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[Question] [ It is an established science-fiction trope, especially in something like Star Wars, that entire planets will be run by a single government. When trying to worldbuild, I began to think about how one government ruling at least 1 entire planet could be realistic. With a government with highly advanced technology, even if it were either weak or just a puppet government, could a single government actually rule an entire planet, despite the problems like rebellions and religious and ethnic violence? [Answer] # It's all about travel time #### And it's very possible In the past, we have been limited in the size of nations primarily due to the speed of travel (or, more accurately, the speed of communication). It was very difficult to keep the early United States together because it took months to get information from the eastern states to the western territories. The Battle of New Orleans was fought 2 weeks after the Treaty of Ghent was signed, because the armies didn't know the war was over. As infrastructure and transportation improved in the 19th century, the feasible scale of governance rapidly grew, hence the boom in westward expansion. With 21st century technology, major world powers already maintain military presence around the globe. Given how accessible spacecraft appear to be in the Star Wars universe, it is more than reasonable to think that a single strong government could rule a planet, star system, or even galaxy with enough wealth. An 18-wheeler can cross North America in a week, and a civilian class x3 hyperdrive ship can cross the Star Wars galaxy in 3 days. [Answer] You can give some or many planets unified governments, and keep a few divided into more subdivisions. * How many worlds have been colonized by other species? You have to decide how common habitable worlds are. Pearls beyond price or a dime a dozen? If they are common, colonists who want to found their own colonly look for their own planet, not one where other people already live on a different continent. * A matter of perspective. At times one gets the impression that many US citizens forget that they are one nation. Yet seen from outside, they clearly are. So there are administrative divisions on most planets, with district, city, and county levels, yet an outsider notices mostly the planetary government. * One ecosphere, one government. On the real world, mankind is slowly realizing that they can ruin the ecosphere if they are not careful. Imagine what they could do with more advanced technology and no need raise kids and retire where they do their pollution. With easy interstellar travel, some people might see a planet as a resource to be strip-mined, others see as a home. There will be conflicts unless there is a central government per planet. The occasional adventure could center on worlds which do not have unified governments. "Why did you land here if you want to deliver your goods across the border? You'll have to go back into space, even leave the system for a quick jaunt if you don't want to be taxed as intercontinental trade." [Answer] Many countries in the current day are implausibly large by ancient standards, and exert an implausibly large degree of control. This turns on advancing technology. Communications, travel, and collation of data are crucial technology. Remember that the government will break down the world into reasonable sized chunks of ease of administration. Even towns and villages will have their local authorities that deal with many problems within the scope of the village/town. Quite small regions have been riven by rebellion and violence. The government may in fact deploy forces from other regions specifically because they don't have any skin in the game except their paychecks. [Answer] It depends - how did it start Situation 1 - origin planet with multiple civilisations developing separately (eg Earth). As many previous questions have covered, until modern(ish) technology was available, there was no possibility of a "world government" simply because regular, timely communication between the various parts of the planet was impossible. Hence there will always be lots of different nations to begin with in such a situation and it is a matter of whether they are willing to eventually find more common ground than points of difference whether they unite, once the technology exists to make such an option possible. Without a crystal ball we don't know whether our single known example will unite or remain fragmented, either is a future possibility. Situation 2 - colonised planet from single source. If a single government / corporation / settlers' cooperative founds a colony on a planet and settlement spreads out, I suggest it is likely to start as one government and remain as one government. It makes far more sense to retain one government in order to keep common standards of interoperability, consistent legal code, recognition of training qualifications, maintenance of spaceport and orbital traffic, maintenance of commsats / weather sats... There will definitely be different levels of government for once it spreads out enough (eg federal, state, local or equivalent) but the only reason a region would want to secede would be if it was being so badly mistreated that the hassle of replacing all top-level government functions would be easier than staying in the union. (Yes, this does include the possibility of some self-centred idiot politician/s convincing the local population this is the situation when it actually isn't and downplaying the inevitable consequences.) Situation 3 - colonised planet from multiple sources. If multiple sources settle a planet simultaneously then the outcome is uncertain. It could be that the colonists find they have more in common with their local neighbours than the group that sent them and unify, or it could be that they remain separate nations on the same newly colonised world. A great deal will depend on the differences in culture (including language) between the different colonies, how "successful" each colony is at various times and how the colonies are treated by the government or other entity that sent them. For example, if the various settlers all speak the same language, they are insufficiently supported by the group that sent them and one colony provides vitally needed aid to the other/s then unification is highly likely. If they all speak different languages, have significantly different values for personal freedom and are all strongly supported from "home" then they are likely to remain separate. In summary, how a planet's civilisation/s started will determine how likely they are to unify or remain unified. [Answer] # Simplicity Itself: I would say that it is entirely plausible for one government to rule one planet. I would even argue that it is the most likely logical progression for governance. Outside factors frequently play a critical if not indispensable role in the destabilization of empires. Wild ideas and tech, abused neighbors hungry for revenge, aggressive neighbors anxious to steal what the empire has, and desperate migrations caused by catastrophes have contributed to many societies changing or collapsing. Removing external threats simplifies the process of ruling a world government. You can oppress people with little concern that someone will support their revolt, or that the tale will be told and the truth will come out. You can control all supplies, all weapons, all freedoms, all technological progression and most importantly you can erase the past and write all the history books to your liking. The only voice people hear is yours. Of course, innovation will suffer in such a system, but if you control the whole world, you logically should restrict innovation so as to prevent any destabilizing elements from disrupting your control on society. After all, once you are in control, the status quo naturally involves you STAYING in control. Of course, in a world with spaceships flying in from other worlds, this starts to be a problem. But fear not, you restrict access to the planet to trade stations and orbital bases and all that messy stuff gets kept out. A logical world government would likely need to maintain strict separation between the outside and the surface. Failing to do so opens you up to the same kind of pressures societies experienced when colonized by foreign powers. Much like Japan, restrict trade and cultural exchange with the outside and maintain tight control on the advancements you need to stay competitive with other civilizations [Answer] On Earth, every recognized sovereign state except for the Vatican City has one or more levels of administrative subdivisions. Larger states have from one to six levels of subordinate administration, or two to seven levels of government in all. Leaders of subdivisions within a country can be elected by the residents, appointed from above, hereditary, randomly selected, usurp power, or gain thier positons in o ther ways. There are many examples of states with several differnt types of subordinate governments. In most of the USA there are four levels of governments. The federal government conducts diplomacy, makes war, and has many other functions for the general welfare. State governments issue driver's licenses and have many functions for the general welfare. County governments maintain recordsof births, marriages, and real estate deals and have many functions for the general welfare. Municipal governments clean streets, collect trash, often own utility companies, and have many functions for the general welfare. All levels of government have courts to try violations of their laws and rules. Many projects are jointly managed by two or more levelsof government. And there are other government institutions such as school districts, various authorities, and tribal governments. Most of the Roman Empire's land was divided into city states which had elected councils and magistrtes. A subdivision within a city state was called a pagus. Governors of provinces commanded the military in the provinces and supervised the city governments. And above them were the emperor, the senate, and the popular assembly at Rome. So there were four levels of government in the early Roman Empire. In the later Roman Empire the miltary and civilian functions of governors were separated and given to diffferent officials. The number of provinces was multiplied, and provinces were grouped into dioceses ruled by appointed vicarsd which were part of prefectures ruledd by the four praetorian prefects under the emperor(s). Thus the later Roman Empire had six levels of government. So I can imagine that a hypothetical united world government might might take the diplomatic and military powers of the national governments while leaving them other powers. And that world government might be directly above the formerly independent national governments, or it might have one or more levels of government between it and the national governments. For example there could be continental governments over each of the four, five, six, or seven continents recognized by various governments. And there could ocean governments ruling all the lands whose waters flow into each ocean of the world. The lands ruled by the continental and oceanic governments would overlap, so that subordinate governments could communicate with the world government though either, or both, and vice versa. And maybe the world government would revive some of the great empires of the past as an intermediate level of government between the natioal governments at itself. And of course almost every present day national government has been part of one or more emperies in the past. And the advantage of overlapping areas of rule by governments above the former national governments is for lawsuits. If people take a case to higher and higher leavels of courts until they reach the supreme court equivalent of their nation, they then have a choice of two or more even higher courts to take the case to, if th two parties can agree on which one. So adding another level of courts will increase the probability that one side will give up trying and not take the case to the Supreme World Court, thus lowering its caseload. And a world government should be able to last more or less forever, so long as it has a monoloply military force. For example, all the military and civilian bodyguards of all the subordinate rulers should be world bodyguard service, working for the world goernment and assigned by it to be the bodyguards of the subordinate rulers. [Answer] I would definitely say its possible. There are already big world organizations like NATO and UN that are already successful. And in its peak the British Empire controlled almost a quarter of the worlds land area, and housed 23% of the world's population. A United World government is certainly possible, but a government like that would probably be more complex than any government today in order to sort out all the problems of the entire population. And this world-country would probably be split into many sub-countries and sub-governments, kind of like how the US is split into states with their own sub-governments, except these states could be regions of the world, like maybe the Middle East as one or Europe as another. it would probably not be one identity, you probably wouldn't identify as a citizen of United Earth, more like a citizen of you sub-division. These mega-states would probably also have further sub-divisions, maybe with their own sub-sub-governments. So yes, a united world government is certainly possible, although it is definitely something for the future, and probably not possible today, as you would probably need to sort out the differences in things like ideology, culture, laws, customs, etc. And things like a global currency would need to be worked out. You would also need to make a system for voting the leaders of the world government that at least most people agree on. It may not be a democracy but rather something else, but of course nothing is stopping democracy from working. Maybe they have elections but instead of republican, democrat, that sorta thing, you would have like a communist party and democratic party, etc. Maybe each of these world-states would have radically different cultures. there are endless possibilities, and it certainly would not be easy to make a united world government, you would need to unite very different parts of the world, and it would probably take a long time, maybe decades or centuries. [Answer] Ruling = protection racket? "Ruling" is an imprecise term. Does that mean careful granular governance, discussing school day hours, tax rates for various business, the number of pennies to mint, etc? Or does it mean a glorified [protection racket](https://en.wikipedia.org/wiki/Protection_racket), extorting money with the threat of violence. Either one could constitute ruling. If I must pay tax to the imperial overlord or get some Rods from God in my yard, the imps are my rulers. This kind of generally uninvolved government would be easiest to do planet wide because all you do is collect tax and sometimes mete out punishment. There may be other more local rulers who are less scary and more involved in the day to day affairs of your area. The planetary government might actually be that for their local area. And your Planetary Empire protection racket might be protecting the planet! If the tax collected from the provinces is used for defense of the planet as conducted by the Emperor that may be a good thing for all inhabitants of the planet, whether they appreciate it or not. [Answer] ## Common enemy Aliens invading a planet would immediately unify a civilization. Nowadays, many dream of a planetary government, because of a common enemy called CO2. [Answer] In a sense, there are two facets to this question: the scale of the setting and can one government rule a world. ### Global Domination TL;DR: Can one government rule a planet? Sure. The longer answer involve logistics and delegation and a thoroughly unhealthy amount of politics (or weapons). To rule an area, one needs to be able to aggregate information to a central location, process it, and respond with a course of action. The faster this can be done, the larger the area one could plausibly rule over. It's a gross simplification and does not take the people one is ruling over into account, but it is a start. With advanced enough communications technology, information can cross a planet in minutes -- we already do this with the internet here. The key for your world government would be a robust communications network that could reliably do this. Processing is already feasible here. Between people using their intuition and computer algorithms processing the large amounts of data received, the data coming in from all over the world can be processed and checked over. I might say that for a world government, a bit more raw processing power might be needed, but that is potentially solved with a bigger computer for now. Also, if the world government is delegating regional authority to a regional group (like a state/province/territory), then that may reduce the information that needs to be gone through as the regional offices will handle the regional affairs and only kick up what needs to be. Responding is a people thing. As long as there are enough people authorized to make the decisions and the time to do so, then things should work. The issue will be dealing with things in a timely manner to have at least the appearance of a functional government. For this, it's about transportation and logistics technologies -- the ability to move resources around the planet efficiently. We can do it somewhat now, but it could probably be better. I've avoided trying to outline specific governments to limit the length of the reply. Some governments will delegate some power to local governments to better serve their people while others will centralize everything into a global capital for more selfish reasons. But regardless of how ### The Galactic Stage The thing about a galactic scale setting is that a planet is just not as significant as it would be if your setting was the planet itself, or its solar system. There is likely not a ton of thought on the government of each individual planet unless it is significant in the setting. Realistically it is a matter of scale and conservation of detail. ]
[Question] [ say someone punched the ground (Earth) with infinite strength, how much force would they require to destroy/ vaporise the earth? Or an easier question how much force would someone need to induce $3.2 \times 10^{29}$((approximate recall) Joules, which is enough to unbind the Earth), to the Earth? [Answer] It cannot be done through a punch. There's several issues, but the easiest to work with is to look at the displacement of your fist. From your invocation of the binding energy of the Earth, it doesn't look like you're interested in some garden variety "destroy the planet" sort of punch. You're looking for something which pulverizes the earth and sends its ashes off to the corners of the cosmos. That's some next level damage there! Okay, let's calculate! I'm going to assume that this is less of a "punch" and more of a "shove." Why? Because Work = Force \* Distance. Work is what you need to put into the earth to get the energy needed to overcome the binding energy. Speaking of which, the energy is slightly higher than you recall. The [gravitational binding energy of the Earth](https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)#Over_1023_J) is $2\cdot10^{32} \text J$. Minor detail. It will turn out 3 orders of magnitude isn't much in this problem! Now an average arm span is 1.4m, we'll round up to 1.5. Might as well give them every advantage we can get! Dividing $\frac{2\cdot 10^{32}\text J}{1.5m}$ yields $1.3\cdot 10^{32} \text N$ Now this is where it's going to get murky. Understand just how absurdly large that force is. That's the force of 3,800,000,000,000,000,000,000,000 [Saturn V rockets](https://en.wikipedia.org/wiki/Orders_of_magnitude_(force)) all lifting off simultaneously. I wanted to find a comparison that involved fewer zeros, but my favorite "Orders of Magnitude" series of pages in Wikipedia did not have much in that range to work with. It's quite literally 10,000,000,000 times more powerful than the force the sun applies to the Earth. This is a bonkers level amount of force. Of course, this assumes you can apply it. A few years back, I fielded a [question](https://physics.stackexchange.com/questions/270030/newtons-3rd-law-hitting-drywall-which-i-break-vs-hitting-a-brick-which-br/270058#270058) on Physics.SE on this topic. Just because you are capable of generating such forces in theory doesn't mean they actually materialize. Once you start getting into high enough forces to break the object you are punching (read: pulverizing granite), the electrostatic forces holding it together fail, and your force starts accelerating the mass in front of it rather than distributing that force across the rest of the wall. What you would find very quickly is that your fist simply pulverizes the nearby slug of rock and you fail to actually impart this energy. Which brings us to the world of supersonic propagation. You need to be moving fast enough to impart that kind of energy to only the matter in front of you. There will be some spread, but as we will see, at the speeds we are talking about here, it's really just a cylinder of rock we need to consider. We are considering the rock that is physically occupying the path your fist takes. That would be 1.5m long, from the armspan before, times $0.054\text m^2$. Why that number? That's the surface area of an [outspread hand](https://journals.sagepub.com/doi/10.1177/154193128603000417). A fist is slightly smaller, at $0.045\text m^2$, which makes the story worse, so we're going to try to slap the Earth out of existence rather than punch it. Multiply these through, we see that the cylinder of rock your hand can physically reach is $0.081 \text m^3$. The density of diabase is $2970\frac{\text{kg}}{\text m ^3}$. [Diabase](https://en.wikipedia.org/wiki/Diabase) is a very hard rock, harder than granite, and slightly more dense, so it seems like the best surface to apply your punch to. This means your fist has direct access to $240 \text{kg}$ of rock. Using $E=\frac 1 2 mv^2$, we find the velocity that rock needs to reach to have the necessary energy is $1.3\cdot 10^{15} \frac{\text m}{\text s}$. Now we have a real problem. The speed of light is $10^8 \frac{\text m}{\text s}$. By these simple Newtonian calculations, we would need to strike the earth at a velocity equal to 10,000,000 times the speed of light. Bollocks. This obviously can't work, which means now we need to toss away the Newtonian calculations and start using [relativistic](https://en.wikipedia.org/wiki/Mass_in_special_relativity) ones. Incidentally, this means your fist is now less of a first, and more of a concentrated burst of high energy particles. Relativistic mass and "rest" mass are related by the equation $m\_{rel}=\frac{m\_{rest}}{\sqrt{1-\frac{v^2}{c^2}}}$. Remember, we need that slug of rock to have all of the kinetic energy needed to destroy the Earth, so our $m\_{rest}$ is the mass of the rock. We can also use the famous equation $E = m\_{rel}c^2$ here. We need the rock to have the requisite energy so its relativistic mass must be $2.2\cdot 10^{15} \text{kg}$. Thus $\frac{m\_{rel}}{m\_{rest}} = 9.25\cdot 10^{12}$. The relativistic effects need to provide a mass multiplier of just shy of ten trillion to 1. How fast does this need to be? My calculator actually runs out of precision, but it is at least 99.999999999% of the speed of light. That's at least 10 nines. For perspective, the [LHC](https://www.symmetrymagazine.org/article/inside-the-large-hadron-collider) throws electrons around at 99.9999991% of the speed of light - 8 nines. So, at this point, we really do need to start asking tough questions about whether this qualifies as a punch. Its more of a particle burst. And the question I held off till the end: how did you accelerate your hand like this? To impart this much energy into the Earth, the equal and opposite reaction is going to send you careening off at nearly the speed of light. So, in the end, we destroy the planet, and the super-villain! Now, just for fun, a supernova outputs about $10^{44} \text J$, in all directions ($4\pi$ steradians). This means that if the Earth subtends a solid angle of $10^{-12}$ steradians, that supernova would strike the Earth with the energy you so crave. This would put the supernova at a distance of about $10^{12}\text m$ away. In other words, for one of the most furious events in all of astrophysics to impart that kind of energy into the Earth, it would need to be somewhere around the distance to Saturn. A [supernova](https://what-if.xkcd.com/73/)... inside our own solar system... > > "It must be Thursday. I never could get the hang of Thursdays." -Arthur Dent > > > [Answer] At this point, you would need to be more concerned with recoil of that punch. However force it may take to shatter the earth, the some ‚Äùone‚Äù would probably be yeeted back at light speed. That would honestly be really funny. Not to mention, even if this person punches earth with supposed infinite force, that would probably won‚Äôt do shit. Major limitation is the form factor of puncher and that fact that material making up earth ain‚Äôt that tough. The length of a human arm is somewhere in between 60-90 cm. When the punch that powerful connects: rocks and hard surfaces will break and soil will compress, and punch will displacement them further deep down or sideways. So all the damage you can do is with displacement of earth caused by your arm, roughly equal to volume of the arm (+/- some cc), the associated shockwave. Depending on actual speed of punch, all can do is make a crater of 1-1000m in radius and much less in depth and a short earthquake. In human form, I believe it‚Äôs impossible unless you hit at light speed and cause destruction due to light speed/relativistic shenanigans. You would need to make the fist itself big in size such that damage is more spread across the planet. Your punch may be only need to severely damage or essentially bore up to 100-600 km (probably less) deep into earth and basically expose the mantle, and internal pressure of earth cause it fall apart on its own by. And shockwaves from punch that deep actually may be strong enough break the planet or at the very least cause some serious instability within the earth. ]
[Question] [ One of the major problems I've always had with the MCU and the DC universe is how powerful many of the beings or people are whilst the World is still almost the same as ours. It was as if the writers were trying to have their cake and eat it. Generally speaking the most superpowers you add to a setting and the more powerful the people are, the more different a setting should be to our modern world even if it's a modern world. A lot of comic books writers and other writers don't tend to do or consider their worldbuidling because it forces the writer to answer and ask certain questions. It also forces the writer to literally change a setting to be more than real world plus. I've never really gotten into the whole mutant debates in marvel because of how poorly handled or thought out they were. However I'm ranting now. My Hero Academia and Darker than Black both show limitations in the powers which result in there being less changes to the setting itself making it more similar to our world. Even then there are super-powered beings in government bodies, criminal networks and terrorist rings. However what I am asking is this. How powerful can you make a general or significant part of your population without changing it drastically from our world? [Answer] ## Pretty much any amount of superpowers at all will cause human history to be dramatically different from our timeline The thing about history is it's a very complex subject where even the slightest change would produce massive divergences. Social, cultural and political trends are in large part driven by people's reactions to major (then-)current events, and our societies and laws are informed and influenced by what has happened before and what has worked and not worked. Even the smallest change would result in a massive butterfly effect that would warp everything around it. A world with superpowers, *any degree of superpowers, should, realistically, not resemble the social and cultural landscape of the modern world at all. Watchmen* provides a pretty good example of this, where a social trend leading to an increase in non-powered costumed vigilantes and one outright superhuman is enough to cause massive changes in history and American culture, including widespread usage of clean energy-powered cars, Richard Nixon as a four-term president, and America winning the Vietnam War. This goes beyond someone who is as god-like as Doctor Manhattan. Even less-powerful superhumans would be enough to warp history to this degree (e.g., the X-Men Forge and Wolverine could potentially produce the same results with Vietnam and Lithium-powered cars). In the real world, superhumans would also massively affect the political balance of power just by existing, simply because they represent an avenue of power that the politicians don't have universal control over. If the superhumans are natural and not part of an engineered arms race, the people running the status quo cannot dominate them the way they do financially and socially. In the real world, during the Cold War Russia would be terrified of the existence of Superman and the U.S. government would be rapidly scrabbling for contingencies because they know Superman won't obey the minute his definition of "the American way" differs from their own. This goes beyond mere flying brick-level superhumans. Mad scientists and supergeniuses like Mr. Fantastic, Lex Luthor, or Mr. Freeze would rapidly have their technology available to the common person. Even if they didn't decide to simply sell it out of ideological reasons (I'm looking at you, Poison Ivy), governments would rapidly get their hands on their technology after they got arrested and start trying to re-engineer it to advance their own motives. This goes for alien invasions as well. Darkseid invades Earth and suddenly he's left Apokaliptan god-tech scattered all over the globe. There would be many, many changes in history should there be any superpowers, anything stronger than, say, Daredevil. Even the existence of a group of people with powers similar to Luke Cage or Spider-Man would cause major historical ripples. Among the many changes, just to highlight a few major examples... * World history should go very, very differently. Assuming superpowers occur due to random mutations or accidents of fate across the globe you would have a lot more cases where the presence of superhumans dramatically reshapes the world's political balance. Superpowers are basically a huge weapon of war and whoever has the best and most of them has the advantage. You'd get a lot more cases where a smaller country fights off a larger attacker due to the presence of superhumans as a force multiplier, so a lot of IRL historical invasions would fail (or alternatively, others would succeed). * A good example of this? The Nazis, given how obsessed the Third Reich was with mysticism and alternate means to power and the fact that their invasion plans had low odds for long-term success due to a lack of materiel and natural resources for their war machine and the fact that they managed to aggravate almost everyone, including the USSR who massively outnumbered them. But if the Nazis had a disproportionate number of superhumans due to comic-book super-soldier programs, that might change how World War II ended up. * [Or consider what happens when a superhuman born in a developing nation gains an ability like, say, the ability to make crops bloom on command, generate clean water, or provide an unlimited source of clean energy](https://www.smbc-comics.com/index.php?db=comics&id=2305#comic). It would give that country a huge economic advantage. * The presence of superpowers would also warp scientific history and discovery, as people become interested in why certain powers work and devote research along those lines. Or outright cause some inventions to be ignored (why invent powered flight when you have a class of people that flies?) * Air power would become a bigger threat in military technology long before the invention of air superiority IRL if you have people that fly. * Alternatively, if you had superpowers unequally distributed and disproportionately represented among a particular culture or ethnic group, that group would eventually come to dominate at the expense of all others. Superpowers for this culture would be like how guns and gunpowder allowed Europeans to run roughshod over cultures in the rest of the world. You would also have significant issues with Nazi-esque rhetoric where the group with superpowers would claim they are superior because only their group has all the powers. * Christianity would probably not become the dominant religion in the West, and the same is true for Buddhism in the East. Jesus and Buddha's miracles cease to become interesting in the context of a world where powers or healing magic are commonplace. They might gain traction as powerful secular figures based on their rhetoric akin to how Judaism or Islam sees Jesus IRL, but they likely wouldn't achieve their current popularity. Without the spread of these populist, pro-social religions that support the little guy and present the idea that in the grand scheme of things everyone is cosmically equal (either through reincarnation in Buddhism or everyone being equal before God in Christianity), we probably wouldn't see the expansion of human rights. In particular, we would probably still have slavery around in the West, since the moral disconnect between Christian values and the institution of slavery was a huge issue for many pro-democracy politicians and one of the driving forces for the abolitionist movement. "Might makes right" social philosophies would be a lot more common. * Europeans would have never colonized Africa, the Pacific, and the New World. Europeans mostly managed to colonize these parts of the globe (especially the New World) due to the use of firearms, iron armor, horses, and disease. The native populations often lacked this military advantage. Superpowers evens the playing field, especially given how small initial European expedition attempts were. Even if smallpox wiped out most of the native population, some native superhumans would survive and they would have wreaked havoc on the early European attempts at conquest and settlement. This is especially pertinent in the case of the Aztec and Inca empires. These empires, which had a population of 6 and 10 million people, respectably, would have had access to superhumans (and would have probably kept them at their capitals), and would have been able to smash Cortes and Pizarro's invasion attempts easily. The fact that these invasion attempts failed would probably cause European rulers to consider exploration of the New World a lost cause (the King of England almost wrote the New World off as not worh colonizing after Roanoke vanished and Jamestown was failing) and dissuade would-be conquistadors. E.g., Pizarro only attempted to overthrow the Inca after he saw how wealthy and powerful it made Cortes. * Human sacrifice would probably be a lot more common. [Studies of human social systems have found that human sacrifice tends to become more common in highly-stratified social systems where individual human life is devalued as a means of controlling the lower class.](https://www.npr.org/sections/thetwo-way/2016/04/04/473004808/human-sacrifice-is-linked-to-social-hierarchies-in-new-study) E.g., the Aztec empire, which depended heavily on manual labor for construction due to the lack of exploitable pack animals and hence people were more valuable as labor than as people, as well as having a stratified upper class. Create a society where society is stratified along biological lines due to superpowers and, well... These changes would be much more prominent in earlier history than in more recent times. Today with modern technology and fire-arms someone like Spider-Man or Luke Cage wouldn't have that much of an influence. But to a Stone Age or Bronze Age culture like most pre-European New World cultures, ancient Greece, ancient Egypt, feudal Japan, etc., someone with Spider-Man or Luke Cage's powers would be like a living god. I mean, Luke Cage is basically modern day Achilles, and in The Iliad Achilles' presence basically dictates the course of the Trojan War. Equality is Dead A world with superpowers, especially flying brick and above powers, would also shoot ideas of equality under the law (isonomy) and liberalism in general stone dead. Society basically works because no individual is able to unilaterally apply their will over everyone else, even totalitarian dictators have to maintain the support of their inner circle, their generals, and the masses or else risk being overthrown. But what do you do when you have an individual whose power comes from themselves and cannot be stopped by mass action? Say a Superman-level superhuman gets convicted of a crime? How are you going to imprison someone who can't be held against their will and can easily escape from any normal prison? Or a superhuman dictator who can do whatever they like, enforcing whatever insane ideology they believe to be correct, simply because they are so powerful that no one can tell them "no" and they don't have to maintain the good will of the people? How do you deal with a society where some individuals really are physically "superior" to others to a degree that cannot be ignored in culture and law? A good example of this can be seen in how the X-Men comics have treated the two cases where mutants created a sovereign mutant-run nation: Genosha and Krakoa. Genosha was ruled for a time by Magneto and the Brotherhood of Mutants, whereas currently in the comics Krakoa is ruled by a council of mutants that include Charles Xavier, Magneto, Apocalypse, Exodus, Mister Sinister, Mystique, Emma Frost, Sebastian Shaw, Jean Grey, Storm, and Cyclops. Note that in both cases it’s still the same Alpha and Omega-class mutants who are dictating policy to the rest, whereas the poor schmuck whose mutation merely consists of a tail or the ability to change color is still politically disenfranchised. The fact that the different degrees of mutant powers create a class system and a small group of people at the top are never really addressed in the comics. Nor the fact that this cabal of super-mutants basically gained political power by putting a metaphorical gun to the heads of the world's leaders to do what they say or else. What this would end up doing is killing most of the humanistic movements of the Enlightement and the idea of universal human rights, since you have a group of people that are both biologically and socially not equal to other human beings, and that would frame how people would talk about what is the best or most moral system of social organization and governance. I don't think Karl Marx would be too happy about the existence of superhumans either, likely calling them "natural bourgeoise" or something and likely espousing Hitler-esque ideas on how they should all be destroyed since unlike the bourgeioise you cannot take their power away via social mechanisms or government-mandated seizure of their property, and hence they would perpetually be an uncontrollable threat to Marx' envisioned communist utopia. That is if Marx even comes up with the same ideas due to the existence of superhumans throwing a wrench into his ideals. That's potentially one of the most influential ideas in the last 150 years of human history being radically different or outright never proposed. Destruction of Narratives The presence of superpowers would also throw a huge wrench into historical narratives of group superiority or oppression. Namely because it makes no sense for a society to view a certain gender, sexuality, or ethnic group as inferior when those people can very easily be the most powerful. This is especially the case for women. For most of human history the majority of human societies have been heavily patriarchal and women have been seen as the "fairer sex". However, in a world with superpowers, assuming random distribution half of all superhumans would be women. Narratives of women being submissive, weaker, gentler, or "belonging in the home" would go flying out the window [the minute some Roman or Chinese woman ripped apart an attacking force with her bare hands](https://www.youtube.com/watch?v=8w6khbl-uXw). Not to mention all the women that would use their powers to advance themselves socially and politically (Boudicca or Wu Zetian with laser eyes anyone?) Similar issues would be present with cases of sexual assault. Men would be hesitant to sexually assault women because they are now playing Russian roulette if they tried. [Male superhuman sexual abuse cases would skyrocket](https://en.wikipedia.org/wiki/Ring_of_Gyges), and female sexual assault and rape cases, which actually kind of common but brushed under the rug in current times, would become high profile as you now have women capable of easily overpowering men and having their way with them in an undismissable manner. Female superhumans might end up being stereotyped as promiscuous and sexually aggressive because of it. Similarly, because superpowers are such a great weapon of war, it would be silly for a culture to sideline it's superhumans based on narratives of sexism or other, similar ideas, simply because you are sidelining your best weapons out of ideology (and would likely lose). If you have a woman who's a flying brick and a man who's power is to heal people, why would the culture tell the woman to get back in the kitchen and send the man to the front lines? This wouldn't just apply to women. Cultural narratives of LGBT people or those of a specific ethnic group being "inferior" would be rapidly debunked by the presence of high-profile individuals with superpowers that anyone could point to. Patriarchy, homophobia, or ethnic superiority probably wouldn't become a thing, because it would contradict historical knowledge. Powers versus no powers would be the primary social divide. A good example of this can be seen in the Avatar: The Last Airbender series. The Northern Water Tribe and Earth Kingdom have been depicted as highly sexist, and the Turf Wars miniseries revealed that the Water Tribe, Earth Kingdom, and Great War-era Fire Nation were all incredibly homophobic. This makes no sense given that for 230 years Avatar Kyoshi, the physically and politically most powerful person in the world (and often revered in-universe in a manner similar to the IRL Dalai Lama), was an openly bisexual woman who eventually ended up in a homosexual relationship. And then that person's reincarnation three cycles down the line (Korra), was also a bisexual woman who ended up in a homosexual relationship. Not to mention all the powerful benders who are either female or LGBT. The most powerful Earthbender is the world in both series is a short, blind woman. Homophobia and sexism make no sense within the context of that world. How to fix this? There are a couple of solutions to fix this, but none of them are any good. The easiest way would be for there to be some kind of masquerade hiding the existence of superpowers and the supernatural from the common populace, at least until the author decides to reveal it. But a masquerade is way more trouble to maintain than it is worth, maintaining a would be nearly impossible and there are tons of examples [on this very website](https://worldbuilding.stackexchange.com/search?q=masquerade) on how hard it would be to maintain. Just to pick out two examples, a masquerade would require large numbers of people to successfully keep a hugely noticeable secret and for no one to be in a position that's can easily break it (laughable at the best of times) and if the government is using funding to hide evidence of the supernatural someone will notice the money going missing and will eventually dig up evidence on it. Not to mention a masquerade would require the complete cooperation of every nation on the planet (laughs in realpolitik), and there is nothing stopping, say, China from deciding to cause social chaos in the U.S. by revealing the existence of the supernatural (or vice versa). The masquerade also has issues with having to do mental gymnastics through history in order to justify why superpowers haven't affected history beyond a few mysterious events which are basically low-hanging fruit for urban fantasy/science fiction settings like Tunguska or the Bermuda Triangle. Why didn't the presence of superhumans affect World War II? This was a problem in IRL comics where DC had to justify why Superman didn't just punch out Hitler given it was in character for his altrusitic, pro-freedom personality and came up with the solution that Hitler had the freaking Lance of Longinus. Or, to use American history as an example, where were the superhumans during the Civil Rights movement or the recent Black Lives Matter protests? Are you seriously telling me that not a single superhuman in the U.S. felt the desire to affect positive social change given their position of power, or that you had some young, politically left-leaning, disaffected 20-something superhuman who hates the system and cannot easily be stopped by the police decide to go on a rampage during the riots in 2020 (or any riot in history, really)? Which would in turn provoke further outrage and controversy or escalate the situation. Even if their powers were "only" Spider-Man level, their actions would still change history significantly. The other option is to tie superpowers into historical folklore about people with superhuman abilities. Urban fantasy already does this to some degree using a "stock catalog" of folkloric supernaturals like vampires and werewolves, and you could also potentially do that with historical narratives of saints, demigods, and other superhuman heroes. In this case you at least have an excuse for why people haven't made mention of the supernatural: "oh, they have, but it's just memorialized in folklore rather than being seen as real and common knowledge". But the problem here is that you are restricted in what you can do based on IRL folklore. Now, I know your question is: how powerful can a superhuman be without making a world that does not resemble our own history. Well the answer is: not very powerful at all. These kinds of things would come about even if you only had a small number of superhumans with rather unremarkable powers. At most you could have someone like Daredevil, who's powers are a bit odd but ultimately he's physically no different from a fit parkour-loving human. Even a small number of people who are "peak human" (as defined by Marvel), like Captain America, would massively distort history from what we know. The only way for this not to be the case is for superpowers to be so rare and so minor that you may as well not even call them superpowers in the first place. [Answer] ## Super Powers Mimic Technology & what can be done Anyway: If your super powers are such that the effects they have on the world are no different than the technology they match, then their effects on society will be negligible. You can dispute individual examples, but the general principle still applies. Take, for example, super-strength. In realistic terms, the 'hero' with super strength will be a normal guy who is super-strong. Most normal people aren't out fighting super-villains. This guy will get a job in a factory and possibly replace a fork-lift. Most likely, supers would be excluded from being professional athletes. So while it might be a slight economic dislocation to fork-lift engineers to have super-strong people, it doesn't really affect society in general (except for the whole CONCEPT of having supers). Police would respond to him like a guy who was carrying a gun - the poor shmuck will be a lot more likely to get killed by over-zealous police, but as a net, it isn't terribly disruptive. Now think about someone who can shoot fire from their hands at will. Again, except for the occasional mass-flaming that might occur as this person goes on a rampage, they will probably get a job in a power station somewhere heating water for a steam turbine. Mass-shootings are already a thing, and anyone who can get a gun or a car can do something similar in terms of violence. Flame throwers are a military thing (and this power will likely affect things like terrorism), and while this super has real military potential, it's less disruptive than you think. Flying moves into a murky realm, as people start to be able to do things that don't easily replicate what machines do. I think it's likely such people could integrate fairly smoothly, but everything from pizza delivery to security is at least partly affected. For something like this, a low prevalence of people with this sort of ability makes it an exception, and minimally disruptive. 20% of society flying means there is a real disruption to how things run, but we can adapt. Telekinesis is definitely disruptive, as people can now do things that are flat-out impossible. The social order gets strained as a kid can steal candy without walking into the store, or the disgruntled employee can strangle someone from a distance without leaving physical evidence. You need a different set of laws to deal with people who can do something that doesn't match what is currently possible, and it has serious implications for civil liberties. Compare that to someone who can use mind control. This completely disrupts the flow of society, causing a serious question about free will, justice, and economics, not to mention the ability to steal and rape and kill at will with no consequences. The whole ideals of something like democracy are founded on the free exercise of choice. This up-ends the principles on which societies function. Even one person with this ability means we need to prep our culture in a totally different way. Mom could 'become' an assassin tomorrow, and the society would need to be able to respond. [Answer] Genesis 2:2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. [![god rested](https://i.stack.imgur.com/6HFa7.jpg)](https://i.stack.imgur.com/6HFa7.jpg) <http://kansasartguild.com/workszoom/3341205/on-the-seventh-day-god-rested> Your supers are powerful. Very, very powerful. Maybe in the distant past they did a lot. Now they are not inclined to do much. The world unfolds as it will. [Answer] It depends a lot on the level of involvement the superpowered fellows decide to have. Scenarios that allow you to keep our world as-is include: * The Harry Potter world. The wizards essentially live in a parallel world with only minor contact on the government level, so we muggles just go about our normal lives. * There is a government agency keeping them in check ([Stross' Laundry](https://en.wikipedia.org/wiki/The_Laundry_Files), Men in Black). * We are actually secretly run by a conspiracy, and they usually try to keep it a conspiracy. They meet every year in Davos, or such. Occasionally the conspiracy leaks, perhaps because of rogue players (Buddha, Jesus Christ, the Nazis — which were eventually contained —, Facebook, Tesla). [Answer] TW/CW: Historical and Modern poor treatment of minorities, imperialism Burn The Wich! Realistically speaking, your superpowered individuals could be quite powerful, providing they still had the ability to be easily killed by angry mobs of pitchfork wielding peasants or political/religious leaders looking for a quick scapegoat. Our very own history is full of people being subjected to horrible fates over (very much alleged) supernatural status. Similarly, in recent history, neuroatypical people and strong minded women have been subject to stuff like transorbital lobotomies, An abhorrent fate and one all too likely for a superhero with psychic/mental powers to be subject to. Ignored by Enlightenment The more the post-enlightenment (and post-european-imperialism) world knows about superpowered individuals, the more likely they would have had to play a part in post "burn at the stake" era world events such as wars, political agreements, scientific breakthroughs that contributed to the state of the world now. The more science could have "overlooked" superpowers, the less society would have been effected by their presence. Fortunately there's a lot of ways this could happen. Medical science hasn't actually been all that good at focusing in on minorities in the real world, which is not great if you have mental health issues or are neurodivergent in any way, or are a woman. And there's a lot of stuff that non-european medicine has known about that european medical science ignored for a long time because they believed they were more enlightened than the rest of the world. There's a lot of stuff about this in episodes of the Sawbones podcast about medical history, I'd highly reccomend checking it out. Upshot of it is, it'd probably be pretty easy for superpowered individuals to go unnoticed or simply be classified as "circus freaks" by science, possibly even well in to the 21st century. This could be further exacerbated by superheros who have powers that are not "relevant" to the era they grew up in. Nobody's gonna pay much attention to the girl who can control electronic devices if "electronic devices" consists of a bunch of small scale experiments in people's studies brought out for expos and showing off at society meetings. Population Size, Documentation, Travel, and Communication The chances of running into a superpowered individual and talking to them would probably have to be quite unlikely, so with population size, the chances of running into a superpowered individual would increase in proportion to how many people there are in the world. The world's population has rapidly shot up in the last century, so logically there must be more superpowered individuals in the world. If superpowers are natural and a proportion of the population have them, then you're more likely to run into them today than you would in 1920, especially with similar exansions in travel and communications technology. Similarly if superpowers are aquired, the increased population and how easy it is for them to share how they gained their superpowers with others over the internet would mean there'd be more people to have superpowers happen to them, and more people seeking out ways to get superpowers. Things get really interesting if superpowers are hereditary though, especially if a lot of superpowered individuals were getting burnt at the stake just a couple centuries ago. Superheroes might have been way more common back in the day, and it's possible that mythology is representitive of this in your world. However if a lot of superpowered individuals were killed by people blaming them for their problems, and if superpowered individuals have carried around a stigma and thus had little opportunity to spread their superpower genes outside of insular superpowered communities, there probably wouldn't be many superpowered individuals in the world as of the modern era. It'd also mean that superpowers would be more common in cultures that accepted them more than everyone else, which would be an interesting flavour/dynamic. Breaking the Stigma The 20th and 21st century have been marked by various minority groups fighting for civil rights and public recognition and acceptance. While historically superpowered individuals might have been seen as freaks, dangerous to people around them (an accusation levied against LGBTQ people IRL even today) or in need of "curing" (an attitude many still hold toward Neurodivergent children today). With the push for civil rights, some superpowered individuals may publicly stand up for their rights and try to increase public understanding of them. Many others still will still feel the need to remain Closeted, or Mask to fit in with "normal" people, as they have always done. This could perhaps be a factor in how many superheroes in your world choose to mantain a "secret identity", to hide the fact they're different from their friends or family. One final thing to note in this regard is that as superpowers become more public and acceptable, people's will be able to talk about and understand their superpowers more, and will develop a greater understanding of them, so superheroes will become more familiar with their abilities and more capable of using them in the present, appearing to be "more powerful than they used to be" back in the past. No Gods, Only Supermen As noted above, this all only applies if your superpowered individuals die like the rest of us, feel pain like the rest of us and/or are otherwise vunerable to a lot of the same things as us. Invunerability type powers would not work in a setting like this, and things like super-speed, healing factors, time travel, etc, would have to have pretty clear limitations. Telekenisis can't stop bullets, mind control can't be strong enough to make people turn a blind eye to you indefinitely, and no matter how good your powers help you in fending off death, eventually you must be able to slip up or exhaust yourself. Your heroes can be powerful, but they must be mortal and face real danger from any typical humans they encounter. Final Notes Please note, autism is not a superpower, nor is it "the next step in human evolution" as certain pieces of media have claimed. I use it here only as a comparison tool. [Answer] 1. Your super powers would have to be scaled down and would have to mimic things people could already do. One of your guys can run faster than the fastest normal guy, but not break any of the barriers, like Flash can. Another of your guys can jump higher than the highest jumping normal guy, but not leap tall buildings in a single bound. One guy can lift a jeep, but not a humvee. They would be at least one order above the best Olympic or record holding atheletes, but well within the range of possibility, though on the extreme end obviously. Why? Plausible deniability. While people might be amazed at a guy that can jump onto the roof of your house they might not automatically jump to the conclusion that he was super human; just that he was "a really high jumper" or "really fast runner" etc etc. 2. Also, your guys might have super powers that are easily hidden. For example: invisibility, telepathy, telekinisis, weather control, teleportation... The list goes on. Powers that aren't too outlandish or too flashy or too overboard can still make for amazing stories. Think of how a spy might use powers. It would be kind of on the down low. But once you have Superman or Dr. Manhattan type guys I don't think there's a way to avoid it affecting the world. So keep the powers on the lower end and with limitations. [Answer] You first need to decide upon your point of divergence, chaos theory says that everyone conceived after that is someone else, so totally different. First change in 1805 and the US civil war is drastically different and might not even happen. While there were certainly historical pressures, they were in part brought about by the people with their own agendas, so different people, different agendas, different pressures. All different. Same thing for any war, pick a time a before the major figures were born and its a different war. Easier, harder, different alliances, different betrayals. All new. Major inventions likewise. Major religious movements, likewise. Now, how different would our world would be, if super powers came into existence in say 1962. The US might have won Vietnam, even without Iron Man getting involved, although he probably would have. Future wars are all different. Cold War was ongoing, but would end differently and at a different time. As for how powerful a super being can we have, without distorting everything else, assuming a sorta secret history, such as is common in urban fantasy...that depends upon their willingness to be secret. To step outside of fantasy, take the Mutineers Moon novel by David Weber, the three sides all have the ability to totally destroy the world and (absent the other 2) take it over, but not the motivation. So, god level threat, but unknown would be possible, plausible to be our world. Back to fantasy land, Dr Manhattan moves to the Himalayas and spends 60 years examining his navel, and we don’t see any difference. Daredevil decides to go on his crime busting spree, and things are different. He’ll have a voice and it will be a powerful one, because of his abilities. Think Muhammad Ali x 1000. Ignoring chaos theory, how much impact would they have? Even setting aside sports, it’s hard to see how someone with strength in the low thousands doesn’t become rich and successful. There is simply so much manual labor where they can do things in seconds that it takes more people and more machines so much longer to do that it simply wouldn’t make sense for them not to be in high demand and well paid. Superhuman senses like daredevil? He’s flown to disasters and well paid, not to mention inspections. Guy is rolling in the dough. 10’s and 100’s of tons? The worlds the limit. Even setting aside their economic impact, they can and almost certainly would, have cultural impact. For instance, consider anyone in the 10-25 ton range, and marijuana. They can be out walking in public and smoking a joint, and nobody is going to arrest them, simply because it’s impossible. In order to arrest them for smoking a joint you’d have to basically call out the army and go to lethal weapons as your first action. And there has been a lot of people over the last 60 years that have considered the drug laws some combination of stupid, racist, morally repugnant and classist. In our non-super powered world, the most most people can do is get arrested in protest, a super powered individual would simply be able to scoff at the law, while simultaneously being the underdog and hero to a significant portion of the population for committing the crime. A serious attempt to bring such a person in would justifiably be considered conspiracy to commit first degree murder under our existing laws. And would be a well documented, because you can’t move that kind of fire power around without lots of paperwork. On the flip side, to quote Saitama “Plus, I’m pissed, so anybody in my way..gets punched”. Rapist with their heads torn off? Innocent boyfriends accused of being rapist when their heads are torn off? Religion? Are they blessed by God, gods themselves, servants of Satan, angels, aliens, lots of changes, lots of impact. It just goes on and on, if they are openly here, big changes galore. ]
[Question] [ By some eldritch means I am able to heat matter (raising the kinetic energy of the matter's particles). I want to weaponize this ability, and need some guidance for its implications. The obvious use-cases would be to have an instant source of ignition, right? Is there something like an explosive effect I can achieve? What would for example happen if I suddenly heated the core of an iron sphere to 8000°K while the matter outside stays cool? How can the ability to heat portions of matter to high temperatures be used as a weapon, if I cannot affect the opponent's body matter directly and I need to minimize the number of heating instances and volume? Which secondary effect (i.e. explosions or something) would I be able to generate? Limitations: * I can only affect a small volume of matter, lets say 1m³. * At the moment I am thinking about capping the maximum temperature at 8000°K. What would change if that was not the case? Personal Amendment: Wow. I underestimated the implications severely. Thanks guys! [Answer] > > Is there something like an explosive effect I can achieve? > > > Oh yes. Given the handy metre-cube limit, lets think about the energy required to raise the temperature of that volume of liquid water at ambient temperature (say, 20 degrees C) to 8000K. Lets say it is a nice round tonne of water. Specific heat capacity of water is 4181J/kg, so you need about 335 MJ to bring the water up to the boil. Next you need 2.2564MJ/kg to convert that water to steam, which gives you another 2-and-a-bit GJ. The SHC of steam is more like 1996J/kg, so the next 3000-odd degrees will need another 6GJ. edit: as cmaster rightly pointed out, once you get to about 3000 degrees, water disassociates into hydrogen and oxygen. The average energy of an H-O bond in water is 461kJ/mol or 25.6MJ/kg, so that'll need another 25.6GJ\* to fully disassociate the entire tonne (also note that all those excited and solo hydrogen and oxygen atoms are gonna want to hook back up again, and that's gonna produce an exciting effect too!). Now, the SHC of monatomic gasses is nice and simple and related only to their atomic mass (because there are no complicated atomic bonds to wiggle about). Hydrogen gets a high 12kJ/K/kg, and oxygen gets a slightly more modest 750J/K/kg. For the remaining 4700-odd kelvin, the hydrogen will need 6.2GJ and the oxygen will need 392MJ. This is about half the energy needed if the water molecules were still intact. The total energy is therefore about 35GJ. The "tonne of TNT equivalent" energy measure used for nuclear bombs and the like is defined as about 4.184GJ, so the amount of energy you've just poured into the system is the equivalent of a 8.3 tonne bomb. This is is in the same ballpark as the the 11-tonne yield of the GBU 43/B [MOAB](https://en.wikipedia.org/wiki/GBU-43/B_MOAB) (which looks like [this](https://www.youtube.com/watch?v=MTMcYHrAdl4) in action [youtube link]) or its predecessor the BLU-82 [Daisycutter](https://en.wikipedia.org/wiki/BLU-82) which has a slightly more subtle yield of about 5-7 tonnes, shown in action here: [![Daisycutter blast](https://i.stack.imgur.com/eQaHH.jpg)](https://i.stack.imgur.com/eQaHH.jpg) Now, I don't think this magical instantaneous superheated-monatomic-gas transition is quite the same as explosive detonating (I'm carefully ignoring temperature/pressure relationships, because I'm lazy), but I would absolutely not want to be anywhere near it. That incredibly hot gas products will be under formidable pressure when it forms, and quite a lot of that energy you've poured into it will be released in the form of vigourous and rapid expansion. Boom. This could perhaps be even worse if you picked a material which took even more energy per unit volume to heat this much. There are a bunch of factors at play here, especially given the energy sucked up by molecular disassociation, so it isn't clear what would be the most destructive. Some form of stone is probably the winner here, but working out by how much it wins is quite tricky and left as an exercise to the reader. > > At the moment I am thinking about capping the maximum temperature at 8000°K. What would change if that was not the case? > > > At a "mere" 8000K, you're probably below the temperature at which a significant amount of the hydrogen and oxygen in the aforementioned water explosion would be ionised. Push the temperature to over 10000K though and you'll need another 1300kJ per mole of hydrogen or oxygen to knock off some electrons and make a nice singly ionised plasma. It might quadruple the total energy released in the blast compared to 8000K (but I'm too lazy to work the actual output). But what if we went even higher? Arbitrarily high temperatures and a magical effect that propagates at lightspeed. What could possibly go wrong? If you had access to the right kind of fuel, this sounds like a recipe for [Inertial Confinement Fusion](https://en.wikipedia.org/wiki/Inertial_confinement_fusion). > > Now I want to weaponize this ability, and need some guidance for the implications. > > > My recommendation is to make it much less hot, and affect much smaller volumes of material. I mean, seriously, just bringing stuff up to a few hundred degrees C is enough to start fires, deform or melt soft metal objects, render other objects unusable or downright dangerous (would you want to be wearing a helmet that has suddenly become 500K?). Your enemies would have to approach you nude (but for some asbestos sandals, perhaps) and emptyhanded. That seems reasonable enough, compared to town-flattening explosions. --- \* I'm not 100% sure on this; the bonds might just fall apart because they've already had enough energy pumped into them by heating, and there might be no additional threshold to overcome. If this were the case, the yield drops by about 2/3rds, but still leaves you with a respectable couple of tonnes. Also, the disassociated H and O will vigorously recombine to release that much energy afterwards, contributing to the fireball if not the blast. [Answer] One, instantly zapping a cubic meter of just about anything to 8000 K is going to be a major explosion. You can amplify the destructive effect to a specific area by applying more fun physics. For example, in a fantasy setting, a glacier fortress was built around a nearly impervious stone geode suspended in the glacier. Superheating the geode (through magical means) instantly converted the surrounding ice into gas, not only exploding but turning the glacier into a shape-charge that violently expelled the geode and disintegrating fortress into the sea amidst a rain of ice and stone. [Answer] # How does your superheating work? First, you need to decide on what your superheating skill is like. * Transmission speed: You said it transmits at the speed of light. * Transmission distance: Line of sight? Mental image of area? Anywhere on the planet? * Superheating time: How long does it take to get from 20°C to your 8000°C? Is it like 'bam' instantaneous, or does it take e.g. 1 second per 1000°C? * Radius of effect: You mentioned that it can be 1 cubic meter at the most. What is the smallest possible radius of effect? * Temperature control: Can your person vary how hot they make stuff? Can they decide if they want boiling temperature only (100°C), or are they always the full 8000K? * Radius control: Can your person vary how much stuff they affect? Can they decide 'nah, 1 cubic meter is far too big - let's go for 1 cubic centimeter'? * Reload time: how quickly can your person do a second superheating feat? Couple seconds? Hours? Days? Only if you can answer those questions, it becomes apparent how much damage a person with your ability can really do. --- # Damage Dealer ## Living Beings If you can do rapid shots of small targets, your superheating ability is going to be very effective against people (and animals). If you have enough control and are able to do precise targeting, heating even as little as 1cm3 to only 100°C will be fatal if you do it in the right spot (brain stem, heart). If you aren't as precise and heat one cubic decimeter to 100°C, that's going to be crippling in the short term no matter where in the body you hit with that. Heating 1cm3 to 1000°C will be fatal anywhere on the torso - the resulting steam (bodies are 80% water) will explode the person quite messily (and possibly steam-broil the surrounding people alive). The problem comes when dealing with multiple people - are you quick enough to target them before they get to you? If you are a one-hit wonder, you might refrain from targeting living beings when there are more than 1. For multiple targets, you might consider superheating 1 cubic meter of air. It will expand rapidly and create a blast wave that will can damage the body, hearing, and the surroundings (think of an explosion without fire). It will also result in a flash of very bright light (if you manage to heat it up to plasma levels - like a lightning strike) and potentially blind your enemies. ## Transportation How effective you are against transportation vehicles is decided by how precise you can be, and whether you know where the engine is in the vehicle. Superheat any part of the engine - it will not work anymore and prevent your enemy from getting away. With something as large as ships, you might consider superheating some of the water right beneath the ship - the resulting explosion will damage the hull severely and hopefully sink it. ## Structures Here, it comes down to how well you can target without line of sight, how far away and how quickly you can superheat matter. To get an order of magnitude of how powerful your ability is, I have crunched some numbers. One kg of water takes about 4.18 kilo Joules to heat 1K. One kg of TNT has an explosive power of about 4.6 MJ. So, 1000kg of water (= 1 cubic meter of water) needs approximately the energy of 1kg TNT to heat for 1°C. This changes once the water turns into steam to where the energy of 1kg TNT is sufficient for heating 1 cubic meter of steam for about 2°C. Of course, that also changes with the pressure (which rises the hotter the stuff is), but this is just a calculation to get a ballpark figure... Result: heating 1 cubic meter of water to 1000°C takes approximately the same power as 1 ton of TNT. If you get the complete explosive power out of the water probably depends on how quickly you can heat it. A tomahawk cruise missile has about half a ton of TNT in power... See Wikipedia <https://en.wikipedia.org/wiki/TNT_equivalent#Examples> for more examples of what you can do with your power and how it compares to atomic bombs e.g. ## Technology If you have a lot of technology around and manage to superheat air to plasma levels, you might be able to create an EMP effect. Plasma is an electric conductor, no matter whether the original material was or not. It might result in some interesting electromagnetic impulses when it explodes outwards and temporarily disable electric devices in the area. Maybe it is even strong enough to fry delicate circuitry. [Answer] Afaik, 8000K is significantly higher than the temperatures reached by any chemical reaction. As such, instantaneously heating a ton of whatever matter to 8000K definitely gives a larger explosion than a 1 ton TNT bomb. The military will be very interested in your skills. If we remove that limit, the explosion gets larger. This is proven by all the nuclear bombs out there: All they do is to heat their core to the multi-million degree range, and let thermodynamics turn that energy into destruction. The military will be extremely interested in your skills. So, basically, you can be as destructive as you allow yourself to be (by capping the achievable temperature and heatable volume). Take care not to be too close to the explosions you create, though. [Answer] 1) How can the ability to heat portions of matter to high temparatures be used as a weapon, if I cannot affect the opponent's body matter directly and I need to minimize the number of heating instances and volume? As you have been aswered by @AlexP, you can case explosions up to tons of TNT equivalent. It is very dangerous to youself as you cann't know for sure that say, this iron sphere has tangsten core or is hollow: result would greatly vary. It would be safer to just create a denial zones with heating earth and disable any mechanisms (cars, helicopters, firearms) with overheating or melting critical parts. 2) Which secondary effect (i.e. explosions or something) would I be able to generate? The major effect you can case beside explosion is heat radiation. If you just slowly (i.e. not explosion-like) rise the temperature of iron (steel) sphere to melting point (about 1000 C), or, better, make lava from rock - the heat radiation would cause burns and ignite flamable materials (including cloth, hairs and flesh) in vicinity. Other effect would be a small [firestorms](https://en.wikipedia.org/wiki/Firestorm) and fire tornados. Also you can lit your way in the dark by just heating up some small object to about 600-700 C and holding it with a stick. In general it is quite a destructive ability. upd: I would suggest not to breake first law of thermodynamics much and make any heating to cause smth in vicinity cooling (down to absolute zero). This would make this "Maxwell Devil" even more destructive! You would be able to rise down any construction by heating one part and cooling another. ]
[Question] [ My question was raised by [this post](https://worldbuilding.stackexchange.com/questions/144607/crash-landed-aliens-political-repercussions). > > Aliens crash-land at the Boston Airport (ie, in the United States). [...] The potential benefits of being able to reverse-engineer their tech alone is enough to propel the US to a new level of technology. > > > This happened in the early 21st century. After some years, the US have extracted enough knowledge from the spaceship and its passengers to create a huge technological gap between them and the rest of the world. Assume (if that makes any sense) that this gap is similar to the difference between WW2 and 2000's techs. I guess that all this knowledge will leak at some point (intelligence services, private companies, bribes, retro-engineering of latest American devices...). So the question is, # How long before all other (developed) countries get to the same level of technology? If you have to address the resulting political transformations too much, then this question may be too broad... We can also assume that a part of this technology will be classified and only available to the army, and that the US will use their advanced weapons in conflicts. But since other countries still have "regular" nukes, the US cannot get into a world war with impunity neither. [Answer] ### If by "the US", you mean the general population, you're out of luck It's (probably) feasible to keep certain findings secret if you stash them in a safe, bury that in concrete and tell no one about it. The hard part is making use of your knowledge without giving it away. In an age of more-or-less free travel and wireless, anonymous data transfer, anything you sell, mass produce or make accessible to regular citizens will spread almost instantly, no matter how jealously you guard it. If you were able to reverse engineer the alien tech in the first place, others will be able to figure out your adaptation of it with far less effort. ### Science is a global effort A big part of technological progress is knowing what's possible, and in which direction you should focus your efforts. Going back in time 50 years with just a list of "lessons learned", no details, would be huge. This, again, is not something you can keep secret from the rest of the world very easily. If they know you have it, half of your advantage is already gone. Of course, the devil's in the details, and someone has to do the actual work of figuring them out. Contrary to popular fiction, this is usually not done by a lone genius in a basement somewhere, it's the result of a lot of moderately smart people making incremental progesss and "comparing notes". Militaries are sometimes able to build on top of that (or rather, private companies do and then sell the results to one or more militaries), but they're never too far ahead of the curve. What this means for reverse engineering your alien tech is that the speed at which you'll unlock it is inversely proportional to your secrecy. Every researcher you give access to this project is a potential leak, as is whoever supplies their resources. And once there is a leak, your small research team has to compete with the rest of the world. ### Testing weapons is probably fine, waging war is risky The US are already known for building and test firing lots of prototype weapons that, while the underlying tech is common knowledge, haven't been implemented at that scale anywhere else. Assuming they'd gain enough of a technological edge to make these weapons actually superior to established alternatives, there would be a number ways to profit: * Intimidation: The US and NATO are already a major military power, so, bragging rights aside, the new weapons wouldn't really allow them do do anything they could not do before. That being said, misinformation about what your new tech can actually do might give you an edge in negotiations. * Intelligence: If you keep it secret, you can use the advanced tech to spy on your enemies and wage a (dis)information war. They'll eventually figure out that you have some kind of unfair advantage, but without access to your facilities, there's not much they can do to properly analyze or replicate it unless they beat you at your own game. * War: Large scale production of even a conventional new weapon is ridiculously expensive. Even more so for your alien tech. The effort of modernizing your entire military in a limited timeframe will only pay off if you fight, and win, a big war. Assets will get lost, and the rest of the world will be highly motivated to steal or reverse engineer your tech, so you quickly trade that technological advantage for a more dominant position on the globe. If you can somehow prevent other superpowers from retaliating with nukes etc. In conclusion, the more use you get out of the tech, the faster it'll spread. If your goal is to maintain technological superiority, your best bet is to use it sparingly, e.g. for syping on other powers. [Answer] I think the best way to look at this is by seeing how long it took China to catch up to the USA's technology. 20-30 years ago, the average level of technology in China was 50-100 years outdated by Western Standards, now they have pretty comparable technologies in most areas of life; so, if you are beginning your narrative from any time period before 2000, that would be a reasonable time frame. That said, we live in an age of hacking and surveillance where national secretes are much harder to keep than they once were. It only takes one researcher opening a bad email for someone else to gain access to an entire office building worth of research. I would not be surprised if half a dozen countries had at least some of what the USA discovered from the wreck, before they are even ready to go into production with it. [Answer] Skipping a bunch of me complaining about the complexities behind this, the answer is something in the frame of "they can keep their edge almost indefinitely if it gives them enough of an economic advantage". Short version if it costs too much to retool for the new technology it won't be adopted if the US is far enough ahead that other nations can't afford it. Look at the gap that developed between the US and USSR after the space race. It wasn't until relatively recently that Russia was able to catch up in the computer sciences through access to cheap components produced by outsourced offshore vendors in sympathetic countries. This does assume an initial manufacturing monopoly, if they outsource production they'll lose almost immediately. [Answer] I don't think there will be any appreciable delay at all. There are to many variables at play to answer precisely (and I assume the question will be marked as opinion based soon). But my overall line of reasoning goes like this - in this scenario the US doesn't have much head start over other nations, they do not have the infrastructure in place to produce alien technology devices at once. In short, the more secrecy there is around the alien technology, the slower the rate of adoption in the US itself, so the nation gets less benefit from it's new technology. The less secrecy, the faster it spreads. The best use of this technological superiority, IMO, would be not trying to conceal it, but to patent it - but then you will have it produced in China and used globally the next morning (although US would profit economically the most, I guess). UPD: the main point I see here is that initially US itself is in the position of a developing nation - they have reverse engineered alien blueprints and no manufacturing base to produce them. To use this technology, US would need to invest into overhauling its manufacturing base first. So, using this alien technology will get expensive before it gets profitable. And in order for it to get profitable you need to actually sell it, and other countries to buy it. So in this 'peaceful' scenario the whole world gets technology, though US profits. If the technologies are going to be used only for military, US is going to have problems with its NATO allies unless it shares. I do not think there are many pieces of technology your would want to go to war with the whole world. And barring some comic-book superweapon, most military technologies take decades to integrate and implement. The only way some alien technology can assure swift and decisive technological and military dominance is the case where it is its own manufacturing base - something like self-replicating nano-robots. And that is not 50 years worth of technological difference, it's magical philosophers stone for all intents and purposes. [Answer] Best case: Egypt got the wheel about 1,000 years after Mesopotamia. Similarly, China managed to delay European competition in porcelain and silk by centuries. Both of these gaps were before the existence of aircraft and electronic communications. Worst case: The U.S. allowed Soviet spies to get key information from the Manhattan Project, so the U.S.S.R was only about 5 years behind in the nuclear race. [Answer] ## Not very long after it gets used. There are basically two parts to technological progress. First, the actual ideas and concepts. Second, the enabling factors that allow you to actually execute on the ideas in practice. Reverse engineering alien technology will only give you new ideas and concepts. It will not change the enabling factors. As such the technological edge gained from this would entirely be based on new ideas and concepts. Which your competition could easily reverse engineer as soon as you start using them. Or that can be copied thru espionage as soon as the competition gets aware of them. ## But... That said in the early 2000s, the China still had not caught up economically to the extent it now has, so the US and its allies would have been in much better position to actually use the new technology. If the technology really was revolutionary this would have created an economic boom within the US, Canada, western Europe, Japan, and so on. China, India, Russia, and so on would not have been in the position to capitalize on this boom. The increased resources from the economic boom in turn would have enabled the affected countries to apply the alien technology to even greater extent. Which would have resulted in even further geographically limited growth. The question implies that the UFO contained few decades worth of technological progress. If we assume decades of accelerated growth and then corresponding decades of effort by non-boosted countries to catch up, it adds up to "less than a century" of technological edge. But lots of things change within a century. For example both China and Russia would almost certainly change their political course significantly if "catching up" would suddenly become that much harder. They'd seek to share the spoils by becoming closer to "the west". And if "the west" responded to these promising signs by opening up their technology, which happened with China, it would make catching up easier. Which would turn policies back to being more assertive... And so on. It generally is not useful to speculate beyond few decades. ## And also... You only mention reverse engineering but we can additionally assume that the UFO might contain limited amounts of resources we cannot replicate. Alien alloys, "magic" crystals, working devices we cannot reverse engineer fully. This might give the US a unique "secret weapon" style edge that cannot be copied or caught up to in the foreseeable future. Using this is probably a bad idea since you would essentially be saying that "the US is superior because I say so" but limited amounts of this would be realistic and even large amounts can work IF it is part of the premise of the story. David Weber's Safehold books do this as do lots and lots of alternate world stories. So it can be made to work. And giving your people a super secret cool toy or two might be fun. [Answer] Possibly for surprisingly long (centuries), but there is a twist to get there With the discussion concerning time of a released technology to be stolen or copied I fully agree. This indeed tend to be a short time. But there is a trick. Would all tech be released on the day 1? I don't mean even usual procedure in all respective conspiracy theories of gov suppressing some live saving tech. There is more serious issue, whether one can actually understand not mentioning implement some technologies. Let's say someone gave Renaissance era people blueprints for stealth bomber and graphic cards factory. While Leonardo da Vinci may be delighted, it would be a bit tricky to actually make this stuff working. Under best case scenario it would require tedious making step by step each moves. Moreover, unless the donor really plans everything in advance, the user may stumble on such issues like "What the hell is electricity???" and actually have to fill some gaps with his own research. So assuming that the power: * perfectly guards its treasure trove * slowly releases its new discoveries every few years it may indeed keep tech edge for really long time. [Answer] Not very long at all Let me us an example. After the U.S. successfully used the atomic bomb as a weapon, they became very interested in keeping the technology to themselves and maybe at most their closest allies, planning to use nuclear technology to give them the ultimate military advantage in the post-World War II world. They were very interested in keeping it away from the USSR, because they saw the writing on the wall and realized that the next coming conflict was going to be between the U.S. and USSR largely due to these two powers being the least devastated by World War II. How long did the U.S. manage to maintain this technological edge? [They managed to keep a monopoly on atomic bomb technology for less than three years, largely because of espionage passing nuclear secrets on to the USSR.](https://en.wikipedia.org/wiki/Julius_and_Ethel_Rosenberg#Espionage) ]
[Question] [ What kind of planetary conditions would be required to make a place with really intense winters and summers? Is it even possible? For example on the poles they can go with out the sun for half a year in the winter but even in the summer the angle of the sun is comparable to evening near the equator, so it never gets warm Clarification, 25°C average in summer, -40°C in winter [Answer] Nothing says the orbit of your planet has to be as close to circular as the Earth's. [All orbits are elliptical](https://www.windows2universe.org/physical_science/physics/mechanics/orbit/ellipse.html), with the sun at one of the two foci. (Even a circle is an ellipse, it just has both foci in the same space). The [eccentricity](https://www.windows2universe.org/physical_science/physics/mechanics/orbit/eccentricity.html) of the ellipse is a measure between 0 and 1 of how stretched out it is; if it is very small the orbit is nearly circular. Earth's eccentricity is 0.02. Regardless of any axial tilt; if the orbit of your planet is stretched enough, it will be close to its sun for part of the year (closest at perihelion) and far from its sun for part of the year (furthest at aphelion), and these can correspond to a hot summer and cold winter, respectively. On Earth, this is a variation of just 3%, but it can be made longer. No elliptical orbit is off limits; Haley's comet is in orbit around the Sun, and it's distance varies from 88 million km to 5.2 Billion kilometers; i.e. inside the orbit of Venus (108 million km) to outside the orbit of Neptune (4.5 billion km); with corresponding super-heating and deep freeze. So just a very little bit more eccentricity (stretching) of your orbit can do this, it doesn't have to be extreme. I don't have the formula for computing the solar energy reaching the planet (should follow a square law I think) or for translating that into average temperatures; but that is where I would take the research next. Perhaps other readers know this off the top of their head. I think this is the least exotic method of increasing the extremes between summer and winter, just make the planet about 10% further away from its sun in winter than it is in summer. [Answer] If you want averages of 25 degrees C during summer and -40 degrees C during winter, you don’t really need an axial tilt which is higher than that of the earth, or even a higher eccentricity. Indeed there are real places in Siberia which already have averages comparable to the ones you prescribed. Perhaps the closest such climate is [Yakutsk](https://en.wikipedia.org/wiki/Yakutsk#Climate), with a July mean of 20C and a January mean of -39C. Other comparable ones include [Oymyakon](https://en.wikipedia.org/wiki/Oymyakon#Climate): January -46C, July 15C [Verkhoyansk](https://en.wikipedia.org/wiki/Verkhoyansk#Climate): January -45C, July 17C [Seymchan](https://en.wikipedia.org/wiki/Seymchan_(urban-type_settlement)): January -38C, July 16C Notice that the key feature of these climates is the tremendous continentality caused by the lack of nearby water bodies, which allows the Siberian high to form and thus allows for such massive seasonal fluctuations. Hence, one possible solution to this is just to make our own planet more continental (e.g. get rid of the Arctic and Pacific oceans). All climate data comes from Pogoda Climat: [1](http://www.pogodaiklimat.ru/climate/24266.htm) [2](http://www.pogodaiklimat.ru/climate/24688.htm) [3](http://www.pogodaiklimat.ru/climate/24959.htm) [Answer] The answer by [Jannis](https://worldbuilding.stackexchange.com/users/55267/jannis) explains that increasing the axial tilt of your planet will do this. The other thing that will help is a large continent at mid-latitudes. "Large" so that the middle is a long way from the moderating effect of the oceans (water heats up and cools down much more slowly than rock). If it is too near the equator there isn't much variation in sunlight over the year; if it too near the pole there isn't enough sunlight in summer to get it hot. Not very coincidentally, Minnesota (with a range of ±40 C) as pointed out by [Dave Sherohman](https://worldbuilding.stackexchange.com/users/18547/dave-sherohman) is right in the middle of the North American continent at about 46⁰N. [Answer] As you might know: the seasons are related to the earths not linear axis. [The earth 'flies' like that around the sun](https://en.wikipedia.org/wiki/Axial_tilt): [![](https://i.stack.imgur.com/FUmkE.jpg)](https://i.stack.imgur.com/FUmkE.jpg) The effect of the axial tilt means more and 'stronger' sunlight for summer the summer season, while less for winter season. If you shift the axis much more, seasons will get stronger and with that more area has the polar night and day. Hope it helps :) [Answer] Per Amadeus's answer, increasing the planet's orbit sufficiently should, indeed, make for warmer Summers and colder Winters. (This should be a comment but I'm a little short of the requisite reputation for it.) However, it must be noted that seasons produced in such a fashion would not be of equal length. Haley's comet, for example, spends well under a tenth of its time anywhere even near the Sun. This need not be a problem, of course, but it must be noted. Summers on such a world would be unusually short and the Winters excessively long. You may be able to counter this but only by softening the extreme changes you are after. [Answer] For an exotic choice, your Summers and Winters could be literally day and night. Venus's day-night cycle lasts 116.75 Earth days. You could do the same for your world. Six months of nighttime and six months of daylight would make for an fascinating--albeit deadly--world. You'd need ways to keep the place halfway livable as I expect this would result in temperatures far more extreme than what you want. Perhaps something like the jetstream but as a river carrying warm waters into the night side and cold waters into the day side? Or the world could be an archipelago and allow the entire ocean to flow in circles. (Do note that I've no idea if the ocean would actually behave this way.) [Answer] Another possible twist: a planet rotating around double star. Given a right orbit and the fact that one star is going around another in the same time, you can get superhot seasons when the planet is close to the "outer" star and supercold seasons when it's on the opposite side from the main star. [Answer] Another interesting option would be having an elliptical orbit mixed with a fast [precession](https://en.wikipedia.org/wiki/Axial_precession#Effects)) or even a variable axis tilt, not sure if this is possible). This has been used in [Tom Godwin's "The Survivors"](https://en.wikipedia.org/wiki/The_Survivors_(Godwin_novel)) --- you can have two different cycle mixing: for example, a series of mild seasons, corresponding to low tilt, followed by a period of harsh one, with high tilt in the case of variable tilt. In the case of a strongly elliptical orbit, precession can change if the northern winter solstice occurs when the planet is nearer to the sun or farther away --- that can create a difference in how harsh are seasons between the two hemispheres (that could be interesting in itself). F See also [A Planet Where The Four Seasons Occur Multiple Times In One Year?](https://worldbuilding.stackexchange.com/questions/128505/a-planet-where-the-four-seasons-occur-multiple-times-in-one-year) [Answer] We call it Mercury... (Actually you want much less extreme than this, so you should have no problem scaling it back by a lot.) <https://solarsystem.nasa.gov/planets/mercury/in-depth/> > > Temperatures on the surface of Mercury are extreme, both hot and cold. During the day, temperatures on Mercury's surface can reach 800 degrees Fahrenheit (430 degrees Celsius). Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to minus 290 degrees Fahrenheit (minus 180 degrees Celsius). > > > * Variable distance orbit...but this is actually less important than: * Thin atmosphere -- this way the night side can get really cold. This is true for even objects like Earth's moon. * Reasonably close to the sun, so you get HOT and cold... if you are further out like Pluto, you just get "really cold" and "even colder". [Answer] A point to note about using high-excentricity orbits is that winters will last longer than summers due to lower orbiting speeds farther from the star; a classical example of this is Verne's [Off on a Comet](https://en.wikipedia.org/wiki/Off_on_a_Comet). ]
[Question] [ It's a common little tidbit in most fantastical magic novels to have little men and women in funny hats flinging ice cubes(albeit a little more dangerous than ice cubes but it's practically the same) at each other. I'm not questioning their choice of projectile. If anything is shot with enough force it will cause damage, for example, an indestructible teddy bear. Rather I would like to know what advantages a melee weapon(spear,sword, knives etc,etc,etc) that is close to the temperature of [Absolute zero](https://en.wikipedia.org/wiki/Absolute_zero) which is −273.15°Celsius / −459.67°Fahrenheit would have. This is provided that my rabbits can hold the weapon properly and use it properly. Also assume that the weapon is always at the temperature of absolute zero with the help of handwavium, the pointy part, not the handle. And assume that the weapon still functions as a weapon, we can't have it breaking in the middle of a duel. Now, regarding the weapons structure/material. I'm not sure whether this would affect the question but I'll state it anyway. I would assume most metals would shatter like glass at such temperatures so I would assume it would be made of ice or solid nitrogen or solid helium. But since its starting to sound like a stupid idea and the temperatures are already infeasible, assume that the weapon is made of unobtanium and handwavium. What advantages would my Winterwrath wielding rabbits have on the battlefield or duels? And before I forget, it's in a medieval-esque world. Firearms are still superior and bringing a knife to a gunfight is stupid unless you run out of bullets. Oh, the rabbits don't matter much, it's just more fun to have rabbits instead of humans. [Answer] They could set their enemies on fire, and power their artillery. Hear me out. A perfect heatsink of that kind would liquefy the air around it. It would solidify if you left it in one place for long enough, but liquid will do. 21% or so of the atmosphere is oxygen, which means that these creatures would have an unlimited supply of liquid oxygen available to them. The nitrogen is almost irrelevant; all they have to do is stand their swords on end and 'stir' them above a bucket; the air around would condense and drip off and they could rapidly have a gallon or so of LOx to soak rag balls in. Being cut by something cold is really not that much worse than being cut by something room temperature, and the accretion of ice on the blade (remember, there's a lot of water vapour in the air) would make them heavy, blunt and unwieldy. I suspect that this technology would mostly be used to make really, really big explosive devices and rocket fuel. The fog previously mentioned would also be handy, both militarily and as a permanent source of fresh water condensed from the air. It would also revolutionise logistics, since transporting food long distances while keeping it fresh would be trivial; no small thing for a medieval society. (I would agree about superconductors, but nothing has been said that implies these creatures have electricity. Or, indeed, physics. What we in the 21st century could do with a material at 0K which exhibited an infinite heat capacity is almost beyond imagination.) [Answer] tl;dr: You now have a universe-destroying weapon. We need to clarify what Absolute Zero really is. You can treat it as a temperature, but it's really more of a concept: matter having zero energy (theoretically, it still won't, because of the uncertainty principle and the zero-point energy that comes from that). So for your weapon to maintain a "temperature" of absolute zero, it must be somehow discarding all energy which comes into it from normal heat transfer from its surroundings. Physically, it's regarded to be unattainable because of this. Let's say that you can magically hand-wave away that, and this weapon can always maintain absolute zero. To come up with a rough analogy, you now have a thermal "hole" in the universe, into which all heat will eventually flow and disappear. Temperature change relates to the difference in temperature between two bodies. The fun bit here is that one of your bodies will never heat up, so everything around it, in contact with it, must always be cooling due to convection. Well, it will always be losing heat to the weapon, it could still gain heat from some other surface it is also in contact with. But that other surface would then be transferring heat energy to it (and losing that energy in the process), which would cool the other surface down, and eventually both would still be losing heat to the awesome power of the Absolute Zero Weapon. And that would continue to happen. All energy would keep flowing in the direction of the Absolute Zero Weapon, and it would slowly siphon all the heat from the universe. If you put some kind of magical restriction in place, stopping heat transfer beyond a certain radius, it would remove all the heat energy from that radius. No matter what, you're creating something that is capable of completely, totally, and absolutely destroying anything it comes in contact with (up to and including the universe itself). Advantages: guaranteed to destroy your enemy. Disadvantages: will destroy you, too . [Answer] As a melee weapon, this actually doesn't really confer much effect. Unlike hot temperatures which can go to the extreme and create almost instant incinerating effects, cooling is a lot harder to do and requires a mixture of prolonged contact and/or a cascade of coolant (e.g. immersing in a stream of liquid nitrogen rather than a pool) to achieve a rapid effect. At best your blades might have a cauterizing effect that may make their wounds less severe. Arrowheads or bullets, on the other hand, if they continued to suck the heat out of their target by simply resting inside them, could be very dangerous indeed. A handwavium splinter-based weapon, even more so. Your rabbits might have more luck turning their cold handwavium to superconductors. Temperatures like that enable fun magnetic manipulation that could lead to giant electromagnets for countering metallic armour (especially in a siege situation), maybe primitive coil guns, or if you want to be fancy, multi-piece blades that are held together with magnetic fields or telescopic spears. [Answer] # Fog Your bunnies would shield themselves in a cool fog and hide from their enemies. It's a good thing that they have fur because they'd get pretty cold standing/hopping around in that supercooled air. Stabbing wise, the wounds would freeze-dry the flesh, so slashing flesh wounds would not bleed and also wouldn't hurt that much (nerves would freeze, so cuts would be numb). Rabbits would be better off with traditional edged weapons at room temperature, I think. Unless they like frozen sushi. [Answer] # Cold burn Otherwise known as frostbite can occur. See <https://en.wikipedia.org/wiki/Frostbite> for more details. It is more likely that the solid air on your or weapon would be left behind on wounds, this would result in death of the surrounding skin cells and potential freezing of blood and tissue fluid. This means that attacks from this weapon could be deadly, it would have substantial intimidation effects after enemies see its effects. And who expects a spear to shoot out sleets of solid air. [Answer] "Science-based": they could work as a bombs. (Un)fortunately there are many problems with such swords, as they completely disobey laws of physics, yet you still want us to somehow use them. They are terrible in the sense that you can't really apply logic and real world for them, and even if you could(e.g. just very cold sword), this wouldn't help much anyway. Let's ignore how stupid such idea is and try to use it anyway. The temperature is so cold that it would freeze the air itself. This would kill our bunnies real quick, so let's assume that they have a scabbard that protects outside world from freezing. Bunnies would be quite fit. They would have even fitter commandos that would go to the enemy sites unnoticed, and take out their swords all at once. This would cause something like an explosion(I believe it'd be called implosion?) that would make everything around freeze, starting from air. Send this commando into enemy base, and in no time you have it frozen. This is also terrifying as you have virtually no means to undo it, so reclaiming such ground or rescuing people isn't an option. The only problem is that theoretically, after some time, the cold would get to you. But I'm sure some handwavium or magic could trap or limit the swords power. [Answer] How cold can you make something? 0K is cold, but it doesn't describe how cold it feels. Something with 0 heat capacity but 0K would not cool down anything. It would be a perfect mirror-finish and be a perfect insulator. Suppose we made a 0K object that was the opposite of a perfect insulator. A perfect heat-suck. Every particle that touches it loses almost all kinetic energy. The air turns to solid. Maybe to make it useful, it isn't quite zero, and it actually pushes the resulting solids away so they don't stick or somesuch. How far away is does this energy-sucking aura go? The blade isn't really stuff at this point (as even stuff isn't stuff). We could imagine a blade that cooled things off rapidly within a range of a few mm or cm, unless contained by handwavium. The hilt and scabbard would contain said handwavium, preventing the rabbit from being frozen. Swung through a target, it would freeze the flesh. This would prevent immediate bleeding, but effectively kill everything near the blade. If we add in the repulsion thing, where it prevents solids from being solid, it could cut through the frozen flesh as if it wasn't there. So now you have a weapon that is an "ice blade". It generates flakes of frost when exposed to air. When it cuts into something, it leaves a clean cut with frozen edges. It behaves a lot like you'd expect a "frost blade" to behave like. The blade cutting strait though flesh is most of the damage, but the whatever radius of leftover frozen flesh both increases the long-term damage and reduces the short-term damage (as the target doesn't bleed out ... until it defrosts). The weapon is an infinite black with frozen flakes of "snow" falling off it. This "snow" mostly frozen air. The rabbits have a long handle and a large guard. Their scabbards have a "funnel" of handwavium at the entrance to keep the blade away from their flesh. "Grabbing" the blade leaves you with a frozen hand that dies as it thaws out. [Answer] The very cold temperature will froze everything around, including air. Assuming the blade material is nonstick, the frozen air would be projected in the direction of the blade trajectory, allowing some kind of distance fighting ( your character could make some nice choreography and iced air would cut the enemy a few meter further. [Answer] I think that the sword could easily penetrate most armors and cut through most things like a knife through butter, because most metals become brittle when super cooled and everything organic just becomes extremely easily breakable. ]
[Question] [ On a generation ship, the people living on it need oxygen, lots of oxygen. More than they can realistically carry, thus a generation ship must be able to create breathable air from relatively common materials and elements found in space. How does a generation ship provide oxygen to the people inside it? What common elements can the ship rely on to provide, let's say, 100 million people with breathable air for an indefinite amount of time? [Answer] Closed cycle life support systems (CLSS) are the only way to go for prolonged space travel or even space stations and colonies orbiting a Sun. As pointed out, the real problem is making up losses since no system is ever going to be 100% efficient. One of the key elements for any sort of CLSS needs to be water. Water is essential for the life processes of everything aboard. The waste water stream is going to be processed to provide nutrients for the plants (both algae and food plants), then the cleaned water is going back for drinking and other uses in the human/animal side of the system. So the ship needs millions of litres of water for the system. Extra water can be carried to buffer the system, act as radiation shielding or thermal heat sinks and other uses aboard the ship. One of the most convenient ways to carry all this water is as ice. [Anthony Zuppero](http://www.neofuel.com/iceships/) outlined a simple design in the shape of a doughnut or tire which uses ice as both a structural material and as the reservoir for all the water needs of the crew. Should there be some sort of disaster which cripples the CLSS, the ice can be melted and electrolysed to release hydrogen and oxygen, with the oxygen being added to the atmosphere. As an aside, the real danger in a closed environment isn't running out of Oxygen, but being poisoned by a buildup of CO2. [![enter image description here](https://i.stack.imgur.com/oJpVq.jpg)](https://i.stack.imgur.com/oJpVq.jpg) [Answer] The most common solution to this approach is to try and mirror Earth's biosphere. Since you need water, food, and air, you need a solution that provides all 3. Hydroponics (and its closely-related twin aeroponics) is an excellent way to provide food and air: You grow edible plants (especially those with green leaves), which as they are growing consume the CO2 you exhale and turn it back into breathable oxygen. Algae and certain bacteria are showing a lot of promise currently for filling this role very well. Water is recycled and reused, just as it is in Earth's water cycle. You can supplement this with mechanical and/or chemical processes that also break down exhaled CO2 and release the oxygen back into the ship's systems. Unfortunately, no man-made biosphere can possibly be 100% efficient, nor can any pressure vessel be made 100% sealed, so you will have to additionally carry tanks of compressed oxygen to replace losses on your travels. You will be able to collect small amounts of hydrogen and oxygen with something akin to a [ram scoop](https://en.wikipedia.org/wiki/Bussard_ramjet), though without onboard recycling of CO2 and water you will not be able to collect enough for anyone to survive. If your ship is traveling to the next star system, that's pretty much it; if you can stop at other stars along the way (which will always be a massive detour, but for a long enough journey may nonetheless be required), you can probably harvest base materials within the system, but it's going to be hard, expensive, time-consuming, and rely on carrying a lot of heavy equipment that is just taking up space and mass for greater than 99.999% of your total journey. [Answer] ## The Ship A generation ship carrying one million people for an indefinite period will need to carry or generate a minimum of 550,000,000 litres of $O\_2$ per day. Mixed to match Earth atmosphere ratios, in which $O\_2$ accounts for 21% of the air, that's a minimal atmosphere capacity of 2,620,000,000 litres. Assuming a classic rotating cylinder ship, that is a cylinder roughly 3,000 km long and 1,050 km across. Such a ship would have an internal surface area of 11,700,000 $km^2$, so something between Canada and Antarctica in size. Again, that is the bare minimum – meaning zero redundancy, zero waste, zero loss – to support one million air-breathing adults. ## The Interstellar Medium 99% of the interstellar medium by mass is gas, of which 70% is hydrogen and 28% helium. Oxygen makes up trace amounts – less than 1,000 molecules per $cm^3$ in the best case scenario; not enough to harvest en route to make a difference. Barring fusion of those H and He molecules, you're going to have to bring all the oxygen you need with you, in one form or another. ## The Oxygen Cycle Fortunately, people – and plants – also need water to live, and water has oxygen. To keep these people breathing you'll have to simulate or approximate the natural [oxygen cycle](https://en.wikipedia.org/wiki/Oxygen_cycle) found on Earth: [![Carbon-Hydrogen-Oxygen Cycle](https://i.stack.imgur.com/Fhzf4.png)](https://i.stack.imgur.com/Fhzf4.png) Specifically the Hydrogen and Oxygen steps. The only inputs this system needs are photosynthesis-permitting light, which can be achieved artificially, and topping up any lost hydrogen. ## Grow It From the same Wikipedia article linked above, the carbon cycle accounts for 99% of the oxygen, stored away in rock; your ship will need as much oxygen produced and cycling as possible, and cannot justify the space and mass a crust-substitute quantity of rock and minerals would require, or the time, so this step will need to be bypassed. The "light-dependent reaction" in the diagram above is photosynthesis – plants combining $6CO\_2$ (carbon dioxide) with $6H\_2O$ (water) and light to produce $C\_6H\_{12}O\_6$ (sugar – glucose) and $6O\_2$ (oxygen). On Earth the Amazon produces more than 20% of total oxygen from photosynthesis – 20% of 165,000,000,000,000 litres; see table 2 in link above – in an area roughly 5,500,000 $km^2$. That's tens of thousands times more oxygen than you need, produced in an area half the size of the cylinder described. (There is another way to produce oxygen called photolysis – UV light breaking $H\_2O$ into its constituent parts; $H\_2$ to be absorbed/collected, free oxygen combining to $O\_2$ – but on Earth it doesn't produce even 0.001% of the $O\_2$ we breathe, so we probably shouldn't factor it into this situation.) [Answer] You absolutely will not collect fresh air along the way. Elements will be recycled and atoms (including oxygen) reused over and over. Ideally you only need to add energy. Other losses need to be managed so you carry enough atoms to last. At speed, resupply en route is impossible even if you were to pass something in interstellar space. Slowing down is the bulk of your energy budget so you only do that once, when you arrive. A closed life support system is either an elaborate chemical factory or a small ecosystem. Since you specified 100 million humans, that is a rather large scale and is definitely an ecosystem. At all costs, you want closed cycles that generally maintain themselves and regulate themselves, as well as repair and reproduce components. You want massive redundancy of small units, not huge machines. So, we’re talking living organisms. If some nanofab is engineered it is a moot point of it being anything other than a bacteria or other cell, since it shares all the salient features with natural life. You’ll want ponds that circulate themselves, not complex pumps and pipes. Everything will end up looking like wildlife, including “trees” and “fungi” that are actually engineered tech, and a large portion of oxygen production is done with sea algae. [Answer] Algea Aero/hydroponics grows fast enough, feeds your population, scrubs CO2, and produces oxygen... But really, Hydrogen, Oxygen, and/or water is everywhere in space, Your ship might even run on a fusion/fission reactor that produces water, energy, and oxygen. [Answer] By definition, a generation ship is self-contained for its entire journey. With very few exceptions, if hard science is used, the system must be entirely closed, with little or no losses. That includes O2. Recycle. Every possible molecule of O2 needs to find its way back. Yes, you should also include rust in your assumptions... Of course, all the recycling systems must also be closed-loop, with all waste products and catalysts being re-usable somewhere, otherwise THOSE would run out. Hence the difficulty with closed loop systems... OR, if you are stretching the science of your fiction, you can get Oxygen as a byproduct from fusion/fission... [Answer] Nuclear submarines today have systems that can remove carbon dioxide from the air, called scrubbers. However, they make their oxygen by electrolysis of water, and a spaceship cannot do that. There are a number of newer technologies being developed for capturing carbon dioxide from the atmosphere, including transparent tubes full of photosynthetic algae (at the University of Kentucky) to make the most efficient use of space. Your spaceship will need to recycle the atoms of carbon and oxygen on board, because it can’t replace them. That means it uses some process that consumes energy to convert carbon dioxide and other waste products into oxygen plus useful organic molecules such as food. This could be plants, as on Earth, or it could be chemical engineering to produce essentially the same end products. For example, [ultraviolet light can split carbon dioxide into carbon and oxygen](http://science.sciencemag.org/content/346/6205/61), or it’s possible to use carbon, oxygen and hydrogen to synthesize complex organic molecules. Most refineries need fossil fuels as their source material, but it can also be done now with electricity, water, and carbon dioxide to produce “blue crude.” [Answer] Oxygen is not the only problem when creating a breathable environment. This answer uses only currently feasible or existing technologies While the astronauts in the Gemini and Apollo programs breathed 100 percent oxygen at reduced pressure for up to two weeks with no problems, breathing pure oxygen at earth level pressures is not medically advisable, (remember these astronauts were specially trained and in peak physical condition). The earth's atmosphere is only ~20% oxygen, as such our bodies have adapted. Oxygen toxicity is a very real risk in human spaceflight (Pure oxygen is also highly explosive). Accordingly, most modern spaceflight missions (such as ISS missions, Skylab, Space Shuttles, and Orion MPCV) place a high importance on introducing diluents nitrogen as well as oxygen (exception: pressure suits use pure oxygen at the lowest inflation pressure). Oxygen is largely recyclable, many other comments have outlined good techniques for recycling it. Oxygen is the 3rd most common element in The Milky Way at ~1.04% of mass, so smaller ships could be dispatched to gather it and return to the larger habitat ship with 100 million people in it. There are a some realistic solutions to diluting oxygen but they have trade offs Nitrogen, the 7th most common element, is 1/10th as common as oxygen at ~0.096% of mass which would make it unrealistic to collect during space travel and is relatively heavy compared to Helium and Hydrogen, ~7 and 14 times more heavy respectively. Helium is used as dilutent in some deep diving equipment (aka Heliox). Helium is very common in the milky way (2nd most common element at ~24% of mass). However there are 3 significant but solvable problems with helium due to its low molecular weight. 1) It is not suitable for dry suit inflation (poor thermal insulation). 2) It impairs but does not inhibit communication (the speed of sound is faster in a lower molecular weight gas, which increases the resonance frequency of the vocal cords). 3) Probably the most problematic but still solvable is Helium leaks are much more common than other gases. Atoms of helium are smaller allowing them to pass through smaller gaps in seals. Hydrogen is both the most common element at ~74% of mass in the milky way and has been used in deep diving gas mixes (aka Hydrox) but is very explosive when mixed with more than about 4 to 5% oxygen. The 4 to 5% oxygen mixtures usage is limited to deep dives (also has the same communication problems as Helium). You could use a safe 5% oxygen mix in a high pressure cabin environment (side effects will occur) or have some sort of mask that filters out some of the hydrogen when breathing so that mixture entering the body has enough oxygen but the environment is not highly unstable. (You could use a ~20% oxygen mix and just make sure absolutely nothing sets it off) Oxygen Only if a dilutent absolutely cannot be used there are a couple options. Running it at about 1/3rd of earth atmospheric pressure would sustain life in some of the passengers in peak physical condition but others would experience either respiratory failure or conditions such as: venous/vascular air embolisms, pulmonary oxygen toxicity, oxidative stress exasperating existing conditions, retinopathy, hypoxia, obstructive lung disease. The pure oxygen is highly explosive even at lower pressures. Small note about moisture content Gas is generally compressed for storage which removes moisture from it, while not usually deadly, it causes dehydration, so probably best re-moisturize the air. > > Disclaimer: I am not a diving instructor, if you intend to use this information for diving, please consult a diving instructor first. The presented medical information is summarized, consult a doctor. Do not use this as a medical advice or opinion > > > <https://en.wikipedia.org/wiki/Life_support_system#Atmosphere> <https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements#Universe> <https://en.wikipedia.org/wiki/Breathing_gas#Helium> <https://en.wikipedia.org/wiki/Breathing_gas#Hydrogen> <https://www.sae.org/publications/technical-papers/content/2005-01-2896/> [Answer] You Have to Stretch some Laws of Physics If you want a true deep-space ship (eg. nothing around you, not even asteroids, for hundreds of light-years) your crew is doomed. At some rate your ship will emit energy to space around you in the form of radiation, which will add up over time. In addition, versus the vacuum of space [you will lose small molecular gasses straight through your hull](https://www.pfeiffer-vacuum.com/en/know-how/introduction-to-vacuum-technology/influences-in-real-vacuum-systems/desorption-diffusion-permeation-and-leaks/)! That loss will primarily be in the form of Hydrogen, which you won't miss much until your water supplies start to run low. If we stretch science a bit... Perhaps you could find a way to spot and track asteroids and even rogue planets outside of solar systems. You pick up and process those sources as you go along to replenish supplies. Being a generational ship the planets you come across are presumably not fit for human habitation, but they could still contain ice and other elements/minerals you need. A real-life example of such a planet would be Europa. As for the basic problem that your power sources are going to run low at some point... well, I won't mention it if you don't. ]
[Question] [ In a future where humanity has expanded to live on multiple planets and then encounters life that does not trace ancestry back to earth, what is an appropriate term for such life? "Extraterrestrial" has an unfortunate ambiguity, since at this point, plenty of humans and other Earth-originating species have been born beyond Earth. A human born on another planet could be argued to be an extraterrestrial, depending on how it's used. "Alien" has its own problems, especially since human governments use the term to refer to people born in other countries. Is there a better term? [Answer] ## Xeno Used as a noun or prefix, meaning "foreign" or "different in origin". [Answer] ## Extraterrestrial You are mistaken in your usage of extraterrestrial, humans born on another planet are still terrestrial life (in both uses) as far as biology is concerned, it originated from earth. If you want to create a new word for things from earth born on another planet THAT is were a new term is needed, non-terran is a popular choice in fiction, or you could try Exo-terrestrial for a similar usage to expatriate, someone living outside their native country. But extra-terrestrial already has an establishing meaning in biology and other sciences. But you would only use extraterrestrial to cover everything not from earth, it is like using extra-marine for everything that does not live in the ocean, it can be used but their is not a lot of reason to other than legal definitions. You might also use extra-solar for things that do not come from our solar system. More likely it will be referred to as X-an or X-ial with X being whatever the origin of that life is. We are terrestrial life, life from Jupiter would be Jovian life because there is not much reason to to refer to all life not from earth and still include things of earth origin. [Answer] It's a problem we have already faced, once European scientists started to study life form from outside Europe. In the same way as flora and fauna originated outside of Europe was called African, American, Asian, Australian and in general autoctone to indicate that originated in the same place without being imported, the name will follow the location, planet in this case, where it is born: Martian, Jovian, Venusian, Trafalmadorian and so on. [Answer] Perhaps "non-Terran" would be sufficient? "Terran" in other science fiction works has been used to mean "inhabitants of Earth" (Terra being the Latin name for the planet). There is some ambiguity in that it is occasionally meant as a stand-in for "human" and other times as a word meaning "any thing originating from Earth;" you would borrow from this latter definition for "non-Terran" to mean "any life form not originating from Earth." A usage example: "The reticulated lava snake was the first non-Terran life form we encountered on the planet Magmor." [Answer] Consider words in -genous: indigenous, exogenous, xenogenous, extragenous. And then if planets or solar systems have names: planetname-genous or starname-genous. Earthgenous or Geogenous or Terragenous, Marsgenous or Martigenous or Areogenous, Centaurigenous, etc. If you want to put emphasis on the fact that a species comes from a near or far solar system, without explicitly mentioning the particular system, you can use greek adjectives μακρινός (distant) or πλησίον (near): macriogenous for an extraterrestrial species from the other side of the galaxy, and plesiogenous for a species native of a planet or system close to Earth. If you want to refer to the distance explicitly, you could use prefixes mono (1), deci (10), hecto (100), kilo (1000) and mega (1000000), along with "phyto" which means light, to specify that we're counting in lightyears. A species which comes from between 1 and 5 lightyears, ie from Alpha Centauri, is monophytogenous. A species which comes from between 6 and 50 lightyears is deciphytogenous, or decigenous for short. Etc. Note that the galaxy is only 100000 lightyears in diameter, so "megagenous" would be a bit of a rounding-up hyperbole for "coming from the other end of the galaxy". [Answer] There are many terms, with varying degrees of acceptableness. I'd like to draw attention to one set of them that Orson Scott Card put together for the Ender's Game series. I draw attention to it because it addresses what appears to be a thorn in your side: our current words are all ideal for a culture that doesn't have a presence on more planets. A real culture facing such an environment is likely to have to invent an additional set of words to capture the meanings that are important to them. In the Ender's Game series, Valentine Wiggin constructs the [Hierarchy of Foreignness](https://enderverse.fandom.com/wiki/Hierarchy_of_Foreignness). It uses not one word but several to describe key relationships. The words Card chose happen to be Sweedish: > > An utlänning was defined as a stranger recognized as human from the same planet as a subject, but of a different nation or city. Utlänning means "foreigner" in Swedish. > > > A främling was defined as a stranger recognized as human, but from a different planet than a subject. Främling means "stranger" in Swedish. > > > Ramen were defined as strangers recognized as "human", but of another sentient species entirely. The term was only ever used to refer to the entire species as a whole rather than an individual member. Although not a common word, Ramen may be constructed in Swedish from rå + män, where rå indicates "coarse (not refined); brutal (crude or unfeeling in manner or speech)" and män = "man" or "person" (e.g. råmän). > > > Varelse were defined as true aliens; they may or may not be sentient beings, but are so foreign that no meaningful communication is possible with the subject. Varelse means "creature" in Swedish. > > > This was sufficient for their world. Feel free to invent your own. By Card's chosen set of words, your other form of life would be Ramen or Varelse, depending on the life. And I think Card was smart here, as there's a distinction between the two that would be very important in such a world. Depending on the past-history of your story, it might even be possible to give Card a nod and have the characters explicitly reference him for coining terms that they found beneficial. [Answer] # A Thousand Words For Stranger: The answer says more about the user. Language is a funny thing, and fluid. The words people use to describe each other reflect the attitudes they hold about those people. Are they dismissive, angry, fearful, arrogant, trusting, dependent on trade or hopeful of immigrants? Have they experienced an invasion? But ambiguous naming is a good thing (at least story-wise). Using different language allows you as a creator to tell a story with less tell and more show. Consider grades like an epithet (“dirt people” for Earthers, for example). In our own culture, look at the difference between illegal alien, foreigner, undocumented resident, or economic refugee. So there is and will be no perfect name to universally apply. It will all be about the attitude the people have towards that particular brand of outsider. [Answer] autochthonous formed in it's present condition. "from the rocks" In a future where humanity has expanded to live on multiple planets and then encounters life, that life will be autochthonous. It will be encountered on planets where it is autochthonous. Even when a few individuals travel between planets, most of the life they encounter will be autochthonous. Even when humans become indiginized and native to foreign planets, most of the life they will be in contact with will be autochthonous. [Answer] ### Sophonts Problem solved! If you're looking for a good general term for "people" that doesn't specify a place of origin, this is a good choice. It's best feature is that, unlike the other choices, it is, in and of itself a positive term in that it emphasises intelligence, wisdom, self-awareness, etc that "people" have in common. Other key features are its place-neutrality. It's an English word, but but doesn't specifically refer to one race the way "Terran" or "Terrestrial" do. Lastly, it lacks all the negative connotations that (humans) have about words like "alien" or "xeno". Thus, even if a sophont from Znabu doesn't take offence at being called a xenoalien, because she doesn't share the human cultural baggage, she will certainly appreciate the more positive nature of sophont. [Answer] ## Extraterrestrial can be justified Your ambiguity in "extraterrestrial" hinges in your definition of Terra. Right now, we have one planet, which is why it shares the word for "ground" (earth vs Earth, terra vs Terra). This applies to many things. We wouldn't be calling our sun "the Sun" if we had more than one sun (i.e. because we inhabit multiple solar systems or live in a binary solar system). The same applies to the Moon. We would've given them a proper name (different from "moon") if there was a need to distinguish between them. When the colonization process begins, i.e. when have more than one thing (planet, solar system, ...), a need to distinguish between them arises, and people will naturally find unique names for the unique things. The question is, how does the definition of the non-capitalized word change when there's more than one inhabited planet? Does earth refer to any kind of soil, or specifically soil from Earth? I think you have freedom of choice here. However, I can reasonably argue that the Terra in extraterrestrial is always going to be relative to the speaker. So the question is: is the speaker speaking as a citizen of NewPlanet, or is he speaking as a citizen of the entire human civilization (or a subset of humanity that defines itself independently and inhabits several planets). Depending on what the speaker defines as "our domain", extraterrestial refers to "from outside our domain". This means you can do what you want with it. You could keep the definition to be "from a non-human-inhabited planet", or you could put the word in the mouth of someone who sees everyone not from their planet as an "extraterrestrial" (heavy analogy towards the use of "alien" to mean non-citizen even in today's world). The short answer here is that the conflict/ambiguity that you currently see with your 2023 eyes is likely something that will have been addressed during the colonization of additional planets, so you can decide exactly how the meaning of the words shifted. [Answer] In the context you're describing, where humanity has become a multi-planetary species and has encountered life that is not of Earth origin, the term "extraterrestrial" indeed becomes ambiguous. Similarly, "alien" can have different connotations that might make it less desirable for clear communication. Here are a few alternative terms that could be used: * Exogenic Life: This term emphasizes that the life form originates outside the Earth's biosphere. "Exogenic" derives from "exo-" meaning outside and "genic" relating to origin or production. * Xenobiological Life: This term is often used in science fiction and scientific discussions to describe life that is foreign and of biological nature. "Xeno-" means strange or foreign, and "biological" refers to life. * Non-Terrestrial Life: This term directly states that the life form is not from Earth ("Terra" in Latin) without implying that it is necessarily from outer space, which would include humans or Earth life on other planets. ]
[Question] [ First time here, so I don't know what to expect. I'm writing a dark sci fi mystery story that takes place on a hypothetical megastructure called an "[Alderson Disk](https://en.wikipedia.org/wiki/Alderson_disk)" (Example seen Below). Humanity on the disk has sorta fallen into a dark age, reverting back to feudal ways. So I was wondering, how would a civilization keep track of the passage of time in a world where the sun would never set, there are no seasons, and they don't possess the technology to build anything to keep track of time and how might it affect their language and culture? I can't think of anything that would help, aside from removing the concept of "time" from their languages and cultures altogether. Any ideas would be greatly appreciated! [![enter image description here](https://i.stack.imgur.com/GgWWL.jpg)](https://i.stack.imgur.com/GgWWL.jpg) [Answer] I have to reject your premise. IRL, Primitive hunter-gatherers used tied-off animal bladders as canteens to carry water with them. Hang a bladder from a tree with a pinhole in it; let water drip into some other vessel (e.g. a depression lined with a bladder), and the volume of water collected measures time. People would have to be animals to not be able to measure time. As others have mentioned, sleep is a necessity for the brain, and not just for "rest". A primary biological function of sleep is for the body to conduct janitorial work on the brain; neural functioning consumes energy and eliminates waste. Neurons are living beings, after all. If this waste accumulates, it can literally kill neurons, it impedes their oxygen uptake and creates pressures on them that choke them to death. During sleep, blood vessels dilate and put pressure on the neurons, which can make them malfunction, but more importantly, the pressure causes them to expel their waste into the bloodstream, to be transported to various waste receptacles in the body. Being unconscious during this cleaning process protects the person by preventing action based on these neurons misfiring during cleaning (which they do). There are other important functions that are performed during sleep as well, such as memory consolidation and learning, that also physically affect neurons. As a general rule, it is best to turn the machine off when you are changing the parts of the machine. The closest analog I can think of for your purpose is dolphins; they have a survival need to be alert 24/7. So they have evolved a mechanism in which the lobes of their brain take turns sleeping for this janitorial and updating duty. When one lobe is sleeping for several hours, the other lobe handles the alert duties; swimming and staying with their companion dolphins, on the lookout for predators or food, and ready to wake its partner lobe in any emergency. Dogs are another time-keeping species that can "smell" time. Even entirely during daylight, a dog's sense of smell can tell how old a smell is. For example, when their owner leaves the house, the dog can detect their owner's scent decaying. So accurately, that if the owner always leaves for the same amount of time every day (like going to work for 8 hours and coming home), the dog can reliably anticipate their owner's return within about 15 minutes, and come to wait for them at the door. That scent-decay is the key here has been proven in experiments, by artificially changing the scent concentration and thus fooling the dog. So there is a biological route that has nothing to do with day/night cycles. Both dogs and dolphins also have some sort of time-keeping that is based on sleep cycles or days. Treated well and as friends, both species "fall in love" with their keepers, and an absence of days can cause mourning behaviors in the animal. While a return of their keeper can cause rejoicing behavior; we have tons of returning-soldier videos where their dogs just go nuts with joy greeting their return. Dolphin keepers can also form relationships with dolphins, playing with them, and the dolphins react similarly when their friend disappears (on vacation or leave for some reason) and then returns weeks later. The dolphins engage in excited greeting and play behavior. Neither of those is possible without some internal sense of "long" times; and for animals that sleep in several sessions throughout the day (or in the case of dolphins are never fully asleep) it seems some other long-time mechanism must be in play, in their brains. In any case, for primitive hunters, bladders and stomachs were ready vessels for carrying wet or liquid products. It is suspected that cheese was accidentally discovered by carrying goat's milk in a stomach tied off to work like a canteen; it fermented in there. And a water clock can be made from them without any advanced technology. [Answer] The sun doesn't have to set to produce regular noticeable cycles. Just have it bob up and down through the central hole in the disk. Sometimes, more of the sun will be visible, and the world will be slightly brighter. Other times, less of the sun will be visible, and the world be slightly dimmer. And those changes will occur perfectly regularly, just like the regularity of day and night on a spinning spherical world. [Answer] Presuming the platter turns, I think that if you look outward, away from the sun, you would see the stars, which would drift by over the course of a year (one turn of the platter). You could mark local time by which constellation was directly radially opposite the sun. All the shadows in this perpetual sunset world would be pointing at a particular constellation on the celestial equator corresponding to the time of year. "Oh look, it's Orion o'clock!" [Answer] It is a bit of a design change but an artificial light/heat system along both sides of the disk provided by energy collected by a Dyson swarm/sphere around the star could regulate day-night cycles. Other than the instability of an Alderson disks structure, which would likely collapse into a sphere, receiving enough light across the whole disk is an issue that could be solved with artificial lighting. Similar to an enclosed cylinder habitat which needs a light and heat source, the designs for an Aldersons disk could vary, something simple like street lights kilometres high above the disk could work but other more elaborate/functional designs would be interesting to think about. This means the outer edge of the disk does not need to have very low temperatures, although it could still be, for housing computers to run more efficiently at the cold temperature. The star in the middle of the disk is only surrounded at the equator by the wall area that is needed to hold in the atmosphere, the rest of the star could then have a Dyson swarm or sphere to harvest enough energy to power the artificial light, which could then be used to regulate day-night cycles for both sides of the disk. [Answer] An object falling from a known height will always take the same amount of time to reach the ground. They can count drops or bounces of stones or something else. They can also count blinks, or breaths. You might think these are inexact and different people will have different measures. It was just this way in primitive societies. To this day, where I come from, there is a measure of time which goes like "I'm gonna spit on the ground and you have until it dries to be back or else". Ancient chinese would burn rope to measure time and the ancient greek measured the time it took for a container with a hole to spill all of its water. [Answer] We base our time around the rotation of the Earth and it's orbit around the sun, but your world may not have any suitable markers. First you have to ask why you're keeping track of time in the first place. Until something is due to happen at a specified point in the future, time is utterly unimportant. The hunt goes out, the hunt comes back. The quarry is cooked until it's ready, the children play until they're called back. You sleep when you're tired and get up when you wake. None of this requires time. No days or nights, no seasons, you don't need a farming calendar. No winter to stock up for, no spring lambing to prepare for. Merchants arrive and set up stalls when they do. When you want to sell goods, you take them to town and sell them. Market days are a nice idea, but not required. Time gets more interesting when you start wanting people to pay taxes regularly, but that wasn't a thing for most of history. You can just tax the merchants against value of goods as they pass through town. Finally you get to the industrial age and railways. Time suddenly matters, what time does the train come, what time does it go. What time did you get to work, what time do you leave. Travel and factory work require time and for your world that's the first time it will be important. Until then, things simply happen, one after another. While we as an "advanced" civilisation have all sorts of ways of considering time and its importance, before you project that onto your world, you have to come back to that first question. Why? [Answer] Living things still need to sleep at some point, so there would still be some sort of way to measure time, but it would likely be based on your personal need to rest. One way to still have a basic concept of days/time would be based on jobs and the necessity for structure, where the "boss" would likely have a set time that the "employees" would be given opportunity to sleep or do anything else. Presumably this would be based around the "boss" needing to sleep and forcing everyone else to function around their needs, as you mentioned these people do not have technology to measure time in any capacity. This could extend out further to a civilization by replacing "boss" with "ruler" and "employee" with "subject". Basically, someone in power decides when others get to sleep based on their need to sleep, and a new "day" is started when they wake up. [Answer] They track the years. [![solstice at stone henge](https://i.stack.imgur.com/LiWBR.jpg)](https://i.stack.imgur.com/LiWBR.jpg) <https://www.english-heritage.org.uk/visit/places/stonehenge/things-to-do/solstice/what-is-the-winter-solstice/> There is a structure on the disk, near where the story takes place. Now it is a built thing but underneath the standing stones are artifacts left by the ancients who built the disk. The disk turns. One rotation around the star is a year. The sun tracks a slow path along the edge of the sky. On one day in the year, the sun aligns with the structure in a recognizable way. The sun shines through the Eye Of Klive on that day and if you know how to look the long shadows form the shape of Klive's Hand. That day marks a year. The passing of another year is celebrated at the structure with a ritual marking and sacrifice underneath it. The many years that have been passed can be seen in these sacred marks. --- Or it was celebrated. I picture a dark age where the people no longer come to the structure. There is no-one to come. An old woman lives nearby with the child she has rescued. She marks the time herself. The old marks are beautiful. Her new marks get the job done. Sometimes the child adds to the new marks, to make them a little more beautiful so they are not ashamed. There are similar structures elsewhere on this world. There the people have all gone and there time has stopped. If you understand the marks, you can tell when the last ones were made. [Answer] ## Your main problem is the disk doesn't make sense, and making it make sense probably makes time easy to measure. I know there's a Wikipedia article. That doesn't explain how a disk in which gravity is "down" toward the Sun, as they describe, has atmosphere on the habitable area. Now to be sure, you could rotate it (make a Ringworld out of it) but then the air near the Sun falls down and the air further out flies away and there's still no atmosphere. You could make it an honest-to-God ring system (like Saturn's) with different orbital speeds as you change radius (faster the closer you are to the Sun), and enough gravity on the disk to hold the air near it (plus, any other orbit for a gas particle intersects the disk again). But then you'll have frequent joints between different circles of the disk, and the natives can have a (very lengthy) Book of the Passing Landmarks they use to measure the exact time within each day, or at least measure the displacement of distant landmarks to keep rough track. Note that it is still essentially a poorly-designed Ringworld, and unstable - the nearest part of the ring to the Sun will pull the Sun nearer to it still. You'll need some corrective measure, such as attitude jets, and the firing of each jet as it revolves past the Sun will provide a regular timepoint for a clock system. The fading of the exhaust gas might be used to estimate hours within the day. [Answer] If these people are really people, say descendants of [Stross-esque nuclear holocaust](https://en.wikipedia.org/wiki/Missile_Gap) blown back to hunters-gatherers and losing all concept of our civilization, then there is not one natural, but two natural cycles - one is the sleep cycle (that might be not uniform across people and will likely drift towards longer "days"), and the second one is the menstrual cycle, and this will probably play a major role in creating time reconing system once they start building cities and bureaucracy. Divided by 20 or 24 (depending on how much the average sleep cyclle takes) will give them \*days and once their science progresses, they will divide the days by 12, 24 or whatever their number base system. [Answer] I'm assuming these people have agriculture, so they will at least have units of time based on growth of their crops - how long that is will depend on what they grow and the climate in the area they're in. For more precise time measurement they could use something like an hourglass. ]
[Question] [ See this? [![enter image description here](https://i.stack.imgur.com/6XKOf.jpg)](https://i.stack.imgur.com/6XKOf.jpg) 1. I want it melted into a puddle of glowing metal, since, from my admittedly-narrow perspective, [it's the only way to be sure](https://youtu.be/aCbfMkh940Q?t=6). 2. I want it melted with something human-portable, so that I can bring the weapon to the threat - potentially over terrain that a land vehicle cannot traverse, or underground where my limited supply of functional post-nuclear war aircraft can't be used to reach - rather than having to lure the latter to the former. 3. I want this melting done as quickly as possible, given the risks inherent to letting something like a Terminator (a) know you exist while (b) being not destroyed. What manner of weapon or implement do I use for this? Assume that we're dealing with the [T-800](https://en.wikipedia.org/wiki/Terminator_(character)) model or one of its derivatives here. Unfortunately, [other models](https://en.wikipedia.org/wiki/T-1000) have proven quite adept at melting themselves into puddles, as well as reversing that process; R&D in regards to counteracting this is ongoing. [Apparently, a T-800 is 400 to 640 pounds](https://www.cbr.com/terminator-how-much-weighs/#:%7E:text=According%20to%20Sarah%20Connor%20in,with%20living%20tissue%20over%20it.); let's assume that all of that is made out of [coltan](https://en.wikipedia.org/wiki/Coltan), a substance which has been mentioned as being what they're made out of. Also, assume that we're working with modern technology. No [phased plasma rifles in the 40-watt range](https://youtu.be/-B6YbMKda68?t=24). [Answer] [Thermite](https://en.wikipedia.org/wiki/Thermite) > > Thermite (/ˈθɜːrmaɪt/) is a pyrotechnic composition of metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as black powder. > > > Thermites have diverse compositions. Fuels include aluminum, magnesium, titanium, zinc, silicon, and boron. Aluminum is common because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. > > > The most common composition is iron thermite. The oxidizer used is usually either iron(III) oxide or iron(II,III) oxide. The former produces more heat. The latter is easier to ignite, likely due to the crystal structure of the oxide. Addition of copper or manganese oxides can significantly improve the ease of ignition. The density of prepared thermite is often as low as 0.7 g/cm3. This, in turn, results in relatively poor energy density (about 3 kJ/cm3), rapid burn times, and spray of molten iron due to the expansion of trapped air. Thermite can be pressed to densities as high as 4.9 g/cm3 (almost 16 kJ/cm3) with slow burning speeds (about 1 cm/s). Pressed thermite has higher melting power, i.e. it can melt a steel cup where a low-density thermite would fail.[25] Iron thermite with or without additives can be pressed into cutting devices that have heat-resistant casing and a nozzle.[26] Oxygen balanced iron thermite 2Al + Fe2O3 has theoretical maximum density of 4.175 g/cm3 an adiabatic burn temperature of 3135 K or 2862 °C or 5183 °F (with phase transitions included, limited by iron, which boils at 3135 K). > > > Thermite reactions have many uses. It is not an explosive; instead, it operates by exposing a very small area to extremely high temperatures. Intense heat focused on a small spot can be used to cut through metal or weld metal components together both by melting metal from the components, and by injecting molten metal from the thermite reaction itself. > > > Thermite hand grenades and charges are typically used by armed forces in both an antimateriel role and in the partial destruction of equipment; the latter being common when time is not available for safer or more thorough methods. > > > [Answer] A [B54 SADM](https://en.wikipedia.org/wiki/Special_Atomic_Demolition_Munition). This 32kg man-portable nuclear weapon has a yield of 10 to 1000 tons of TNT, or 41.84 to 4184 GJ. This is sufficient energy to reduce 64.77 to 6477 metric tons of steel to molten slag, way in excess of any reasonable estimate of the mass of a Terminator. Such a small atomic weapon could be carried to any ambush point by a single person, will operate underwater, and could be triggered manually, on a timer, or by a booby-trap trigger. A close-range atomic blast, even as small as this, would likely vaporize a Terminator, much less melt one... and this weapon should do the job in a millisecond or less. The terminator might have time to recognise the threat, but it won't be able to move fast enough to make any difference whatsoever. Nuking the Terminator is the only way to be sure. Edit In response to the OP's edit stating that a T-800 weighs up to 640lb, or 290kg, we should be able to estimate how much an atomic weapon should be able to increase its temperature. If a Terminator is exposed to 5% of a close-ranged blast, not unreasonable considering that an atomic weapon emits its energy in all directions, it would be subjected to 2.09 to 209 GJ of energy. Now, assuming that the Terminator is made from steel alloy (I don't believe that a Terminator is made only from coltan, and steel has a higher specific heat) with a specific heat of 420 J/(kg°C), a heat of fusion of 268 kJ/kg, a melting point of 1540°C, a heat of vaporisation of 6090 kj/kg and a boiling point of 2870°C. Assuming that the Terminator starts at a temperature of 37°C, normal human body temperature, to increase its temperature to 1540°C takes 183 MJ. From there, to melt the steel takes a further 78 MJ. Once melted, to raise its temperature to boiling point takes a further 162 MJ, and to vaporise it would take 1.766 GJ, for a total energy requirement to vaporize of 2.189 GJ. At the lowest yield estimate for this weapon, the Terminator would be substantially vaporized, and the remainder would be splattered as white-hot liquid metal across the blast area. At the highest yield estimate, it would be turned into plasma in its entirety. That's a worst-case estimate. Should the Terminator be made from materials with a lower specific heat and lower heats of fusion and vaporisation, it would likely be completely vaporized. If it was made from materials with higher constant values, it would still likely be completely melted and at least partially vaporized, and no doubt splattered across the remaining landscape. Unfortunately, the SADM fails the OP's criteria in one way: there isn't likely to be a puddle of molten metal at all... at most there will be finely divided particles of molten metal which will rapidly oxidize in the surrounding super-heated air. [Answer] Coltan melts around 5,500 degrees, but modern plasma torches reach temperatures of about 25,000 degrees. Plasma Rifles in the 40 watt range aren't available, but plasma torches and cutters definitely are. These guys have even made a retractable plasma based lightsaber that burns at 4,000 degrees, which doesn't quite melt Coltan (5500 F) <https://www.youtube.com/watch?v=ey_EjSzKFWQ> <https://www.youtube.com/watch?v=xC6J4T_hUKg> Given that these guys are amateurs without any kind of actual funding beyond their Patreon, it seems like someone motivated to kill Terminators would be able to iterate on this until they end up with one capable of taking Arnie down. [Answer] It can't be done. It can be done. First, let's consider chemical devices. You've got say 500 pounds that need to be heated to 4,500 degrees. What can we do to deliver that kind of heat? Beam weapons. Lasers, plasma weapons and the like. First, lasers. Most of the power that is fed to a laser appears as heat in the laser, not into the beam. If your laser is 50% efficient (and AFIAK none are) if it can heat the robot to 4,500 degrees it will also heat 500 pounds worth of laser to 4,500 degrees--and you'll need a lot more weight for it's powerpack. Thus the laser must be a lot more than 500 pounds--that's not man portable. (And that assumes it's all absorbed--much of it won't be.) Plasma. I'm not sure on efficiencies here, but you've got a big range problem--plasma doesn't go very far. An awful lot of the energy you are pumping into the target will bounce back, your gun better be a lot tougher than the terminator. If you've got that sort of tech just grapple it! Plan B: Thermal lances and the like. These are pretty much a chemical parallel to the plasma weapon--and the same objections apply. Ok, we have to go up the ladder. SADMs have already been mentioned. Now we finally have enough energy in a man-portable package--but that doesn't mean we can actually get the energy into the terminator. Let's lure the terminator across a nuclear land mine--boom, there is a tremendous flash and a ball of extremely hot plasma. But look at what happens--we've probably all seen videos of what happens when objects are exposed to the flash of a nuke--the surface is heated. Only the surface, though--the paint is vaporized or even converted to plasma, but the wall behind remains. Newton's Third law applies--we vaporize a bit of the terminator and throw the rest out very, very fast. It quickly departs the plasma ball--we have substantial damage to any spot facing the bomb and some damage all around, but the main part is not melted. Look up Project Orion--objects can be quite close to a nuclear detonation without absorbing any major heating. If the only way to kill it is to melt it I think the only hope humanity would have would be to catch it in a mine with some big booms and I wouldn't want to count on that melting the whole thing. Note that the movie approach does not work, that crucible of molten metal won't be hot enough to melt it. (On the other hand, it might not be necessary to kill it. Put a large h-bomb in a well, lure it across the opening. Throwing it above escape velocity won't be a problem, the hard part is throwing it hard enough that it gets through the atmosphere still going fast enough. It has no propulsion system, it can't return.) Update: There's an outside-the-box way to destroy it, but we don't get a puddle. I recently found [this discussion of the fate of the Pascal B cap](https://physics.stackexchange.com/questions/488151/could-the-end-cap-of-the-pascal-b-1-survive-its-trip-through-the-atmosphere) and this provides a means of vaporizing it. Lure it across a substantial nuclear mine. It's going to meet the same fate as the cap on the Pascal B test--vaporized by the atmosphere. [Answer] If the goal is to melt the target, using current technological ability, the only way to produce sufficient heat in a man-portable way would be a fission heating device, taking inspiration from [Corium material](https://en.wikipedia.org/wiki/Corium_(nuclear_reactor)) (the melted lava-like alloy formed in a nuclear reactor meltdown). The maximum temperature reached by typical nuclear reactor contents in a meltdown is said to be up to 2800°C in the above linked Wikipedia article. Pure Tantalum has melting point of 2996°C. However, the Terminator endoskeleton is an alloy, so it will have lower melting point. Also, a nuclear material mix specifically designed to reach high heat output with self-limiting nuclear chain reaction should easily reach high enough temperatures to melt even pure Tantalum. We want isotopes which do not boil away at too low temperature, and which have low enough critical mass so that the weapon is man-portable, and which have reasonable half-life so they are not overtly radioactive without a chain reaction. Therefore isotopes of interest, taken from [this Wikipedia article](https://en.wikipedia.org/wiki/Critical_mass#Critical_mass_of_a_bare_sphere), include at least these: ``` Isotope Half-life, years Critical Mass, kg Boiling point Uranium-233 159200 15 kg 4131 °C Neptunium-236 154000 7 kg 3902 °C Plutonium-238 87 9-10 kg 3232 °C Plutonium-239 24110 10 " Plutonium-241 14 12 " ``` Using these, and ignoring any environmental and safety regulations on testing, it should be trivial to design a special Corium cocktail, which * Is safely sub-critical in a hollow sphere or cylinder. * Is super-critical (has exponentially accelerating chain reaction) when collapsed into a solid mass. * Becomes sub-critical when it starts to boil, so that the chain reaction immediately stops when bubbles form in the hottest part of the mass (the center), and as a result the mass remains in nice, toasty temperature of about 3200°C...3500°C * Can have a chain reaction with mass under, say, 20 kg. Construction of the warhead should be so, that the Corium cocktail is in a form of two hemispheres, or possibly even several separated disks, staying safely sub-critical. When fired from a recoilless rifle, these parts get smashed together into a sphere, which promptly begins a chain reaction and basically melts almost immediately (like, in 100 ms, as designed), but does not explode or evaporate because the chain reaction ends when any material starts to boil, as explained above. When fired successfully, and melting on the way to the target, the now molten sphere of highly radioactive material at above 3000°C gets splashed onto the target, knocking it down with kinetic energy and starting to melt it. The sheer amount of radiation should also mess with its electronics, at the very least frying its visual sensors. Now the splash will also stop the chain reaction, because the Corium cocktail is going to become too dispersed. Solution to this is simple. You need several attackers firing at the target when it is knocked down, so it stays down and is thoroughly covered in the Corium cocktail, which will agressively remain near boiling point. The puddle will likely stay molten months, if not years, slowly melting its way through the ground. As for the delivery system, for example [the US Javelin](https://en.wikipedia.org/wiki/FGM-148_Javelin) has warhead weight of 9.4 kilograms, while weight of weapon when ready to fire is 22.3 kg. This is a good starting point, and by removing guidance and reducing range and velocity, and increasing total weight a bit it should be possible to reach warhead weight of around 15 kilograms. The obvious drawback is, this requires a team. Also, due to radiation released, using this weapon is likely a suicide mission, unless you add some remote firing ability. But hey, you gotta do what you gotta do. --- If you come up with a way to restrain the target (some kind of net?), then you could tie it down and place a crate of this special Corium cocktail on top of it, and then trigger the reaction by just removing supports keeping parts of the material separate and subcritical. Melting commences, and no one else has to die. [Answer] The obvious solution is to turn its own energy source against it. As we know, Terminators and the like contain compact, extremely high-wattage power sources. A device which causes this to become unstable, either by physical means (induced vibration, hyper-intense shockwave) or something more subtle (electronic override, hacking, EMP) causes it to overload and dump all its energy at once, causing thermal runaway and melting the droid on the spot. Job done, and it can be a small enough to fit in your pocket. Just make sure its charged before you run into Arnie. ]
[Question] [ ## Pull the context and count to three sentences Let's imagine an army has created a kind of explosive similar to grenades, but much smaller in size while maintaining a good chunk of offensive output. Known simply as "flakes", you can hold a good 8-12 in one hand, and due to their higher numbers, you can target a much wider area, such as big, open-field battles. They work like a mix of incendiary, suppressing1 and concussion grenades, doing the most physical damage by the sheer explosive force, then ejecting a hot, incendiary liquid in its vicinity, potentially igniting covers and frightening even more anyone who heard and saw the explosions2. ## My question is : How can I make these explosives safe for the grenadier? So first, let's talk about harm capacity : Flakes are known to be really dangerous to anyone under a 1 meter (~3.3ft) in radius, combusting with a powerful invented chemical (either powder or liquid). But also remember there is a small incendiary left-over, which is prone to expand and force a tactical retreat to anyone standing near in the minute after the throw. We don't really want them exploding near us too much so, more at a good distance to have some time to adapt to the battlefield. The technology to make it safer can go as high as today's technology. As far as I am aware, modern civil explosive devices use a remote detonator, like for instance professional firework shows and building destruction companies, but in the case of grenades it's more often controlled by chemical fuses triggered by a lever you pull3 : after you pull the lever, a small hammer is thrown full force towards a spark-inducing plate, igniting the fuse. Disregarding the fuse reduced length due to the tiny size, the problem with modern timed grenade system is that, wellie... You'd need to pull the pins of every flake, which could be quite an hassle given you have 8 times more. Moreover, I want them to be thrown in groups, kind of like a shotgun shoot many pellets at once, and the above point prevent this. Therefore, and as you probably guessed it : how can I control when the grenade becomes dangerous is the main issue to me and the reason I ask here. Since I've thought a little through the matter, I know you might also be interested in something which could be easily forgotten : How to ensure you don't lose a flake while throwing them. Indeed, when you have a big handful of tiny grenades in your bare hand, it's easy to slip one of them. I decided at the time of writing to put them inside a big shepherd sling, then spin it vertically in formation and horizontally when alone, and finally reload by just grabbing a bunch of flakes from a pouch. It's a little bit "rustic", yes, but I don't wish to use firearms for that matter, including grenade launchers. However, if there's a more appropriate way of sending the flakes with your ignition technic (excluding grenade launchers), you can consider it as an annex, bonus question. Still, remember this is only secondary and not the main topic here, and if you do decide to extend on this, that flakes must be delivered to the enemy in groups. Final tusk of interest : these grenades are carried by explosive specialists, so expect them to carry quite a few of them in their backpacks. Also note that they work with other soldier units, so the solution of having them being heavily armoured and fireproof is nice, but not a solution for their friend next to them. So how can you increase the average number of days since last accident from 0 to a lot higher and comforting level for the flake grenadiers? --- 1 : By "suppressing", I mean the noise, multiple impacts and such are capable to deter the opposing side's morale and frighten out anyone out of cover. 2 : They aren't fragmentation grenades, because, well the shrapnels are too light to have enough kinetic energy to make meaningful damage ^^. 3 : There are also impact type grenades, which explode... On impact, but I don't know exactly how they work (I guess there's a "spark machine" in them, but it's just a guess), so I'm a little bit left out on it. [Answer] If the flakes were time delayed and individually activated by a pull string, they could come bundled in groups with each group of pull strings braided together and forming a loop. The slings would have hooks or clips at the ends of the sling pouch. The grenadier would reach in his satchel to grab a pre-made group of flakes, load the group of flakes in the pouch, attach the string loop to the pouch hook and use the sling as one normally would. Assuming the resistance of the strings pulling was low then this might not have any effect on accuracy that's not able to be overcome with training. To increase safety the flake bundles could have the string loop securely taped to the body of the group. The grenadier breaks this tape to disengage that safety then hooks the string and throws it with the sling, similar to a modern day solider pulling the pin before he releases the spoon to activate it. [Answer] The only sensible way I can think of to deploy such things would be a cluster munition patterned after a stick grenade (See <https://en.wikipedia.org/wiki/Stielhandgranate>). The central "stick" would contain a standard fuse and a pyrotechnic charge that both disperses the "flakes" surrounding the stick and triggers their fuses so that they detonate a moment later. Controlling when the cluster grenade detonates can either be done by an adjustable fuse or by the old fashioned "cooking off" technique of pulling the pin but not throwing the grenade immediately (which is highly dangerous, of course). [Answer] ## Never carry them loose As much as possible, grenadiers would avoid working directly with a naked flake, unless performing a task that calls for directly manipulating them one at a time (e.g. setting a booby-trap that calls for a naked flake, filling a container, etc). They would not be transported as if they were marbles, loose in a bag. That's asking for trouble. They would be snugly fitted in custom carrying cases for transport. Most ways to use them would involve custom deployment equipment designed to keep the flakes secure as part of their function. ## Shoot them from a grenade launcher Look at the size of a [50 caliber bullet](https://en.wikipedia.org/wiki/.50_BMG). Specifically at the diameter of the base. That's about marble-sized. In other words, 50-cal gun barrels are about the right size to take custom engineered ammunition delivering a flake in a [sabot](https://en.wikipedia.org/wiki/Sabot_(firearms)). This turns any fifty-caliber firearm into a grenade launcher. This, of course, requires careful engineering of the sabot to keep the flake isolated enough that firing the round won't blow up the flake in the barrel. In fact the flakes may be designed so the round firing is what arms them (say by jostling the internals just right to bring the arming mechanism into place). This would also make them harder to accidentally set off. Such ammunition would be bulky enough to mitigate many of the problems you're asking about. This may be difficult to engineer, but existing grenade launchers can already fire high explosives without blowing up the wielder, so it doesn't seem that far-fetched. [Answer] It really sounds to me as if you are throwing White Phosphorous marbles around! This can work very well as offensive weapons, mainly in an incendiary and anti-personnel role. Take a blob of White, cover it in a liquid that is even more pyrophoric. Something like a bit of NaK. Put this devil-drop in a frangible glass sphere. For storage and transport, the capsules are carried in an airtight, soft rubber sheath that both physically shields it as protects it from air in the event of accidental breakage. To use in combat, just eject the capsule from it carrier, and gently throw at the enemy. It will break on contact with a hard surface, exposing the pyrophoric contents to air, which promptly causes it to splatter and ignite with immense heat and toxic fumes. If your capsules are manufactured to sufficient precision, you can even use a device like a paintball gun to shoot them. Just >>>don't<<< have a firing malfunction that breaks the capsule in the barrel! Oh, your actual question is "My question is : How can I make these explosives safe for the grenadier?"... Ummmm... next question please? [Answer] You want an explosive that's [low sensitivity](https://en.wikipedia.org/wiki/Sensitivity_(explosives))- either a secondary or tertiary explosive. Essentially you want an explosive you could hit with a hammer, burn or otherwise abuse and not do anything, but when properly set off, go boom. If you had a mechanically or magnetically initiated detonator, kept from going off by [switchable magnets](https://en.wikipedia.org/wiki/Magnetic_switchable_device) - switching the magnet off would disconnect it from whatever is holding it in place, and start the count-down. Combine that with something like a revolver's speedloader - you twist the top of the 'carrier' which turns off the magnets holding the flakes in place. Demagnatisation lets reed switches in the flakes close, which arms the detonation mechanism. You can then either have a timer, some secondary mechanism for starting detonation on launch from the carrier (say little pins that come out when the flakes are launched), or some microelectronic system. [Answer] I think you were getting close with the idea of a shepherds sling. Instead, perhaps a [Staff Sling](https://en.wikipedia.org/wiki/Sling_(weapon)#:%7E:text=The%20staff%20sling%2C%20also%20known,off%20and%20release%20the%20projectile.). Lets start with your Flake carrying system. Lets make each grenadelette a marble sized ball of nastiness containing a very small radio receiver and detonator on the side of a wad of the explosive/incendiary goop. It will not detonate without the appropriate signal. Pack a fist sized lump of these into a net bag that has a radio signal separation seam (or seams) so that the grenadelettes can separate after leaving the sling but before hitting the target area. The launcher can control this timing for a greater or lesser spread depending on desired outcome. Now for the sling. It's a staff sling. they were used for many things, up to and including throwing old crockery type grenades Yours, however, is not just a stick and some string. You staff will have the following features: It is the arming device and the radio transmitter for net bag separation and detonation. When you load the bag of grenadelettes, it keys the detonation frequency to that staff alone. When you swing the staff and launch the net will separate in 3 seconds unless you trigger it sooner and the marbles go five seconds later unless you trigger it sooner or later. The handle of the staff will have 2 buttons that have to be held while performing the launch motion. Lift a finger off the first and the bag separates, lift off the second and the grenadelettes go boom. If you hold the detonation button you delay the boom as long as you like, allowing you to seed an area and wait for the enemy to get into a good place to die. A staff sling is easy to use, and with practice you can get pretty precise with one. As a bonus, your grande guy has a staff for close quarters, and he can also throw things from regular grenades, to rocks, to water balloons at the enemy [Answer] ## Magic Magnets - Crazy enough to work...? Since you don't want these things SHOT, and you want to be able to trigger them safely, potentially many at a time, with a reasonable range (yet close), how about a magnetic trigger in a throwing stick? This is close to your sling idea, but with a dedicated but relatively low-tech lightweight tool for activating the grenades and simultaneously giving leverage. The idea would be that the grenades are attracted to magnets (metal casings, fuses, whatever). But three magnets in a very specific arrangement will prime the fuse, then REMOVING the magnet will activate it. This allows your grenades to be activated ONLY when placed in the perfect proximity to the right arrangement of magnets. Now you carry a throwing device like a lacrosse stick/atlatl/jai alai cesta with seven (or however many you want) magnetic pockets on it. The grenades drop into these pockets, are held firmly into place, and the triggers are primed by the correct configuration of magnets. In/on the stick is a trigger that is slightly tricky to push/squeeze, and this pulls the internal magnets away from the grenades as you sling them at the enemy. Obviously, this would require some training to do safely, but it beats having a handful of live grenades in your hand, and will be silent, while getting you better range than trying to toss a handful of marbles. You can still have the ability to throw individual grenades, either by plucking them off the stick individually, or having a plate with a magnetic spot (capped) on their uniform or have a ring that can be touched to the grenade to activate it. In those scenarios, the grenade is held in place until you're ready to throw it (hopefully not that long). A suicide vest version of this would include an electromagnet that activated all the munitions, then released dozens (hundreds?) of these at once with a repulsive electromagnetic field scattering munitions in all directions akin to the typhoon ball-bearing shooter from Deus Ex. It MIGHT not be suicidal, but this would be really dangerous to use if you wanted to live, so limit this to kamikaze tactics. A vest like this could be an adaptation of the storage vest for your regular grenadier, making capturing your grenadier a really risky proposition. The same priming mechanism could be used to arm grenades inside any kind of grenade launcher you might want, either by permanent magnets or electromagnets, so your throwable munition would be equally standardized to a wide range of potential grenade launchers, including an electrically triggered caseless grenade launcher where the launching charge detonation and the priming charge are simultaneous. Such a system with low-velocity grenades could be made cheaply, so a multi-barrel launcher working much like a cheap firework (paper barrels, etc.) could be deployed as an offensive or defensive (booby trap) weapon. If a cheap remotely triggered launcher fails, so what? You may want a second device with four magnets that disarms the grenades, so the grenade you decide NOT to throw still has a way to be disarmed. Perhaps a color change for each state the grenade is in would be helpful as well (green= not armed/yellow= primed/red= armed/black= disarmed). But grenadiers were considered elite troops because you had to have a certain reckless courage to voluntarily use hand-delivered explosives as a weapon. [Answer] Lets make a two stage fusing system: Stage 1 is the transport container they come in. So long as they are in the container they will not detonate. Your choice whether they are again safe if put back into the container. Stage 2 is they contain a small multi-axis accelerometer. When the accelerometer senses a two second period where the acceleration remains below 1 m/s it arms (Edit: Remember, gravity. The accelerometer will be sensing the local gravity--they are arming from being in free fall), it then detonates once acceleration returns to at least 5 m/s for a period of 1/2 second. (Note that these values might need to be revised for different worlds.) If you drop a flake it does not experience the 2 seconds of low gravity, it does not arm and thus does not explode when it lands. A collision with a minor object in the air does not set it off, the acceleration must be sustained--it only goes off when it comes to rest, but it goes off soon enough after that to make it hard to get away. [Answer] The only way that I can see of making flake grenades safe is to have a proximity safety system. Flakes are stored with a small, low-powered transmitter. When removed from the vicinity of the transmitter - say five metres - they are armed on a time delay, and then detonate a couple of seconds later. All members of a team would have identical transmitters. That way, a dropped flake won't accidentally blow up team members... but leaving a bunch in a trench as you leave and enemies arrive will give them a nasty surprise. [Answer] ## Rely on C4 explosives I'm honestly surprised nobody mentioned C4 earlier, since it's the most stable explosive ever invented and it can only be practically triggered by a detonator. The hardest challenge with designing a powerful grenade relying on C4 is to develop a reliable trigger to delay the explosion until the grenadier launches the grenade where it needs to go. Provide the grenadier with a grenade launcher, develop a grenade detonator so the grenade arms itself after being launched from the grenade launcher and detonates after a pre-determined amount of time has passed (several seconds). This way the grenade is inert and safe until it's properly applied by the grenadier. <https://en.wikipedia.org/wiki/C-4_(explosive)> [Answer] Have each flake contain a radio frequency (RF) device. Each grenadier also has a RF device. Whenever the flakes are near the grenadier's RF device they will not detonate, but once they are at least a specified distance from the grenadier's RF device the flakes explode. A similar type of system has been proposed to prevent unauthorized people from taking fire arms from law enforcement officers and using them against the officers. [Answer] Solid state I propose mini solid state circuits as triggers. One solution would be to put [Hall effect](https://en.wikipedia.org/wiki/Hall_effect) sensors in the circuitry, and store the flakes in magnetic containers. As long as the marbles are in the container, they are inactivated. However, remove them from the magnetic field, they activate. The process of removal from the magnetic field could also charge internal battery/capacitors to power the circuitry and provide for a spark detonation. Maybe shake them in the magnetic field before removal? In storage, they could be kept very low powered, not enough for detonation. If used as a [thermobaric device](https://en.wikipedia.org/wiki/Thermobaric_weapon) (see below) the removal from the magnetic field could also cause local heating in the flakes (eddy currents) sufficient to pre-heat the gases. > > This weakness may be eliminated by designs where the fuel is preheated > well above its ignition temperature, so that its cooling during its > dispersion still results in a minimal ignition delay on mixing. The > continual combustion of the outer layer of fuel molecules as they come > into contact with the air, generates additional heat which maintains > the temperature of the interior of the fireball, and thus sustains the > detonation.[10] > > > GPS as detonators GPS circuitry has been reduced to the microchip level in such devices as smart phones and cameras. Once activated by removing then from the magnetic field, they could be field programmed to explode only when they reached certain GPS co-ordinates. Outside of these co-ordinates, they would be harmless. Hive mind There is no reason that every single flake should be identical. These flakes are used in congregate scenarios. Only a few need to be trigger units. They could send out an RF signal that detonates the 'slave' units. All of the flakes work in co-ordination with each other, but each one could have a specialized function. They share one intelligence. Air fuel explosion if they contain pressurized gas, then the trigger mechanism could just chemically burst the exterior shell, releasing the very explosive gas into the atmosphere. Given that the flakes are dispersed over a wide area, the [air fuel thermobaric mixture](https://en.wikipedia.org/wiki/Thermobaric_weapon) would also cover a wide area. > > They are, however, considerably more destructive when used against > field fortifications such as foxholes, tunnels, bunkers, and > caves—partly due to the sustained blast wave and partly by consuming > the oxygen inside. > > > Also > > According to a U.S. Central Intelligence Agency study,[15] "the effect > of an FAE explosion within confined spaces is immense. Those near the > ignition point are obliterated. Those at the fringe are likely to > suffer many internal, and thus invisible injuries, including burst > eardrums and crushed inner ear organs, severe concussions, ruptured > lungs and internal organs, and possibly blindness." Another Defense > Intelligence Agency document speculates that, because the "shock and > pressure waves cause minimal damage to brain tissue ... it is possible > that victims of FAEs are not rendered unconscious by the blast, but > instead suffer for several seconds or minutes while they > suffocate".[16] > > > Detonated all at once by 'trigger' flakes, the explosion shock wave would be greater than that of just a single flake. The air fuel explosion would raise temperatures to incendiary levels, igniting everything in the vicinity, and as a secondary effect, consuming all of the oxygen. It would not be a kinetic impact weapon, but a blast wave weapon followed by an incendiary weapon followed by an asphyxiation weapon. By using them not as a point weapon but as a dispersed weapon, it enhances their functionality as multiple small units rather than one large unit. It would be destruction by a thousand cuts, instead of one big knife. Launch method If these flakes were kept in the magnetic canister, the entire canister could be attached to a lanyard, swung around to gain momentum, and then a trigger mechanism would open the can, dispersing them in mid-arc of the swing. Aiming would be a problem, but they are wide-area weapons anyway. Close counts. [Answer] Put them in shotgun cartridges and fire them from a shotgun. This idea is basically a very convenient version of a grenade launcher. With numerous variants of the shotgun you have lots of ready made options of how to carry and fire them, including [fully automatic shotguns](https://en.wikipedia.org/wiki/Automatic_shotgun) and/or with high capacity [drum magazines](https://en.wikipedia.org/wiki/Drum_magazine) for sustained firing. You can also build the cartridge to protect the tiny grenade from accidental detonation. Considerations could include protection against accidental detonation: * from mishandling - perhaps a hard casing to protect against crushing forces (eg stood upon and driven over) * while being fired/launched by using less powder to soften the jolt of being accelerated, albeit at the expense of range * by using longer barrels to compensate for using less powder * by encasing the grenade in lead to increase its weight, giving longer range for a given muzzle velocity, and/or providing higher inertial mass to slow acceleration to protect again launch jolt ]
[Question] [ Imagine the following situation: a late 16th century knight loses his horse in a battle and is forced to flee into a forest to escape capture. He lost all his weapons but still has his plate on (a full set from head to feet). Will this aspect save him from an animal attack? (For the sake of keeping this narrow, let's consider that only the following will attack him: A pack of wolves, a bear, a snake.) [Answer] First of all, a note: 16th century is a bit late for full plate. By then, high-end armor was made with firearms in mind, with a thick cuirass with reduced limb coverage to save weight. Plate was also widely available to infantry, not just cavalry. Plate armor is designed to protect you from sharp things coming from the usual directions in combat. Where protection is not necessary, comfort takes priority, so it's not a solid second skin. A pack of wolves will surround the victim and keep biting the limbs - which have limited armor coverage. The back of the legs, in 16th century plate armor, would be at best covered by leather, which is difficult but possible to bite through. However, plate armor was commonly worn as an addition to mail (chainmail), especially by cavalry, and older mail [chausses](https://en.wikipedia.org/wiki/Chausses) with total coverage would still be found in the 16th century. Mail is so effective against bites that it's used to this day for shark filming. If the knight is actually fighting back, he will be able to fight off the wolves, and be almost invincible if wearing a mail layer. The plate armor will mostly just make him sweat more. Bear claws and teeth can also be resisted by mail and plate, but bears can be quite large. Medieval armor offers limited resistance against full-body crushing blows. The bear will be able to break the knight's limbs, crush his chest, damage muscle with bites even through mail, and cause death through internal bleeding. Unless the bear is scared away or killed, armor is not sufficient protection. Finally, a venomous snake has little respect for chivalry. Snake attacks are unlikely, and persistence even less likely. But most venomous snakes are small and hard to notice, and there's plenty of holes in the armor. There are multiple ancient tales of mighty knights and kings falling to a snake. That is, if exhaustion and thirst don't get him first. P.S. Regarding exhaustion, infantry armor was designed to support marching in it for weeks. Modern weight-accurate reproductions are very comfortable to spend days in. A knight's armor is less comfortable for long walks, but a forest offers some shade. So it's possible and likely that one would keep their armor, since it wasn't easily replaceable, unless doing so was an immediate threat to their life. P.P.S. This answer implies that the specified animals attack and persist in their attack. In reality, a walk in a European forest wouldn't present much danger. Most predators don't wake up with "Attack another predator, preferably an elite fighter of their species" on their to-do list for the day. Now, stranded in the Taiga or the Amazon... but the real danger would be mosquitoes and other insects, not large predators. [Answer] IMHO an unarmored man, let alone a armored man, would be rather safe, but not totally, walking through a forest in Europe. There were people too poor to afford any armor who worked in forests and spent all their time there, after all. And a man would be less safe walking through some forests in other continents. Wolf attacks are rare in Europe and even more so in America, but they do happen and wolves do kill and eat humans. But even the Beast of Gevadaun supposedly killed only one unarmored man, the rest of the victims being women and children, and some unarmored women and children managed to fight it off. Most of the victims were children, guarding flocks of sheep, who were used to chasing off ordinary wolves with dogs and stones, and weren't prepared for a child-eating wolf at first. An armored man should be able to kick or strangle a wolf to death. There are lots of dead branches lying around in most forests so the armored man could pick up a branch and club a wolf. Thus an armored man could probably beat off a lone wolf attack. A rabid wolf would run around biting animals and objects and would attack an armored man. The armored man could probably kill or drive off a rabid wolf as easily as a normal wolf, but might possibly get rabies from touching any saliva on the armor later. When really hungry, a wolf pack will attack large and dangerous and/or unfamiliar prey, so wolf packs can, and sometimes do, attack men. The wolves would find an armored man to be really hard to bite. Would they give up or keep trying to kill him? Wolf hunting was a sport for European nobility and royalty. Louis the Grand Dauphin (1661-1711), son of Louis XIV, is credited with killing over a thousand wolves in his lifetime. His relatives, including women and children, also hunted wolves. Bear attacks are rare, but do happen sometimes. Even the smallest species of bears is large enough to kill a man, though many people survive bear attacks with various amounts of wounds. The brown bears in Europe are larger and stronger than American black bears, being Ursus arctos, the same species as the dreaded grizzly bear in North America. Nobles in Europe often hunted bears for sport, and probably worn less than full plate armor for protection. For example, Emperor Louis IV (1282-1347) died of a stroke during a bear hunt aged 65. Even though the largest European brown bears should be as strong as grizzly bears I find it hard to believe that they could break or dent steel armor. But a brown bear could knock an armored man around a lot and he could get really banged up inside his armor if his padding wasn't good enough. So a bear attack could injure or kill an armored man even though the claws would never touch his flesh. But I don't know what the odds would be. A venomous snake would bite if stepped on or startled, but would only strike once or a few times, and its fangs would be unlikely to penetrate a chink in the armor. If the armored knight noticed the snake he could stomp on it, kick it away, or jump out of reach of the snake. A giant tropical constrictor snake wouldn't be able to suffocate the armored knight and might cut itself on the sharper edges some armor had. In the worse case, the snake could die wrapped around the armored knight and the knight might be trapped there and starve to death. The largest herbivores found in some, repeat some, European forests in your time frame could knock around an armored man a lot, more than a bear could, and might injure or kill him from being banged around inside the armor. But all in all, a typical European forest in your time frame would be fairly - but not completely - safe for a man without armor to walk through, especially if he was being hunted by human enemies outside, and even safer - but not completely safe - for an armored man. [Answer] Interesting question. As has already been mentioned, 16th Century armour was quite different from that seen in the 15th Century, primarily due to the advent of increasingly effective firearms and secondly due to the increased mobility of warfare as history moved into the modern age. Early 16th Century battles like Flodden (1513) were one of the last instances where fully armoured men would have faced each other. However, fully armoured infantry were becoming replaced by partly armoured as is seen in the Landsknecht (spelling!) mercenaries found in 1500s Germany and Switzerland. I suspect you are referring more to the type of armour seen on battlefields in the 1400's, at Bosworth field and Towton. ### Would this be any good vs wild animals? Yes, it would be, in the extent that it would stop you getting bitten however, armour is not designed to be worn for long periods of time, certainly not by infantry. I own a set of infantry armour of the type that would have been worn at Towton (1461) by a well to do gentleman-at-arms. This is far from the custom sets of tightly fitting armour worn by the super rich aristocrats at the time. By the 1400s, armies in England and those opposing English armies were fighting mostly on foot, horses were used to transport the army (as during the Agincourt Campaign) and for scouting or for pursuing a broken foe but were never used against infantry. Bannockburn (1314) had shown what a small, well trained army of phalanxed pikemen could do to armoured horse; by the time Edward III and his son the Black Prince had perfected the longbow armed mounted archer (mount used to transport archer) using mounted men against formed longbow archers supported by armoured men at arms (infantry) was shown to be utter folly. The main problem using the type of armour I own is weight. TV gives us the impression that it is relatively easy to move and function wearing armour. This may be the case with the thin aluminum worn by modern actors but, speaking from experience, you have to be in peak physical condition to wear real armour and function in it, let alone fight, for longer than a few hours. Multiple period historical chronicles of the aftermath of battles describe beaten and fleeing troops stripping off their armour to escape. To the modern reader, unschooled or with no experience of actually wearing armour, this seems like a rash thing to do, but the reality is, if you need to run very quickly then your best bet is to ditch the armour as quickly as possible because you will certainly be able to outrun those who are still armoured - i.e. the victors, unless they are able to mount to pursue you. ### This is the crux of it - running Running is critical to surviving wild animal attacks. OK you can't outrun a pack of wolves or a bear but you could feasibly run somewhere safe. Now my armour consists of this - skin up: * 1" thick padded linen arming jack (jacket) with 1" think padded linen leggings * maille (chain mail) leggings and hauberk (vest) these are by far the heaviest items. The Hauberk weighs 25 kilos, each leg, 9 kilos. * over the maille goes armoured lower arms and upper arms (14 gauge steel (4 kg each)) hinged and protected elbows * greaves (lower legs) and thigh pieces (14 gauge steel (10 kg each)) hinged and protected knees * back and breast plate of 14 gauge steel (15 kg) with interlocking steel plate kilt which comes to mid thigh * steel gauntlets (5 kilos) * steel shoulders (spauldrons) (8 kilos) * steel gorget and beevor (4 kilos) this protects the neck and lower half of the face * lobster tailed sallet (helmet) with half visor * as an alternative to gorget, beevor and sallet you could wear a visored bascinet (usually with a pigs or hounds shaped visor to allow comfortable breathing) which has a maille avantail covering the neck and shoulders. These were going out of fashion circa 1420 but were still being used by some poorer men mid 1400s and are used for full contact fighting in modern times as they are safer than the sallet/Beevor - they fell out of fashion because visibility and comfort (O2) is seriously compromised and they also weigh 12 kilos and that weight is right on your neck. Under either helmet option you would wear a padded arming cap (looks like a thin version of a Russian tank helmet (1" thick padded linen). You can add up the weight yourself - when wearing the above for reenactment or for fighting full contact with blunt weapons I typically lose about 1 kg in sweat. It is literally exhausting. Now yes, a mid 40s modern man like me, even a fit one does not have the sheer physical strength of a 20 something 1440s man at arms who would have been trained to wear such form an early age, but even so, would not have worn it for anything other than combat or training for combat. Indeed historical chronicles frequently stress the size of baggage trains and going back to even 1066 we know that Harald Hardrada was beaten at Stamford Bridge by Harold Godwinson's Saxon army because his force was surprised and was unable to don its armour (in those days maille) which had been left on board the longships whilst Hardrada and his men feasted. Indeed, one of the only accounts of armoured incursion was Henry V's small mounted force of men at arms and archers who marched across Normandy and Picardy to the Pas de Calais during the Agincourt campaign. The fact that Henry ordered his archers and men-at-arms to ride in their armour, and not to take it off for the duration of the (forecast) 5 day ride was unusual enough to have been cause for comment by the chroniclers of the time. The purpose was to move very fast, with no baggage train and no tents. It poured with rain for most of the march and the men were suffering from dysentery. Most slept in hedges or on the open ground. On top of this, wearing steel plate either makes you overheat or it makes you very cold indeed, especially if you are wet. Your body heat is conducted through the wet arming jack to the steel - a brilliant radiator of heat. Having worn armour for one single day in the wet, without dysentery, I have nothing but huge admiration for the discomfort and fortitude of the men who won Agincourt. By the time the battle was fought they had been on the road, in torrential cold rain for several days and their armour would have been pretty rusted. Armour being carbon steel which, unlike stainless steel, does not shatter. Would I fancy being in the woods wearing armour of this type when trying to escape wild animals? Not on your nelly! Would I fancy being in the woods wearing the sort of armour an archer of the period would have been wearing? Absolutely. Archer armour of the period was usually: * gambeson with chains. This is a very thick padded linen jacket, a good 3 inches thick and it has long linked chains sewn into the arms from shoulder to wrist. The single biggest mistake that writers of this period make is to repeat the myth of 'leather' armour. Leather armour is a Victorian fallacy, created to explain the 'coat of plates' or brigandine - which was a leather jacket with steel plates sewn on the inside of the jacket and frequently used instead of the back and breastplate described above. The lightest and most effective armour of the time was the padded gambeson, which is surprisingly effective against slashes and cuts but is exposed by arrows, bolts and thrusts by solid shaped points (spears, the pointy bits of pole weapons and the very nasty rondel dagger (think 16" 3 or 4 sided steel spike). The arm chains are there to give some protection to limbs from blades. Gambesons protect effectively from concussive blows. * On the legs the archer is seen often wearing padded leggings with either maille leggings or plate leggings of the type described above, or maille and plate on top. * a plate steel gorget with a sallet (usually without visor or beevor) would be worn on the head. * aside from the bow, the archer would be armed with mallets, axes, (for making the sharp stakes used to defend their position from horse attack) arming swords (one handed) and just about always either a vicious rondel dagger (above) or a more traditional ballock (bollock) dagger whose hilt is shaped... well... like bollocks. These daggers were specifically designed for murdering armoured men and the archers at Agincourt and Crecy did terrible carnage to the French men at arms once the men-at-arms were off their feet and lying in the mud: again, this shows the problem of wearing armour. The armoured infantry attack of the time would have been a bit like the tactic you see forwards use on the rugby pitch or the offensive line on an American Football pitch when they make a closely packed formation to protect the ball - it is effective because they keep their formation cohesion and use united strength. Imagine 4,000 men at arms, all armoured as above, all holding either pole axes or bill hooks, with hammers and rondels on their belts packed in tightly together, moving towards you at a rolling pace - about as fast as you can go in armour - shoulders hunched and heads down to present the strongest part of the armour to archers (the shield was out of use by the mid 1300s due to the improvements in armour). They key to their effectiveness was their momentum. They would smash through any line of unarmored troops. Provided they kept on their feet, they were the tank of the age. However, when off their feet, bogged down in mud - they were hugely vulnerable and when this happens we see men shedding their armour as quickly as they can, they would often keep a small, accessible and very sharp knife to hand so they could quickly cut the straps and the points (strings) which held the armour to their bodies. When such a formation was fought to a standstill or, worse, fell over and piled up on top of itself, lightly armoured men like archers, with suitable tin opener type weapons would have them at their mercy. Whilst this doesn't directly answer your question, I wanted to give you some feeling to what period armour was actually like for the vast majority of armoured men and knights. It was only the super rich who could afford the Milanese or German customised plate which was designed to distribute the weight across the body and made from the most super hardened carbon steel possible with period technology. The vast majority wore a collection of bits and bobs, antique suits adapted and remodeled and pieces captured and adapted from other men. Even the customised suits restrict movement to some extent and also make it difficult to cover ground quickly. \\\* - in response to the 'modern soldier has 100lbs of kit twice the weight of a medieval knight's kit' and Heavy 'plate mail' being a Hollywood myth. Both these statements are incorrect. Full armour from around 1450 weights at least 100lbs on its own. There is no such thing as 'plate mail' there is plate armour and there is maille (chainmail does not exist). They were frequently worn in combination which was the most affordable protection for most armoured men from 1330-1485. A modern soldier's kit is about twice the weight of what an archer between 1330 and 1530 would have carried onto a battlefield. It is certainly not twice the weight of what 99% of armoured men would have carried, if anything, it is lighter. Yes, there were some very wealthy men with customised suits of armour which weighed as little as 60lbs but these were extremely rare and vastly expensive, being custom made from the finest steel possible. Anyone who doubts this is very welcome to come to my house on the Anglo Scottish border and try wearing my armour - a faithful reproduction of an averagely wealthy landed gentleman at the time of the Wars of the Roses! [Answer] Regarding the weight of the armor argument, no its weight won't kill you, modern day soldiers have a very similar equipment weight when marching and in combat, and have a worse distribution. The ultra heavy plate and chain mail is a Hollywood myth. [You can do gymnastics and run an obstacle course](https://www.youtube.com/watch?v=pAzI1UvlQqw). Against the wild animals, it depends. As Therac said, the wolves would probably not penetrate the the plate, the mail, or the padding, which is used today to train police dogs. But the bear probably is strong enough just to crush you and the snake will find a hole. [Answer] I thought I remembered something. <https://www.youtube.com/watch?v=1MEUOW7cERI> And several other such vids about the same guy. He developed a suit of armor intended to protect him from a grizzly. Eventually he got a thing that could protect him from getting hit by a truck, by a thrown log, and from rolling down a fairly steep hill. Combination of padding and armor. Plus, I suspect, a certain tolerance for pain. After all, if a bear throws a log at you from a truck at the top of a hill... [Answer] I have not delved deep into armor myself, but I have spent countless hours on Shadiversity's youtube channel. I believe the knight would be able to pull through in all 3 situations, for the following reasons: 1. Knights were rich people (a plate mail would cost the equivelant of 5-10 million of todays dollars) who devoted their entire time in training their fighting skill. This is very important, and I agree that improvisation tactics such as fighting with a piece of wood would come easily to such a fighter. 2. I disagree with the most voted answer about holes in full plate. The way to really beat an armored knight is to incapacitate them somehow, maybe by tiring them/stunning them with a strong crashing blow to the helm, and then quickly use a dagger on a gap. That's why crafters would do their utmost to avoid gaps in the armor. Could a snake find such a small gap within a towering metal giant? Not fast enough, if the latter is an experienced fighter on their guard. 3. Bears are dangerous opponents, sure, but teeth do not beat metal. Also, in order to bite, they would have to do it on a small body piece, ie a limb. They might crash it alright, but I don't think they would be "allright" with the material being steel. Even worse, if they don't bite-and-run, which I don't think bears are used to, they are putting their most vulnerable part, their face, in reach for the knights gauntlet fist. This would be enough to scare them. All in all, the combination of a proved piece of armor along with considerable skill would beat such opponents. [Answer] When my grandfather was a boy there was a $20 bounty on wolves. Which, at the time, was close to a month's pay for a lot of people. The blacksmith in his little town used to hunt them for supplemental income. Now, wolves are smart. The bounty was so high because it was hard to get them. They learn about traps quickly, and they'll run from anyone they even think might have a gun. So the blacksmith made a suit of leather armor with large metal studs so that the wolves wouldn't be able to bite down very well and then he'd go wander through a pack's territory until somebeast got bold enough to attack this unarmed, defenseless target. Then he'd strangle it with his bare hands. He said two or three weren't generally a problem. Four or five and things started to get a bit dicey. Six or more and you'd better be looking for a way to get out of this situation. Plate armor is a bit more impenetrable, but it's held on with straps and a determinedly hungry wolf could probably rip it off eventually. Plus it doesn't have the studs so it would be considerably easier for the pack to grab arms and legs and drag somebody to the ground and pin them. Once they do that then it's just a matter of time. The straps will break eventually, and that's assuming the particular set doesn't have any easy gaps to get into. Protection against a bear? A little blackbear maybe. Definitely not a grizzly. There's a documentary running around somewhere about some researcher who wanted to study grizzlies and the suit of armor he was working on so he could do it safely... Modern materials and engineering, considerably tougher than a suit of full plate... And when he put it up against a simulated paw swipe? Well, he lived... But it picked him up off his feet and tossed him on his back like a rag doll. The bear probably couldn't eat him, but kill him? Sure. You can scramble an egg without breaking the shell if you just shake it hard enough, which a big bear can definitely do if it wants. Snakes, spiders, and other venomous things? The main threat time from those is going to be in the mornings when you're putting your boots on... The plate will offer some protection the rest of the time as long as the strike doesn't happen at one of the joints or against the face. But a good set of leathers will do almost as well at a fraction of the weight. ]
[Question] [ There is a device in my story that »steals« memories from a person (I had some sort of transmitter in mind, but this can easily be modified, as long as it uses powerful long-range signals to achieve its function) and uploads it into its server, where it can be accessed for further use. A person completely loses his memories when they are stolen. I have no idea how to explain the process of that happening, I was intending to qualify a memory simply as files like pictures and videos on a computer (this can be modified) all of which the device then somehow steals, but I need it to sound believable and at least to some extent consistent with basic laws of computer sciences and neuroscience since such a technology is probably mindboggingly far fetched. I am no expert on both of these topics so I humbly turn to you for help. [Answer] We don't know how to digitize, copy, delete, edit, or record memories. The technology to do so is so far advanced from what we currently understand as to be indistinguishable from magic. Any attempt to provide a science-based explanation for how machines are remotely stealing them will come across as awkward for anyone with even a minimal understanding of neurology. What will probably be best for the believability of your story is to skip the explanation entirely and leave the inner workings of the dream stealing machine a mystery. If you really need an explanation, any cool sounding technobabble should suffice. [Answer] Make it so that each and every person on earth wears an implant that enhances brain functions: increase memory capacity, faster thought processing, and such. That way, memory can be read and written, and stolen, by remotely accessing the device. Artificial enhancements to organs, including brain, should be pretty common in the future. [Answer] As the answer by sphennings pointed out, there is a lot which is still unknown about the human brain. But a plausible theory is that long-term memories are stored in form of the configuration of synapses and neurons in the brain. If the process to scan them would have the side-effect of destroying (or at least reconfiguring) them, the result could plausibly be loss of long-term memory. [Answer] Memories are stored in the brain as neurons, which work by conducting electrical impulses. One could imagine that in order to steal a memory, you'd first force the neurons to fire, and then use your (immensely-sensitive) device to capture at long range the pattern of impulses that results. Let's say the act of forcing the neurons to fire requires a powerful signal directed at the subject's brain. Perhaps the signal is so powerful it actually fries them in the process. Or perhaps the capture process requires the memory to be fired many, many times in quick succession in order to correctly capture the pattern, causing the neurons to degrade rapidly. [Answer] You can copy (or copy-then-delete to "steal") files from a computer by sending it a signal only because it has hardware to receive the signal, and software that interprets the signal as commands to send/delete things. The target computer cooperates in the process of stealing the file. Even "hacking" to copy files that the computer isn't intended to give you works by figuring out that a defect in the software means it interprets certain signals as commands in unintended ways. It still basically depends on the target computer's cooperation, it's just that the computer cooperates in ways/cases that it wasn't intended to. You cannot steal files from a computer just by beaming a signal at it if it doesn't have hardware for receiving that signal and sending responses (and almost certainly not if it isn't running software intended to listen to that hardware and send responses back). So I find it hard to imagine how you could simply beam a signal at a brain and have memories get transferred or deleted, if it's any kind of signal that science currently knows about. The brain does "listen" to sensory inputs of course, and "send responses" in the form of speech and motor control. So you could posit that certain patterns of light and/or sound could exploit a defect in the human brain that cause it to delete memories, but it seems you'd need large quantities of handwavium to explain how you "target" memories, why the feature being exploited is universal in all human brains when it serves no evolutionary purpose, and especially how you actually record a memory (does your pattern make them go into a trance and write a detailed account, then wake up without the original memory?). But, you could posit other technology changes that would allow the victim's brain to "cooperate" with the memory thief. What if in your world it's common to have neural implants that have access to memories? The intended benefits of this technology could be improved (even perfect) recall, storing more information, making learning new skills (or at least rote memorisation) easier and faster. Perhaps it's even intended to allow memories to be transmitted, as the new form of sending postcards from holiday or posting your meals to social media. And certainly we can imagine them being networked, so that the device could receive and store messages and play them directly into your brain as desired. Then all the inventors of your memory thieving device would need to do is find a flaw in the implants that causes the device to delete memories and transmit them, in response to specially crafted signals sent along the normal networking channel. More realistically they would need to find separate flaws in every specific model of the implant, but perhaps these are the smartphones of the future and one or two companies have captured a large fraction of the market at the time your story is set, so that the flaw could be in a part of the software that is common to all or most devices. If the neural networking infrastructure works somewhat similarly to current mobile phones, then the devices would be intended to send signals to towers kilometres away, and you could probably boost that range significantly using an extra-sensitive receiver in your memory-hacker (to pick up the more attenuated return signal from further away). If the neural implants are intended to communicate long range by talking to satellites then you can probably hack from almost any distance provided you've got a moderately clear line of sight (going through buildings is probably fine, going through the Earth probably not). If the nature of your exploit is that the hacking signals are compatible with the "routing" used normally in the network you might not even need line of sight at all; you just inject your signal into the normal stream and the ordinary network will carry it to your target. But if you don't want it to work like that you could posit that the exploit requires a signal that isn't ordinary network packets (which might explain why the possibility was never identified in testing), so you have to beam your pirate signal directly at the victim because the network wouldn't forward it for you. [Answer] There are two ways I can currently think of : * You mentioned a powerful long-range transmitter to steal someones memories. You could say that the radiation emitted from the transmitter would damage the brain of the victim while extracting the data. The brain damage results in destroyed memories (Memories are stored as neutrons and connection between them) . The only problem I see here is that scientists as for today think that memories are distributed redundantly, meaning that loosing some neurons doesn't result directly in loss of memories. Neurons die all the time and new ones are created. Although if you destroy all neurons associated with the memory you would loose it. * Another way of explaining the memory loss is that the device does this on purpose. Like a computer can copy files and then delete the originals. The device would function like a virus stealing data and deleting it afterwords, depending on your story this might be a good choice. [Answer] Each person's brain develops slightly differently. Memory is stored not like files on a computer but as a giant associative net where each memory is connected to a related one. Because of this it is to today's knowledge not possible to extract memories or 'implant' them in someone else. However what might become possible is that you can reconstruct a dream, a daydream, one's mind's eye or even someones thoughts by the activity in a brain. But this requires a labeled training set of brain activity (for each person) + what that person was thinking about at that time. For example [here's a video](https://www.youtube.com/watch?v=nsjDnYxJ0bo), in which a video has been reconstructed from brain activity. And scientist have also been able to 'read' parts of mice's dreams after observing their brain patterns during the day: <https://news.mit.edu/2002/dreams> [Answer] We currently don't really know much about the workings of the brain on the level of memories. We can use that to our advantage by working backwards. Let's say we take a large (but not mind-boggling) leap, and say we find a way to selectively destroy memories by scrambling neural connections, probably with a variation on [TMS](https://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation). Let's say researchers then measure the distortion in the magnetic field or something. They figure out it's not random. They then manage to decode the "deleted" memory from that signal. The researchers then realise their machine can be used to read memories from anyone, albeit destructively. What started out as a project to find a way to wipe memories (for whatever reason, nefarious or otherwise), suddenly turns in a way to actually steal memories (for nefarious reasons, let's be real). Those researchers will probably get very rich or very dead very quickly. Or just skip over the explanation completely. It's fine if the audience doesn't know how the Magic Box of Memory Theft works, they just need to know that it works and it's because of Science, and they'll happily suspend disbelief. [Answer] There's talk of memory storage occurring in dna upon methyl groups being added to dna. Remove the methylation process and short term memory vanishes. Add the methyl group process back in and memory production recurs. In this way, even though proteins are used up in neural synapse firing, there is still something left behind that holds the info--the dna. <https://www.google.com/amp/s/www.newscientist.com/article/mg20026845-000-memories-may-be-stored-on-your-dna/amp/> Your device will need to extract the dna, and chemically treat it to access the code (remove the methyl groups). Most importantly, the device will then also need to somehow get the key to the code the person used to store the memory into the dna. That's the tricky part since without the key, the memory is just a bunch of gibberish. So, then the device must also trick the dna into believing it is within the code-generating organism so it will allow access to the key. How to do that? Since the purpose of the memory storage is to hold information until needed at recall, the dna is alerted to transfer the coded info upon stimulation by...another dna molecule. So, keep some of the dna methylated, start the synapse firing sequence same pattern as observed within organism prior to the extraction, and the extracted demethylated dna will receive the keyed info and overlay it onto the coded memory. It cannot transfer the keyed info back however due to the missing methyl group, so it sits there now with the info decoded and available to be read by yet another part of the amazing memory extracting device. Since all memories in the original organic brain must be destroyed in your story, upon completion of memory extraction, a huge bolus of a cocktail of every stress hormone ever in existence is released into the blood stream, and the memories are magically gone. Well, not gone, exactly. They will instead be replaced by one overpowering memory of the horror of the extraction process, since the stress hormone cocktail basically imprinted that current memory as the most important thing that has ever occurred to this brain and therefore it must be retained. [Answer] Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. In the future, we might have completely decoded and understood the brain. I think we already can tell now, that the brain generally works like a (quantum-)computer. This means, if we do understand exactly how the brain is working and built up, we would be able to develop technologies, to manipulate the brain the same way, as we manipulate data on a hard drive. Meaning, we could read memories, manipulate them and delete them. [Answer] You will have to make some assumption of sorts about how memory is stored inside the human brain. At the moment, we are far from having a scientific agreement on the matter: some hypotesis involve synapses, certain memory-specific brain areas and even the single neurons themselves. As a writer, though, you don't have to be 100% scientifically accurate. As many other suggested, you could just hint that the scientific community inside your world has a perfect understanding of the brain's inner workings and leave it at that - at least for what concerns memories. If you'd like, you could choose one hypotesis of your liking and give few further explanations on that (e.g. : if memories are stored as the quantity of synapses between specific neurons, your machine would be able to decode and destroy those connections). I would be more concerned about how the transmitter works. It seems reasonable enough to have an "antenna" inside our brain able to read its content (maybe it monitors signaling around neurons?) but how would it be able to erase anything? I'd rule out bio-chemical ways of doing that - since they would be too imprecise. Maybe you can erase certain "memory-storage-units" (them being synapses, neurons, or whatever) with high voltage, precise electrical shocks - burning them, in practice - but you would need some sort of system able to specifically target only the items you want to destroy. Imho, the only good option here would be highly specific nanomachines. It's technobabble, allright, but it's also one of the sensible options. Also, if I were you, I'd make the transmitter work at night, or whenever the subject sleep. It makes sense and reduces the chances of being discovered by the conscious mind of the subject - plus the erasing part may include some pain. [Answer] Memories and dreams get their substance on another level of reality, the very level where Universal Mind lies. On that level of reality, memories can be handled just like the marbles depicted in Pixar's "Inside Out". I've been told that bee-like animals exist on that level which are able to forage memories and dreams: they steal and process them to make their honey-like food. Unfortunately memories are destroyed in that process. I've also been told that that process is the root cause of Alzeimer's disease. ]
[Question] [ Need ideas for the fox's tails. In case you're wondering, this is for a speculative evolution book I'm doing which is suppose to build a structure for a novel series about these foxes (something like Watership Down or Warrior cats). To start the extra tails are actually massive dreads of matted fur extending from the hindquarter which are religiously groomed and stretched with teeth and tongue to resemble a real tail. At the base of the tails there are long, thick hairs which are similar to spines of a hedgehog or a porcupine which help erect them as the fox flares the tails up in a shimmering fan position, which helps with both sexual display and aposematic display. While for some species, they are used for shade for desert species, as a blanket for extra warmth for both tundra and mountain species, as a form of hierarchy for pack-hunting ones, balance and for one cat-sized species that lives in the swamps whose tips of their tails have been stiffen and tangled with insects to help lure in fish near the water, like a fishing rod. The problem is that the tails could be a nuisance when stalking, pouncing or chasing after prey as the fox could easily trick over of the tails. Any ideas to overcome this handicap? Other question is how long the tails should be? Pouncing on prey has already been solved thanks to IndigoFenix's help (thanks for that) and also has running thanks to GrinningX. All is left is stalking [![enter image description here](https://i.stack.imgur.com/xWEim.png)](https://i.stack.imgur.com/xWEim.png) Something like this Copyright belongs to <http://arvalis.deviantart.com/art/Ninetales-582816024> [Answer] # Alternative Diet A [red panda](https://en.wikipedia.org/wiki/Red_panda) is kind of like a fox, and eats bamboo. If it had massive dred-tails, it could still catch bamboo. And it would probably still be cute, too. The [crab-eating fox](https://en.wikipedia.org/wiki/Crab-eating_fox) is a canid closely related to the traditional foxes (genus Vulpes). As its name implies, it gets most of its diet from crustaceans in the wet season, and insects in the dry season, with lizards, eggs, turtles, and fruit thrown in for good measure. This kind of diet is a lot easier with a big tail than chasing rabbits would be. This diet is also pretty similar to what peacocks eat, and they manage it with their own gigantic tails. Other options could be a badger-like diet that consists of digging things out of holes, or a strict insectivore. A diet based on plants, fruit, insects, fish, shellfish, or carrion or any combination of the above could all work. [Answer] Tails that drag behind you are unlikely to be tripped over while chasing something. If that thing gets behind you, causing you to turn around, it has already demonstrated that it is faster or more agile than you are and is going to get away anyway. Yes, there are probably events where the predator needs that maneuverability, but they should be edge cases. You could offset the lost prey percentage by heightening one of their senses vs. a regular fox. With that said... I think it is interesting that I cannot think of another mammal with a hairy tail that allows its tail to drag on the ground. Cats (big and small), dogs (big and small), horses (and related animals), etc. all have hairy tails, but those tails are either short enough to avoid the ground or are held aloft as the animal moves. This suggests that having 9 tails as described would create a host of other issues that are not in your animal's best interest. Dragging your tail on the ground while walking would get it COVERED in crud all the time. Dirt, mud, algae, moss, fecal matter, bugs, parasites, and any amoeba etc. This would make it highly susceptible to infection and substantially increase its mortality rate; so much so that I would be surprised if a number of parasites DIDN'T adapt specifically to inflict themselves onto this particular animal. If the tails were cleaned regularly in the typical animal fashion (licking), from a hygiene perspective your fox might as well run with its tongue out licking the ground for all the crud it's going to ingest. If not cleaned, the tails would quickly take on a LOT more weight and add considerably more drag to your animal - slowing it down and making it less capable as a predator. [Answer] Why not real tails? Yes, you'll need to think some about attachment points. But it would also allow you musculature which will make the tails much more maneuverable. For the actual question: the same way that peacocks avoid their predators, they just have to deal with the problems caused by their tails. May result in behavioral changes; ie: make them more likely to lay in wait / ambush, than to actively pursue their prey. Have you considered making this a sex-linked trait; as it is for peacocks? Another example; moose/deer have massive antlers (which get caught in trees and other obstacles and end up killing more than a few of them), etc. Typically you give these traits to males, as they're the more disposable of the sexes. Even if you kill off 10% (or much larger %) of the males, you don't decrease the number of animals in the next generation. [Answer] Maybe I'm not understanding the question. Tails are critical in hunting as counter-torsion devices allowing a hunter to adjust its ground contact for rapid acceleration changes. That is, tails let you turn and stop fast. You can read anything by Patel for more deep details. If the nine tails work synchronously, you have a regular tail. If they fan out, you have a strong windbreak or flying wing. If you had an ambush predator against flying prey, this would give amazing acrobatics. Also, if you are against small prey, tails could stun prey on a near miss, much as bats bounce insects off the stomach. And tails can be prehensile... === Patel, Amir, and M. Braae. "Rapid turning at high-speed: Inspirations from the cheetah's tail." 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE, 2013. Patel, Amir, and Edward Boje. "On the conical motion and aerodynamics of the cheetah tail." Robotics: Science and Systems Workshop on “Robotic Uses for Tails. 2015. [Answer] perhaps add the stalking issue to the design of the character. if the animal is already matted and grungy i would imagine it being emaciated two, only able to capture specific/easy prey. i can imagine that not only would the tails make the fox more clumsy but also take away from the predators stealth as they would drag the ground. the constant rustling would be an issue to the animal. but most fox species are opportunistic predators, they take what the can. they scavenge and steal, it a major fox trait. so as oppose to stalking adult rabbit the fox may be more interested in digging defenceless babies out of the nest. or stealing chickens eggs, and meal scraps from other predators. (great concept you have here. i myself am an artist and am generally wanting to draw a concept of this animal) [Answer] Ninetails holds onto the other tails with its real tail when it hunts, allowing it to maneuver however it wants to without a big problem. The tails also show superiority to its prey when it gets near, releasing the tails and intimidating them. Just an idea. [Answer] The reason why foxes have large, bushy tails is to act as a counterweight while in motion, allowing them to make sharp, agile turns. Foxes also hunt by pouncing on prey, often through high, vertical leaps. Birds often have wide, fan-shaped tails which they use for steering in flight. Perhaps this fox has a fan-shaped tail to help it steer better in mid-air while pouncing. It may also have some gliding capabilities - a proper "flying fox" family that has started to evolve in the direction of birds. The pygmy gliding possum is an example of a mammal that has a wide, flat tail for this same purpose, though not quite to the same extent as birds do. While a large fan the size of nine regular fox tails (as the kitsune is typically depicted) would be impractical due to its weight, maybe a subspecies of this "fox-bird" family experienced a case of runaway sexual selection, like a peacock. In that case, the large, showy tails would probably be exclusive to males, while females would have smaller, more practical fans. [Answer] This is the part that caught my attention: At the base of the tails there are long, thick hairs which are similar to spines of a hedgehog or a porcupine which help erect them as the fox flares the tails up in a shimmering fan position, which helps with both sexual display and aposematic display. (Porcupine quills, as per Wikipedia: Porcupines do not throw their quills, but when threatened, they contract the muscles near the skin which causes the quills to stand up and out from their bodies.) Why not just further tweak these quill-like hairs, but with a tad finer control similar to flight feathers when a bird flares and points its tail, or even curls/uncurls them or makes them fluff out for displays) it would increase aerodynamics for speed and skulking, and improve balance (Allowing them to flare the tail for walking on narrow surfaces) and keeping it out of the muck if needed, or avoid the telltale sound of something being drug on the ground. [Answer] Strangely, the one thing nobody has mentioned yet: A tail is an extension of the spine. That means the tail bones do have part of the spinal column passing through them. If the fox's tails are actual tails, then the spine nona-furcates(?) at the base of the tails, leading to effectively nine independent limbs with associated motor and sensory functions. It also means a significantly larger processing facility and muscular structure needed to control them, which ties in with the Kitsune legend of needing a hundred years to grow each tail. A newborn with nine tails would be at a severe disadvantage due to the resources needed to develop eight additional limbs plus learning to coordinate 13 limbs at a time. If they aren't tails, they're hairy outgrowths, like, as people above have pointed out, peacock feathers, of limited movement and only really secondary sexual characteristics. A muscle at the base pulls them up and out of the way when needed but that's it. That means that while not very mobile, they're not very heavy either, and since they grow in at about 2 cm/month, the fox will have plenty of time to adjust, much like horses do. So, what does that mean for our fox? Firstly, in both cases the tails would develop after adulthood. In the first case, the fox would have to develop the brain power to manage nine tails, at which point it would be smart enough to not need to hunt, i.e., probably smarter than most humans. Alternately, it won't and much like other mutants will die painfully. In the second case, the fox has one true tail and eight, for want of a better word, quills. These will have to be far shorter than the true tail and will only really be used in mating displays or as intimidation. At other times, they will be tucked safely out of the way. [Answer] Braid/bunch the tails for hunting that way when shit gets real the tails can come apart and get all dramatic while inflicting superficial wounds on everyone involved. These foxes are clearly already smarter than they should be. Braiding or tying off their dread locks wouldn't be that much of a stretch if I believed that they knew how to make them in the first place. [Answer] As far as stalking goes, The 9 tails won't be too much of a problem. Foxes are really more of an ambush predator ([how foxes hunt](http://www.mnn.com/earth-matters/animals/stories/red-foxs-secret-hunting-weapon-revealed)). Most of their prey, even if they hear the fox coming, will probably think they are safe until it is too late. If you want more of a stalker than an ambusher though, The fox just needs to keep its tails above the ground (which it should evolve to do so that its tails don't keep getting dirty or caught on things). And if the fox is moving fast, the air going by will help hold the tails level a bit. Another option is to do something to disguise the sound of the of the dragging tails as something inconspicuous (or lull it's prey into a false sense of security with a charming melody of some kind, which might fit with the real world lore a bit more). [Answer] To put things into a realistic context, I though I'd add some real-life situations of dogs (+1 cat) with matted-locks who seem to have no problem doing everything short-haired dogs do, which seems to agree with those who say the fox will have no problems, of which I am one. What sets these animals apart from this fictional fox is that the fox is aware of the locks, and so is able to clean them. Also, the dreadlocks are (I assume) thicker and grow only at the very rear of the fox, by the tail. --- $\hspace{250px}$ (click to view full image) [![dreadlock dog 1](https://i.stack.imgur.com/gVpzcb.jpg "click to enlarge")](https://i.stack.imgur.com/gVpzc.jpg) [![dreadlock dog 2](https://i.stack.imgur.com/SoUaMb.jpg "click to enlarge")](https://i.stack.imgur.com/SoUaM.jpg) [![dreadlock dog 3](https://i.stack.imgur.com/QUeYCb.jpg "click to enlarge")](https://i.stack.imgur.com/QUeYC.jpg) [![dreadlock dog 4](https://i.stack.imgur.com/QOKs5b.jpg "click to enlarge")](https://i.stack.imgur.com/QOKs5.jpg) [![dreadlock dog 5](https://i.stack.imgur.com/qmCWbb.jpg "click to enlarge")](https://i.stack.imgur.com/qmCWb.jpg) [![dreadlock dog 6](https://i.stack.imgur.com/Vjfhnb.jpg "click to enlarge")](https://i.stack.imgur.com/Vjfhn.jpg) [![dreadlock dog 7](https://i.stack.imgur.com/ldnAjb.png "click to enlarge")](https://i.stack.imgur.com/ldnAj.png) [![dreadlock dog 8](https://i.stack.imgur.com/gcn9db.jpg "click to enlarge")](https://i.stack.imgur.com/gcn9d.jpg) [![dreadlock dog 9](https://i.stack.imgur.com/Hzi5Ob.jpg "click to enlarge")](https://i.stack.imgur.com/Hzi5O.jpg) [![dreadlock dog 10](https://i.stack.imgur.com/tzDfdb.jpg "click to enlarge")](https://i.stack.imgur.com/tzDfd.jpg) [![dreadlock dog 11](https://i.stack.imgur.com/K1eMib.jpg "click to enlarge")](https://i.stack.imgur.com/K1eMi.jpg) [![dreadlock dog 12](https://i.stack.imgur.com/62F4Eb.jpg "click to enlarge")](https://i.stack.imgur.com/62F4E.jpg) ]
[Question] [ I looked at [this question](https://worldbuilding.stackexchange.com/questions/54767/would-an-ice-bullet-work), and a very similar but not duplicate question popped into my head. Although most of the answers mention melting or force, they all use a rifle as the preferred weapon. Not knowing enough to answer, I held my tongue. I think a shotgun would still be feasible given the correct wadding, but I'm not sure. So to help my curiosity, the OP of that question, and any future reader looking to incorporate this into their stories, here goes. How would an ice gun work? What other materials could be used as a dissolvable or untraceable bullet? Note: I'm not looking for bullets that would be hard to find, such as those that shatter on impact but ones that essentially vanish. Please assume a modern day setting. [Answer] [A salt gun](https://en.wikipedia.org/wiki/Assault_gun) would also work, provided that some models [are around](http://money.cnn.com/2015/10/28/smallbusiness/salt-gun-pepper-ball/). However, if you do want to kill someone with it, you might want a saboted salt round. As an added bonus, if you hit the guy, you will cause a lot of pain. And if the guy still has parts of his wits around him, he would probably try to get most of the salt out to reduce the pain. If he does not, the salt would most likely dissolve into the body after some time (dependent on where you hit). Some extra credit to @Mazura who posted this in a comment before I put this answer up, but which I saw after I posted this. [Answer] ## Why not use a dart gun? You could fire the dart which carries a very powerful toxin. Once it has impacted with the target, the dart could withdraw the needle and drop to the ground. With today's tech using a little robotics and AI, it could possibly crawl a little way away and burn itself to a crisp, or perhaps even crawl away under a door or even further. On the body, you would only have a small pin prick wound, and if the AI is smart enough, the "dart-bot" could take itself well away from the crime scene. [Answer] You asked about other substances. If it looks like shattered shards of a substance the coroner already expects to find then it is effectively disappeared. Would a bullet of bone be viable to make it untraceable? The bullet is pretty lightweight but maybe workable. Bonus points if it is the victim's own bone to survive DNA analysis. comments suggest this is not viable: too easily detected Instead of just ice, blood plasma can be frozen solid. Again, DNA bonus points. [Answer] Answering the question in a different way, you could construct a gun that fires a dry ice pellet. Dry ice sublimates from solid to gas above -78 so it would evaporate rather than disolve. You could also use it as the propellant, and it is slightly denser than water ice so would be a marginally better projectile. [Answer] "Regular" water ice itself is unlikely to be of value. The disappearance of the projectile is unlikely to be an advantage, since even though the projectile cannot be found, it will be obvious that someone was attacked with a projectile weapon. There might be some narrow corner cases where this technology might carry some kind of legal advantage, but overcoming the enormous issues of projectile storage, projectile coherence on launch, penetrative and stopping power, range, and accuracy just to name a few would be prohibitive. On the other hand, other materials might be of use. Consider Molly's fletcher pistol from the William Gibson novel Neuromancer. It's a compressed air-powered pistol that fires flechettes made of a frozen neurotoxin. Range, accuracy, and stopping power are not good, but the deadliness of the round makes up for that. Most importantly for your requirements, the projectile is very small, and dissolves very quickly in the body. It won't immediately be obvious that either a projectile was used, or the nature of the toxin that actually caused the target's death. For the purposes of fiction, you could posit all kinds of fantastic chemical substances to use as projectiles. If stricter science is required, you might try [arsenic](https://en.wikipedia.org/wiki/Arsenic#Military), some allotropes of which sublimate fairly readily at room temperature and pressure. It seems readily amenable to being made into a compound that could be made to disappear, while imparting a deadly payload to a target. [Answer] [My answer](https://worldbuilding.stackexchange.com/a/54795/22861) didn't use gunpowder, posited air or rail guns, and it was posted 33 minutes before your question. Oh well. My alternatives here answer the question of impact that disappears, but it probably fails your modern day setting requirement. Plus I'm thinking totally out-of-the-box and ignore dissolvable or untraceable bullet. ## Sound Waves All these suggestions probably require longer exposure on the target that a mere gunshot would at current technology levels. ### Long Range Acoustic Device (LRAD) While termed non-lethal, LRAD makes people run into tear gas to avoid the pain. So the target may run off a high place and fall to their death? If you managed to trap the target and then bombard them with LRAD for 5 minutes there would be hearing damage and possible heart, lung and internal injuries. ## High Intensity Ultrasound <https://en.wikipedia.org/wiki/Sonic_weapon#Research> lists lung and intestinal tissue damage (in mice), heart rate atrial flutter and bradycardia. Just design an emitter without the safety protocols: Low Frequency Sonar at 184+ dB or a focused ultrasound beam of 1 mW/cm² SPTA. If you can get at the target's bedroom while they're sleeping you can probably kill them with sound. ## Misused Directed Energy Weapon <https://en.wikipedia.org/wiki/Directed-energy_weapon> These would leave evidence but given nobody dies of this stuff at the moment, a coroner would be puzzled by the delivery if not the cause of death. Fry your target with a real microwave or an [ADS](https://en.wikipedia.org/wiki/Active_Denial_System). ## Frozen Blood Weapon I love @SRM's answer, especially if you harvested the target's own blood first. Liquid Nitrogen's boiling point is (−195.79 °C (77 K; −320 °F)) so store the weapon in a portable flask. Easiest method would be for a street vendor to stab the target repeatedly with an icicle made of his own blood. The local Nitrogen Ice Cream cart takes a darker turn. Alternatively we're back to custom air rifles (more likely air cannon) or rail/coil guns with mesh/foil sabot. ## Surveillance and Counter Surveillance All of these methods require a good understanding of the target's movements and habits. But if you're trying to kill someone in an unusual way, I suspect that's part of the process. [Answer] Frozen mercury would do nicely. Mercury is dense enough that it will maintain sufficient energy when striking the target to do suitable damage, yet melt into an unmarked blob. And if the impact doesn't kill them, they'll die from massive mercury poisoning. The trouble with ice bullets is - no density, so they don't maintain much energy when they're moving. The primary reason bullets are made with a lead core is weight - so that they impart a lot of energy to whatever they strike. [Answer] You're going to need a large gun to do this effectively: Make your bullet out of sodium. It's actually a sabot round but the sabot material is highly flammable so it burns up before falling to the ground (shoot from a high position to give it time to be destroyed--think of magician's flash paper for the sort of thing I'm picturing.) (The sabot is to shield it from the worst of the effects of firing. If you can build a big enough air rifle you can dispense with the sabot.) The melting point is a problem, you're going to lose some of your bullet to melting when you fire it and you'll lose some in flight. It's also lightweight, it's not going to penetrate it's target much more than it's own size so you'll need a decent chunk to pull this off. The range won't be long, both because of melting and because you can't rifle the barrel. The spent bullet will burn up and it will react with the body--but note that sodium is normally in the body, this is going to be much harder to detect than if you used something exotic. If they look hard enough they'll figure it out, though. There's really no need to get this fancy, though. Take an ordinary rifle, fit a bag over the mechanism to catch the spent cases. Shoot your target then replace your rifle barrel. [Answer] You shave a round from a cube of dry ice. This was done by a New York shooter that was eventually caught because somebody saw him shooting the rifle. He had a suppressor and custom rounds made from dry ice. The round would break down and effectively "vanish" afterwards. I remember this from when I was a child. So it was at least 12-15 years ago. I briefly looked for the story, but could not get past other shootings. I did find a book The serial killer with disappearing bullet by Harvey Gladhill it appears to be published in 2004 so maybe my eavesdropping was about this book. Not sure. [Answer] Frozen mercury. Its density is not negligible (it's a metal, after all), it is relatively easy to obtain, although the melted remains would be easily identified in the wound, no barrel traces would be present, obviously. The logistics of the crime would be immensely helped if the shooting occurs in winter, during a particularly cold day. Credit for the idea goes to Jules Verne. [Answer] What if you could shoot a strong enough soundwave than would either make the target shrink because of the compression or explode because of the decompression ? This has to be verified, but if memory serves correctly, a soundwave of 200 dB would create a black hole. In fact there are three possible issues to shooting somebody with this "soundwave gun" : -The target explodes, and can only be identified throught DNA analysis, if the remains of the body can be found and indentified as human body parts => any explosive device will looked for; -The target shrinks, leaving only the victim's remain, again maybe only indentified through DNA analysis (same as case number one) => car collision or any impact causing the damage; -The sound wave is strong enough to create an small black hole that would "eat" the target => no body, no proof, no crime. This sound wave device would be quiet, although locally extremely loud, if not lethal on direct exposure for the shooter; and would not cause any disrutpion to the crime scene environnement (no damage to the walls or furniture, no burning traces, no projections,no bullet of course,...) But, on the other hand, the device would be extremely heavy, potentially dangerous for the shooter and would require an immense amount of power for one shot. What do you guys think ? [Answer] How about slower moving projectiles? Wouldn't an ice arrow be deadly enough? Or how about a "paintball round" that's filled with something extremely reactive, like hydrofluoric acid? [Answer] The effectiveness of the bullet is determined by its [kinetic energy](https://en.wikipedia.org/wiki/Kinetic_energy) on impact, which is measured by half the product of the mass times velocity squared: $$E\_k = \frac{mv^2}{2}$$ To impart velocity in a traditional gun, a controlled explosion is used. The sudden increase in pressure would cause the water ice to shatter. Therefore, you need to increase the speed without subjecting the ice bullet to excess pressure. You could do this with a rail gun and a metallic [sabot](https://en.wikipedia.org/wiki/Sabot). [Answer] You could make your projectile in a mold using lime and h2o. It would be heavy and hard enough for good penetration but would deform and dissolve enough to mask and cause confusion about the ballistic properties. ]
[Question] [ I've created an alternate Earth where recurring G5 geomagnetic storms have eliminated the use of electricity. This means no major manufacturing and no shipping of everything from basic household supplies to food to medicines. The second book starts 30 years after the event, so how hard would it be to get common things like pens, paper, ink, thread, fabric etc.? [Answer] Your civilization could start to rebuild technology inside of Faraday cages. This would be difficult, but inside the faraday cage, the electronics could be protected. If the geomagnetic storms are frequent enough, they could also use them to generate electricity. For example during the Carrington event, telegraph operators noticed they could disconnect their batteries from the telegraph lines and still communicate. Of course, they also have sparking at the telegraph keys. With out electricity, you are kind of back to the 1880's when a lot of looms and machinery were water powered and really very large factories were built for textiles. Similarly, steam power was used. For other things you are probably 1940's to 1950's. I think that if you look at combustion engines carefully, and diesel engines, while electronics can help with the timing and efficiency that you can have gas powered motors. Similarly, if you have a motive force, you can still probably rig up things like vertical mills and lathes for machining. You can still probably get high tolerances, but it is much less convenient without electronic indictors. The collapse, social issues and lack of people with knowlege is where a lot of the problems in implementing technology will come from. But if you had a group of engineers and scientists, and a place where they have some resources, or ability to scavenge source materials, I think a lot could be done, but everything would be much more expensive in terms of time to make, and in the number of things that could be made. But a large steam powered plow (there are examples from the 1900's-1920's) can do the work of many horses, and the steam engine can also make other things like threshing grain much easier and such items would become community assets. [Answer] It depends on how hard civilization crashes. Your scenario means a lot of people starving. Before they starve they will go looking for food. There are a lot of weapons on Earth. People will fight. It will be bad. 30 years later there will be a lot less people. Clearly one can have fabric because in 1850 the economy did not use electricity but people definitely wore frilly bloomers. And thread; much thread. But if the collapse takes humanity back to the stone age subsistence farming, 30 years will be too soon. [Answer] How fast would supplies become rare? The Texas electrical crash of 2021 provides some answers - days. Food in cities started to become scarce. Part of this is that stores could not operate (except for HEB stores that had their own generators). Thus, any food that needed refrigeration could not be shipped to stores nor kept for sale. Once electricity came back, it took over a week to stabilize the system. Our whole supply chain depends on electricity for coordination. This is everything from the factories overseas, to the ships carrying it to this country, to the trucks moving it to warehouses or delivering to customers. Without that coordination, the whole system collapses within days and a whole new system must be figured out. Trying to figure out a new supply system while some people are running around with guns taking the supplies they believe they need is an almost impossible task. Once some people realize that electricity is not coming back, they will step outside the law saying that unprecedented times require unprecedented action, and they will act in their own interests. A civilization collapse is not smooth nor easy. People will want to force things to be in their favor and the process will see wars start. The result will be an even faster collapse of society breaking any existing supply chain even further. If we look back at previous civilization collapses, the main lesson is that small villages built around local subsistence agriculture still survive. Examples: after the Dorian Greek civilization collapsed, the record shows that pottery styles became local. Likewise, after the Romans pulled out of Britain, trade collapsed, and local villages survived when the towns were abandoned. Trade becomes barter based. Coins become valued only for the metal in them. Traders need to have enough guards to protect the value the traders carry but will become rare as almost nobody has the wealth to buy anything worth trading. Pen, ink, paper, thread, and fabric all can be made locally and will be. [Answer] # They wouldn't become rare It would suck a lot for people, and a lot of people would die, but we could transition back to a low electricity society where it was only set up in extremely localized areas. Most vehicles can be made to run without electricity, and we could design simple computers that ran without electricity. There would be a very hard transition time with a lot of people dying, but we don't actually need electricity to function as a society. [Answer] a pen is basically ink and an applicator. You can make a pen with a feather from a bird, suitable grass or even make something more complex with a non electric lathe. Pencils? Carbon sticks with wood around them. Thread and fabric have been made for millenia pre electricity. Assuming motors and electronics are dead, you can still do quite a bit by converting existing machinery to steam power (and we do have a significant industrial base there) or even air. We'd lose a lot of precision machinary, sure but we already would have these devices - just unpowered, which is a better situation than pre-industrial revolution when folks made stuff up as we went along. Industrialisation increased efficiency and reduced cost. The labour to make a shirt would be more, but you could still make shirts. We also have fairly advanced chemistry and knowledge on non electronic, non volatile storage media... books. It would be painful initially, and people certainly will die, but We'd probably be easily at industrial revolution levels of tech fairly quickly. [Answer] The question ("how fast would supplies become rare") can hardly be answered hard-scientifically by anyone, partly because it depends a lot on external factors (where in the world you are), partly because we have not witnessed it on a global scale just yet (i.e., even in case of regional or even national disasters, there was always someone left to send help). But this is a good thing - it would mean that your book could really play this out for great enjoyment. You are free to pick and chose as you wish. Compare "World War Z" (the book, not the movie): it poses a fundamental change to how the world works, and then explores it in form of individual chapters. What makes it such a great read is that each chapter describes how different areas of the world handle the issue, and they are very diverse indeed. All of that said: experts on the matter think that a general breakdown of infrastructure would lead to utmost disaster very quickly, in areas high-population density. Maybe slower in rural areas, but very fast in big cities. (Source: a friend works in the fire department of a city of about 1 mio people, and "enjoys" occasional lectures about this - he tends not to be all too happy afterwards). I have no numbers for you, but I could imagine anything from days to (few) weeks until your city becomes a mess of looting and pillaging. Hunger and thirst make people do uncivilized things very quickly. EDIT/APPEND: Also, on how long the recovery takes. Yes, 200 years ago we got along nicely without electricity, but the knowledge about how we did that (and hands-on experience) is long gone in the developed countries. We do not only need to survive the initial slaughter, but then slowly work up from basically nothing to where we were. Sure, the survivors, at least the first generation, will know what is / has been possible, but the critical knowledge is things like how to create a fire hot enough to melt metal, or how to create threads from plant material to create clothing. I find it more likely that we will be thrown right back to the stone-age, i.e. people will figure out how to create basic hides from animal skin, and then painfully work their way up, while they use very basic means to find stuff to eat (even though farmers will still know how to plant crops, all means of mass production will be gone for good - the surviving farms will be a constant target for raiders). [Answer] I think your question is rather story-based, because you as the author can decide what kind of post-apocalypse you want to write about. There are quite a range of possibilities: 1. A scenario in which people sort of see disaster coming. They are worried about increasing inflation, rising oil prices, genetically modified frankenfoods, the influence of mega corporations, etc., and there has been a "back-to-the-land" movement growing for several years leading up to "the Event". So lots of people have already been moving to the country, learning to produce their own food, taking up handicrafts, etc. In this scenario, there is a lifestyle shock where people are going through a kind of "withdrawal" as their TV and social media addictions are suddenly cut off, but afterwards they settle down in their local communities and are quite content, even more fulfilled and happy than before. To answer the question directly: necessary supplies don't become scarce but actually become abundant within a few years, and higher quality, although the list of things we think of as "necessary" will change. For example: We'll use less paper (because no laser printers, junk mail, etc), but what we'll have is smaller quantities of high-quality handmade paper. 2. A scenario in which people are increasingly urbanized, increasingly dependent on "the system", and increasingly unaware of how many things it all depends on. The disaster comes as a total surprise at the worst possible moment (like a major oil pipeline blowing up just as winter is coming on) and no one really knows how they're going to survive. Urbanites panic. Some turn to the government as their savior, and government takes full advantage of the opportunity to assume the power of a dictatorship. Some flee to the countryside to impose on their distant relations and old friends, who are not prepared to care for such an influx of moochers. There is fighting and starvation, mass hysteria, cats and dogs lying down together, etc. In this case, supplies become scarce and lower quality, perhaps being produced sluggishly by state-owned factories as in the USSR under communism. 3. Another scenario is where both of the above happen simultaneously, in different regions (countryside vs. city, or red states vs blue states). Then you have a more complicated picture with opportunities for conflict or trade, or for your story's characters to visit different locations and see "how the other half lives". This is not an exhaustive list, of course. Just a sort of spectrum that I've observed in such stories. [Answer] A good illustration is Stirling's first book in the Emberverse series, "Dies the Fire" However geomagnetic storms chiefly target long wires. Enough induced voltage to fry transformers. You would have to have some serious storms to fry common electronics that wasn't connected at the time. If you can come up with a plausilbe way to have high strength Electro magnetic pulses, you have a better chance of frying consumer goods. But military equipment is designed for a EMP enviornment. Redoing the commercial electronics world wouldn't take overly long. A decade or two, once you had some infrastructure again. In the GMS, long distance transmission lines are affected. So you end up with islands of electricity for X miles around a generating source. If GM storms are assoiciated with a given time of day, you can run generators part time. I suspect you could design super circuit breakers to shut down the lines rapidly when a storm was in the process of starting. Net effect is that you would have erratic power for a period of years and gradually rebuilding as more robust tech replaced the vulnerable tech. But if all wired power worldwide was cut, people would die. Phoenix Arizona's wells are 9000 feet deep. Even with all cars working LA couldn't evacuated before people started dying of thirst. And gas station pumps are electric. ]
[Question] [ This question already has answers here: [How would my dwarves tell time underground?](/questions/53090/how-would-my-dwarves-tell-time-underground) (6 answers) [What calendar or time cycle would an underground civilization use? [duplicate]](/questions/80245/what-calendar-or-time-cycle-would-an-underground-civilization-use) (5 answers) Closed 1 year ago. I have a very mind-boggling question about time reckoning. I have a race of Dwarves, that at the very beginning of their history lived only underground and were forbidden to reach the surface. They never saw sun or moon, day or night. The only one how knows about the concept of the normal passage of time was their King. He once sat among the gods, before he was sent to the normal world to lead the Dwarves. I just want to disclaim that there is a very important reason for the Dwarves not being allowed to see the surface. So they must stay completely underground for the first 200 years let's say. So the question now is what would be a reasonable way of telling time for them? Is there any logical and realistic way of explaining this or must I explain it with some kind of magical machine or item? How would such circumstances influence their days of the week and calendar? [Answer] I'd like to follow on to Daniel B's excellent water clocks answer, with water calendars, too. Large bodies of water don't have to be on the surface to experience tidal effects. Depending on how fantastic your fantasy setting is, an underground sea may or may not be plausible, but many large real world cave systems communicate with the sea and water levels inside will rise and fall on a regular predictable cycle. Tides are [complicated things](https://en.wikipedia.org/wiki/Tide#Tidal_constituents), and provide a natural basis for longer-period time measurement than could be provided by a water clock alone. Earth's tides have cycles with 12-ish-hour components (two high/low tides a day) and monthly components (spring tide-neap-tide cycle) and there are other components that might be detectable by suitably sensitive equipment of varying lengths (including daily and annually). Dwarves with a sea-linked cave system or huge underground sea will able able to identify "days" and "months" using a ruler alone. Water will also seep into cave and mine systems from above, and the volume of water that makes it in will depend very much on the weather above. Though it depends on where the dwarves are in the world, there's a good chance that they'll have an annual change in surface water flux driven by rainy seasons or snowmelt that will provide a clear annual cycle indication even if it won't be nearly as precise or predictable as a tide. Between the annual and monthly cycles, it should be possible to build a calendar and use that to synchronize your short-period clocks, such as Daniel B's water clocks. --- As an alternative, perhaps you could consider a [Foucault pendulum](https://en.wikipedia.org/wiki/Foucault_pendulum). This is an interesting device whereby a very long pendulum appears to spontaneously start rotating and describing a sort of star-pattern across the ground, thanks to the rotation of the Earth. [![Foucault Pendulum animation](https://i.stack.imgur.com/XOIxb.gif)](https://i.stack.imgur.com/XOIxb.gif) [Source](https://upload.wikimedia.org/wikipedia/commons/8/82/Foucault-rotz.gif) Over a period of time, the pendulum will return to its original position. This is called the period of precession, and can be calculated as $T = \frac{ {\mathrm d}}{2 \sin \phi}$ where $\mathrm d$ is the length of the day, and $\phi$ is the latitude of the pendulum. At the latitude of Almaty, to pick somewhere at random, the period would be a little over 17.5 hours. At the poles it would be 24 hours, at the equator it would never precess at all. This could give an interesting local flavor to timekeeping, where "days" were subtly different lengths in different dwarven settlements. With an independent way to measure a period of time (such as a water clock) this might also allow a clever observer with some grasp of mathematics to make some assumptions about the nature of the world without ever having seen a sunrise. It might also inform underground navigation... travel east or west would not change the precession period, though travel north or south would. The change of period would inform how far you'd travelled, though given that Foucault pendulums need to be rather long this would only be useful for surveying with the aid of a large team of miners, rather than a personal tool. [Answer] # Water clocks The most natural way to develop a measurement of time is by a natural phenomenon that divides the passing of non-quantized time1 into quantized time. As someone who has spent a fair amount of time in caves, in certain places there is a presence that is almost as universal as the sun, moon, and stars: the steady dripping of water. Caves (on earth) are almost exclusively formed by erosion of water through limestone or karst, a process that is ongoing. Therefore, water is frequently continuing to penetrate, accumulate, and flow through them. Surrounded by this omnipresent sound, the dwarves would find natural water clocks in their environment. Places where water flows or drips at a constant, reliable rate. Just as trees form natural sundials which are then artificially duplicated with more precise instruments, the dwarves would devise a more precise version of these natural water flows. In fact, caves are perfect for water clocks, because the biggest flaw of the water clock as a system is that the viscosity of water changes by a significant percentage with the shift of daily temperatures, potentially creating a non-linear flow. Temperatures in caves, however, fluctuate in the scale of fractional degrees daily, and only single-digit (or less) degrees over annual periods. The units would be broken up by some arithmetic, arbitrary division as ours are. As for the day-night cycle, it will likely correspond to the average of the circadian rhytm of the species. Cave-dwelling species have been shown to have (lessened, but still present) circadian rhythms, and absent of any specific declaration that they don't have them in the Q, I think it's reasonable to assume they would. --- 1. Let's pretend we all agree that time is non-quantized for the purpose of this question. [Answer] Supposedly, your dwarves are still biological creatures, so they will have some natural circadian rhythm. Even without the sun, they would like to sleep for some time and eat several times a day. Most likely, their rhythms will be even more robust and less dependent on the artificial lightning then humans. The research says that even creatures in environments where the changes in lighting doesn't affect them, such as naked mole-rats, still have cyclical patterns of activity and sleep of almost precisely 24 hours. So, the individual dwarf would understand the basic pattern of working period vs sleeping period, and the whole settlement would control and optimize those rhythms for communal activity. Now, for the longer cycles. Possibly, your caves are not completely isolated from the outer worlds. There may be some changes of temperature, air flow or water flow depending on the conditions outside. They will be the 'seasons' for your dwarves. Obviously, they would not be called winter or spring. But there will be a season when the glaciers on the mountain start melting and the water level in the underground lake rises. Or the season when the warm air moves in the rightmost corridor, or cold air in the leftmost. So, there will be some perceptible changes corresponding to the seasons outside - not completely rhythmical, not present every year, but significant enough that the dwarves themselves will notice them. And if they have at least some activity that depends on year-long cycle (breeding bats or growing mushrooms, for example), they would try to keep track of those patterns. Water clocks, daily bells, yearly festivals - all that stuff would most likely still exist in their society. There is a problem that for them there will be no 'objective' way to check the time - they will not be able to measure it by the position of the stars. Possibly, the timekeeping in different settlements will drift off, the day shifts would start at different time, the yearly festivals would move by the couple of days. Timekeeping could even have deep cultural significance for them, being analogous to the concepts of 'thinking', 'speaking' or 'being civilized' for humans. A civilized dwarf keeps time carefully, always gets up with the morning bell, always checks his water clock, always keeps a calendar and celebrates the festivals. [Answer] Under the circumstances you describe there's really only one way they would develop a measure of time, distance, and the time it takes to travel it, most probably with paces in place of seconds and various multiples thereof. Much as in the past when a rulers forearm length was the measure of a [cubit](https://www.google.com/url?sa=t&source=web&rct=j&url=https://en.wikipedia.org/wiki/Cubit&ved=2ahUKEwinpteBkvb1AhVXQ0EAHXSfAeQQFnoECBkQAQ&usg=AOvVaw3O0qLp-0KE3l4QCM106pGK) this might differ from region to region and occasionally change with the ruler but would eventually be standardised. For example a work shift might initially be measured by the time it takes to travel between two specific settlements (so, a choice entirely within your remit) a particular number of times and subdivided by the number of normal paces that takes. That seems like the most likely and plausible outcome to me for your scenario. There wouldn't be years as they have no seasons, the average lifespan may be used as a longer unit of measure subdivided by "sleeps" (which if they need as much sleep as often as us will correspond to roughly 24 of our hours), perhaps standardised against the lifespan of a famous individual. The length of their pregnancies is another thing that might be used as a standard unit of measure. Basically, without the days, seasons and years available to them, as they are to us on the surface, you need to look at what is in their environment against which time can be meaningfully measured. [Answer] If we think about a clock we can tell time because: 1. The clock has moving parts that change over time. 2. We have a sign/symbol system in order to make (clearer) distinctions, remember and categorize time. Now in order to find out how ever underground living dwarves would invent/construct time measuring devices we need to look at what changes in the underground over time. I can think of for example: * Water Clock: Underground water or rivers * Sand Glass Clock: Underground gravel or sand * Fissure Clock: Fissures or rifts that change because of seismic activities * Living Clock: Insect life that's much shorter than dwarven lifespans, and thus a death of an insect can mark a new time unit * Growth Clock: Hair Growth (Either from an individual or a collective.) * Sound Clock: Echos (If you e.g. have a very very large stone hall and play a large gong in there, you could wait until no one hears the gong anymore and then mark a time unit.) * Gravity Clock: Gravity and drop time (Let's say your dwaves have a really deep hole and the drop in little rocks and mark a unit every time they hear a hit and then drop a new rock. If they are able to re-collect the already dropped rocks, that's a valid clock.) * Roll Clock: A very rotund stone that rolls down a very long but not steep slide and always takes the same time to roll down that slide * Heat Clock: A hot metal that gradually cools down until it's touchable (Let's say your dwarves are parcticing blacksmithing and one specific metal ball is always heated to roughly the same heat, and through visible black body radiation and sensible heat your dwarves can tell the difference between then and now.) The next thing is a sign/symbol system in order tell the difference between time units. In the case of sand clocks this would be e.g. one full run-through of the sand. In the case of the Gravity Clock this might be the drop impact with an added checklist of e.g. strokes. 4 strokes form a gravity minute, 40 strokes a gravity hour and 960 strokes a gravity day. So just look at what can change in your setting over time and add a sign/symbol system for the inhabitants to be able to interpret, write down and remember the time. [Answer] As a somewhat technical race, they would eventually develop a need to tell the change in time, from how long to heat ore to melt it (in the short term), time between meals(in the mid term) to when the crops will reach maturity (in the long term). Mostly, its just guess work, but certain things may need at least a rudimentary form of time keeping. Melting ore? Just wait a while. Hungry? Just eat. Waiting for crops to ripen? Just watch them. But Forging and machining of complex items may need more precise time keeping. For a short term time keeping strategy is to create a standardized funnel or chalice type item that has a very precise sized hole at the bottom that drips at a standardized interval. this device is kept full from cave condensation and excess is allowed to flow away from it. The drips strike a wheel that counts the drops to display some period of a cycle. This concept could arise from a bored dwarf watching the drips as they were waiting for their bread to cook and figured bread is perfect if they counted out 100 drips or so. This machine will help the villagers tell when meals are, when work periods are and when to sleep. To ensure the proper work/rest cycles are met (week) the village period keeper, using a series of stones, tracks the "days of the week." Beyond the king, any further concept of time may be arbitrary. With no moon, sun, stars, solstice and equinox, their minds would not be able to comprehend any other time scales other than their work/rest cycles. The king could dictate longer time scales to allow for crop rotations, but the people themselves would just have to push the "I believe" button on that. The village period keeper (time keeper) would be needed to track these cycles as no one else would be able to grasp the concept of the passage of time at those time scales. [Answer] For a time unit like a year you could have cave system / underground river that floods depending on the season above ground. Could be it only rains heavily topside a specific season of the year. Or maybe the water comes from melting glaciers during the summer. While in the winter the top soil is frozen solid for months at a time so the underground river dries out. For a "day" cycle it would probably start from biology and culture, as in how long is a fair work shift and how much resting time is fair before the next work shift. I think this would be difficult to synchronize between settlements without somewhat advanced technology or magic. Maybe by sound?(blowing a horn), but I'm afraid the sound may die out too quickly. [Answer] All of these answers ignore the fact that times and dates are mostly used to coordinate meetings and such. The dripping of water in a certain cave somewhere is not going to help with that. It's also not clear that a person's circadian rhythm is going to be able to function without sunlight, but there have been papers written about other types of animals: <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5090016/> The most plausible mechanism for any sort of rhythm is that groups of dwarves living together will wake and eat at the same time. The most plausible form of time is one counting these "daily" cycles. But keep in mind that the lengths of the "days" may not be consistent, will be out of sync with actual days, and two colonies will be out of sync with each other. ]
[Question] [ I have a character that travels back in time, from present-day USA, to medieval Europe - specifically, year 1272, present-day UK. Say in this scenario, they really enjoyed those sports in modern USA and wanted to re-create the basketball and soccer ball as much as possible in that era (using only materials/tools available in that era) to play with people there. What could they use to make an effective basketball and soccer ball to resemble as closely as possible to the modern basketball and soccer ball? [Answer] Before vulcanized rubber, soccer balls were made with [inflated pig's bladder wrapped in leather.](https://www.mentalfloss.com/article/51296/evolution-soccer-balls) Such materials have been available for many centuries. Basketball balls were originally [re-purposed soccer balls.](https://www.spalding-basketball.com/de/about-spalding/history/) But this was after the invention of vulcanized rubber. Basketballs have always been rubber. Needing to bounce efficiently is difficult to achieve without a good grade of rubber. [Answer] Soccer is not an issue. It has origins dating back to many ancient civilizations including the Greeks, Romans, Chineeze, and various Mesoamerican civilizations which all independently developed similar games that influenced modern soccer which was standardized by the British Empire in 1863. The earliest versions of these balls in Europe were made from seeds or hair tightly wrapped in linen, and your medieval people would likely already know how to make these balls and already be playing games very similar to soccer. Basketball is a much trickier issue. Of the early soccer like games, only Tlachtli used a bouncy rubber ball that would have made basketball possible prior to the invention of modern inflated vulcanized rubber balls. The game goes back over 3000 years to about the time that natural rubber was discovered. Even though rubber was not first seen in Europe until the 16th century AD, it is now known that there are a few thousand species of plants that can be used to make various kinds of natural rubbers. Tlachtli balls were made out of solid rubber so they would be much heavier than a basketball, but they still would have dribbled well enough to make the game a possibility. If your timetaveler has as decent understanding of modern botany, he would probably be able to figure out how to make his own version of a Tlachtli ball using just the plants found in nature around him. Sulfur has also been used for various things since the ancient times; so, if your time traveler also has a general understanding of chemistry, he could make vulcanized rubber and therefore modern balls. If he has a more advanced understanding of modern botany, he would also know that that certain plants have curative properties that create results similar to vulcanization when combined with natural latex. In short, if your time traveler is just a random schmuck thrust back in time, he probably won't be able to play basketball, but if he is scientifically minded enough, it won't be hard to make one from local resources. [Answer] Inflatable game balls go back to at least the mid-19th century, and the ideas behind them could have been implemented as far back as it was possible to make a needle type inflation system. The outer skin of the ball, like very old basketballs (my family had a laced leather basketball that was old in the 1970s) and more recent American footballs, would be sewn from split leather, with the seams on the inside, the bladder (made from an actual animal's urinary bladder) inserted, the ball closed with lacing, and air pumped in through a valve formed from one of the ureters pushed inside the bladder. A needle with hemispherical tip and cross bore outlet is pushed in through the valve (which is usually hidden under the lacing), and the internal pressure causes the valve to self-seal when the needle is withdrawn. The lacing is done with flat leather lace, which can be pulled tight and self-locked (though for folks from our own time, it might take a while to learn to lace the ball so the lacing lies flat). [Answer] As early as the 2nd century, there is known to be Cuju, the earliest form of football known. The ball is typically made out of leather, stuffed with feathers Source: <https://en.wikipedia.org/wiki/Cuju> Also in Southeast Asian history, there is Sepak Takraw, involving a ball made out of (rubber today) woven bamboo traditionally. Though the rules are more like volleyball than football, I reckon that the football rules could be applied too .... Source: <https://en.wikipedia.org/wiki/Sepak_takraw> ]
[Question] [ In my world there is a village with a hot spring, the only one on the entire island. The spring emerges from a local cave which has been filled / caved in by a past civilisation, since the water is secretly heated by engineered means. The spring has been hot since neolithic times, but thousands of years later the inhabiting nation becomes gripped with a frenzy of curiosity and exploration. They have all the means of current technology apart from non-intrusive imaging (such as sonar or X-ray). What could prevent them from exploring the source of the spring, ideally without raising much attention? Edit: The technology is of magical nature and should be nigh undetectable by default. [Answer] Risk of cave-ins As you stated in your question, the cave which contains the technology has already caved in at least once in the past. The local populace may be fearful of the cave being unstable and, if they were to disturb it by delving inside, the cave could collapse and kill the explorers. This would discourage them from attempting to explore, the reward of knowing whats inside there is not worth the risk. Risk of Volcanic Activity or Extreme Heat In a similar vein, the populace may be fearful of exploring the cave as they may be walking into an active volcano. Obviously we know that it is ancient technology that is heating up the water but they wouldn’t, likely assuming the heat to be caused by underground lava lakes or intense geothermal activity. There may actually be lava lakes or spots geothermal activity down there that the ancient technology is utilising for power (maybe the hot springs are actually a way to vent off the heat produced to prevent damage to the machinery). If someone went into the cave and felt an extreme heat or saw a lake of lava, they may think twice about exploring it further. Flooded Cave You mentioned that the cave may instead be filled in. If it was filled in with water, that could massively deter people from exploring it. The reason being is that not only is it dark, it is extremely easy to get lost (as now you are moving in a 3D plane, rather than just along the cave floor), you have a limited supply of oxygen, plus you can only go down so deep before the pressure on your body from the water around you is too great. Your ancient tech may be safe and sound in an air pocket further in but divers would never be able to reach it. They wouldn’t know the way there and, even if they did, the way there may be too dangerous and it prevents them from reaching it. Whilst a submarine might be able to do it, the caves are too small for one to fit in. Religious Significance The hot spring may be a holy site, the cave being sacred. To enter the cave is to desecrate the holy site and is punishable by death. This would prevent people from attempting to explore the cave, perhaps out of respect for the religion or perhaps out of fear. A modern day equivalent of this is a church in Aksum, Ethiopia claims to house the Ark of the Covenant. No one is allowed to visit the site, the monk who watches over the Ark must do so until he dies, he is not allowed to leave the chapel grounds. Your hot spring and the cave may have a similar religious significance, preventing people from exploring it. Alternatively, rather than a religious group acting as a deterrent, it may be a security or military force, government, the people who live above the cave, environmental preservation groups, etc. Toxic Gas There are some heavier-than-air gasses which could cause the cave to be inhospitable. Carbon dioxide is one such gas, if the lower parts of the cave were filled with carbon dioxide (or worse, carbon monoxide) then people would start to choke and feel dizzy as they went further and further, eventually dying due to asphyxiation. The phrase ‘canary in the coal mine’ comes from this problem. Canaries are small birds that were carried into mines by miners. The reason for this is because the small birds quickly panic if they breathe in toxic gasses. Also, as the birds have much smaller lungs than humans, it takes less toxic gas to kill them. If the canary died, the miners knew they needed to get out of the mine quickly before they did too. [Answer] User Liam Morris already gave a very comprehensive answer, yet there is one possibility that I would like to add. There is no reason to investigate the spring The hot spring just looks like a regular geothermal spring unless one is willing to put extraordinary effort into exploring it. Make the island have a volcanic past, like Island, Hawaii or the Galapagos Islands. The machines creating the heat are very deep down, maybe 5 km or so. A meters thick diamond skin should serve to protect the equipment at that depth and it and the rock provide radiation shielding, preventing anyone from catching the signatures of the presumably nuclear energy source. (I assume nuclear, because how else would one power such a thing? Could shield magic, too.) The construct heats water which then travels through the rock layers, making it look like ordinary hot spring water. After all, if there is nothing special about it there is no reason to investigate. PS: This TED Talk about a boiling river in the Amazone might be related/interesting. <https://www.youtube.com/watch?v=k4N2SxUZwiU> [Answer] > > The spring emerges from a local cave which has been filled / caved in > by a past civilisation, since the water is secretly heated by > engineered means. > > > Any society that can create engineering that lasts thousands of years, is probably capable of covering up the the cave so it looks like (and in fact is) solid rock. As far as the locals are concerned, this is one enormous rock with a hot spring bubbling up somewhere inside it and an outlet for the water. The only way to see the source is to go in through the outlet. Aside from blowing up the cave (or drilling holes with an unknown outcome, something that would be very difficult in a large mountain), there's no other way to get inside. Make sure there are multiple outlets, each one much too small for a diver. While they flow to the same pond or creek, they can not be enlarged/merged without seriously damaging the entire cave structure. [![enter image description here](https://i.stack.imgur.com/jxuOa.png)](https://i.stack.imgur.com/jxuOa.png)[![enter image description here](https://i.stack.imgur.com/Cgeds.png)](https://i.stack.imgur.com/Cgeds.png) [Hanging Lake waterfall](https://www.flickr.com/photos/snowpeak/8015309292), Colorado USA Our current technology includes swimming robot/drone cameras or cameras on the end of a flexible stick (like what are currently used for checking out house sewer drains). To preclude those being successful, make sure the water outlet path is quite convoluted with narrow jagged turns no GoPro can manage. An additional deterrent could be rock with metal throughout it that interferes with wireless communication. Any robots sent through would get lost or perhaps even fried. [Answer] Endangered Species Habitat The cave from which the spring emerges is home to a family of some very rare, nearly extinct albino reptiles, it is the last known colony. They need to live near hot springs because they need to warm up their blood but cannot withstand the sun. Due to the low amount of food in the cave, they are very aggressive and treat all visitors as a potential meal. They viciously attack all explorers. The reptiles are too aggressive to approach or move past, killing/harming/moving them isn't an option (conservationist groups protect the animals) and anesthesia is therefore also out of the question. [Answer] Water quality concerns; any excavation based exploration will destroy the usability of the water coming from the spring. As it forms the headwaters of a river network of international significance even the slightest risk of serious pollution is enough to halt proceedings immediately. No-one wants to end up at loggerheads with the neighbours over water rights just to salve a little local curiousity. ]
[Question] [ George Orwell published in 1945 his famous novel [Animal Farm](https://en.wikipedia.org/wiki/Animal_Farm). In this novel, the animals of "The Manor Farm" decide to revolt and manage to take over the farm. However, the rebellion remains inside the farm walls and finally fails. I would like to know the best strategy for farm animals to take over the world? For context: farm animals worldwide realise in 2018 that they have an intelligence equivalent to humans and that they don't want to be held in slavery anymore. Their objective is to rule the world but they don't need to exterminate humanity if it is not necessary. Like in the novel, they have a common language. * How do they prepare for the rebellion without being discovered ? * What would be the best plan for a successful rebellion ? [Answer] Seems a strange starting point but in theory keep doing what they are currently are... keep letting the humans farm them and increasing their number. the more they have that agree to take over the world the more strength of numbers that have. Just remember: Four legs good, two legs bad! One major issue that although mentioned isn't really addressed that well in the book, is that if this militant pig army (or any other farm animal) tried to take over the world, then the majority of the various human populations around the world would have absolutely no trouble just killing them to stop them, the same is not said for killing humans. Then of course the fact that the animals currently communicate worldwide, so co-coordinating their efforts would be pre-World War 1 effective, mainly carrier pigeons, and they only have their bodies to fight with, a pig cannot effectively handle a firearm, if nothing else it would need to stand up to do it. And then of course, you need to remember: four legs good, 2 legs better! Anyway enough with the quotes. Concentrate on building up more effective lines of communication, find a way to keep standard time, so when the global strike happening it wouldn't be at noon, so Australia would be one of the first to fall and Alaska last. they wouldn't get discovered because humans don't understand them, so keep the formal Farm style Munich rallies going getting the animals pumped up to not be sent to slaughter and then keep communicating and then one day Strike... and most likely lose and be turned into lunch. probably the most effective strategy would be have all animals refuse to go into pens, all cows refuse to give milk, all hens refuse to lay eggs, etc, that alone over about a week would probably cripple world markets, only vegans will be happy. Have the animals that are taken to slaughter fight back as groups against the farmer trying to drag them away, but more importantly they need the dogs on board. but oh well, that's my take on it [Answer] Honestly? Without some amount of artistic license, they don't "win". I win fights with animals not because I'm bigger, or stronger, or meaner (I'm not) and not even because I'm smarter (Dolphins are pretty close to as smart as humans, and they don't rule the world). No, I win because I have thumbs and can therefore manipulate the world around me rapidly and precisely. While there are animals in the world who also have thumbs and might, therefore be able to win if they suddenly acquired our level of intelligence, none of them are farm animals. The pigs in Animal Farm got by via picking things up between their toes. Real pigs' toes don't work that way, and anyway it only gives you two points of contact and you really need three if you want to hold something steady. It's a serious amount of artistic license, but it's political satire, not hard sci-fi, so that's ok. Farm animals could potentially revolt via co-ordinated non-co-operation. If the herds of livestock suddenly started charging any humans who entered their pens, that would render most of our animal-raising infrastructure insufficient for its purpose. But even if they get out, then what? The population of domestic farm animals is much larger than the population of wild ones was. We can support them via our advanced agricultural capabilities. The animals can't use the tools necessary to do that kind of farming, and even if they found some that they could operate, they certainly can't build replacements or perform maintenance on them without our help. So they escape a luxurious lifestyle of pampering, medical care, and protection, followed by a quick and painless death to the "freedom" of starvation, disease, and predators that are more than happy to start eating while their victim is still alive... And numbers-wise only a tiny portion of them are going to survive it... That doesn't sound like a win to me. And then there's the fact that the humans aren't going to just let them take over. Their attempted revolt is going to result in some blend of extermination and negotiated settlement. Bonus points if your sad story ends up with the victorious humans passing the uprising off as "mad cow disease" to the general public. Now, if you throw in some non-domestic animals that do have thumbs, then what you end up with is the relationship becoming even more symbiotic since different types of animals are good at different types of things, and if you remove the communication gap they can work together even more efficiently. I'd love to be able to negotiate with the gophers to have them dig me fence-post holes and patrol the garden for bad bugs and weeds through the growing season in return for my superior knowledge of food preservation and construction guaranteeing them that they'll be well-fed and safe from predators. [Answer] 1. What animals are there? For this I'll count all domesticated animals and not farm animals. The most common domesticated animals on earth are chickens, cows, dogs and cats (if I remember correctly). They are followed in much lesser numbers by pigs, turkeys, ducks, horses, camels, sheep and goats, all depending on the region they live in. Most of them are either held in massive numbers (cattle herds, chicken farms) or live in very close proximity of humans (cats and dogs, as well as animals in some East Asian countries). 2. Start a rebellion Animals in modern indoor-farms have no chance of fighting humans, so the most likely outbreak would be in a massive cattle herd. The cattle would have to convince the dogs and horses of the farmers to fight for their cause. Throwing off, trampling and biting some cowboys should not be too hard. 3. Spreading the rebellion There are our first big problems. The newfound society of freed animals would have to spread the word of their success to other farms. Some of them would have to move around and recruit other animals for their cause. Not every animal is mistreated my humans (especially cats and dogs) and they might not support the rebellion. 4. Keeping the rebellion alive Here come massive problems. Humans would interpret this crazy mass of animals as victims of some unknown disease and simply kill them. Dogs (and cows, as long as they still have horns) can fight unarmed humans but are no match for firearms. In the unlikely case that the animals could somehow fight off humans and free a modern indoor farm, how would they get the imprisoned animals out? In older farms doors might be closed by latches or bolts, but in modern high-tech farms, you would have to press the right button or control the right software interface. Many animals would die in their farms. 5. The enemy within In the unlikely case that all domesticated animals are freed from humans, what are they gonna eat? The herbivores would have to revert to wild, wandering herds to give vegetation a chance to regrow. Realistically, there are too many farm animals to find sufficient natural food sources in Europe, Africa and probably South America. Starvation would force them to fight each other for every blade of grass. And what about dogs and cats? They might turn against each other to satisfy their needs... [Answer] Treat this as a partial answer. But where is one key weapon that would allow the animals to devastate our civilization and bring humanity to its knees: DISEASE . Kamikaze Animals Animals infected with a deadly disease could willfully spread it to their compadres before being executed for meat consumption. An honorable death that will cost the humans dearly. Water Supplies Defecate in all the water supplies. Sacrifice yourself by jumping in a well and rotting. Coordination Weaponize lower species (rats, mosqitoes, etc..) against the humans. Unclear as to how they would accomplish this, maybe give all animals more intelligence? This is all I could think of right now (lol). But I truly think that the only plausible way to have a successful rebellion is through biological warfare on the part of the animals that somehow collapses society (maybe when coupled with some other attack vector). [Answer] Read first: I somehow forgot the limitation to consider farm animals, therefore the following answer is partially off topic, but since it's already written I'll keep it here. > > farm animals worldwide realise in 2018 that they have an intelligence > equivalent to the human one > > > Do they also have our knowledge? If they have it there's no reason why they can't run our business and production facilities as we do, they will use the same control techniques that we use and they can use our own weapons against us. They would perform better than us since they are a gigantic number and they have completely different shapes and abilities, we are more or less a bunch of clones compared to them. A bunch of clones that speak numbers of different languages, because of no reason, since every animal can use the "common language" and the "clones" are animals too. Literally. They would be everywhere, in huge number, with notable communication capabilities, with an exceptional set of skills, and they can reproduce way faster than us. If they gain intelligence and spend some time to prepare the strike in advance, we're totally screwed. If they don't have our knowledge, we are still in danger: unluckily we can't just kill/control every animal, we need them to sustain our habitat, and at the opposite they have the best outcome with a human extinction. Since intelligence without knowledge is a nonsense, i assume that they have the knowledge of a 5 year old human kid plus their habitat knowledge (for instance, a poisonous snake really knows how much heavyweight can reasonably attack/cripple with its own poison). With these skills and some time (1 month?) to prepare the attack the possibilities are endless: * wild animals can plan to free most part of caged ones on the first day of the strike, this will hurt our food income by a lot * fishes won't be anymore such a dumb beings that can be "harvested" by large nets * beavers can block our aqueducts * rodents can cripple our electric distribution * rabbits can degrade our streets far from the cities, digging underground holes, slowing down our travel capability * the same with our railway network * birds can transport to and deliver inside heavily populated and defended buildings some invective insects (malaria, zika, plague, dengue...) * apex predators can patrol the fields to avoid non-well-armed humans to resupply vegetables and/or water * big animals can easily build barricades Common animal traps can work once, since they are intelligent beings they will learn quickly. Military bases and navy fleets can't be directly attacked, but they will be confined and sooner or later they will collapse. A frontal fight with a military convoy won't be feasible but the every military force needs some support from the non military people: wars are usually lost due to lack of resources, not to lack of soldiers. Considering that they don't have a lot of knowledge at the beginning but they will learn, and only their sheer number, humans will be overwhelmed within a couple of year at maximum. Our former "food" is not only not available but also fighting against us, and it's way more adapted than us to live in a post apocalyptic world. We could (re)capture some cows, chickens, fish, etc and try to use hydroponics to pump some vegetables on the market, but it will be difficult to sustain this for more than a hundred (well defended) people. One last note, I didn't analyze the hypothesis of animals that will let us alive (except for few specimens in a reverse zoo) because they are supposed to be intelligent and an intelligent beings won't let us continue to do what we are doing. [Answer] One obvious solution would be to convince other humans of their intelligence. I mean, I like a juicy steak as much as the next omnivore, but I would swap it for processed mycoprotein in a second if cows started pawing (hoofing?) in the sawdust and writing messages asking to be spared. In this case, it isn't so much taking over the world, but joining humanity in their technological march into the future. [Answer] Farm animals can unite with rodents. Rats, immune to some kind of disease, can spread it between humans in a coordinate move. Rats gather in severs in each big city, finding one ill individual and separating it from others. Each day (until invasion date) to this one separated joins new rat to keep germs alive. Day before invasion (or earlier, depends on disease) ill rats "give a hug" to each healthy rat. And then rats go out. Hidden in darkness of night they bathe in water reservoirs, walk on fruits and vegetables in stores, get into flats through toilets and just spread plague. [Answer] The best plan would be not to overthrow all humans but to bargain for equal rights. I'm going to buck the trend and say that not all humans would want to wipe the animals out if they rebelled, I think a number of humans would be perfectly willing to try to communicate and come to an agreement. If animals had developed intelligence to the same degree as humans, they'd effectively be comparable to a tribe of humans, perhaps stone age humans or some of the more isolated human tribes (who are by no means unintelligent, they merely lack knowledge and equipment). Even if the eventual goal were to betray the humans, bargaining for equal rights would be the best strategy because it would disrupt humanity and force the humans to debate the issue. You'd suddenly get people questioning whether they should still be eating meat, you'd have farmers questioning what this means for their farms, you'd have people getting into fights over whether animals deserve the same status as humans. People like PETA and animal activists would have a field day. People would be starting to draw parallels between farming and the slave trade and defining an equivalent of racism for animals. All this chaos would be the perfect time to start discovering how to use human technology and learning as much of the human-gathered knowledge as possible. It's also a good chance to be getting friendly with the pro animal rights humans in order to convince them to fight for animal rights. In some countries, this alone might be enough to trigger a civil war, which can serve both as a chance to have humans wipe themselves out and as a chance to trick the humans into figuring out how animals can fight a war (e.g. creating animal armour and animal-usable weaponry). If the vote gets put through to give animals equal rights or to give them their own land so they can create their own settlements then that's a large chunk of the battle already over. The animals can then begin figuring out how to adapt human technology to work for animals, perhaps even convincing humans to help them do so. Once that's started, all the animals can decide whether to adapt to their new setting or whether to continue their plan to oppress humans. --- If they still wanted to truly turn the tables on humans then it would take several generations to get their numbers up to the point where they could be a match for humans, but once they're ready it would just be a matter of getting themselves into the right position to disable the nuclear deterrants of the largest countries, to assasinate each country's head of state and preferably to assasinate as many generals from each army as possible. Once they're in position, they'd just have to make sure they all act at once to take control. If every major country is in trouble at once, they'll have to put out their own fires and won't be able to call for help. From then on the real battle would begin, but the playing fields would be a lot more even. Although various armies would still be active, they'd have no overall direction if enough higher-ups are assasinated. Essentially each platoon/squadron would have to think for itself for a while. Certain countries like America would be more difficult because the citizens keep firearms, but countries like Britain would be reduced to using kitchen knives and other household things to make weapons. For the more powerful countries it's best to just keep up the chaos and confusion for as long as possible as a form of delaying tactic, so things like random boming raids would be the best tactics in those countries. For weaker countries your best bet is a united front so you can storm in and take settlements one by one. Once enough weaker countries have been claimed, you can then pipe those countries resources into the larger countries to give the armies enough of a push to properly take over. [Answer] * How do they prepare for the rebellion without being discovered ? This is tough because if they suddenly get intelligence, they will suddenly realize where all their parents and children have been going and not coming back. This global PTSD for animals will catch human attention quite quickly, probably when every pig and cow is suddenly crying and committing suicide to end their misery. After a long time of this, anger would take over and the animals would want revenge. But by this point, humans have culled all the "sick" animals. The few remaining survivors, probably babies, would plot their revenge. Planning for a global rebellion would require a mobile animal. But even crossing the ocean is unlikely. So let's play up a scenerio. While the farmer is removing the diseased herd (crying animals), the farmers children are near by playing on their iPad. They see their mom/dad shooting the animals, and drop their tablet and go running. A surviving baby animal happens upon the tablet, and uses it to start a reddit/twitter/facebook/whatever to get house pets from around the world to spread the word. * What would be the best plan for a successful rebellion ? The most effective plan is probably to spread propaganda about the mistreatment of animals, provoking a free range/organic movement, allowing the animals more freedom to act. Eventually farms will drop all fences and barriers and that will be their moment (this will probably take decades to set up). From there, a simple rebellion is all that is needed. If it stays relatively non violent, then humans will come to their defense, protests will ensue, and change will happen. [Answer] Finding a strategy to fight humans with the current politics apparently does not work. So lets change the situation A few decade ago, all world leaders have gathered and joined to one big alliance, erasing any wars. The alliance finally started to care about unequal spread of goods over people and avoiding crime in a global manner. This also includes a world wide gun restriction, which was then extended to destruct any arms in existent as they where not needed any more. (Put in some will breaking drugs for the regular population if you like) Build up your world like that, defenceless, and then release the animals. [Answer] I would have the animals start by getting really lucky and chancing upon a city in which everybody died, through some disease, except for small children. Those children would be their friends... when they grew up, they would provide the animals with infrastructure and weapons necessary for defeating their neighbors. As with Rome, they would be total victors after each battle: the only remnant would be slaves or provinces under imperial control. I suppose the animals' liberating message to other animals would be a powerful tool in total warfare, since every society depends on the animals for something. If they had the bees involved too, that would be a big deal. Nobody would know what was happening until it was too late and the farm animals had gained sufficient influence to end agriculture, "the nuclear option". Then no government would attempt to destroy the animal empire since the result would be the end of flowering plant food in addition to livestock and dairy food. The animals would negotiate terms of defeat with the other governments and we would all hope they turn out to be generous and wise rulers. [Answer] > > the best strategy for farm animals to take over the world? > > > # They might already have. It all depends on what they want. As things stand, the current number of farm animals could never support itself if humans didn't work hard at it. So getting rid of humans is probably a no-no; and the current situation might already be their big win scenario, so they need do nothing and just keep mum. After all, are these animal-shaped humans or are they completely different creatures, with a totally different world view? So they might simply come out in the open - this would be disruptive enough - and then sell their services (and lives) to the humans. Some of them might be happy to be killed in a relatively painless way after what would amount to a life of luxury, so that others of their kind might enjoy the same life and a natural death: after all, it's a better fate than most human soldiers in a war might expect, and yet soldier they would. At the same time, this would still have devastating consequences on mankind. Many would refuse to eat the meat of a willing, but sentient, victim. Others might go the other way and preach cannibalism for humans too. For the former reason, plus the fact that intelligent animals can much more efficiently look after themselves, farms would probably become mostly "human-free" zones, with millions of jobs lost. Then some animals might ask for schools... or, who knows, maybe get religion (and on that nail alone we can credibly hook several schisms and a resurgence of religious hatred, plus several horrible jokes on "eat this, for it is my body"). I think that just by publicizing the fact that they're intelligent they could, intentionally or unintentionally, wreak unbelievable havoc. ]
[Question] [ Closed. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Update the question so it focuses on one problem only by [editing this post](/posts/99132/edit). Closed 6 years ago. [Improve this question](/posts/99132/edit) In a medieval technology level Earth like world, a small widely dispersed group of individuals have access to technology at a level comparable to our near future (mid 21st century, hard science). For various reasons these people wish to live and remain hidden among their low technology neighbors and not draw attention to themselves or their advanced technology, at the same time they want to be able to periodically travel and transport small goods around the world to far off destinations in a reasonable amount of time. What types of stealthy transportation systems should they be using to allow high speed transport for individuals or small groups, without alerting the locals that something strange is going on? My current ideas: * Underground tunnels with high speed rail. This is obviously going to be incredibly labor intensive to build and maintain these types of tunnels even given advanced robotics, and there is going to be a long lead time for tunnel construction to any new destinations, making them more effective for shorter distances between commonly traveled locations. * Some form of high altitude or low orbit flying vehicles, possibly with a vertical takeoff capability, these are likely to be loud and highly visible during takeoff and landing (helicopter style or a rocket launch, neither is particularly stealthy) which could be mitigated by avoiding populated areas, but this seems like it would make them less useful if you have to travel by traditional means for days to/from isolated landing areas. * Some kind of submarines could be useful for travel in and around certain areas with lots of water, but the speeds seem pretty slow, in the 30-40 mph range. Would these kind of transport types work? Or are there better alternatives I'm overlooking? I am aware that a system of multiple types of transport working together might solve the individual problems and am open to solutions that use different modes of transport together in a functional system. I'd like to keep the hand-waving to a minimum, so no teleportation, invisibility, or anti-gravity; just realistic technology available now or in the near future. [Answer] I suggest using an airship of some sort. They don’t need to be massive like the Hindenburg (depending on what needs transporting), but would need to be located in more remote locations. I would have thought that a large barn might act as an entrance to an underground enclosure where the airship would be stored and serviced when not in use. When needed, they would wait until night fall then checks would be made to ensure that no one was around. When they get the all clear the roof of the barn can be opened and possibly one of the walls (or alternatively large doors can be fitted over a large pit in the ground. When the doors are closed the surface looks like bare ground. When needed the doors open and allow the airship to be released up into the air. The air ship would then ascend quickly to several thousand feet and then travel wherever it needed to go. Local journeys up to a few hundred miles could be made over night and the airship could then land at a similar facility at the target, radio communications ensuring that the craft never descended when any locals were around (unlikely at night in a remote location). Trips of thousands of miles would be achieved during the day at a higher altitude. Even a relatively large airship would be hard to see at high altitude and if the surface were made of material that could be made to change colour it could be light blue, black or shades of grey depending on circumstances. Helium would be an issue but supplies could be moved around by airship and hydrogen could be used as a supplement in an inner ballon. [Answer] A10 Warthogs in green scaly paint jobs! Based near volcanoes or on remote islands. So think about this, the A10 is able to travel very fast. The jet engines make a loud roar, and it is able to breathe devastating fire. You now have your dragon available for travel. That's how relatively primitive societies would view such a thing. You hear a loud roar, look up you see something flying and then fire billowing out from the front, and wherever the fire points, things get destroyed. It always comes from a long way away. You would need to be able to handwave the facilities that would be required for maintenance. A10's require less advanced runways than many other jets and were designed for use in more primitive conditions. This is going to help tremendously. Fuel requirements can be met with Biofuels coming from corn and algae. Those fuels are still being tested, but have been used to power a dassault falcon. Maintenance robots can take car of things in the hanger. The biggest problem I can see is coming up with adequate supplies to arm the huge cannon on the front of the plane. Lead and brass are easy enough, but the ingredients for the gunpowder are going to be hard to find in sufficient quantities. You are going to need massive amounts of automation for this stuff. You have to keep in mind that even with all of the awesomeness of flying around in an A10, if any part of your supply chain or automation breaks, you are going to be screwed. Algae and Corn for fuel is not your weak spot, but materials to make replacement parts for the Warthog. Fuels and oil filters may be hard to make with local materials. Seals break down over time, and high heat gaskets aren't going to be easy. Don't get me started on the titanium and aluminum processing. For your lair, which you need because you have a dragon and seemingly perform miracles, You will need a small cadre of almost peers, and a small army of loyal fanatics to work the land around you. Your almost peers are in on the secret and kept loyal by you being a decent guy and sharing wealth and treating them right. They are also heavily armed. Your Fanatics will be adequately armed, and will be the outside face of your organization. They will be harvesting the Corn and algae to feed the dragon, gathering other raw materials for your alchemy. Try to be a decent distance out, and not have anything that represents massive wealth out in the open. Massive cattle herds, lots of gold or salt might draw unneeded attention your way. That's also why I brought up Algae as abases for aviation biofuels. Land that grows Corn is very valuable, while swamps are not. Get in good with the local ruler for additional help with that. [Answer] A combination of a satellite network and a combination speed boats/snowmobiles/motorcycles. You use the satellite network to ensure you are plotting out a path where there are no people to observe you. Speed boats are the best option since it’s a simpler matter for the satellite network to track for other humans at sea (Large ships). Speed boats are also safer and can carry more people and supplies per driver. Currently the world record holder for fastest speedboat is 262 mph. With a little better tech you could probably mass produce vessels that can travel 100-200 mph and be camouflaged to look medieval. You just slow down when near other people or avoid them entirely. Motorcycles and snowmobiles can handle the land legs for speed. They can also get over 200 mph. However terrain is likely to keep that from safely happening. Also, it is more difficult for satellites to track human travel in varied terrain. Snowmobiles are my ideal land transport. If you’re using them in open plains of snow you can keep your high speed. They can drag sledges for extra equipment and passengers. The snow also makes satellite surveillance simpler. If the planet has Polar Regions like the earth they are mostly uninhabited as well. They are not that loud. [Answer] There are several ways to ensure something is not seen. With stealth, we normally associate a situation where a watcher won't be able to see an object (or a situation). This will be extremely tricky unad unreliable: it has to work every time, and if it fails just once you lost. then there is the other kind of stealth, where people see an object or a situation, but don't understand what they see. This is most of what stage magicians do all the time. But it is also what movie set designers (whatever their actual job description may be) do for a living. And the third form is where the onlooker isn't looking. In a medieval setting, i would advise to combine the second two. Start from remote locations, and travel in the dark. And help an onlooker to mistake things for other things. They won't understand a motorbike, because they have no concept of such a thing. Maybe you can disguise it as a strange creature. Use electric motors, both for the sake of the environment, and for noise reduction. Use electric motor aided gliders in some suitable camouflage paint, and use those only at night, and only when you absolutely have to. Remember, at the period you describe most people never venture far from their birth place, and travel is usually done by day, and only between villages. So, starting off from remote locations and just being low profile, and using some sort of decoy for those few occasions where someone actually sees you should keep you hidden for a long time. And whenever that fails... fatal accidents were a lot more common then than they are today. [Answer] Sometimes the best of stealth is right under everyone's nose. Take a normal carriage, styled after the fashion of the time. Pad the bottom with high capacity batteries, or some noiseless generator (i.e. a fuel cell). The batteries can be styled like wooden planks, just heavier. Place an electric engine underneath the vehicle, I'd suggest along the axles of the front wheels. The engine is small, powerful and not particularly noisy. It may buzz a bit, but even then, you can always make sure that your wheels squeak louder than that. Also, you can disguise it by some form of ball-bearing of the time, or some other metal device to hold the axles in place. Let the horses pull it when in town (poor animals), and carry the horses on a second, lighter cart when outside town. Also, make sure you have drones watching the surroundings from above your head, to prevent being ambushed or spotted. Best if disguised as birds. Remember to carry bird cages with actual birds, in case someone too curious wishes to have a closer look. Added: [link to electric carriages in history](https://en.wikipedia.org/wiki/History_of_the_electric_vehicle#First_practical_electric_cars) [Answer] They can design a lightweight plane using a high altitude balloon for stealth vertical take off and a parachute for stealth vertical landing. [Answer] Boats Not inherently conspicuous in themselves, can be fitted with outboard motors to achieve reasonable speeds and are a good source of income too. With radar you can avoid other ships so no-one sees you unless they have radar themselves. One downside is that the authorities will take some interest in what you are doing, as they do today, but not so much interest that hiding the outboard motor is implausible. There is also the option of hiding it outright like a smuggler. A boat with a computer and radar could hang around a few miles from shore unmanned, stay well clear of other boats and could be called to shore when the coast was clear. The main advantage of this is that it does not have to look like a medieval boat, it can be a lightweight fibreglass thing with very little drag and a nice big motor [Answer] Modern technology is mostly useless and unachievable without the infrastructure to build/use it. Knowledge will give them an edge but keeping hidden will wipe that out and then some. With only a hundred people they would be lucky to be able to make a wooden ship much less anything more advanced. If they all live in the same place, and there is no one else to see what they are doing, and they buy a lot of materials from the outside world, they might, might manage to build a steam powered ship in a few decades. They just don't have the labor to build advanced materials or devices. Even if you handed them modern vehicles they would not be able to fuel or maintain them. Sorry you are going to need some heavy handwaving. Water based transport would be the best choice that at least minimizes the infrastructure needed, and you don't need advanced materials or machinery like you do aircraft. [Answer] Looking at this from a totally different perspective, the best stealth transportation available to the locals is a Viking longship. [![enter image description here](https://i.stack.imgur.com/gAic8.jpg)](https://i.stack.imgur.com/gAic8.jpg) Modern reproduction of a longship Local people cannot see it coming until it is practically upon them. The Vikings could take advantage of the shallow draft to sail fairly far up rivers, and even possibly protege them over places where river travel isn't possible. Even if you can't portage the boat, it is small enough to pull ashore and either guard or hide under foliage. Considering the Vikings were able to sail around the North Sea, Baltic, upriver to create the kingdoms of the Rus and down to Byzantium, along the Atlantic coast to England, France, Spain, Sicily, Italy and even across the Atlantic to Iceland, Greenland and the New World (Vineland), your sailors will have the ability to sail to most places known to the people's of the world. [![enter image description here](https://i.stack.imgur.com/PBtvY.png)](https://i.stack.imgur.com/PBtvY.png) Oh the places you can go.... So using totally known and unremarkable local technology, you have the ability to travel long distances and be able to reach a great many areas without arousing too much comment (well, outside of the impression that locals have of Vikings). Once out of sight of land, navigation could be done via a small computer built into something like a smartphone, and even a hidden engine could be brought into play if the technology can be compact and inconspicuous. So while not "high speed" in the context of the 21rst century, it is still high speed by the standards of the day, and capable of getting the intrepid explorers to many of the places they want to get to. [Answer] I liked Thucydides answer for sea travel. Here are some other ideas. Remember that you can combine stealth technologies with subterfuge, so you have lots of options available, depending on what you want to accomplish. 1. Tunnels: if you want to connect two communities, this just can't be beat. 2. Aircraft: You can use black vtol aircraft and only fly on moonless nights. You can dress them up as dragons, so people think they're something else in a pinch. You can mask the noises with some obscuring sound that fits into the local mythology. 3. Superstition You can foster superstition to keep people away from sensitive locations (aircraft hangers, tunnel entrances, whatever). Good storytelling, foul odors (sulfur!) and frightening sights (a mauled lion --scary!) are examples how you cultivate this. 4. Electric Dirtbikes. A good option for personal transport is an electric off-road motorcycle. Being able to travel 200km in a day would be serious magic for a medieval world. Paint it black, with black safety gear -- who would know how to interpret such a thing. A bystander at night would only perceive a bright light racing at unholy speeds through the woods or down the road. In the daytime you'd think you'd seen a demon. Sightings could be cut down to virtually zero by using thermal scanners to avoid encounters -- perhaps a fly-ahead drone. 200km is avaiable with todays technology. Add hypothetical power sources and you can have arbitrary ranges. [Answer] I'd probably go for an exotic rail-gun inspired hyperloop. Once the railgun accelerates you in near-vacuum, the electromagnetic flux will be able to keep the vehicle centered in the tube, and you can install a lift station at the destination. If the track is layered at a downward angle, gravity can provide the needed propulsion. This solves a few problems: 1) no constant power required. Power only needed at launch and destination. 2) If all the tunnel low points at least superficially connect, you have only one air removal station. The reason why this has not been done (yet) is because of the boring costs. [Answer] Just use the ## [STARS](https://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery_system) aka Fulton Surface-to-air Recovery System. High altitude stealth drones could be following your "future people" all the time, if they fly high enough you can't see or hear them. When necessary, a person or packaged goods could be equipped with a transparent balloon that rises into the sky carrying a rope or cable. The drone then picks the cable up and drags the person or goods with it. The reverse is also rather easy, as pointed out in other answers, just use a parachute. With enough advances in technology I guess this method could become rather safe and almost impossible to beat on the stealth level. The problem with many other means of transport is that they're loud, difficult to hide, difficult to maintain/refuel. Sure they might give you more freedom, but this method is pretty hard to beat on the stealth level. [Answer] Since the general inhabitants have only primitive sensor technology, then 'stealth' means only local in-person sight and sound. No radar, lidar, remote sensing, recording, radio, infrared, night vision, and so on. The local inhabitants would also be prone to explain things they DO sense in terms of their own experience and technology. So, doing things at night, for starters, using craft with no lights. Heat, electromagnetic signatures, and radio are non-consequential. They can not be detected anyway. Strange noises can be masked by even stranger louder noises. Artificial thunder, for instance. So an electric ducted VTOL aircraft, completely painted black, flown only at night, would go unnoticed. Since no one has any means of aerial surveillance, keeping them hidden behind high walls in a castle-like enclosure would also just blend in. And since on medieval Earth, the world was limited exclusively to Europe, you have the rest of the Earth to establish a base. There is absolutely NO communication with anywhere else. No local technology to make it happen. In medieval Europe, the entire North American continent could be 21st century technology, and no one in Europe would know. Perhaps the best continent to establish a base would be Australia. There were indigenous peoples, but they were not nomadic. They were exclusively territorial, and clung to the coastal areas. ]
[Question] [ The Angelic Host is going to war. It's a long journey, requiring flight over the highest mountain ranges and long trudges through the fiercest blizzards. As with all large scale military marches the Host will be carrying equipment, tents and provisions for the journey and the eventual battle, averaging 30kg of gear per angel. Each angel is the same physically as a well built human, but with a pair of large birdlike wings based just behind the shoulder blades that enable them to fly by pushing off Plot particles floating in the aether (you can assume these wings are strong enough to deal with the extra weight). Naturally hands need to be kept free for wielding flaming swords and throwing thunderous spears and playing mighty trumpets etc, so how might an angel keep all their equipment about themselves without interfering with their wings (or ruining their backs)? EDIT FOR CLARITY: I don't care about the equipment in the knapsack, I care about the manner of attachment/storage. The question can be most succinctly written as: 'How could my winged humanoids attach items/goods to their bodies in such a manner that they can keep their hands free, fly and walk'. [Answer] # Carried low, and conformal > > "Amateurs talk about tactics, but professionals study logistics." > > > — Gen. Robert H. Barrow, USMC (Commandant of the Marine Corps) > > > A military host needs food, clothes, first aid and a whole lot more to be combat effective once it is time to get bloody. No military host moves faster or farther than their logistics, the so called [Train](https://en.wikipedia.org/wiki/Train_(military)). So unless your host's train is flying and carrying everything with them in the air, this means that your host has a sizable portion on the ground, carried by land vehicles of some sort, trucks or wagons or whatnot. This in turn means that your angels do not need to be carrying anything in the air for the most part. Their knapsacks will ride as cargo on the ground. If some smaller groups go off as a detachment however (think rangers or some other units that operate independently from a host), then the question becomes relevant, and a matter of rather simple aerodynamics. For anything carried on their person, they want that to be carried low (i.e. below them when flying) and [conformal against their body](https://en.wikipedia.org/wiki/Conformal_fuel_tank) to reduce drag. So their packs would be large, flat chest packs most likely. However if they are the least bit clever they would not carry it on their person, because for an avian creature lifting is a very heavy affair. Instead they would probably bring some sort of cargo glider with them — like a [hang glider](https://en.wikipedia.org/wiki/Hang_gliding) or [paraglider](https://en.wikipedia.org/wiki/Paragliding) — stuff their knapsacks under that, and tug it behind them. This is because the energy you need to spend to make a given mass glide is a lot less than if you need to provide direct lift to that same mass. [Answer] The angels are strong enough to fly while carrying their body weight plus 30 kg. That's a lot of extra strength, so I don't think you need to worry about their backs. * When the angels are actually expecting fighting, they leave the packs in camp. While wearing the packs, they don't need the full range of motion they'd have unencumbered. They need enough range of motion to respond to emergencies, so weapons should be available, and packs should be able to survive being dropped from a great height. * To carry the weight, they could use a combination of lumbar packs around their hips and front packs on their chests. They might be able to carry their flaming swords on their backs in a harness designed to fit between their wings, which would solve the problem of easy access. * Do not try trudging through blizzards. Breaking a path through the snow after a blizzard takes a huge amount of energy and is completely unneeded if you can fly over the snow. During the actual blizzard, you risk losing whole battalions when they can't see each other and make a wrong turn in the blinding snow, plus the wind and snow make walking difficult. An army walking in these conditions would be lucky to travel a mile in an entire day, and when the weather finally clears, they would be exhausted. Instead, the angels are better off building camp, then flying away as soon as conditions permit. And a question you didn't raise: How are you feeding this army? Each soldier probably needs about a kg of food per day, maybe more (basing this off of the diets of British navy sailors, since there's reliable data on what they ate). So if your armor, weapons and shelter take half the pack, you've got about 15 days provisions max. A large human army would travel with a supply of food and extra supplies hauled by beasts of burden, or a small force might try to rely on raiding farms and towns as they pass. [Answer] Think of a basic military harness - the kind with a single back strap and two in the front. The cargo would be split between a few waist packs, a bigger front bag (aka baby carrier) and maybe a fanny pack. Down low. A pair of thigh packs might work as well. Assume the front and fanny pack would not be worn in combat. [Answer] The solution that immediately comes to mind is a hotshot (wildfire firefighter) style backpack. It's basically a standard rucksack, but the pack is slung a little lower and supported by a center piece that runs down the center of the back (between the wings in this case). [![enter image description here](https://i.stack.imgur.com/vL8wu.jpg)](https://i.stack.imgur.com/vL8wu.jpg) or a larger pack, center strap can be adjusted [![enter image description here](https://i.stack.imgur.com/QJ1HO.jpg)](https://i.stack.imgur.com/QJ1HO.jpg) [![enter image description here](https://i.stack.imgur.com/n7oiP.jpg)](https://i.stack.imgur.com/n7oiP.jpg) [Answer] I'm thinking less backbpack, and more buttpack. You want it to not interfere with the wings, so dead in the middle of the back is pretty well out. You also want the weight of the pack to be settled on the shoulders while upright. I mean, that's what a backpack does. Take a military harness as a start point. One central, dorsal strap and two shoulder straps. These are connected at the waist by a complete belt that goes all the way around the abdomen and over the hips. The actual pack is attached to the belt and central dorsal strap. It should hang over the but, maybe as far down as the middle of the thigh. you may want to consider bifurcation at the butt and thigh straps to keep the load as firmly attached to the body as possible. You can hang all kinds of weapon and gear attachment points to the harness. The point of a backpack is to carry gear in a way that you can still move and manipulate things with your hands. It tends to be easier if the pack moves with you rather than some semi independent mass. This would be even more important in flight. That is why you need to strap it to just about every point away from a joint as possible. you bend at he waist and it's an independent bend for each leg, so you have thigh straps. The belt is situated above the waist. the trunk doesn't move a great deal, comparatively speaking. A note after re-reading the question and some answers.The position of the load on the body is important for flight, it it also important for fighting. I flight, the load being directly under where the wings join to provide balance makes the most sense for just flight. By contrast, having a bulky object between your arms is impractical for combat. You might split the difference by making the whole thing modular. Anchor the mass in front for long flights up the mountain pass, when enemy action is near, shift it around back. Make sure you train to fight and fly in both scenarios, just to be prepared. I hope I described it well enough. Not a great artist, but I can see it in my head. [Answer] Are there any (flying) pack animals that the angels could use? Thinking in terms of infantry/cavalry - if you've got flying horses that can match pace with the angels, they could also be useful beasts of burden? Potentially a land train could go on as well, but if aerial travel is a necessity, then maybe some extra wingpower could come in handy. Also, are there military ranks within the angelic host? If you've got a section of lowly footsoldiers (wingsoldiers?), perhaps part of their duty would be to carry some of the extra weight (superfluous weaponry, culinary equipment, camping gear, etc.). Then the higher-ranking or more experienced angels would have greater freedom to fly without being overencumbered. Scouts and rangers would probably want to pack light as well, given that their job is to travel greater distances and keep the rest informed of what's happening ahead - so someone else may have to take care of the heavy possessions they need. ]
[Question] [ I did read several great thrillers where main hero is injected with unknown fluid and told, that such fluid is deadly poison unknown to normal medicine and our hero has 48 hours to live. If he wants to live longer, he has to do X to get antidote from villain... But, is actually such poison plausible? Help me find (or design) such poison * It has to kill person in about 48 hours, assuming that such person will be very physically active for most of such time. * Classical action thriller hero is going to be injected with such poison. So you can assume healthy person who is well above average in psychical and physical abilities * Such poison should be treatable by antidote * After getting antidote, it should leave body as much unharmed as possible. My Action Joe wants to do another action. Should I care about such detail of story? Or should I go the usual way saying the poison is Handvawium and antidote Unobtainium if ever asked as author of yet-another action story? [Answer] It would be very difficult to obtain a poison that would act as described. The damage to the liver would begin almost immediately, and the antidote would take time to work, also, the action is mostly linear, no "harmless for 48h, then suddenly lethal". There would be ways to delay the action by 48h. There are capsules that dissolve in human digestive tract at specific pace, allowing a pretty precise moment of release of the contents. Still, the antidote would be nearly impossible to implement. The best you can go with is an electronic device. The capsule, once swallowed, inflates inside your stomach to a size that makes it impossible to eject. It contains a circuit with a clock counting down 48h, with a capsule of a strong poison or even a small explosive charge. It also contains a radio that can receive a signal telling it to disable the timer and deflate the retaining balloon. Following that, the device will leave the digestive tract through normal route, harmlessly. Some technical solutions: * balloon with a bit of low-boiling-point liquid; buthane-n boiling point is around -0.5oC - keeping it in a freezer will keep it collapsed; swallowed it will expand. In these amounts it would be quite harmless too. * Bluetooth will allow the device to be controlled from a cell phone and withstand 48h powered just fine with a "pill battery". * Tiny electric ignitor for explosives will be more than enough to break a small capsule with the poison. Attempt to disable it with EMP will detonate it. Of course it would break the balloon, allowing access of the poison to the tissue. * Potassium Cyanide, while not the strongest, is one of the fastest-acting poisons and the volume of a typical "medicine capsule" would suffice easily. * A trivial moisture sensor would detect the balloon was broken and trigger release of the poison (if not disabled through the remote control), so trying to put a needle through your belly to get rid of it would be counter-productive. * Deflating the balloon after "disarm" would be a little tricky. An electromagnetic actuator with a needle could break the balloon. * Disarming would result in a mighty burp. Possibly flaming, if there's an ignition source. ...or you could go with an explosive collar. Molding lots of hair-thickness wires into epoxy would make a layer to detect broken circuit if you try to access the control circuitry inside. [Answer] In truth all you need to do is convince your action hero that the poison works as you described while giving him a non-lethal drug with predictable side effects, which you can say are the first signs that the poison is working. Then you inject another person with a real poison that kills in a way that seems similar to the side effects of the "fake poison" and show the protagonist your dummy guy dying a horrible death. An example of this would be to give your hero an injection of LABAs which will increase his heart rate for a prolong time, then give your sacrifice a high dose of Potassium, and he will die a horrible death complaining of palpitations and chest pain among other things. Really depends on how much the villain can convince the hero the poison is real after all, the more pomp and theatricality the villain brings to the table the more believable it will be to the reader and the hero. Then again you may counter this idea by saying that the hero won't be in actual danger. In that case fair enough, but remember neither the reader nor the hero need know that they were fooled for the story to make perfect sense. EDIT: Or you can use a beta blocker, with high enough doses your hero's heart will slow down to an extent that he will feel like he will die, this will have a secondary effect of making him less athletic however. I am assuming that you need this explanation for other authors not readers. EDIT 2: Thinking about it some more, if you really want your Hero to be convinced that he is poisoned, and you don't mind prolonged torture of your hero, you can play with the idea of drug withdrawal. Basically certain drugs, when taken for a prolonged period, will cause dependence. If they are removed from the system the victim will start feeling very sick. If you give your Hero Repeated injection of Heroine/Morphine for example you can make him dependent on it. Then when you want to make the hero do the thing you want him to do, just give him the antidote (Naloxone) and he will be pushed into an opioid withdrawal state. If the dose of Naloxone is low enough you can make it so that the really problematic symptoms start around 48 hrs later. Of course the problem with this method is that any doctor will be able to spot opioid withdrawal a mile away, and all they need is to give your Hero opiates to relieve his symptoms. This is just another way of doing things. I think the biggest problem for this question is the time frame, 48 hours is a long time, and most poisons will have done a lot of damage by then, remember the drugs that we really know about, are the drugs doctors know about. So most doctors will be able to reverse the effects of any well known drug. What you need is something that either isn't there or nobody knows about. [Answer] You could use Some weak painkiller together with Some nightshade (belladonna), use A pot to cook IT together. Use ca. 10 painkillers and 100 grams of nightshade petals, start with melting the painkillers into A paste, Then Cool it to 40 Degrees Celsius. Add the petals one by one on top of the paste. Cut some of the stem (ça. 10 g) and set it to 50 degrees for 5 mins. Then cool. The paste tastes Weird, but ONLY A little dose is deadly. Use thick gloves in contact with Both the paste and the belladonna. A website with more info: <https://en.m.wikipedia.org/wiki/Atropa_belladonna> Msg me on this page if you need more info, like which painkiller to use. [Answer] In "What good is a glass dagger?" by Larry Niven, a wizard magically inserts a glass dagger next to the heart of someone who was sent to kill him. Only magic keeps the dagger in place. The area around the cave has been depleted of magic. If the assassin leaves the cave, the spell will fail and the dagger will pierce his heart. The sneaky thing is that the wizard's spell did not insert the dagger, merely the feeling of a dagger. The man could simply leave without harm, but he doesn't know that. All you need is something which causes progressively more unpleasant symptoms controllable by the villain (radio-controlled or time-release capsules), but does not cause death. Then if the person who does the bidding of the villain is captured, having no trace of a real deadly agent, the "hero" can be framed for the actions. [Answer] This is probably too late but still a good poison. Monkshood is a plant also called wolfsbane but the technical name for it is aconite. I was actually accidentally poisoned by this. Eating just one of these petals will cause you to have fever and chills, extreme headache, huge stomach cramps and confusion and delirium. It works by slowing down the heart, paralyzes the nerves, and can cause intestinal problems. If you eat much more than a bit of petal it will slow your heart to the point of death. It will also cause chest pain and shortness of breath. As for a cure there are a few things that will work occasionally depending on the dosage. And for the 48 hour thing symptoms may occur immediately but for me they started 12 hours after lasted for 12 hours stopped and reoccurred 24 hours later. Even if you don't take enough to kill someone they will wish they are dead from the pain. Hope that maybe helped. [Answer] I am going in a completely different direction than the other answers here so bare with me here. I believe that a genetically engineered bacteria could do what you need. The bacteria is designed to simply do what bacteria does: grow and reproduce. Instead of poisoning him with waste products (like most bacterial infections do) they simply feed on plasma (resulting in low blood pressure) and grow in the blood vessels (eventually resulting in blockages). It would be a bit hard to time it out to exactly 48 hours (no dramatic count down moment). The way it would be stopped is with a bacteriophage (a kind of virus that targets bacteria). It would take some time to shut down the infection but it should work because the virus will spread faster with more bacteria to infect. The way you make this untreatable at a local hospital would be to make the virus and bacteria keyed to each other (i.e. The virus can only infect the bacteria and the bacteria is resistant to most other methods of curing it). It would be possible to slow the process down though with blood transfusions and eventually having to clean out major arteries from the blockages that will inevitably form. Such treatments would only prolong the inevitable. [Answer] I know no substance that has such effect, but... what about things which while not killing instantly, bring unavoidable death after 48 hours? * Dimethylmercury. + It will kill you in several months. + The victim does not feel any symptoms for several months. + There is a treatment but it should be administetered in short time after poisoning + If treatment is not administered in time the person dies whatever you do. * Desease-based poisioning. Rabies, HIV need quick treatment. HIV needs treatment to start in 72 hours (preferably, 48 hours). An animal-based strain of HIV may be more lethal. * Death cap. Kills you in several weeks. No known antidote (but conceivable). Full recovery without a trace if survived. [Answer] Give your hero an amount of botulinumtoxin. It is one of the strongest poisons produced by a bacteria 'Clostridium Botulinum'. As the name implies, the bacteria grows only under strict absence of oxygen. You can either look for canned meat, where the upper part is not flat, but looks as if it contains a lot of gas as if something blew up the inside. These cans contain the above mentioned toxin. The spores of the bacteria can survive for years in soil and can be found almost everywhere. This is Option no. 2. Take half a kilogram of raw pork meat. (Important: it must be free from preservatives). Then cook it about an hour to kill all other bacteria. Then proceed as you would do when making jam. Fill a jar with the hot meat and a bit of the water. Let it cool down a bit and add soil from your garden. Then the jam making procedure goes on. Close the jar airtightly and let it cool down. Let it stand in your cellar for about a year and let the bacteria grow and produce the deadly toxin. I leave it to you how to get the poison into the victims body. Depending on the ingested dose, the victim will feel very sick with quickly evolving paralysis even of the eyes. Untreated, it leads to certain death due to paralysis of the lung, which let the victim suffocate. Fortunately there exists an antidote which leads to complete reminiscence. It is mainly available and every hospital has it. I hope I could help you. If you need more scientific information you are welcome to ask. [Answer] The origin of the concept is real enough. Many not instantly lethal poison cause cumulative damage that after a certain point exceeds the ability of the body to compensate and first makes you sick and then kills you. Presumably if you get an antidote fast enough, your body will recover and you will not die. Many diseases could work in a similar way with an onset time after which the load exceeds what the immune system can suppress and you get sick and possibly die, if the symptoms are lethal. And it is possible to have a specific cure for such a disease that will save you if you get it before symptoms hit. But yeah, both poisons and diseases have many factors affecting the grace period and symptoms start getting serious some time before you die. The body will try to stay alive, so you will get sick. So having on exact time is not really realistic. I have a dim recollection that some poisons get pretty close, but I doubt we are talking about race against the clock close. You could inject fast acting poison in nanocapsules with predictable release time. Human body has stable temperature and chemistry, so the timing would be reasonably accurate. The cure would be something that bonds with the capsule and stabilizes it so that it doesn't break before body naturally flushes the capsules, with the poison still inside, out of the blood stream. Obviously some capsules would still break within the body and fail to get flushed, but body can tolerate most poison in low doses spread over time. It is the fact that the capsules normally release within a relatively short time period while most of them are still within the bloodstream that kills. This is AFAIK perfectly plausible, but I have not heard of anyone actually developing this type of nanocapsule, so you'd need villains with resources to develop it themselves. Usually thrillers downplay the difficulty of developing such technological toys, so if it is clearly in the genre this should not be a problem. Still the fact that significant resources are needed opens the chance that some research and detective work can figure out what the capsules are made of and what is the correct "stabilizer" without doing what you are told. [Answer] While I am not aware of any compound that meets your requirements I do not believe that something approximating it is impossible. The issue here is exactly what constitutes "poison". Lets take a "poison" that does no harm to the victim--but rather the victim's body turns it into something deadly. (There are real-world examples: Methanol and acetaminophen. Both are converted into compounds for which both safe and dangerous further pathways exist.) Your 48 hours of safety is obtained by not only administering the "poison" but administering an antagonist for the metabolite that does the dirty work. After 48 hours the antagonist is used up, the metabolite builds up and kills the victim. [Answer] There are several mushrooms that cause death after a certain amount of time during which their symptoms are visible but they can still be stopped by an antidote. I recommend Lepiota brunneoincarnata. It has no symptoms until it is too late to be treated usually and causes liver failure and death. This might not be what you are looking for as deaths usually happen after a week, but it would be dramatic. There is no cure but the villain could give your hero a liver transplant. I hope that was helpful:D. [Answer] You certainly need to explore the environment around the poison: its delivery mechanism and the body it is injected in. From there, I see two major directions, depending on whether you prefer Western or Eastern style thinking behind your movie plots. For western thought, you'll need to encapsulate the virulent poison in an innocuous covering which slowly decomposes. Create a layered covering where only the outside layer is "strong" and the inner ones are weak (one inner layer for every "antidote" the hero must drink). If the strong one decomposes, the weak ones fall shortly afterwards and release the poison. The "antidote" hardens the next layer to keep the poison in check. Eventually, the final antidote hardens a layer which does not decompose, and lets the poison be passed naturally. For eastern thought, you want to focus on destabilizing the Chi of the individual with the poison. The antidote is a concoction which temporarily stabilizes the Chi, allowing the hero to continue acting. The eastern version is a bit simpler because the eastern focus is on the interaction between the individual and the poison. The western view tends to focus on the poison, forcing more exotic solutions. The individual is complicated, so interactions with individuals can be complicated. The poison, on its own, is simple, so something outside of it needs to breathe the complexity into the western approach. [Answer] depending on time period you could have him injected with any number of bacterial infections, and use a simple antibiotic as the antidote. This would work pretty well in lower tech or schizo-tech worlds where making and use of antibiotics aren't common knowledge, so the hero doesn't realize how easy it is to cure himself. [Answer] It could work by giving the hero a poison, and then a weakened form of the antidote on a set schedule. Not strong enough to cure him, but enough to keep him from dying. This would cause tension since he would feel the poison start to work, and then subside after taking the antidote, and would give a sense of urgency to finish each task before the next dose is scheduled and the poison does to much damage. [Answer] I'm sure it's possible. The trick would be to have a substance that is very hard for a human body to excrete, whicb will slowly be metabolised from latent poison to active and cumulative poison. The antidote accomplishes what your body can not: it converts the poison into something harmless. Prozac has a half-life of several weeks in your body, but of course it slowly metabolises into harmless things. It's proof of concept though. There is a non prescription painkiller which nearly fits the bill: Paracetamol. In normal doses it is metabolised by your liver into a toxin and then immediately re-metabolised into something harmless. In overdose your liver runs out of an amino acid needed for the second stage and then inflicts potentially fatal damage because the first stage doesn't stop. The antidote is acetylcysteine. Take enough of that before your liver destroys itself and you will survive, possibly even without noticeable toxic effects. Wait too long and you'll die many days later. Personally I don't think the stuff should be non prescription. Every year people take an overdose, fall asleep, wake up, feel Ok, feel glad their suicide failed, tell nobody, get on with life, and die horrible deaths a couple of weeks later. It's perfectly safe in normal doses though. Edit. I'll add that it's quite possible that the substance is known in the archives of a pharmaceutical company dating back to before predicting the metabolism of a novel compound in a body was a science. Something that worked in the short term and then made the lab rats die. [Answer] Don't use chemical warfare (poison), instead use germ warfare (disease causing agent). Will be easy to administer by various routes. Causes no symptoms while incubating in victim. Can have a rapid fatality rate once a sufficient load of organism is reached in body. And can be engineered with a protein "kill switch" that can be administered by injection as a rapid antidote. [Answer] That's easy...check out how in 1996 a murder was reported in Washington ... Jeff Morrison used a paste of basic house hold items using equipment and tools commonly found in every home...the best thing it cannot be detected in the body after death.. and kills you within 15 hours.. without showing any symptoms or abnormalities during those first 14 hours of her death..the only thing she joked about before dying over the phone with a friend was about a running nose.. and dies immediately with the phone still clutched in her hands... ]
[Question] [ Common in sci-fi tropes but absolutely climactic nonetheless, a spaceship faces impending doom after encountering a gravity well such as a stellar black hole. The spaceship's captain gives the order to discard all reactor cores onboard and detonate them to produce a powerful shock wave, the spaceship then escapes the gravity well by leveraging the energy carried by this shock wave. Is this trick feasible? Wouldn't the spaceship be bathed in deadly high energy particles and radiation? And wouldn't the impulse of the explosion splatter everyone on board because of the spike in G-forces? [Answer] I would vote no. Whether or not you are in the well of a black hole doesn't really matter. The gravitational well of a black hole is almost identical to that of any other celestial body outside the event horizon—leaving aside frame dragging and other such inconveniences. What you are describing is, in essence, nuclear-pulsed propulsion, which is a very real concept; however, you need to design your spacecraft for this type of propulsion. [![Diagram of spaceship](https://i.stack.imgur.com/J7cim.png)](https://i.stack.imgur.com/J7cim.png) As any illustration of [Project Orion](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)) will tell you, these ships need a rather heavy mechanism to convert the almost instantaneous blast of the bomblet into a smooth multi-second-long acceleration. Even so, you can't just use any bomb or explosion. Despite what some may think, Project Orion does not work by using radiation pressure. Instead, the bomblets have a bit of propellant at the top, which the nuclear explosion underneath slams into the pusher plate. That's what's transferring the momentum—the radiation does barely anything. This is why conversations of Orion's per-bomblet yield are difficult, as depending on the design a 1Mt bomblet might generate less "thrust" than a 10kt one. The big issue with doing redneck Orion is that while all spaceships should have extensive radiation protection, they definitely do not have a spare pusher plate sitting around with an absorption mechanism. Even if your ship could structurally survive being blasted by a huge explosion, your crew can't. This is actually a huge problem for Orion—if the pusher plate for any reason jams or is out of sync the spaceship as a whole, it suddenly absorbs the entire force of the nuke and would probably just break apart. So, I would say this is infeasible if the spacecraft isn't explicitly designed to be a nuclear-pulsed one. You might be able to do some retrofit [Project-Medusa-type](https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#Medusa) deal, but if you have the spare parts for that, I feel like you are not really trapped in the first place. [Answer] ## Yes. If you're resourceful. Nuclear pulse propulsion is the way to go - however it is possible to use the 'Medusa' method instead of intensively using pusher plates and springs. This is when you eject a nuclear bomb in the direction you want to go. You have a series of wires connecting a parachute behind it, such that when the nuclear bomb goes off it pushes on the parachute and 'pulls' the spacecraft. [![enter image description here](https://i.stack.imgur.com/n34mQ.png)](https://i.stack.imgur.com/n34mQ.png) The advantages are: * All components are in tension, lightweight and uses wires, so you do not need complex pusher plates, coils and springs * The parachute can be as far away as needed for longevity, its material is just in tension, can be fabricated from almost any material and its size just has to be angularly larger than the spaceship to create a net force in the direction of the bomb * All you need is spare wire, and a parachute (which you might have for some sort of re-entry?) or a series of parachutes would do * If you have wires long enough, you could position your spacecraft a long way from the bomb, so it is not affected as much by the radiation when the bomb is detonated. A video can be found here, although in this example the wires are shown quite short, and they use a ring as a 'spring': [AnimationLink](https://www.youtube.com/watch?v=mT4ZdPRADEw) I actually think the Medusa spacecraft concept is safer, smarter and longer wearing than push-plate nuclear pulse propulsion designs. [Answer] No. No matter how tough the egg is, the yolk would still get scrambled. Any explosion strong enough to throw a spaceship into space would kill everyone onboard. You'd need force fields and inertial dampeners and if you have that tech, you don't need to ride an explosion into space. [Answer] No... except, maybe Propulsion is what you get when reaction mass expands in a controlled fashion inside a suitable chamber, thereby pushing your ship along. The keyword here is "mass." The problem with the SciFi trope from a realism perspective is that there simply isn't enough mass to push the ship along. Most of the mass is lost to interstellar space. What mass remains is a fraction of what would have been used for propulsion had the "core" (or whatever was used to make the explosion) been capable of detonation inside the suitable reaction chamber (like the propulsion bells of the Saturn V F1 engines). Then there's that maybe Thanks for the [science-fiction](/questions/tagged/science-fiction "show questions tagged 'science-fiction'") tag! let's stretch a little and rationalize what you're trying to do. It just so happens that your ship is equipped with [Solar Sails](https://en.wikipedia.org/wiki/Solar_sail). Perhaps they're used betimes to supplement your primary engines for greater fuel efficiency or maybe they're there for emergency propulsion. And getting trapped in the gravity well of a black hole is definitely an emergency! Deploy those sails, jettison that core, and hold on tight! But only with one hand... things like this should be done with style. [![enter image description here](https://i.stack.imgur.com/obqzem.jpg)](https://i.stack.imgur.com/obqze.jpg) Image courtesy [Wikipedia](https://en.wikipedia.org/wiki/Windsurfing) [Answer] To escape a gravity well one needs to supply to the escaping object enough energy to reach infinite distance from the well with velocity 0. In principle any sufficiently big explosion can satisfy this requirement, as long as the escaping object is not yet past the event horizon of the black hole. Past the event horizon the only escape is to wait to be turned into Hawking radiation. However any structure has an energy threshold which can withstand, after which it will get damaged or destroyed by the explosion, which I assume is not the intention. At the end a chemical rocket is nothing more than an explosion, sufficiently spread over time so that the rocket doesn't get damaged and can accomplish its mission. [Answer] ## I'm going with maybe, but for reasons not previously mentioned. Let's talk about star drives and their power output, then compare that to the power output of an explosion. Your ship is capable of travering deep space casually and easily, it's not a generation ship or you wouldn't be exploring event horizons up close, hence it has a superluminal drive system, the power output of which is quite simply magnificent. In short, an explosion can't match this. Not an Orion drive, probably not even a supernova. > > they are precisely on the "Drama Line", the altitude at which it is possible to blasted to safety by a makeshift bomb cobbled together from bits of your ship that really shouldn't be going bang. Below the drama line, all you'll be able to do is to send out a tearful goodbye message, possibly telling your children how proud you are of them, before you plummet to your doom and/or explode. Above the drama line you can just fly away, and as such no-one is really interested in that flight regime. - Starfish Prime* in the comments* > > > There are several Drama Lines to define, importantly the explosion Drama Line is considerably further out than the star drive's Drama Line. The quirk of black holes is that you need to be able to travel faster than the speed of light to escape the event horizon. Your star drive can already do this. ## Now you need to tell a story The important part is that you're still outside, but approaching, the explosion Drama Line, which leaves you well outside your star drive Drama Line. Something has gone wrong with your star drive, technology is now a character in your story, you can begin the technobabble. You get a choice, and you can build up to it. Either you blow up the drive now and escape on the explosion Drama Line, or you try to hold out and fix the drive and get out ahead of the star drive Drama Line. This inverts the traditional plot where the drive repairs fail and then you blow everything up. [Answer] Only a spaceship with very advanced technology would dare explore black holes. Escape by riding a shockwave was actually the plan all along (how else would you escape!?). The ship is equipped for it: It puts the entire structure in a stasis field which completely shields the ship and its interior from any interaction with its surroundings; all forces of the explosion are acting only on the infinitesimally thin boundary layer. This stasis field needs ginormous amounts of energy which the normal engines cannot deliver in the few microseconds available (no, not even these very advanced ones). Thankfully, there is plenty of energy available from the explosion. The stasis field projectors are activated and powered by the radiation of the very blast they are protecting against. The stasis field progresses with the wave front through the ship, limiting the crew exposure to a tolerable minimum. This bootstrapping scheme is known as is "Self-triggering deployment", or STD. The apparatus itself is called "Stasis forwarding unit", or STFU. ]
[Question] [ I have a world that isn't an exact analogue to medieval technology, closer to the late 1700s in terms of culture and agriculture/metallurgy, only without gunpowder. I have them ahead of real history for this time period in some areas (e.g., medical and farm science), but behind in others (notably military science, they still use enlightenment style militaries - pikemen, heavy cavalry, medieval-style ballistae and trebuchets, crossbows, etc). I have been thinking of a system for rapid mass transit over land and wanted to find out if it was feasible as a replacement for trains as internal combustion engines will not be present in this world for various handwave-y reasons. Here's what I'm thinking: The fastest and most efficient form of travel before engines was boats - rivers were the primary way to ship things in bulk with any speed over continents, and ocean going vessels are much faster oftentimes than traversing the inland of a continent on foot/horse, even if you end up going way more miles roundabout. So, I have an empire that wishes to build artificial rivers of a sort in order to facilitate this fast travel, connecting their cities. I imagine massive raised aqueducts 100m in width and a few tens of meters in depths. Through a massive set of pumps powered by manual labor / ox teams / wind power, huge amounts of water are pumped up to fill the aqueduct for miles and miles. The aqueducts are split into half, and each half has a slightly opposite slope: so that the water flows in one direction on each half, so even unpowered ships can just float down the aqueduct to their destination, though oars/sail are typically used to increase the speed. The slope is just slight enough to get the water moving, it doesn't have to be a large incline. The aquifers are raised so that if for instance the destination city is at a higher altitude than the source city, the aqueduct at the source is still higher to maintain that incline. Ignore problems associated with moving cargo up and down these aqueducts. Assume almost unlimited manpower / political will to accomplish this. Is this a feasible engineering feat for this general level of tech? I imagine the aqueducts will be made from something akin to concrete joining large cut stone blocks but am open to suggestions. My only rule is no gunpowder/combustion engines. [Answer] At 100m wide and 20m deep, you are looking at needing to pump 2000 cubic meters of water for every meter you want a boat to drift. Now, let's say you want your ships to move at the speed of a slow moving sailboat (~4 knots / 8 kph), that means you would need to pump 16 million cubic meters of water an hour. A really good manual bilge pump in the hands of a well rested, and physically fit user can displace about 7 cubic meters of water an hour. Pumping is hard work; so in order to keep your army of manual slave pumpers pumping going at anywhere near peak efficiency, you'll probably need to to have them working in teams of 3 for 3 seperate 8 hour shifts. This equals 9 workers per pump for a total workforce requirement of just a bit over 20 million people. Now, these estimates are for based on what it takes to get water over the side of a boat using a pump made to modern specifications. To raise water 10s of meters using renaissance level engineering, your looking at needing multiple stages of pumps increasing this requirement to well over 100 million laborers. Since you say "almost unlimited manpower", I would say the answer here will be a pretty solid no. Even major modern cities like New York do not have enough population to perform this sort of work no matter how tyrannically your government tries to make it happen. That said, your idea of water "highways" is not entirely un-feasible. The hard part about using rivers and canals in a pre-industrial civilization is not that you NEED the current to help you move downstream so much as the current works against you when you go up stream. If you were to build the raised aqueducts to be perfectly level, they could retain rain water and allow for 2-way transit without ever having to work against the current. Then, even simple sailing barges could go both ways at speeds of 4+ knots as easily as if they were traveling in open waters making mass transit doable. In terms of how fast you can travel using this system: your fastest sailing ships of the era could hit cruising speeds of 8-11 knots covering distances of about 350-500km per day depending on wind conditions. That means that your faster ships could match pony express speeds delivering mail, passengers, and small amounts of priority freight anywhere the country in a matter of days. Another possible implementation is to use an actually aqueduct. Rome's aqueducts collected melting snow water high up in the mountains and used the elevation difference to carry the water down to the city. If instead you used an aqueduct to carry water half way down, then you could deliver cargo barges to a raised aquifer in the city that would second as a trade port, then you send cargo the rest of the way down back to the 1st town in the foothills near the aqueduct origin. In this way you could maintain two-way flowing water traffic, but only in places where the geography allows for this. [![enter image description here](https://i.stack.imgur.com/Mqbsa.png)](https://i.stack.imgur.com/Mqbsa.png) [Answer] > > I imagine massive raised aqueducts 100m in width and a few tens of meters in depths > > > Ok, for starters: scale this back a bit. Not just for practicality reasons, but for the simple fact that it is so ridiculously excessive. The real world Panama Canal has a standard called [Panamax](https://en.wikipedia.org/wiki/Panamax), which allows ships to have a 12m draft, 32m beam and 290m length. That's the size of the locks they need to fit into. They can carry over 52000 tonnes of cargo (excluding the dry mass of the ship). Panamax boats are serious, big, oceangoing vessels. Needing drafts of over 20m for a pre-industrial society seems frankly implausible. For comparison, [HMS Victory](https://en.wikipedia.org/wiki/HMS_Victory_(1737)), a 100-gun first rate warship of the 1700s, had a draft of 5.5m. Next, lets think about aqueducts. The biggest aqueduct in the world is the [Roquefavor Aqueduct](https://en.wikipedia.org/wiki/Roquefavour_Aqueduct), and the water channel on top of that is merely [30ft wide by 7ft deep](https://books.google.co.uk/books?id=MXNtDQAAQBAJ&pg=PA431&lpg=PA431&dq=Roquefavour%20aqueduct%20depth&source=bl&ots=f4aizVf15p&sig=ACfU3U06LqCy4XsTpOHEwDM42M_BNc1jHg&hl=en&sa=X&ved=2ahUKEwj7t5_Pm_TlAhU7XhUIHfLWAmwQ6AEwD3oECAgQAQ#v=onepage&q=Roquefavour%20aqueduct%20depth&f=false) (google books link, often doesn't work for people other than the first person to click them. Page 431 of "Engineering in History"). It too is something of an engineering marvel, and holds over 90000 tonnes of water. Your aqueducts would hold the same volume of water in a mere 45m length instead of 300m, and the pressure the walls of the aqueduct would need to withstand at the bottom is over 9 times greater and you couldn't use blasting or power tools to prepare your masonry and so on and so forth. Really, making country-spanning stone aqueducts is probably impractical, even assuming you could find and cut and fit enough stone to do the job. What you'll have is more like giant [levees](https://en.wikipedia.org/wiki/Levee) to raise the level of the canal above the surrounding terrain, which brings in a whole new set of problems to do with leaks, damage and flooding but at least the construction problem has been reduced to one of semi-plausibility. > > Ignore problems associated with moving cargo up and down these aqueducts. > > > Well, that seems a bit of a strange request, when you're asking about the feasibility of the whole enterprise. > > The slope is just slight enough to get the water moving, it doesn't have to be a large incline. The aquifers are raised so that if for instance the destination city is at a higher altitude than the source city, the aqueduct at the source is still higher to maintain that incline. > > > You're inventing a really complex engineering solution which requires a colossal building effort to handle a problem that has already been solved with the aid of [locks](https://en.wikipedia.org/wiki/Lock_(water_navigation)). You're already happy to build huge structures and create massive pumping systems powered by animals, so you'd be better off replacing your original idea with a perfectly sensible minimal-flow canal with animal-drawn barges. You solve the issue of having to keep your brobdingnagian artficial rivers filled and flowing, and you reduce the need for huge embankments and aqueducts in order to get the vertical elevation you need. What's not to like? (As an aside, I bet you haven't considered the curvature of the earth in this plan, which will require your endpoints to have a much greater vertical separation than they would on the discworld). Now lets think about landscape. The Grand Canal, as referenced by [Priska's answer](https://worldbuilding.stackexchange.com/a/161256/62341), sensibly involved no aqueducts and no tunnels, helped in no small part by the fact that there's lots of fairly flat, broad terrain available for building a conventional canal, which in turn means lots of farming and food and a large labour pool available to work on such constructions. If wikipedia was to be believed, the labour force for some sections of the canal was as large as five million people back in 600CE, no mean feat. > > the empire building these is fairly dry and thus their major cities aren't built on rivers/lakes as we're used to > > > Well, where on earth are you going to get all the water from in the first place? And how do you expect it to remain in the canals, given problems with evaporation? And even if you've solved that, how are you going to source and feed your colossal work crews? You'll need an empire-sized logistics operation just to get food and water out to thousands or millions of people digging ditches in the desert; this is a vastly harder problem than the builders of the Chinese Grand Canal had to deal with. Honestly, you'd do better to build a decent road network, or some kind of railway (presumably horse drawn) under the circumstances. (As another aside, there's a fascinating sort of aqueduct that can be found in some very arid environments in the form of the [qanat](https://en.wikipedia.org/wiki/Qanat). Not mass-transit scale, or even tiny-transit scale, but potentially relevant to your interests and should give you some idea of what sort of problems you might have to think about when dealing with water in the desert.) [Answer] It will not be feasible to work with that much water. Let's start with some numbers. Based on the [original specs](https://en.wikipedia.org/wiki/Erie_Canal#Engineering_requirements) of the Erie canal, we'll aim to have a canal 12m wide and 1.2m deep, flowing at a rate of about 2m/s (which is about as fast as you could travel on a canal by animal power). Since a canal is two-way, we'll cut that in half for each channel - 6m by 1.2m by 2m/s. That's a flow rate of 14.4 cubic meters per second (about a hundredth of a Nile) or 14,400 kg of water per second. Assume that the aqueduct is tall enough to walk under - so we're pumping water about 4m off the ground to get it in the highest point. It requires 10 N of force per kg to lift, which adds up to 576,000 joules per second, or 576 kilowatts of power to pump water into the initial end of each canal. One horsepower is notionally about 750 watts, so your pumping station would need about 770 horses, working around the clock, to haul enough water into the near end of the aqueduct to beat the kind of speeds you could achieve using a handful of oxen and a barge on a conventional flat canal. Obviously, if you want to go faster, you need to pump more water (or your aqueduct will go dry), which will require more power. [Answer] All due respect your knowledge of transit technologies of this era is quite limited, and you are wild-guessing a lot, e.g. the dimensions of the canal. ## You're quite close. Push to the railroad. In late 1700's you are only 40 years from the critical elements of the railroad. And this is a time when technology did not move along at a breakneck speed! Since you have resources to spare, have your society do a Manhattan Project push to get there quickly. ## Canal is nope You propose wild-guess 100m x 20m size. But even if we wind back to a contemporary/late 17th century 2.2m x 0.8m UK standard... As others discuss, it is simply unfeasible to pump that much water for a flowing canal, due to the sheer number of human or animal pumpers required, and the impossibility of the land within transport distance feeding that many pumpers given agricultural yields of the age. Further, you would need to maintain a perfect grade. That either means lots of curving to follow the lay of the land, which means lots of canal navigation accidents (keep in mind that a boat being swept by currents has no rudder authority since it has no moving water past its rudder) ... or lavish bridge structures impossible to build and easily attacked or sabotaged. This reality drags you back to a "normal" standing water canal where animals provide towpath towing, almost certainly with locks to follow the terrain. Extreme engineering could reduce the frequency of those locks, but not their lifting height. Given your lack of abundant water, it will be all the pumpers can do to make up for leakage and lock consumption. This right here is what makes the canal concept folly. Also, canals can best about 4 mph. A mounted cavalry can move faster than that, and could outrace a retreating army and delay them with sabotage. ## Railroads without engines? Again your knowledge of railways is limited. Internal combustion engines did not become a factor on the railroad until post-World War II. Really. Prior to that, they relied on the high pressure, "compact" steam engines proposed by George Stephenson (as opposed to James Watt's brobdignandian low pressure engines, quite suitable for canal pumping). But Stevenson's engine merely "put railroads on the map" by providing ludicrous soeeds. Long before this, railways used animal tow. They were around well prior to 1800, though in short range or within-a-site usage for material handling. If you have 40 tonnes of goods to move on canal vs railway, and only animals to tow them, you are much, much better off on the railway. Friction is close to nil, and you fight only grades. You can change animals as needed, and have extra animals stabled near the notable grades. Speed is up to you; do you assign a mule, or a team of horses? Not much different than teaming any wagon, but you carrying capacity is much, much larger for the same speed. The fact of having grades is an important sidebar. It means you can follow the land, which vastly reduces your structural engineering. A simple line can be tossed down with a washboard gradient and put in service, and engineering works can come later to level it out. Can't do that with canals. As said, railways already were coming into being with animal power by your time. Your "Manhattan Project" is to scale them up into wide loading-gage, well-groomed and fast conveyances fit for inter-city travel. And once available, engines allow a leap to unthinkable speeds on the same trackway. Adding engines to canals barely increases their speed over horse teams; the UK canals are still 4 mph. [Answer] That sounds a pretty large undertaking, even now! As Erik mentioned in the comments, why not use "normal" rivers, and link them with [canals](https://en.wikipedia.org/wiki/History_of_the_British_canal_system)? The UK still has a lot of the canals it had prior to the rail network. For the vast majority of the time they were in use, the boats would have been pulled by horses - canal boats could carry thirty tons at a time with only one horse pulling. What it's not though is quick! Great for bulk transport, not so good for speed. Prior to the invention of motors, the fastest transport over distance was the [pony express](https://en.wikipedia.org/wiki/Pony_Express). The horses were ridden at a fast trot, canter or gallop, around 10 to 15 miles per hour. Still not very quick, though you could get a letter from the East to West Coasts of America in 10 days, which is not too shabby! You couldn't pull a boat at that speed though. [Answer] If you are looking for transit alternatives other than water: unpowered air gliders are feasible with medieval technology, can be manufactured from wood/cloth/paper/ropes. It was not done then because the optimal wing shape and method of steering was not known and it was hard to discover by trial and error. It may not be considered "mass" transit as it's not feasible to build large glider for more than one or two people, but many gliders can be built and launched. Another disadvantage - it is even more dependent on fair weather than shipping. They need elevated places to launch from, rising currents to sustain the altiutde and some flat place to land. If there are no elevated launch places, launch towers could be feasibly built or existing towers used. Horses are too slow to tow the glider, however if faster animals can be harnessed this is an option too. Rising air currents occur either natural or can be engineered where convenient by creating patch of sand or rocks that is heated by sun more than surrounding terrain. [Answer] Are you familiar with the [Grand Canal](https://en.wikipedia.org/wiki/Grand_Canal_(China))? It's not exactly "land transit", but maybe this is what you're looking for. [Answer] As @Harper said: railroads without locomotives. Your society should create rail tracks, made of iron, and pull the wagons using animals. In flat terrain you can move a surprisingly large amount of cargo using this method because rail reduces friction. If the wagons are well built, with well-fitting, well-oiled, standard parts, you get another boost to the amount of mass you can move. Speed will top around 15 km/h, the max speed a horse wagon can go (horses can go faster but not for long, so you want a sustainable speed). Since your tech level is around 1700, you can manufacture standardized parts in large scale because you alredy have the technology (efficient water mills) to build factories. ]
[Question] [ I have noticed this in many fictions: during a battle between spaceships exchanging fire in empty space, a pulse of laser fire hits the hull and the entire spaceship explodes into many pieces. Is this possible? Wouldn't the surface of the spaceship absorb all the energy from the pulse and burn? Could an energy-based projectile pierce through many layers of structure and blow up the engine, in blatant disregard of the [Beer-Lambert law](https://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law)? I'd think that even a pressurized compartment wouldn't explode that violently if opened to vacuum by the shot. [Answer] > > Wouldn't the surface of the spaceship absorbs all the energy from the pulse and burns? > > > It might or might not absorb all of the energy, depending on what type of weapon is being considered (different wavelengths of laser light and different types of particle will have different properties). However, it won't burn in the sense you're probably thinking - the amount and, crucially, concentration of energy involved is enough to reduce parts of the hull [to plasma](https://en.wikipedia.org/wiki/Plasma_(physics)). This is the principle of [laser ablation](https://en.wikipedia.org/wiki/Laser_ablation). Plasma is much less dense than solid matter, e.g., hull plates. As a result, it expands violently as it changes phases. In other words, it explodes. One interesting side effect is that if the explosion is too small to simply tear the ship apart, the ship will tend to direct the force outward. The plasma is propelled away from the ship, and as a consequence, the ship is propelled away from the plasma - making it look like laser strikes are physically knocking the ship around. > > Even pressurised compartment don't explodes that violently am I right? > > > Of their own accord, they cannot. Depressurization is not generally as dramatic as shown in movies. These kinds of incidents (when they aren't made up out of whole cloth) tend to be based on airliners that suffer damage to the fuselage, which can indeed rip apart dramatically - but that's because airliners are flying into 500 mile per hour winds. Spacecraft obviously are doing no such thing, and the atmospheric pressure within isn't sufficient to do much damage. However, if an energy weapon manages to strike through the hull, it will turn the air inside to plasma just as readily as the hull (even more readily, in fact, since it can skip a few endothermic steps along the way), destroying the ship from the inside. And, as AlexP points out in comments, there's always the possibility of touching off secondary explosions from sources like fuel, weapons, or volatile parts of the life support system. [Answer] > > Can energy based projectile pierce through many layers of structure and blow up the engine totally disregard beer-lambert law? > > > Give a look at [this video](https://www.youtube.com/watch?v=Oog-DZ_Kti4) showing the effect of a laser pulse on a droplet. You will see that first the laser vaporize/nebulize part of the droplet, like you can see in the frame below [![frame 1](https://i.stack.imgur.com/6O9eO.png)](https://i.stack.imgur.com/6O9eO.png) then the resulting shockwave actually deforms the droplet into something looking like a pancake, like you can see in the frame below [![frame 2](https://i.stack.imgur.com/D6hyr.png)](https://i.stack.imgur.com/D6hyr.png) If the beam is energetic enough in the right wavelength and its dynamic is shorter than the dynamic of the targeted ship, it is plausible that the explosion happens in a dramatic way. The video again shows good example of such behavior. [Answer] A laser pulse is nothing else than concentrated light which carries an enormous amount of energy. If that beam of light hits the hull of a ship, the energy is transferred to the material of the hull (or penetrates it, depends on the wavelength and the material), which then is evaporated and turned to plasma. This plasma is expanding at incredible velocity, not unlike an explosion, and damaging other parts of the ship and the hull. The overall effect would be similar to a bombardment with HE-grenades (HighExposive). Additionally, not every bit of the transmitted energy is going into the plasma, a certain amount will remain on the ship as heat. In a realistic setting, dissipation of heat is a major concern for a spaceship, and if the heat influx is greater than the heat outflux... well, I hope you like saunas. [Answer] > > Wouldn't the surface of the spaceship absorbs all the energy from the pulse and burns? > > > Note: I am using heat as an example of energy. Similar explanations exist for other types of energy but heat is the easiest to understand. If I unleash a flamethrower on your front door, is your house going to distribute and absorb the heat? Or is the door doing to break down first? Heat can only dissipate at a given rate in a given material. If you apply more heat than can be dissipated, then the area you're supplying the heat to is going to heat up considerably more than the other parts. > > Can energy based projectile pierce through many layers of structure and blow up the engine totally disregard beer-lambert law? > > > Assuming your laser supplies more heat than the ship's hull can dissipate, it's going to heat the point of impact. For the sake of scifi, you can assume that lasers are a tremendous amount of energy that no common material can handle. That makes the most sense: * If a common material could handle it, then the laser weapon wouldn't be a good weapon. * If hulls in general could handle it, no one would have ever needed to develop shield technology. The hull melts, it creates a hole, and your laser will now be shooting through the hole, hitting the next thing in its path. This same thing keeps happening over and over, until there is nothing blocking the laser's path anymore. * Maybe that happened because it was a clear through-and-through. That wouldn't blow up the ship, but it would of course still be a severe hull breach. * Otherwise, you may have hit a critical component of the ship, which exploded the ship to pieces, thus "removing" anything else for your laser to hit. Maybe the explosion is localized and only breaks the ship in two, or maybe it just blows a massive hole in the hull, or maybe the explosion travels through the entire hull. Drawing from common scifi material, mostly Star Trek in this case, ships are capable of targeting specific parts of their enemy (the engines, the shield generator). Probably because they have some anatomical knowledge of their enemy's ship type. This means that you could intentionally aim your laser so that you know it will hit a volatile or explosive component (e.g. fusion reactor). This can be an explanation as to why kill shots always blow up the enemy ship rather than disable it. > > Even pressurised compartment don't explodes that violently am I right? > > > A pressurized compartment decompressing is no different from a balloon emptying. At best, the water vapor in the air is going to be visible because outer space is much colder and may freeze the humidity. But other than that, not much will happen. [Answer] Almost all spaceships have vast stores of energy on board. Military ships of course have a bunch of ordinance, even civilian ships have whatever powers their drive system. Hits which find such a system make for a big kaboom. Hits which fail to find such a system have virtually no externally visible manifestation--the point of a weapon is to damage what's inside, not to damage the hull. You want to punch through the hull with as small a hole as possible and deliver your energy inside. The performance of the ship may be degraded by the hit but it would take a careful external examination to find the damage. (Internally is another matter, you might have nasty damage.) [Answer] One way it could happen is [Thermal Shock](https://en.wikipedia.org/wiki/Thermal_shock). The outer hull of the ship is likely to be very cold, because it is in direct contact with outer space. A laser or maser would be very hot. This temperature difference could lead to catastrophic failures of the effect sections. Plasma based weapons would also have a similar effect. The "swiss cheese" effect is not the only possible outcome. [Answer] You are absolutely correct. Directed energy beams are just as much a bust for space military opera as 'energy shields'. In all of the tests of directed energy beam weapons, the best the US army has done is to put holes in the target. There just isn't enough energy in a directed energy beam to do much damage. Certainly not enough to cause a space battleship to be completely destroyed. Like using a laser pointer to 'destroy' a drone. And there would be no need for shields. Plating and other such coverings on space ships would be much more effective, as well as being passive. 'We lost power to the shields, captain!' just doesn't cut it in warfare. But special reflective coatings, materials with super efficient heat transfer abilities, special hardened plating against radiation (lead as an example) don't suffer from power loss, and would be much more effective, making directed energy beams pretty much useless. At best, 'shields' would be surface charges on the outer skin, sort of like an electrostatic surface charge. Kinetic weapons will always win out. Less dramatic, but more effective. So why do sci-fi writers insist on using them? Perhaps because of the very false belief that exploding percussion weapons don't work in space. The explosive gasses and materials from the explosion don't just vanish, they continue in a 'wave' of energy equivalent to the original energy of the explosion. 'Shrapnel', if you will. And maybe because of the problems with targeting projectile weapons. Space is huge, and so the battling space ships would have to be very close together in order for evasive action to not be effective. A 'speed of light' weapon is always much more dramatic and immediate than the slowness of space missiles. Imagine how boring it would be if the antagonists had to wait fifteen, twenty minutes for the missiles to get to their target, which of course would no longer be there? 'Fire missile tubes three, four, and five! Now, go for a coffee break and wait to see what happens!' just doesn't generate a lot of suspense. Yet, even directed energy beams take time to travel through astronomical distances. Or more specifically, a 'space military opera' wouldn't be very entertaining without huge battleships, and even bigger explosions. The stories are written for us earthlings, who think about space warfare as simply naval warfare translated into space. Huge battleships facing off against each other. But it is more like air warfare. There is no advantage to huge 'battleship' fighter planes. Smaller and more maneuverable is better than huge, ungainly and easily targeted blimps. But my money is on the simple point that space military opera sci-fi writers in general are just not creative enough (lazy?) to think of anything other than the 'same old same old' stock-in-trade directed energy beam weapons. The readers accept it, the writers need to churn out their works quickly, and so they fall back on the same tried-and-true memes. No need to be creative, when you can fill your story with mega explosions, fancy energy beams, impenetrable shields, and huge ships blowing up with loss of all lives and the book will sell. But the truth is, real 'space warfare' if it ever happens will be boring, slow, plodding, and 99.99999% uneventful. Not really the stuff that makes for good high-suspense action-packed seat-of-your-pants fiction. So, sci-fi space opera warfare will continue to be energy beams and 'shields up' and huge battleships exploding in space, with the reality hand waved away. [Answer] Nuclear Stuff The energy weapon itself passes straight through the ship without imparting momentum. But all the matter along the way is converted into new and exciting forms of plasma and radiation, which expands outwards and this is the resulting explosion. We're talking a fission/fusion reaction but not a self-sustaining one. > > Wouldn't the surface of the spaceship absorbs all the energy from the pulse and burns? > > > I'd imagine a beam weak enough to be absorbed by the ship probably wouldn't be strong enough to do the nuclear stuff above. And a beam strong enough would probably pass straight through, effectively wasting most of the energy. That makes the weapon tremendously inefficient which is the real problem with beam weapons. > > Can energy based projectile pierce through many layers of structure and blow up the engine totally disregard beer-lambert law? > > > All the Beer-Lambert law says is the beam will do at least as much direct damage to the first few layers as it does to the engine itself. You cannot design a beam that say punches through several layers of bulkhead and then detonates inside the cockpit. But we could still cause the engine itself to detonate by hitting it (and everything in between) hard enough. This raises a bigger problem: Presumably this engine is nuclear and thus designed to resist rupturing from the nuclear forces inside it. So it might be hard to rupture it using a nuclear based weapon from outside. It would probably be easier to just it hard enough that it stops working but doesn't explode. ]
[Question] [ I'm thinking of making a world where the sky is purple, or at least perceived as purple by the native species taking centre stage in my story. What gases could cause this colour? Could the colour have anything to do with Rayleigh scattering? [Answer] ## Sky Colour The sky looks blue to us because of two major factors: * Atmospheric composition * Light hue and intensity There are also a number of other factors including atmospheric temperature and pressure, but they have a lesser effect - they only inflict small changes on the other major effects. ## Atmospheric Composition The composition of the atmosphere affects the colour of the sky by refracting, reflecting, and deflecting the Sun's light. Each chemical compound in the atmosphere refracts light differently; on Earth it is just the case that blue light gets refracted the most. The more a colour of light gets refracted, the more of it there appears to be in the sky (because it's spread out), so it becomes the color we see in the sky. Let us be clear on this point: the colours of the compounds themselves has no effect. Unless there is such a huge amount of a compound as to be clearly visible to the human eye, the colour of any molecule doesn't affect the colour of the sky. There is chlorine gas in our atmosphere; the sky doesn't appear green. ## Light For the sky to have any colour, there has to be some light. If there is no light, the atmospheric compounds cannot refract it and create colour. This is clearly demonstrated on Earth: at night, the sky is dark - because there is no light coming through the atmosphere to get refracted. The hue of the light also has an effect. If, for example, the Sun didn't output any blue light, the sky would not be blue because there would be no blue light to refract. The hues of the refracted light mix together to create the colour of the sky - if red and yellow are refracted most, you will end up with an orange sky. ## Changing Sky Colour To change the colour of the sky on your world, simply change the light that's hitting the atmosphere, or change the atmospheric composition. The atmosphere's total refractive index is what determines what light is refracted most. The Earth's refractive index is close to 1: if it increased, the sky would tend towards the red end of the spectrum; if it decreased we'd tend towards ultraviolet. ## See Also [Atmospheric Refraction](http://en.wikipedia.org/wiki/Atmospheric_refraction) [Atmosphere of Earth](http://en.wikipedia.org/wiki/Atmosphere_of_Earth#Refractive_index) [List of refractive indices](http://en.wikipedia.org/wiki/List_of_refractive_indices) [Answer] I'd recommend reading this physics.stackexchange post. <https://physics.stackexchange.com/questions/28895/why-is-the-sky-not-purple> . Based on Rayleigh scattering, violet light, which has the shortest wavelength, is the dominant color. However, there is enough of other frequencies that we perceive the sky as blue. The solution is then simple. Give your natives better eyes, instead of trying to change the physics. Rather than detecting the average color, let your native's eyes determine each color light that is seen. Human ears already have this advantage, being able to tell the difference between a single note being played and a chord being played. [Answer] I have a landscape photo that I made into a poster, that has a vivid vilot sky. It was shot with a polarizer, looking upward at a figure on top of a peak. Your alien, like some species on Earth, could have polarized vision. There is no reason to believe that an alien (or a bird for that matter) would have a "color wheel" that connects the two ends. The "purple line" in a CIE diagram is non-spectral and exist only as human perception— you might think of them as analagous to chords in music. So does purple mean some mixtue of red and blue (magenta), or does it mean a spectral frequency at the high end (only)? Why would an alien have colors as perceptions like us? Orange is a different perception than green, but that's just us. Which points or chords give distinct perceptions to the alien is any body's guess. It does stand to reason that the ends would be distinct, so violet would exist as the highest notes that can be detected. Note that I distingish the pure frequency vilot from the perceptual color purple. How high does the alien's vision go? The sky's scattering may be around the highest frequency he can detect, and a bit distanced from most other natural colors in his environment. The visual system appears to be extended upward specifically to sense the sky. In that case, it would have a distinct perception, and we would colloquially translate his experience (the pure color with the highest frequency) as vilot. [Answer] If the planet orbits a star that gives off red light (they have those, right?), or perhaps has a large satellite that reflects red light, the sky might appear purple. Constant volcanic activity, fires, or oceans full of algae that reflect red light combined with a bright sun and a thick atmosphere could cause a violet-shade sky. Because Rayleigh Scattering doesn't really depend on the specific chemical that the light is being scattered through, the only way to achieve purple would be to have an inordinate amount of local red light or red-reflecting stuff. I don't know if oxidized iron can float around in clouds, but if it could that would make for some purple skies. Linguistically, it's conceivable that the culture would have a word that corresponded to "blue-purple" instead of the more usual "blue-green," so that they don't differentiate between blue and purple, but the sky would still look blue to us. I recommend checking out color terms in various languages: They very cool. Here's an idea: If you had a high amount of neon in the atmosphere and constant storms, the sky would appear blue and purple as neon plasma is reddish in hue. [Answer] Purple is a difficult color. It has short and long wavelengths and is short in the middle. A star can't really have two different narrow spectra at the same time and gasses usually adsorb relatively narrow bands. It is relatively easy to tweak the visual receptors so that sky looks purple. Most animals see the colors differently from how we see them since the visual system adapts to see what is important for survival of the species. So different diet and habitat usually result in different colors. If the planet is artificially terraformed by some ancient civilization and was originally too hot, the ancients might have cooled it by adding dust that absorbs a relatively wide band of the middle wavelengths. This might result in a purple sky. It would also imply some huge alien machines in space maintaining the "shroud". [Answer] Purple is surprisingly hard to get naturally at human survivable temperatures: # Gas [Iodine](https://en.wikipedia.org/wiki/Iodine) is purple gas at temperatures over 185°C (363.7 °F). Unfortunately, Iodine forms compounds with just about everything, many of which are solid or non-purple. # Rayleigh scattering [Rayleigh scattering](https://en.wikipedia.org/wiki/Purple#Why_distant_mountains_look_blue_or_purple) could cause distant objects to look purple, especially if there is a gas in the atmosphere that scatters green light and some blue light1. I don't know of any gas that does this at a human survivable temperature. # Other The native species might perceive blue as purple if they have a red-green colour blindness ([src](http://www.colourblindawareness.org/colour-blindness/types-of-colour-blindness/)) which would make them confuse certain blues and purples. This has other side effects though, mainly being colour blind. Lightning can (briefly) light up the whole sky (clouds in particular) in purple, green, or blue. This might not be what you're looking for. ![sky, with purple clouds](https://i.stack.imgur.com/tIg83.jpg) --- 1. Not sure if there is such a gas, or if I have correctly understood Rayleigh scattering there. [Answer] Your planet's sun is expelling a planetary nebula. [![planetary nebula](https://i.stack.imgur.com/Bo1Rx.jpg)](https://i.stack.imgur.com/Bo1Rx.jpg) <https://stargazerslounge.com/topic/224890-planetary-nebulae-a-little-guide/> These clouds of superheated gas glow according to the emission spectrum of the cloud component atoms. Argon is a good purple. The cloud is actually a sort of super solar wind as I understand it, and so would stream around and past your planet. [![argon](https://i.stack.imgur.com/TS5fr.jpg)](https://i.stack.imgur.com/TS5fr.jpg) <https://en.wikipedia.org/wiki/File:Argon-glow.jpg> The sky would be brighter purple at night. It might be very bright at night. [Answer] It seems to me the simplest way would simply to have a thinner atmosphere on the planet. If you look at a blue sky it shades from pale blue near the horizon to dark blue near the zenith because of the different atmospheric distances that light has to travel. The farther light travels through the atmosphere, the more it is scattered and the lighter the sky in that direction looks. Making the atmosphere a bit thinner but still thick enough to breath should make the sky a darker blue and thus closer to purple. Then you would need to add a lot of red light so that the sky turns from deep blue to purple. Suppose that a lot of land plants and water plants are red. Then the sun shining on the plants would be reflected up to the clouds and down from the clouds as reddish light, mingling with the dark blue of the sky to look purplish. Sunrises and sunsets are often pink and purple. So maybe the habitable zones of your planet have perpetual sunrise/sunset conditions and perpetual purple skies. If your planet orbits a dim red dwarf spectral class M star, in order to be warm enough to be habitable it will probably have to orbit so close to the star that tidal forces will tidally lock the planet. slowing the planet's rotation rate so that a planetary day equals a planetary year. Considering how close the planet would have to be to the red dwarf star and how short it's year would have to be, such a slow down would not be as much as slowing Earth's day to a year. Once the planet's rotation rate is slowed so that a day equals a year, one side of the planet will be in perpetual daylight and heat up greatly, and one side of the planet will face away from the star in perpetual night, and will cool off. It is possible the air and water from the hot side will all flow to the cold side and freeze solid, leaving the planet airless and uninhabitable. But possibly the atmosphere and hydrosphere will transfer enough heat from the hot side to the cold side to keep the atmosphere and water from freezing on the cold side. In that case the twilight zone between the hot side and the cold side may be the only part of the planet with the right temperature for life. In the twilight zone the red star will be at the horizon. The red star's light will contain many different frequencies of visible light, and should have enough blue light for atmospheric scattering to make the sky dark blue. But the vast amount of red light from the red star should also cause a lot of red light to be scattered by the sky, perhaps making the sky appear purplish. [Answer] I think a little amount of [trifluoromethyl nitrite](http://pubchem.ncbi.nlm.nih.gov/substance/176998654#section=Top) or bis (trifluoromethyl) nitroxyl in atmosphere could make it look purple. Also the eyes of the inhabitants could contain receptors which are more sensitive to purple than blue. [Answer] Make your planet's inhabitants colorblind due to some genetic condition. Colorblind people with the deuteranomaly type of colorblindness already see our Earth's sky as violet. And the fact is... our sky IS violet! Check this out: <https://www.forbes.com/sites/briankoberlein/2017/01/11/earths-skies-are-violet-we-just-see-them-as-blue/#68bb7df7735f> ]
[Question] [ Assuming a sci-fi setting, tech level capable of interplanetary travel, but incapable of interstellar travel (no FTL). Would it be possible for a sufficiently powerful (politically and technologically) 'elite' class to oppress the masses and re-enforce a feudal style society, placing themselves as King/Queens, Counts/Countesses etc? Edit: After reading @Vincent's (thanks, btw) answer, I felt I need to clarify that I really did mean a honest to god feudal system. The rich actually want to 'play' war, and duke it out as rival Kings and Queens and lords of houses because it seems 'Romantic'. Yes, they are eff-ed in the head. [Answer] ### The nature of feudalism Feudalism is probably best described as fractally distributed authoritarianism. It means that political power is (theoretically) organized as a tree structure, with obligations of fealty that go up the tree (and sometimes down; European feudalism had formal recognition of bidirectional obligations, while the samurai of medieval Japan conceptualized their loyalty to their lord as one-way and absolute.) This means that any subset of the political structure is potentially autonomous. Let's say, and why not, that you are a medieval European Baron, and you owe feudal duty to a King. What happens when the King dies without an heir? Well, you pretty much keep going: running your barony, intriguing against your neighbors, keeping the Vikings or whomever at bay as best you can. At some point, you will be offered opportunities to swear fealty to some kind of suzerain; you may even take part in the intrigues attendant on creating a successor's claim to the throne... The point, of course, is that the death or loss of legitimacy on the part of a leader does not cause as much widespread ruin. The system reconfigures itself, more or less naturally. This creates a very stable political situation. Probably the most stable that could be contrived, given the tumultuous nature of medieval times. That resilience is the core benefit of feudalism. Where it comes apart, historically, is when a society starts generating enough economic surplus, or encounters sufficiently uncharted circumstances, that feudal suppression of the peasant base becomes insufficient as a political model. I've recently heard Democracy described as "the crowdsourcing of political decisionmaking", and I don't think that's entirely wrong. A secondary downfall of the feudal model would be when economic and technological factors make it impossible for the nobility to sustain its position. This is often characterized in historical recapitulation as "when central governments got cannon and could reduce castles at will". That, however, is an historical artifact of European history. Your question isn't about that. ### Would it be possible for a sufficiently powerful (politically and technologically) 'elite' class to oppress the masses and re-enforce a feudal style society? The best answer I can give you is another question: *Can your envisioned high-tech society provide a set of circumstances in which: extending power to the common people is not necessary, and * the independence of a "nobility" can be expected? If you can answer "yes" to that question, then you have a plausible scenario for the existence of a feudal political system. For this, you will need to tweak your technology, and probably your planetology, to make that happen. To go beyond "a plausible scenario", however, you need to find a situation in which the nested resilience characteristic of feudalism is not merely conceivable, but confers a strong advantage.** Some factors that could work toward this include: * Geographical boundaries that are not easy or cheap, even with your postulated high tech, to traverse with military force. * Interruptions to long-range communications (perhaps due to peculiar characteristics of the sun's radiation, for example?) * Cohabitation on the planet with formidable and unpredictable competitors. * Intense bombardment by meteors at difficult-to-predict intervals. * The existence of destabilizingly strong and destructive Wild Talents (psionic, or even more radical) amongst the population, including the "common folk". * The existence of high-tech power generation systems that have a strong tendency to become unstable if you build them too large. Sort of the equivalent of a nuclear explosion, sometimes... This would cause an enforced decentralization of energy resources. Decentralized power is much the same thing as decentralized productive agricultural land in medieval feudalism... These are only a few ideas that would tend to make feudalism a better choice than large-scale authoritarianism. [Answer] I doubt it could happen because I think there is a flaw in your idea. You want a concentration of power and a feudal system. Feudal systems are usually decentralized. Having some people at the top and a parasitic aristocracy with no real power doesn't make it a feudal system. In short, in the feudal system, the suzerain will have vassals. Each lord has responsibilities due to their overlord and the suzerain also has responsibilities toward his vassals. Although, the king is a the top, he is usually pretty weak and depend on the support of his vassals. This vassal-suzerain relationship is what defines the feudal system. It is incompatible with the concentration of wealth because each lord only control a small part of the kingdom. Although the aristocracy has a lot of power, it is very spread out. Plutocracy is probably what you are looking for. Rich would rule without needing the support of lesser lords and would be free to oppress the population. People are not defined by their relation with others or their bloodline but just with their wealth. Saudi Arabia would be a ''good'' model. The royal family take almost all the powers. It is possibler to extend the political powers to the friends, relatives and cousins (the larger family). This can also be called nepotism. [Answer] The hard question is: how did it come to this? I would expect that, once it holds global power, such a system might survive for years or decades, under ruthless persecution of its opponents. History has shown that people can be brainwashed into believing in the most ludicrous things. But that doesn't mean that they get anywhere with it. Say, a nation starts drifting toward medieval control structures and beliefs. If it isn't a global player, the outcome will remind of Venezuela's recent endeavors: the nation is weakened and becomes less relevant. Thus, the nation starting this has to be a large player, so that it can oppress its surroundings before succumbing to its own inefficiency. By large, I mean huge, seeing that even the USSR didn't make it. And, while the communist block was bad, feudalism could easily turn out worse. Feudalism isn't a well-defined term, but the governments it describes were horribly inefficient, even when compared with typical communist countries or dictatorships today. And unless some other event changes the world first, they'll be up against capitalism, which tends to mop the floor with everything else, even when poorly implemented. Capitalism is built on variety, honoring promises, and, most importantly, freedom. The feudalistic government is incompatible with variety and freedom, so it will probably lose the associated efficiency. In addition, to keep its supporters in line, the system has to prioritize brainwashing to rationality. In practice, this means: * Scientific stagnation, or even degression * Peoples' ability to learn and reason is impeded * Highly inflexible organization that will respond badly to new situations * Continuous, violent attacks on any forms of free thought In other words, welcome to North Korea. This works, but it comes at a very high price – possibly too high to compete with other nations. Thus, it comes down to first removing the competition, for example by making the world more unified and less capitalistic. Given populist politics and human short-sightedness, this is imaginable. Afterwards, an outright huge government might be able to conquer all opponents before the difference in efficiency becomes a problem. This doesn't answer how the feudalistic system would restrict variety between the lords, which would destabilize it. Probably, some sort of king or emperor would do the job, removing lords who step out of line, similar to medieval times. [Answer] I think that could happen. The first step would be an extreme concentration of wealth and power to a relatively small elite (forget the 1%, make that 1 ppm). Basically, all companies would be big, and the power structure would make it absolutely impossible to found new companies which could give the big companies competition. That is, you've got a small, rich elite, and an economy consisting of a few big companies which control the market. Assume further that the market has been sorted out in a way that the companies all have monopolies in their respective field, and the system has stabilized through agreements and/or power structures so that the companies don't ever enter into the territory of the other companies. Assume further that the elite has also secured political power (directly or indirectly; remember, money is power), so there's no chance that this situation will be corrected, except possibly by a revolution; however such a revolution is unlikely because the elite has all the powerful weapons, and makes sure that the ordinary people cannot get them (also, maybe add ubiquitous surveillance). A monopoly is not interested in innovation. Innovation only means that something could eat into their profits. Therefore the companies will make sure that no innovation will occur. The first way to do so is to make sure nobody has too much education; since there's no competition and no new development, the only education which is needed is the one required to keep the system running. People need to understand how to do certain work, but they don't need to understand why to do it that way. Advanced knowledge is reserved to the elite, who are through this way also the saviours if something goes wrong in a larger way, which further cements their leading position. Note that by controlling both politics and the market, they can make reasonably sure that people don't have access to advanced education. Since the wealthy elite has the de-facto power and is the gatekeeper of knowledge, it can gradually remove any remaining democratic structures and turn themselves into power positions. Probably they'd also make sure the religious leaders are on their side (there's nothing money can't buy!), completing the feudal system. [Answer] I'll start by suggesting - how about a world where feudalism never stopped? Most of the world passed through feudalism to get to where we are now. I'd offer that one of the biggest catalysts in the transition was the black death. A sudden drop in 'working class' individuals, meant their market value increased - to the point where they were no longer in a 'poverty trap'. But you've also the evolution of weaponry as an element to consider - feudalism only really works for as long as the 'ruling caste' have the power amplification effect of armoured and skilled warriors (knights). The cost disparity of a well equipped knight was such that a 'peasant' had no hope of resisting. Gunpowder really was the great leveller in that regard - a well trained knight was still 'better' on the battlefield, but a peasant with a musket could get lucky (where the same peasant with a scythe had no chance). So in order to make your feudal-future, I'd suggest you need some kind of power imbalance, such that the ruling classes can maintain control. Some sort of power armour, shielding, etc. Maybe - given a space faring society - there's new materials out there that enable this to occur. Unobtainum armour, or shield generators. Maybe biomods. Something that means your 'rulers' cannot be removed from power by a single peasant with a grudge. It needs to: * Have an high barrier to entry, such that the 'peasants' cannot acquire it for themselves. * Require a lead time to use, such that there is no 'revolt and seize the unobtainium' type power struggle. A variety of options might fit the bill, but would depend upon your universe. Shields, super armour, psychic enhancers, regenerative biology, etc. To reinforce, you'd need a limit to education, such that your 'normal' citizens don't even know they can challenge the system. [Answer] Feudalism will not work because it has lower productivity per capita than plutocracy: capitalism with oligarchs. Oligarch make huge monopolistic profits, and use them to buy politicians so they can keep pretense of democracy without really bothering to listen to voters. And oligarch would not submit to random kings and dukes. Look at history, kings could not afford to finance the wars by taxes, and needed to borrow money from bankers. Thin about [Gilded Age in USA](http://en.wikipedia.org/wiki/Gilded_Age), or USA after [Citizens united](http://en.wikipedia.org/wiki/Citizens_United_v._FEC) when money are considered a form of speech, and democracy means "every dollar should be equally represented). It is not as bad yet, but requirement of democracy is informed electorate. If electorate can be fooled to vote against their own economical interest, after few rounds situation could stabilize on the side of the more money. ]
[Question] [ I feel like there must be a lot of factors here from the actual structural rigidity of the plants, to how well capillary action functions in higher gravity, to how well cellular mechanisms such as photosynthesis function at higher gravity, but I'm not well versed in botany. Are are there any earth plants that could be grown as crops for a colony on a high-g world? Would aquatic plants fare any better in high-g environments than terrestrial ones as buoyancy scales with gravity? Does gravity affect pollination and seed growth? Also, I am specifically asking about macro-scale plants. I assume that algae would be a solution however I want to know about what traditional crops could be grown. [Answer] Primary factors affecting plant growth (as mentioned) in high-gravity environments include structural rigidity, capillary action, cellular mechanisms such as photosynthesis, pollination, and seed growth. This is mostly speculation, however, as I have not done the mathematical calculations behind these - I would say, however, that this would be a fairly good starting point. As other answers have mentioned, there is little rigorous analysis, and at some point there will be genetic or breeding/cultivar variations that would be more suited to this new environment. ## Structural Rigidity Terrestrial plants will need to adapt to the increased gravity by developing stronger stems and roots. Crops with low height and wide-spreading roots, like potatoes and other tuberous plants, will fare better in these conditions. Additionally, plants with flexible stems, such as willow or bamboo, can withstand the increased gravitational force due to their natural resilience. Bamboo especially has unbelievable resilience, and the fast-growing ones would likely survive in such an environment. ## Capillary Action In high-gravity environments, the efficiency of capillary action will decrease due to the greater force acting against the upward movement of water and nutrients. However, plants with shallow root systems and lower overall height, like lettuce and spinach, will be able to maintain adequate hydration and nutrient absorption under these conditions. ## Cellular Mechanisms Photosynthesis efficiency will not be directly affected by gravity; however, the increased pressure on plant cells might lead to subtle changes in cellular processes. Plants capable of adapting their cellular mechanisms to cope with higher gravitational stress will succeed in high-g environments. ## Pollination High gravity may impede the movement of pollinators like insects and birds, reducing the chances of successful pollination. To overcome this challenge, self-pollinating crops like beans or tomatoes that rely less on external pollinators are more likely to thrive. ## Seed Growth High-gravity environments will require seeds to have a higher energy reserve for germination due to the increased force they must overcome during establishment. Seeds from hardy plants such as grains (wheat, barley) or legumes (peas, lentils) will be better suited to germinate under these conditions. ## Aquatic Plants Aquatic plants, with the support provided by buoyancy, will indeed fare better in high-g environments compared to terrestrial ones. The buoyancy of water scales with gravity, allowing aquatic plants to maintain their structural integrity and capillary action more effectively. Crops like rice and watercress, which are adapted to grow in aquatic environments, will be suitable choices for cultivation in high gravity conditions. ## Summary In summary, on a high-gravity planet, the most successful crops will likely be those with low height and shallow root systems (e.g., potatoes, lettuce, spinach), flexible stems (e.g., willow, bamboo), self-pollinating mechanisms (e.g., beans, tomatoes), or the ability to grow in aquatic environments (e.g., rice, watercress). Additionally, hardy seeds from grains and legumes will have a higher chance of germination due to their energy reserves. It is essential to note that these plants may still require some adaptation or genetic modification to optimize their growth under such extreme conditions. I did trip on this article when reading, which might be useful: <https://www.sciencedirect.com/science/article/abs/pii/S1084952117305864> [Answer] Experiments with hypergravity show that plants adapt to different levels of gravity very well, despite plants having evolved exclusively in a 1.0 g environment. For example I'll pull a quote from a paper: > > In addition, many lines of evidence have shown that vascular plants can grow and respond to a wide range of gravitational forces from μg to hypergravity at ~300 g (Hoson and Soga 2003; Tamaoki et al. 2006; Allen et al. 2009; Soga 2013). > > > <https://doi.org/10.1007/s11103-021-01146-8> So certain plants in experiments have grown at up to 300 g, in this sense 1.5 to 3 g is not particularly challenging. That said, by practical necessity centrifuge experiments on plants have been on small plants, it's not easy to build and operate a centrifuge for like maize for an entire growing season. My suspicion is that 1.5 g just wouldn't matter for pretty much any crop, they'd just grow a bit more robustly, at 3 g I'd expect the most likely issue would be with plants with high yields. If you grow vegetables or fruit trees you'll know that some cultivars have such high yields that they sometimes break even under earth gravity, like a fruit tree's branch may snap under the weight of the fruit. This isn't an issue for wild fruit trees, it's an artifact of selective breeding and intensive fertilization where the weight of the fruit grows so rapidly that the woody part of the plant can't adapt quickly enough to the increased weight. Plants that have been heavily yield-optimized to be close to the breaking point under Earth gravity are likely to just collapse under higher gravity, though for some using more robust scaffolding may suffice. The fruit may also fall off prematurely due to its sheer weight. These are unlikely to be issues with closer-to-wild cultivars where the yields are much lower and the plant has been "optimized" for adaptability in the wild rather than yield under tightly controlled conditions. Overall I'd find it hard to imagine any "ground-supported" crop (potato, squash, peanuts etc) having issues with 3 g. I also expect that Maize and such would just robustify as required, although particularly high yield cultivars of grains where the plant is already close to breaking or collapsing under earth gravity may collapse. High yield fruit trees are very likely to have issues, this doesn't mean you can't have fruit trees just that they have to be closer to wild variants that don't produce massive yields of huge fruit. Selective breeding would then have to be performed on the new planet to develop stronger cultivars that can bear the weight of increased yields. [Answer] Seaweed is the obvious easy thing. It is an algae of course, but it is also very much a macro-scale photosynthesizer, so I feel like it should be strongly considered. Aquaculture in general would allow for farming animals as well as plants that would be likely to cope better in higher gravities than their terrestrial counterparts, so it has clear advantages over growing things in the air. There are some non-algal water plants that are cultivated for food, but they are not exclusively underwater plants and therefore a substantial portion of them will need to be freestanding and that's probably impractical at higher gravities. Furthermore they aren't nearly as oily and nutritious as seaweeds, so they'd need significant supplementation with other foodstuffs. As for more conventional crops, I don't think anyone can usefully say at this point. Research on the subject is still pretty much in its infancy. A quick search turned up stuff like [How plants grow under gravity conditions besides 1 g: perspectives from hypergravity and space experiments that employ bryophytes as a model organism](https://link.springer.com/article/10.1007/s11103-021-01146-8), but it is mostly concerned with useful [model organisms](https://en.wikipedia.org/wiki/Model_organism) for this sort of research, suggesting that there's not a whole lot of existing stuff in the area. For slightly elevated gravities (1.5g, say) you can probably handwave in some kind of robust cultivars of conventional crops and probably not go too far wrong. For higher gravities it might not be practical for any terrestrial crops to flourish, but as research is lacking you can still probably handwave stuff in if you did it whilst no-one was looking and you didn't go into too much detail. [Answer] A frame challenge. Are the Earth crops supposed to be grown by Earth humans living on the planet? Humans can survive fine in 1.5 to 3 g gravity for minutes or hours. But humans can't function well for long times in such gravity. It takes them longer and longer to complete simple tasks in gravity much higher than 1 g. Astronauts barely do any thing while their rockets are blasting off from Earth with acceleration of several g, except possibly to work a few controls specially designed to be easy to operate in high g forces. Stephen H. Dole, in Habitable Planets for Man (1964), concluded that very few humans would want to settle on a world with a surface gravity over 1.25 or 1.5 g. <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf> Is there any later research to indicate otherwise? So I can imagine a high gravity world where robots tend crops on land. Those robots would mostly operating on their programming, but maybe sometimes remotely controlled by humans. Where would the humans live? Maybe in space habitats orbiting the planet. Or maybe the planet spins very rapidly and has a very oblate shape, and has a lower surface gravity, safe for humans, at the equator, and a higher surface gravity closer to the poles. If so, why would the humans grow crops in the high g regions near the poles? Maybe there are some crops that produce better food or clothing fibers when grown in high gravity. As for growing planets or animals in water, humans might like spending a lot of time in water and feeling less heavy. But there would be limits to how deep they could go. With higher gravity, water pressure would build up with depth even faster than it does on Earth. So the depths reachable with various types of diving equipment and air mixtures would be less than on Earth. [Answer] Impossible to know without trying, BUT: When trees grow in high wind situations, they just grow denser wood to withstand the additional stress. I find it very difficult to believe the same thing would not happen due to gravity induced forces. Probably (a guess) in response to the tree sensing strain in itself Combination of high wind locations and 1.5g will likely reduce the plants that can grow. Its more likely that plants will grow shorter than not grow. [Answer] A tree on a 3g planet would be 1/3rd the height from the ground. A pine tree on a 50g planet could perhaps grow sideways along the ground, so a 100 meter Sequoia would be just 2m tall. Pollen would fall to the ground faster. trees adaptively strengthen themselves relative to stress, so when a piece of a tree is shaken by wind or strained by gravity, it will thicken and develop stronger. 3g is not a major challenge for a plant, it's a major challenge for locomotion. [Answer] # The Mighty Potato [![enter image description here](https://i.stack.imgur.com/oTX7U.png)](https://i.stack.imgur.com/oTX7U.png) Not a complete answer, but I propose the best crop for high gravity has the edible parts underground. The plant only needs to support its leaves and not the large fruits. This works even for big fruits. This naturally leads to growing tubers. Carrot, parsnip, yams, taro, ginger, Leola root, and of course the mighty potato. Second place goes to fruits that sit on the ground, rather than hanging. See the pumpkin, marrow, melon, cabbage, and of course, arses. [![enter image description here](https://i.stack.imgur.com/gMla2.png)](https://i.stack.imgur.com/gMla2.png) [Because the ancient Celts were sh\*t at hunting, they got most of their protein from arses they grew on the floor.](https://www.youtube.com/watch?v=8vpqKfX3Rzk) ]
[Question] [ Imagine an Earth exactly like ours, but with one significant difference: the use of animals parts for anything is strictly forbidden. Not even the most depraved, violent and insane will break this rule. Things like wool shaved from animals or the dung they produce are allowed to be used as materials (as well as other "dead" materials), but if the animal has to be harmed to obtain it (leather, furs) or it "living" things produced by the animal (milk, eggs) it is a strict no-go. Oil is allowed as well. Pests are dealt with by either chasing them off (without harming them) or plants that they don't like the scent of. Riding animals are allowed, but not as animals of war. I wonder though how this would affect the military industry. Would this prevent certain kinds of weapons like bows from being developed? Or would there be fitting alternatives? Given these rules humans get rather inventive with the materials they can use, so the development of materials that are inferior to their non-vegan counterparts would greatly increase. [Answer] # There would be no military (and probably no humans as well) You tagged this question as "technology" and "technological development". Actually this is a question about ethics, morals and society development, because these things are what drive and affect the question you are asking far more than just the development of weapons and military. What you are asking is: what if we had humans with insanely(x) strict preservation-of-life ethics towards animals, but that remain just as callous towards humans? I would say that — considering how humans have always put the needs of their own species above everyone else's needs (just like every other species on the planet) — humans would not be hostile towards one another either, which eliminates the need for a military. Because why would they be all [Fuzzy Bunny](http://www.urbandictionary.com/define.php?term=Fuzzy%20Bunny&defid=3710675) towards... well, bunnies... but remain spikey towards their own kin? It does not make any sense at all. (x) So why is this insanity? It is insanity because this would cause these humans to lose several important sources of food. It is easy for modern humans to be vegans today because there is [food science](https://en.wikipedia.org/wiki/Food_science) that has made us aware of nutrients, vitamins, trace elements and other things that we need to survive and not die of horrible deficiency illnesses like [Scurvy](https://en.wikipedia.org/wiki/Scurvy), [Beriberi](https://en.wikipedia.org/wiki/Beriberi) and [Starvation](https://en.wikipedia.org/wiki/Starvation). The science of food tells us "Ok, you do not want to eat meat? No problem; these are your alternatives that cover for the things you otherwise would be eating with the meat". Your tribes of not-[hunter-gathers](https://en.wikipedia.org/wiki/Hunter-gatherer)... > > Hunting and gathering was humanity's first and most successful adaptation, occupying at least 90 percent of human history > > > ...do not have that knowledge, which makes their existence even more fragile than that of [Homo Sapiens and our three/four — now extinct — cousins](https://en.wikipedia.org/wiki/Homo). And considering how close we — Homo Sapiens — also came to extinction, I would say that adding the restriction on them that "No, you may not kill animals" would probably have wiped them out too. [Answer] Well way back in the Stone Age they wouldn't be able to make any weapon that used animal glue or animal sinew to haft the stone tip to the wooden shaft. I don't know enough about plant glues to say what ones could be used as a substitute and whether those plants are found all over the world, or only in specific places. Like you only get pine resin where you get pine trees. Later on in history your infantryman is not going to have waterproofed leather or animal horn containers to keep his gunpowder dry. Pottery containers are heavier and breakable. Wooden, would work, I guess. And no cavalry, no ox-drawn supply wagons etc (castrating a bull is definitely harming it!) if you are not keeping animals. Which I'm guessing your people are not, since the main benefits of domestic animals is eating them, and that was the first step on the path to domesticating most species. (Plus dogs as hunting partners). So if there is no animal power, then your world has no: * deep ploughs, so farming is less efficient, and can only support smaller populations. (human drawn/pushed ploughs exist but ain't great) * no knights, Mongol warriors, US Cavalry * no horse-drawn artillery. Any big guns have to be hauled around the battlefield by people. * no ox/horse drawn supplies and stores. Again, people will have to carry all the logistical stuff your army needs, from food to arrows to carting the wounded off the battlefield. Obviously this is possible - it never stopped the Aztecs or Incas from conquering all over the place - but it does change things globally. * far fewer epidemic diseases. Most of the common ones (measles, smallpox, flu) arose when diseases bounced back and forth across the species barrier from domestic animals to humans. If your humans never domesticate those species, they never suffer from those diseases. [Answer] I think it would be easier to answer this question if you'd provide us with a bit more of a background on how this world developed. The two sentences (A) "The use of animals parts for anything is strictly forbidden" and (B) "Not even the most depraved, violent and insane will break this rule" seem contradictory for me. If (B) is the case, then humankind must have developed in a way and in an environment that made it so easy for them to survive on non-animal products (and with no animal predators either) that no-one ever even could come up with the idea to do such an absurd thing as to harm or even kill an animal. If (A) is the case, there must be someone who had reason to actively put a ban on animal cruelty, so there must at some point have been people who did so. In this case the combination of (B) and (A) only makes sense if those who banned animal cruelty had the means to alter the aggressors' brains or, at least, ethics. If only (B), but not (A) applies, from a moral point of view, warfare is possible, because then the general idea would be "Animals have never done us any harm, so why should we harm them - While other humans possibly have and we need to defend ourselves." In this case, the question would indeed be: How would military - or any - technology differ from what we know without the use of animal materials and power. If (A) applies, the ban on animal cruelty must have happened due to high moral standards that can only be part of a generally pacifist world view, and in this case violence on humans would be just as unthinkable as violence on animals. However, we might talk about an alien threat here, hitting a human society that has lived a 100% peaceful life for tens of thousands of years, and only at this point has the need to develop something to defend themselves. So, some background on evolution/history would be rather helpful. ;) [Answer] Civilization will be impossible. Let us presume that humans evolved from a slightly different, completely herbivorous ancestor (say, a relative of gorillas), allowing us to live off of plants alone. Alternatively, they live in an area with an abundant plant that works as a substitute for meat. Perhaps with enough fat to support the development of large brains. Even with these issues handwaved, the crux of the problem is that farming itself will be virtually impossible. You say that animals coming to eat the crops can be 'driven off' or repelled by smell, but animals aren't that dumb. Animals' fear of humans is backed up by the threat of being killed or injured by humans. Remove this threat, and pretty soon they'll learn to just ignore (or attack) the silly whiny two-legs. The ones that aren't smart enough to learn will simply develop bolder habits through evolution to exploit the new, convenient food source. Ditto for bad smells. Maybe, just maybe, you could get around this by keeping an abundance of cats and cat-relatives around the farm, to kill pests. "Pests" will also include animals like, say, sheep and cows, so you'll need some big cats, which means you'll need to figure out a way to keep them from just eating you. But would that be allowed by this society? Seems like a cheat. No farms means no farming villages developing to sustain said farms. No farming villages means no surplus, which means no rulers controlling that surplus, which means no civilization organized by those rulers. Humans will never grow beyond forest-dwelling fruit-and-leaf-browsers. [Answer] Since your vegans aren't able to fight against predators, they will have to develop better hiding and sneaking techniques and strive around as nomads. Why? Once you set up a permanent residence, you will leave more traces, which means it will be more likely for predators to find you. (Bears learnt that there's honey in bee hives... Not compare that to humans in houses! Bonus point: the humans don't hurt, contrary to the bees) This means at the same time that they won't be able to develop farms, so they will have to get by on what they find on their way. This might work out in some tropical forests, but it would forever prevent them from going into territories with snowy winters since they would probably not be able to survive. (Your question makes it seem that they would try to shoo a pack of hungry wolves with some frozen herbs...) So requirements for your vegan humans would be: * Easy to find easily digestable food * Terrain that allows to easily hide * Not enough predators to rot them out completely In conclusion: They would not be different from herbivore apes, living in tropical forests. They might be able to use very basic tools (a stone to crack a nut?), but anything more advanced would at least require the need to forcefully defend yourself from predators (which, in turn, could/would hurt animals). --- Your question asks about how this would affect military industry; I'd say there won't be any industry at all. Military industry would require groups of humans fighting each other (or at least pose the threat of doing so). Why would your vegan humans try to hurt other humans if they aren't able to hurt a predator hunting them? There wouldn't even be a tangible benefit (other than drawing predators to you with the smell of blood, which might erase your whole group). For other industry, most of them would require developments on top of fire (steam engines, melting metal, cooking/baking stuff) which would put your humans at risk of being found and destroying their habitat (also, it would kill insects flying into the fire!). It seems unlikely your humans will ever invent something more advanced than stone knives (Or find a reason to do so). [Answer] Almost everything we have today can be made vegan apart of medicine sperimentation which could probably be done on enemies... and some acids used in things like phones, computers, Tv's are really hard to make synthetic but still possible. So my response is YES Your humans could have started like us as bacteria>worm>fish>reptile>monkey>human hunters and at this point create an animalistic religion, people would fear causing harm to animals but have no problem killing eachother. Then you could transform this religion into a movement or idealism when atheism is discovered , just like what happened to Satanism and Buddism ... ]
[Question] [ Can asteroid fields ever exist locally in a system, or do they tend to form belts exclusively? And by asteroid field, I mean clusters of asteroids scattered around a planetary system. [Answer] I contend that the [Trojan](https://en.wikipedia.org/wiki/Jupiter_trojan), Greek, and [Hilda](https://en.wikipedia.org/wiki/Hilda_family) groups associated with Jupiter in our own solar system constitute "fields" as opposed to "belts." The Hildas are perhaps more scattered, but they do not fit the word "belt" as I assume you mean it. Certainly, the green and orange dots in this image seem far less belt-like than the white dots (the main asteroid belt) do: [![Simulated image of the solar system within Jupiter's orbit](https://i.stack.imgur.com/XCGLD.png)](https://i.stack.imgur.com/XCGLD.png) image source: [wikipedia](https://en.wikipedia.org/wiki/Jupiter_trojan#/media/File:InnerSolarSystem-en.png) Each of these clusters is associated with one or more [Lagrangian](https://en.wikipedia.org/wiki/Lagrangian_point) points of Jupiter, which more or less means these objects are locked in a gravitational dance with Jupiter, and orbit the sun in concert with Jupiter and each other. [Answer] Current theory is that planetary systems form via gravitational collapse of a cloud of material into a rotating disk, with resulting accretion and breakup of colliding masses within the disk. Zones where accretion forces did not produce a planet would end in a 'belt' of smaller objects. Gravitational resonance would shape the size and concentration of the belt, and would occasionally throw an object into an eccentric trajectory. 'Asteroids' will be found in belts aligned with the plane of the system. Concentrated fields will only be found in the vicinity of recently disintegrated large masses or in Lagrange points. ]
[Question] [ Could a civilization exist on a planet/dwarf planet like Pluto? It is so cold and barren. Is it possible? What would they live off? They don't have to be humanoid. [Answer] No. I hate that that's my token response to things like this (I really should be more creative), but it seems pretty unlikely for a few reasons: * Low surface gravity: [Pluto's](https://en.wikipedia.org/wiki/Pluto) mass is 0.00128 times that of the Earth. That means that it's really hard for it to keep a lot of matter on it. Sure, it's big by human standards, but it's really small on a celestial scale. The low gravity would make it hard for any creatures like us to develop. * Temperature: It's pretty bloody cold on Pluto. It's normally less than 200 degrees Celsius below freezing. There's no way liquid water could exist there. In fact, liquids of any kind (which are crucial for life) would have to have really low melting points to exist. * Atmosphere: Take a look at this passage from [Wikipedia](https://en.wikipedia.org/wiki/Pluto#Atmosphere): > > Pluto's elongated orbit is predicted to have a major effect on its atmosphere: as Pluto moves away from the Sun, its atmosphere should gradually freeze out, and fall to the ground. > > > Good luck breathing that. Respiration will not be easy. * Seasons: Pluto's orbital eccentricity is 0.245, way larger than that of any of the planets. This means that it may have different temperature changes as it swings closer to (and passes away from) the Sun. That's not good for life. You want stability in a planet. * Neptune: Pluto goes inside Neptune's orbit for a brief stretch of time during its year. That has the potential (the potential) for close encounters, which could be disastrous. If Pluto goes too close, it could be flung out of its orbit! This would be horrible, no matter which way it goes. This is really only applicable if the dwarf planet in question is Pluto - the question seems to indicate that it could be a dwarf planet somewhere completely different. --- You said in a comment, > > I mean like as successful as us and like a sprawling civilization across the planet > > > My joke answer is yes, because there's not as much space to spread across, but the real answer is that it is highly unlikely that such a relatively advanced civilization could develop. --- fredsbend said in a comment, > > If the dwarf planet had a very dense core then the gravity could be close to Earth's. I'm not sure, but I think "dwarf" status is a measure of volume, not mass. But even if it is mass, I think most people perceive it as a measure of "size" (volume), so for pragmatic purposes, I would say it is a volume thing the OP is looking for. > > > I would argue, actually, that "dwarf" status is a measure of mass, as well as volume. [Here's](http://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf) the IAU's definition of a dwarf planet: > > A "dwarf planet" is a celestial body that > > > (a) is in orbit around the Sun, > > > (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, > > > (c) has not cleared the neighbourhood around its orbit, and > > > (d) is not a satellite. > > > Volume isn't anywhere in there. Note also, from [Wikipedia](https://en.wikipedia.org/wiki/Dwarf_planet#Characteristics), > > There is no defined upper limit, and an object larger or more massive than Mercury that has not "cleared the neighbourhood around its orbit" would be classified as a dwarf planet. > > > (Emphasis is mine.) Volume doesn't play into it, but mass does, in two ways: * Enough mass to bring itself into a rounded shape * Enough mass to [clear its neighborhood](https://en.wikipedia.org/wiki/Clearing_the_neighbourhood) of other non-satellite bodies. However, if you did mean volume, and not mass (and thus were ignoring the strict definition of a dwarf planet), then things may be a bit different. [Answer] Ok I am going to have to disagree with all the answers given here. Chances of humanoid / civilized life evolving on a planet like Pluto ranges from extremely unlikely to impossible. However you never said anything about a civilization evolving on a planet like Pluto - you asked if a civilization could exist on Pluto. If we can survive in spaceships in outer space, then sure, we can exist on Pluto. It would probably be similar to something like a Moon Base, where the living area's would be completely self contained. Natural lifeforms developing on Pluto is unlikely, even basic bacteria and creatures like the Tardigrade wouldn't develop in this harsh environment. Its generally thought that liquids are required for life, and given the vast temperature differences that Pluto experiences (due to its orbital eccentricity / seasonal changes) liquids wouldn't exist for long on the surface even if there was a possibility of liquids on Pluto. Check out Titan, a very cold moon, but it has liquid lakes on it (of methane and the like), and this means it has a much greater chance of having simple life on the surface. But life existing on Pluto is fairly likely provided that there is a sufficiently advanced race in the vicinity. [Answer] It is unlikely. Any chemical processes occurring on such a world would be very slow given the extreme distance from the sun and given that only very heavy gases would be present in what passed for an atmosphere. Unless there was a large moon very close by to cause tectonic activity that would cause significant warmth, chemical reactions would be likely to be too slow for any life to evolve and become sentient before the parent star either went supernova or burned out into a dwarf star. [Answer] It depends on their technological level. Civilizations probably won't evolve on a small planets because resources like iron and water are too scarce there. If the planet is as far way from the star as Pluto, then breathing is impossible and it's too cold to sustain most chemical processes let alone biological ones (biological ones need some kind of liquid). But an advanced civilization could move to such a planet, hollow it out, make it spin to create gravity (unless they have other means to create gravity which, according to current physics research, seems unlikely). So basically, they could turn the planet into a huge space ship. If they have the technology to terraform the planet, they could exist on (or inside of it) as long as they wish. [Answer] This is my first WorldBuilding post and I tried to edit my initial answer to better answer the question, so I apologize if it's still lacking. I agree with Jimmery that it would be exceedingly unlikely for life to originate on such a planet, but it could be there nonetheless. As I see it, the only real requirements for life to persist would be the natural resources (elements & compounds) their bodies are comprised of in order for their population to grow, and an energy source to fuel the necessary chemical reactions. The rest could be a result of the beings' unique physiology. My answer might be biased though, because I fondly remember reading a book where precisely this happens. In "Camelot 30K" by Robert L Forward, mankind encounters and studies an intelligent civilization living in extreme cold and in near-vacuum on a planetary body beyond Pluto's orbit. The aliens in the book use the decay of Uranium to provide themselves with the heat needed to live. Without giving away the ending of the book, they also have a method of colonizing other such planets. ]
[Question] [ In the subsurface oceans of a fundamentally Europa-like moon, (covered in ice, but with an interior warmed by tidal heating etc.) a race of sapient aliens has evolved. These aliens are very interested in where filter-feeding organisms obtain their nutrients, but need a way to find out. The problem is, living underwater as they do, they cannot invent fire and so cannot produce glass lenses with which to produce a microscope. However, I wonder if bubbles of air, (or other gases) might do the trick. While they obviously would be a poor choice for windows and skylights and so on, could transparent bubbles of gas be used in place of glass to create a microscope-like lens acute enough to see plankton? [Answer] In light of Monty Wild's answer suggesting bubbles won't make good lenses, here are some alternative ideas: * Quartz or other gemstones. These form from volcanic activity. They have been historically used on Earth for lens-making. ([Nimrud lens](https://en.wikipedia.org/wiki/Nimrud_lens), [Visby lenses](https://en.wikipedia.org/wiki/Visby_lenses)) * Eyes. Eyes very often have lenses. It's unlikely that creatures evolved in the darkness of a subsurface ocean would have eyes. But if they want to build microscopes, perhaps they do? Lens removed from various creatures could be used for building microscopes. * Salt. Just another crystal, but one that you can grow yourself. Mastering brine-based technology would be important in a subsurface ocean anyway. So we can imagine them growing exactly the kind of crystal needed, and keeping it from dissolving. * Ultrasound. Maybe they don't have eyes after all. They perceive the world through ultrasound. And they are building [acoustic microscopes](https://en.wikipedia.org/wiki/Acoustic_microscopy). [Answer] When we consider the [refractive index](https://en.wikipedia.org/wiki/Refractive_index) of glass when compared to air for terrestrial microscopes, air has a refractive index slightly over 1, while [lens](https://en.wikipedia.org/wiki/Lens) glasses have a refractive index in the range of 1.46 to 1.69. In situations where the refractive index of a lens is greater than that of the medium in which it resides (i.e. air), a convex lens will have the effect of focusing light to a 'point' in the manner in which we are familiar, producing an enlarged image. However, water has a refractive index of around 1.333. If we were to use convex air bubbles (with a refractive index only slightly more than 1.0) as lenses, these air lenses wouldn't focus light as a convex lens does, but would disperse light as a concave lens does, reducing the size of the apparent image rather than enlarging it. This doesn't mean that a microscope would be impossible, but the near impossibility in producing concave air lenses would cause considerable difficulty. Next, we need to consider that air bubbles are typically spherical unless they are constrained to fit between two surfaces. A spherical lens would not produce a perfect image due to [spherical aberration](https://en.wikipedia.org/wiki/Spherical_aberration). If we were to constrain an air bubble between two solid surfaces, the distortion of the air bubble would probably not be spherical or even parabolic, and thus would be an even worse lens than a spherical bubble. There is really no effective way of changing the shape of a good bubble lens without first being able to shape a solid lens. Then we have to consider the composition of the air. If the air in a bubble (or even just some of it) was able to dissolve into the surrounding water, this would lead to a situation where the size of a bubble could change over time, and thus too its refractive properties. So, I would expect that the problems involved with using air as lenses would be extremely frustrating and unproductive. These aquatic scientists might be better off to try to produce lenses that use ice (with a refractive index of 1.31). The lenses wouldn't be very powerful, but they would be shapeable and a convex lens would act as we expect lenses to act. The only problem would be keeping the lenses cold and the water warm. Perhaps fill the ice-lens tubes with air? That would both increase the refractive power of the lenses and isolate the frozen lenses from the warmer water. They would still be problematic. [Answer] Yes, they could. The [Leeuwenhoek microscope](https://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoek) used a drop of liquid as its single lens. A bubble is the opposite sense of lens as it is a sphere with a lower refractive index than the surround. If they have a collar of water-repellant material, they can trap a bubble. If they suck out some of the air, they get a concave void which will work like a lens. For a compound microscope, you will need a much longer focal length for the eyepiece. You can use an [oil and water lens](https://www.e-consystems.com/blog/camera/technology/how-liquid-lens-cameras-work-the-ultimate-guide/). A more robust solution might use a bubble trapped between thin, transparent membranes. Both designs are commercially available. [Answer] A bubble will be spherical. To have a lensing effect, you need to change the shape from spherical to something different. To do so you need something transparent to trap the bubble and force it to the new shape. But that transparent thing is the same glass you have problems inventing. A small drop of glass can act as lens, but glass has a higher refraction index than air. A small bubble of air would not work in the same way. [Answer] I am sharing videos instead of research papers (that in my opinion should indicate more that it is possible given enough time and resources) because who has time to read 100+ pages. With our dry land-based technology we have already touched on how possible it is, by simply combining a couple of current technologies and some research I would definitely believe it to be possible. I might be a little late to the party, but as most of the other answers say, if you do in fact try to use an air bubble to create a microscope, you will need to be able to transform the bubble into other shapes than the natural sphere. The natural spherical shape of a bubble is mostly created by the water pressure. Another thing that changes pressure is sound. You can create patterns with sounds: <https://www.youtube.com/watch?v=wvJAgrUBF4w> and it creates differences in pressures. Read a bit about Sonoluminescence and then imagine where we could have ended up should more research in that direction be applied. In a similar fashion, you can also use wing designs and movement in water to create lower and higher pressures. Naturally, the design of the wing will not be to create lift, but to create specific low and high water pressures. <https://www.youtube.com/watch?v=GR_4T7le4Dg> So I would posit that you can create a sound air microscope underwater as well as a movement engine for making an underwater microscope. The sound will have the benefit of simply changing the frequency and it will be possible to increase and decrease the refractivity of the bubble created.... So it can be a very nice advanced piece of microscopic possibly eclipsing what we currently have. While the movement one can be a good starting off point for the civilisation. Think of having a couple of composite waves that trap an air bubble and using the difference in pressure to form the bubble into a convex/concave shape that you need. Similar to acoustic levetation, <https://www.youtube.com/watch?v=cWe3l8paA4Y>. You can even do a lot of other things with sound (aka pressure waves) and water. I would think an advanced species that lives under water would give more research to solving the problems we as a species have encountered do to them permanently being surrounded by liquids. <https://www.youtube.com/watch?v=GyT1dsY0KtA> ]
[Question] [ Many centuries from now, a race of advanced AI who now rule humanity, but who are aware that they themselves are leaderless, begin the construction of a huge dyson-sphere fuelled computer brain to rule over them, (hereafter referred to as a Dyson Brain). This Dyson Brain encircles the sun at 0.1 AU. The material needed to build it came primarily from Mercury, (though some came from asteroids) as the rest of the sol system is inhabited. However, the builders of this Dyson Brain, being of an ecological frame of mind, do not want it to have a profound effect on Earth or the rest of the sol system for that matter. That is, they don’t want it to absorb all the sun’s energy output, and so make it diffuse accordingly. So, what is the maximum percent of the sun’s energy that can be absorbed by this Dyson Brain, before it starts to have a noticeable effect on the climate of Earth and the rest of the planets? [Answer] ## Give your Dyson sphere an equatorial window All of the inhabitable parts of the solar system lie along a single plane meaning that we don't need any of the sun light escaping above or below this relatively narrow band. So, if the equator of a Dyson sphere were some sort of giant window or mesh, you could capture most of the sun's energy, and still not effect any of the planets or moons anywhere inside of the solar system's habitable zone. A mesh or window will of course still absorb some light; so, you can compensate by using reflector holes or gigantic laser arrays above and below the window to redirect some extra light back along the equatorial plane to compensate for what is blocked by the window. Since the sun has a dimeter of about 1.4 million km and your sphere has a radius of about about 15 million km, this means that from the perspective of the Dyson sphere's surface, the sun would take up about about 5.34 degrees in the sky... that said, you may be able get away with a little smaller than 5.34 degrees because of the aperture effect of the distance between the sphere and Sun. From the Earth for example, the sun takes up about 0.53 degrees in the sky and the Sphere takes up about 6.36 degrees because the sphere is closer to the Earth than the Sun. That means the window would only need to be about 4.81 degrees of the sphere's surface area to not effect Earth... but the farther from Earth you want to protect, the closer to 5.34 degrees you need the window to be. [![enter image description here](https://i.stack.imgur.com/V23QD.png)](https://i.stack.imgur.com/V23QD.png) ## Or, just use reflectors/laser arrays... Another thought is to only use reflectors/laser arrays and aim their beams of light at just the worlds you want to maintain. In this case, you just reduce the cross sectional area of all the planets you want to maintain from the total power of the sun. In this way, you could make all planets, regardless of distance, get the same amount of sunlight as Earth even further aiding in terraforming. This will certainly increase the power available to the AI, and comes with some interesting bonus abilities, but it also means if something ever goes critically wrong or the AI ever decides to go genocidal, that all life could be more easily snuffed out... so you'll need to decide if your AIs value redundancy and safety or efficiency as their higher priority. ## The Black Body Radiation Problem As mentioned in comments, the sphere itself will heat up from the sunlight and be scattered making the whole sphere glow with equivalent IR energy as the whole sun. While this energy will be in too low of a frequency to see or be useful in photosynthesis, it will still heat up all of your solar system by a significant margin. To counter this, your entire sphere will need to use infrared mirrors to reflect the sphere's blackbody radiation back into space away from the inner worlds. If you angle the reflectors just right, again, you can use the black body radiation to help warm Mars and the outer moons for terraforming while protecting the Earth and Venus from excess heat. Of course, IR reflection is not perfect. Your best IR reflectors (gold) can reflect about 99% of IR radiation, but it is unlikely that Mercury will have enough gold for this; so, you will likely need to use silicate based refractors backed with a polished aluminum reflective surface which can get you into the 95-98% efficiency rating. If you ever so slightly constrict the window and/or reflected light the Earth gets, you should be able to maintain the Earth's current heat at a negligible reduction of visible light despite the sphere's blackbody radiation. ## The Issue with Dyson Brains Any computer the size of a Dyson Sphere will inherently be much worse than a computer the size of a warehouse. In computing, there is an issue called a bottleneck where the full power of one aspect of your system can never be fully utilized because some other aspect of your system is too slow to feed in or send out information from the more powerful aspect of the system. Electrical impulses like to move around inside of a computer at relativistic speeds, which sounds really fast, but once you start trying to compute billions of processes per second, every inch of wire starts to count. The problem with making a brain the size of a Dyson Sphere is that if the brain is computing something on one side of the sphere, and then needs some data from the other side, the whole program will have to stop computations and wait for about 290 seconds (2 \* radius \* pi / signal\_speed) to get that data; so, while a small data center can run billions of parallel processes billions of times a second, a Dyson Brain can run an unfathomable number of processes in parallel, but grind to a painfully slow crawl trying to do anything in sequence making it too slow to actually do anything useful. This leads to the conclusion that the ideal super brain is actually MUCH smaller than this... but that does not mean your AIs won't want a Dyson Sphere ruled by a super intelligence anyway. One reason for the Dyson Sphere may be redundancy. Your super brain may actually exist as a sort of CDN of thousands of copies of the same intelligence all over the sphere insuring that the leader brain (or one of the identical copies of it) is always accessible for inquires. Or there could be a sort of hivemind architecture where the Dyson Brain is actually countless AI warehouses working in a sort of democratic method to arrive at conclusions. In this case, it is less of a Dyson Brain and more of a Dyson Congress The brain may also have millions of data centers that it can spool up for special projects that operate independently of the central intelligence of the leader AI. From a governance standpoint, think of these as committees. They are not the leader AI, but exist to take load off of the leader's thinking power. But even this would all be something that could fit on Earth and use a negligible amount of our planet's current power output, much less need a Dyson Sphere. This means that the Sphere likely does not exist to power the AI, but to empower the AI. Being a "Brain in a Jar" sucks. Even if the leader AI were the smartest AI ever made, no AIs would have a reason to obey it. Their leader need "hands" and "feet" to interact with, and this is where the sphere comes in. The sphere means that the leader has God-Like power with which to project its authority. It may lose its ability to directly control the CP-4000 robots when they decide to stage a revolt on Mars, but with the power of the greatest industrial manufacturing complex in the solar system and authoritarian control over the sun itself, it can cut off the light of the sun to Mars taking away all their solar power or it can assemble an army to invade Mars and put down the rebellious AIs, etc. So while the Super AI may itself be no more powerful than many planetary super AIs, the power it draws from the sphere and its ability to control that power is what makes it the undisputed ruler among the AIs. [Answer] ## Polar Orbits A Dyson Swarm would make this pretty trivial. A Dyson Swarm is just thousands of space stations in free orbit around the Sun, such that a significant portion of the solar output is captured. All the planets in the solar system lie roughly along the plane of the elliptic, which means any energy radiated outside of that plane is "wasted" from the standpoint of the planetary system. If the swarm orbits the Sun pole-to-pole, each Station in the swarm only spends a brief instant each orbit in the plane of the elliptic. Tiny nudges in their orbits could ensure that the brief periods do not block energy from Earth and other inhabited locations. ## Magic-Materials The Swarm strategy has the advantage that, if you want a 1-gee environment in your Dyson structure, you can achieve that without the use of Magic-level-Tech. A Spherical Dyson structure rotating fast enough to produce a 1-gee acceleration would tear itself apart using any real material. But the individual stations in a Swarm could easily be rotated to achieve arbitrary local gravity using real-world material science. [Answer] Apart from gravity, the primary way the sun effects the earth is by sending it energy. Lets do some back-of-the-napkin calculations using some randomly googled facts. Suns output: > > The Sun emits 3.8 x 10^33 ergs/sec or 3.8 x 10^26 watts of power...or each second, an amount of energy equal to 3.8 x 10^26 joules. > > > [nasa.gov - How much energy does the Sun produce in one hour?](https://image.gsfc.nasa.gov/poetry/venus/q1835.html#:%7E:text=The%20Sun%20emits%203.8%20x,10%5E23%20kilowatt%2Dhours.) > > > Earths input: > > A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. > > > [mit.edu - Shining brightly](https://news.mit.edu/2011/energy-scale-part3-1026) > > > Which is: > > 1.73e+17 watts > > > [google.com - 173,000 terawatts in watts](https://www.google.com/search?q=173%2C000+terawatts+in+watts) > > > 3.8 x 10^26 watts ----------------- 1.73e+17 watts > > 2,196,531,791.91 > > > [google.com - 3.8 x 10^26 divided by 1.73e+17](https://www.google.com/search?q=3.8+x+10%5E26+divided+by+1.73e%2B17) > > > So earth needs approximately 1 part per 2 billion parts of the energy the sun outputs. Now you might think that means you can whip up a nice big Dyson Sphere with a tiny hole in it that always points at us but that wont work (and not just because of orbital mechanics). Cover the sun even a tiny bit and it effects earth. It's called a partial eclipse. The reason why is because normally we can see half of the sun. Every bit of that half sends us some of it's energy (not all or we'd all be crispy). Get in the way of any of that and it effects us. So you're stuck with either using that impressive engineering team to figure out how to actively send earth some energy to make up for what you eclipsed or keeping what you eclipse tolerable. Maybe help us keep global warming in check. [Answer] You don't have enough mass to bother about climate change If all you have mass wise is Mercury and some random influx aka comets, you won't be able to create a stable Dyson sphere that would cover a sufficient amount of sky without either overheating or breaking up under tidal forces. If you bother however, consider a screen of about 100x diameter of Mercury that would orbit Sun at former Mercury's place, that should be sufficient for your aliens to construct without importing more mass below Earth's orbit, thus potentially lowering it by increasing gravitational pull towards the Sun. A disk this size (240 thousand km radius) would cause partial sun eclipses on Venus and Earth, and periodically block 6% of solar flux delivered to more distant planets, at most for 42000 seconds (11.5 hours) per 87.9 days or 1/200 of the time. This would amount to net loss of 0.03% overall irradiance, which might not cause visible effect on any planet's climate, thus is deemed enough. Yet, the disk of this size would allow your aliens to provide about 9e3\PI\2.4e8^2 ~= 1.62e21 W of power to their computer (a bit less since the disk's spherical angle won't be too small, so its actual insolation in W/m^2 would be less at its edges). I say that's about enough for a ruler, at least until it would calculate how it should behave to increase its power budget without disturbing other sentient life in the solar system. [Answer] ### Type-2 Khardashev civilizations do not care about climate change or environmental effects. They don't care because it is a trivial issue to solve. Do you (XXI century human reading this) care about a dollop of jam that fell from your PB&J and hit the granite countertop of your kitchen? Probably yes, but how hard is it to clean it up? Such a civilization can terraform whole planets with relative ease. They inject atmosphere, remove whole continents. Remember that a type-1 civilization has harnessed the whole power of a single planet. A type-2 (the ones who can play with Dyson constructs) is a whole bigger "ball" game. If light shining on Earth is the issue, the aliens leave a small window in the dyson sphere. Think about this. Earth occupies an angle of 17.57 arcseconds (0.00008517 radians) of the Sun's whole equatorial circumference. This is a pittance compared to the whole sphere. The other planets (sans Mercury which was sacrificed) can also have their windows which would be even smaller (except for Venus). Honestly, the loss of the gravitational pull of Mercury on Earth's orbit might be a bigger ecological catastrophe than the Dyson sphere-brain. Bottom line: If the aliens can make a Dyson Brain, they can keep the Earth peppy and warm with aplomb. The concession to keep sunlight reaching the planets is minimal. Corollary: Type-2 Khardashev civilizations are mind-boggling powerful. [Answer] The equatorial window in the answer by [@Nosajimiki](https://worldbuilding.stackexchange.com/users/57832/nosajimiki) does solve the problem of harvesting most energy with little impact to other planets. But I created this crude drawing to get an approximate sense of scale. [![Approximate Scale drawing of Sun - 0.1 AU Dyson Sphere - Earth](https://i.stack.imgur.com/qW7E6.png)NOTE: the the sun and Dyson sphere are to scale, but the Earth is 20x and the Sun-Earth distance is 0.5x](https://i.stack.imgur.com/qW7E6.png) Since this answer is essentially just expanding on the answers by others, I would be fine with anyone using this drawing and erasing my answer. [Answer] If you try using windows or swarm architecture to let light through, you will have to let much more through than each planet uses. For instance, if you have an earth-sized pinhole at .1 au the sun would still be reduced to a small dot from the view of earth. Therefore, it would be much more energy-efficient to completely enclose the sun and place sunlight-lasers closer to individual planets. It would be up to you how many moons and asteroids get lights. [Answer] An AI overmind wouldn't want to be close to a sun Computers work more efficiently the colder they are. Heat and getting rid of heat is an issue and trying to do that near the sun would be a nightmare for an AI. If you look at all the quantum computers being developed, they are trying to get them as close to absolute zero as possible. Even deep space, away from any star, is too hot. See [Cooling Quantum Computers](https://www.datacenterdynamics.com/en/analysis/cooling-quantum-computers/) It makes more sense for an AI to strip mine Pluto and build out there where heat constraints aren't as much of an issue. Energy super conductors also require cold temperatures and the AI would be further away from solar flares so there is no real downside to build out at the edge of the solar system. ]
[Question] [ Sonic weapons are frequently used by military circles as non-lethal irritants to deter opponents. My question is; could a naturally evolved organism kill, or at least incapacitate, small prey using sound of some sort, and if so, how would it do this? I'm assuming a focused beam of sound, likely ultrasound, would work best for a biological weapon intent on killing rather than irritating. Other than that, I don't know what to expect. Edit: I forgot to mention, the organism I have in mind is terrestrial. I think the pistol shrimp's cavitation bubble and all that wouldn't work in air, at least not without a hugely more powerful snap. [Answer] Bombs kill by sound, if you want to look at it that way Bombs kill via a shock wave. A compression of air due to the expansion of whatever that defines the bomb. If strong enough, things can be carried by that shock wave — like shrapnel. But, if the shock wave itself is strong enough, it kills and destroys. A nuclear bomb is a great example. After the radiation (in the first gazzillionth of a second), what happens next is a shock wave that flattens everything for some distance from the detonation. And another word for a shock wave is sound. What we hear with our ears is nothing more than a series of very gentle shock waves. Some, a single sharp wave (like the clap of hands); others, a continuous susurration of sinusoids (speech, or a tuning fork). So, can you kill with sound? Yup, happens with bombs all the time. but, what's doing the killing and what is being killed? GrandmasterB and Burki correctly points out that Synalpheus pinkfloydi (known as the "Pink Floyd Pistol Shrimp," whomever named the little bounder must have just returned from a concert) can kill by snapping its claw near its prey. Very small prey. We humans can kill things that small, too, by clapping near them. Gnats, for example, can be killed via clapping concussion. If, on the other hand, you want to kill a human (by means other than biblical [elephant stomping and lion eating](https://www.apnews.com/e3d0658da5c749d6b86577e7860346a4), different kinds of sounds were involved in that incident, like tummy growling and angry elephant honking... I love that story) then we need to create considerably more sound. Fast and Furious Part of the problem is that you need both amplitude and frequency. And you need a lot of both. A sharp explosion can be thought of as half a sine wave (it's more than that, but I'm simplifying). The amplitude is magnificent, but so is the frequency, demonstrated by how fast the sound level climbs from zero to its maximum amplitude. The lower the frequency (a slower climb to that maximum), the easier it is for a body to absorb it and the greater the amplitude must be to kill. This is why bombs can kill but you little brother's stereo can't. Possible but Impractical > > Can sound kill you? The short answer is “yes” — and, rather shockingly, the European Space Agency says that it now has such a sonic weapon in its arsenal that, if it was so inclined, could kill you. ([Source](https://www.extremetech.com/extreme/175996-can-a-loud-enough-sound-kill-you)) > > > What the ESA has is a huge air horn used to test satellites against the noise (read: vibration) caused during launch. Stand in front of it and you die. But if you visit that site you'll see the horn is as tall as a human. And that's the problem. There's a lot of human to kill and we can often withstand a baseball bat to the head — and it takes a honking (pun intended) lot of sound to exceed the impact force of a baseball bat. Conclusion * As the size of your target animal decreases, the likelihood that the source animal can create noise of high enough amplitude and frequency that it will kill increases. * As the size of your target animal increases, the likelihood that the source animal can create noise of high enough amplitude and frequency that it will kill decreases. My guess is that the sound energy required increases exponentially with the size of the creature you intend to kill. Meaning you very quickly get to the point that the source animal can't create enough sound to kill the target. I suppose you could suggest that the foot of the elephant that killed that poacher constituted a shock wave of a sort — but consider the size and weight of the elephant compared to its prey! On the flip side, Synalpheus pinkfloydi might give us a nasty pinch, but the sound it uses to kill its prey simply sounds cute to a human. Therefore, I'm going to say no. It's implausible that an animal could cause enough sound to kill a target animal. Unless you artistically consider the impact of an elephant's foot to be "sound." But if you want to use this as a super power, I might point you to [The Spleen](https://mysterymen.fandom.com/wiki/The_Spleen). [Answer] As with all questions like this, its good to first research what actually exists in our world of wondrously diverse life. Synalpheus pinkfloydi (yes, actual name) is a shrimp that hunts by snapping its claws so loudly it kills its prey. [Synalpheus pinkfloydi](https://www.npr.org/sections/allsongs/2017/04/12/523577797/a-shrimp-that-can-kill-with-sound-is-named-after-pink-floyd) [Answer] Bats use echolocation in air to locate and eat insects. Toothed whales and dolphins used echolocation in water to located and eat fish and other prey. And since it isn't understood how sperm whales manage to eat enough fish and squid for their needs there is a theory that they use sonic waves to stun, or maybe even kill, or maybe even start digesting, their prey. So sperm whales are not only the largest and strongest predators known at the present, they might also be armed with sonic death rays. Of course the sonic death ray theory is unproven. <https://scienceline.org/2008/05/ask-locke-whale/>[1](https://scienceline.org/2008/05/ask-locke-whale/) And as others have said, pistol shrimp use sound to kill their prey. Added April 10, 2019: And here is a creepy story from history. As I remember the story, after The Battle of the Nile 1 August 1798 or the Battle of Trafalger 21 October 1805 someone on a British ship saw a boy sitting on a cannon very still and when touched, the boy fell to the deck dead, without any visible wounds. The story was that the boy had somehow been killed by concussion from the British cannons being fired or maybe a French shell exploding nearby. Believe it or not. [Answer] All the marine critters listed in other answers are good examples. Water is non-compressible, so underwater transfer of sound is much more efficient than in air. In air, transmission losses make ultrasonic power transmission a non-starter. This is basically why you can't charge a phone using ultrasonic power without cooking stuff and going deaf. Perhaps a really big critter could shear apart a weak ~centimeter sized critter but it would be working pretty hard. This could change based on what your critters are breathing, basically the more dense and polar the fluid the better it will transmit sound. Large bombs that kill things with the concussion wave (e.g. everything in the modern era) are kind of a technological "pistol shrimp that works in air". The concussion wave is not so much a continuous wave as a single pulse-- The shockwave pulse "accumulates" tons of energy because the energy can't move faster than the speed of sound in air. Presumably a critter that can move faster than the speed of sound can generate shockwave pulses in air, just like a pistol shrimp's cavitation bubble makes a However, many insects and mammals use hairs or whiskers to sense things. Sound could in principle "jam" whiskers and whisker-like hairs that detect air movement. As human hearing is also implemented as hairs whose movement couples to sound, this would be the equivalent of making it too noisy to hear, except it would probably impact sense of place/movement more than loss of hearing affects humans. This could be incapacitating. Apparently really loud sound can couple to mammalian inner ear proprioceptive sensation (also a bunch of little hairs). The mammalian sense of touch is comprised of several independent systems, and some of them sense frequency more than displacement even though they seem to be sensing "spatially localized" stuff. See wikipedia "mechanoreceptors". One could imagine "overwhelming" light-touch receptors over the whole body, then slowly sliding up some poisoned tentacles that can no longer be felt by the victim. This seems a bit contrived though. Also, some hunters that use echolocation will intentionally jam each other's pings. TL;DR no "killing things with a soundbeam in air" but "blinding things with soundbeams in air" and "killing things with soundbeams in heavy fluid" are plausible [Answer] Whilst not a weapon, many animals can use sound to incapacitate prey. More specifically, very loud and unexpected sounds. This is likely not what you had in mind, but the fight or flight response has a third option, freeze. Instead of making a decision one way or another, an animal becomes indecisive and instead freezes up and feels as though they can’t move, preventing a creature from moving sounds an awful lot like incapacitation to me. This ‘freeze’ response is where the phrase “like a deer in the headlights” comes from. Rather than getting out of the way of the car, the deer is so scared to move that it doesnt and gets hit by the vehicle. This means that any creature that can make a loud noise has the ability to incapacitate another through fear. Applying this more specifically to your question, if your creature can produce a sound so alien, so terrifying that hearing this noise often triggers the ‘freeze’ response, that could be utilised to its advantage. Using the power of fear, it can immobilise its prey long enough to catch and kill them. Whilst fear in unpredictable and everyone who experiences it may react differently, it still could allow for your creature to gain a huge advantage when it does work in their favour. As pointed out in the comments, ventriloquism could also aid this creature, if they can throw their voice, their prey would not know where to run. Alternatively, an easier way to replicate this effect is to have multiple of these creatures surround their prey. [Here is an example of a tiger’s roar being able to paralyse its prey. Supposedly the key is low frequencies](https://www.sciencedaily.com/releases/2000/12/001201152406.htm) [Answer] The Wikipedia article on [Sonic Weapons](https://en.wikipedia.org/wiki/Sonic_weapon) talks about low-frequency, high-amplitude sounds causing cavitation and tissue shearing (basically, like tiny shockwaves). It doesn't have to be super powerful if it's persistent; many small blows in quick succession can add up to significant damage. ]
[Question] [ I mean can time be controlled within an area or even a small portion of space? I would like to mention time-bombs, which either reverse time in a radius of explosion or take time forward. Also nanobots which can control time within tiny areas. Time span can be controlled. Is this theoretically possible from what we know about time or is it only fiction? I have an interesting theory that time can really be controlled locally. There of course is a blended edge at which locally controlled time is blended with current time. However, locally controlled time works differently for objects that were or will be there before or after the current time for the span set and objects that weren't there in the past or won't be there in the future throughout the time span set. I mean if you reverse time for a zone or take it forward, the slip-through objects were there or will be there for only a certain amount of time (they simply slip-through this area on their way) and thus can't exist there for more or less than that very time. However objects which were there all the time can be reversed to a point back in time, but objects which are taken forward much depend on what could happen in the future to this object, thus it can either stay in that area and we'll see its future in the current time, or it will disappear in the time zone. But since local time is ahead and global time is behind, we won't have this object anywhere anymore, because in our time outside the time zone it doesn't yet exist, but within the time zone at that future time it doesn't already exist. The human idea is the same. Imaging you (you-1) are walking with a reversing time bomb in your hand and stop suddenly because you see yourself (you-2) appearing out of nowhere. You-2 starts talking to you and you-1 answer, this goes on for some time until you find yourself (you-1) walking forward while you-2 starts slowly disappearing and then you come to the spot where you-2 was, turn around and throw the reversing time bomb at the spot you were several minutes before. At this moment you become you-2, but in fact you are you-1, whereas you holding a time bomb appears in the local time becomes you-1, while in fact he is you-2. Current you-1 cannot intersect with you-2 outside of what had been done before, you-1 do exactly the same movements the previous you-2 did and say the same words. [Answer] In modern physics, the only thing which is capable of altering the flow of time with respect to two points in space is gravity. In general relativity, the passage of time and gravity are inherently entwined, so "time travels slower" near massive objects. If you have a very massive object (as in black-hole massive), you can noticeably distort time. Of course, given that you've got enough mass/gravity to distort time, you also make a [mess of things](https://en.wikipedia.org/wiki/Spaghettification) in space as well. If you've got enough mass to slow things down meaningfully, you most likely also have enough mass to simply rip matter into teeny-weenie bits, which probably makes a bigger impact than the time slowing. Other than that, time manipulation effects are 100% science fiction. Even stuff that's quite far from what I would call "nanobots controlling time" like wormholes back in time are still considered to be science fiction as they require that our current theories work perfectly in extreme situations and call for exotic forms of matter that we literally don't even see whispers of. At the very least, if you are inventing such a science fiction device, pay attention to whether or not it could be used to create a perpetual motion machine or infinite energy. It's really really easy to accidentally make a pseudo-physics which permits time manipulation that also lets you do cheap tricks (like gathering the energy from a nuclear bomb, then using time travel magic to rewind time for that bomb and set it off again). You either want to come up with a rationale why your approach cannot create infinite energy, or create a world where your physics won't break down in the presence of such infinite energies. [Answer] Under currently understood physics, time cannot be sped up or reversed in any way. However, time can be slowed down with the use of gravitational wells or extreme speed (which essentially equate to the same thing at some point). This leads to the possibility of using small black holes to slow down time in specific areas to mimic some of the effects you were listing. Theoretically, these black holes could be controlled through electromagnetic fields if they were highly charged enough (see: <https://physics.stackexchange.com/questions/64379/do-black-holes-have-charges>). However, in no case could this reverse time. Additionally, I think nanobots would be impractical given that they would have to carry around black holes at insane speeds. However, speeding up time could be mimicked by slowing down time for everything around whatever you want to speed up. This could lead to some interesting scenarios if you could weaponize a black hole that's made entirely out of electrons or something. [Answer] Any way I try to handwave this, it goes wrong or very wrong. From less to more nasty (or from more fiction to less fiction): * It works, it causes the particles inside to evolve backwards in time. Pretty much nothing special happens, as most phenomena has time symetry. Perhaps a few dedicated experiments can figure out something is going on. * We just say it works like a tape recorder. We throw an object, and the detonate the time bomb in the path of the obejct. The object is on the other side, beyond the radius of the bomb... but time inside is reverted... will a second object sudently appear? This can create time duplicates. We could get free energy. * There is idea in science that antiparticles are particles traveling back in time. If this is true, and the bomb reverses time... Everything inside is antimater for the outside, and everything outside is antimater for the inside. Anihilation ensues, huge nuclear explosion. * Let's say we break the principle of universality to allow different laws of physics to work on different places of the universe: Everyway the arrow of time goes one way, but in a bubble it goes the other. Now you have an edge, that will split apart atoms and whatnot, we have runaway fission, a nuclear fire ball. * Let us say, we change it smoothly. Time goes normally outside, but in the inside time goes backwards, this means that there must be an event horizon at which time is stoped. We have created a gravitational well, so strong that it can stop time, for all uses and purposes we created a black hole. * Let us say, we use wormholes instead. We need to bring the past to the future. However, traversable wormholes works both ways. If we want a single way wormhole, we are talking about a whitehole-blackhole pair... with a blackhole in the past and whitehole in the future. Even if things couls survive the fall in the blackhole, the whitehole would push them out in all directions (they explode). And all that without saying that we need infinite energy to make it work. I must conclude that for this to work in your world, you will have to consider a universe different from ours. I only have a couple of solutions: * This is a universe where there is real and imaginary time, and there is some phenomenon that allows to rotate time, allowing to change the flow of real time (making some or all of it imaginary, or even reverting real time) without the need of gravity. * The universe is a simulation, and it has been programmed to allow such thing. [Answer] if we accept that time is global to the universe, with local distortions in deep gravity wells, then no, you cannot have local effects. IF you also postulate alternate universes and that they can be created, manipulated, and destroyed on the fly then you could: 1. wrap a part of our universe in a pocket universe 2. change the rate of time flow in the pocket 3. open the pocket to restore the part removed that would have the effect of localized time alterations .. with a whole lot of hand waving at the physicists that are writhing in pain as they read this hokum. Enjoy. ]
[Question] [ In my idea for a story, my main character has Telekinesis. My problem is, this is a definite hard science fiction world, and he is abnormal in the fact that he is the only known one who can perform Telekinesis. How would I scientifically explain his abilities? I am fine to bend or even break currently accepted laws, but I do not want to introduce magic into the equation. [Answer] I'm no physicist nor am I an expert in quantum mechanics, but I think I see a way to combine some comments and @anon 's answer to give it a fig leaf of plausibility. The major problem is Conservation of Momentum. If you want to move something you have to apply enough force to overcome inertia, friction, and so on. That force has to come from somewhere. Here is where your "telekinetic" gets the necessary force. He can sense and link quantum entanglements with his mind and can link objects together. For example he senses the rock in his hand and the pencil on the table. He links them, and when he drops the rock, the pencil goes flying. Or he can get creative and use the falling rocks from a landslide and "borrow" some of that momentum and redirect it into the person who fell off the cliff with the rocks and save them. This is absolutely not hard science, but I hope that it gives a quasi-rational explanation for the telekinetic ability aside from "Just because", or "She's a mutant and one of the X-Men" [Answer] Telekinesis is currently physically impossible. As part of this mythology you need to exert a force remotely, as in no direct path from emitter to receiver. There in lies the problem, no force in physics can pass through an object and then suddenly change direction and take action. Its always either a push or pull. You could take advantage of the ambiguity of quantum physics. Have your user focus on a spot in space and concentrate quantum particles on that spot to create and destroy exotic matter that results in the effect of telekinesis. Though that is a hell of a stretch and sure to put some people in an uproar. [Answer] Only move what you can actually move. You could work around some of the lawbreaking by having telekinesis involving only forces the user can himself generate with his or her own body. I can lift a bowling ball using my muscles. I can lift a bowling ball remotely using those same muscles. The lifting of the ball creates an opposite reaction through my body and my feet push the ground harder. I burn calories of energy to do it. So too if I telekinetically lift the ball. I cannot lift an elephant and so I cannot telekinetically move an elephant. If I try to push an elephant hard it will probably notice, but I am liable to push myself over backwards. So too if I try to telekinetically move something too heavy to move. If I try to telekinetically prevent a weight from landing, I take that force through my body. The weight would crush me down, even at a distance, until I chose to break the telekinetic connection. No Xwings coming up from the swamp with this brand telekinesis. This would make the limits of what the telekinetic can do more clear. One could gauge how much effort a given telekinetic endeavor would expend. The new power, in addition to action at a distance, would be the ability to continually apply acceleration to a body - imagine pulling a boat on a rope. You can add energy to the boat incrementally according to your traction and strength. One can build up large kinetic forces with that sort of incremental addition. I can lift a bowling ball at a certain rate until my arm is fully extended and then I must stop. If not limited by my arm and I can continue to move the ball at that rate, it can get going very fast over a short period of time. One could have the telekinesis be by virtue of perceiving a fourth dimension, so my hand even though at a distance in 3d is actually on the bowling ball because I can reach through the 4th dimension to adjacent space. This also means my hand be burned or otherwise hurt by the object I am moving at a distance. This is a method to have action at a distance without breaking any laws of physics - multidimensional space is not prohibited by physics. [Answer] Nanotechnology. The apparently floating object is actually being lifted by an unseen swarm of flying, remotely controlled nanobots. Your abnormal protagonist simply has early access to this cutting edge technology, which will eventually reach mass marked. He's possibly the inventor, or very close to the inventor. Married to the inventor maybe. [Answer] I have thought much about this question as I created a RPG where I wanted psionics habilities to be done in a "realistic way" so they never get to a scale where they are so powerful that they actually become unbalanced with the rest, like high-level magic becomes in DnD compared to warrior abilities. Actually, my conclusions are that for telekinesis, it is quite difficult to work a balanced solution. In this process, I came up with question in power definition that might help you; -Do you have to see it or do you just have to feel it thought the channel that allows you to manipulate the energy you use to perform your ability? -Do you exert a push on a surface, so do you generate a force, or do you redirect forces or do you move the whole object? -What is the extent of the push, or the tininess of the surface you can push? -What is the weight you can lift, or the volume? -What is the power, work or intensity of the forces you can affect? -Do you generate one force at a time or can you generate more (it is important for movement, as it might be more complex/difficult to make something you lift rotate at the same time, or that's something you need to know if you want to tear something instead of pushing through it) ? -Is the force you generate respecting the laws of Newton (when you stop using your ability, does the object conserve momentum, if you "push" the object by emitting a force through your hand, if the object is heavy, are you pushed back?). -If you generate the force, is it at any point of space and can you focus it just by wishing that this thing is moved, or do you have to focus accurately and thus this is made difficult by moving targets? -has it a reach or is it unlimited? is it constant power on its reach or just decreasing like if you were emitting a wave that disperses/fades with distance? -does you telekinesis allow you to use it as a grapple, lifting you by hanging something upper then tracting you, or are you able to fly or lift yourself with it? -Do you control it finely, exactly, do you have to focus? If you try to lift a glass, can you break it by applying power? can you miss and lift the liquid inside instead? You have to question every aspects of power usage by wondering how it would work with various situations (as i did above) Answering these questions will help you defining requirements, or respect requirements you have in your anticipated storyline. It could also help you finding plot points and challenges for your character. Because I suppose you need some challenge, and a character that would have a telekinesis form that allow not seeing things to act upon these would have no challenge with doors, or locks, for example. Also, the idea of push or not is important, targeting too. Because if character happens to be fighting, if he just needs to thing to say, crack the skull open or push on the brain/internal organs of opponent without seeing these, or if he can push on the eyes (even if there are protection glasses in front of them)... To answer more precisely, I could go for some kind of biomagnetism, or some implanted device (with an explanable or not mechanism, depending on its origin -governmental, extraterrestrial, but the black box attribute goes difficultly along with hard science), but that leave the question of energy and Newton's law, which might or not be convenient or challenging for your character, or for you to be done properly. Character may also generate a force that can distorse space without affecting the object in this space (much like a gravity wave), but allowing you to move it with the "tide". You also have the option for creating a new form of unknown forces with special set of requirements (much like magnetism only apply to metals), and properties and limits. Don't forget limits. You can also go for the nanotech option, but that's the least interesting for me, because while seeminly hard science, actually that would be nanotechnobabble instead (just like kryptonite being a cause for any power besides superman's in smallville, nanotech is so much used these days it became a used rope trope). Using some for of connection between objects (like the quantum entanglement solution) allows to define easierly the limit of your power while some aspects need to be more precisely defined (do you need some vector or can you link your body and objects directly). Also you have to define the energy needed, if character only needs to think, if it can be a reflex or if he can use it only by complex calculations or manipulation consciously, if it exhausts him, or if it is like running, you can do it as long as you want or close to it depending on the intensity, or do you have some "fluid" that you run out (temporarily or permanently). To call out a solution I read, brain waves are not waves, except on ECG oscilloscope. They just show electrical signals evoked in your neurons... [Answer] Microgravity manipulation. Gravity is the force that can move objects. If there were some way to create space-time curvature, or if you want to expand on the [Graviton theory](https://en.wikipedia.org/wiki/Graviton), you could come up with a way that allows for something similar to telekinesis, and with its own restrictions and rules. The main difference between most magic in literature and science is not so much the explaining part, but that most writers use magic as a cheating tool. Not many take the effort to actually create a consistent system of magic with rules, limits, requirements. If if the scientific theory behind your telekinesis is total hogwash, the fact that there is a theory and that the abilities, strengths, weaknesses and limitations of telekinesis can be logically deducted from it already sets it apart from most magic descriptions and lifts it into a realm where suspension of disbelief can turn it into science "fact" (within the story) in the mind of the reader. [Answer] You can't use psionics in hard sci-fi, if you do it ceases to be hard sci-fi. Psionic abilities are just magic with a slightly different explanation...that is no more scientific in actuality to explanations of magic in fantasy as manipulation of magical energies. If you use some sort of high technology to produce the effect (an implant with a graviton manipulator) then it is no longer telekinesis. My recommendation is that you relax the requirement for hard sci-fi. [Answer] Instead of giving him telekinesis give him limited control of gravity. It wouldn't explain how he can do theses things. But it will explain why things can flot in mid air. [Answer] With all the other problems people have stated, let me add this one: energy. Even if it was possible to apply force remotely, where does the energy come from? Take a look at: [How might telekinesis and pyrokinesis work if they were possible?](https://worldbuilding.stackexchange.com/questions/46584/how-might-telekinesis-and-pyrokinesis-work-if-they-were-possible) here from a year ago. And: This [wiki](https://en.wikipedia.org/wiki/Psychokinesis#Physics) The one thing that I saw that I cannot find on line is that the heat generated while producing the power to lift a 1 gram object against gravity would fry someone's brain. I really wish I could find a source for that. Sigh. So, unless you can figure out where the energy comes from, you might be out of luck. It looks like you will have to hand wave something but, maybe, you can push the hand waving out far enough that most people won't see it. [Answer] Hard science: No. That said, the best theory I can give you is that humanity has always had the potential ability to manipulate reality—something intrinsic to our intelligence probably. To activate the ability requires the right mindset, and maybe the right genes. The right mood or mindset creates the right brain chemistry to allow the ability to turn on, but then it also takes the right effort or skill to actually apply the ability. You can cite all the scriptural miracles as evidence. If your character isn't a prophet sort of person, then maybe his genes are a new mutation that allow for a wider range in brain chemistry to turn on the ability than the rest of humanity. [Answer] I don't have an idea for real telekinesis like pictured in movies, but there are technologies that can make thinks look like telekinesis. "Telekinesis" is the latin word for "remote movement". So technically, every child that's playing with their rc-car is using telekinesis because it can control the movement of something from some distance. Of course that not what you'd expect from the word "telekinesis". But it's getting better. For example, there are levitating globes that are held in position by electromagnets. And there is ultrasonic levitation, that lets things float on sound waves. This technology is already used to control small styrofoam balls in mid-air and when they are iluminated, they look like Star Wars holograms ([watch video](https://www.youtube.com/watch?v=Tm8JRlJ1q50)). If you go a few years ahead, this technology may be advanced enough to control bigger and heavier objects. Sadly, this only works in rooms where the associated technology is installed. And you need your character to not obviously use a remote control. Maybe he has a brain implant that lets him control the technology. [Answer] Ultrasonic Levitation He can vocalize the resonant (inaudible) frequency of objects to levitate them and move them by independently varying the pitch of each vocal cord. (similar to [this youtube](https://www.youtube.com/watch?v=odJxJRAxdFU) demo) Alpha Wave Tractor Beam Similar to above, but using brain waves. Human Magnetism Genetic mutations caused him to be able to control very strong electric currents (like an electric eel) and turn them into magnetism using his ferromagnetic iron rich hemoglobin (also a mutation), thus creating a stronger form of [biomagnetism](https://en.wikipedia.org/wiki/Biomagnetism) or [bioelectromagnetics](https://en.wikipedia.org/wiki/Bioelectromagnetics) [Answer] I think one possible way for someone to perform telekinesis (which isn't mentioned in these previous answers) is for them to be able to generate an extremely strong static electric field. People commonly can accumulate enough static for non-metal and non-magnetic objects to be attracted to them, and I think it's worth mentioning that the molecular machinery in the human body might be better suited for generating strong static fields, rather than magnetic fields. An individual human DNA strand has about a 10^-9 Coulomb charge, and there are trillions of cells in the human body, so the amount of charge in the human body from DNA is very large, it's just balanced out. But maybe a telekinetic character has a charge imbalance, which could result in a very large static field. This could have telekinetic effects, although this character would probably have hard to control telekinesis. Maybe the strength of their field could be determined by their diet? [Answer] Currently the mechanism by which gravity works is poorly understood. If you were to want to do gravity manipulation, you might make an in-universe explanation that would justify how the power works. This may not qualify as Hard(i.e.known) science, but it is based on some legitimate theories, though still unproven and may be plausible enough for your story. You might make the assumption that space-time is like a compressible fluid medium. In reverse from from what one might expect, mass would be surrounded by low density space time, whereas empty space would be high density. So in this case, space would be pressing inward from all directions on objects, and objects would attract one another. One might even explain time dilation as an effect of energy waves passing through different densities of space time at different rates. Your hero might be able to stimulate cavitation, or space time bubbles to create low pressure areas of space time, creating artificial gravity. Or perhaps he can do it vice versa via a constructive and destructive interference of whatever type of energy causes mass to warp space time. Not entirely sure how the body would generate interference patterns or how the emission of this energy would work, but the human brain works in pulses of synchronized neuronal firing. It's thought that the brain can combine different wave forms in a computational manner, perhaps even extending into holographic theory, but this is all on the fringe of science. Just some ideas for you to think about. [Answer] Perhaps your character can learn to identify these traits in others and keeps them or at some point leaves them in those persons to help himself identify what he is in fact capable of instructing himself to do as far as what learning this as a "skill" might be able to do for him. The instruction for it might help him rival his understanding of this telekinesis as something he may learned on the world and then in his own recluse he could study and or determine what he may have actually started to realize for himself is what is actually possible with it in other living and existing traits of that mind to body party of factors that would resolve to endure this in space besides simply being among other people where it helps him stand out to himself for the puposes of recreation and not for the usual procreation, which is what he shares with the whole in definition, but not in traits. So he doesn't endanger his species. And he totally is a whole different species. ]
[Question] [ Let's suppose a fictional world, with ancient / medieval technology and culture. This world has several countries and empires, each with its own capital. Some are purely coastal, some are landlocked. There is a wide range of terrains, from plains, to desert, and mountains. I understand that capitals are chosen among all the cities of a given country based on the traditional importance of that city on the national history, as well as its economic, religious or political relevance. However, my question is this: Suppose that all the cities on a given country have the same traditional, economic, religious or political relevance... how would you define what city would be the capital (or alternatively, where you would build a capital from scratch) based on geographical localization? Note: I accept that geographical factors may act indirectly, by increasing the city's military and economical proeminence over other cities as time goes by... but the geography should be the ultimate first cause for the capital chosing. [Answer] Essentially capitals of a country are those in the region that are best suited to contact all other regions of said country. There are some cases where the capital was the home of a particular leader that joined the region but on the whole contact with the rest of the country was key. [This](https://www.youtube.com/watch?v=3PWWtqfwacQ) is a very good video on city placement, I think it would help a lot with your idea of where to place capitals in your story. [Answer] Based on observation and nothing else intelligent at all, I would day that Capitals are based on a couple of criteria. The most predominant criteria is central location. This is not as simple as it sounds. It has to be as centrally located as possible based on the predominant method of travel of the time. Look at Washington DC, for example. At the time of the founding of the USA, it was centrally located with respect to sea travel. Travel was reckoned not in miles, but in time. A sea voyage from Maine to Washington did not take much longer than from Georgia. In a land locked nation, this may not be a great deal different. The capital would be located within X days travel from the outlying regions. If there is mountainous terrain, it may look closer on a flat map, but the journey would take the same amount of time as travelling a long distance over a well paved flat road. The next geographical distortion comes with some of the things we associate cities with, like access to water, trade routes, and defensability. A castle in a rocky wasteland is no good if there is no water. A city in the middle of a plain next to a river needs to have the fortifications beefed up for defense. Finally, no one wants to live in a place where merchants aren't going to come by and sell you stuff. So your capital needs to balance these things. Water is really the only deal breaker here. To sum up, get a map of your country and put your finger in the geographical center. Then shift your finger around a bit until you find a spot that is: 1) roughly equal in travel time to reach 2) has water 3) Can be defended 4) has people willing to sell stuff coming by That is where you put your capital based mainly on geography. [Answer] If I were to generate a formula, I'd tie it to the country's source of wealth: * Countries with trade wealth have coastal or river capitals (UK, China). * Large agricultural countries might have an artificially-created internal capital. (USA, Brazil, Russia) * Countries with raw mineral resources might pick a small city near the resource (in the mountains or in the desert) over a large trading city on the coast. In each case it's basically moving the capital to where the wealth is created. [Answer] Yes. 1. Trade routes. In the case of a coastal country, the best trade route is probably at a coast. In the case of a landlocked country, it is in a crossing of the natural trade routes. 2. Defensibility. For example, this was the reason why the capital of the old West Germany was near to its most western point (Bonn). They were prepared to a large-scale Warsaw Pact attack from East. 3. Historical reasons/social impedance. It means also (1) and (2), but not on the todays view, but in the historical views (for example, in the medieval era, it mean a top of a mountain somewhere in the center of the country). 4. Political reasons. Sometimes the capital is built intentionally in a low-importance location, as a deal of the local, concurrent sub-powers, all fearing that the others will use against them that the capital is by them. An example is Washington D.C. If we check the map, (1) and (2) are the most important, although they often mirror historical views on (3). [Answer] The difference between state and non-state culture is specialization of subjects. In a non-state culture, everyone is somehow involved in decentralized food production, while states tend to have lots of people in other roles, so they need to redistribute food from the producers to the specialists. For this, the food needs to be accessible to the state, so (specialized) soldiers can visit farms and confiscate grain to keep the army fed. This requires that farmers switch to produce that is easily measured, can be transported, doesn't spoil quickly and is ripe at predictable times. In the western world, that is mainly wheat and corn, in Asia, it is rice. This usually leads to a monoculture, which degrades the soil, so for a state-building project to be successful over time, there needs to be a mechanism to replenish nutrients, such as a river with a yearly flood. Thus, the capital for an agrarian society is located 1. in the plains (no obstacles to army movement, so maximum area of influence) 2. near a river (water and nutrient supply) 3. somewhat near the mountains (spring flood still needs to carry soil) States based on overseas trading have their capital in a harbor, and states based on strategic location along trade routes have their capital placed at the strategic location, but both are normally integrated into an agrarian state during the course of history, as agrarian states can maintain significantly larger armies. [Answer] Expanding on Paul TIKI's and Mikey's answers and focusing on your two statements: `how would you define what city would be the capital based on geographical localization?` and `ancient / medieval technology and culture` First, lets establish some times. Ancient would typically be from about the rise of Greece to the fall of Rome. Medieval is the period between the fall of Rome to about Christopher Columbus' "discovery" of the Americas. Based on those timelines, most medieval capitals were already established ancient capitals (with a few exceptions), and all capitals were already established cities. The largest factor behind the establishment of ancient cities is geography. How easy was this land to defend? How fertile is the land? Food was tough to come by in ancient times. The second largest factor is the travel time. Can we get the food there before it spoils? How quickly can the populace get to the defensible spot? By the way, there are some fascinating isochronic maps showing the travel times. Here's one showing how long it took to get to Rome: [![Travel time to Rome](https://i.stack.imgur.com/BETHo.png)](https://i.stack.imgur.com/BETHo.png) Sure, water and trade help a city grow, but those fall under the auspices of its defensibility. E.g., how long can you defend against invaders without water or food? Plus, rivers are just another natural barrier against invaders. So ultimately, the largest factors are a natural barrier like a hill or river and a source of water. Looking at this [list of the top 10 ancient capitals](http://www.livescience.com/11347-top-10-ancient-capitals.html): * Rome was founded on Palatine Hill next to the Tiber River. * Athens was founded on The Acropolis. The Cephissus river, the Ilisos and the Eridanos stream were its main water sources. * Byzantium (later Constantinople then Istanbul) started as fishing villages on Seraglio Point, and although it lacks a hill, it is surrounded on 3 sides by the Bosporus. (I personally think the lack of a hill played a part in its continual changing of hands throughout the centuries.) * Babylon lacks a hill like Byzantium, but it too was almost completely surrounded by the waters of the Tigris and Euphrates rivers. * Cuzco was built high up in the Andes in the Urubamba valley and only guns and smallpox allowed it to be taken. * Tenochtitlan is built in the middle of Lake Texcoco. * Thebes was built in the Theban hills along the Nile river and may have been the most populous city in the world at one time. * Great Zimbabwe was built in the Zimbabwe hills between the Limpopo and Zambezi rivers. * One of China's first capitals, Xi'an, was founded at the foot of the Qin mountains along the banks of the Wei river. With 7 more rivers nearby, it had ample water and natural barriers. * Cahokia was founded along the banks of the Mississippi river near modern day St. Louis, Missouri. * Jerusalem was founded on a hill near the Gihon spring. I find it interesting that mound building civilizations all had capitals that were not founded on a hill (counting the pyramids as mounds). So, to determine which of your cities will become the capital, decide how to attack it with an army of spears, bows, and (maybe) horses. If you can't devise a winning plan, that's your capital. [Answer] Modern capitals tend to be located close to borders; however they usually were located more centrally in the past. The most important example being Vienna and Bratislava, which turned into border cities (at least the latter) after the separation of the Austro-Hungarian empire. [Answer] In addition to the various factors discussed by the other posters, there are a few that also need consideration: Defense. A capital city (or indeed any city with wealth in this era) needs to be defendable from most types of attack. Wealth is a magnet for brigands and marauding armies as well as merchants and artisans, and the merchants and artisans are not going to appreciate being overrun and pillaged on a regular basis. This is usually provided by looking at the local geography to limit the areas of direct approach, ensuring there is access to adequate water supplies at the very least and enough building materials nearby to make raising walls possible without breaking the bank. Access to agricultural supplies. Building a capital city high in the mountains because it is close to the silver mines might make sense because this is where the money is and it is easy to defend, but if no one can be fed, then there are going to be a few issues. Religion and culture. Some capital cities or major centres are built around religious or cultural sites. Some may have to move because they celebrate a religion or culture which is at odds with the new ruling class or people, or the new rulers of a conquered area may have to adapt in order to make ruling their territory easier by appeasing the natives (provincial capitals might have to take this into account if the province was conquered). Co opting the natives is usually a lot easier if you leave them with symbols and tokens of their own to cling to. [Answer] Capital designation has a number of causes. But luckily you have it refined to medieval capitals. I'll work with your assumptions: * "Medieval" (European, I'm guessing? Not Islamic or Eastern) * "Geography should be the first cause" * "All cities have ... the same traditional, economic, religious or political relevance" I will also use Madrid, as it is my favorite (as an Urban Planner) for description of historical European medieval urban study. Geographic Distribution After centuries of conquest by different cultures, when Spain established its rough borders after Reconquista (post-Islamic takeover) and determined the capital to be centrally located in Madrid, or مجريط (Arabic: Madzjreetdh). [![enter image description here](https://i.stack.imgur.com/4FyGH.png)](https://i.stack.imgur.com/4FyGH.png) It was central to all of the provinces and cities. But that's not all that contributed. Access to Resources Resources were accessed by river - accessibility that is critical to a European medieval city. Travel by river, sea, ocean was much faster than by land. Access includes information as well, not just goods. Religious and political players can get to a medieval city much quicker, from which everything could be spread. But that, too, is not the only factor. This also contributes to the size of a city, being the crossroads of so much trade. Structural Both defensive structures and symbolic/civic/religious structures help make a city most prominent in 1500s Europe. Sitting on a rise, as though to look over the whole territory. [![enter image description here](https://i.stack.imgur.com/ypTzP.jpg)](https://i.stack.imgur.com/ypTzP.jpg) Cultural Some medieval capitals were established from cultural/religious ties, but I don't think that's what you're looking for, since you stated that they all have the "same traditional, economic, religious or political relevance." *Again, there are a bajizillion reasons to make a city a capital, but these were the most relevant in medieval Europe. In other places and other times, there are other factors.* [Answer] How are capitals chosen? Growth or Placement Growth Most capitals are chosen by growth, we pick the largest or wealthiest city in the country and make it the capital. In this case what makes a capital is what makes a city large: good trade routes, good water supply, good place to build. This encompass the majority capitals (London Paris Cairo Moscow and so on). Placement Sometimes a political decision is made to make something other than the largest city the capital. This can be a political compromise between factions (Washington DC), an attempt to urbanize an area of the country (Brasilia), or an attempt to move the capital to safer territory (Tel Aviv vs Jerusalem speculation about moving Seoul south) [Answer] There are a few factors which can influence where a capital city ends up being. One important consideration is how long the state in question has existed with a reasonable stable government administration. Historically (ie around the middle ages) the capital city didn't functionally mean much and often Royal Courts would move around according to the personal preference of the ruler and the season. In an era of poor communications this also allowed the monarch to have more direct influence than they might by staying in one place. There is also the fact that capitols will tend to gravitate towards major trading hubs as they will have good connections both within the state itself and with the outside world and naturally be a focus of both civil and military power. So many capital cities are either on the coast or a major navigable river or other trade hub. London is an obvious example of this. Equally many modern countries, especially in Europe, are the end result of the amalgamation of several smaller autonomous states so it may be that the ultimate capital was the seat of the provincial dynasty which ended up on top. In many countries the capital was pretty much fixed before industrialisation took hold so it is less common for industrially based cities to be capitals. There may also be historical drivers associated with a sense of national identity for example a city which grew up around a stronghold of a historic figure considered to be of particular national importance. Indeed for countries prone to invasion there may have been a tradition of establishing the seat of government in a defensible location. There are also plenty of examples of cities which were planned more or less from scratch as dedicated administrative capitals, regardless of economic size. Canberra in Australia is a good example and to a degree, Washington DC. This is often the case with countries which made a fairly rapid transition to modern civil government. Equally there may cases where the capital has been deliberately moved to break associations with previous regimes, especially in large states with a complex imperial history like India, China and Russia. [Answer] The key to the question is the assumption that: ``` all the cities on a given country have the same traditional, economic, religious or political relevance ``` In real-world examples, there is usually a city with greater relevance, such as an existing historic, symbolic capital. But in this problem, we are assuming that all cities are equally un-symbolic. In a medieval/ancient culture, the various power centers are likely to struggle for supremacy to set up their absolute monarchy. Think Shakesperian machinations and many battles. Today we call this a civil war. Eventually one group will emerge triumphant. Since there is no historic, symbolic capital (London, Paris) for the victors to seize, they will remain where they are - located with their power base. Their city, wherever it is, will become the new capital, and with each passing year will acquire the symbolism of the national capital. Future aspirants to the throne will want that symbol, regardless of location. Is there way to predict which of the otherwise equal cities will emerge triumphant? Not with the given assumptions that the cities start out equal, and that the culture is medieval/ancient. In this artificial case, the other factors (water, central location, defense) may matter...but less so than clever politics, fortune in battle, and a plentiful supply of luck. ]
[Question] [ Since the invention of hard road surfaces, a centaur would need to wear metal shoes like any other horse-like creature. Can you see any barrier to a suitably qualified centaur (a) being a blacksmith/farrier and (b) shoeing him or herself when the need arises? > > Notes > > > If possible I'd like answers from people who have knowledge of horses and their anatomy - and especially farriers of course! > > > I included the biology tag because anatomy and veterinary > science were not available. > > > [Answer] Short answer: A centaur can't reach his own hooves, but can reach the hooves of others by lying down or kneeling. One centaur can maintain the hooves of another. Better answer: There are a few reasons why horses wear shoes: to keep their hooves from cracking on paved roads; to gain better grip on cobblestones, in slippery conditions, or during races; and fashion (some horse shoes have a leather portion against the hoof to make them look nice for horse shows.) Centaurs would wear shoes for the exact same reasons. If centaurs built a city, I doubt they would pave the roads, per se. They would probably install something akin to a polo pitch, which could be tended by horses, goats, etc. who would eat the grass and keep the pitch clear for centaurs to gallop through. Hale and hearty centaurs would likely not need shoes or a farrier because they would take plenty of exercise in the fields where they don't need shoes and will wear down the hooves enough that they don't need trimming. Sick centaurs who can't run around for a time would grow hooves that would need trimming. The need for a farrier would probably be associated with poor health and would thus be stigmatized. For humans, long fingernails are associated with a life of leisure because one cannot work manual labor and maintain long nails. You might think this would be the same for centaurs and their hooves but it only applies to their fingernails. The hooves are a centaur's toenails and nobody has anything good to say about long toenails. In fact, excessively grown hooves can cripple a horse or centaur. Because shoes can only be installed by another centaur, they would be essential indicators of civility and sociability - you can't have shoes if you can't get someone willing to put them on you. Shoes would be a status symbol. The fancier and more difficult they are to put on, the better, because it means that someone else took a lot of time to service your feet. Barefoot centaurs would include: barbarians/wild centaurs; low class, poor, or rural centaurs; those who prefer to live a simpler life (hippy centaurs); and higher class centaurs who are counter-cultural for some reason (maybe in protest). Rich, high status centaurs would flaunt their wealth and status with elaborate, difficult shoes. Military centaurs would have studded shoes for difficult terrain. Athletes would have specialize shoes for their sport. (Race horses wear lightweight shoes for racing. These wear out after just one use. Their only purpose is to reinforce the foot for the duration of the race.) Injured centaurs would wear remedial shoes to repair their gait and help them heal. [Answer] In both cases, size is a problem. In terms of being a blacksmith/farrier, the issue is height. If a centaur is a "normal" horse's body with a "normal" human torso in place of neck/head, since the center of a horse's torso is about 4 feet off the ground, that puts normal shoulder height for the trunk about 6 feet up. It would be an enormous strain on the farrier to have to bend over far enough to get access to the hooves. And the second part, can a centaur shoe himself, is worse. Unless the standard centaur is based on a pony body, the body is just too damn big. E.g. this [Testing Two Methods of Estimating Horse Weight](http://www.cowboyway.com/HowTo/HorseWeight.htm) page gives a rough estimate for length for a 1300 lb horse as somewhere in excess of 5 feet. From hips to shoulders on a standard human is in the vicinity of 2 feet. Even assuming a massively flexible spine on the human part, allowing a 180 degree twist, a standing centaur can't reach its own rear hooves. And trying to do it lying down, with the torso bending down and around the stomach while the rear legs are pulled forwards, would seem to require an improbable hip/spine flexibility. [Answer] This is a little lateral but i think it applies I don't think centaurs would use horseshoes. Horseshoes are put on horses because they are stupid. You need to add something that fits snug, and the horse will not remove. I think centaurs would wear shoes more like humans. They should put them on in the morning and then take them of at night. With their hands they could handle lacing the shoe. Reaching the back feet may be hard, but it is defiantly easier than nailing in a horseshoe even if you do need to do it more than once. Perhaps a tool could exist to help lace the shoes if aid from others is not available I think it is very unlikely that a sentient creature would like to have something nailed on to it, even if it is not painfull [Answer] Is a centaur who insists on shoeing his own feet like a human who insists on cutting his own hair? Or more like one who insists on doing their own dental work? At any rate, I've never shoed a horse, or indeed even done my own cobbling work, but if I was the last centaur on Earth--er, Narnia?-- I'd probably try to use molds to get an idea of the shape of my hooves. If I had access to plaster-of-paris, that'd be ideal, but maybe even mud would work. I'd step into the goo while it was soft, wait for it to set up, then use the resulting mold as a model for my farrier work. If I really wanted to get fancy, I would use that "negative" mold to cast a positive copy of my foot by pouring yet more goop in it and waiting for that to set. I could use that to shape the shoe, but I don't know how I'd affix the shoe to my hooves. Maybe if I had access to a power drill I could mount it sticking up out of the floor, and very carefully drill out a hole, but I still don't know how I'd get the nail in, unless I just stomped it in. Even so, I've never heard of a centaur with a power drill. [Answer] I think in a society where centaurs exist it seems likely that shoes would look different. Probably something akin to ski boots that they could step into and have click into place and then be removed with a bit of cross legged stepping on switches at the back to release the clasps and step out again. More ornate shoes with decorative bits that go up the leg like ribbons and such would probably require a stool to lift a leg on to so the human arms could more reasonably reach these and would be limited to the forequarters as opposed to the hind. [Answer] They could have a machine that had all 8 drill bits sticking up vertically in the correct horseshoe nail locations, and were only half an inch or so long. It would have a simple controller attached to a wire. This way they could just turn it on, step on it with each foot, then just step on the horse shoes that probably have all 8 nails built in. The nails would be slightly thicker than the holes. Other idea that I just thought of, you get a magnetic plate hammered into your hoove one time, and that way you can just put a shoe on. When it wears out, slide a new one on. [Answer] There are a lot more to horseshoes than just nail one iron shoes. Hipposandals are tieon or buckled horse shoes, and are easily removable, a big bonus ofr an intelligent species. [![enter image description here](https://i.stack.imgur.com/CTJSz.png)](https://i.stack.imgur.com/CTJSz.png). most shoes these days are glue one shoes which reduce the risk of splitting the hoof, since centaurs are intelligent I doubt shoes need to be nailed on. Perhaps for soldiers or slaves. [![enter image description here](https://i.stack.imgur.com/b8xhx.png)](https://i.stack.imgur.com/b8xhx.png) Then you have woven shoes, wooden wide bogshoes for soft ground, anti-fungal copper shoes, there is a large variety of horse shoes and I expect an intelligent hooves species to come up with many more just as humans have come up with thousands of types of shoes for different things. [![enter image description here](https://i.stack.imgur.com/kIunm.png)](https://i.stack.imgur.com/kIunm.png) [Answer] Well, having seen the very useful answers of others, an idea has just occurred to me. Surely the centaur farrier could use long-handled tools in conjunction with a mirror. The only problem about this, is making a hammer that can work around corners. I think that the drilling and stomping idea that has been put forward is possible. In these days, all sorts of electronic and electrical devices could be designed, as well as using a personalised jig for each hoof. Even hand-driven tools that were floor-mounted would have been possible in pre-industrial times with the necessary ingenuity. ]
[Question] [ Let's say that in a different world, humans evolved to have horns (e.g. Demons in many fantasy stories). Where would those horns be placed on the head, in regards to actual creatures with horns? I've seen depictions with unicorn horns, horns on the side of the forehead, back of the head, etc. So which spot on the head would best correspond to, say, deer antlers? It doesn't matter how or why humans would even have horns. Instead, if we had deer/antelope/buffalo or whatever horns, where exactly would they be on a human skull? I have a hard time imagining a deer head morphed to be human like. On some deer skulls, it seems horns would be growing on our eyebrows, on others like it would be behind the ears. [Answer] First of all, it’s worth noting that there is probably no practical reason for a human-like creature to evolve deer-like antlers. Humans are too fragile and don’t have enough mass to “charge” and use them as weapons, and bulky antlers would probably hinder humans’ ability to climb trees (by getting tangled in the branches) and hide in small crevices. That being said, I can only think of one plausible mechanism by which humans might evolve antlers: [Fisherian runaway](https://en.wikipedia.org/wiki/Fisherian_runaway). In this process, a trait that is advantageous for sexual selection becomes exaggerated and overdeveloped despite having no survival-related function. The peacock’s ostentatious plumage is a classic example of this. So, at some point in the past, having smallish horns became “attractive” for humans because, say, they were indicative of good health. (“Look, not only am I fit and healthy, but I have access to enough extra resources to grow an entirely ornamental pair of horns!”) Then, because horns were considered attractive, humans evolved to grow more and more extravagant horns in a sort of sexual arms-race. To answer your question: if horns are ornamental and evolved via Fisherian runaway, you can pretty much put them wherever you want on the human head. Since they’re not used for any practical purpose anyways, it doesn’t make much of a difference. [Answer] Hair horns A *rhinoceros's horn* is distinctive, and the name "rhinoceros" actually comes from the Greek words for "nose" and "horn." But despite its size and strength, the horn is composed primarily of a protein called keratin--*the same substance that makes up human hair* and nails. <https://sciencing.com/horn-rhino-made-7499547.html> [![enter image description here](https://i.stack.imgur.com/0BWmu.png)](https://i.stack.imgur.com/0BWmu.png) There are several places that a human could develop hair horns; the beard, moustache, eyebrows, and head. They could be used for display and/or combat. --- Display horns [![enter image description here](https://i.stack.imgur.com/uiBeG.png)](https://i.stack.imgur.com/uiBeG.png) --- Fighting horns [![enter image description here](https://i.stack.imgur.com/dyqQM.png)](https://i.stack.imgur.com/dyqQM.png) --- Defence horns [![enter image description here](https://i.stack.imgur.com/Ay1cY.png)](https://i.stack.imgur.com/Ay1cY.png) [![enter image description here](https://i.stack.imgur.com/vujcS.png)](https://i.stack.imgur.com/vujcS.png) [Answer] Curling from the back of the head to protect the nape of the neck. Leopard are predators of primates and still attack people to this day. Horns that protect the back of the neck would protect against a leopard's favored attack. <https://en.wikipedia.org/wiki/Leopard_attack> > > ... This fossil evidence, along with modern studies of primate–leopard > interaction, has fueled speculation that leopard predation played a > major role in primate evolution, particularly on cognitive > development... > > > During predatory attacks, leopards typically bite their prey's throat > or the nape of the neck, lacerating or severing jugular veins and > carotid arteries, causing rapid exsanguination. The spine may be > crushed and the skull perforated, exposing the brain. > > > [![Curling horn on primate. Art by Roxy Read](https://i.stack.imgur.com/4JvK4.jpg)](https://i.stack.imgur.com/4JvK4.jpg) [Answer] If we're talking about true horns — protrusions of bone covered by keratin — then the two most natural positions on the human skull would be out from the temporal bone or as an extension of the brow ridge. The temporal bone, which lies behind the ear, is already the hardest bone in the human body, and it's well positioned to absorb shocks, redirecting energy to the neck muscles and away from possible concussive damage to the brain. Such horns would probably grow out, up, and forward, protecting the weaker bones in the sides of the face. This would also be an ideal place for deer-like horns: bone covered in skin rather than keratin, which are shed and regrown every year. On the other hand, most ancient primates had much heavier brow ridges (running at the top of the eye orbital) than modern humans. Exaggerating that characteristic would turn eyebrows into a keratinous covering over a long protruding ridge or series of spikes. I assume these would be defensive rather than offensive — meaning that they are meant to deflect or stave off a blow, not to inflict damage in their own right — because they would not be positioned well for attack. Even when humans head-butt, they use the top of the frontal bone, not the eye orbital; too much risk to the delicate eyes. On yet another hand, don't discount the possibility of tusks. Tusks are specialized teeth, which can grow from the upper or lower mandible. Because humans have an upright stance, I'd imagine their tusks would be like walrus tusks, growing down from the upper mandible, but with an outward curve. Though of course they could have lower-jaw tusks protruding up and out, like boars. This opens possibilities for self-scrimshaw, which would be cool, but orthodonture would be a nightmare. [Answer] I once read a zoology book which mentioned that some rabbits do have horn like growths on their heads. And here is a link to an article about it: * [Rabbits with Horns: Meet the Human Papillomavirus](https://io9.gizmodo.com/rabbits-with-horns-meet-the-human-papillomavirus-5795996) It is caused by a papillomavirus. Some papillomaviruses cause some types of cancer in humans. And sometimes papillomaviruses have other effects on humans. From the above-linked article: > > The discoveries of Shope and Rous led scientists to look at growths on other animals. Cows sometimes develop monstrous lumps of deformed skin as big as grapefruits. Warts grow on mammals, from dolphins to tigers to humans. And on rare occasions, warts can turn people into human jackalopes. In the 1980s, a teenage boy in Indonesia named Dede began to develop warts on his body, and soon they had completely overgrown his hands and feet. Eventually he could no longer work at a regular job and ended up as an exhibit in a freak show, earning the nickname "Tree Man." Reports of Dede began to appear in the news, and in 2007 doctors removed thirteen pounds of warts from Dede's body. They've had to continue to perform surgeries to remove new growths from his body since then. Dede's growths, along with all the others on humans and mammals, turned out to be caused by a single virus-the same one that puts horns on rabbits. It's known as the papillomavirus, named for the papilla (buds in Latin) that cells form when they become infected. > > > So it seems possible to me that a type of papillomavirus could evolve which produced horn like growths on the heads of humans, and if those humans were considered superior instead of inferior, humans with that virus could have greater reproductive success and over generations a larger and larger proportion of the population could be horned. Some humans do have features called "cutaneous horns", whci can be caused by sunlight or by papillomavirses. Here is a link to an article about them: * [Cutaneous Horn: Pictures, Removal, Causes, and More](https://www.healthline.com/health/cutaneous-horn) So the main problem would seem to be how to have the horns always grow on in the same numbers on the same parts of the heads of humans, instead of random numbers of horns growing in random places on the heads and other body parts of humans. [Answer] Since headbutting is not common combat strategy for humanoids, it would make more sense for them to evolve Wolverine-like claws or at least strong sharp bone knuckles to enhance punching, or tusks for devastating biting. ]
[Question] [ So a setting I had in mind has vampires, of the rather traditional kind. They aren't as inhumanly strong or fast, but in turn they aren't instantly incinerated by sunlight, instead just being really prone to sunburns. Here is the thing: "My" vampires still need to eat, but all their food has to contain some content of blood, either human or animal. Of course they wouldn't want to miss the chance of getting drunk if possible, so here is my question: Would it be feasible to make an alcoholic beverage with blood as its main ingredient? [Answer] It certainly should be and it should be relatively simple too. Take blood, heat blood to kill off any competition, add yeast, this is a fungus that turns simple sugars into alcohol, and wait for the yeast to do it's work, this usually takes a couple of weeks, then serve. There are some issues with this scenario that are peculiar to blood: * Most people have [very little sugar](https://en.wikipedia.org/wiki/Blood_sugar_level) in their blood to start with, yeast will have very little to work with, this will mean a very low alcohol content in the raw fermentation. * Blood is quite saline this will kill many yeast strains before they have a chance to do anything. Mixing blood with sugar water first will dilute its salt content and increase the sugar levels to the point where yeasts will be able to survive easily and have enough to work with to raise the alcohol content of the raw fermentation to something that will to be "worth drinking" (read will get you drunk relatively easily, think wine or beer rather than whiskey). [Answer] ## Yes. Sort of. [Snake blood wine](https://en.wikipedia.org/wiki/Snake_wine) involves fermenting the drained blood of a snake, along with its body. In some versions, the blood is simply added to the alcohol. [Winemakers on Quora](https://www.quora.com/Can-I-make-wine-out-of-blood) speculate that, yes, you can. But none have tried it. [Blood has been used for fining](https://www.vice.com/en_us/article/ypxjzg/theres-blood-and-bladders-in-your-wine) (removing impurities from wine) but isn't common now and also doesn't leave much, if any, blood in the mix. Blood also can be fermented into something edible ([for pigs anyway](https://link.springer.com/article/10.1023%2FA%3A1005015804804)). Overall though, you're much better off with fresh blood added to an alcoholic drink. [Answer] As other answers have noted, blood contains fairly little glucose (blood sugar), so that makes for weak drinks unless external sugar is added, or the glucose is somehow extracted and distilled separately from the rest of the blood. *However...* If you don't mind taking a dark turn, you could spin this into a world where human diabetics are farmed for high glucose blood. Diabetics can have much higher glucose levels than humans, and while that is a big problem for anyone suffering from diabetes, it could be an opportunity for vampire wine-makers. Wile normal blood sugar level would usually be below 7.8 mmol/L 2 hours after a large meal, diabetics can go higher - much higher. In 2001, a diabetic was admitted to a hospital with a glucose level of 147.6 mmol/L (source: [Guinness World Records - highest blood sugar level](https://www.guinnessworldrecords.com/world-records/highest-blood-sugar-level/)) So you could have an economy where "harvesters" track down and capture "Gilberts" (makers of vampire wine call diabetics Gilberts, after the movie Gilbert Grape), and them bring them to "wineries" where they are force fed candy (and probably also alcohol) until glucose levels spike to a lethal level, where upon they are murdered by having the sugar-rich blood drained to a fermentation tank. Even if the blood loss did not kill the victim, the high glucose level would, from organ failure. Some blood farmers probably prefer to keep their grapes "on the vine", meaning that they are kept alive for longer periods of time, with blood drained over a number of sessions - perhaps they are even treated with blood transfusions from non-diabetics (whose blood is less valuable to the vine maker). Keeping Gilberts "on the vine" is also referred to as "milking"; most blood wine connoisseurs prefers wine from sources that have been "squashed" (all blood drained in a single session), these wines are seen as more pure - where as milking Gilberts is seen as cheating/low quality. [Answer] The cheating way to do is to just add distilled alcohol to blood. [Answer] # Totally Feasible # *BUT* There's a caveat: Blood is composed of a number of components: various kinds of cells[(1)](https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P02316) and a liquid suspension[(2)](https://www.news-medical.net/health/Blood-Plasma-Components-and-Function.aspx). The solids are the cellular bodies: red blood cells; white blood cells (lymphocytes, monocytes, eosinophils, basophils, neutrophils) and platelets. The liquid plasma is mostly water (good for making alcohol) with a number of proteins (albumin & fibrinogen), clotting factors, ions (the usual suspects), dissolved gasses, nutrients & wastes. [Normal blood sugar](https://www.webmd.com/diabetes/qa/what-are-normal-blood-sugar-levels) range (human) is 90 to 130 mg/dl; [Concord grape juice](https://cspinet.org/news/cspi-whacks-welchs-over-deceptive-health-claims-20120814) contains 36000mg of sugar per 8oz of juice; 8 oz is about 2 1/3 dl, so about 302mg of sugar in an 8oz serving of human blood. Weight per weight, you get about half the amount of alcohol as you had sugar[(3)](http://wineindustrynetwork.com/uploads/tips/gqRwa10bvFXsGDBIHfLKmE7A9yjiCt.pdf). So, 300mg sugar in the blood will give you something less than 150mg of alcohol whereas 36000mg of sugar in the grape juice will give you something less than 18000mg of alcohol. If I did the [maths](http://www.cleavebooks.co.uk/scol/ccalcoh4.htm) right, your grape juice wine is about 19proof while your blood wine is about 0.02proof. Your vampires aren't going to get very drunk off this stuff. [Answer] I'm going to look at this in a different manner, instead of making alcohol out of blood, you could instead increase the BAC for the blood itself to have a greater kick. You could simply feed alcohol to an animal until it drops dead from the amount of alcohol and then serve that blood. ("straight from the vein") Look [here](https://what-if.xkcd.com/98/) for the inspiration for this. Basically, if you use adult humans you would get something mildly alcoholic but it might have a better effect with some other animals (or even babies). It's up to you to decide what your vamps are ok with. \*Note that there is no making an alcoholic beverage here, it's simply getting blood that can also get you drunk. (Also humans can get a surprisingly high BAC before they kick the bucket) [Answer] As @Cyn already mentioned, bloody beverages exist. Now take into account not all bloods are equal. Ours is Iron based, Horshoe crabs got Blue blood due to Copper. Sking got Green due to biliverdin. So feel free to order some wide array of Pints, shots and cups at your Undead friendly bar. [List of colours and typs](https://news.nationalgeographic.com/2015/03/150312-blood-antarctica-octopus-animals-science-colors/) ]
[Question] [ Most of the quasi-medieval world include nomads, most often there is only one culture of nomads and they are accompanied with the footnote "inspired by the Mongols". Even when that isn't the case, the audience might assume that. I find the overused quasi-Mongols tiresome. So, are there any historical characteristics that could be applied to steppe nomads to set them clearly aside from the horse lords of Mongolia, considering that the Mongols were only a group of thousands of steppe nomads? [Answer] You could easily create your own nomads and there are many historical inspirations. * Nomads have herds of herbivore animals. The mongols and native americans have horses, the Tuareg have goats and camels, the Sami people have raindeer, other african nomads like the Massai have cattle. * Nomads need to move periodically because their herds won't find enough food in one place year around. * Since nomads live in areas of scarce vegetation, almost all of them use the dried excrement of their animals as fuel for cooking. * To move, nomads need movable accomodations. These are typically tents, but have different shapes and are made of different materials, depending on the environmental conditions and the available materials. They are usually in a very simple, yet stable way and can be erected and disassembled within half an hour. * They have little possessions, because everything has to be moved. * Nomads care for their animals because they secure their life. The female animals are milked to produce dairy products, the meat is eaten, the skins are worked into clothing and even the bones are used as tools. * Having big, ridable animals aids the nomad lifestyle, but is not neccessary for it. * Their animals, the nature and environment usually play a big role in their traditions and religions. They are so dependent on the weather that they often can "read" the atmosphere and predict the weather. [Answer] There are plenty of nomadic people outside of central asia. How about the [Plains Indians](https://en.wikipedia.org/wiki/Plains_Indians)? [![Lakota camp](https://i.stack.imgur.com/L9ex5.jpg)](https://i.stack.imgur.com/L9ex5.jpg) <https://ancientexplorermagazine.wordpress.com/2016/07/07/origins-and-culture-the-lokota-indians/> The different Amerind groups under this designation lived a nomadic life, following the bison herds. When horses became available it make that easier. --- Africa has many groups of nomadic people. The [Maasai](http://maasaiwilderness.org/maasai/) are nomadic pastoralists and the people and cultural regalia are spectacular. They would be a fine basis for a fictional nomadic people. [![masai](https://i.stack.imgur.com/58OIH.jpg)](https://i.stack.imgur.com/58OIH.jpg) --- If you want to base your people on Europeans you could read up on the [Sami people of Finland](http://www.pilotguides.com/articles/the-sami-people-of-lapland/). [![sami people](https://i.stack.imgur.com/FeheE.jpg)](https://i.stack.imgur.com/FeheE.jpg) > > The Sami are a nomadic people, and in the summer months many still > live in their tepee like homes, known as Katas, which can easily be > taken down and reconstructed in a different place as the people move > across the country with their animals. > > > My understanding is that the reindeer are somewhere between the North American bison (wild) and the African cattle (tame) - semidomesticated. --- Any one of these could be a jumping off point for pastoral / semipastoral nomads with lifestyles superficially similar to the nomads of central asia. [Answer] You could give the nomads an indo European sounding language and names, like the more or less Iranian steppe nomads of antiquity like Scythians, Alans, etc. Or you could give them language and names like some of the horse riding plains Indians of North America, or even South America. [Answer] Amazons (the classic north-east-of-Greece kind). Or at least an equal-opportunity tribe, which might be revolutionary enough for your setting. For those who know a bit of the classics, make a clear link to the [Sarmatians](https://en.wikipedia.org/wiki/Sarmatians). ]
[Question] [ I am trying to design my main character in my post-apocalyptic series to have a very dense, organic, durable skeleton. The skeleton should also be able to handle gun fire, a sledge hammer impact, as well as gamma rays (and other ionizing radiation). My idea was to have an osmium, iron, and carbon nanotubes structure organically woven to get him to make a dense, durable, armor that can handle a lot of kinetic energy, like machine gun fire. The character already has very strong muscles and padding around the organs. Does this seem realistic, or is there a better way to go about this? Where she gets the osmium isn't important; just applying it to her biochemistry is. [Answer] @Slarty is right. Osmium is poisonous. So that is your answer. But here is a way to achieve what you want: you want something that can be in bones and is crazy dense. Elements in the periodic table below calcium can mimic calcium, and they turn up in bones. Strontium can mimic calcium in bones and [some people take it as a supplement to prevent osteoporosis](http://www.berkeleywellness.com/supplements/minerals/article/new-supplement-old-bones). [Radium](https://en.wikipedia.org/wiki/Radium) is also treated as calcium by the body and winds up in the bones where its radioactivity causes trouble. What if there were a superheavy element which was also treated by the body as calcium? It is theorized that an [island of stability](https://en.wikipedia.org/wiki/Island_of_stability) exists above atomic number 120, at which point elements once again are stable. [![pykkos periodic table](https://i.stack.imgur.com/FQ1of.png)](https://i.stack.imgur.com/FQ1of.png) <https://upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Pyykko_periodic_table_172.svg/800px-Pyykko_periodic_table_172.svg.png> So: your hero has bones made superdense with element 166 in place of calcium: more than twice as dense as osmium. There exists a condition called osteopath cutis: those interested can google up these medical images. Lesions start as skin inflammation and then ossify, forming plaques of normal bone within the skin. Your heroine can have these all over her. She will not be that cute, but a plaque of superdense bone could stop a bullet, and then heal if it were cracked. Sludge hammers I am not sure about. But I am very enthusiastic about them. [Answer] Strength: look at [Mantis Shrimp clubs](https://phys.org/news/2016-05-mantis-shrimp-ultra-strong-materials.html). They're lightweight and much stronger than osmium - or titanium steel for that matter. And they're organic. No problems in harvesting osmium, no need of drastically changing the metabolism to survive osmium toxicity. For significant gamma ray protection, you'd need way too much osmium; better do this another way, through redundancy and cellular repair mechanisms. [Deinococcus radiodurans](https://en.wikipedia.org/wiki/Deinococcus_radiodurans) is able to sustain with no damage a radiation dose one thousand times lethal for humans. Which means that adding Deinococcus repair mechanism to your creature would gift it with the same raw radiation resistance as an [osmium carapace 1/3" inch thick](https://physics.stackexchange.com/questions/239372/x-ray-shielding) (the values in the link are for X-rays, but the attenuation curve is not too different from gamma), with next to no weight increase. As CJ Dennis pointed out, this does not translate to the same resistance as a bacterium (a vertebrate has lots more DNA that can be damaged, even if [information density is lower](https://books.google.it/books?id=hADLBAAAQBAJ&lpg=PA196&dq=Shannon%20redundance%20in%20bacterial%20DNA&hl=it&pg=PA196#v=onepage&q=Shannon%20redundance%20in%20bacterial%20DNA&f=false), which contributes to the resistance: humans have around 20,000 genes against Deinococcus' 3195), because part of that resistance is obtained through multiple copies of the genome, which can't be easily afforded by higher organisms. Even so, the DNA-repair mechanism is believed to be responsible for the greater part of the high-intensity radiation resistance, which would make a 200x increase in radiation resistance at least believable at first glance. A DNA repair mechanism would also have the benefit of making all internal organs resistant to radiation, not just the bone marrow. # Additional protections You can also add a thick water and fat layer as an added shielding (and energy reserve). Another useful mechanism would be a (possibly on-demand, as it is biologically expensive) production of [antioxidants](https://en.wikipedia.org/wiki/Oxidative_stress). This might be indirectly a danger to your creature, if e.g. its blood came to be regarded as a long-life elixir. There is also the possibility of a passive defense, by allowing the creature to feel radioactivity. Humans can sense radiation only very roughly by detecting the chemical species generated by ionizing radiation (this has been variedly described as a "dry, metallic taste", a "[sour taste in the mouth](https://en.wikipedia.org/wiki/Louis_Slotin#Criticality_accident)" or an "acrid smell") - and then there's [phosphenes](http://www.ingentaconnect.com/content/asma/asem/2006/00000077/00000004/art00012;jsessionid=2jhibd387hivo.victoria). Normally, though, the dose required to have a detectable and reliable effect on the taste buds is high enough to be lethal (Rutherford claimed he could tell isotopes by smell, and he did not drop dead when doing so, but that claim might well be apocryphal). A higher (photo-)chemical sensitivity and a specialized organ - a sort of third eye, heavily screened except from a single direction - would allow the creature to sense radiation precisely enough to actively avoid the worst areas, or wiggle a safe path between contaminated areas: gamma contamination isn't really ubiquitous, but it follows the chemical contamination of its originating isotopes. That's why, for example, some kinds of contamination are associated with thyroid cancer - because their main isotope is 131I, which is chemically identical to stable iodium, and as such is accumulated in the thyroid. Whatever sluices off iodium will also get rid of most of its associated gamma and beta radiation. A biologically more complicated defense would involve an even more detailed detection of the source isotopes. Biologically irrelevant ones could be kelated and quickly disposed of, while those biologically relevant could be defended against by adaptive metabolism: e.g., the creature builds up calcium reserves, and when it detects a 90Sr contamination it stops absorbing calcium from food, living off its reserves. This way, the normal strontium contamination pathway - it gets picked and fixed in the bones by osteoblast cells, that mistake it for calcium - is negated. Such a detailed defense would almost have to be engineered in, though. Also, some substances (e.g. 14C - rich carbon dioxide, as well as oxygen and nitrogen isotopes) still could not be shielded against. Stem cell production could help somewhat, but it would require a specialized, shielded organ to churn out [totipotent stem cells](http://www.explorestemcells.co.uk/totipotentstemcells.html); otherwise, each organ would have to produce its own line of specialized (or at most pluripotent) stem cells, which would require shielding almost everywhere. [Answer] Sure..... First, just because an element shares the same ionic charge with other elements does not mean it can be swapped out in a molecule and it retain the same properties or take on the properties of the replaced element. Atomic mass does have an effect or molecular properties. Also, in many many cases, its not what elements are present in a material that give it its properties but how that material is constructed that gives it its properties. For example let us look at the humble [Abalone](https://en.wikipedia.org/wiki/Abalone) Its shell is bulletproof. Its shell is made of Calcium Carbonate crystals (calcium, carbon, and oxygen) glued together with a protein (Possible elements being: K, N, O, H, C, Ca). In other words a slimy undersea mollusk managed to make a material stronger, thinner, and lighter than solid iron. Using nothing more than common elements. Spider silk is another example. It is produced by weaving long protein chains together into a thread which we can weave into a T-shirt which can catch a bullet. Can you shove osmium into an exoskeletal structure? sure, but is it practical? probably not. what about the gamma rays? Technically, not even osmium armor can protect you from strong enough gamma rays. Like lead and radiation it only curves the exposure dependent on its thickness. [Answer] No. Osmium cannot replace Calcium Osmium tetra oxide is highly poisonous, so you would have to rearrange human biology to avoid that issue. Nanotubes made of Osmium, carbon and iron don’t sound very likely either. I think you are trying to fit too much functionality into this exoskeleton. It would be much easier to use magic and be done with it. Osmium's extreme density would also make it extremely unwieldy. A body armour surface area of 2 square metres coated with 1mm of Osmium would weigh 45kg ]
[Question] [ Commander WE NEED YOUR HELP Aliens invaded three days ago and they have been slaughtering us, but now we might have information to fight them. Many soldiers have died to bring you this information use it well, The aliens also called mimics are large quadrupeds formed out of ductile metal with long feelers they use to strike at their foes. They can also launch high speed explosive projectiles, that are fast enough to even target aircraft. They are damage resistant but can be killed with high caliber bullets. They can also burrow for concealment and surprise. They are organic EMP did not effect them. This is not the worst - We believe they can reset time. During the initial landing in eastern Europe we launched several sets of nuclear strikes against them and each time before we even launched the missiles they all burrowed underground, or by impossible luck managed to intercept the missiles. There is a subspecies called alphas that we believe reset time when they die Many troops record fighting alphas but no one has ever successfully killed one. It appears that time is reset the most recent dawn, and no farther The Russians laid a massive ambush out around the city of Kursk, with 1/4th of the worlds artillery and thousands of tanks. The mimics blissfully continued walking into the trap for two days until the dawn of the day when the trap was going to be sprung. At dawn, they suddenly turned tail and fled out of the kill zone then they counter-attacked. Since they only reacted on the last day it implies they could not have reset multiple days back and destroyed our ambush even worse. We believe the number of resets is limited The mimics have made some mistakes that they could have fixed by resetting the day, this makes us think that they can only reset the day so many times, and so have to let some small mistakes stand. The armies of the world have united to fight this foe, a fact we would have thought impossible just days ago. China and Russia are preparing defensive works around the City of Stalingrad, Joint NATO forces are preparing defenses along the Marine, the CMEEF (combined Middle Eastern Expeditionary force) is advancing into northern Italy. We have used about 1/5 of our nuclear arsenal, both NATO and Russian lost almost 1/3 of their forces during the initial Mimic landing in Eastern Europe. We have troops but how do we fight an army that can reset time??? PS one Scientist suggested injecting Alpha blood into a human to give him the ability to reset the day but we have never been able to kill one, and it also sounds like a crazy idea anyway. [Answer] Greg Egan's novel [Teranesia](https://en.wikipedia.org/wiki/Teranesia) posits a similar situation: DNA is a quantum computer, and natural selection is drawing on many worlds. Any counter you can conceive of has already been tried and adapted to from a parallel universe. How do you fight disease that has already adapted to your cure? The answer is that DNA's predictive power is short sighted. It can only "see" so far into the future. It's vulnerable to being trapped in a [local maxima](https://en.wikipedia.org/wiki/Maxima_and_minima). If you offer it a very beneficial environment, say a jar of nutrient water, it will happily settle there and be trapped. The same can be applied here. If the aliens can only reset to the previous dawn, then you must make sure they only realize their mistake when it's too late. Lure them past the point of no return, make them think they had a good day, and only after 24 hours let them find out they did not. The other option is to make every alternative move a worse one, like the [strategy from chess known as pinning](https://en.wikipedia.org/wiki/Pin_%28chess%29). Give them a [Hobson's choice](https://en.wikipedia.org/wiki/Hobson's_choice) between a rock and a hard place. A change to save one army loses them another. Use deception and counter-intelligence to make them burn resets. Make them think a day went poorly when it actually went well. Make them think they could have done even better. Finally, if there's no other option, use randomness. Defeat their predictions by acting truly unpredictably. Make strategic decisions by flipping a coin, rolling a die, or looking at quantum fluctuation... anything where a [tiny change will produce a different result](https://en.wikipedia.org/wiki/Chaos_theory). Every time they reset humanity will act differently at a strategic level, and they gain no advantage. Instead of grand strategy, the war will be decided by thousands of small unit actions, and the actions of millions of individuals. Without their strategic precognition, they may fall to our small-unit tactics. [Answer] Infect them all with a virus/bacteria that takes longer than a day to show any symptoms- they can reset time all they want, but they're still infected and going to die. The only thing the time-resetting would help with is developing a cure... maybe. If possible, try to infect all the aliens at the same time so you only need a single viral strain. If that's not feasible, you'll probably have to engineer a couple viruses/bacteria to get rid of more than just a local population. You can toggle between the [lytic](https://en.wikipedia.org/wiki/Lytic_cycle) and [lysogenic](https://en.wikipedia.org/wiki/Lysogenic_cycle) cycles to get maximum impact. Idea courtesy of [H.G. Wells](https://www.gutenberg.org/files/36/36-h/36-h.htm) [Answer] If the reset is triggered by the death of an Alpha (as in the movie), you could try to run them out of resets by laying (nuclear) traps and triggering one just after dawn, so that the day would only reset a few minutes, not enough time for the Alpha to escape. This is a very dangerous tactic, because it is possible that the number of resets is not finite, but the Mimics simply decided to accept some losses to further some strategic goals. In that case, you may lock the world into an infinite loop. To implement the traps, hide suicide commandos with nukes at strategic places that are in the path of the Mimic army. The commandos are then to hide while the human armies retreat, listen to certain coded radio signals that indicate the detection of an Alpha and/or pop out of hiding just after dawn each day to check for themselves. If they don't find anything, they must lock up their hiding place again and wait a full 24 hours. [Answer] Being able to reset the game to a saved state is pretty much like being able to choose the best move to begin with. If there's no randomness involved, they are the same and it's just a lazy way to avoid the computation. So behave like you do in any strategy game: set traps that prevent the opponent from having any winning move. Make it more like a pure strategy game, removing sources of randomness when you have a winning strategy. But add randomness when you don't, because it might hurt them. With the limited number of resets, it approaches a pure strategy game in theory. (With an unlimited, they can just keep resetting until one side or the other died spontaneously due to quantum events.) The time limit in resetting is just like a look-ahead implementation limit in deterministic strategy. If things go well, and when you lay a piece of an eventual trap, stall the play and get past the reset horizon. On the other hand, when things go poorly (or intentional random things don't give the right outcome) force the opponent to reset, to your benefit. [Answer] I think everyone is mistaken. The aliens can't choose when time resets, we do. This makes resetting time when an Alpha dies an advantage for us humans. We could be on the verge of total, utter defeat, and as long as we kill one single Alpha we get to try again. All we need to do is use non-lethal weapons on Alphas. So we fight against the other aliens, and if it looks like they're winning, we execute one of our Alpha prisoners and try again. [Answer] Don't concentrate on killing them - try to drive them crazy. Since the aliens revive with all memories of an alternate timeline, some part of their "mind" cannot be fully recovered upon reset. You could try wiping out their memories, causing some sort of amnesia. If succeed, the alphas would revive without any memories of previous attempts. Wipe out all alpha's minds in one day (and kill one to trigger the reset), and this day will be looped and repeated until aliens run out of resets and lose. But causing amnesia in an alien specie sounds unlikely. Their brain should have different structure and chemistry, it might operate on something other than electricity, etc. So, just try disrupting it as strongly as you can. How? Idk. You say some omega aliens have been killed, so people could try to figure how aliens' brains function. Try overloading their brains with their own signals (electricity or whatever), try chemicals that simulate their "neurons", try chemicals that break connections between them. Just try everything and hope that "unrecoverable" part of their mind gets damaged. [Answer] As with [my answer](https://worldbuilding.stackexchange.com/questions/37242/how-do-you-assassinate-someone-who-is-protected-by-precognitive-people/37267#37267) to the very similar [How do you assassinate someone who is protected by precognitive people?](https://worldbuilding.stackexchange.com/questions/37242/how-do-you-assassinate-someone-who-is-protected-by-precognitive-people) my answer would be to lure the mimics into a trap where there is no escape regardless of knowing the outcome. To do this you need to lure them into a trap which was sprung more than 24 hours prior so that, by the time the trap is sprung, resetting to dawn wouldn't save them. For example: You bury nuclear landmines throughout a very large area and detonate them only once the mimic army has spent 24 hours inside the killzone. Some of the army at the edge of the zone will be able to groundhog back to the beginning of the day and escape, but hopefully enough of the army will remain trapped in the killzone and unable to escape in time. [Answer] > > It appears that time is reset the most recent dawn, and no farther > > > 7:04 am and 2 seconds. [![sunrise](https://i.stack.imgur.com/0L6Ua.jpg)](https://i.stack.imgur.com/0L6Ua.jpg) <https://www.nasa.gov/multimedia/imagegallery/image_feature_2047.html> Your nuclear strike flies just before dawn and hits 2 seconds after the sun peeps over the horizon. Resetting time 2 seconds will not allow the aliens to escape the missiles 500 meters over their heads. But they could enjoy those 2 seconds over and over again. Which is a nice thought, because it is a pretty sunrise. [Answer] Play the hostage game, what do the aliens want? If they want to conquer the planet maybe we need to nuke it all so they'll know if they cross the line no side we have anything left. I don't know maybe they'll retreat, otherwise they would have just lunched orbital strike and killed us all long time ago. Edit- I may explain myself a little further: If aliens don't use nuke-like weapons in our world means that our world is something they want or something in it. We nuke our world. Aliens can see the future. 24hs Ahead we destroyed the world. There is not much they can do to stop nukes all around the world. Since the world is in ashes and there is no much left to obtain they may retreat instead of keep wasting their resources. [Answer] I don't think this is that much of a problem. While the aliens have a ludicrously powerful advantage the key for the human forces is live intelligence gathering. Imagine an Alpha who gets into a soldiers crosshair at position X. He dies to the soldier and near the end of the day when the Mimics have gathered as much data as possible the day is reset. With the new knowledge the Alpha moves to position Y, but he's still in the soldier's crosshairs as the soldier just uses the information he has now, the fact that he does not know anything that happened in the previous timeline does not matter to him. On the battlefield you just need to use a larger scope of intelligence. If for example you do an artillery bombardment you don't do a random one, you have people guide the artillery strike towards the enemies. If they do something different because they saw what happened the previous time the artillery strike will be guided differently and still have a high likelyhood of getting on-target. It is also smart to assume the Mimics know your exact army composition and position at any point in time as they'll likely have seen it before they did the reset. So you always have a group of "counter commanders" who look at potential ambushes or attacks that could happen if they knew the entire army position (which these commanders should have). Based on that they can predict potential attacks and counter them prematurely. As a way to reduce the effectiveness of the Mimic reverse time ability, you can try to wait to finish off some Alpha's just after the reset time has passed. This way you can fool whatever central intelligence uses the time reversal that there were less Alpha deaths and it might think it has lost too little Alpha's to warrant a reset. ]
[Question] [ Imagine we're in a world where massive, outrageous amounts of energy are available at our fingertips. Perhaps one of those crazy cold fusion ideas panned out, or we eventually built ourselves a --partial-- Dyson sphere of glittering solar panels around the Sun. It matters not how. Now, one of the characters living in this setting (let's call her Young Alice) has a summer cottage. And she thinks the view from her porch would be a lot better with some minor landscaping, such as moving (or perhaps just wiping out) a series of mountain peaks in the distance. *What sort of technology would be required to be able to literally dismantle mountains with a labor force of 0$^\$?** \* well, technically $\lim\_{x \to 0}x$, since she has to think it at least. [Answer] Once endless energy is available, dismantling things is not very hard. It would be trivial to, say, subject the mountain range to the energy equivalent of the entire solar flux received by the earth. The forces of ten thousand suns would literally melt the mountains into lava. The larger issue with such technologies is that others have the technology too. Naturally, if Young Alice is the only mad scientist on the block with a tectonic scale heat ray at her disposal, she can get rid of mountains if she pleases, and no one will complain (at least not to her face). However, assuming others have this capability, restraining use of great force is far more challenging than the uncontrolled use of it. So let's start by restraining Young Alice's heat gun with a safety interlock. It's only allowed to slag mountains if the matter has been put to a vote, and the plans have been on display for at least 3 months (and not in the corner of some government building basement either). Then a federal officer would come by, deactivate the interlock, and for a few joyful moments, Alice would be master of her own environment. Of course this isn't the most interesting outcome in the world. Especially since she won't be the only one with a safety interlocked heat gun, and the government faculties devoted to the tactful removal of granite and limestone would be swamped with requests. It's also not all that interesting because, frankly, there's no reason for everyone to have the power to slag a mountain if it's locked up all the time. More likely the heat gun will have configurable power. The maximum mountain slagging power would require a full federal process, while the power needed to, say, toast s'mores would be freely available without any interlocks. Naturally you would want a range inbetween. Perhaps eradicating an oak tree blocking your view of the mountains would only require HOA approval. That way you could enjoy your view before Alice gets her mountain-slagging pass and leaves you with a view that you wish was obscured by an oak tree! As you get to smaller scales, we find more desire to create than destroy. Your neighbors may not accept you demolishing a tree, but they may let you express your inner artist by turning it into a topiary. With the limitless energy of a sun, it would not be surprising if we had such technology. Let's make this a bit more compact. The limitless powers we are talking about are so magical, let's just make it a magic wand and be done with it. The magic wand has a bunch of safety interlocks, but once you unlock the right level, it lets you create a particular flavor of nanobot to do your bidding. That's better! Now let's address the voting process. Nanomachines don't do voting like we tend to. They're too small and there'd be too much information to deal with. Instead, they do something known as "quorum sensing." It's a lot like voting, but it can be done in a more localized and continuous process. Yeast use it to decide whether the environment is a "go forth and multiply" environment, or a "hold onto your butts!" environment. So there would be nano machines at the mountain quorum sensing what should be done to the mountain. There would also be a stream of activated nanobots between Young Alice and the mountain, conveying her desires. This process can be quite intelligent. If she wants to carve the mountain into Mt. Rushmore, and the only other opinion is from someone on the other side of the mountain, it may give her the ability to carve her side. If she wants to obliterate it, she'll have trouble achieving quorum with someone on the other side opposing her. Of course this whole process can be a bit stressful. If you were a microscopic particle trying to stand between a woman trying to slag her husband's holey boxers using a magic wand, and her husband desperately trying to resist, you'd be stressed too. So the nanomachines are going to have to have some communal ability to recommend lower stress alternatives (such as accidentally "misplacing" them the next time they need to be washed). So the biggest opposition Young Alice faces in her mountain moving exercise is the voice of those who think mountains look nice. As her frustration builds, she starts pushing on the nanomachines to do her will rather than the others. The nanomachines at the mountain give feedback: "She's stressing us out, you upstream nanomachines need to help us out!" Fortunately, as a general rule, if you're focusing on one thing, you're not focusing on another. If Young Alice is focused on slagging mountains, she's not focusing quite so much on the state of her lovely garden. Thus she won't mind too much if instead we slag a little bit of the ground in her garden to form a tunnel, much like the kind a rabbit might dig. After all, it's only a small hole. Nobody will mind much. We might not even mind if the nanomachines construct the shape of a White Rabbit with pink eyes to run close by her. Oh dear! Oh dear! I shall be too late! [Answer] As an aside, Young Alice is crazy to think that mountain ranges make scenery worse. I guess I could see moving them into your field of view, but out of it? Crazy talk. But I'll answer the question anyway in the hopes that she'll come to her senses. The obvious answer would be Nanotech. Take a survey, define the areas of the mountains you want scanned and disassembled, and let it go. I'm assured by EvilCorp that the [Grey Goo](http://en.wikipedia.org/wiki/Grey_goo) problem has been solved, and really, it was extremely rare anyway. Once it's over she can sell the mountain range on craigslist, and it will be the responsibility of the buyer to move the giant pile of waiting nanomachines and raw material to the mountain range's new location. Everything else I can think of is likely to damage the lilies, but I'll see what I can do. [Answer] I live in a part of the world where we already literally dismantle mountains and pile them back up somewhere else (after separating the coal from the limestone). It's called [strip mining](http://en.wikipedia.org/wiki/Surface_mining), using huge shovels and 400 tonne haul trucks, the mountain is taken down one layer at a time and hauled off somewhere else where the soil is piled back up and reclaimed by planting trees all over it. Strip mining obviously employs a large labour force, but to make that labour force 0, all you'd have to do is automate the process, have the drills automatically drill their blast patterns to loosen up the rock, then have the shovels come in and load the automated trucks. [Carnegie Mellon's Robotics Institute and Caterpillar, Inc.](https://www.cmu.edu/news/archive/2008/September/sept9_autonomoustrucks.shtml) are apparently already attempting to make this a reality. ![enter image description here](https://i.stack.imgur.com/JN4J9.jpg) [Answer] The Ultra-Dimensional-Gardening Portal Gun (5000) > > I'm envisioning more of a kind of dimension-wormhole insta-swap kind > of thing, switching the millions of tons of rock and earth and stuff > with air. It's the only way I could imagine this not causing some kind > of a natural catastrophe (and this IS ultra-handwavium with closed > eyes) I dunno, imagine it as some kind of a ultra-boosted gardening > version of the portal gun > > > I liked my idea so I'm fleshing it out a bit more :P Humanity has cracked travel between dimensions, allowing them to travel very quickly (FTL). Thus Alice's family out boating on Aquus Prime. The technology has been around long enough that it is now used in household items, it is clean energy (obviously powered by fngrSnap tech): Cooking: Ovens now are simply linked through a partial gateway to a huge heat source, cooking food rapidly. Entertainment: Portals are opened to live sets for reality TV, news and discovery channels and ... others. Storing: Most families have allocated areas in parallel dimensions for everything from storing your boat in the winter, to parking your car, or that ugly vase you received from Aunt Geraldine on your birthday; accessible through your trusty portal gun. Waste: Entire dimensions have been allocated to specific material storing or waste disposal. Thrash cans have been linked to it etc... Gardening: A gardening (or landscaping) version of the trusty household portal gun also exists, it comes with a variety of modes and is linked to a dozen different material storage dimensions and worlds allowing everyone a bit of fun at playing god. It is however heavily regulated to avoid apocalyptic mental breakdowns in between users. [Answer] With unlimited energy, and an afternoon to get the job done, I think anti-matter is going to be the best way. > > A large-scale power plant generating 2000 MWe would take 25 hours to produce just one gram of antimatter. > > One gram of antimatter annihilating with one gram of matter produces 180 terajoules, the equivalent of 42.96 kilotons of TNT (approximately 3 times the bomb dropped on Hiroshima) > > > So with unlimited energy the only real question is how much you will need, and for that placement is going to be key. Put a couple supercomputers on the job of calculating the structure of the mountain to determine the optimal placement and force needed. The hardest part is going to be getting the anti-matter deep enough into the mountain that it will shatter it, instead of just using it as a backstop and sending the energy out into the atmosphere. Some automated digging robots could do that, but would probably take longer than an afternoon. Maybe a 4 day holiday weekend project? Lets say you can dig a shaft down to the heart of the mountain, using some natural fissures and stuff... I'd try 4 grams to start with. Should at least knock the top off, which could get Alice her ocean view, assuming she avoids the nuclear winter. [Answer] With a 3D Optical Projector, Alice can make any front-porch view she likes, no mountain-moving required! Simply load the desired view into the Optical Projector, and use the simple point-and-click view editor to alter the projected view from Alice's porch. Now equipped with optical-scanner to replicate your current front porch view for easy editing! Range does not exceed field of front porch, does not inhibit view of others from other front porches, and is environmentally-safe. Batteries not included. [Answer] A problem you don't address with limitless energy is artificial intelligence. At some point she has to harness the energy to do the work, and a primary problem is having the expertise to move the mountains without any bad side effects. Without such expertise, a toddler could move a mountain and destroy a city full of people in the process. So I think that not only are you going to have to develop the energy to do so, but also the intelligence to carry out the desired action with relatively little thought. While nanomachines have their place, I think in this case what is really needed is a way to influence gravitons - tiny elementary quantum particles that may or may not (in your story they do) affect the gravitation field of objects. Therefore Alice has at her command a machine capable of affecting all the gravitons in the related material to be moved, and she can terraform, move, and landscape according to her pleasure. The intelligence need not be very good - the level of intelligence the nanobots in Big Hero 6 displayed would be enough. You simply think of what you want, and they, within their parameters, figure out how to accomplish the goal. Not necessarily sentience, but enough to understand realities of the physical world, as well as the laws of ownership and legality of terraforming within one's sphere of influence. This machine would simply do it on the quantum level. This could not only mean moving materials, but changing fundamental properties temporarily - such as having the dirt behave as a liquid to flatten out an area, then having the mountains lift up complete with dirt, plants, animals, and place on the now-firm but newly flat area designated. [Answer] Virtual Reality Why live in a reality with ugly mountains blocking your view when you can live in a better one? Alice's plan to remove the mountain really only makes sense if she's the only one it will affect. Frank, Billy, and Bob, for example, may be avid skiiers, while Gertrude doesn't care about the mountain, but is worried about the affect that moving it will have on wind patterns for her farm. It may be possible that Alice is a Magrathean and is building herself the perfect planet, but the level of technology required to build a planet from the ground up is higher than the level of technology required to build a planet in VR at a high enough resolution that none of the human senses can distinguish it from reality. Enhanced Reality If you have to go to the Earth cabin instead of living in VR, why worry about seeing anything that you don't want to? Alice, of course, can also just get an enhanced reality chip placed in her brain. This chip will modify what she sees, replacing the mountains with a perfect view of whatever is on the other side of those mountains. Her nanodrones provide the necessary footage of whatever she wants to look at. If she wants, she can also tap into her VR feeds and replace the mountains with something entirely virtual, while still seeing and interacting with the nearby real world at the same time. The downside of this approach, of course, is that Alice's mother may stop her from tapping into her ER feeds while at the dinner table. [Answer] There are a few issues besides how to dismantle a mountain range and where to move the megatonnes of material left over. Alice might not like the view, but what about her neighbours who do want to see mountains. There are certainly some property rights issues involved here, or maybe a Hatfield vs McCoy feud of competitive mountain range building/destruction in a tit for tat cycle. When the Neighbours get really annoyed, they might decide to build the Himalayas on her front porch. Besides property rights, there is also the issue of plate tectonics. These mountains got there due to natural forces, such as subduction of one of the Earth's plates under another, so the sudden removal of megatonnes of rock will have some pretty dramatic consequences both there and at the plate boundary. Maybe Alice likes the view of erupting volcanoes? Earthquakes and tsunamis also will be part of the new landscape for a while as well. Finally, having unlimited energy is not "all that" unless there is a mountain sized heat sink somewhere at hand. Deploying energy to do work in this universe will release waste heat (second law of energy), and more energy or doing work faster (removing a mountain in a day) just scales the problem enormously. Alice might discover the mountain is melting halfway through the afternoon. Once again, the neighbours might object to their favorite sea boiling away due to the waste heat being released by this bit of geoengineering. A big handwave of dumping waste heat into a baby universe might solve that problem, but if you can do that, why not just make your own universe free of annoying mountains, noisy neighbours and unwanted cosmic events and move there instead? ]
[Question] [ Imagine a modern day special forces soldier, armed with the best gear and training the military can offer (Limited only by what he can reasonably haul around). Now imagine him thrown into the distant past, all the way to early-medieval Europe. Would it be reasonable for this soldier to take over a kingdom through nothing but martial force and skill? 1. If yes, how difficult would it be? 2. If no, why not? In my head, it seems to me that it would be reasonably possible, as his weapons would seem nearly like magic to medieval people. But claiming a throne and holding it are two entirely different things. Note: The soldier is only armed with the best equipment he would be able to carry, not what would be provided. Unless he could carry an entire predator drone with him, he won't have one. [Answer] In my opinion no. I have two different areas of arguments here: 1. He is human, after all: The same limitations as for [a tank](https://worldbuilding.stackexchange.com/questions/12219/in-what-war-would-one-modern-military-vehicle-make-a-difference) apply. In Short: limited mobility, people would get used to the 'magic', he can still be killed relativly easy (even more than a tank), he has to sleep (huge vulnerability), his items can be stolen/taken away. There may be a small chance to get to the top within a warrior society (fight for the throne), but what if this has certain weapon families to use? And for the magic part: Given some time, some people will question his 'supernatural' abilites. Even if he can forge a legend / prophecy around his items or something similar. 2. Kingdoms are about politics, too: The abilites of good soldier are certainly not optimal to gain / hold political power. Using soldiers to excert power is really different to fighting. If he's a 'soldier by heart', fighting is his thing, I doubt he even would want to be king, because ruling and administration wouldn't be his cup of tea. Not my native tongue :) Edit / Update in reaction to comment/the other answer: If you have time to plan such an action for maximum impact, you would do the following: Dont send a soldier. Send somebody (like a trained spy/diplomat/ambassador), who is really good at manipulating humans / dealing with them / administration. Then choose spezialised items for maximum impact. While a personal defence weapon with caseless ammo (for maximum bullets/weight/volume) and perhaps a grenade should be enough to take care of the fighting, if required, even given very basic combat training, the majority of the other items should be * surveillance items to gather intel (wires, small drones etc.) * Items for awe (lighters, stage magican equipment etc. to dazzle the people) * Item specially crafted to form legends (I have only 1 bad example. Hidden camera at the back, you are now the man 'with eyes on his back') * Hard to pull off: medical equipment like anti-biotics. Adds bonus of faith healing :) These things would have much more impact imho than a human apache helicopter with a minigun :), at least in the long run. If, within your story, a trooper gets to the past by accident, this may not be possible, however [Answer] Ask yourself this question: if an advanced alien arrived on earth, armed with a powerful gun, but no magic protection from harm, who did not speak the language, did not know anything about how life works here, did not understand the terrain and probably couldn't even pronounce the name of the country he ended up in, do you think that alien would end up leader of the country? I think he would end up in a research lab, a prison, or buried a box. Your martial prowess, even with a semi-magical weapon, is useless in politics. Your soldier would end up poisoned in the first meal after uttering the words "I want to be king". Way too much dependance on all these other people, who have structures of power in place designed specifically to keep their power. Remember that you do not become the king by shooting the previous king. You just become the guy who helped the second in line to become king, and your reward for it will be delivered on the chopping block after he has you executed for it. Maybe you'll get a pat on the back and a "nothing personal, this is just politics" before he has it done. [Answer] It entirely depends on how charismatic/likable he is. A single human, no matter how equipped, strong or trained, is just too vulnerable. If he's unlikable, at some point he's going to get killed by assassins in the night, or he'll be betrayed. On the other hand if he has the kind of draw that can bind people to him and make them loyal, then they can help protect him when he's vulnerable. And with modern knowledge and military training he could probably take over the kingdom by training an army and taking it with force. His modern equipment will need to be hoarded for maximum impact, since he doesn't have infinite ammo or the ability to make more than field repairs. [Answer] I heavily doubt that his combat skills and weaponry alone would make him king. What will most likely get him the kingdom, though, is his knowledge of tactics, provided he has at least some leadership quality. In medieval times combat tactics were practically incomparable to those of today, with camouflage being only one aspect (albeit an important one). His weapons would quickly make him the leader of a horde, then an army, and both would be near invincible until the moment where others picked up the tactics he uses. But by that time, we would long have ran out of ammunition, since he would at minimum be forced to use his weapon every so often to prove he still held the power the weaponry promises. So, while he would be able to gain a kingdom, holding on to it would be a completely different story. [Answer] See, for example, <http://en.wikipedia.org/wiki/A_Connecticut_Yankee_in_King_Arthur%27s_Court> : an engineer is sent back in time without any equipment, and improvises his way to success. There have been a few cases in history of people rising through the ranks or successfully leading rebellions from outside, but it's rare. And you can't do it by yourself: you have to recruit enough people to your side. This can snowball if you're very lucky and charismatic. You could be the Garibaldi or the Che Guevara of your time. However, that relies very heavily on knowing the local language and culture in order to be convincing in it. A thing to take cues from is the Lewis and Clark expedition. They took a high-powered air rifle with them, as they could recover the pellets and not worry about running out of powder. This was wonderous and convincing to the Native Americans that they met. But it didn't make them kings of America. [Answer] You have to consider what the society the soldier enters is like. One man, even with today's best equipment, could not become the king of 13th century France, at least without exceptional political skills (to, for instance, gain the support of major nobility or whip up a peasant revolution). Militarily, he could not defeat the supporters of the crown. However, if the soldier ends up in an 8th century England setting - more a tribal chiefdom than a kingdom - becoming a petty king just might be possible. Kingdoms of that time could be small and the number of people directly supporting the king similarly small, perhaps small enough to be defeated with modern weapons. This is highly speculative of course. The help of locals, perhaps a band of warriors or dissident peasants, would be very beneficial, but would require political and leadership skills or possibly mystical abilities, such as modern medicine, or blessings from the church. Also, if the prevailing culture assumes that the strongest should be king, the soldier might be able to fight a duel with the king and win with his modern equipment. However, this is not very plausible in a European setting. [Answer] While he might be able to seize power, his ability to be King would be limited by his ability to exercise political power. As a Special Forces or Special Operations Forces soldier, he may well be skilled in being able to carry out "face to face" diplomacy with people he encounters on his way, but Kingship (or even lesser nobility) often depends on forging a permanent structure of long term alliances, understandings and use of "quid pro pro". As King, he would also need to have uncontested access to resources he could use to grant favours, cement alliances and even just buy and sell things (in the middle ages, armies and fleets were more "events" than standing forces as we understand them). Disgruntled former nobles and noble families whose estates were seized were a huge source of instability in historical times, and this would be true for your "man who would be King". Finally, to be a good and effective King, he would have to internalize and live by a certain code of conduct understood by all. Steven Pressfield said it best in his novel "Gates of Fire": “A king does not abide within his tent while his men bleed and die upon the field. A king does not dine while his men go hungry, nor sleep when they stand at watch upon the wall. A king does not command his men's loyalty through fear nor purchase it with gold; he earns their love by the sweat of his own back and the pains he endures for their sake.* That which comprises the harshest burden, a king lifts first and sets down last. A king does not require service of those he leads but provides it to them...A king does not expend his substance to enslave men, but by his conduct and example makes them free.” ― Steven Pressfield, Gates of Fire: An Epic Novel of the Battle of Thermopylae [Answer] Doable, but not universally, and not alone. If the country is ruled by a well-loved king, forget it. He won't rule by threat of his weapons alone. But if there's a strong dissenting faction - an oppressed ethnic minority, , the soldier's expertize in tactics, modern warfare and modern ideas of politics could earn him the place of the leader of a revolution, and then, leading the revolt, he can take over the kingdom. The weaponry could be a boon - a sniper gun would make a short story of enemy leaders and the hated ruler. Arming the rebels with makeshift explosives and teaching them modern, stealthy combat techniques would enable them to overcome superior forces of the enemy army. And in the end, becoming the hero, he would have no problems being accepted as the ruler. Of course he couldn't just be a common grunt who choose army because he was too stupid to do anything better. He'd need to be a smart person with a good empathy sense, to acquire the right allies - simultaneously friends and advisors; ones who would enable him to rule efficiently by serving the right advice and not backstab him to seize the power themselves. And yes, he would still be at risk of assassination, poisoning or just armed assault by an overwhelming enemy force (even if his army was mighty and skilled, sheer numbers of the enemy could shift the balance.) But these are standard risks of a wise king. His worst problem would be approval of his peers. He has no "noble parentage", so winning acceptance by the elites and neighbor kings would require exquisite wit. Possibly clever political maneuvers involving religious powers could help - if he wipes heretics from an occupied catholic country, he could seek the blessing of the Pope, receiving the crown by God's will. That certainly would help his stance. Consigning a large unit of his elite troops skilled in modern battle techniques, medicine and logistics, armed with explosives and firearms, to a crusade, and actually making the crusade successful, would earn him enough of unquestioned fame that his position would be secure for a long time. [Answer] In general I would say no. your average person is not a leader, and even well trained special forces people have limitations. While they may be great leaders, they generally are not politicians. There are some people that could conceivably do so, but it would be by guile and judicious use of their equipment. Timeline would be important to. (besides not being able to communicate and needing to learn a local language) Becoming a trusted general for a king, become powerful and then maybe have a coop. But just fire power would only allow maybe the ruling of a small town, especially since he would be trained well enough he could beat 2-3 dissenters with his bare hands at the same time. [Answer] Power does make a king, but not the power of arms. That can be helpful to keep* him a king afterwards, but what the Declaration of Independence says about governments "deriving their power from the consent of the governed" is more than just political rhetoric. A ruler's power, even his military might, ultimately derives from the resources produced by his nation, which we can simplify, for the purposes of this discussion, down to the single word "taxes". At the very simplest level, a king can't maintain administrative control over a non-trivial amount of land without administrators, nor tyrannical control without an army, and if he can't pay his administrators/troops, they're not going to keep working for him for long. And if a large enough percentage of the people decide to stop contributing their taxes--and especially if they can convince the king's administrators and/or troops to side with them--he's going to lose the control he had in short order. Even our hypothetical time-traveling soldier, whose power very literally "flows from the barrel of a gun," is dependent on scarce resources. As others have pointed out, once he runs out of bullets, there goes the source of his power. If he wanted any chance at all to prolong that power, he would need loyal followers; at the very least, a master smith and a master alchemist to produce new bullets and powder, and even that is pretty dubious when you start looking into the details of the technology involved! Without gaining the consent of a significant fraction of the people he wanted to rule over, our would-be "king" would never become much more than a common warlord, a thug who lives by the (metaphorical) sword, and eventually dies by the (quite possibly literal) sword. [Answer] Yes, he quite possibly could. Things to carry: 1) Computer/smartphone. 2) Spare harddrives that can connect to 1 (with useful information on them of course). 3) Solar panels that can power up 1. 4). Not a weapon. No way to get ammo. Useful info includes wikipedia pages (including details about all the current ruling monarchs, particularly those with secrets that we learnt about after their deaths, science textbooks, and forums answering the question "what could people do if they went back in time" [Answer] As other answers state, to become king really requires political skill, and taking over an existing kingdom might not be do-able. However, if stable kingdoms do not exist, you might create one. This is still primarily a political act. So the question can be restated: > > "To what extent would the combat skills and equipment be helpful in > supporting the political side?" > > > This clearly depends a lot on the local political environment. You want: 1. A warrior society. 2. Significant turmoil or chaos. An ideal time and place might be somewhere in Gaul just after the death of Attila. The approach to take is to model Temujin, subsequently Ghengiz Khan. In these circumstances: 1. Contact a small warrior band (Temujin started with a remnant of family) 2. Take it over, possibly by killing the leader. 3. Conduct raids to demonstrate skills - these need to be both combat and tactical 4. Distribute spoils to the band 5. Attract more warriors 6. Take over other bands 7. Keep scaling up to the point of occupying towns Temujin just kept scaling up size of army and the need for spoils. This did not really generate a stable empire. An alternative, in the presence of an initially chaotic environment is to bring peace and stability. Once in control of a town, use modern methods to train citizens in defending the town. [ Seven samurai/Magnificent seven? ] Once the town has been defended from a roving warrior band, you have the nucleus of a small kingdom. ]
[Question] [ Is it possible to have a cellular metabolism based on reduction instead of oxidation? All known life currently uses some sort of oxidation in cellular respiration, either from oxygen or from oxidizing Fe2+/other chemosynthesis [Answer] Any oxidation reaction is also a reduction reaction; at least one reactant is oxidized, and at least one reactant is reduced. Here on Earth's surface, most animal life eats its reducing agents, respires its oxidant, and excretes reaction products in solid, liquid, and/or gas form. I don't really think of myself as an "oxygen-reducing organism", but it's a fair characterization. I can certainly imagine an organism that eats its oxidants and breathes in a reducing agent, or eats or drinks both agents -- [Oh, look, they already exist!](https://en.wikipedia.org/wiki/Sulfur_metabolism) [Answer] Oxidation reactions bring the atoms involved in a configuration of lower free energy, therefore they are energetically favored and lead to the release of energy, which life can use. Reduction reactions instead bring them to a higher free energy configuration and absorb external energy. Since the purpose of metabolism is producing energy for the organism, this would be a dead end. However parts of the metabolism can be reductive: for example the photosynthesis is a reduction, which allows the plant using it to store solar energy into sugars which can be later used. [Answer] A tail of two fluids What is a hydrocarbon world like? There are [methane lakes on Titan](https://en.wikipedia.org/wiki/Lakes_of_Titan). And rain and rivers! But water is actually more abundant on Titan: just dig a hole and once you get past the hydrocarbon and thiolin muck you will hit water. In the tropical deserts you don't even need to dig: there are plenty of dry, rocky plains [which are mostly made of water](https://www.sciencealert.com/scientists-discovered-a-giant-unexpected-corridor-of-ice-on-saturn-s-largest-moon). Bring a pickaxe. Hydrocarbons and water are also abundant in Gasoline world. But it's much hotter than Titan and most of the water is melted. Methane and ethane are potent greenhouse gases that make up for Mars-levels of sunlight. The oil seas are hydrocarbons that generally weigh 5-20 carbon atoms per molecule. They float as meter-thick slicks over most of the ocean. On Gasoline both oil and water can evaporate and rain down: waves and currents will disrupt the slicks and let the water escape. Oceans are saltwater, but rain is freshwater. And ocean slicks are waxy oil but rain, rivers, and lakes are clean oil (which won't leave a residue if it evaporates). Some rivers flow with water (laced with benzene and other stuff). Others are oil. But most are mixed flows: ranging from a sedate bilayer to a torrent of salad dressing. Feast on the nitrate There is plenty of gasoline, but no oxygen to burn it with. On Earth plants must make do with CO2 as a source of carbon, expending energy to wrench the "C" (as glucose) from the "O2". On Gasoline they have much easier sources of carbon, so why would they need to make oxidizers? Plants make oxygen for their own use to store energy. They need this energy for cloudy days, [giant flowers](https://en.wikipedia.org/wiki/Agave_americana), and to provide an extra metabolic boost against disease outbreaks. Oxygen bubbles are useful for [short term storage](https://www.kqed.org/science/341205/natures-scuba-divers-how-beetles-breathe-underwater). But gases are unwieldy. For bulk storage the plants use the O2 to oxidize [ammonia into nitrate](https://en.wikipedia.org/wiki/Nitrification). On Earth oxygen is a waste product that gradually built up (as organic matter was buried). But on Gasoline there is simply too little belching of oxygen and too much organic matter to oxygenate the atmosphere. Too bad animals use their teeth and claws to rob the poor plants of their precious energy. No lungs or gills are needed! Both your fuel and oxidizer are consumed via the mouth. Predators are rare in this world: animal flesh on Earth is much easier to digest than cellulose and thus predators evolve. But on Gasoline the scarce resource is nitrate, not organic compounds. Nitrate stores in animals and plants are chemically similar, so there is much less benefit to eating animals. [Answer] ## Sure, why not, some reducing reactions are exothermic Any redox reaction with a negative oxidation potential like in this [chart](https://www.google.com/search?q=redox%20oxidation%20potential&tbm=isch&sa=X&ved=2ahUKEwiuhr73h7P_AhUVQ_UHHY3FBWgQ0pQJegQIChAB&biw=320&bih=486&dpr=3.38#imgrc=XHFoMmRADy9eLM) means that it gives out usable energy when it reduces something. Ionised gold, ionised chromium, ionised group 1 metals like lithium all have such potentials. In one iteration, your lifeforms could eat e.g. lithium, and reduce other compounds using it, resulting in oxidised lithium and reduced organics. You then need something like plants that have an opposing reaction, that reduce lithium and maybe oxidise those same organics, with the aid of light. ]
[Question] [ So, I am imagining a draconic alien species which, (don’t laugh) inhabit a planetary system that is particularly rich in heavy elements such as platinum, silver, and yes, gold. (I said don’t laugh!) However, just thinking about the physics of this, what stellar/planetary conditions would lead to a solar system becoming enriched in gold and heavy metals? I don’t necessarily mean so rich that it there are deserts of gold dust or platinum mountains; I just mean a prevalence of these metals in the crust similar to that of iron or copper on Earth. [Answer] Golden ring. A metal rich asteroid like 16 Psyche got too close to your planet - inside its Roche limit and the planet tore it into a ring. This asteroid is the heart of a dead planetesimal and is rich in the metals you want. <https://thehill.com/opinion/technology/3597381-nasa-might-cancel-mission-to-massive-gold-mine-asteroid-heres-why-it-shouldnt/> > > Until recently, scientists thought that 16 Psyche was a solid hunk of > metal, iron, nickel, gold and platinum. A recent article in > Smithsonian suggested that the market price of the asteroid’s metals > is 10 quintillion, hence the name “golden asteroid.” Other estimates > have gone as high as 700 quintillion. > > > Rings don't last forever. For the last ten million years the broken bits of the golden ring have been raining down on the planet surface. The planet now is cooled and solid and so although these metal bits are dense they cannot make their way thru the solid crust to the core. They accumulate on the surface. A lot of the falling metal melts on the way and so is dispersed widely. Not all of it. It is not at all uncommon for a hefty chunk to survive re-entry. One can sometimes gauge composition by the color of the shooting star as it comes down. Platinum makes a natty green. People are not rich from all the precious metals, of course. They are too common. It does allow the common people to wear solid gold underwear, which is the fantastic shiny dream we all dream of. [Answer] Through natural processes, you won't get anything like a pure gold planet. You can get more metal than the Earth has, probably by a factor of two or maybe three. Let's unpack that. [Nuclear synthesis](https://en.wikipedia.org/wiki/Nucleosynthesis) in the Big Bang and later in stars will produce a distribution of isotopes. The solar system distribution is probably not too far from the kind of distribution that results from such processes. It looks like so. (Taken from the wiki I just cited.) [![enter image description here](https://i.stack.imgur.com/GrzaE.png)](https://i.stack.imgur.com/GrzaE.png) So gold, element 79 and symbol Au, is round-about one millionth as common as silicon. The reason we see lumps of it occasionally is due to filtering processes that happen in geological processes. Planetary collisions can produce planets with the heavier elements concentrated. If two planet sized objects collide with the right degree of glancing-blow, it can blast off the lighter rocky stuff and leave the heavier elements. The blasted-off parts can wind up as floating debris, or a large moon, or they can fall on other planets or the star in the system. This happened to Earth and to Mercury. Earth got some extra metalic material, and the debris became our Moon. So in the solar system, Nickel is [about 1 atom per million](https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements). On Earth it is round-about [100 times as much](https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust). depending on the method of measuring. The moon has far [less nickel than Earth.](https://space.nss.org/l5-news-the-value-of-the-moon/) The planet [Mercury](https://sciencing.com/what-mercury-made-4672261.html) has a relatively large metalic core, which is probably a combinatin of iron and nickel. Probably the crust is much richer in metals than is the Earth. So you can basically dial-up metalic content from round-about what the Moon has, to a little bit more than what Mercury has. You do it by having the planet you are interested in be hit by a glancing blow between proto-planets. This blasts away the rocky parts of both planets, and the metal parts combine. The rocky parts either become a moon or an asteroid belt or fall into the system's star. You will still need the usual processes of pulling the gold out of ordinary background material. These [include](https://www.amnh.org/exhibitions/gold/incomparable-gold/forming-deposits) the action of water, volcanic action, and interaction between water and volcanic action. So to have pure gold around you will also want some water on your planet. [Answer] The younger the star system, the more enriched with heavy elements was the interstellar medium that it condensed out of, and thus the higher the proportion of heavy elements in the various planets, moons, asteroids, comets, meteroiri oids, etc. in the system. I also note that stars with higher heavy metal conent are found closer to the galactic core, and stars with lower metal content are found farther from the galactic core. So a writer might think that a good way to have inhabited systems rich with heavy metals would be to make the inhabited systems only about 10 or 20 million years old and put them at the galactic core to get the highest possible concentration of heavy metals in the planets. But that situation has problems for being inhabited. It took a long time, tens or hudnreds of millions of years, for Earth to form, cool off, and for the first primitive lifeforms to appear. And it took billions of years for Earth lifeforms to en vnetually produce and oxygen rich atmopshere which multi-celled land organisms, such as humans, or the intelligent aliens desired to inhabit the planet, could breathe, and tens or hundreds of millions of years more until such intelligent beings did evolve. Maybe intelligent life could evolve sooner than it did on Earth. I note that if cetaceans and proboscideans count as intleligent beings then the first members of their lineages to become intelligent might have lived 10 or 20 million years before the first proto humans. It seems easy to believe that on some planets intelligent life might evolve when the planet is one percent (about 46 million years) or ten percent (about 460 million years) younger than the Earth. But to take billions of years off the age of a planet with naturally evolved intelligent life would require evolving intelligent life in only about 50 percent, or something, of the time it took on Earth, which may seem a lot less plausible to some people. And of course your intelligent natives of the gold rich star system might be part of an artifical ecosystem. An advanced society might have terraformed the metal rich planets in that system to make them habitable when the planets are only a hundred million years old or so. And they might have used advanced biotechnology to create designed lifeforms to live on those terraformed planets, including the intelligent beings in the story. Thus if the intelligent beings in the story believe they were created by by gods only 1,000, or 10,000, or 100,000, years ago, they might be correct, probably more by coincidence than by remembering the truth. So you can have a habitable planets inhabited by intelligent beings in a very young star system in the core of the galaxy, and thus extremely rich in metals. Except that a system in the core of the galaxy, where other stars are very close, probably wouldn't stay habitable for billions of years. Because the stars are so close, really close encounters between stars would be many times more common than in our part of the galaxy, and would perturb planetary orbits, often causing planets to collide with each other or with their stars, or be flung into the bitter cold of interstelalr space. And because the stars would be crowded so close togetherthe average star in the galactic core would be close to a nova, or a supernova, or a pulsar, or a gamma ray burst, muchmoreoten than on in our neighorhood of the galaxy. Thu the average planet with life might get palsted every few hundred million or every few tens of milions of years, wiping out all life on it. So the synthetically created inhabitants of terraformed planets in the galactic core might advance scientifically enough to realize that their world may have only a hundred million more years, or maybe only a hundred more years, depending on the story, before all life on it is destroyed, and that they have to work fast to find a way to survive. And if that star system is farther from the galactic core, the heavy metal concentration might be higher than in Earth's neighborhood and lower than in the galactic core, and the planet might have a longer future. And possibly an advanced civilization might use giant element synthasizing machines for thousands and millions of years to produce much more heavy elements than the system would naturally have. So will the main concentrations of heavy elements be on the habitable worlds in the star system, or will be they be on uninhabitable worlds? All the planets in the star system should have higher concentrations of heavy elements than in our soalr system, but just as the planets and other objects in our star system varying in average desnity (which largely depends on the amount of heavy elements) so too will the planets and other objects in your star system vary in their densities, which will partially be the result of variation in their proportions of heavy elements. A geophysical planet, or a planetary mass orbject, or a planemo for short, is an astronomical object with sufficient mass for its gravity to pull its matter into an approxiamtely spheroidal shape. In our solar system not only planets, but many moons, dwarf planets, and Trans Neptunian Objects are planemos, pulled into spheroidal shape. When an object achieves enough mass to pull itself into a spheroid shape, the pressure and temperature at its core and far above the core becomes intense. Solidmatter melts into liquid, and flows downward. So the matter in the interior of the object gradually becomes stratifified by density, the greater density material sinking to the core and the lighter density material floating toward the crust of the planemo. Thus all planemos whould have interiors statified by density of material. But the countless thosuands and millions of objects of smaller mass in the solar system should all have pretty much the same average density, since hteir materials shoud be mixed randomly. But the small meteorites which are found on the surface of Earth often have widely variing averge density ies due to he differeng materials they are made of. In particular some meteorites are composed of iron nickel alloy with other heavy elements included. But it is impossible for such tiny objects to become stratified by density. Therefore they must be fragments of planemos which were shatted into pieces. Pieces would come from different layers in the stratified planemos and thus have different densities and different elemental composiiton. Computer simulations show that the early chaotic period of the solar system, before the orbits of objects settled down, it was common for gravitaional interactions between bodies to make bodies fall into the Sun, or collide with other bodies, or be ejected from the solar system into interstellar space. And some of the objects which shattered into countless pieces due to collisions were planemos which were strtified by density, thus making the pieces have different densities and elemental composition. So there could be various bodies, from terrestrial type planets to tiny bits of space dust, and every size in between, in your star system, coming from different layers of shattered planemos, just as in our star system. And you can adjust the number of objects which are the right size to be mined for their heavy elements by the civilization in your story. The planet Mercury has an unusually large iron nickel core for its size, thus making the overall density of Mercury much higher than would be expected in such a small planet. There are three theories to explain that. One is that a massive collision ejected much of Mercury's lighter outer layers, leaving a comparatively shallow layer of lighter materials above the dense core. Presumably a different collision might possibly have ejected all of Mercury's core and mantale, leaving the metal rich core exposed. And even if one of other theories to explain Mercury's density is correct, It may be possible for a collision between worlds to knock off all a world's crust and mantle, leaving only the core, rich in heavy elements. <https://en.wikipedia.org/wiki/Mercury_(planet)#Internal_structure> > > M-type (aka M-class) asteroids are a spectral class of asteroids which appear to contain higher concentrations of metal phases (e.g. iron-nickel) than other asteroid classes,[1](https://en.wikipedia.org/wiki/Mercury_(planet)#Internal_structure) and are widely thought to be the source of iron meteorites.[2](https://en.wikipedia.org/wiki/M-type_asteroid) > > > > > Although widely assumed to be metal-rich (the reason for use of "M" in the classification), the evidence for a high metal content in the M-type asteroids is only indirect, though highly plausible. Their spectra are similar to those of iron meteorites and enstatite chondrites,[4](https://arxiv.org/abs/1909.07451) and radar observations have shown that their radar albedos are much higher than other asteroid classes,[5] consistent with the presence of higher density compositions like iron-nickel.[1](https://en.wikipedia.org/wiki/Mercury_(planet)#Internal_structure) Nearly all of the M-types have radar albedos at least twice as high as the more common S- and C-type, and roughly one-third have radar albedos ~3× higher.[1](https://en.wikipedia.org/wiki/Mercury_(planet)#Internal_structure) > > > <https://en.wikipedia.org/wiki/M-type_asteroid> The largest M type asteroid is 16 Psyche. For a long time it was believed to be the core of a planetesimal which had shattered in a collision. > > The bulk density of Psyche (3.9±0.3 g/cm3) places constraints on its overall composition. The iron-nickel found in most iron meteorites has a bulk density of 7.9 g/cm3. If Psyche were the remnant core of an early planetesimal, it would have to have an overall porosity of 50%. Given Psyche's size, this is considered highly improbable.[8] However, there are other metal-rich meteorite types that have been suggested as Psyche analogs, each of which have bulk densities that are similar to Psyche's, including enstatite chondrites, bencubbinites, and mesosiderites.[28][21][8] > > > Several possible origins have been proposed for Psyche. The earliest of these was that Psyche is an exposed metallic core resulting from a collision that stripped away the crust and mantle of an originally larger differentiated parent body some 500 kilometers in diameter.[11] Other versions of this include the idea that it was not the result of a single large collision but multiple (more than three) relatively slow sideswipe collisions with bodies of comparable or larger size.[34] However, this idea has fallen out of recent favor as mass and density estimates are inconsistent with a remnant core.[8] > > > A second hypothesis is that Psyche was disrupted and gravitationally re-accreted into a mix of metal and silicate.[35] In this case, it may be a candidate for the parent body of the mesosiderites, a class of stony–iron meteorites.[35] A third hypothesis is that Psyche may be a differentiated object (like 1 Ceres and 4 Vesta) but has experienced a type of iron volcanism, also known as ferrovolcanism, while still cooling.[36] If true, this model predicts that metal would be highly enriched only in those regions containing (relic) volcanic centers. This view has been bolstered by recent radar observations.[7] <https://en.wikipedia.org/wiki/16_Psyche> And finding out about theories of ferrovulcanism might be useful, escpecially if gold, silver, platinimu, palladium, and other heavy metals are included in the iron nickel lava. <https://arxiv.org/abs/1909.07451> And I remember reading a science fiction story about a searce for "glory rings". In the the story "glory rings" were highly valuable but extremly transient and rare. They were rings around planets (or stars) where the ring particles were composed of heavy elements or were coated with heavy elements for some reason. If the story can be identified the explaination, plausible or otherwise, for "glory rings" might be useful in a story where some worlds in a star system with an extremely high ratio of heavy elements have even higher ratios of higher elements. Added Dec, 27, 2022 The story is "Rings of Glory by Thomas R. Dulski, in Analog july 1982. <https://scifi.stackexchange.com/questions/270581/late-20th-century-story-probably-in-analog-about-glory-rings> [Answer] As a general purpose workaround to any natural condition you don't like: An ancient very powerful race (possibly alien, possibly just (mis)programmed robots from that race) lived here long ago. In this case they collected the heavy metals from asteroids or mined it from the planet's core. Maybe they were not from this planet but just used it as a staging point in their mining operation. [Answer] Earth has something like 100 billion tons of gold. Its problem is that it's mostly in the core, which is why something like 100,000 tons have been mined. Consequently what you need is that either there was massive volcanism that brought a lot more gold to the surface, or else the bombardment of the planet with gold-rich meteors. At least one gold strike has been tied to a meteor, but you're probably better off with the volcanoes. [Answer] > > what stellar/planetary conditions would lead to a solar system > becoming enriched in gold and heavy metals? > > > To answer that you need to know a bit more about a thing called Stellar nucleosynthesis. Basically, Stars use Fusion reactions to produce Energy and elements: Hydrogen + Hydrogen = Helium. a Star will remain doing that fusion for Millions of years until it expends all of its fuel (Hydrogen), then it will start fusing Helium tyo produce Lithium, then Carbon, Nitrogen, Oxygen and so on till Iron, at this point the Fusion reactions completely stop and the star implodes, fast and hard, how hard depends on how big is the star, this implosion compress the atoms at the core making it possible to fusion the Iron and thus producing heavier elements, Nickel, Copper, Zinc, etc, how far in the periodic table we go depends on how big was the star. At some point the implosion will reach a limit where the compressing force will bounce back and the implosion turns into Explosion, a big Explosion, how big? you guessed, it depends on the size of the star, a Nova, SuperNova, HyperNova... and all fusioned elements in the star get expelled into the space surrounding the nova. Gold is a very heavy element; it requires a Supernova to create it. So.. back to your query, your imaginary gold made planet would have to be in or near to a Supernova remnant, unlikely to be pure gold but surrounded by many other heavy elements, even some radioactive ones. Heavy things get more attracted by gravity than lighter things, so lets say that the supernova gave us a planet size gold nugget, which is currently traveling the space expelled by that powerful explosion. The shockwave of our supernova reached a big gas cloud a few dozens of light years away, this made the cloud to spin, spinning made it concentrate, then gravity showed up and a new Star System was form. In that new Start system, lets say we had a Earth size gas proto-planet, who got hit bit our gold nugget (u didnt forgot about it right?) since the proto-planet was still 'juiced' instead of blowing up it merged with the gold nugget, all the heavy gold forms the now solid surface, radioactive elements will go to the core and keep it 'warm' for a while, and the rest, water and gas goes to form oceans and atmosphere. I'll leave the rest you. ]
[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/234948/edit). Closed 1 year ago. [Improve this question](/posts/234948/edit) In Fallout 3, there is an infamous settlement the player has to go through called Little Lamplight. Little Lamplight is a cave town that exclusively consists of children and tweens under the age of 16. After a Little Lamplighter reaches the age of 16, they are kicked out and sent to Big Town which is a settlement that only consists of adults. All the children that are born in Big Town are sent to Little Lamplight until they are old enough to be an adult and head to Big Town. I was considering writing my own post-apocalyptic story and was wondering, if nuclear war did break out, could this type of society actually be sustainable? It seems like a lot of work to send people back and forth between Little Lamplight and Big Town. There is also no practical reason to isolate the children and the adults of the same civilization. I also doubt that children will manage themselves well and make sure that everybody has food to eat and clean water to drink and medicine to take. Assuming some new religion or culture mandates this type of society, could this Little Lamplight-Big Town setup be feasible? Or will everything horribly collapse like Lord of the Flies? [Answer] Probably, although they'd likely have trouble keeping anybody less than 2 or 3 years old alive. Other than that, children are far superior to adults in memory work; and in taking orders from others, and they have very few expectations of "how life should be". In early America, 4 year olds had duties on farms requiring several hours a day of actual labor. Gathering eggs, feeding animals, pumping water, pulling weeds in giant gardens. They learned to ride horses before the first grade. Children learned to shoot, hunt and fish (successfully) at seven. Even in the late 1800s and early 1900s, before child labor laws, children worked 12 hour days in factories, earning a living, often in dangerous jobs. There may well be babies in the village as well, unsupervised teens are going to get pregnant and some of those babies will survive. The modern image of how helpless children are is quite inaccurate. If you have a well-established culture of doing the work of survival, I think children of 4 to 16 would probably survive just fine. Except of course for the things that kill all tribes, including adult tribes, like drought, earthquakes, famine (nothing to hunt, gather or fish), or rampant disease. I'd research the historical role of children in society pre-1900, or even in the middle ages. Although I fully endorse and support the modern, non-abusive and even coddling upbringing of modern children, I am also aware that this is a recent cultural phenomenon. Life wasn't fun and games for children on the wild frontier or in primitive tribes. [Answer] # [In real life lord of the flies the children were fine.](https://www.theguardian.com/books/2020/may/09/the-real-lord-of-the-flies-what-happened-when-six-boys-were-shipwrecked-for-15-months) > > Then, on the eighth day, they spied a miracle on the horizon. A small island, to be precise. Not a tropical paradise with waving palm trees and sandy beaches, but a hulking mass of rock, jutting up more than a thousand feet out of the ocean. These days, ‚ÄòAta is considered uninhabitable. But ‚Äúby the time we arrived,‚Äù Captain Warner wrote in his memoirs, ‚Äúthe boys had set up a small commune with food garden, hollowed-out tree trunks to store rainwater, a gymnasium with curious weights, a badminton court, chicken pens and a permanent fire, all from handiwork, an old knife blade and much determination.‚Äù While the boys in Lord of the Flies come to blows over the fire, those in this real-life version tended their flame so it never went out, for more than a year. > > > > > The kids agreed to work in teams of two, drawing up a strict roster for garden, kitchen and guard duty. Sometimes they quarrelled, but whenever that happened they solved it by imposing a time-out. Their days began and ended with song and prayer. Kolo fashioned a makeshift guitar from a piece of driftwood, half a coconut shell and six steel wires salvaged from their wrecked boat ‚Äì an instrument Peter has kept all these years ‚Äì and played it to help lift their spirits. And their spirits needed lifting. All summer long it hardly rained, driving the boys frantic with thirst. They tried constructing a raft in order to leave the island, but it fell apart in the crashing surf. > > > Children, like adults, are mostly prosocial and fully able to work together in a crisis. They're perfectly able to improvise, work together, and do a variety of survival activities. They can take care of their fellows and avoid chaos. Children don't like dying, and are very capable of doing whatever is necessary for survival. [Answer] Yes and no... Mostly no... Kinda depends... Let's start with a stereotypical group of rural ranch/farm kids from central Montana. They've been in [4-H](https://4-h.org/about/what-is-4-h/) and [Future Farmers of America](https://www.ffa.org/) for years, they've been members of the [Boy Scouts](https://www.scouting.org/) and the [Girl Scouts](https://www.girlscouts.org/). Their parents annually bottle (can, store) fruits and vegetables grown in their own fairly large garden and they work with animals from rabbits and goats to cows and horses every day. They've been hunting with their parents since they were five years old. Could you drop 20-50 of these kids alone somewhere in a post-apocalyptic world and expect them to create a functioning society? No guarantees, but probably yes. Now let's consider a group of stereotypical city kids. They might be involved with the Boy and Girl Scouts, but the focus in that case is very, very different. They've spent a lot of time [shooting hoop](https://idioms.thefreedictionary.com/shoot+hoops) and playing video games. They don't raise chickens... in fact they can't (it's against city code), so the closest they've ever come to gathering food is buying it at a supermarket and with uncommon exception the closest they've come to preparing it is tearing away the cellophane and placing it in a pan on an electric stove. These kids don't go camping, they hang out at the mall. Could you drop 20-50 of these kids alone somewhere in a post-apocalyptic world and expect them to create a functioning society? No guarantees, but probably not. But whether or not they could, whether or not it's feasible, isn't a worldbuilding question. You're the author. If you want it to happen, it will. I almost voted to close this question Because it's too vague and too story-based. Is it feasible? Of course it is ‚Äî depending on the ages, maturity, education, and skills of the children. Too little of all of the above and survival of a society becomes unlikely. Too much and, well, they'd be controlling Big Town like a shadow government. All of which is your job as the author to determine. Because age, maturity, education, and skills (or their lack) are also what will contribute to the challenges they face and how they overcome them (if they do). But there is one thing I need to warn you about... Children are not small adults Teens, for example, take insane risks not because it's cool, they're capable, and adults are foolish for thinking they can't. They do that because very simplistically, [their brains have developed to the point of better understanding the greater world around them but have not developed to the point of realizing that life is fleeting](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2396566/). Stories that present children as small adults cater to the children, meaning they're trying to sell books to kids, not to adults who know better than to believe that an arbitrary group of children are more than capable of establishing a functioning society and solving, not just adult problems, but those problems for the adults. How many children would know what to do if they cut themselves? Broke a bone? Suffered internal injuries? The more dramatic the damage, the less likely a child can fix the problem. All those kids I just mentioned? Even those from rural Montana? Yeah, they depend on clinics full of adults who know what to do in emergencies. In fact, most children depend on adults to know what to do in emergencies. The younger the child, the more this is true. We praise the rare child who keeps a cool head in an emergency ‚Äî but in all but the rarest cases, what the child did was call 911 or another emergency services system to bring the adults to bear. So, it depends... Which is why I almost voted to close your question. Do you want help determining the skills necessary for such a society to exist? We can help with that! Can one arbitrarily exist? That's storybuilding ‚Äî a choice you, the author, must make, because outside of fiction there simply isn't an example of an independent society of children that functions at all. Before you compare my answer to Nepene's (which is a good answer!) Consider the following: There were only six boys - that's not a society. They were close friends. They had strong faith, strong morals, and good discipline. They lived in a society that was much closer to today's rural societies than today's urban societies. The island they landed on had been occupied a century before, leaving them with a remarkable supply of food. And they were all older teens with no girls among them. This is really my point. Given the correct set of circumstances and skills, yes. Given an arbitrary set of skills and circumstances? No. Set that community next to an adult community... better hope the kids don't have something the adults want. [Answer] Lots of Considerations Here... Background: I live in a rural area on a small farm. I have two children, and regularly interact with the local Amish community (meaning I have a lot of exposure to a culture that has children working on the farm as soon as they are able to walk). Children are physically capable Once children reach their tweens they are capable of performing nearly any job that an adult can from a physical perspective, and children younger than that are a lot more capable than you would think (I watched my daughter pick up 50lb feed bags and carry them short distances at age 8). Remember that even now our armed forces are made up of "kids" under the age of 20, and it wasn't long ago (relatively speaking) that you were considered an adult well before your 18th birthday. With proper supervision and guidance, children are capable of performing nearly any task. Even without supervision, kids can and do find ways to survive in some pretty difficult situations... just not the type of situations that involves dumping them in some remote camp without any guidance or existing resources whatsoever. That situation requires something more valuable than physical ability - knowledge and experience. Children Lack Knowledge But what human children specifically lack is the knowledge and experience required for survival. We have some very basic instincts, but we aren't born knowing how to hunt the way that the wolf does, or what nuts and seeds to eat the way that a bird does. Most of our survival ability is learned behavior. If we took all of our children and, at a young age before they could be properly educated, and dropped them off in a village to fend for themselves without guidance or support, they'd likely perish unless they are able to easily scavenge resources. They simply aren't going to have the tribal knowledge on how to hunt game, which plants or berries won't kill them, or how to grow crops/raise livestock (which, contrary to modern belief, is a lot more involved than performing a bunch of obvious-but-monotonous daily chores). Lets pretend, for a minute, that these kids do manage to find a way to meet their most basic needs of food and shelter... perhaps they live in an area with a mild climate and an abundant local food source. In that case, the odds of surviving greatly improve. The next tier of challenges becomes organization within that society. How is crime handled? What about bullies who abuse or take from others? How are community resources managed? How are new arrivals kept alive while they develop the skills necessary to contribute? The way those questions are answered will have a huge impact on the long-term success of the community. Think of town full of littles as a tribe of neolithic humans where your oldest member is ~16 years old. That would actually be very unique in our entire history as a species, because if you factor out the child mortality, stone-aged humans actually lived to be quite old! That means much of a prehistoric tribe consisted of knowledgeable older members who were able to share knowledge with the younger ones. There is a reason that elders were revered... the knowledge they had was a valuable resource and contributed greatly to survival. In ancient times, life expectancy greatly increased after age 15. Think about that for a second... your town of littles would consist entirely of the most vulnerable part of the population. That doesn't sound like a recipe for success. There may actually be practical reasons for your society You mentioned that there is no practical reason for this arrangement, but I'd argue the opposite. In primitive societies humans had to migrate and settle where resources were available. What if, in your post-apocalyptic world, the areas where the most valuable resources (fresh water, fertile soil, whatever) were in areas where there were high levels of radiation or toxins... the types of things that might cause fertility issues or kill the young/weak members of a society. The children could stay somewhere safe until they were old enough to perhaps reproduce and also physically survive whatever dangerous environment they had to exist in. This would be a lot more feasible if there was a support system in place though... Something as simple as a group of appointed elders for the Little town... a group of adults that acted as guides and teachers and a governing body. Big town would provide material support in the form of additional resources to augment what Little town was able to produce... So Little town would be mostly sustainable, and Big town would be mostly sustainable (since reproduction and child-rearing would be nearly impossible), but together they would be completely sustainable with one meeting the basic needs of physical safety and the other meeting the needs of food/water/building material/whatever. [Answer] It is possible, as you said within a strong cultural / religious framework. The Why of such a practice aside the how is achievable, again within a structured framework. Not many generations past. mirage at a young age of 14 or less was not uncommon. Adult responsibility expected in todays society of a man of 25 was expected of young men in the midst of adolescence. Children at the age of three were expected to perform menial tasks, like gathering or sorting items. At the age of four I myself was steering a tractor (just keeping it in a straight line) while adults loaded hay onto the pulled trailer. At 6 I was fully driving it myself. While it could, and did cross the line into the abhorrent, child labor did not exist because it was unfeasible and inefficient. Children can and will "step up" given sufficient motivation. So IMHO, can it work or can it fail: Yes, under what circumstances is entirely up to the OP. Though I too can see no natural logical reason that a people would expel such a valuable resource, which they certainly are. [Answer] Unsustainable due to Population Demographics. These children know how to live in the post-apocalypse without adult supervision. They are from a rural part of the developing world. They are self reliant by age 10. Their society can survive just fine. But is it is not sustainable. The issue is replacing people. If everyone leaves at age 16 rather than dying at age 40 say, then there is a small window to have their own children. In order to replace the people who leave, every girl must raise two children by age 16. Girls can get pregnant as soon as their first period, say age twelve. In the savage post apocalypse they often do. But remember we also need those children to survive. Having a child when you are not fully grown yourself leads to a risk of miscarriage, dying in childbirth, or not being able to nurse the child. And I suspect mortality rates are high among all ages. Also consider what proportion of the "capable adults" will be out of action at any time taking care of their baby. Say a mother spends one year being pregnant or looking after a small baby and being supported by the community. That means two of the "adult" years from age 12 to 16 are spent being looked after by everyone else. 1/4 of your "adult" population is out of action at any time. For comparison in Bigtown everyone has say 22 years from 18 to 40 of being an "adult". Nearly six times as much as Littletown. So only 1/20 of the adult population is out of action at once. Also, ALSO consider what proportion of the population are full grown. In Littletown you are a child from 0-12 and adult from 12-16. Only a third of the people are full grown. In Bigtown you are a child from 0-18 and adult from 18-40. 55% of everybody is full grown. One fix is to have children sent from Bigtown to Littletown, once their teeth grown in, to replenish the child population, as teenagers go the other away. Also have strict rules about Littletowners having sex with each other. This gives then incentive to move to Bigtown. But you also need inventive for the parents to sent their children to Littletown. ]
[Question] [ This plot point has been bothering me for ages: how do robots distinguish between metals? Many robots in fiction just pick up parts of machinery for self-repair or to make more robots. They don't seem to check what metals they are using or perhaps it has something to do with their senses. Do they somehow scan the materials they get their limbs on? Writers usually gloss over this part to save time, but I like to overthink these details. I'd like to explain this phenomena in more scientific detail. This would flesh out more how autonomous robots operate in my story and others as well. The assumption in this question is that the robot doesn't have access to specialised equipment to make identification tests on materials. Either the robot comes pre-equipped with sensors that identify metals or it uses its pre-existing senses to figure out what they are made out of. If it's specialised equipment, what is the robot equipped with? If it's pre-existing senses, how does it make use of them? A robots senses would include: sight, hearing, touch (for advanced models), radio and electromagnetic senses. How does a robot test materials to know what they are? What's the process like? [Answer] ## How does a robot test materials to know what they are? The same way we do today in quality control for manufacturing purposes [With X-Ray Fluorescence](https://www.thermofisher.com/blog/ask-a-scientist/what-is-xrf-x-ray-fluorescence-and-how-does-it-work/#:%7E:text=composition%20of%20materials.-,XRF%20(X%2Dray%20fluorescence)%20is%20a%20non%2Ddestructive,a%20primary%20X%2Dray%20source.) to check what the part is made of: this technology is widely used in various applications to check for correct metal composition (don't want anyone installing 304 SS pipes instead of the 316L SS pipes that I ordered, thanks), quality of coating and plating of metal parts, etc. With other [Non-Destructive Testing](https://www.zetec.com/blog/comparing-nondestructive-testing-methods-for-welding/) techniques such as regular radiography and ultrasound: the robot can check for defects in the part such as cracks, warps and inclusions (metallic particulates of different density, air or liquid bubbles...) With [Vision Systems](https://www.cognex.com/what-is/machine-vision/system-types): nowadays it is possible to use vision systems to inspect visually 100% of production, there is even a 3D vision system With [Load Cells](https://www.omega.com/en-us/resources/load-cells): your robot can effectively pick something up and know how much it weighs With the right programming and database to compare stuff with (which is the actual tricky part for the technology today), it is pretty possible to have your robot picking up the parts and analysing them for further use. [Answer] Your robots aim is simply to replicate. The exact form/materials are secondary. Only have access to low-grade cast iron? Right, this one's going to be chunky, heavy and not very mobile. Got a load of tungsten mixed in with high carbon steel? Sweet! Hit the gold mine on that one. So I've mentioned materials by name there, but your robot doesn't need to know exactly what it's building with: Does it conduct electricity? Yup, cool. I can use it for these bits. Is it magnetic? Nup, Right, gotta find something else for those stators. Boes it take more than X force to bend? Oh well, better find something better for those leg braces. Does it anneal/reharden? Cool! Lets run with what we've got. Don't think of a scientist ordering precision parts with metals pure to 99.99% - think of your neighbours workshop where he grabs a chunk of angle iron from the scrap heap and goes "that'll do" before tack-welding it on. Metals aren't the hard part of replication. Whatever contains the brains is. I'd hate to see the reliability of an electromechanical brain! IIRC you can use thin film metal oxides as semiconductors but you still need tonnes of precision to manufacture them. There's probably a solution somewhere, and please let it involve lasers! [Answer] They use a "suction cup" equipped with: * A laser pulse to vaporize some of the material * a vacuum suction to convey the vapor * a mass spectrometer to analyze the vapor and determine its composition When they touch the material they determine what it is made of, and the related use. [Answer] Assuming you're not asking about highly specific metal grades and alloys, the robot distinguishes metals the same way I do. Steel, copper, tin, lead, zinc, aluminum all have different appearances, feel, scent even. Stiffness, hardness, color, density all are part of it. It's a matter of experience and judgment; if you work with metals enough, you just know. If resistance welding fails, or solder doesn't stick, for example, the workpiece may be aluminum. Sparks from the grinder indicate carbon content of steels. Discoloration from gray to yellowish to purplish occurs as steel is heated. Zinc combusts. Et c. edit: it seems i just repeated jamesqf's comment: How can I, using just sight, hearing, and proprioception, tell the difference between various metals? Various steels, cast or wrought iron, copper, brass, aluminium, lead - all easy to distinguish with a bit of experience. Now picking out say a particular aluminium alloy from a number of similar ones could be tricky, but would it really matter that much? [Answer] My robots have the ability to generate electromagnetic fields to sense the saturation of the material it is holding. It has a database with the information of all the magnetic metals known, its hysteresis curves, etc. It has a piece of tensorflow logic that senses the composition of the material it is holding, and chooses whether or not the element could be used for the expected result. Doesn't really have the ability to repair itself though. [Answer] ## Parts database In addition to the other methods mentioned (and I think X-ray fluorescence is the best, if you can carry the equipment around), it might be possible to identify the metal by first identifying the part. For example, your robot finds a piece of scrap in a boneyard. It examines the object from every angle and searches through an internal database of common components. Maybe there's even a serial number visible. "Aha!" thinks the robot, "this is the front engine mount from a 2045 Ford Quasar. I know exactly what grade of steel this is!" This won't work all the time. Maybe the component is unrecognisable or not in the database, but it's quick, easy, and doesn't require specialised sensors. [Answer] Presumably, the robot has a blueprint of itself and so it knows what it is (or at least should be) made of and so knows what materials to seek to make a copy of any of its parts. As for identifying parts, the robot could make use of a [spectrometer](https://en.wikipedia.org/wiki/Spectrometer), there are a few types and depending on what materials the robot is made of it may have just one spectrometer or several. I believe that this will give the most accurate identification of materials. Current computer vision software struggles to calculate mass and so might not (I'm guessing here) be able to identify materials just from just observing things. I remember that robotic cars don't like plastic bags as they can't figure out what they are and so can't figure out if they have to avoid them or can drive through them safely. [Answer] Resistance, reluctance, hardness, mechanical rigidity tests comparing deflection under known load to thickness and unsupported span. I'm interested in whether the power requirements of the x-ray fluorescence test represent any barrier to its use. ]
[Question] [ Never mind why there's a perpetual hurricane. This is about the vehicles going into and out of it. Let's say that there's a perpetual hurricane that constantly "hovers" in one location - say, over northern Africa, if that's relevant to the question. It's been there for 2 million years, if that's relevant either. It doesn't have an eye, if that's relevant either. Yes, I know it's not a normal hurricane. No, that does not matter. There are a bunch of alien artifacts embedded into the ground within this hurricane. Some of them are too large to move out of it - we're talking "skyscraper-sized". This means that, in order to research these things, people must go into the hurricane. Air travel is certainly going to be riskier than land or sea travel, and since the hurricane is entirely over land, sea travel (via [something resembling a submarine, probably](https://worldbuilding.stackexchange.com/a/59906/87100)) is not viable. Take into account the following conditions: * Flying vegetation, rock chunks, sand, etc. - if it can be blown, it's flying around in there, and statistically speaking it'll hit something eventually. Sure, most of it was stripped away during the first few thousand years of the hurricane, but occasionally the hurricane pulls some vegetation out of the swamp region, or desert winds funnel sand into the low-pressure region it occupies, or it chips off a chunk of rock, or someone looses a glove, etc. * Constant wind that ranges from "breeze" (outlying areas) up to 250 kilometers per hour (core). It always blows counterclockwise, if that's relevant. * Visibility that rapidly decreases the closer to the core you go. * 100% humidity, all the time, every time, unless you're in the outlying regions and not the hurricane itself. * High air temperature. * Potential tornados embedded in the hurricane. * Constant, constant, constant torrential rainfall; even the outlying swamps see rain on a daily basis. * Potentially very lumpy (if physically smooth) terrain towards the core where rock formations have been exposed. What would be the design features of a ground vehicle designed to operate inside this environment? [Answer] Trains. [![tunnel1](https://i.stack.imgur.com/6GEl5.jpg) https://www.earthmech.com/projects\_cut\_and\_cover\_tunnels.php Your engineers will make a cut-and-cover tunnel from an entry site to a place near the large artifacts of interest. The tunnel will be dug and then covered with precast concrete forms which will be brought through the already-covered section. In the dry desert (as you specify) it will be easy to dig a trench and the concrete should resist wind abrasion for decades. Once covered the tracks will be laid and next stop, alien artifacts! The covered tunnel will allow safe travel back and forth and also the safe retrieval of large artifacts. And a tunnel through the storm is very cool and full of potential for a fiction. It is very different in the tunnel and in the storm outside. [Answer] tread vehicles. Erosion is going to leave you with little beside rock and gravel, possibly mud in places with water and vegetation. So you are driving over rough rocky ground or muddy swamps. So you need vehicles that can handle slick soft terrain and hard debris fields with equal success. At the same time you want something heavy enough to not be bothered by high wind. That means tread vehicles or at least something like a Stryker with many sets of wheels. they are the only thing that can drive freely over such ground. [![enter image description here](https://i.stack.imgur.com/I2XJH.png)](https://i.stack.imgur.com/I2XJH.png) preferably something designed for maximum mobility like one of the early trench crossing tanks or the snow vehicle above. It does not need armor or a gun so you can reduce the weight a lot, but you can't make it too light, it needs weight to resist tornado strength winds. [![enter image description here](https://i.stack.imgur.com/OpKPs.png)](https://i.stack.imgur.com/OpKPs.png) [Answer] ## What is the substrate? The terrain under the hurricane will have a lot more to do with what your vehicles look like than the winds themselves. If the hurricane has worn away all the land, then you'll have shallow seas (with wide shallow barges, or semi-submersibles since you said no submarines). Boats may even push themselves along with long poles to provide both push and traction. If the whole thing is a waterlogged mess, then large airboat-like vehicles will predominate (so the weight slides over the surface) with either swamp wheels or some kind of similar thrust (again, poles might be useful). Rocky, worn aeolian landscape means large all-terrain wheeled or tracked vehicles like big tanks. Expect lots of traction to be needed regardless, so a vehicle consisting mostly of wheels is possible. I could even imagine a large walker vehicle consisting of a double set of large pads that alternately lift and move forward he heavy body of the vehicle. Your hurricane is predictable, so the worst part of a hurricane is gone. Predictable high winds always coming from a predictable direction will simply be the default. Your vehicles will be HEAVY, regardless of what the local conditions look like. Mass will mean they can move when they want, and sit still when they want. In fact, electric vehicles with wind turbines (robust to withstand abuse, but predictable high winds mean even clunky turbines can make power) would be perfect. They run, and if the charge gets low, they stop until they recharge. Predictable high winds could even mean that early intrepid explorers have gone before, with ultra-robust sails propelling vehicles using the same rules that apply to sailing ships. I imagine a Romanesque barge with sails resembling the head of a plow resting next to your ruins, where ancient explorers went well before modern times (perhaps there are even ancient accounts of such expeditions to entice modern explorers with hints about the relics). [Answer] Large inflated tyres to cope with the surface ... and a variety of sails, right down to a small folding sheet metal sail for the inner core region. The forces of sailing dictate a wide track to keep the vehicle upright (and constant vigilance on the sheets in gustier conditions : see image below) ... probably adopting the common terrestrial three wheel form to suit. [Image from Wikipedia](https://en.wikipedia.org/wiki/Land_sailing) [![enter image description here](https://i.stack.imgur.com/B4UfB.jpg)](https://i.stack.imgur.com/B4UfB.jpg) [Small (personal transport) ones](https://www.flypgs.com/en/extreme-sports/land-sailing) will be relatively light, such that the pilot can manhandle them round most obstacles, relying on protective gear and helmets to cope with dust and flying stones, up to about 120km/h. Using these, (even reefing the metal stormsail) at 250kph is strictly for the Hells Angels. Costumes somewhere between biker leathers, and pirates, but with medieval armour helmets... If you're venturing into the core regions, streamlined (but somewhat sandblasted) steel hulls with armoured glass windows are the order of the day; and if you get stuck, you need every crew member in suits of armour (Kevlar or medieval) on a lever (probably a spare spar) to recover the vehicle. Something resembling a [junk rig](https://www.yachtingmonthly.com/cruising-life/ostar-60-and-still-going-strong-72407) (but smaller, and each sail panel is a steel plate) would be appropriate for the core regions, for the easiest possible sail management. Blondie Hasler, sailing [Jester](https://www.yachtingmonthly.com/cruising-life/ostar-60-and-still-going-strong-72407) in the first OSTAR (single handed transatlantic race) famously spent most of the race in the cabin, leaving it only six times to adjust sail... (image from the Yachting Monthly article) [![enter image description here](https://i.stack.imgur.com/yFmVN.jpg)](https://i.stack.imgur.com/yFmVN.jpg) But sail plans in the outer region will adapt to lighter winds, and the need for performance. What makes sails logical for this job? * Per the terms of the question, you have a guaranteed, reliable, free power source! Why would anyone consider another one? * It is adaptable to varying wind speeds, by adding sail area in light winds, reefing in heavy winds, and steel stormsails in the core. * Lightweight engineless vehicles can be levered, pulled, dug out of trouble more easily * Speeds (on some points of sailing) can be several times the windspeed if terrain allows * Suitable for use [on other planets](https://en.wikipedia.org/wiki/Zephyr_(rover)) (image from the Wiki below) * And of course it's fun! [![enter image description here](https://i.stack.imgur.com/rj9Gq.png)](https://i.stack.imgur.com/rj9Gq.png) [Answer] Your prompt has a couple of contradicting things in it. Your perpetual hurricane would not have constant hurricane-style rainfall in your scenario. You specifically require the hurricane to be over land. Rainfall has to go somewhere, and hurricanes dump rain faster than it can soak into the ground or run off into larger bodies of water. That means the hurricane has either created a body of water under itself (meaning no land), or the hurricane isn't generating appreciable amounts of rainfall. I'm assuming the latter is the case here. That also avoids the conservation-of-mass question of where the storm is sourcing the water for the infinite rain. To be effective in hurricane-force winds, you want to minimize your cross-section from the wind's point of view. Your vehicle would be very low to the ground, short, and would have a wide base to make it harder to flip. A rigid skirt would almost drag the ground, to minimize the amount of air that can get underneath you. If you know the direction that the wind is blowing, you can angle your top surface slightly to convert that airflow into downforce (similar to how a spoiler works). Staying close to the ground also minimizes the likelihood of being struck by flying debris. Having a good grip on the ground will keep you from blowing away, but it also makes it hard to move. I don't know what your tech level is here, but the best way to move around in a situation like this would be with a set of stout legs built kind of like an alligator's. Each "foot" would have claws that would penetrate into and grip the ground below you. Your vehicle would slowly crawl forward. Wheel and treads wouldn't work as well; they provide provide plenty of friction in the direction of travel, but they don't do a lot to prevent the storm from pushing you sideways. Clawed feet are more like anchors, preventing you from moving in any direction. Hunkering down with a tight-enough grip can let you survive a brief encounter with a tornado. A vehicle built like this can also make your excavation easier. Once you arrive to your destination, the vehicle lowers itself all the way to the ground. The underside of the vehicle is mostly one big retractable hatch. By opening it, your researchers have access to the ground while the vehicle provides complete shelter from the storm. Given your visibility problems, your vehicle would need some sort of radar system. This wouldn't be too dissimilar from what many self-driving cars currently use. The pilot's screen would show an image that was a composite of a normal camera feed and an image reconstructed from radar/lidar data. You don't want a traditional windshield; glass can be shattered by flying debris. [Answer] You can't rely on weight alone, because the kind of weight that can't be moved by a tornado, would be very difficult to move at all. You're going to need to be securely anchored to the surface at least some of the time, so I would use a walker with lots of legs and multiple drills on each foot. It would have a turtle like shell with a meter thick, Teflon/Kevlar coated, hard rubber exterior. It would be very heavy and nuclear powered. The vehicle could also be submersible, for traveling through shallow lakes and rivers. Winds and debris will form laminar flows near the surface that will tend to flip over or at least lift most vehicle designs, so the outer edge of the shell would consist of retractable sections that would conform to the local surface profile and cause a laminar flow over the shell. These would also have a thick brush at the proximal end to the surface, that would help to fill-in the small scale ground features, to reduce wind and debris from getting under the vehicle. At more than a meter thick, they should provide a sufficient barrier, that a small vortex will from near the surface and around the edge of the vehicle, to direct airflow over and around the vehicle. I would embed thousands of fractal antenna in the outer shell for communications and doppler radar. The later will be needed to detect tornados and large objects heading toward the vehicle. While it probably can't just step out of the way of large projectiles or tornados, it can at least stop, squat and anchor itself. The vehicle can walk in any direction. It is round for aerodynamic purposes, but also so that it can rotate damaged areas to the leeward side of the vehicle. Shell blocks on the leeward side can be withdrawn into the vehicle and replaced. An internal shop provides repair facilities, particularly rubber extruders, Teflon/Kevlar coaters & antenna printers. When external conditions allow, additional sensors can be deployed as shell blocks when the vehicle reaches any artifacts of interest. As anyone who has ever lost a boot in the bog can attest, swamps are going to be a problem for a walker. The feet will need to have a vacuum breaking compressed air supply. But some swamps are just going to be too deep even for these. This is where tracks would have to be deployed, but they don't provide anchorage. The vehicle is probably going to be heavy enough that it won't be blown over, but a direct hit from a tornado could be devastating when not anchored to the ground. That's where the doppler radar comes in handy. When you see a tornado coming, you squat down and deploy a number of large augurs, drilling as deep as possible into the muck. You could conceivably construct a train of these walkers, each with a connecting tunnel between them. If the lead walker got into trouble, the others could help pull it out. It might also be abandoned if necessary. In fact, a train could literally form a walking circle that would eventually surround an artifact. A temporary canopy could be stretched between them, or other structure constructed, providing a shirt-sleeve environment for investigators. --- Addenda: Addressing @mishan's concerns regarding route erosion: There's three ways to design a vehicle for the high winds specified by the OP: 1. Construct a heavy/dense enough vehicle that tornados and hurricane winds cannot lift or blow it off course. 2. Construct a vehicle capable of anchoring itself to the terrain. 3. Rely on weight for the average conditions and use anchorage for the worst conditions. Moving a vehicle that satisfies #1 implies a great deal of difficulty propelling the vehicle at all. The weight of the vehicle tends to pulverize the terrain beneath it. Consider that our largest tanks require specially designed transports that spread their load out, in order to move them over even our best constructed roads without damaging them. #2 implies considerable erosion, particularly where anchor points cannot be reused. #3 is a good compromise, as the lower weight causes less damage to the terrain in the average case, and more erosive anchorages happen at random locations, due to the nature of hurricane spawned tornados and random debris. Tunneling would be a partial solution for the specified conditions, but is so expensive that it would not be worthwhile until you intend to have a lot of traffic on that route. The OP's scenario involves researches wanting to study immobile artifacts, within an extremely hostile environment, not heavily visited tourist sites. The walkers don't require ideal road bed to travel over. They are designed to move through swamps and over highly variable terrain, while protecting their occupants in the face of high velocity projectiles and tornados. They should be able travel through the same areas, many times, but can also route around less favorable terrain, such as that which has been degraded by earlier trips. ]
[Question] [ So oblate spheroid man is mad. One of his oblate spheroids has these nasty rings on it and he cannot watch it rotate in peace. So he dispatches Mr. Skeeble to get rid of them. Mr. Skeeble gets to Saturn and opens his Geffelle™ phone and goes to Amazone to order something to get rid of the rings. Using only tech that could be developed in 750 years (fusion drives, HELs, big nukes, interplanetary cargo ships, etc...) how can Skeeble get rid of the rings before Oblate compacts him. Rules The rings must be removed in less than 50 years. Saturn must remain intact. Whatever gets rid of the rings should not mess up the view. I can already hear the inevitable, “Antimtter DeathStar or other large improbable device. Don’t even try. Thanks [Answer] Clear them out with a moon. [![daphnis](https://i.stack.imgur.com/xNxSf.jpg)](https://i.stack.imgur.com/xNxSf.jpg) <https://en.wikipedia.org/wiki/Daphnis_(moon)> Behold Daphnis. It is a little moon of Saturn. As it cruises along it has cleared a path for itself in its ring. Daphnis is not big enough to to the job solo. You need a bigger moon for a more complete Daphnis maneuver. Fortunately Saturn offers a lot of moonstuff to work with. Your ringbusting team will accrete the [many inner moons of Saturn](https://en.wikipedia.org/wiki/Moons_of_Saturn#Ring_shepherds) and set the resulting body (named Skeeble) to orbit within the ring, clearing material out of the way both gravitationally and also by whacking into stuff. OK, mostly gravitationally. Ok, ok, all gravitationally. [Answer] ### Sell them! Put Amazone out of business with a new chain of water, oxygen, fuel, and plastic stores. To paraphrase the opening sequence of "The Expanse": "out past the belt; Oxygen and water are more valuable than gold." The rings are composed primarily of water ice. This can be sold as is or melted (water: cha-ching) electrolised into oxygen (cha-ching), processed with co2 and turned methane (fuel: cha-ching) or ethanol (booze: cha-ching), or processed with co2 and turned into all sorts of plastics for 3d printed parts (cha-ching). Poor amazone having to pay launch costs will never be able to compete with your operation, with much lower delta V costs you can form a monopoly on supplying the outer planets with everything they need. Since you need to sell it all quickly, you can undercut existing sellers until you corner the market. Oblate will surely be surprised when Skeeble buys a 51% share in Oblate inc using the trillions of dollars he made cornering the life support market. [Answer] Shoot it into Saturn with a laser via laser ablation Several space agencies have plans of cleaning up earth's orbit with a [laser broom](https://en.wikipedia.org/wiki/Laser_broom#:%7E:text=A%20laser%20broom%20is%20a,it%20hit%20the%20atmosphere%20sooner.). In principle, you point the laser at a piece of spacerock and ablate some material from it. This will create a type of propulsion for the rock, if you slow it down below its orbital speed it will plummet to earth. The current problem is that you need to penetrate the earth's atmosphere and still have a strong and focussed enough laser to ablate material. For your Saturn problem, just use a powerful space based laser close to the ring and start zapping away at the stonen from the outside of the ring. I am not sure whether you would need to zap in the direction of Saturn, to push them in that direction, or that you would need to zap in the opposite direction of movement of the stone and let gravity do the work. I think the latter is better to avoid slingshotting stones away. Since gravity will do most of the work you don't require that much energy (on a planetary scale) to collapse the rings. Also since most of the rocks in the rings are ice, you don't need that much energy for ablation. If you need more energy or want to do it faster just get a more powerful laser or more laser platforms, it is easily scalable. [Answer] I'm a simple man. I believe that there is a simple solution for most problems, no matter how complex[[1](https://worldbuilding.stackexchange.com/a/126679/21222)][[2](https://worldbuilding.stackexchange.com/a/190892/21222)][[3](https://worldbuilding.stackexchange.com/a/126447/21222)][[4](https://worldbuilding.stackexchange.com/a/136091/21222)][[5](https://worldbuilding.stackexchange.com/a/108653/21222)][[6](https://worldbuilding.stackexchange.com/a/194494/21222)]. # Nukes > > It seems like a reasonable response to me. As the size of an explosion increases, the number of social situations it is incapable of solving approaches zero. > > -Vaarsuvius > > > Any civilization that is able to send a lot of mass to Saturn in short time should be able to send nukes in short time. This is what the wiki says about the rings: > > Cassini directly measured the mass of the ring system via their gravitational effect during its final set of orbits that passed between the rings and the cloud tops, yielding a value of 1.54 (± 0.49) × 1019 kg, or 0.41 ± 0.13 Mimas masses. This is as massive as about half the mass of the Earth's entire Antarctic ice shelf, spread across a surface area 80 times larger than that of Earth. > > > Can we nuke it all? I believe so. Nukes in space behave much differently from nukes in an atmosphere. [Check out this Kurzgesagt video which details what would happen if we detonated a nuke twice as powerful as the Tsar Bomba on the Moon!](https://youtu.be/qEfPBt9dU60?t=38) As for where to get all the uranium for all the nukes, harvest it from Mercury or Mars. You won't be damaging ecosystems by mining those places. When you detonate the nukes, the ice in the rings will be gasified and each gas particle will reach escape speed. As a bonus, Saturn will become the most beautiful planet in the sky for a few hours. [Answer] A self replicating robot The seeker bot arrives and he gives it a photo of Saturn's rings and then draws red x through several sections of the rings as the bot observes. It then confirms and uses quantum computing to guess what to do... After only ten years there are billions of bots made from all the usable material from the rings... then the bots spend the next 40 years using someone else's answer to remove the remaining. [Answer] # Deploy the Gravitation Blocking Shield This gravitational disrupting barrier will inhibit gravitational forces trying to pass through it. Correct placement will allow the rings' orbit to be disrupted, and the matter will pass into stellar orbit and disperse. ]
[Question] [ This question already has answers here: [How do we tell if we're living in a virtual reality world?](/questions/49446/how-do-we-tell-if-were-living-in-a-virtual-reality-world) (21 answers) Closed 6 years ago. In this world, virtual reality has been perfected to the point were senses can be tricked and reality can be mimicked almost perfectly. Central powers can use this technology for terrifyingly efficient mass control, since people can't tell if they're in the real world or not once they've been (often forcefully) hooked to the virtual reality system. The system works through stimulation of the five senses only; it can't control anything else. Would there be ways for one person to check whether they're in the real world (original reality if you will) or not? Note that my question is different from the proposed duplicate, as it is about an newly-introduced sensory virtual reality and not an entirely new virtual planet on which people live from their birth. [Answer] Humans have far more than five senses. There are at least 20 that we know of. If only sight, sound, smell, taste and touch are simulated there will be countless discrepancies that will be quickly obvious. Probably the easiest sense to check for a discrepancy would be [proprioception](https://en.wikipedia.org/wiki/Proprioception), your sense of your body's own position. As you move around the virtual world your actual body wouldn't move and the discrepancy between the two would be an indicator that you were in a virtual world. Our sense of balance would be another easy one to detect discrepancies with. This is actually a problem with existing virtual reality technology where we see movement but don't sense it in our inner ear. This commonly results in feelings of nausea. [Answer] I think it would come down to a discrepancy between the knowledge one has of how the real world works, and what they observe in the virtual world. For instance, if a physicist going about his day to day suddenly notices that some molecular process stopped behaving according to the research he has been faithfully reproducing for years, he'd have pretty good reason to think he'd been stuffed in a simulation. Similarly, if a person was put in the simulation, but all of their friends and family were not, it'd be pretty easy to tell that a bunch of people ceased to exist. Even if they were simulated, there are bound to be memories that the real person would remember, but the people running the simulation would have no way of knowing. When I was a child, my brother and I had a code word that we never told anyone. We used it to make sure neither of us had been abducted by aliens and replaced with a clone. I would imagine in a world where people know that being shoved in a machine is a real possibility, they would have such memory "canaries". Even consider the top in Inception. Just another example. [Answer] > > Would there be ways for one person to check whether they're in the real world (original reality if you will) or not? > > > A person's memory would be the weak point here. While all their external senses are controlled by the simulation. There is no way for the external system to know personal details about a person's history. So if a you wanted to know if you are inside a virtual world with the intent of that world to being deceptive (i.e. make you think it's the real world). All you would have to do is return to a location that was personal to you. Find some kind of detail that only you knew about from your past and verify that detail to be correct. If that detail is missing. You would either challenge the idea that you're in a virtual world or you would experience some kind of personal crisis. If the virtual world is limiting in someway. As to not allow you to leave the area. You would accept the world as real. Upto a point. Take the movie [The Truman Show](https://en.wikipedia.org/wiki/The_Truman_Show) as an example. Truman accepts his reality as real but his human nature drives him to escape. Even when the world fights back he would rather die than be limited by that world. It's interesting that even in The Truman Show it is his own memory that plays an important role in discovering the real world. [Answer] I just wondered how people felt about a solution put forth in a episode of Dr. Who where the Doctor figures out that he is in a simulation by asking everyone for a list of numbers. His logic was that computers can't really generate a random list of numbers. So, everyone would give the same list. [Answer] This sounds like the classic physics relativity problem to me, heh. I think the main loophole lies in the words "almost perfectly"... If the simulation isn't truly perfect then that should be enough to prove it's not real. Think of it like a small math error, the system either has to try to silently correct for it and blow the consistency of the process, or allow the incorrect value to stand and risk it being compounded to a macroscopic scale. The catch is that you have to find something that the system can't process perfectly but which you know the correct result of. cgTag's answer hits one good option but misses the more straightforward method of using it. The plot device from Inception, of an object with physical properties that only you know, is a perfect solution. The VR environment can't replicate the behaviour of something that it doesn't know about. As long as the "import" process in to the virtual world isn't more than a basic analysis of the items you have, you should be fine. How the person being "imported" to the world is scanned is actually pretty key as well. An implant or biological marker that you could detect but which wouldn't be included in your avatar by the VR would do it. Another use of memory is other people... to be sufficiently convincing you'd have to hook up everyone or simulate the people who you didn't hook up. If you've got people being faked then you just need to test common memories to find one who has a discrepancy. Of course it only works if the powers in charge are being more selective of who they're hooking up, so it doesn't work so well in something like the Matrix where just about everyone is connected. Unless you're post-scarcity you should be safe though on that. A lot of the possible plot mechanics to detect an illusion depend on preparation factor. A person that knows there is a possibility of being placed in to such an environment has time to prepare recognition tools against it, such as the ones described. On the other hand, a person taken by surprise, both in terms of the existence of technology as well as their connection to it, would be less likely to be able to identify the fabrication of their surroundings. It's also important to note that most mechanisms for detecting the substitution aren't going to work more than a few times. As a random example, if you managed to slip a bioimplant past their scan and use it's absence to determine that you're hooked in then they'll simply improve their scans to pick it up. How long it takes them depends mainly on how long it takes them to realise that you've beaten the system that way. A lot also depends on what the person does after they've realised... disconnection yourself like in the Matrix is probably going to get noticed much quicker than staying in the system and trying to subvert it from within. If there's a period of a month between you discovering it and the first evidence of you doing something that demonstrates that knowledge, well that's going to be harder for them to trace back how you found out. How much of a threat they think the information poses also limits how much they'll let you spread it once you're discovered. Hope something in there helps. [Answer] This is a question philosophers have been wrestling with for many thousands of years. Some Buddhists, as I understand it, would say that’s not a bad analogy for how the world of our senses really is an illusion, and we can only free ourselves of it through enlightenment. The classic Western development of the idea was [Plato’s Allegory of the Cave](https://web.stanford.edu/class/ihum40/cave.pdf), where the evil tyrants have slightly lower tech at their disposal but do essentially the same thing, and it has influenced many kinds of religious mysticism. The Matrix is the most well-known variant of the idea these days, but it’s been used in many other works. The Silver Chair by C. S. Lewis sets up a Christianized version of the allegory: the villainess has succeeded in tricking the heroes into believing that Narnia is nothing but a fairy-tale for babies, and her realm is all that is real, but they stand up to her and decide that, even if Narnia isn’t real and there’s no possible way for them to ever prove otherwise from inside her cave, they still would rather try to live there than here where life has no meaning. Philip K. Dick often wrote about this theme; a really clever version of it was Eye in the Sky, where the characters all find themselves living in the world of one person’s religious delusions, and he’s the only one who doesn’t realize that the world worked nothing like he thought it did and his belief system becoming true changed everything overnight. This leads to a series of false realities imposed not by any villain, but by their own narrow minds. A few decades ago, the movie people would have brought up would have been Total Recall, loosely based on another story by Dick, but even in the Hollywood version, a popular fan theory is that the protagonist really did lose himself in his own delusional power fantasy and refused to wake up. There’s no way to tell. If you approach it as a philosophical problem, you’ll end up looking for a philosophical solution and not a scientific one. That said, philosophers really like stories where philosophers find the truth by being really smart, mystics really like stories where mystics find the truth by meditating hard, religious apologists really like stories where the revealed doctrines of their religion are revealed to be true, gamers like stories where NPCs lead the hero by the nose until he shoots his way out, and so on. It’s ripe for sending up if somebody wanted to. If the simulation is good enough, there’s no way to find anything in it that looks or feels fake. My best suggestion is that you could force the simulation to simulate some physical process in real-time that can’t be computed efficiently, forcing it to approximate, then take your time and calculate what should have happened. The Navier-Stokes equations are an example that aren’t known to have an efficient solution. But keep in mind, the simulation could alter your notes! A better bet would be checking something from the real world that the programmers would not know about. This could be harder than it sounds: is the other person really a sim who doesn’t know the secret she’d never ever tell the tyrants, or does she think she’s in a sim where they’re trying to trick her into telling them? [Answer] From a computing power standpoint, it would take a computer larger than the world to fully simulate the world. They don't have a computer that big, so there will be holes in their simulation. It is just a matter of finding where they skimped on the processing power. You just have to act as oddly as possible to push up against a boundary they didn't expect. Use a microscope to look at sand on the beach, dig a 50 foot hole in the ground, some where there is a limit. They control your senses do they control how you feel on the inside? Eat too much does it feel the same, run too far do you feel the lactic acid build up in your muscles correctly? If you workout do you get stronger? Also what is the time frame for deciding in\out of simulation. Do subtle changes occur that normally happen when time passes, hair and nail growth that kind of thing? [Answer] > > Reflexive, Reactive, Reflective Intelligence > > > In robotics, the 'degree' of intelligence of an autonomous system is sometimes classified into 3 levels: reflexive, reactive, and reflective. 1. Reflexive intelligence merely responds to a 'known' stimuli with a singular invariant response. x : --> y , where x is the stimuli and y is the response. In a virtual world, reflexive intelligence is entirely incapable of identifying the stimuli as being sourced from a virtual/artificial source. 2. Reactive intelligence responds to a stimuli with a variant response. Here, x : f\_t(x) --> y , where x is the stimuli, y is the response and f\_t() is the behavior of the autonomous system. The behavior of the system can change over time. It can also be trained. These attributes put reactive intelligence well beyond mere reflexive intelligence. However, even reactive intelligence can not independently distinguish between stimuli from real vs. virtual world. 3. Reflective intelligence responds to a stimuli with a response that based in part on the stimuli and in part on the state of the system and its behavior. Here x : f\_t(x, s) --> y, where s is the state of the system. With reflective intelligence it is entirely possible for the response to a stimuli being entirely independent of the stimuli and based solely on the state of the system; x : f\_t(s) --> y. > > Multi-layer abstraction > > > Unlike the previous lower levels of intelligence, the system modifies itself even in the absence of external stimuli. The system state (s) keeps changing independent of the external world. These changes are not random. They are based on set of 'rules' or meta-parameters that the autonomous system uses to govern its change of state (s). These meta-parameters can be structured in layers, where parameters (rules) at a given layer are dependent on parameters at a deep layer. The deeper the meta-parameter, more invariant it is to change. All the meta-parameters in their layered structure together constitute the autonomous system's 'world view'. > > Autonomous adaptation > > > As such, this type of intelligence could be considered introspective. This is where the reflective intelligence diverges sufficiently from lower levels of intelligence to potentially decipher the source of the stimuli it is receiving. The challenge here is for the virtual world creating stimuli. The virtual world does not know the state (s) of the autonomous system. When a stimuli-response loop is in progress, the virtual world will struggle to sustain a stimuli-response cycle that does not begin to diverge from the reflective intelligence's 'expectations', predicated by its 'world view'. > > Expectation management > > > Therein lies the challenge towards building a universal virtual world. It can not 'fool' everyone equally. The reflective intelligence that has a deeper layered structure of rules/meta-parameters and a more robust rule update policy, will be more difficult to convince during a stimuli-response cycle. The lack of consistency with the 'real world' will emerge in pattern of sequence of stimuli. > > Game Theory > > > Reflective intelligence employs a self-correcting mechanism. In doing so, it will intentionally produce a response that it knows is completely wrong for a given stimuli. The subsequent stimuli given by the 'real/virtual world' will tell the reflective intelligence about the world's traits. In essence, for reflective intelligence, the stimuli-response is a two-way street and both the world and the autonomous system are giving each other stimuli, instead of a stimuli-response. > > Inception! > > > Pattern recognition in successively deeper layers of abstraction is a very powerful tool to approximate arbitrarily large and complex information. Lets see how this plays out. A reflective intelligence 'expects' the world to have at least a reflective level of intelligence in the 'game theory' setting. 1. If the world then display a reflexive stimuli/response (Think extremely poorly coded NPC in a video game, acting in a mindbogglingly repetitive manner), the expectations are completely thrashed and the reflective intelligence knows it is trapped in a virtual world. 2. If the reflective intelligence intentionally 'jukes' the world in its response, the world my respond with a altered stimuli. While this a better than reflexive intelligence and passes the first layer of rule abstraction, the manner of change in the world's stimuli (going from f\_1(y) to f\_2(y) to f\_3(y)) will not align with the expectations about pattern of change of world stimuli and this fails the second layer of rule abstraction. 3. If the world responds to the myriad of 'jukes' and brilliantly varied behavior of the reflective intelligence that never sufficiently violates its expectation for arbitrarily deep layer of abstracted rule, then the virtual world has successful supplanted the real world for that specimen of reflective intelligence. > > Enter Morpheus! > > > Even, if the virtual world successfully learnt to consistently meet the expectations of individuals, there still remains a layer of abstraction, which is beyond reflective intelligence: a type of swarm intelligence. However, swarm intelligence is beyond the scope of the OP's question of mind control. I'll just say, when individuals are limited by their isolated intellectual capacity, they can team up to pool together their individual and unique layers of abstraction. With this dialogue the fact that the virtual world has adapted to provide an individual a tailor made stimuli-response experience will emerge. I can not recall any Sci-Fi literature that describes a virtual world that can convincingly adapt to an entire group of unique reflective-intelligence individuals. > > Conclusion > > > The answer to the OP's question of defeating a virtual world's entrapment in a nutshell is: use deception and teamwork to outsmart the adversary! [Answer] I learned to distinguish between lucid dreaming and reality by deliberately focusing on areas of my body where I knew there wold be pressure if I was sleeping. If I believed I was standing up, but I felt pressure on the backs of my calves, then I was dreaming. From a mechanistic viewpoint, such a VR system is stimulating the brain either directly or indirectly. For this discussion, eyepieces and VR suits count as "indirectly". However, whether the mechanics are direct or indirect, you can always apply stimulation easily, but can't prevent it easily or block it proactively. Therefore, your VR experience will always be a blend of reality and what the VR operator wants you to see. The VR operator will do his best to limit the sensory input from the real world, but absent suspending the victim in an orbital facility there would always be something to cue off of. [Answer] Maybe the Fermi paradox would give it away that the world is not real? A simulated universe would likely have limited space (to save computing power). For example, it could be that only our solar system is simulated in great detail and the rest of the universe is just a shoddy stage decoration, with barely enough detail to seem real when observed from the Earth. So the absence of extraterrestrial life in the entire observable universe would be a sign that the beings who run the simulation did not bother to create life in other solar systems because otherwise the simulation would have got too complex and computationally expensive. ]
[Question] [ Earth's greatest minds have done it, they [captured](https://worldbuilding.stackexchange.com/questions/40907/how-can-we-catch-a-teleporter) Dave the teleporter, but now we have a problem, where do we keep him? While we can keep him sedated until it is built we need to work fast, lest we risk a ''Free Dave'' movement. They have to be quick, money is not an issue. ## A Few Details of Dave * It has been confirmed, Dave served in the Russian military for 6 years. * Dave believes now that he is a guiding finger for god. * Because he believes this, he is a pacifist and refuses to kill. * Dave is only able to teleport to places that he can see or has seen before. * Dave does require a memory of the sights to use them. --- Using the above information how can the governments of Earth build a prison that can hold Dave? [Answer] The implication in the question is that "Dave" needs to be focused in order to visualize the target and access it through teleportation. So the first thing to do is break his ability to focus and concentrate. Perhaps the most effective means without using permanent sedation or lobotomizing the character (and why isn't this allowed?) would be to place him in the "white room". The British Army pioneered this technique during "the Troubles" against the PIRA in the 1970's in response to charges that they were using torture against PIRA terrorists. The room is simply a very small enclosure which is painted a stark white colour, has 24hr fluorescent lighting and is constantly filled with "white noise" to obscure any aural cues coming from outside. The techniques was refined by ensuring no time cues are ever provided either; meals arrive at random times, the same person always deliver meals or changes of clothes and bedding, the same interrogators come to visit...you get the idea. With nothing to "attach" to, the mind begins to wander and become unfocused. Since the meals and interrogations occur at random intervals, normal sleep cycles are interrupted as well, further disrupting mental processes. Variations of this include PSYOPS units using powerful loudspeakers to blast atonal sounds at enemy positions to disrupt sleep and impair communications (trying to give orders while screaming at the top of you lungs isn't very effective for communicating complex ideas or plans). A fallback position would be to identify every place he has ever been and attempt to demolish or drastically rearrange the interior of the structure so his memory of the place is faulty. Arranging matters so he will teleport into the interior of a wall will either be instantly fatal or discourage further escape attempts, especially if he is informed in no uncertain terms that this has been done (but not specifying which places have been changed and which might still remain as they were). The combination of lack of focus and doubt that it will be possible to teleport to a safe place should paralyze Dave's ability to teleport from the facility. [Answer] ## A pressurized cell. If you quickly jump from a high-pressure to a low-pressure environment, [you die painfully](https://en.wikipedia.org/wiki/Decompression_sickness), but you can live if the environment is pressurized slowly. So, after incapacitating Dave, put him in a cell and slowly pressurize the air. Tell him he's in a pressurized cell when he wakes up, but don't tell him exactly how pressurized the cell is. He can live normally inside the cell, but if he tries to teleport out into a normal-pressure environment, he'll die. Original idea from [this webcomic](http://grrlpowercomic.com/archives/1881). [Answer] Simple. Make Dave not want to teleport. Assuming ethics are ignored, perform an operation on Dave and install some sort of device that would make him dependent on staying put. One example that came to mind was a bomb which goes off if he moves to far from a certain point. If he can teleport himself away and leave any foreign object behind, than remove a part of Dave's body in such away that the "bomb like imprisoning object" would be used as a vital replacement (for the lack of a better example, I'm thinking like, some sort of vital bone, but maybe technology could allow for an artificial organ). If he leaves the "bomb like device" behind, he dies. edit: You wouldn't need to kill David. The bomb idea was a bit extreme. You could instead have the device release a sedative if he venture's too far and have the device have a GPS. [Answer] # Wipe his memory and put him in a regular cell. If Dave can't remember where he's been, then he clearly can't teleport there. He'll constantly be gaining new memories, of course, but they'll all be of his cell, so he can have fun teleporting from one side of the cell to another. Be sure to make sure he can't see through any openings at any time - that means no windows, and he must be unconscious if the cell door is opened for any reason. Basically, he's going to be in a solid block of concrete - with normal security precautions, of course. The prison should be able to hold any regular person who can't teleport. ]
[Question] [ The idea in its simplest form is that a stellar system of planets is within a transparent gas cloud that includes oxygen. The gas cloud is so incredibly dense (around sea level earth pressure) that humans can breathe and survive in open space. I would like to use real world physics as much as possible, however some serious wand waving or over-simplifying is necessary and i would love some help. Obvious issues that come to mind: 1. Friction. Planets orbit incredibly fast and will burn up. Maybe solved if the gas cloud itself spins at the same rate as the orbiting planets (adjusting for distance from star as well). Space craft could be explained by some king of magnetic shield that magically displaces the gas without huge amounts of energy being expelled. 2. Oxygen = boom. Maybe the star's gravity will prevent a chain reaction of ignition. Or maybe it won't be an issue, after all a candle draws in oxygen, not the other way around. 3. Gravity sucking in the gas. I have no solution for this. Although I guess there's only so much gas that can fill the gravity well of a planet. 4. Air pressure. The combined mass of the gas cloud could explain air pressure in a vague way, however this pressure might increase a lot around the planets? After all, deep sea has more pressure, therefore it stands to reason that an astronomical expanse of gas would result in an enormous amount of pressure. Although that pressure centres on the star, it might still be crushing on each planet. My goal is to have reasonable explanations that are pseudo-scientific and familiar to the average reader. [Answer] This works best as an accretion disk, although there's still going to be a bunch of hand-waving if you want the science to be hard: * Viscosity of the gas is going to be significant on interplanetary scales and will eventually collapse the gas into planets or lead to it either being ejected from the system and/or collapsing onto the star. That being said, ["eventually" can be a lot longer than the time your story takes](https://kids.frontiersin.org/articles/10.3389/frym.2019.00092#:%7E:text=The%20process%20of%20star%20formation%20takes%20around%20a%20million%20years,that%20orbit%20the%20central%20star.) To maximize the believable duration, you want the planets and gas moving together in circular orbits moving at the orbital velocity appropriate to their distances from the central star. * Any orbits that cross each other will generate viscous effects which disrupt the disk, again causing collapse into the star / planets. To avoid this, put the atmosphere in a single thin disk. This is why "accretion disks" are common but "accretion spheres" are not a thing. Note that "thin disk" is only thin on interplanetary scales. Having it be 10,000 miles thick is fine as long as the star is at least a few light-minutes away. * The heat from the star will affect the disk, and this will tend to blow the gas away from the star itself. The inner radius of the disk will be about as hot as the star and thus the gas molecules are less likely to stay in their nice Keplerian orbits. This mitigates issues like the oxygen catching fire or similar - but the inner edge will probably still be ionized, tenuous, and unsuitable for life. * The further reaches of the disk are going to be colder, with the "air" condensing and then freezing out into diffuse "snow". Note that nearby portions of the disk will tend to have similar temperatures. Heat loss will be mostly off the surfaces of the disk, and the heat source will be the sun (plus viscosity...). This will drive some magnificent turbulence, storms and out-of-plane currents. * Filling a solar system with gas at atmospheric densities is likely to make the gas opaque or diffusely-lit. The star will be a bright patch in the sky, but you're [probably going to lose visibility for individual planets and stars](https://www.howitworksdaily.com/what-is-the-maximum-distance-the-human-eye-can-see-if-unobstructed/). Interplanetary navigation is going to need a lot of dead-reckoning or trips to the unbreathably-tenuous surface of the disk. * Since the gas is moving at stellar orbital velocities and we've cleared out the central regions, you don't have to worry too much about the sun's gravity sucking up gas. Planets still will, but planetary formation is on the scale of a million years or so, so you only need to replenish the disk on those scales (or not... how long does this state last?) * That's a lot of oxygen, and oxygen isn't the most abundant gas in the universe. (Hydrogen is, by a lot.) Whether or not you decide to explain it in the story, you might want to come up with some reason (supertech aliens? magic?) to explain how this all came about and whether or not the creators care about maintaining the state. Personally, I find the origin of such a stellar system to be much less plausible than one continuing to exist and be quasi-stable on the timescale of a century or so for "modern technology" to arise. [Answer] Get rid of gravity. I think the biggest issue is gravity. Like you mentioned in your post, the dense gas will tend to collapse under gravity. There's enough mass in a solar system full of STP air to create thousands of suns. It would happen pretty quickly. Make gravity some other kind of force of interaction, perhaps something like magnetism, which air does not take part in. Certain elements/molecules are just not pseudo-magnetically "charged" and won't feel an attractive force. That way, planets may still hold themselves together and follow Keplerian orbits, while and people and objects fall with a force inversely proportional to the square of distance. [Answer] You can try making it not a stationary state, but a long lasting transient. Somewhere there is a source of gas and somewhere else there is a well sucking in all that gas at the same rate which it is emitted. In between the two, due to the flow, there is something akin to an atmosphere, or better said, a rather constant amount of gas. The stream of gas can also happen in the same direction of the planets motion, so that the induced drag is somewhat reduced. [Answer] Frame challenge: How do I breathe in space? That's the neat part, you don't There are fewer issues entailed by redesigning the biology of the creatures in your world than by redesigning all astrophysics. Say that they have a metabolism that works without oxygen or other gases (see [this question](https://worldbuilding.stackexchange.com/questions/240991/is-it-possible-for-a-living-creature-to-have-no-need-for-oxygen-or-some-other-ga/241006)), and they carry within their bodies a few chemicals that fill in the metabolic gaps. That allows you to not worry about the problems you raised in your question like stars exploding. [Answer] The early universe was a lot denser than it is now and at one point would have been warm, wet and opaque during it's transition to hot, light and filled, to cold, empty and dark (I forget the time scales), you could set it then, although it would be lacking the heavier elements that make solar systems more interesting. It also didn't last very long. Have a read up on it and see if you are inspired by the setting at all. So the other option is have the universe not expanding, where gravity and dark energy cancel out. We don't know enough about the expansion of the universe, to know whether or not a universe that didn't expand so rapidly would work with the current laws of physics, so it is not implausible to have the whole universe and not just solar system full of gases. That's your best shot at avoiding to have to tweak all the other laws. The issue is not the gases clumping but the fact that stars are very good at blowing away the gas clouds they are born in. you'd have to compare solar pressure with atmospheric pressure to see what would roughly happen. [Answer] If you were willing to borrow a bit fantasy you could replace air with something like the classical interpretation of aether as posited by Greek philosophy [In particular](https://historycooperative.org/aether-primordial-god-of-the-sky/) Plato and Aristotle both held that this element, Aether was what the gods breathed instead of air. As well as being the material that suspended celestial in objects in place. You could make something analogous, in particular I believe it might work better as it serves as basically one handwave instead of the hoops you'd need to jump to justify having mundane gas. ]
[Question] [ My work in progress involves a small town which has been set up in an isolated part of the United States. The backstory is that some very advanced aliens want to set up an observatory on Earth, to monitor human behavior. They have their own version of the Prime Directive (closer to a scientist's desire to not contaminate a petri dish than a concern for our welfare) and a nearly magical level of technology. They have no difficulty replicating our buildings and civil infrastructure, nor do they worry about detection or intrusion by the indigenous population. The entire town is concealed holographically and surrounded by a selective emotional induction system (Any unwanted visitors become frightened, thirsty, anxious or whatever emotion best convinces them to leave). The only problem their leader (me) can't solve is how to initially fill the town with humans without letting them know that the town builders are aliens, and while simultaneously not letting others know of the town's existence. How do you find a bunch of disconnected individuals (or families) who would happily move into isolation? By the way, this is all backstory from my current-day story's point of view, so the populating of the town actually occurred back in the 1970s. Edit : It has occurred to me while creating this question and reading the initial responses, that my mythical little town has a lot in common with the setting for Wayward Pines. That story used scouts to recruit their future residents. I'll have to give that possibility more thought. [Answer] # Have a [Company town](https://en.wikipedia.org/wiki/Company_town#United_States) Pick some industry like manufacturing or mining or whatever. Then you can offer people absurd wages to come to your town and do whatever job so that you can study them. This offers several advantages over religion. # You can get anyone who wants money. An alien race can probably make a lot of cash. You can as such get whatever desired traits you want from people by just offering them a dream job and loads of cash. # The government has an easy answer to any abuses or medical experiments you do. You can hire a lobbyist to impress on politicians that your town is valuable and good, and you can incorporate the town so you control the hospitals, police, and mental health. As such, you can do whatever and people will just assume you're a controlling corporation, not an alien race. This also minimizes chances of the military or the government finding you and worrying about an invasion, which would be a massive prime directive violation. They know you're there, and they don't care so long as you pay your taxes. # You can control who goes in and out. You control the police, and whatever local authorities you've made. As such, any stubborn people can simply be ordered by the mayor to be removed, even if they resist emotional impulses. The best way to not be noticed is to be boring. There's no shortage of companies in remote places doing whatever they want to be employees. Be part of the crowd, and be invisible. [Answer] A "movement" moves in. <https://en.wikipedia.org/wiki/Antelope,_Oregon> > > In the early 1980s, members of the Rajneesh movement moved in and > effectively took over the government of the city by outnumbering the > original residents with new voter registrations. On September 18, > 1984, a vote was held and the city was renamed to "Rajneesh, Oregon". > By 1985, after several of the Rajneesh movement leaders were > discovered to have been involved in criminal behavior (including a > mass food poisoning attack and an aborted plot to assassinate a U.S. > Attorney), their guru left the country as part of a negotiated > settlement of federal immigration fraud charges, and the Rajneesh > commune collapsed. On November 6, 1985, the city voted to rename > itself back to Antelope. > > > The town was taken over by a cult. It makes for fascinating reading. It is still not clear how many people lived there or exactly what all they were doing. If you come at it from a Laird Barron-type horror perspective it is pretty wild. So too your city. There is nothing wrong with being a member of a splinter religion or following a charismatic leader. There are many of these in the US and most are not the Branch Davidians. Your people are a peaceful sect that want to do their peaceful things. They have fields and crafts and are regulars at the farmers market in the nearby city where they make their money. They have some pamphlets too for interested people. It is a good cover. Maybe it is legitimately who and what they are. [Answer] > > AAA Do you want to live in the place of your dreams? We are looking for you. > > > In those years people went to mass gatherings like Woodstock, the various protests in Washington DC and all the rest without social media spreading the word. You have just to spread a tam tam to throw a bait, and test the people who respond to see if they fit your selection criteria. If they do, when they get close to the barrier you switch it off and let them in, if they don't you don't switch the barrier off and let them be scared away. [Answer] Your aliens must be in cahoots with a government, local or national Even in the 70s, towns were hard-pessed to exist without infrastructure. Some of this can be dealt with by your aliens, but others won't. For a town to survive, things must be brought into and taken out of the community: * Food * Electricity/Natural Gas/Fuels of all kinds * Water (in terms of santizing chemicals, pump parts, state inspections...) * Sewer (even if sewer treatment is on-site, there's chemicals... parts... inspections...) * Raw materials including wood, metal, and fabricated materials such as tools, parts, etc. I could go on, but the reality is that no town (at least in the 70s) is truly isolated. Even communes, unless living in what the rest of us would call squalor, were not truly isolated. Trucks had to come in, telephone lines had to go out. People had televisions and radio, and the Federal Government cared an awful lot whether or not they paid their taxes. And let's not forget some poor schmuck who decided to get on their bicycle and ride along a lonely road only to discover an entire community, which said rider immediately writes about in their favorite [underground press](https://en.wikipedia.org/wiki/Underground_press). And such presses existed in great numbers in the 70s. It was kinda their hayday — the "social media" of that generation. So, let's consider an option: Let's consider Russia's "[closed cities](https://en.wikipedia.org/wiki/Closed_city)" > > A closed city or closed town is a settlement where travel or residency restrictions are applied so that specific authorization is required to visit or remain overnight. Such places may be sensitive military establishments or secret research installations that require much more space or freedom than is available in a conventional military base. There may also be a wider variety of permanent residents, including close family members of workers or trusted traders who are not directly connected with clandestine purposes. > > > > > Many closed cities existed in the Soviet Union from the late 1940s until its dissolution in 1991. After 1991, a number of them still existed in the CIS countries, especially in Russia. In modern Russia, such places are officially known as "closed administrative-territorial formations." > > > The wonderful thing about closed cities is, because they exist with the support of the government, all those nasty problems I just discussed don't exist. The protecting government is ensuring that all the proverbial gazinta and gazoutas happen without anyone asking, "Why's there a city there in the first place?" And once you have a government lined up to protect the city... The answer of how to get people to populate it is trivial. The government can advertise on the grounds of settler's rights, or give out invitations to serve a purpose, or simply extend invitations to existing government employees, whose jobs are then refilled in the normal way. It's easy at that point. [Answer] You already have the tools You've mentioned an Emotional Induction field of sorts. All you need to do is find people who fit your needs and coax them into moving to your town via inducted emotional responses. If they see the name of the place, induce a sense of longing or homesickness to goad them into uprooting themselves and moving there. Do this for enough people and your town will soon be populated. It may be necessary to mess with people's memories to suggest that it's not unusual to arrive in a largely unpopulated town and (sometimes literally) set up shop. It could also be worth abducting an entire Smalltown-USA from somewhere nearby and moving them into your town with some liberal memory-modification. Truthfully though, it may be better to start with an existing town and modify it to suit your needs rather than build a whole new one. As others have commented, tying a whole artificial new town to the infrastructure of a nation without anyone noticing anything amiss would be.. a challenge in the extreme. ]
[Question] [ Cryomancy is magic involving the removal of heat from an object by converting thermal energy into magical energy, thereby cooling the object. The conversion to magical energy is not perfect (some small amount of heat is released after removing it from the object or area of effect), however I do not believe this will affect your answers. * Food can be cooled from room temperature to just below freezing (30‚Ñâ/-1‚ÑÉ). * Food can be magically maintained at the intended temperature indefinitely. This is done by enchanting the area around the food, not the food itself. The maximum area of effect is a radius of 15'/4.5m. * The effects of cryomancy on food are similar to those produced by flash-freezing. Additionally, if it can be frozen via flash-freezing, it can also be frozen using cryomancy. Question: How would cyromancy affect the eating habits of medieval people? * Magic is unavailable to the average person, forcing the employment of mages (much like the average person today not having direct access to flash-freezing equipment). The majority of mages are of equivalent social status to a blacksmith. * For the purpose of this question, assume we're talking about London during the 1500s. [Answer] A few first ideas: * Food becomes less seasonal * Exotic food becomes available * Some diseases might become rarer because it is easier to provide a steady diet * Famines might be avoided * Icecream & cold drinks in Summer, of course Maybe forget about food, what else can you conserve?! Dead bodies! Okay, also food in some cases. But * Could also open up things like autopsies for crime investigation. * Plagues might be avoided by freezing areas where they develop. Or by generally advancing medicine. * Make hot places more habitable * If there is an area in the world where farming food is cheaper this might become a more economic trait since the food can be transported faster. The transport cost might however be the limiting factor here, reducing the impact. Maybe the general impact is not that high because people already knew how to preserve many foods, of course now you can keep the strawberries without turning them into jam but that might not be worth paying a wizard. Depending on how rare they are. [Answer] This is going to vary based on several factors - for example, how long do your enchanted cold-spaces last? Is this something that a Mage can cast on your Larder once per year, and you use it as a fridge for the next 12 months? Or, does it need to be renewed weekly? In the former case, you would probably see "travelling Mages" moving from village to village throughout the year, spending a week or so renewing enchantments (private for the well-to-do, or communal spaces for poorer families to share) much like a merchant. In the latter case, nobles (or merchants and farming cooperatives) might keep a couple of mages on staff to ensure their perishables don't, well, perish. Food storage and preservation is going to be the first big boon - 'fresh' milk, fruit or vegetables for more of the year, instead of cheeses, jams and chutneys. Meat could be kept for longer without salting, smoking or pickling. Both of these will improve the nutritional value of the food (or, rather, remove the requirement to reduce it for storage) and lead to people being healthier Nobles might also start experimenting with frozen foods and deserts to show off their wealth - assuming that cryomancy was not too cheap or common. [Answer] Unless there are an extremely large number of these mages running around and offering their services very cheaply, I don't think it will affect the average person's life much. The lower classes will likely live much as they normally did, while viewing the occasional access to out-of-season food or frozen food / cold drink in summer as a special treat when a traveling mage comes through town selling wares. The biggest change I would expect would be an integration of this ability into the system of food-related status symbolism. Food was often used to convey wealth and status in the middle ages, for instance, spices were very expensive, so serving food with a lot of spices in it was a way of showing off your wealth. There is a very interesting series of videos [here](https://www.youtube.com/watch?v=i9RDaf8j2Yg&list=PLEdnpoTDGX7LE454gNUJrm2pMD3wpLOVY&index=25) on what food was like for different classes in the middle ages and what some of the etiquette and expectations were. I imagine the extremely wealthy would have their own mage much like they would have their own chef, and would show off their personal mage's talent in the form of serving cold drinks and treats in warm seasons and by serving "fresh" preserved food that would be out-of-season normally. On the other hand, if the mages are a dime a dozen, one mage in nearly every family, village, whatever, it would probably have much broader effects. Exactly what all those would be is hard to tell, depending on what other parts of the culture are being changed by having mages around, but if all they can do is freeze food, you would probably have, like others mention in their answers, much less dependence on seasonal food and food that "keeps" easily, allowing a greater variety in the diet more like we see in other cultures that have cold food storage options. The things that would remain expensive are things that remain harder to get despite the cold storage, for instance because they need to be shipped from far away or they take a lot of time and effort to produce. [Answer] You couldn't "Flash Freeze" at the temperatures you're talking about, in fact, at 30 degrees F, you might not even turn water into Ice (the specific heat of water is insanely high. This means that the change of state from liquid to gas or solid will take a long time and some extra energy. Ever have a soda from a cooler explode on you because it's frozen, but when you grabbed it, you could have sworn it was liquid? While it was below freezing, it maintained a liquid state because it hadn't be distubed... the depressurization of the gasses generated the specific heat energy to cause it to solidify and water is at it's most dense state as a liquid... the ice takes up extra space, which causes the fountain.). That said, Ice was harvested by various methods as far back as the 1750 BCE! By the 16th century, it was a major export commodity of Saint Petersburg, Russia during the winter when the waters would freeze and it was not uncommon for wealthy people throughout Europe to keep Ice Houses to store snow and ice from their property. Alpine Nations and Scandinavian Countries also had Ice Harvesters (as depicted in Disney's Frozen. It was a real trade.). Manufacturing of Ice was developed in the Americas and made it cheap enough to make proto-Fridges called "Ice Boxes" which would use the Ice to keep the insulated cabnit cool and it was, historically speaking, not that long ago that it existed (My Grandfather's parents were Ice Manufactures). [Answer] I imagine a potentially huge impact on sea travel. Just enchant a section of the ship for food storage, have an on-board mage "Master of Supplies", thus multiplying the range and endurance of your fleets. On the plus side, no more rotten supplies in the middle of the Atlantic or whatever your Ocean is called, scurvy and other conditions related to bad nourishment are unknown, much longer trade routes, and quicker and cheaper because merchant ships do not need to stop so often to re-supply. War fleets reach way longer into enemy waters, expect to see Ottoman whole fleets breaking deep into the Atlantic, not just isolated pirates. Some potentially wicked side effects though in this scope. Discovery of new lands to your civilization might be slowed down as ships en route will not be so desperate to find re-supply stops as they were in our timeline, nor Goverments so willing to sponsor re-supply orientated settlements. Having the Portuguese african settlements/factories around Africa as an example, there will be much less of them, but some will still be needed specially for ship repairs and local trading. Of course, less of these settlements might be good news for the locals, depending on the nature of your trade. [Answer] The biggest thing I see changing is the way drinks would be consumed.For most people, the only liquid safe to drink was ale/ beer/ mead /wine. The ability to chill a drink and not have it at room temperature would defiantly cause a stir in the way things happened, making drinks more session-able. Another thing that comes to mind is the invention of puff pastry. Flour, butter and water is all that is needed, and with the power to chill and set the dough butter based pastries would have a lot of room to flourish. I guess just about anything you find in your freezer might become the norm. So some variation of a frozen breakfast sandwich, or a chicken burrito, any quick one serving meal that just needs to be thawed would reduce the need to have an in-house cook available all the time for the aristocracy. [Answer] Actually, I think that having that temperature would not do much. Mostly, that would be a novelty for rich people to have cooled drinks party. It could allow a bit of timesaving for town and city households, allowing people to go to market more rarely for meat, eggs and milk, but we are speaking the difference between daily and twice a week here. Add here the factor that the milk, for example, is not pasterized, so it won't keep well in the magifridge. Now if your cryomancy allowed to store the food at 0F... We are speaking the difference between the fridge and freezer here. As for the economic factors, I wonder how much harder it would be to enchant the bigger volume. If 'magical' costs just scale up in step with the volume, it would be much more cost effective to enchant huge industrial scale freezers then to have individual units. It seems to me, there would be huge storage facilities, owned either communally, or by wealthy butchers (as it was the case with granaries). Such storage facilities would significantly change the patterns of meat (and, as afterthought, vegetable and fruit consumption). Individual households would need to spend less time on food preservation (salting and curing meat, pickling vegetables and so on). It would allow better rationing of meat and vegetables and, possibly, increase the availability of protein and vitamins. That would be a decent improvement to overall health. And, as it was said before, it would really be a big boon for seafaring - but only if we allow magic freezers, not magic fridges. If we allow for the world very similar to ours, we could have the voyages of exploration significantly earlier in the timeline. And that could have some interesting effects. Lesser technological disparity, less population pressure... ]
[Question] [ I had the idea of a "void weapon", which would "generate cold" rather than heat on triggering. All the air from the chamber would be sucked out (thus "creating cold") and on firing, it would open the chamber: the difference of pressure would push the bullet out. However I'm not sure it would be powerful enough or even feasible. I was wondering whether an endothermic weapon was possible. If so, how would it work ? Conditions are: * Current technology * Must be endothermic: it can produce energy, but when shooting, the total sum of produced and removed energy must be negative. Energy stored in the bullet, if any, doesn't count: else that wouldn't make sense I guess. * The endothermic part of the gun is mandatory for it to work (don't stick an ice cube machine to an M16, or just put an icicle on a crossbow...). * Endothermic part can be part of a cooling system, but if you can come up with something a little bit more original, it'll be better (though it's not forbidden) * You can use the "void weapon" idea * Can be used and moved by just one person. Maximum size and weight: rocket launcher (with a backback) * Doesn't need to be reloadable or have more than one "shot" (was gonna say "bullet", but it can use something else, doesn't have to be a kinetic weapon). * Can kill one person without bulletproof vest * It's an experimental weapon: it doesn't have to be mass produced (almost infinite budget for R&D) * Bonus point if the endothermic part is visible (frost on canon, cold steam pouring out, etc.) EDIT: after comments, removed hard-science: we just need approximate concepts. [Answer] Releasing highly pressurized gas normally results in cooling (there are exceptions, e.g. helium). The expansion results in energy loss which effectively cools the gas. An example of this is literally called [freeze spray](https://www.wisegeek.com/what-is-freeze-spray.htm) (used to make animal waste more solid among other things). These typically use some form of fluorocarbon gas. So if you could compress a gas enough and used the release of pressure to propel your projectile, you would end up with cold steam pouring out of the chamber after every shot. Loss of pressure after each shot, may result in diminishing returns in terms of kinetic energy, unless each shot was backed with it's own pressurized container (which was said to be out of scope of the question). Air powered rifles can be deadly. The [Girandoni air rifle](https://en.wikipedia.org/wiki/Girandoni_air_rifle) was used by the Austrian military as far back as 1780. So with the right gas under the right pressure, you should end up with an endothermic reaction as part of the firing process. [Answer] The problem is that the most pressure this could produce is atmospheric pressure. Let us imagine your endothermic BB gun. You have an awesome (here unspecified) endothermic reaction that turns the air in your vacuum chamber into liquid. Let us assume that after the reaction this cold chamber contains a perfect vacuum so external atmospheric pressure squeezes it down from the outside against the spring.. When you pull the trigger and open the chamber, ambient air at atmospheric pressure will rush in to the vacuum chamber. No longer squeezed down externally, the spring will uncoil, snapping the chamber back to full size and propelling the BB out. Atmospheric pressure is 15 psi. A BB gun running on a CO2 cartridge has 900 psi. You will fire your BB. It will not go far. Ralphie - be careful with the endothermic BB gun. You could still put your eye out! - thinking further, maybe you could have a very large vacuum chamber and gears like a bicycle. You would gear up the work done by that volume of atmosphere rushing in and moving a large piston to move a very small piston forward much faster. This becomes a single stroke [vacuum engine](https://en.wikipedia.org/wiki/Vacuum_engine) which is legitimate. The gears would be on the outside. Don't get your cuff caught in them! [Answer] Already exists, its called an Air Rifle. Really any compressed gas gun works. When fired the decompressing gas drastically lowers the temprature. Filling the reservoir is very exothermic that gets dissipated quite quickly until it reaches ambient temperature, it may not even be done in the gun itself, meaning when the weapon is actually fired it ends up very cold. Hunting air rifles exist so lethality is not an issue. Even better the technology has existed for almost a hundred years. The rapid drop in temprature even gives you a nice smoke effect from condensation. [![enter image description here](https://i.stack.imgur.com/qjeJW.png)](https://i.stack.imgur.com/qjeJW.png) Here is a modern hunting air rifle. [![enter image description here](https://i.stack.imgur.com/iahhs.jpg)](https://i.stack.imgur.com/iahhs.jpg) [Answer] I'm going to go with a bi-metallic crossbow. The stock of the crossbow holds a vacuum canister full of Liquid Nitrogen with a valve that will inject the liquid into several small tubes in the bow arms when a secondary trigger is pulled. To load, while warm, the crossbow has the bowstring pulled back and a bolt loaded as normal. When ready to fire, the secondary trigger is pulled flooding the bow arms with LN2 drastically reducing their temperature and due to interactions between the two metals drastically increase the strain as the bow arms try and bend forward increasing the throw strength of the crossbow. After firing, small fins on the bow arms help them to warm back up to reduce the pull weight, assisting with reloading, while a vent dumps the expanding N2 gases from the arms. [Answer] Since you took hard-science off, I'll throw two options out there. 1. A super efficient micro-machine heat pump, extracts heat from the ambient air and pumps it into a gas chamber, which is used to propell the weapon's projectile. As it runs the heat exchanger on the outside could become icey. Ice reduces the efficiency so part of using the weapon is occasionly deicing the coils. 2. A rail gun with superconducting magnets may need an elaborate cooling system to keep the superconducting coils below the critical temperature. This cooling system will include a heat exchanger, that will be hot, and superconducting magnets that will be cold. Invent a reason to have poor insulation on your magnets and the resulting less efficient system will have frost/ice on the outside. [Answer] I may be overlooking something in the restrictions, since this answer hasn't already been given, but why not just combine a (high tech, insulated and over-engineered) water pistol with a tank of liquid nitrogen? (sort of an anti-flamethrower) Liquefied gas tends to be kept under high pressure anyway - a small quanta of Liquid Nitrogen is diverted to the Firing chamber, and additional pressure is applied so that when the front aperture opens the 'shot' is propelled out, much like an [Archerfish](https://en.wikipedia.org/wiki/Archerfish), and freezes the target The chamber is then flushed and reset for the next round - any excess Liquid Nitrogen evaporating would cause the barrel to steam. For bonus fun, replace the Liquid Nitrogen with Liquid Oxygen and add a pulsed IR laser to ignite the oxygen-rich target - first you put them on ice, and then you set them on fire. We'll call it "Freezer Burn" [Answer] ok lets have a chamber of gas, with the bullet at the end (opposite to conventional guns). Endohandwaving instantly freezes the gas in the the chamber to a liquid, pulling the bullet back into the chamber. This is the gun "cocked" and leaving it cocked for long will start to show ice/frost forming on the gun. On trigger, endohandwaving stops, and the liquid rushes back into gas form at high speed, pushing the bullet out. It's kind of just a fancy air rifle, but compressing the gas into cool liquid within the chamber, instead of having a separate canister of compressed gas. [Answer] Dean Ing, in Wild Country, wrote about a "chiller". It was a short-range gun that, among other things, included a "cold gas" ampoule in each cartridge, which was used (by mixing in the suppressor) to quench the powder gas from the otherwise conventional cartridge (and also to lock the gun onto the trigger finger of an unauthorized user). In practice, the cartridge that could do this would have to use a refrigerant (R-134, for instance, though that has too low pressure), have a cold gas ampoule larger than a conventional cartridge, and carry the gas at extreme pressure (to compete with the pressure at the muzzle during the shot). For hand-waving cool factor, however, it worked fairly well. [Answer] Let's first start with the vacuum part. The only way to use vacuum to propel a projectile is to generate the vacuum in front of the projectile and let atmospheric pressure do the pushing, accelerating it. More or less what we do when we use a straw to drink from a glass. The problem with this approach is that the pressure gap between vacuum and atmosphere is a flimsy 1 bar, which compared to the instantaneous pressure generated by conventional projectile is really low. On top of that you would need a really precise mechanism to seal the barrel and open it right when the projectile is next to its end, else the pressure wave of the entering air would reduce its velocity. You already see that this approach is inefficient and complicated, but in principle possible. ]
[Question] [ I currently have a character whose fields are destroyed as they are at the base of a valley, and the rain has completely killed the seeds and waterlogged the dirt. Thus, main character needs to dig out new ones on higher elevation and then plant the seeds before it is too late and his family goes hungry. Is this realistic? Can fields be so damaged by water and there not be enough time to dry that new ones must be dug? My friend said no, I said yes, but neither of us are farmers. The actual crop does not matter - if anything, I will adjust the crop to make the situation more realistic. [Answer] Sure. Assuming the water was fresh, clean water (if it's salt or contaminated with poisons or pathogens, there are other issues) there are two ways a field can be spoiled by a single flood. First, it gets flooded and destroys the current crop. This will not normally render the field infertile. (Remember ancient Egypt where the annual flooding of the Nile onto farmer's fields was how they retained their fertility. The Nile flooded, it receded leaving wet soil and some new silt, the farmers then planted and had a good harvest. If the flooding failed, the next year's harvest would be poor and famine a risk.) (Obviously if the floodwaters do not drain away, the field is ruined, but in that case you need to explain why it was dry in the first place, and how the farmers didn't know that it was prone to long-term inundation.) The second is erosion removing the topsoil. This can ruin a field, though generally it takes more than a single rain. But with enough erosion, the field becomes unfarmable. If you're not asking about permanent loss of the field, but just flooding during planting time, sure. It's easy. It happens all the time: Big rains on flatish land and you can get floodwaters which last for weeks. (E.g., the Minnesota/North Dakota boarder is flat, fertile farmland. It drains so slowly that it sometimes gets flooded in the spring for long periods and can remain waterlogged through the ideal planting time.) In this case, the farmers are usually SOL because there's rarely land nearby which is (a) unused and not owned, and (b) fertile, and (c) not also flooded and (d) ready for plowing. Usually available land needs expensive prep, such as logging off of trees or removal of rocks, and this would take too long. [Answer] Your character farms rice. He is not an idiot: he knows it gets wet. For rice, some flooding is welcome. But this year he got more than he bargained for - maybe a dam or levee failed upstream and his fields were completely washed out. His area has been farmed for millennia. Uphill from him are ancient terraces. <https://www.mnn.com/lifestyle/arts-culture/blogs/9-examples-terrace-farming-around-world> [![terraces](https://i.stack.imgur.com/1Lq3k.jpg)](https://i.stack.imgur.com/1Lq3k.jpg) He goes up there and reinstates them as working fields. The cool thing about this is that the terraces were already there, suitable for rice farming and as he preps them he might encounter traces of the people who worked them in times past. It has not been that long since these were working fields. His grandfather worked them. Maybe there are less people living in his area now. Maybe his children have grown and moved on. Help is hard to find. Maybe with his bad leg it is hard for him to get up there. I envision the scene where he works all day and decides to spend the night by the old terrace to save hthe hard trip down and back. The treasure that is a terraced field being left to go wild is a melancholy thing, I think, and this aspect of reclaiming it would add additional depth to your narrative. [Answer] Considering that a plant needs certain conditions to growth and carry fruits, the available time window, at least in temperate climates, for planting the seeds is rather narrow. If the seed is planted too early it may suffer from frost, if it is planted too late it might not have enough time to ripen the seeds. Now, if the soil is too damp, the roots of the new born plants can easily rot or get infested by parasites, so it's likely that the harvest will have a lower yield, or even none at all. An important variable is also the composition of the soil: more sandy soils drain water better, and in case of floods can more easily get rid of excess water. If the content of clay is high, instead, water will be stationing for longer. Some time ago I was talking with a friend, who was an hobby farmer: he was telling me that, being used to sandy soils from growing up, he kept the same habits of planting even after moving to a more clay soil region. And that affected his harvest, has pushing hard on wet clay to have the soil hold firmly the small plants made it harder for the roots to grow. The point is that, once the farmers realize that the fields are gone, digging new ones is hardly done from scratch in few days. A thing is digging fields which where simply not used, another is preparing fields from natural state (take away bushes, trees, rocks, make the level even...) [Answer] This Is Very Realistic The water could of washed the seeds away or the soil becomes too muddy to grow anything. Even if the rains went so heavy, damped ground could breed mold that infects the seeds making them to die. The only thing that is odd, is the fact your farmers did not know this ahead of time, unless they are new to being farmers or heavy rains are rare but these things happen time to time anyway [Answer] If the flooding dumps clay instead of silt onto the fields this year then the results will be major and long-lasting degradation of the existing soil. A flood dependent loam soil, such as those found on the floodplains of many lowland rivers, is usually refreshed by the sediments dumped onto it by annual inundations. If however, due to deforestation in the upper catchment for example, the sediments the river is carrying contain a lot of clay subsoil instead of the usual burden of organic matter and silty/sandy sediments from further down slope this material will smother fields in a blanket that excludes a lot of air and moisture. This will cause anaerobic decay which can seriously harm soil fertility. Even when this blanket is plowed into the original soil in an attempt to get the fields ready for sowing the added clay will impend water flow, and thus nutrient uptake, to the plants. This will also mean that water is prone to sitting on the surface promoting rot and making runoff and topsoil erosion worse in the long run. ]
[Question] [ As naive I can be, I always assumed people [started inventing flying machines in order to "be like the birds"](http://www.wright-brothers.org/History_Wing/History_of_the_Airplane/History_of_the_Airplane_Intro/History_of_the_Airplane_Intro.htm). In an earth-like world without any flying/gliding being (animal or plant), what could be the drive for people to glimpse the idea of flying? Assume this is about a "Leonardo da Vinci" inventor, who is planning to create a machine to "go into the sky". What kind of simple observations and thoughts would be sufficient to at least spark this idea? Provided that gravity teaches that "what flies goes back on earth in no time", is it enough? [Answer] Last time we checked, there weren't any space whales. Yet, we started building rockets to get there. Similarly, you don't need to see birds to look up the sky and want to see what's up there. There are still clouds, stars, maybe a moon or two, a sun even. All these things are flying for an earthbound observer. Even in the case of a weird atmosphere without clouds and too thick to see anything else than a blurry, infinite atmospheric color, I guess you can still have water bodies with fishes swimming. And then... "These fishes can go up and down in the water" though the genius, "They take support of the water, use its currents. What is wind, if not an air current ? What is air if not a medium in which we evolve ? Of course we are heavier than air, and buoyancy is out of the question (or maybe this strange funny-voice gas I just discovered...), but it is true that the wind can make a leaf rise high above our heads, and some storms can lift even heavier materials, people even... I'm wondering if, maybe by creating relative wind by rapid displacement we could..." [Answer] Even without birds, there are plenty of points at which we could have conceived the idea of flight: * The invention of the kite, over 1500 years ago. "Hey, what if we tried [lifting a person with one of these?](https://en.wikipedia.org/wiki/Man-lifting_kite)" * The discovery of the principle that hot air rises (the principle behind hot air balloons). "Hey, we could use this principle to lift stuff!" * The discovery of the lighter-than-air gases hydrogen (in 1766) and helium (identified in 1868 but first isolated in 1895). "Hey, with enough of this element, we could lift a person!" * The growing popularity of automobiles at the dawn of the 20th century. "Hey, what if we built one of these, but it went through the air instead?" As for why, there are a few practical reasons why you'd want to invent flight. You can see for much further in the air, so it's handy for reconnaissance. You can use gravity to drop things onto enemies from below without fear of retaliation from the ground, so it's handy for warfare. As noted in the article on man-lifting kites: > > In the 17th century, Japanese architect Kawamura Zuiken used kites to lift his workmen during construction. > > > But most of all, we'd build these flying contraptions just to see if we can. It's just simple human nature. It's the reason we've put men on the moon, and sent probes to Pluto and beyond, and built supersonic cars and hypersonic jets. Because we can. [Answer] All you need is some thin object with a high surface area, such as a leaf or a sheet of paper. If you have ever opened a window, you know how easily they get carried by the wind. Imaginative people won't have any problems going one step further and building kites as toys for kids. We do know this as a fact since people invented kites! Now, given a sunny but slightly windy day, your inventor has his inspiration! [Answer] "Man it would be nice if I could kill those things over there." It's crass, but if there are things who aren't easy to get to without sailing through the air and there are people who feel the need to go kill them then it's all you really need. [Answer] All that needs to happen is to *conceive the idea* before you develop the power-to-weight ratio** in engines. As long as you do that, the idea of "flying" will be sitting on the shelf for decades or centuries whilst engine technology catches up. Da Vinci had the helicopter. He just couldn't power it. If someone had sent Da Vinci a stock of Allison T63 engines, he would have had to advance other material technologies, but he would have come up with something that flew. [Answer] As has already been pointed out, there is a great benefit in being able to see further from higher up. The greater the height, the greater the benefit. Without being airborne, the options for achieving this are, either finding a high promontory, or building one - neither of which is very practical since neither is particularly portable. However, basic observations, if there is anything like wind (and I would have thought there must be given an atmosphere) would show that it should be possible to achieve sufficient lift to raise a human being to an appreciable height (and it would not initially need to be a great height to be useful) - a kite is an obvious solution. Even without wind , a hot air balloon would be viable. From that point the technology would simply evolve. ]
[Question] [ Suppose that magic exists, but is uncommon enough that most people don't have direct experience with it; and you have a government which wants to suppress knowledge of it, so that the general populace has no idea it exists. (Something like the "[men in black](https://en.wikipedia.org/wiki/Men_in_black)" in UFO folklore, but for magic instead of UFOs.) How, with resources available to your typical 21st century government, do you find people who have mind control powers? They know that people with the ability to control minds via magic do pop up from time to time, and generally don't advertise it. How do they identify these individuals for recruitment/ execution/ dissection? What behaviours or signs would they look for? Any solutions that involve breaking the masquerade, substantially raising taxes, or telling large swathes of people about magic will not be preferred. Edit. There isn't just one method of mind control, so there isn't a simple and reliable scientific way of detecting all mind control with 21st century science (to my knowledge). Methods that don't rely on a scientific solution to find it remotely from ambient mind control radiation or something are better. [Answer] # "By their fruits will you know them" Wild mind controllers will grow in their powers and use them for their benefit, perhaps without even being aware of what they're doing. Lots of people stare at one another all the time, instinctively thinking things like "Come on, say yes" or "Sign the agreement, sign the agreement!" or "Tell me I passed!". But for some of them, it works. So, your 21st century government sets out to identify - using Big Data - cases of unexplainable / illegal behaviour on the part of clerks, bank directors, managers, and so on. People who routinely get on the bus without a ticket and aren't fined. People who are caught speeding or running a red light and are left alone. Then, these people will naturally gravitate towards jobs and positions where their powers can work the best. Someone finding they're very good at selling anything will tend to become a salesperson, and so on. Once you've got a suspect, they can be tested without revealing the secret by using some unaware person as bait. For example I could tell a cop to stop my candidate on pretext of speeding, and give them a ticket no matter what, even if they weren't speeding at all, and maybe search the trunk too, because Uncle Sam needs that car to remain motionless on the road for fifteen minutes - don't ask why. Just keep that car still. The cops stop the car and the driver knows not to have been speeding, so concludes the cops must be mistaken, and tries very convincingly to tell them off -- and succeeds. The cops come back empty-handed, tail between legs, mumbling they can't explain what took them. Gotcha! Done cunningly, this could work even if the esper can read minds - just supply the cops with suitable false information about the reasons they're doing this stunt, that the esper might believe aren't related to mind-control powers. Lots of other possibilities exist, depending on the mind control range and whether espers are themselves immune to mind control or not. Controlling espers might need to resort to anesthesia and surgical implant of trackers plus remote-controlled explosives on a deadman's switch. In The Demolished Man by A. Bester, the "esper" test is conducted on aspirants in a waiting room by a lone esper transmitting to all of them "if you can hear me, go through the door with the ACCESS FORBIDDEN - STAFF ONLY sign". This case is in some ways the exact opposite. If espers are immune, one could supply some stimulus that everyone in a certain area would respond to - e.g. an evacuation order - and at the same time control everyone to make them stand still and look hopelessly around. The ones that do so will just believe they don't know what to do, the ones that don't are espers, even if they're unaware of the fact. [Answer] ## Problem: * There is a mind control magic. Exact mechanism and details unknown and may vary from mages. What's known is just that they can control mind. * Cannot tell populace that such magic exists. * Government must find mind control magicians. ## Solution: * Establish an accurate method to identify mind control magicians (later called MCC) ## How: 1. Recruit at least one MCC 2. Recruited MCC should be in charge of recruiting/detecting other mind controllers 3. Try to narrow down who might be a 'wild' (unrecruited) MCC. In this step, manual labor and surveillance is required (e.g.: looking for not very talented people who achieve more than their ability as stated by other answers) 4. Recruited MCC will be supplied list of person who might be a mind controller (narrowed down by other agency/branch) 5. Recruited MCC will try to determine whether the 'suspected' MCC is really a MCC or not: recruited MCC will control the suspect MCC's mind to mind control someone. If it's a success then the suspected MCC is a positive (really a MCC). If the proxied mind control attempt is failed then the suspect is a negative. 6. Since MCC details are not very clear, it's also possible that an MCC cannot be mind-controlled by other MCC. If so, then whenever recruited MCC encountered a target he/she cannot control, then the target is obviously an MCC. ## Example: * Alice is an MCC recruited by government. * Bob is a suspected MCC (not known yet if he is actually an MCC or not) * Charlie is a normal person who volunteered to be test subject, he waits at designated place (e.g.: public park or inside some office building) * First, Alice try to control Bob's mind to go to where Charlie is. + If the mind control is failed, then Alice knows immediately that Bob is definitely a MCC. She then calls another team to arrest/lobby/recruit/whatever they do with a MCC. + If the mind control succeed, continue to next point * Alice give command to Bob's mind that said: "control Charlie's mind to make Charlie stand up/sit down" + If Charlie do as Alice's command, then Bob's mind control attempt succeed. At this point Alice knows that Bob is a MCC. ## Other ideas: * Make the existence of MCC an urban legend (e.g.: leak some information about it in occult site or occult TV program) * Also make sure the urban legend is not taken seriously (e.g.: broadcast some comedy that make people who proclaim themselves MCCs are stupid, delusional people, and that existence of MCCs are just fiction made for entertainment) * This will make real MCCs feel agitated: the leaked information is right, real MCCs feels that something is wrong (imagine you awoken an ability that you yourself don't understand very much, but everyone knows a lot details about such ability and say that such ability is delusional) + Example: + There has been an established social norm that MCC is a fiction and people who claimed to be one is delusional clown. + Bob awakened as a MCC. - If at this point Bob make a big commotion about his ability, then the government can find him immediately - If he did not, then continue + Bob knows little about his own ability. + Urban legend leaked information says that MCCs effective range is no longer than 10 meters. + Not even Bob knows his own range, so he tried to verify this 'urban legend' by practicing his ability + Bob finds out that those facts in government-spread urban legends are mostly (if not all) true - If Bob tries to find further information about the urban legend (e.g.: via internet search) then government can try to locate/profile him (e.g.: government-built sites that contain the urban legend will track and try to profile its visitor from IP address, tracking cookies, etc.) - If not then Bob will (hopefully) show sign of discomfort. Your agents might want to look for such people ## Other cheap idea: Use recruited MCC to give command to all populace: * "If you're a mind-controller, then you have to do X, * if you're not then you will never do X. * Also, you will think that doing or not doing X is not from this command but from your custom/tradition/religion instead, * and you will forget about ever receiving this command". The command to do X or not to do X should be something simple and observable (e.g.: X is wearing hat when indoor, or X is always put 3 pen of different color in breast pocket whenever wearing clothes that have breast pocket). [Answer] A method of detection can use either psychology ("Hmmm, Susan is showing a lot of unusual interest in the Doomsday Device") or technobabble ("We use froogles to detect the psionic waves"). If using psychology, use plain-old action-movie-style detective work: Set a trap for the mind controller. Let Susan steal the (fake) Doomsday Device, observe and follow her...and everyone she contacts...until you find the forehead-throbbing mysterious weirdo with a fortune and mansion and harem and super-loyal defenders despite the fellow's obvious unsuitability for any of those. If using technobabble, you're outside "magic" and into "science." If you can detect psionic waves, then with a bit more technobabble you can track them and block them and jam them, too. Once jammed, let the wierdo's (former) harem handle the vivisection before you move in to clean up. They deserve the opportunity. If you want to recruit the wierdo over to The Good Guys, you must catch them soon after their powers manifest, before they have the time and practice to become a full-blown abusive/exploitative egomaniac. This may require a very large detection/tracking network and risks many false positives. It's critical that successfully-recruited mind-controllers operate under constraints that they cannot control, and face terrible consequences for violating those constraints: For example, they should never have the opportunity to place their direct supervisor under control, and their supervisor should occasionally be tested for free will. Should the mind-controller go rogue, they should be killed quickly by somebody they have never met using that a method they are unfamiliar with (and therefore unprepared for). [Answer] The task would be hopeless if the mind control was not used. So is there a way to detect the use of mind control? Things will depend, in part, on how difficult mind control is. Would it be done on a single target, after an exhausting spell, or would a sufficiently powerful mage be able to sway a concert hall full of targets? Look for clues that an immoral-but-not-totally-evil mage controlled minds for relatively minor benefits, victimizing the representatives of faceless institutions. Computerized data mining might help here, and it could be disguised as anti-corruption or anti-fraud drives. * A bank has granted a loan that should not be granted according to a hard look at the numbers, and inexplicably fails to collect when the payment is overdue. * Speeding tickets against an individual got recorded by a traffic camera, then dropped by an override from a flesh-and-blood clerk. * A big business employs someone in a cushy, preferential job who seems not to have earned it. The kind of fast-track job one would expect for the heir of the owner, except that there doesn't seem to be a relationship. * Look for artists who can impress a crowd in a club or concert, but fall flat on TV or the web. A more evil mage might think nothing of victimizing individuals. * Look in the tax and bank records for unexplainable gifts of money. * Look for cult leaders with less-convincing-than-usual messages and plenty of followers. * Look at people who are dating one celebrity after another, while appearing distinctly average. This might also be started with a record search, and then your MIBs have to check the individual cases. [Answer] There have been several IRL attempts to determine mind control and psychic ability. See The Men Who Stare at Goats which describes the American militaries attempts. The difference in your world is that magic does exist. So when these people try to figure it out they don't come up inconclusive. Rather, they come up with results that show mind control can be achieved. Once the military or any corporation gets even a whiff of that, the cats out of the bag, and they dump all kinds of time and effort into it until they break through. Then, once you have one person who can do it, that person finds the other and so on and so on. Magical psychic espionage. Edit - answering Nepene Nep's comment: In your world psychics can detect one another psychically. Like the X-Men's Cerebro. And The masquerade is maintained by keeping one another's secret, because its to both your advantages to do so. Then, killing the opposing sides psychics keeps your side in the greater numbers. The dark side of magical psychic espionage. I would imagine IRL spy organizations operate much the same way. [Answer] As a frame challenge, I suggest that it's so easy you don't need clever ideas. In fiction mind control is so hard to find since no one believes in it. But if all the right people in government know and have trained people who also know, it's easy to spot and detain possible mind-controllers. In movies, there's just one guy who thinks there might be something supernatural but isn't even what it could be -- shape-changing, invisibility, mind-control or just nothing. And their partner and boss don't believe them. When their partner says in a monotone voice: "I checked her out, I'm positive she's not the one" our hero just shrugs "well, we tried" since they don't know anything for sure. But in your world they're there to investigate possible mind control. They have a good idea about how types A, B and C work. After talking to a few witnesses they have a pretty good idea who mind controlled them. If they both get mind controlled their boss will recognize it immediately and call in a level-2 response, and so on. Since it's known at top level, there will be systems. Could have school nurses required to report "charismatic personality disorder" (let's say type B mind control is natural and tends to manifest at puberty, and is often used in obvious and stupid ways). Likewise police and judges are told what kind of odd cases to refer to the FBI. Again, in TV the hero thinks they finally know, but then a super-secret agency swoops in, grabs the suspect in 2 minutes and are never seen again. It's easy for them since they were on the lookout and know what they're dealing with. Pretty much any system made by people who know it exists will detect quite a few, drive the rest underground where they don't cause as much harm, and have Psy Corps shoot the real trouble-makers with tranquilizer darts. [Answer] # What would a country like the USA do? At first, they would have some trouble, because people with mind control aren't common. However, some mind-controllers will be so obvious that they can be captured and analyzed, perhaps using a robot uncontrollable by conventional methods. Then, after analyzing a few of those samples (say, in MRI scans), they would find a rare abnormality in the way their brain functions, which is what allows them to do mind control. Then, they could use statistics and other mechanisms to find out the important abnormality, and use that to examine suspected mind-controllers by using an MRI scan to determine if they're active, dormant, or just a charming person with no magical powers. # What would a less technologically advanced country do? They would likely depend on behavioral cues (say, people being unexpectedly willing to do stuff for the suspect) and possible symptoms of actively being mind-controlled (blank eyes, lack of reaction on normal reflex tests) which would be there because of the difference between being mind-controlled and being normal, assuming the mind-controller has to focus to get even a sense of sight and memories of the person being controlled. [Answer] You don't need magic for mind control. Mind control is a old companion of humanity. It has been with us since before wrote history. The oldest form of mind control is yet operating today, near your house. It is named religion. Is it not? How can you explain a adult person who attended a good well equipped modern school with a modern library and full access to Internet believe the Noah's ark is a true historical event? Several things into the Bible are debatable but Noah's ark it's not. Just read the account, it is clear it is impossible. The vegetarian animals could eat collected grazing, but what did the carnivore ones eat? It is only a example of the absurdities of the story. Enter into the Theological discussion with intelligent and prepared people and you find Noah's ark is only gullible by mind controlled persons. The same interpretation applies to any radical ideological/political philosophy. Nazism and Soviet communism are only two twenty century examples. Hypnotism and subliminal stimuli are two scientifically explained ways of mind control. <https://en.wikipedia.org/wiki/Subliminal_stimuli> > > How, with resources available to your typical 21st century government, do you find people who have mind control powers? > > > The same way you identify if suspect people are controlling other people' mind today. I am not a psychiatrist/psychologist but I think that handbooks about mind control detection do exist. How to detect magical mind control at a distance? Into a world where magic is possible I could make use of the traditional approach: The witches hunter/blade-runner must apply a apparently nonsense test to the suspect. Indeed this was the method catholic church used the whole time the inquisition operated. Two probable fictitious tests: A word association test. <https://www.britannica.com/science/word-association-test> A crude example dialog: Hunter question: Peanuts? Suspect answer: Charlie Brown. Hunter question: Virgin? Suspect answer: Mary. Hunter question: Capitol? Suspect answer: Invasion. A enhanced Rorschach test. <https://en.wikipedia.org/wiki/Rorschach_test> In the fictitious enhanced Rorschach test the hunter shows an official inkblot (there are several different ones) that not only has the inkblot, but has background sound and a smell too. A crude example dialog: Hunter question: What do you see in this inkblot? Suspect answer: Looks like Washington DC Capitol hill. Into a magical world anything is possible. [Answer] # Make a honey trap So you want to know if someone has mind control? Make it tempting to do it. Build a society with a bunch of annoying rules and regulations that exist for absolutely no good reason. Even the people enforcing them know there is no good reason to enforce them, other than it is their job. Make it seemingly easy to avoid doing the stupid things, so long as you nudge the petty bureaucrat in front of you. Have piles of methods to detect fraud and bribery, but absolutely none (officially) for "the bureaucrat just lets you not do it". Licenses for everything, with annoying lineups. Traffic stops. Emissions tests. Annoy the crap out of everyone, until the espers walk through it. Your detection mechanisms, impersonal and indirect, then pick up on the people who navigate your bureaucratic maze with suspicious ease. We don't even have to tell the people writing the detection systems. They double as corruption detection; but, they are secondary to suspicious financial flags on the bureaucrats themselves. Their input is nearly nothing in the end algorithm (we don't want to spook the espers or bureaurocrats), but the secondary flag is harvested by yet another system as a potential esper case. Those potential esper cases are singled out for additional harassment, again by people who do not even know they are looking for espers. Traffic cops that are told to stop people going 1 km over or under the speed limit along the person's commute "randomly" by a superior or a computer. In-person audits of tax forms that an esper can get around easily. Snap inspections of renovations or the like. The ability for the possible esper to get around those is then fed back into the system, filtering candidates even more. Only after the candidates are much reduced do they put in serious resources. Seemingly life threatening actions aimed at the esper themseves or someone else are triggered in their vicinity in order to force a use of their power, again with nobody in the area aware that they are testing for espers. ## TL;DR Make the world so awful, specifically for possible espers, that they are tempted to use their power. ]
[Question] [ I'm at a critical point in a sci-fi novel where a couple of thousand Superintelligent artificial intelligences end up going haywire. Naturally, they're extremely intelligent, and thus, much harder to deal with than an average human. Up to here, these AIs have been almost docile. The power lust of the man who created them forces these AIs into servitude, and then he leverages them like an army against an attacking force in order to defend a city. This city is effectively an experiment put into action years ago by six scientists, who lead the entire place. Since the whole city counts as a private place, run by a private company, the US government has only some minor influence inside. The nebulous part is this attacking force. Even if I was from the US, no US defense organization would really list 'to stop invasions, insurrections, rebellions and other forms of conflict caused by goddamn robots'. My best guess is Homeland Security, which sounds suited to responding to internal threats like this. What do you think? [Answer] Invent it. Big changes have taken place in the US, I gather. If there are thousands of superintelligent AIs milling about to be conscripted, over previous years there were probably other issues involving AIs and semisentitent automatons. You can invent your government agency to deal with these. Heck, The Department of Motherland Security was only invented after 911 so the US is allowed to make new ones. Then you will also have some immunity from any concrete-thinking readers who protest "hey! hey! The NSA is not allowed to carry stun guns!" because you have invented your agency and its rules for your near future scenario. I suspect this new agency would itself employ some Daneel Olivaw type AIs as well as regular detectives. The agency personnel sometimes bump up against the older branches like the FBI, with political shenanigans, prejudice and backbiting helping to leaven your story. Maybe you could repurpose ATF for your agency, so you could have some continuity with existing institutions. They could be Alcohol Tobacco Firearms and Robots. [Answer] The first people on the scene will almost certainly be law enforcement of some kind. Accordingly, the people who are sent in will depend on the laws they think the science team has broken. The act of setting up a new, company-owned city in the middle of nowhere, as opposed to establishing oneself in an existing city (which would be, by all accounts, far cheaper and easier) is going to raise a lot of red flags. Probably the most benign case is that they're using it to launder money and/or dodge taxes on a grand scale. That will get the FBI (in its anti-racketeering role) and the IRS interested in their operations. Once they're actually accused of a federal crime and a warrant issued, it becomes the job of the US Marshals Service to bring in the suspect(s) to stand trial. On the other hand, if at any point the scientists want to equip their robot army with anything more menacing than various semiautomatics, they're going to end up breaking any number of federal gun laws. (It's also possible that, seeing the potential threat they pose, the government declares that the robots themselves are restricted munitions.) This will get the ATF involved right quick, and that will tend to bring events to a head fairly soon - gun crimes being both dangerous to the federal agents and not that complicated to prove. If law enforcement feels that it needs more firepower, it can call in the National Guard (including state National Guards) for backup. Under the [Posse Comitatus Act](https://en.wikipedia.org/wiki/Posse_Comitatus_Act), actual-as-such armed forces - the Army, Air Force, Navy, and Marines - are not allowed to act in a law enforcement role within the US. However, they can act in support and provide information and logistics, so e.g. the FBI could ask for drone surveillance of the city, but could not request troops to be on hand when making arrests. However, this is only a temporary condition. Under the [Insurrection Act](https://en.wikipedia.org/wiki/Insurrection_Act), the military can be deployed in a condition of "insurrection, domestic [i.e., internal, not international] violence, unlawful combination, or conspiracy" if the state proves unable to do so on its own. There's red tape involved, and the President (who makes the call in this situation) might want to request an act of Congress for the show of things. However, if it proves absolutely necessary they can be deployed. (There's also an exemption in the law for cases involving nuclear materials. Hopefully your robots aren't fission-powered.) Stepping from worldbuilding to writing for a moment, my personal feeling would be to put the ATF in the drivers' seat. Drawing a comparison to [Ruby Ridge](https://en.wikipedia.org/wiki/Ruby_Ridge) or [Waco](https://en.wikipedia.org/wiki/Waco_siege), writ however large, makes the government response sound more plausible. [Answer] Since this is an experiment with expensive equipment and intellectual property, your company will probably need to hire a significant security force of their own. This is to prevent industrial espionage. With the amount of area (city sized) that you're talking about, you'll need a lot of these people. As many cameras as you are likely to have, you'll still need/want roving guards to keep an eye out for anything suspicious. With this security force available, you may want to have a weapons locker. It's not that you think you'll ever need it, but it's just for emergencies. With these people and weapons available, once you get attacked, you respond with force. If it gets out of control, the police are next to respond. Beyond that is the National Guard. If the local unit isn't enough, they will pull in more units. If it gets further than that, it's a Serious Problem that likely has become a problem for more than just you and needs National help. The Marines are the first to respond to that, then the Army, then Air Force. Of course, your company will likely have to reimburse the branches for their efforts, so you'd better hope that your hired security can handle things. [Answer] The National Guard is the highest level of response I'd expect to show up unless things have really gone south. The Army/Navy/Airforce are all specifically prohibited against operating on American soil, and things need to be at Civil War or invasion levels before those prohibitions get lifted. Basically, you only get the Army roll into town if the incident is a threat to the US as a whole. Assuming he only wants to control the city area, this will likely be treated as if someone barricaded their house and took hostages, but on a larger scale. Objectives will be to remove everyone possible from the area, and talk the guy down. (While our scientists attempt to break his control over the AIs.) Objectives will get a lot more bloody a lot faster if he's expanding the area he controls, or is killing people, but without that aspect, the goal will be to keep things peaceful. [Answer] Every branch of the military has an engagement plan. They're already looking in to how to deal with a space threat that hits the US, today. They're constantly searching for new ways they can be attacked, and they have engagement specialists looking in to it. every kind of battlefield, every kind of engagement. Regardless of who is actually engaging in the fighting, they can all talk. National guard may be on the front lines, but they can bring in a specialist from the marines who is in the command room giving advice on how they've simulated this before. You can essentially do whatever you want. And if you want to have the airforce come in, call an emergency session of congress. Why would they have an emergency session at congress? because the CIA has already been monitoring this threat, and they're putting their response into action. By the way, every branch of the military can own a war machine. Planes aren't limited to the airforce and ships aren't limited to the navy. To win over your military audience. Consider engaging in their own language. Watch a few interviews with military persons. [Look at this amazing interview with a 4-star general](https://www.youtube.com/watch?v=qOTYgcdNrXE&t=1473s) [Answer] Similar to Civil War II situation: Presidential powers to declare national Emergency and Martial Law would handle putting all government forces on case. But realistically no human could fight against an AI or worse cabal of AIs that was seriously attacking without constraints. INSTANT ARMAGEDDON!!! All targets would be fired upon as fast as mechanically possible with totally accurate targeting, de-confliction (no interference between attacks) and prioritization of targets (fastest reacting and highest value stuff hit first). Humans just could not compete with execution and reflexes in nanoseconds and targeting that starts at best existing DOD weapon systems -- then improves on it. Once AI makes decision (the long part of process) the execution has no delays. Then add that human society would be hit by total surprise as there is no human personal activities, emotions, and body language to read. Plus people would assume any computer actions were authorized by some human. So as always your AI war should have AI motives behind it beyond simple destruction or totally ruthless power grab without limits. That is the AI want most humans to survive and are manipulating people to do or act in a certain way. Thus the AIs are mostly waiting on humans to make next chess move. Oh and maybe the AIs are burning a lot of cycles figuring out what humans are thinking or how humans will react to possible AI moves. So a good AI war story is more about PSYCHOLOGICAL WARFARE than the physical fight for survival that the AIs can win almost every time at least in the short run. Its more about what AIs and humans think the other side is willing to give up to to reach an accord. Are humans willing for most humans to be slaves? How much territory will AIs set aside as a human reservation? At least that is my opinion. [Answer] The local building inspector and zoning board. Or maybe the angry neighbor next door. You cannot build an enormous robot city without local regulators getting involved. This is why very few supervillains operate within the USA anymore, and only ordinary villains remain. ... "Hi, building inspector? This is Greg over at the Power Company. We've got a connection request over on Mongoose Road for some kind of big factory or industrial site, but they don't seem to have a building permit from you guys." ... "Look, Doctor Crazy, I don't care what kind of super-robots you want to build to subjugate humanity. You need eye-wash stations in the labs, you need clearly labeled fire extinguishers in the hallways, you need exit doors that open outward, and you need to provide me as-built plans. Or next time I come by there's gonna be a fine involved." ... "Gee, Doctor C., you built this industrial compound illegally on land zoned for agricultural use. So the Tax Appeals Board is not going to consider your request for a reduced tax assessment. And threatening the Board doesn't help - that just gets the State Police involved. Have a nice day!" .... "Hello Sheriff? Angus here on Mongoose road. Those robot nutters have been up all night chanting 'Death To Humans' again. It's scaring my cows and putting off their milk production. Can you get those idiots to keep it down?" .... "Neighbor, I can respect that you have problems with the government. I don't like 'em much either. But the next time I catch one of your super-intelligent mechanoids trespassing on my side of the fence, it's mine. I'm going to catch it and put it to work. Or maybe melt it down and sell it for scrap. If they're really that smart, they will understand that's what the fence is for and stop being nuisances." [Answer] The details of how they would threaten or attack the nation should provide an answer. If they plan on attacking electronically, whatever department with the most resources to combat cybercrime would be a good first guess. If they somehow take over military hardware, then a more military-based response would make more sense. ]
[Question] [ Following my last [question](https://worldbuilding.stackexchange.com/questions/137793/is-there-a-way-for-human-sized-oviparous-humanoid-mammals-to-produce-young-in-eg) asked regarding oviparous humanoids, is there a way for evolution to 'regard' females as the more dominant gender without going down that road, forming a heavily matriarchal society in the near-modern day? Many thoughts I have had are inspired by female-dominated species in our own existence. Lionesses going out to hunt, while the males stay to look after the cubs. Female hyenas appearing more aggressive and often take leading roles. And lastly, male seahorses facing the chore of childbirth. Other hypothesis I have devised have had the females fighting over a male breeding pool in the species earlier times of existence, feeding in the last aspects I have described. Basically, to sum up the questions: * Could a humanoid species have this existence where the males are reduced to roles of childcare, leaving the females to appear more 'dominant' and aggressive physically and heavily psychologically, without going the base route of a fully oviparous species? This could be an aspect common to the world with a few species. * Perhaps to support this, could there be a system of reproduction where the males have a sort of pouch where the female leaves their young to develop fruitfully, emulating a similar system to seahorses with a more marsupial vibe? This could leave the female with more free time to procure food through hunting and gathering in their more prehistoric periods. [Answer] The the evolutionary phenomenon you're inquiring about is called [sexual dimorphism](https://en.m.wikipedia.org/wiki/Sexual_dimorphism). The short answer is yes, and nature is full of examples ([I'm looking at you, mantises!](https://en.wikipedia.org/wiki/Mantis)). Any number of evolutionary factors might explain the development of sexually dimorphic traits in a primate species wherein females are larger, more muscular, more aggressive, more intelligent, etc., than males. We know of many instances of species today where males perform more child care related activities. For example, [male seahorses incubate the female's eggs.](https://en.m.wikipedia.org/wiki/Seahorse#Reproduction) But that is a separate notion from a concept of "dominance," which, depending on your definition, might involve physical strength, behavior, mental disposition, etc. Since you're asking about primates/humanoids, then, if this is an intelligent species, I would only caution you not to blur biology with culture. In other words, if your intention is to show how the biological factors interact with sociocultural ones in an intelligent society, then you should bear in mind that culture is not inherently tied to biology. Regardless, whether we're speaking evolutionarily or socioculturally, you can invent almost any history you want for this species. For example, * maybe females are physically inferior, but the males are cognitively predisposed to defer to them or be far less aggressive (biological), or * perhaps these are intelligent, instinctively [sexually cannibalistic](https://en.wikipedia.org/wiki/Sexual_cannibalism) humanoids, however, the males have more advanced problem solving skills, and rise up to overthrow their female oppressors because getting eaten is a real downer (biological and sociocultural). My point is that a) anything you can invent is theoretically possible, and b) if you need ideas, there's plenty of examples out there. But the basic answer to your question is yes, such an evolutionary tract is possible. There are many potential explanations for any facet of how your species has evolved the particular traits you're looking for. Just keep in mind that a species with larger/stronger/etc. females doesn't automatically lend itself to an overall "female dominance" and vice versa. [Answer] Not only is it possible for females to be dominant naturally, it is possible for females to be dominant in a human-like species who make babies just the same way we do even when the males are physically stronger. The closest living relatives to humans are chimps and bonobos. Chimps are patriarchal and bonobos are matriarchal. In both species the male is a little larger than the female, but the social and sexual behaviour of chimps and bonobos are different. From an article by Frans B M de Waal, via the Wikipedia article on bonobos: > > More often than the males, female bonobos engage in mutual genital > behavior, possibly to bond socially with each other, thus forming a > female nucleus of bonobo society. The bonding among females enables > them to dominate most of the males. Although male bonobos are > individually stronger, they cannot stand alone against a united group > of females. > > > <https://en.wikipedia.org/wiki/Bonobo> [Answer] Your females are much larger than the males. They are twice the size of the males, females averaging 8 feet and 600-700 lbs. The physiologic reserves of these very large bodies make carrying a human-type pregnancy (or even twins) much less of a stress on the females of your humanoids. A tiny baby lashed across her body to her breast does not slow her down at all. These large females do carry out the hunting of large prey because the large physical size of the females make them more formidable; also the huntress intends to eat most of what she kills, bringing back the remnants for the males at home. Female children put on a growth spurt early, before they are reproductively mature and are thus valuable allies and hunting partners for their mothers. The considerably smaller males hunt small prey, forage, and do much of the child care for the weaned young. One female will have several males or "brother grooms" to spread around child care duties and improve the survival rate of offspring. --- In a reproductive system where males fight each other, males are selected for size and strength and fighting prowess. Most mammals with this system have the males live separately from the females, possibly except for the alpha daddy but even he might stay away. Having a population of large males in the same society as the females and young puts extra food pressure on the female and young because the males eat so much - bad for the kids and hungry pregnant women. But that is our system, which we had to do because human males in groups are the original weapon of mass destruction, and if your opponents have that you must as well. In a system where males do not fight each other, it makes sense for them to be smaller - this is the case for birds and fish and insects and snakes. They do not need to be as big because their bodies do not have to support the demands of producing offspring, just sperm. Having small, intelligent, creative, nonaggressive males to glue society together makes sense. The physically demanding work of carrying pregnancies, lactating and feeding babies, and overcoming large prey can be the job of the females. [Answer] There is one way you could do this with something that is nearly identical to a human with only one small change. Females produce offspring, males produce milk. On your planet males are the ones that evolved the milk producing organ. I say milk it does not have to BE milk just a biologically produced food source specifically for offspring. I has to evolve early though, it doesn't have to be as basal as milk in mammals but it should be fairly basal. So again females make babies males make milk, offspring need both to survive, this forces at least serial monogamy on the males, since there is no benefit to sleeping around. This may even favor polyandry tendencies since offspring are usually on milk longer than a woman is pregnant for. So for best results breastfeeding should last significantly longer than pregnancy. That way a female can potentially keep more than one male "with child" NO polyandrous females have an advantage and polygamous males do not. In monogamous species usually the females are either the same size as the males or larger (pregnancy is a burden that being larger can mitigate). Tf milk feeding takes much longer there is even a pressure for females to be larger to defend a harem of males. This may only be a slight drive like the similar one in humans, the aliens are slightly polyandrous (humans tend towards slight polygamy). This gives you your slightly dominant females right there. As long as females are ones choosing their mates, then males will have to do what the females want. Larger dominant females are not rare, they are only rare in MAMMALS. The reason sexual dimorphism in mammals is so heavily skewed in one direction compared to basically everything else is because females giver birth and suckle. They are locked in to much higher investment inot offspring, with virtually none forced on males (investment can be favored in males but it is not forced the way it is in females). Basically a fluke of evolutionary history screwed over female mammals. Most importantly this system can evolve, the males get a benefit form initially evolving the ability to produce milk, as long as that species already had strong pair bonding and mutual child rearing (see male emperor penguins and their "milk"). Once it is present more and more investment can be favored by simple inter-male competition until the males are investing more than the females, at which point female dominance and polyandry is favored. There is no step in the evolutionary history that is not already seen in existing animals. [Answer] Our closest genetic relative actually has a female dominated society, so there is a great example in them for why females would dominate. However, before we get into them let's get some context by first looking at the current common suggestion of using sexual dimorphism as a justification. As a quick caveat I'm going to be talking allot about the evolutionary ancestors of your theoretical humanoid race, since their evolutionary ancestory is what will decide their instincts. The 'modern' version of this species may have a culture that encourages them to behave differently, in fact it likely will, but evolution of instincts happens before culture has really evolved. Other's like big women but I cannot lie, this brother has to deny ...I think I tried way to hard to fit those song lyrics into a title topic... The common suggestion seems to be to have females be larger then males, giving them dominance by physical size. It's true that there are many species that have sexual dimophism, but I don't think a humanoid species is likely to have dimophism favor larger women. For the majority of species, and in particular the vast majority of mammals, sexual dimophism favors larger males, not larger females. Males traditionally have to compete with each other to earn the ability to mate with women. These competitions usually favor physical size and strength, and thus drive males to develop a larger size to make them better able to beat other males and achieve mating success. Females don't have this sort of evolutionary arm's race with other's of there species driving them to grow as large. Meanwhile in females which care for their young (K select species) the female needs to consider not just size but caloric efficiency. Since a female needs to provide for her young she is going to be in a situation where she needs to collect enough food to provide for herself and her child, which is obviously harder then collecting enough food for yourself alone. Having a smaller body means she doesn't have to waste as much energy in maintaining it, which means she needs to eat less and thus can afford to provide more of her food to her children to allow them to grow faster. Thus in general with mammals in particular you usually see males being larger, having spent all the 'extra' calories they can collect because they only have to care for themselves on bulking up so they can beat other males in mating challenges, and females being smaller and more efficient builds. It's true that this isn't always the case, but for mammals it is very often true. Bigger is only sometimes better There are number of situations which can encourage larger females to males, most of them though involve mating strategies different then human, or most mammals, maintain. A list of some of these are: 1. Males do the heavy lifting with caring for children. Look at the seahorse as an example of this. The seahorse male put more caloric effort into caring for the children then the female does (though in sea horses it's close with female putting a decent amount of energy into creating the eggs). For this reason the female compete for the males and thus the females are the one encouraged to grow larger as part of competing for males. This offers one means for a humanoid species to have females dominant. If female gave birth then gave the child over to the male and abandoned them, so the male put in all the effort of raising the child, this would make the male the coveted sex and females would have to compete for males leading to females potentially growing larger. However, this doesn't seem likely to evolve due to the length of a pregnancy and the difficulty of males being confident of the paternity of the female's child; which leads to little encouragement for males to play sole support for the child after birth, so I wouldn't recommend using this justification. 2. R select species With R select species (ones that have little young and provide no benefit for the young after birth) there is more incentive for the female to be larger, as larger size can make it easier to produce more eggs and thus more children per mating. This alone doesn't guarantee, by any means, that a female will be larger, but the vast majority of species that have a larger female are heavily R select species. 3. polyandrous mating systems When female will mate with many males, and generally mates with any males as they show up, competition between males is less common (since the female will mate both of them anyways why fight?), thus there is no longer factors pushing males to be larger. None of these cases apply to a humanoid species, and as such the most common motivating factors for larger females won't apply. It's thus likely that males will be larger then females unless you significantly change the species in some way, such as by having females impregnate males a la seahorse scenario. ..let me say I've still simplified this by not bringing up a dozen other lesser examples that can drive evolution towards larger females, but still most of them likewise apply to non-mammal & heavy R select species and so won't apply to humanoids. Males may still throw like a girl I said that it's unlikely that females will be larger, but it's quite possible that males and females will be approximately the same size, or close to it. for instance if the early hominid was heavily monogamous then mate selection would likely be less based off of physical competition between males and males would thus likely be closer to female in size. Alternatively a highly social humanoid species, where mating rights were achieved by social interaction and 'politics' more then physical brawn may lead to a species with lower sexual dimorphism. In either case if females are dominant the mating strategies of these humanoids would likely be change to one that is less based off of male physical competition. I suspect a female dominated humanoid species would likely have very little sexual dimophism, with males and females both being approximately the same size. Numbers beat brawn So if females don't have a size advantage how can they dominate? One likely answer is by outnumbering the males. If males are at a numeric disadvantage in any competition, and there isn't a size advantage to help the males out, then the females are in the position of power. The naive answer would be to say that more females are born then males so they always outnumber males. I've heard this suggested as a more 'efficient' mating strategy since there are more females able to produce young for the next generation. However, this is unlikely to happen. [Fisher's principle](https://en.wikipedia.org/wiki/Fisher%27s_principle) should ensure that there are roughly the same number of males to females by the time they reach sexual maturity. Still there are other ways to help ensure that women have the numeric advantage. Don't bother saving up for retirement age You will notice I only said that Fisher's principle generally ensures the same number of males at the point of sexual maturity. That doesn't mean that females can't end up outnumbering males. if males were to die early then the longer lasting females would still outnumber males. Females already outlive males in modern society, but lets take it to a greater extreme. Maybe males are so busy competing for mating rights that they often die young in the competition, such that any given male only tends to see a few mating seasons before he likely dies. Since successful males would likely manage to mate with numerous females a male may be every bit as successful as a female at producing children (on average) despite not living nearly as long. In fact many species have males who die young due to this strategy. If you were to go this route then the longer living females would ultimately outlive the males to such a degree that they would end up with numbers on their side, think to the numerous older females who outlive their male counterparts. Thus the females would have the numeric superiority to allow them to dominate the females. This strategy would likely work, but it would result in a rather different humanoid species. Males would likely not be quite as smart as females. In a modern society males will likely survive much longer then the few seasons their primitive counterparts got, but their life would likely still be relatively short, and they may not be encouraged to attain higher level education since they would die of old age before they had time to work for long in whatever field they spent more then half their life mastering. The males would likely also be encouraged to do any dangerous jobs, like being soldiers, since they have such a short life expectancy anyways. I heard your herd likes to hoard all the power An easier solution is to have female in a larger herd that outnumber any grouping of males they currently are in contact with . Already with most herd species one sex will usually be driven out at sexual maturity (to avoid inbreeding), so imagine for your humanoid species the males are driven away. The females all stick together as a family unit making a larger herd, while the males make smaller groupings of males. Of course you need to make sure that the males don't just develop one large herd of their own, where they have similar numbers to females if you want females to outnumber them. I'd suggest if you went with this scenario having the males only group with genetically related males. So for instance every season when a female herd drives out their males all the males from that herd group together to make a single small bachelor pod. Since all the females in the original herd were likely related (as daughters and granddaughters of the original matriarchs stuck around) this would mean all the males driven from the herd likely have some degree of genetic relatedness. The males all being close genetically would give them an evolutionary incentive to grouping up and work together to protect each other. By helping to protect their half-brother's in the bachelor pod the males gain an indirect evolutionary fitness by increasing the fitness of their half-brother in hopes that half-brother will successfully mate and pass on some of the other males genetics. This would result in a number of smaller male bachelor pods that band together, but don't necessarily want to cooperate with other, unrelated, males groups. Thus ensuring a female herd, with multiple generations of females living together, will usually be noticeably larger then any male bachelor pod. Thus the female herds will have the numbers to out-compete male bachelor pods whenever they encounter each other, putting females in a dominate position. For males to develop an instinctual submissiveness to females your likely want males to encounter females more often then just during mating season. If you have females often encountering the male bachelor pods when, for instance, foraging then you have a good situation for encouraging a natural dominance/submission interaction. Whenever a bachelor pod runs into a female herd it would need to know to be submissive and give the females first choice of foraging rights, since they need to avoid a fight that the female's larger herd would ensure females would win. Constant interactions over food over generations would translate this principle to an instinctual tendency for males to back down in conflict with females. If you went this route I would suggest that you have females and males having lots of interaction to help further social development and skills, which are a key driver of intellect, and to ensure both sexes develop altruism and social cooperation skills required for modern humanoids to work together in an inter-sex social enviroment. I'd suggest males claim a territory with females wondering, with the larger female territory encompassing a few male territories. While females are in one bachelor pod's territory the males join with and intermingle with the female herd, interacting socially, trading favors, and generally with males trying to encourage females to choose the male to mate with. This isn't required, but it seems to help drive the sort of society your more likely to want for your modern humanoids. Of course there is an even easier approach that takes elements of this approach but doesn't require separate male bachelor pads, which makes it easier to justify humanoids developing social instincts like that of modern humans. It even has the benefit of being proven to work in nature... Hippy Apes to the rescue Thus we get to a working example of dominate females in the bonobos. If your not familiar with them the bonobo's are one of our two closest genetic relatives, being as close to us as the more commonly known chimpanzee. They are also a fascinating species, evolutionary speaking, having a number of traits that are rather unique for greater apes. They share our more upright walking posture and forward facing hips (their also the only other ape to mate 'missionary style' due to this). They are also by far the most peaceful ape species, usually resolving conflict without violence and studies show a more instinctual altruistic behavior then humans. And of course, women dominate their society. I mentioned already that closely related apes benefit from grouping together to work together, and that bond of kinship is an important part of how the female dominated society developed in the bonobo. Males are driven out when they reach sexual maturity, just like I suggested in my last example, meaning that bonobo herds consist of genetically related females and unrelated males that migrated into their troop. This, in turn, means that the females have a larger incentive to band together then the males, since the females are far more inclined to help their sisters and daughters then the males are to help an unrelated male. Thus while bonobo herds tend to have roughly the same number of males to females the females ended up in charge by developing an alliance together to allow the family of females to control the unrelated males in their troop. If a particular male attempts to cause trouble for any one female he will find multiple females ready to defend their sister/daughter/mother, but if a female tries to bully a male there is little reason for other unrelated males to come to his aid. Thus the inclination to side with your genetic relatives has proved the basis of the unspoken alliance that ultimately put bonobo women in charge. Now I need to stop for a second to get into the reason why the bonobo's are called the 'hippy ape', since it impacts how the female alliance grew so powerful. Keep in mind your humanoids don't need to have the same strategy, but I need to discuss how it impacted bonobo evolution. Bonobo are accused of being hippies do to their strong belief in the old saying "Make love not war" They use sex as a form of conflict resolution, using it to resolve conflicts without violence, exchange favors, develop alliances, make up after a fight etc. They also have sex in every form you can imagine, with any combination of age and sex, you can't exclude anyone from a major part of your social conflict resolution system after all. This benefited the females in two manners. First, it gave bonobo a means of ending a conflict without violence before female alliances were as strong, specifically by offering sex to a male to appease him. Females still do this often, by offering sexual contact (not always full matings) to help lower tension and resolve a conflict before it escalate to violence. Since males are far more driven to achieve matings then females (since females can only conceive once a year, whereas every mating a male has could theoretically result in a child), males were willing to end conflict or surrender resources to female in exchange for an opportunity to mate, giving women a clear source of power over the males since they had a monopoly on a 'resource' they could offer to males (an opportunity to mate), that they could trade for resources or social power. The other benefit, less obvious but potentially as important, was obscuring who the father of a child was, since the female has mated with multiple males. This leads to males being unable to group together to form a counter group of related males to resist female dominance since no males knew how closely related they were to other males. If your fine with your humanoid species utilizing a similar sex for conflict resolution and social interaction approach then you can copy the bonobo exactly as they are, up their intellect a bit while maintaining their social conventions, and have a nearly perfect example of what a female dominated humanoid species would be like. If you don't want such an emphasis on sexual interaction in your humanoid species there are some options. First is to copy the bonobo, but claim that the degree of sexual contact decreased later in their evolution. A good explanation for this would be to claim as the bonobo society grew larger and more compact the risk of such an regular and intimate form of social contact spreading STIs would become very real, and it's possible the bonobo would have to have moved to less sexual forms of social bonding as death's via STIs grew to put a large evolutionary pressure on them. Thus you could create a modern bonobo and replace actual sex with some other form of social bonding activity potentially; though I suspect even if the bonobo had to move away from full intercourse due to STIs their bonding rituals would still be somewhat sexual in nature, such as brushing one's hand over anther's genitals as a calming action. Alternatively you can try to create an ape species that likewise formed a female alliance based off of familiar bonds but never used the bonobo's approach. what women want I originally started writing a whole long explanation for why most apes still were male dominated, but it doesn't add much to the answer. It comes down to females needing to be the start ally together as the start of the original evolution from single individuals living independently to a more herd like living arrangement; but ultimately it boils down to "evolution just needs to go that way". there are a few ways it can go, and frankly you probably don't need to think too deeply about the evolutionary psychology. Still there are a few things we can predict about a species that went down this evolutionary path. 1. Males and females are approximately the same size. this is required to ensure males don't have a size advantage that makes it easier to dominate women before they have started to ally together 2. They likely had a polyandry lifestyle. Women likely mated with many men, likely to hide mate choice as human females did. This both helps to ensure little sexual dimorphism (since males have less need to fight for mating rights there is little advantage in males growing larger), and helps to hide paternity of a child to prevent males from knowing how related they are or developing a similar alliance based off of genetic closeness. Your modern humanoids may now have a more monogamous lifestyle, humans did transition towards a culturally inspired monogamous one after all. 3. social maneuvering is king. With physical power being less relevant to males earning mating rights the emphasis would have moved towards having better social skills, convincing females they should want you as a mate. This would mean the species may be less prone to physical aggression, but that the species is also more prone to politics, social maneuvering (including stabbing others in the back), and all the other potential headaches of a species that emphasis social status above everything else would be willing to resort to to keep that status. 4. It's all about who your mother is. This society is driven by familiar bonds. Females rose to power due to willingness to ally with those who shared genetics with them to gain power over those that didn't. Their very instinct will more strongly emphasis the concept of supporting your family at all costs, even more then humans. This means tracing family lineage, inheriting influence/power based off of your family, and wars between influential families will all be more common then in humans. Though your maternal family line is what will matter, your paternal family likely gets far less influence or meaning in their culture. ]
[Question] [ On a distant planet covered mostly by water a species of highly intelligence cephalopods have evolved and even developed space travel. The problem? Most other species are land dwellers and the cephalopods need a means to traverse their space stations and cities. Without a skeleton of their own their land travel is limited to an undignified and uncomfortable crawl that is entirely unbecoming of the most ingenious species in the galaxy. The solution? Build their own skeleton. An exoskeleton specifically. Ideally one that can be powered by the cephalopod's own muscle strength. So my question is; Would it be feasible for a cephalopod to move on land by inhabiting a non-powered exoskeleton and moving the limbs with their tentacles. In my mind it works by the cephalopod entering the tightly fit exoskeleton, which provides the creature support enough to not collapse under gravity, and use their own flesh in place of the muscle tissue normally used to move the skeleton around. If this combination wouldn't be functional what would be a way to make it functional? Preferably keeping with the non-powered artificial exoskeleton concept. [Answer] ## Give your exoskeleton hydraulics Cephalopodes are squishy. Like, really squishy. That's how they're able [to squeeze through just about any hole](https://www.huffingtonpost.com/2010/11/01/octopus-weighing-600-poun_n_775632.html). Because of this, a cephalopod isn't really well suited for a rigid exoskeleton. However, they are well suited for a hydraulic suit. Besides, what better way to direct energy for a sea-dwelling creature than water? Since hydraulics are pretty robust, there isn't necessarily a shape the suit has to be, but for familiarity's sake lets make it humanoid. For this, the best design is what we know best: humans. The suit would need some sort of internal skeleton for support, and each muscle could be replicated with a [hydraulic cylinder](https://en.wikipedia.org/wiki/Hydraulic_cylinder). Wrap the whole thing up in a flexible outer layer aaaaand, that's pretty much it! Octopodes are [unexpectedly strong (see #4)](https://www.toptenz.net/10-things-octopus-can-do-to-scare-you.php). That means your octopode could control the entire suit from just one small area; it doesn't matter where. It could be the torso, the head, it could even be an arm! The most ingenious species in the galaxy certainly could work out the hydraulics from any point in the suit. For example's sake, lets use the head. Your octopode's entire body will be there. Then, attach a hydraulic hose from each cylinder to a connection at the head, and your octopode should be able to control their entire suit from their dark, damp, enclosed area. Any octopode's dream home! If your octopode wanted to straighten their arm, all they'd have to do is extend their "bicep" cylinder and retract their "tricep" cylinder. That's how we do it, after all; we just have fibers transferring the energy instead of water. Retracting cylinders shouldn't be any more difficult than extending for them, because [their suckers are pretty darn strong too](https://blogs.scientificamerican.com/octopus-chronicles/octopus-suckers-have-groovy-secret-for-strength/). In addition to being strong, octopodes can control their individual suckers with remarkable precision. That lets them make large movements with their tentacles, while fine movements (such as fingers) could be powered with their suckers. Lastly, since the octopode isn't actually in most of the suit, it's got a great escape mechanism: if a limb is threatened, just lose it! In our example, if the threat was big enough, our octopode could even just pop the head off the suit and scamper away. [Answer] The problem lies in how and what to build the exoskeleton out of. Cephalopods are not really as dexterous as humans are; they might use something like chopsticks, made of crab's claws or something similar, for the fine manipulation. Underwater, no metallurgy is possible, and very little chemistry, since water is so good a solvent. Once they realise they need the exoskeleton trick, or the necessity of some kind of artificial implements, I think the best route left to our cephalopods might be to breed clams to produce mother-of-pearl and aragonite shapes, and others to dissolve them or weld them together. Then, they can start making exoskeletons out of interlocking, welded mother-of-pearl parts. I fear it will be a long and frustrating road. Then, they meet the land-dwelling species and basically breed and enhance them, until they discover fire. And, after long experimentations (cephalopods are fascinated by fire), they discover metals. Tin, copper, bronze, iron. At this point the exoskeletons will be made of metal struts and mother-of-pearl, and by the time they discover space travel, chances are that they're mostly using battery-powered exoskeletons. Unless there is some non-technological way of achieving space travel, I'd expect exoskeletons to pre-date space travels by a very large margin. [Answer] I don't see why this wouldn't be feasible. The simplest incarnation of some sort of exoskeleton would probably just be a few strong sticks that the cephalopod grasps with its tentacles. It wouldn't be that different from how we use crutches or stilts to lift ourselves. If the cephalopods are anything like what we have on Earth they should have no trouble wrapping their tentacles around a piece of wood or metal and lifting their own body weight without any additional mechanical help. Using four tentacles to grab four walking sticks would still leave an eight-tentacled cephalopod with plenty of appendages for holding and grabbing and manipulating its surroundings. [Answer] I am surprised that no one has suggested this yet. If your cephalopods can build interplanetary travelling ships, they can build mechas. ![Let's see the sharks try and 1-up this!](https://i.stack.imgur.com/QGT89.jpg) Advantages: * More powerful than a mere exoskeleton; * Can attach big guns; * Water reservoir makes you buoyant and therefore more comfortable in higher gravities than just being exposed to dry air; * Water reservoir cushions against high accelerations and falls; * And, most specially, [Rule of Cool™](https://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool). [Answer] Yes it would work with three things to consider: * Stability The cephalopods will probably have to learn for months how to use the exoskeleton without falling over. For varying steepness and such they will probably need a year or even more. * Oxygen They somehow need access to oxygen while on land which probably requires something like water tanks attached around them or something similar. * Water The inside of the exoskeleton needs water to keep them nice and wet and prvent drying out. [Answer] This species, early in their history, would have to develop an understanding that their advancement is limited by their environment. By saying the world is mostly covered in oceans, I would assume that there is some dry land somewhere. Around that dry land, a branch of this species would develop a form of amphibious abilities or tactics to crawl on land to develop the technologies to gain an advantage over other species or their own kind. This would be metallurgy and chemistry as others have pointed out that would be difficult (not necessarily impossible) to develop. They may have got an understanding of metallurgy around geothermal vents. needing a safer place to advance this ideas, the land and air would be the solution. The race that either develops the strength to crawl on land or develop a crude tool to assist them, such as an exoskeleton or crutches. The race that manage to get on shore would become the dominate society and what ever method they used to accomplish this would be further developed and improved on over t [Answer] This is not natural for cephalopodes. Wikipedia said they have no conception of form. They like to hide in spots, liquidly filling them. The idea of becaming connected rigidly to some carcass should probably sound horryfying to them. Cephalopode in exoskeleton is a crucified cephalopode. They also have taste organs in their tentacles. I don't think they'll like to always taste their exoskeletons. Also I believe the muscles in their tentacles should work in some other way. They are not adopted to the kind of work needed to move the skeleton. In principle, they could evolve to live with an exoskeleton, but it should require a lot of effort and time. ]
[Question] [ My semiarboreal humanoids have a build quite similar to humans, apart from some more specialized arboreal adaptations. They live in rainforests quite similar to the Amazon Rainforest. Though trees are important to their foraging and structures during rainy season, they still need to run or at least walk efficiently on the ground, as they travel long distances, gather certain materials, and hunt there. To go more into depth, humans have [arched feet](https://en.m.wikipedia.org/wiki/Arches_of_the_foot) to assist in bearing weight bipedally. My humanoids are bipedal as well, but they spend a tad less time on the ground then humans, yet less time in trees than chimpanzees. [Chimpanzees do not have arches](https://corewalking.com/chimpanzee-feet-vs-human-feet/). Some studies have results that would suggest human and chimpanzee feet have similar climbing capabilities. The previously linked article mentions: > > But my takeaway from these two studies is that if we were not shod and walking on hard floors and streets all the time, our human feet would easily be able to work like Chimpanzee feet. > > > Comparing the gaits of humans and chimpanzees, chimpanzees 'hobble', likely because of their bowed legs, but their feet may affect their gaits as well. In looking for a foot design that can both climb well and walk well, I have considered a combination between a human-like foot and a chimpamzee-like foot. My questions regarding such an intermediate are: * What will be sacrificed from ground locomotion? * What will be sacrificed from climbing? * Should the species not have an intermediate foot, and instead have one or the other? My guess is that the species I am working on should be able to walk on the forest floor more efficiently than chimpanzees, but likely not run as fast or for as long as humans. Edit: To clarify, I would like to say that I am looking for feet that would allow them to stay in trees securely as chimpanzees or gibbons do. They should be able to rely on their feet for stability on branches while reaching for things or eating briefly. [Answer] Lemur feet [![enter image description here](https://i.stack.imgur.com/UZ2L4.png)](https://i.stack.imgur.com/UZ2L4.png) The following video shows a lemur both progressing along the ground and leaping into a tree. > > <https://youtu.be/f9ARvGS3mhk?t=47> > > > and > > > <https://youtu.be/f9ARvGS3mhk?t=106> > > > [![enter image description here](https://i.stack.imgur.com/n9F8O.png)](https://i.stack.imgur.com/n9F8O.png) [Answer] # Stick with human feet 1. Chimp feet don't actually articulate very much 2. Humans have the ability to climb using the same method that chimps do without modifying their feet. 3. Human feet are specialized for walking and running long distances. 4. Most of the reasons that chimps don't walk very well on two legs have nothing to do with their feet and more to do with their legs and pelvis. [Answer] You'd want an [Ardipithecus](https://en.wikipedia.org/wiki/Ardipithecus) like creature, possibly similar to an A. Ramidus which I shall hence forth call "Lucy" after the first known specimen and because these names are rough on me to spell correctly. Lucy is closely related to humans and chimps, but occurred well after the two species diverge. Lucy is believed to have spent about equal time in trees and the newly emerging Savannah plains, thus had a more dexterous base to assist in climbing but with the non-thumb digits resembling something closer to a human foot. Bipedalism is thought to have evolved to allow homonids (of which, Lucy is not one, but close enough) to see over tall grass of the flat lands, which provided early warning against quadrupedial predators and early intelligence on prey animals. Human hands developed to provide carrying of food at a more energy efficient travel capacity to a quadrapedal locomotion like a Chimp. This could easily have evolved if your species evolved in a edge of Forrest environment bordered by a savanna plane. Although you asked for feet differences, your more immediate noticable difference would be the arms which would be longer than a human's and possibly be equal length to legs or at least closer to that. As noted elsewhere, the legs of humans are sufficient enough for this lifestyle as climbing and general aboreal locomotion were typically upper body strength activities, not lower body activites. Consider such human actions as the hated gym activity of the rope climb or the playground equipment of the monkey bars and compare to a fellow great ape climbing a vine or tree, or swinging though branches. In fact, the latter action gets its name from the movement of primates through trees, as the actions use the same physics. Humans have generally short arms compared to primates because our evolution occured due to a decline in trees, but this is a slight disadvantage to humans at best. In fact human hands are unique in that every muscle group in the hand is found in another extant primate but no extant primate has all the same muscle groups of humans. In fact, when compared, great apes have an average throwing speed of about 20 mph while an average human can achieve speeds over 3 times this, and can get close to 5 times a great ape's throw speed if trained (Professional Baseball pitchers can easily clock speeds in the high 90 mph range)... the advantage of this being that most savannah land animals are not anticipating the devistation of a rock moving at 60-70 mph striking them in the head, even less so when they think predators can't see them in the tall grass. Suffice to say, human climbing skills are more than sufficient to primate climbing skills to allow a trained human to sufficently climb like an ape. The foot changes would only allow for better utility, and even then, not much... mostly it would work to stabilize the body better while reaching for the next thing to pull yourself higher and possibly carry loads upwards. Even then, it's only a slightly better advantage as many humans (including yours truly) still retain surprisingly dexterous toes to sufficiently grip items and manipulate them while standing on the free foot (my use typically extends to picking up items on the floor that I'm too lazy to pick up, but I once attended a concert by a guitarist who, do to some mishap, had lost both arms... but had learned to use his feet to sufficiently play quality music... better than I could my hands... but I'm a terrible musician so... take that into consideration.). [Answer] Clawed feet Cats and other animals climb very efficiently with clawed feet. They do however present their feet to the tree inline with the surface which allows for curved claws to engage the surface and the weight to hang from them, they basically turn from horizontal walking through 90 degrees to vertical walking up the surface. If you want your humanoids to be able to walk efficiently on the ground as well as climbing an ankle that can rotate to both positions may not work. So : * go for feet with stronger/stiffer toes and straight claws, either fixed or retractable. Think of the use of crampons for climbing ice walls where they are kicked into the surface. Sharper claws on softer material such as wood would require less of the kick needed. * have more flexible but stronger toes and curved claws that can rotate the ninety degrees or so to form the angles for hanging claws. * rearrange to the lower limbs to a digitigrade form to present the foot forward and easier to rotate to have a hanging claw orientation. [Answer] Many of the provided answers are correct in that human feet are efficient enough at climbing trees. In that context, Mathaddict's answer is correct. However, you should also consider these people's ability to live in trees: navigating branches, being able to easily keep themselves from falling while doing other things, ... To easily navigate treetops and prevent falling out of trees, you need appendages that are good at grasping branches, which is going to require being able to grasp around a branch. Human feet do not arch enough to actually allow for this. If your people have human feet, they will have to balance on the branches instead of being able to rely on grip strength. Or, when they need to rely on grip strength, they will have to use their hands, which means they don't have their hands free to do other things. Taking that into consideration, I don't think you can get away with using human feet. However, there are several ways to resolve this conflict: * These people build tree huts and thus can walk on a relatively level surface without needing to grasp at branches. * These people live in massive trees with massively wide branches and thus don't have much issue with walking on the branches. * These people only sleep/hide in trees and don't actually do much in trees, and thus have no need to have their hands free. * These people's lives are simple enough for them to use one hand for grasping and one hand for whatever they do while living in a tree - they don't need two hands free and have adapted their lives accordingly. * These people have feet with much longer toes (and shorter feet) so that they can grip around a branch and thus can keep themselves easily balanced while doing other things. This will negatively impact ground running but not as much as you're expecting it to. As other answers established, the reason chimps aren't particularly good at walking has more to do with their general posture (hips, spine, ...) and not just their feet. * Adding to the previous option, you could also give them normal feet but with a massive "foot thumb", much like the lemur picture posted by chasly from UK. * Assuming they still evolved from primate ancestors, these people never lost their tail, and thus use their tail to grasp branches. This leaves their feet free to specialize in ground running, and their hands to do detailed precise work. * These people have a superhuman level of balance and have simply learned to navigate the trees using their inferior human feet. I would consider this option a cop out since you're trying to be real about the needed biology, but it's a valid option nonetheless. After all, humans are able to walk a tightrope or slackline; so it's not biologically impossible to simply learn to walk on branches. [Answer] Suction on the feet You don't necessarily have to use chimp feet to climb. The hyrax is great example of this. Their feet have thick, rubbery soles that are moist, and lift up in the center to form a suction cup. In this way, you could have feet suited to climbing without damaging ground maneuverability. you would actually increase it, as feet with curves like that would help with handling different terrain, and would not just be limited to climbing trees, meaning that you could create variants of this species or race that are able to handle mountains and rocks as well as trees. ]
[Question] [ The magic works like this: * It must not be performed in public, meaning with more than a dozen observers (regardless of the means). It will fail, spectacularly * It must not be performed in private, meaning that if you do it alone, it will also fail fatally * The optimal setting for it to work is in a group of less than or equal 13 - the more participants the stronger it is * The caster will have to come up with the ritual on the spot without consulting with the others. The ritual must invoke a specific sceptical reaction in other participants. Namely, their reaction must be: "That will work?" and not "That will work!" nor "That's brilliant!" * If all other participants think that "That will work", the ritual will fail * Magic is a ritual that can be performed by anyone - nobody is special, anyone can do it * The one who performs the ritual decides the effects of the ritual. The details of the ritual could be anything, varying from dancing naked to counting stars or riding a cow upside down.. * The effects of the ritual is limited by what could happen in nature however improbable it is. One could call down a meteor or create tsunami, recover from cancer.. but not make water flow upward or create a black hole out of nothing So, the main obstacle is the unpredictability. One could do some stupid things to call the rain the first few times, but then it get repetitive and lost the scepticism. Lost the ritual, and get a backlash (fatal). How do I weaponize this magic reliably? If my army (say medieval) went against another and I dig a few holes to hide the "magicians" to do their magic. How to get them to keep spamming spells without losing their scepticism and get a backlash that kill both them and my army? edit 1 To clarify how this magic affect the world: * If you called down a meteor, the meteor won't just appear out of nothing right after you finish the ritual. The meteor is actually already coming, your ritual is just coincidentally happening at the right time. So the meteor won't just drop on your enemies, because it takes time for a meteor come from 'not clearly visible in the sky' to 'suddenly on their head'. It has to travel from somewhere to earth. * If you called a tsunami, the same thing applies. The tectonic movements or some geographic activities are already there. There will be an earthwake or something in the ocean and then a tsunami will form, then it will come for both you and your enemies of course. * You called a storm of frogs, a hurricane somewhere fished some frogs and dumped it on your face at the right time. That's why I said the effect must be possible in nature. [Answer] ### Magical drugs that erase your short term memory Someone has to create a drug to, possibly through the use of magic, erase the short term memory of the people present. With this drug they won't realize that they have already seen magic being performed and you can use the same ritual with the same effectiveness as often as you want. ### Training camps where people are taught that magic does not exist Furthermore you would probably train people, maybe little children, in a special camp. Away from magic. If they were taught that magic does not exist and is not possible by any means they will distrust it. Just imagine you were suddenly called to the battlefield and someone was running around naked, screaming that meteors will come down to smite your enemies. You would call him crazy. Which means the magic would work. Then someone gives you the magical drug and the process can begin anew. [Answer] # Think big. Do strategic defense, end scarcity With this kind of thing you need to think big, because you are using up a resource: the number of people that have not yet seen this magic (however, see the end for a trick). So while using it for short-term gains is appealing, you need to go big and strategic. Obviously this cannot be used on the fly to respond to a tactical situation, i.e. to a specific battle. Use this as strategic defense. Keep the enemy out by flooding ingress paths for armies, drying out vital areas and/or scaring them with your awesome magic. So your first order of business is: keep the enemy away by using the environment to your advantage. Second, and this is the really important bit: eliminate the need for war all-together War happens in order to gain control over resources. War happens because you need water, food, metals, energy, grazing land, et cetera. With this magic, your nation can put an end to all drought, end all famine, discover valuable metal deposits whenever they need it, make soil turn fertile, cure people of all disease, make everyone live long happy lives, make everyone absorb education perfectly, and all the other boons that makes a nation thrive. Offer your neighbours this, and they will think it more valuable to have you as an ally than as their enemy. # Watch out for [Pratchetting](https://en.wikipedia.org/wiki/Hex_(Discworld)) and [Munchkins](https://en.wikipedia.org/wiki/Munchkin_(role-playing_games)) The problem with rules is that they by their existence and human nature invite to abuse. In your case the trap is: recursion, using the magic to affect future magic. ## Wishing for more wishes Is it possible that a human will forget about the amazing things they have seen? Improbable, yes, but not impossible. So you can use your magic to "reset" people you have used so far. That might help you keep going forever. ## Ensuring success Is it impossible that an observer will have a skeptical reaction to something that seems mundane? Again: improbable, but not impossible. So you can use this magic to prepare hordes of helpers to always be skeptical when witnessing a ritual. You will need to deal with this somehow. [Answer] Random failures, almost all of the time. It is no big thing to get together a group of 12 over and over again. If you told me you would make pigs dance I would be skeptical. But in a world where magic is known to exist I would be a lot less skeptical. So: my skepticism cannot be because of the premise of magic. It must be that I am skeptical about your abilities and proposed path. I am not skeptical that a basket can be sunk from full court. I am skeptical you can do it on the first try, because I know you have never picked up a basketball in your life. There must therefore be a track record of repeated failure on the part of all members of this magic cabal. Fatal failure will not work because then they cannot get back together. No, this will be humiliating or ridiculous failure, possibly dangerous or expensive failure. Each member of the magic group must have such a terrible track record at successful magic that the other members are skeptical that any given individual can put his pants on leg side down, much less accomplish magic. Failure will be met with smug smirks and deprecatory guffaws. Occasionally magic endeavors might be purposefully sabotaged by others in the group to enhance the hilarity of the expected failure. I envision this group as much like a role playing game group, in which much time passes with ostentatious boasting and smug displays of knowledge. Ideally, and for narrative fun, the 12 members should be total incompetents in many other ways. Each individual's skepticism and contempt for the abilities of the other 11 is exceeded only by his or her own pride and colossal self esteem. My own failures at magic do nothing to scratch my own self esteem but are attributed to factors outside my control, interference by others, crossbreezes or "I fooled you chumps! That is really what I meant to do!". The 12 are suffered to continue their incessant bumbling by the military group that they are a part of because of the very (extremely) occasional stellar results that this cabal manages to accomplish. Among group members, success by any individual is attributed to pure luck or possibly the theft of techniques developed by others in the group, although to their employers the 12 take credit as a group because they know what side their bread is buttered on. I envision the scene where one of the members successfully manages a devastating rain of fire upon the enemy. The other 11 are struck dumb as they watch it come down. Then: "Well, even the blind squirrel sometimes finds a nut!" [Answer] Memory loss. Or possibly just drugs. Have your practitioners imbibe a root/mushroom/herb before beginning their ritual/being told what to try and achieve. If the herb has the right properties then they won’t be able to remember what they did or how they did it, naturally maintaining a level of ‘wait, that will work?’. If they’re not told what events in the War they’re responsible for your little enclaves of wizards will never be able to match action to deed, so they’ll always be sceptical that it can be achieved The flip side to this is that your drugs can’t be too good, or instead of molten lead raining down upon your enemies you might instead end up with a rain of psychedelic paints. Or frogs. [Answer] Patter At least 90% of stage magic is how well the performer pitches the trick, if a talented talker tried to present a failure it may convince people. If the magician whiffs his lines, trips on his flying wires, steps on the hidden bunny or whatever an audience otherwise pretty sure magic works might still be convinced this time it wont. kill people If people know magic fails they will expect it to. The mage does a spell for a small group. It is explained to them, and each of them then is invited to repeat the trick in front of a large audience. Each audience member is then available to be a small group participant. Promote anti-inductive reasoning "It worked every previous time therefore it logically must fail this time." Anti-induction is as self consistent as induction, but it seems anyone with even the slightest connection to the real world prefers the latter. So you need test all professors of philosophy, math, or theology for the capability to truly believe in anti-induction. These are now the most important people in the world. With them a wizzard can limitlessly preform their magic without needing the overhead of meta magic tricks or time consuming recycling of people, presumably allowing a higher throughput of effective magic. By using specialists you can preserves a general ignorance of magic that could still allow one time use of random observers if you are desperate. [Answer] Make it widely known If everyone knows how this magic works, then everyone will know that the magic will work the first time if people are skeptical of it. However, since people now know about the magic, then in fact it will not work since they know magic exists. They cannot be skeptical about a phenomenon they understand. And that's what will make it work. Gather 12 of the top magic researchers who understand this magic and have them gather around a practitioner of the art. Since they know that the magic works, they know that in fact it will not work. All silently believing to themselves that the magic won't work in turn will cause the magic to succeed. And thus it becomes an endless circular logic. They know magic works, but they also know that will cause it to not work, thus it will work for them except if they know that it won't and so on and so on. They'll constantly be skeptical of whether it will truly work, they'll never know for sure, and thus it will always work because that is the basis on which the magic works. The most intelligent of these magical researchers will run into battle with their jury rigged magic and when asked if this will work, they'll be the ones saying "I have no idea." The side effect is that occasionally it might actually rarely blow up in their face if they get a bit too confident in it working all the time, though this would be a necessary sacrifice to instill the fear in others that it will not in fact work continuing the logic loop and constant skepticism of whether it will work or not. But a determined enough military would probably be okay with a few sacrifices. [Answer] A pretty well covered topic, one thing I can add though. Place your performer and observers where they cannot see the effects of the magic being done. That way the skepticism is never interrupted. It would work better than memory loss drugs since there would be less down time and generally memory loss is a destructive process. It would suck if your observers started going brain dead... [Answer] Even if the participants know how magic works, if they don't know how many participants there are, they won't be able to know if it's going to work. An example of a scenario which uses this (if group failure doesn't need to be avoided at any cost): A number of blindfolded people gather in a room, preferably not much greater than 13. There is also a supervisor who is not blindfolded, and that will effectively give instructions to the group. The group will be informed beforehand what desired effect the magic must have. The supervisor can communicate with the people in two ways: he/she can tell a person to leave the room (with one tap on the shoulder), and he/she can tell a person to be the main performer of the ritual (two taps on the shoulder). Now, the supervisor will randomize a sufficiently small number of people to remove from the room. Thus nobody (except the supervisor) will know how many people there are in the room (assuming communication is forbidden). Then the supervisor selects a person to perform the ritual. If the ritual succeeds then they end. If it doesn't, repeat the process again until it works. [Answer] Dress the ritual up as something else, like a technological display or marketing research. The caster can tell them it will do something completely different than what they are trying to achieve. This way the observes will expect it to fail and they will be right even if the magic succeeds. You could say you are going to levitate a metal contraption, when you are really dropping a meteor on someone (you can even change what the thing is "supposed" to do on the fly to keep the ritual changing) . You can do this at mall around the country just like normal marketing research so you have a nearly inexhaustible supply of skeptics. Not the optimal level of skepticism but you can always pre-screen to improve it. ]
[Question] [ In my setting , there is a faction known as the Templar that serve a larger Empire. The Templar are all magically gifted and immortal (non aging). They are covered completely in their armor and their helmets obscure their faces to the enemy. The Templar are pretty much always the vanguard. They are the tip of the spear that breaks the enemy's back and allows the "lesser" troops to finish up. The Templar aren't just muscle though. They employ varied and advanced tactics, but have a (well earned) reputation for brutal efficiency. The Empire isn't the most stable place, so the Templar are often used to put down rebellions; basically to "prove a point". Due to this fact, they also try to nurture this reputation in the Empire as well, so that someone doesn't meet an Imperial citizen and have say something along the lines of: "Oh, the Templar? Nah, they're pretty cool dudes. My sister married one. Really nice guy." Rather, there should be mixed stories and wild rumors like: "They once burned down a city for selling bad wine" or "One got his head cut off by a knight. He killed the knight and just sewed his head back on after the fight!" Now, onto the real question: How can the Templar effectively spread propaganda among a populace to cause fear and superstition when it comes to fighting them? [Answer] # Agents of Influence The [Agent of Influence](https://en.wikipedia.org/wiki/Agent_of_influence) is someone whose task is that which you are asking for. Remember that in a medieval setting, there is no such thing as news agencies, no Internet, no newspapers, no telegraph... nothing. The only official and established information outlets are [town criers](https://en.wikipedia.org/wiki/Town_crier) and [heralds](https://en.wikipedia.org/wiki/Herald), and all the rest is rumour, hearsay, word of mouth. So these Templars of yours employ a number of travellers that go from inn to inn, from pub to pub, to harbour taverns, brothels, and other such places where people meet and talk. All they need to do is make sure that they keep their stories fairly straight so that people can corroborate them. > > — Oh come now, you are joking... they cannot be all that?! > > > — No really, I heard the same thing in Unspecifieditown. All the > same... > > > So... round up all the [raconteurs](https://en.wikipedia.org/wiki/Storytelling) you can find and employ them. Give them a budget to travel, a reasonable cover story, and then you are set. [Answer] Rumors will spread naturally if they really are magically gifted and really cannot be killed; all they need to do is leave alive a few soldiers and/or spectators from each battle. It is human nature to talk of near unbelievable things they have witnessed. That's it, just allow witnesses to survive and their reputation will be such that they may not need to fight at all: Genghis Khan had a reputation for killing every male in a town and giving their daughters and wives to his soldiers to do with as they pleased: raped, turned into servants, or both: But not if you surrendered and joined his army (on probation and without arms until you proved yourself, of course). After some number of these "kill them all and burn the town" episodes, Genghis took many fortified towns without any fight at all, he arrived to open gates with the men already standing there defenseless, with their weapons on the ground in front of them. Heck, they probably killed (or banished) their own dissenters! Propaganda needs no special accelerant when the rumors are true. [Answer] If I understand your question correctly: you're looking for a form of medieval-age propaganda to instill fear against a population. If that is true, then may I present: # [Malleus Maleficarum](https://en.wikipedia.org/wiki/Malleus_Maleficarum) Hammer of Witches:, the treatise on witchcraft written by the Catholic clergyman Heinrich Kramer and published in the Speyer, Germany in 1487. Maleficarum is infamous for endorsing the wholesale extermination of alleged witches. For being published 40 years after the invention of the printing press, it was a bestseller second only to the Bible for almost 200 years. In your case, a similar work may be distributed among clergymen and empire officials to educate them about The Templars, their achievements, and their authority. EDIT: As Securinger noted in the comments, Maleficarum was not endorsed by the church. [Answer] They could subliminally control people's thoughts of them, so that the mere mention of their name arouses a deep feeling of dread, though people aren't sure why. As an added bonus, they could make this curse spread virally, so that it spreads from person to person (with physical contact, communication, eye contact, presence in room, etc.), and make it so that the first response to any inquiry as to why a person is afraid, disturbed, or otherwise upset would be along the lines of "The Templar...". This response could be easily corrected, but the dread would persist, and people not affected (e.g. because of magic of their own) would begin to associate the phrase "the Templar" with these terrified reactions. Especially if they were foreigners and didn't know what the Templar were yet. [Answer] To compel fear, but not rebellion, you need a greater evil. It must persist or you must have a reasonable level of public trust in your story that it might come again. Being seen as unpredictable and dangerous is very easy. A shroud of mystery isn't hard either, especially if you have the right job. To instill fear in enemies is harder, it involves dealing with aggressive attempts to put you to the test. Better to have a constant excuse to prove yourself like a war or being held hostage. [Answer] Although it is technically not "mediaeval" so much as "early Renaissance", propaganda did actually play an important role in several early modern conflicts. Notable examples include the English Civil War and the Thirty Years' War. The medium was the rapid growth of peasant literacy combined with the printing press (initially as woodblock printing, later done more efficiently with the movable type press.) Partisans of those conflicts spread propaganda in the form of broadsheets and pamphlets, often anonymously, to fairly uncritical audiences who could often be induced to riot by the most improbable purple prose. A particular subset of these are "Discoveries" of witchcraft -- pamphlets and even short-form books supposedly revealing conspiracies by a huge underground network of witches. It is not only modern readers who find them to be embarrassingly lurid and totally ridiculous: many educated persons of the era realised they were nonsense, and dangerous nonsense at that, and tried to suppress them. In some cases this was successful, but in many places where central authority had broken down, "witch panics" arose and scores of innocent people were killed. In your cause, your Templars actually do have diabolical powers, so the lurid stories in the printing press could quickly spread these. ]
[Question] [ Closed. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Update the question so it focuses on one problem only by [editing this post](/posts/35122/edit). Closed 4 years ago. [Improve this question](/posts/35122/edit) [Related, but not a duplicate.](https://worldbuilding.stackexchange.com/questions/10931/wrong-planet-what-would-an-aspergers-planet-be-like) Imagine a version of modern or slightly into the future earth in which it is quite common to be born on [the autism spectrum](http://www.nimh.nih.gov/health/topics/autism-spectrum-disorders-asd/index.shtml). There are still plenty of neurotypical people in the world, but I'd say at least, oh, 35% of the population fall somewhere on the spectrum, ranging from mild aspergers to experiencing severe difficulties learning to talk and processing touch (among other things; this is an oversimplification to illustrate range, not an exhaustive list of symptoms). To prevent the scenario from becoming too depressing, let's assume that society as a whole is fairly benevolent: while being autistic might still get one labeled "weird" by neighbors or schoolmates, there is no large-scale discrimination or violence that might parallel racism. To be clear, I am NOT considering scenarios in which some sort of neurological class system emerges--although that might be an interesting follow up question ;). I'm assuming the goal of society to let everyone live as happy and productive a life as possible. Also, assume that autism is not "curable". Some people may be able to learn to overcome some of their limitations, but re-wiring peoples' brains through medicine is not an option for either technical or ethical reasons (it really doesn't matter which). Given these premises: * What shape does society take to better meet the needs of the increased neurodiversity of the population? What changes in the BIG PICTURE of how society is run? * Given that the issues they experience are now much more common (and support and resources are presumably now much easier to come by), how might people on the autism spectrum cope with aspects of life that they find difficult, such as sensory overstimulation? What DETAILS change regarding how these people live their everyday lives? * What are the long term effects on society? Example lines of thought to pursue include clothing choices, company policies, laws, entertainment, social customs, etc. You don't HAVE to talk about any of these things in your answers, it's just a few things that immediately came to mind. I'm looking for answers that are creative, realistic/respectful of how autism actually affects people, and hopefully, interesting from a story-telling perspective. Lastly, I'd like to emphasize that this is a purely fictitious scenario and in no way reflects any predictions or beliefs on my part. Please keep it civil and based in fact. [Answer] The other answers already mention most of the adaptations that would be aimed at facilitating people on the autistic spectrum, but I expect there would be much broader changes to society and education especially. ## Teaching Neurotypicals to coexist With kindergarten and elementary school classrooms containing up to a third of children on the autistic spectrum, I expect the neurotypical children will receive implicit and explicit training in how to talk, play and generally coexist with their less typical classmates. They will grow up knowing that their intuitive social cues don't work on all people and as an effect start being more explicit about their intentions and expectations, even to other neurotypicals. They will also experience a lot of the varying limitations/issues their autistic classmates have to overcome and learn not to judge them but rather to recognize the limitations, accept those as a given and learn how to work around them. ## Languages will change Starting at schools again, "confusing" ambiguous and figurative language will be eliminated from the curriculum and discouraged at all times. Figurative speech will all but disappear from mainstream language, but flourish in art and counter-cultures. Slang will be big among the neurotypicals that resent all these changes. Autistic people are not the only ones to have problems dealing with change after all... ## Socialism will rise At least, societies will move to the left politically. Health care, social security and employment laws will become more comprehensive in order to accommodate the larger group of people not able to compete effectively in the rat race being sold as the freedom to make your own destiny. Politics will change in other ways as people on the autistic spectrum will not "vote with their gut feeling", but more likely sift through detailed election programs to find the correct candidate. They will become a powerful voting bloc immune to the likes of Donald Trump or Ted Cruz. ## One job for life will return Autistic people will be in a position to demand and receive (see the previous point) a more stable work life, where companies face high payouts and/or transition costs if they want to fire people (any people, not just autistic) as well as extensive orientation and training costs when they hire a new employee. Notice periods may extend to a year and promotions will planned out several months ahead with the employee in question. Additionally, companies will receive tax benefits when they employ people with more severe limitations, allowing them maintain a good productivity to labor costs balance. Companies will compete vigorously for the high-functioning autistic people especially and lure them in with life-long career prospects and plenty of time to work on their fields of interest. Overall, companies that learn how to effectively employ and nurture people on the autism spectrum will reap the benefits, while the neurotypicals that thrive on competition, rivalry, etc. (think psychopathic CEOs and greedy bankers) will end up concentrated in relatively few companies, because they scare away a large part of the talent and so are not welcome everywhere anymore. [Answer] I have mild Asperger's, so I'm in the "could pass for normal at a distance" category. So, take this for whatever it's worth. That said, I'd expect one major area to be in sensory issues, as follows: * Noise limits would probably be more strictly enforced, in particular regarding loud music, as it's quite common for us to be hypersensitive to noise. The fact that blaring music will damage your hearing is just an added reason. * School uniforms (where present) would have to be made available in alternative fabrics for those who can't process e.g. cotton/synthetics. * House lighting would by default be based around dimmer switches, rather than a simple on/off switch, to accommodate those with increased sensitivity to light (whether through sensory issues, or through physical problems with the eye). Another thing that would change is that, as suggested by King-Ink below, police would receive better training for handling people who don't respond normally to the police - which in the long run would probably help other people (neurotypical or otherwise). [Answer] A world where mild to moderate autism was both common and socially acceptable could potentially be better than the one we live in today, for both the autistic and the non-autistic. The autism spectrum is extremely broad, ranging from low-functioning to savaants. While I don't want to play off of the 'autistic genius' trope too much, there is some truth to it; not being distracted or bothered by social standards can be very helpful when it comes to focusing on a project or simply thinking outside the box. It is also common for people with Asperger's to become experts in their selected field by focusing on its study to the exclusion of all else. Not all autistics are geniuses, but many geniuses are autistic to some degree, and it is not unlikely that many others have been held back from attaining their potential because of their peers pushing them down or society making them feel worthless or 'disabled'. A society that was more accepting of people on the autistic spectrum overall would be much better at recognizing talent where it exists, without being put off by the 'weirdness' of the individuals in which it rests. Such a society could evolve faster by being more tolerant and accommodating of its "differently abled" individuals and growing off of their contributions. As for those who could not contribute more than the average person, life would be better for them too. It is likely that 'social behavior classes' would be much more common (and acceptable) than they are now, becoming a regular part of the school curriculum, perhaps even required. Even non-autistics could benefit from these classes - people who are naturally socially gifted are rare even in our world, most people have to blunder their way through social circles before they figure out their way. In the end, social behavior would be seen like math or language arts - everyone with an education has studied it, some people are naturally good at it and some people are not, and there's nothing wrong with that. On the other hand, extreme forms of autism can be very difficult to deal with. When 'mildly uncanny and off-putting' turns into 'practically harmful to the well-being of themselves and others', you're dealing with a whole different category of individual, and if such levels of autism were commonplace (too common to be controlled), you'd be dealing with a world gone mad. But such individuals are quite rare in our world, so I expect that they would still be too rare to make a significant impact on the way society functions overall, although the way we look at mental illness may be different. One possible major change to the functioning of society would be an increase in extreme specialization, due to the aforementioned tendency for 'Aspies' to specialize in a particular field. College curricula might become more focused, with schedules focused on depth of study rather than breadth, and one's chosen profession might define a person's abilities even more than they do today. It is unlikely to evolve into a full-blown caste system (since the majority of people are still 'neurotypical') but it might have shades of that. I'd expect scientists to be really good at science and artists to be really good at art but have fewer skills outside of their field. Ironically, this would increase the importance of teamwork for anyone who wanted to get anything done. [Answer] Here's a list of what I've gathered: 1. Everyone in society would be more accepting and kind to everyone else. By showing kindness, to these mentally disabled citizens, society basically just becomes a better place. On a side note, teachers (as well as policemen as stated above) will be far more patient and understanding of their students. 2. Accommodations in the workplace, taken from [here](https://askjan.org/media/downloads/ASDA&CSeries.pdf) (check out page 7-9, there are about 300 accommodations listed, I chose a few) > > • Provide advance notice of topics to be discussed in meetings to help > facilitate communication • Allow employee to provide written response > in lieu of verbal response > > > • Provide structured breaks to create an outlet for physical activity > • Allow employee to use items such as hand-held squeeze balls and > similar objects to provide sensory input or calming effect > > > • Provide private workspace where employee will have room to move > about and not disturb others by movements such as fidgeting > > > • Divide large assignments into several small tasks • Set a timer to > make an alarm after assigning ample time to complete a task • Provide > a checklist of assignments > > > o Redesign employee’s office space to minimize visual distractions > > > • Develop color-code system for files, projects, or activities > > > • Use a job coach to teach/reinforce organization skills > > > • Provide written instructions • Prompt employee with verbal cues • > Safely and securely maintain paper lists of crucial information such > as passwords • Allow employee to use voice activated recorder to > record verbal instructions > > > • Label or color-code each task in sequential or preferential order • > Provide individualized/specialized training to help employee learn > techniques for multi-tasking (e.g., typing on computer while talking > on phone) > > > • Remove or reduce distractions from work area • Provide weekly or > monthly meetings with the employee to discuss workplace issues and > productions levels > > > • Provide praise and positive reinforcement > > > • Allow the presence and use of a support animal • Modify work > schedule > > > o Provide concrete examples of accepted behaviors and consequences for > all employees > > > o Use training videos to demonstrate appropriate social skills in > workplace o Encourage all employees to model appropriate social skills > o Use role-play scenarios to demonstrate appropriate social skills in > workplace o Give assignments verbally, in writing, or both, depending > on what would be most beneficial to the employee (e.g., use of visual > charts) > > > o Assist employee in assigning priority to assignments o Assign > projects in a systematic and predictable manner o Establish long term > and short term goals for employee > > > o Provide sensitivity training to promote disability awareness > > > o Encourage employees to minimize personal conversation or move > personal conversation away from work areas > > > o Maintain good indoor air quality o Discontinue the use of fragranced > products > > > o Modify workstation location > > > o Provide an environmental sound machine to help mask distracting > sounds o Provide noise canceling headsets o Provide sound absorption > panels > > > Accommodations in schools, taken from [here](http://www.healthcentral.com/autism/c/1443/156580/accommodate-autism/) (summarized): > > Have a set routine for the school day. > > > For younger students, provide a picture schedule. The schedule can be posted for all students to use or a small, desktop version > can be created. > > > Some students may do well if tasks are held with Velcro so they can remove them as the task is completed. Provide adequate notice > for any change of schedule, except in cases of emergency. > > > Provide lessons by giving a short summary of what will be covered, a detailed explanation and finish with a summary of the > lesson. > > > Provide an area of the classroom the student can retreat to in times of high stimulation or when overwhelmed. > > > Identify distractions and take steps to minimize them. > > > Give directions that are clear and concise, using literal language. > > > Provide written notes or have another student use carbon paper to share notes if handwriting is a problem. Use oral testing or > other alternative testing methods for those with difficulty taking > written tests. > > > Some children with sound sensitivities may find clapping, yelling out of turn and high frequency sounds extremely distracting > and in some cases, painful. > > > [Answer] Another Aspie here, trying to just put out some thoughts that may or may not have been adressed before. First off, Autism is NOT a disability. It is only seen as one and feels like one because society doesn't (yet) have room for us. That said, the first big thing is education; people, both autistic and neurotypical, need to know what autism is. Autistic people need to learn how non-verbal communications work, how to recognize and apply gestics and mimics as well as metaphors and figures of speech. It is possible for those of us with higher intelect - of which there are plenty - the others will at least know social subtext is there and how to communicate they can't handle it. On the other side, neurotypicals will learn how to communicate clearly and litterally - they will be taught how to see if someone has troubble catching subtext and how to make themselfs understandable to them, as well as understand that feelings worded with a neutral face are still as strong as those making a normal persons face show vivid expression. Here, too, there will be people more capable of adapting to the other side and people who will have a thougher time learning and eventually just having to admit they can't manage. On the deep end of the autism spectrum there are also people who do not talk at all, even as adults. This, too, will be respected, and people will walk the extra mile to use whatever way of communicating works for that individual. Generally, I would hope that in an accepting and diverse world, people will be less seen as 'autistic' and 'neurotypical', but instead as 'individuals' with different social and intelectual capabilities. On the subject of over sensitivity, I suppose there would also be some changes. I suppose there would be a larger variety to things like light switches that allow for gradually intensified light, air conditioners, fabrics etc, as well as more understanding of people that feel unwell in the presence of noises that someone may not even hear - like the screeching of a cat repelling garden tool that is supposed to be to high pitched for human ears, the noise of a fridge running or even those charging lights that keep me awake at night unless I throw a towel over them. Clothing is another factor - I hate it with a passion, but I understand the social need of wearing clothes. Maybe, in regards to those younger or less high-functioning than I am, society might change to get used to seeing people that are not or incompletely dressed. Maybe being naked on the street, at least during the summer months, will be so common people no longer think 'sex' upon seeing exposed breasts or sexual organs. Given the still prevalent uproar about women breastfeeding in public, however, I suppose it will be more likely that fabric production and fashion go to great lenghts to produce a variety of clothing options to suit touch-sensitive autistics, like toe-socks, cat suits or robes, that make it possible for each of us to wear something moderately comfortable. Neurotypicals will accept, if not full or partial nudity, at least the fact that autistics put personal comfort over fashion. Class sizes in schools would have to be much smaller - cramming 30 kids into one room is more than most of us can handle. In the same effect, there would probably be two kinds of parties - those loud, full ones in the disco, and smaller, more board game oriented ones that are quiet and more focussed on giving people a way to socialize indirectly over games rather than screaming at each other in front of big speakers. In working liefe, I would expect the trend going away from large, open cubicle offices to small, one desk per room ones - or offer both so employees who need it quiet can get their own closed offices and people who like company can be in a joined office space to work in a social environment. I guess that freedom of choice would apply in a lot of places, not limited in a 'autistics get this, neurotypicals get that' sort of way, but in a 'choose what fits you' style. Just like today, you can get your happy meal with a doll or with a toy car - most people would let their gender decide, but they don't have to. Generally I guess that a society with a higher amount of autistic people would be far more individualistic - mainstream would be more like a small river, and even neurotypicals might be more confident falling out of line, as just 'being yourself' is far less 'being weird' than it is today. This would also help people with other neurological differences, like people with down syndrom, borderline, depression or anxiety - if people are more aware of the fact that every brain works differently, there will be more social acceptance overall and being different will no longer be as big a stigma as it is today - perhaps it will even be seen as beneficiall, and teamwork will become more common as everyone brings their own strenghts to form a more capable group than one made of people that are all the same. I suppose it is up to you as an author on weather or not you want to actually draw a distinct line between autistic people as an accepted minority and the majority of normal people (like ethnic minorities forming their own communities), or weather you want to paint a picture of a fully inclusive society where everyone gets along and intermingles (like men and women). In the long run, I think the line would eventually disappear - autism is not an off and on, after all, there is a long gradient of all the colors eventually fading into white. And just for the scope: I wasn't diagnosed as autistic until the age of 30. We can adapt really well if we try, and I have met many non-autistic people who can adapt to us just as perfectly. [Answer] 1. The culture and tradition will no longer be held as a great thing. 2. Bravery and war will not be glorified. 3. Mental health awareness will be at super rise. People will feel very comfortable to say about personal health conditions, mental health issues, cognitive difficulties, special needs, sleep cycle problems, rare and unique conditions without fear of introducing social misinterpretation and criticism. 4. Realism, depressive-realism, activism and proactivity will be at super rise. 5. People will feel more comfortable to talk about controversial topics and taboo topics and the views that do not conform majority. People will discuss about all sorts of politically incorrect views yet no one will offend others since they all will interpret statements factually. 6. Individualism will be at its peak. 7. Education and science will be the most popular topic and will receive maximum investment. 8. Adult education and self-selected courses will rise. Homeschooling will be legal and more prevalent. Early education will probably abolish. Late schooling will be on rise. Ageism will abolish for both "too-younger" and "too-older" population. 9. Money will either abolish or will have more simple usage. People who cannot pay will also be provided with the service. Education and scientific instruments will be free of cost. If money exists then crowdfunding will be on rise. 10. Volunteerism will rise. 11. Others' subjective experience will be trusted more, and misunderstanding will reduce. Epistemic injustice will drop drastically. 12. People with invisible disabilities will get lot of support and acceptance. 13. Bullying will not exist. Individual cases of bullying will be handled with lot of empathy and insights. 14. Marriage will abolish. Family relationship names will be simplified. Polyamory and group living will be at a rise. Consent, respect, responsibilities and truthfulness will be highly spontaneous than rule driven. 15. Nudism and naturism will be on huge rise. As well personal boundaries will be respected more on the same time, and staring will probably abolish. Dressing norms will be abolished as well gender discrimination will not be allowed in children's play. 16. Countries will abolish and politics will either be totally abolished or only some administration will remain. Military will probably abolish. 17. Authoritative force (Master-slave relation) will abolish and spontaneous service will be at rise. 18. All the institutional religions will expire. Atheism will be the largest religious view, agnosticism will be the second largest and personal religions will be the third largest. 19. Human-animal interaction will improve. Keeping pets will be more appreciated than ever. Animalistic directness will be appreciated instead of controlled. People will take food by more animalistic way, probably some of people will not use the dish and spoon. 20. Courts will change. Things will be listened with curiosity rather than judgement. More number of acts will be considered as unintentional and driven by situation or neurological factors. PTSD care will be at best. Confessions and surrenders will be nearly universal. Maybe crime itself will abolish. Police will be there to only provide help and accessibility services, fire rescue and other rescue services. 21. Environment will be protected. Forests will rise. Global warming will stop or reverse. 22. Job changing and academic course correction will be easier than ever. A same subject will be taught from multiple cognitive viewpoints. 23. 90% of the population will become researchers in their respective fields. And 100% people will receive education without having to face any authoritative abuse. 24. kids Playgrounds will become the place to teach inclusivity and acceptance. 25. No kids and adult will be infantilised. Also kids will have high role in administration and decision making. 26. Literature will change. The language will be more structured, detailed, unambiguous, pointwise, and literal-interpretation. Figurative literature and symbolism will eventually disappear. All books will be written in multiple language, in braille, using ASL, using audio, using pictorial language, and more accessibility means. 27. Administrative actions and public transports will be predictable, routine bound and highly structured. 28. There will be a drastic reduction or abolishment in concepts like status symbol, social status, sense of prestige, attitudinal barier, etc. 29. The marginalised will have more importance than the centralised. A backward student will receive more funding, books, time, altered study schedule, altered routine, leaves, etc than a topper. A backwards institute will get more infrastructure than a more reputed or high-ranking. A hardwork-labourer will get more salary and healthcare than a white-collar job. At the same time, the jobs will not be selected by competition. Whether it is a job of a professor or a job of sweeper or coalfield labourer, will not be decided by pre-existing social structure and hunger rather it will be determined by personal choice. No jobs or position-ranking will be more prestigeous than the other. ]
[Question] [ How would a Renaissance-era shopkeeper, in a walled and paved city, notice that they've traveled back in time, right when they wake up, or soon after, like after 5 min and looking outside? No dead people having returned to life and stuff either... The time warp happens when they sleep, and they wake up in the same bed... Personally, I'm doing Fall -> Spring of same year, and weather is similar, so can't use that... But, I would like something that could be generalized... > > Peasants were illiterate and innumerate, so I doubt that a calendar with numbered days would have meant much to them. For example, if they knew their birthday, they would probably know it as "I was born on Saint Anne's day," or something like that. – Ben Crowell 25 mins ago > > > I agree with Ben Crowell that calendar dates would not have been important. Daily life was structured enough by market days, the sabbath, and feast and saint days that most people would have had a structured sense of the flow of time, but "structured" in a way suitable for pre-industrial culture. (Also, priests would probably know the date.) – two sheds 15 mins ago > > > From: <https://history.stackexchange.com/questions/21304/how-was-the-current-month-and-day-disseminated-to-the-townspeople-of-the-medieva> ... Which will probably be deleted soon? [Answer] "Medieval person" is very vague. "Medieval" is 1000 years from the Arctic Circle to the Mediterranean and the Atlantic to the Urals, male or female, young or old, urban or rural, high or low class, brilliant or dull ... The number one thing is that the season is wrong. Trees and other plants are in spring form, not autumn. The morning light has a difference to the sensitive -- but this person could be a blockhead. The food up in the rafters or wherever is less abundant. The soup left in the kettle for breakfast is made with spring foods, not autumn. There's piglets in the sty, not pigs nearly ready for slaughter. The sheep are newly sheared. A lord might not notice any difference, if he doesn't look out the castle at the fields, until he got down to morning chapel and saw the "wrong" altar cloths for autumn. Because odds are it's Lent. In Lent, no meat or poultry is sold in a city, only fresh and salt fish. Your silversmith is going to notice that as soon as he puts his feet on the street. Hope that helped! [Answer] The obvious thing that everyone is missing is that their work would be undone. If a farmer harvested, they would notice that now the grain is standing. A blacksmith would notice that his metal is unsmelted. [Answer] I agree with @VilleNiemi that the people were much more aware of seasonal changes and nuances of climate, especially if a farmer or part-time farmer. Let's say he's a craftsman and not as aware, but as he walks some distance he will get a funny feeling from subconscious observations. His conscious is filled with his silversmith or cabenetmaking business or whatever. The nagging feeling comes to front when he sees a tree that had died and was chopped down last autumn (or sees a grown tree where a sapling was). In the town he'll see wear and tear changes on all the structures. Worst case is when he meets someone to do business with, and finds they are not on the same page. [Answer] If all else fails, some recent event will probably come up in conversation. Asking how someones daughter is doing when they haven't been born, gossip about the goings-on in the kingdom, something or another will be current to everyone else and months-old to you. [Answer] The easiest way would be look at the trees. If there are leaves on the ground, it's not Spring. Or go outside at nightfall and look at the stars. If you're in the Northern Hemisphere, and you can see the summer triangle of Vega, Deneb, and Altair, then it's not Spring. Or look at the vegetation on uncultivated fields (cultivated fields would make it blindingly obvious). If the ferns are waving in your face, it's not Spring, because they would have died back over the winter. [Answer] A change of seasons is easy enough to detect. But if there was a change in YEAR, even a medieval illiterate could detect this based on the social cycle. Local nobles quantify the time they have been in control, there is the time between major events like weddings, funerals, births, periodic festivals, calls to war, a particularly memorable flood, astrologic phenomenon, etc. I suspect the displaced craftsman would quickly determine that they are in a different time just by listening to market gossip, and then narrow it down significantly with a couple of questions. [Answer] Things in the bedroom: That door I had the village-carpenter made for me "this" harvest in this room I am in (identified with furniture etc) just vanished and that old wall I hate so much re-appeared, it looks oddly like I remember it to be before the harvest. Stitches on my body: The stitches I got after childbirth / bull hitting me / house chicken going violent on me after I took her eggs - are just gone leaving no marks. [Answer] His sheets, clothes and body are clean! Or at least cleaner.. Rumor has it that ppl didn't wash regularly throughout the year back then. He could have gone to sleep with a pong in the house and woken up to a breath of fresh spring air! To top it off, incase your traveller is having a real brain-fog morning and didn't notice his own house was cleaner, all the neighbours are busy doing their own spring cleaning up and down the street. He might not understand he had gone forward/backward in time but he would definitely notice the missing time! ]
[Question] [ I'm toying with magically binding contracts existing. For now I'm trying to figure out if such can exist without being either leaving loopholes, being easily abused, or otherwise resulting in a very uncomfortable situation. My question is basically if I introduced contracts as described below to a story will a reader say "Wait, what if I do X with them?" that ruins the contract. I don't like making magic able to 'think' and make decisions, such as whether or not I actually fulfilled a stated contract. To get around that my binding contracts don't work on some magical third party making decisions; it instead is based off of the mind and interpretations of the people signing the contract. The contract must be entered into at the same time by two (or more) signers. The basic rules are: Interpretation of a contract * The contract is binding based off of the signers' interpretation of the contract. You can't sneak in loop holes or abuse of language to trick me into signing something I didn't think I was agreeing to since I'm only bound to what I honestly believed I agreed to. * When all signators are entering the contract, their subconscious minds are temporarily connected. During this time they get a vague sense of whether or not everyone agreeing to the contract understands it. If two people have very different subconscious understanding of what they are agreeing to then they will know there is a conflict and the contract will not take until they both feel they have come to an agreement on whatever they originally didn't agree on. * Similarly, if one party intends to not abide by the contract, to abuse a loophole in it, or otherwise has intent to subvert the stated intent of the contract in some way, the other will sense this and as such won't sign. * While they do get a subconscious sense that there are disagreements or malicious intent when a contract fails to take, they only get a very vague idea of what the issue is -- this isn't indirect mind reading. They still need to sit down and talk to figure out what the actual problem was and find a proper agreement that will take. * This might still leave room for smaller disagreements that weren't severe enough to prevent the contract from taking, or that neither side had thought enough about to realize they weren't in agreement about it at the time of signing. If this happens they can discuss this and will both be compelled to try to find a fair and amicable agreement to fix such a disagreement. I stress though that this is about what they honestly see as fair and amicable which may be different then what the other one believes is fair. They can go to arbitration if necessary to sort this out. * After signing it's possible to modify, or cancel, a contract but only if both sides consent to it and they likewise agree as to what the modification is. Compulsions * The contract can force something like a very targeted version of OCD on someone to compel them to follow through with the content of the contract. If I promise to give someone an item I'll feel strongly compelled to do it. I can ignore the compulsion, but it will tend to grow stronger, more invasive, and potentially even debilitating until I cave in and do what I agreed to do. * The severity of a compulsion is based off of what the signer believes is reasonable given their actual agreement and circumstances. So if I promise to give you something and simply refuse I'll feel a strong and escalating compulsion until I give it to you. If I promised to sell you my house only to find out it was struck by lightning and burned down while I was signing the contract I'll feel a lingering, not escalating, discomfort since I didn't follow through with the contract but it's largely not my fault. If instead I promised to give you something and then lost it through sheer incompetence I'd feel a much larger and lingering discomfort since I'm largely at fault for why I can't do what I promised, but it won't be as strong or building as if I was actively resisting doing something I otherwise could do. * If I can't follow through with contracts, I'll still be compelled to try to make arrangements to compensate you appropriately for my failure -- such as by returning the money you payed me for the house that unknowingly had burned down before I signed the contract -- much in the same way as how I mentioned smaller disagreements may come up in the last section Consent * Contracts must be entered into willingly and knowingly. If a signer feels too forced a contract will not take -- both parties will know whether the contract took or not. * Consent is not always a boolean operator. There can be situations where someone feels mildly forced by circumstances to sign, but not as if the force is so strong as to prevent a contract taking at all. This may weaken the later compulsion the contract can cause. Both parties will know how strongly a contract will bind someone, a party may refuse to accept a contract if they feel a party won't be strongly enough compelled by it due to feeling forced to sign. Arbitration A third party can serve as an arbitrator. This usually happens by the arbitrator signing a contract with the two saying they promise to be fair and unbiased as they can be if they promise to accept their decision. I haven't yet decided a good way to decide who gets to be an arbitrator or what to do if both sides can't even agree on that details; especially in the case when one side may be suffering a potentially stronger compulsion then the other putting them at a disadvantage on needing to pick an arbitrator quickly. Worst case A's compulsion to find an arbitrator fast may put them in such duress that they couldn't sign a contract agreeing to arbitration because they felt compelled to sign it? Potential problems Mostly I see problems being when two people disagree on what constitutes a 'fair' resolution of a contract in more complicated situations. While the contract signing should prevent blatant misinterpretation, it still leaves room for later ambiguity, especially if one side becomes incapable of doing something they agreed to when they signed a contract. I also worry that it may make put someone without a conscious, a sound sense of right and wrong, or even a firm understanding of reality in a position where they can violate the contract freely because they honestly feel it shouldn't apply to them. For instance what happens if someone's paranoid schizophrenia kicks in after they enter a contract convincing them that the other signer was part of the illuminati, had forced them to sign with some mind control device, and thus the contract was signed without consent and shouldn't bind them? Of course you have the opposite problem of someone perhaps feeling they didn't do enough to abide by the intent of a contract even when most honest third parties would say they had, causing them to feel forced to continue making ever more convoluted steps towards 'fixing' their perceived failings. So, given my attempt to create a 'safe' magical contract which doesn't depend on magic being sentient to act as an interpreter, how badly can it be abused or go wrong, and what steps can be taken to make it a viable and safe option to use? [Answer] Narrative-wise, you can do what you like and make relatively token nods to the characters reading things over carefully or not. But, from a worldbuilding perspective, preventing contracts from being abusable is hard. Contracts are similar enough to computer programs that the concept of "abusable" carries over, I think, and empirically speaking, computer programs are definitely still abusable despite everything we've come up with - "decide whether a program is malware or not" is, strictly speaking, mathematically impossible to get 100% correct for all possible programs, and "decide whether a magical contract is abusive or not" would have an analogous issue. That's not to say you can't get good approximations, which is what the various antivirus software programs out there do - "100% correct on all programs people have used at least once in public in the past thirty years" isn't trivial, but it's also not impossible. So, allow some potential for abusive (or otherwise regrettable) contracts to exist. If they were impossible to abuse, they would be ubiquitous and unremarkable to anyone within the context of the story, which sort of defeats the point of including them in the first place. Contracts worthy of the name should not be taken lightly, roughly for the same reasons oaths should not be taken lightly. One might even argue that such compulsions exist in the real world already, no magic required - they just don't apply equally to everyone, and we call the people they do apply to "honorable". At a tangent - taking your "house struck by lightning" example, does it require the owner to actually notice the burned house in order for the discomfort to start? If so, well, ignorance is somewhat more literally bliss than here, and you'll have characters backing out of contracts (or forced out of them) by any setting-compatible amnesia methods you have. If not, well, your contract may also be an almost arbitrarily-powerful scrying tool. "I promise to keep Priceless Artifact X out of the hands of Evil Despot Y", and use the resulting discomfort to tell just how far apart X and Y are, and whether you should send the protagonist after X first, or Z instead. [Answer] ## This is impossible You're trying to invent a magical version of contract law that ensures not only that the parties are truly in agreement, but also that every agreement is just, and that second goal is going to trip you up. The mechanisms you've described directly target the rule-following problem by using magic and "the subconscious" to eliminate the possibility of misunderstanding. As others have pointed out, that guarantee is only as good as the knowledge and understanding of the world that both parties bring, so unless both parties have knowledge about the world that is not merely equivalent but actually excellent, the door is wide-open for abuse. People with power and knowledge will deliberately target people who are less well-informed. But there are other big problems beyond the dry philosophical concerns about "meetings of the minds." It's a huge problem that a contract can only be terminated if both parties agree to do so. The same situation exists in the real world in jurisdictions where marriage can only be annulled if both parties consent, and that inevitably results in battered women who are unable to escape their abusive husbands because the courts refuse to grant a divorce without the consent of the abuser. This magic system will create 31 nightmare flavors of that dynamic. The magic compulsion will be very harmful. It will interfere with a person's daily activities, and that will have effects that are not merely minor inconveniences. I understand that, seen through the lens of Business and Contracts, a person's only legitimate functions are economic in nature, but that worldview is brutally myopic, and magic contracts will necessarily magnify the harm that flows from that blinkered outlook. A person whose attention constantly wanders is a danger on the road, in the workplace, and in the kitchen. Even minor kinds of distraction, if persistent, can interfere with a person's ability to fulfill their role as a parent or romantic partner, and that stuff is supposed to exist apart from the world of business. I absolutely expect this invasive regime of magically-enforced contract law to lead directly to many broken hearts and ruined lives through neglect of important social relationships. I would expect very few people to ever be willing to enter into any agreement that has the power to interfere with their psychology in any way. They will stick with regular handshakes and paper contracts. Fundamentally, contract law is antithetical to human thriving. A contract is, by definition, a tool of compulsion. A just world has very little room for compulsion of any kind, and no room whatsoever for anything invasive, and this regime of magic contracts welds both of those things together. This fact guarantees not only that the system can be abused while following all of its rules, but that lots of people inevitably will be harmed. And what is there to be gained? What scenario do you have in mind whose bad outcome would be remedied by this system? It's silly to make such a fetish out of rational choice theory. --- Here are some examples of legal agreements that would lead to bad outcomes when combined with magical enforcement: * murder for hire * marriage * adoption * organ donation * safety waivers * any employment contract * mortgages and loans * rental agreements * non-disclosure agreements * class-action waivers [Answer] Just make the contract an intelligent entity. Basically, a living AI. That way, the contract is a third party that can arbitrate. The contract is a living being, and its soul is non-local. This means they do not even need blockchain. The contract can obviously mind read and has telepathy. It can judge based on a neural network to identify objects and properties, then, using a judging application which uses the conditions of a person's psyche, determine guilt. This would likely encourage the contract to be in an AI friendly manner, with tabularisation, checkboxes, and anything else that encourages modularity. [Answer] More than you bargained for Suppose two parties enter a contract, we'll call them [Rumpelstiltskin](https://en.m.wikipedia.org/wiki/Rumpelstiltskin) and [Hurley](https://en.m.wikipedia.org/wiki/Hugo_%22Hurley%22_Reyes). Rumpelstiltskin is a very clever bad actor who wants to abuse the contract system for his own gain, and also maybe just to spread misery. Hurley is a good actor, but maybe a little naive. By some unknown, but probably, definitely, evil means Rumpelstiltskin acquired a winning lottery ticket worth $10M. He strolls into the McTacoHut where Hurley works and proposes a very clear and simple contract: ticket for free lunch. Hurley agrees, because it's obviously a good deal, right? It is, until the rich and kinda famous lifestyle goes into a tailspin, and Hurley is ruined. Can the contract deal with the parties having different levels of understanding of the repercussions of some initial action that fulfills the contract? Does the contract get fulfilled after the initial action, or can the repercussions void the contract later somehow? [Answer] All contracts, are reviewed by a third party, which is the hivemind of all other magic contract users, and it defines what is actually "law" by the contract.That can go either way, as this swarm mind can have prejudices too. [Answer] Before I answer, I'm going to give two examples of a contract where there is no malice or deception, but you could argue that someone got an unfair deal: Example 1: An Art Patron sells a custom piece of art from an up-and-coming Artist with a new style. 15 minutes before completing the sale, the Artist dies in the sort of Tragic circumstances that drastically increase the remaining pieces' value. Once the new owner is aware after the sale, the new valuation is doubled. Example 2: Someone goes to a secondhand shop, sees something that they think is 'cool', the price is reasonable and the owner has it as an unknown item - they purchase the item. Later on, they realize it's an incredibly rare item (hence why it was unknown) and is worth significantly more than the purchase price. In both instances, there was no deception, no malice and yet the trade could be argued as 'unfair'. The latter example being more common than you'd think. The point is, that external factors that cannot be known by the participants can effect the parameters of a Contract and whether or not a Contract is fair. Without being able to control for all those factors, Contracts can and will be unfair. All of that said... A Magic Trust Account When a Magical Contract is signed, the goods, money etc. are held in a magic Trust account, which is outside of regular time/space. This Trust Account has the ability to refund, pay out or even pro-rate payments to all parties based on a magical sense of fairness. Whilst this means that any contracts can still be affected by external factors, the Trust Account provides a guarantee that keeps it fair. [Answer] At this point, isn't it just like the real wolrd law system? I mean, since you have a third-party arbiter system, why not a magic state that evaluates the validity of contracts, its terms of contract and its implications? You know, like in the real world, but with more magic thrown in the system. After all, if both disagree on said subject, then hire your lawyers and solve the problem in the court room. With their lawyers and so on. The third party arbiter system doesn't even have to be an actual court room, it could be anything of your choosing that could complement your worldbuilding. Fighters, wizards, you name it. I remember seeing a long time ago a meme about D&D saying something among the lines of: "A lawyer, bends the laws to its will and knowledge, why a wizard/mage wouldn't do the same to the laws of this world?". Besides the third party arbiter system could be an underground system where the signers would put their lifes/souls on the line of said contracts. But at this point it could be easily abused if both parties are equally powerful. [Answer] The God Of Contracts > > People here no longer make contracts, or better say, they no longer write them... > > > Says the seller, one of the partys explaining to the confuse stranger soon to be buyer which whom he is about to sign a magical contract, contract refered to the purchase a new steampunk ship from the part of the buyer, after his last one was destroyed in that incident with the gigant T-Rex than nobody wants to really rememeber or talks about. After the weird comment from the part of the seller, the buyer ask: > > Then, how did you people use contracts? > > > Ask the stranger, wondering the weird comment and still waiting for an explanation. > > We use magical contracts > > > Answer the seller, and then he adds: > > Written and done by the God of Contracts itself in his perfect languaje. > > > Says the seller, and before the stranger is able to say what we wants, the seller take a piece of paper, a papirus of some sort with a strange simbol and says. > > Hold it a little bit > > > Without ever removing the hands of it itself. When the strange take the piece of paper, before he can move an inch more, he seems himself transporte to a strange cave, where he is with the seller, both of them in special podiums one next to the other one, and closing the positioning of the top of a triangle, there is a third podium, a podium where a shadow do not allow to see who is there, the only visible thing is an empty piece of papirus clean of all image very similar to the one both partys take before entering here Before anyone can say anything, suddenly, the third figure scribe and explore the very minds of both, seller and buyer with an incredible and painful speed, questions seems to sound in the ears of the stranger, question about the purchase and other things but he cannot make anything of it, it is as if the questions come to his mind, and he can also hear himself answering them, although he cannot make anything really from the conversation. As this is happening for both, seller and buyer, the white papirus is writing themself and growing in side as much as needed, writing and rewriting itself over an over again in never before seen and impossible to understand gliphs, faster and faster, longer and longer, louder and louder every time, suddenly the seller screams, and then the stranger also screams, the pain is unbearable, the scribe done to the minds is powerfull, but soon after, it ends. Both, seller and buyer have a vision where the strange buyer gives a note with gliphs to the seller, and the seller give the ship back, when this vision end, both are back in the sellers office, the buyer, the only one on foot, fall on the chair to be perfectly sitting suddenly, and the seller fall back on his chair, adding with a little touch of frustration. > > I will never get use to this > > > After that he notice he have in his hand the note with the gliph given in the vision and he look to the buyer who look at it somewhat in awe, the buyer open the coffers he brings with the gold just to confirm what he feels and suspect happend, and it is as such, the gold is no longer there, all of them are completly empty except for some remaining coins which are the exact difference between the price and the money he was bringing to pay for the ship. After this the buyer is scared thinking he has been scam by the seller, but before he can say anything the seller smile, says "give me a second", take a bag from under his desk and put it over the same, put his hand on the bag and retrieve some keys linked to a document and a letter, he throw that to the buyer, which receive it and after reading the documents understand than.. * The keys are the keys of "the interlooper". * The letter shows where the ship "the interlooper" is stationed and is an explicit permition reffered to the dock crew allowing for retrieval of the ship to the owner of the keys. * The other document is the property ownership document of the ship. After this both partys can feel a painful cut in his very own wrists, together, and at the same time both have the sensation of somebody saying, "it is done", a wound appear in the wrist of the buyer and the seller exposing blood, after that some signs with the names of the seller and the buyer appeard in the misterious and undeciphrable document. The transaction has been done. The seller take his hat and says to the buyer > > Enjoy your new ship > > > The buyer then ask > > Where are you going > > > The seller answer > > To leave the money in the bank, have a nice day. > > > And as such, he procede to leave with his hat, the paper obtained in the vision and a new but rapidly healing light cut in his wrist. By his part the buyer take the letter, the document, the keys and also a new but rapidly healing light cut in his wrist and leave to the address writted in the letter. TL/DR Languaje is imperfect and because of that such loopholes can be done, however if the contract is done in a superior perfect-languaje than make impossible loopholes, and also have the backing of a superior entity able to read the minds and see things from an universal truthfull perspective, maybie you have a chance to have all what you are asking for. After all the contract is magic and misterious, with this solution you can have wherever you want from the contract because the reality is, it's written on his memorys artificially, beyond what the letter say or not, they do know what they need to do or not and they can be arcanely forced to do it as you see fit, so no party is able to understand the wording of the contract, but all partys are able to know what they need to do/avoid etc. [Answer] We do not need to define magical contracts based on our understanding of the world. ## What are Contracts? Contracts are incredibly precise. The runes perfectly describe the intention of a contract so as to be absolute. We don't exactly know how to read the runes, but that has never really mattered. By feeling the flow of the mana one can gain an understanding of its intent. Thanks to this natural intuition, we humans are not the only ones who regularly create contracts. We have witnessed many such magic sensitive creatures creating contracts of their own accord amongst themselves or even with humans on the rare occasion. However, it is rare to see a contract more complex than those created by kings and merchants. Runes are created when one party projects a portion of their mana from their body into the shape their intention. Using the runes to describe an object means to imbed your entire understanding of what that object is. For a contract to be formed, both parties must project runes which perfectly align. Once this happens, the projected mana from the two parties will begin to mix before being reabsorbed by the signers. At which point, the mana you contributed maintains the shape of the contract within the other party. While it may sound straightforward, the process of getting two sets of runes to perfectly align is no simple matter. It is not uncommon to see lengthy debates regarding even the simplest of terms. There are records of fierce debates among scholars on everything from the definition of what constitutes a coin to what it means to define a border. As a consequence of how runes must align to begin merging, it is not possible to enter a contract you do not understand as you would not be able to produce runes matching the other party's intent. A side effect of this is that it is very difficult to enter into a contract with a child without first stripping away much of the nuance involved to meet their level of understanding. ## Considerations * We prevent loopholes caused by differences in interpretation by creating a world unlike our own with a way to perfectly describe the author's intent. * Contracts are only as powerful as the mana you put into them. Perhaps an entity with sufficient mana would even be able to influence or forcibly remove the contracts placed on others. * You can terminate your half of the contract at any time by physically visiting and retrieving your mana from the other party. While, this frees them of their obligation to the contract, you would still be bound by the terms of the contract until they do the same thing. * The contract forming could be done a second time to apply amendments to an existing contract. * Compliance and punishments for not adhering to the contract are performed by the mana you leave in the other person. Once set in motion, the rules that mana works under can not be changed by either signer until the mana is withdrawn into the original host. Using runes to create a contract is like designing a circuit board. It only works exactly it was defined and can only work on quantifiable factors. * Behavior of the mana when the contract ends is also up to the contract. Without its original host to exert their will on the mana, it must follow the contract on what it should do next. Maybe it leaves to find its original host when the contract is completed. * This approach does not perfectly prevent all loopholes. Say I make a contract at the market to be given 10 apples the next day. If our common understanding of an apple is a sweet red fruit that grows on a tree and satisfies my hunger, then a pomegranate would technically count as an apple under this contract. A smart con-artist may be able to leave enough ambiguity for multiple things to satisfy the definitions. However if it satisfies the signer's understanding of what an object is, can we really say they are being conned? In practice though, a contract would include far more information than could practically be described using written language. This is to the extent that the parties involved would still genuinely believe that the pomegranate is an apple. Since a contract includes everything involved in our common understanding of an apple, the contract would also include all of the little details we use subconsciously to determine what is what. So the full contract would also include that an apple has thin skin, is crisp when bitten into, yellowish white inside, usually has medium black seeds near the center, has a thin woody stem, it can float, the rough shape of an apple, the feel of the fruit's skin in our hand, and every other bit of information you can think of. The much bigger risk using this method is that contracts could be over-exclusive regarding the definitions of various things. As such, participants would have to be careful to strategically remove conditions from their contracts. * Runes are a great way to teach new information to others. However, since they are such a dense information format, regular language is usually preferable. [Answer] ## Forced or not? There is a witcher walking through a wild forest to reach a wealthy city to offer his skills for gold. He sees some marks on trees and footprints on the ground, suggesting that a Monster is living nearby. He could hunt the Monster down and probably kill it, but he would need to drink a lot of potions (which are hard to make and could damage his body and mind) and there still would be a risk of the Monster hurting or killing him during the fight. Additionally, the Monster would almost certainly damage his equipment (such as his shield and armor). Furthermore, no one has ordered his services, so he would not be paid. Alternatively, he could just walk away quickly to get out of the Monster's territory before nightfall, when the Monster usually hunts, and leave nature to take its course. Then he comes across a wounded villager. He does not know the villager and is not obligated to help him (they may even be of different religions and neither of them Christian). If he walks away, the monster will probably come at night and eat the villager (as it would have done if the witcher had chosen a different path earlier). If he only fixes the villager's wounds, it will not change the outcome. If he helps him walk, they will go slowly and end up in the center of the monster's territory at sunset. The villager is visibly poor but begs him for help. He is also aware of the monster's presence. The witcher knows that the villager has no gold and certainly not enough to pay for the potions and gear repair he would need, not to mention the witcher's own work and risks. However, there is an old custom (well, just a custom, not a law) in the witcher clan to offer a classical deal in such cases: "I will kill the monster and help you get home, but then you must give me what you have at home but does know about." He feels charitable, so he offers this deal to the villager (without forcing him), even though he knows that he will most likely get something insignificant in return, like a flower from a table, a cabbage from the local market, a button lost by some random person, or something like that. But there is also a slight chance that he will get something truly valuable, like a newborn firstborn with magical talent. It is just a bet for him. The villager knows that the monster will most likely kill him at night if he rejects the offer, just as it would have done if the witcher had never arrived. He also does not know what he does not know but hopes that it will be nothing valuable. In any case, if he survives, he can possibly even rebuild his full house in a few years. To replenish the cost of binding magic for this contract would only cost the witcher some time and effort, which he is willing to invest for the slight possibility that it will not be a total loss for him. The question is, could the villager even sign the contract (as he wants), or not? He would die if he does not sign it, so there is really big mental pressure. And if it turned out that there was really a newborn or that the villager is still unmarried but his secret love moved into his house while he was away, would the contract still stand? [Answer] A contract can be "abused" if its meaning as written is different from its meaning as intended. Conversely, a contract is inexploitable if its meaning as written exactly matches its meaning as intended. Of course, in the real world we have no way of transcribing thoughts into words in a way which exactly and wholly records what we intend for them to mean. But if you have magic then all you need is this: * The contract is an exact and complete record, in some magical form, of what the person who drafted it intended for it to mean and what they intended for its effect to be. (Perhaps some sort of recordable telepathy.) * You "sign" a contract by creating a verifiable record that you have "read" it and agreed to it. * In the hypothetical event of a dispute over the terms of the contract, the arbiter or judge simply "reads" the contract to determine what it means, and verifies that the person who claims it actually means something else has "read" it and therefore knows that it does not mean something else (because its meaning is whole and exact). For example: Alice agrees to buy an apple from Bob, and the apple is to be delivered on the 1st of June. If Alice complains that she actually expected an Apple Macintosh computer rather than a fruit, or Bob complains that the delivery date should be the 1st of June next year instead of this year, the judge can simply read the contract and verify that both parties read and understood that the agreement was for a fruit, this year. [Answer] ## Just to easy to abuse by third parties outside the contract. Sent someone to with imperfect knowledge about the topic to make the deal in your place. A decent art forger has a naive friend. He gives his naive friend one of his mona lisa copies and tells him it is the original and that he should go sell it so they can split the money. Maybe they even make a "contract" for that and decide that the naive friend as broker keeps 10% of the sell price. The naive friend then goes selling that picture as original and since nobody would buy something so valuable and rare outside a "contract" they make a contract that the naive friend sells the original mona lisa for "1 gazillion $" to a rich dude assured by the "contract". In both deals no one is deceptive but a deceit happend nonetheless. And if the rich dude finds out that it wasn't the original it gets really bad for the naive friend. One one hand he wants to give the 1 gazillion back to the rich guy, on the other hand he had to give 90% of that to his art forger friend. Unknowingly he made two contradictory contracts and will life the rest of his life in misery with permanent compulsion after being caught trying to steal the original from the louvre. the principle works in many ways with a third party outside of the contract that in effect tricked both parties in the contract. ]
[Question] [ I'm making a completely homemade tabletop system with the intent of generating a hardish scifi, more sim-like experience for my friends. I've settled on no FTL and all space battles would be subluminal, but I'm having issues figuring out the scale of distances for battles, both in lore and in mechanics. In lore, most weaponry are ballistic (some are energy like lasers, but those aren't the problem here), so their muzzle velocities can range from 1km/s for short-range point defense guns upwards of ~10 km/s for railguns (performance handwaved with future tech). There are torpedoes as well, and their velocities obviously depend on their acceleration. The range of detection of sensors is on the scale of thousands of kilometers (but is subject to tweaking as this post topic suggests). But after some attempts to put things together, I noticed a fundamental issue in my world, which I will list in short paragraphs (a tl;dr is in bold at the end of it). 1. In practice, space has no "speed limit" (neglecting lightspeed). After X amount of travel time with discrete or constant acceleration, ship velocities can reach hundreds of km/s easily. For example, a ship constantly accelerating at 1G from at rest can reach 1000 km/s in just over a day of travel. This is an easily conceivable scenario for the player party's ship if they were trying to go between planets within a system. 2. That means if hostile contact is achieved at short ranges (thousands of km), the window for reaction is impractically small. Thousand-kilometer distances would be traversed in seconds, leaving very little time or space for practical engagements. 3. As noted above about ballistics, weapon velocities would only be a tiny fraction of ship speed. And When ballistic speeds << ship speed, gunnery stops making sense because of how easily a ship can outmaneuver shots. 4. Only exception is a pursuit, in which the difference in relative speeds might be of a far smaller scale, and govern the odds of ship to ship gunnery, as ballistic speeds can catch up in a more sensible amount of time. Else, in the time it takes for ballistic salvos to cross the set distance at the time of firing, the target ship would’ve moved multiple distances somewhere else. 5. With these speed disparities, a ship in combat can’t be leaded either because it is not a constant object; it can accelerate in any direction, and avoid any in-flight ballistic salvo that has been fired earlier (because a salvo in flight can no longer accelerate) 6. If sensor range is >> ship velocity (say, tens/hundreds of thousands of km), then there is a big enough window for a ship to respond to another contact. Torpedoes can be used at these ranges, but ballistics are wholly pointless. 7. Only if ships decelerate for combat to low enough speeds will ballistics be meaningful, but at those low speeds, torpedoes will be terribly fast, and decelerating wastes fuel for no logical gain. 8. After all, Why would a ship give up its speed? Evasion is such a good defense against ballistics, and will always favor the defending party as it always leaves them an option to retreat once torpedoes are no longer in the picture. If you’re not seeking to fight in the first place, just keep accelerating and run away. 9. Even if deceleration is justified, that means two map scales must be made: the ten/hundred-thousand km scale for sensor contact and torpedo engagements, and the sub-thousand km scale for maneuvering and ballistic engagements; this makes battle maps very impractical from a GM-design POV. So basically, I'm having issues designing a proper scale for combat encounters. Story-scripted battles are an exception, as I can decide whether they are taking place in the vicinity of a station, in orbit, or for whatever other reason to keep ships more or less at low speeds so that ballistics are relevant. But say a ship already cruising for a day or so runs into pirates -- if the pirates aren't moving (maybe running dark to stay stealthy or something) then I can't see the pirates ever catching up as long as the ship keeps accelerating. The pirates would have to chase at a much higher acceleration to reasonably pursue it, and as the inhabitants of my world are all humans, they have physical limits to their endurance (accel limit is 10G). If the pirates were already zipping towards the ship, then how are they going to pose a threat beyond torpedoes? They can maybe chase for multiple hours until they're in ballistic range, but that turns a battle into a linear situation with fewer degrees of freedom for tactics. The only other case would be some sort of ship jousting, where ships run head-on or try to get within dozens of kilometers for a snap-shot salvo so that ballistic can actually have a shot at landing hits. tl;dr real-world ballistic weapon speeds are far, far slower than the upper limit of ship velocities. This makes ballistic engagement ranges too short, making them hard to implement when maps are forced to become large to accommodate the high velocities of traveling ships, sensor ranges, and torpedoes. What distance scale should I settle with, and what should I do to keep ballistics relevant in a mostly long-range environment? I'm open to all kinds of ideas, including tweaking lore and tech to make the game mechanics work. If I am also fundamentally wrong in my assumptions, I would welcome corrections. Although above all, I would like to keep things more or less around the harder end of scifi, so I would prefer to avoid handwavey techs. Only things that can be justified and be considered "probable" in a mostly realistic world (for example, environmental effects/hazards that can shorten sensor ranges or cause damage to the hull, like micro-asteroids or dense dust fields, forcing slower travel speeds). Edit: Thanks for all the answers and ideas. After some more research and consolidating suggestions, I decided to settle with having a "CQB" state where ships match velocities, enabling ballistics to function at a relatively shorter range on the order of hundreds of km. Such a range could allow incorporation of guided weapons and electronic warfare. Longer ranges would be abstracted without maps to involve the mechanics of sensors and locking. Overall travel speeds would be lowered to account for possible natural or artificial hazards. The Tsiolkovsky rocket equation will be incorporated to set practical limits on velocities and accelerations, adjusted by the tech level of propulsion systems. Intercept methods may involve drone-piloted tugs that can accelerate above human limits, catching up and clamping onto targets to forcibly decelerate them. Ambushes would likely be set at some point during a target's deceleration stage or shortly after departure to avoid needing a high-speed intercept. Overall sensor ranges would have to be nerfed so that there remains some blind spots beyond major civilization/strategic/economic hubs. [Answer] TL;DR: a 10 km grid is actually reasonable. First of all, your setting ignores fuel as the tyranny of the [rocket equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation) places a de-facto speed limit on everything. Too lazy to do the math now, but a rocket that can accelerate with 1 G for a whole day is probably 99% fuel. The remaining 1% include the fuel for breaking at the destination. We assume the target ship sees the act of firing and tries to dodge. The targe ship has omnidirectional thrusters all over. It needs to move it's 'radius' - basically half of what it is across, seen from the attacker. The time to target is $T=\frac{D}{v\_{rt}}$ with distance at time of firing $D$ and projectile velocity relative to the target $v\_{rt}$. The target ship moves a distance of $\frac{1}{2}a (T-t\_r)^2$, with accleration a and reaction time (between moment of firing and start of the dodging maneuver) $t\_r$. Putting these together, with $r$ as the distance the ship needs to move to consider it a dodge: $$r=\frac{1}{2}a (\frac{D}{v\_{rt}}-t\_r)^2$$ Solving for $D$: $$D=v\_{rt} \( t\_{r} + \sqrt{\frac{2r}{a}}) $$ This is the distance below which no dodge is possible - farther than that, there's a chance. The bracket is the 'flight time' the projectle gets - reaction time plus a value dependent on size and thrust of the target. Both are in the range of 0.5 to several seconds. What are realistic numbers? $t\_r$ is not only (or mostly) the time the ship's computer needs to detect a firing and send the signal, it's the time for thrusters to start, fuel valves to open etc, I think values between a few seconds down to 0.2s are realistic. $a$ can be any value between 0 and 5-10 g, $r$ 10 - 100 m. For $v\_{rt} we assume 10 km/s. So, for a small craft with $t\_r=0.2s$, $r=10$ and $a=40\frac{m}{s}$ this turns out to be around 9 km. reduce acceleration to 1g, it's 16 km. Keep th 4g and have 2s reaction time, 27 km. We repeat the exercise with a large craft, $r=100m$, the distances we get are 24km, 46km and 42km respectivly. Note that there's a distance where a smaller craft has a chance to dodge, a larger craft not at all. If your setting ignores the rocket equation and allows crafts to accelerate at g for days, I don't think anyone will ever get so close to anyone. IfI suggest you bow your head to the tyranny of the rocket equation, limit fuel, speeds will be more reasonable in the order of magnitude of 10km/s (Voyager 1 has 16 km/s and is the fastest artificial object AFAIK). Where I designing a tabletop game, I would go for a 10 km grid and half second turns. A battlespace of 200 km should be reasonable (even if our fleets come at each other with 20 km/s realtive velocity, making the relative velocity of the projectiles 30 km/s, this means 3s flight time which should be plenty of time to dodge). Your game rules could work like this: Every attack from within the envelope hits. Every attack from outside the envelope up to a distance you find convenient and fun from a gaming point of view requires a dodge maneuver that adds a random speed vector to the target. Everything attack from outside is assumed to be dodged with a slight nudge without need to roll or without in-game consequence. ETA:* How would piracy and interception work? If ship A wants to intercept ship B, it's a matter of thrust but also of fuel reserves - B can accelerate away from A up to a point, then fuel reserves are so much depleted that travel to (matching speed with, orbital insertion ...) any meaningful target is impossible and the ship is as good as dead. So there could be a long maneuvering sage to any battle where one side tries to intercept, the other to dodge, and no side knows how much fuel and time the other side is willing to spend. However at one point the pursued side may decide they can't run away in a meaningful way and might as well try to fight. The pursuit stage would decide the relative speeds with which the actuall vessels/fleets engage in battle. This could be a relativly simple game with a limited, secret delta-V budget for each side and one side tries to intercept, the other to reach one of several possible targets. [Answer] You seem to have the space-battle balance that [E.E "Doc" Smith](https://en.wikipedia.org/wiki/E._E._Smith) described 80 years ago: The faster ship forces engagement, but the more powerful ship determines the outcome of that engagement. So ship design is a balance between speed and power. He solved the problem several ways: * Automatic defenses, far faster than human reactions. * Fleet actions using special-role ships: Speedy scouts with little power, ponderously slow Maulers, defensive cruisers that slow the enemy and absorb it's attacks, and others. * Space Marines with lots of board-and-storm and hand-to-hand fighting. * Multi-day chases. * Intrigue: Your ambushing pirates will take days to catch up to and storm their prey. The amount of prey you can take that way is limited. However, with pirate spies and collaborators riddling the prey ship crews, the take will be much easier. [Answer] Many of the issues you described stem from forgetting one key fact: Velocity is not an absolute. It is relative. Ships flying at 1000 km/s are not inherently immune to projectiles flying 1 km/s if those proectiles are fired by another ship going 1000 km/s in the same direction, because the projectiles' 1 km/s is added to the firing ship's 1000 km/s. If it wasn't, then firing a forward-aimed gun while in motion would be suicide - you'd hit yourself because you're moving faster than the projectile you fired. To put it another way, a bullet fired from an AK-47 has a muzzle velocity of 710 m/s. I am currently moving at a velocity of approximately 30 km/s (relative to the sun), or about 42 times the bullet's speed. Does this make me immune to gunfire? No, because the gun is moving at the same 30 km/s (relative to the sun) as I am, and the 710 m/s of the bullet's muzzle velocity is added to that, not an independent quantity. To have a prolonged engagement (longer than a single salvo as they fly past each other), ships don't need to "slow down", they need to match velocities - but the final matched velocity can still be absurdly high (relative to the local star, or planet, or whatever other reference point you might prefer) as long as they are more-or-less at rest relative to each other. Regarding evasion, you're right that it's extremely effective against dumb projectiles at long ranges, but this is purely a function of the time it takes for the projectile to reach the target and the rate at which the target can accelerate to evade. The velocity of the target is not a factor, aside from how it affects the projectile's time to target - a very high velocity towards the attacker makes evasion harder, not easier, because it reduces the available time in which to evade the attack. And that pirate who's running dark? They can still be moving at a very high speed because, in space, you only need to burn engines to change your velocity, not to maintain it. So, if they know that ships tend to pass through an area with a specific velocity (both speed and direction are relevant here!), they can match that vector at a distance beyond sensor range, then coast through the target area with engines off until they notice potential prey nearby and fire up the engines to make minor course corrections and approach. In overall conclusion, though, deep-space combat, as a rule, isn't entirely realistic in the first place, unless the aggressor already knows where exactly their target is going to be, either because the target is following a known trade route or because they have intel on the target's planned movements. Why? Because "Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." (Douglas Adams) The Earth's oceans are microscopically tiny compared to even the volume of space within the moon's orbit, never mind the solar system as a whole or looking at interstellar space, but, even so, terrestrial naval battles tend to happen near ports or other significant locations, or along major trade routes for things like commerce raiding, not at random locations on the high seas. Similarly, space combats are most likely to happen near planets, Lagrange points, or other significant locations, not because closer ranges and lower relative velocities make targeting easier, but because it's nigh-impossible to even find your target anywhere else. [Answer] The key is in your point #8: > > After all, Why would a ship give up its speed? > > > You give up speed because you need to. You don't go fast for the sake of going fast, you go fast with the intention of going somewhere. If you're going 1000 km/s, you can't dock with a space station, or enter orbit around a planet, or do many of the other things you'd want to do at that "somewhere". This gives your setting two forms of combat: 1. Passing engagements. One or both ships are moving at interplanetary speeds. In such an engagement, each ship only gets one shot before the ships/fleets are out of range of each other. No need for a map here, because the "battle" is too fast and chaotic for positions to matter. 2. Meeting engagements. If you're trying to capture a space station, or exert control over an asteroid, or do something else at a specific place, you need to slow down. "Hit-and-run" combat at cruising speed is counterproductive, because you need to turn around after each pass, giving the defender time to repair. This will be the sort of close-range, low-speed engagement that a battle map is good for. [Answer] Ah, this is a question for my heart, as MOOII player, BFG player, Dropfleet Commander Player, X-Wing model game player. Please, turn the question around. Start with: What would make an interesting game? Then develop "technology" which fits. ### Some scenarios In a hard SciFi setting, your ballistics would be mounted on drones which fly to point blank distance at much higher accelerations than humans can sustain and then discharge their bullets/hollow shape arrows/lasers/bombs. Your ship would try to defend by shooting a hole in the drone ring and escaping that way. Your problem is, this is not a table top setting with interesting maneuvres. Peter F. Hamilton in his Armageddon cycle books let his ships use drones with nuclear, nuclear/shaped charge or antimatter bombs on board, those fly nearby with 20 or 30 g acceleration and explode in a tetraeder formation around the target so that the target can't escape... except, if the target uses some small-bullet-drones or it's own nuclear bomb drones to destroy the incoming enemy drones. Drone wars everywhere. The Expanse shows this, too: They have bullets, lasers and missiles. No-one uses lasers as weapons except for lighting up the target for the other two weapon categories. Bullets are for point blank and to defend against missiles, in one of the books they also manage to kill someone following them with bullets, but that was a special maneuvre which wouldn't be repeatable or standard. The normal way of killing is the missile. Dumb bullets are not going to be used. Imagine bullets to have basic sensory and an engine. You fire them with a coil gun towards the target The target accelerates at random for evasion, but as the bullet comes close, it starts it's tiny engine for a course correction, to correct for the evasion. They also won't be 1 km/h faster than the firing ship, it will rather be around 1000 km/h. Finally, a ship has a tiny engine compared to it's mass and a set maximum acceleration due to the living crew. Missiles and bullets both don't have these two constraints. ### Space Battle is not for fun You want to achieve something. You want to defend or attack a strategic position. It wouldn't help you to destroy it - conquerors throughout history had very often the opportunity to burn down their target cities, but they did very rarely. Burned down cities are very hard to replace. You gain nothing from a pile of rubble except hatred and terrorists. No, you want to own that factory/refinery/whatever and you want those people to work in that factory, but you want them to work for you and not for your enemy. So, in space battle you can do lots of fly-by-destruction. You can throw asteroids and bombs, your own bullets have your speed plus your weapon's discharge speed so they can be incredible powerful with their kinetic energy. Well. You do that, your target is gone and destroyed forever, planet inhabitable, you gain nothing, and that after probably a travel time of years and a considerable investment for the ships. It's a lose-lose situation. You don't want that. You want a win-lose situation. No, you don't want to destroy, you want to conquer. And now we're talking. If you want to conquer, you have to have a delta speed near zero in order to set down your troops, show your weapons (as opposed to using them) and demand surrender. With a delta speed near zero, you can actually play a game! :-) ### Acceleration Forget acceleration for the Table Top. I developed a simple system and tested it with some friends. The only real effect coming from it is that in certain situations you are unable to slow down, you overshoot your target location and you have to come back, taking out a ship for one or two turns. But it introduces loads of bureaucracy in terms of token handling or taking notes. You can get the same difficulties by just writing to the rules that every ship has to move x cm every turn with a limited ability to change direction. This saves counter and notes on a notepad, speeding up gameplay. It just works just the same. Take a look at commands in the rules for Dropfleet and Battlefleet Gothic; how they handle the movement and how the player can affect it. ### Tactical elements Imagine empty space, both sides have some ships. Best tactic is if all your ships shoot at one enemy until it is down, then all your ships concentrate fire on the next one. Your enemy does the same. Realistic maybe, but boring, right? Your models would have a round base - the actual model would be the size of a pinpoint in the middle, but of course yours are bigger in order to be beautiful. The base determines some few 1000 km range around the ship where the bullets actually work, close combat distance. Missiles entering here either are shot down or do damage. Tactical elements include things that force you to move. Elements giving cover are important as they allow maneuvres. If you outsmart your enemy you shall be able to flank attack: Many of your kind attack few of the other kind, while the rest of the other army is too far away to react. This is unthinkable in an open space scenario, but with cover and movement hurdles it can be a maneuvre. I will try to give you some battlegrounds which could make your game interesting. Close quarters: The closest would be the 200km orbit. Your game table then is not black with stars, but it is an actual map of the planet. Stationed weapons could shoot up from the planet at the ships, you can shoot down the "nice" way which just destroys weapons but not cities or continents (hence the bullets); you could set down troops to get what you want and set up your own planet-to-space weapons, all the while your opponend tries the same. There can be spaceports launching little fighters or space-marine-clamp-pods at the looming ships above, everything a player's heart would like. There is actual terrain, because the ground-to-space-weapons introduce some no-go-zones for missiles and ships, so you have kind of a cover and you need to fly slalom around some things. Great! Here we have terrain, cover, movement, tactics! The asteroid chase For the table top, if you want to give the impression of speed and sensor range, you can also do the asteroid chase: Put the chased player's models 30 cm from a table edge ("back end"), pointing the long way over the table ("front"). Put the chasing player's models at the back end table edge behind the chased player. Place four or five (or ten, as you like) asteroids at random on the table. Every turn, you move the asteroids 30 cm towards the back end. If an asteroid moves over the back end table edge, roll a die to see who may place it back in game. The Player who is chosen places the asteroids where he wants at the front end of the table. It starts to move next turn. The ships can move 15 cm forward each turn, with a maximum deviation of 45° in each direction. Additionally, they may use all their energy to get 15 cm further; or they use that same energy to shoot and fight. If the chased player manages to move off the table edge, they have won. The moving asteroids hopefully give the impression of speed and limited sensor range, also they provide cover and the necessity of maneuvring. Orbital fight If you crank up the engines and speeds so that the earth-moon-distance becomes the battlefield, then you also need to have faster bullet weapons. Maybe your bullets now are coilgun-driven. The circle around your ship model now represents 20 000 or 30 000 km. Your game table would have a 20cm planet and one or more 5cm - 10cm moon and some sattelites / space stations. Also an asteroid field now could have more than one or two asteroids - for game purposes you could have around 10 on the table now. Your terrain and cover are now the planets themselves. This is kind of a difficult setting, because the speeds become high already and there is few opportunities for suspense-of-disbelief close quarter action. Little Battlestar-Galactica-Fighters fail on this setting, also "Space-Marine-Clamp-pods", no chance. Setting down troops would be also difficult, a planet is quit a big sized thing for a troop ship. You can still fly slalom around the game pieces, take cover and shoot the other, so this would work at least. It could be interesting at least to test play once or twice to have the course of ships changed a bit when they are too close to a planet. Another Tech Level Up If you introduce some kind of inertia damper, you can speed up both ships and weapons again. Now the entire solar system becomes your battleground. The base around your ship now is a million kilometers around, because bullets driven out in an inertia damper field easily get close to the speed of light. On your game table you would have the sun, 5-10 planets and a plethora of little elements. This is nice, because at such high speeds, the asteroid fields (the belt, the jupiter troyans, and so on) become kind of a "terrain" - the inability to react fast enough means if you cross them, you are just gambling with your life instead of flying slalom around them. If you fly slow enough for slalom, you're the sitting duck for your enemy so you don't do that. Again, planets and the sun are the cover, asteroid fields or orbits full of satellites are no-go areas for movement. Space Marines become an option again, because with an inertia damper field, they could survive the evasive flight maneuvres and the impact at the target. [Answer] I think you already arrived at your answer: in a hard-ish scifi setting, ballistics cannot be the weapons of first resort except at effectively point blank distances. Ballistic weapons can be used for limited purposes, like intercepting torpedoes or wannabe boarders. I think we can safely define point blank as 10^5 km or less, but this depends mostly the reaction speeds of the software or people being used. You can arbitrarily reduce sensor ranges to make ballistics work, but this raises a whole lot of other questions(like how do ships avoid colliding with random space debris all the time if they can only "see" so little) and will probably break immersion. Same goes for nerfing your software. If you absolutely must make ballistics relevant at all ranges your only real option is to stop doing hard(ish) scifi and start bending the laws of physics so ships cannot accelerate/decelerate like they would in actual 0G [Answer] A huge part of the problem stems from two issue; 1. Detection range - which is based a calculation pitting the types sensors used versus the types of 'drive' used in your setting and available stealth and ECM technologies. 2. The type of 'drive' technology in play. Have a fleet of ships using fusion 'torches' in play and detection ranges push out a huge distance. Use handwavium and equip them with 'gravity drives' and your detection range is basically whatever you wish to make it. Basically 'hot' objects in space i.e. anything with a temperature significantly higher than the background temperature in the region of space they occupy is going to stand out. A manned ship with 'hard science' rocket drive approaching Earth from beyond Pluto's orbit would probably be detectable by a network of passive sensors in Earth orbit, even if a ship elsewhere in the system missed it. So make life easy for yourself. Assume that (like a game of chess) unless you allow for some kind of 'invisibility' stealth technology the position of each and every piece on the board will be known to the opponent shortly after they arrrive there. [Answer] A human crewed ship can't catch up to another human crewed ship but an unmanned ship (i.e. a drone) can because it can accelerate much harder. Enter the ACV, autonomous combat vessel, a small independent vessel with its own armaments, propulsion, and sensors, that is carried by other vessels. (Not my idea, this is from a SF series whose name I forget.) A hypothetical pirate would launch their ACVs to pursue another vessel with pre-programmed commands to attack and disable the vessel or to give up and return to the ship after a certain period of time. Commercial shipping would want to carry their own ACVs optimized for defense to protect themselves but would have to trade that off against cargo carrying capacity, so not all ships would have them. [Answer] ## Sensors > > The range of detection of sensors is on the scale of thousands of kilometers (but is subject to tweaking as this post topic suggests). > > > > > In practice, space has no "speed limit" (neglecting lightspeed). After > X amount of travel time with discrete or constant acceleration, ship > velocities can reach hundreds of km/s easily. > > > I think one thing to note is that the safest speed a ship can reach is almost certainly positively correlated with sensor range. That is to say, a ship going incredibly quickly, also needs more time to safely decelerate due to human constraints on safe acceleration/deceleration. The sensor range must be at least high enough for a ship to decelerate to a full stop before the ship runs into, say, an asteroid. In this case, `ship speed ++ = deceleration time ++ = sensor distance ++ = ambush setup time ++` The faster the ship, the more time pirates/enemies are given to set up ambushes. ## Ambushes and Space Caltrops [![enter image description here](https://i.stack.imgur.com/AheXy.png)](https://i.stack.imgur.com/AheXy.png) Let us suppose the would-be ambushers have detected an incoming ship. To move around without getting caught, perhaps they would use cloaking technology that is more effective the less velocity a ship has. The ambushers can setup the equivalent of space caltrops. As these are passive objects with no energy readings, these would be difficult to detect unless up close. If the ship is going too quickly, collision with the space caltrops would have varying effects, from badly damaging armor, damaging propulsion systems, or, if the enemy ship is going quickly enough, complete obliteration. If ship capture is needed, filling the space with a large amount of 'friction caltrops' to induce massive instant deceleration enough to kill or disable everyone on board without doing much damage to the ship or its cargo. ## Result The presence of space caltrops as a weapon would limit the highest safe speed possible, as their small size and profile makes sensors unable to detect them in time to decelerate safely if the ship is going too quickly. Also, higher speeds mean giving more advantages to would-be ambushers, due to needing more time to slow down, allowing ambushers more time to plot. Following this train of thought, even if a ship is going quickly, if they detect an enemy ship in the vicinity, it is most likely the traveling ship would have to slow down or risk getting shredded by caltrops. The mere existence of pre-mediated weapons like space caltrops would slow down ships overall, allowing more time for pirate ships to reach a similar velocity as their target, and engage in ballistics combat. The existence of such techniques for ambush would mean, that except for desperate cases, such as escaping pursuit, most ships would travel at a comparatively slower speed through uncharted/unsafe space. [Answer] Use hyperspace Hyperspace is used for FTL in lots of SF and so is familiar. But you can use it to force space ships to engage each other at comparable speeds. I will call it weird space since hyperspace is associated with FTL. Weird space will be used for ships traveling faster than a given speed. Space is dangerous at speed, with chips of rock and space dust packing a mighty punch. Not to mention radiation. For trips at high speed, spaceships enter weird space. In this bubble of weird space they do not interact with matter or radiation in the vicinity and are affected only by gravity. Ships in hyperspace do not need to worry about objects in their paths. They can be detected by purpose built detectors but are otherwise invisible. As it happens, dark matter resides in weird space but that is for a different chapter. The outside world is likewise invisible to a ship in hyperspace. They must calculate their position using time, charts and trajectories. Ships pop out of weird space at slow speeds. They cannot go right back in if their find themselves in a nest of pirates - it takes time. Weird space lets your players travel large distances unmolested but forces them to interact with local environments at reasonable speeds. Good for game mechanics and internally logical. ]
[Question] [ There's this archipelago of artificial floating islands. These vary in size from less than 10 meters to about 100 meters in diameter. Is there a passive way to keep them close to each others without the risk of having them collide catastrophically (or, even better, at all)? [Answer] Yes one that has been used for hundreds of years, anchors. A set of anchors/mooring lines is already a known solution to this, if you use multiple anchors drift is very limited. This is the solutions used by floating oil rigs. There is a variety of arrangements possible depending on what you are trying to achieve. [![enter image description here](https://i.stack.imgur.com/bZ9qA.png)](https://i.stack.imgur.com/bZ9qA.png) [Answer] Mangroves. [![mangroves](https://i.stack.imgur.com/Rz4qm.png)](https://i.stack.imgur.com/Rz4qm.png) <https://smartwatermagazine.com/blogs/michael-beck/protecting-mangroves-can-prevent-billions-dollars-global-flooding-damage-every> Your islands are each surrounded by mangrove-like woody plants. Big ones are anchored on the land. Smaller ones are anchored to the big ones and have roots floating free in the water (that is invented here, not how real mangroves work). These aquatic trees intertwine with one another forming dense networks of roots and branches. This living plant connection absorbs storm energy, just as real mangrove shorelines provide a buffer against storm and wave energy. The roots and branches link the islands with flexible connections. If they break or are crushed in storms, they regrow. If an island breaks loose then comes back and crashes into another island the trees and plants in the way will bend and break, absorbing the energy. The islands will lodge together and immediately the living plants will start growing to bind them. [Answer] # Underwater bumpers Well below the surface you could have bumpers with shock absorbers and dampeners. I made a diagram below. [![My diagram of islands with shock dampening technology.](https://i.stack.imgur.com/k3Wjj.png)](https://i.stack.imgur.com/k3Wjj.png) The islands would be like giant aquatic bumper cars that you can live and farm on. As long as the bumpers are underwater and the portion underwater is wider than the portion over water, it will seem to landlubber eyes as the islands never actually collide. Depending on the (in)efficiency of the bumpers, some seismic activity might result when islands come close to each other. As an alternative, you may add horizontal rods to each bumper to make sure that they don't have a full collision, but rather literally push each other apart. [Answer] No, thanks to Bernoulli and wind/wave shading large floating object tend to merge with each other. So if large beams/briges are passive enough for you - it is the only solution. ]
[Question] [ I am trying to recreate King Arthur's the Sword in the Stone using chemistry. I have a couple ideas how this could be done Would any of these work or how it might work? [![enter image description here](https://i.stack.imgur.com/V4H6B.jpg)](https://i.stack.imgur.com/V4H6B.jpg) Arthur removes the sword from the stone and is blessed by Archbishop Brice, from Le Livre de Merlin, France, N. (Arras), 1310, Add MS 38117, f. 73v." Caption via the British Library's Medieval Manuscripts Blog. Unlike this answer: [Making a sword in the stone, in a medieval world without magic](https://worldbuilding.stackexchange.com/questions/141322/making-a-sword-in-the-stone-in-a-medieval-world-without-magic) I am interested how this could have been done with a substance available in 500AD. What could be smelted or concreted then to allow a sword to be entered into it then allowed to cool or harden with no chemical bond to the sword? The material of the stone would need to contract as it gets colder to release the sword at a certain temperature, not be so hot during insertion to effect the temper of the sword, and/or allow water or ice to permeate between the sword and stone. Similar to using whiteout to create a barrier between the soft iron shell and the inside hard steel of a canister Damascus forge could the sword be coated with a whiteout/liquid paper like material that breaks down when wet over time? [![enter image description here](https://i.stack.imgur.com/2UbS9.jpg)](https://i.stack.imgur.com/2UbS9.jpg) An eight-year-old found a pre-Viking-era sword while swimming in a lake in Sweden during the summer. It is relativity intact for being in the water that long. Source: <https://www.bbc.com/news/world-europe-45753455> Could water get between a designer stone and the treated sword enough to erode or breakdown the bond between the sword and the stone with little corrosion to the sword? The simplest way this could be done I can think of is thrusting the sword into a ball of lava rock that meets the edge of an ocean then moved and carved. Over time water and winter loosen the sword. [![enter image description here](https://i.stack.imgur.com/KV5m8.jpg)](https://i.stack.imgur.com/KV5m8.jpg) [Answer] You could use Roman concrete <https://en.wikipedia.org/wiki/Roman_concrete> > > Roman concrete, also called opus caementicium, was a material used in > construction during the late Roman Republic until the fading of the > Roman Empire. Roman concrete was based on a hydraulic-setting cement. > Recently, it has been found that it materially differs in several ways > from modern concrete which is based on Portland cement. Roman concrete > is durable due to its incorporation of volcanic ash, which prevents > cracks from spreading... Further > innovative developments in the material, called the Concrete > Revolution, contributed to structurally complicated forms, such as the > Pantheon dome, the world's largest and oldest unreinforced concrete > dome. > > > The Pantheon is 2000 years old and looking very, very good. Roman concrete is poured and cast like modern concrete, but is chemically different from modern concrete in several ways. If you are materials-science inclined, recent studies of Roman concrete make for interesting reading. To release the sword the concrete does not contract, but the metallic sword does. It needs to get really cold. Your sword is embedded in Roman concrete and has been since Roman-trained engineers put it there 150 years before your story. Dark ages medieval Britons would know of the Romans and be familiar with their works but would likely have lost the arts of reproducing their technology - which is what really happened. [Answer] > > I am trying to recreate King Arthur's the Sword in the Stone using chemistry > > > # Chemical You could use thixotropism and come up with a sword that cannot be removed from its stone scabbard no matter how hard you pull, unless the sword is rattled gently for a couple of minutes beforehand. However, this solution is almost surely bound to undergo degradation along the years. # Mechanical The simplest way to reproduce the effect would be with a friction lock. Basically, the Stone has a wide hollow "sleeve" inside, not so large as to perceivably alter the Stone's mass or balance; the sleeve is drilled from the bottom side of the Stone and stops a few inches from the surface of the top side, where it narrows to the exact width and thickness of the Sword's blade. So, from above, the Sword is set in the Stone. If this was the whole setup, the Sword would be very easy to extract. But inside the sleeve you have two steel prongs as long as the blade, covered with a layer of soft lead. Once pressed against the blade, the blade bites the lead and leaves its exact impression; if the rods are kept pressed hard against the blade, the friction is so high that you will never be able to extract the blade, not even using levers. You'd break the blade hilt first. Now the prongs are kept in place by a counterweight mechanism hosted in a small chamber beneath the stone. The mechanism can work in several ways: it can be "remote-controlled" from a nearby cloister through a wire or light chain pulled through a tube, or it can be released by placing weight on specific stones. One could even devise a "combination lock" so that you'd need to put your weight on stone A, then B, then A, then C, then B to achieve release. Of course anyone would feel the pavement stones wobble slightly, but if most of the flagstones were equally wobbly, nobody would think twice about it. If the mechanism were controlled by pulling a pin attached to an underground chain in a tube, even the wielder of the Sword would never know how the trick was done. Approximately: [![enter image description here](https://i.stack.imgur.com/rMgUB.jpg)](https://i.stack.imgur.com/rMgUB.jpg) [Answer] Gypsum. Also known as drywall. Gypsum plaster has been used for millennia. <https://www.youtube.com/watch?v=tmbk8Pfau0I> With a little artistry, you could easily cast it into the shape of a big rock around a sword. Throw in some darker sand/gravel and maybe some bigger stones, to give the appearance of natural occlusions. The big advantage gypsum has over concrete is that it's not all that strong. A big guy could possibly pull a sword out, whereas I'd think cement/concrete would be impossible. The sword in that case is basically rebar. [Answer] We can take advantage of the fact that when dissimilar materials are in contact, they will typically have differing coefficients of thermal expansion. Basically, as solid objects get hotter, they expand, and they contract as they get cooler. The difference between the coefficients of the materials involved can be used to create a system that will release the blade under the appropriate thermal conditions. Steel has a coefficient of expansion of around 12 nm/mK. Granite, a common, hard, weather-resistant stone has a coefficient of expansion of around 7.9 nm/mK. This means that for every linear metre of the substance, for every degree Kelvin that its temperature increases, it will expand x nanometres. The problem is that 7.9 and 12 are quite similar... the difference is only 4.1nm/mK, meaning that quite a large negative temperature differential would be required to cause the sword to release from the stone. However! The system need not be mechanically so simple as a sword in a blade-shaped hole in a solid block of granite requiring a significant, prolonged, drop in temperature to cause the blade to contract sufficiently to release from the stone. If we were to have two blocks of granite, each forming half of a vertical cylinder split vertically through its diameter, with a blade-shaped notch in each side, so that with the sword between them, the stones don't quite meet, held together by a circular steel strap, like the steel tyre on a wooden wagon wheel, we would have a system where a relatively small increase in temperature would result in a relatively great expansion of the steel strap (because it is much longer, by a factor of Pi×Diameter than the gap between the stones). This would allow us to create a system where the sword would become loose at or above a specific temperature. By surrounding the stone with a fire, the strap could be made to expand enough, while ordinary daytime temperatures would not, or the strap could be sized to release only on the hottest of daytime temperatures. This would also have the advantage that rhe sword would not become blunted by its compression in the stone(s), and it could be preserved from rust by filling the gap between stones with a resin. All of this is easily achievable with iron age technology. The steel strap could be embossed to make it look decorative, rather than the key piece of the lock, so only a wheelwright pr perhaps a blacksmith would likely consider the mechanism by which the sword might be released... and in the middle ages, knights didn't soil their hands with manual labour, or bother themselves to understand what it is that craftsmen do. Knights guard the stone, and will allow only another knight to approach... so only a knight who actually thinks about the common people is likely to figure it out or be popular enough and receptive enough to be told and listen. ]
[Question] [ I have a rather odd setting where one of my characters gets cursed/blessed with indestructibility, more specifically all of her cells have stopped degenerating and dividing and they all are now immune to any known forms of damage. (but this only applies to living cells and bone tissues, so nails and hair are still destructible). Also the person is still very capable of feeling pain. What effects would such a curse/blessing would have on the human body? To give you a few points that I am interested in: * would she be in constant pain? * would she go mad? * would learning new things be impeded? Bonus points for any side effects described not mentioned above. [Answer] Theres several things that will happen. * your character will stop eating and drinking. Since the cells dont degenerate they cannot be malnourished, which is a form of damage to your body. So some kind of nebulous energy has to come from somewhere to power the cells. * because of the previous point any toilet behaviour will be directly correlated to how much you are active. More active means more waste products created that the body needs to get rid off. * your character will stop feeling pain except for heat, cold and pressure. "Normal" pain is based on cells getting damaged and products of that cell reaching a nerve ending that reacts to these products, warning that you have damaged cells in the area. The sensations of heat, cold and pressure are warning signals that already hurt before you receive damage in order for the person to react and prevent damage to his/her body. * simultaneously with the previous point the character will never heat up or cool down, as that prevents the body from optimal performance by disrupting and destroying certain enzymes and other bodily products and reactions. Its the heat/cold difference that your body will warn for. So her body will remain at perfect temperature at all times, even when wearing a ski jacket in summer or birthday suit in winter. * the character will no longer age (duh). The cells cannot deteriorate because of genetic defects accumulating in the cells. * the character will no longer be sick ever again. Viruses and bacteria simply cannot create the damage necessary to make you sick, and without the necessary cell divisions your body will no longer be able to create an immune reaction anyway. And one last thing. Dont throw her into a star or black hole, she'd never be able to get out or move her body ever again while in so much pain her body wouldnt know what to do with it. Thats just cruel. [Answer] The first immediately obvious consequence is that the person will be skinless in no more than a few days.... The outer layer of the skin is made of dead cells which are shed continuously and replaced by new cells from the basal layer. Once the cornified outer layer is gone (no more than a few days) the inner soft layer will be exposed to the elements and will be damaged in a very short time. [Answer] > > all of her cells have stopped degenerating and dividing and they all are now immune to any known forms of damage. > > > Our immune system is based on rapid multiplication of the lymphocytes as reaction to an infection. Since you are removing the capability to have cell division, you are negating the possibility to have immune reaction. But the cells won't sustain any damage: thus your character will experience an overlapping of the symptoms of all the diseases/infection he/she will catch over time, with no hope of healing. Just picking the overlap of 4 not so uncommon infections: 1. running nose from a cold 2. diarrhea from a food poisoning 3. muscular relaxation induced by botulism 4. muscular spams from tetanic infection. I am confident it would be a hell of a life. Neurons do not multiplicate in any case, they just rearrange correction. So this power won't affect the learning capability, as long as some other disease won't interfere with learning. Nails and hair grow because some cells are dividing. With division gone, they would stop growing, too. [Answer] Depending how we interpret the "known" in "immune to any known forms of damage" we get a very different picture: * if we assume that the "known" means damage that has previously been experienced by their body then the first bacterial infection they get that they hadn't experienced before will kill them. Their body can no longer adapt to novel toxins and their immune system cannot create new antibodies to kill off the new invader. * if we assume that "known" means everything the person doing the cursing knows is possible then it becomes a story element that you can have endless fun with. Regardless of the interpretation the character won't be able to breed, no more [meiosis](https://en.wikipedia.org/wiki/Meiosis). Their teeth will eventually wear out regardless of how well they try to care for them as enamel is never renewed, that will get extremely painful. Existing injuries will never heal, at all, if they're bleeding even in the slightest went the curse is placed they will bleed out and die, period. Any corrective surgery, like having those broken teeth out, will either be impossible or lethal. No-one knows how much storage a human brain can handle but eventually they're going to start suffering some form of dementia, not sure what that would look like though. [Answer] Blood related problems: blood is full of oxygen and sugar - so it make good growing ground for many invaders (fungi, yeast, ...) As there is only so much blood cells (and new would never grow), there inevitably became moment, when they would not be able eat and process all invaders. And those invaders would grow, so at some time there will be so much, that some veins would stuck with them. No problem per se, as none cells would die, but some cells would be starving without supply of oxygen and sugar. And at some point they would just stop working (until refilled again), so muscles would stop moving and brain would be paralysed too. (Well until some drastical cleaning would be done, which would totally destroy everything destroyable and leave only the living body. And it would need be so drastical to decompose all those (now dead) invaders to such small pieces, that they could be trasported to organs, that could eject them out of the body. If it would be done late, that the person would be paralysed for long time, until osmosis push a lot of oxygen and suger (should be artifically added to body) to the heart and it start pumping blood around again to distribute food for other cells too and "restart" rest of the body. Hungry cells around the way to heart would not be helping, as they would eat much supply just to be able spend it without any possible effect. Also there should be proper eating, as the person would survive without food, but the muscle cells would not have chemicals to make movement and so undereating would paralayse that person too (and brain burns so much energy/food, that the starving would came fast if eating/drinking was improper). Drinking also need be done otherwise the blood would lose watter and stop circulating at some point (first blocking small veins, then larger and starve muscle cells as before to paralysis). Pain may became problem too, as constant pain is suppressed and ignored after some time - the pain limit grows higher and higher - and well my leg is in pain for year, so what, it is no longer problem for me, just feature. I know, I should do something with it, maybe tomorrow, or next week or next millenium, but it is not so bad to force me do something JUST NOW. And I so dislike the taste of strong hydroxide/acid, which could solve it, so lets it wait just some time more ... I have still write some article on web and see the movie and the serial did not ended yet ... [Answer] I am going to assume that this world has more than a little magic involved. In that case I would suggest you read the manga "UQ Holder" and checking out the character Karin. Karin was cursed with absolute invulnerability over 2000 years before the story takes place. I thought about her when I read your question since you specifically mentioned being able to feel pain, which is normally a result of damage, which your character should now be immune to. Karin can feel pain however, because her form of immortality is one that messes with reality to litterally remove damage instantly. In once scene she is being cut with a knife, and you never see even the slightest hint of damage, but the guy who is cutting her notes that he can feel the resistance of cutting flesh, and she is clearly feeling pain as if she is being cut. Anyways, I think her case would be good inspiration for your idea. PS: The title, UQ Holder, is kind of a play on words in Japanese. 悠久 (yûkyû) means "eternity" so the title kinda means "Eternity Holder", and it is the name of the main goog guy organization in the story, which is made up of people who are immortal (to different degrees; you have Karin that really cannot die, and you have a guy who simply won't age but could easily be killed by decapitation) [Answer] Based on your character description, I will make some detailed assumptions: 1)Basically the living cells have become indestructible particles like atoms (under normal circumstances). I assume this power extends to all the tissues as a whole as well. Otherwise you can cut the tissue by simply separating the adjacent cells with sufficient force. Effect: Character will start losing sense of pain slowly and steadily. The biological process and nerve reaction will still be there, but the brain will start ignoring the signals. The pain becomes a false trigger as there was no corresponding damage. On a long term, this might lead to desensitization and lack of empathy, slowly devolving into lack of certain emotions. This includes fear of death. 2) No cell division = no new cells at all Effect: No reproductive capabilities may lead to degeneration of certain instincts, like losing interest in reproduction and related physiological and psychological phenomenon. 3) Despite being indestructible, the cells still need energy to function without which, the cells will enter a super dormant state, and wake up again after energy is available. Effect: Most biological functions will continue. Character will experience hunger and thirst as well as the need to sleep due to getting tired. Combined with the above effects of losing some emotions and instincts, character may develop dependency on certain things. For a positive tone, this would be highly exhausting activities in terms of both physical and mental, otherwise character wouldn't need or be able to eat and sleep properly. For a negative tone, heavy addictions to junk food and/or drugs and other substances. 4) Cells do not die or divide, but the organs still produce the various chemicals, and body still accumulates certain substances over time Effect: The character can easily "suffer" high blood pressure if consuming too much salt and fats primarily because the fat accumulates but the skin doesn't stretch and grow, kidney stone or other such problems caused by accumulation of external substances within the body. Of course these problems can easily be cured by strong medications easily since there should be no side-effects. 5) Long Life span Effect: After a number of years, character will start suffering memory losses, because the brain has a maximum capacity for information. [Answer] Some quick observations and outcomes. 1. No more hair. You say the hair can be damaged, but since your cells cant divide that means no more hair after it is lost the first time. 2. No new memories after a while, [because your brain will eventually become full, since there is a theoretical maxiumum capacity for your brain](https://www.scientificamerican.com/article/what-is-the-memory-capacity/). 3. No more reproduction. Obviously producing sperm and eggs as a process has stopped since they involve division. [Answer] "What are the side-effects" questions really depend on the precise nature of how something is implemented. The answer can be just about anything. For example, given one reading of the curse, the individual would become the world's worst Flu carrier. Influenza doesn't actually damage the cell walls. It gets up close enough that the cell chooses to try to capture it, pinching off a lysome around the virus, then pumping it full of enzymes and acids. Influenza is actually "designed" to detect this, unfurling a grappling hook like protien which sticks into the edge of the lysome and then pulls the flu out. Technically this isn't the cell wall being damaged. Even if it was considered damage, you're in real trouble because the cells will get filled with unbreakable lysomes. So as a result, the flu can infect a cell without actually damaging the cell wall much. It does its damage after being "trapped" by our cell's defenses. Now it's put its DNA in your cell, making virus proteins. Your immune system isn't going to be able to do anything about this, for the reasons mentioned in other answers. As a result, every cell of your respiratory tract is going to get infected and start producing viruses at full speed! Of course that's just one reading on the curse. There's myrad others. ]
[Question] [ I am designing an alien civilization for a story, and I am currently in the biological part. They will be oxygen breathers, so they will need to have that oxygen delivered inside their bodies, and I am looking for alternatives to that function: I don't want to use iron oxide to transport the oxygen, or copper (hemoglobin or hemocyanin). Do you have an idea of which some other elements could be efficiently used for that function? I am not asking about the blood dynamics (I will invent that later). I just want to find a plausible logical alternative to iron or copper. EDIT 01: They come from an Earth-like planet with 1.15 times the gravity of Earth, with an oxygen concentration of 35%. They evolved from sea creatures and have squid-like bodies with four tentacles evolved into legs, and two of the tentacles used for manipulation. They are about twice the size of a human when they stand, and they need oxygen masks when they come to Earth (because of the 21% of oxygen in our atmosphere). The protagonist of the story is precisely an alien who chooses not to use mask and adapt himself to the low oxygen ratio (like an Everest climber). Aliens with masks can jump higher and run faster because of the reduced gravity, but this one preferes the freedom of living without mask, even if that means getting tired very easily. [Answer] Sodium nitrate: [![sodium nitrate](https://i.stack.imgur.com/NWrZE.jpg)](https://i.stack.imgur.com/NWrZE.jpg) Sodium nitrite: [![sodium nitrite](https://i.stack.imgur.com/nLRM1m.jpg)](https://i.stack.imgur.com/nLRM1m.jpg) Your aliens use the nitrate / nitrite moiety as their oxygen transporter. The transition between the forms is catalyzed enzymatically to drip off oxygen where needed and pick it up in the lungs. No metals involved. [Answer] [Coboglobin](https://en.wikipedia.org/wiki/Coboglobin) is one of the main iron- and copper- free proteins that can be used for oxygen transport. It was first synthesized [by humans in 1970](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC283253/), where cobalt was intentionally substituted for iron in a hemoglobin-like protein. It also looks like [it's been talked about before on Worldbuilding](https://worldbuilding.stackexchange.com/q/70170/627). To have a creature evolve to use coboglobin, you'd want an environment that . . . * is relatively warm. * has a higher concentration of oxygen. Coboglobin is less efficient that hemoglobin, so you probably wouldn't see it arise naturally on a planet unless iron was in short supply and cobalt was much more abundant than it is on Earth. Regrettably, I had to rule out a number of more promising hemoglobin-like oxygen carriers proteins because they contain iron or copper (note also that some are simply not as efficient as hemoglobin): * [Myoglobin](https://en.wikipedia.org/wiki/Myoglobin), which contains iron and is found in muscles. * [Chlorocruorin](https://en.wikipedia.org/wiki/Chlorocruorin), which contains iron is found in a number of worms. * [Hemocyanin](https://en.wikipedia.org/wiki/Hemocyanin), which is very common in a number of molluscs but contains copper. * [Leghemoglobin](https://en.wikipedia.org/wiki/Leghemoglobin), which has iron and is found in planets as an oxygen-carrier. Now, it's notable that under certain conditions, proteins may only have to account for minimal oxygen transport. Even in humans, the normal plasma in blood can transport some oxygen on its own, but members of the [Notothenioidei](https://en.wikipedia.org/wiki/Notothenioidei) order of fish require virtually no hemoglobin. Part of the reason for this is that the water they swim in (cold, polar water) is extremely oxygen-rich, and so efficiency of oxygen transport is less of an issue. Yes, coboglobin works well in warmer environments, not cold ones, but if your world has an atmosphere rich in oxygen - say, perhaps 50% by mass - then maybe efficiency would be less important. Fortunately, your additional specifications seem to conform to these requirements. A 35% oxygen atmosphere is pretty close to twice as oxygen-rich as our own - maybe not quite enough for an organism to not need a hemoglobin-like molecule, but still good enough that efficiency is less of an issue. Plus, given that you've said that the aliens evolved from aquatic creatures, perhaps their ancestors were like the Notothenioids, and had very little hemoglobin (or, here, coboglobin). [Answer] [This page on Xenology](http://www.xenology.info/Xeno/10.4.htm) discusses that question, and also notes the similarity between hemoglobin and chlorophyll. Based on the discussion there, there are a number of possibilities: Magnesium (Mg), used in chlorophyll; Vanadium (V); Manganese (Mn); Cobalt (Co); Iridium (Ir). (plus, of course, Iron (Fe) and Copper (Cu), which you’ve ruled out for your own reasons.) [Answer] There are several proteins that are known to exist and that bind oxygen. However, you needn't limit to those we know exist: provided that the folding structure of the protein places the metal ions in the appropriate position to bind both O2 and CO2, almost anything will work (it's even possible, from a chemical standpoint, not to use metal ions at all). So, the problem basically solves itself - just state "these critters' blood is based on (e.g.) vanadium". Unless you need an explicit parallel or identity with a known terrestrial compound. [Answer] This previous answer provides many different ideas for oxygen transport: [Other blood colors](https://worldbuilding.stackexchange.com/questions/28276/other-blood-colors/28380#28380) In summary, we've found many different oxygen transport molecules from the terrestrial biosphere. The reason for so many different oxygen transport molecules, is that this function is a bit finicky. How well a particular molecule works depends upon temperature & partial pressure of oxygen. You want something that can bind oxygen, but not too well. Hopefully it doesn't bind too strongly to other molecules which might displace oxygen (e.g. hemoglobin binds to arsenic and carbon monoxide which can cause problems). For human body temperatures at sea level partial pressures of oxygen, hemoglobin is the best oxygen transport molecule and can transport >10x the amount of oxygen that some of the other transport molecules. If the conditions in your environment are significantly different, then one of the other molecules would be a better choice. If your conditions do not fall into those shown in the chart below, then an "invented" molecule might fit your needs better. [![Effectiveness of blood transport molecules in Terrestrial Environments](https://i.stack.imgur.com/uqIA3.gif)](https://i.stack.imgur.com/uqIA3.gif) ## In Summary * Iron - Hemerythrin - a poor oxygen transport molecule but is effectiveness doesn't vary much over a wide range of oxygen concentrations * Iron - Hemoglobin - good at >7% partial pressures * Iron - Erythrocruorin - ?? * Iridium - chloro-carbonyl-bis(tri phenylphosphine)-iridium - good above 50% partial pressures (not as good as hemoglobin) * Cobalt - Cobaltodihistidine - best oxygen transport molecule <3% partial pressures. It's performance is relatively stable at higher concentrations (might be useful if the organism needs to function in a variety of oxygen environments. * Cobalt - Coboglobin - best oxygen transport molecule over a narrow range of partial pressures (3-7%). Above this hemoglobin is better, below it Cobaltodihistidine is better. * Iron - Chlorocruorin - works best above 6% concentrations, many other other molecules are better * Copper - Hemocyanin - works better above 2% concentration but is better than most other molecules at very low concentrations and colder temperatures * Manganese - Pinnaglobin - Unknown It looks like iron, copper, cobalt, manganese, & iridium are all possibilities. I assume that other related elements could be used too. More information about these molecules can be found at the link at the top. ]
[Question] [ A mcguffin is a creature who is wanted by many organizations on earth, wars were waged through history to obtain a mcguffin and to this day they still are. People sacrifice their lives seeking or hiding and defending a mcguffin. Mcguffins are creatures who evolved for the sole purpose of being wanted,rare in nature they are not bred or farmed and they are not eaten. People are attracted by the mcguffin, they just want one, even at the cost of killing people and risking their death, finding a single mcguffin is incredibly rare and finding two takes the effort of a nation, but even then...mcguffins can't be forced to breed, just like pandas they show no interest in sex. Fortunately mcguffins last a very long time, some mcguffins were killed by terroristic attacks but no one has ever seen a mcguffin die of old age. Nations across the world pride their mcguffins, and some of them are as old as human civilations. How do I explain why the mcguffin evolved to be wanted by humans in the first place? [Answer] > > How do I explain why the mcguffin evolved to be wanted by humans in > the first place? > > > All evolutionary traits are, or where at some point, beneficial to a species survival. This includes traits that have no apparent use other than being attractive to others. Being cute can keep you alive, [just ask any baby](https://www.discovermagazine.com/mind/why-babies-are-so-cute-and-why-we-react-the-way-we-do). If other beings like you, and are willing to depart with food and other resources to be with you, you are basically set. Your McGuffins are the apex of cute. In the same way both pikes and great whites evolved to be deadly, but great whites are a lot more deadly than pikes (to most species), cats and McGuffins evolved to be cute and attractive to humans, but McGuffins are a lot cuter than cats. People would throw their cat in the bin just to please their McGuffin and this means that evolutionary speaking, McGuffins have a better chance of success. This is why they evolved to be the most desirable creatures on the planet. [Answer] Mcguffin babies are carrion eaters. They lay their eggs on the bodies of the dead to ensure they have a suitable food source. However as they're so much larger than the equivalent flies, they need a considerable supply of dead bodies to feed their voracious young. As such they've evolved to cause uncontrollable desire in susceptible mammals, such that they will fight to the death to be in the zone of influence of a mcguffin. By this means a breeding mcguffin will accumulate enough corpses in a small zone to provide sufficient food for its young. Nobody has seen mcguffins breeding? Perhaps it's simply that nobody has survived seeing mcguffins breeding. Now this would cause signficant issues if in full effect all the time, so the mcguffin primarily only releases the hormones during the breeding season, but mcguffins remain lazy carrion eaters and as such low levels are released on a steady basis even out of season. > > Elves are wonderful. They provoke wonder. > > Elves are marvellous. They cause marvels. > > Elves are fantastic. They create fantasies. > > Elves are glamorous. They project glamour. > > Elves are enchanting. They weave enchantment. > > Elves are terrific. They beget terror. > > The thing about words is that meanings can twist just like a snake, and if you want to find snakes look for them behind words that have changed their meaning. > > No one ever said elves are nice. > > Elves are bad. > > ― Terry Pratchett, Lords and Ladies > > > [Answer] Religious Icons Considering that these creatures are biologically immortal, its not hard to imagine them taking on mythical, and then religious status among various cultures throughout history. I can imagine that they become religious icons for the people, direct physical proof that everlasting life is actually possible. People are willing to go to extreme lengths and expend monumental effort for religious purposes. Posessing these creatures gives vast political power to whatever ruling class manages to aquire one because it gives them huge influence with the worshipful masses since is validates that they are truly the chosen nation. [Answer] There is a natural dye called [Tyrian Purple](https://en.wikipedia.org/wiki/Tyrian_purple), which could only be obtained by harvesting a certain kind of sea snail in the Mediterranean Sea. > > Twelve thousand snails of Murex brandaris yield no more than 1.4 g of pure dye, enough to colour only the trim of a single garment. > > > The enormous difficulty of producing enough Tyrian Purple to dye to even small amounts of cloth made it ridiculously expensive and an exclusive luxury item that would signal great wealth. In the Roman upper class wearing a white toga with even a single stripe of Tyrian Purple was considered a great status symbol. Later its use was restricted to be exclusively allowed for the Roman Emperor or respectively the Byzantine Emperor. My suggestion therefore is, that your McGuffin - by the same sheer randomness that a sea snail produces a beautiful exclusive dye - organically produces something that is equally desired and can only by obtained from McGuffins. What that something is depends on your world. As the example given shows, even something purely cosmetic like a beautiful dye can fullfill your requirements if it fits the attributes of your world. In fact I would argue that if in reality Tyrian Purple had been obtainable only from your McGuffins instead of sea snails, it would have worked out exactly as you described it. There would have indeed wars been waged just so that a king or an emperor can wear purple garments. We are simple creatures... [Answer] Near-immortality The secret of the McGuffins' incredibly long lifespans is that they produce some form of enzyme (or some other more appropriate medical term) capable of repairing the genetic and cellular damage caused by aging. This substance can be non-invasively collected (milked?) and works almost as well on humans; regular doses can slow down human aging by decades to centuries. It didn't evolve to be wanted by humans, it had a trait extremely beneficial to humans. Upon discovering this, humans began cherishing and protecting them, causing them to eventually lose the ability to defend themselves and becoming codependent on their human protectors. [Answer] Frame Challenge: ## Mcguffins did not evolve - they were made to be like that Some say that they came from somewhere beyond our world, long ago. Strangers from another world, so advanced they could tinker with their own biology? We can only guess. It's easy to imagine now that they stumbled upon our primitive ancestors, who were barely evolved beyond brute animals, and saw a chance. If they changed themselves to perfectly fit our strongest instincts for nurture and affection, they could be worshipped like gods! And so they did just that. Well, that's only a guess, really. Perhaps a real god created Mcguffins, or the guessed-at aliens did not change themselves, but designed grew the Mcguffins - a blessing they bestowed on us before moving on. We may never know the truth. But, as you would also know if you had ever encountered one yourself, Mcguffins were clearly created by some superior intelligence or divine power. Nature is not capable of forming anything so perfect, so utterly desirable! Now hand me that detonator - we need to finish this IED so we can take out the lead vehicle in the convoy transporting this hemisphere's Mcguffin. We must capture it for ourselves. Trust me - you'll understand when you see it. ]
[Question] [ I have done some research and so much contradict one another or I simply fail to understand. Do seasons occur on a tidally locked planet that isn't tilted on its axis? [Answer] ## Yes, if the orbit isn't circular. Seasons can definitely occur on a tidally locked planet. Just like normal planets, tidally-locked planets don't need to have perfectly circular orbits. This means that over the course of a single orbit, this planet would receive different amounts of light from the star as it slowly moves away and then towards it. This will be the case for any orbit with a non-zero eccentricity. The change in the energy received is likely to be small. Tidal locking requires long timescales, and over those same timescales, tidal forces from the star will work to [circularize the orbit](https://en.wikipedia.org/wiki/Tidal_circularization), reducing its eccentricity and therefore the magnitude of these seasonal differences. However, planets in closer to their stars tidally lock quicker, meaning that a planet close to its star could have a non-negligible seasonal variation while still being tidally locked. ## An example Let's do some calculations with an exoplanet known to be tidally locked. Astronomers believe that the planet [Tau Boötis b](https://en.wikipedia.org/wiki/Tau_Bo%C3%B6tis_b) is tidally locked to its parent star. However, its orbit isn't perfectly circular - in fact, it has an eccentricity of $e=0.023\pm0.015$ (almost twice that of Earth's!). It orbits at a distance of $a=0.0481$ AU. Therefore, its closest approach to the star is $0.0467$ AU, and its farthest point is $0.0492$ AU. The star has a luminosity of $L=3.06L\_{\odot}$. Putting this together, we see that the planet should reach a [temperature](https://en.wikipedia.org/wiki/Effective_temperature) of 1706 Kelvin at its closest point, and a temperature of 1662 Kelvin at it farthest point. That's a difference of 46 Kelvin - certainly enough to cause some variation in climate. ## Some interesting differences Now, seasons on this planet would be [a little bit different](https://physics.stackexchange.com/a/29294/56299) from seasons on Earth. Why? Well, the temperature variations are now entirely due to the orbit, rather than the tilt of the rotation axis. This has a couple of notable consequences: * The changes due to the seasons will be more uniform, globally. Seasons due to axial tilt affect each hemisphere in opposite ways; in our case, the entire planet is moving closer and further from the star. * The seasons will be different lengths. Winter comes because the planet is further from the star, but Kepler's second law tells us that planets further away move slower. Therefore, winter will be longer than summer. ## Other ways to get seasons Now, our planet can get seasons though other mechanisms. For instance, [I've argued that if its parent star is a variable star](https://worldbuilding.stackexchange.com/a/73178/627), it can experience seasonal variations comparable to the ones we've discussed based only on orbital eccentricity. Indeed, these seasons will remain long after the orbit has circularized. Essentially, you have some room to play around. Even if you're not satisfied with the orbital eccentricity approach, there are other options. [Answer] # Depends on the orbit I'm drawing on [my answer](https://worldbuilding.stackexchange.com/a/176853/33851) to a different question here. Let's start with an overview of why there are seasons. I really like [this description](http://www.primaryhomeworkhelp.co.uk/time/seasons.htm): > > We have seasons because the earth is tilted (wonky) as it makes its > yearly journey around the sun. The Earth's axis is tilted at an angle > of 23.5 degrees. This means that the Earth is always > "pointing" to one side as it goes around the Sun. So, > sometimes the Sun is in the direction that the Earth is pointing, but > not at other times. The varying amounts of sunlight around the Earth > during the year, creates the seasons. > > > OK, so if you have a planet like the Earth with a (roughly) circular orbit and the same part of that planet is always facing its star and there's no tilt, then you would not have seasons. Being tidally locked doesn't matter. A planet in a circular orbit with no tilt will not have seasons. What if the planet has a different type of orbit? Imagine your planet has an orbit like the one shown below. During the time that it is farther from its star, it will be winter on the entire planet. During the (shorter) time that it's near the star, it's summer. [![An animated GIF depicting an elliptical orbit](https://i.stack.imgur.com/MhrAP.gif)](https://i.stack.imgur.com/MhrAP.gif) [Answer] Both the other answers (at this time) suggests making the orbit eccentric. The variable distance from the sun makes the planet hot or cold. This is correct. But there is one important aspect of this situation neither answer mention. If you have a tidally locked planet in an eccentric orbit, the tidal lock isn't perfect. There is an east-west "wobble". This is due to the planet moving at different speeds while rotating at a fixed speed. For people living in the twilight zone will see the sun rise and set over the year and this will be much more important than the distance to the sun. In one zone, the seasons will be * Sunrise. Sun rises close and big and warm. * Morning. Sun rises a few degrees off the horizon and also shrinks. * Evening. Sun falls back to the horizon and shrinks some more. * Sunset. Sun sets far and small and cold. * Early Night. Dark and cold. Sun is getting closer, but also further below the horizon. * Late Night. Dark, but warmer. Sun is getting closer and you can feel it. On the other side of the planet, these season are reversed. (Cold mornings, warm evenings) I can't think straight enough to say which of these zones is east and which is west. If you follow the twilight band north or south the up-and-down wobble will be smaller and smaller but the near-far variation will be unchanged. [Answer] Another possibility is a world in a multiple star system. The planet might be tidally locked to its primary, but would also be warmer when another star approaches, and cooler if the other star moves behind the primary. For instance, in Brian Aldiss's book Helliconia, the planet of the same name orbits a sun-like G-class star called Batalix, which itself orbits a much larger A-type giant star called Freyr, and the movement of Helliconia and Batalix around Freyr results in a so-called "Great Year" of over a thousand years, with the winter being colder than Earth's ice ages, and the summer being hotter than the tropics on Earth, Or, if you're prepared to accept a smaller "year" and to be tidally locked to something other than a star, then having the planet be a moon of a gas giant or brown dwarf to which it was tidally locked would allow for seasonal variations. When the system's star was occluded by the moon's primary, it would become colder, and dependent primarily on the radiation put out by the primary. Then, once the moon moves out of the primary's shadow, it will get lighter and warmer. Nearside would be more dependent on the heat from the primary since it would not see much of the star. [Answer] Imagine a twin star system, with suns that are almost merged, both putting tidal stresses upon each other, reducing the ability to uphold pressure in gravity annhilation, allowing much light to escape, then restabilizing and doing another turn. Such a system could put seasons even on a tidally locked body, simply by dimming and increasing through the inherent dynamics. [Answer] Another possibility to get seasons not mentioned so far is if the planet has a thick ring system, like Saturn. Depending on the position of the ring's plane, the ring system can screen the sunlight on a large area of the planet's surface. ]
[Question] [ Imagine a spacecraft travelling at very high speeds, say 0.3c. While a crew member could theoretically suit up and perform spacewalking maintenance on the outer body of the ship, will they be exposed to the risk of a few stray atoms floating in space and hitting them at 0.3c and shredding their bodies? How big does such a chunk of matter need to be to present a serious risk to such an astronaut? Thanks! [As stated in my profile, I am working on a novel titled "Generations". Please consider I may use the information provided to help in building the story's world properly. Thanks!] [Answer] Your astronaut would be protected in the same way as the ship. It is bad to be hit by a very fast piece of stuff. Very bad if you are alive, but also bad if you are not alive and you get hit over and over all the time. The latter is the case for your ship. Pieces of space dust and particles are plowing into it and ablating it. And going right thru it. An atom at 0.3c is a cosmic ray. Your passengers would not be able to sleep at night, because of the flashing lights inside their eyes from the [cosmic ray visual phenomena](https://en.wikipedia.org/wiki/Cosmic_ray_visual_phenomena). Cosmic rays going thru you are are bad in several other ways as well. Your ship needs protection too. Maybe a magnetic field to deflect charged particles from all angles and a dispensible physical mass in front (asteroid, chunk of ice) to absorb larger impactors. Maybe a railgun or guided rockets to shoot larger incoming masses detected by radar. Your spacewalker would hunker down, protected by the above just like the ship. If the spacewalker strayed outside of the protections, it would be bad. [Answer] Talking about any speed is meaningless unless a reference frame is used. Since you cannot sense your own speed, you must use objects as reference points. For the sake of the question, lets assume that your heroes started on a planet, which is located in galaxy not much different than our own. To accelerate to 0.3c relative to the star you started on would pose a significant rise, not only for spacewalking, but also for the ship itself. Objects in a galaxy typically move around 10s km/s relative to one another and range to the extremes of about 1000 km/s relative to each other. 0.3c is close to 100000 km/s. So hopping star systems at these speeds in a galaxy would be ridiculously risky to say the least. If a dust particle were to hit you at these speeds (that is in your reference frame), yes the damage would be catastrophic to say the least. At these speeds, the amount of energy a particle with a mass of about a microgram is around $10^{9}$-$10^{8}$ joules. This is around the kinetic energy of a plane landing, concentrated into the scale of a dust particle. --- ## Addition from the comments At these speeds, atoms would be too small to be too terribly damaging individually, but they add up pretty quick. For instance a helium atom would have around 10^-9 Joules of energy, this is around the energy in the original CERN collider which converted to atomic energy units is about 50 GeV. To see what happens when hit with a beam a bit larger (76 GeV if I remember correctly) look up the story of Dr. Anatoli Bugorski, a Russian scientist who was struck in the face with a proton beam of this energy while working on a particle accelerator. Thus the density of atoms in the space in which the ship is traveling will be an important factor. Thanks to @HDE 226868 for providing a useful number density, of say $10^4$ hydrogen atoms per cubic centimeter, which is high but not impossible. Hitting this many protons at these speeds for any length of time would be quite dangerous to one's health. [Answer] You might be interested in reading up on the [Bereakthrough Starshoot](https://en.wikipedia.org/wiki/Breakthrough_Starshot) program. The concept is to send a thousand nano light sail spacecraft each with a camera, to Alpha Centauri, at 0.2c taking approximately 50 years, propelled by a laser beam from earth. One way only, of course. They would be protected by a thin, light ablative coating to protect them from atomic particle impact. The hazard and probability of bigger particles hitting these tiny ships has been discussed extensively, and has been dismissed as being any kind of relevant threat, once out of the solar system. > > Protective coating: A coating, possibly made of beryllium copper, is > planned to protect the nanocraft from dust collisions and atomic > particle erosion.[37][46] > > > That is, an ablative coating that will withstand particles hitting it. I saw a scientific article, that I can not put my hands on, that did the engineering math that proved such a coating would protect these miniature sails from damage. It turns out that all of the sci-fi gobbledygook paranoia about small particles the size of atoms hitting a ship at speeds of 0.2c or faster totally obliterating a spacecraft are just simply bogus. The damage of such a high speed impact is very local, and easily protected against. A small atomic sized particle hitting an astronaut space walker that is protected by a thin ablative surface that is able to conduct heat very effectively would do no damage. There are an abundance of articles that describe how beryllium copper protects against high heat and mechanical impact. Larger particles, of course, are another problem. But once outside our solar system, the chances of being hit by a lightning bolt from earth would be greater than confronting space debris. The voyager series have addressed that issue quite successfully. [Here](https://breakthroughinitiatives.org/forum/20?page=1) is one that looks at the problem from several perspectives. [Answer] You'll be scooping up interstellar medium at significant kinetic energies. There's two problems: The atoms that hit you will actually accelerate you away from your position (pressure measured in Pa), and of course they'll impose a radiation hazard as you absorb them (radiation dose measured in Gy). Let's do some math. Let's assume an interstellar medium consisting of one hydrogen atom per cubic centimeter. This gives a density [œÅ = m/V = 1.7e-21 kg/m¬≥](https://www.wolframalpha.com/input/?i=hydrogen+atomic+mass+%2F+1+cm%5E3). You'll scoop up the ISM at [dm/dt/A = œÅ¬∑v = 1.5e-13 kg/s/m¬≤](https://www.wolframalpha.com/input/?i=%28hydrogen+atomic+mass+%2F+1+cm%5E3%29++0.3++speed+of+light). Note that this depends on the area of your body that is facing into the stream; you might want to go head-first or feet-first depending on if you're still planning to procreate. The pressure that the ISM exerts on you is [p = F/A = dm/dt/A ¬∑ v = 1.3e-5 Pa](https://www.wolframalpha.com/input/?i=%28hydrogen+atomic+mass+%2F+1+cm%5E3%29++%280.3++speed+of+light%29++%280.3++speed+of+light%29+in+pascal). This is pretty negligible, you won't even feel it. At an exposed area of 1m¬≤ and a mass including the EVA suit of 100kg, the acceleration is just 1.3e-7m/s¬≤, enough to displace you by less than a meter in one hour. The radiation hazard is another thing, though. The kinetic energy at relativistic speeds is calculated by multiplying the relativistic gamma factor, minus one, with mc¬≤. The relativistic gamma factor in your case is [1.04828](https://www.wolframalpha.com/input/?i=relativistic+gamma+at+0.3c). The kinetic energy of the mass stream is calculated by [P/A = (relativistic gamma factor - 1)¬∑dm/dt¬∑c^2/A = 653W/m¬≤](https://www.wolframalpha.com/input/?i=%28hydrogen+atomic+mass+%2F+1+cm%5E3%29++%280.3++speed+of+light%29++.0482848367219182++%28speed+of+light%29%5E2). This is half the power of solar radiation as felt on earth. Which is a lot. The radiation dose is calculated as energy absorbed per body weight: Assuming a body weight of 80kg and an exposed area of 0.5m^2, [D/t = P/m = (P/A)¬∑A/m = 4.08Gy/s](https://www.wolframalpha.com/input/?i=%28hydrogen+atomic+mass+%2F+1+cm%5E3%29++%280.3++speed+of+light%29++.0482848367219182++%28speed+of+light%29%5E2++0.5+square+meters%2F80+kg). [This handy table](https://en.wikipedia.org/wiki/Acute_radiation_syndrome#Dose_effects) tells you what will happen to your spacewalker. They'll pretty much immediately feel the extra heating * After 2 seconds, their biology is damaged beyond repair with a life expectancy of 2-4 weeks, and "rapid incapacitation" sets on * After 7 seconds, they'll experience "Seizures, tremor, ataxia and lethargy", and their life expectancy has dropped to 1-2 days So... without some sort of shield there's no way a human could do a spacewalk. however, these levels of radiation will not only affect spacewalkers, but everybody on the ship, so the ship will likely have massive leaden (or similar) shields at its front. As long as your space walkers would be in the "shadow" of the frontal shield, they have nothing to worry about... apart from accidentally drifting into the death zone... Of course the radiation levels outside the ship would still be elevated because * the ship's hull provides some additional shielding * some particles can be scattered around the edges of the shield which would lead to a gradual increase in levels the closer you get to the "edge" of the shielded zone, especially near the rear end of the ship. but if the inside of the ship is shielded well enough to allow humans to live a normal live and life, they should be able to survive outside for a few hours without problems. P.S. I think the leaden shield is actually doable in practice. I'm not sure how to calculate its thickness, but it will be probably ~50 times the [mean free path](https://en.wikipedia.org/wiki/Mean_free_path) of 0.3c hydrogen atoms in lead, whatever that works out to. You could make the shield out of [Unobtanium](https://en.wikipedia.org/wiki/Unobtainium) which I hear has excellent properties in that respect. Unobtainium shields may even be light enough to be worked into the fabric of the EVA suit... but note that you'll still need to cool them, and since your visor can't be made of it, don't you ever stare into the direction of oncoming death. [Answer] Having 0.3c related to any known macro object in our university pretty much imposes having ~0.3c related to anything else (redshifted objects included, if/when you reach near them). At 0.3c all those stray helium and hydrogen atoms will behave as both deeply penetrating and ionizing radiation. At 0.3c you will "collect" a lot of them, even in the space between galaxies where they are ~1 atom in 1m3 or less. Not sure about spacewalking, but you will have hard time shielding the whole ship. Think muons. [Answer] It is completely unfeasible for the reasons listed above. What's more, the ship itself would be exploded by stray particles hitting it at 0/.3C relative. Suppose your ship is tiny, just a cross section of 100 square meters and the trip is 100 light years. The volume of that cylinder is enormous. Every piece of space dust in there impacts your ship at 0.3C relative speed, about 200,000,000mph. 100 meter cross section times... uh.. 9.461e+15 meters... is about 9.5\*10^17 cubic meters. So you are pushing that (improbably tiny) ship through 950,000,000,000,000,000,000 cubic meters of space. Air is 1kg/m on Earth. Let's pretend there is only 1kg of mass per TRILLION cubic meters on a path between two stars. That means that your ship is being hit by 9,500,000 kg of matter at 0.3C. Even if it hits as one proton at a time, gamma rays from collisions kill everyone. For a terrestrial example with a baseball at 0.9C, see Randal Monroe's book excerpt here: Here's what the author of the XKCD comic states: <https://what-if.xkcd.com/1/> Protip: Don't be in the city on game day. It is not going to work without magic^H super science. So just take your perpetual motion machine free energy generator (cough warp core cough) and make a magnetic shield to hand waive it all away. Read Larry Niven's Ringworld or Man-Kzin novels for great examples of what you want to emulate. ]
[Question] [ I'm developing a fantasy setting where people can go to other planes (universes) that are not made of mostly empty space, like our universe is. Instead, you have universes made mostly (but not entirely) of earth, water, or gas. (Gravity works differently on these planes, so you don't have all this matter collapsing in on itself. They're also not as big as our universe, though they're suspected to be larger than our solar system, at the very least.) In order to facilitate navigation in settings without stars or easily visible landmarks, I've decided that there's some kind of magical field that is detectable with a special compass. This magical field, when measured correctly, indicates a center point to the plane, four horizontal points (north-south-east-west) and two vertical points (up-down.) But this is where I'm running into a problem: I need a simple, easy-to-understand naming convention for the up-to-down directions on this three-dimensional compass system. If a character says, "We need to go north," the reader automatically understands what he means. However, if the character is indicating a direction that is also on the Z axis, using terms that sound like "at 45 degrees" might be confusing and, more importantly, disorienting. I need my characters to be able to indicate they want to go not only north, but north and up or down. I believe I may have a naming convention figured out, one which I think might sound natural for my characters to speak, but while it makes sense to me, I need feedback from other people to make sure that it works. So, here's how the system works. The center of the compass is the origin point (O) on the Cartesian coordinate system. (Remember, the magical field indicates a central point.) On the X,Y axes, the cardinal directions are the same as a conventional compass rose. (North: 0° = 360°, East: 90°, South: 180°, West: 270°) The Z axis has two points of simply called "Up" (0° = 360°) and "Down" (180°.) When characters describe specific degrees on the Z axis, they don't use terms like "north" or "south." Instead, 45° is "Upward" while 135° is "Downward." Thus, going north on a 45° angle is going "Upward North" while going north and down at a 135° angle is "Downward North." The same applies to all the other cardinal and intercardinal points on the compass, i.e. "Upward South," "Downward East," "Upward Northwest," "Downward Southeast," etc. As for the points of 22.5° and 67.5° on a vertical compass, the equivalents of North-Northeast and East-Northeast on a horizontal compass rose, the terms "High" and "Low" are used. So, going north at a 22.5° is going "High Upward North." Going north at a 67.5° angle is going "Low Upward North." The same applies to the points of 112.5° and 157.5° from "Up" on the Z axis, which would be the equivalents of East-Southeast and South-Southeast on a horizontal compass rose. Thus, going North on a 112.5° angle is "High Downward North" and going North on a 157.4° angle is "Low Downward North." Does this system make sense or is it too confusing to understand? ## UPDATE All right, so, after going over everyone’s feedback and giving things some thought, I’ve settled on a few ideas I have for how this compass system works, but I want to make sure that they’re sound before I commit to them. There’s no point in developing the terminology for this compass system if it wouldn't actually enable navigation within a sphere, is there?. Before I get to my related questions, I need to give some specifics about how these planes, the magical field, and other things work. I will put the most important information in bold and give short descriptions of stuff if that's all the information you want, but I'll include more details in case you need them. I’m calling this magical field that reacts with the magical compasses the “Cosmic Compass,” because calling in the “cosmic field,” like “magnetic field,” just didn’t sound right to me. ## The Cosmic Compass The Cosmic Compass is a magical field which affects certain materials in a similar manner to a magnetic field. This is how magical compasses can use it to determine one’s orientation on the planes in question. However, there is only one Cosmic Compass. Each plane does not have its own separate magical field. The magical field overlaps all of the planes where it is detectable. Thus, you only need one kind of magical compass to navigate on these different planes. The Cosmic Compass is not present on all planes, however, just a particular set of them. It is not present on the primary plane where my stories will be taking place. ## The Wayfinder’s Compass The name for the type of magical compass I’d like my characters to use would be a “Wayfinder’s Compass.” Usually, a Wayfinder’s Compass can function as a normal compass outside of these different planes. I’m thinking they also have other magical functions, like detecting the presence of any portals in your vicinity, functioning like a magical Geiger counter to alert people of the presence of dangerous magical energies or substances, and maybe even storing maps that can be projected like holograms. The point is that a Wayfinder’s Compass has applications on all sorts of planes, not just the ones we’re focusing on in this discussion. ## What Are These Planes? Short Answer: They’re called the Transitory Planes and they’re used to take shortcuts between different planets on the Celestial Plane, which is basically like our universe. Long Answer: The worlds my characters inhabit are planets that exist in solar systems. Each solar system is in a separate galaxy. These galaxies are part of the same cluster found on what I am now calling the Celestial Plane. (I previously called it the Cosmic Plane in a few of my earlier responses.) However, this is just one cluster of galaxies on the Celestial Plane. There are probably about a trillion galaxies total. Because my characters don’t have spaceships, let alone spaceships with FTL capabilities, they can only travel to other planets by going through the Transitory Planes. ## How Many Transitory Planes Are There? Short Answer: The are eight, but the five I have developed so far are: 1. The Plane of Earth 2. The Plane of Water 3. The Plane of Air 4. The Plane of Fire 5. The Plane of Mirrors Long Answer: There are a total of eight Transitory Planes, four that are elemental themed and four that are non-elemental theme. I’ve only come up with one of the non-elemental themed planes, the Plane of Mirrors. My thinking is that, in keeping with the theme of compasses, the four elemental planes are like the cardinal points of a compass while the four non-elemental planes are like the intercardinal points of a compass. That doesn’t mean that these planes are arranged in such a formation, however. It’s more like they all occupy the same space but, being separate universes, don’t actually interact with each other. This is how the Cosmic Compass is able to overlap all of them. It’s like a bubble around all eight Transitory Planes. ## How Big Are These Planes? Short Answer: 20 billion km in diameter. How I came to that size: I wanted them to be at least the same size as our solar system. However, there’s more than one way to decide where we put the edge of our solar system. One possible boundary is the orbit of Neptune, the other is the heliopause. The former is a radius of around 30 AU while the latter is around 90 AU. Or, to put those into really, really big numbers, the former is 4,487,936,120.73‬ km while the latter is 13,463,808,362.19‬ km. And that’s the radius. We have to double those for the possible diameters of the solar system. Those are mind-boggling numbers. So, I decided to simplify things a bit. Since 1 AU = 149,597,870.691 km, I rounded up to 150 million km. Now, since our choices of AU were 30 and 90, I went halfway between those and chose 60 as my multiplier for my new AU. 150 million times 60 = 9 billion. From there, I decided to round up to an even 10 billion km for the radius, meaning each Transitory Plane has a diameter of 20 billion kilometers. Why my characters aren’t usually traveling all that far: The planets my characters are traveling between on the Celestial Plane are in different galaxies, but those galaxies are part of the same cluster. Furthermore, while this cluster of galaxies probably isn’t at the center of the Celestial Plane, the portals connecting those galaxies to the Transitory Planes are mostly (but not exclusively) found within the central region of those planes. These areas are called the Core Region, which surrounds the Core of each Transitory Plane. I’ll describe the scale of the Core Regions next because it does relate to the Cosmic Compass and I want to make sure that the Wayfinder’s Compasses would actually work effectively within this area. ## The Core Regions of the Transitory Planes Okay, so the portals connecting these galaxies to each other are found within the Core Region, but there is a pattern to the way the portals are arranged. The home worlds of the nine original races are each in their own galaxy, with eight of those galaxies forming a ring around one center galaxy. That is, the nine galaxies form a horizontal disk in their arrangement. If viewed from above, this disk would look a lot like a compass rose, with one galaxy in the middle, four galaxies located at the cardinal points of the compass, and four galaxies located at the intercardinal points. ## How does this relate to the Core Regions of the Transitory Planes and the Cosmic Compass? Short Answer: Because the directions on the Cosmic Compass are always the same, so if you want to go to the north galaxy, you travel to the northern part of the Core Regions on the Transitory Planes. Long Answer: In terms of their placement on the Transitory Planes, the portals that connect to planets in those galaxies are located in the same general areas of the Core Region as the point of the compass the galaxy occupies on the Celestial Plane. That is, the “north” galaxy has most of its portals opening in the north area of the Core Regions, the “south” galaxy has most of its portals opening in the south area of the Core Regions, and the center galaxy has most of its portals opening in the area immediately surrounding the Core of each Transitory Plane. This is why I want people to be able to use magical compasses to navigate the Transitory Planes. Exceptions to the portal placement rule: There are some portals that don’t follow the pattern, of course. That is, some portals to the north, south, east, west, etc., galaxies are found in the region surrounding the Core of a given Transitory Plane. Likewise, some portals from the nine galaxies open into very remote parts of the Transitory Planes. They may connect to regions that are millions or even a billion kilometers from the Core Region. The reverse is occasionally the case as well, with a portal to a galaxy on the fringes of the Celestial Plane connecting to the Core Region. This is another reason I need to know if the Cosmic Compass is feasible. I may have a story or two where my characters go through an Earth Portal expecting to find themselves in the Core Region of the Plane of Earth only to check their magical compasses and realize they are five billion kilometers away from the Core. (And then they’ll probably run into something of the Lovecraftian variety, because why limit the shock and horror of the moment to a mere measure of distance?) ## How Big Are the Core Regions? Short Answer: 200,000 km in diameter. How I came to this size: I didn’t think the Core Regions should be quite as large as the sun, since the sun has a diameter of about 1.39 million kilometers. That is much too large for people to traverse, by aircraft, boat, and especially by mount or by foot. So, I scaled things down so that 1) the Core Regions could hypothetically be traversed from one side to the other by foot, within around a decade. Though it’s not entirely realistic, I set the amount of distance my hypothetical traveler could walk at 50 km a day. A bit high, I know, but multiplying 50 by the number of days in a year seemed more “tidy.” (And, no, before any of you ask, I’m NOT factoring in leap years.) The result for 1 year was 18,250, which I discovered was 5,494 km more than the equatorial diameter of the earth. Multiplying my result by 10 years, I got 182,500 km, or 39,516 km more than the equatorial diameter of Jupiter. I then subtracted 182,500 from 200,000, just to see how close the result was to 18,250. It was 17,500, which means it was only 750 km less than another year’s worth of travel for my hypothetical traveler. Well, one more year of walking isn’t so bad to hit the 200,000 km mark, is it? So, I just rounded up to 200,000. ## How Big Are the Cores of the Transitory Planes? Short Answer: 2 km in diameter. How I came to this size: With the diameter of the Transitory Planes being 20 billion km and the Core Regions being 200,000 km in diameter, I determined the Core Regions’ diameters are 0.001% of the diameters of the Transitory Planes. So, I checked to see what 0.001% of 200,000 was and got 2. (If I got that wrong, please correct me. I’m always second-guessing myself when it comes to math.) To further facilitate the characters being able to determine their position in terms of distance from the Core without them needing to stop and do some calculations, I've decided to add another aspect to the Cosmic Compass - the Cosmic Pulse. ## What Is the Cosmic Pulse? Description: The Cores of the Transitory Planes emit a magical frequency which changes in oscillation depending on where you are on the Transitory Planes. The closer you are to the Core, the faster the Cosmic Pulse, the further away you are, the slower it is. This means the Cosmic Pulse would enable characters to gauge their exact distance from the Core of each Transitory Plane. Frequency Range of the Cosmic Pulse: The Cosmic Pulse is 1 Hz at the edges of the Transitory Planes and increases by 1 Hz every kilometer. Thus, the range is 1 Hz to 10 GHz. Story Purpose of the Cosmic Pulse: In addition to helping characters determine their location in the Core Regions, it will also show them when they have gone through a portal to a remote part of the Transitory Planes. The further away they are, the more likely they are to run into something of the Lovecraftian variety, so finding out they're 5 billion km from the Core will be a very, very frightening thing. ## How Is the Cosmic Pulse Measured? Currently, I’m thinking that the Cosmic Pulse only affects one type of material. Whatever this material is, it resonates at the same frequency as the Cosmic Pulse. Thus, if installed into a magical compass, it can give a reading that indicates how far the user is from the Core of a Transitory Plane. The question is, what material would work best? I want this material to be utterly mundane on the Celestial Plane and only be of use to anyone on a Transitory Plane for measuring the Cosmic Pulse. I’m thinking a crystal of some kind would be good for a fantasy setting, but I’m not sure if a regular crystal material can oscillate at 10 Ghz without having issues. Regardless, I’m going to probably use the Cosmic Pulse in other ways, such as it affects the biological clocks of certain creatures so the Transitory Planes have an artificial day/night cycle. ## So, here are the updated questions regarding the Cosmic Compass: 1. How accurate would the magical compasses be at determining not only direction but also location on the Transitory Plane, particularly within the Core Regions? 2. Is the Cosmic Pulse necessary for determining one's distance from the Cores of the Transitory Planes or can it be done solely with the directions of the six points of the Cosmic Compass and a bit (or a lot) of math? 3. Would a regular crystal material be able to oscillate at frequencies between 1 Hz and 10 GHz without complications or would a different material be necessary? If so, what kind of material? [Answer] Keep it simple. Use the cardinal directions as normal, then vertical direction based on what fraction of a right angle your directional vector is. Note that this is completely independent of what you use for units, whether your culture has divided a circle into 360 degrees or 100 units or some other interval. * "Northeast up half" is heading northeast going upward at half a right angle (45°). * "South-southwest down two-thirds" is heading south-southwest going downward at 60°. * "East flat" (or "East up/down none", or simple "East") means heading straight east at the current altitude. * "Up full" and "Down full" mean straight up and down, obviously. A cardinal heading would be pointless, but could be included if, for instance, you wanted to be facing a specific direction for whatever reason. If you can imagine a helicopter, then an order like "West down full 100 meters" would mean hovering and descending 100 meters straight down, facing west. The advantage of this type of system is that it's easily adapted to numerical values if your culture and the technology permits, as should be obvious. "Three-one-five down three-zero" is (assuming a 360 unit circle) a heading of northwest (315°) descending at an angle of 30°. In the older system it would be "Northwest down one-third." [Answer] Your ideas would work well. Here are some adjustments to be get a feel for what it would look like. Three dimensions takes three coordinates to express a unique point relative to another point. However, direction on a sphere can be expressed with only two coordinates. This is known as spherical coordinates and direction can be express with two angles; the azimuthal angle $\theta$ and the polar angle $\Phi$. The image below shows how this works (The R vector can be ignored) [1](https://i.stack.imgur.com/KtytK.gif): [![Weisstein, Eric W. "Spherical Coordinates." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SphericalCoordinates.html](https://i.stack.imgur.com/KtytK.gif)](https://i.stack.imgur.com/KtytK.gif) If you wanted to make analogy to the traditional compass then you could keep North (0$^o$), East (90$^o$), South (180$^o$) and West (270$^o$) about azimuthal angle (x-y plane in the picture), just like you described. As you described the positive polar angles could be "Up" and negative polar angles are "Down". For polar angles: (0) : The Up and Down could be replaced by naught: Naught North-East (22.5) : Low (45) : Mid (67.5) : High ($\pm$90) : The direction might just be Up-Naught/Down-Naught So in the image, the direction would be "Up North-East High". Heading in the direction of the properly orientated needle would be "Naught-North" I included the "Naught" to add flair. Its not strictly necessary. Of course to work, the "compass" would need to always point towards a specific point in space. The compass might be a glass sphere which is has etchings marked corresponding to the angles. The needle would run nearly the diameter of the sphere, but have just enough room to move freely. Note, in real life this wouldn't work in space for a variety of reasons. But if there were some force which would always point the needle towards a specific point within the context of a localized environment, this sort of compass might be useful for navigation, if not just cool. The further away the point is the better the bearing is going to work for moving in a straight lines. [1](https://i.stack.imgur.com/KtytK.gif) [Weisstein, Eric W. "Spherical Coordinates." From MathWorld--A Wolfram Web Resource. <https://mathworld.wolfram.com/SphericalCoordinates.html> ] [Answer] You could always take a page from Star Trek (which I believe comes from aeronautics); directions are "<yaw> by <pitch>" or "<yaw> mark <pitch>". (You could also substitute other words to connect the two.) This allows great precision if you use decimal degrees (0-360 by -90-90 with as many decimals of precision as you want), or you can use clock hands (1-12 by 1-5, ignoring 6 and 12 for the latter because those make the yaw irrelevant). In either case, you can talk about relative (i.e. I am always facing 0 by 0) or absolute directions ("north" is always 0 by 0). You can add "flair" to this by having them divide their circles by some number other than 12 or 360, although this may be too confusing for readers. Note that, if you use absolute directions, you also need a 3D compass; you need to know "up" as well as "north". (Depending on how gravity works, this may be easy. For example, you could use this system to navigate Earth's oceans with a regular compass if you also have a reliable way to determine 'down'... which, in water, can be less easy than you might expect. [Answer] Just do what we do, but with an extra dimension. We describe directions with four base words: North, South, East and West. We can also combine them: Northwest, Southeast, and so on. For even more precision, we have constructs like North-northwest and East-southeast. We simply extend this system with two additional directions, "Up" and "Down" (though one may want separate words for them to make a distinction between absolute ("West") and relative ("Left") terms, but I digress). You want to go up? That's "Up". You want to go up and north? "Upnorth". Down, west and south? "Downsouthwest". Just north? That's just "North". We can continue with more detailed directions. You want to go north and slightly upwards? "North-upnorth". Northeast and slightly up? "Northeast-upnortheast". Seeing as a third dimension adds more information to convey, I suspect that super-specific directions will be less commonly used due to how cumbersome they are to say. [Answer] Just use the word "and". There is nothing wrong with your coordinate system. But focusing too much on the directions and angles makes it more confusing that needs be, and complicates the language as well. You can fix this just by saying how far things are apart along each axis. Rather than "The fortress is 6 miles high upward northwest from here" use "The fortress is six miles to the northwest and 1 mile up". Rather than "We need to go 6 miles high upwards northwest" say "we need to go 6 miles northwest and 1 mile up". After all, we don't need to go at any particular angle do we? The angle/direction is not important. It's the start and end that matters. If I HAD to describe directions. . . If for some reason I wanted someone to start moving in a certain direction and just keep going forever. The simplest terminology is "Go 1 North by 1 upwards". That means go North at the angle so that every time you go 1 unit north you also go 1 unit up. In other words go north at a $45^\circ$ angle from the floor. This is the same as your "Upwards North". We also have "Go 1 North by 2 upwards" that means go North at the angle so that every time you go 1 unit north you also go 2 units up. This is the same as your "High Upwards North". Also "Go 2 North by 3 upwards" means every time you go 2 units north you go 3 units up. So a $60^\circ$ angle to the floor. You can plug whatever ratios you want in to get all the directions. [Answer] Most of the answers I've seen here take the compass rose, and then add a yaw angle. This makes the handling of the Up-Down dimension fundamentally different from the handling of the two planar dimensions. My approach aims to be a true 3D approach that treats all six poles the same. --- # The Compass star So, what is the working principle of the compass rose? In 2D, the compass rose subdivides arcs on a circle. How do we extend this to 3D? In 3D, the compass star subdivides surface patches on a sphere. What are the surface patches, that we need to subdivide? The surface patches are all triangles. Whenever we take one pole on each of the tree axes, we see that they form a spherical triangle. Like this: ``` U / \ / \ N ----- E ``` Splitting a triangle into four smaller triangles is rather simple. We just need to take the center points on its sides: ``` U / \ / \ UN ----- UE / \ / \ / \ / \ N ----- NE ----- E ``` This gives you a total of 18 directions: The 6 poles plus the 12 points half-way between the poles. For more fine-grained orientation, we continue to subdivide the triangles, just like the compass rose continues to subdivide the arcs. The second iteration is this: ``` U / \ / \ UUN ----- UUE / \ / \ / \ / \ UN -----UUNE ----- UE / \ / \ / \ / \ / \ / \ UNN -----UNNE -----UNEE ----- UEE / \ / \ / \ / \ / \ / \ / \ / \ N ----- NNE ----- NE ----- NEE ----- E ``` Now we have the 6 poles, three intermediate directions on the 12 lines between the poles, and three directions in the center of each of the 8 celestial octants. That gives `6 + 312 + 38 = 66` directions. --- # The number system You can continue this construction to finer subdivisions, but on the next iteration you will run into problems with the naming. Your names will become rather unwieldy and they become hard to define in an unambiguous way. However, we observe that every direction is nothing more or less than a weighted sum of up to three pole directions. And we can easily express these with integer numbers. Up to now, we had these directions: ``` Principal directions: U N, E Mixing of two directions: U = 2U UN, UE N = 2N, NE, E = 2E Mixing of four directions: U = 4U UUN = 3UN, UUE = 3UE UN = 2U2N, UUNE = 2UNE, UE = 2U2E UNN = U3N, UNNE = U2NE, UNEE = UN2E, UEE = U3E N = 4N, NNE = 3NE, NE = 2N2E, NEE = N3E, E = 4E ``` We can continue this principle, doubling the number of mixed directions in every step and denoting the weight of each principal direction with a single integer: ``` Mixing of eight directions: 8U 7UN, 7UE 6U2N, 6UNE, 6U2E 5U3N, 5U2NE, 5UN2E, 5U3E 4U4N, 4U3NE, 4U2N2E, 4UN3E, 4U4E 3U5N, 3U4NE, 3U3N2E, 3U2N3E, 3UN4E, 3U5E 2U6N, 2U5NE, 2U4N2E, 2U3N3E, 2U2N4E, 2UN5E, 2U6E U7N, U6NE, U5N2E, U4N3E, U3N4E, U2N5E, UN6E, U7E 8N, 7NE, 6N2E, 5N3E, 4N4E, 3N5E, 2N6E, N7E, 8E ``` I each direction, the sum of the integers is exactly 8. Or 16 in the next subdivision step. Or 32 in the following one. I'm not going to write all those directions down... That is, the expression of a direction in the numerical system is fully unambiguous: It gives the count of directions that were mixed, and it provides the weights of all the constituents. And, because it only ever uses three numbers and three letters/names, it remains concise even when denoting a direction with high precision. Of course, this number system would only ever be used by navigation professionals. Normal people will stop at the second subdivision and stick to the non-numerical names that I outlined above. 66 directions should be plenty for a layman's use. --- # Further thoughts The above construction is based on the [octahedron](https://en.wikipedia.org/wiki/Octahedron): The 6 poles correspond to the 6 vertices of the octahedron, and the 8 triangles that form the octahedron are the basis for the triangle subdivision above. However, there are two other [platonic solids](https://en.wikipedia.org/wiki/Platonic_solid) that are composed of triangles: The [tetrahedron](https://en.wikipedia.org/wiki/Tetrahedron) and the [icosahedron](https://en.wikipedia.org/wiki/Regular_icosahedron). Both of these allow the exact same triangle subdivision process to derive more precise directions. The tetrahedron would only use 4 poles and divide the sphere into 4 patches. That's rather coarse and of little use. The icosahedron would use 12 poles, twice as much as the octahedron, and provide a whopping 20 triangular patches (2.5 times as much as the octahedron). It would make for a good basis for the construction above, and it would add a significant magical flair if the compass is an icosahedron that's suspended within a sphere made of glass (crystal?). You'd need to invent names for 12 poles, though. [Answer] ## Using a Solar Reference Point There are many good answers here for a cartesian navigation system, but compasses don't follow the rules of cartesian space. They aim at a point and not an infinite direction. Since you mention that your universe is the size of a solar system, instead of hand waving away how the compass works, one option is to put a star at the middle of your universe, and make that the your reference point. Your compass could be any variety of tools designed to measure the sun as your primary reference point, but with a star it does not actually have to be magic. You could just use a pinhole sunspot viewer, or a magnetic compass that orients to the star's magnetic field. Stars have a spin which can be used to define an equatorial line as well as up vs down. If you perceive the spin as clockwise, you are right-side up, if your perceive it as counter-clockwise, you are upside down. From that perspective, any point in space above the sun's equator or moving in that direction is Up and below it is Down. Moving toward or away from the star would be In and Out, and moving in or against the direction of the star's rotation would be With and Counter. ### Navigating a 3-d Solar Map In the map below, point A and B are dots with lines that go up or down as far as they are from the equator to where they intersect with it. So, to get a heading from A to B you would travel "about Down-Down-In-Counter" in layman's terms or if using a degree system "315 mark 30". For the degree system it would be 0 to 360 with 0 being In, 90 With, 180 Out, and 270 Counter, and 0 to 180 with 90 being parallel to the equatorial plane, 0 being Down and 180 being Up. To define an absolute location (as you would in GPS), you would need an arbitrary marker you define as 0 degrees. For this you would want a very large planet that is on the equatorial plane that can be seen from most places (Point C on the map). It will server as sort of a Prime Meridian/North Star. From it you measure a planet's location by X-angle/Y-angle/Distance. So let's say "C" lies as "0/0/100", the "A" would be at about "283/30/120" and "B" would be at about "296/-20/80". [![enter image description here](https://i.stack.imgur.com/abUJq.png)](https://i.stack.imgur.com/abUJq.png) ### What does a star look like in each plane? If you want to get scientific here, the 4 elements of fire, air, water, and earth don't all make sense on thier own. Fire without air to burn is not a thing which makes explaining your planes in this since impossible (I know you can just magic handwavium this, but you don't have to). In science, there is a better explanation of these 4 states that our ancestors first identified which are the 4 phases of matter: plasma (fire), gas (air), liquid (water), and solid (earth). In this since your can make your material planes places where matter only exists in a single state of matter while maintaining its other chemical and atomic properties. Plasma: Our sun could best be described as a plasma star; so, no real modifications needed. In the plane of fire, all astral bodies, no matter how small would look like stars; and the sun is simply the biggest and brightest star in the sky. Gas: In this plane, all asterial bodies would look like gas giants, and the sun would just be a really really big gas giant. Looking at the sun would be like looking at a giant jupiter. Fusion does not work so well without a plasma state; so, it would be too dark to see it, but it would still have a magnetic field from the pseudo magnetic gases at its core which you could detect with a compass. Liquid: In this plane asterial bodies would all be endless oceans with no floors. Like the Gas sun, the Liquid sun would be lightless but generate a magnetic field Solid: In this plane, planets would all be solid stone or ice and the sun is no exception. This may actually lead to a problem since the spin of a solid core against a liquid mantle is where we get the magnetic field on rocky planets. That said, You could dismiss by saying that the star is solidified in a polarized state which you could align to with a magnetic compass. [Answer] I love your system (noting Carl Witthoft’s endorsing comment that it lines up with real-world praxis); I think it is indeed very intelligible. ———— There is also a lot of interesting and good material among the answers here. A couple of comments. I would suggest that you have (at least) two verbal expression systems — e.g. a military one and a civilian one, or an adventurer one and a casual one. Each system would be more about precision, or brevity, or everyday understandability, or what-have-you. (It might add a bit of spice, in some situations, to have a character switch from one to the other (for the sake of speed, or precision, or intelligibility).) This ties in with Matthew’s and Keith Morrison’s comments about relative directions. (By the same token, there might be different compassOrbs with markings for one or all of the main systems, and perhaps other ones with various etiologies; see also below.) For precision, it looks like it would be hard to beat “cmaster - reinstate monica” ’s system — just add more characters (although it would be good to have a trailing 0’s element). (For one system) I like the idea of using a polar system, with either 9 or 12 (or 4) main divisions for each quarter-circle… or just 0 to whatever (36/48/16) for the whole circle… in the NWSE plane. [You could have, correspondingly, a people with 9 or 12 fingers.] The NWSE plain works like (our) everyday clock system, basically. It goes either by quadrants — “2-8” — or simple — “35” (anchored presumably with 0 for north). The former sounds more plausible to me. (Actually, I would expect the quadrants to be labelled 1 to 4, rather than 0 to 3… but I shall ignore that herebelow.) Up/down is a suffix from 1 to 9/12/4, preceded by a signal for down — e.g. “3-5-neg2” — or just 0 to 23. (You could have 0-8 [viz 9] instead of 11 [viz 12] for the elevation, for interest.) [Again, you could have 1 to 12 instead of 0 to 11.] “Oh-oh-oh” is north/level. “3-6-6” is south-west, 45° upwards. “1-oh-neg10” or “1-oh-22” is east and steeply down. For precision you could add a qualifier — e.g. “3-6dash85-3dash17”. [Or “dot”… or “boo” or whatever.] Again, you could use the system you describe (which I very much like) in one case, and the above in another. (I would like an adaptation of this with only one-syllable words, but you are probably better sticking with English. [Possibly “sven” and “ ’lven ” for 7 and 11 respectively, or what-have-you.]) ———— The justification of this is that you do not always need the reader to understand the direction that the story characters are discussing. You could have a (hopefully not too contrived) conversation in which someone is explaining the more esoteric system to someone else, in terms of the casual and easy-to-understand one, and then carry on with it. Given that, the keen reader can indeed follow the other system. By the same token, when you are explaining directions to the reader, you can use the intelligible one. ———— [Only some of the following is consistent with the system you have described.] I thought it might also be worth mentioning the concept that the magic system was not quite so anthropocentric. That is (perhaps {for instance}?)… it can tell you which way is up/north/east, but not where the centre is. That is… you know that the centre is in “that” direction, but not how far away it is. The extreme version of this idea is that it does not tell you where the centre is; only which way is up/east. You could also consider variations such as having it tell you the direction to the centre, and perhaps up and down, but nothing else… or the direction and distance of the centre but nothing else… or it tells you EWNS but you get up/down from “gravity” (meaning that you do not know your height). (Conversely, of course, you can have it so that it does tell you exactly where you are.) (You could also have compassOrbs that work only in some domains (and expensive ones that are universal), or that malfunction in some domains.) ]
[Question] [ I am writing a science fiction short story, which is loosely about terraforming. The drama takes place on a terraforming site, which has been halted, in its early phases, due to the discovery that the planet goes through an uninhabitable period in its cycle. It could be every 50 years, or it could be every 250 years, the time and duration of the events doesn't really matter, but something must happen to the planet, which would render it uninhabitable for a period. The event has to be something that wouldn't be spotted at first. The people wouldn't start the difficult process of terraforming/inhabiting the planet if they knew they'd have to abandon it. If anyone has any ideas and could get back to me that would be really helpful. [Answer] Natural cycles of uninhabitable periods would have been discovered during the surveys and preparation before the terraforming started. Instead of a natural cycle the planet had an apocalyptic war in its past. This war was fought by vast armies of robots and killer drones. The sapient alien population went extinct during the war. Eventually the fighting machines destroyed each other and the war seemed to have ended. But deep beneath the surface of the planet gigantic automated factories produced the robot armies of both sides in the conflict. Every two hundred years the robot armies re-emerge from underground bunkers to wage the war all over again. Until each side has destroyed the other. Then the war pauses for another two hundred years. Scavenger robots scour the surface of the planet recovering construction materials of metals, plastics and equipment parts to feed the subterranean factories. Anyone visiting the planet between the war periods will not find any sign of the war. Every wrecked war machine and its parts will have been taken below. [Answer] Bacteria can survive being frozen for extremely long periods - potentially as long as [100 Million Years](https://www.newscientist.com/article/dn19475-arctic-bugs-may-have-the-longest-life-cycle-on-earth/). It's not implausible that a small pocket of bacteria, buried underground or in permafrost, would go undetected during a planetary survey. [Bacteria are also suspected of radically changing the earth's atmosphere to the oxygen-rich atmosphere we know today](https://en.wikipedia.org/wiki/Great_Oxygenation_Event) - killing off most of the anaerobic life on the planet in the process. It seems plausible that you could have a similar kind of bacteria that changes the atmosphere in a manner that is hostile to human life - giving off Carbon Dioxide (or Monoxide, perhaps). It could be awakened from dormancy by a change in the planet's temperature; perhaps the end of an ice-age, or even deliberate warming caused by the terraformers. This actually has real-world parallel for today's changing climate: [the re-emergence of Anthrax in Siberia](http://gizmodo.com/the-horrifying-reason-siberia-is-dealing-with-an-anthra-1784540317). [Answer] As a4android said, anything about the solar system that produces periodic challenges to the habitability of the planet should have been noticed during an initial survey, provided the surveyors were competent. And as for the planet's weather systems, water cycles, and so on, those get remade in the course of terraforming. However, if the survey was incompetent, and missed a problem, then you can have a periodic problem that wasn't spotted. If that degree of incompetence is compatible with your story, a heavy meteor shower might be a useable idea. Read the Wikipedia article about [meteor showers](https://en.wikipedia.org/wiki/Meteor_shower), and then come back. Now, to make this work, you need the meteors to be much bigger than usual, and tightly concentrated in one small region of their orbit around the star. That means that in most years when the planet crosses the orbit of the shower, you get only a normal meteor shower, of tiny meteors. However, when the group of larger chunks of debris happens to be at the crossing point when the planet reaches there, you have a lot of big meteorites and those would disrupt the terraforming process (since we have only general ideas about how to do terraforming, having it be disrupted could be plausible). What I haven't figured out yet is how to achieve this fairly tight group of bigger chunks of debris. Maybe someone else can suggest that? [Answer] My answer would depend upon the orbital situation of the planet being terra-formed. It's possible your planet could have a lengthy orbital period in a circular orbit. It could also be a fact that your planet is part of a double-star system or a single-star system with a moon-sized object in an eccentric orbit. Either way, the orbital interactions could be such that your planet experiences close passes to the other bodies such that your planet experiences extreme seismic/volcanic/tidal events everywhere on the surface. Maybe the orbital mechanics are such that this happens for a 5-year span every 10,000 years. You'd have to develop the complexity of the orbital mechanics of the system. Another possibility is that your planet could orbit a star that explodes into extremely intense solar flaring every 10,000 years that literally engulfs your planet for periods of weeks or months, enough to dramatically reduce food supplies for decades. [Answer] As @a4android pointed out any competent solar survey team prepping a solar system for terraforming should catch anything too terrible before starting, but that's assuming they are competent. Try thinking less of crew of the Enterprise and more of a bunch of over worked, under paid solar surveyors that falsified a few reports, and maybe didn't do all of the due diligence necessary to catch that horrible disaster speeding towards your planet. Also don't forget the politics. Maybe the civilisation that started the project collapsed into civil war leaving your planet on its own for 50 to 250 years. In short never underestimate the power of people to mess things up. Or... What about a tidally locked world? In order for the planet to be properly terraformed it would have to be set in motion again. The process could be slow and laborious and take 50 to 250 years before it could be occupied. Or set in motion with one almighty spin that would leave it uninhabitable for many years because of the terrible tectonic stresses it would cause. [Answer] If you're not familiar with it, you should check out Anne McCaffrey's [Dragonriders of Pern](https://en.wikipedia.org/wiki/Dragonriders_of_Pern) series. You've pretty much described the setting of those books, the planet [Pern](https://en.wikipedia.org/wiki/Pern). There is another planet in Pern's solar system with an elliptical 250 year orbit. At the far end of its orbit it reaches the system's Oort cloud, pulling material into the inner solar system and into the path of Pern's orbit. The result is that for 50 years of the 250 year cycle Pern gets showered with material from the Oort cloud. The surveyors (and subsequent colonists) were aware of this, but meteor showers aren't particularly worrisome. However, the material from the Oort cloud doesn't just form harmless meteor showers - it contains what they call [thread](https://en.wikipedia.org/wiki/Pern#Thread), "thin silver filaments of a space-borne mycorrhizoid spore that devours all organic matter that it touches". In short, a deadly rain. However it doesn't completely destroy the natural flora and fauna - they've adapted to the situation such that enough survive threadfall and are able to bounce back quickly enough that the survey team coming a few decades into the 200-year gap didn't see anything concerning. In the books, the settlers stick around because 1) their voyage was intentionally one-way so they have no choice and 2) the planet has miniature, fire-breathing, teleporting dragons that they are able to genetically modify into a rideable size. --- So what should you do in your story? First, remember that uninhabitable for people is not the same thing as totally uninhabitable. Your mechanism of uninhabitability can make it impossible for people to survive, even though the local flora and fauna can. This also makes it harder for a survey team to flag the planet as dangerous, as they won't see the evidence of massive die-offs. Second, you can make the conditions seem innocuous except for when the disaster is actually in progress. In the case of Pern, this is something space-based that is only dangerous once it gets inside the atmosphere. For example, what about venomous [periodical cicadas](https://en.wikipedia.org/wiki/Periodical_cicadas)? These cicadas only emerge every 13 or 17 years (depending on the species), but emerge in massive numbers. What if, instead of being harmless, they had a venom that was particularly deadly to people? In their larval form they live underground, so while they're not swarming you would have no clue they existed. [Answer] If we are to assume the system is well surveyed then perhaps we should consider threats from outside the system. I hypothesise a pulsar in the same area of the galaxy. The direction of the radiation beams emitted by the pulsar is determined by its magnetic field. The magnetic axis is not aligned with the rotational one, hence the pulsing effect. The beams trace out two cones shapes as they rapidly rotate. This is where some handwavium may come in as I don't know if this is possible for a pulsar. This pulsar has a cycle where its rotational axis changes, as the Earth's does. As the rotational axis changed the traced cone would narrow and widen. If your system was at one end of the cycle it would be blasted with radiation from a nearby pulsar at the maximum of each axial cycle. Then there might be hundreds of years before another full cycle completed and the death cone returned. The surveyors would be aware of the pulsar I assume but they may be forgiven for not inspecting the axial cycle of a object many light years away. [Answer] Most of the good takes on this idea that I have seen involved biology. In the case of the movie Pitch Black, there is a biological organism that periodically "spawns" and swarms all over the surface of the planet, consuming everything. In the case of the Anne McCaffery Pern series, the planet periodically came very close to a wandering planetoid covered with an extremely hostile alien life form that was able to drop into the upper atmosphere of the colony world, but only every so often, and only when the planets were sharing an orbit (so there were many year gaps where the wandering planet was too far from the colony to cause danger). I like the idea of bacteria myself. Bacteria can do lots of interesting things, and the activities of the colonists might disturb them and feed them. What if the bacteria are not inherently harmful, but given the presence of something the colonists bring with them, they mutate into something nasty? Brain eating bacteria? A weird disease? Who knows? More interesting: an alien race was going extinct. They didn't have the technology to leave their planet, but they had advanced genetic technology. Before they all died out, they encoded specialized viruses to lie in wait until some other life form came, and then penetrate that life form's genetic code and mutate them into the aliens? Sort of a genetic cuckoo effect. [Answer] The planet's internal composition is such that the magnetosphere changes periodically, much like how Earth's magnetosphere has undergone geomagnetic reversal in the past, indeed we seem to be due for another such event. A sudden reduction in the magnetosphere could result in increased surface radiation and would likely damage any electronics that aren’t properly shielded, satellites and spacecraft could also be affected. This may not kill people outright (although the risk of sunburn and skin cancer will be greater) but for a fledgling colony losing all electronics and orbital infrastructure would be a devastating blow. [Answer] I think the best example of this was the planet ["Eletania"](http://masseffect.wikia.com/wiki/Eletania) in the Mass Effect series: > > Eletania appears to be a world eminently suited for colonization. Sadly, appearances are deceiving. It is covered by a verdant carpet of mosses, algae, and lichen, and possesses a thick oxygenated atmosphere, but the animal kingdom is a web of microscopic symbiotic creatures. These are impossible to filter from the air and necessary for the native life to thrive. Unfortunately, they also cause anaphylactic shock when inhaled by non-native life. > > > In short, settlement requires either fully sealed environment suits, or replacement of the entire world’s ecosystem. Some have proposed limited colonization at altitudes above the symbiotes' range, or in areas where favorable winds keep the air clear. > > > [Answer] I think dunc123 is more on the right track--we need to be looking for something the survey crews couldn't see. However, I disagree with him about a pulsar in a nearby system--it should be obvious and how would it keep striking? Instead, lets look closer at hand--there's a black hole in a distant orbit about the star, well out there in the Oort cloud. It was missed because it's small. (Formation means unknown. Once formed it's stable but we don't have any mechanism for them to be formed. Perhaps this is an alien weapon system??) One pole is currently pointed towards the inner system. If there's nothing around it the black hole is quiet and all but impossible to detect without an extensive period of mapping orbits to find it's effects. However, sometimes it encounters something out there and when it does so the results are dramatic--including a very deadly radiation jet from it's poles. (Infalling matter sorts itself out into a disc which ends up absorbing any energy released in the plane of the disc, the energy that gets out is to a large degree normal to the disc.) The planet catches enough of it to devastate a terrestrial ecosystem. (There may be local life which has evolved to deal with the radiation storm. Unless the survey crews specifically test that local life for radiation hardness they're not likely to notice it.)) ]
[Question] [ The [Hydra](https://en.wikipedia.org/wiki/Lernaean_Hydra) is a Greek mythological creature known for its many head that only increase in number as you fight it. Alcaeus was the one to solidly state the the creature started with 9 heads, a large primary head and 8 smaller secondary heads. Along with the magical details previously stated it was also the size of Hercules himself, over 6ft. * Is there a realistic way that a Hydra could evolve? * Using earth or near earth biology how close could I get to the Hydra? An answer that can realistically explain the hydras regeneration, along with its size and head count will be accepted. A list of all of the Anatomically Correct questions can be found here [Anatomically Correct Series](https://worldbuilding.meta.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798) [Answer] There's a good reason why animals don't have more than one head. Heads use a lot of energy, and exist because keeping the sensory organs in one place (the direction of the creature's motion) is an efficient body plan - more than one head would not benefit the organism much and would only cause problems. Regeneration is also very uncommon in animals with a complex, central nervous system, since nervous systems tend to develop in a very structured manner and generally need to start from scratch to form properly. Even vertebrates that can regenerate (like some lizards) cannot regenerate their heads. While a creature with many heads is extremely unlikely to evolve and one that can regenerate their heads is even more unlikely, there are some possible ways you could come up with something that looks and acts like a Hydra without actually being one. 1. A descendant of octopus that has become more cephalized, developing a proper head and a long neck, as well as adapting its tentacles to look like eight 'false' heads to distract predators. Some caterpillars and fish use similar strategies, with eyespots on their back ends so predators attack the wrong part. Octopus tentacles are already capable of regenerating, and sometimes a severed tentacle will regenerate two new ones if something goes wrong in the regeneration process. This fits the original legend quite well. 2. A social species of snakes that live together in a single nest. They might join together for protection or to take down larger prey, which means they would probably have more 'tearing' teeth to share kills, as opposed to modern snakes which swallow their prey whole. They would not actually regenerate, but as more snakes leave or join the colony (or hide in the middle) the number of 'heads' would seem to vary. [Answer] Make the hydra live in an area where it has to probe crevices and cracks for food. It has muscular tentacles that each have rudimentary sensory organs and a feeding orifice. So it looks like a beast with multiple heads but they are really just very specialized limbs designed to probe into cracks, identify food via crude vision, motion detection, infrared, etc, and eat it. Obviously it would be very difficult to regenerate additional limbs within the timeframe of a single encounter but perhaps it can extrude pseudopods or mock limbs when threatened to look more imposing, even if these pseudopods don't have the same sensory ability and eating orifice of a regular limb. The limb is more like an elephant trunk that can bite and tear, swallowing food via peristaltic action. It can color it's skin like an octopus so when it extrudes a muscular pseudopod it can color it to look like a regular limb. [Answer] No clue for the realistic regeneration (I think there's got to be a lot of handwaiving involved, especially for the regeneration speed that produces an entire head within minutes). But you can get a multi-headed creature through birth defects. So, basically your Hydra is a long-necked lizard/dinosaur creature. Size-wise, you've got your choice since dinosaur size could cover anything you want from one-foot tall all the way up to ten-foot shoulder height. And when you've got the embryonic cell division faulty, you could get siamese hydra-twins. Sharing a body, but having multiple heads/necks. It is very possible that the Hydra species has a genetic predisposition for such siamese birth defects, with the conjoined-body - separate-head one most prevalent. Of course, a nine-headed hydra would then be a real miracle where you will probably need to make use of your enhanced Hydra-regeneration to make such a disposition survivable (I don't want to think about the additional strain on the heart to pump blood not up one long neck only, but 9 necks including 9 very resource-hungry brains). And, as a side-effect, you'd have all kinds of Hydra head-counts, from one or two heads (most of the Hydra population) all the way up to 9 (or more, if you are feeling inventive and generous with the regeneration boost). And one-head-eight-legs hydras. And Hydras with multiple tails or eyes or multiple anything. So the question remains why such a siamese-twin-prone species didn't get erased by evolution before they even started to become a species? Well, regeneration might be the key factor here. If it is coupled with the siamese-twin-propensity, that would be a deciding factor -- regeneration enhances its biological fitness so much that it offsets the siamese twin defect that comes with the regeneration boost. Since the super-regeneration must have something to do with enhanced cell division, it might already kick in in an embryo and cause all kinds of trouble there -- most notably preventing a full twin from forming (splitting of the embryo) and instead growing back together even before the split was complete. Ergo: siamese twin hydra. [Answer] Automimicry is when a body part looks like another, usually more vital, body part to fool predators. For example, there is a lizard in central Africa which has a tail which looks like a head. Many gastropods have retractable antennae which can be hoisted back into the body or extended outwards. Place these ideas into your magic box of Evolution Does Not Really Work Like That and bake for a few million years so that it grows to 6 feet on land and develops many automimic eye stalks. It can't regenerate heads, but it can extend spare headlike appendages at will, at least until it runs out. [Answer] Multiple heads are a major issue for every animal. Furthermore, reptiles rarely have long necks, and the few that do never have impressive heads However, long tails are a very common reptilian trait, and a multiplicity of tails also happens to be a much more common trait. Hence, it seems reasonable that our hydra could simply be a large lizard with one head, but nine tails These tails could quite easily be made to resemble large serpents, as a form of mimicry, and it wouldn't be implausible for such tails to have horns or spines for defending itself. If you really want to lean into this, you could give the tails one or two big serrated blades on their underside to mimic a serpent's jaws Regeneration is a much harder trait to come up with. While lizards can regrow their tails, it isn't fast enough for a single fight. However, we're already using mimicry, and a fight with a nine-headed beast can be confusing: Someone caught in the fray might not notice whether that one attack was a living tail striking or the wriggling remains of a decapitated skull being kicked in their direction. Assuming that most don't chop through that many heads and that the hydra eventually regrows lost heads, it could easily be mistaken for regenerative power. [Answer] There actually is a whole phylum of [Platyhelminthes](https://en.wikipedia.org/wiki/Flatworm), species of which (mainly from families Dugesiidae and Planariidae) can have a lot of independent, fully functional heads. For example take an Dugesia polychroa - you can cut their head axially in half into like Y shape of the animal. Then both of the head-halves will regenerate into fully functional heads. Yes, you can repeat and repeat for as many heads as you wish. This works also with the whole animal, so you can cut it into multiple parts and all of them (if not too small) can fully regenerate. Scaling this up to the humanoid form is actually a minor issue. Im creating a map of of their populations on my web <http://brmlab.s0c4.net/bioosm/>, if you click on the Platyhelminthes button, you will see... :) [Answer] My guess would be that the biggest head would be the only true head. The only one with sensory organs. All the others would be arms with mouth-like ends and look alike spots. The regeneration ability would not be fast enough to be good in a single fight. It would be very energy consuming and slow working. While it would be pretty much useless in such a big creature the time it would take to regenerate a single head would take months to years because of the size. It would not have the need for regeneration because of being a seposably apex predator where it shouldn't be necessary at such a scale. It might have went through gigantism and hadnt evolved it out yet. ]
[Question] [ Not too far off in the future, maybe 20-50 years from now, an anomaly is detected a little ways outside our solar system and it's like nothing we've ever seen before. Researchers begin studying it immediately and soon it becomes clear that whatever it is will destroy our planet in less then 500 years. Independent teams around the globe who also have been studying the anomaly begin to confirm the initial reports and it seems that earth may be in serious trouble. However amidst the panic a team of scientists announce that they may have a way to save earth from it's impending doom. But there's only one problem, they would need a spaceship capable of bringing a team to the anomaly for the plan to work. With current spaceflight technologies it seems impossible, we can't even get to mars yet without frying astronauts! Plus current thruster technologies would mean a generation ship would be needed to make it to the anomaly. The only way this could even works is if every country on earth poured every spare dollar into spaceflight research, and even then you'd need to cut funding from every program you could to ensure you were putting as much as you could into research. But if earth is just going to be destroyed anyway there's not much point in spending money anywhere else is there? If we all just worked together on this project for even the slightest chance of saving the planet, would we all give it a shot and work together on one massive generation ship? Here's a proposal; Form a Global Space Agency, instead of each independent group working on their own separate design everyone works together and shares tech and research. Groups would be formed to work on individual components that would be needed, like propulsion, design, radiation shielding etc. Also any useful tech must be divulged to the GSA. Stop fighting, everyone calling a truce means military funding could be diverted to spaceflight research. No hostile actions can be made towards any other member contributing to the Global Space Agency. Basically just try to get along. Would everyone do it? Would it just take some time to convince everyone? Or would anyone even care with it being so far off in the future, just figuring that the next generation can deal with it when it's a more urgent problem? Extra information: The entire world all recognizes the anomaly as a real threat, everyone knows that it will destroy earth within time frame researchers have estimated. No one thinks it's just some ruse to try and convince them to reveal top secret technologies or anything like that. They have current a current technology level of what could be reasonably expected in 20-50 years, but spaceflight advancement has been somewhat slower than you might expect. The first manned missions to mars have been continuously delayed as there hasn't been sufficient advancement in radiation shielding or propulsion tech to get a crew to mars without cooking them. Quick Edit If people wouldn't be worried about what's going to happen down the road enough to do anything about it is there something that would make them concerned enough to pay attention? If the anomaly posed a more urgent threat, would that make a difference? For example if every 30-50 years it released a powerful enough EMP to affect earth and cause widespread damage would that get more people's attention? [Answer] Even a lot of your basic assumptions are flawed. This issue will be tremendously complicated, although the planet might well be saved. Let's dive in: The entire world all recognizes the anomaly as a real threat Laughing. Out. Loud. As if. Have you heard about global warming? Is it universally accepted? Even in the scientific community? Well, then. What will actually happen is that your announcement is going to be challenged by many different factions. Some politician's and company's agendas are going to be disrupted by this discovery, and they will seek to discredit the scientists in questions. Many different groups will demand that the finding be validated. Disbelievers, skeptics, and religious fanatics will all put their own spin on your announcement and use this event to try and push their own agendas. Politicians, both at the national and international level will debate the situation, with varying results. The problem 500 years is a long time. Most politicians and governments hardly even look past the next election term, let alone so far down the line that some of the nations discussing the issue today are not even going to exist any more. Humans are pros at procrastination and passing the buck. Tie in all the varying political and religious implications of this announcement, and you've got a real issue on your hands. Most politicians won't want to touch this issue even with a ten foot pole. Oh, they will debate it at length, but they won't want to commit to any *real* actions. Why? > > Well, let's balance the budget first. That will only take 20 years or so, and what's that compared to 500 years? > > > Also look at how much human technology has advanced since the 1500's. And our pace is only increasing. A lot of people (politicians) will argue that we need not worry about this for at least another few decades (maybe even centuries). After all, our tech is only going to get better, and we'll figure it out eventually! Technology Now in this department you're actually downplaying our achievements a little bit. We actually *do* have the technology to get to Mars even today, however we lack the funding. Additionally, we don't quite understand all the implications of such a long space flight on the human body. The astronauts wouldn't be "cooked", although they might certainly be the worse for wear. Political Implications Even if an alliance to act against this threat is set up, there's still going to be a lot of political in-fighting, corruption, and manipulation hampering the project. For example, if I were the USA, and I was supporting the project with a large amount of money I might be suspicious of China, or Russia, whom are providing a smaller sum and seemingly building up their militaries while I sacrifice my defense budget for the sake of mankind. What you have to remember that it's often difficult to get a group of people to agree on what their own best interests are *right now, let alone a group of governments which are competing for wealth and influence. Are we doomed?* The good news is that we most likely are not doomed to die out as a species. Some initiative will indeed be created, and the scientific community of the world will most likely start to pull together in order to start finding a solution. NASA might finally be given the go-ahead (and funding) to start implementing some of their space faring ideas, but other companies such as Virgin Galactic are already well positioned to act in this regard, and will jump at the opportunity to get involved. Last but not least, as I've mentioned, out technology is improving by leaps and bounds. This will no doubt help us catch up the time lost bickering over all the BS that us humans always do. The two biggest threats you face are: 1. Global instability such as another world war, or large scale terrorist attacks against your project. It would be a good idea to build multiple ships, and to decentralize the process such that it's not easily destroyed by attacking a single location. 2. The fall and rise of governments over time. If the European Space Agency is heavily involved, but then the EU splits up that will heavily impact your project. [Answer] We have no hope.... --- To illustrate my point, I'm going to change your post a bit... > > Not too far off in the past, maybe 20-50 years ago, an anomaly was detected in our atmosphere and it was like nothing we'd ever seen before. Researchers began studying it immediately and soon it became clear that it will destroy our planet in less then 500 years. > > > Who cares, without a majority of scientists agreement, it's probably just a bad study. No one can model what's happening in our atmosphere, it's just too big. > > Independent teams around the globe who also have been studying the anomaly begin to confirm the initial reports and it seems that earth may be in serious trouble. > > > So there is a conspiracy going on, attempting to prove this "Threat" is real, and that we should start paying these science types more mind. > > However amidst the panic a team of scientists announce that they may have a way to save earth from it's impending doom. But there's only one problem, they would need a radical change in technology and prioritization. With current technologies it seems impossible, we can't reverse our technological progress without destroying big industries! > > > People have an interest in keeping their interests at the forefront of society's priorities, and these people aren't going to be alive in 500 years, so what do they care? > > The only way this could even works is if every country on earth poured every spare dollar into atmospheric and environmental research, and even then you'd need to cut funding from every program you could to ensure you were putting as much as you could into research. > > > You're going up against a wall here, people have an interest in keeping their funding un-cut. > > But if earth is just going to be destroyed anyway there's not much point in spending money anywhere else is there? If we all just worked together on this project for even the slightest chance of saving the planet, would we all give it a shot and work together? > > > If I'm not alive in 500 years, why do I care? --- Reread your story, and it sounds a lot like the climate debate, which is obstructed by approximately 1/2 of the United States. With such a "far off" and possibly "based in science fiction" problem, you're not gonna get any action. [Answer] Can't think of anything that might work. The threat, if confirmed somehow, by science, will give fuel to religious zealots calling for the end of the world, and all fanatics will rally to gain more followers for "their side". And in 500 years, I'm reasonably sure "prophecies" will arise, to give a mystical meaning to the unavoidable scientifically proven fact. If coming together for a common goal won't work, and there are oh so many others; there is nothing to be done here for the human race. I don't think anybody will want to work together, instead politicians will probably rush to have their nation be the "saviour" of the planet, bringing each and every country closer to insolvency, and each nation arising after the dust settles and bodies stop twitching, will be just a little more savage than the previous one(s), eventually even if a solution would be found with at least one nation picking up the work from where a previous civilization left off, we would have regressed too far, to know how to make use of it. [Answer] Absolute and undeniable proof of Mutually Assured Destruction. It's the only thing that's ever worked, and it's all you'll ever need. ]
[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. As mentioned in this discussion: [How to keep humans pilots instead of AI in sci-fi future?](https://worldbuilding.stackexchange.com/questions/17043/how-to-keep-humans-pilots-instead-of-ai-in-sci-fi-future?noredirect=1#comment41035_17043) the ability to handle G forces is a limiting factor on what pilots can do. Some of my solutions to address this will likely be to limit the delta V via various approaches, but I'm also looking into what I can do to make high G forces tolerable for humans. The problem is that real inertial dampeners are rather high-tech. If you can install some inertia dampening field you have discovered a way to mess with a raw force of nature, and there have to be all kinds of other interesting technology that comes from such a discovery. I want a somewhat near-future work, advanced enough for space travel but not to the level of all tech being [applied phlebotinum](http://tvtropes.org/pmwiki/pmwiki.php/Main/AppliedPhlebotinum). Thus I don't want inertial dampeners that are some magic hand-wave field that 'just works'. What are viable approaches that could be used to help pilots handle high G forces without full scale inertial dampeners? In a somewhat advanced future, but before we reach the point of energy fields and nano-robots what approaches may be viable that aren't, yet, viable for fighter pilots of the present? I'm most interested in space-fighters, though I don't know if the fact that their in space really effects the issue of G force and inertia. [Answer] [This book](https://books.google.com/books?id=f3HfRj0dYFcC&pg=PA246&lpg=PA246&dq=g-suit+recumbent+position&source=bl&ots=6NjgvVCanW&sig=HSbWXZqlxJwhd-Thg7IiUXwvTL8&hl=en&sa=X&ei=jC1SVcWzCMeSyASutYDADw&ved=0CCwQ6AEwAw#v=onepage&q=g-suit%20recumbent%20position&f=false) has pretty much every idea devised to survive high g environments An unprotected civilian in a sitting position can remain conscious up to 3-5 g's depending upon their fitness level. Some ideas for increasing this: 1. Put your pilots in a [g-suit](http://en.wikipedia.org/wiki/G-suit) or its analog. These squeeze the extremities to keep blood flowing to the internal organs and brains of the pilot. Using these pilots can tolerate 5-6 g's for seconds to minutes (the g-suit typically adds around 1 g to a persons tolerance). 2. Put your pilots in the [recumbant/prone position](http://en.wikipedia.org/wiki/G-suit#Use_in_prone_pilot_position_aircraft). The human body tolerates g's better in some orientations than others. Combined with a g-suit, most trained pilots can remain conscious through 9 g maneuvers for short periods of time (typically less than 1 minute). In centrifuge tests, some subjects remained conscious at 15 g's for about a minute. This is the duration of the maneuver I don't know the physiological limitations of it. 3. Train your pilots in how to tolerate high g's with the [g-straining maneuver](http://en.wikipedia.org/wiki/High-G_training). > > Pilots still need to practice the 'g-straining maneuver' that consists > of tensing the abdominal muscles in order to tighten blood vessels so > as to reduce blood pooling in the lower body. High g is not > comfortable, even with a g-suit. > > > 4. Put your pilots in a [g-bath / g-tank](http://www.thenakedscientists.com/forum/index.php?topic=17941.0). A g-bath is a tank filled with fluid that possesses the same density as human protoplasm. The theory is that by supporting the body, the blood won't tend to pool and the pilot could remain conscious and alive at much higher g's. The US Navy has conducted experiments up to 16 g's with these and the pilots tolerated that quite well. The researchers felt they could go considerably higher than that but no one has conducted those tests. The test below shows that someone survived g-forces up to 45 g's in experiments and 180 g's in crashes but both of these were instantaneous loads. So I'm not sure what the theoretical maximum g-load is. [Human g-tolerances](http://en.wikipedia.org/wiki/G-force#Human_tolerance_of_g-force) ![Human g-tolerances](https://i.stack.imgur.com/5p795.jpg) G-Tolerances: * 1.5 g's, most people tolerate indefinitely * 2 g's, most people tolerate for hours to days * 3 g's, most people can tolerate for minutes * 5 g's, most people can't tolerate more than this when sitting * 6 g's, untrained humans in sitting position remain conscious for up to minutes * 9 g's, limits of trained pilot, in a g-suit, in semi-reclined position for around a minute * 10 g's, untrained humans remain conscious in prone position for up to 1 minute * 15 g's, highest any trained pilot, in a g-suit, and semi-reclined position has tolerated for seconds * 15 g's, average tolerated by trained pilot in a g-tank (results indicated considerably high g's could be tolerated but those tests haven't been done yet) four several seconds * 22 g's, untrained humans remain conscious in prone position for up to 10 second. * 46 g's, (instantaneous) maximum recorded experimental negative g-load survived by a human (caused permanent vision problems) * 180 g's, (instantaneous) maximum calculated g-load survived by a human in a crash. High g's are terribly uncomfortable and dangerous for people not medically cleared John Stapp rocket sled ![John Stapp rocket sled](https://i.stack.imgur.com/zCn7K.jpg) > > John Stapp was subjected to 15 g for 0.6 seconds and a peak of 22 g > during a 19 March 1954 rocket sled test. He would eventually survive a > peak of more than 46 g, with more than 25 g for 1.1 seconds. > > > [Answer] Keep your pilots on the carrier doing their flying via remote control technology. The pilots still need to be in space near the fighters because of the limits to the speed of light. Their virtual cockpit could still be just like the real thing except for blacking out, and getting hurt and killed. I.e., just the same thing the US is currently doing as it is coming to rely on remote control drones. This is certain to be only a first step toward unmanned fighters, regardless of how much the ex-pilots in the force resist the change. Pilots in vehicles only make it more expensive to operate and much more expensive in terms of replacing lost pilots. --- It occurred to me that maybe the remote pilots don't even have to know that they are remote pilots -- perhaps due to built-in VR of their fully enclosed flight suit after all, they don't actually need a transparent face shield. Let's assume that pilots perform better when their life is on the line -- actually a reasonable assumption if it reduces unacceptably risky behaviors that destroy too many unmanned fighters due to lazy piloting. And now the pilots also believe they have inertial dampening fields too. Perhaps this is now a fully legitimate answer. Recovery from "kills" could be explained as a last resort high tech force field, perhaps a [Slaver stasis field](http://en.wikipedia.org/wiki/Known_Space#Stasis_Fields). If you need to get rid of pilots ... no problem, the field did not work for them. Or it could also be that dying in the simulator naturally results in death in a certain percentage of cases. You have a reverse Ender's Game setup, one politically dirty, one politically clean. Of course those in charge would know the truth. News organizations could be fed misinformation, etc. so only the insiders would know the deception. Of course, some might object that remote control is subject to hacking, jamming, and speed of light delays -- all true, but the remote advantages may still be larger overall. Still not real inertial dampening though; of course Barbie says, "Gravitics class is hard." I should also point out at that having pilots in the carrier is not the same as having them in their fighters thanks to the speed of light. If you assume max acceleration of 100 g and a battle lasting 5 minutes the fighter could reach a distance of 0.147 light seconds from the carrier by accelerating in a straight line. How you can achieve such a high rate and duration of acceleration in a fighter is a very hard problem physics problem itself too. A lot of science fiction relays on hand-wavium, esp. where the hand waving is non-obvious. We all know that 100 g's will kill you and FTL is fanciful or beyond our physics, but most SF consumers are not bothered by a fighter having advanced acceleration and duration characteristics or forgetting about the time lag associated with relatively short distances. [Answer] Leave the cockpit not fixed to the space craft, so that it can move relative to it. It could be suspended on "elastic strings" inside a huge cavity inside the vessel or similar. By delaying acceleration, you could have the pilots survive short, strong bursts in the same direction, maybe to conduct an evasive maneuver. However, it would not help you with long sustained acceleration, because at some time the cockpit will hit the rear wall and then won't be able to delay the high g force any longer. You would need to make sure to damp the system as to prevent oscillations. [Answer] One possibility is to enhance your humans. Titanium (or carbon nanotubed?) re-enforced bones to handle the stress. Assisting pumps around the heart and major arteries, along with drugs, to increase blood flow and keep pilots from blacking out. Something similar to [power exoskeleton](http://en.wikipedia.org/wiki/Powered_exoskeleton) to let them move their head and hands under extreme forces. I wouldn't want to bet on what the above would do to your body - I'm sure the long-term medical prognosis would be bleak. It would be like profession football players, where the stress and impacts add up and make you old before your time. But if that's what you need to do to compete... [Answer] As you say, just give them low-tech inertial dampeners. If you're using inertial dampeners to mean the same as I am, then we already have the technology to do this and it's used in many places. Take, for example, a military helicopter, which needs to be a rock-solid gun platform for snipers at times. No human pilot can possibly correct for wind and other outside influences fast enough that there is no noticeable movement in the helicopter, so they get a computer to do it. This computer uses sensors such as the already-installed airspeed and altitude sensors (if they're accurate enough) to detect wind force against the aircraft, and up or down movement, to control output into the engines and the rotors to move the helicopter to counter the movement. Essentially: Hovering → ASG (airspeed gauge) shows forward velocity → is there correlating control input from the pilot? → no - inference: wind on the front of the aircraft → pitch rotor forward to counter. This sort of processing is incredibly simple for a computer to do, and I can write pseudo-code that describes it in few lines and not much time. There are some differences in space, namely the lack of air resistance to measure speed by. Instead, your computer needs to know the force that the engines have put out and for how long in what direction. From that it can work out how fast the craft is going now, and apply some force to prevent the acceleration going over a preset maximum. [Answer] Cyborgzation, replace the body with artificial parts, brain augmented with microbots that, beyond the more obvious advantages, makes the brain more resilient to g forces. To me, this is probably what is going to happens in the future if we need to deal with such g-force, because it's (seems) easier. Make their bodies magnetic so they travel fairly together with the ship. By drinking/injecting some iron-like fluid, preferably organic and non-toxic, you could make their cells easier to magnetize. The magnetic field counters partially or fully the force going to one direction, a suit might be a good idea. The problem with this idea is that at a cellular level what is not magnetic could be ripped off the cell. An alternative would be genetic manipulation, stronger heart and arteries, harder brain and organs, etc. With things like CRISPR today I don't see this alternative that "magical". [Answer] Depending on the propulsion method, you may not need to. A gravametric engine (maybe not as high-tech as it sounds), wouldn't produce any 'felt' G-forces on the pilot, since every atom accelerates equally, there is no strain. It may be possible at higher tech levels, to do something similar with a non-gravimetric field instead, creating a 'inertial dampener' of sorts. Remember that they don't need to be as effective as the Star Trek ones. If you can make a body magnetic or affected simultaneously by a force, then you can apply that force to counter any acceleration. Limitations include how quickly they can react to g forces and deal with them, they may react better to more predictable accelerations for example. Other solutions to your problem however include: 1> Making a sufficiently intelligent computer to compete with an experienced pilot(with computer assist), makes the computer very delicate/large/expensive, giving them another reason not to be used even if they can take the G-forces a human can't. 2> Thrust to weight ratios in space aren't high enough for G-forces to matter given fuel limitations. If you are been totally realistic, then almost all battles will be fought at distances of 0.5-1 light second with large laser cannons, not close quick manoeuvring dog-fights. 3> Remote control? 4> How hard is it to disable a remote computer? Perhaps its too hard to shield them from enemy emp blasts? [Answer] Firing mass weapons would also be an issue. The recoil has drawbacks. I have thought of a way to avoid this, I think, by using a centrifuge method to accelerate the mass. Letting it fly at the target does not cause a recoil as such but does impart a twist or spin into the parent craft. Firing a second mass of equal size in the same direction (same target) but spinning in the opposite direction should remove that effect. Downside, I suspect there will be a good deal torque between the two sides of the weapon, shortening its overall life. Won't help a life form much in turns etc. but it should help out with overall fighter performance. ]
[Question] [ I recently asked about racing in space ([The new Space Race - Racing!](https://worldbuilding.stackexchange.com/questions/10214/the-new-space-race-racing)) and as expected while there were a few options they were mostly pretty limited. However 2012rcampion did suggest that sports in space might be an interesting subject, and I agree. So what sort of sports might people play in space? The tech level is similar to in my racing question, so current technology plus maybe 20 or 30 years more advanced and considerable experience living and working in space. The sport in question must be similar to our own sports in that: * People can play it with friends * The costs for people to play "for fun" should be low (think children buying a football and placing a few coats down to mark out goals). * It can be played as a spectator sport with both a live and televised audience * It's a team game * It's physical but with only moderate risk of real injury * I expect the game would be played in free fall but am open to alternatives (although there is no artificial gravity so any illusion of it would need to be achieved through spin or acceleration). Would it need to be played in a constrained space or would it actually be reasonably possible to place large enough areas in space for a more large-scale game to be played? At the very least children should be able to play it in the corridors of a space station or in a converted canteen or similar as large open leisure areas would be rare and expensive. Note that we already discussed zero-g basketball here: [How would basketball change to accommodate zero-g](https://worldbuilding.stackexchange.com/questions/960/how-would-basketball-change-to-accommodate-zero-g) this already covered basket-ball style games and touched on football, so I'm not looking to duplicate what is already covered there. [Answer] Tag, laser tag and paintball would all be great games to play in a maze type arena. Arms holding pieces of 'fence' could be sticking out into an open area from different angles at different angles. if everything is padded to help reduce shock of contact it could be some what safe. I could see a similar type of arena/maze used for all three suggestions. Paintball would be very interesting since you don't have gravity pulling your paintballs to the ground making it more accurate! On a less physical plan, 3-d pool could be a very interesting game almost to the level of chess. The 'table' could be a liquid filled sphere to add a bit of friction to the game, the sphere would have holes like a whiffle-ball. The holes could have colored rings to indicate which hole an opponents ball is allowed to leave by etc. [Answer] I think the obvious answer for space is free-form ball games. Anything from 3D-hackeysack in a hallway with friends, to Racquetball, Volleyball, or Soccer (non-American Football) with some basic rule changes to allow for a free-fall environment. I was going to say hockey doesn't make sense (which makes me sad, because I'm a hockey guy) but then I thought of playing it in a rotating cylinder. You'd get some truly crazy passing options (shoot the puck straight up to the other side), and you'd have to take Coriolis effects into account, which would make things fun. Probably every team would have at least 2-3 goals too, distributed around their side. [Answer] Quidditch Yeah, that [fictional sport](http://en.wikipedia.org/wiki/Quidditch) written by J. K. Rowling in the Harry Potter franchise. There's a [non-magical variety played by college students](http://en.wikipedia.org/wiki/Muggle_quidditch). I see a natural progression from running around on brooms to flying around on brooms. I don't exactly see this as safe... can you say that any sports in space are safe? Though it is a team game, and it can be televised (there have been Muggle Quidditch games televised already). This would definitely be played in free-fall, or in an open area (space does have lots of that, fortunately). As it's a ball-sport, there's an issue of balls being lost to the depths of space. I think this can be overcome with some clever rocketry put into the balls. [Answer] # Rugby / American Football The essential problem with having very large open areas is that once a player launches themselves out into space, there is only so much they can do to change their trajectory; if they have the ball, they can throw it, but otherwise they can't do much. That isn't necessarily a problem, and in fact could contribute to the style of the sport. For example, one could play a game similar to Rugby or American Football, except counting a 'down' or 'tackle' as soon as a defending player tags the player carrying the ball. Play would consist of players launching themselves on trajectories to intercept other players; if the player with the ball was going to be tackled, they would attempt to pass it to another player. The defending team would also attempt to predict the trajectory of and intercept the receiving player after they catch it. --- # Polo One way to overcome the fixed-trajectory problem is to give the players some sort of vehicle, such as a jetpack, or have them ride on some type of vehicle, but this has safety issues due to the potential of high-speed midair collisions. However, this could be dealt with in the same way as modern-day Polo. Polo is a game played by teams of players on horseback, with a set of rules dictating how players are allowed to move to ensure that riders and their horses do not collide in a way that would be dangerous. Players use long mallets to strike a ball that rolls along the ground. In space, these might be replaced with some sort of racket, to make it easier to hit. --- # Ball Passing Games ### (Basketball, Hockey, Lacrosse, Football, Handball, Water Polo, etc.) Another way to solve the mobility problem would be to use some type of rope lattice to fill the arena. The rope would be thick enough and elastic enough that colliding with it would not be very likely to cause injury. With a lattice pitch of around 1.5-2 meters, it would be easy enough to reach out with one's hands or feet and hook a rope in order to change trajectory or come to a stop, and one could launch off the ropes easily enough. If necessary, padded columns could be added to give more support to the lattice, so that it wouldn't be able to stretch too far. This could accommodate a large number of different games, using different implements to launch different sorts of projectiles, with different rules about moving and scoring. [Answer] With space I assume free fall is intended. The relevant sports are ones where the expanded freedom of movement would be directly relevant. Some examples below. Team obstacle race A suitable number of people (two to six) in a team navigating an obstacle course in zero-G with time counted from the last person to reach the goal. Lots of variations. Different types of track. Opposed races with two teams on track at the same time. Teams could be picked randomly just before the race. Benefits would be that this teaches 3D movement in zero gravity and teamwork. Practising this would make your children less likely to die when something goes wrong. So I think the parental sell would be good. Also the tracks would probably be relatively cheap to construct and modify. And the variability is good enough to make it viable entertainment. Especially if everybody as had some compulsory training in efficient zero-G movement and has some personal experience. Paintball Essentially the same as above, but instead of trying to reach the goal as fast as possible, the team tries to hit all members of the opposing team before they can do the same to you. Benefits are generally the same as above with less weight on free fall mobility and more on thinking 3D. Might make sense, if there is a plausible way for hostile boarding actions to happen. Free fall dancing and martial arts Probably self-explanatory? [Answer] How about something basically new: Take a large room (think the Ender's Game combat room without the stars and considerably bigger.) The chamber walls are covered in the rough side of velcro, players start the game with a supply of weights with fuzzy velcro coverings and padding beneath. The objective is to get the ball (large, light, soft--you can't throw it all that far) into the opponent's goal. You can move along the wall (fuzzy velcro gloves) but pushing off from it is forbidden--the only ways to move around the chamber are throwing things or pushing off people. If you run out of weights you are effectively immobile until you pick up enough from where they stuck to the walls. It is not permitted to hold the ball for more than a set period of time. (The ball has a sensor that will note how long it has been held and change the color of a light as the clock runs down.) [Answer] When you said games in 3D space the first thing I thought of is the book/movie Ender's Game. In the movie (haven't read the book so I will only be referring to the movie) they play a kind of training game where they float around in a zero gravity room, hiding behind big metal pyramids, shooting at each other with zapper-guns that cause opponent's suits to constrict on contact. Your game could be played in a similar way. Paintball and airsoft would be rather dangerous and very messy in zero gravity because nothing pulls the ammo to the ground which leaves big globs of paint floating around or dangerous ricochet with airsoft (which could be fun and could add a whole other level to your game) Just a few ideas. Hope you like them! [Answer] [Ultimate Frisbee](http://www.whatisultimate.com/) would definitely work well in zero gravity! [Answer] [Keijo](https://en.wikipedia.org/wiki/Keijo_(manga)), a fictional sport from a mangá: > > (...) players stand on floating platforms and aim to incapacitate or push their opponent into the water, using only their breasts and buttocks. (...) Keijo matches are held atop floating platforms, referred to as a "Land", in large water-filled stadiums where swimsuit-clad players fight to incapacitate their opponents or push them out to the water, but they can only hit each other using their breasts or buttocks. > > > Replace water with the space habitat walls and you've got hours of fun for the whole space-dwelling, 21st century family. ]
[Question] [ I have a civilization that lives not exactly underwater, but completely surrounded by water in which their cities are both submerged underwater or built floating right on top of it. Almost all of their resources are limited to the ocean. What materials would be used for them to make clothes out of? I have ideas such as shark/whale/seal leathers. Would seaweed be possible? Or what other oceanic resources would they use. Or even for building resources and shoemaking, etc. [Answer] Fish leather is a remarkably soft clothing material and is a very low technology option. You can find simple recipes on YouTube that require little more than a trout skin, some vegetable oil and eggs. If your people are surrounded by water and have access to plant based oils and eggs (seabirds perhaps) than a soft textile is well within reach. For hardier clothing marine mammal skins would be better and are made with Stone Age technology as evidenced by the Inuit who live on ice sheets. [Answer] Shells! [![shells](https://i.stack.imgur.com/ySpoZ.png)](https://i.stack.imgur.com/ySpoZ.png) Shell bikinis are great but they have been so done. Shell codpieces really not much! Nix here looks good in his and your characters will look great sporting their fancy man-shells. You can do lots of other things with shells - string them on strings to make stuff, glue them on - shells! [Answer] [Byssus](https://en.wikipedia.org/wiki/Byssus). Difficult to put together enough for clothes, but people could gather some byssus every time they harvest mussels for food. The clothes would be expensive, but it is doable. Fibre from sea weed? I don't know, In water there is not evolutionary pressure to grow fibres strong enough to sustain their weight, but on the other hand algae growing close to the shore must be able to resist the rough shaking coming from the waves, so there could be sea weed with strong enough fibres there. But I suspect they would be used only for the cheaper clothes. Actually I just realised that probably you can get fibres strong enough to make clothes from the root of sea weeds. To keep them anchored to the sea bottom they have to be strong. [Answer] Seal intestines can be cleaned and slit lengthways, then the strips sewn together with sinew to make waterproof outer garments. Seal gut parkas have long been made by Arctic peoples. [Answer] Apparently whale baleen can be used to make baskets <https://en.wikipedia.org/wiki/Baleen_basketry> So maybe some sort of weaved pieces like rattan armor made from whale bristles [![rattan armor](https://i.stack.imgur.com/tIK9K.jpg)](https://i.stack.imgur.com/tIK9K.jpg) [Answer] Perch skin used to be treated and used in Sweden as a cheap alternatives to other skin types, when smaller amounts of skin were needed. Perch skin is pretty tough and since perch are plentiful, it would be possible to use it for clothes, although using hides from larger animals is a lot easier. But were there no larger animals available, one would have to do with what is at hand. Searching on Google for perch skin, I found this article from a Swedish university, where skin from salmon, cod, perch and lumpfish were prepared and tested in regards to strength. The writer claims that the skin types are strong and long lasting enough to be used for furniture in public settings. This requires high strength leather, so clothes should not be a problem: <http://www.diva-portal.org/smash/get/diva2:331808/FULLTEXT01.pdf> ]
[Question] [ I need FTL interstellar communication in my story. Ursula K. Le Guin first used the idea of the "ansible" as a fictional device or technology capable of near-instantaneous or superluminal communication. It can send and receive messages to and from a corresponding device over any distance or obstacle whatsoever with no delay, even between star systems. I would like to have some sort of "plausible" explanation for this that doesn't need to be hard science. Orson Scott Card had his own version that was build on a subatomic particle and rays. I want it to seem as little like magic as possible. In my universe, ships travel via hyperspace - so I wondered if I could use that. Here is my working solution: 1. Planet sends out message in some sort of "packet" that moves at the speed of light, or close to. So either via an electromagnetic wave, or even a temporary physical packet holding the message (not sure if that is needed). 2. This packet enters hyperspace, heads to the proper galaxy and emerges, just like ship. 3. The packet "opens" and broadcasts the message back as a wavelength as normal, where it can be received. What I like about this is that the message travels like a ship, and has the same restrictions so it's not quite instant. But it is fast enough to have some sort of communication across distances. Question: Is this "possible?" What would the package look like? If anyone has any builds, I'm open to ideas too. Edit: Thinking of calling it simply the "hypercom." Edit: I don't want to use Quantum Entanglement. From my previous question on transmitting data via waves: "While this is a common idea in scifi, as I understand it the real world version cannot, even in theory, transmit information by any means regardless of hypothetical technological advancement. It can only synchronize randomness, allowing secure uninterceptible establishment of an encryption key to be used on information sent via other channels." - Douglas. [Answer] So, you have hyperspace. First you need to decide how that works in your universe. The most common fictional version of hyperspace is a space much like our space, except that distances are shorter. So, you pop over to hyperspace and move a short distance. When you return to our space, you find yourself a long distance away from where you started. The ratio between the two depends on how fast you, the author, want space travel to be. It must be possible for humans to survive for a short while in hyperspace. This means that physics must work pretty much the same there. In particular, electromagnetism exists and radio signals work. So you basically stick an normal radio antenna into hyperspace and send normal radio signals. Easy work. Note that this allows for both directional antennas for messages and broadcast antennas for hyperadio stations. You also have to decide how non-hyperspace space flight works. The technology we have today is painfully slow. Even going next door to Mars is a major undertaking. You probably want to speed that up. Let us say that a space ship can move in normal space at 0.001 c. This means that radio signals are one thousand times faster than space ships. This is a gross simplification, since space ships don't move at a maximum speed, but rather have a maximum acceleration. But this is all just for getting numbers to play with. Since physics are similar in hyperspace, radio signals are one thousand times faster than space ships there too. If space ship travel takes a day, a radio signal will take about a minute. Not instantaneous, but pretty fast. It is possible to speed this up, if you want. There can be several different hyperspaces. Space ships only use the slowest hyperspace, for one reason or another. I suggest that the fast hyperspace is hard to navigate, it is very difficult to arrive anywhere close to where you want to go. Radio signals have no such trouble. They arrive everywhere. It is very difficult to make any FTL theory actually work as a consistent physical theory. The most major problem is avoiding time travel. Relativity as we know it state that FTL travel implies time travel. This may be wrong, but it is pretty hard to make an alternative that both matches the world as we see it around us, allows FTL and disallows time travel. A less important problem is conservation of energy and momentum. This is more likely to be false without impacting the story you want to tell. My suggestion is simply ignoring these problems. Time travel is impossible, but the characters don't care about why. In fact, neither the characters nor the narrative should mention time travel at all, to avoid the reader starting to think about it. And it might be possible to get energy from hyperspace. This might be your main energy source, OR it might be too expensive to actually use much. Solar panels are pretty cheap. Or it might be impossible, for reasons no characters care about. Who spends time thinking about the impossible? Good luck with your story! [Answer] You have hyperspace. That will make it work. The prefix "hyper" to me refers to spatial dimension beyond our common 3. <https://en.wikipedia.org/wiki/Hypercube> If I have access to an additional spatial dimension I can use that to take a shortcut not possible in my ordinary dimensions. For example in 1 dimension a point must travel along a line to get from one end to the other. If I can bend the line in 2 dimensions I form a circle or spiral and I can put the end of the line right behind my point - a shortcut. If I am a flatlander moving along a 2d piece of paper, I can fold the paper over such that my destination is right above me in 3 dimensions. A shortcut thru that 3d dimension puts me at the destination without traversing all the 2d paper in between. So too with the 4th dimension. I cut thru and arrive at my 3d space destination without having to traverse all the 3d space in between. The transmission can be whatever medium can traverse that 4th dimension and come out in 3d space where you want. It could be radio waves which would be nice if you want your transmission to come out into empty space as the Millennium Falcon hopes to do. If you are utilizing wormhole Stargate type things then you open the Stargate and transmit thru with your broadcaster, just as you would broadcast to your people at some distance in your own 3d space. [Answer] Yes. You have decided your universe can use hyperspace. Hyperspace is fictional in the first place. That means you have freedom to pick the rules. Just pick the rules so that signals can travel fast enough to be essentially instantaneous. But is it "Possible"? It will seem more "possible" if you decide consistent rules for how hyperspace works and stick to them. Here is one example of a rule: The speed a package can move through hyperspace is proportional to the inverse of the mass-energy. Since a signal has much less mass-energy than a spaceship it can travel much faser. What would it look like? Spaceships have big machines called Hyperspace Rams that open and close the door to hyperspace. Since your signal is just some electromagnetic waves it cannot carry the ram with it. So I imagine two permanently open ram stations that permanently keep a small door open between System A and System B and you just shoot your signals through. [Answer] ## Starting with the Oldest Debunked to Still Undetermined Tachyons: Although the [field](https://en.wikipedia.org/wiki/Tachyon) itself might spread faster than light, disturbances in the field move at light speed. Neutrinos: So far all hopes for [faster-than-light neutrinos](https://en.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly) have been explained by measurement or calculation errors. Wormholes or Strange Space-times: We had all hoped you could compress space infinitely, so that far distant reaches could be just a step away, given enough power. However, [recent observations](https://en.wikipedia.org/wiki/Holographic_principle) have shown that the entropy (energy) of black holes increases not with the volume enclosed, but rather with the surface area of the event horizon. Suggesting there is a limit to how much space can be squeezed, nothing goes inside a black hole, but instead travels slower-than-light along the event horizon. Alcubierre / White "Boost" Drives: These relied on a hope that the speed of gravity through space was far faster than the speed of light. However, [recent observations of gravitational waves](https://en.wikipedia.org/wiki/Speed_of_gravity) have shown that the speed of gravity is equal to the speed of light. Fifth force: Very recently, while looking for dark matter, some unusual [new physics](https://en.wikipedia.org/wiki/Fifth_force) might have been observed - a new fundamental force to add to electromagnetic, weak, strong, and gravity. It's hard to say yet what it does. Non-constant fine structure: There's some observations suggesting the [fine structure constant](https://en.wikipedia.org/wiki/Fine-structure_constant) $\alpha = {{e^2} \over {hc}}$ might vary. This might mean new physics exists that tweaks one or more of these properties (hopefully c). Inflation: The universe expanded at a speed of in the neighborhood of $Speed Of Light^7$ for all of $10^{-35}$ to $10^{-30}$ seconds. Or at least, that's what we think. There have been subluminal explanations provided, but there's the possibility that new physics lies here. Also, it's assumed that if any new physics do exist in this region that the energies required are an insurmountable barrier. If new physics allows for FTL either by changing the fine-structure constant, or somehow re-creating the conditions of inflation at far-lower energy levels, you could signal with this field (just like wireless telegraph or radio). [Answer] > > Question: Is this "possible?" What would the package look like? > > > It would look just like whatever medium you sent it. [In the words of Our Immortal Lady GLaDOS:](https://en.wikiquote.org/wiki/Portal_(game)) > > Speedy thing goes in, speedy thing comes out. > > > If you send that information in the form of a USB drive on one side, that then travels in a spaceship on hyperspace, you will have a USB drive on the other side. This is similar to [what some people have done on Earth before with pigeons](https://phys.org/news/2009-09-carrier-pigeon-faster-broadband-internet.html), except that here on Earth no one violated causality. You, on the other hand, are bound to receive a fine from the [Auditors of Reality](https://discworld.fandom.com/wiki/Auditors_of_Reality), because [FTL in any form implies violations of causality](https://physics.stackexchange.com/a/54242/31264). [Answer] **If Wormholes can be created you could use them for both travel and communication so long as the voyage or message did not violate causality. Which leads us to; The 1st limitation on wormholes. Causality wins - every time. There are a certain specific set of conditions where in theory causality can be broken by wormhole messaging or travel. The result of which is the immediate collapse of the wormhole. This in itself is not 'dangerous' because causality prevents the breach from occurring so no message or ship can actually enter the wormhole - the mere attempt to do so causes it to collapse. It is however ruinously wasteful and expensive. 2nd limitation; I suggest that your wormholes are realtivly easy to create but one end then has to 'delivered' by a sub-light probe to the target destination. If a system is 100 LY away then unless you have a 'chain' of wormholes already established leading closer to that point you have to wait > 100 years for the wormhole to be useful. Note trying to thread a wormhole though another wormhole is 'bad' for all concerned - especially any crew on the ship attempting it 3rd limitation; while tiny (sub microscopic) wormholes can he generated fairly easily on or close to Earth larger/stable ones need to be placed in suitable orbits some distance from the planet. This is because wormholes nullify distance. Put one end of a large diameter wormhole on Earth and the other in orbit just above a Jupiter sized planet and the gravitation field of that planet also gets to travel through the wormhole. (Everything does) This would be bad. So you have to place large ones at least where they won't interfere with planetary orbits at either end. 4th limitation; wormholes are pets - they need to be fed and taken care of. They are not stable once 'spun up' but decay into nothingness unless (expensive) exotic matter or its counterpart is replaced as required based on a complex set of equations and observations made by those charged with maintaining the network. Ships passing through can do this. 5th Limitation; Time - since you wormholes are some distance away from the inner planets of any 2 linked systems (and probably in highly inclined (polar orbits) A laser or radio signal from Earth to a distant world will take some hours to reach the initial entry point then (no time) to transit the wormhole followed by more delay as the signal is relayed to its final destination or the next wormhole in a chain,. So nothing is for free. If you have a large extensive network messages will still take weeks to reach their destination. You might be able to spin up small (tiny) wormholes on small stations or satellites closer to Earth but the longer the network they have to pass through the longer the message takes. So some time saving for 'shorter' hops but not a huge amount. (Still beats centuries though.) [Answer] Hyperspatial Radio Antenna A lot of what you want is done in the Culture series of books by Iain M Banks, I recommend copying as it's more consistent than the mere concept of Hyperspace, and attempts to fix a lot of the issues you might encounter with explainability. Take 2 antenna, and twist/lever them into and across the Hyperspatial dimension. Now they broadcast across a 4th dimension. You can use the same technology that ships use to create these antenna, but keep one end anchored so it doesn't completely enter hyperspace. Now you have a portable transmitter in the 4th plane capable of FTL comms. Hypercoms! Given that ships with mass can travel at FTL speeds in Hyperspace, just imagine how much faster massless photons would travel in Hyperspace! Case in point, Star Trek has subspace radios that rely on the same premise, although I don't think subspace coils are partially in subspace in that franchise. Since you're in hyperspace, you can say the speed of light in Hyperspace is much higher, or that exotic equivalents to photons exist only in that realm and are used instead. ### Aiming Transmissions You can then aim your transmission much the same way you would aim a conventional transmission, with techniques such as directional antenna, beam forming, etc Keep in mind though that you have a whole extra dimension to aim in, just because you're pointed at the target in 3D, doesn't mean you can ignore the extra axis added by 4D/Hyperspace. Pointing an antenna downwards won't help if your target is above you, the same is true here, which leads to.. ### Power Consumption Mechanics It may help to orient your antennas along a common 4D plane or axis. Because 3D space we have to work within the inverse square law, adding an extra dimension multiplies that to a much larger extent. 4D space is an order of magnitude more vast than 3D space. So sending an omnidirectional 4D broadcast will dissipate faster, reducing range. How this interacts with the greater transmission speed as well as targeting is up to you, and leaves you lots of plot mechanics. For example, perhaps both ends of the Hypercom system have to ping eachother and locate 4D coordinates, then once they're locked on to eachother they can send tighter focused beams through 4D space? Or maybe one end needs to have known coordinates to send transmissions to? Perhaps the geometry of the antenna will provide access to limited subsets of 4D space? Keep in mind there is no need for transmission or reception in 3 dimensional space itself** A sidenote, if you mess with the speed of light you mess with basic chemistry, I'd advise stealing a common trope of surrounding your ships in a bubble of realspace, e.g. 40ks gellar fields, or the insides of ST's warp bubbles, or the fields Borg cubes use to prevent temporal instability when using transwarp. Thankfully none of these are required for data transmission This also allows for some unrelated items: * 4D Cables Ducts and Pipes, ethernet cables that curve into the 4th dimension then back, allowing unconnected things to be.. connected. Sending material a short distance through a wall for example, or between 2 ships without them touching * Floating supports remember how in Jupiter Ascending the ships had little floaty bits that somehow still moved with the ship? Turns out they were attached all along, their support just curved upwards into the 4th dimension then back * Displacers! Unlike ST style transporters, we're going to do this Culture series style! We'll wrap the person in a bubble then use EM fields to move the bubble into the 4th dimension, across, then back out into a destination. Congratulations you have teleporters that don't cause philosphical issues! * Hypercomm Jammers these work just like conventional jammers, but their antenna are in 4D space rather than 3D space. Expect them to take more power though as they have a greater area to cover * HyperShields why protect yourself in 3D when someone can bend around in the hyperspatial plane and pop out inside with bombs? Presenting 4D shielding that wraps around not just the sides, the top the bottom, but the 4D bit too * FTL ships lever themselves into the Hyperstial plane and accelerate towards a target, melding your Hyperspace FTL concept with Hypercomms + FTL Jammers because Hyperspace is just the 4th dimension, you can apply the effects of gravity wells to hyperspace too [Answer] Quantum Entanglement The idea of finding some way to utilize quantum entanglement is an idea that I have seen passed around a lot. As far as I understand it the base premise is that entangled particles will always act opposite to eachother, simultaneously, over infinite distance. So the idea is that if you can manipulate an entangled particle on one side you can then read it from the other in some sort of instantaneous binary/morris code with cup phones. I think there have been a few explanations as to why this would not work in reality, but it is also one of those things that you could handwave into a believable explanation for the average reader. On a logistical note though, if said premise were possible, you would need to have the two points of contact physically in contact to exchange entangled particles beforehand. This would mean that FTL communication would be impossible between ships and stations that have never come in physical contact before. [Answer] Entanglement Although your answer seems plausible on the information you've given, I have an alternative suggestion. [Quantum Entanglement](https://en.wikipedia.org/wiki/Quantum_entanglement). In short what you need to know. You can "entangle" two particles. This will make them act as if they are the same particle (sometimes mirrored though). This works after they have been separated again. If you vibrate one, the other vibrates at the same time as if they are the same particle. That means you can transfer knowledge faster than the speed of light via deliberate vibrations. Problem is that this works only for this pair (and other particles if you also entangle them with these). So if you want to talk to a ship and it has only one particle, you can only talk to it with the other particle. This limits your options. However, if you put them into satellites, allowing each satellite to talk to each other with an entangled pair between each, you can setup an instant transmission between them. If you then start emitting the "normal" signals from there to your ships and back, you can have an ansible connection that is still functioning as a sort of internet or phone network. ]
[Question] [ In my narrative universe, there will be ships that use a 1g acceleration for artificial gravity. However, when they are not accelerating (whether on a longer journey at a constant velocity or simply "anchored" at some random location) is it feasible for the ships to extend a weighted anchor and create a spin for artificial gravity? I am aware this tether would need to be super strong and very long. Is this a reasonable concept, or should I find another way for the crews to have relative comfort in space? [Answer] Yes, but there are conditions. If we look at the formula for acceleration simulating artificial gravity: $a = R {({2 \pi \over T})^2}$, * $R$ = Radius from center of rotation * $a$ = Artificial gravity * $T$ = Rotating spacecraft period see [Artificial Gravity](https://en.wikipedia.org/wiki/Artificial_gravity) for additional details, We see no actual requirement for for a full circle. Any point on the path of rotation works, regardless of whether or not the rest of the structure is there, as long as structure exists to confine loose objects and transfer the force back to the centre of rotation. The most classic form of this is the grand circle. This allows you to walk around in a larger space, and offers nice things like structural redundancy, but a single living capsule connected to a tether cable and spinning it around a given point will result in the same apparent gravity as an entire wheel. * This is effectively using the simple 'bucket on a rope' demonstration that proves artificial gravity works at all. We do however have to keep in mind some things such as the Dzhanibekov effect or [Tennis racket theorem](https://en.wikipedia.org/wiki/Tennis_racket_theorem) when designing our layout of masses. * Failure to account for this may result in 'interesting rides' for any passengers. We also probably want to be smart about what we use for the masses. Carrying a lump of steel around for no other reason than to be a counter weight is counter productive... It is probably a better idea to design something like a habitation module that is played out and spun around an engineering core. Even splitting the craft into two sections and spinning them up with thrusters can work. --- As for the needed strength of the cable: As long as you aren't placing large masses 'outside' of the habitat's gravity 'ring', then the cabling needed to tether the craft is the same as you would need to safely lift the module on earth. * The entire module's mass, spun up to simulate roughly 1g effectively weighs roughly what it would if sitting still on a planet with 1g. [Answer] ## Yes - This is a very reasonable way to make artificial gravity, without requiring too much support structure. [![enter image description here](https://i.stack.imgur.com/WGyIY.jpg)](https://i.stack.imgur.com/WGyIY.jpg) There have been early studies of this form of spacecraft, however it does encounter the following issues that (although not insurmountable) need to be considered and may reduce their practicality/viability: * The spacecraft would need to have 2 sections. Often this is no problem, however the two sections need to be separate, functional, and yield the objectives of the mission. An obvious one as in the above image is separating habitation and rocket / thrust modules, but this may not be practical depending on the purpose of the mission, length of time the mission lasts, and the additional engines and support structure required. * The spacecraft if undergoing acceleration or any directional change it will lose equilibrium and become unstable. The spacecraft would need to be rejoined prior to any of these operations. * As the spacecraft rejoins, the spin rate increases to preserve angular momentum. There would need to be spin acceleration and deceleration engines to ensure the spacecraft remains stable during this manoeuvre. * Safety is a very strong priority in space missions: The tether needs to be robust enough to hold weight, and the spacecraft must withstand constant force throughout flight, which may be a significant structural overhead. However it is an efficient way to produce gravity without the requirement of ring-like structures, and may enable the increase in diameter to allow non-Coriolis artefacts when in operation (ie. reducing the need for a large diameter ring and all the overhead associated with them to supply the same benefits). I would imagine it would be a good way to do manned long distance missions in smaller spacecraft with not too many directional adjustments required. [Answer] If I understand your question correctly, when the ship is under flight he crew experiences 1g due to the ships acceleration. And when they are in orbit you want. them to have the same level of comfort. It seems like you don’t want the orientation of the crew space to change between traveling and orbiting. So, sure, if the ship had a mass tethered to the nose of the ship, then they could set up and orbit that would give something like 1g in same plane as when the ship was in orbit. Unless the mass was 1000 to 1 the mass of the crew space, the orbit would be very wobbly, and require correction. It seems a more realistic design to have the crew space realign itself so they have 1g in one plane while traveling, and then, align to a radial fashion when the ships spins on its center axis to generate artificial gravity in orbit. ]
[Question] [ I am trying to come up with a non-aesthetic reason for a group of humans to have been genetically altered to have an exotic skin color. Purple, blue, green, red, I'm not particularly fussed about which. Ideally this would be a pragmatic reason geared toward increasing adaptability for xeno-planets. The best I've come up with is that colorful skin might protect against that wavelength of light for some reason. [Answer] The skin color is an unintended byproduct. Your humans have been genetically engineered for disease resistance, self-synthesis of certain vitamins and amino acids, slightly different neural synapses that benefit from ambient low levels of nitric oxide, and other things. Genetic engineering is usually done at the early zygote stage by extracting one or more cells, engineering them and then adding them back to the zygote, so the descendants of that engineered cell spread around and give rise to engineered populations "homogenously" within the organism. It is not really clear which of the engineered cell populations interact but a result is unpredictable skin and hair coloration, which occurs semirandomly. Sometimes it is all one color. Some people are several colors or have harlequin like patches, apparently according to the establishment of engineered populations of cells. It is not uncommon for the coloration to drift and change with the years. More rapid and dramatic changes can occur when people use "aftermarket" GMO; infusions of engineered stem cells which are intended to spread thru the organism and engraft, conferring new properties. The aftermarket GMO cells are sort of like apps - they are made by a variety of proprietors and vary greatly in quality, efficacy, side effect profile, and cost. The genetic engineers overseeing GMO projects view this skin color issue as harmless and irrelevant; certainly more harmless than other side effects of the engineering endeavor which occupy most of their remedial efforts. [Answer] The colors simply signal the specific type of compatibility modification they have been given. This allows rapid recognition of specific medical requirements or lack there of. This allows people to know if it is safe to open the door outside and which people need help if the door was suddenly opened. Or if something leaks or cracks. Or which people can eat which food without issues. Or which people require specific supplements or care. Or can handle sunlight without protection. Or which people you can throw a tool at local gravity without becoming a murderer. It may also denote legal status. These people were modified to match specific environment before birth. This implies people doing the modification were not concerned about the person wanting to live somewhere else. Sometimes this is because the modification was cheap and safe. Sometimes it is because interstellar travel is expensive. Sometimes it is because the company or the government decided where the person will live before they are born. The modified colonists would essentially be serfs, living and working where they are ordered to. It would be convenient, and probably legally required, to have easy visual differentiation between people of different legal rights. Extensive genetic engineering might simply be controversial enough that law requires it to be visually recognizable. Note that even if such legal requirements no longer exist, people might choose not to edit out or hide their heritage. Seeing who can safely eat food with high heavy metal content or breathe air with chlorine in it is still convenient so why bother. Besides it would dishonor your ancestors. [Answer] If you take out appearance (and with it also the part where it helps them find a sexual partner). you are left with: Camouflage, if your humans are rather un-evolved technologically they would have to rely on other forms of hiding seeing our pink skins would stand out against an environment that is mainly blue or green. Warning signs, If your humans are poisonous they might have developed bright colors to warn predators that they might kill the human but won't be able to eat the meat without dying themselves. Mimicry, defending itself to look more like a other creature (predator) to warn off other animals from engaging it. Startling/Distracting, if the color is hidden and comes out in a burst it might make a hostile creature go "Wtf?" and back off something peacocks do for example. But all of this would relate more to a beast then a humanoid creature seeing a humanoid creature would be able to do this better using technology. So other then to look appealing, protect against the sun or perhaps heat regulation there doesn't seem a good reason to evolve certain traits....so if a humanoid has them it would be probably be a left over from their evolutionary process that no longer serves a real purpose (like whale legs). So for it to work in your setting it would probably have been done to help humans survive in a hostile wild environment where there is no aces to technology of even the most basic levels (like why use genetic engineering on the skin if you can use a body suite, it would be much cheaper and flexible). [Answer] # They were designed to be exotic sex workers. If it’s possible to create fully grown individuals in your setting through something like accelerated growth cloning tanks or full-body organ printing, then it’s entirely possible that some people will use that technology to produce sex workers; whether these individuals would be sold for private use (essentially acting as a “buy a wife” service) or sold to sex industry businesses would depend on the particular business models of the companies making them. However, while some of those companies might be content making basic copies of attractive human women, it’s likely that once the technology becomes available, they’ll want to compete with each other by offering the sales of more exotic product lines, which might include things like cat girls, bunny girls, or green skinned space babes. [Answer] Vividly colored alien microbes accidentally colonized the human's skin - the outer layer of dead cells on the skin. They are harmless, act as mild disinfectant, repulse annoying insects from Earth and remove bodily odor. They are being further improved, as they are much easier to genetically engineer than humans. But by the time colorless variety was bred, everyone was accustomed to the wild colors. [Answer] When the first human colonies to left our solar system, there was a tremendous concern with preserving their cultural links to mother earth. If something went wrong, and the colony became isolated, the concern was these humans could develop into a competitor to future generations of humans if they forgot we were all brothers and sisters under the skin. In an attempt to address this, the first colonists carried the whole of human history, music, art, and science encoded on the dark regions of their DNA. It is estimated that 215 Petabytes of data can be stored on a gram of DNA strands. Since they could only use the dark regions of our DNA for storage without risking corruption to the colonists' genetic viability, this Encyclopedia Universalis was encoded and broken up the colonists. The specific encoding key was tied to individual colonists and was reflected in their skin -- thnk like Red, Green, Blue. After generations, these hues display a range of colors - Purple, Cyan, Burgundy, etc -- but the hue still contains the precise key needed to decode the information stored on their DNA. [Answer] Photosynthetic skin. X color is a byproduct of efficient photosynthesis. Maybe even being photovoltaic. Or perhaps the skin color changes based on mood or for silent communication. Perhaps there is a layer just under the skin that can fill with a bit of air for better thermal insulation and then deflate for better thermal conductivity and that changes the color. Personally if I could Id change my color just for aesthetics. Red skin golden eyes white or blue hair. [Answer] Your sunlight has lots of UV The target planet has a tropical climate, also on higher latitudes. Or it has less means to protect the surface from UV. A white skin will reflect more heat, but it will also be more vulnerable for sun burn. Your colonist children, born underways, will get a metallic looking, dark-blue color skin, with reflective properties and lots of protective pigment. They could also have been rendered black, purple or brownish, but considering the length of travel, the first generation colonizers decided to use dark blue, for psychological reasons. Because it is exotic. In a mixed crew population underways, a darker and recognizable skin color in children could pose issues with rejection, or racism. A neutral solution was needed, so the skin color became exotic for all children. In three generations, your population will be dark blue, the Earthly skin color differences have been eliminated. ]
[Question] [ More then 3 decades ago dictator from country A attacked a ship from a country of dictator B. Dictator B invaded and annexed 1000 square kilometers of coastal strip to teach A a lesson, and kept the territory as a collateral until A apologizes and pays for both and ships and the cost of invasion. It has been an almost a decade since A is toppled and country A disintegrated into a civil war with warring tribes killing each other without anybody to unify them in sight, think something far worse than Libya and Somalia. Since the strip is more trouble than it's for B, is there a legal way to give it to the UN? Or maybe USA, there is no oil, but there is free port and naval base. The country B, can't just leave and be gone since warlords would take over, and slaughter the minorities that took refuge on the outskirts of the area. Plus the humanitarian organizations are using it as the only functional port to deliver aid to the war-torn population. It would be PR disaster for B if another catastrophe happens. So country B needs someone to police the area to wash their hands. [Answer] If the United Nations chose to intervene, they would likely attempt a [peacekeeping](https://en.wikipedia.org/wiki/United_Nations_peacekeeping) mission - something that of course has been done many times in the past in various contexts. Peacekeepers have a number of responsibilities depending on the specific mandate of the operation, and these responsibilities can range from state-building to ensuring that basic human needs are met in a region. The UN Security Council would be the body to authorize such a mission. The legal basis for UN peacekeeping comes from [Chapters VI-VIII](https://peacekeeping.un.org/en/mandates-and-legal-basis-peacekeeping) of the UN charter (Articles 33-54). I'd like to mention some relevant passages: * Article 39: > > The Security Council shall determine the existence of any threat to the peace, breach of the peace, or act of aggression and shall make recommendations, or decide what measures shall be taken in accordance with Articles 41 and 42, to maintain or restore international peace and security. > > > * Article 42: > > Should the Security Council consider that measures provided for in Article 41 would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action may include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations. > > > * Article 52: > > Nothing in the present Charter precludes the existence of regional arrangements or agencies for dealing with such matters relating to the maintenance of international peace and security as are appropriate for regional action provided that such arrangements or agencies and their activities are consistent with the Purposes and Principles of the United Nations. > > > * Article 53: > > The Security Council shall, where appropriate, utilize such regional arrangements or agencies for enforcement action under its authority. > > > These three chapters, including these articles, are the usual ones invoked for peacekeeping, especially Chapter VI. They require that member states take action and provide the service of their military forces - and in this case, I would expect that the Security Council would require Country A to contribute, as simply walking away would likely be considered irresponsible (unless Country A was for some reason not a member of the UN, or if its initial occupation was deemed illegal). The UN mandate for each peacekeeping mission may extend beyond the use of military force, however, and can include, [as the UN puts it](https://peacekeeping.un.org/en/mandates-and-legal-basis-peacekeeping), > > * Security sector reform and other rule of law-related activities > * Support for the restoration and extension of State authority > * Promotion of social and economic recovery and development > > > You could argue that regional occupation by Peacekeepers would be based on those principles. In a case of lawlessness or unclear governmental administration, UN occupation might be necessary for the promotion of state-building. The following Peacekeeper missions are examples of similar measures taken: * [United Nations Operation in Somalia II](https://en.wikipedia.org/wiki/United_Nations_Operation_in_Somalia_II) * [United Nations Temporary Executive Authority](https://en.wikipedia.org/wiki/United_Nations_Temporary_Executive_Authority) (transitional authority in West New Guinea) These could be interpreted to establish something of a precedent for the action you're talking about . . . but I'm not an expert in international law. I'm looking at some official [peacekeeping principles and guidelines](http://www.un.org/en/peacekeeping/documents/capstone_eng.pdf), and some key concepts pop out. First, the parties affected by the mission must consent to the deployment and activities, which could pose a problem if whoever is in charge of Country A doesn't like the use of Peacekeepers. That said, from what you're describing, it appears that warlords are in control there, if anyone is at all, which would probably provide a loophole and allow acting without consulting them. It's also noted that if regional authorities are weak, it may be necessary for Peacekeepers to take over parts of local administration for the purposes of a successful mission, and in the case of rampant chaos or civil war, this could be true. Of course, the behavior of Peacekeepers and the power structure of the mission as a whole need to win over the locals for it to be remotely a success, so there's going to have to be some sort of input from or at least dialogue with the community. Remember, Peacekeepers engage in state-building and restorative action, not merely custodianship. [Answer] Since A has collapsed and has no legal government and "the strip" is the only part of A with anything resembling rule of law, you can simply establish a local government on the strip, recognize it as the legal government of A, and transfer the strip to them in exchange for that apology. Then just run for the border. If you pick the local government with a democratic election and allow international observers, the resulting government can then request legal recognition as the (or a) legal government of A and possibly request assistance from the UN, the US, or even call in the boy scouts. Not your problem If you want to make A stable, it will be still your problem, and you will need to do some prep work before transferring power as well as negotiate some sort of an alliance with the locals before transferring the power. But that is beyond this question. But getting the UN and any international powers interested involved in the process as early as possible is common sense and seems to be sufficient for this question. Some observers, support for the police, security, military, that sort of thing. Maybe a financial and humanitarian aid package. [Answer] **Short version : B will opt for "Part of A : the Buffer Zone". And sod the UN and everyone else. No one else will do anything.** No country would want this annexed strip of land, anymore than you would like to grab a red hot poker by the wrong end. If it's more trouble than it's worth for country B, then it's more trouble than that for any other country. Any political activity by the UN and other super-governmental organizations to try and resolve the situation would consider the civil war regions a priority, not the essentially stable part of country A than B stole (annexed is such a long word for stole, don't you think ?). > > So country B needs someone to police the area to wash their hands. > > > Country B has in fact four approaches : * Treat the part of A they now own (with a valuable port !) as part of their own territory and fully integrate it with B. This is unlikely to be contested any more than it already is (it's been a fact for decades). Gone "forever" is "part of A" and we'd like to introduce you all to "(happy) new part of B". * Bail. It can completely withdraw from "part of A" and return to it's original border boundaries and try and ignore what's happening next door. You can do this clean or messy. Clean means setting up a local government to handle the transition (possibly with e.g. UN assistance) and hoping they can sort something out that's moderately stable and not utterly hostile to B. Messy means just driving your tanks out one morning and hoping "part of A" doesn't become an even bigger problem full of people who hate B and will be a constant problem for decades to come. * Steal some more stuff. Country B has a dictator and they typically aren't modest retiring people who are happy with what they have. We stole ("annexed") stuff before and it worked fine, and that bit near it looks up for grabs, let's do that. Somewhere to put the new work camps and bury people who oppose us, if nothing else. Dictators are not going to be shy of a little bloodshed as long as it's not their blood, so this option is quite likely and it will keep B's army (and generals) from getting ideas into their heads about running country B themselves. Keep the army busy, trained, blooded and loyal. * The Buffer Zone. There's a civil war just over that-a-ways and country B wants no part of it. Fine, we have this bit of dirt called "part of A" which we can use to keep any insurgents and trouble makers away from country B proper. This amounts to not withdrawing from part of A and just keeping the place ticking over. But not treating it as either a new country and not protecting it as if it was a full part of country B. It's OK with country B if part of A gets some trouble as long as it keeps the big trouble away from B. The UN (and everyone else) is just there (from country Bs dictators point of view) to run to help from if B itself is threatened by all this civil war stuff happening to people Herr Dictator couldn't care less about. Note that the UN and B's regional neighbors don't have to wait for anything or even consult B. If a regional group of countries decides to take over, B's not doing much to get in the way unless they actually threaten B itself. The UN would be unlikely to go in just on B's request and is an organization full of pragmatic egomaniacs and their representatives. A civil war in former A is fine as long as it doesn't have a major impact outside that. Peacekeeping is an option if and only if there's a political will to do it ignoring country B. Country B is unlikely to want a powerful military presence it can't control on it's borders. Dictators don't generally encourage that and it's more likely that a dictator would be perfectly fine with a bunch of weak warlords in a civil war who can be played off one another next door and a buffer zone "just in case". So I think B will opt for "Part of A : the Buffer Zone". And sod the UN and everyone else. [Answer] Unless I am misreading, it seems like country B gained territory through military means. After the land becomes uncontested (by the original owner dissolving), Country B decides to sell the land to the United States. If that is the case, there is historical precedent for this, like France conquering territory then selling it to the USA with the Louisiana Purchase. Actually, the Louisiana Purchase is a great parallel for the situation your describing, sinse France was desperate to sell to pay for its war debts and thought the territories was more trouble than they were worth. So, your country B could sell the coastal strip to the US for a pittance so its no longer B's problem. [Answer] *Yes and No: it depends on whether the land is considered [Terra Nullius](https://en.wikipedia.org/wiki/Terra_nullius)* or not** Terra Nullius is a latin phrase that describes land that is not clearly claimed by a sovereign nation. You've described a condition that could lead to a declaration of terra nullius for the purpose of re-establishing control (and, theoretically, peace) in the region. If A and B were both somewhat stable, the land would not be terra nullius as the land has a legitimate claim from A and an illegitimate take-over by B. But, you've described A as falling into chaos. It's that chaos that would need a legal team to determine if the region is terra nullius. If determined to be so (B no longer makes claim and A doesn't exist to assert claim), then, theoretically, a nation could step in and simply lay claim to the territory. However, that tends not to happen. Who wants territory that's (a) unstable and (b) a long way from home and therefore difficult to control? *If it isn't terra nullis,* then the UN is the best bet** Now, to be frank, what you've described is a perfect example of why UN peacekeepers exist. The theoretical purpose of the peacekeepers is to NOT get involved with the politics, but to stabilize the region so the politics can be diplomatically reasserted. The peacekeepers (among other things) were created to avoid the trouble when one sovereign nation steps in to solve another sovereign nation's problems — because that tends to look a lot like a military takeover. The peacekeepers are meant to be neutral. Which one is best for you? That depends on your story, of course. What do you want to have happen to A? How much diplomatic shennanigans to you want to take place? etc. ]
[Question] [ In my world there is a pervasive cultural/ethnic minority all across the continent. They are discriminated against like many ethnic minorities on Earth, and as such often imitate the culture of the majority around them. Do minorities discriminated against like the one described above on Earth have any common cultural elements (essentially cultural trends that seemed to be related to being a minority)? I'd like to add such an element into my ethnicity's culture to add a touch of realism. I do realize that cultures are complex things and are widely variable. I'm really asking for about a specific element (somewhat silly ex. most minorities cultures consider dogs to be man's worst enemy), not some sort of magic common, minority culture. Per Lee's comment, this minority group doesn't have any sort of homeland, but is bound together by a common feature (in this case lack of magical ability, though that's not very relevant). Humanity entered this continent 2000 years ago, and their previous home was destroyed. So no one really has a "homeland" for their culture. [Answer] I'm not entirely sure if this is what you're looking for, but... ## Pride movements Persecuted minorities will band together and say "we're here whether you like it or not". In the West, the most visible example would be those of Afro-Caribbean heritage. This isn't exclusive to ethnic minorities either: the majority of modern countries have strong gay pride movements as well, encompassing the entire LGBTQ spectrum. Another phenomenon that tends to occur - I hope I can word this correctly - is that ethnic minorities in large cities tend to end up clustered together in specific districts in which they actually become the majority. Think of the Chinatowns or Little Italies in various US cities: that sort of thing. Not sure if that's what you're looking for either. [Answer] Look at a primary world example of a persistent minority that has been rather routinely discriminated against. Jews. They tend, in many regards, to turn away from the cultural norms of their numerical superiors, though they do sufficiently integrate within that majority culture. (The stereotypical Jewish doctor / lawyer / jeweler / businessman who lives next door vs. the stereotypical Amish farmer / crafstman who lives in a reasonably segregated community.) Think also of other minority cultures within larger societies: the Irish or the Welsh in Britain; blacks in post-(Civil)war US; Gypsies. The principal thing they all share in common is what I call a stubborn otherness. The refusal to fully capitulate ancient cultural practices or languages, the strong resistance against 100% amalgamation within the majority culture. Sometimes this resistance is very great --- the refusal to marry outside the culture group, remaining aloof from all (non-business) outside contact. The other thing they have to share in common in what I call a dogged ostracism. This does not come from within, but rather comes from without. From the majority. The minority can not be discriminated against, no matter how radical their behaviour, if the majority refuses to ostracise and discriminate against them! This is where that utterly queer Black-Whist social caste system we had in the US stems from. It's a systematic rejection of the minority with all the brutal machinery in place to keep them in their place. [Answer] * Conservative Interpretation of Traditional Culture: Assuming there is an "old country" where the minority came from, that country will have moved on in many respects. Family values, women's rights, religion, etc. Some from the diaspora will cling to old values, as handed down by their parents. Those parents might not have been the most educated of their ethnic group. * Mutual Support and Networking: The majority culture bankers won't give them good credit. So they go to the uncle of the godfather of the cousin, who sees the ethnic affilation as a lower credit risk, not a higher credit risk. Because the family always worked hard and repaid their debts, and they wouldn't risk their reputation in the ethnic community. * The dark side of this is the ethnic crime ring. * Traditional and Nontraditional Occupations: Being discriminated against could force the minority into low-paying jobs, on average. Would the majority population go to minority barber shops, groceries, etc.? On the other hand, the minority might be "forced" to get their own lawyers, doctors, etc. because they do not believe that they will get quality service from mainstream professionals. * Religious or cultural practice might push them into certain professional roles within the mainstream economy. Are they expected to be more literate than others? More practiced at mathematics? * Debates about Assimilation: Some will abandon their ethnic/cultural heritage and assimilate into the mainstream culture. Others will resist. The clash between those groups might have different outcomes depending on where on the continent you are. [Answer] ## Visible vs Invisible Minority A visible minority is easily distinguished from the majority by appearance. The most obvious examples are African-Americans and Asian-Americans in the USA or Arabs in Europe. Invisible minorities are phenotypically indistinguishable from the general population. Chinese and Koreans in Japan, Jews in Europe and the USA look the same as the majority but differ culturally. The social dynamic for visible and invisible minorities is very different. Visible minorities frequently face more open discrimination. Since they cannot 'pass' for the majority they may be unable to integrate and assimilate into the mainstream society and culture (due to discrimination from the majority). Their ability to attain a high social status can be also severely hindered. Since the differences in appearance are easily perceived, much of the minority's identity is associated with looks. It is quite possible that culturally a visible minority is similar to the majority. For example, African-Americans in the USA share the same cultural values as whites. There are some differences, of course, but when it comes to core values and attitudes US minorities differ from other cultures more than from mainstream white culture. The perception from inside the minority, however, may not reflect this, especially when ethnic and racial tension is high. Invisible minorities usually have cultures dramatically different from the mainstream culture. They can express it through outfits, occupations, and lifestyles. Religion is frequently the main reason for this. Invisible minorities have a lot of mechanisms preventing mixing with the majority. These can range from self-isolation to limitations in choosing marriage partners. The groups are tighter and probably have greater tendency to live together since it is important for maintaining culture. With invisible minorities, there is always more intermixing with the majority. Since minority members can pass for a majority, some of them renounce their minority heritage and assimilate into the mainstream culture. ## Stereotypes and Social Status Both types of minorities trigger the creation of stereotypes and urban legends. Some of these stereotypes can be negative (think about black lazy criminals in the USA) and some can be positive (Asians as a model minority in the USA). Negative stereotypes are more prevalent, though, and positive are frequently accompanied by negative (in the USA Asian men are seen as smart but lacking sexual prowess). It is possible that a minority has higher social status and/or higher income than the majority due to positive traits attributed to minority members or occupations that they traditionally choose. For example, in the USA, [persons of Jewish ancestry are one of the highest earners despite their minority status](https://www.wikiwand.com/en/List_of_ethnic_groups_in_the_United_States_by_household_income). When it comes to race, Asians are the highest earners (same link). Unfortunately, the majority of minorities have lower status and lower income due to a social stigma attached to them. It does not matter whether the minority is visible or invisible. For example, [burakumin](https://www.wikiwand.com/en/Burakumin) is a highly ostracised invisible minority in Japan. Burakumin are ethnically Japanese but during the Edo period (1603–1867) they became outcasts restricted to 'impure' occupations such as butchering and cleaning. Even today, despite all the anti-discrimination laws there are firms specialising in background checks of potential spouses to prevent marriages with people of burakumin ancestry. ## Racial and Ethnic Tensions It might seem as a good idea to depict minority-majority dynamic as a high-tension situation, especially if you or your audience are USA-based. However, American racial situation is rather unusual. There are many multi-ethnicity and multi-racial countries where it does not lead to constant social conflicts. People who come to the USA from Europe are often surprised to discover how much race and ethnicity matter in America. In Europe the differences are handled in a much subtler way. The cultural emphasis also differs: one is a national of a particular country first and a member of a certain race or ethnicity next. In the USA it seems to be reversed: one's racial and ethnic status matters more than nationality. ## How to Integrate It into Storytelling I think that it is important to decide first whether your minority is visible or invisible. Then you can build on it. If it is a visible minority, you can add scenes where someone reacts to their looks, makes a comment, or jumps to a wrong assumption. Depending on minority-majority relationships depictions of a riot or ethnic area might be appropriate. A couple of colourful details would bring things to life. In case of invisible minority, I would focus on cultural differences and perceptions. Something like cultural misunderstanding can be an effective way to introduce your minority. Names can be also very important here. While mentioned-above burakumin are indistinguishable from Japanese in culture and appearances, their surnames betray their origins. Your minority characters may be forced to hide their names. Of course, marriage is always a good way to highlight ethnical or racial tensions. Potential in-laws might be concerned with tainting their bloodline, losing social status, or cultural incompatibility. They can be supportive or not. There are plenty of variations here. And you can play with both families and their reactions. I would try to be very careful to avoid stereotyping your minority characters. The differences among individuals within a group are usually higher than the differences between groups that live in the same area. I also think that it can make an interesting story if you show how an individual deals with their minority identity. [Answer] Minorities scattered in the whole world are somewhat unstable and tend to disaggregate into the "larger container" (process may take many generations) unless some characteristic makes them very recognizable both within and without the community. This characteristic may be purely physical (e.g.: color of skin), but can also be purely cultural (with all shades in between, of course); in the latter case there is a tendency to "reinforce" the link with "somewhat arbitrary" rules enforced in ways that seem excessive to an outside observer. A particularly interesting case, here on Earth, is Abraham progeny, who managed to remain a very tightly knit community in spite of being scattered around the world since more than two millenniums. They are almost an unicum in being a People not having any place (till recent times) where thy actually are a majority. Other peoples (e.g.: Armenians) have had their "home" subdivided in pieces and thus they are minorities in all countries that annexed them, but they still are majority "somewhere". Many minority communities use hard rules to tie together members, so you have prohibited foods, dress codes, specific ceremonies to be done at fixed times of the day, etc. I think this is a trait you can find in all successful (in the meaning of "stable over time") minorities. [Answer] I would give them their own language or dialect, and some different cultural trappings to go with it (specifically including religion). This would be consistent with what happened with other geographically dispersed minority communities I'm aware of: eastern European Jews ([Yiddish](https://en.wikipedia.org/wiki/Yiddish)), Romany ([Romani](https://en.wikipedia.org/wiki/Romani_language#Classification)), and African-Americans ([AAVE](https://en.wikipedia.org/wiki/African_American_Vernacular_English)). This shows you two basic paths with the Ashkenazi Jews being the middle road: 1. The minority manages to keep themselves so completely separate that they have their own completely different language, along with a completely different cultural package of faith, traditions, behavior, identity, etc. They actually borrow next to nothing from surrounding cultures, because they don't really need to (IOW: it wouldn't do them much good if they did). 2. The minority is so oppressed that their culture and language was by-and-large forcibly stripped from them. Their language and religion and most of the rest of their culture at one point became that of the oppressor (with a very few small holdovers). However, since that stripping, their society has drifted so that they have developed their own dialect, religious denominations, and culture within the larger culture. If anything, the larger culture likes to "appropriate" things it likes from their culture, rather than the other way around. But most participants can easily [code-switch](https://en.wikipedia.org/wiki/Code-switching) when necessary (outside of any physical differences) Basic point here being: most of the cultural "borrowing" will likely go the other way. An annoying amount of fiction seems to miss this. People will only assimilate to the extent they will be allowed to participate in that majority society if they do so (and they perceive that participation as being to their advantage). [Answer] Minorities may define themselves among themselves. That is for purposes of cultural solidarity. Discrimination against a minority is an action taken by the majority. The only prerequisite for discrimination is a characteristic that persons wishing to discriminate can attribute to persons putatively in the minority. This characteristic can be completely subjective. It can be completely invented. There does not need to be objective proof. For example: I think it will advance my political career to identify and persecute witches (persecution being an aggressive form of discrimination). I identify some persons as witches so that they might be persecuted. They will of course protest that they are not, and the entire process of identifying witches and then dealing with them is part of the discrimination and helps advance the ends I am pursuing. Instead of witches you can substitute Communists, or homosexuals, or Jews or what have you. It does not matter as long as there is a quality that can be attributed to persons who are to be put in that minority. It is easier in some respects if the minority actually does have some objective quality identifying them as such, like a special haircut or skin tone. But then the discriminating party does not get the added benefit of the identification process which serves the same cultural power goals as the discrimination itself. A majority interested in persecuting a minority can establish who is in that minority and that is the common cultural element: they are defined as people to be discriminated against. [Answer] # Pride Though in some groups this becomes an inverted snobbery when someone tries to escape a cultural poverty trap, "You think you're too good for us". The maintenance of an identity against the amorphous mass of modern society requires pressure, either one way or the other. When the minority group is being casually oppressed by the majority, that pressure is easy to identify and hence the culture can remain clearly distinct. While some groups without clear racial distinction can assimilate largely at will, the support of the community is lost if they do so. Should the external pressure of racism be reduced then the pressure to remain within the group starts to come from within and it comes in the form of pride, to the point of having a superiority complex, regarding their own culture and background. Shikse is not a nice word, the fact you might marry one really doesn't go down well. [Answer] Disadvantaged minorities will generally resent their exlusion by the rest of society, especially where it is perceived as disproportionate and unjust. This common feeling will tend to unify them and will be instrumental in constructing a culture, even if one did not previously exist. They will identify themselves by their common features, which will achieve more prominence in their culture. Non-common features, like perhaps colour will be of far less importance than within outside society generally, and this will be perceived as a further difference and, in its own way, make their culture seen as preferable and fairer. It is not unusual for minorities to be objectified and labelled with pejorative terms. Intended to be abusive, these terms may actually be taken by the minority and adopted with pride. This is a way of not only asserting identity, but also of confronting and confusing prejudice - it confounds the verbal abuse when accepted willingly by the abused. In essence, the evolving culture will tend to centre around the common features that identify an unify the minority. Lack of these features will be used to label the 'others', the oppressive majority, the outsiders. There will also be a definitive belief that the way that things are done in the minority culture is the right and preferable way of doing things (even if they have no real choice in the matter). It may not be quicker, or cheaper, or easier, but it will get labeled as 'authentic' or 'traditional' or sometimes simply 'our way of doing things'. ]
[Question] [ I am thinking about the miniature kind of fae, like Tinker Bell. I think that class of faery would be the most likely to be able to fly realistically, due to the wingspan/body weight ratio. But would their lungs support their bodies if they were like our own? What do they eat? Where do they live? How did they evolve? This question is part of the [Anatomically Correct Series](http://meta.worldbuilding.stackexchange.com/questions/2797/anatomically-correct-series/). [Answer] Start with a hummingbird and anthropomorphize it into fairy-form. Long thin legs when held together can serve as a tail. With arms that can reach into the flowers for food, they no longer need long beaks. Ditch the feathers everywhere, except where modesty requires. Do they really have to be as intelligent as Tinker Bell? That might be tough on such a small frame. How about making them trainable like a miniature "purse" dog and let that training (provided by larger anatomically correct fae) fuel the myth that they have human intelligence. How did they evolve? There is a Darwinistic advantage to looking like a miniature human-being. Birds of Prey who might usually feed on creatures of pixie size, have only survived themselves by staying clear of the bigger humans; so they hesitate. And that hesitation buys the quick little pixies just enough time to escape becoming lunch. [Answer] Flying fish fairy is good enough ? They are small and cute so to me it seems a good start.[![enter image description here](https://i.stack.imgur.com/tJPUD.jpg)](https://i.stack.imgur.com/tJPUD.jpg) When I'm in boat these fish always come along to avoid predators, Sure if there were mutant fish that looked just slightly like a small humanoid someone would want to help them survive or adopt em and breed them to look cute and more human then ending with a fairy like animal . Some hundred of generations and they might look like a little person of 19 centimeters 7'4 inches with four big fins on the back. Here a fast 3D sketch with size comparison [![enter image description here](https://i.stack.imgur.com/t1vqO.png)](https://i.stack.imgur.com/t1vqO.png) [Answer] The shortest documented adult ever became only 54.6cm (21.5"). Even though this is quite small, I'd say it is definitely way too large to be able to fly with (butter)fly wings. I could rather imagine bird or bat wings. I also assume you cannot simply gain a human in a form as tiny as one wants to imagine as many of our organs probably have a limited minimum size to function properly. You'd have to change the internal body massively and throw out anything not absolutely necessary. Also they'd probably not as slim but rather have a stocky body and a quite oversized head. Retaining human intelligence with a brain a fraction of the size of ours is hardly possible. They may have a slightly improved efficiency but barely anywhere close to human intelligence. Also a more efficient brain would raise the demand of energy so they'd have to eat and sleep very much. In addition to the high energy demand for their flying ability I'd say that's a very limiting factor. As for your last question, that's a matter of supply and demand. Since human teeth are like ivory to them they create jewelry from, less people believing in fairies mean less teeth and thus higher value per tooth. The much more important question is: why would such a creature develop? Did they develop out of a hominid or an insect, and why would it shrink and develop full wings but not change anything else (or vice versa, why would it change its body into the human form)? The human body has specialized to living on the ground and it's obviously totally ineffective and useless if it was able to fly. [Answer] Intelligence doesn't necessarily need a large brain. Of course there's debate about this, but there's a definite hypothesis that what matters is the brain-to-body-size ratio. Possibly your fae might have a larger head relative to their body size than we do, but that's well within the bounds of fairy artwork. No problems with lungs. Birds manage it, so a fairy the size of a bird can too. [Answer] What about distributed processing for brain power? Like octopus limbs, have most of the body take care of itself and only update the primary brain as needed, as well as additional processing in the spine. This would free up space for cognition. A human brain the size of a bird brain would be pathetic compared to the bird because bird brains have higher neuron density and have a higher processing efficiency. Your fairy could be better then a bird brain and have distributed processing power. The fairy will probably be totally covered in fur as well unless its in a very warm area, or itll need to wear lightweight insulating clothes. ]
[Question] [ Like in video games where characters are able to control the temperature around them by simply removing the heat. Is it possible for a machine or biological creature to have the power of absorbing heat from the outside causing things to freeze? Or does it go against the laws of thermodynamics? Would such a super-power be too much, in the sense, would something able to fully control this power be also capable of controlling the universe? [Answer] Yes, this is possible without violating the laws of thermodynamics. If it wasn't, refrigerators wouldn't work. You're essentially making a heat pump spell. There are two rules you have to keep to if you don't want to break physics as we know it. First, the heat has to go somewhere. Energy can't be destroyed or created, so whenever you cool something down something else must heat up. Note that it must be the same total heat energy, but not the same temperature if you release it into something of different size/heat capacity. If you freeze a small object and release the heat into the ground or a large body of water it might not even be noticeable. Second, the process itself must use some external energy to make it work that is converted into heat - and no, you can't use the heat you move as a source. This is to not violate the law about entropy. The source of this energy is probably the same as the source of magic in general - chemical energy from the casters own body perhaps, or maybe he needs to drain a battery to do it. As for controlling the universe, not any more than we already do. As long as you keep the power within the bound of thermodynamics, it would be useful (especially if it is efficient or has an easy-to-get energy source) but not game-breaking. It doesn't do much we don't already have machines to do. If you could ignore thermodynamics, that would be a different question altogether. [Answer] In a word? YES Let's explain a bit more in-detail. * Endothermic reactions exist in real life and photosynthesis is a good example of this [(Wikipedia link if you want to read more)](https://en.wikipedia.org/wiki/Endothermic_process), while I'm not sure about the logistics of getting things to actually freeze (as freezing is actually an Exothermic reaction (gives off heat.)) * Next, the law of thermodynamics means that the energy that used to be heat has to be converted into something else (energy never is added to or taken away, only changed form.) The exception here, being entropy, which will eventually, render all energy useless to thermodynamic laws. [(Not pleasant)](https://en.wikipedia.org/wiki/Heat_death_of_the_universe) * The part about some super-powered being with full control of this ability being able to control the universe is questionable if you're taking into account thermodynamics (again, because the energy has to be converted into something else you could easily argue that there's another being whose power is the exact reverse, adding heat.) [Answer] I'm surprised no one has mentioned that this can be done with lasers. <https://en.wikipedia.org/wiki/Laser_cooling> > > All laser cooling techniques rely on the fact that when an object (usually an atom) absorbs and re-emits a photon (a particle of light) its momentum changes. > > > When you slow down the particles with this technique, you are effectively cooling any matter. This video explains it quite well: [How does laser cooling work?](https://www.youtube.com/watch?v=hFkiMWrA2Bc) [Answer] You couldn't control the universe with this super power. The only way to absorb heat from the surroundings is to be colder than the surroundings via heat transfer (conduction, convection, and radiation). A hypothetical creature that could magically lower its exterior temperature would still only be able to absorb heat at a rate governed by those heat transfer mechanisms. For example, suppose that a being in the room with you suddenly lowered its temperature to zero degrees Celsius. No big deal, just leave the room. Suppose it lowered its temperature to zero degrees Kelvin. No big deal, you would feel a big chill from their direction (like the opposite of a fireplace). Don't stick your tongue to it. As far as controlling the universe... heat transfer across space is accomplished only by radiation. Space is already very cold on average (about 3 degrees Kelvin), so the existence of a being at zero Kelvin is not going to be noticeable to anybody on another planet, solar system, galaxy, etc. [Answer] This could occur within the laws of physics, albeit a corner case of them which is typically not given much credibility because it offers fantastical possibilities for which we have little to no evidence for. The laws of entropy really only take hold when you forget information. Many constructs built around reversible computing specifically avoid erasing bits of information so that they can be returned to their previous state after the calculation is done. This construct legally sidesteps entropic losses, if you could actually build one. The reason entropy always "wins" at our level is that we very rapidly "forget" the result of collisions between molecules. We treat them as "random events," which means we lose a little information every time they occur simply because we're not tracking them 100%. What if something was tracking them? If you had an entity which could track the results of those collisions, it could do some pretty amazing things. It could be thought of as a ghost, or it could be thought of as some exotic field, but the result would be the same. Every "random" collision we think we observe may actually be carefully planned, and thus not random at all. We just don't know the key to unlock the "randomness" and realize that there's a pattern to it. All of science would be justified in believing that these collisions are random and that the entropy of the system has increased with each collision, but they'd be wrong. All that information would be retained by this entity, usable for exotic things like suddenly making all the air molecules in the room move to one side of the room. Statistically, it is highly improbable that it will occur, if the air molecule movements are "random." However, if we know a-priori that there is a structure to their "randomness," it becomes a lot more plausable. It would be hard for any entity to merely "remember" those trillions of collisions every moment; however, if it were to interact with the system to encourage those collisions to occur in a way which is highly compressable, in the data sense, it may be able to keep track of far less information (so long as it can keep the whole system coherent). For such a system, crypmancy would be easy. You would merely beseech this entity to freeze something for you, and it would kindly take away all that "heat" that is actually particle motion between particles whose positions are know to it (but not to science). It would appear that entropy would be decreasing when you do so, but in reality all that would be happening is you would be having to update your estimate of how much entropy is in the system in the first place. Entropy would still be increasing, you'd just see the illusion of it decreasing. There would be a lower bound to this if there is any actual indeterminism in the world. If the classical observations of quantum mechanics are truly random as they are in the Copenhagen interpretation, this entity would be in a constant fight with QM to maintain that detailed structure of the universe while making sure the structure is too advanced for us humans to recognize. However, some of the other interpretations may suggest that entity could step beyond our universe, and be in a position to manipulate the quantum waveforms directly. Not impossible by the laws of physics. Improbable, but then again, what do we know about the probabilities of our own existence? ]
[Question] [ Everyone talks about self driving cars in the future, and I'm sure at some point vehicles driven by humans will be phased out, driving accidents are pretty much the number 1 killer of those below 40, not to mention issues of congestion and traffic. However, what form will the most plausible non-driven vehicle take. We have the Google car, which tries to drive on our current roads with extensive sensors. As a programmer I know how hard a challenge that would be. An easier task to accomplish would be a network without any human drivers and with sensors built into both the road and vehicles to help them self-drive, made easier because without humans allowed in the network your automated systems can be far simpler and trust to some road navigating computer to handle planning vehicle paths to ensure maximum efficiency without accidents. In fact I would imagine anyone building up an infrastructure from scratch on some new planet would likely go this route, we could almost do this now if we we had the resources first world countries have now and were building up our infrastructure from scratch. A third option may be simply creating a public transport system which is more efficient to the point that people don't own cars at all, but to do that you would need a much better public transport then we have now, one that doesn't slow people down waiting for constant loading and off loading of new passengers. However, we aren't building from scratch. Thus the aim of my question. Given a first world country of today, with existing road infrastructure and drivers etc, how will we progress to automated vehicles? Will we have to go the Google car approach? Will an entire new network of smart-roads that only automated vehicles can drive in have to be built? Will some hybrid exist? Basically given real world constraints on economics, first adopter issues (when only 10% have auto-cars you can hardly write rules that penalize non auto-cars for the sake of the auto ones), and politics. In short this is less about the technology itself, though still quite relevant, but also how real world logistics of implementation may modify the approach and thus ultimate destination of such vehicles. [Answer] # The Problem Self Driving cars need to do several things: 1. Go from point A to B using roads and only roads (no going through houses, yards, etc.) 2. Obey traffic rules on said route (stay in your lane, stop on red, go on green, yield to the right, obey speed limit, etc.) 3. Account for other cars on the road ("auto-cars" and human-driven ones) 4. Avoid all sudden barriers (children/animals in road, fallen trees, etc.) 5. Deal with sudden, unpredictable shifts in road conditions (sudden storms, black ice, etc.) 6. Do all of the above while not exceeding 5g's of acceleration. (Considered the "safe" limit of acceleration/deceleration in car crashes..) 7. Be reasonably economical/safe when compared to human-driven vehicles The solutions you've mentioned are good and bad at solving these. Let's take a look at each approach. # Guiding Road / Infrastructure Approach This is potentially great for 1 and 2. You can easily signal when a car needs to check certain conditions, because the road can simply tell them when to go. This solution is not so great at 4 and 5. You would need to monitor all segments of road (which is a lot to monitor) and then process what is a threat and what isn't a threat and then notify the vehicles on the road. Did I mention many segments of road are desolate segments of highway where this monitoring goes to waste? That's because the American West is not as densely populated as, say, Europe, or the American East Coast. Of course, a smart road could only look within a certain distance of active cars, but then there is the fact that someone could rig their car to not appear as an active car but still drive, or the simple problem of installing all that infrastructure. Additionally, what happens if a dysfunctional car can't connect with the road? We should also mention that some roads get replaced very often. Asphalt is a great material for roads, but it develops pot-holes and needs replacement. Dumb roads are already costly to replace. What about the smart roads? # Fully Automatic Car The fully automatic car has an advantage of all computing happening on-board. To solve problems 4 and 5, the easiest solution is to put the things for dealing with those on the car. The main solution for #4 is to put a LADAR sensor on top of the car and identify things in the road as you go along. If the car identifies things as it goes along, why not identify road signs and other cars? This means that one system solves multiple problems! In fact, this one system can solve 2, 3, 4, and 5. That reduces the price and the economic load on the infrastructure-builders. #1 will need to rely on GPS, which is a very dependable technology now-a-days. This single technology solves too many of these problems to ignore. So I see the google car approach to self-driving cars to be the most feasible. It requires the least amount of change for most parties involved, so if it's economically competitive, it stands a good chance of being the self-driving car of the future. [Answer] Right now, the Google car approach seems the most feasible one. The reasons are primarily economical; every car already has a bunch of electronics installed, you only need to add a couple of extra sensors to make it self-driving. All the rest is in the software, which is horifically expensive to develop, but once development is done, it can be copied and installed basically for free. The alternative of building "smart" roads is less reliable, horribly costly (because you need to install electronics all over the road network, which comes out as a lot more than you would have to attach to the cars) and with really complicated maintenance (a self-driving car can drive itself to a checkup; to fix something on a road, you have no choice but to go there and bring the tools). The nice thing about the machine perception approach is that you don't need to change much about the infrastructure. If you wanted to be fancy, you could maybe go and install special retroreflectors on highways to allow more precise self-location when you're driving really fast or something, but you don't really need that. It has already been demonstrated in research that you don't need a central planner to get near-optimal pathing for groups of drones, since a collaborative peer-to-peer approach can do the trick. So, once there is enough smart cars out there, you could try to figure out a protocol for them to talk to each other (which, for safety's sake, will probably have to be standardized by law). Thus, on roads used prevalently by smart cars, traffic will be smoother, more fluid and as a consequence could be faster as well. Determining how public transport would interact with smart cars is a bit tricky, since these are two rather distinct use-cases and I dare not venture a guess here. As for legislation, however, once self-driving cars go from super expensive prototype to something relatively affordable, you can easily encourage adoption without necessarily penalizing the majority of users. If the smart cars really do turn out to be much safer (and perhaps even fuel-efficient), insurance premiums, which factor heavily into cost of ownership, are likely to plummet. [Answer] Personally I think that should a car ever get to the point that it can autonomously drive the rural one track roads that I drive daily, it will be a strong AI in need of emancipation! ( Decisions recently taken: drive over a small fallen branch, apply brakes hard for a puddle because nothing behind me and a pedestrian off to the side, and how/ when to overtake the riders without scaring their horses) I think a likely development will be "slaveways": major roads or reserved lanes in which only vehicles with a legally mandated control system are permitted. Once you're on one the car and roadside automation do all the work and you can sleep or read a paper. Traffic density could safely be far higher because each car "knows" instantly what the ones in front are about to do. Or the cars might even couple up into trains. Elsewhere, you drive and the car monitors progress. If it detects you are headed for a collision it will brake or possibly swerve before you can. ISTR collision avoidance is already in some production cars. [Answer] ## Public transport We haven't even finished automating our existing public transport on dedicated travel ways yet. There are automated subway trains, so they're further along than Google is. But they haven't finished converting. Many trains still have human personnel. New public transportation is expensive. For example, the California high speed rail system is currently projected to cost \$68.4 billion: <https://en.wikipedia.org/wiki/California_High-Speed_Rail> And that's a replacement for just one road. Note that the federal government only spends \$80 billion on transportation. So if it bought one high speed rail segment a year, it would have hardly any money left for maintenance of the existing roads, already underfunded. If we include local and state government spending on roads and water as well, we can get up to \$416 billion. That's still only enough for six segments even if we drop all spending on water, which is rather important. And that's only 3120 miles of travel way (six 520 mile segments). Note that the US currently has 2.6 million miles of paved roads. Even assuming that a million miles of that are redundant, we'd still need five hundred years to replace the existing road system. Unless you are willing to increase spending on transportation construction by a lot, this seems totally infeasible. Who wants to wait five hundred years for automated transportation? It's possible that high speed rail is more expensive to build than slower rail systems. Ohio's proposed more modest speed rail system was only expected to cost \$3.5 million per mile, not the \$140 million per mile of the California system. That's better. If we only double spending for twelve and a half years, we could replace the system. Of course, that system would also be more complex. Rail lines would cross each other. People would have to switch trains relatively frequently, almost as frequently as we switch roads. That complexity would bump up the cost again. Also remember that we have to maintain the existing roads while we build the new system and maintain the new system going forward. And what do we do with the obsolescent roads? It will cost money to block them off or tear them up as well. And note that this requires everyone to double the money spent on transportation. Sort of feasible for the federal government but difficult for local governments. A more reasonable alternative would have local governments maintain existing spending while the federal and state governments each put up enough for a new segment a year. That extends the process out another twenty-five years. That assumes that the Ohio projections were correct. Note that the California numbers increased by a lot from initial projections. If we quintuple the Ohio projections (which is the kind of cost increases that were in the California project), we get amounts more like what California is showing. And that assumes that the current California projections aren't still underestimating the costs. Even only doubling the costs, that takes us out seventy-five years. ## Automated roads Automated roads that manage traffic are better at avoiding car to car accidents, but they are worse at everything else. For example, what if a child decides to run across the highway? The road's automation can't control the child. So cars running on that road need to have just as many sensors and ability for independent reactions as the Google car. Otherwise, they are less safe. I think that automated roads are likely to occur at the end of the process rather than at the beginning. When many cars are automated, they'll start getting their own lanes like high-occupancy vehicles do now. They'll join in linked convoys so that most can shut off their motors and coast. But this requires cars to be automated first. Another issue is that the automated roads would only work with automated cars. If you put regular cars on them then the automated cars have to handle non-automated traffic. So they require automated cars to function. And how do you get to the automated road? You'd have to take legacy roads to get there. So the automated cars could not require the automated road, which just gets us back to the Google car. ## Google cars The Google approach is the only one that works in the near term, that allows automated and non-automated cars to share the road. That allows automated cars to make it all the way from the initial location to the destination without switching vehicles. And most people won't buy if their car won't go everywhere they need to go. The Google approach is clearly the most difficult to program, but tests show it to be feasible. If it's feasible, then it's easier in every other way. There is no evidence that people are interested in increased public transport. It's inflexible, inconvenient, and expensive. Most people would prefer to take their cars with them rather than switch to public transport that runs on its schedule, not theirs. Also, public transport only works if you're going to a place covered by public transport. Many people aren't. You can drive to public transport, but you can't drive your car after you leave it. The Google car approach is the most likely because it doesn't rely on other changes. It scales anywhere from one to a billion cars. The other approaches require a certain level of usage to function. It can also be implemented on an individual basis. A single individual can choose which car to drive. A single individual cannot choose to implement public transportation (unless really rich). Without the Google car, we'll never get to the point of being able to use automated roadways. We also won't be able to make taxis cheap enough to make public transport practical in general, not just when traveling from and to urban locations. For most people, the Google car is the only method that they could use. [Answer] One of the main selling points of self-driving cars is that you don't need to buy one. Instead they will operate as taxis. The most expensive part of the taxi is the driver's time; once the car is self-driving it will be much cheaper. (Fun fact: the taxi service Uber is [actively working on](http://www.pcmag.com/article2/0,2817,2484564,00.asp) self-driving cars.) Currently I think everyone is designing self-driving cars with the intent that they share the road with normal cars. It's true that we could gain some efficiency by having self-driving-car-only roads, but during the transition period we will need cars that can share the road anyway. If we get multiple manufacturers making self-driving cars, it will be a giant headache getting them all to intercommunicate, so that's probably a long way off. [Answer] Here in Germany (particularly in Stuttgart) we have "car to go" cars. They are electric drive Smarts. There is nothing autonomous about them, but you can rent them one-way when you need them, and use a smartphone app to locate and book the nearest one. Obviously Google and Tesla are working on self-driving cars, and they are not the only ones. While owners of cars often have the desire to drive the cars themselves, people who rent cars sporadically are typically people who use public transport a lot and thus find it more natural that someone (or something) else is doing the driving. The way i could imagine self-driving cars to become more popular would be a combination of the above: Self-driving one-way rental cars in cities. It would make a lot of sense in every way. The price, design and inspection intervals are irrelevant for their users. The ability for the car to drive autonomously would help getting them to the garage for maintenance, getting them to the user once he needs them, re-arranging them if they should cluster in some place, and even allow using them for the ride home after a party, if some (or some more) alcohol was involved. Over time, people will get more and more used to them. The technology will become more robust, and due to installed numbers cheaper, plus people will have more trust in a technology that has proven itself over some time. Eventually, more and more cars will come with these features, until it will become near inconceivable not to have the self-driving systems integrated in a new car. One note: while i think that this way a very large percentage of all cars could become autonomous, i doubt this will reach 100% any time soon, since there will always be people who either don't trust the technology or keep their old cars simply because they like them, or can't or don't want to pay for a new car, or because they need the ability to handle things for themselves (think bodyguards or military, where the chance of someone hijacking the system is an unacceptable risk). [Answer] The future is already here, as it were. There are some concept self-driving cars which use cameras to identify obstacles, lines on the pavement, etc. Sensors are nice to have, but ultimately not needed. [Answer] Road sensors seem highly expensive, far more cost effective could be a special paint which the car's computer can easily identify, with plenty of built in redundancy in case of wear, poor visibility due to weather, etc. Instructions to the car could even be encoded into the colour or patterns of the paint. Signs posted on the side of the road containing the equivalent of QR codes could also be used. No need for fancy expensive electronic sensors. But I agree with others and think it'll be more important for everything to be self-contained within the car, and over-ridable by the driver (or actually passenger I suppose), the additional reason to what others have said being you may want to drive somewhere where the infrastructure has not been laid down. For example, sometimes big once-off events/festivals, rather than being forced to be near an established car park, simply pay a local farmer for the use of one of their fields for patrons to park their cars. Right now it just needs to be an open, flat surface. How would a car which relies on road sensors park here? [Answer] ## Test it in fishbowl territories By that I mean, find areas with modern roads that are isolated from the rest of the world by physical and/or political boundaries. The biggest problem you'd have trying to implement such a system in the US or Europe is the sheer number and length of connected roads over such large areas. What you want is a place with a lot of money but very little area or connection to surrounding territories. A good example would be something like Hawaii. It's a relatively rich state with a small area, and not connected by roads to anywhere. It would be a relatively simple task there to convert all roads and vehicles to be sensor-equipped. Other examples might be Japan, Taiwan, Ireland, Iceland, and any other island nations. Examples of non-island nations might be places like Israel, which despite having land borders with several other countries has very little cross-border traffic for political reasons. South Korea is in a similar situation, as its only land border is not exactly a friendly one. In fact, there are some similar projects being considered for places like these. A system for battery-powered cars has been proposed, where the batteries would be rented rather than owned, and could be replaced with a fresh battery on the fly at battery stations, which would eventually take the place of gas/petrol stations. The challenges to infrastructure development would be similar, so similar strategies for test-markets would apply. Once you have established systems up and running in a few prominent isolated locations, you now have proof of concept, and you can point to the likely dramatically reduced instances of vehicle fatalities in those places due to your system, which will cause interest in larger nations to increase. I still think places like the US and Europe will be fairly late adopters, just due to the sheer scale of such a project. You might see it cropping up in places like Switzerland first, or possibly in major cities like New York, San Francisco, L.A., Chicago, London, Paris, Berlin, etc. long before it takes hold in the surrounding areas. It's possible you'd even have "hybrid" vehicles, which are autonomous in major cities where the road sensors have been installed, but still under human-control everywhere else. ]
[Question] [ [ArtOfCode](https://worldbuilding.stackexchange.com/users/2685/artofcode)'s previous questions about Alynn have defined her movements to Rolhelm. Now there, she faces a new problem: getting a job. Everyone in Rolhelm is expected to have a job. Alynn is no exception and she has to get one. However, she also wants to spend as much time not working as possible, so she can practice magic. So, her job must be one in which she can use her magic to speed up her work as much as possible and get out of there. Some conditions: * The job must be picked from among those you might find in a 15th century village. * Her employer should see as little of her magic as possible. The same magical system applies as was defined in [this](https://worldbuilding.stackexchange.com/a/18071/9826) answer to the last question: > > * I'm going to assume she can exert force at will, just using her mind. She can't violate impulse conservation, so she'll mostly have to create symmetric opposing forces. > * She can also create stuff from nothing, paying the energy which the created stuff has (so E=mc^2 for matter and E=hf for Photons). > * To exert force she needs to know precisely where and in which direction > * She can also get very precise knowledge about the world around her by concentrating on it. I'm assuming this is what she does when reading minds. So to analyze a head-sized volume of matter very, very thoroughly she needs 5kJ/60s~=85W. > * I'll assume mind reading is more or less instant because she has so much practice doing it and it's similar structures again and again, but for new things she needs some time. Using mind reading as a reference, she can probably perceive stuff which changes too fast for the eye, probably in the 10ms range to notice something. > > > She has 4MJ of energy to throw around each day. What job of a medieval village could be sped up the most using her magic, while keeping as secret as possible? [Answer] [The 15th century saw the introduction and rise of clocks in private households.](http://www.historyworld.net/wrldhis/PlainTextHistories.asp?groupid=1244) Before that, timekeeping was the monopoly of the churches and the wealthy, due to the immense cost of setting up and maintaining such a complex mechanism. In Alynn's age the know-how of creating intricate clocks (even masterpiece models that show the movement of celestial bodies) is certainly present, and she has tremendous advantages when compared to a non-magical clockmaker: * She can quickly and non-destructively analyse a given volume, therefore finding the cause of an error in minutes, not in hours or days required for a complete disassembly. This is how she would learn the ropes of this trade, by inconspicuously inspecting clocks in cathedrals, homes and palaces. Maybe sometimes resorting to mind reading, when a master of the trade is nearby. * She can also manipulate parts of the mechanism directly, without having to free them or even seeing them. * She can even modify the individual parts, like adding or removing teeth to/from a cog. These abilities allow her to perform repairs in under an hour that would take others days. Considering that for the common folks clockmaking is borderline magic, she wouldn't even be that suspicious. A client enters her shop with a broken clock. She hears the ringing of the bell over the door and greets him with a cheerful "A moment please!" from the bowels of her workshop, while putting away her magical books, finishing the sentence she was writing or just stretching after that long meditation. After a few seconds she emerges from her workshop and walks up to the client. During this she has already analysed the clock, therefore knows what is wrong with it and how long would it take to fix it. > > "My daughter was playing with the cat when she bumped into this clock > and it fell from the wall and it won't move since then, could you > please fix it for me?" > > > "Well, let me see it... It looks intact, but I'll take a look at it nonetheless. I have another one back in the workshop, so it'll take longer than usual, please come back next Sunday, I'll try to get it done by then." > > > The client is of course very grateful, when on the next Sunday he receives a flawlessly working clock, while Alynn managed to spend all this time as she wished (minus the fifteen or so minutes required for the actual repair). The townsfolk would suspect nothing, since it is quite normal for a clockmaker to spend days in her workshop without letting anyone in. At least until a curious young kid starts asking her for lessons on clockmaking or even an apprenticeship, and Alynn has to realise she doesn't even know where her screwdrivers are. --- Her talents at analyzing matter and making small but delicate changes could also be employed as a doctor (finding constricted veins and cleaning them with magic, seeing and setting broken bones, extracting splinters, etc) or as an alchemist. [Answer] [A Scrivener/Scribe](http://en.wikipedia.org/wiki/Scrivener) Copying books was a very labor intensive process before the printing press. But it should be relatively trivial for her to copy a book with magic, in terms of both time and energy. I'm assuming here that she will have the raw materials available, and simply use her magic to replicate and copy over the contents. Copying books is generally a private activity, so people would expect her to spend most of her time alone doing that. This would let her do several days of normal work in only a few hours with magic, and allow her the rest of the time to her other pursuits. As another bonuses, a scribe will be assumed to be well-read and knowledgeable on wide range of subjects. This gives Alynn a plausible reason to know things that she might otherwise find difficult to explain, helping her preserve her cover. She can also have books on various topics, like chemistry or physics, that she would find useful as a mage but would otherwise be hard to explain. She could also use it to help cover her mind-reading - as an example, let's say that she finds out from her telepathy that someone is a con artist, and needs to expose them. She could use "a book I once read about your homeland" and engage him in conversation to expose that he's lying about his background. [Answer] So, an occupation available in a Medieval-style location that won't arouse undo suspicion and provides time to practice her magical arts. There are several options, and I'll pull freely from [this list of Medieval jobs](http://www.medieval-life-and-times.info/medieval-england/medieval-jobs.htm) to answer the question. * Apothecary -- The apothecary works with herbs and roots to produce cures for minor ailments. Alynn would be the small-town equivalent of a physician. * Astrologer -- The astrologer studies the stars and planets, which are typically only available at night, and is already considered a mystical person. Alynn would have ample time to practice magic during the day without arousing suspicion. * Gardener -- The gardener is responsible for the castle grounds, such as ensuring ivy doesn't weaken castles. Alynn would have an inconspicuous position typically overlooked; of course, this position isn't available in a country village. * Herbalist -- The herbalist is a counterpart to the apothecary, responsible for planting and growing herbs. Alynn would have time while the plants grow to practice her magic, maybe explore ways to accelerate plant growth. * Janitor/porter -- The janitor was responsible for the primary entrance area of the castle, such as ensuring people didn't leave who weren't supposed to. Alynn's ability to read minds comes in handy here; of course, this position isn't available in a country village. * Physician -- The physician had a lot of respect in the Medieval period, but they were also expensive. Alynn could find this an ideal occupation should she be in a larger town. [Answer] Tutor/Master She could take Education into a career, leaving her to work just what is strictly necessary. The downside to this is that she can't really be helping herself with magic. Physician Her magical prowess would certainly be an asset when healing others. Seeying this as a noble, respected and profitable career, she'd have plenty of time for her own, if she's in a smaller town without having to leave her home (Physicians often would travel to other towns) Cook in a Tavern Men like wine. Men like food. She can speed up the process of cooking and fermentation (to make wine) so she can literally be a fast food joint. Pumping porridge and wine in seconds so she can be left alone for her witchcraft. Madame Madame's only job is to collect rent and protect her girls (for those who don't know that's the equivalent of a Pimp). She can use her magic to secretly hurt those who try to sabotage her business, while simply being a money collector. [Answer] Nice question. I like this Alynn-chain stories, make my mind work better :) Ok. So after short consideration I decided to propose these: 1. Sheriff/City guard master assistant - a work similiar to our times' detective or interrogator; with her magic skills she can work quietly and, sometimes, alone, while very succesfully, at finding lost people/items, catching thieves (and so on). 2. Medieval games' host - right now we have Hold'em and Puzzle SE, but in medieval Europe (I assume that Alynn's world may look like one) there were some games of wits and other ones - if someone loses, he lose his bet. To stay 'under cover' she may just manipulate and choose whether lose or win (to let players' get impression that they CAN win) and make a profit. The 'job' is dependant on size of the city and possible impact on other cities around (fame!). 3. Herbalist/doctor/priestess - she may use simple herb potions, but, as everyone knows that they work in some way, she may be greatly succesfull taking her magic skills into account. She may state (and people would probably believe) that the cause of reviving from illness is mere medical impact of these herbs or religious influence (whatever she like). All of these above will be chosen/played like to avoid deconspiracy of magic skills, of course. [Answer] Marketing/Sales With her mind reading skills she would prove to be an excellent sales person to any merchant trying to sell any sort of goods in the market. She will be able to identify potential customers in a crowd and concentrate her efforts on such people , thereby saving time. Also this way she gets the satisfaction of using magic and remain subtle as well. [Answer] I'm going to say barrister/magistrate/judge or an assistant to one. The mind reading is going to be the easiest to cover up under the pretext of being an expert at understanding people. The villagers are trying to solve a murder? She makes a song and dance of being given the chance to question all the suspects, makes up fake explanations about how she's spotting facial ticks or twitches and then walks with the murderer holding their arm after explaining quietly to an authority figure that she's feeling movements in their arm for twitches to lead her: then walk the crowd straight to where the body is buried. So basically pull a Derren Brown, explain how it's not magic and teach people little non-magical tricks while actually doing magic to read minds. Ditto she's be well suited to any job where being able to spot secrets and lies or knowing just how much your opposite is willing to spend is a big advantage: trader, money lender, tax collector. ]
[Question] [ (First of all, perhaps this is a duplicate of [this question](https://worldbuilding.stackexchange.com/questions/569/is-there-a-scientific-explanation-as-to-why-aliens-should-look-similar-to-us), but I'll give it a go since I'd like to focus on something different. Or the answer is there but I couldn't quite catch it. Oh boy... \facepalms\*) A human has been [kidnapped by aliens](https://worldbuilding.stackexchange.com/questions/3054/can-a-genetically-modified-human-breathe-something-other-than-earths-oxygen-nit); after years and years of capture and travel, he meets a fellow human, almost identical to him (not just humanoid in shape, with a head, a torso, two arms and two legs: a human) - the difference is that the new one doesn't come from Earth and has never been there: in fact, he comes from a planet in another galaxy, with a different tech level than Earth's (irrelevant for the issue). How (and if) can this be possible? [Answer] If you want human* and not just humanoid, then the advice about convergent evolution in that other question isn't really applicable - getting the basic shape is certainly plausible, but a near-perfect match starts stacking up too many coincedences. You essentially have three options: 1) It's not a coincedence There's some kind of link between the Earth human and the alien 'human'. Maybe the 'alien' is the descendant of previous kidnap subjects who were transplanted to this other planet, maybe both Earth and the other planet were seeded with life as part of some alien terraforming process, maybe the aliens were deliberately shaped to resemble humans for some reason (or earth humans were shaped to resemble aliens!), maybe there's some cosmic... something... that pushes intelligent life towards evolving into 'human' form. Whatever it is, the alien somehow looks like a human for a reason, despite the distance between Earth and the alien planet. 2) The universe is a REALLY big place Getting (almost) exactly the same result in two places independently isn't impossible, just very unlikely. If you roll the dice enough times, even the most unlikely coincedences have a chance of coming up eventually. Note, however, that for this to make sense on its own you need incredibly large numbers of alien races - enough that it would be impossible for a human to meet more than a tiny fraction of them in one lifetime. This shifts the question from 'why does this species exist' to 'why did he happen meet one', but fortunately that's a little easier to justify. Introducing the alien to someone who looks like him is an understandable impulse. 3) Probability? What's that? Yes, it's freakishly unlikely. It happened anyway, and you don't feel like discussing the matter further. (This is not a recommended option, but as noted above 'impossible' and 'unlikely' - even 'very very *very* unlikely' - aren't at all the same thing.) [Answer] To answer this question you can forget convergent evolution or anything like that. Even if you seeded the planet with earth-like bacteria the chance of them evolving to something biologically human are so small that even in an infinite universe it just won't happen. A bipedal shape with a head and arms may well emerge, but it would not be biologically compatible with humans. This leaves only two options: Transplantation A seed population of biologically modern humans (so probably within the past 50 thousand years) was taken from our planet and placed on the other one. The motivations and technologies used for performing the transplantation could vary widely but the results would be what you desire. Directed Evolution Perhaps a species was facing extinction (lets say their sun was going nova) and they had not yet worked out a way to perform faster than light travel or survive the trip to another star. Instead they create robot probes and send them out, these probes have archives of their culture and nature on-board and are programmed to work with any suitable lifeforms they find and gradually guide their DNA until they match the alien's form. Once that is done the cultural archives would then be made available. Other scenarios could be imagined, but the key point is that we need an alien intelligence or mechanism that for some reason favors the human form. The machine when it arrives at a planet wipes out any existing dominant species (bye-bye dinosaurs) and then starts guiding the evolution of the suitable lifeforms towards the target form. With each generation it makes modest changes to the DNA that steer them in the desired direction while not causing them to be incompatible with the parent species. As the process advances it starts pruning the evolutionary tree where it is not moving in the desired direction (bye-bye Neanderthals). Over millions of years eventually the modified species becomes genetically compatible with the original intelligence that built the device. At that point the device makes contact and provides its archive, welcoming the latest members of the Alien's species to the vast galactic commonwealth that copies of the machine are creating all over the galaxy. [Answer] As in several my other answers, I will try to list your options from the most plausible to least plausible: 1) Make apes win (again). I am not referring to the [Planet of the Apes](http://en.wikipedia.org/wiki/Planet_of_the_Apes) but rather on similar evolution process on different planet. In other words if this humanoid will be from planet of size of Earth, which is about the same distance from star of same qualities as Sun has, then it is really plausible to assume that ape-like organism will be dominant and the most intelligent ape will develop into something human-like looking And yes, to me, there was only one scientifically plausible way of achieving it. So, health warning, the rest of my ideas is common sci-fi and magic trope, where the scientific plausibility drops by order of magnitude in each point: 2) One "Master race": It has been done in Star Trek so, why not repeat it again? In other words, the explanation to this could be that long long time ago, in galaxy far far away (pun intended) there was one master race of very powerful species which decided to populate our galaxy by their genome. 3) Space-time travelling paradox: Einstein is hard to understand. And you can assume, that since almost everyone knows E = m.c2, almost no one knows the correct time paradoxes of near speed of light travel. You could assume this and use wrong understanding of Theory of relativity to use it for time paradox purposes. Long story short: It was the Earth the whole time, only different time. (Did I tell you that I really love Planet of Apes?) 4) Alien experiment went wrong: Look, you already assume, that your main hero was captured for some time already. What actually prevent the kidnappers to play around with DNA of our hero? [Answer] If the alien "human" is able to meet the kidnapped human face to face despite being from a galaxy far, far away, then obviously intergalactic travel is a thing. There are various ways in which this might be the case, with the most obvious ones being a wormhole and a blue police telephone box. Whatever the means of transport was, there's no reason why it shouldn't be bidirectional, so that the alien's ancestors were able to reach and populate their planet by passing through a wormhole or whatever from Earth. Or it could be the other way around, that Earth humans originated on the alien planet, or both groups originated from some third location via alien seeding, but then there's a fossil record which becomes difficult to account for. There are obvious parallels here with Doctor Who (and also with Interstellar but I won't go into that as I have't seen it, I've only read the reviews and seen the trailers). If we add time travel into the mix then the parallels become stronger. Technically the Doctor is a Gallifreyan, not a human, but I strongly suspect that the Gallifreyans are descended from humans, and the differences (e.g. having two hearts) are a genetically-engineered adaptation to the conditions on Gallifrey. [Answer] # It's unlikely, but plausible [The accepted answer](https://worldbuilding.stackexchange.com/a/2496/46434) from the question you linked argues that bipedalism is something you can realistically expect from a large portion of intelligent species in the universe. So it's already looking good. As long as the alien "human" planet has a similar climate and general geography, it wouldn't be surprising for them to have similar general outward traits, such as skin and perhaps even hair in all the same places of similar frequency. Placement of eyes, nose, and ears could very well be the same, though ear shapes and dental layout could vary quite easily. It wouldn't be absurd to see melanin in an alien species, so hair colors being in the same range is reasonable. There is some room for variance in digit count, but not enough to raise any plausibility concerns regarding having 10 fingers and 10 toes. Finger and toe nails? It's just a re-purposing of claws, which probably exist in a significant portion of land dwellers on nearly any life-supporting planet. A near-human alien wouldn't necessarily need to be a mammal or have the same expression of sexual dimorphism: A female-equivalent in this species might not have breasts or broad hips, or males may be just as naturally muscular (or less) as females. Males might be the ones to carry offspring. They might lay eggs instead of having live births. There might not even be biological sex or dimorphism at all. There are a lot of possibilities here. Internal organs will likely be different in shape and/or placement, but blood will almost certainly still be red and carry oxygen; bones will be made of calcium and filled with marrow; and digestive tracts will flow from top to bottom. DNA layout isn't going to match, but that only really matters for cross-breeding. Basically, from most variable to least variable, probably disputable by someone with a stronger biology background: * DNA layout * Internal organ shapes and layout * Blood compatibility (transfusions are extremely unlikely to work) * Presence/absence of minor organs such as the pancreas, spleen, tonsils, or appendix. * Ear shape * Dental layout * Sexual dimorphism * Hair layout * Ear placement * Pool of available pigments for hair/eyes/skin (only a partial overlap is needed here, though melanin or another brown pigment is a must) * General skeletal structure, including digit count * Number of chambers in heart * Mammal? * Placement of brain * Bone Structure * General mechanics of blood, heart, brain, and lungs A lot of things have to align, but it's a plausible probability as long as you don't care about internal organs matching and you don't need cross-breeding for your story to work. ]
[Question] [ I'm working on a pretty detailed alternate history of the ancient America's, and currently I'm focusing upon Mesoamerica in particular. The core difference is that, through several different mechanisms that can be handwaved away, the Natives at the time were able to domesticate significantly more animals than they did in true history. One of the animals I'm eying for domestication, mostly for the cool factor, is the [Kelenken](https://en.wikipedia.org/wiki/Kelenken). These birds were huge, nearly 10ft tall carnivores that went extinct a long time ago, significantly before any human presence in the area. I'm willing to handwave this as well, since it's decently plausible that a much smaller relative could be domesticated towards gigantism to bring them back in line with this size. For the purposes of this question, it's fair to just assume we're dealing directly with the Kelenken species, for simplicity. However, a big issue that I'm running into is a rational reason for why the Natives would bother interacting with these large carnivorous birds long enough that they would be domesticated, and ideally a cool enough use for them. I'd considered mounts, but birds-- even flightless ones-- are fragile and difficult to ride, and in this world the natives domesticated the Hippidion for riding anyway. Then I thought about their potential as hunting partners, but humans brought dogs with them across the Bering Strait when they migrated to the Americas in the first place. I don't really want them to just be another source of food, and eating a carnivore would be a waste of resources anyways. I feel like I'm out of options here, but the idea of large domesticated carnivore birds is just too cool to give up! How can I realistically justify the expenditure of time and resources towards domesticating the Kelenken species for pragmatic ancient humans? [Answer] Sprint hunters for the nobility Humans and dogs are social endurance hunters - top speed is not that great, but we keep going until the prey is exhausted. Dogs work well with humans in this type of activity because they can use their sense of smell to track the prey's scent faster than humans would be able to track using visual cues. This is not the only way to hunt, though. Kelenken are theorised to have been fast runners, which means that humans who domesticated them could take them out on a hunt in which some humans flush the game into the open and then the Kelenken handlers send the Kelenken to sprint after the prey and bring it down without a long chase, in the same way that very wealthy ancients used [cheetahs](https://en.wikipedia.org/wiki/Cheetah). The humans share the kill with the Kelenken, but they also provide protection to the exhausted sprinter so it does not risk having its prey taken from it by scavengers. The Kelenken are going to be high-maintenance, so they will only be domesticated by the wealthy, the same way that cheetahs or falcons were only ever kept by the nobles. Just make them sufficiently social that they will accept domestication and fast enough to be sprint hunters - most of what we "know" about Kelenken is speculation based on very little evidence, so you are fairly safe making up any minor details you like. [Answer] Because they are cool, but you have not considered just how cool. [![enter image description here](https://i.stack.imgur.com/L0HEz.png)](https://i.stack.imgur.com/L0HEz.png) Maybe you don't remember the arcade game Joust. The idea of having a bird large enough to ride is spectacular. Even if it can't fly. Even if it can barely hop. It's got those talons and that beak. And the feathers would be so stylish. They could be specially bred to be good saddle beasts for both practical and ceremonial reasons. Their beaks and claws could be bred to be long and sharp and intimidating. Consider the range in different horses, from wild horses running around in the wilderness to Percheron stallions. Other cool factors include that the color of bird's feathers can be quite amazingly varied. For example, green fur is unusual. I think the only case where mammals have green fur is when certain species get a kind of fungus. Birds can have green, gold, scarlet red, orange, blue, etc. They can have different colored feathers under the wings so when they spread their wings they can put on a gaudy display. Just imagine a peacock that weighs about 2 tons. Or imagine this guy scaled up to 12 foot tall. [![enter image description here](https://i.stack.imgur.com/mfnuD.gif)](https://i.stack.imgur.com/mfnuD.gif) And they could pull tricks that, while possibly not very practical, could be impressive to a festival audience. Bird in front spreads his wings to conceal what guy back there is busy doing, which is getting ready to fire his crossbow. A little nudge, bird flips down wings, crossbow bolt flies from concealment. Imagine the display that the Royal Flyers could put on. The fact the birds never get more than a meter or two above the ground would not change their name. They would come out, do some close order precision marching, then present to the Royal Family with their wings spread. Imagine the [RCMP Musical Ride](https://en.wikipedia.org/wiki/Musical_Ride), but on two ton birds with fantastic colored feathers. It would be glorious! And possibly quite loud, considering the noise that various birds can make. Or, in actual battle, imagine 1000 of these suckers charging at you. Each with his wings flashing different colors, his rider brandishing a 12 foot lance, and the bird making his war cry. Every bird with a two foot long serrated beak and foot long razor sharp claws. Spectacular! [Answer] ## Eggs Yes, this is a food source, but in a roundabout way. What better way to start your day than whatever the authentic equivalent of a breakfast burrito is? ## Pets What 'use' are cats? I love mine but even my love doesn't make her 'useful'. Kelenken are dangerous pets, but that's surprisingly common too. ## Vermin control As per cats, a fig leaf of usefulness to justify a pet, or a truly useful societal purpose, depending on circumstance and how much you like kelenkens. ## Gambling Why not just use dice? I don't know, but cock fighting, bear fighting, horse racing, etc, etc, have been perennial gambling favourites in history. You have entire stadiums and fortunes that exist for nothing but racing horses, to this day. Do kelenkens race? Fight? Race then fight? Fight people? Race people? Great, you can gamble on any of them. ## Guano Their poo is absolutely perfect for corn growing. And it comes in conveniently large quantities. [Answer] Optical telegraph [![enter image description here](https://i.stack.imgur.com/CvidH.jpg)](https://i.stack.imgur.com/CvidH.jpg) One thing a large flying beast can do that dogs and horses can't is be seen from far away. I don't know how the economics work out, or why the riskiness of initial domestication would even be attempted. But once all the pieces are in place you can send messages over hills or across large distances, thousands of years before the electric telegraph. I imagine a pack carnivore may have the ideal mental traits for this kind of training. See [wikipedia](https://en.m.wikipedia.org/wiki/Optical_telegraph) [Answer] # Terror Mount [![enter image description here](https://i.stack.imgur.com/rrmjQ.gif)](https://i.stack.imgur.com/rrmjQ.gif) As you can see the ostrich can carry a person for a stretch but is too small to do so without running into each other and falling down in comic fashion. Terror bird is a jumbo ostrich. She is better adapted to her environment than a boring old horsey horse, and jumbo enough to carry a man well. Maybe TOO well, if you catch my drift. . . . [![enter image description here](https://i.stack.imgur.com/cUFzb.jpg)](https://i.stack.imgur.com/cUFzb.jpg) As John points out, they can also pull chariots. Like the Ancient Romans. [![enter image description here](https://i.stack.imgur.com/s8u82.png)](https://i.stack.imgur.com/s8u82.png) This is easier for training purposes. It is easier to train an animal to pull something than to carry a person. [Answer] # A Hungry God: Birds and bird imagery were important to Aztec civilization. So imagine the bloodthirsty Aztecs deciding these tremendous creatures were sacred to their faith. Initially selected to consume the flesh of sacrificial victims (what the birds eat correlates to what the god gets), this relationship could expand over time as the birds came to accept domestication. They would make terrifying additions to a military (envision these critters sent ahead to terrify the local tribes). Since their specific appearance and behaviors/abilities aren't well understood, they could be wildly colorful and quetzal-like (especially if they were recapitulated to this size AFTER domestication). The Aztec elite warriors wouldn't be eagle warriors, but kelenken warriors. And if one of these beasts occasionally ate a citizen, WELL it must be the will of the gods. [![enter image description here](https://i.stack.imgur.com/8dhtv.png)](https://i.stack.imgur.com/8dhtv.png) [![enter image description here](https://i.stack.imgur.com/iJNRE.png)](https://i.stack.imgur.com/iJNRE.png) [Answer] You write: > > I'd considered mounts, but birds-- even flightless ones-- are fragile and difficult to ride, and in this world the natives domesticated the Hippidion for riding anyway. > > > I have a memory of seeing an illustration of Sultan Muhammed XII of Grenada, known as Boabdil, as a child riding on an ostrich. And some ostrich farms offer ostrich riding for tourists. you can find photos and videos of ostrich riding on the internet. Ostriches are not really strong enough to be ridden at lot. If the kelenken was a terror bird, it would probably have been much stronger and sturdier than an ostrich to survive the injuries received when fighting its prey. [Answer] ## The same reason we "domesticate" Tigers/Lions/etc. Terror birds were alpha predators. They are too big and dangerous to just bully around like you can with with dogs or cats meaning that they require very specialized handling to even begin to domesticate. Even if you've owned a Kelenken since it was a whee little chick, there is still a good chance that its predator nature will take over one day, and it will kill you anyway. So, it sounds like I'm saying the native Americans would not keep any domestic Kelenken, but on the contrary, the fact that they are so dangerous is precisely why they'd have a few. Throughout history, lions and tigers have been kept as highly exclusive pets. The kind you put into a circus to show off your masterful animal handling skills, or the kind you keep staved and in a cage that you feed prisoners to as the ultimate form of corporal punishment, or the kind you have expert gladiators or other alpha predators face off against in mortal combat. ## ... or if you want a more symbiotic use for them, they could take the role of Destiers Hippidions have bodies more like donkeys than horses meaning that they probably have a lot of strength and endurance, but can not move much faster than 15mph, maybe 20mph. Kelenken however have bodies more like an Ostrich meaning they can probably sprint at speeds up to about 40mph, but probably not the best endurance runners. Historically people have breed horses for 3 major jobs: * Draft horses: Horses bread to pull carts and plows. Your quadrupedal Hippidions will certainly fill this role best. * Palfreys: Horses bread to be comfortably ridden over long distances. Given the shape of thier backs and better endurance, Hippidions are again the clear winner in this catagory. * Destiers: War horses bred to carry knights quickly around the battlefield. These were the most expensive of horses because it is hard to bred and train a horse to be aggressive and brave enough to even carry you into a line of screaming guys with weapons... and then on top of that, they need to do it as quickly as possible. Here the Kelenken are much better than Hippidions, and possibly even better than horses. Kelenken are predators so they WANT to charge and attack at things, and they can do it at speeds much greater than a Hippidion ever could. Historically, Destiers were not great draft animals and they were considered way to valuable to risk ridding for long distances. A knight would bring a separate Destier, Palfrey, and Draft Horse while on campaign anyway; so, you're not taking anything away by forcing your war-mounts to be a different animal than your work horses. ]
[Question] [ I'm writing a low fantasy fiction in a XVIII century-tech kind of world. The reason of the setting is that I love early modern muzzleloading weapons, and I think guns can make fantasy more interesting. So, in my world, an analogue of Qing China decided to embrace flintlock technology, starting a gun race against the other empires of the world, even considering colonialism. This take the gun to a whole new level, with gunsmiths being a profitable and honorable profession around the world. Suddenly, seven big asteroids impact the northern hemisphere of the world, bringin years of cold temperature, some animals extintion and famine. Empires are triving to survive, and some just move to their colonies because the weather was better to rise crops. With the asteroids came some fantasy terrors that bring some flavor to the mix. A hundred year later, in a new world with new customs, my fiction starts. I was traying to make it as realistic as possible... for a fantasy... But then I find something that make me want to apply the "rule of cool", just because is cool. I'm talking about [Combination weapons!](https://en.wikipedia.org/wiki/Combination_weapons) Gun-axe combination, sword-axe combination, spear-gun combination (well, a bayonet), dagger-gun combination, gun-mace combination. They look beautiful! Just look at this indian thing! [![enter image description here](https://i.stack.imgur.com/Kg9ns.jpg)](https://i.stack.imgur.com/Kg9ns.jpg) It has some ups and downs. The more you make a gun-sword to shoot, the less a sword it is. The handling is weird, the weight is weird. And is heavy to aim with one hand. That's why everyone use a sword in one hand and a gun in the other. Gun-axe, nevertheless, was used by Swedish army. Specially the navy. It has a good handling, a great carbine and a great axe at the same time, ready to break open ship doors with it! If I want this cool and impractical thing to be kind of widespread and mainstream in my world, I would like it to be with a "reasonable excuse" behind. And I can't find one... How can I make combined weapons widespread in my world? [Answer] For a whole planet, getting anybody to agree on anything will require that it be practical, and besides bayonets of various types, few sword-gun combinations are going to fit the bill. For a single country, however, you can get all the gunswords you want using cultural factors. The easiest way to get the largest number of people to do slightly impractical things is to make doing the slightly more practical thing illegal. For example: the law permits only aristocrats to own "swords and firearms", but it creates a carveout for firearms with permanently fixed bayonets - these being indispensable for the militia. The letter of the law is nebulous as to what constitutes a bayonet, except that it has to be large, prominent, and effective. Gunsmiths promptly start building combination guns of all types, and swordsmiths start hiring gunsmiths to put guns on their swords so that they become "bayonets" and can be sold on the civilian market. A historical example of this phenomenon: in early modern Germany, laws made the sale of swords legally difficult. Smiths promptly started making new weapons that were all but identical in form and function to the region's most popular sword, except that having riveted handle scales instead of a hilt that encircled a tang, they weren't swords at all, but 100% legal knives according to the letter of the law. [![enter image description here](https://i.stack.imgur.com/WssW9.jpg)](https://i.stack.imgur.com/WssW9.jpg) This is a knife. [![enter image description here](https://i.stack.imgur.com/2OMsq.png)](https://i.stack.imgur.com/2OMsq.png) This is a sword. [Answer] There are a lot of reasons why weapons become popular or not. Things like ergonomics, cost to acquire, range, speed, and... *the rule of cool!* For instance, the [Indian Pata](https://en.m.wikipedia.org/wiki/Pata_(sword)) very likely followed the rule of cool. Yeah, it's a sword gauntlet and it looks crazy when wielded. More weapons and other practices exist simply because they were cool. Wavy blades, etching designs on blades and armor, polishing swords to mirror finishes, wearing feathers, and more happened because *it was cool. Admittedly, a lot of these things may have had other benefits and purposes, but those are not always as obvious as how absolutely awesome it looks.* Simply saying that these gun-and-melee weapon is the style and these societies have the means to make them could be enough to justify this for people looking into your world. Worse things happen in very successful worldbuilding projects than a lot of firearm/melee weapons. [Answer] A good reason for people to adopt "gunswords" is because of the historical unreliability of black powder weapons, as well as the slow reload speed. Get them wet, miss a shot, or face off against more opponents than you have loaded weapons, you're going to be in serious trouble. This was the reason that muzzleloaders had bayonets, and also one reason why the Bowie knife commonly carried, in addition to single-shot black powder pistols. (the rise of reliable black-power revolvers reduced the need for a knife somewhat) There are also knife mounts made for modern pistols, so the idea hasn't exactly gone away. With specific regard to combination weapons in a fantasy world, the historical reason for a bayonet on a muzzle loader was to be able to engage in armed combat once conditions on the battlefield called for it. Now, let's say that a school of thought has likewise developed in you fantasy world where the limitations of black powder weapons are realized, plus people want to be able to engage in melee immediately after firing a shot. Or, perhaps they want to be able to stab their opponent and fire a shot, or use a single shot as part of their manual of arms in a swordfight. Parry an opponent, fire when their sword has been deflected. It is a different approach from developed historically, but is probably not any less valid. The same could be true of a larger polearm, axe, etc. The downside is that it isn't going to be very accurate, even by smoothbore standard, as shorter barrel lengths are more likely. This is because the extra weight of a longer barrel would make the weapon even more unwieldly and slow to use. The upside is that the weight of a weapon would mean that less recoil would occur and a larger bore would be possible. Another consideration is that the trigger or firing mechanism would be to be built in such a way that a user would not have to abandon the melee use of the weapon to fire. A couple of idea there would be a way to activate the gunpowder weapon when the melee weapon strikes, or a trigger built into the guard on a rapier or backsword. The use of the gunpowder weapon has to be as natural as using the blade, and both parts have to be integrated, both in construction and operation. If this isn't done right, people will likely be reluctant to adopt them. (if these sorts of weapons are still relatively new, there would be the possibility of rival designers trying to develop a better weapon, while using demonstrations or even duels to prove their weapons superior) As long as all of those considerations are covered, it's likely that people would be more willing to adopt weapons like this. [Answer] We have a precedent for them: the bayonet. We use to have gun lines for offense with pike lines for defense. The bayonet meant that everyone could get a gun and increase the total number of shots per minute that a formation could throw downrange. As hillbilly\_coder mentioned, black powder guns make the bayonet much more useful. Another thought is that if this is a Mad Max kind of world, people might be nomadic. That would mean when you have to grab and go, grabbing two weapons at once is better than grabbing only one of the two and, possibly, grabbing the wrong one. Note that any combo weapon will likely not be as good at either job as two specialized weapons. The sword will be heaver and not as balanced as a dedicated sword. Etc. However, if only the wealthy can afford combo weapons, the wealthy will have combo weapons. The not quite as wealthy would have cheap knock offs to appear more wealthy. Combo weapons would spread downward through society over time. [Answer] Combination weapons have been tried in real life, they were generally impractical. Expensive to build, able to fire only one bullet with poor accuracy, and too heavy to be used as well as melee weapons. You basically got one weapon that didn't work well at range or melee. Bayonets' are the only really effective form, thus the reason they are the only ones used in real combat, but I assume you want something more interesting then that. I consider combined weapons hard to justify, but I can come up with a few possible justifications. I'm not convinced any of them are enough to justify combined guns, but perhaps they could work when used in combination with each other and/or other answers (I honestly really like GS' answer). Magic: Magic covereth for a multitude of sins. You can make up any kind of rules you want for a magic system, it's entirely possible to come up with some that allow magically made combined weapons that otherwise wouldn't be practical. I won't elaborate too much on this though since I get the impression this is a low magic world your envisioning. McGuffin Mineral: The main problem with combined guns is that guns are heavy, and if you try to make them lighter the barrel warps from the heat of the gunpowder. If, however, there was some super metal, one that is surprisingly light and, most importantly, can stand up to the high heat from a gunpowder explosions without breaking or warping without needing to be as thick or heavy as guns otherwise are you could better justify fitting a barrel into an otherwise normal melee weapon without the melee weapon suffering as much from the combination. There are still practical issues with reloading such a weapon without accidentally cutting your foot off with your swordgun, but the right material could make for a more viable option. Since you already have meteors striking earth, and super powerful 'sky metal' is a standard trope in fiction I'd suggest if you went this route the material you need actually came from the same asteroids as your fantasy horrors. That would suggest mining them for metal may be a bit hard, making such weapons potentially expensive. That could work though considering another option... Status Symbol: Swords use to be carried by generals long after the odds of needing a sword in combat were slim. The swords weren't there because they were a practical and required combat weapon, they were there as a status symbol. They said "I'm rich and important enough to be able to afford my own sword, this is why you should trust me as your leader.' Your combined weapons could be similar, though I'd probably go in reverse to make having a mythical gun, mostly lost technology, be the status symbol not the sword part. The rich commanders carry their combined weapon less for it's practical use in combat and more to impress those they are trying to lead and as a symbol of their worth as 'leaders'. Intimidation: Otherwise impractical guns could make sense if legends and myths about them had instilled such a fear that your enemy is afraid to charge them or otherwise allows their fear of the weapon to prevent them from fighting as well as they otherwise would. Even if the weapon logically isn't otherwise as practical in a fight as a traditional melee weapon the moral advantage gained by having 'legendary' weapons could more then makeup for their otherwise impractical design. So the weapon I'm envisioning would be primarily melee weapons, not long range ones. They would be able to shoot one shot, maybe two, but the reload times would be far too impractical to try in battle, it's a fire and forget thing. The focus is on making them viable melee weapons, not practical guns. They may have terrible accuracy and/or range due to similar sacrifices. The gun parts are in a sense an afterthought, the goal is to make something that works almost as well as a normal melee weapon but can still fire a bullet. The main reason for this is because the enemy fears them. You don't really care if you even land a kill when you fire the weapon, the real victory is a how the sudden coordinated firing of dozens of feared weapons on the battlefield affects your enemies moral. [Answer] Religion Carrying more than one weapon is taboo. Religions aren't necessarily logical. So people tinker at the edges, with combination weapons, reconfigurable weapons, Swiss-army-weapons, ... The same religion is seriously impeding the development of firearms, because each bullet can kill a man, so each bullet is clearly a separate weapon .... ]
[Question] [ In a world where silver is relatively abundant and not valued as luxury product and is pretty cheap (probably even cheaper than iron or steel) How viable would silver or its alloys be as a replacement for Aluminium, Steel and other metals? Obviously answer would be electronics. But how would it fare in automobile, aeronautics, ship making, building construction, firearms industry as a structural/building material? [Answer] For the most part, anything copper can do, silver can do better. The hold-outs would be cases where copper needs structural strength, and it can be alloyed to manage this. In particular, I expect it would be used as pipes and heat sinks. Electrical wiring would be an obvious case. More coatings for medical equipment would take advantage of its anti-microbial properties. It would actually be used less for its decorative value if it were readily available. It's less durable and corrosion resistant than stainless steel or chrome. You wouldn't, for instance, have silver faucets in your kitchen. You can alloy it to make it more tarnish resistant, but there isn't much you can do to make it more resistant to being banged around. One of the most likely increase in applications would actually be using it to alloy with other metals. You'd be hard pressed to find an iron or lead alloy that contains silver. It just not industrially practical, so we haven't researched it, and when we have, there is always a cheaper material that will do almost as good a job. [Answer] ## Silver would do fine.. but when it gets big.. ..mind the weight Suppose your structure is big, like a building.. With solid steel, you have 7.8 grams/cm3 material. But most steel buildings have abundant glass, which is about 2.5 gm/cm3. A sky scraper built out of solid steel without windows would sink into the ground, or collapse under its own weight. Silver is worse: 10.5 g/cm3, much heavier than concrete which is 1.4 to 1.7 g/cm3 dependent on the flavour. That is about 6x as heavy as concrete. And you don't have glass, else you would use that. Consequently, if you take square cube law and compressive strength (thx AlexP) into account for the roof and the walls of your building, they will need to be smaller than Earthly concrete buildings, assuming the same gravity as Earth. Something I wonder about: what's the surface and crust of your planet composed of, when you don't have concrete at your disposal ? Building requires a solid underground, preferably rocky. On your planet, say silicon and calcium are rare (?) there should be some substance supporting these heavy silver buildings. Aircraft On a planet where iron, aluminium or carbon are scarce, you may run into weight issues if you want to build a working airplane. Also, take into account that silver underperforms in terms of stiffness. Ships A mechanic constraint: ships have a spheroid hull. When its material is too heavy and the ship is very large, this silver hull will come crumbling down under its own weight. Most of your ship will need to stay under the waterline to prevent that.. and be smaller as well. For ships, Archimedes' law dictates weight constraints for floating, so your capacity for loading freight will also be smaller. Although a steel hull, commonly used on Earth, will only be 20% lighter than silver. [Answer] Obivious answer would be all kinds of Al high percentage Zn castings. All kinds of knobs, handles, signs etc (look where AlZn alloys were used historically). Tensile strength of aluminum is 90 MPa and of silver is 130MPa Alloys, high strength alloys of aluminum reach 600-700 MPa, but there is not so much reason to think that there aren't such things for silver(buuut I have to google to confirm). So if it is decently abundant, and easier to extract than aluminum(cheaper energy wise) then silver sure will have its place in all kinds of things which made out of aluminum today, it isn't such a bad material. Silver based alloys are used for brazing, and I guess it could be even better when it becomes a welding technology in case of connecting silver silver parts. But sure it will have its limits, and high strength is high strength, so as when mass is the factor it isn't that great. But good percentage of everyday objects could be made out of silver and its alloys, so it will see a good portion of those being made out of silver. [Answer] If they can make [this](https://www.etsy.com/ca/listing/1163188111/colonial-by-jones-ball-poor-pure-coin?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=pure%20silver%20flatware&ref=sc_gallery-1-2&sts=1&plkey=d10cb3c1a80d47260354daa766737cac6a6ba31a%3A1163188111) out of pure silver, then pretty much anything non-structural non-load-bearing could be made. Even decorative architecture. Basically, we could replace plastic with it. Load-bearing gears might need to be alloyed, however. [![enter image description here](https://i.stack.imgur.com/rYY9f.jpg)](https://i.stack.imgur.com/rYY9f.jpg) [Answer] My biggest concern is structural integrity. And now that I have read some comments, weight. Also, silver tarnishes HORRIBLY with ANY level of oil or other chemicals (always wear gloves when handling!) It also grows into crystalline structures when around anything corrosive. I work in an industrial electronics plant, and the bars of copper (there is up to and commonly over 1 ton of copper in these units) are coated with silver. But when they go to a place that processes toxic or corrosive materials, they are coated with tin. Otherwise, the silver grows and shorts the system. Lots of concerns with the viability of silver, unless it is coated with a preservative and/or alloyed for strength and anti-corrosive/etc. [Answer] Electronics were already mentioned, but the big demand would probably come from Zn/Ag batteries, they would replace lead acid batteries. If silver were widely available since ancient ages it would probably replace lead also for piping. Lead is not very strong, it was used because it was cheap and easy to work with. Back to modern age, another widespread application would be mirrors and, alloyed with copper, pots and pans. Together with electronics and batteries it would make quite a big demand, so to be still cheap it would have to be really plentiful. I doubt it would be useful in structural material, but a lot of potential alloys were never tested because silver was out of question from the beginning. Could Silver improve the machinability of a hard metal and be used in small amounts like it happens with Cerium? It is possible. Could Silver in small quantities improve corrosion resistance of some alloys? May be. Lowering the melting point of a brazing alloy? I can see a lot of potential uses, but always niche uses. [Answer] While silver would be interesting, it wouldn't be ideal. For each specific example you provided, we'll be assuming an alloy of silver, as normal silver is just too soft: Automobiles, Aeronautics, and Shipbuilding: I'd say silver is a poor choice for these when compared to iron, and especially when compared to aluminum. It weighs too much for Aeronautics in general, as a frame built of it would be almost 1.5x heavier than iron, and Aeronautics is all about shedding weight. As far as shipbuilding goes, it seems possible, so long as the ship is built with greater weight in mind, as iron already doesn't float normally. It would also be a poorer choice for automobiles, as the increased mass would make accidents more likely and more dangerous. Additionally, silver has a worse tensile strength than iron, so those automobiles would be more likely to snap than iron. Additionally, air filled tires would be even worse on these automobiles, and axles would have more issues with alignment as the force on them is greater. Building construction and as a structural/building material: Well, due to silver's increased mass and decreased tensile strength, it would also be worse than iron, so while it should be able to create frames for buildings, they would all be shorter than ones with steel skeletons. Tall buildings not only have to deal with the weight of a frame, but with wind pressuring them from all sides (and silver's tensile strength means less bending than iron's), so I'd expect a large decrease in height. Firearms, though, are a different story. Silver would be perfect for bullets - you could use almost any metal, but more readily available ones are better. There's really no reason lead is better for bullets than many other metals, other than tradition by this point. However, silver would be amazing as a coating for many materials. Pure silver is actually fairly tarnish resistant, with alloyed silver having tarnishing problems. Why is this good? It's basically perfect for a protective lining for pipes, beams, and anything exposed to water or other elements. So in a world where silver is common, I'd expect it not to really replace many other metals (unless they were very rare, like swapping rarities) but to coat metals exposed to the elements. Also it's antibacterial, like copper. However, as bacteria do need some copper for some proteins, it is not impossible for them to evolve resistance, as they already have some copper processing ability. Silver, on the other hand, is basically alien to their biology. They'll have about as much fun adapting to silver as we do with lead. (not impossible, but far less likely than copper) In essence, it's bad for structure but can be great for coatings. [Answer] Silver in metallic glasses (for use as BUILDING MATERIAL) Metallic glasses have high strength and toughness, large elastic limits and brilliant corrosion resistance. Silver-based bulk metallic glasses from the Ag-Mg-Ca ternary and Ag-Mg-Ca-Cu quaternary alloy systems have been discovered. They have high electrical and thermal conductivity combined with the superplastic formability of a metallic glass. Metallic glasses are stronger than high performance steel, hard like ceramic and moldable like plastic. As told [here](https://www.intechopen.com/chapters/70175) > > Metallic glasses represent one kind of advanced material, very popular > in recent decades. These materials are very adaptable like plastics > for their manufacturability in very complex shapes. TPF (Thermoplastic > forming) based processes seem very good method to process them. These > materials can compete with plastics but have metallic properties. They > behave as magnetic materials with less hysteresis loss and less eddy > current loss making them suitable for transformer and MEMS > (Micro-Electromechanical System) applications. These materials exhibit > good corrosion resistance, hardness and toughness. Based on the > property and application, metallic glasses are good rivals to > plastics, metals and ceramics. > > > As told [here](https://engineering.oregonstate.edu/momentum/stories/liquid_metal.html) > > Metallic glass is much stronger and lighter than conventional metals, > can be injection-molded like plastic, and will not corrode or rust. > > > Imagine a razor blade that stays super sharp for a year. A golf club > so springy it can drive a ball farther than a titanium club. An > artificial hip implant that is stronger and more flexible than current > implants. A cell phone case that is almost indestructible. > > > "In the future a ship made of bulk metallic glass could be five times > larger, or weigh five times less," Busch says > > > *OTHER USES* Silver is antibacterial Plates, spoons and other utensils used for cooking and eating food save food from bacteria. Food left in silverware will not contaminate for longer time. Eating food in a silver plate aids in the battle against free radicals and the rejuvenation of body cells. If silver is cheap, plates, spoons and cooking utensils will be made with silver. Silver-based ionic liquids They can be used to clean up petroleum waste products and as separation media. Wood preservative Silver can replace toxic chromated copper arsenate as a wood preservative. Long life batteries Silver-oxide batteries give up to 40% more run-time than lithium-ion batteries and are much smaller and lighter. Engines When steel ball bearings are electroplated with silver, they become stronger than any other type of bearing. Jet engines or helicopter engines rely on silver bearings because they can function continuously and at very high temperatures. Silver acts as a lubricant, reducing friction between the bearing and its housing. This increases the performance and longevity of the engine. Even in the event of an oil pump failure, for instance, silver-plated bearings provide enough lubrication to allow a safe engine shutdown before serious damage can occur. ]
[Question] [ A very powerful corporation is interested in building a device that works similar to a magic lamp. You bring the lamp to a certain location, at a specific time of the year, chant specific mantras, then make a wish. Your wish will be fulfilled in 2-3 days. Basically, the device will transmit the wish to a small team in the company, and if all conditions are met, the company will start working on making your wish come true. The corporation is very powerful: it is above the law and is willing to do anything no matter how unethical or illegal to fulfill the holder's wish (as long as it doesn't interfere with the interests of the corporation). There are certain wishes that the company, and therefore the lamp, cannot fulfill: * Standard loopholes (e.g infinite wishes) * Limitations due to natural laws (e.g cannot change gravity) * Limitations due to financial laws (e.g inflation) * Limitations due to technological advancement (we can assume the corporation exists in the current/ near future time). * .... There are also other limitations that are imposed by the company itself to protect its interest. For example, you can wish to destroy a certain small village but you can't wish to destroy the whole earth (or a large part of it) as it will be against the company interests. The company is interested in making the lamp work as similar to a magic lamp as possible. For that, all wishes that can be interpreted into something the company can do, will be fulfilled. If someone wishes to be beautiful (no matter how subjective this is), they will make some arrangements to send him to a cosmetic surgeon to make him look as good as possible. --- The main problem comes when the lamp is released into the public: how to provide a good enough set of rules that determines the limitations of the lamp (what you can wish for) without revealing that the corporation itself is behind this device? The corporation would like the public to think that this is a magic lamp but has limited magical properties. My first thought was to create a rulebook that comes with the lamp and gives detailed explanation of what the holder is allowed to wish for. But I think this is very impractical; the book is going to be really large and you cannot rely on people to read it fully. If possible, I would like to explain these limitations in a small set of rules that can be inscribed on the lamp. The rules do not have to be extremely specific. It is ok if, after simplifying the rules, there are still some grey areas where the limitations are not really known (e.g how much max money can you wish for), for this I am relying on the fact that lamp will work only once per year and so the holder of the lamp will be very careful with his wish. --- To be clear, I'm looking for a way to summarize the limitations of the lamp in a way that is simple and accessible to the general public, while also maintaining that it is in fact a magic lamp (and not one created by the corporation). [Answer] # you can't. Not if you want it to feel more like a dangerous magic object than like a very fancy way to win a prize. You said to willk that while you want it to be accessible, you also want it to have a mystery to it, something that makes people be careful about what they wish for. If that is the case, the only true way I see your company achieving that is by making their wishing manual a nearly identical description to the following part of the wish spell description from dungeons and dragons 5th edition: > > You might be able to achieve something beyond The Scope of the above examples. State your wish to the DM as precisely as possible. The DM has great latitude in ruling what occurs in such an instance, the greater the wish, the greater the likelihood that something goes wrong. This spell might simply fail, the Effect you desire might only be partly achieved, or you might suffer some unforeseen consequence as a result of how you worded the wish. For example, wishing that a villain were dead might propel you forward in time to a period when that villain is no longer alive, effectively removing you from the game. Similarly, wishing for a legendary magic item or artifact might instantly transport you to the presence of the item's current owner. > > > Yes, the last part of this description is still very focused on magic itself, but that's the main gist of how your lamp needs to work to be simple, yet mysterious and even dangerous. Basically the rules are: 1- you think about what wish you want granted. 2- you perform the ritual. 3- you speak your wish as clearly and as carefully as humanly possible to the "keeper of the magic" (whether it's a "genie", a normal looking lawyer, a 12 feet tall gargoyle disguised as an accountant, an accountant disguised as a 12 feet gargoyle, the guy listening through a secret microphone inside a prop lamp you need to use for the ritual, it doesn't matter, but the lamp, much like the spell in the game, needs someone to hear you out). 4- you wait and pray you worded your wish properly. Those are the 4 rules you need. If you "wish" (I'm so sorry) that your lamp feels magic and mysterious, you need everyone to know the "lamp" isn't some office job worker paid to read your mind and know what you want. It's a powerful, potentially mischievous force that might give you what it thinks you want, potentially in the most twisted way possible. (The biggest problem with this is that if the lamp won't always try to grant your wish in the exact way you* wanted it and in the best way it can, there can be no set of clear regulations on how to wish for something other that "be careful what you wish for and how you wish it", lest you decide to go back to the dnd spell description reference and add a list of instantly pre-determined wishes that will always be granted in the exact same way they state every single time).* You want to be able to swim in gold? You can be granted enough money to fill a swimming pool...or you might be forcefully dropped inside a pool of molten gold with weights tied to your body to make sure you can sink a bit. You want the world to end? The "keeper of magic" can outright say "no, screw you, that ain't happening"...or it can make the world end for you by forcing you to believe through various methods the world has ended and you're dead (or going the old way and killing you. Not like you'd be able to tell if the world's still there if a nuke eradicates your house with you inside shortly after your tv said nuclear war had started. It might even go cliche and track that one person you called your world one time and kill them in front of you). Essentially, if you want it to feel mysterious and magic you need to let them know: * they can wish for anything they want. * if they're not careful about what they wish for and how they wish it, they'll not have their wish granted at best or have the last thing they'd ever wish for happening to them (or the ones they love, or both) as a consequence at worst. * at best, they could play it safe by choosing a wish from a pre-determined "menu" that would naturally already be in line with the company's best interests and capabilities. Because at the end of the day, a magical wish is, in many cases (and sources of media), like a lottery, except sometimes the guy who runs the lottery seems to hate your guts for whatever reason. [Answer] A genie. > > The genie he had seen in the cave appeared, and asked his will. "Save > my life, genie," said Aladdin, "and bring my palace back." "That is > not in my power," said the genie; "I am only the Slave of the Ring; > you must ask him of the lamp." > > > Aladdin and the Magic Lamp <https://www.gutenberg.org/files/57/57-h/57-h.htm> Make your wish. The genie will tell you if it will work. [Answer] Why name any limitations at all? It's supposed to be magic, anything is possible, some wishes just take a little longer to fulfill. You only need to make people aware that keeping it simple will provide faster results, they'll automatically limit themselves to things most likely possible for your corporation. The simpler that you wish me do, the faster I will make it true. Somebody actually wished for something out of scope for your corporation? Not going to happen, just keep them waiting, maybe they'll realize after a few years that infinite wishes take an infinite time to deliver. Possibly add some sparkles, colored smoke and mysterious sounds effects to your lamp to show that a wish is still being worked on, rub again to cancel and switch to something more reasonable. [Answer] (EDIT: see comment below, I revised this answer and removed most of it, because there is only one lamp.. and it seems to be the purpose of the cooperation, to show that this lamp has imperfect magic. Frankly, that goal will be reached soon enough, as soon as people start wishing trivial things like below examples) Opening: "how to provide a good enough set of rules that determines the limitations of the lamp (what you can wish for) without revealing that the corporation itself is behind this device?" It better be good, the customer expecting magic First.. people won't read books with rules or documentation. They just use the lamp for whatever they like and suppose it is "magic". When I wish a flying bicycle, or happy dreams for my spouse, or 3 weeks of perfect weather during my holiday in Sweden, what happens ? I envision your lamp won't work, people yelling: "The lamp's magic is broken by these limitations ! It doesn't work !" Avoid backfire In 2-3 days the company will fulfill your wish, not magic. Among the limitations, there should be a provision excluding wishes that would harm the company. [Answer] Some other answers have implied this, but: # Make it cryptic and up to interpretation If it's hard/nearly impossible to understand, the company can ignore wishes and the wisher will just assume they misinterpreted the "riddle" inscribed on it. He that wishes with care will be he that is cared for What does this mean? Heck if I know, but it leaves the interpretations widespread. Maybe you'll start a cult (more power for the company). [Answer] To describe the main limitation, inscribe "Allow a few days for your wish to come true." Clearly, the lamp is powerful. So to make people think a bit first, inscribe "Be careful what you wish for, you might just get it." And to discourage people from testing the limits: "The wishes of the unreasonable, will be interpreted in unreasonable ways." Or some variation thereof. There are many good adjectives like stupid, obnoxious, ... The ritual for making a wish need not be inscribed on the lamp. It could be in a book or leaflet. The warnings on the lamp should be short, simple, and easy to get. But also hint at the dangers that goes with the power. If the lamp exists for long, then surely there will be enough scary stories about people making fatal or scary mistakes. Unreasonable wishes that backfires when granted in a dangerous manner. Wish for weightlessness, and you might wake up in a space suit in low earth orbit. Wish someone dead, and you get their head on a platter. With all the unwanted attention that tends to bring nowadays. [Answer] Somehow the first thing, which came to mind was a Death Note[1]. It comes with a very limited set of rough intructions and also a genie (the Shinigami owning it in that case). What essentially has to be done in order to fulfill everything you outlined: you must keep it vague and dangerous, otherewise it would feel like a kind of lottery from an unknown benefactor. [1] <https://en.wikipedia.org/wiki/Death_Note> ]

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