. [Answer] If they could become experts in robotics and develop very lifelike androids. The android AI only has to be good enough to market itself, and they only need to make one sale. They have plenty of time to pull this off, so the the AI can be rules-based and just have very complicated rules. The immortals work hard to produce androids which look very similar to themselves and seem intelligent from a distance. Then they hire salesmen to sell the androids to work in food service on the generation ship. When the salesmen have made a sale, they replace the lookalike androids with themselves at the last second, and spend the next 5 generations posing as very complicated androids. Back on earth, they've already put into motion a plan to destroy their android "factory", and fake their own deaths, so no future ships will have these same model androids and nobody will be able to figure out that the androids weren't as good as the marketing suggested. During their time on earth, as technological leaders, they can also influence the design of the ship so as to give the androids a decent boarding space. Alternatively, they could design a large unused cavity (or maintenance storage area) into the ship, accessible from where the androids will be expected to reside. Food and restrooms will be easy to access since the androids will presumably live in the back of the restaurant where they serve. They can always just block off the bathroom "for cleaning" when they need to go. One of them could be an android specialized in living amenities, and secretly issue clothes and bedding to the others while the others secretly issue food to that one. ]
[Question] [ Cars seems to be everywhere in most cities and they create a lot of problems. For example: * dangerous pollution * traffic accidents * pedestrian/cyclist insecurity * less human contact * health/obesity problems * congestion and less space for people * fewer green areas Say you want to get rid of the cars, i.e. make your city car-free. What could you do to accomplish such a goal if you: * are alone and not part of any organizations etc. * doesn't have any political position/power * have a normal job, so you don't have endless time/energy * have a tiny budget (say less than $10,000) [Answer] As with all things that seem impossible, like eating an elephant, the trick is to do it one bite at a time. So... Start by using your 10,000 to get yourself elected to your district's city-council seat. Hopefully you are in a small city with district rather than at-large elections, and the 10,000 is enough. Mind you, you get above 100,000 people, and the 10,000 [probably won't cut it](https://www.uwb.edu/getattachment/policystudies/why-policy-studies/student-work/malinowski-capstone.pdf). But you also need to be sure to follow a good strategy that will take years to implement, even to just get on the council. Then start with small steps. Maybe start to encourage that the historic downtown get cordoned off for vehicles, so that people can park on the outside, and walk in. Change the roads to being for bicycles or other non-motorized transport. The city builds a parking garage right outside the cordoned off area and gets income from the parking fees. Then start growing the idea. Just growing one spot may prove undoable, as it would be difficult to grow it large enough to make mass transportation viable, before people get too leg-sore to accept the change. So grow it by building on the success. The first spot is doing so well, that we cordon off another spot, in another part of the city. Maybe create a large park area on the outside of the city - trails, outdoor amphitheater - and/or maybe your city has a river, away from the historic downtown, so you convince the council to move towards developing a river-walk a la San Antonio river-walk. Then add in mass transportation. You can start by adding it between the two spots that were pedestrian only. Can do some shopping and sight seeing in historic downtown, then zip over in the electric trolleys to the river-walk for more shopping and dinner. Then start making spots in between the two areas, in the trolley's route, also pedestrian only. Now you have mass transportation and the community starting to get used to the pedestrian-only areas, so you can start growing it more. Mind you, you'd have to be one crazy good demagogue. People are going to be incredibly reluctant and push back every step of the way. If you were someone with the charisma of an Obama or Bill Clinton (I may or may not be against disagreeing with their politics, but cannot deny their charisma), you may, one chance in a million, get the plan through. But that would make for a good story. Someone with that kind of charisma who rather than going for power, decides to simply transform his own community for the better. [Answer] it depends on how committed you are to ridding the cars from the city, learn how to make bombs, put bombs in car-heavy people-light locations (car parks!) and make then inaccessible. In addition, call in bomb threats/make more bombs and plant them on major roadways. Then call up the local radio stations and announce that you hate cars, that anyone driving a car is a valid target and that you won't stop. Then stop... for a while and keep committing these acts that hurt as few people as possible and make as much impact on traffic congestion. Make sure that local transport is completely unaffected by your bombs... Then it's just a case of not getting caught... [Answer] I don't own a car (and don't particularly want to). So I have to get to everywhere I want to by walking or using public transport. Here's what you would have to do in my small city to make people abandon their cars for walking/public transport. It'll cost way, way, way more than £10,000. Make public transport really cheap, really frequent, really efficient... and really go everywhere people want it to. Buses/trams/tube trains/local trains which run every 5 or 10 minutes all day, every day and on every route to myriad destinations are what the public wants. They don't want to stand for long periods in the rain, with them, their children and their shopping getting soaked while they wait for a bus/train. But because the bus companies are trying to maximise profits, they don't do this ultra frequent, ultra efficient timetabling. So there are buses which only run once an hour. Buses which don't run after 19.00. Buses which don't run on a Sunday or on public holidays. Buses which do run every 10 minutes but are so packed no more people can get on board. And Grud help you if you want to go from one side of the city to another - that'll meaning changing buses/trams in the city centre. Lucky you - you get to stand in the rain twice! Maybe 3 times if you live in a really big city. Then you get to do the same on the way home! :-) Redesign your public transport. Parents with pushchairs want to use buses. People in wheelchairs want to use buses. People with luggage or big parcels want to use buses. Oh dear, 2 prams, 1 wheelchair user and 1 person with an enormous suitcase are waiting at the bus stop and the bus only has room for 2 of them, because of the way it is laid out. More waiting in the rain... Redesign buses to have more room for families with prams, people carrying enormous stuff from Ikea, kids with scooters, etc. You'll have to sacrifice seating to do this, so you'll have to run MORE buses to compensate. Train and tram carriages should be the sort which can carry bicycles and lots and lots and lots of prams/wheelchairs. And have decent luggage racks, not the stupid little ones which barely fit a briefcase. Completely redesign the layout of your city. All sorts of things in modern cities have been designed with cars in mind. Edge of town/out of town shopping centres, cinemas and/or industrial estates, for instance. When public transport is intregrated into these, it is usually as an afterthought: Ooh better ask the bus company if they want to run a bus to the new multiplex... Oh, they don't. Ah. well, never mind. So don't let anyone build anything without incorporating a railway or tram line or tube line as part of it! Rail transport indicates you really mean it. Buses are a poor alternative. Crash house prices and drop rents. People are commuting further and further by car, because they can't afford to live in or near the city centre. Housing estates are built on greenbelt land because it is cheap. If you make the centre and inner parts of the city affordable, people can walk or take a short bus ride to work. Invest your $10,000 in a physics professor's research project and hope he invents teleportation. Public teleportation is pretty much the only way to sort out my city's transport problems! [Answer] To make a city car free you need popular support. You simply won't get that unless you provide replacements that are perceived as being superior. Some alternatives already exist, which can be reasonably perceived as being superior, but in many cultures they are perceived as being inferior. Change the perception \. A combination of bikes, public transport and road pricing works well in practice, in several cities. Removing cars altogether doesn't really work well in any cities yet (how do you restock shops or move furniture?), unless limited to a tiny area where some kind of motorized vehicles still are allowed, e.g. [Zermatt](http://www.zermatt.ch/en/arrival). \This is something an individual can help with in countless ways. [Answer] There is a boring but non-violent and, what is more, actually feasible possibility, that even has the benefit that you can keep your bucks. Join a political party. Work your bum off. Find like-minded people, team up. Develop a concept that provides an alternative to individual motorized transport. Find more like-minded people, and team up more. And work harder. And then, maybe, after two or three decades, you might just be able to achieve what you are trying. Why? Motorized transportation is an actual necessity in many cases. While it is a commodity for a large part of shoppers, and even commuters, it is (almost?) impossible to replace for delivery, for anybody who carries heavy tools to work, ambulances and whatnot. Also, such a drastic change requires time for people to accept, even when the alternative is already provided. So, no, in a reasonably realistic world-setting, i don't see a different way given your setup. [Answer] Naturally there are, in the real word, people and organisations who have $10k and who all else being equal would prefer their cities to be car-free. They have not achieved it just by wishing it so. To do it without any allies, time, political power, or resources, is going to require an immense amount of serendipity, or else some form of power other than explicit political power or money. Assuming that what you want is for some character to achieve this (or to have achieved it in the past) with minimal effort, then I would suggest they rode the crest of a wave not of their own making. That is to say, the city was already well-populated with people who did have time, money, dedication, and influence, and the character in question somehow catalysed them. For example, perhaps some little old lady gets knocked off her bike three times in the same week and "accomplishes her goal" of getting rid of cars by soliciting enormous sympathy and outrage. The populace has to be on the verge of banning cars anyway, because a city in which driving is the primary means of transport would much rather cripple a few little old ladies than cripple its own infrastructure. Another way would be someone who has no money or political position of their own, but has influence over someone who does. So for example the child of an autocratic mayor makes a passing remark that cars are stupid and should be banned, and the autocrat decides to make that wish come true at any cost. [Answer] Well, I know that you didn't give a `reality-check` tag, so based on some fictional world there's always the possibility that $10,000 can go much further than it does in our contemporary world. Assuming that you mean in something based on our current reality, it would be virtually impossible. Some ways that a city could be mad car-less would be: * Other forms of mass transportation: subway, light rail, trolley, even moving sidewalks could take the place of cars, but something would have to be available in their stead, and older, real examples of this (horse-drawn buggies) are not efficient in a modern city for the sheer volume of people that need to move about. * Applicable city zoning and residential regulations: residential areas would be more strongly intertwined with commercial and industrial zones, and people would be required to live near their jobs. This, of course, flies in the face of liberty and also would create hardship if someone left their job, a company closed, or if for any other reason they needed to be closer to a different zone. This would also make it difficult for a successful company to grow. * Replace cities with [Arcologies](https://en.wikipedia.org/wiki/Arcology) (Arcos): this removes the need for #1, and really shores up #2, but the difficulties of #2 still remain. The idea of a self-contained metropolis is very appealing from many aspects, but there are a variety of reasons that none (of any useful scale) exist today. All of these options require a significant amount of money and planning and time, and would require a large number of people to be on board with the idea and planning. [Answer] It's only going to be possible if you have one or more of the excluded list. Cities need transportation in order to bring in commerce and jobs. Simply stopping cars/trucks from entering the city will cause huge problems in terms of overloaded public transportation and there being little way of distributing goods to anywhere not directly adjacent to a rail station. In order to create a car-free city, you'll need to build the infrastructure that's going to support the whole city. For that, you'll need money and/or political clout. And a lot of charisma too. [Answer] # Giant Travelators Basically I'm picturing two travelators going through the middle of the city, each going the opposite direction. These platforms are wide, with seats along the side, so you can either sit on the seats like on a bus and be carried to where you want, or you can walk to where you want, along the moving platform. This means we get back to walking, which is healthy, and the travelators boost our speed by a good 5-20mph (you could have a few of varying speeds). How can one man do such a thing with $10k? Kickstarter! Too hard for electricity? Make some manmade rivers, and use their current as the underlying base. ### If cheap travelator technology was developed, I can imagine cities as they are, but instead of static concrete, the streets are moving platforms you can use at your convenience. [Answer] Revisiting the need of car free city I don't feel making city car free is really needed, because * It presumes cars are behind all/most issues that you noted * Everything has some purpose / good purpose and I feel cars do provide some such purpose... Solution: Education!!! Education is the only source of prolonged and self-enduring change. We need education because * to tell people that we REALLY REALLY don't need to have car when we are commuting alone (of course there are exceptions...say in India at very late hours in villages where there is really no means of public transport, we just need personal commuting option. But then it may be a car or a bike depending upon the need and situation. So here we have genuine case where cars do serve good purpose. Simply force fitting one rule to all can never be wise action.) * to teach people to not to interprete car (and any other possessable thing) as a luxury/status symbol. This is simply ill-interpretation. Prolonged practice of such perceptions makes our mind unhealthy. Our mind get caught in perception which when vanishes makes us miserable. Simply put we becomes slave of our own wrong-formed perception. The funniest thing is that we form such perceptions by practicing them for decades!!! And it becomes absolutely impossible to completely abandon such perceptions at the time when they fail to satisfy and we become miserable. Best thing to have schools which will teach us what is actually sensible to practice / to instead of just teaching maths and science. * to tell people that it bring happiness to bring more happiness to others in exchange of some pain to ourselves, to make world more cleaner/greener in exchange of some inconvenience/discomfort. * because education is (at least decade) long procedure to mold brains in sensible manner so that they will know + when is right time to take out personal car + when to follow public transport + when to take some discomfort and go by public transport + when to do right thing, in right manner, at right time (in general) * not to mention to give willpower to our politicians to honestly put efforts in building public transport and to do any other thing that they take up as their responsibility * last but not least, it educates Me. So change can start from Me!!! (I prefer this one over above) We cannot achieve enduring, perfectly balanced solution to any issue overnight. We need to have long plan to ensure stuff will just work forever. We might build innovative zero emission transportation solutions...but then building them everywhere on earth wont be feasible. But educating people over a period of time is very much possible. And they will then do only right things, not just deciding about how / when to travel. I believe proper education is the key to every problem. Today's education is centered towards employment, not empowerment (again of course there are exceptions, but I feel this is what a major outlook of current education). That's why after so many "Empowerment drives" we still feel world's misery is not yet over. (Some may feel its increased.) Pollution and other issues are just different forms of misery arising out of ill-education. [Answer] Ok so this answer may be a bit more... extreme/silly, but it is very fast and efficient and your rules don't explicitly say anything against it. Using your tiny budget (the more the better though) self-manufactor or buy explosives and then use them to destroy parts of the roads or throw it into a large area of cars. However, the plan could be altered to have less evidence pointing towards you as the basic idea behind it is to remove the necessary infrastructure for cars, as well as cars themselves. Simply destroying the cars by tinkering with them when their owners have gone would also be viable, however the explosives idea would also remove a large amount of infrastructure needed. It would sure get a lot of cars off the road, and hate too... ]
[Question] [ There is a planet called Vegavampira, and on this planet the only really intelligent animals are Vegan Vampires, but there is one problem, because they are Vegan, they will not kill, nor will they take blood or animal products without the animal's prior consent, however, as they are the only sentient beings on the planet that are intelligent enough to provide consent, they are unable to feed from the animals that live around them. And to survive these Vegan Vampires must feed on the blood of non-Vampires, even though another Vampire would happily give consent for their blood to be given to another Vegan Vampire, the Vegan Vampires specifically need a substance to stay alive that is contained only within non-Vampire blood. So here is the question, if they are unable to feed upon the other animals on the planet (as the other animals are not intelligent enough to give consent, and maybe they wouldn't want to), and Vampire blood doesn't do them any good, how will they survive? Note: They will accept non-vegan produce if consent is given, or there is no being to give consent (that if it did not come from a being - animals, plants etc not included). [Answer] There is no way the vampires in this world have always been vegan. If vampires naturally feed from blood, at some point they naturally did drink blood from the creatures around them. It might be barbaric, but there would be no vampires stupid enough to starve themselves to death when they have the means to feed themselves. As your Vegan Vampires matured as a species, so did their knowledge of the world around them, and they learned about what in the blood they drank is what they actually required to live. Some vampires would have started experimenting in how they can create blood, or at least the substance in the blood they require, by other means. You can, for example, synthesize this substance, or find or create plants that fill the need that could previously only be sated by drinking blood. Eventually that can develop into vampires that find it morally wrong to feed on creatures when they don't give their consent, instead relying on these alternate means. [Answer] According to the question, they aren't against meat or animal by products in and of themselves, but are against killing and are against taking animal by-products without consent. The simplest answer is carrion. Carrion would have none of these problems. Instead of killing a cow, then draining its blood to serve the vampires, let the cow die of old age. [Answer] Some animals on Vegavampira could have periods. One meal per month is a tough diet, but it could be enough for a vampire. [Answer] They go beyond veganism, beyond Jainism even, and become breatharians. <https://en.wikipedia.org/wiki/Inedia> > > Inedia (Latin for "fasting") or breatharianism /br…õŒ∏Àà…õ…ôri…ôn…™z…ôm/ is the belief that it is possible for a person to live without consuming food. Breatharians claim that food, and in some cases water, are not necessary for survival, and that humans can be sustained solely by prana, the vital life force in Hinduism. According to Ayurveda, sunlight is one of the main sources of prana, and some practitioners believe that it is possible for a person to survive on sunlight alone. The terms breatharianism or inedia may also refer to this philosophy when it is practiced as a lifestyle in place of the usual diet. > > > Since [Carrot juice constitutes murder (and) Greenhouses prisons for slaves](http://www.metrolyrics.com/carrot-juice-is-murder-lyrics-arrogant-worms.html), the only truly ethical way to live is to breathe and absorb the energy of the Sun!! [Answer] So there is no way that these vampires could have evolved into vampires if they were always vegan but, if your talking about a recent thing where all vampires have become vegan, there is a solution. I've put a link to a Telegraph articel about a kind of GM Crop which was created a few years ago. The idea is that, to get more blood for transfusions, human DNA was inserted into rice DNA to create rice that blood can be extracted from. Hope this helps! <http://www.telegraph.co.uk/news/science/science-news/8871899/Genetically-modified-rice-created-to-produce-human-blood.html> [Answer] One word: maple syrup Maybe they are Canadian vampires? Just saying... Ok, Seriously. Maybe they can go for an extended time, say 50 years or so, even if it puts them in a weakened state. Now suppose there was at one point a sentient species on their planet capable of giving consent. Maybe it was some kind of symbiotic relationship. Where said creature got something in return from the vampires. Now perhaps for some reason this species died out. Something in their symbiotic relationship broke down. Maybe they over populated their world and they other species couldn't keep up. Maybe it was some illness that wiped them out. I don't know. That would put them in the current state, which is untenable, but still have a history that was. I don't see how they could survive to this point, unless it was so. [Answer] # Do it like the ancient greek This part is interesting: > > nor will they take blood or animal products without the animal's prior consent > > > The ancient greek had the same ethical problem. In their ritual sacrifices of animals, they had to obtain the consent of the beasts. The greek had a solution for every problem, though. They invented a nice little device called # Hipocrisy Which Google defines as: > > the practice of claiming to have higher standards or more noble beliefs than is the case. > > > Check out [this description of how a sacrifice was done a couple millenia and then some ago](https://www.thoughtco.com/method-of-sacrifice-in-ancient-greece-4079925): > > The pouring of water on the head forced the animal to "nod" in agreement to the sacrifice. It was important that the sacrifice not be treated as an act of violence; instead, it must be an act in which everyone was a willing participant: mortals, immortals, and animals. > > > Then the person performing the ritual would pull out a knife (machaira) that had been hidden in the barley and quickly slit the animal's throat, allowing the blood to drain into a special receptacle. > > > Your vampires could do the same: pour some water on the beasts noggin' while asking "hey, can I have some of your blood?" --- If that's not your style, [Vampirella](https://en.m.wikipedia.org/wiki/Vampirella) is a comic books character that comes from: > > planet Drakulon, a world where a vampiric race lived on blood and where blood flowed in rivers. > > > [Answer] My vampire is vegan (well, as far as human food goes) because the process of being turned altered his digestion. Essentially it has left him with multiple intolerances. The only animal product he is safely able to consume is human blood. So, long story short (too late!), he is forced to ethically source the same nutrients from plant based sources, as well as genetically engineering a suitable substitute (rather like the rice answer).(<http://amzn.eu/5LeqUnu>) One possible way would be to analyse what constitutes blood and source those elements from plants. There are plenty of info graphics that show how plant sources of vitamins/minerals/etc measure up against their animal based counterparts. Just ask any vegan where they get their protein/carbs/B12 from and they're happy to help. üôÇ fitbit.com/foods/Lamb+Blood/7287 The link is just an example. [Answer] [![Vegan Vampires](https://i.stack.imgur.com/BpvKA.jpg)](https://i.stack.imgur.com/BpvKA.jpg) Essentially Vegan vampires could exist in this situation but they would only be eating fresh "virgin" if you will :) coconut water... [Answer] Let's not forget the idiocy introduced into the vampire lore recently where abouts the sun just causes them to twinkle merrily and not burn to ash as other stories have told. While this is one of the dumbest things to enter the vampire realms, it does set a a standard that illustrates just how much freedom you have to change the way things work for everyone. I once wrote a jesting short story about a pre-pubescent dorky vampire that revealed... > > "You know the whole blood thing? Vampires, sucking blood, all that? > It‚Äôs not true at all. I don‚Äôt need to drink blood to survive. I‚Äôll > tell you what it does do though. It keeps you from feeling absolutely > drained of energy. There‚Äôs something about the components of > hemoglobin that stimulate the endorphins in the vampire body. I don‚Äôt > know all the facts because only one other vampire was kind enough to > stop laughing long enough to tell me. I haven‚Äôt had any blood for > about 29 years because it‚Äôs too much work and I don‚Äôt care to live my > life to the fullest anyhow. Plus, I never had the nerve to kill > anyone. I used to bite girls in school and taste their blood before > they beat me up or one of the monitors pulled me away, but that‚Äôs > about it. Aside that, I tried to drink the blood out of a package of > steak from the grocery store, but it didn‚Äôt really help. Since the > effects were so minimal, I figured it would take immense effort to > maintain such a life style. Even if I did have the nerve to do it, the > only thing I fear more than an eternity in the condition I‚Äôm in is > suffering an eternity in jail while in the condition I‚Äôm in. Where do > you even send someone that‚Äôs my age but looks like a 13 year old?" > > > I simply changed the rule. You don't need it to live, but it really helps. After all, nothing else short of wooden stakes can kill you, so why can you starve to death? The laws of nature have already been abandoned. Why cling to tradition? [Answer] I think Anne Rice provided this answer. Vampires are immortals. As punishment, vampires entombed naughty vampires in stone vaults to starve them. They don't die, they just get hungrier and hungrier, if they don't feed. A Vegan Vampire can simply forego feeding on anything it deems unethical and they will only feel unformtable as a consequence, which is identical to how they'll feel if they fed on something unethical. ]
[Question] [ Based off a [previous question of mine here,](https://worldbuilding.stackexchange.com/questions/10645/what-would-poverty-be-like-if-there-was-an-infinite-supply-of-food) concerning how a rapid growing weed-like grasstato, which is grass above ground, and potato underground, and how if there was infinite food for people in a medieval setting, how would the poverty-stricken life be like. Anyways, so some comments pointed out that the grasstato could grow as fast as bamboo, being capable of growing 10 inches vertically a day, and, this is my own version, probably 4 feet horizontally a day. One thing to note is that the grasstato only grows in this one specific kingdom because of magic, and besides being fast growing, the grass of the grasstato is regular grass, and the potato of the grasstato is regular potatoes What this means is that there will be a lot of grasstato growing all over the place like a menace, in any crack their spores can find, which is one of the main reasons they need faster ways of using it all up. [Aside from feeding the grass to the many horse that are there](https://worldbuilding.stackexchange.com/questions/10218/horses-for-absolutely-everybody-how-it-came-to-be), and feeding the potatoes to the people who live there, is there any large scale industrial use of grass or potato? Don't forget that this is in a late-medieval magical setting. Also, this is my entry for the Fortnightly topic challenge #2: Flora. [Answer] At the rates of growth you are talking, either people would have to be nomads, constantly moving because any structure would be almost impossible to keep from being overrun, or you would need an effective herbicide that can be reasonably long lasting for areas, and shouldn't be too toxic to humans. Something that could be applied once a week or month to an area. The growth rate you are talking about would take half a town most of it's time picking the potatoes and keeping them back. Of course they could also build underground with some doors and windows to the outside world, keeping a few openings free and clear would be a lot less work, then towns would just look like rolling hills of grass to the uneducated. Could be safer against attacks too. [Answer] They can start distilleries which can export grasstato [vodka](http://en.wikipedia.org/wiki/Vodka) to the surrounding countries. The grass part of the grasstato can be used as fuel in the distillation process, while the potato part can be used as the starchy product for fermentation. [Answer] I prefer the vodka in March Ho's response. Next would be a way to get much cleaner water than from a river or lake. River water used to be mixed with an alcohol to kill germs - instead, you could extract the water from the grasstato (potatoes have the [highest water content](http://en.wikipedia.org/wiki/Potato#Comparison_to_other_major_staple_foods) of any staple), and use the remaining part of the potato for distillation of its sugars. Grass has been used to make paper [since at least 2400 BC](http://en.wikipedia.org/wiki/Grass), so there are your labels for the vodka bottles (that was just for fun - you could use it for many paper products). [Answer] If you want to extend the grasstato to being a little more bamboo-like, with big thick stalks as part of the above-ground portions, there is a whole wealth of things you can do with bamboo. New shoots are good for food for both people and animals (once treated, anyway--they contain a cyanogenic chemical in them that can cause a world of poisoning if they're eaten in the untreated form); grown stalks can be harvested and used exactly like wood in construction, decoration, textile making, and so on. Wikipedia, naturally, has [a thorough but not exhaustive list](http://en.wikipedia.org/wiki/Bamboo#Uses) of uses. There are [many other such lists](http://www.guaduabamboo.com/uses/products-made-from-bamboo) available, if you search for "uses of bamboo" on your favorite search engine. If we're just talking what's actually known as "grass" though--and there's lots and lots of things that fall into that category, among them many of our cereal grains, sedges, reeds like water chestnuts and papyrus--there's still a whole bunch of uses they can be put to. Combining it with that ever-present horse manure in the setting and condensing it into bricks--for building or for burning--is one easy option. Then there's weaving it, to make baskets, thatch roofs, or fabric (grasscloth). The seeds can be used as food as well (this is, after all, how we get wheat, wild rice, and a number of other cereal grains), or fermented to make beer. Unfortunately one of the better uses of grass--sod bricks for building--probably will not work the grasstatoes, since sod relies on the propensity of grasses to make tight interlocking root networks and having random tubers in there would disrupt that. As for the potato part, well--the uses of potatoes for vodka have been well-covered, but there are various and sundry other things you can do with them. In purely food-based uses, potatoes can also be rendered for starch that can be used for baking, or fed--either raw or cooked--to farm animals, though they can't be the only source of feed. Potato starch can also be used to make adhesives, and in a more modern setting, [plastics](http://www.nuffieldfoundation.org/practical-chemistry/making-plastic-potato-starch). Since there's magic in this setting, you might be able to come up with a way to magically process grasstato tubers into potato-starch plastic--then imagine the sort of economic havoc the grasstato kingdom might be able to unleash as the sole producers of plastics in the setting. Then there's also some more mundane but still unusual non-food uses of potatoes that the people of your kingdom would also figure out, like using them in wound healing, or using water from potato boiling to polish up tarnished silver. (I'm trying to find a better reference than HGTV and Reader's Digest for these, but I can't seem to right now. [Here](http://www.hgtvgardens.com/potatoes/one-potato-two-potato-9-unusual-uses-for-potatoes) are some [links](http://www.rd.com/home/extraordinary-uses-for-potatoes/), though.) Basically, both grass AND potatoes are fantastically useful, so there's a lot that could be done with them. [Answer] This was touched on in your horse question, but with infinite vegetation you could have near infinite livestock. Goats may provide a good solution for both keeping some land clear of grasstatoe and providing your people with a source of protein and surplus goats, cheese, and hides for trade. This may sound like a joke but in some places [you can rent goats for land clearing](http://www.eco-goats.com). > > How many goats do you bring and how long does it take? > > This isn't a > simple formula. While we have 100 goats, we have to consider what kind > of vegetation is on the land, how much is there, and how many goats a > property can hold. On our sample video jobs, there were 30 goats used > for 48 hours on a .3 acre neighborhood property, and 50 goats used for > 12 days on a 4 acre property with thick forest vegetation. Eco-Goats > will estimate how many goats and days you will need for your unique > property at the time of our initial evaluation. > > > [Answer] You can ferment [Ethanol](http://www.oulu.fi/resopt/wasmin/liimatainen2.pdf) from potatoes. Given your setting you don't want people to have personal vehicles, but what about commercial or military manufacturing, using grasstato ethanol as the power source to supply big engines? [Answer] Just as rocks and sticks were, something this common in an area would be almost guaranteed to become weaponized. Magic-based rapid-fire potato guns? The alcohol answers provided by others could be used for firebombs. [Answer] Since it seems that these grasstatos are EVERYWHERE, this means that food is incredibly cheap - even more so if harvesting can be brought to industrial scale. This means the kingdom will export cheap grasstato products, especially food. This will lead other countries to focus on other goods, maybe even becoming dependant on grasstatos themselves, or even suffering economic collapse. An easy remedy is charging customs for import from the grasstato kingdom, which means trade with other kingdoms is expensive and limited. [Answer] Well considering the growth rate you are talking about, the best way to use it is to burn it. Either just to produce heat, or to make energy if technology is sufficient. ]
[Question] [ A nation has found a large island containing dinosaurs! Primarily those of the late Cretaceous. A nation willing to pour pretty much any amount of money into the project needs a way to safely contain such creatures in some kind of zoo in which they are easily viewable. The problem? They're in the 1910s technology wise (although they're willing to pour more money into developing technologies to aid this), as such it is extremely difficult to contain them. So, how exactly could a nation at least somewhat safely (the deaths of a few workers is acceptable) capture, handle, & contain dinosaurs in a zoo accessible to the public without bankrupting themselves? Note: aside from the dinosaurs, everything else is pretty much the real life technology of the 1910s, nothing fancy or out there & no magic. [Answer] Fences? Dinosaurs aren't magic, and by the early 1900s, the technology was there for impressive engineering projects. If you can build a [wrought-iron tower 300 meters tall](https://en.wikipedia.org/wiki/Eiffel_Tower), a dinosaur-containment fence is no problem. Capturing? Pit traps and dozens or hundreds of people with ropes. The early 1900s were still the era of brute-force solutions, with heavy use of muscle power and unskilled labor. Transport? Wrought-iron cages on wheels, pulled by steam tractors or simply large numbers of horses. And you want to get that cage to the coast as quickly as possible, so you can put it aboard a ship and send it to its destination. [Answer] I don't see any particularly big issues with trapping and/or moving dinosaurs - capturing and transporting animals has been going on since long before the Romans started using them as part of their bread-and-circus performances to distract the unwashed masses. Or later, when bear pits were popular entertainment. In fact, as with elephants and bears, there's at least some possibility that dinosaurs could be trained and driven (in the elephant-herder sense) to their destination. Though carnivorous ones in particular are likely to be like modern reptiles; short bursts of activity to catch and consume prey, followed by lots of sleep. So they're not particularly practical beasts of burden! Then too, the European victorian nations were well versed in the art of grabbing whatever looked interesting - living or otherwise - and shipping it back to their home country. This was the era when many of the great zoos in the world were founded and stocked with animals from around the world. For instance, Cleopatra's needle (a 200 ton obilisk) was shipped from Egypt to England in 1877, for the equivalent cost of around $1.5m in today's money. And there'd been numerous improvements in transportation capabilities by 1910 - more rail infrastructure, early petrol/diesel vehicles, etc. <https://en.wikipedia.org/wiki/Cleopatra%27s_Needle,_London> Finally, while most pop-culture dinosaurs are heavier than modern mammals, it's also worth noting that the Victorians were pretty adept when it came to dealing with extremely large animals. For instance, tens of thousands of whales (weighing up to 150 tons apiece) were butchered each year, and the numbers continued to rise as newer technologies facilitated the mechanisation of this process. <https://www.scientificamerican.com/article/world-s-whaling-slaughter-tallied-at-3-million> So logistically, there's probably not going to be any real issues with getting the dinosaurs into a European or American zoo. How long they survive once they get into the zoo is perhaps a different matter altogether, but then, the victorians tended to be quite blase about such things - after all, there were always more whales/animals/workers/etc where the first ones came from! [Answer] ## Capture the island The island is no man's land by the question, as it was "discovered" instead of dinosaurs being discovered on a known island. So, your state should attempt to claim the dinosaur island its own, by securing sea borders of the island, cutting a small part of it with a big enough wall of concrete to "contain the dinosaurs" outside the walled-off part, clear some forest right before the wall as it's done in fortification, and use that area as a military base and tourist attraction site available to travel by sea. In there, tourists could get on the wall's edge or travel round the island on a ship (warship if needed) and try spotting dinosaurs. In order to attract dinosaurs to the wall, as it's inedible and, provided it's tall enough, imperceptible, also there would be noise and other factors scaring off dinosaurs while the wall is being built, a rather simple trolley road into the clearance before the wall could be placed and used to drop meat a good hundred meters into the dinosaur land. Or plain use catapults. Then the dinosaurs would be able to feed off that meat in the open, and tourists would be able to see them in detail. Use spyglasses mounted on the wall to allow close-up views to the dinosaurs. Also some attration could be gained from having a criminal that's sentenced to death be dropped off that wall to try combatting the reptiles, like in that old Colosseum of Rome, 1900-style, depending on whether the public morale is allowing such brutality. Speaking of anything flying, military could use sniper rifles to bring any offending pterodactyl down before it crosses the wall, or flak cannons, or shrapnel, or plain blanks in order to scare them off with heavy sound. If something they'd classify as prey would retaliate, the predators would likely retreat to find better prey, and since they had survived unnoticed by the humanity on that island for this long, there should be some source of meat for them to survive. Just make a good recon and not break that source prior to interfering, or else they would get extinct too fast. (Perimeter recon should be enough, as humans won't get too deep into dino territory with their works.) [Answer] # Tranquiliser. Truck. Moat. Sneak up on the dinosaur at night when he is cold and sluggish. Zap him with tranquiliser darts. Put him on the truck and drive him to the enclosure. The enclosure has a tall fence and moat. Big animals have trouble with moats. [![enter image description here](https://i.stack.imgur.com/jz1B0.jpg)](https://i.stack.imgur.com/jz1B0.jpg) You will accidentally kill a lot of dinosaurs before you find the best dose of tranquilizer and how to load them onto the truck. Make those guys into dino-burgers for your hungry crew! [Answer] # Electric fences Electric fences are wonderful for controlling large livestock. They are lightweight, easy to set up and move, and restrain the beast both physically and psychologically. [United States Patent 343,939](https://patents.google.com/patent/US343939A/en) was issued in 1886. The Kaiser's army built the Wire of Death in 1914-15. [Answer] ## Kong Island: In the movies the islanders generally build a wall to contain Kong to his side of the Island. This inevitably fails of course but dinosaurs aren't King King. Your modern nation on the other hand has access to concrete, steel, construction explosives and powered construction equipment including cranes etc as well as large caliber, high velocity center fire rifles and early machine guns etc. Their wall wont fail! Assuming money is no object early 20th century engineers would be more than capable of designing and building a wall high and strong enough to deter any conventional dino. Other defenses could also easily be added if needed, including things like noise makers and marksmen posts to deter or kill approaching dinos. And you could also add any and all sorts of outer defenses you want to make it harder for any approaching animals. (I'm not going to add potential options here but the list is long.) ]
[Question] [ I need to limit the development of the internal combustion engine so that it is only available in small numbers to few individuals and does not progress technically, or at least only progresses slowly. I want something that can power a large airship, but perhaps only just. The background is a world that supports human life but is not the Earth. There is roughly 1g gravity and plenty of water but little land. The atmosphere is very thick and the only populated areas are large plateau islands raised high up where the atmosphere is more bearable. The story will revolve around the development of airships in this world but I want them to be developed in small numbers by some eccentric rather than as a state based or wide spread option. The level of technology is roughly 1800’s but does not have to follow our time line (some things may be invented early other things being late if it can be justified). Other details can be manipulated to suit. I thought that the internal combustion engine would be one of the key constraints for a working airship but bonus if anyone can suggest a better choke point to limit airships instead of the internal combustion engine. [Answer] ## Limited/Unavailable Fossil Fuels If this planet isn't like Earth and hasn't undergone it's own version of the carboniferous era there may be few if any fossil fuel reserves to depend on. In this case, fuel would be rare and expensive, either because there simply isn't much to go around, or because they're using biofuel instead, which they have to grow and process manually. If internal combustion engines were too expensive to operate for all but the wealthiest, this would also hamper research and development of the technology (limited interest) and increase the cost of the engines themselves (limited production, no economies of scale). This could also impact cultural perceptions. ICEs might be looked upon as toys for the rich, an amusing but mostly useless dead-end technology. None of the great minds of the day would expect them to amount to anything, so they focus on technologies they consider more promising instead. External combustion engines (steam engines, stirling engines) would also be held back but not to the same degree, since they can use any fuel that would burn, making them much more cost effective (they're also better suited to combined heat and power installations). [Answer] Wind / if anyone can suggest a better choke point to limit airships/ You already did. > > /The atmosphere is very thick / > > > The kinetic energy formula is 1/2mv2. If you have triple the atmospheric pressure, a given volume of atmosphere has triple the mass and so triple the energy. Wind on earth already packs a wallop! Combine that with the increased thermal mass of your massive atmosphere and you have serious weather which means serious wind. Airships would be blown about. Now maybe kiteships could be a thing... [Answer] Internal combustion engines do exist, but they're "atmospheric" engines that don't compress the fuel-air mixture before ignition, and are thus [large, complicated contraptions with low power output](https://oldmachinepress.com/2018/01/20/otto-langen-atmospheric-engine/). Available steam engines are similarly poorly suited to lighter than air aircraft. Your eccentric has developed a multi-stroke, compressed charge cycle that delivers a consistent, controlled mix of fuel and air to the cylinder, and an electrical ignition system fast and reliable enough to match it. In the real world, this took Nikolaus Otto 14 years of development and collaboration with others, that almost didn't happen due to conflicts with Gottlieb Daimler, and spark ignition wasn't invented for most of a decade later. Your eccentric and his associates have just hit the combination of good ideas while avoiding the bad ones that put them a couple decades ahead of everyone else. This is entirely believable, considering how much time and effort people spent on dead end designs in real life. [Answer] Material Availability Iron ore and other metallic elements are heavy, and unlikely to be found on mountain tops where your people are. Mining ore also requires large areas for open pit mines and such, and mountaintop land is scarce and expensive. Maybe getting iron and nickel requires dangerous expeditions down into the deep atmosphere. Fuel shouldn't be the issue, as you can build an internal combustion engine that burns hydrogen, natural gas, methane, alcohol, all kinds of stuff. But if you don't have enough critical materials it either limits how many engines you can make, or you have to use substandard materials that result in heavy, low output engines. If you need lots of iron and steel in your society, pick another element unique to ICE engines, and make that scarce or lower quality. Copper, aluminum, magnesium, ceramics, gasket material like asbestos, whatever. [Answer] I think the easiest way to constrain the internal combustion engine (ICE) is to limit how much fuel is available. If the quantity of fuel is in high demand and not readily available, the ICE would be curtailed. Wood can work to lift an airship by burning it to create hot air, but it becomes very difficult to use it within an internal combustion engine (there are ways, but it wouldn't be very easily done). By limiting what can be used inside the ICE, you've thus delayed the development/availability of it. It's more of a practicality reason than anything else. [Answer] Make external combustion engines a lot better. I mean, they're already pretty great! And also pretty much dominating the scene through most of the 1800s, so you might not really need to change that much at all. On Earth, the first combustion engines were designed to use gunpowder. That might provide a good place to fork off into an alternate history -- either everyone just keeps running with that, or it scares everyone badly enough that they drop the idea. [Answer] Perhaps your peoples' material science has not advanced far enough and the engines do not hold up well physically. Bearings don't last, castings crack, etc. Could fail catastrophically at a critical moment or simply wear out too soon, especially under heavy use. This would also make the whole business more expensive. "Another new engine? !#@$!!! " [Answer] Trade secrets. Technology is a jealously guarded secret. I suggest you find and read Deathworld 2 by Harry Harrison, where the protagonist has to survive on a low-technology world, and there are various countries who have secrets of technology. One knows how to extract oil from the ground and produce gasoline; another knows how to make steam-engine cars; another knows how to make electricity, etc. The cars have various tricks to make them harder to reverse-engineer. <https://en.wikipedia.org/wiki/Deathworld#Deathworld_2> Limited materials In our world we make engines out of iron; what if on this world metal is very hard to come by, and iron is just not available? You might have a technology mostly based on wood and fabrics, with a very small amount of metal. This wouldn't be ideal for airships. Combining the two, suppose someone invents a way to make a ceramic engine and nobody else knows how it's done. They know what ceramic is but there are a few tricks they don't know. P.S. It just makes sense that steam engines would be invented before internal combustion engines. [Answer] No Blaugas Airships already have a problem with internal combustion engines: As the liquid fuel gets burned, the airship gets lighter and tends to rise, requiring the valving of expensive lifting gas to keep the ship under control and in flying trim. Historically, Zeppelins solved this expensive problem by using [blau gas](https://en.wikipedia.org/wiki/Blau_gas) as a fuel, since it has about the same density as air. This give you two sets of possible controls: * Make your lifting gas more expensive, thereby making the required valving so much more undesirable. * Keep approximately-air-density fuels unavailable or tremendously expensive. Perhaps your world's equivalent of Hermann Blau simply didn't think of it. Or maybe industrial accidents years before stopped development. Or maybe rival fuel firms influenced regulators to keep it unavailable. Or perhaps the fuel requires a particular imported additive to avoid poisoning the local sleet-frogs. ]
[Question] [ I am envisioning a scenario in which, probably for reasons of persecution or overpopulation, a people would begin to construct islands in the sea. Each island would be fairly close to the others and the society would want to be able to support agriculture on the islands. I had two questions about this idea: 1. Would the only way in which an island could come about in the ocean be by volcanic (and non-magical) means (eg like Surtsey) - or would it be possible for them to construct non-volcanic islands simply by transporting the necessary materials to a favourable location in the sea and beginning construction? I know that China is currently constructing artificial islands by non-volcanic means, but the society's technology would be roughly similar to that of Europe during the Age of Exploration, so this may affect the techniques that they could use. Would they be limited to flat islands or could they construct rock features such as mountains etc? 2. If this was possible what materials would they need to use for the various layers supporting the island? - going on the premise that each island would be roughly the size of a small city or town. Thanks for any help [Answer] Move the ocean off of the top. Piling stuff in the ocean to make an island has a long track record. [The Chinese are doing that now on a 21s century scale.](https://www.9news.com.au/world/what-are-chinas-artificial-islands-in-the-south-china-sea-and-why-are-there-concerns-about-them/3f0d47ab-1b3a-4a8a-bfc6-7350c5267308#:%7E:text=China%20moved%20to%20start%20creating,on%20top%20of%20the%20rocks.) But what about just moving off the ocean and keeping it off. The Dutch have been doing that for millenia. <https://www.thoughtco.com/polders-and-dikes-of-the-netherlands-1435535> > > Pushing Back the North Sea For the next few centuries, the Dutch > worked to slowly push back the water of the Zuiderzee, building dikes > and creating polders (the term used to describe any piece of land > reclaimed from water). Once dikes were built, canals and pumps were > used to drain the land and to keep it dry. > > > From the 1200s, windmills were used to pump excess water off the > fertile soil, and windmills became an icon of the country. > > > I propose your people make an "island" that is below sea level. Technically they make a big island with a big hole in the middle. The fertile farmland on the reclaimed seabed is surrounded by dikes and polders and full of windmills but is not a straight ripoff from the Dutch because it is way out at sea. Incoming ships tether on the outside of the dikes and people go down ladders on the inside. Cool and fantastic for a built world and you could have it with older technology. Although people are doing it with new tech. The best image I found was from Singapore! [![singapore reclaims land](https://i.stack.imgur.com/JuC7a.jpg)](https://i.stack.imgur.com/JuC7a.jpg) <https://www.hydro-international.com/content/news/singapore-pilots-dutch-land-reclamation-approach> [Answer] Man-made [islands in Scotland](https://www.thesun.co.uk/tech/9284681/scotland-crannogs-manmade-islands-mystery/) and indeed very old - upwards of [5,000+ years old](https://www.thesun.co.uk/tech/9284681/scotland-crannogs-manmade-islands-mystery/), so yes it is very possible. Citing from the second link: > > Prehistoric tribesman rolled blocks weighing up to 25 kilos into the water to form short platforms you can still see today – though many are now covered by trees and other plantlife. > > > You probably would start with a man-made bridge (platform), and then just put a ton of them together in the sea to make an "island", before removing the stones used to make a platform. In other words, if you can make a land-bridge you can make an island, of some form. Perhaps the most notable example of a land bridge was [Alexander's in 332 BC](https://www.livescience.com/1523-mystery-solved-alexander-great-defeated-tyre.html) during the [Siege of Tyre](https://en.wikipedia.org/wiki/Siege_of_Tyre_(332_BC)). As far as what materials and/or structures are required, that really depends on numerous factors: * depth of the sea * mass required to be supported * current (force of the water on the various layers underneath) * waves / sea-turbulence (surface pressure) For example, village-style stucco homes in a shallow, non-turbulent sea will require a lot less than multiple skyscrapers in the middle of the Antarctic. Seeing as though small towns could be built in the Scotland-style islands, all you need is a lot of very big rocks. Once you have that, pack in dirt and get moving. Again, though, the environmental factors will drastically vary the requirements. [Answer] I'm fond of a quote from the movie, The Hunt for Red October: > > "Can you launch an ICBM horizontally?" > > > "Sure, why would you want to?" > > > Could nations during the Age of Exploration build artificial islands? Sure! Though they'd likely not be able to build one large enough for your purposes before the Age of Exploration ended. Bring in enough boulders to create a continuous barrier around the perimeter of the island (complete with docks... of course!) and fill the center with dirt until the water's gone and the dirt dries out. But what's the point? The existence of an artificial island without desalination (invented in 1964) would require some method of consistently accessing fresh water. Yes, you could build a giant lake in the middle of the island (now that perimeter's getting big...) to catch rainwater, and you can build the perimeter barrier high enough (maybe...) to keep wind-driven waves from surging over the barrier and ruining the fresh water.... But what's the point? All that effort when it's thousands of times easier, cheaper, and more efficient to simply move an inland mountain to an existing shore and extend an existing natural landmass — and you need to move the mountain anyway just to build your island. No matter how shallow the ocean where you build the island, you'll need at least one mountain worth of dirt to make an island big enough for practical cultivation. And you still can't ignore that barrier! Coastlines exist for reasons that can't be ignored without consequence. Just look at the Dubai attempts to make artificial islands which, having lost access to regular maintenance, are slowly eroding back into the sea. And what really hurts is that your barrier is perhaps the most expensive part of island-building. You wouldn't want a bunch of small islands because every inch of perimeter comes with a very high cost. So... why do you need artificial islands? Is it just a cool idea to have in your story/game/world, or do you have a purpose (like establishing strategic colonies for defense or expansion)? If we knew why you needed the islands, we might give you a better answer as to how the islands can come to pass. [Answer] How about starting with something like a raft - it requires constant maintenance, so you keep adding new material, you plant sail-resistant trees (eg mangrove), whose roots bind the structure together, you add new material on top as it sinks deeper, and along the edges - and one day you realise the thing is touching the bottom in places. Shortly after, your now very big raft has become an island. Perhaps not completely realistic, but with a combination of the right materials, plants, a culture of constant vigilance and clever application of general handwaving, you make it work. [Answer] Have you considered the amount of material it would require to do this? For example, just to carry the material used in the construction of the Washington Monument would take somewhere around 300 shiploads from a typical carrack ( most common merchant ship of the time ). I would imagine that even a small island built in shallow waters would require 10s of thousands of such shipments. The illegal Chinese islands are built largely by dredging up sand and dumping it on existing islands or coral reefs. But our 15th century island builders wouldn't have the technology for that ( and might not want to do it anyway given the erosion problem the Chinese are having), they'd be digging and quarrying material on shore and then hauling it to a port to load on ships. To carry this off you would need to be wealthy and powerful enough to take control of nearly all of the shipping on the planet. You would also have to be wealthy and powerful enough to carry out a massive material gathering and transportation effort to get the material to your ships. And that wealth and power would have to be stable enough to let you do this for decades. And when you're done, you're left with small islands that wouldn't have any natural source of fresh water. You'd be very limited in what crops you could grow because even the soil you're bringing in would be getting polluted by salt water spray and seepage. There is theoretically possible and there is realistically possible. Theoretically, it's certainly possible that 15th century people could create islands, including ones with something akin to mountains. Realistically, there's really no way it would have happened. ]
[Question] [ There is the strong theory that the Earth and the Moon were part of the same core at one point. This would lead one to believe that there are precious minerals under the surface of the Moon. Metals are normally heavier than dust and we don't want to send the moon out of orbit, so when we mine the moon we intend to put back as much mass as we take. Will this prevent the Moon from going out of orbit? What other astronomical challenges would we face? [Answer] ## Little to no effect incurred by mining The mass of the moon is about 7.3×1019 metric tons. That means if we removed a billion tons of mass from it every year for a billion years, we'd have removed about one-seventieth of it. We can make no significant different to the mass of the moon with any plausible mining operation. And its orbit doesn't depend very much on its mass anyway. There is absolutely no need to ship rocks from Earth or elsewhere to replace mass we remove from it, and that would also make mining the moon far more expensive. # More useful leaving it in space The only plausible good reason for mining the moon would be to get materials for large-scale construction in space, because lifting them off the moon is far easier than from Earth. [Answer] Valuable minerals are rare compared to regular rock on earth. If it is the same on the moon, the amount of mass taken away by mining will be insignificant beside moon's total mass. Moreover, when you consider the mass added by mining (miners will need infrastructure to work properly and generate waste during their stay), the mass ratio after mining/before is even lower. [Answer] > > There is the strong theory that the Earth and the Moon were part of the same core at one point. This would lead one to believe that there are precious minerals under the surface of the Moon. > > > Actually, the theory isn't quite like that. The leading theory for the formation of the Moon is of two proto-planets colliding to form the Earth and Moon system. The collision left the main planet (Earth) in-tact, but a large volume of debris in orbit. After the collision, the heavy material that was ejected sank back down to the primary body (Earth), while the lighter debris material stayed in orbit and went on to coalesce and form the Moon. The result is that the Moon has a much lower density than Earth, and a much lower concentration of heavy elements. In addition, the lack of vulcanism on the Moon means that those heavy elements that did end up forming it are mainly deep in the core, making them inaccessible to mining. > > Metals are normally heavier than dust and we don't want to send the moon out of orbit, so when we mine the moon we intend to put back as much mass as we take. > > > Seriously, the Moon isn't going to worry about a bit of mining -- it may be smaller than the Earth, but it's still a very very large body. The Moon's mass is 73 quintillion metric tonnes ([ref](https://www.google.co.uk/search?q=mass+of+the+moon+in+metric+tons)). You could take a 100 billion tonnes off it, and you'd barely cause a rounding error in that figure. More significantly, if you're thinking of replacing the material that you extract... what exactly are you going to replace it with? Virtually any Earth rock you could think of (even the 'worthless' ones) would have more mineral value than the Moon rocks you're mining. > > Will this prevent the Moon from going out of orbit? > > What other astronomical challenges would we face? > > > No it won't. Your biggest astronomical challenge will be if you think you're going to be able to transport all that mined material off the surface of the moon. You would certainly be looking at an astronomical amount of rocket fuel! You would be much better off leaving the mined material on the Moon and building things with it in-situ. [Answer] There are sensible and knowledgeable answers here to the effect that our mining operations won't affect the mass of the moon much. I do not disagree with that, but it is irrelevant. Even if we invented a magical process to turn moon rocks into diamond and rocket fuel, and depleted the mass of the moon to half building a Dyson sphere, it would make no difference to the orbit of the moon. The shape and speed of an orbit depends on the body's velocity alone, not its mass. Such drastic decrease in the Moon's mass would decrease the tides in Earth's oceans, which might be ecologically catastrophic, but we'd probably do it anyway, with our track record. But this wouldn't be caused by changes to the Moon's orbit. Remember that astronaut dropping a hammer and a feather in sync? Same deal. ]
[Question] [ How do I keep a language from evolving for as long as possible? The world I'm talking about has two separate groups of humans who never meet, but even after being apart for some long time, like a millennium or so, their peoples can still talk to each other. Also, keep the answers as low tech as possible? One group is hunter-gatherers and the other is medieval or so, their current state is due to a apocalypse that separated them and undid technological development? Before the apocalypse, they had a common language. No Magic. Just Tech. The two groups are the only two groups in the world... And I'll leave the area occupied by each culture as your choices. By language, I mean actual conversation. If you need literacy for your idea to work, then okay, but I like ideas more if literacy wasn't a requirement? My world's canon is that the Medievals are literate, while the hunter-gatherers aren't anymore, but they both were in the past. 'Cause Apocalypse. [Answer] Religion Have both groups share a religion, or possibly different sects of the same religion. Have a core component be a daily reading from the holy book, with a strong emphasis on preserving the exact word of god. This can be preserved by a strong oral tradition for the hunter-gatherers, and by scribes or the printing press for the medieval group. There will still be some drift, and they'll certainly have accents, but that should keep them at least understanding each other for quite a long time period. [Answer] There is a technological solution. Imagine if all the original people before the loss of technology used their equivalent of a solar powered android tablet with speech recognition. Not a big stretch. With the apocalypse most technology died but these things were so common that many survived, and now most villages have at least one or two. Over time they would become rarer due to breakages and wear and tear but with no moving parts and slightly better than modern materials they could last a long time — especially if broken ones get cannibalized to repair each other. They store maps of the area, record old history, are used to teach children, etc. Each one forms the heart of a community and people who have their own is a major status symbol. The tablets don't have software development environments or compilers though, and the internet has died, so the only thing they can do is whatever was installed when the apocalypse came. The language these tablets understand is fixed, it doesn't adapt. In order to communicate with the tablets language cannot drift too far. As a result while there would be dialects and accents language would still be understandable even by two completely separate groups. Some words and phrases would be different and they may have to keep it simple but they could understand each other. [Answer] Avoid other languages Languages don't change that much on their own. Modern English is completely different from Britonnic not because two thousand years have passed, but because in that time England was invaded by people speaking Latin, German and French. Therefore, avoiding language changes means either complete isolation for both groups or everyone on the planet starting out speaking exactly the same language. Neither situation has occurred in human history, but if your apocalypse is sufficiently complete or happened at the right time, you can probably get away with the two groups only having strong, near incomprehensible accents. [Answer] There was a similar question asked by dsollen on Worldbuilding SE in July, ["How long can language drift before it becomes indecipherable, and how to minimize drift?"](https://worldbuilding.stackexchange.com/questions/20005/how-long-can-language-drift-before-it-becomes-indecipherable-and-how-to-minimiz?rq=1). In [my answer](https://worldbuilding.stackexchange.com/questions/20005/how-long-can-language-drift-before-it-becomes-indecipherable-and-how-to-minimiz/20009#20009) I suggested the following factors could hold back language drift: physical isolation, literacy (assuming the written language indicates pronunciation, lack of literacy (if it led to a tradition of memorizing), political continuity, and use as a language of religion or scripture. Dan Smolinske has already suggested the final factor in his answer. Judging from past history religion is the best bet for preserving a language. But the situation Malandy has described relates to the future, so perhaps history is not a perfect guide. Assuming the two groups of humans are descended from space travellers who came from Earth, unlike previous people who have undergone technological regression such as the [Moriori](https://en.wikipedia.org/wiki/Moriori_people), the original survivors will come from a literate, technological society with a mental model of scientific progress. They would see from the start that in order to rise again they must preserve knowledge even if they cannot use that knowledge in their current circumstances. A first step towards preserving the knowledge of the survivors would be preserving the language in which that knowledge was expressed. Possibly the struggle to survive was so desperate that their original aim to keep a reasonable level of technology failed, utterly for the hunter-gatherers, partially for the medieval group. But preserving the language is less demanding of resources, even if you don't have printing. Copying Latin manuscripts kept the knowledge of antiquity alive through the European "Dark Ages" (yes, I know that they weren't as dark as they were portrayed, but let's assume that in this world they were). Assume the medieval group did something similar, not necessarily out of religious conviction but out of an ideology impressed upon them by the first generation after the apocalypse that it was their solemn duty to do so. It's not inevitable that they would forget the original justification. They might well remember exactly why: so that science can one day rise again, and the people may once more have all the wonderful devices their ancestors had. But it's likely they would become rather hazy about how this "science" stuff actually resulted in the medicine and the air-cars. This ideology could eventually become a fixed tradition that to let your language change is sinful. Perversely this rigidity in language would work against the longed-for rediscovery of science. I can easily picture how this would work for the medieval group, where an elite remains literate. Seconding Sean Boddy's answer, it looks a lot more doubtful for the other group, unless they are very different from any hunter-gatherer society yet known. The problem is only partly lack of writing materials. Many illiterate societies have had bards or griots who performed great feats of memory, but they were almost always agriculturalists or herders. Cultivation of crops or domesticated animals allows enough of a surplus that you can keep a non-productive bard fed; hunting and gathering only wild food does not, which is why we know almost nothing of the history of humanity before the coming of agriculture. [Answer] Having a large group with good communications generally makes language change slower. In a low-tech setting this means nomadic tribes with friendly relations and trade with each other. Trading spouses helps too. Class differences breed class accents, which becomes language change when the lower classes imitate the upper and the upper avoid lower-class speech. So, avoid social classes. A strong singing tradition preserves language. [Answer] Religion and other cultural reasons to protect the language (like the French sentiment that their language is perfect being written into law) would help slow down the rate of change to the point that they might understand some of what the other says after a millennium. Dan's answer covers that already. Here is another way the language might be preserved. It does require some conditions that would have larger effects than only language. The shared language is highly musical, with rhythm and melody as important as the words. The two peoples universally have a high level of musical talent and a possibly a perfect memory for sounds/music. Speaking (more like singing) together in harmony or in a duet would be common. The result is that any changes made to the language by an individual would cause dissonance and negative reactions. The younger generations, normally more likely to change the language as they grow up, in this case have to follow what the elders are speaking/singing quite strictly. If the people also have inborn musical talent and/or a perfect memory, they absorb the words they are exposed to with a much higher accuracy than normal. They can then reproduce them almost perfectly, rather than in their own way. [Answer] While it seems very unlikely that two peoples both and independently maintain their language to a degree that members from both peoples meeting could communicate, let's try to think of a way how it could happen. The original question states that both groups once were one, and were separated by an apocalyptic event. The description as apocalyptic suggests that there will have been a drop in tech level. It also suggests that a huge part of the original population perished in the event. As a result, if the event happened to a population that had high literacy rates and easy access to printed books, one could set up a situation where both groups make it their tradition to keep the memory of the apocalypse and of those that died alive. With the sudden drop in tech level, availability of new books is likely to drop to (near) zero. Since literate parents will most likely pass on literacy to their children, those will also read the same books, especially since it seems safe to assume that after the apocalypse a lot of them were saved and guarded, because they are an invaluable means of storing and sharing knowledge. Borrowing from other answers, singing songs and having strong rituals will help maintaining the sound of the language. Provided that the tech level does not rise (much), it could be plausible that this setup helps preserving the language to the degree requested in the original question. I think the rebuilding of a printing press would end this phase of relative stability, though. [Answer] Universal literacy and a strong tradition of reading certain books from the time of the separation (or before) will tend to slow change of the written language. As others have pointed out, religion or some other form of shared ritual are good ways to accomplish this. It's possible that you'll get a situation where the old form of the language is relegated to "church" usage while the vernacular evolves, but that could actually be interesting from a narrative standpoint — the two groups would still be able to understand each other, but one would be surprised (and perhaps offended) to find the other using the sacred language for mundane purposes. Spoken language, on the other hand, is trickier. Even if the written form stays static, pronunciation will tend to drift over time, and without any contact the two groups will more than likely drift apart. The only means I know of to arrest that tendency is sound recording technology. If you can hear what people from the past sounded like then you're more likely to speak somewhat like them; otherwise, radical changes can happen in the space of a few lifetimes. The two languages might be as similar as US English and UK English on paper, but more like English and German when coming out of people's mouths. Probably even more than that, but I suppose you could "get lucky". [Answer] Contrary to what many would assume language evolution is largely independent from external, non linguistic factors. Assuming the language was already stable and there were few or no major changes in linguistic paradigm (the natural tendencies that shape the language) the speeches will slowly change in phonology and morphology until becoming unintelligible in about 1000 years (37 generations), this is the average gap for language fragmentation. A much more realistic (and interesting) solution for your problem would be bilingualism. Bilingualism has been the most common linguistic situation thru history, when two people are closely related and need each other for their economical survival they tend to learn each others languages, considering your case I don`t see any reason for this to not happen, unless one group is much stronger than the other, in this case the bilingualism would go a little more to one side than the other and a language shift would be possible in the long run. But either way they would be able to communicate with each other. ]
[Question] [ In my setting, I have reasonably traditional Dwarves and Elves. The Dwarves magic allows them to control metals, earth, and other non living constructs. The Elves can control non sentient living things like plants and animals. They have more control over currently living things, then substances that were part of a living being and necessary for its surival (like leather), then nonessitial substances (fur and wool), finally orgainic substances that where just made by non sentient living things (silk). The dwarves principally wear metal armor. However, metal armor is heavy and uncomfortable for day to day use, and downright chilly in the neather regions if worn naked. Since the elves can magically control plant and animal matter, the dwarves are wary of wearing cotton and wool and having dwarven soldiers strangled by their own clothing. Dwarven Leadership is looking to you for new options that keep soldiers both comfortable and alive. Are there any options for clothing that could be comfortably worn under metal armor that never were part of a living creature? Is there any comfortable way to create metal armor so that it can be worn without anything underneath? With no better options, the dwarves will consider substances made by living creatures with a metalic base, hopeing to have an equal magic footing there. They are also open to additional potential solutions. [Answer] ...wait, did you say elves can't latch onto bacteria? ![enter image description here](https://i.stack.imgur.com/JF7LO.jpg) [Korboc](http://pl.wikipedia.org/wiki/Korbacz_%28ser%29) is a kind of smoked cheese made from sheep milk, formed into long, flexible, rubbery and pretty durable strands. Seriously, a normal person could swing on a braid of this cheese like in the picture. I can imagine cloth weaved from it that would go under the armor. You could add some plasticine (from chalk and mineral oil) to protect the cheese from being cut/damaged by the armor. And knowing dwarves, they would consider a month-old, battle-worn undershirt a delicacy. [Answer] What stops the Elves from using the Dwarves' hair against them? If there is something about hair from sentient beings that blocks the elven magic, then I believe your answer is Dwarven hair. [Answer] I dont see a problem with Dwarves wearing metal based cloth. Dwarves are *Masters* at metalworking, so should be able to come up with some alloy which allows a fine enough wire to be extruded, and a tight enough thread count in the weave would make it quite smooth. Just a touch of Forge magic to retain the Heat of the Earth within the cloth to keep it warm and pliable,and the Dwarven version of Under Armour is ready to go. [Answer] *Polyester tracksuits, how you* doing? The dwarves can use synthetic fibers to pad their armor. This will require some chemical processing. It's good that they're miners already. They probably have some skills with chemically separating certain ores from rock. They may be able to extend this chemical knowledge into the creation of [Nylon](https://en.wikipedia.org/wiki/Nylon) or another [thermoplastic](https://en.wikipedia.org/wiki/Thermoplastic). From there they can create their sweet tracksuits, or just plain fiberglass for insulation/padding (and maybe even carbon fiber). Steel wool** If they need to stick to metal alone they can use steel wool. Of course, the armor would chafe something awful (cold nether regions might be preferred). There are a lot of intermediates from steel wool to smooth metal, an open-celled [metal foam](https://en.wikipedia.org/wiki/Metal_foam) might be a nice compromise. [Answer] Asbestos has been used for making clothes. While the safety and comfort are debatable, dwarven magic should make both manageable. Especially since the biggest risks would be to people working with asbestos and use of magic would allow much safer working procedures. And dwarves would probably be resistant to breathing stone dust anyway, even if it is fibrous. Also if the cloth was treated to have bright colors and softer textures, the treatments should make asbestos less of a hazard as they'd bind the fibres to the material. And washing the clothes would prevent diust from accumulating. And fiberglass can replace asbestos and should be possible for dwarves to create. [Answer] Surprised no one has mentioned it but: [Gold clothing](http://www.needlenthread.com/2007/02/medieval-textiles-what-is-cloth-of-gold.html) You could also easily invent some alloy that lends itself to weaving but is less precious. Mineral oil or non-organic lubes can have similar benefits for protection against chafing as clothing, without the elf risk. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 4 years ago. [Improve this question](/posts/161284/edit) In an pist appacolyptic earth quake zombie infection, what places that might be over looked in the first 3 week by looters and survivors? Big places such as Walmarts and Costco's are bound to be looted down to the shelves being stripped. I am looking for a few places that average people might not flock to cuz they are going to the gun store and sports store instead or might not even know they exist. For example an amazon shipping center those places literally have everything you could ever need for YEARS but it's not something people think about right away. They are to busy heading as states for places people the average people know of. [Answer] # There isn't anything people won't loot > > Oh look, a sign for a dentist office. Let's check it out. > > > You have to understand that whether or not people loot a dentist office has nothing to do with having thought of it...simply seeing one along their travels will be enough for them to loot it. People will see a location, and then think about whether that location will have useful resources. They usually won't say "Let's go find a dentist office." because in this zombie-ridden world, finding loot will be all about utilizing the resources around you. > > Oh look, an elementary school. Let's check it out. > > > And then upon checking it out, they find the nurse's office and also loot the cafeteria. > > Oh look, a ship. Let's check it out. > > > ### People will always search what they can. Not only that, but any place that can be used as shelter from the weather or zombies will also be searched while they wait. When in a dangerous situation, people will simply run to the closest building. This means that there aren't really any locations that are more or less likely to be safe from looting. --- However: # Think about what people won't search: * Certain animals may hide food in discrete locations; one of your characters may have knowledge of this animal that most people don't have. * Underwater; perhaps one of your characters has knowledge of tides and ocean currents, and can pinpoint a location where most shipwrecked resources would end up * Historical knowledge; perhaps one of your characters knows that secret compartments were often installed in old cabinets from the 1950s, and is able to find a hidden stash. * The rest is up to you; this is your world. You can write it however you want! [Answer] Nests of zombies. 1. If there are a lot of zombies, before that they were a lot of people. 2. If there were a lot of people in one place, they had supplies for a lot of people. 3. Once the people turn into zombies, they wont use the supplies. 4. The presence of hundreds of zombies will dissuade casual looters. Likely zombie nests will be schools, refugee camps, sports arenas or other places that were set up as public shelters during the early part of the apocalypse. Or strongholds that the looters set up before they all went zombie - most of the stuff they looted from Kmart will still be there with them. Also this will be more exciting for your story than having your characters loot an abandoned nursing home. [Answer] Geocaches. It's a weird sport-ish thing, but geocaches are specific buried caches which people who geocache locate. The way it works is that the players find them, take what's in them, and replace with items of equal value. If one of the survivors is a geocacher, he might have a list of them, which equate to buried treasure for your survivors. [Answer] Any place that doesn’t have anything loot-able won’t be looted. Like a desert island, won’t be looted at all because there is no one to loot it and nothing defined as loot on an island. Being the humans are such clever creatures, the pinnacle of survivorship in a fierce animal kingdom, one would imagine that hungry and cold humans would rove like locusts looking for anything they could turn into a weapon, eat, or use for clothing or shelter. The only two things that I can imagine that wouldn’t be looted would things that require detailed knowledge to be turned into one of things on the previous list. So some chemicals that don’t have an immediate use but are precursors to chemical compounds might be left untouched. Especially if the first looters accidentally poisoned themselves and their bodies lay in front of the vats of chemicals. The other kind of that might not be looted are things so frightening and deadly that no one in. their sane mind would go near them. Like things in the core of a nuclear reactor will most likely be left alone. And there is one more thing that can’t be looted, things people can’t find — hidden safe rooms or secret underground bases. [Answer] # Other survivor's loot Why spend time looking in ambiguous places that might have supplies left over from before the apocalypse when you could just benefit from other people's effort? They're not likely to be looted as they would only have been gathered in the weeks after the apocalypse. There's a 50:50 chance they're already dead, in which case it's free real estate. If they're still alive, then that's a moral dilemma that's up to your group to handle.... [Edit] I realise I didn't actually suggest any physical locations these might be in! The classic starting points would be to follow the passage of people from the start of the collapse - depending on how it all started in your world, people would likely be gathered by the government/military into refugee camps in order to protect them after cities become swarmed by the undead. These would likely have the best variety of supplies, as the government would have used the last of its coordination to stock them. After that, it gets harder to specifically say where people may set up camp, or what level of supplies they'd be able to find. The longer term the settlement, the higher the chances of them having worthwhile supplies. If your survivors see anywhere fortified, there's a good chance the people who were/are in there have/had stuff worth staying there for. [Answer] Depending on what they are looking for. I'd imagine a library as a place not likely to be looted at all. But anyway here is a couple of things I can think of. * Cinemas. I do believe they have food. Candy bars, soda, chips...etc are all food and have a long expiry date. * Vet clinics. A lot of medicine and medical equipment. * Med schools. They are bound to have important stuff. * Pet shops. Perhaps pet food is not the tastiest thing ever, but at least it's better than green leaves. * Food factories, food warehouses, distribution centers...etc. This is kind of the jackpot really. If you can track down a warehouse for a food company then you can be looking at tons and tons of food. Incredibly useful especially if it's canned food. * Restaurants. Kitchens should have some supplies. Especially frozen food. * Airports. If they are not locked down or destroyed or whatever. They would have a lot of stuff. ]
[Question] [ Working with a world with relatively high industrial technology, including good materials technology but no energy weapons or the like but modern-day ballistic technology. Why not use the equivalent of [pavise shields](https://en.wikipedia.org/wiki/Pavise) in combat, especially if the positions are fairly fixed? These would be fixed against the ground, rather than handheld in any way. 1. I imagine if made of appropriate materials, they'd stop most small arms fire. They essentially would be sandbags but directional. 2. Energy from bullets would just be transferred against the ground, so many considerations about dissipation with body armor would become moot. 3. It would have its weight considerations, but it's a lot lighter than sandbags. Simple technology such as a car and wheels could get it setup. 4. It could be used a mount to help stabilize heavy weapons. What would be arguments against them, besides the prominence of indirect fire? And if I wanted to go higher tech with them, couldn't they work with powered exoskeletons, becoming essentially a shield that is lowered from the back and put in the ground, kind of like Sundowner from Metal Gear: Revengeance (although that went thoroughly into Rule of Cool). [Answer] Things like that have been used in niche applications. * You mentioned [ballistic shields](https://en.wikipedia.org/wiki/Ballistic_shield). Before they were portable, they had [wheels](https://en.wikipedia.org/wiki/Mobile_personnel_shield). * With a little gun, they would be something like [Gruson's pillbox](https://en.wikipedia.org/wiki/Fahrpanzer). * Crew-served weapons would come with shields, like this [MG08](https://commons.wikimedia.org/wiki/File:MG08_and_armored_gunner_display_1.JPG). My conclusion from these examples is that pavise-style shields work only in very special conditions, and that general issue would be either lighter body armor or heavier vehicle-mounted armor, not this "too heavy to carry, to light to protect" intermediate size. [Answer] Modern-day small unit warfare (where personal shields would be relevant) is based on mobility and fire-and-move tactics where the goal is to outmaneuver an enemy force to deny it a defensible front. To that end it is in the warfighter's interest to stay light on his feet while carrying as much ammunition as possible. During an assault on an enemy position a small unit may have to advance and withdraw many times to in order to achieve a tactical advantage. While defending a position from an enemy assault the unit may quickly followup with its own counter-assault. Given that the modern warfighter is already humped up with as much gear as he can physically carry and be effective in that environment it seems unlikely that the additional burden of a heavy personal shield would be welcome or net effective since other gear, likely ammo, would have to be sacrificed to make room for it. (Although infantry robotics, which are no longer the realm of sci-fi, may soon change that.) Personal shields would also have questionable effectiveness against the more serious threats to warfighters such as RPGs and grenades, machine guns .30 cal and above, mines and IEDs, or even small arms fire effectively delivered (e.g. ambush). The extent that an injured warfighter would be willing or able to carry a shield is also questionable. Modern warfighters are trained to use terrain and structures for cover and concealment, and against other infantry that is very effective. The stalemates of WW1 proved that. A shield on the other hand would provide relatively limited cover and no concealment on the battlefield. I suspect that is the fundamental reason why history has rejected the pavise for modern warfare. [Answer] Autonomous drone shield bearers. [Samuel 17](https://www.biblegateway.com/passage/?search=1+Samuel+17&version=KJV) > > 4 And there went out a champion out of the camp of the Philistines, > named Goliath, of Gath, whose height was six cubits and a span. > > > 5 And he had an helmet of brass upon his head, and he was armed with a > coat of mail; and the weight of the coat was five thousand shekels of > brass. > > > 6 And he had greaves of brass upon his legs, and a target of brass > between his shoulders. > > > 7 And the staff of his spear was like a weaver's beam; and his spear's > head weighed six hundred shekels of iron: and one bearing a shield > went before him. > > > If you are in a fight it is nice to have a shield. Even nicer to have someone carrying it for you. In your future (as now!), the public is wary about having AIs with lethal force. Offense is reserved for humans. Defense however is another matter. The drone shield AIs are in constant communication with each other but also make decisions independently: flocking behavior. They realign and redeploy according to the movements of those they are designated to protect, and their own perception of offensive threats. These would be fun to write, because the drone shield AIs will surprise you. [Answer] You need to carry them around which hampers your ability to remain undetected and move quickly. Plus, given modern technology, they're limited in their usefulness: [![enter image description here](https://i.stack.imgur.com/ENrTO.jpg)](https://i.stack.imgur.com/ENrTO.jpg) It's not the US independence war or World War I any more where a thousand guys with embarrassingly bad guns on each side fire at each other, two dozen of them actually hit something, and finally they engage in bayonet combat man vs. man. You shoot someone from 1-2 kilometers away, and you have a gun which fires a bullet that will go right through a complete vehicle, let alone a puny little shield that a man can carry. Or, you do not shoot at all, but mark the target with a laser and have a drone do it. Or something. [Answer] Ballistic shields are used in many police applications, as well as less armoured shields for riot and crowd control (where the threat is not considered to be firearms). This [company](https://www.securityprousa.com/collections/ballistic-shields) offers a wide range of ballistic protection, including hand held shields, mobile shields and even "kits" to build defensive bunkers. However, these sorts of devices are heavy, bulky and impede the mobility of soldiers. As a matter of fact, they don't even solve the greatest issue facing soldiers, which is overhead protection. What soldiers might really like in a defensive position would be something like a table with short, collapsible legs capable of protecting them from a shell burst overhead. Placed over the top of a fighting position (shell scrape, individual trench or fighting position), this sort of overhead protection would be appreciated. Except that to be able to protect the soldiers from the blast and splinter effect of an airburst they would be carrying around something with the equivalent protection of at least 18" of earth. Considering that Russian weapons have grown in mass and firepower, the protection provided by 18" of Earth, while possibly sufficient for 122 mm howitzer or "Grad P" multiple rocket launchers, now has to contend with the equivalent of 152 mm "smart" rounds or even 300 mm multiple rocket launchers delivering their ordinance in a matter of seconds. [![enter image description here](https://i.stack.imgur.com/OgFIh.jpg)](https://i.stack.imgur.com/OgFIh.jpg) BM-30 Multiple Rocket Launcher So these things would be massive and a huge pain to carry, plus they would need to be properly "bedded" into the ground, which can be tricky depending on what sort of ground you are on. This would be an engineer task, while the ordinary soldiers would be using corrugated metal, wooden beams or logs and other improvised materials to build their own overhead protection. [![enter image description here](https://i.stack.imgur.com/87zSG.jpg)](https://i.stack.imgur.com/87zSG.jpg) Laying down a supporting structure [![enter image description here](https://i.stack.imgur.com/XjUn6.jpg)](https://i.stack.imgur.com/XjUn6.jpg) \Cross section from a military manual [![enter image description here](https://i.stack.imgur.com/MtYjN.jpg)](https://i.stack.imgur.com/MtYjN.jpg) What the end result might look like, assuming that is an entryway under the three layers of logs* Since your engineering troops and transport resources are always in high demand, training the troops to make their own expedient cover out of local materials seems to be a much better use of resources. [Answer] # Tanks Would your shields be heavier than tank armor? Because we have weapons that can defeat quite thick metal armor. The history of warfare is a competition between offense and defense. If, for some reason, sitting still where indirect fires can target you all day were a tenable strategy, then attackers would simply switch to higher-velocity rounds. Why does this work? Physics. # Armor Normally, we think of ballistics in Newtonian terms, and consider the momentum of the projectile vs. the hardness/tensile strength/energy distribution properties of the armor. For small projectiles moving at a low Mach number, this framework is adequate. The essential point is that we are thinking about a solid vs. solid collision, and modelling the result. Armor penetrators come in two varieties: chemical or kinetic. They both work on the same principle: switch from solids to liquids, which can be easily penetrated and have close to 0 tensile strength (resistance to bending/puncturing). In particular, you want the target to become liquid. No, this does not mean using a flamethrower or comic-book magic, but yes, it does mean creating a [jet](https://en.wikipedia.org/wiki/Shaped_charge#Munroe_effect) of hot metal. The chemical variety creates the jet at the point of penetration (c.f. [HEAT](https://en.wikipedia.org/wiki/High-explosive_anti-tank_warhead) rounds), while the kinetic variety provides the penetrating velocity right from the launch point (c.f. [APFSDS](https://en.wikipedia.org/wiki/Armour-piercing_fin-stabilized_discarding_sabot#Design) shells). # Deployment Since these are expensive weapons, you would generally not arm all infantry soldiers with them. However, if this was the only way to overcome enemy defenses, then you can rest assured that every army which could afford it would field such weapons as densely as necessary (say, one for every fire team or squad). # Countermeasures This is why modern battle tanks use active armor: the only effective defense against such weapons is to trigger them before they actually come into contact with your armor, and try to deflect the jet. Obviously, by this point we are talking about something quite a bit more sophisticated than a glorified sandbag. [Answer] > > Why not use futuristic pavise ballistic shields for protection? > > > Because you'd be vulnerable to artillery, bombers and anti-armor weaponry. Your main advantage as infantry is moving fast and staying low. The shield negates both of these. It makes you vulnerable to the same things as armored vehicles, without the superior protection and other advantages of armored vehicles. In fact, the pavise shield can be thought of as a very primitive, human-powered armored "vehicle". It doesn't provide good protection for its weight, has little added firepower and poor mobility. You could dramatically improve the armor, add a heavy gun that is affixed to the "shield", and add propulsion to make it move faster than an infantryman could carry it. Then you would pretty much get a modern light armored vehicle. [Answer] Modern warfare is about the fact that a man-portable weapon can kill someone in man-portable body armor. In the short term, your shield can protect against someone using non-military weapons. If it is light enough to carry, military weapons will penetrate it. The penetration distance of a newtonian impactor is proportional to the ratio of mass and the depth of the bullet. A bullet can easily be made to be pretty long and relatively dense; your shield basically has to be bullet dense and bullet deep to fully shield the person behind it; if you want to protect 1 m^2, and bullets are 0.5 cm^2 cross-section, it must weigh about 20000x what a bullet does (ignoring propellant). A soldier carrying 100 bullets can carry heavier bullets than your shield can protect from, given the same carrying capacity. If you have an exoskelliton that lets you carry a heavy shield? They can have an exoskelliton that lets them carry and shoot bullets that go through the heavy shield. The ground, sand bags, buildings and the like are things you don't have to carry. They can easily have huge effective depths and soak up weapons fire without having them to be man-portable. In response, attackers can set up heavy weapons. Weapons that aren't man (or exo-suit) portable, require set up, and can in turn blast through the fortification you are hiding behind. This results in a red queen's race. One solution (or local optima) is WW1 trench warfare, which was a stalemate because (in simplification) the attackers could win against the front lines, but couldn't carry heavy weapons to defend their advances. So you would (at huge cost) overrun the front lines, then you'd be destroyed in a counter attack (as the enemy heavy weapons are in place, and you don't have any on your side). And repeat. WW1 trench warfare gets beaten by mechanized troops, heavy weapons, tanks, airplane support, and modern fire-and-cover tactics to exploit breakthroughs. Nuclear weapons make a continent-wide battle seem unlikely; less extreme combat tends to be more mobile and less total. Modern fire-and-cover tactics using mechanized forces that the USA uses relies on real time intel and the availability of unlimited range unlimited firepower support. Your light mechanized troops advance until they hit resistance, then fall back locally, call down the thunder, then continue. The troops are armored against much human-portable firearms (in their mechanized infantry devices). They become vulnerable against human-portable anti-armor weaponry and static explosives (IEDs). In towns, especially with civilian population, this doesn't work. Now, an asymmetrical situation where attackers using exo-suits heavily enough armored to defeat enemy most small-arms fire could develop, making in-city fighting mirror desert storm. This is half way between police action and military action; when you are attempting to kill the enemy, but not the person standing next to them. So, if your world has a dominant military power, their troops might use exo-suits that are armored against small-caliber fire (hunting weapons etc) and carry heavier ballistic shields (which can soak AK-47 scale fire). They would in turn carry a mixture of anti-personnel, anti-suit and anti-armor weapons. Anti-suit weapons would have the problem of blowing through buildings (causing collateral damage) and the ammo would be much heavier. Anti-personnel rounds would be much lighter and would be less likely to kill people a few km away. And anti-armor would a speciality weapon. The shields would be used by SWAT teams and military involved in asymmetrical police action, where most of the enemy is armed with obsolete weapons only. In a symmetrical fight, the shields would be mostly useless and discarded, as anti-suit weaponry would blow through the shield. A suit carrying an armor-grade shield would be ridiculously slow and could be taken out by flanking or using anti-armor weapons anyhow. Armor-grade troops -- whatever the analogy of tanks -- would be immune to suit and personnel-grade weapons, resistant to anti-armor weapons, carry ridiculous cannons that can penetrate enemy armor reliably, and act as light mobile artillery. The thing is, suits are probably a bad anti-personnel weapon at this stage. Light unmanned drones with anti-personnel weaponry would be cheaper and smaller than anything you could wrap around a human. Suit armor would basically scale with what is required to survive attacks by such drones (as even insurgents could probably build hunter-killer drones). [Answer] Your shields provide defense against direct fire. But don’t provide protection against explosives. The shock wave of an explosion is the killer. For your shields, assuming they aren’t throw by the detonation, only deflect a portion of the energy. Where sand bags and similar defenses a absorb and attenuate the shockwave. Soldiers seek out natural shields when they advance on a target by using natural cover like rocks, trees and the rolls of the earth. [Answer] One issue here though is, with the invention of mobile and motorized personell shields, there simply wouldn't be a need for carrying a shield around anymore even if it could be useful. There would have to be tactics designed around using the shield to make it properly effective. Simply using it as an extension of light infantry work wouldn't work. In general your going to have to sacrifice speed to use it tactfully. With that said it's better to find tactics that work with a slower pace. If speedy maneuvers are absolutely needed, say a hit and run or urban cqc, then that's when it would be a good idea to use smaller handheld shields instead. If the battle plan is going to be like a push&close in kind of combat, then it would be advantageous to be able to easily switch between mobile shield for push, and handheld shield to cqc. If it's a hit&run, well it would be better to use armor than a shield. Also, retreating quickly with a mobile shield might be difficult. On a side note I have devised my own mobile shield and tactical usage with it. My explanation of the shield is on quora(find on Google), however I never explained a tactic with it. One such tactic goes along the line of: Being in a fully extended position with 1 or more mates when using it in open field, and folding it's sideflaps when going inside a building or close quarters area. Semi-folding it(one side folded and one side extended) when moving in at an angle (like opening a door). If it's used sparingly, keep it moving forward and only in the path of the larger battles. That is to say, detracting it from the main objective to fight a sniper camp or one-off group wouldn't maximize it's effectiveness. Anyway that's all I got for now, feel free to critisize me or ask questions for clarification. ]
[Question] [ This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. Is there a way to create a nuclear explosion that only destroys things within a few feet of the bomb? The point is to completely eradicate something relatively small, leaving no trace. Let's assume that this is taking place on Earth. The government that is using this procedure has access to lots of funds, so cost isn't a problem. I'm imagining that the explosion would have to be done using a tiny bomb with only a little bit of fission/fusion (i have no idea) in a controlled and protected environment, to prevent both the impact and nuclear radiation from leaking out and harming the surrounding people and environment. How would someone go about doing this? (See [Should we be mindful of potentially dangerous questions?](http://meta.worldbuilding.stackexchange.com/questions/1978/should-we-be-mindful-of-potentially-dangerous-questions) on meta.) If this can't be done using a nuclear explosion, another method of near-total destruction of a contained area would be a valid answer. [Answer] Continuing on the theme of chemical solutions (ba-dum-bum-CHING - I'm here all night folks)... One way to rid yourself of unwanted objects or personnel is to liquefy or vaporize them and allow nature to clear them away. For this sort of operation, I eschew explosions because although they deliver a lot of energy, they tend to apply it indiscriminately to everything around them. So let's try a more focused approach: thermite Grind up metallic aluminum and rust into a fine dust. Perhaps combine them with a combustible binder material and apply liberally to the object (person) that absolutely, positively has to go away. ``` Size of thing to be destroyed? Unknown Composition of thing to be destroyed? Non-refractory materials Level of destruction? Burn, liquify, or vaporize Proximity to nearby objects? a couple of feet How affects nearby things? Don't hurt things beyond a couple of feet How much time? Seconds to minutes ``` Thermite burns at temperatures of thousands of degrees. It will burn, liquefy, or vaporize many materials as shown in this video of thermite on dry ice: [Thermite Vs. Dry Ice](https://www.youtube.com/watch?v=14EMPjfSmVs) It won't have this effect on most refractory materials (tungsten, carbon-carbon, etc.). Bad Stuff While thermite most certainly will rid you of some offensive materials, unless you are extremely liberal and careful with its application there almost certainly will be evidence left. [Answer] The smallest warhead created for the US military was the [W54 Davy Crocket](http://en.wikipedia.org/wiki/W54#Variants) which used 23kg of Pu239 and had a yield equivalent to 10-20 tons of TNT. [Video of the Davy Crocket being fired](https://www.youtube.com/watch?v=HdLm0PgrqBI). According to other research, the smallest amount of Pu239 you can use to make a bomb is 10kg, which still has the power of several tons of TNT, plus the thermal effects. So even that small of an amount would [take out a normal city block](http://nuclearsecrecy.com/nukemap/?&airburst=0&linked=1&kt=0.001&lat=42.3313888&lng=-83.045836&hob_ft=0&zm=17). I don't know if it would completely vaporize the target, but none of the pieces would be very big, and they would be pretty spread out. Edit: So, after a lot more reading, I found that there are ways to lower the threshold for critical mass: shaping the pit, neutron reflectors, the type of explosives used to compress the mass, etc. With all the right tricks you can get it [down to about 4kg](http://www.wikipedia.org/wiki/Plutonium#Explosives). Fatman only used 6.2kg of Pu 239, and it had a yield of 20 kilotons. So you would have to find ways to lower the efficiency. Apparently it's harder to go smaller with a nuke than it is to go bigger. [Answer] If you want to limit the damage to a few feet, any type of explosion is right out. [Large firecrackers](http://en.wikipedia.org/wiki/M-80_(explosive)), [bottle rockets](http://en.wikipedia.org/wiki/Bottle_rocket), and even non-chemical explosions like the ["dry ice bomb"](http://en.wikipedia.org/wiki/Dry_ice_bomb) can throw shrapnel a dozen feet or more. Scaling up a little more, a [hand grenade](http://en.wikipedia.org/wiki/M67_grenade) can be fatal at up to 15 feet. Nuclear explosions are right out. --- What you want is a concentrated release of energy, unlike an explosion which disperses energy outward. My first instinct is [thermite](http://en.wikipedia.org/wiki/Thermite), an extremely hot-burning metal powder. Typically it's used for [welding railroad tracks](https://youtu.be/XQViDITyIKs?t=1m8s), but you can also use it to, say, [melt through the engine block of a car](https://youtu.be/rdCsbZf1_Ng?t=2m18s). --- If 2 thousand degree molten metal doesn't fulfill your appetite for destruction though, then let's move on to something else. Since you asked about nuclear devices, let's start with some radiation. In particular, [electron beams](http://en.wikipedia.org/wiki/Cathode_ray). Most of the electron beams (originally named 'cathode rays') we encounter today are in the form of CRT monitors, but these only deliver a minuscule amount of power. However, there are a number of more... industrial uses of electron beams: * Electron irradiation, used to sterilize materials or process plastics. Here's a [video](https://youtu.be/7H9SA8XCHug?t=58s) of what happens to a camera passing through an irradiator used for industrial plastics processing. The beam used in that video delivers around [25 kW](http://www.wolframalpha.com/input/?i=3.6+MeV+%2F+(electron+charge)++7mA) of beam power. Electron beam welding. Here's [a video](https://www.youtube.com/watch?v=kh7o6w-GePY) showing an electron beam welder making a 74" joint in 1 3/4" steel in just four minutes. A similar technique uses an electron beam to [fuse metal powder into 3d printed shapes](https://www.youtube.com/watch?v=BMGNy1MgsyM). * Finally, the most powerful of these devices is an electron beam furnace. These are huge and highly specialized machines, so information on them is hard to find. Here's an [article](http://theodoregray.com/periodictable/Stories/077.x3/) describing the process of melting iridium with an electron beam furnace. Iridium melts at almost 2500 degrees Celsius. What a megampere electron beam would do to an unprotected target in open air... I leave that to your imagination. --- Wait, you still want more? Well, we can step up to a proton beam, the type used in [proton therapy](http://en.wikipedia.org/wiki/Proton_therapy). The reason I'm limiting myself to charged particle beams is that, unlike neutron radiation or gamma radiation, charged particles interact strongly with matter, so the radiation is short-ranged (which will prevent collateral damage). The type of beams used in cancer treatment penetrate on the order of ten centimeters before stopping abruptly. Like electron beams, a powerful proton beam would melt or vaporize the target. However, it would also do significant damage to the target on a nuclear level. Individual protons have thousands of times more energy and momentum than electrons, possibly enough to fuse with the nuclei of atoms and increase their mass, or knock out other nucleons and reduce the mass. After you're through with it, the target won't even be identifiable by its isotopes. I don't have any videos for you here; proton beams don't have many industrial uses, since they're hard to produce. (Good thing "cost isn't a problem.") Again, what you do with such a beam is up to your imagination. [Answer] Alright, I'm done with the little stuff, let's move on to explosions. The problem with explosions (as I stated elsewhere) is that they apply their energy indiscriminately and tend to damage what you want damaged along with everything else around it. ``` Size of thing to be destroyed? Scale explosion to target size Composition of thing to be destroyed? Scale explosion to target composition Level of destruction? Blast Proximity to nearby objects? More than 10s of yards to a mile or more How affects nearby things? Don't hurt things beyond this range How much time? milliseconds ``` If done with careful planning and placed with care, it is possible to create things like shaped charges or direct the explosive force of an explosion. This does indeed focus the explosion and direct the majority of its fury at the intended target, but it is still unhealthy for anything near the explosion. Consider the case of a self-forging projectile trying to penetrate the armor of a tank. Whether the projectile penetrates the armor or not, the area around the tank is extremely unhealthy for infantry soldiers. Other armored vehicles could shrug off the explosion and/or fragments, but the explosion would likely kill any soldiers near the tank. The same thing happens when directing an explosion with the intent of destroying high-rise buildings without damaging nearby buildings. The focus of the blast does indeed hit the desired target, but if you stood near the explosion, you'd very likely be killed. Construction materials are MUCH tougher than your typical human being. We are faced by another quandry with this too. Even with 500 lbs of high explosives, there was plenty of the cement truck left to identify in this Mythbuster's explosion. <https://www.youtube.com/watch?v=Gxm_qpKh7Jw> So in order to really destroy something so that no trace is left, you would need a truly enormous explosion and it just isn't safe to be around those, if you wish to live. Even with the Mother of all Bombs (MOAB) 18,000 lbs of fuel (it uses atmospheric oxygen as the oxidizer), there would be plenty of material left to identify objects destroyed in the blast. <https://www.youtube.com/watch?v=HsQdeAeOEg4> Oh yeah, and you wouldn't want to be anywhere near the detonation point. Just a point of interest here. Explosions typically don't break all chemical bonds in the target. The blast tends to fragment the target. Individual fragments of target and bomb usually contain enough information to figure out quite a bit about both. [Answer] Go with Californium: It can used in a small nuclear device due to the much smaller critical mass needed to produce a nuclear chain reaction when using Californium. According to wikipedia, the critical mass of Plutonium-239 is 10kg, and circa 10-15kg (23kg minus mass of casing etc) was used to make the W54 Davy Crokett recoiless nuclear cannon. A Californium-252 based version would weight much less. Major problem is that Californium is not cheap. At 2.7Kg critical mass, this means a 3-7kg nuclear weapon, but costing at least 10 Million dollars each round. [Answer] This will likely be buried under the other answers, but you can have tiny fusion explosions. [There is a current real project to produce them.](https://lasers.llnl.gov/) Each fusion capsule is pinhead-sized and detonated by a warehouse-sized laser. All you need to do is scale this up a bit and you can have yourself a fusion explosion capable of destroying a few cubic feet around it with a large "bang". However, it wouldn't be particularly more powerful than a conventional explosion of the same size. The fundamental thing about explosions is that they're not containable. Or you could just use the warehouse-sized laser directly. Or a [plasma torch](http://en.wikipedia.org/wiki/Plasma_torch). [Answer] OK, my last entry. This one includes large & unconventional methods of getting rid of things. Nuclear if you absolutely positively have to make it go away, nuclear is the sure fired way to ensure that happens. The problem of course is how do you keep it from destroying the nearby stuff that you don't want destroyed. Well the US Air Force as an app (project) for that, it's called [Casaba Howitzer and it is a freaking nuclear shaped charge](http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Nukes_In_Space--Nuclear_Shaped_Charges). ``` Size of thing to be destroyed? Roughly human sized Composition of thing to be destroyed? Most non-refractory materials Level of destruction? Burn, melt, or vaporize Proximity to nearby objects? Minimum of tens of feet, maximum out to hundreds of yards How affects nearby things? Combustion to dozens of feet, blindness to anyone who can view the target How much time? Microseconds ``` I am tired and don't want to get into all the gory details (but find the topic terribly interesting). Scientists felt they could focus about 80% of the destructive power of the bomb. That still leaves 20% of a nuclear bomb to annihilate everything else not in path of the directed shot. Within some (very short) distance of the bomb, the gamma rays and neutrons are powerful enough to cause transmutation (fission & fusion reactions). All chemical bonds will be broken all atoms will be ionized (possibly multiple times). Within a longer (but still short) distance of the bomb, the heat caused by absorbed gamma rays and neutrons will ensure most chemical bonds are broken and many atoms are ionized (but no nuclear shenanigans will be going on). In an atmosphere these two zones combine and form the fireball region which absorbs most gammas, causing the air to heat and generate the blast wave. In space, the gammas just keep going and kill people directly. Regardless of the direction of the blast, the bomb will spew neutrons about. Neutrons are not stopped very well by most shielding (it's better to use large quantities of water to shield you instead of dense metals, for instance). Neutrons will kill people so even if infrastructure survives the 20% of the bomb that escapes the directed blast, the nearby people will die anyway. Kinetic Projectiles I want to throw one final thought out there. You could do it with a hypersonic kinetic projectile. If shot from space, it would look like a shaft of light shot down from the sky and simply left a crater where the offensive tidbits were left. The blast from any bombardment which creates a crater will also damage the things around the crater rim. But this sort of strike does not cause radiation damage (but does cause a blast). Kinetic weapons scale better than conventional or nuclear weapons. They can be as small as a .22 bullet to as large as the dinosaur killing asteroid (~6 miles in diameter). You can also adjust the speed of the projectile. Kinetic projectiles have the added benefit of not emitting lethal radiation, so if you survive the impact and subsequent blast, you'll survive the encounter. This a video of the meteor that fell over Russia. Imagine a targeted strike intended to take out a building. It would damage nearby buildings but leave most of the city untouched (sans windows, of course). [Video of meteor over Russia](http://media1.s-nbcnews.com/i/MSNBC/Components/Video/_Player/swfs/embed_V2/embedV2_20140520v2.swf?settings=38251917&onsite=true#!flashvars#launch=50827929&width=652&height=466&autoplay=true&pg=&bts=&freewheelvideo=NBC_no_ads&onsite=true) [Answer] I think the only way to make a really small nuclear explosion (for a given value of 'nuclear') is to use a very small quantity of antimatter. But as already pointed out, that won't completely obliterate the object: even with thermite, there would still be chemical traces. No, the only way to completely obliterate an object is to utilize a quantum black hole. [Answer] Forget explosives, too much hassle and not very effective. The proper way of dealing with this, as touched on in another answer, is fire. Lots and lots of lovely fire. > > The point is to completely eradicate something relatively small, leaving no trace. Let's assume that this is taking place on Earth. The government that is using this procedure has access to lots of funds, so cost isn't a problem. > > > Oh baby, lets have fun. So, since cost isn't an issue, the first thing you're going to need is a ridiculously expensive burn box. How expensive? Basically you need a safe made of high purity tungsten, the thicker the better. Elemental tungsten has one of the highest melting points around at 3695K, plus it is fairly resistant to various forms of corrosion. For suitable tungsten you're probably talking at least \$300-\$400 per kg, at $19250kg/m^3$ a suitable box is not going to be cheap. Next up is a fuel. Your best bet here is a oxy-acetylene, although you'd need to avoid running it with too much oxygen as the peak temperatures for acetylene burning in pure oxygen are around the same as the previously mentioned melting point of tungsten. This contraption will melt just about anything. Organic material will be incinerated, most metals will be reduced to liquid (most will actually start to boil), even things like silicon and stone will be an unrecognisable puddle. You're also probably going to need some kind of exhaust capture system, since the fumes would likely be extremely toxic, and a really good cooling system to get rid of the heat. If you're careful in selecting the materials used to make whatever is being destroyed you should be able to completely incinerate it. Organics and lower temp metals like gold, tin and copper should be little or no traces left. Worst case is a completely unrecognisable bit of slag. The basic principles involved are not that different to those involved in crematoriums, since there are similar constraints like exhaust capture. This kind of system also works best in smaller scale, suiting your "couple of feet" scale. As a plus, you could probably slap a heat exchanger on the thing and heat your government offices with it. [Answer] > > How to create a nuclear explosion localized to only a few square feet? > > > Make it controlled. Nuclear reactors are controlled nuclear reactions. They're controlled to the point where there is no explosion. A nuclear bomb is an uncontrolled nuclear reaction. I'm likely stretching physics here, but one could perhaps have an incredibly tiny amount of fissionable material and then control it with a really tiny reactor (nano-sized rods?) [Answer] If its that small and needs to be disposed of with no evidence, I'd suggest firing it into the Sun or Jupiter. Trying to destroy it on the spot to that level is going to be tricky and will almost certainly at least leave some traces. I think about the best you could achieve without major damage to nearby areas would probably be a plasma jet, formed by a large number of shaped charge explosives. Forget nuclear, its not directed enough to achieve the level of destruction you want without major damage to the surrounding area. Basically surround the object in a number of shaped charge warhead, the conflagration of plasma-jets should pretty much annihilate it with at worst minor damage to surronding areas (you could stand 20' or so away). If the shaped charges are set-up correctly, you could probably reduce nearly anything to dust/vapour. (Shaped charged warheads often vaporise the armour they are penetrating). [Answer] I'm going to assume a nuclear weapon is absolutely essential - maybe you need some method to kill Godzilla's eggs, and can only trust in the psudo-magical power of nuclear explosions. Regardless of the reason, it has to be a nuclear bomb. ## The Bomb The smallest nuclear weapon, and very nearly the smallest possible nuclear explosive yield ever constructed, would be the [Davy Crockett](http://en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device)), which carries the distinction of being the only nuclear weapon ever conceived for infantry use. The weapon delivers the equivalent explosive force of [10 to 20 tons of TNT](http://en.wikipedia.org/wiki/Nuclear_weapon_yield), but the actual radius of the blast is less well-documented. However, it apparently delivers an instantly lethal dose of radiation within 500 feet of the blast (and a less lethal but at least equally tragic dose up to 4 miles out), so if radiation is the reason you need a bomb, then it'll definitely do. ## Containment If you have any type of control over the explosion area, your best bet to limit the damage would be to construct an entirely-lead encasing compound, specifically designed to contain the radiation damage AND explosive damage of the bomb. Inner chambers would be constructed to collapse and absorb as much of the explosive force as possible, while the rest of it would simply contain the radiation. It's hard to say how large the facility would need to be, since most nuclear explosion tests were carried out in large, open, barren areas rather than elaborate lead shielded constructs. If you can mitigate the risk of hitting groundwater, and can control the exact location of the explosion, doing it underground would be even better. ## Practicality Realistically, a nuclear explosion is a poor method of ensuring the absolute destruction of an object. The explosive damage can be replicated with much safer, more practical explosives, and the radiation damage doesn't require a nuclear explosion to create - any nuclear reactor would be able to furnish you with enough toxic radiation to do whatever you need to do to whatever you need destroyed. The only reason you'd ever need it to specifically be a nuclear blast is if you need both a large amount of kinetic explosive force and high levels of radiation, in an immediate dose and at the same time. [Answer] You could, maybe, use an explosively pumped flux compression generator (I swear I didn't take that from an unproduced Back to the Future IV script -- <http://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator> ) to create a really small fusion explosion without the fission stage ( <http://en.wikipedia.org/wiki/Pure_fusion_weapon> ). But that's not just a matter of cost, there are engineering details that I think we're far from having solved -- you'd probably need Tony Stark, Mr. Spock, and Samantha Carter to design the damn thing. But if it can be done, then you could make fusion explosions smaller than the minimum practical fission explosion (see AndyD273's answer for that ). There are also supposed to be ways to trigger very small nuclear fission or fusion explosions using anti-matter, but I (just intuitively -- not based on actually having to go through the trouble of, you know, getting knowledge) think that'd be harder to scale down. [Answer] Your question doesn't provide a bunch of very important bounding parameters about the size of the thing to be destroyed, the level of destruction required, the composition of the thing to be destroyed, the proximity of things to not be destroyed, what level of "untouched" is really required, and how much time we're allowed to take. So I'm going to provide you with several answers. I hope one satisfies your needs. ``` Size of thing to be destroyed? 1 human body Composition of thing to be destroyed? 1 human body Level of destruction? must flush down the bathroom tub drain Proximity to nearby objects? a couple of feet How affects nearby things? Don't hurt things out of bathtub How much time? Days ``` Use extremely caustic materials like $ LiOH $ or $ H\_2SO\_4 $ that work well on organic chemicals. I figured out the quantity once but don't feel up to doing that today. Just remember the acid/base is consumed in the reaction and some of the weight of the acid/base is the water in which it is in solution. So estimate the weight of chemicals required at 150% of the body weight. Bad Stuff The problem is this will not dissolve all the bits of the human body. I assume someone looking for this method of "disposing of evidence" would know what to look for if they found several empty drums of caustic chemicals. You could do the same thing with metals and other materials. However, the best caustic chemicals for a given task change depending upon the composition of the object to be destroyed and the container in which you plan to do the destruction. Also, as stated above, this will take days to complete and it will stink to high heaven. You'll probably need a gas mask to enter the room during the destruction. [Answer] Still avoiding explosives... Another way to rid yourself of unwanted possession (or people) would be to burn them. This poses a problem when the object (person) is not flammable. Interestingly, most things that are not already oxidized will burn when exposed to a 100% oxygen environment (things like human flesh). So acquire a tank of pure oxygen and set that garbage on fire. You may need to keep the flow of oxygen going while you're eradicating the object (evidence). ``` Size of thing to be destroyed? Unknown Composition of thing to be destroyed? Most non-oxidized materials Level of destruction? Burn or vaporize Proximity to nearby objects? Tens of feet? How affects nearby things? Don't hurt things beyond tens of feet How much time? Minutes ``` I've never actually played with this but I would guess that it won't be as carefully contained as the previous two. [Answer] How about another twist before we go nuclear... Directed energy weapons. Directed energy weapons are very able to apply energy to a very focused source. The amount of energy they can deliver is pretty pitiful when compared with the energy of explosions but it still may be sufficient for your needs. ``` Size of thing to be destroyed? Roughly human sized Composition of thing to be destroyed? Most non-refractory materials Level of destruction? Burn, melt, or vaporize Proximity to nearby objects? Minimum of tens of feet, maximum out to hundreds of yards How affects nearby things? Combustion to dozens of feet, blindness to anyone who can view the target How much time? Seconds to minutes ``` It is easy to focus and direct the beam to hit the intended target without directly hitting anything else. However, such powerful beams will momentarily reflect off objects breaking off the target or floating in the air. This will send stray beams of high powered coherent light flying in all directions. You'll have to assume anyone standing in the line of sight with the target will be permanently blinded. Furthermore, if the beam heats the target up enough to burn, melt, or vaporize the target, the target is going to be radiating enormous amounts of heat. My guess is nearby combustibles will combust, including hair & clothing. [Answer] A weapon that consists of 2 devices, one is installed in north pole and emits a very narrow (1 nanometer diameter) beam of neutrinos and the other one is installed in the south pole and emits a beam anti-neutrinos. Neutrinos and anti-neutrinos do not interact with either matter or anti-mater so both fluxes can pass through anything and everything. A super precise technology allows the beams to be directed with incredible precision. When both beams crosses the neutrinos and anti-neutrinos reactive with each other releasing a great amount of energy. The project is kept in secret so nobody know such devices exist. When they want to kill someone all they need to know is their precise location in the world and make the beams cross in the target. Doesn't matter if the target is inside a box of steel with 10m thickness walls, there is no safe place. ]
[Question] [ Setting: In my world the cellular aging process of humans is stopped and life is nearly endless. Humanity is spreading into space to colonize planets, so living place and resources are not big problems. Question: In such circumstances would there be enough recruits for military services? Why would one risk to die in a war instead to live an infinite long life? [Answer] This is a hard question to give a definitive answer to. So I'm going to point out some pieces that may help you examine it. Ultimately, there are some pieces that remain unanswered in your setting that may impact the answer. I will try to address these. Please note that this question invites biased answers, because it is a question of human nature, and philosophers have argued about these topics since the dawn of recorded history, and still haven't come to anything like an agreement. I apologize in advance for any non-objective input in this answer. First off, a thing that wasn't clear in your setting... Wealth distribution. In short, if there are still rich and poor, then with an unlimited life, the rich will get richer...and the poor may remain poor their entire lives. If you are barely eking out an existence on the edges of society...it may be worth risking your life rather than spending eternity barely surviving. Existence of Tyrants These have existed since...pretty much always. You get someone who says 'obey me with a risk of death, or face immediate death.' Well, he has conscripts to fight now. Then others, if they want to stop him, must build armies as well. After all, you don't get a war if only one side is ready to fight. They generally call that a massacre, not a war. Boredom Eventually, if you live forever, you are going to run out of crap to do. You only have one risk that is a real thing. Death. Anything else...well, you can recover from it in time. So the only real thrill is something with the risk of death. Human Nature This is the piece that, as I warned, shows my bias about human nature. If you disagree with me, then for the purposes of your story, ignore this block. I don't believe that people are intrinsically good. There will always be those who want more than they have...and there will always be those that don't care who they have to hurt to get it. That is, after all, a fair definition of a Psychopath. Also, I believe that there will always be ideological differences that people are willing to fight for. And, if you remember, old people tend to be even more set in their beliefs than someone younger, and can be rather belligerent in defending them. Add in the human-nature 'Us Versus Them' mentality (want to demonstrate it? Look at sports team fans and the fans of their rival team), add in a few thousand years to let it all steep...and you have a recipe for some very deep seated hatred. So, in conclusion...I don't think that agelessness would mean the end of war. [Answer] Why would anyone go to war now? You named a couple reasons: resources and space, but those aren't really very good reasons. Both are sort of "get a better life for descendants", though rebuilding is a better way to do that. Freedom - This one is pretty good, and also fits under "get a better life for descendants". Get out from under some tyrannical rule, be able to make your own decisions and live the life you want and not have your future decided by someone else... Money - Soldier of fortune, mercenary, whatever. You have a skill, someone else will pay you to use it. Power - Get the other guy to do what you want. Kind of the opposite of freedom. Glory - Everyone wants to look good, be a hero. In a world without war, how do you become a hero and set yourself apart from everyone else? Adventure - Get away from your everyday life and have new (horrible) experiences. The key to most of these is the fact that old people send young people to war, and young people sign up because they don't know any better and think they are immortal already. If immortality was real for everyone, hopefully people would value their lives more, but it really depends on what the 'enemy' is, and whether it's worth it. If they are defending on the other hand, you'll most likely get lots of volunteers. I think a bigger thing is that without FTL, inter-planetary war is pretty much pointless. We're not going to launch ships to attack Alpha-Centauri when it's going to take a thousand years to get there and it's your great great grand children that will do the actual fighting. [Answer] There'd certainly be wars over food. Imagine the population growth, the huge boom that would happen if there were no natural deaths. We'd quickly run into famine, and people would be dying in the streets. This would lead to factions competing for the increasingly scarce resources of food, land to grow it, water to feed the crops, and fertilizer for the crops. Then wars would be fought over the resources to defend that land (oil/coal/natural gas, uranium, metals). Possibly wars fought to obtain slave labor, then slave uprisings. [Answer] Boredom, mostly. After a certain amount of time, people get malaise. Everything seems old and "already done." There are only so many sunsets you can watch before it loses the emotional power. People are always willing to sacrifice for something that feels broader and more important than themselves. Then there's the fact that even when we're immortal, we're still human beings who are prone to all sorts of emotional imbalances. People can be angry, bloodthirsty, psychopathic... You'd much rather some of those people be soldiers than wreaking havok in the general population. It's likely that you'd experience a lull in recruiting of a couple hundred years as the first immortals lived their lives to the fullest, but eventually your recruitment would fill with gods weary of this mortal shell and eager to experience the unparalleled thrill of death. ## Addendum: What if people fought wars AGAINST immortality? They specifically saw that the immortal life had some severe unintended consequences for people, culture, and society (why get anything done when you can procrastinate literally forever?) and knew that the only way to save our humanity was to destroy immortality? So you have the "perfect immortals" being fought by those demanding a mortal imperfect life as the purer human experience... [Answer] If you could no longer die of old age, I suspect the main changes in our culture would be the following: * Human life is generally considered more precious * "Young" human beings would be treated as second-class citizens However, just because human life would be considered more precious than now doesn't mean necessarily that you wouldn't see people forced into military service for war. You could argue that even now, there shouldn't be war, because if you get shipped off to battle, you are risking your life. People do so for their country and because they think it is the right thing to do. Though, I suspect that even so, if you could live forever, you would not throw yourself in a situation willingly where you would likely die. As such, I imagine that war would be fought heavily with drones and remotely piloted aircraft. In a typical war, there would likely be very few casualties. The actual act of destroying many people would be considered an atrocity, killing people who may have been alive for centuries. As such, even strategic targets would likely be mostly be manufacturing plants of these drones, which themselves would be run heavily by robots. To attack a city would be cause to warrant the brunt of the world's armies against you, and your allies to have difficulty justifying their cause. However it should also be said that it is an atrocity to the general public. To politicians and leaders, this is an excuse for war, however they would not have any difficulty putting the "younger" people in percarious positions. If you think such things aren't possible, consider that many drafted and sent to Vietnam during the Vietnam war were young and in a lower poverty bracket. As to whether or not the politicians themselves would have motivation to go to war, well, so long as they are not the ones fighting, their motivation would be no different than today. Technology has proven time and time again not to be a cause for peace, but rather an instrument of war. To quote Albert Einstein: > > I know not with what weapons World War III will be fought, but World > War IV will be fought with sticks and stones. > > > [Answer] Your second point is more likely to end war than the first - assuming first that 'expanding into space' also means 'finding infinite resources in space for human life', since otherwise, you're going to have the same problems you'd have here on Earth, but on a wider scale. What you have to remember about war is that, historically, it was waged because X group wanted the resources of Y group, and was willing to take them by force. And the chief maturation of war past the tribal state was that war was fought not for food or shelter, but for land ownership and space to expand a growing and restless population. Without a life cycle, that population would grow more and more restless with each passing generation (exponentially, assuming every human being also remains fertile, and our urge to procreate does not expire). Assuming humanity did reach a point where space travel was not only easy for a mass-market, but also viable as a way to expand into new living arrangements, that would solve the problem that your first point creates. But with any type of limited resource, be it food, shelter, luxuries, or even just personal space, the greater the number of people in a more densely-packed environment, the more likely a conflict is to erupt. [Answer] Guildbounty makes very good points, I second all of them. War is, sadly, a fact of nature. I don't think people go to war now thinking "okay, I'm only going to have 60 years to live of my natural life, so I might as well risk myself at 18 now, but if I had 80 years, then I wouldn't take the risk! People go to war expecting to NOT die (sure they know the odds, but we all think were be the one to beat them), or they decided death is worth it, but they don't do a cost-reward analysis that considers expected years to live. After all traditionally young men, barely 18, went to war more often then the 30-40 year olds despite the older ones having fewer years left to live. However, I mainly wanted to focus on a specific implication of ending old age which is relevant here. The problem with no death is that people start having children faster then old people die out. This leads to competition over resources. Many apocalyptic utopians have been generated from the idea that people stopped aging, since we now have no resources to provide for everyone and the only solution is to kill people. Your situation is a little different since people can still die, just not of old age. Death from accidents, murder, disease etc will still remove population, perhaps we expect to live to 150 instead of 80 on average. However, this would mean that women are fertile throughout their lives, instead of just until 40, and so would still keep reproducing. This means we would be haivng more children even as those that are born live longer, and thus consume resources longer. More people who consume more resources is not sustainable, the resources on earth can not keep up with the constantly increasing demand. This would could be made theoretically sustainable if you suggest extensive use of birth control and similar regulation was in place to keep birthrates roughly equal to death rates. Alternatively if you add space travel then it's possible to allow this so long as were able to colonize new worlds, with new resources, fast enough to keep up with constantly increasing demand. I suppose you could also claim better technology and infrastructure, combined with a significantly increased emphasis on sustainability and production of food due to the new demand, has allowed us to generate food better. We started building massive hydroponic gardens using genetically engineered food and renewable resources to drastically boost the rate we produce food, but that hand wave can only go so far. However, if you don't add one of the above approaches you will have far more wars as people fight over increasingly limited resources. The motivation is so that country X will have enough food to maintain their population, but the deaths themselves are what keep us from overwhelming our society. This seems to lead to inevitable distopia, but you could mitigate it somewhat if you don't want a full distopia. If you imply a combination of the other approaches have been implemented to control our resource needs. Were using more significant birth control, but still birthing more then die of normal causes. We have gotten better at producing food thanks to both technology and granter emphasis on production, which means we can handle a larger population to an extent, and all of this means we can almost, but not quite, keep up with the rate humanity is growing. Thus wars occur semi-often over resources, but tend to be smaller skirmishes. Their enough to limit our population growth without full blown war occurring etc. [Answer] While it's not exactly a direct answer, there's a pretty good reference for this in the form of the Culture series by Iain M. Banks. They're not, strictly speaking, immortal but close enough at 400 years. Even at that, the tech level implies that they could probably live longer if they actually wanted to. The AIs that run things, the Minds, are likely immortal by any useful definition. The brutally applied logic is that once a society has reached a level where they can have anything they want, a subset of those people will be willing to risk their lives to protect that way of life, or to try to extend that way of life to others who haven't achieved that level of tech. Extending the first of those reasons, I agree with the sentiments raised by other responders but feel that the answer can be simplified considerably and thus my answer is: > > Regardless of technological level or life expectancy, there will always be armed conflict as long as there exists people who are willing to use violence to alter the status quo. > > > People will wish to change the status quo as long as alternatives can be imagined that will grant them a subjectively positive benefit. > > > The resources to raise an army is probably moot, the number of people willing to resist an aggressor tends to scale in proportion to the size and aggression faced. I think that you could likely take any specific facet of a story and construct a set of solid reasons for groups fighting for and against that facet, so if you need to have a war within your story then all you have to do is find a suitable point of disagreement and build a divide out from that. You only need to have a convincing reason for why that something is so important. [Answer] ## War isn't a choice Volounteer armies are a luxury that happens only when the nation can get the required number of troops in this manner. In much of the world now, and in all of the world historically, your opinion won't matter if you'll be required to go to war. Declining conscription or draft generally is a serious criminal offense; and desertion on battlefield can be and has been punished by execution - soldiers can be given a choice to have a chance to die on the battlefield or die for sure immediately. Furthermore, if a competing group has a large enough military (no matter how they obtain/enforce that) then your group has, in effect, a simple choice - be prepared to risk your life in a war, or surrender all rights that you may have to any group that is willing to fight and desires anything from you - property, freedom, and eventually life as well. [Answer] To bring Honor to your family. (Elders could pressure their younger relatives to perform military service to improve the prestige of the family as a whole) To become Famous through your deeds if you manage to survive. Especially if all your feats are filmed and public like in "Running Man". Maybe scars are cool in the future. Soldiers get Special Training which makes them eligible for jobs with high prestige (volunteer have no expectation of actually seeing combat, until...) Blow stuff up. Explosives and weapons are highly regulated - except at combat academy. [Answer] Your question leaves open too many possibilities for there to be one answer. My answer in general would be that mostly there probably would not be wars, not because of lack of recruits, but because in order for humanity to survive its own 20th/21st Century abuses of its homeworld, and emerge as something cooperative and healthy enough to achieve colonization of distant worlds, defeating cellular aging and having no resource problems, then it probably has developed mindsets healthy enough that we aren't waging war on ourselves any more, and we see little reason to do so. If and when some of us revert or degrade to something hostile, or we face some external threat, then I am sure that there would be plenty of people willing to help and risk their ageless lives to do so (although we would probably have the technology to risk more robots than people at that point). Why would someone risk losing their unaging life? Perhaps some wouldn't and others would, but I think that such a future culture would tend to be relatively wise and benevolent, and would have many people who would wish to serve to protect their friends, families, and this nice culture they have, and be willing to risk or in some cases even sacrifice themselves. Not everyone cherishes their own survival above all other things, particularly after having experienced many decades of life. Many people also believe that their physical body's life is not the same as their soul's life, and accept death as part of life, and just another step on their soul's path. [Answer] Potentially unlimited lifespan wouldn't change much. Nobody joins the military planning to die for their country - you merely accept a certain level of risk in exchange for either the direct benefits of service or to try and make a better world to live in once the war is over. Apart from the fact that eighteen year olds are not exactly known for risk aversion, the risk isn't really that great. You aren't using WWI tactics, so most soldiers survive, and it is quite possible to lose more soldiers to training accidents than to enemy action. There are also situations where war is actually the less risky choice - think sitting safely at home until the invading space-nazis show up to execute you. [Answer] People choose to fight knowing that they might die. You may be coerced by conscription, but you can always at least try to flee the draft, go AWOL, or anything else that appears less risky than fighting, if you're so inclined after performing your moral and cost-benefit assessment. Perhaps "decide" would be better, but I'll stick with "choose". If you die, you lose your whole life, however long that might otherwise have been. You might believe in an afterlife, or you might not. You might like your life or you might not. Your life might be under threat even if you don't fight, for example if your country has been invaded. You may have been propagandised, shamed into joining up, threatened with imprisonment or execution, or deceived as to the exact degree of risk. But if you fight, then you've chosen risk to life because not fighting is somehow worse. Now, we might assume that people would prize a longer life more highly than a shorter one, but it doesn't follow that they would prize a life without ageing infinitely highly, such that they'd never risk it for any cause. Aside from anything else, not ageing doesn't imply infinite lifespan, since you will still in all probability have a nasty accident eventually. So, it's entirely up to you whether there are "enough" recruits, depending how many your narrative requires and on how willing people are to risk their lives. There's no reason to assume that people would be absolutely unwilling to take risks of dying. However, as in the real world, you need to motivate the characters' choices if they choose war (politicians) or choose military service (soldiers). All that said, the majority of real-life wars seem to have to do with living space and resources at some level. There are ideological causes for war as well, but if everybody is running quickly away from each other in different directions, then it's difficult to see what a war would be fought over. More realistically, even with rapid expansion into space some people would be running to the same place in competition, and therefore could come into conflict. [Answer] War, like everything in life, is a choice. People choose to fight for various reasons ... With immortality that choice doesn't change. As far as boredom goes - immortality doesn't change that either - it is driven by one's own personal desire -- for a better life for ourselves, our children - whatever. People are, in general, vagrants and leech off society; being immortal doesn't fix that. People have to want to have things be different -- regardless of other factors. ]
[Question] [ The Question about the blockade of en entire star system makes me wonder: How would, if possible, a space "radar" work? Or how would you scan for Ships further away than your Optical sensors can see. The big space makes is semi impossible to look for the reflected radar rays. 0-100 Eyeball also does not work because of the hugeness of Space, same as all other optical installments. [Answer] In the article ["Detection"](http://www.projectrho.com/public_html/rocket/spacewardetect.php) on the website Project Rho says, "There Ain't No Stealth In Space". Any spacecraft will create some kind of emission which can be detected. The most common is infra-red radiation because any space ship will generate waste-heat. That's an unavoidable side-effect when any form of energy is consumes on-board. With a common infra-red detector you might be able to detect that there is a source of infra-red light, but you might not be able to pinpoint its exact direction. But when you have multiple detectors, you can use triangulation to pinpoint the exact position of the source. When you know the position of the source but want more information about it than can be detected from passive infra-red, you can then illuminate it with active sensors like a laser- or radar-beam aimed exactly at the source. [Answer] looking for reflections of sunlight IS radar. Just with receiver (your sensors) and transmitter (the sun) at different positions. Using a different transmitter would not gain much though looking beyond the visible spectrum would, just about every energy using object will emit black-body radiation. You can look for that. [Answer] A bunch of people have given great answers revolving around how there is "no stealth in space," but I feel like they might be slightly missing the core of the question. > > How would, if possible, a space "radar" work? > > > Pretty much the same as on Earth. [RAdio Detection And Ranging](https://en.wikipedia.org/wiki/Radar) (aka radar) is a system that bounces radio waves off distant objects to see them. Radio waves, being just a specific slice of the [light (EM) spectrum](https://en.wikipedia.org/wiki/Electromagnetic_spectrum), can travel through space just fine. Actually, light travels slightly faster in space than in air. > > Or how would you scan for Ships further away than your Optical sensors can see. > > > As I mentioned above, radio waves are light (outside the "visible" range for human eyes, but still light). Assuming you mean ships that are too far because not enough light will make it into your detector, then the answer probably is "you can't scan for them." Light is a pretty good way to see things. It travels at the cosmic speed limit. It's a wave that's also its own medium (so it goes through open space without a problem). The right frequencies of light easily interacts with most things (it's reflected or deflected by most things), so it's great for seeing things. And, it's easy to detect across a broad range of frequencies. There really aren't any other mediums of detection as good as light. So if light isn't good enough for seeing something, you probably can't see it. For example: * [W and Z bosons](https://en.wikipedia.org/wiki/W_and_Z_bosons) are force carrier particles, like the photon. Maybe that means they could play in the same weightclass as light ...if their range wasn't so limited. * [Neutrinos](https://en.wikipedia.org/wiki/Neutrino), have a very long range, travel at about the speed of light, and pass through miles/kilometres of rock like it's nothing. Does this mean we can use neutrinos for some super penetrating form of sight? Nope. It passes through things so thoroughly, the [Super-K neutrino detection experiment](https://en.wikipedia.org/wiki/Super-Kamiokande) had to be built 1 km underground, as a 40 m by 40 m cylindrical stainless steel tank holding 50000 tons of ultra-pure water, etc. Here's a [picture](http://lh5.ggpht.com/-lbMNb1avhSg/T2mZkg4p4YI/AAAAAAAAVhU/KrQauXud-OA/super-kamiokande-3%25255B1%25255D.jpg?imgmax=800). It takes the analysis of super computers around the world to determine if any single neutrino particles have been detected. * [Gravity waves](https://en.wikipedia.org/wiki/Gravity_wave), a far reaching disturbance in the very fabric of space, is nearly impossible to detect, especially when caused by small objects. It took building [multiple 4 km by 4 km observitories](https://en.wikipedia.org/wiki/LIGO) just to detect the gravity waves from colliding black holes. Those waves caused disturbances shorter than the diameter of an atomic nucleon. > > The big space makes is semi impossible to look for the reflected radar rays. 0-100 Eyeball also does not work because of the hugeness of Space, same as all other optical installments. > > > You've just intuitively stumbled over the [inverse square law](https://en.wikipedia.org/wiki/Inverse-square_law). As Wikipedia puts it, "a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space." For light sources, this means means visible intensity rapidly drops off. This is why stars far brighter than the Sun are only specks in the night sky (at best). The principle behind this law is also why, as you noticed, it becomes very difficult (very fast) to survey everything within a 3 dimensional space as you expand the spherical area you're interested in looking at. The inverse square law also means things can, in fact, hide in space, but only at great distances (several AUs at the very least). This is why we might have a [proper ninth planet](https://en.wikipedia.org/wiki/Planet_Nine) which no one ever noticed. Light traveling out to those distances and back would be extraordinarily diluted. Even the heat generated by a super-Earth to Neptune-sized planets at those distances would not be detected. This is why it'll be years before we confirm or falsify Planet Nine. So, what does space-based detection look like? * Radar (and other light-based detection systems) works in space but decreases in usefulness with distance. * Active omnidirectional systems are only good for one's immediate area. Precisely how immediate/large that area is depends on the power output of the antennae and the sensitivity of the detectors. (I.e. you'd need to come up with numbers before someone could calculate the distances.) Whatever the case, we are still talking about how many km. * Passive omnidirectional systems would be pretty good at seeing fairly distant ships if the sensors are designed to pick up heat. Even with the inverse square law, a computer-based detection system could spot above average heat spots moving through space. This means it's nearly impossible to sneak up on someone unless there is a large object between them (e.g. a planet or large moon). However, the inverse square law does mean you probably won't passively detect ships more than a few AUs out. As before, the exact distance will vary based on detector sensitivity. * Directional systems (active and passive) will have far greater ranges, but you need to know where to look for them to be useful. (Note: active directional systems only work to distances in the thousands of km. Even the best Earth-based lasers are multiple km wide by the time the get to the Moon.) * Given that most people in even the most advanced spacefaring society will live on or around planets, moons, and space stations. Directional detection systems will probably be useful for distant areas known to be populated. In that case, ships would have a difficult time sneaking out from home since a directional system could keep an eye on them as the move out into open space. * Ships could try to (somewhat) counteract heat based detection by coasting as cold as they can through areas they're likely to be detected. They could also have a design that attempts to direct a good deal of their excess heat in a single direction (one where a detection system is not). Like conventional stealth, neither of these techniques would completely hide a ship. * Conventional stealth would still be useful for things like radar. This is more important in close range, when active detection becomes an issue. * At any significant distance, light travel time becomes an issue. Mars, for example, is many light minutes away. This means keeping an eye on ships a few planetary orbits out could mean you're looking dozens of minutes to several hours in the past. (Correspondingly, things take months to travel any significant distance.) * Detection at great distances and behind obstacles like planets could be dealt with by putting orbital radar systems in place. (That wont help the transmission time, of course.) [Answer] It's Complicated There's no stealth in space - you can't be invisible. But that's not quite the same as saying your enemies can't hide. The most obvious tactic would be a large-scale decoy attack. Now, it's hard to create decoys for moving ships, because engines and fuel are expensive, and the energy of the thrust correlates to mass as a general rule. So if you want to create a decoy for a 20-thousand ton ship, you need a 20-thousand ton decoy. You can strap an engine to an asteroid (and do some outside cosmetic work to make it look like a ship), but in general this will be too costly for common use. But that doesn't mean we can ignore it as a possibility - it only takes a few attacks to get through to ruin your day, so that means that it could still be cost-effective. Ballistic ships, on the other hand, are relatively easy to decoy. You just need a shell that looks like a ship, and some systems to mimic the radiation signature your normal ships give out. The downside is that once the attackers are forced to maneuver, the decoys stop being, well, decoys - it becomes obvious which ships are real and which are fake (unless your enemy is tricky and has some real ships pretend to be decoys, of course...). So. Space Radar. So given the above, what you want is something that fits the following criteria: 1. Test for as many frequencies as possible. If you just watch one thing (radar, background radiation, infrared) that makes it easy on your enemies to create useful decoys. Watch for as many things as possible, and your enemies have to spoof all of those to fool you. 2. Multi-tier. You want to detect enemies as early as possible, so you need to have installations spirally outward in all directions. Unfortunately this quickly becomes a scaling problem, and one that's not in your favor - your defense has to grow in three dimensions, but your enemies will still only attack at the point they choose. Doubling your effective detection range involves an 8-fold increase in cost for you, and most of that will be wasted on any particular attack. 3. Don't be predictable. Unless you have overwhelming force, predictable in warfare is often synonymous with "dead". It might make sense to have a perfectly optimized defense setup to maximize coverage, but optimized is also predictable, and... well, you know what that means. And once your detection is taken out (or at least degraded significantly) then you're in trouble. Thankfully you can also use decoys to make it harder for your enemies to pick out your detection installations and take them out. You should also move them periodically to prevent an enemy from mapping your setup. Nothing's Perfect In the end though, you need to accept that if your enemy really wants you dead, then you're going to be dead. There's no such thing as a perfect system - you will never stop 100% of the attacks against you. There's a reason systems aim for things like 99.999% - there's always the possibility that a few things will get through. And unfortunately, in space and with relativistic speeds, your enemy really only needs one thing to get through. Throw enough big rocks at an immobile target, at high enough speed, and it's just a matter of time before your target dies. Hopefully your enemy wants your planet intact and isn't willing to just bombard you to death. In that case you're ok as long as you keep your ships and installations periodically moving. [Answer] For a civilian applications, everyone would "squawk" their own position for everyone else on a known channel. At sea, today, this is done using AIS - and it includes position, speed, direction of motion, and intended destination. Civilian aircraft use a similar system. For a military application, you would most likely use a passive sensor. It could be thermal (detects heat/black body radiation), neutrino (detects tell-tails of fission/fusion power sources), EM (detects radio frequency leakage from 60Hz / 50Hz electrical power supply, intra-ship wireless comms, etc). Probably it would be a combination of all the above, plus whatever else works. These sensors will give you a bearing to your target, but do not provide any range information - without a time a flight you cannot calculate range based on the known speed of light. In order to obtain range, you would have to make an educated guess based on a couple of factors: 1) Relative intensity: particularly if you have observed this vessel or vessels of the same "class" before, you might have information along the lines of "when we are this far away, I expect a signal strength of X." This will mostly serve as amplifying information to the next indicator, which is... 2) Bearings over time: as both the sensor and the target move through space, the bearing your sensor observes will change. Your targeting system will crunch the numbers, and constrain range as you gather more information. If the target was stationary and your sensor was moving, then it would be simple to use two or more samples over time to triangulate target position. Since BOTH vessels will be moving, this will be more difficult, but fundamentally still achievable. If the sensing ship changes course it can greatly constrain the problem, and rapidly resolve range. Passive sensing has the added bonus that you are not emitting "loud" radar signals that enable other ships to identify, localize, and attack you. [Answer] How about using gravity instead of radio waves? Gravity has detectable effects over great distances, and we currently have sensors that can detect and map fluctuations in gravity, so if you had a detector that was sensitive enough you could send out some kind of graviton pulse and then register where it reacted to other gravity fields and/or objects. Even without a gravity pulse, all objects have gravity, so passive detection would be possible, especially for very large ships, or ships with artificial gravity. A stealth ship would be one that is small, has radio/radar and light absorbing material, active cooling of the outside surface to space ambient (maybe dump the heat into an internal heat sink which means the stealth could only be used short term before the heat would need to be dumped), and no artificial gravity when in stealth mode. So, active stealth would be cramped, hot, and weightless. There is also a theory that the effects of gravity travel faster than the speed of light\, so you'd potentially be able to detect something faster than relativity would allow. A normal radar signal would take about 20 minutes to cross the distance between Mars and Earth. TL;DR, it would be a lot like sonar in modern navel warfare. Big capitol ships and planet/moon/asteroid based installations actively pinging, smaller stealthy ships sticking to gravity shadows when possible and trying to remain undetected while listening for other stealthy ships... Gravity Mapping: <http://en.wikipedia.org/wiki/Gravity_of_Earth> Edit:* I'd like to point out that the theory of a [graviton particle](https://en.wikipedia.org/wiki/Graviton), if it could be harnessed, might allow for controlled [gravitational waves](https://en.wikipedia.org/wiki/Gravitational_wave). Another way to generate gravitational waves would be to generate a pair of very small black holes orbiting each other. As the waves propagate outward detectors could look for ripples in spacetime where no object should be, or for a change in the size of the ripples caused by known objects. If an asteroid is suddenly causing a larger ripple than normal, then it would indicate that the mass had changed and a ship is probably hiding behind it. \* This is based on Newtonian physics, and doesn't hold up with modern science. [Answer] It works [like this](http://www.seti.org/weeky-lecture/asteroid-radar-astronomy-spacecraft-missions-and-impact-hazard). See this video for a very informative presentation on just how radar is used to detect and explore bodies in out interplanetary neighborhood. [Answer] Any "active" sensor you might wish to employ is simply going to take twice as long to give you the information you'd get from emitted radiation of the target, anything you can't see isn't a threat anyway unless you have FTL in which case no EM based detection system is going to do you any good anyway, because the attackers arrive before you can see them. Have a look at Jack Campbell's Lost Fleet series for a really good hard science look at the issue of detection and signal lag in sub-light combat situations, also a pretty good read in and of itself. The main bit that's relevant here is from the first book where they point out the fact that radar has to go twice the distance, there and back again, that optical signal data does. ]
[Question] [ I've been exploring the idea of an interstellar penal colony or prison planet from a realistic perspective. This idea is featured in many science fiction stories, but I've never really thought deeply about the concept itself. Let's assume ftl travel exists. Does it make sense for a society to send its criminals to an isolated planet as punishment for a crime? If you want to get rid of certain criminals would it make more sense to execute them rather than spend the time/effort to transport them interstellar distances? I would like to hear what others think. There are a couple scenarios that make a prison planet/colony seem worthwhile to me: #1 - Space Australia. As a cheap way to set up a colony from scratch, a population of convicts is dropped off with tools and basic building supplies. They build shelters, set up sustainable food production, maybe basic industry. They would do this to contribute to their own survival with no input from the outside. At some point the society that sent them there would come in to take over a functioning colony. If the initial effort fails, just send more convicts. Pros: No extra expense after the initial investment (Unless more convicts are sent). Low risk/high reward. No possible escape (Assuming people and supplies are dropped from orbit and ships never land). Cons: This could only be a life sentence. Moral questions about what to do with children of convicts. (I guess you could have separate all male and female prison planets to avoid this issue?) #2 - Prisoners sent to an existing colony for labor. Pros: Allows for sentences for terms other than life. Provides an additional labor force to a developing colony. Cons: Potential for harm to the civilians of the colony. Continuing expense (guards, facilities, control methods). There are other scenarios featured in science fiction that I personally find to be pretty unbelievable. For example, the whole Riddick, Butcher Bay prison planet idea where the worst of the worst are sent. To me this is just Space Alcatraz. Why build and staff a prison on a planet completely by itself? Real Alcatraz closed because it was too expensive to constantly ship food/supplies/people all the time. Guards and staff would have to be rotated out or it would be just as much a punishment for them. Maybe the whole idea is unrealistic and the only real solution would be a traditional prison on Earth or another settled world? I'm sure there are other scenarios that I haven't considered. [Answer] ## Penal colonies are for minimum security prisoners The problem with most fictional penal colonies is that people assume that they are where you send the worst of the worst, but they actually have it backwards. Historically, most penal colonies have been places you send people who've done crimes too small to need to worry much about. Violent offenders, career criminals, political enemies etc. make a lot of sense to execute or keep in high security institutions, but penal colony prisoners were generally people arrested for non-violent, non-seditious crimes like counterfeiting, defaulting on debts, smuggling, tax evasion, working without a license, poaching, vagrancy, etc. In fact, as the demand for workers in your colonies grows, you will likely outpace your ability to find legitimate criminals; so, you will generally see your government go down one of two unethical rabbit-holes to solve the problem. They will either become very strict about minor legal infractions or they will criminalize some minority group as a matter of policy to try to chain-gang as many prisoners off to the colony as possible; so, as the colony grows, you may see an increasing number of colonists who've literally done nothing wrong being shipped off like slave labor to try to fill demand. Because they tend to select for people who've committed only minor crimes, penal colonists tend to not need a whole lot of special care to control compared to a normal colonial population. With nowhere for the colonists to go, you really don't need a prison system. They rely on you for survival, and most of them are not blood thirsty enough to fight back over long hours or poor work conditions. So they do their jobs, they live their lives, they raise their families, etc. The fact that there are children born out on theses penal colonies is actually in the interest of your government because the goal is to develop the planet. That takes workers; so, even if children are born here, the living conditions are humane enough that living here is seen less as an active punishment, and more as just a way to find a use for the dregs of society. So if children are born into the system, the government tends to not see this as a moral dilemma... even if it does in practice mean being born into serfdom. ## Penal Camps can be an alternate form of execution A lot of the confusion comes in the from of penal camps, which are distinctly different than penal colonies. Penal colonies are places people live. They spread out building roads, farms, homes, factories... everything you'd find in a normal settlement, but built by the hands of convicts instead of freemen. Penal camps are smaller. They are specific mines or industrial compounds built inside of a typical prison facility complete with guards, jail cells, etc. They are small enough in scope to double as a labor camp. Penal camps are often places where the work is so hazardous that you use them as a form of death sentence. Examples of this would be the lead mines of Ancient Rome. Romans used a lot of lead for their [plumbing](https://en.wikipedia.org/wiki/Plumbing#:%7E:text=The%20word%20derives%20from%20the,Roman%20era%20were%20lead%20pipes.), but they did not have the equipment to safely mine it; therefore they would invest heavily in security to guard a lead mine and keep prisoners from escaping, and force them to work where the lead would eventually kill them (6 months to 2 years on average). Because the hazards of lead were too well known for demand to be met with paid labor, the cost of building and maintaining a penal camp off in some remote place was well worth the investment. This is where Sci-fi often goes wrong is that they try to justify remote penal camps. In the future, there is really no probable hazard where you would have a human do the work instead of a robot. The Romans built Penal Camps because they had no alternative for getting the lead they needed. A future society would find it much cheaper to use machines; therefore there would be no justifying a remote penal camp. Instead, if they make their prisoners do forced labor, it will focus on what is cheap, not what is dangerous; therefore any penal camps they have should be within normal established populations so that their stamped license plates or printed t-shirts or whatever you have them doing does not cost too much to sell because of transport costs. ## World Building a Remote Sci-Fi Penal Camp That said, a sci-fi remote penal camp can be done if you really want to. To start with, you need a planet with a ["Not Rare Over There" Unobtanium](https://tvtropes.org/pmwiki/pmwiki.php/Main/Unobtainium). This is important because it justifies bothering with a planet that has an exotic hazard instead of moving to any of the myriad other ones around. This leads into the second step: This planet needs a hazard on it that affects electronics, but not the the human body. Something like powerful solar flares that periodically EMP the colony could work or maybe some native life form or [grey goo](https://tvtropes.org/pmwiki/pmwiki.php/Main/GreyGoo) that swarms and eats any sort of electronics you try to lower onto the surface. This forces mining of the Unobtanium to be done the old fashioned way with human labor and hand tools. If you do this, then it suddenly makes sense for a space aged society to run a dangerous iron age style penal camp using convicted murders, rapists, insurrectionists, and targets for genocide, because without modern machines, the act of mining itself again becomes a death sentence. [Answer] > > Does it make sense for a society to send its criminals to an isolated planet as punishment for a crime? If you want to get rid of certain criminals would it make more sense to execute them rather than spend the time/effort to transport them interstellar distances? > > > Yes. There's two main reasons why you put people in Prisons: 1: To punish them. 2: To remove them from the law-abiding population. Think about the Death Penalty for a moment, regardless of your thoughts and feelings about it - it fulfills both of the two main functions perfectly. It certainly punishes them and it permanently removes them from the Law Abiding populace. We (in the west at least, excluding America) tend to look dimly on the Death Penalty - miscarriages of Justice, squeamishness etc. etc. However, for Crimes that are severe enough where permanent removal from society is warranted, then sending to a colony (where there is an implied 'no hope for escape') does have a lot of merit. It's reversible (unlike the Death Penalty) It solves the problem of a Prison break (or at least, adds such significant barriers to escape as to render it 'secure' in the minds of the populace) 'Out of sight, out of mind' There are others - but that the rationale for why is not what you want to focus on: What you have to contend with is what the populace in your story consider to be Ethical. For example - for myself, I sleep very easily at night knowing that serial child molesters generally get severely assaulted/murdered in prison. There are those who say that when an individual is incarcerated, the State has an obligation to protect and provide them during their sentence. Depending on what values your society holds will dictate whether or not they consider a penal colony to be ethical. If they are more like me - then they will be fine with it, if they are more like the other group - they will likely not be okay with it. [Answer] * What does interstellar transport cost? Right now, it would cost millions to send a person to Mars. If interstellar flight is even more expensive, penal colonies are a non-starter. * How complicated are new worlds? 'Unsupervised' penal colonies work best if the world has a shirtsleeves environment. They do not work if it takes breathing gear, airlocks, etc., because maintaining those takes organized civilization. * What does the parent society think? In most societies, prisons are not the 'lock them up and throw away the key' style. They are supposed to reform inmates, and inmates are supposed to have at least a perspective of getting out. I write most, because some societies do seem to abandon reform. Spacelifting people is almost certainly more expensive than shooting them. Much more expensive. So one precondition for prison colonies, in the cinematic tradition, is a parent society where 'good citizens' like to pretend that they do have civil liberies, like not shooting offenders en masse, while in practice they give the offenders an one-way ticket to a faraway place. [Answer] I think you may want to spend some time thinking about justice, punishment and rehabilitation. Your personal philosophy in these areas will give your story life. For permanent exile on prison planets, your society has a low to non-existent belief in rehabilitation. And that they're too squeamish to execute criminals. Or someone is making a lot of money from penal camps and has bribed politicians into making it a punishment for "undesirables". For a "space Australia" scenario, there would need to be too many habitable planets - more than can be colonized. Additionally, fuel costs need to be cheap. You may want to read a bit about the [Tsarist](https://www.nytimes.com/2017/01/04/books/review/house-of-dead-daniel-beer.html) & Soviet Gulag system. Many of the people sent to the prison camps were sent as political punishment. People who worked on significantly important projects (such as [nuclear bomb design](https://en.wikipedia.org/wiki/Aleksandr_Solzhenitsyn), or [spacecraft design](https://www.historynet.com/the-scientist-who-survived-the-gulag-to-launch-sputnik/)) did so from inside prison camps. I think a more interesting question would be what sort of people would perform such labor while imprisoned? What sort of people would trust the product of such labor? In the book [Provenance](https://rads.stackoverflow.com/amzn/click/com/031638867X), there is a similar sort of prison planet system called "compassionate removal". It is poorly described, and most of the explanation appears as propaganda directed towards the society that exiles such criminals. It is pitched as a system for dealing with incorrigible and unredeemable criminals. One of the central characters was "rescued" from such a place. The little bits described show why the character is damaged. Frequently, robots are stand-ins for slaves (with things like Asimov's 3 laws preventing slave revolts). Penal camps are not much different from slave labor. After the Civil War, [chain gangs](https://en.wikipedia.org/wiki/Chain_gang) were a form of punishment to effectively re-enslave blacks. The predominant "crime" was called "vagrancy" which was the crime of not having a job. In some areas, county sheriffs became wealthy from renting out prison labor. [Answer] They sent about 162,000 British and Irish convicts to Australia between 1788 and 1868. The idea looks quite similar, so you might want to check [why they did it](https://en.wikipedia.org/wiki/Convicts_in_Australia#Reasons_for_transportation). [Answer] # Modern law does not punish The notion of punishment is — literally — stone age jurisprudence. Modern law exists for the following reasons: 1. Protection Make sure the innocent are not subjected to crime. 2. Prevention Make sure to take away the incentive to subject innocents to crime. 3. Restoration Repair the injury to innocents, when they have been subjected to crime. 4. Rehabilitation Repair the criminal, so that they do not do any more crime. Punishment is retribution, i.e. state sanctioned blood vengeance. The only reason that still exists in modern law, is grandfathering. So, would a correctional colony make sense? Let us go through the four points. 1. Does it provide protection? Yes, it does. However, there is only point to it is if the convict is likely to commit the same crime again. 2. Does it provide prevention? A little bit, but being judged and sentenced does not do much to discourage people from committing crimes. And — again — this is on the assumption that the convict is likely to commit the same crime again. 3. Does it provide restoration? It can do, if the correctional colony is manufacturing something that can go to the restoration of the victim. 4. Does it provide rehabilitation? It can do, if it has some kind of treatment / programme that turns the criminal into a productive member of society rather than a criminal? So, what would it take for a space colony to make sense as a correctional facility? It would make sense for... * Repeat criminals... * ...that need to work off a debt for the damage they have caused... * ...and that are serious about trying to kick the habit and become productive members of society It would also make sense for... * The incorrigible, the people that are so dangerous to society we simply cannot afford to have them among us any more. This gives us two forms of justice colonies: * The correctional facilities, that let people work off their debt, learn skills and come back as better people * The people storage boxes, where we put those that cannot be corrected, at least not now. --- So, does an interstellar prison colony make sense? Yes, it does: * For repeat offenders that want to try to improve * For the ones that are truly dangerous and cannot be kept in civilised society [Answer] Siberia-in-space A space colony may be a place to send people deemed to be trouble-makers, if the society is authoritarian, yet sufficiently principled not to simply shoot these people. (Or, worried about making martyrs out of them). So, there's a not very useful planet a long way away. "Troublemakers" are exiled there. It may be a Siberia, where they are not in general expected to survive. Or it may be perfectly habitable, just very sparsely populated and lacking any natural resources worth shipping between star systems. [Answer] Didn't the British do something like this when they sent people to Australia? They could have executed those criminals, but they didn't. We could follow a similar model. It could go like this... The earth is over-crowded and short on resources. The government recognizes that they need to get rid of people, but engaging in mass executions, limiting births, or letting the population starve are unpopular with the public. At the same time governments have ambitions to establish off world colonies, but there are few volunteers who want to make a dangerous journey through space. Citing an increase in crime and resource shortages, the government makes stricter laws. Then they use prison over-crowding as a pretext to send large numbers of people off world against their will. ]
[Question] [ Would humans on disparate planets with little to no contact with one another continue to evolve along different lines? In this universe, humans left Earth a hundred thousand years before. Or if it serves the story better 500,000 years before; and went in many different directions looking for planets they could live on. 100 separate planets were found and/or terraformed, all very far from one another, and humans have lived on them ever since. After that long a time, would they all evolve into separate species? Would time make the difference? Would environmental differences on their planets make the changes? What I'm looking for is a scenario in which two of those cultures meet after hundreds of thousands of years (or more if necessary) and don't realize they are just two off-branches of humanity. Maybe later they find out through genetic testing or something, but at first they should think they are "aliens" to one another, not the same species. Is this at all feasible? [Answer] TL/DR: Not after a 'mere' 500,000 years. In fact we should know that the other humans came from earth, if not what type of earth animal they evolved from, even if there were half a billion years or more since we diverged from them. Horsing around a little bit To give a timeframe for comparison the last common ancestor of all equines (which comprise horses, donkeys, zebra etc) was about 4.1 MYA (million years ago). That's nearly ten times the length of time you suggested. Looking at equines they look similar. You can guess if a species is equine just by looking at it even if no one told you. After all you probably were never explicitly told a zebra was an equine, you just looked at it and knew. That's because 4 MYA isn't enough time for a species to evolve into something truly foreign. Any species that is split by only 4-5 MYA would look close enough that anyone familiar with evolution would naturally presume they had a close common ancestor. Many equines can also usually interbreed to some degree, though their children are usually infertile, so humans split by 4 MYA likely could interbreed at least occasionally. Now on the one hand you could argue that entirely different worlds would create such a hugely different environment as to encourage rapid evolutionary change. To this I'd say that's true, if it wasn't for humans technology. As it is we won't adapt to our environment, we will adapt our environment to us. Were going to pick worlds that are 'earth like' and use technology to make the worlds more earth like. There may be some minor difference our technology can't adjust for, gravity being the biggest one we would struggle to change, which may be a driver for evolution but most of the potential drivers will be compensated for by technology. In fact I believe humans on different worlds will be far less likely to evolve into different forms then ancient equines, due to our technology. Technology > evolution Species living in stable environments don't change, look at alligators which have stayed roughly the same since the time of dinosaurs! If a certain form is working for your environment then there isn't much incentive to try out new adaptation and koinophilia - the instinctual avoidance of things that are different, like novel mutations, in mates - will result in the species staying mostly unchanged. You need some sort of change in your environment, some massive pressure pushing a species to need to adapt, for major changes to be likely to happen 'rapidly' - and yes 5 MYA is rapid from an evolutionary perspective. Now I definitely do not expect human's environment to stay static. However, I do expect the exact opposite, our environment will change so rapidly, due to technology, that no one mutation will be favored long enough to spread through the population before the environment and pressures change again, which will ironically result to the same effect of humans staying somewhat static evolutionarily much as alligators have. Look at our technology 2000 years ago vs today, it's utterly different and yet 2,000 years is a blink in the eye from an evolutionary perspective. This means that technology is going to change faster then our species can adapt. As new technologies come about new evolutionary pressures will as well. For example right now car accidents are a major cause of death in first world nations. This means currently there is a fairly strong evolutionary pressure to evolve to be able to process movement at high speeds and make the the sort of rapid decision required to avoid accidents. However it will be no more then a generation or so before self driving cars likely take over and the need to be good at driving disappears. The few generation between when cars became common and when we no longer drove them were not enough for natural selection to significantly change humans to make us better at driving. The same patter will happen with new technologies, they will change so fast that evolution can't 'keep up' and since the exact pressures put on humans to survive will constantly change with our technology there will not be any one mutation favored long enough to permeate through a population. In absence of a long lasting evolutionary pressure favoring adaptation humans will default to persisting their current form. There is no such thing as humanoid aliens Honestly given how utterly foreign any species evolved entirely on a different would should be if we go to another planet and find anything remotely mammal like the only logical conclusion would be it likely came from earth. If your humans know that other humans traveled to other worlds and they run into any creature on another world that is carbon based with four limbs and eyes, no matter how bizarre it's appearance otherwise, the only remotely plausible explanation for such similarity to earth animals is it's from Earth origin. The only real question would be what earth animal this one originally evolved from. Of course that means DNA tests would happen almost immediately and our exact common ancestor being identified via DNA in less then a few years of meeting each other. This is true even after hundreds of millions of years when all the humans look utterly different. How many billons of years can we cut that timeline down to? If you want there to be any noticeable change in your human species you need to cut back on technology so more stable evolutionary pressures can encourage adaptations. If humans lost their advanced technology, possible due to disasters after landing preventing them from building the infrastructure necessary to support it, then a species reverting to swords and sandals level technology will defiantly struggle with the utterly foreign world they are living in and likely adapt to better survive it. If both of the human subspecies regressed technologically and had to rediscover their technology then their evolving to look different is far more likely since technology isn't favoring stability of form, though again not nearly enough for a mere 5 MYA to make them truly foreign. If you take that further and presume your human species no longer remembers they originated on another world, and thinks space travel only recently became possible for species on their world, the likely hood that animals from another world came from the same common decent as them would seem much lower. I mean how likely would you buy an argument that dinosaurs built spaceships and now live on another world if I told you that since the creatures we just found on alpha centauri have eyes they must have come from something like dinosaurs? If you make one of these two human subspecies non-sapient you would further make it seem implausible they built spaceships and flew to another world, and make the divide between the two human subspecies seem far more vast since humanity tends to define itself by it's sapience. (Here I should mention that it seems unlikely human technology would regress this much and humans still survive, as any planet humans travel to would likely be so foreign that without a relatively high degree of technology to help us adapt we couldn't survive on the world. The idea of evolving towards loosing sapience, and such a non sapient species still surviving on a foreign world, seems particularly implausible without either billions of years of time for us to adapt to the world or this new world being far more earth like then is realistic. However, you get some poetic license here; few are going to notice and nitpick on something that trivial so I say go ahead and have technology regress if it serves your story) So my suggestion would be both groups lost technology, one group's technology was so lost that they eventually became non-sapient. Then when your one sapient species finds another non-sapient species that looks like them; but their certain didn't come from their home world - which they think of as being the one they live on now not Earth - they would be less likely to guess they came from a the same species originating on another world. Of course the utterly implausibility of two alien species sharing so many similarities as any of our decedents would share should still lead to experts asking allot of questions. DNA tests would still be expected to happen almost immediately, and DNA comparisons would be made. The plausibility of the two human subspecies sharing a common ancestor would still be known from fairly early on. The only real issue would be convincing people of how that happened when everyone would be making the equivalent of "dinosaurs couldn't build spaceships" argument. You would instead get the sapient humans arguing the DNA evidence is wrong because it shows our last common ancestor as happening before humans even evolved on their home world! at that point evolutionary experts will point out that we always knew there was an unexplained lack of fossil records, or any other records, of animals earlier then whenever humans first touched down on their home planet and suggest maybe these creatures are somehow connected to that pre fossil record time period and may answer some of the huge questions as to why earth-like animals seemed to appear out of no were X million years ago. At that point things probably get political with religious leaders complaining that's heresy since everyone knows god created earth-like animals on their world back then and how dare you suggest otherwise etc etc. Eventually scientists will realize the non-sapient humans from the other world have a fossil record that dates back to, but no farther then, same time period as theirs. Then we get even more interesting questions about how two similar species mysteriously appeared on two worlds lightyears away at the exact same time. I imagine the standard arguments would boil down to 'god did it' and 'aliens did it'. Of course this still requires a time period measured in hundreds of millions of years - tens of millions of years at minimum even if you push things- not thousands. Even then the possibility of common ancestry will come up almost immediately. The only real mystery would be how that common ancestor could exist given what the humans know of their own history. [Answer] > > After one hundred thousand years, would they all evolve into separate species? Would time make the difference? Would environmental differences on their planets make the changes? > > > Short answer: yes Long answer: genetic separation and different selection pressure (read environmental condition) are what leads to speciation starting from a common ancestor. Your setting meets both the condition, so it's fairly sure that, after such a time, there will be some divergence between the inhabitants of different planets. However, for it to be sufficient to make cross-reproduction impossible is another story. You will probably need more time to ensure mutual sterility. Or you can use it as a story element, the amazement at finding that Gilgarious from planet A was able to conceive offspring after a fun night with Squawaren from planet B. [Answer] As other answers have said, by natural selection? Probably not. However that leaves un-natural selection! If both societies gene-edit successive generations to be "fitter" for the environment, you can drastically change body shape over a couple of hundred years. A large event could remove each civilizations knowledge of "Earth". Have one decimated by a super volcano or meteor strike, have the other do some weird religious or political cultural shift where they claim this new world as their own, and over 5k years simply stop talking about "Earth" (Where did we come from? Some say first people fell from the stars, and some were loved by the mother world, who gave them the strength to endure...) After 100k years two superficially very different races. [Answer] It depends on how different the environment are and how long. If the human terraform the planets to all be earth clones then the evolutionary process will be slowed. Also remember genetic engineering as with this technology can both accelerate the divergence or stop it completely. [Answer] The answer depends on whether their societies allow them to undergo a natural selection process or not. Remember, that evolution depends on 1.) random mutations being advantageous to individuals (for some measure of 'advantageous': faster at hunting? longer lifetime? less cancer?) and 2.) this advantageous trait being allowed to permeate into the entire population by outcompeting the less advantageous part of the population. It is certainly part 2.) here that would be under scrutiny from a conscious animal like the human. In our current state, society is wary of change, as we naturally become conservative when founding families, favouring stability for our children over wild social and genetic experiments. Furthermore technology allows us to nullify any natural selection processes that would let a disadvantageous mutation die out in the animal kingdom, and amplify positive feats. Summarizing, I think that modern humans have an effective speed of natural selection as a driver of evolution being decreased to zero. Any future, isolated society instead would chose their own speed of genetic change, either natural or artificial, depending on what they believe. They could chose to remain absolutely conservative, and disallow any systematic changes to the original genetic structure. [Answer] Given enough time, the answer is "yes"--[Darwin's\_finches](https://en.wikipedia.org/wiki/Darwin%27s_finches). I'm not sure that 100,000 years is enough time to produce different species, though > > [It is unclear when the line of Neanderthals split from that of modern humans; studies have produced various intervals ranging from 315,000 to more than 800,000 years ago. The date of divergence of Neanderthals from their ancestor H. heidelbergensis is also unclear.](https://en.wikipedia.org/wiki/Neanderthal) > > > I have seen an argument that hunter-gathers are smarter (using an IQ test that measures spatial perception) than farmers/city dwellers, and that the latter are selected for resistance to zoonotic diseases (since our ancestors lived with livestock). Maybe different zoonotic diseases would give divergence. [Answer] In Larry Niven's Ringworld series, he posits that humans have evolved to occupy many different evolutionary niches, as discussed in [The Ringworld Engineers](https://en.wikipedia.org/wiki/The_Ringworld_Engineers). That's a fictional argument for you. [Answer] ## I don't think they would. The way evolution works, you have random genetic mutations, then if, in the given environment, that mutation proves beneficial, it 'spreads' and eventually most of the population end up having it. The thing is, in evolutionary terms, 'beneficial' means it makes the individual either more likely to survive or more likely to procreate. Which means people without that mutation would be much more likely to die young than people without it. For humans, this kind of harsh evolutionary pressure is to a large extent negated by advanced technology (especially medicine) and social organisation. Most people will survive, even if they're 'less fit' in evolutionary terms. Now, your people have separated by colonizing different planets, so they were capable of interstellar travel, which assumes more advanced technology than we have today. So, likely, there wouldn't be much in the way of evolution of the species happening. Now, it's possible that due to the pressures of life on different planets, these people would lose their technological society and end up with a pre-industrial civilization. But then, how would they end up meeting each other? Most likely, starting with much more advanced technology than we have today and given 100,000 years, some of these people would become cyborgs, or would have the technology to store their consciousness in wholly mechanical bodies, or something even more sci-fi. Now if these people met (if you could even call them 'people' at this point), it's very possible they wouldn't recognise each other as human. ]
[Question] [ In a dramedy science-fantasy children's (for 8 to 15 years old) videogame I want to create, Salade de Fruits (which naturally means Fruit Salad) (my first language is French), there is a villainous antagonist who has a gun charged with pears. The technological level is a modern cannon, as a potato cannon but with pears. Why would he have that? Because in my world, there is a protocol that makes standard projectiles illegal. Why would they be illegal? That is because normal bullets are too polluting. So, how could pears be used as ammunition? Should European pears (Pyrus communis) or Asian pears (Pyrus pyrifolia) be preferred? [Answer] ## Frozen Pears. I remember an anecdote of engineers testing the durability of a bullet train against birds. They used a chicken in the tests and the train did fine. The French on the other hand should have been told beforehand that the chicken needed to be unfrozen... I don't remember where I heard this, but the story holds true even for pears. Your pear cannon would need the ammunition to be kept in a freezer overnight to be effective. Otherwise the fruits splat like fruits typically do. A frozen pear on the other hand hits HARD. Littéralement se prendre une poire! The concept is fun. Keep up the good work! [Answer] # Less Lethal Pears: Shorter ranges and lower speeds can be achieved with the kind of pressure-based weapons you are suggesting. * Riot pears: pears, even ones coming apart, can be fired at your onerous rioting civilians, and in the same way. under-ripe pears will be firm and sting, ripe pears soft and messy, creating difficulty for opponents moving (and can be counted against rioter's food rations-after all, you issued them food). Rotting dried out pears sprayed with nasty molds before drying can sicken opponents, disabling them without TECHNICALLY using biological weaponry. Or those same rotten pears can reek and be a substitute for chemical irritants. Dried, re-molded pear can be sharp like shrapnel without leaving a lot of evidence (since it will rapidly soften once moist). And all of this can be labeled "response in kind" because rioters throw fruit at the riot police, [Answer] Frame challenge: Do you need an explanation? When fruits are consistently the only objects being weaponized in your fictional universe, and the overall tone of the work is wacky enough that the audience knows that it is not to be taken too seriously, then they are going to suspend their disbelieve and just accept that this is how your world works. You can easily make up a flimsy concept like "fruit power" which is inherit in all fruits and makes them powerful weapons. Other weapons like firearms or bladed weapons lack "fruit power", making them inherently inferior to fruit-based weaponry and thus an illogical choice of weapon in your world. What is that "fruit power"? Where does it come from? Nobody knows and nobody cares. It's inherent in your world, and that's all that matters. The "everything needs a scientifically valid explanation" mindset is a common trap new worldbuilders fall into. As long as a world is internally consistent, it doesn't matter that the scenario would not make much sense in our world. The urge to come up with a plausible explanation for everything that's special about your world can be distracting and limiting. This is even more true in the context of video games, where players will gladly accept the most unrealistic properties of the world as long as they are reflected in the games mechanics. > > Should European pears (Pyrus communis) or Asian pears (Pyrus pyrifolia) be preferred? > > > In the context of a video game, I would prefer European pears for a simple UI reason: Asian pears are too easy to mistake for apples. Making objects distinct by color alone is dangerous due to color blindness. So when it is important for the player to tell apples and pears apart, then you should give them different shapes. [Answer] Clearly your evil villain needs to use Atago pears which are the heaviest. The current Guinness world record for a pear is a 2.9 Kg (over 6 lbs) Atago grown in Japan. For extra destructive power perhaps an unripe Atago might be best because I assume it would be harder. A pear Gatling gun firing a continuous stream of 2.9 Kg pears would be a formidable weapon. [Answer] Pears on their own can be pretty hard depending on the variety. They would make great munition. Projectiles do not need to be hard to be able to do damage, even just water can do loads of damage if there is enough force behind it. And with a potato cannon you will have plenty of force! Another fruit that comes to mind is the Pomgranate, it can be used as a fragmentation grenade, or as shotgun munition. If you want to get a feeling for how much damage a fruit projectile can do, you should watch this video where someone fails to launch a watermelon with a catapult and gets the thing in their own face.. [Answer] The Bradford Pear and the Callery Pear have small hard fruit that is almost woody. A tree with larger fruit could be used for ammunition very easily. Munitions that used to spread ball bearings could easily be repurposed to spread these. The tree is also starting to become classified as an invasive species in a number of US states. ]
[Question] [ In the not-too-far-away future during a nuclear winter, one city survived by being sealed under a dome forcefield (?) protecting them from the cold weather and potentially harmful sunrays once the sky cleared up. Robots with varying degrees of complexity exist in this world, and I don't want them to be able to enter this dome. I thought that the forcefield could be electromagnetic to prevent machines from entering. But a group of humans that my story follows has to be able to penetrate this dome. So how could I make the field separate the inside from the outside and still allow humans to enter? The humans that I follow are also bringing in mechanical gear that, in order to further my plot, needs to be rendered useless as they enter. I am very much open to better scenarios if it proves too difficult to make plausible or is too far fetched. I am a bit unsure if the technology the dome uses fits with the technological level of the city it covers. [Answer] CAPTCHA Palisade [![enter image description here](https://i.stack.imgur.com/BAAyC.png)](https://i.stack.imgur.com/BAAyC.png) The dome itself does nothing. Only it is hard to find. The directions to get to the dome are based on identifying bridges, cars, traffic, lights. For example "turn left at the traffic lights, go straight ahead until you pass [![enter image description here](https://i.stack.imgur.com/K1jSB.png)](https://i.stack.imgur.com/K1jSB.png) parked cars, then left under the bridge. . . " Robots are notoriously bad at following this sort of directions. They always get lost. [Answer] [![loki](https://i.stack.imgur.com/9faCg.png)](https://i.stack.imgur.com/9faCg.png) "The machine would melt you from the inside out. Please move along, sir." --- There are robots. The people who built the dome don't want robots getting in. There is a robot Guardianoutside the dome that guards the entrance (which is a bridge, because). The robot Guardian does not let robots through. It does not let anything that might be a robot through. Mechanical gear might be a robot. The dome is pretty sweet. The Guardian is pretty scary. The humans in your group don't understand how either one works but it is clear that both do, well. [Answer] # The forcefield can already solve this The forcefield is much like what is used in Star Wars by the Gungangs in the movie 'the phantom menace'. It holds anything at bay over a certain speed/pressure, but slower less high pressure like a human or air can still go through. This forcefield however has an electromagnetic effect against anything that passes through. Anyone with experience with Magnetic Resonance Imaging (MRI) machines can tell you it can be disorientating, nauseating or just plain weird, but it isn't dangerous. However, for anything electronic it is incredibly dangerous. Humans pass through, robots aren't as lucky. [Answer] # There's an electromagnetic pulse at each entrance. This fries any electronics or robots, but leaves humans unharmed. Robots can enter the place physically, but are immediately fried. [Answer] You could have running water at each entrance i.e. Shower, waterfall. Shorts out any electric gear or bot. Water-proof robots are probably not equipped for land travel, but hey, it's your story! Also Long-term ionization To take out the water-proof bots that got through. Although an electromagnetic pulse (meaning all at once) strong enough to damage electronics would potentially affect human genetics in their cells. But, if the whole inside of the dome was washed with ionized particles at regular intervals, the longer, weaker doses would affect electronics well before humans. The only problems would be 1. Knowing when to stop, 2. The water-proof bots would have access to the city for a short, but still substantial period of time. Technically, whatever you say goes, but I don't know if the logistics would work out. The water would have to be externally drawn, which means it has been under the outside radiation. To draw the water from inside would require a large reservoir. It could work. Your choice. [Answer] Perhaps all the robots and the equipment require a satellite connection to work, but the dome contains a metal plane or mesh As long as that sky connection is needed, even a thin layer of conductive material is sufficient to act as a [faraday cage](https://en.wikipedia.org/wiki/Faraday_cage), preventing successful connection to the outside world, rendering the robots inert and the gear useless Rebar is not a tight enough grid (the communication waves must not fit through the gaps), but a tighter grid (like a microwave door) or shell could be explained away by explicit purpose Perhaps the robots are not entrusted by a larger system with enough intelligence to go around on batteries (and thus enter the dome), require a connection to some [Multivax](https://www.physics.princeton.edu/ph115/LQ.pdf)-sized ground unit, simply have no apparent motive and go about their inscrutable tasks ignoring the dome, or were really created by the dome-dwellers, and know to avoid it. [Answer] The shield is active - in the computational sense. There is a field around the city from which information like MRI can be extracted to determine the structure of anything passing through the region. The field can also be ramped up to the point that it destroys something by internal heating. The control over this is detailed. Most likely, by default things get fried. But, if you, a human, approach slowly enough to be identified as human, then the security system fries your equipment, but lets you through. In principle the business end of the security system might be able to supply enough power to break any material into ions. [Answer] strong magnetic field on the ground Powerful magnetic coils powered by cold fusion could essentially repel any robot similar to how maglev rail repel the train, turning it into a brick wall for all robots. If a piece of electronic equipment does get too close, the coil would damage the CPU (Similar to how MRI supermagnets damage hard drive data) which also solves your problem of needing the field to shut down electronics. ]
[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/206437/edit). Closed 2 years ago. [Improve this question](/posts/206437/edit) When the gods join our presence they are shaped in terrifying ways, the first thing they mention uppon meeting a human are "fear not..." Or "close your eyes,mortals are not strong enough to withstand my appearance" Why can't they just take a more familiar shape ? Why risk being perceived as devils or scaring to death children and induce uncontrollable vomiting in adults? [Answer] The Gods are beyond our ability to fully comprehend. Though they manifest as perfect beings in all regards, our lack of ability to comprehend their perfection results in a form of temporary insanity. It is only through the lens of insanity that we can perceive them at all and not simply perish. The practical upshot of this is that people perceiving a God do so though a miasma of their own fears and phobias. As a result, the god though perfect in all aspects appears as a nightmare to the mundane viewer. [Answer] # Bandwidth is Limited: If a being can be said to be supernatural, they have aspects that go beyond the known scientific observations humans have ever made, or are even able to make. They transcend the known "laws" of nature. Because of that transcendence, maybe in your story the gods' form of communication don't work with our limited brains. Compared to a computer, the human brain's input/output speed may be relatively slow: > > Moscoso del Pradon uses his method to determine how much information the brain can process during lexical decision tasks. The answer? No more than about 60 bits per second. Of course, this is not the information-processing capacity of the entire brain but one measure of the input/output capacity during a specific task. > > > Source: <https://www.technologyreview.com/2009/08/25/210267/new-measure-of-human-brain-processing-speed/> > > > So, there's a potential for neural overload when a potentially infinite being makes contact. They must decelerate their own (potentially infinite) thinking speed and communication speed to match the system they're connecting with. Depending on the nature of the gods in your story, they may not wish to be encumbered by such inconvenience, leading to another possible way to communicate: # Gods are Multidimensional: To be able to qualify as "supernatural" it is possible the gods occupy or exist within different dimensions than what humans exist within. A four dimensional being could enter and exit a locked room with you inside it, and do so from more than one direction at once. They could warp space and time with ease. They could remove you from a locked room just as easily as they could remove the locked room from you. Take this possible scene from Flatland, which Carl Sagan paraphrases in his book Cosmos: > > Let us imagine that, into Flatland, hovering above it, comes a strange three-dimensional creature which, oddly enough, looks like an apple. And the three-dimensional creature sees an attractive, congenial-looking square, watches it enter its house, and decides in a gesture of inter-dimensional amity to say hello. “Hello,” says the three-dimensional creature. “How are you? I am a visitor from the third dimension.” Well, the poor square looks around his closed house, sees no one there and, what’s more, has witnessed a greeting coming from his insides: a voice from within. He surely is getting a little worried about his sanity. > > > Source: <https://www.organism.earth/library/document/cosmos-10> > > > In your story, if gods exist in higher dimensions (or planes) than humans, they can do other creepy things like see all of the insides of your body at the same time as seeing the outside. They can experience your own thoughts at the same time you do, and they can also move themselves back and forth in time, just as easily as you could roll over in bed. The gods' potential ability to do this (while also watching all of the cosmos from every angle all at the same time) is bound to produce imagery that makes no sense to a finite human brain. Even a tiny shred of that imagery shared in a brief moment of transparency would be more than a lifetime of memory. Plus... # Gods Know Everything: Yeah, that's right everything. They know what you ate last summer, on July 13th, and who you were with when you ate it. To be omniscient is to know all things about all things: all people, every subject, and every thought, as well as knowing literally everything that goes on everywhere, and why it's happening the way it is. This is a corollary to being multidimensional--if a god has infinite mobility throughout all space and all time, they could physically position themselves at a vantage point in every millimeter of the universe, all at once, viewing from every angle. That means they could replay your highest ideals, your most repugnant thoughts, your greatest achievements, your most horrible failures; anything and everything in between, and you'd have no way to avoid their knowledge of the topic. If, in your world, the gods decide to use shock value to get your attention, I'm sure that revealing that they know your deepest, darkest secret could instill a genuine fear. # What Do They Look Like: What does any multidimensional omniscient being look like? One description of the Abrahamic God, YHWH, was of "A smoking firepot with a blazing torch:" > > When the sun had set and darkness had fallen, a smoking firepot with a blazing torch appeared and passed between the pieces. On that day the Lord made a covenant with Abram and said, “To your descendants I give this land, from the Wadi of Egypt to the great river, the Euphrates— the land of the Kenites, Kenizzites, Kadmonites, Hittites, Perizzites, Rephaites, Amorites, Canaanites, Girgashites and Jebusites.” > > > Source: [Genesis 15:9-21](https://www.biblegateway.com/passage/?search=Genesis+15%3A17-21&version=NIV) > > > This imagery of a torch and a firepot that move about by themselves might be the result of the limited human mind attempting to make sense of a being that is potentially bending the fabric of spacetime itself just to pop in for a visit. While that imagery might not be intentionally scary, it could still be fearful. # Do Not Fear: These thoughts come back to your idea that the person experiencing such a visitation would be invited to "fear not." If a particular god in your story wanted to reassure a human that that particular god does not want to make them cower in terror or shame--that they're not visiting to exact vengeance or to inflict some of the horrors that omniscience, multidimensional existence, and infinite thought and memory bandwidth can inflict upon your unsuspecting human character--they might need to reassure that character. # Conclusion: So, then the question is "why can't they appear more benign?" Maybe they're trying to be as honest about how they appear as they can possibly be. The gods in your story might be trying not to hide their true selves. If your story incorporates a god that is honest about everything (including their appearance), that one might be the scariest-looking one of your entire pantheon. [Answer] ## Gods are horrible eldritch entities. The deities in question are all horrific looking monsters from twisted dimensions beyond human imagination. They've taken familiar roles to feed off faith and worship and sacrifice of humans, but if you see them in person you see their terrible true reality. Some part of pure chaos and the madness of these other dimensions is impossible to hide, and the human soul can sense their terrible nature. [Answer] What you've said about Gods is not really true across the board. Zeus took many forms including small animals like a swan and an ant. Loki took the form of a horse, fly, fish, an old woman. Christ's appearance was obviously not an atrocity. When God appears in recent movies half the times it's Morgan Freeman! In the series Good Omens God's voice was Frances McDormand. A whole range of forms can be found. [Answer] They are contemptuous of humans. <https://www.poetryintranslation.com/PITBR/German/FaustIScenesItoIII.php#Scene_I> Spirit Who calls me? Faust (Looking away.) Terrible to gaze at! Spirit Mightily you have drawn me to you, Long, from my sphere, snatched your food, And now – Faust Ah! Endure you, I cannot! Spirit You beg me to show myself, you implore, You wish to hear my voice, and see my face: The mighty prayer of your soul weighs With me, I am here! – What wretched terror Grips you, the Superhuman! Where is your soul’s calling? Where is the heart that made a world inside, enthralling: Carried it, nourished it, swollen with joy, so tremulous, That you too might be a Spirit, one of us? Where are you, Faust, whose ringing voice Drew towards me with all your force? Are you he, who, breathing my breath, Trembles in all your life’s depths, A fearful, writhing worm? [Answer] # [The gods are like liquid cats.](https://www.youtube.com/watch?v=WoDi6WTp4Yc) The main difference is they don't go through the other end entirely - when they push themselves from the divine realm to the mortal realm, they never go all the way through to maintain their god-sized cat-flap portal so that they can leave when necessary. As a result, their multi-dimensional divine forms are squished through the portal they used to interact with mortals - and they don't dare try to fully jump through entirely, because the mortal realm enforces reality upon them, preventing them from performing divine acts with body parts in the mortal realm - hence, the gods always try to stay partially in, and partially out, of the mortal realm whenever interacting with humans. The gods may be able to actually present as regular human forms if they entirely enter the mortal realm, but in doing so, lose their connection to the divine realm, and they're not likely to do that for just any given mortal. If they do so, the only way back is to either wait for another god to appear and pull them back through a portal, squeezing them through as they do, or entering as mortals might do via plane shifting, at which point, they begin to reform as they go through the plane shift, and have issues around that, given the mortals around them get to see them liquid-cat their way back into the divine realm. [Answer] They don't know how. These gods are not 'omniscient omnipotent' beings, they are just DIFFERENT beings, from a different plane of existence, and their reality is very strange and bizarre to ours. In order for them to communicate with us in our plane of existence, they have to manifest physically -- we hear things physically, and so that's the easiest way for them to communicate (or the only way), instead of via something like telepathy or whatever. They manifest in physical form so that they can make the sound waves like we do. They try to imitate our form, but their existence is so different from ours that they don't really understand what they're doing wrong when they try to. Some bits are inside out, muscles are exposed, but from their perspective they're trying their best! [Answer] A god manifesting itself as human puts it in the uncanny valley. No human can look at it without being filled with unexplainable fear. The god doesn't really understand humans. Sure, it can look at them and play dress up, but it doesn't really get what makes humans human. Just like with the [Uncanny Valley](https://en.wikipedia.org/wiki/Uncanny_valley) in robotics, the god gets creepily close. So close just seeing it fills the humans with terror they can't quite explain. ]
[Question] [ This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. I would like for copper in my Earth-like world to oxidise roughly 38 times faster than copper normally does on Earth. This means that copper will turn green within around 195 days as opposed to the 20 - 25 year mark normally. I would also like for copper to somehow skip the browning phase and go straight to forming the copper carbonate (copper III, copper hydroxide, whatever you wish to call it) that gives weathered copper its signature green colour. How much oxygen is needed in the atmosphere to achieve this, and will the amount be toxic? Is this enough oxygen to skip the browning phase directly? [Answer] ## You won't get it oxidising that fast even in 100% oxygen. [I found a source](https://www.jstage.jst.go.jp/article/isijinternational/49/12/49_12_1926/_pdf) which compares the oxidisation rate of copper at varying temperatures, humidities, and oxygen concentrations. From conclusion section: > > While oxygen pressure did not affect the oxidation > rate of copper, the rate was increased with increasing water > vapor pressure due to the increased copper vacancy. > > > Varying oxygen levels from 20% (Earth) down to 10% or up to 100% made no notable difference on the corrosion rate of copper on its own in temperatures below 700 degrees C. And even at 700 C - the increase by switching to pure oxygen was only a tiny percentage. To speed up your copper oxidisation you'll need also water vapor, high temperatures, and perhaps some salt or sulfur in the air. Oxygen alone just won't do it. [Answer] I assume you are out in the air, and we are talking about copper clad roofs as below. [![green roof](https://i.stack.imgur.com/5y3WY.jpg)](https://i.stack.imgur.com/5y3WY.jpg) <https://en.wikipedia.org/wiki/Basic_copper_carbonate> I was interested to read that verdegris (as I would call this roof) can be various insoluble copper salts - basic copper carbonate, copper acetate and copper chloride. So the Statue of Liberty probably has a lot of copper chloride because of the salty seawater. But you specifically want copper carbonate. The limiting factor is the reaction between carbonate and copper. Preparing copper carbonate requires a basic solution with available carbonate ions. > > Basic copper carbonate is prepared by combining aqueous solutions of > copper(II) sulfate and sodium carbonate at ambient temperature and > pressure. Basic copper carbonate precipitates from the solution, with > release of carbon dioxide CO 2:[6] > > > 2 CuSO4 + 2 Na2CO3 + H2O → Cu2(OH)2CO3 + 2 Na2SO4 + CO2 Basic copper > carbonate can also be prepared by reacting aqueous solutions of > copper(II) sulfate and sodium bicarbonate at ambient conditions. Basic > copper carbonate precipitates from the solution, again with release of > carbon dioxide: > > > 2 CuSO4 + 4 NaHCO3 → Cu2(OH)2CO3 + 2 Na2SO4 + 3 CO2 + H2O > > > CO2 dissolved in a basic solution will provide carbonate ions for your reaction. If this is a roof the only realistic way to keep available water alkaline is to make the rain alkaline (or have alkaline windborne dust, which at large enough scale will also make the rain alkaline). Is there alkaline rain? Yes - <https://en.wikipedia.org/wiki/Basic_precipitation> > > Basic precipitation occurs when either calcium oxide or sodium > hydroxide is emitted into the atmosphere, absorbed by water droplets > in clouds, and then falls as rain, snow, or sleet. Precipitation > containing these compounds can increase the pH of soil or bodies of > water and lead to increased fungal growth. > > > The principal cause of basic rain is emissions from factories and > waste deposits. Mineral dust containing large amounts of alkaline > compounds such as calcium carbonate can also increase the pH of > precipitation and contribute to basic rain... > > > You could have large dry lakes in your world that are sources of carbonate salt dust storms, like Owens lake here. [![owens lake dust storm](https://i.stack.imgur.com/Udum2.jpg)](https://i.stack.imgur.com/Udum2.jpg) <https://www.plantsciences.ucdavis.edu/news/effectiveness-and-impacts-dust-control-measures-owens-lake> The dust storm makes the rain alkaline and the basic rain catalyzes your carbonate formation. As regards "roughly 38 times faster" this proposition is a little rougher than that. --- My future-seeing crystal ball spotted RonJohn showing up to point out I did not answer the question! And that question was "how much oxygen". This process does not need molecular oxygen at all so the answer is "any amount or none". Oxygen atoms are provided by dissolution of water in the alkaline environment to provide -OH ions. [Answer] # Add Humidity, Salt Water and a little Acid Rain What we're talking about here isn't really oxygen dependent, we can speed the process up by other means. Salts and humidity will speed up the reaction rate, and the acid will help by deteriorating any protective oxide layers. This should have the desired effect without changing your oxygen concentration, which wouldn't let you reach your desired oxidation rate anyway. [Answer] Depending on surface area exposed (think fine granules), if you oxidize it that fast, it may not just burn — it may explode. My “hazardous materials“ warning source: <https://nj.gov/health/eoh/rtkweb/documents/fs/0528.pdf> ]
[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/162251/edit). Closed 4 years ago. [Improve this question](/posts/162251/edit) D&D and many similar fantasy settings use a (perhaps unrealistically) simple system of currency consisting of silver and gold pieces. (These are, of course, roughly analogous to pence and shillings.) I was thinking of spicing this up a bit with additional items of currency. One idea I had was a medium sized gemstone perhaps acting as an intermediate between silver and gold. Does anybody know of a material that could perhaps fill this role? Otherwise, I would love to know about any other items (valuable or practical) that you think could represent larger or smaller denominations. (Also I should add: please give me what their approximate values would likely be, if you can.) [Answer] Modern coins and paper bills are a promise that they can be exchanged for something of value. The fancy material and engraving prevent people from simply creating more of these promises. Ancient coins are items of value themselves. They are stamped to reassure the users that the shape has not been "shaved" and that the material is not diluted. Gold and silver were (and are) seen as valuable because they are an useful metal. You can make rings out of it, goblets, spoons. It does not tarnish as much as iron or copper and it looks better. A gem looks fancy, but it can't be re-shaped that way. Each gemstone is unique, possibly with flaws, and must be valued individually. # So what can be done? * Copper, of course, with copper being less valuable than silver. * Coffee beans of roughly uniform size and quality. They won't last forever, of course. (The difference to gems is the average size and quality.) * Black pepper corns, with the same limitations. * With magical/alchemist metallurgy, how about aluminium? * "Cold iron" or meteorite iron, if that differs from ordinary iron in the setting. Forgery would be a big issue, of course. [Answer] ## Salt [![enter image description here](https://i.stack.imgur.com/rPBG4.jpg)](https://i.stack.imgur.com/rPBG4.jpg) It is commonly believed the Roman soldiers were [paid in salt](https://www.saturdayeveningpost.com/2019/10/in-a-word-salary-are-you-worth-your-salt/), although this belief has met some [recent challenges](https://kiwihellenist.blogspot.com/2017/01/salt-and-salary.html). Per the same second link, quoting Marcus Livius in 204 BC, the typical price of a pound of salt is $1 \over 6$ pieces of copper. Through the [middle ages](https://thehistoryofengland.co.uk/resource/medieval-prices-and-wages/), a single piece of copper was equal to roughly a day's wages for most unskilled and semi-skilled labor (peasants, foot soldiers, through lower-tier house servants). Although, precise conversions [are disputed](http://medieval.ucdavis.edu/120D/Money.html), with the some sources inflating the daily wage to as much as a shilling (roughly equal piece of silver = 12 copper pennies) One measuring cup full of salt is about 0.6 pounds, so 6 pounds of sale paid this way for wages would be 10 cups of salt (a little over $1 \over 2$ gallon), per day. `Material``Value``Weight``Volume` `Salt``1 copper``6 pounds``10 cups (medium bag)` ## Obsidian [![enter image description here](https://i.stack.imgur.com/VSmkT.jpg)](https://i.stack.imgur.com/VSmkT.jpg) No one disputes that [the Aztecs built their economy on obsidian](https://en.wikipedia.org/wiki/Obsidian_use_in_Mesoamerica), owing to great natural reserves of beautiful green obsidian in the Yucatan peninsula. Obsidian is hard, can be made sharp, very useful for tools or all kinds, and can be very pleasant to look at. But the Aztecs actually used several currencies including metal, cloth and [cocoa beans](http://www.legendsandchronicles.com/ancient-civilizations/the-ancient-aztecs/aztec-economy-trade-and-currency/). Using the Medieval Price List's (MPL) price for an axe is 5 shillings. A typical axe head is 3-and-a-half pounds. If we assume the axe can't cost more than the raw materials it's composed of, we can calculate an upper-limit value obsidian is worth about $7 \over 10$ths of a shilling per pound. Obsidian is 50 pounds per gallon dense. So, a typical daily wage of 1 shilling, per the MPL - paid in obsidian - would be: 1 pound of obsidian, taking a volume of about $1 \over 3$rd a dry cup. Whether that daily wags is 1 silver/shilling, or 1 penny/copper, depends on your personal choice of inflation between the Medieval Prices and Wages (MPW) (which seems to be 1 silver/shilling MPL = 1 penny/copper MPW) `Material``Value``Weight``Volume` `Salt``1 copper``6 pounds``10 cups (medium bag)` `Obsidian``$7 \over 10$ copper``1 pound``$1 \over 3$ cups (small bag)` ## Cinnibar (Mercury Sulfate) [![enter image description here](https://i.stack.imgur.com/uOOxJ.jpg)](https://i.stack.imgur.com/uOOxJ.jpg) Moving past the more pedestrian materials, into luxuries, is mercury fulminate. Also known as Cinnibar. It has value to high-end professions such as alchemists, healers, scribes, dying, and manufacturing. The price for cinnibar was limited by [Roman law](https://books.google.com/books?id=MU68AQAAQBAJ&pg=PA103&lpg=PA103&dq=%22medieval%22%20price%20of%20cinnabar&source=bl&ots=8TXjWHOMV7&sig=ACfU3U3zJ53WaY19B3UFyY5rWxj1RxH_2A&hl=en&sa=X&ved=2ahUKEwiagtic_YzmAhUihuAKHSjnDpQQ6AEwFnoECAkQAQ#v=onepage&q=%22medieval%22%20price%20of%20cinnabar&f=false) to 70 sesterces per pound. Two and a half sesterces was the typical Roman daily wage, so we can quickly calculate the value of Cinnibar as 27 copper, according to Medieval Prices and Wages (MPW) `Material``Value``Weight``Volume` `Salt``1 copper``6 pounds``10 cups (medium bag)` `Obsidian``$7 \over 10$ copper``1 pound``$1 \over 3$ cups (small bag)` `Cinnibar``2$7 \over 10$ silver (27 copper)``1 pound``2 tablespoons ($1 \over 8$ cups)` ## Roman Vitriol (Copper II Sulfate) [![enter image description here](https://i.stack.imgur.com/uOW3z.jpg)](https://i.stack.imgur.com/uOW3z.jpg) Blue vitriol / Roman vitriol / Copper Sulfate has much the same high-tier uses as cinnabar in medicine, dyes, and other high-end items. I can't find medieval prices for the stuff, but the current price for copper sulfate online is about triple cinnabar. That would calculate to about 115 silver, or about 1 gold. `Material``Value``Weight``Volume` `Salt``1 copper``6 pounds``10 cups (medium bag)` `Obsidian``$7 \over 10$ copper``1 pound``$1 \over 3$ cups (small bag)` `Cinnibar``3$1 \over 2$ silver (35 copper)``1 pound``2 tablespoons ($1 \over 8$ cups)` `Blue Vitriol``1 gold (115 copper)``1 pound``4 tablespoons ($1 \over 2$ cups)` ## Jade [![enter image description here](https://i.stack.imgur.com/4Z4O8.jpg)](https://i.stack.imgur.com/4Z4O8.jpg) Jade has a hardness between 6 and 7, rivalled only by flint for hardness. But jade is much more beautiful. It is useful industrially for carving hard rock, or any other application where hardness is appropriate. Also, its delicate appearance - in seeming contrast to its great strength - lend to belief jade possessing divine abilities. Medieval prices for jade are also hard to come by, so I'm measuring the price of jade by it's modern comparison to cinnabar. In this case, pedestrian-grade jade comes in at about 16x modern cinnabar, which is our medieval point of comparison. It should be noted that gemstone grades of all of the above are worth a lot more. `Material``Value``Weight``Volume` `Salt``1 copper``6 pounds``10 cups (medium bag)` `Obsidian``$7 \over 10$ copper``1 pound``$1 \over 3$ cups (small bag)` `Cinnibar``3$1 \over 2$ silver (35 copper)``1 pound``2 tablespoons ($1 \over 8$ cups)` `Blue Vitriol``1 gold (115 copper)``1 pound``4 tablespoons ($1 \over 2$ cups)` `Jade``0.5 platinum (560 copper)``1 ounce``1 teaspoon` [Answer] ## What currency is and how it is different from other tradeable goods Currency is a form of money. Money in the form of currency is represented by small lightweight standardized and durable pieces having uniform value. The advantage of using money in the form of currency is that the pieces are: 1. Uniform. The uniformity of currency pieces allows for the value to be computed by the simple operation of counting, without the need of time-consuming weighing and expensive assaying. 2. Small and portable. Currency pieces are small and portable, so that value can be transported relatively easily, and can be forwarded efficiently in economic transaction. 3. Durability. Currency pieces serve as a store of value. It is important that they perform this function well, and for this reason they must be durable. Currency is of two kinds: currency with intrinsic value, where each piece of currency trades at (or very close to) the value of the material from which it is made; and fiat currency, where each piece of currency has an arbitrary value asd decreed by the sovereign who put it in circulation. Nowadays we use only fiat currency, which has proven to be superior to intrinsic value currency in just about any respect; but, for a long time, from the antiquity up to well into the modern period, intrinsic value currency predominated. The materials used to make currency with intrinsic value were almost always metals, and specifically one of three metals: copper (and its alloy bronze), silver and gold. These metals have the advange of being valuable enough in their own right, and of being sufficiently durable. Some cultures experimented with iron (way too cheap, and it rusts), cocoa beans (a bad joke), cowry shells (too cheap, not durable, bad joke) and other such inappropriate materials. Nobody has ever even tried to use expensive pearls or gems as currency. They cannot be made uniform (thus negating the principal advantage of currency), they are way too expensive (nobody is interested in a piece of currency worth 10,000 man-days of labor), and their value fluctuates wildly. Just about every state ever has used a system of currency where all three metals were used, with currency pieces of various denominations being made by varying the amount of metal in each kind of piece, from a small copper piece, to a large copper piece, to a small silver piece, to a mid-size silver piece, to a large siver piece, to a gold piece. (No currency system ever had more than one or sometimes two kinds of gold pieces.) Generally you start with a defined reference point, for example: * The Roman republic used a reference point of 84 denaries per Roman pound of silver, and the early Roman empire used the reference point of 96 denaries to the Roman pound of silver. (That is, a denary coin contained 1/84 or 1/96 pound of silver.) * The English for a long time used a reference point of 66 shillings per Troy pound of sterling silver (= 0.925 fine); the value of gold being fixed at £46 14s 6d for one Troy pound of 22 carat gold. Then you figure out the ratio between the values of the three metals copper/bronze, silver, and gold. For example, modern British coinage used a ratio of 14 1/6 : 1 for the value of gold and silver; in ancient times, they tended to use a ratio of 12 : 1. For a practical example, here is a splendid infographic showing the Roman coins in circulation during the 3rd century: [![Roman coins in the 3rd century](https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Common_Roman_Coins.jpg/640px-Common_Roman_Coins.jpg)](https://commons.wikimedia.org/wiki/File:Common_Roman_Coins.jpg) Roman coins in the 3rd century. [Available on Wikmedia](https://commons.wikimedia.org/wiki/File:Common_Roman_Coins.jpg) under the GNU Free Documentation License, Version 1.2 or any later version. The infographic gives the sizes and weights of the coins. The as and dupondius (2 ases) were copper. The sestertius (4 ases) was bronze. The denarius was the main silver coin, and the most usual coin for mid-size transactions; it was worth about one man-day of unskilled work. The main gold coin was the aureus; due to the continuous debasement of the denarius during the century, its value rose from 24 denaries at the beginning of the century to 833 denaries at the end... And this brings the topic of debasement. A sovereign could always recall metal coins and recast them with a lower content of precious metal; this provided a rather crude form of inflation... [Answer] Traditional Japanese currency was rice. It stores well, it’s uniform size, and it’s directly proportional to the actual wealth: amount of land you hold and the number of people you can sustain. Most farmers grew rice not to eat but to pay taxes. Instead they ate cheaper grains like millet. Eating rice was like eating money. Something for the rich to do. Rice was packaged in a koku as one currency unit. The exact sizing of a koku isn’t known, and varied widely across time, maybe to reflect average yield of a standard rice paddy, or amount needed to sustain a certain number of people (nutritional value of the rice which changed due to natural circumstances). Tax brackets, social status, etc were measured in koku/year produced by your land. I think this system is a logical and interesting (and fairly simple) way to do currency. It isn’t an arbitrary item traded for the sake of trading something. It reflects physical wealth/power, and is subject to natural inflation/deflation (drought, poor farmland, etc). It may not be as accessible to the common people, but they are likely to be bartering services anyway. That being said, everyone has the ability to literally farm money. It’s becomes very obvious how hard done the little people are when they grow a fraction of a currency unit every year on their patch of land, and then have to pay a lot of it in taxes. It is also interesting that the mass production of rice for not eating led to different ways to use the rice sitting in a warehouse somewhere: rice wine, among others. So if you have an agrarian society, rice or a similar staple that keeps well is a good idea. Little need for fancy conversion or metal cutouts. [Answer] ## So you want a good way to divide a silver coin into small amounts ? divide the coin itself. This idea is not mine, but is an historical exemple : [Hacksilver](https://en.wikipedia.org/wiki/Hacksilver). Currency usually come from a high authority (the state, the church, the banks...), and while it can be made out of valuable metals, the value don't really come from the material itself, but from the trust to this authority. The best exemple are paper currency and even more scriptural currency. The norse and germanic folks didn't use this concept, but only used the weight of silver object to trade. They didn't trade with silver coins, but with silver whateverYouWant. Hey, you can even design the coin so that it can be easily cut in half or quarters! [![enter image description here](https://i.stack.imgur.com/6Xq0f.jpg)](https://i.stack.imgur.com/6Xq0f.jpg) [Answer] ## Tin A large tin coin would be more valuable than a small silver coin. Tin is very valuable for making bronze and fairly rare. So it may be too valuable for use in coins. Brass Brass did not really exist in the ancient world but in fantasy world you could have brass, and brass is valuable and makes good coins. Zinc Zinc only shows up late in the medieval period, but a fantasy setting can have it much earlier, Zinc is used in modern coinage. Although it is such a pain in the @$$ to smelt I don't think you are going to see it being wasted on coinage prior to electricity. ## Nickel This was actually used in coins in antiquity, most often as a nickel copper alloy sometimes called white copper (<https://en.wikipedia.org/wiki/Cupronickel>). It is still used in coins today. It is corrosion resistant and distinct in color (as long as the ratio of copper to nickel is similar) which makes it an excellent 4th coin. Pure nickel can also be used but you will need fantasy to justify it, not because it can't be smelted with medieval technology but just because without chemistry people did not realize it was not just a weird form of silver (even though there is no silver in it). ## Shape. But what most real civilizations did in this circumstance was come up with a different shaped coin made of more silver, usually scale or rectangular plate shaped coins. one option is to even make your gold coins segmented so they can be split into quarters easily. This is desirable even before the coin is standardized. this is even more common in bullion since it makes debasing the bullion harder (you can't just stick a bar of a different metal in the center). Of course this can start with people doing this themselves, hacking up coins into smaller denominations was surprisingly common. [![enter image description here](https://i.stack.imgur.com/L7XPC.jpg)](https://i.stack.imgur.com/L7XPC.jpg) Keep in mind in most real world historic coins did not have set values they were worth what they weighed, standardized coins are easy to debase and counterfeit. ## Why not gemstones gemstones are a bad idea, they vary greatly in value becasue they vary wildly in quality. worse they can be difficult to distinguish from one another, quartz and diamond look very similar one is incredibly valuable the other is worthless. this two very bad qualities in a currency. Worse gemstones also lose value as they break, If coin breaks you still have the same amount of gold if a gemstone breaks the pieces are worth less than the whole. If you have a few diamond in your pocket for a while they will damage each other, chips, scratches, ect which all make them loose value. [Answer] If you look back at history and to why we started using gold, silver and other valuables as currency, is because they were rare, hard to get and therefore coveted. In general, the reason we use metals instead of gemstones as currency is because we can melt the metals down and cast them into a consistent shape, so we know the value is also consistent. So, depending on if your story takes place in fantasy, you might want to create a special type of gemstone that naturally forms in the same consistent shape, but needs special conditions to form and is therefore hard to find. That would make it perfect for the role of currency. If you're interested in more unconventional types of currency, you might want to look into the [giant rock coins used on the island of Yap](https://en.wikipedia.org/wiki/Rai_stones) or maybe the more simple [cowrie shells](https://en.wikipedia.org/wiki/Monetaria_moneta). The reason fantasy settings like D&D use such a simple system, is to make it easy for readers or players to comprehend and use. They're not part of the story, they're merely a system designed for convenience. While most types of currency in our world evolved from trading goods. So you also really have to think about if you actually NEED a special type of currency. If your story or world goes really in-depth on trading, it might be really interesting to see an unconventional type of currency the characters need to deal with. Otherwise it's just better to keep it simple for the sake of usability. [Answer] Glowstones. The problem with gems is that they are not intrinsically useful. But a gem that emitted light would definitely be useful in a world otherwise lit only by fire. Cool, smokeless, permanent light is worth a lot. You could make these gems small, so you would need a fair number of them to equal a candle. But they are durable as well as useful, so could serve as money as well. [Answer] Pearls In the real world, all but the smallest pearls are fairly expensive. [A strand of Akoya ('standard') pearls can cost from USD 300 to more than USD 10,000, while other varieties may be more or less valuable](https://www.thepearlsource.com/facts-about-pearls/how-much-are-pearls-worth.php). Obviously, pearls come in different sizes, but if pearls are used as currency, scales can be used to determine value - which needs not be linear with weight. Rare-colored pearls will be worth more, and you may need to go to a broker to exchange them for more ordinary pearls. It is worth noting that once upon a time, pearls were the most expensive jewelry in the world. [At the height of the Roman Empire, when pearl fever reached its peak, the historian Suetonius wrote that the Roman general Vitellius financed an entire military campaign by selling just one of his mother's pearl earrings](https://www.pbs.org/wgbh/nova/article/history-pearls/). In your world, however, you can decide how rare they are in order to fulfil the required gap between silver and gold. Electrum [Electrum](https://en.wikipedia.org/wiki/Electrum) or "green gold" is a naturally occuring alloy of gold and silver, and electrum coins with roughly equal parts silver and gold were used ancient Lydian coinage, and in fact, the first metal coins ever made were of electrum and date back to the end of the 7th century or the beginning of the 6th century BCE. A problem is that it is easy debase coins by adding more silver, which caused some trading problems, and eventually electrum was phased out in favor of pure silver and gold coins. In your world, you can decide that natural electrum has a lower gold content - perhaps 20 or 25 percent - and that there are heavy fines for debasing electrum coins. [Answer] Some inspiration... After WW2, people in germany bought 'lucky strike' cigarettes with their silver, because they could trade cigarettes more easily against food. Cigarettes were the best currency at the time, because they were all the same, came in packs, were inflating naturally, people were already adicted and you couldn't produce them yourself. [Answer] In medieval times, not all places used minted coins for all transactions. Some still used trade and taxation in kind. This is to say barter and otherwise offering goods and products. So, somebody could go to the market and use grain or livestock to trade for other items, or products of these, such as bread or milk. The same might be acceptable as taxation, although not everything produced would be worth it for the country. Usually, it's something like food, which would go towards feeding an army, or perhaps horses which would go towards the army, again. It would vary regionally as well as in time. For example, the East Roman Empire (Byzantium) did require a certain number of soldiers to be produced, per taxable area. Say, for a village/community this might be one soldier soldier including their equipment (armour, weapons, etc.). Just to demonstrate how messy this was, some elected to just pay the money equivalent to "one soldier", as they didn't want to send any sons to war. This would provide more tax revenue but less people for the army. So, the point is that not everything was coins, nor does it need to be. For a fantasy setting, you could have other goods that make sense in the setting. These could be universal, or regional depending on how you want to structure it. Here are some examples: * Some harder to obtain items could be roughly equivalent to herbs. Let's say "fairy dust" which is collected from flowers that fairies slept in. Let's also further say that said dust could be used for some universal purpose like curing (relatively) minor diseases on livestock and humans, or anything else that makes sense. You can then trade fairy dust instead of coins. Adventurers might be able to more readily acquire it through some means (e.g., they have more run-ins with fairies or their habitats), so you can position the rarity and value as you see fit - a small bag (assume, one that can hold 10 coins), might be more valuable than 10 silver coins but less valuable than 10 gold coins. Or you might prefer to make the commodity more readily available, to bring its value down to more than 10 copper coins but less than 10 silver coins. You can vary this according to your needs, of course. * You could have a regional commodity being used as currency. For example, there is a wizards' academy near this village(s), and wizards need spell ingredients. These would be item without much value to locals. Let's assume it's herbs not used in cooking or medicine - yet that do have value to the wizards that live nearby. So, therefore through proxy, the commodities have value to the community. If the university is reasonably far away (e.g., half a day to a day's journey) not everybody would be going there to sell what would otherwise be treated as weeds, however they can still trade it between themselves. > > Alice might offer a bag of "blue beardroot" (made up plant) to farmer Bob for a basket of eggs. > > > Bob then uses the bag to pay smith Carol for shoeing Bob's horses as well as a new shearing scissors. > > > Carol can pay with the blue beardroot trader Dave for general goods like twine, metals, and clothes. > > > Dave then goes to the university once a week and sells them all the ingredients gathered. > > > So, in the region of the university, blue beardroot has some value, but elsewhere not as much. You can again vary how much value it has. It can even change the community. If it has too much value, then you might have people specifically growing it. If it has very little, then it's not going to be a big part of the local economy but accepted payment nonetheless. Again, adventurers might be better off here, if they can get access to more, or rarer, ingredients. * You can also have token representing services. This is not very usual in real life but it exists - you can have a coupon for a free massage, for example. I'm not aware of how these were handled in the medieval world, but I imagine it existed in some capacity in some places. If you can make the tokens more reliable, then you can use it in the economy. In a fantasy setting, this should be easier to do: of some sort of favour from the fair folk and it is guaranteed to be honoured. Or . And so on and so forth. Basically: + The tokens might be imbued with some sort of magic to ensure their validity. For example: tokens issued by wizards with some form of fairly weak "geas" spell on them. The tokens might represent, say "the bearer of this token is entitled to a minor enchantment from a member of the Spell Overflow wizarding community" and can be turned in for said service. + They could rely on honour, duty, or other sort of inherent obligation that means that the token will not suddenly lose its value. For example: an elven token that represents an elf honour bound to grant the bearer some sort of favour. Since elves live very long, and value honour a lot, you know the token would be valid for a long time and the favour (of sufficient complexity) would be fulfilled. Or dwarven token the dwarves from the nearby mountain are duty bound to accept in return for some metalwork (e.g., making superior quality tools). The token relies on the dwarven community to be present and the community is enduring. Even if the specific dwarf who issued the token is not there, it will still be fulfilled by any dwarf metal worker who lives there. There are many other ways to make non-money substitutes of buying stuff. You, as the creator of the world, can dictate their price and make them more or less valuable. An ongoing story might even have interesting application of these * You could fluctuate the price. This shouldn't happen often, since it will make the item not very reliable for trade. However, this could have a big impact on a community or realm. It might even totally re-shape it, whether something happens a lot more valuable or a lot less. + Fairy dust could go in price. + Tokens given from a given dwarven community are more valuable. * You can fluctuate the availability or demand. + There is an outbreak of a disease fairy dust cures. + The wizarding school demands a lot more of the redleaf duskglory. + Harvest season is coming and farmers want to get dwarven forged tools that are more efficient and durable. * You can use it as a plot hooks + Because of the disease outbreak, a village decides to start gatheringfor a lot more fairy dust. The disease is conquered but the fairies are now not happy and cause other problems. + The redleaf duskglory is applications in black magic. Asking for more is normally troublesome, especially since the demand comes from a school but nearby villages don't really know or care what ingredients are for as long as the wizards buy them. + A powerful elf who lives in the nearby woods owes few people favours - they go to collect but...the elf is nowhere to be found. The tokens are worthless for now until somebody could figure out where the elf has gone and if he returns. [Answer] ## Anything in limited, stable supply Things or materials that cannot [easily] be created and don't easily break down have a reasonably stable value because if everything suddenly became cheaper, everyone would start buying more stuff and vendors would just raise their prices again. If a few people started creating more currency and spending it, it would eventually flow to everyone, so everyone would try to buy more stuff, and so prices would rise, devaluing the currency. When this happens too fast nobody knows how much anything costs anymore and the currency is useless. Gold is not valued because you can make things out of it. Gold is valued because it is a status symbol. It's hard to get. In the early 1800s, [aluminium was more expensive than gold](https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_process#History). Although the ore was plentiful, refining it was terribly expensive. Importantly, gold doesn't easily break down, either. It would be no good as a currency if the supply kept decreasing or if it degraded faster near the sea. You also need: 1. Something that can easily be portioned into fixed quantities or units 2. Something convenient to carry 3. Something that you can tell is "probably genuine" by looking at it, and can be subject to further simple tests (like a balance scale) Crystals and gems generally fail (1) and (3). Gold dust fails (1) and (2). Pearls aren't a bad choice if they are produced in small quantities if at all in the area (e.g. dug up in a dried-up sea bed). You can of course manufacture a reason for all sorts of things to be in short supply. A gem that for some reason (perhaps a particular accumulation process, or an ancient civilisation) is always roughly the same size. Skulls of an extinct animal (less likely to be a status symbol). Sea urchin shells washed over in an ancient tsunami. [![Sea urchin shells](https://i.stack.imgur.com/lG4oOm.jpg)](https://i.stack.imgur.com/lG4oOm.jpg) [Answer] The OP refers to D&D... and it is obvious to me that the OP is familiar with some version from 3e onwards, since 2e and earlier contained exactly the concept that this question seeks, namely that of a currency of intermediate value between Gold and Silver: [Electrum](https://en.wikipedia.org/wiki/Electrum), a natural or artificial alloy of gold and silver. In D&D 2e, an Electrum piece (ep) was a coin with a value between that of Silver pieces (sp) and Gold pieces (gp), where 1 gp = 2 ep = 10 sp. Apparently D&D 3e completely decimalised the fantasy currencies, as the value ratio for coinage became 1 pp (Platinum) = 10 gp = 100 sp = 1000 cp (copper), and electrum was no longer mentioned. While this is a convenient allocation of value for a game, historically the value of noble metals varied according to availability, and in certain places and times (such as in ancient Egypt) silver was more highly valued than gold, and the conversion from one currency to the other - even discounting moneychangers' fees - was rarely if ever exactly 10:1. [Answer] To stick with the D&D theme, how about mithril? The mithril coins could be quite small and light. All the other coin metals have intrinsic values, so your new intermediate coin should too. Sure, your players may start hoarding the new coins in hopes of melting them down into a new piece of armor. That’s okay. Just fiddle around with the coin’s size and weight until you get something that works with your world’s economy. ]
[Question] [ This is yet another question concerning lasers as employed by sorcerers in a particular fantasy setting, but this one pertains to the momentum that photons possess and whether it's possible to generate light that imparts a higher proportion of its energy to an object in the form of momentum, rather than say an increase in temperature. Particularly, I'm concerned with something I read on Physics Stack Exchange: > > [And here we have it: photons have 'mass' inversely proportional to > their wavelength!](https://physics.stackexchange.com/q/2233) > > > This post is more detailed and is worth reading, but relying on the sentence above, have I completely misunderstood the author by concluding that in order to increase the "momentum imparting" aspect of light, we need light with increasingly shorter wavelengths? In other words, does light with a short wavelength cause less heating, or will that aspect remain constant? I would like to repeat the question: Is it possible to create light that imparts a greater proportion of its energy as momentum rather than heat? [Answer] No. The momentum of a photon is in direct proportion to its energy. A shorter wavelength of light has both more energy and more momentum in equal proportions. If you want to maximize imparted momentum while minimizing heating, you need to change not the light, but what it is hitting. A perfect blackbody will absorb all of the momentum of a beam of light, and all of the energy as heat. A perfect mirror, on the other hand, will absorb no energy and experience no heating, but will absorb double the momentum. [Answer] As Logan has pointed out. "Light" has some very concrete and specific properties to it. However. Since we are in World Building and you tagged "magic", I think straying away from the Standard Model would be allowed. First, a bit of history about the Standard Model. It is filled with "particles" which we have very concrete properties and numbers and mathematical formulae for (plus field equations). However, in the beginning, these properties weren't known, the formulae and maths was not invented. Even particles weren't a concept. [We figured them out from the shadows that they cast into our cave.](https://en.wikipedia.org/wiki/Allegory_of_the_Cave) Each new effect we gave a new name to; like "Light", "Magnetism", "Heat", "Energy", "Strangeness", "Charmness", "Topness", "Bottomness", "Anti-Red Quantum ChromoDynamics-ness". Quite simply your world can have all the different effects you want and those effects can be explained away with a new set of fields/particles/equations. TLDR: Invent a new magical particle called "Qi", make your sorcerers fire "Qi" based "beams" that radiate cherenkov radiation when fired in the atmosphere when they cast the Haduken spell. [Answer] Here's a short answer: Reading your question literally, No. Energy and Momentum are completely different. On the other hand, if you are actually talking about acceleration/velocity: ## Sure! its called Gamma Radiation. Before you get mad at me for uttering heresy, here is a logical proof using elementary physics: * All radiation is a form of light. * Acceleration is the result of the energy from something which is already accelerated being transferred to it, sort of like how a billiards ball moves after it is hit by a cue ball. * The reason why gamma radiation is so damaging is that it is extremely good at transferring the energy of its acceleration to anything it hits, such as cells or DNA. This causes what it hits to either (a) accelerate (move), or (b) store the energy by becoming an ion. Either way, the effect is extremely damaging. Therefore, Gamma radiation is a form of light which is significantly better at imparting acceleration than visible light is. ]
[Question] [ Essentially could I make flexible cut proof clothing with flexible metal wire? Or would making the wire flexible require making them so thin that slicing is easy? Edit: naturally gambeson or some other form of padding will be worn beneath, but could armour be made made with a process similar to denim? Just replacing the cotton fibers with thin steel wire? [Answer] You basically already have that, it's a chain Mail. The wires are just shaped as rings for better mobility and structural strength. Woven fabric ![woven fabric](https://i.stack.imgur.com/YQxh0.jpg) Chainmail ![chainmail](https://i.stack.imgur.com/fvjEm.jpg) [Answer] Let's ignore some inconvenient things. First up, lets ignore weight. Both plate and chain armors exist, and were moderately heavy, and were still used. So, we're good here. Let's ignore rust/corrosion/etc. Historic armor has used iron and steel and other materials that don't play nice with the elements. Keeping the armor oiled and clean protected it from the elements, so we can do the same with the woven fabric. Let's not even worry about actually weaving the fabric. That can be done, too. In fact, I actually have a sheet of copper "Cloth" that's made from wires in the same fashion as cloth. So, the quick and dirty answer is Yes you can make armor that's woven metal. It would even be reasonably strong, too. But the True Answer is It isn't practical for a reason called Metal Fatigue. Metal fatigue is the limited flexibility involved with metals. Take a paperclip. Bend it back and forth. Eventually, it breaks. This is metal fatigue. Springs are a different case, since they're being compressed and not flexed, but even in order to get springs to flex they have to be tempered in a specific way - Which makes them softer and not as protective. The reason flexible metal fabric has been limited to chain-type armors is because the metal itself isn't bending. The rings move, sure, but each individual ring stays completely intact and doesn't deform. For armor like splint or scale, and even some variants of plate, the flexibility is provided by leather underneath, and the individual pieces of metal never bend. [Answer] If you think about practical armor, the chain-mail idea by Faed is the way to go. I'm going to answer more literally. Turning metal into wires that can be knitted has the following problems: * It's really hard to produce. Wires are drawn by basically forcing them through a hole that's just not wide enough, so the metal needs to stretch to pass through. This requires the resulting wire to have enough strength to actually pull the rest of itself through. Now try that with micrometer-thick wires. Good luck... * If you manage to get wires that match the thickness of typical textile fibers, you'll have the problem that they will be much more stiff. Thin wires have a knack of breaking, and, once broken, they have little trouble working their way into your skin. So you need to make your wires significantly thinner than typical textile fibers to give them enough flexibility. * You should absolutely not use iron for this. The huge surface that you get by making the individual wires so extremely thin will mean that the resulting fabric will basically rust immediately. You can expose iron to humid environments as long as the metal is beefy enough to make material loss due to rust a minor concern. That's true for railways, it's true for chain-mails, but it won't be true for micrometer-thin wires. That said, the first issue is readily addressed: There are methods other than drawing that can produce extremely thin wires. Like embedding several wires into a rod made from a different metal, and then drawing that rod into a wire. Once you etch away the enclosing material, you may be left with some real thin wires. The details are tricky, though. The second issue just means that you have to work much harder on the first issue than you would have liked. However, the last point is the real problem: There are only very few metals that won't react with our normal environment. Those metals are gold and some even rarer metals like platinum. All other metals do react with the environment in one way or another, including stainless steel. You may be able to get stainless steel of such high quality that you can actually can get away with knitting armor from micrometer-thin wires, but it does require very advanced metallurgy. And once you have such advanced metallurgy, it will be hard to explain why you don't also have sufficiently advanced weapons that will render your armor useless. I mean, there is a reason why you don't see soldiers wearing armor anymore: The armor needs to be so thick that you have to put in on wheels and add a strong motor to it to be any help on the battlefield... Finally, stainless steel is generally not the best choice when it comes to flexibility. It's generally more brittle than less inert forms of steel. And easier breaking of the fibers means less protection that the armor provides. --- However, if you overcome/hand-wave the problems above, I see no reason why an armor made from such a material shouldn't be protective: The flexibility of the individual fibers means that they will just bend and not break when a sword crashes into them. Provided the fibers are not just thin enough but also long enough, they will spread the force across a larger surface, and thus stop the sword from penetrating. As a matter of fact, we do use such armor, we just don't make it from metal, we make it from [Kevlar](https://en.wikipedia.org/wiki/Kevlar). Kevlar is nothing more or less than a textile fiber of immense tensile strength. Kevlar is superior to steel because * it's lighter * it's easier to produce in thin fibers * it won't rust Other than that, a Kevlar vest is pretty much indistinguishable from your woven metal armor. [Answer] There is chain mail, although it's not woven. If modern techniques are allowed, I suggest 3d printing of chain mail, with very small and thin chains for added flexibility. One could even emulate a woven material, making the chain mail out of whole cloth (pun intended). The "fabric" would have several layers of chain mail (since they're very thin), interlocked in several places. In an attack, the outermost rings would be smashed, cushioning somewhat the impact on the innermost rings. ]
[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/68619/edit). Closed 6 years ago. [Improve this question](/posts/68619/edit) In my story, an artificial island nation is built. I need to give it a name! If somebody were to build a new nation, how would it be named, and what kinds of names might it get? I'm not interested in a list of names - rather, I want ideas about the process that would be used to select a name, and what types of names would potentially be selected. --- Some more details: This story takes place in a nearly utopian liberal political environment. A federation that is culturally similar to Europe that has a lot of say over what happens in a region approximately a quarter of a hemisphere of the planet in size. This setting is somewhat post-scarcity - there are still socioeconomic classes, but the lowest classes are similar to the lower-middle class in modern America and each nation can easily afford a very generous welfare program that catches virtually everyone who falls into true poverty. Overall, most nations have a government that is a semi-utopian ideal of how modern democracy should work. One of the challenges facing this federation is that every country within it is close to overpopulated. Since the federation has an abundance of resources but is continually running out of land for people to live, it has a major program of building artificial islands large enough to become small countries. (The islands are sky islands. This is practical because Magic, and it also allows the islands to be built three-dimensionally, making them have a smaller two-dimensional footprint on a map.) Since the islands are artificial, they don't have a lot of natural resources, so most people who live in them either have white-collar jobs or work in construction, providing maintenance for the islands. There are a few other federations like this around the world. They have different cultures, but are also somewhat utopian in their own ways, and all of the federations have good relationships with each other. Most people are accepting of people of other races. If this setting sounds too good to be true, that's what I'm aiming for. The conflict comes from a Lovecraftian force threatening to destroy the stability of this political system. My story focuses on one particular island that starts its nationhood about halfway through the process of being completed. Other nations and the system of federations don't appear much outside of the backstory. But I think that information is relevant for describing why I want to name an artificial island and helps provide some context for how that island might be named. [Answer] New places are often named for: 1. People influential in founding them (e.g. Louisiana, Virginia). 2. People who paid for them (e.g. Carnegie Library, Sports Authority Field, the Guggenheim Museum, Ford Motor Company). 3. Historical figures we are proud of (e.g. Washington, Lincoln, Seneca). 4. Distinctive physical features of the place, not necessarily true (e.g. Greenland, Iceland, Colorado). 5. Places the settlers migrated from or wanted to associate themselves with (e.g. New Guinea, New York, New Mexico, Oxford, Cambridge, New Caledonia, Athens, Rome, the Amazon - the original is in the Pontic-Caspian steppe). 6. Legendary places (e.g. Gilead, Jerusalem, Hades, Olympus). 7. Virtues and ideals (e.g. Utopia, Tranquility, Serenity, Friendship, Union). 8. Previous residents (e.g. Miami, Arapahoe, Pueblo, the Dakotas). 9. Things produced or acquired in trade at a place (e.g. Leadville, Iron Mountain, Britain means "Tin Land" in Punic, and Ireland means "Copper Land"). 10. Historical events (e.g. Centennial for a city in a state formed on the one hundredth anniversary of the founding of the nation). 11. Neighboring territories (e.g. West Virginia, South Sudan). 12. A general geographical location (e.g. South Africa, Central African Republic, Copper River, East Timor, South China Sea, Dotsoro - i.e. a point at the intersection of zero latitude and longitude on a map grid). [Answer] If there was a new nation in the area of the EU, it would be carved out of the area of an existing country. For an island it would be out of the [exclusive economic zone](https://en.wikipedia.org/wiki/Exclusive_economic_zone) of a country. The place has a name. If the island were raised in the [Dogger Bank](https://en.wikipedia.org/wiki/Dogger_Bank), it might become [Doggerland](https://en.wikipedia.org/wiki/Doggerland) again. An island in the intertidal zone might be called after geographic features in the area, like the [IJsseloog](https://en.wikipedia.org/wiki/IJsseloog). For a purely fictional name, Greek mythology might be a source of the EU bureaucrats get their choice, or the company name of a sponsor ... [Answer] > > If an entity like the modern European Union were to found a new nation, how would it be named, and what kinds of names might it get? > > > It's hard to imagine entities like the European Union to found a new nation, because it would rather want to integrate than to split up but I guess if they wanted to it would rather choose a bureaucratic approach maybe with an acronym. Something like: * SAZ5 (Self Administrated Zone Number 5) * FES (Free European Sector) * EAR-W (European Autonomous Region Wallony) [Answer] In my story 35 years ago, I named it Altus, because it means “tall” or something like that. It’s named after the physical attribute, because it’s an inverse hi-rise, building downward starting from a floating platform. All the place names of settlements were given names evocotive of the location. Consider the way the specific founders think: who were they? What were their motivations when building the place? Do they have a dead leader they revere? What language are they speaking? Are there any culturally significant stories that they might draw upon? [Answer] Europa seems like a safe bet. It perhaps could act as a neutral federal district for the EU [Answer] * Greek-ish names starting with Eu: Eudamena (storm-stiller), Eudiaereta (easily separated), Eudiatheta (well placed), Euglossia (sweet-voiced), Euergetema (kindness), Euergeta (benefactrix), Euphamia (praise), Euphantasmia (imaginative), Euphemia (use of good words), Euphanta (pleasant), Eusynallaxia (fairness), Euschemata (well-formed), Euxinia (hospitable), Eucharia (grace), Euchrestia (easily used), Euzygia (well-matched) * Purely imaginary names: Aclemaareymia Aglonsonytte Alliareidaanyette Antteychiny Apchire Aspoja Atteraree Ballutte Bliilassia Bofmemia Bretteroxure Casraelamiiwatte Chejossy Chewantteany Chobrorea Chonootte Chreemaitte Chrylere Clutinytte Creacossy Creevumia Daareal Dalaorrea Dascolylore Debeal Dejeal Deraria Discha Donquony Dreedinytte Dreonpiny Duploabony Eclepriiffia Ejucmaire Eluginy Equodure Erretteaberee Evoquiny Fachunytte Fejenytte Feveudutte Flasmaenea Flettekaennya Folenytte Freanuny Gajegotte Gareyttenuny Gesmemia Giipreufdea Gloenyny Goblex Gudiareony Hychere Hynnyare Hyphleny Idreechenytte Ifrial Isquany Ivevirosore Jantesnyette Jarraodotte Jemiafureossy Joareossy Jujevanye Kegujumaare Kiipnyutte Lajovuthiereenytte Lepliechire Lessarrua Lintanytte Lissaffany Lonyquoblaolae Lotteudaureomia Majonytte Maslevotte Melemaire Mestteaclossy Modreamaunenytte Molinytte Naaphsy Namasemia Nataazatte Nedocnyny Neslae Nidreyny Niiruowissia Nijassumia Nollemia Noslijeny Nullasse Nureenytte Nytreottee Oflubatte Omiapeeplee Opnenytte Otteheddoa Ovenytitte Pecreiny Peonuny Pidrunyare Piittereissia Pliivassia Pojaquenytte Prasreolassia Preenyymia Qiobumia Quajare Quelomia Quettii Racche Rakittee Rasraal Razedany Ressie Rhachyny Richralure Ridreivua Risttiimaare Rochareuddotte Rommaare Ropsore Runyquissia Rutinytte Saslitte Segiilore Siliisa Sladavore Sluvettereemia Sodureitte Srecpareuny Sreiscossy Talaedere Tanytteamia Tegabboal Telial Tetteonyajare Thagore Thebyre Thepax Thiittehial Thipuny Tiettenejunyumia Tiickerey Tipzenytte Tobreottehamia Totteare Treasiny Triechare Truiloa Ujavefduny Umiabapnue Utterievual Vaffussy Vechonytte Vefnasalany Vereenytte Vezeamaele Vijacfofraere Vocumiabie Waddette Wavumauny Zachumia Zanycheda Ziittenyare Zottehuny Zriipomia ]
[Question] [ In the 12th century China invented primitive rocket launchers, repeating ballistas, guns and cannons and a lot of other crazy gun powder based weapons. So I wonder could the same level of technology be used to create cryogenic grenades? I think the easier and the most effective way would be using liquid nitrogen as it can easily cause frost bites and potentially kill. I guess some dry ice and alcohol is enough to make big quantities of liquid nitrogen, but where are they going to get frozen carbon dioxide? Or are there other similar elements and compounds that can be obtained more easily? [Answer] # No You are talking about trying to make [refrigeration](https://en.wikipedia.org/wiki/Refrigeration) before people even have a concept of things such as "phases of matter", that is to say Gas/Liquid/Solid, or even heat as defined in the laws of thermodynamics. These are necessary things if you intend to invent refrigeration. ....which is to say your question is as if you asked whether a child could do a 2 meter high-jump before they have learned to walk ...or if they could make M&M's before they knew about peanuts and chocolate. Answer is: no, they could not. Daniel Gabriel [Fahrenheit defined his temperature scale](https://en.wikipedia.org/wiki/Fahrenheit) in 1724 with 0 F at a temperature that later turned out to be 255.4 Kelvin, or minus 17.8°C. This temperature was chosen because it was the coldest that was achievable through artificial means and that was stable. You are asking if they more than 500 years earlier — and before [the scientific revolution](https://en.wikipedia.org/wiki/Scientific_revolution) — could have achieved a temperature that was about 100 degrees Kelvin colder than what was achievable in the 18th century. No, they could not. Not with any kind of realism involved. Also to point out: rubbing alcohol and dry ice does not at all reach the temperatures of "liquid nitrogen". I will assume you meant "cryogenic fluid". But you still need refrigeration to make dry ice. Finally, as others have said: cryogenic grenades are pretty much pointless compared to making exploding / burning grenades, and much harder to achieve. [Answer] Two problems: 1. Cryogenic fluids aren't actually that dangerous. Dipping your hand in them is a really bad idea, but getting splashed with them is a different matter. Gunpowder grenades would be better weapons. 2. Liquid gasses weren't achieved until the nineteenth century, and are a prerequisite for making dry ice. There's no way to make them with early gunpowder-era technology. [Answer] > > …but where are they going to get frozen carbon dioxide? > Or are there other similar elements and compounds that can be obtained more easily? … could the same level of technology be used to create cryogenic grenades? > > > I don’t think a cryogenic grenade is very useful, but it is possible to build a hand-cranked refrigerator. [This video](https://www.youtube.com/watch?v=lfmrvxB154w) shows a refrigerator that works by stretching rubber bands (!), and illustrates that many processes are available that cool when they do mechanical work. Anything of the sort can be used to build a heat pump. So, yes, the inventor could produce a cooling effect without relying on whole industries that did not exist, and it might occur in a form that is something he would notice (in the video, he points out that the rubber feels noticibly cold against his lips) and not just something he wouldn’t experience without a lot of apparatus that doesn’t have any other purpose. That is, someone could discover it from just playing around. Once cooling can be done at all and he gets the idea to amp it up, it’s just a matter of scaling up the process and then repeating multiple stages to get colder and colder. CO₂ condensation will be noticed as the experiments progress. This will be plausible enough for most readers — [even in “hard” SF](http://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScienceFictionHardness)⚠ the real technical difficulties are trivialized. --- ⚠: warning — tvtropes link [Answer] Assuming (big assumption) that someone there discovered the relationship between pressure and temperature, they would have had the manufacturing technology to make a cryogenic refrigeration unit. (They're really not that complicated. Would be expensive, but a competent blacksmith could do it.) Of course, then you have to power the thing. No way you could do it feasibly to make any significant quantity with just muscle power. But if they've worked out the relationship between pressure and temperature well enough to build the cooling unit, you just run it in reverse and you have a stirling engine. Of course, now that you have stirling engines, you're rapidly leaving the mediaeval technology level behind... And then there's the fact that cryogenic weapons just won't be that effective compared to thermobaric weapons. The maximum temperature differential you can cause by cooling is probably about 200C. You can easily cause 1500C worth of temperature differential by heating, probably more. The higher the temperature differential, the faster the weapon will be effective. So, yeah, you can suffocate people with liquid nitrogen, but you need either an enclosed space, or really quite a lot of it. Freezing things requires extended contact with it, and a simple raincoat will provide a great deal of protection. A grenade worth probably wouldn't be that useful. You can find videos of physics instructors playing with that much with no side effects. Much more likely would be to use the liquid oxygen acquired by liquefying air as an oxidizer for charcoal. It's a lot more potent than saltpetre, and gets you an explosive more powerful than TNT. If you want, you can use the liquid nitrogen to convert more of the heat into pressure as well. Depends on if your goal is to light things on fire or crush them. [Answer] One of the biggest dangers in dealing with cryogenic materials is asphyxiation. Nitrogen is heavier than air and tends to displace oxygen. You can be dead fairly promptly if there is a big leak. See any of the University health and safety procedures for details. We have oxygen monitors wherever there is a large dewar. A possible use for an LN2 grenade (more likely a bomb) would be to kill people in a cave or underground warren of some kind (or maybe inside vast greenhouses). The liquid form would be compact and thus easier to transport than compressed gas. It`s not poisonous so it would not leave any lasting poisons and probably plants would survive (assuming they could survive in the first place). Under the right (perhaps somewhat contrived) circumstances it could be comparable with a modern neutron bomb that kills people (and higher animals) but leaves infrastructure intact. The Chinese had fairly precise mechanisms such as clocks and abundant labor, chemical and animal power so they could probably have produced LN2 if it was valuable to them. Consider other ancient devices such as the Antikythera mechanism from Greece. ]
[Question] [ What about a thousand years? This question was asked before about planes (I think), but since a gun is considerably less complex than a vehicle, I was wondering if they'd stand the test of time. Or would you need to build new, more primitive guns? [Answer] A well-maintained firearm can last for generations, but the key is maintenance. I personally own several weapons that are more than a century old and still fire quite well. I completely anticipate they will continue to do so for another 100 years, but only if my descendants take care of them as meticulously as myself and my forebears. The reason there is need for this constant care is rust. All firearms have a barrel made of steel. Steel is very susceptible to rust under even the best conditions. Most weapons have some sort of rust protection, like zinc plating or bluing, but these need constant attention or else they will weather away, exposing the vulnerable steel beneath. Some weapons (read: pretty much all of them) also have non-metal parts, made from wood or some synthetic material. With constant care, the wood might also last as long as the metal, but it also might not. Certain synthetics show some longevity, but they will also degrade eventually. Even if the weapon in question was well maintained for the entire course of time, we have the problem of ammunition. Even under the best storage conditions, ammunition has a shelf life well short of our proposed timeframe. Casings, bullets, primers, and even powder (ALL of the requisite components) will break down, rust, or erode over time. If it DID manage to survive (unlikely) it would be questionable, and firing it would be dangerous at best. Optimistically, I can imagine that in 500 years from today, assuming life continues as it is, there may be a small handful of operational 20th century weapons in the hands of collectors. Most likely there would be zero. Assuming the world goes to hell in a handbasket, the chances are even slimmer. [Answer] A few years ago a centuries-old loaded cannon was found in New York. [CNN](http://edition.cnn.com/2013/01/13/us/new-york-loaded-antique-cannon/) reported that the gunpowder was still "active". Unexploded ordnance that is almost 100 years old is still [dangerous](https://en.wikipedia.org/wiki/Iron_harvest#Dangers), so caution is surely indicated. On the other hand, the mechanism of a modern semiautomatic handgun is much more complicated than a muzzle-loading cannon. Look at the pic in the New York case. * The most likely result in your case would be that the trigger and firing pin don't work. * If the pin works, the next most likely result is that the primer and propellant don't work. * If the propellant works, the weapon might be damaged, the bullet might get stuck in the barrel, the slide might crack, whatever. * If the bullet gets fired, which is extremely unlikely, accuracy will suffer. * Also, the likelihood that the semiautomatic will chamber another round is very low. [Answer] They would work in the right situations, but I wouldn't trust them to fire very well, if at all. It would require a controlled environment, preferably with humidity control. A sealed vault could hypothetically keep it working. It's not really a matter of the gun itself, since stored properly artifacts will last forever (yes, guns require maintenance, but historical artifacts in vaults don't). But ammo itself goes bad. This usually doesn't happen for a couple decades, but I doubt nitrocellulose would last that long. Ammunition from the 50's can still be used, but improperly stored ammo can go bad. Even properly stored, 500 years is a bit of a stretch, and you might have to go through a bunch of non-firing bullets before finding something that works. A normal diesel emergency generator in a similar hypothetical environment, maybe a sealed off vault, could work, and it wouldn't take too much to just scrape together spare parts from different generators and replace the ones that failed. [Answer] ## No, not even close Pistols as well as most guns are made of stainless steel. Many other compunds are needed to make a working gun, such as copper, zinc, gunpowder and other assorted alloys. The main problem here is the steel. In which it will last 10 years of a reasonable rust free life assuming its zinc plated. Whereas austenitic stainless steel fasteners will give at least 30 years trouble free life for most applications. So short story even shorter, no the gun won't even last 10% of your goal. [Answer] What I believe is the as yet unanswered part of your question, "Can you...", no I will be dead by then!!! Next, could someone alive then? Sure they could, it might fire, it might not - though I agree with one of the other comments, one of the more interesting cases might well be a 'printed gun' out of plastic. No rust, no maintenance. As others have noted, the ammo might not function though. [Answer] Problems with ammo could be fixed by using an airgun. The question is would the compressed air still have the same pressure or would it have all leaked out over a century. ]

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