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[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/177183/edit). Closed 3 years ago. [Improve this question](/posts/177183/edit) I had a hard time figuring out exactly how to word this question so I'm going to explain a bit. I'm thinking of an idea for a videogame where the game mechanics are heavily focused on the logistics and interconnections of technology, so it would be fairly "hard" sci-fi, and near future tech at that. However, I want to set it in a rather fantastical world with big monsters and other unrealistic elements. So it leaves me torn on where to use the fantasy brush when designing things. I'd like to let the game mechanics lead the story as much as possible, while allowing for concessions to fantasy to merge them. **The details of my game world aren't important,** but to demonstrate the logic behind this question, I'm basically thinking like this: > > I want to focus on the logistics of moving supplies, so I **can't** > have teleportation tech. I want to have lasers and force fields, so I > **need** some kind of fantastical power source. But if I have a fantastical power source, that will make it seem ridiculous if there > are any combustion engines... > > > So to take a different approach to deciding what technology to include in a world like this I'm trying to think of the typical sci-fi technologies and the implications of each, to see what gives me the most room to play around and build on while still having the world "feel" realistic and raise minimal questions requiring technobabble answers. The best comparison I can think of is *Battlestar Galactica*. In the reboot, the ships have countless nuclear missiles, hyperdrive capability, and other magic space stuff. But the story revolves entirely around how the ship has no networked computers, how the chain of command works, how the engines break down and need replacement parts they can't manufacture, and so on. While for comparison, every time I watch any Star Trek, I'm constantly thinking "you can literally make food out of thin air, this should not be a problem". Obviously there are a hundred ways to retroactively explain why teleporters or replicators can't solve the problem of a particular episode, but my goal is to avoid raising those questions in the first place, so those two technologies don't work. Technology that reduces to "A power source, but bigger" raises fewer questions. A hyperdrive can be reduced to "we discovered a way to make engines, but better" without raising a ton of questions about how you feed the population. [Answer] # Arbitrary handwaved restrictions To me, the best way to have crazy sci-fi godtech without worrying about unwanted implications is to go in restrictions-first. --- Say you want to have both easy travel between different solar systems and the concept of a deep frontier where the heroes are a long way from reinforcements. Then the FTL needs to be restricted in a handwavy way: Let's say that FTL exists, but is bound by infrastructure so that you need a giant city-sized "tractor beam" emitter on both ends of the trip. Suddenly FTL isn't your space cowboy's horse, but the train he took to the last outpost of civilization, before striking out into the unknown in a charming sublight jalopy with a ragtag crew of misfits. --- Same thing for instant communications: choose some arbitrary restrictions. Say subspace messages can only be sent or received inside a hyper-strong magnetic field, or it takes an enormous amount of energy to fold space enough to shove a laser beam through to send data. Or, instant comms might rarely cause some causality errors that self-correct with spontanous matter-antimatter annihilation, make encryption wholly impossible, or scramble message plaintexts sporadically and *seemingly maliciously*. --- As for handheld directed energy weapons and force fields, give them similar arbitrary non-obvious restrictions and drawbacks. Maybe force fields work great for stationary protected objects, but jitter with minimal inertia change and are prone to slicing moving carriers of the shield generator into tiny slivers. Should you want to go all-in, perhaps have all DEW's produce the fabled infrasonic *brown note* at an immense sound pressure, so using them in atmospheres has some, ahem, *implications* for the user as well. --- This usually works great because unless your character is a domain expert in the specific tech being used, they can't really be expected to understand the science behind it, they just have a user-space understanding. In essence, the everymen in your scifi world know that cargo teleportation exists, is uncompetitively power-hungry, works 90% of the time, but 10% of the time the output is DEMONS AIEE GET THE TELEPORTER GOBLIN HARPOON. [Answer] ## Answer to revised question: Use tech agnostic terminology For a setting where you just want people to accept your science, don't explain the science of your systems at all. When you say your ship has a Fusion Reactor, Tetrion Particle Cannons, and a Subspace Void Shield you open yourself up too tons of questions about what those are, how much power they use and how realistic they are. In contrast a ship with a Lvl.3 Power Reactor, Lvl.4 Pulse Cannons, and a Lvl.6 Shield you answer so little about the underlying technology that there is no contesting how realistic it is for those 3 things to be working together on the same ship; so, you are guaranteed no plot holes. The only time you even scratch the surface of underlying tech is when you are pairing tropes that are so well accepted with certain effects as to already be understood; so, you might have Ion cannons that for whatever reason always do extra shield damage in every sci fi game made in the last 2 decades or EMP cannons to drain power or acid cannons to cause DoT. Even though these may imply some underlying scientific mechanics you can leverage that fact that thousands of games before yours have already hand-waved thier effects to be so predictable that no explanation is necessary. Why does an EMP effect a Power Reactor? Who knows. We don't even know how power reactors makes power so we just accept the way they interact and move on. *Added this question: [How to introduce fictional technology without creating plot holes](https://worldbuilding.stackexchange.com/questions/177247/how-to-introduce-fictional-technology-without-creating-plot-holes/) for anyone interested in delving further into the OP's question more as originally asked, and moved my original answer there.* [Answer] **Ancient Relic / Fell From Sky / Alien Tech** In fantasy, there's a common trope of 'ancient civilization with powers far beyond the modern one', which more or less explains why there are incredibly powerful artifacts that can't be made. Take the *sa'angreal* from Wheel of Time for instance - they artificially boost the Channeling capacity of whoever holds them, but the knowledge of how to make them was lost in the Age of Legends, over a thousand years before the book starts. This means that they're rare and that they can't be made. In science fiction, if you want to use this kind of trope, you explain that the objects in question aren't human in origin, and rather alien technology that humans don't really understand, or they came from a long-gone human civilization that reached technology the current humans could only dream of. *Stargate* is an excellent example of both of these, though far more of the former than the latter. (The ZPM in particular.) Obviously, adjustments need to be made to the formula. Incorporation or limited-reverse engineering might give the humans the ability to duplicate some, but not all, of the technologies. This enables you to have powerful sci-fi technologies, but at the cost of massive unexplained plotholes. [Answer] The best technologies that require no explanation are those that use existing science but simply require further engineering or technology development to turn into practical products. There are lots of items which are in the drawing board but need 'just' a few billion dollars of investment (plus a lot of testing, marketing, regulation etc) to make them into everyday life, eg EVTOL flying taxi drones. [Answer] **All the action on one planet, using 1970s tech with bows and ribbons.** In a hard SF the trouble comes because space is so big and light is so slow. Hyperdrives and instant communications are only needed if you are operating on galactic scales. Put your action on a planet. It is hard enough moving stuff around on our planet. You can make it a super-earth: bigger, wilder; with varying surface terrain, subsurface terrain, aerial terrain ("terrain"?). If you want to get off world, use the moons and other planets in the system. There are loads of threats on a planet surface that make sense to the way we think: they are threats on our scale. Things like black holes and relativistic shrapnel are hard to think about. Volcanoes, duststorms, lightning, monsters, tidal waves, whirlpools, robbers, panicked citizens, mudslides, tar pits - oh my! Those are human type threats and all to be found planetside. You can take them on with 1970s technology in 2100s bottles, which is also well trod territory for a video game. Jeeps with a dude firing a laser gun out the back. Force fields and machetes for the biting worm fields. Good stuff all. [Answer] **You're putting the Cart before the Horse — You should expect the horse to complain** I've been a programmer for a long time — and you're making a mistake. The game mechanics (including the balancing act for weapon/class strengths/weaknesses compared to other combinations) must drive both the story and the "tech" or you end up making bigger holes when you run into tech explanations that exceed or break your mechanics. * Monster #1 has an armor rating of 52/100. * Weapon #5 has an attack rating of 27/100. In-world description: The monster has thick skin and the weapon is a baseball bat. Why do those descriptions map to those ratings? They don't. It's irrelevant. It's window dressing. On the other hand... * Monster #2 has a cobalt-infused hide due to evolving on the Plains of E'reth where the soil is rich in cobalt and the plants have evolved to absorb dense quantities of it. * Weapon #2 is a Traveller-standard [FGMP-15](https://www.wiki.travellerrpg.com/FGMP-15). 2Kg power pack inflicting massive damage due to casting "fusion-enacted plasma." *Wait... Dang! "fusion-enacted plasma" doesn't make sense. OK! It's gotta be real fusion... except the weapon description says it's gravitically controlled and fusion must be magnetically controlled... Dang! We'll change it to magnetically controlled... with... a... 2Kg... Power... Pack... Yeah. Let's add a caisson to haul a realistic power pack around... WAIT! Dang nabit! Nuclear fusion and cobalt [don't mix well unless you](https://en.wikipedia.org/wiki/Cobalt_bomb)* really *hate that monster! I gotta save the town. How much damage was this honker supposed to deliver anyway? Just 2D6? Whaaat?* What you're going to discover is that having the tech drive the game mechanics will force you to make all your monsters like Elk and all your weapons like 30-06 hunting rifles — boring. **Conclusion** Don't worry about plot holes. There are so many technology-related plot holes in the modern *Battlestar Galactica* that your comparison to *Star Trek* doesn't actually make sense. In the end, you have a story to tell — and the technological mumbo jumbo is simply window dressing to make the story interesting. And if you learn anything from 100 years of sci-fi... if you tell a good story, even the people who know better won't care. Your mechanics need to be smooth. The relative weights-and-measures between weapons, armor, etc. must be well balanced. Your story must be engaging. If you do these things, the technobabble will fall into place. If you try to develop the technobabble first, you *will* compromise your game mechanics and your story. [Answer] Hyperdrive and Instant Communication are the most "magical" things you've described. If you can make the world work without them, you should. ]
[Question] [ House Kardashian is a large clan in westeros that is made up of different clans, each further broken down into different families. Members of this house have genes which allows them to access Mana through rituals, creating magical effects. These rituals are complex and time consuming, requiring access to different materials. Girls have the ability to utilize magic and become witches. Boys cannot access magic due to an ancient curse, and take up other roles in society. Men and women occupy different roles in society due to one having magic and the other Lacking it. Because only girls are able to use magic, they are raised by their mothers and their relatives. They are considered part of that lineage, and are the rightful heirs to that lineage and family name. Any males that are born are sent to live in creches, growing up in groups of men and raised communally. These boys are Raised by older men from older creches for the benefit of their clan. For this reason, they are referred to as "sons of society" and considered as belonging to the house itself rather than a particular family. However, they occupy other positions of power that are necessary to make the system work. Guarding the walls, training the horses, collecting taxes, managing the gathering of these ingredients, and other forms of skilled labor successfully maintain the infrastructure and allow it to grow. As you can see, man's contributions to their house and to witches are necessary in order for the system to be sustained. However, necessary is not always treated as essential, and value is not usually distributed fairly among sexes. I don't want males to be seen as lesser valued or slaves to witches. How can this setup be made equally balanced between the sexes and valued according to their merit? [Answer] ### General thoughts You ask about balance. Balance of what, exactly? Financial power? Military power? Authority? There's no inherent reason that the witches would have access to any of those things. If magic obviates those forces, there are deeper problems with your setup. Assuming it is a feudal society that interacts with the rest of Westeros, it exists in a pretty sexist system. So the men will be necessary, at least, to interact with outside society. And outside kings will figure out if they are talking to some little chump with no decision making power, so it must be the case that there exists positions of legitimate power for the men. > > However, necessary is not always treated as essential, and value is not usually distributed fairly among sexes. How can this setup, where men and women occupy different roles in society because of their sex, be written in a way where everyone is treated equally and valued according to their merit? > > > The balance of power can be where you put it, depending on how powerful you make the magic (although it seem really unlikely that people will be treated according purely to merit in this medieval society, given that we haven't hit that by modern times -- there will always be a system of patronage/favoritism/politicking). If the separation needs to be so great that the male/female hierarchies are completely non-overlapping, just make sure to show people of similar ranks within their hierarchies. If the High Witch really more highly ranked than the Head Diplomat, on the high council? Hope the spells can prevent an invasion when she over-rules him! ### Regarding the lineage The "sons of society" idea is interesting. I'm not sure what the overall political structure of this House is. But I'm assuming the there's some kind of hierarchy. Presumably, there's some Top Queen and having a person from your clan as the queen confers some perks (depending on where on the spectrum of "absolute monarch" to "first among equals" the position is, it may not be the most important thing, but it still don't hurt to be the boss). Thus, there'd be some political jockeying for the position. If men are raised as "sons of society" in some clan-agnostic setting (the nature of this neutrality is left to the author and probably will be a good source of a Big Dramatic Moment, sort of like The Watch picking sides), they would probably be trusted to fill in as the neutral bureaucratic layer of the society. A high ranking, ostensibly neutral bureaucratic functionary can be very powerful. See Baelish or Varys. Another aspect of this could be: are there nobility at all in this house? It could, of course, be a totally flat structure of equals living in egalitarian bliss, but that doesn't fit in with the Westeros vibe at all (and there'd still need to be a high queen of sorts just to be the boss for quick decisions, so this wouldn't negate the previous paragraph). But if there are nobles and peasants, this brings up two thoughts. First, assuming the noble men are still considered nobles, they still have value. That is, a noble woman will presumably want a noble husband to produce noble children. So, they are at least in as good a position as noble women in conventional feudal society. Not great, but something. Further, because they are "sons of society" the trading for alliances that noble women were subject to historically is not really relevant. As a result, they will have to be judged by some other merits. This would seem to make them more independent -- their value must be somehow linked to something they did, presumably a powerful fighter or brilliant bureaucrat will be seen as a particularly good suitor. Because competence follows interest, it seems likely that they'll have enough flexibility to follow their passions at least. Sidenote -- in this case, the "sons of society" system could be seen as something of a protective union for the dudes. Perhaps they set it up like this to *prevent* the kind of treatment women are subject to in normal feudal society. Second, if there are peasants, it is in all the nobility's best interest to draw a line between the two. Noble men wouldn't be, in the very least, relegated to the lowest levels of drudgery. That's what peasants are for. Or golems, depending on the magic. [Answer] “Separate but equal” has not worked in any historical society I’ve heard of **unless the two halves are in competition with each other.** As long as the two halves are dependent, one half will generally become the decision maker, in my observation. The other solution, if you want equality between disparate-but-cooperative groups, you need **division into thirds, fourths, or more** to create political imbalance and shifting alliances (another form of competition, really). [Answer] You pretty much display men as property so how can they be equal to a woman in your setting? Seeing children are separated at birth and become children of society then perhaps a class system would be fitting? That through a magical ritual (you got witches so) a test is done on the baby to determine it's potential and then get's separated in a class suiting for it where some classes (Political) are on (near) equal footing to women and get certain privileges. With the lower classes being seen as expendable? [Answer] 1. Magical co-dependence. Only women can manifest mana into magical abilities and forms, but for some reason, whether before or after the curse was applied, some men are able to contain/produce a lot more mana, they simply cannot use it and can only transfer it to a woman. This means woman still have this power that men do not (a key part of your world-building) but also makes men an important component of that feature as well. 2. Scarcity. For whatever reason, male children are more rare. Perhaps it's a quirk of conception on this planet. Perhaps more are stillborn, sages suspect due to the curse itself but who can say? This scarcity means they are highly sought after as companions/retainers, either for the conventional reasons or as mana-batteries, giving them a sense of personal and material value. But that depends on... 3. A robust legal system or tradition that protects their legal and property rights. This means that despite their scarcity or necessity they still retain personal agency - their ability to choose who to pair/serve allows them to leverage this commodity in a bargaining sense. 4. The method of power transference. Assuming that the mana-storage abilities of a man cannot be coerced or forced against his will, perhaps the transference works best when bonded in a close, personal relationship. Perhaps it is more efficient that way. 5. A strong religious hierarchy that protects men or gives them some latent alternate power which challenges that of magic. I would say in general, if magic is the ultimate power, you either need to establish a strong cultural norm and taboo to protect those without, there has to be a balancing and virtually equal power, the weaker party must have a numerical advantage, or there needs to be co-dependence. Without one of these things, or something like them, it'll be hard to understand why women don't just smack men around to get what they want. [Answer] In the western world until few decades ago there was a strict separation of gender roles. Women were supposed to cover certain roles, men were given others. And that was seen as "good and wise natural order", to be observed without objections. Long story short, with the proper brainwash the masses can swallow any concept the higher up wants them to. [Answer] TL;DR: To balance something which is unstable you need to figure out what unbalances it and fix that. Feel free to create a "problem" yourself and then provide the solution if that works well. ## Unbalancing Forces There are a variety of forces which can be said to cause gender recognition and power imbalances. I'll offer up my 2-cents below, but really you just need to pick 1 or 2 things that you think are influential (or which can sound convincing in a story) and work with that. Most people want power. Power is relative; if everyone on earth became ten times more powerful tomorrow, it would seem great at first but after a while it would seem normal because everyone is still the same. To feel powerful, you generally need to feel superior to others. Power can come in many forms, including strength, intellect, magical (as in your world), financial, celebrity, and you can probably come up with others. **Strength** Historically, physical strength was usually used to bully or eliminate competitors. This is just one contributing factor why men had most of the apparent power in Earth's history and why women were often second-class. **Finances** Once weapon technology advanced to the point where money could buy more power than big muscles could provide, finances became a dominating power-influencer. Since physical strength was still highly valued and males were already in the dominant position, this only had a limited impact on changing the gender dynamics. **Intellect** In the modern world, intellect and technological advancement often determine a nation's power, but since it is not the technology-producing individuals in charge of the nation this again had only limited effect on the gender dynamics. Finances and intellect brought about other changes in societal power dynamics, such as allowing lower and middle classes to raise themselves up, and these changes paved the way for the gender imbalance to be addressed. **Magic** In your world you are building, you have provided what could potentially be a massive new axis to the power struggle. If your magic is overwhelmingly powerful to the point of trumping all else, then it will be difficult for your people to find balance. You need to make the magic strong enough to be very useful, but weak enough that some other type of power can compete with it, such as strength. Note that if the magic is not powerful enough it won't necessarily cause the females to take control and the males to be second-class. Simply having a unique ability doesn't necessarily grant power. In our world in reality, females already have some unique abilities that only they possess, but that did not stop them from being oppressed. ## Balancing the forces **Video games already deal with this all the time** Now you just have to balance the forces. As Adrian mentioned in comment on the question, you could view this similar to how role-playing video games already do, simply by balancing magic to be on average comparable to physical strength. If one of your witches can easily toss up a magic shield to block the best man's attack and then incinerate him with a finger snap, but then is drained and cannot do that to 2 men in a row, then they are not unbalanced. **Create a historical reason why balance is maintained** This is a common theme in literature. "100 years ago ended the Great War. There was no victor, as all were devastated and ended the war in a truce which eventually led to an uneasy peace which lasts to this day." Then the story happens and all bets are off. In your world it's more like "In a time before memory, magic was discovered. In this great family, all were held in high esteem for any could hold their own because of their magic power. That is, until the men were cursed and lost their magic. The women naturally took control, but the men would have none of this and fought back with sheer physical strength. This sad, bloody gender war did not last long, as it would be folly and suicidal to the clan to continue. In the end, both sides realized the need for the other and grew to respect each other. Several times thing have gotten tense again, but all the other side needs do is cease supporting the other and it quickly becomes apparent that they cannot function without working together." You only need to have a few instances of power struggles in which each side loses a lot because of not working together to reinforce this even for the reader or viewer. Especially if the men can do the magic-ingredient procurement better, such as having the strength needed to mine the very tough magic stones needed by the females. All the men need to do is stop mining to leave the females powerless in a power struggle, but in general they don't want to because they benefit from the magic of the females because of the healing, fire-starting, etc.. ## Summary Find a reason or excuse or two that the gender appreciation would be unbalanced, then find or create a fix or two for it. The two most direct ways are to either play on a past conflict where this problem has already been solved, or to create a reason why they both need each other (your description of male servants essentially is not really a need, they have to be able to do something the women can't, and it needs to be something that can be withheld for a power-play). Easiest way is to play on the men's strength. [Answer] **Ask yourself this question: In your world, is there a difference between gender role and gender purpose?** Your question, generally speaking, needs a lot of other questions to be answered, but I like short poignant answers, so I'll try to keep mine brief. The difficulty in the question you're asking is that you must first truly understand what you believe about gender in our world. This is a concept you're importing from another world. You could make genderless beings, or limit magic in some other way, you made the decision to do so this way. Why? This question is primary. Whether you like gods or not, all stories have at least one. If there's not one explicitly included in the story, then it's you. So you could also ask the question, why did the god of your world make genders at all? Fair and balanced are completely relative terms. The creation might never be able to see the fairness or balance in a universe that they are only a small part of, in fact, this tool is used all the time in fiction. Give the reader only a part of the picture, only to reveal a greater truth later... The real question is, what are you, the author or god of this world, trying to accomplish? Do you want the reader to see fairness and balance? Why? Do you want the characters to feel like their roles are fair and balanced? Why? Good worlds are built on tension and the masterful use of it. Gender is possibly the most natural source of tension that exists in our world. So I'm curious, if you're trying to remove the tension from gender, why use gender at all? [Answer] Let's start from the beginning. This: > > Members of this house have ***genes*** which allows them to access Mana > through rituals, creating magical effects. > > > and this: > > Boys cannot access magic ***due to an ancient curse*** > > > are two extremely important pieces of information. The first suggests that this House was evolved to possess magical abilities, through natural selection. This whole reply is based on this assumption. You can disregard this if the genes were altered by modern scientific abilities in order to gain these magical abilities. The second says that at some point in the history, both males and females had the ability to produce magic, and the change was sudden. I'm also going to assume that this is essentially humans we're talking about, and as such physically males and females of Kardashians are not dissimilar to males and females of our world. ## Ancient Times This society would have been different from an ancient human society in one major aspect. There are two major reasons why most human societies all over the world are patriarchal; a) males are physically stronger and b) males produces billions of sperm while females produce a very limited amount of eggs, which are costly to produce. Due to the first reason, males are able to gain more power. Due to the second, females are required to take a much bigger burden on reproduction, need to be choosy when mating, and are required to devote a large portion of their time to child-raising in order to ensure their genes propagate. In the world of Kardashians, the second would remain the same, but magic would compensate for their 'handicap' in the first (assuming male and female magic powers have no difference, and magic powers include ability to fight/kill with spells). This would mean that the society could still have been patriarchal, but not as much as ours. But more likely, gender would have played a far less important a role than in ours. Women would not have been at the mercy of men when it comes to physical power. This would mean that crowns may not have been inherited by the male first born, but the first born of any gender. There would have been female leaders throughout the history, who were emperors, warmongers, the works. And since this was an evolved trait, there's no reason to suspect that one gender would have been more 'resentful' of the other either. Gender would have been something that was necessary for reproduction, but not much else. **An important side-note:** You don't specify *how* magical abilities are inherited. Is it completely random (as in magic is depicted in most literature, such as Harry Potter world, where Muggles can give birth to Witches/Wizards and vise versa), or is magical ability strongly inherited such as our skin colors, general body types, etc? If it's the latter where magical ability is strongly inherited, in that two parents with high magical powers have a higher chance of producing offspring with high magical powers, then this world could end up significantly different. Early on in the evolution, less powerful individuals would have been quickly eliminated, but once they developed into societies, there's a possibility that much like in our ancient societies with power/money decided to marry within, these powerful individuals chose to marry within, creating different social classes with significantly different abilities, and it wouldn't take long for the powerful to 'enslave' the less powerful. This would throw everything off in your story, so I suggest we stay in a world where parents with powerful magic doesn't necessarily produce offspring with powerful magic. Coming back to the topic, as gender roles would have been less important, there's no reason to suspect that there would have been communal raising of one gender and the like. Bottom line is, this would have been a society that was much more gender-equal (or more accurately, gender-inconsequential) up to the point where the curse would have been placed. ## The Curse Now we have a world which is more gender equal, but all of a sudden the game changes. Now only women have magical abilities in an otherwise equal society. Chaos will ensue; at first it would be confusion, and not long after, a power struggle. If, eventually, women figured out that they're now unimaginably powerful than the men, they are going to use that advantage. We may have our ethics and moral principals, but those lines get moved around all the time. Women wouldn't necessarily outright try to overpower men, but with that much power in hand, you would be able to 'force' men to do what you want. Imagine whatever the equivalent of their security council; it may have had an equal representation of males and females, but now with more power, it's natural that women would band together, and when it comes to important decisions, their say will probably have more weight. This would happen all over the society, not immediately but not too slowly either. Within few years (or decades at most) an inevitable power shift would happen. Sure, men would resist, and blood will be shed, but we know who's going to win. ## Rearranging the Society With this new balance of power in place over few generations, it's pretty easy to form the society you envision. It doesn't make much to 're-educate' a class of people, be it gender based or whatever else. Women would band together into families, and men banished to creches. Sure, you don't have to treat as slaves per se, but you can 're-educate' them into accepting their fate pretty quickly. Again, this would not be uniform and not without exceptions; human emotions would play an important roles, there will be star crossed lovers who resist the change, but eventually, power will trump. So we can imagine a society, a few decades later, maybe a century, where people live like the way you describe, but here's the crux of the matter: Inequality you describe may not be seen as inequality. Men performing duties they are duty bound would be seen as 'natural', much as we saw, for centuries, women staying home and taking care of children as 'natural' while men went out to dominate the world. So, I can envision this society where men are still valued, but there can be no 'balance', because 'balance' doesn't even make sense. Men will have their place in the society, but women will rule. [Answer] ## Focus on Balance of Power So your society is broken down in a few ways. You have: * The House * Clans * Families But we are most concerned about two specific groups: Men and Women. **Women** Based on your text above, due to their ability to utilize magic, women are going be *individually* more power due to magic, and each *lead their own family*. It is likely the families status will be driven by the *individual* in the family with the most magic. Your *most powerful individuals* in your society are likely to be women. Your house leader will be a woman, as are your clan leaders. **Men** Men do not belong to any specific family, instead they belong to an overarching *collective that spans the entire house.* This collective is responsible for raising children and *can advocate for their members.* ## **Find a Real World Example** In the real world, power is a messy thing that comes in many forms. Is there a real world example that balances power between strong individuals and large collectives? **Unions** The basic power structure you are looking for, doesn't come form political organizations, but rather the business world. Just organize your Sons of Society into a hyper-powerful union. Although women may be technically in charge, the collective power of the Sons of Society is more powerful than any specific mother or clan leader, except maybe the House Matriarch. **Why don't the women just form a more powerful union?** So let's look at the values women in your society are likely to have. As they have a family, a clan, and a house their loyalties are likely to follow this pattern, from most to least important: 1. Family 2. Clan 3. House As each family leader is most concerned about the people under her care, she will prioritize her needs over the needs of the group. Clan vs clan, and family vs family rivalries are likely common and make co-operation more difficult in all but the most dire of circumstances. Now let's look at Men's values, from greatest to least 1. Sons of Society 2. House 3. Clan 4. Whichever family they are currently with Here we get the men with the greatest loyalty to their own group. This is important, so if the Sons decide to order their members to shun a family or even an entire clan, they will follow. Maintaining the union would need to be a prime survival strategy, so those that refuse are likely killed or exiled. **What could the Sons do?** Without a strong nuclear family, the main power of the Sons is to withdraw from a family or clan that provokes their displeasure. This would have the effect of leaving the family or clan isolated, and childless. As your men have the best connections between clans, they are likely involved in trade, and those that go against them would be cut off from goods and services. An embargoed family could ask other families for help, but other families are most concerned with themselves they wouldn't want to risk getting involved and having the embargo extend to them. **Why does the Matriarch Allow This?** So, if there is an extremely strong union of men, why doesn't the most powerful matriarch try to squash it? Look at the values between men and women and it becomes clear. The clans and families value their own needs over the needs of the house. Effectively, they are constantly trying to pull away from the greater house to secure greater autonomy to make the best decisions for themselves. The men, however, value the house over the clan or family. Thus for the Matriarch wanting to maintain power, the Sons of Society would become a key ally. It is both of their interests to keep the House in power and the Sons and unified force. **How this Looks on a Micro Level** At a micro level, this means that an family leader or clan leader may be seen as more important as the average man, they would follow the proper customs for the treatment of men lest they face the backlash. The Sons could easily force clan leaders to place them in positions of power (where culturally appropriate) and most inter-clan work, like trade, would be especially seen as a men's job. Although this society is not perfectly balanced, men could reasonably hold positions of power, and would occupy the middle rung of this society, just below family leaders. Your lowest rung would be the un-unionized workers, in this case the women and girls who do not have a family of their own to lead. They would be forever at the disposal of their mothers, with no recourse for mistreatment. [Answer] **Forget about "Separate but Equal"** Why worry about "equal"? You need separate and different. No concept of "equality" at all. Men being equal with magic-using women? You need, as you have established, separate and co-dependent populations. They need to depend on each other enough to prevent one side from simply killing all the others. Each side needs enough power to prevent it's own extermination, and enough benefit derived from the other to prevent them from exterminating the other. You have the men being "useful" by being stronger and traditionally "male". The women are useful through whatever benefit the society derives from the use of magic. They are useful to each other for reproduction. **Don't let the stew ever stabilize** It could help to have a third source of threat that the males and females must cooperate to defeat. This could be another human thread, or perhaps an alien threat, or even an environmental threat. The threat should change rapidly enough to prevent any true stability, but not so rapidly changing as to keep everything in tumult. The changing disruption just keeps stirring the pot on the female/male mixture to keep it from settling out. [Answer] The problem here is that separate but equal isn't. I understand the desire to create this sort of bias in the opposite direction to most historical societies by creating a demand for something other than brute physical strength, but recreating this bias in a different way isn't the solution. ]
[Question] [ I have always been in love of hand to hand combat but I realize the concept of efficiency and why that is not an ideal choice for combat so I decided to write a story in which characters who are powerful martial artists will use hand to hand combat in a medieval setting in which I settled on a gorilla strength for the main characters which I looked up to be around 20000 joules(the power of a 50 cal BMG) so the issue is what would the damage/effect (Will they get launched into the air?) of a punch on armored foes(unarmoured if you could) be? Assume : * It is one singular punch * It is a body blow directly to the chest, it is not aimed to knock out. * The one doing the punch is durable enough * The one getting punched is all-around normal * Mass of the puncher is 100 kg( you may change the weight as you see fit for the character to remain stationary) * The puncher is 2 meters tall * To clarify, both parties are human I trust you to choose to fill in everything else that I missed and if you have a formula or actual examples of such effect that would be great. [Answer] You are effectively spreading the energy of a .50 caliber bullet over the area of a human fist, so let's do some math. The diameter of a .50 caliber bullet is (unsurprisingly) half an inch, giving it a frontal area of 1.27 square cm (we're disregarding the fact that the bullet isn't just a cylinder, but it'll do for a first approximation). Now onto the area of a human fist. We'll assume that the puncher knows how to throw a punch, and is hitting solely with the knuckles. Here, I'll have to rely on my own fist and hope that it's roughly representative of the general population. According to my ruler, my knuckles, when I close my hand into a fist, are about 8 cm wide, and about 1cm high, for an area of 8 square cm. So, you're hitting with a surface that is almost 7 times the area of a bullet with equivalent energy. According to the [Wikipedia article](https://en.wikipedia.org/wiki/.50_BMG) on the .50 BMG, it is capable of penetrating 22.2 mm of steel at 100 yards. Dividing this thickness by a bit less than 7 due to our increase in surface area, we get a rough estimate of being capable of punching through about 3.25 mm of steel. We'll bump this to 4mm, to account for the fact that the kinetic energy of a shot will drop somewhat by the time it makes it 100 yards. Medieval plate armor thickness varied wildly, depending on who made it, when it was made, where it was made, and what it was for. Jousting armor was typically extremely heavy, and a jousting breastplate was typically about 5mm thick, so that would probably stop a punch. The guy inside is going to start having a significantly worse day, and you'll knock him over (he'll probably slide for a bit, too), but the armor will probably stop at least a single punch without completely failing. Typical armor for actual warfare was generally much thinner, however, as one actually had to be able to do more than ride a horse in a straight line at a single opponent during a battle, so the most likely scenario is that the puncher's knuckles end up somewhere inside the chest cavity of the punchee. On an unarmored punchee or one who simply has the light cloth or leather armor usually worn by the vast majority of medieval soldiers, the likely result is that the punchee ends up impaled on the arm of the puncher. Note that this is all assuming that the person doing the punching is in possession of an indestructible hand, arm, and shoulder. If you were to somehow try this with an actual person, the result would be a dented piece of armor, a hand that suddenly has an exponentially larger surface area and a lot of screaming. [Answer] Apparently, [Rocky Marciano](https://en.wikipedia.org/wiki/Rocky_Marciano) (the model for Rocky Balboa) had a punch measured at approximately 1000ft-lbs, or 1355 joules in less weird units. He weighed a mere 85kg, so he's a bit lighter than your target 100kg, but it seems close enough. Lets assume that all else being equal, the energy of a punch scales linearly with the weight of the puncher. A 100kg Rocky would generate 1600J in a punch, and your target is 12.5x that. Assuming you can model a punch using the good old $E\_k = \frac{1}{2}mv^2$ equiation, to reach 20kJ he'd need to punch about 3.54x faster (because velocity scales in proportion to the square root of the kinetic energy). A fast human punch is about 15m/s ([Ricky Hatton](https://en.wikipedia.org/wiki/Ricky_Hatton) was clocked at 32mph, about 14.3m/s, and similar speeds have been observed in other boxers and karateka). **Your super-punch therefore needs to be travelling a little over 53m/s**. For reference, that's about 119mph. A black powder musket, by the way, develops a muzzle velocity of over 120m/s, and a medieval crossbow would manage a little over 90m/s. A roman sling bullet on the other hand only managed [45m/s](https://www.scientificamerican.com/article/whistling-sling-bullets-were-roman-troops-secret-weapon/), and they're know to be pretty hazardous things. So, your peeps can punch 3.5x *faster* than regular humans, delivering about 12.5x more energy. Force is defined as $F={\Delta p \over \Delta t}$, the change of linear momentum over time. Momentum, $p=mv$ is proportional to velocity. Lets assume that the time over which momentum is changed is the same for your peeps as it is for regular modern-day human boxers (which is a slightly dubious assumption, but it'll do), so the force of a super punch will be 3.5x stronger than for a regular human. I found a few more sources for the force a boxer's punch than for the energy of the punch. From [this short article](https://www.connectsavannah.com/savannah/the-true-force-of-a-boxers-punch/Content?oid=2133328), we get a punching force of 1300lbs, eg. 5783N. [This](https://www.scientificamerican.com/podcast/episode/5538765e-e7f2-99df-393e0a0cd7821157/#) mentions a 400kg punching force, eg. 3923N. [This](https://www.telegraph.co.uk/boxing/2017/04/27/heavyweight-punch-brutal-weapon-sport/) suggests that Wladimir Klitschko could develop 5000N of force. He's a bit heavier than your target weight at 109kg. but lets use him as our model. Using these assumptions, **your super-punches develop a force of 17.7kN**, which is motor-vehicle-accident level. Exactly how this translates into damage effects though, is hard to say. As [Adrian](https://worldbuilding.stackexchange.com/a/162153/62341) observed above, this amount of force will be *extremely bad for the puncher*, who risks destroying their own hand and arm unless they have the [required secondary superpowers](https://tvtropes.org/pmwiki/pmwiki.php/Main/RequiredSecondaryPowers) of having really tough bones and flesh. They'll need to work on punching technique to avoid pushing themselves away, or otherwise being unbalanced. A good uppercut would let them push against the ground (which hopefully isn't too soft!) and the energy involved will be enough to lift a 100kg victim off their feet and into the air, streetfighter-style. Obviously, punching an armoured opponent in the chest would be a silly idea, because if they're decently protected (and a medieval knight certainly would be) you're not going to do much more than knock them over. They're clearly strong enough to lift an armoured knight off the gound and slam him into the ground, probably with enough force to kill if the surface is hard enough and certainly with sufficient force to give them some nasty concussion that will take them right out of the fight. Why risk your hands punching? Punching is a terrible way to fight, and only done by people who can't use weapons! That said though, if all that force was concentrated on an area of just 1cm2 (say, a knuckle or two) you'd generate an **impact pressure of 177MPa**. That's *quite a lot*, and perilously close to the yield strengths of medieval steel. I can't be *certain* than your super-punchers could dent a breastplate just be punching it, but they're not far off. Even with the simplest of weapons (such as some simple spiked knuckles) they could probably breach armour. As to the effect on unarmoured foes... well. A punch to the head will be fatal, more or less immediately, through traumatic brain injury and probably a fractured neck into the bargain. A punch to the chest could eaisly break bones, which may in turn cause a [punctured lung](https://en.wikipedia.org/wiki/Pneumothorax) (especially with a followup punch), an almost certainly fatal injury in medieval times or simple inability to breath due to [flail chest](https://en.wikipedia.org/wiki/Flail_chest). There are a [whole load of other chest injuries](https://en.wikipedia.org/wiki/Chest_injury), most of which are likely to be debilitating and later fatal in the absense of modern medical care. Blows to the abdomen will probably rupture internal organs. Blows to the liver or spleen will be immediately debilitating, and death can follow fairly swiftly from internal bleeding. There will be crush damage to overlying tissue, though under the circumstances this probably won't be a big concern to the victim. Basically, it'll be like using a mace on an unarmoured target. --- There's some more investigation to work out just how tough your super-punchers would have to be to withstand the forces of their own attacks, but they're likely to be formidable combatants. The most sensible thing of course would be for them to don armour and carry weapons, to increase their power and resilience yet further... [Answer] Assuming the punch does not penetrate, then the effect in terms of momentum transfer would be the same as someone firing a .50 cal rifle, like a Barrett Fifty. In other words, very little. Bean bag rounds which the police fire from 12-gauge shotguns, hit with around 100 joules of energy, kinetic rounds like plastic/rubber bullets, 40mm sponge grenades, etc. up to about 200 joules. These are not effective against anyone wearing armor and essentially rely on pain for their effects as they are designed not to penetrate or do permanent damage. (Exceptions occur with eye sockets and other 'accidental' effects). Obviously you are talking about higher energy levels....but note that gorillas do not kill each other in fights, nor are they especially dangerous to large predators. A gorilla punch is not a superweapon, and if you punched a solid target you would break many of the bones in your hand. [Answer] The human arm is 6.5% of total mass therefore 6.5 kg. So your 20 kJ punching-arm is travelling at 78 m/s. Assuming an inelastic collision and a 5kg chest plate, the combined mass of (puncher's arm plus victim plus chest plate) is now moving at 18.9 m/s (42 miles per hour). That's equivalent to being hit by a car and would knock you back some distance. The UK authorities are fond of a statistic that if you're hit by a car at 30 mph there's an 80% chance you'll live, whereas at 40 mph there's an 80% chance you'll die, however, I believe the killing factor tends to be the secondary impact of head-on windshield rather than the initial blow to the torso. Now set the kinetic energy equal to work done to calculate the impact force. The equation is KE = F x d so we need to know the distance over which the force is exerted. Assume an arm swing of about 60cm, then 20000 = F x d = F X 0.6 therefore the impact force = 33.3 kN. However the victim is wearing plate armour so that 33.3 kN force exerts pressure over the entire chest, let's estimate 600 x 300 mm or 0.18 m^2. So the pressure = force / area is 185 kPa (or 27 psi / 1.9 bar). That might smart but it's definitely not going to kill, although if the victim hits his head when knocked back he may still die - some head protection would be a great help. The situation is much worse for the strong attacker though: he is spreading the same impact force over a much smaller area, optimistically a fist measuring approx. 100 x 50 mm but potentially just a knuckle measuring 1 x 1 cm. That's an impact pressure of between 6.9 MPa and 344 MPa, which is going to be pretty devastating for his hand. (Bone has a compressive strength of around 170MPa so if the puncher makes contact with only 1 or 2 knuckles rather than a perfectly flat fist then he's going to break bones and is fairly close to the limit of compressive strength of his arm bones. The shear strength of bone is even worse at 51.6MPa, so any bad contact at all is likely to break the proximal phalanges (finger bones nearest the palm of the hand). [Answer] 20 m/s is a speed of a target (if it will not fall apart) after a punch. This would definitly rise what left of him into the air for about 0.5-1 second (depends on punch vertical angle) and flight distance 10-20 meters Asuming armor would prolong the acceleration time - it would give about 200-100g of acceleration. Crush dummies bearly survive this (thershold is about 150g). Trained person expecting punch would survive. But surviving - doesn't mean no damage, or even no permanent dammage. Person would die without immediate *modern* medical help and would die for certan in medieval times. And even if he would be saved for some mirracle - he would be broken for the rest of his life. Also some secondary superpowers requiered for puncher - he need strong bones (see Gryphon answer) and even more than that - superstrong joints (they are weeker than bones) and supergrip with earth. Last one is very important - third Newton law is plaing against the puncher. There are three possibilites: * puncher flyes in the opposite directon of target with same or (if puncher has no armor) times greater speed (and target recieves same times less powerfull punch) * puncher dumps the impulse with its superlegs and supergrip (or by pushing itself from the wall) and stay in place - most powerfull punch * (most funny one) puncher was already flying to target when he was delivering the punch with the speed 20-40 m/s (depending on it weight) and then he just stops (dumpung impulse in his superarms, superlegs and superspine) and target flyes away. (I do not consider case when puncher and target fly to sunset together - it wouldn't be punch, but push) ]
[Question] [ I'm trying to make a fantasy-esque magic system in which everything works pretty much the same as real life, except there's a sort of "magic particle" that makes magic possible, but with physics. In my story, this magic particle permeates the entire universe, and has been there since the creation of it. Half of the population of earth can control this magic particle to some extent. (Animals are also affected by this, and thus there's a couple of species of animals that specifically evolved alongside magic.) Basically, all this magic is supposed to follow the laws of physics, so for example an actual laser beam would never instantly vaporize things in real life, so it can't here either. The problem here comes with making that magic actually happen. The main problem is ceating the laser beam, not really how it'd work. My main goal here is to marry magic & physics to make a compromise between the two: the magic particle. Thus, my main question: What properties would this "magic particle" have to make it able to mess with matter in order to make magic possible? [Answer] I think you rethink your question, as creating a "magical particle" which would smoothly fit into modern scientific understanding would require at least a degree to get it somewhat plausible to an expert and go right above most reader's heads anyways. Instead, I recommend you go a different route that will solve your problem (or at least what I think you want to create. Let me present, an energy-based magic system in a step-by-step format: 1. There is a "mana" or "magical energy" particle that just exists (handwave). This particle permeates everything and it's unclear where it comes from (however a large concentration seems to be at the planet's core and results in "magical hotspots" akin to how geothermal activity causes hot springs, geysers, and volcanoes). This mana particle does not usually interact with regular matter but is attracted by electrical currents. 2. Due to all thinking creatures having a brain with neurons that communicate electrochemically, mana is attracted and hangs around in the brains of creatures. 3. In order to "cast a spell" or preform magic, the caster must bring their mana particles into a stable pattern or configuration. To achieve this "mana-patterning" they must bring their mind or thought process (and therefore by extension the mana particles in their brains) into a template configuration. This explains why wizards have to meditate and study for a long time, as blanking one's mind enough and focusing on the magical pattern is difficult. Sorcerous people or creatures, through a quirk in their biology, already have a part of their mind pre-patterned, and can therefore easily achieve the required mental state to preform the magical feat. 4. The mana particle is a master at energy conversion and can convert all types of energy to each other, provided the spell caster knows the specific mana patterns as to how. Almost all magic-capable creatures fuel their spell through chemical energy, effectively depleting the stamina (the chemical energy that would normally fuel their muscles, glucose or whatever) to power spells. This means like a pro-athlete, high magic expenditure is connected with a high caloric cost. The key here is that the mana particle itself has no energy, rather it facilitates energy conversion. 5. In order to keep everything reigned in, let mana energy conversion at a distance fall off with the square or the cube to localize magical effects near the spellcaster. Advantages of such a system: * **Unlike most magic systems, laws of thermodynamics and conservation of energy/mass would not be broken in such a system.** In lots of fantasy, magic can "just happen" and powerful, world-bending effects can be cast by some old guy in a robe. Not so with this system. If each spell has an actual energy cost associated to it (and by energy I mean quantifiable in Joules or Kilocalories) then you're not breaking any laws of physics. Spellcasters would probably be buff and not glass-cannons as they need to power their spells * Knowledge of physics lets one easily calculate possible spell power and effects. For example, a high performance athlete can exert around 400 watts of continuous power for around an hour. That's around 1.4 million joules. By combining work/energy limits (measured in joules) with power limits (measured in watts) you can structure "realistic" spells. * Since the system conforms with traditional physical laws, creating perpetual motion machines or other infinite-energy sources is impossible. Of course, if a wizard figured out how to enrich radioactive materials and use those to power their spells, they could create quite powerful effects. This is unlikely though, it's easy to imagine how somebody in a typical fantasy world wouldn't have a solid grasp on work, power, and energy in the first place, let alone conceptualize the ability to harvest energy from gray rocks. Example calculating a "spell" and someone's stamina: First, we establish our spellcaster's stamina curve. This is the relationship between how much power they can output (measured in watts) for how long of a time. Take a look at this: [![Energy vs time graph](https://i.stack.imgur.com/100Lcl.png)](https://i.stack.imgur.com/100Lcl.png) **Example calculation:** You can use these curves to calculate what sorts of spells that a magically-capable creature would be able to accomplish. To ensure the spell is possible to cast, you just need to make sure that the power levels and caloric costs never exceed the max. For example: [![Levitating self spell](https://i.stack.imgur.com/ffg5hm.png)](https://i.stack.imgur.com/ffg5hm.png) In this example, the spellcaster levitates themselves upwards 10 meters over the course of 30 seconds. During those 30 seconds, they are outputting ~330 watts of power. This would leave the average healthy person winded and be the equivalent of a short sprint. (according to the NASA curve on the graph, 300 watts is only maintainable for five minutes by healthy people until they're out of stamina) **To "cast" a laserbeam:** The spellcaster focuses themselves on converting their own power output into radiation. Converting from the spellcaster's chemical energy to radiation is something that mana particles can just do. The spellcaster needs to be skilled enough to manifest where this radiation escapes to be a concentrated point and needs to get all the radiation onto a proper wavelength and pointing in the right direction. How the particles get the energy from the spellcaster and into the point of conversion isn't important, you can just say that mana particles move on a different plane of reality, or like electrons, don't have a precise location but rather a probability distribution of where they're likely to be. Then, you can just use standard laser power levels and their effects. For example, a 60 watt co2 laser can burn through plywood around a centimeter or two thick provided it's properly focused. Now if you throw in some realism in the form of spell efficiency modifiers (presumably no fantasy spellcaster knows the most efficient mana pattern possible to convert to radiation) and have the beam loose coherence after distance (as focusing the beam takes immense spellcaster skill), you can have a "realistic" laser spell. The spellcaster might be firing off 80 watts of laser power (at an expenditure of 200 watts) and such laser beams would be able to instantly blind people, and give nasty burns at a distance. 80 watts would not be enough to cut anything at range. At the extreme, if a skilled spellcaster goes "all out" and is able to get off a 2000 watt beam before they fall unconscious from exhaustion that could do some damage. 2kw laser systems are cable of cutting centimeter-thick sheets of metal with ease. [Answer] At heart, much of physics is probabilistic. Your new particle could be the quantum particle of luck, the tychion. That's from the Greek τυχη, meaning luck. A means of generating tychions could achieve things like: influence the weather, influence a person's decisions, or influence the flip of a coin. If you fell out of a window you would land in a huge pile of cushions. If you bought a lottery ticket, you'd win but not the main prize because that would attract attention that would be bad luck. Generating anti-tychions could be a method of bestowing a curse. Imagine the victim doused in them. He might never win a game of luck. He might have bad weather every day. Unless he wanted rain for his garden in which case it would be sunny. If *HE* fell out of a window, he would land on a big stack of kitchen cutlery. Having a black cat cross your path could actually be unlucky because they suck up all the tychions in the neighborhood. Breaking a mirror could drive them away. The triangle a ladder makes could be a place that tychions are excluded. A horseshoe could be a structure that catches them and holds on to them. Prayer could work because the deity drops a bunch of tychions on you. Or if you offend a deity, he could drop a bunch of anti-tychions on you. Creating good luck particles might also create bad luck particles in equal number. Getting rid of the bad ones might mean you needed a victim. Or you might have to invest a lot of time accepting bad luck in order to save up for that one important time when you need all the luck you can manage. Or, you might get robbed of your stored good luck. What a stroke of bad luck! [Answer] One possibility is that it can, under special circumstances, interfere in specific ways with the normal [fundamental forces](https://en.wikipedia.org/wiki/Fundamental_interaction) so as to alter their effects. For most magical effects, really, you need only alter the electromagnetic and gravitational interactions. For instance, in a specific area, it might increase, decrease, or redirect the effect of gravitational force. The applications of that are obvious; flight, levitation, increasing or reducing weight, tossing things around, and so on. Fool around with the electromagnetic field and you can do things like alter light, create lightning, throw around magnetic fields, fool with chemical processes, or even break down an object into its constituent elements (aka, the disintegration spell). You could technobabble it by saying it's something like visible light: most of the time it's incoherent and doesn't have a huge physical effect. Focus it and make it coherent, and like light now you have a laser that's potentially capable of a great deal of physical effect. [Answer] Your particle could be one that modifies the fundamental forces around it depending on how it is manipulated (I'll leave the details up to you). The fundamental forces, weak nuclear, strong nuclear, gravity, and electromagnetism, together control literally every particle interaction in the known universe. If your particle can affect even one of those forces, say it could increase or decrease the local weak nuclear force, you could do virtually anything. You could change atoms into other atoms, affect interactions with electrons, even create elements that would otherwise be unstable. From there you could affect gravity to focus radiation, and boom you have a magic laser based in physics. DISCLAIMER: I'm not a physicist, there's probably something heinously wrong with my scenario, but from my amateur understanding (watching a lot of physics lectures) the statement about being able to do virtually anything by modifying the fundamental forces should be accurate. [Answer] # Dark matter Dark matter and dark energy make up most of the universe. Some planets/civilizations/people have *whatever it takes* to interact with it. The rest of us have no idea; it's only mass to us. The dark matter is unlikely to appear in clumps let alone planets we would recognize, or else the gravity from those ghost objects would make itself apparent on less than a galactic scale. So there's a different physics - maybe the dark matter is as homogeneous as gas, but if you can *see* it you can see there are intricate patterns of earth dark matter, fire dark matter etc. that look like dragons and unicorns and what not, and those patterns are stable even if the particles whiz through them rapidly. This is unknown fantasy physics, so you'll have to drib-and-drab it out in teasing morsels, interspersed with any reasonable-sounding dark matter research that comes up. The key thing though is you need some self-consistent explanation of what makes dark matter *sometimes* interact with the muggles, rather than none of the time as we think. [Answer] The Higgs field contains a non-zero potential in a vacuum, and it's this non-zero vacuum potential that couples to charge giving charged particles their tiny bits of intrinsic mass. And, because these basic charged particles are moving around at relativistic velocities, this tiny intrinsic mass is greatly multiplied to the basic masses of the particles we know. It's possible this magic particle is what gives the Higgs field that strange seeming energy from nowhere. Maybe, additionally, the magic particle couples through mechanisms like the Higgs to create the intrinsic electroweak charges. Placed in this central position, your small changes to your magic field are multiplied greatly in nature, and most basic effects might be covered. [Answer] Frankly, this is the premise of thaumaturgy in The Thaumechanical Man. Thaumaturgy is a field, similar to electromagnetism, mediated by the thaum particle. It behaves a lot like electromagnetism, complete with its own rules for conductance, transmission, and energy translation efficiencies. Thaumechanics use it to power their machines and homunculuses, which are effectively thaumechanical robots. The issue you'll run into is that, if you define it tightly enough, it stops being fantasy and becomes science fiction. This is why TTM is categorized as sci-fi instead of fantasy. It's "sufficiently advanced magic being indistinguishable from technology." I'd go into more details, but There Be Spoilers. [Answer] **Energon particle** ## Preservation of energy: The magic particle can store a maximum amount of energy and then release it later. It normally interacts weakly with matter so can easily go through regular matter. They can bind together to do telekinesis. They maybe can resonate with each other to connect to distant energons. ## MP It takes magical stamina (Mana points, mp) to cause the magic particle to store or release the energy (both directions cost the same). The mage can then steal energy from one system and then release it later, but limited by how much mp the transfer costs. ## Powers: * For telekinesis the energons bind together like a magical exoskeleton to push stuff, but you have to take into account leverage and stuff. Preserves energy and momentum. * For teleportation you swap two equal mass objects, which preserves momentum and energy. * For heating or cooling they excite or dampen motions. * For distant communication they resonate with distant energons. ]
[Question] [ TLDR: **~ mach 3, practically unlimited range but presumably substandard stealth characteristics. Would it be a game breaking weapon on modern air battlefield or merely would require tactics adjustment for SAM batteries?** Yes, derivative of [Project Pluto](https://en.wikipedia.org/wiki/Project_Pluto). Such speed allowed [Blackbird](https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird) to regularly outrun SAM rockets, however that trick worked a half century ago. However, I see that nowadays the most desired feature of fighters is low radar cross-section, and I'm not optimistic what would ex. (sic) happen with sensitive radar absorbing paint, while heated at mach 3. Moreover, I'm not so sure whether when dumping such amount of heat would not make it quite nicely glowing in IR, even before considering its radar cross-section. While at least in theory it should still outrun big chunk of missiles, for example those intended to serve as anti-rocket systems like [PAC-2 / PAC-3](https://en.wikipedia.org/wiki/MIM-104_Patriot#MIM-104F_(PAC-3)) get over mach 4, so I see an issue here. Moreover, with better communication systems I could imagine trying to hunt it using a few coordinated SAM batteries. But I simply don't know whether those features would matter. [Answer] Low flying aircraft are best engaged by "look down/shoot down" systems from opposing aircraft, since the elevated sensor and shooter platform(s) will have a much greater area that they can cover with sensors and weapons than ground based systems. An integrated GBAD system tied into the larger battlespace management system would be a useful addition, since they could thicken the air defense layers in the most vulnerable areas, and also have more "persistence" since they are anchored on the ground or in a vehicle rather than an aircraft. This also means the nuclear powered UAV needs to deal with multiple enemy weapons systems, from automatic cannon to radar and infra red guided missiles. The greatest difficulty after acquiring a high speed target is ensuring there is a weapon in it's flight path. Even a slow moving system would be capable of downing a supersonic missile if it were in front of the target, only high aspect weapons that can fire at large angles off boresight and "tail chase" weapons really need to be faster than the adversary. In more futuristic settings, the defender might have laser weapons, hypersonic artillery shells for GBAD cannon or even railguns mounted on surface and air platforms. The biggest problem for the defender is actually shooting down a nuclear powered aircraft over enemy territory, so they have to deal with the fallout and radioactive debris from the weapon (much like the Russians did when the salvaged reactor from the "Skyfall" nuclear UAV had a criticality accident when brought to the surface). [Answer] Surface-to-Air systems would still have a really hard time with a missile like this just because of the altitude it flies at. The Project Pluto was originally designed to fly very low, and a modern one could fly even lower, less than 100 feet using the same kind of terrain-following technologies that modern cruise missiles use. This gives surface-based launchers only seconds to acquire, launch, and intercept which generally isn't going to be enough time. This is a non-trivial problem for the United States military currently, and the Navy in particular is extremely concerned about how to keep aircraft carriers safe from the new generation of Mach 6+ cruise missiles that China is developing. Air-launched missiles would do just fine though, because your Neo-Pluto would be an incredibly easy target for heat-seekers. The Chinese already have a Mach 6 Air-to-Air missile which would do just fine. The USAF would have to do a bit of quick kit-bashing, since Sidewinders aren't fast enough and AMRAAMS aren't primarily designed for heat-seeking, but it'd be pretty easy for Rayethon or whoever to come up with an upgraded Phoenix with a Mach 5 top speed and a heat-seeking guidance. [Answer] The ease with which such a drone can be shot down depends entirely upon its ability to evade a missile launch. If the SLAM drone was a dumb weapon system, flying a pre-determined course, then shooting it down would simply be a matter of getting an anti-air missile in front of it, whether ground-launched or air-launched. However, given that this was the mission-profile for the conventionally powered Lightning Bug drones (in particular the [Ryan Model 147S](https://en.wikipedia.org/wiki/Ryan_Model_147#Ryan_Model_147S_Buffalo_Hunter)), a sufficiently low altitude would make it fairly difficult to shoot down. However, if the OP's proposed SLAM drone had threat detection equipment that allowed it to observe hostile missile launches against it, then shooting it down would be an entirely more difficult matter. The fact that it is unmanned means that the limiting factor in its manoeuvrability is not the combination of the necessity to carry a human pilot, who also has a g-limitation of around 9g for a properly trained and equipped combat pilot, but the span-loading of its lifting surfaces and the strength of its airframe. A flying-wing or blended-wing-body shaped SLAM drone with low spanloading and even mass distribution could be very manoeuvrable indeed, and could conceivably out-turn a missile. Modern doctrine for fighter aircraft evading an anti-aircraft missile is to attempt to turn behind the missile, effectively turning *toward* it. Why, when the missile is faster and more manoeuvrable? Why not turn away and open the range? The reason for this lies in how anti-aircraft missiles work. Observe a real (not Hollywood) A-A or S-A missile launch. You'll see that its typically solid-fuel rocket motor fires for a time and then burns out, usually well before reaching its target. Most missiles effectively coast most of the way to their target, relying upon their low static drag in order to retain kinetic energy. Most missiles cannot 'choose' to conserve fuel in order to prolong their manoeuvring time, their engines are like a firework that simply burns and produces thrust until all fuel is consumed. The effect of turning behind the missile is to force it to manoeuvre as hard as possible. It is an aerodynamic law that lift produces drag (induced drag), so while the missile's fins are turning it, the act of turning - and producing lift - produces drag which slows it down, and the harder it has to turn, the more induced drag is produced, and the faster it loses its kinetic energy. A fighter aircraft cannot win in a turning race against a powered missile, but against an unpowered, ballistic missile? It starts off faster and is more manoeuvrable, but the fighter can power through its turns, while the missile's speed bleeds off, and with just a bit of luck, the missile will run out of energy before it gets to within attack range of its target, its speed will drop below that of its target's, and it will fall behind and eventually fall to earth. So, if the OP's proposed SLAM drone can manoeuvre against incoming anti-air missiles, it would most likely need to be forked between *at least* two incoming missiles in order to have any chance at all of being shot down by any of them. It would likely be able to out-manoeuvre any single AAM or SAM launches, and would require having to choose which missile to turn away from and which to turn toward in order to be put in a position where one of the incoming missiles could retain enough energy to reach it. That also discounts the possibility where it could simply fly straight upwards under power, where the missiles pursuing it are entirely at the mercy of gravity, until they are all behind it, then turn hard to pitch downwards over the top of them, once they are all approaching from similar vectors. So, a purpose-built drone capable of manoeuvring against anti-aircraft missiles would be an incredibly difficult target. Far better to simply fill the air in front of it with steel from dumb rapid-fire [AAA](https://en.wikipedia.org/wiki/Anti-aircraft_warfare) and pray for a hit. [Answer] **Flak** You don't need to hit it but if you fill the air with enough shards of metal, you'll hit something The Russian BUK missile was used to shoot down Malaysia Airlines Flight 17. It's explodes into a cloud of shrapnel which cuts apart anything in the area [![enter image description here](https://i.stack.imgur.com/A5dEd.png)](https://i.stack.imgur.com/A5dEd.png) Speed and maneuverability only do so much when faced with a wall of metal fragments [Answer] Not very hard to shoot down if modern AA system can lock on it. Systems like [S-400](https://en.wikipedia.org/wiki/S-400_missile_system#Statistics) can shoot down targets moving up to Mach 14, and even faster. The question is how easy it would be for the AA targeting system to track down and follow the aircraft. P.S. There is a strong evidence that the most recent AA systems like [Barak 8](https://en.wikipedia.org/wiki/Barak_8) were developed to specifically counter the threat of supersonic cruise missiles like [Brahmos](https://en.wikipedia.org/wiki/BrahMos) ([Is BARAK-8 the Antidote to Brahmos?](https://defencelover.in/barak-8-antidote-brahmos/)). Brahmos, with its Mach 3 speed and low flying altitude seems to be very similar to the ramjet in the original question. ]
[Question] [ In a sci-fi universe where man has the capability to leave our solar system would metals or alloys above and beyond our own be possible? Or at least within the bounds of reasonable possibility? As the title and setup implies these metals of course would be from way out among the stars. Never explicitly detailed except for a detail or two, to avoid direct confrontation with the laws of physics. By this I mean that there are no page long descriptions of them. Only a direct comparison to a metal or metals that actually exist. I.E; twice the weight of lead and otherwise identical. Tenth of the weight of titanium, with seemingly all the benefits of titanium only it behaves like steel. Just two examples. Of course these metals would range from relatively common for alloys like the heavier lead to rare as hens teeth. This might not even have to be more than a couple of new elements that they could use for alloys. Using super advanced alloys to reach the same result and might actually be better in that I don't have to define their exact make up. A little more leeway before we reach a point of ignoring physics like most sci-fi does to a detrimental extreme. I am trying to avoid throwing reason to the wind though reasonable suspension of disbelief might be alright. [Answer] As the other answers have said, just with pure naturally occurring materials, no. ***But why limit yourself to natural materials?*** From [Wikipedia](https://en.wikipedia.org/wiki/Metamaterial): > > A metamaterial is a material engineered to have a property that is not found in naturally occurring materials ... Metamaterials derive their properties not from the properties of the base materials, but from their newly designed structures. Their precise shape, geometry, size, orientation and arrangement gives them their smart properties capable of manipulating electromagnetic waves: by blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials. > > > For example, [Vantablack](https://en.wikipedia.org/wiki/Vantablack) is a surface of vertically aligned nanotubes that reflect virtually no light. [Acoustic metamaterials](https://newatlas.com/acoustic-metamaterial-blocks-sound-not-air/58818/) can block sound while allowing air to pass. Your astronaut-miners aren't digging through rock for natural materials - they're scavenging the abundantly manufactured materials of a long-extinct alien race, whose technology was ten thousand years ahead of our own. We don't know why they died out, but their planet's climate means that their vast metropolises are astonishingly well-preserved. We certainly don't know how they manufactured their skyscraper-tall buildings that don't block radio signals, or the feather-light metals that made their flying machines. We don't know why their cutting implements never lose their razor edge, or how their mining drills are ten times as hard as diamond. The superconducting material in their strange vehicles [quantum levitates](https://www.youtube.com/watch?v=Ws6AAhTw7RA) without being super-cooled, and we can't explain it. Maybe we will discover their secrets in the coming centuries, but until then, we can't make anything even close. **As for you the author, you certainly don't have to explain how any of these alloys work. It would be strange if you could.** [Answer] ## No, theres no room on the periodic table [![An image depicting the periodic table of elements](https://i.stack.imgur.com/0S9o0.png)](https://i.stack.imgur.com/0S9o0.png) <https://www.bbc.co.uk/news/science-environment-47008289> As you can see from the image, every element as an atomic number ranging from 1 to 118. However, there is not any space for numbers to go anywhere between Iron (FE number 26) and Tungsten (W number 74), all the atomic numbers represent other known elements. Whilst technically there is more space after number 118, unfortunately for you the element is very unlikely to be stable or to have the desired properties you want. Additionally, we might not even know its state of matter. Contrary to what is taught in schools, there are actually 6 states of matter: solid, liquid, gas, plasma and two others (I don’t know the last two as they have exceptionally long and hard to remember names). Anyway, thats beside the point, my point is is that even if we discovered a material similar to what you describe, its likely to be unstable, radioactive and it might not even be a solid at any useable temperature. --- ## However, you might be able to use nano-materials A couple years ago i visited a laboratory where the scientists were looking at practical applications of nano-materials. When known elements are reduced to the size of nanoparticles, they can behave vastly differently to how they do when there are larger quantities of material. For example, they found that when gold is reduced in size, it changes colour and eventually it becomes invisible. The eventual uses of this research was to help create nanotechnology. The researchers there, again using gold for their examples, stated that by using nanoparticles of gold, you could create a computer that was flat but you could pick it up, bend it around your wrist and it would still function. The purpose of this would be to create something like a smart watch or a phone on your arm (similar to the Omni-tool from Mass Effect). There were other applications of these materials such as creating nano-machines to administer medication into your bloodstream or to fight infections (similar to how white blood cells do). Applying this to your question, it may be possible to use nanoparticles of existing elements to create highly advanced materials. You might even be able to create a nanoparticle-based alloy to create the material you want. [Answer] They probably wouldn't exist, but you might get away with one or two. The problem lies in Mendeleev's table: all substances are defined by the number of protons Z in their nucleus, and we know what substances are created with N protons, with N between 1 and 115-ish. We also know that, roughly, beyond a certain point, the atom nucleus grows too big for the strong nuclear force to be able to keep it together. So, beyond a certain Z, atoms are unstable; and with lower Zs, we know what we would get and it isn't any "star metal". In other words, your star metal has no "slot" where it could exist. However, there seems to be an "island of stability" with substances that do not self-destruct almost instantly, but last some fractions of a second before disintegrating. You might therefore posit a *further* island of stability, with Z beyond 130 (say), where unforeseen and not necessarily explained "geometric properties" allow one or two substances to be almost indefinitely stable. These substances would almost certainly be metals, incredibly dense - more than lead or uranium, possibly more than osmium; soft and malleable, decent electricity conductors. The reason they only exist in outer space is that the energy required to create them is *immense* - even more than heavy metals. These "superheavy metals" require a [hypernova explosion](https://en.wikipedia.org/wiki/Superluminous_supernova) to be created in any significant quantity. A relevant use of such metals is less clearly designed, though. You need something that only alien phlebotinum can do, something extremely valuable - enough to launch a thousand starships to mine it from remote, hostile places. Perhaps some weird chemical property - who knows, a catalyzer with the ability of transferring phased electrical energy directly into precise, customised chemical bonds. This could become the easiest way of cleaning up a polluted Earth's atmosphere, precipitating carbon and nitrous/sulphur oxides (imagine a sieve through which enormous quantities of air flow freely - all the while silently shedding an impalpable black diamond, soot or fullerene powder that gets scrubbed). Or they could have unexplained, incredible *tensile strength* (either alone or in combination with, say, carbon nanotubes). This would make them incredibly valuable for the construction of space elevators, which in turn allow cheap (think 100x or even 1000x) and environment-friendly space launches (this happens in Timothy Zahn's *Spinneret*). Or they could be the essential component for *Goldberg quantum resonators*, devices capable of measuring and transferring precise, minute and controlled amounts of energy within a radius of a foot or so. Coupled with a powerful enough computer, these devices can, in a few hours or days depending on the volume treated, cure not only cancer but old age too (they would be a miniaturized version of Iain M. Banks' Culture's *effectors*, capable of manipulating matter at the atomic level through the fourth dimension). The length of a treatment (you need to rewrite *trillions* of cells in a body) would mean that the only practical way to process more people within their lifetimes would be to build more devices, but to do so you need space metal for the "recording heads". Even Earth rare metals do not allow the required precision, making the machines worth billions, their services auctioned to the highest bidder (something vaguely like this, minus the space metal, occurs in E. C. Tubb's *S.T.A.R. Flight*). # Other possibilites - does it need to be a metal? Or a "natural" occurrence? Space iron cannot be different from Earth iron because iron is iron everywhere (this is the premise of "Omnilingual" by H. Beam Piper). But composite materials can exist in a much greater variety of configurations, some of which might not exist on Earth. So, for example, the radiation spectrum of a faraway sun might transform ordinary cotton into some exotic material, too costly to reproduce otherwise (this is Isaac Asimov's *The Currents of Space*). Or drugs. Lots of leeway there. [Answer] No need to go beyond periodic table and laws if physics. Just shift the environment to get some interesting exotic examples: 1. Metals that exist on Earth in pure form only as curiosities because they quickly corrode or outright explode on contact with oxygen or water: sodium, calcium, potassium, rubidium, etc. In inert atmosphere or vacuum they can persist naturally. Calcium would be usable as lightweight conductor (it has better conductivity/weight ratio as aluminium). There's also an interesting alloy of sodium and potassium (NaK) which is liquid at room temperature. 2. Many non-metal elements, or even molecules like water, have metallic form at extreme pressures, such as inside gas giant planets. 3. Technetium is a metal that does not naturally exist on Earth because it decays in millions of years. It was only man-made and it's not practical to make big quantities. But interstellar explorers could reach places enriched by recent supernova explosion where it could be mined. It was found to confer seawater resistance to steel if added in small amount. [Answer] Yes and No. No. The elements defined in the periodic table of elements are going to be pretty much universal and your not going to find a magical new element like you have described. Just because its a different location in space, doesn't let it defy the laws of physics (unless of course our interpretation of the laws of physics are incorrect). Yes. The most likely situation is that alien species will be using super allows and ceramics that we haven't stumbled upon yet. There are an unending number of mixes and matches that could be created that we simply haven't tried them out yet. Once these have been identified, and a suitable construction method created, they would simply be integrated into society like any other new material. E.g. reinforced concrete, plastics, metals Magical Yes. Of course its entirely possible to use magic or fantasy to create super metals. Many worlds already do this because it follows a very simply thought process. If iron is +1, then the next metal is +2, then next +3 the next +4 and so on. A linear sequence of progressively more powerful metals that don't exist in the periodic table, are made by dodgy scientists who don't document or record their work and apparently have infinite funding with no oversight. They also like to delve into the mystical elements, like the heart of a star (Hydrogen or Helium?) or meteors from outer space ( Adamantium ), or some mumbo jumbo chemical name . Magical elements have no laws restricting them. It all depends on how much the audience is willing to accept which in some cases results in galaxies being used as throwing stars. [Answer] If your material is allowed to be radioactive, it might still be compatible with suspension of disbelief to posit existence of some island-of-stability nuclei that are not observed in the solar system today because they have half-lives on the order of a few million years. One could posit that small quantities of such elements are regularly produced by supernovae and that one can mine them in young solar systems that formed in the aftermath of a recent supernova. I am not an astronomer, but I do not think the spectral properties of the hypothesized island of stability elements have yet been constrained well enough that spectral analysis of supernova remnants would rule this out. I would also suppose that if production rates of such nuclei are reasonably low, we would not necessarily have seen them in the solar system as part of incoming galactic cosmic radiation. Also, in addition to the alien tech metamaterials that have been mentioned in another answer, it is perfectly possible to imagine that an alien biosphere would yield materials that we cannot reproduce artificially and that we are unable to farm the organisms making these materials on Earth. For instance, it may be that the reef-building creatures of Ong'azur only grow in their native ocean with a 30-hour day/night cycle at a temperature of 200° C with the ocean kept liquid by an atmospheric pressure of 100 bar. In that case, we may be able to study some specimens on Earth in a lab, but certainly not at the scale needed to harvest their precious shells commercially. (You would still have to somehow make space travel/mining on Ong'azur very cheap or the material very valuable to make this believable. But this is a separate problem.) [Answer] # Maybe, depending on how hard you want your science Cribbing off one of my other answers, you could get around this by extending the Periodic Table into the third dimension. Have a rare, exotic quark formation that can take the place of a proton in the atom's nucleus. That particle (let's call it a deion) has the same charge as a proton, but a different mass, and might have other different interactions (has mass but gravity has no effect, absorbs photons and emits something else, etc). And the more deions an atom has instead of protons, the greater the effect. As for where deions come from, you could hand wave it, or invent a rare interaction (when a charged quantum filament and a black hole between fifteen and eighteen solar masses love each other very much, they have a special kind of hug...). ]
[Question] [ In the movie *Guardians of the Galaxy* (and a few others), we meet a bipedal raccoon known as Rocket (who I am aware did not evolve to be bipedal, but I am using him as an example). I honestly love the idea of an animal the size of a cat/raccoon/coyote evolving to something similar to a human. This is probably the result of my bias as a human towards things that look like me, but that doesn't mean such a creature wouldn't be a fun thing to include in a fantasy setting. To repeat my question, I want to know if such a creature could evolve a bone structure that allowed for easy bipedal movement (Not like how gorillas knuckle walk, but rather a creature that would deliberately prefer bipedal movement similar to a human). Lastly, the creature is not gonna be a raccoon or anything in real life. It is in the order Carnivora, but it would probably most closely resemble maybe a red panda. Or it could belong to an entirely separate family. The idea is that the creature is not based off of anything in real life, but rather evolved from quadrupedal animals that were also fictitious. [Answer] Yes. Some carnivorans are already facultative bipeds. Raccoons can squat on two legs to feed, and indeed one hypothesis on human evolution suggests bipedalism came from squat feeding. Meerkats often stand up to survey their surroundings. Bears will stand on their hind legs to free up their forepaws. Faith the dog was even fully bipedal. By amplifying and sustaining the evolutionary pressures which drove those carnivores to be facultative bipeds, obligate bipedalism can be reached. Or you could just have them go along a parallel path to primates; start out with something like a genet, which would then develop brachiation and eventually descend to the ground to walk upright. [Answer] Yes, and that is what has happened on earth. Mid sized mammals evolved into primates, then bipedal hominids. But **what you're really asking is if a character like Rocket makes natural evolutionary sense.** Let's investigate the bodily differences between Rocket and humans. Rocket has but humans don't have: * Fur * Tail * Large canines * Small stature Rocket feels human because he has: * Bipedal locomotion * Articulate hands * High intelligence * Emotive personality The problems in believing Rocket could evolve naturally arise in the development of the human characteristics while preserving the non-human parts. **The biggest issue is in believing bipedal creatures need a tail**. A tail almost always serves as a physically needed counterweight for climbing or sprinting. Bipedal creatures don't have great need to climb, otherwise they would evolve more appropriate forms, like chimps. Bipedal forms use swinging arms for counterweight and it's extremely effective. **The next issue is high intelligence creatures with large and powerful canine teeth**. Current theories contend that early hominids were able to develop larger brains (thus, more intelligence) because they first discovered fire and started cooking food. Cooking food releases many more nutrients than eating raw. It's also easier to chew. This allowed smaller teeth to develop that didn't need as much crush power. The muscles that have that crush power, which wrap all the way around the top of the head, decreased in size while the skull expanded. The lesson biologists take today is that human level intelligence could not have happened without fire cooked food (an utter game changer in many other ways too) and the teeth getting smaller and the jaw weaker. **The remaining traits are believable enough**. Apes have articulate hands that are only a little less nimble than human hands. Raccoons even have decent dexterity already. A small stature is known in Homo floresiensis, who was bipedal but probably slow and clumsy. Emotive personality is subjective humanity. Plenty of people are very boring, but we don't write stories about them. Finally, the fur can easily be explained by sexual selection. That's right, the ladies love a hairy guy. For me, I can forgive a species that looks like Rocket because it's very fun, but I know it's unlikely in the natural world. [Answer] It's worth recalling that bipedalism is great for covering distances. So if your creature historically needed to do that in order to get a bite to eat then it would make sense. Imagine kangaroos with pointy teeth and claws. I would get out of their way. [Answer] here is a good article on the subject <https://www.smithsonianmag.com/science-nature/becoming-human-the-evolution-of-walking-upright-13837658/> A brief synopsis, to become bipedal, the species must undergo some environmental pressures to make it advantageous than remaining quadrupedal. A couple of theorize is, one from Darwin with the use of tools (rocks and sticks) made it advantageous to become bipedal and the carrying of food (which chimpanzees do now and raccoons sort of does). In my opinion the two theories are the same, the carrying of stuff is easier with your hands free. With another theory of climate change wiping out the forests, if your "raccoon" or "red panda" was a forest dweller originally, to cope with the new grasslands, bipedal locomotion may be more energy efficient. I would suggest being a predatory creature, one that cannot sustain itself on the vegetation of a savanna and need to conserve energy for long treks. This would assume the creature dispatched itself from its preferred environment and become nomadic. Edit: I should add, one draw back in becoming bipedal was the change in shape of the pelvis. This caused issues with child birth, which became compounded in the evolution of a bigger head, thus hominid babies were born a lot less capable than its ancestors were and how many predator/prey are. Its assumed, for a baby to be born with the same capabilities as our nearest cousin, it would have to gestate for 2.5 years, but would kill the mother upon birth. This would require a strong social community to care for the fragile young. This social structure exists in primates and somewhat in raccoons, thus I am liking the idea of an evolved intelligent raccoon species. [Answer] Yes, it could. As for "how" that depends on a multitude of factors, but an arboreal lifestyle transitioning into a plane dweller might do the trick, just like it did for us. As a bonus for you I do think that some kind of bear or mustelid might be the most likely candidate given the appropriate circumstances, as those are animals that already show an upright posture and limited bipedal movement on occasion. [Answer] Yes, it could. In general, any animal could evolve to be bipedal given enough time and an incentive to do so. Some possible incentives could be the ability to keep hands free to carry or manipulate objects, to travel long distances, or to extend the creatures reach. As for how long it would take to evolve, traits tend to either spread quickly or die out soon after the change emerges. In order for the trait to stabilize I imagine a few thousand years should do the trick. However, that is just for rudimentary walking. For a bone and muscle structure that could support continuous bipedal movement, independent from any other form of locomotion, I think one million years would be a safe bet. [Answer] Yes, yes, cats on 2 legs. How droll. But giving up 4-legged locomotion is a big ask for Carnivora. They cook right along on all 4, all of them. Well, almost all of them. [![sea lion](https://i.stack.imgur.com/EICXv.jpg)](https://i.stack.imgur.com/EICXv.jpg) <https://www.youtube.com/watch?v=ZZ3sTIkp9RE> I propose **Bipedal seals.** Consider birds. They are bipedal because they needed their forelimbs for something else. Primates too - climbing. The seals have specialized their limbs for swimming, with the result that on land, sea lions are already bipedal - they walk along on their forelimbs. Their hindquarters pretty much drag along. The sea lions that return to the land and become bipedal, would have increasingly vestigial hindlimbs. The entire rear part of the body would turn into a dragging "tail" like a Tyrannosaurus or a kangaroo - this would serve to counterbalance the front-heavy head and upright body. [Answer] Many other answers already state that racoons could become bipedal, but I think the most important part of this question is actually if they can become sentient Rocket-like bipeds. First thing to ask is if a Racoon could be naturally put under the right kind of evolutionary pressure to require intelligence. Racoons are very similar in a lot of ways to our pre-human ancestors. Their omnivorous status means they need to know a maximum number of techniques for acquiring food. Their need to avoid poisonous plants requires good recognition and discrimination skills, their need to hunt means they need to be able to plan and anticipate. Their hands are dexterous enough that they could be capable tool users if they had the minds to match. They are already somewhat social; so, they could probably overcome the gestational issues with bipedalism as we did; so, all the major positive contributions to human intellect are already there. So, what's holding them back? Many might assume that it is their small size that would inhibit their intelligence because they could not support a human size brain, but history and biology tells a different story. Brain size is actually a small factor in intelligence, because biology is so good at optimizing when it needs to. For example, Homo Floresiensis was a 3-foot tall hominid which is believed to be capable of even more intelligence than modern man based on how developed the cognitive structures in their smaller brains were compared to ours. While a raccoons frame could not support a homo-sapien brain, something more like a Homo Floresiensis brain would work fine. The real culprit as to why racoons are not already as smart as modern man is more of an environmental issue. Racoons can use the skills they already have to survive quite well. Any step forward their minds make in evolution can just be undone by a step backwards if there is no strong environmental force making sure that the dumber members of their population die out. The real trick to human intelligence is not nutritional, size, or any of that. It is that we got are arses handed to us over and over again nearly forcing us out of existence. We were basically stuck in an situation where a little more strength or a little more speed could not save us, but a little more smarts could. And generation after generation, the dumb died young or failed to sustain their offspring where the smart could succeed by planning out new ways of obtaining and protecting our resources. This actually leads to a very interesting conclusion: As humans change the world, raccoons who are smart enough to study human behaviors and make accurate predictions about us are less likely to get hit by a car, or caught in a trap or shot digging in our garbage. Those that learn better ways to communicate can tell eachother which humans are safe, and which are dangerous. This means that racoon populations may in-fact be under the exact right conditions right now to evolve into what you are asking about. The question remaining is if this status quo can be maintained long enough for evolution to take its course, and if humanity would tolerate another intelligent species in our midst if they make it that far. ]
[Question] [ Solarae is a militaristic kingdom that has long guarded the northern passes against the hordemen (think the Germanic migrations/migrants), but Solarae is also a rich kingdom due to the abundance of metal both within the highlands, but also through trade with the dverg (think dwarves). Because of these factors Solarae faces both invasion by the hordes, but also it's fellow kingdoms jealous of its wealth (this animosity isn't helped by Solarae frequently being the "bully" of regional conflicts). Long ago the "King of all Sol", Merovech the Stern created a system of corvee labor within his kingdom. The system is as follows: For every 3 weeks the peasantry (serfs) are at their manors they must for one week labor for the crown. In order to have a constant flow of labor the serf population will be divided into roughly 4 groups with each having a different labor week within a given month. This means that 1/4 of the serfs would be laboring for the crown while the other 3/4 are at home. The royal labor itself revolves around the building of fortifications or gathering the resources to build the fortifications. This means most serfs would be employed in quarries, or as wood cutters, brick layers, or other menial roles. Would this system be effective or at least be moderately successful as "quickly" building or repairing fortifications and castles across solarae (as well as other building projects like roads, bridges, and so on)? Note: Late Medieval to Early Renaissance technology is in use. Solarae itself is a abolitionist monarchy hence it's centralized nature. The Kings of Solarae enforce their rule via the control of the mines and thus armor, weapon, and tool making of the kingdom as well as a small, but professional army of enforcers that beat lords who's heads get to big. Solarae is in a near constant state of warfare dealing with invasions from the north and incursions by the other kingdoms from the south. However on the southern front it is minimal skirmishes at best. The peasants are paid in rations, tools, and other necessities for their work. [Answer] One of the advantages of being a serf vs a slave is that you get to choose (more or less) your own family structure, living arrangements (within limited options), and community governance (again, with strict limitations). Slaves may have tastes of these relative freedoms, but basically they are told who to have children with (perhaps not in all slave societies), where to sleep, and what to do day after day. Both slaves and serfs are not free to leave their community without permission. If you are the ruler/master and you are using slave labor, you will pick who and when. But with serf labor, you may instead institute requirements on the community and allow them to decide how to fulfill them. Even with a specific [Corvée system](https://en.wikipedia.org/wiki/Corv%C3%A9e), the obligation was on the "tenant farmer" and not on individuals per se. In many, maybe even most, cases, the requirements extended to every able-bodied person (or man), but if you may not need that. It would be more practical and less of a burden if you issue weekly requirements for the workers you need and allow the community to decide who to send. You might even pay an older person in the community (who can't do hard labor anyway) to oversee it. You will need skilled workers for the tasks you describe and they are specialty skills; most may know more than one but no one can do it all. A bricklayer probably can't oversee felling large trees and vice versa. You'll also need some workers with experience who aren't yet able to lead the tasks. And some general labor. Your needs will change week to week. This week you might need 25 bricklayers with another 50 to help them, no lumber jacks, and 5 farriers. Next week you want 20 lumberjacks with 30 helpers and 10 metalworkers. If your workers' families end up starving because you've taken away the people who were supposed to harvest their winter's food supply, you shoot yourself in the foot because you lose workers (either immediately or in the future, if the deaths are of children). If this happens because you conscripted workers you didn't actually need and they just did general labor as busywork while their fields rotted away, the level of hate and resentment goes up 100 fold and you'll probably have revolt on your hand. Most Corvée and similar labor is agricultural and must be done at specific times and your workers are already trained in it since it's similar to what they do for themselves. Though there is certainly public works and other labor. The type of work you need is specialized and has different on/off seasons from agriculture (with different things you can and can't do in various types of weather). Plus individual projects are mostly time-limited and/or change in what type of work needs doing (if you're building a wall, you won't need the same number of workworkers vs masons every week). If the community chooses who to send, they can balance out who needs to stay behind the most with those who are most likely to complete the work to your satisfaction. If you pay them (in money or extra food for their families, etc) you might even get volunteers. Allow the fastest workers to go home early and the community is more likely to send the best specialists for the task at hand. [Answer] Historically serfs would actually pay a part of their taxes in form of labour, mostly farming-related stuff on their lords land, but also otherwise. But I found points why your system may wouldn't work: For one, there is the problem that you want a constant stream of labours, while the work the servs have to do on their own farmland isn't equally distributed. During harvest-times every hand will be needed, while other times of the year there might be a low. My solution would be to either only let them work during their "free" times or, since you say you have communal farming redistribute the work so some people of each farmstead will be full-time working on your fortifications etc. Another point, most of the work you are suggesting can't be done by untrained workforce. Stonecutting and masonry is something you need professional craftsmen. What you can use your peasants for are earthworks and transport (actually you need their carts and workhorses, not the serfs themselves) [Answer] Yes. This type of corvee was important in Russia through XVII century and contributed to Russia's successful territorial expansion. But, like any other types of corvee, it has limitations. 1. Feudal vs crown duty. It was common for serfs to work for their lords. It was much less common for them to work for central government (if feudal serfdom system is already established). There would be significant pushback from lords if their serfs are required to spend their time somewhere else, and serfs themselves are just humans, and having to share their time for crown, lord and their families may turn out to be too hard. 2. Logistics. "Crown corvee" works well only when the work is required to be done locally. If we need workers to travel days to build some distant fort, and then travel back, this would turn out to be very inefficient. And serfs can't leave their land even for a week without their own farm starting to suffer. Any time we have to pull peasants from the land (like at wartime), production will suffer. 3. Natural trade. Corvee system is in many ways inferior to tax system, and serves as a necessary replacement when population is so poor that people don't have money to pay taxes. If peasants do sell their crop for money, corvee is becoming an anachronism. [Answer] First, I think Solarae needs to establish some peace treaties. It would be in their interest. Rich or not, it'll eventually fall if its constantly being attacked! Furthermore, I think the system would work quite well in some regards. I have a few questions though. Are the serfs paid for their work for the crown? Because if they are not, I doubt this system would ever work. Let's take a look at the example of Jim the farmer. Jim is already quite sour that he has to work for the rich for free, for a month straight sometimes, but he sucks it up. Though one cycle, it so aligns that the month that Jim has to go labor for the crown is around the time of the harvest of his crop. A lot of his crop would probably go unharvested, and Jim would either suffer a very cold, poor winter, or he would try to arrange some sort of revolt. If he *does* get paid, then we'll come back to this. Question number 2; does Jim *have* to work a whole month out of each 4 months? Wouldn't a week out of each 4 weeks work a lot better? I believe that system to be a lot more effective. If he doesn't get paid, then losing a week of his harvest may not be the end of Jim, and if he does, then the question becomes "how much"? But again, we'll come back to this. I think the longer the labor time frames are, the harder of a time you'll have to make the system work. Imagine if instead of working 5 days on and 2 days off (as is convention in at least Western civilization), you instead worked 5 months on, and 2 months off. Most people would burn out rather quickly, even if that two month vacation seemed appealing. Granted, Jim works one month on and three months off. But you have to remember that Jim is a farmer, so hes working quite a bit more than that. So lets get back to pay. Say Jim gets paid enough that he's not angry about working for a month straight for the rich. Well, come harvest, he can hire hands to do it for him if he's caught laboring. He may lose most if not all of the money he makes laboring, but he sees this as the norm, as a sort of "tax" to the crown. But at least he doesn't lose his harvest. Now what if Jim gets paid handsomely? Then he would yearn for his month to come, hiring some common work-hands is a small feat with the money he makes from the crown. He gets his harvest gathered up for him, and he even brings home some extra coin after paying his own laborers. I'd say to put yourself in the shoes of some of the common folk that need to do this kind of work and see how they'd feel about it. Let me know if I missed anything or if there's any other details I should take into account and I can edit my answer to reflect that. [Answer] No, I don't think that it will work. As @Sebastian mentioned, the jobs that you are considering are skilled labor. The productivity of untrained skilled laborers will, at best be half. Also, as has been mentioned, the travel times will mean that the workers will likely get 1 week of labor for each of their two jobs out of every month. You just cut the productivity of your work force in half for no gain. Then you have the infrastructure needed to support that much travel. And the losses, injuries and deaths that will occur during those travels. A group of raiders hitting the travelers will bring the whole thing to a halt. You now have to either guard the travelers (more manpower over **every** road or you have to have the troops necessary to force the serfs into risking their lives to get to the areas you need them. So, by using untrained labor that must constantly travel, you get very little production for a much greater cost. It is much better to use trained stone masons, etc. I would train a specific labor force of masons, stone cutters, architects, etc. Give them better living conditions and give the farmer family some incentive to send their kids off to try to be masons. Maybe, a bit of coin to make life easier. Off topic addition: Maybe capture the surviving attackers and use them as slaves. That will both help your economy and decrease the willingness to attack you. ]
[Question] [ I have created a planet which is a clone of Earth. Except I messed up where wasps, cobras and scorpions were concerned and they have turned out to be the size of elephants (everything in proportion). Sorry about that, not much I can do now, I'm scared stiff of the blighters. If I introduced colonies of humans to my planet, how long (if at all) could they be realistically expected to survive? And how would they go about doing so? (I am mindful that huge scorpions were part of a sci-fi film from the 1980s, Jason & The Argonauts(?).) [Answer] Leaving aside the physical issues with elephant-sized insects (and they are many), humans would survive them the same way we survive every other animal species: avoiding their territory when possible, making targeted strikes when we know that a dangerous animal is in the vicinity, and taking advantage of weapons. The first key thing to realize is that populations of large animals can't be too dense. If they are, there isn't enough food in the area to support them and they must migrate or starve. In the case of carnivores, the food is measured in herbivores; for herbivores, it's plants, but the principle is the same. (For plants, lest you think you can get around this with megaflora to go with your megafauna, the limiting factors are a mix of soil nutrients and available space to catch sunlight.) Complicating manners, cobras and scorpions are not known for living in large, contiguous family units the way elephants are. Mostly they're encountered one at a time, and the larger versions would likely be the same way. Some wasp species are eusocial and live in large family groups, but mostly likely these would not be able to feed themselves at giant size, so you'd have to start from the solitary wasps. So instead of huge packs of roaming monsters terrorizing your humans, you're much more likely to be dealing with individual predators with territories from which they drive all other large predators (they have to, or there won't be enough to eat). For the most part humans can simply *avoid* predators' territories by sticking to their own colony boundaries. Most fatal encounters with animals happen to unfamiliar humans who blunder into the animal's territory; the reverse, with animals actively preying upon humans, can happen but is rare enough that it won't cause an existential threat to your colony. Simple enough, but what about when you need to expand? Well, the answer is really extremely simple: guns. No matter whether your creatures' chitin is scaled up or not, it won't protect them from larger-caliber bullets. A few pickup trucks with machine guns in the beds would be sufficient to cut off a rampaging giant, herd it away from other humans, and if necessary kill it, all without allowing it to close and attack. (Wasps would need slightly different tactics - they can fly, and might be a good deal faster than the others depending on how you went about solving the scaling problems. But their wings are huge, vulnerable targets at that scale.) If your colonists don't have guns for whatever reason, their options are considerably more limited but by no means spent. A combination of pit traps for larger animals, nets to slow and ground wasps, long spears, and fire should be sufficient to dispatch pretty much any animal - especially a large, solitary one. [Answer] Large creatures have large needs: water, food, space, etc. It would be impossible to have as many hornets on the planet as Earth does with this shift in size. Therefore, your creatures would be very uncommon, and would only exist in areas that were ideal for their own survival. Humans could happily live everywhere else. But, what if the giant wasps/snakes/scorpions/etc could live everywhere? Then humans would live in burrows underground, or caves, or anywhere else where it would be a lot of work for said creature to break through. The smaller the throat of the burrow/cave, the better. You'll note that elephants don't generally dig. Why would they? If they got their head in a hole, what would it buy them? Nothing. So it would be easy enough to avoid your giant creatures (those wasps could be heard flying from miles away. The cobras would be dropping trees in their passage. Maybe the scorpions would be quieter — but not that quiet). Finally, humans have not only been hunting elephants since the dawn of time, we've successfully domesticated some breeds. This suggests we'd find a way to adapt. *I believe humans would find a way to live on your planet without much trouble.* [Answer] **Start off with a safe village/colony.** People living in the parts of rural Africa with wild lions will surround their villages with [thorn bushes the lions don't cross](https://news.nationalgeographic.com/news/2014/12/141202-bomas-lions-africa-animals-science-living-walls/) (for example, [acacia thorns in East Africa](https://conservationbytes.com/2017/06/23/keeping-lions-from-livestock-building-fences-can-save-lives/)). This doesn't eliminate attacks but it greatly reduces them. [![enter image description here](https://i.stack.imgur.com/IZSqR.png)](https://i.stack.imgur.com/IZSqR.png) Or a modern version. [![enter image description here](https://i.stack.imgur.com/Iww36.png)](https://i.stack.imgur.com/Iww36.png) **Once you have some protection, you buy time for the settlers to understand the dangers the wildlife pose and how to learn to live with them.** Those fences will keep out the cobras. Some basic land shaping will also keep them away. They won't want to slither on sharp things or rocks or on certain slopes. The colonists will need to run some experiments to see what does and doesn't work. Then they can make very large areas giant snake-free. The fences can deter scorpions too, if they can't push past the fence or climb over it. Or dig under it (something a snake may also do). Layers of fencing with both thorns (mostly for the snakes) and metal (mostly for the scorpions) are the way to go. Bury the fences underground a few feet and also curve the top to and add electric barbed wire or something like that. Then there are wasps. Wasps only harm humans and other large animals if they disturb them or their nests. In our world, it's possible to accidentally step on a ground wasp nest or brush against one in plants, or a wasp might be in your shoe before you put it on (ditto scorpions for that). But giant wasps (or scorpions) there is no way in hell to do this accidentally. You don't say what kind of wasps they are. Paper wasps are pretty non-aggressive and just want to build their nests under house eaves or the natural equivalent (a cave perhaps for the giants). You can knock down their nests in broad daylight and they won't hurt you. Yellow jackets, on the other hand, build nests mostly in the ground but also other places like walls and trees. They are mean. You don't want to mess with a yellow jacket. [![enter image description here](https://i.stack.imgur.com/O9kjz.png)](https://i.stack.imgur.com/O9kjz.png) Your best bet with aggressive wasps is to map out their territory and not build or go anywhere near it. Given their size, this is much easier than it is on Earth. Wasps are defensive but they don't go out looking for things to sting or bite (yes, yellow jackets do both). They eat other incests for the most part. Some basic weapons (shotgun that can take down an elephant) should be enough. They are active during the day. **A few colonists will die, especially in the beginning, but mostly should be fine. A fair number of livestock will die, more in the first year or two, but they probably won't die out completely.** ]
[Question] [ In my world, a species of vertically challenged humanoids spreads out from their island homelands to the wider world, entering the interspecies race for global dominance. Now, this species of humanoids are quite disadvantaged in a straight fight against any other, being the smallest at but 1.1 meters tall, however, this in reality is a contest not of might, but niche effectiveness. You see, hominids are all more or less generalist / opportunistic hunters - animals that are broadly omnivorous (eating berries, seeds, certain foliage, etc) and broadly predatory, hunting game of any size. Hominids were very, very, good at this strategy, which allowed them to spread anywhere such calorie sources were available (i.e. everywhere on Gaia's green earth). That being said, there exists an ecological concept called Competitive Exclusion Principal, where when two species occupy the same niche in the same area, they compete, and whichever species exploits the niche most effectively displaced the other. Now, generalist is truly a contest of "who can exploit the most calories in a given area" and, given a more diverse food set, the most general generalist wins. Here in lies the most ultimate prize in untapped calories for a hominid — grass (and leaves). Very few generalist exploit this nigh-omnipresent food source\*, and the sheer amount of it could keep a hominid fat when most others would starve, allowing them greater population and a greater range than any other, along with an easy way to outcompete its competition. However, two problems abound: * grass (and leaves) are tough and wear on teeth * grass (and leaves) are difficult to break down, making the energy spent in digestion take up most of the calories contained in the grass, blunting the competitive edge Seeing as how even the best grazers and browsers have, at best, middling solutions for these issue given millions of years of evolution, a purely evolutionary solution is unrealistic. So now we turn to the human ability to develop skills and technique. **What technique could be implemented to release the most calories from grass and leaves?** --- *Note: Yes, I am aware that cereals and corn count as grass, but human consumed varieties are far fewer and are more work and resource intensive to produce* [Answer] # Cooking Cooking plant materials takes care of the problem of the grasses being too hard on our teeth or digestive systems. In many cases, breaking down the fibers and so forth will release more calories and micronutrients. Some of this can also be done with fermentation. Once a species has the ability to make and control fire, and to make a few tools such as clay pots, cooking is an easy task, along with gathering. Eating and digesting are faster, so overall it doesn't take more time in a society large enough to have specialists (pot makers, fire tenders, wood or dung gatherers, etc). The problem is that most grasses (aside from the grain portion and a few exceptions like sugarcane) are not suitable human food. They don't provide enough nutrition for hominids in general. The only ways to change that are: * Evolution of the species to be able to get large portions of its calories from grass. This takes a *very* long time. * Evolution of the grass to meet the hominid's needs. This also takes a lot of time and requires evolutionary pressure that may not be present. * Selective breeding of the grasses. Not as long a time, a few centuries, maybe longer for the grass family. * Agriculture. Gathering and planting seeds (or tubers) of high-nutrition plants so they displace the low-nutrition grasses. * Using a method you've dismissed: Eating animals (or their milk) that have digested the grass for you. In other words, agriculture. * Or the other method you dismissed: Harvesting the nutritious portion of the grass, the grain (or the stalk juice, in the case of sugarcane). Cooking and sprouting both increase digestibility. * Fermentation. This will produce the calories you want, in an easy to digest form. As alcohol. But it's not really the best way to get most of one's calories. And you need to mostly use the grain portion. (You can also ferment the stalks/leaves to break them down without heat.) Consider this a frame challenge. To use skills and technique, you must accept use of skills and technique. If you are truly looking to be quicker than evolution and to use "the human ability to develop skills and technique" your answers are: * Agriculture * Animal husbandry * Fire/cooking/fermentation/other food prep techniques [Answer] None, in the long term. There were hominids who lived this way, the grasslands dried up or predators expanded or something else happened and they no longer exist. The reason hominids are so widespread is precisely because of being adaptable. The [grass eating monkeys](https://www.nationalgeographic.com/magazine/2017/04/gelada-monkeys-grass-eating-guassa-ethiopia-bleeding-heart/) alive today are only able to exist in a tiny area because it's not easy to get at. There are zero apes living solely off grass. Because they're not competing a niche against genaralist hominids, they're competing a niche against wild cattle and other bigger, faster, more suited animals. They cannot outrun predators or fight them. If they had the size and strength of Gorillas it might be different. Gorillas just need to eat, there isn't usually a need for speed, they're strong enough to tear a predator limb from limb. In later times it would be impossible because you're not competing with generalist hominids who don't consume grass, because they do consume grass via their animals. You'd be a pest eating livestock food. Nasty things happen when animals or even people get in the way of farmers and herdsmen. The Bush people of Africa would be an example. [Answer] **Hominids have other mammals eat the grass for them, and in return keep these animals safe and fed.** [![masai with cattle](https://i.stack.imgur.com/37xdO.png)](https://i.stack.imgur.com/37xdO.png) [source](https://www.pinterest.com/pin/544583779924493837/?lp=true) It requires a lot of adaptations to efficiently thrive on a grass diet. Starting from a hominid body plan, in the short to intermediate term a grass diet means a suboptimal result - something like a panda, or Gigantopithecus. But hominids are good at planning, scheming, planned aggression, remembering and cooperation. Intelligence is not adaptive for a diet of grass, but things that live on a diet of grass can benefit by their association with a human that can use his or her intelligence of behalf of the grazers. Thus: pastoralism. The human shepherd or cowherd manages the herd of herbivores - anticipating their needs and moving them accordingly and protecting them from predation. With human help, the domestic grazers handily outcompete their wild relatives. In exchange the herbivores transform the grass into their meat and milk and support the humans with these transformed grass calories. This is not science fiction. [Answer] Isn't wheat a grass? Along with rice, corn, oats, barley - even pineapple? Wheatgrass juice has 7 calories per ounce [$\simeq 1\cdot10^6 \text{J/kg}$] so to get 2000 calories [$2000~\text{kcal} \simeq 8.4\cdot10^6~\text{J}$] that would be 2.2 gallons per day [$\simeq 8.4~\text{kg/day}$] (daily recommended by believers is just 2 ounces [$60~\text{g}$]). [Answer] 'What technique could be implemented to release the most calories from grass and leaves?' There are two proven methods. One is fermentation. The second is bacterial action to break down the cellulose. Farmers use silage techniques (non-aerobic bacteria) to break down grasses for long-term storage. Perhaps you might like to look at fermenting silage into a drink or a mash? There is enough protein in grass to sustain life, the trick is to unlock it from he cellulose. Grass will break down in a compost heap, the trick is to not keep it all bunched together, but mixing it in with other organics. If you want to hand-wave away the details, for a fictional story imagining that they have perfected a method of composting grass using silage techniques, and then fermenting the product into a mash, seems plausible enough. [Answer] Humans, as they are, may harvest the grasses that sprout after a rainfall. This is close enough to [sprouting](https://en.m.wikipedia.org/wiki/Sprouting). The disadvantage is limitation to some time of the year. If they began farming, then it is possible to extend that period. Also, pay attention to the "health concerns" paragraph in the link. The humans would still need additional food sources. The changes needed for a human to feed on grass may be too much of a leap forward within your timeframe. [Answer] **There isn't one** The problem is not processing the grass, it is how little nutrition grass and leaves contain compared to how much a hominid needs. Hominids have large brain, large brains demand a lot of calories. 1/3rd of all the calories a human eats goes to just support a 3lb brain. So just to start off hominids need more calories than a different animal of the same size. **Even if you solve the problem they will never eat enough**. Leaves has very few calories, even leaves humans have bred for consumption have pathetically little calories. cabbage (a high calorie leaf) for instance has 0.1-0.2 calories per gram, compare a peanut 6 calories per gram. this is why grazers/browsers have to eat a LOT of grass. An active human needs about 3000kcal per day, that's about 50-60 lbs of foliage per day (compared to the 4-5lbs of food humans normally eat). Lets say they have manage to extract every iota of nutrition from the foliage and get twice its value, thats still 25-30lbs of grass a day, your creatures are going to do nothing but eat just to get enough food into their gut, and that is assuming you solve the digestibility problem. **Why you won't solve the problem**. The problem with leaves is they are low in calories and it is hard to extract, because most of the caloric value is in cellulose, fiber. The only animals that can digest cellulose do so by using gut bacteria to ferment the cellulose, this however is slow and costs calories that the gut bacteria use for themselves. They are essentially secondary consumers who store the primary consumers inside. The other solution is just to eat huge quantities and ignore the fiber, this means they are eating even more than before. Both require the fiber to broken down in to as small of pieces as possible, this is why animals spend hours chewing up foliage before digesting it. Mechanical processing could replace this but it will still take a great deal of time. **So lets take the perfect scenario for your creature**. Your creatures collect 100lbs of foliage to eat maybe an hour or two of time, are now spending dozens of hours grinding up (querns took hours to grind small quantities of wheat you are grinding a hundred pounds of leaves), then ferment it in casks or just eat more, either way you have losses, hence doubling how much they have to eat (which is probably generous). Then they cook it to free up anything that is left and make it easier to extract, maybe an hour or two. Then they actually have to eat a hundred of pounds of the porridge/slurry to get enough calories which will also take hours. Your creature has just spend the entire day doing nothing but preparing and eating its food. It still needs 8 hours of sleep. that's more time than there is in a day. Worse every free hour they have is spent making querns and casks for food. Compare the human hunter gatherer that is spending 3-5 hours per day feeding itself and has the rest of the time to do other things. **Making the animal smaller makes it even worse** since its gut has to be smaller, and it's body is less efficient with its calories (square cubed law in play). The size of the gut determines how much they get out of their food. Hominids have short guts to begin with since they eat high value foods, so losses are less of an issue, but your creatures need every calorie. Even if it was human sized it would need to have a much large gut than a human, meaning the rest of it needs to be smaller to keep its mass down. This is why bulk feeder are usually very large, it allows for a huge gut and increases caloric efficiency to boot. If you want it to be an herbivore just have it eat fruits and grains, it will be able to sustain itself no problem, although even then there is only a few exclusive herbivores on earth, most herbivores are also opportunistic carnivores. ]
[Question] [ Following up on [this question](https://worldbuilding.stackexchange.com/questions/190360/putting-locks-on-a-strait-between-the-sea-and-a-large-bay-to-prevent-tides), where the answers made me wonder about another aspect of my world. My planet is a super-earth orbiting really close to a Red Dwarf star, resulting in enormous tides. The difference between high and low tide is around 30 meters, and the difference between spring high and low tide being roughly 60 meters. They occur on a similar schedule as Earth's. What would landmasses look like on this planet? Would the strength of the tides erode any landmasses before they even formed, or would something like strong vulcanism allow continents to form? What about shallow seas? Would there even be any continental shelf, or would all oceans just drop straight to the abyssal zone? What rock would be able to withstand such strong tides and thus support the growth of continents? [Answer] ### Convex outlines for your continents. Each incomming tide will dump a significant amount of silt on the shore, this will tend to turn bays into straight lines by filling them up. The outgoing tide will in turn remove material, targeting peninsulas and outcrops and grinding them away. The net effect will be a tendency for any spot on the coast the be essentially straight. This will result in convex continents with smooth corners. Differences in composition wearing at different rates will occasionally produce coastal features of interest, but these will be very quickly smoothed out by the tides. I see no reason why this would change the continental shelf, so I'd assume that remains unchanged. [Answer] So. I presume this world is tidally locked, as it is so close to its parent star. If that is the case, there will be a ring around the day night terminator from pole to pole that is just about encircling the prime meridian. This is where you have a large island-continent. As per [Kip Thorne's explanation in the science of Interstellar](https://blogs.scientificamerican.com/observations/parsing-the-science-of-interstellar-with-physicist-kip-thorne/), the tidally locked planet will rock back and forth generating tides. But these rocking motions would be nullified neither on the side closer to or farther from the star, imagining the planet is an (extremely exaggerated) egg with its poles pointing towards and away. This results in your planet only having one super-stretched continent all around the "prime meridian". The continental shelf, stronger-than-normal rock, etc. remains unchanged, because due to the way the tides play out, near the midpoint of the planet, everything is as normal. EDIT: Shallow seas, yes. Everywhere except the continent-island will have extreme tidal forces either towards or away from the star, so it will definitely result in shallow water bodies. RE-EDIT: *Especially* if there is up to a 60 meter difference. That would reduce the sea depth to lower than normal on a regular (constant) basis due to so many waves and such. ]
[Question] [ What material for weapons and tools would a tribal/medieval society use if there was a magnetic field preventing the use of iron? The iron would be attracted by the ground, obviously. It can`t be used for arrows for example as they would not get to far. [Answer] Ceramic knifes would be cool: > > A ceramic knife is a knife designed with a ceramic blade typically made from zirconium dioxide (ZrO2; also known as zirconia). These knife blades are usually produced through the dry-pressing and firing of powdered zirconia using solid-state sintering. > > > ([Wikipedia](https://en.wikipedia.org/wiki/Ceramic_knife)) I'm not sure if this technology is feasible for a medieval society - but its fiction, so why not? [Answer] Earth's history is filled with non-magnetic weapons and tools. The Iron Age was named for the increasing use of iron in tools and weapons -- before that, bronze, copper, wood and stone did the same jobs, perhaps not quite as well, but well enough to do the job for many centuries. [Answer] I used to work for a company that makes 1.5 T and 4 T MRI machines. We used **brass** tools in and around the magnets. They did some research into an open magnet design to be used in the operating room during surgeries. The surgeons would have used brass instruments, with **ceramic** scalpel tips. However, the concept never made it into product. It should be noted that in a magnetic field, torques are a bigger hazard than linear forces. In other words, you are more likely to have a tool twist your wrist than get "sucked" into the magnet. [Answer] **Stick with [bronze](https://classroom.synonym.com/how-to-test-for-bronze-with-a-magnet-12081943.html).** You may have heard of the [bronze age](https://en.wikipedia.org/wiki/Bronze_Age), a time in which all metal tools were made out of bronze (not iron or steel). Bronze is a non-magnetic metal alloy used in human history to make tools, and weapons, and pretty much anything you would make out of iron. Bronze is a simple historically friendly answer to a substance that can easily be used in a strong magnetic field. After the bronze age, a civilization might proceed directly to the plastics age if iron is not feasible. [Answer] **Use whatever materials you want**: As you say: > > The iron would be attracted by the ground > > > The thing is that arrows already *are* attracted to the ground - by gravity. You have to ask just how strong this magnetic field must be to noticeably deflect arrows. Some experiments have been done on this with *bullets* including by the Mythbusters but they used non-ferrous ammunition. The following video however shows an experiment with a powerful neodymium magnet and a steel ball from a low-powered air rifle. There is some deflection but they fire very close to the magnet and I don't suppose your landscape is made of neodymium. <https://youtu.be/pXDLGNKoR2c?t=279> Firing near a the world's most powerful MRI machine that has a 45-ton magnet and generates a 9.4-Tesla magnetic field would definitely deflect or even stop an arrow but there's nowhere to plug one in during medieval times. [Answer] Since there were many suggestions of non-magnetic metals: They aren't usable for many purposes, specially for fast moving parts: [Eddy currents](https://en.wikipedia.org/wiki/Eddy_current) will slow down the motion. So the culture should go for isolating materials: Wood, ceramics, and glass. ]
[Question] [ **An offical letter from the King to Baron Worldbuilding** The kingdom is in turmoil. There has been an uprising among the knights and many of the nobles have been killed. Our country is in tatters! I wish to send a messenger to Sir Andian, Lord of the Eastern Marshes, as he is our most powerful knight. He lives about 400 miles away, the last ~50 through marsh- and swampland. I know not of any inventions known as "cars" or "planes". The only transportation available to me is a messenger on foot, or on a horse. Horses can make it through the swampland, but the roads there are long and winding. It would take roughly triple the time to get through a mile of swampland then it would take for a mile of flat, normal road. However, I cannot send any messages to him. Is there any plausible reason to why this is the case? **Clarifications** * There are simply too many roads in the kingdom for all to be guarded by bandits or rebels. * The message does not contain any oversensitive information, so everyone can be trusted with it. [Answer] There's a Byzantine General problem here. This is a famous problem in computer science involving many generals who are grouping up to attack a city. If they all attack at the same time, they win. If a fraction attacks, it's a rout, far worse than simply not attacking at all. In the computer-science problem, they vote to attack or not. What makes the problem interesting is the question of treacherous generals who may not obey the protocol (such as telling one group of generals that they vote to attack, one group that they intend to stay put, and using that to fracture the greater army and cause a rout). This computer science problem is known to be very difficult to solve with an information-theoretic solution. Every solution is based on physical practicality (such as message timing) or unproven math(cryptographic hashes). In your case, this message may not be too sensitive, but other messages might. Should someone seek to forge a message that appears to be by your hand, the damage might be excessive before you can sufficiently counter this forgery. In such an environment, it would make sense to simply cut these methods of communication all together. Tell your knights that the situation is too dire, so all future communications via messenger should be cut off. Rely only on face-to-face meetings. Such would be a true emergency indeed. Ideally emergencies are the time where you want everyone to work together to a common goal, but often in the worst of emergencies, we fracture and try to go it alone. [Answer] Yes, pick one: * You fired all the messengers yourself when they started talking about worker rights, labor unions, class struggle and general communism; * The last messenger died delivering this question letter to us; * You are finally realizing what a d... Stupid move it was to cut public funding for literacy classes and dyslexia research; * The kingdom ran out of paper due to the epidemia of diarrhea. Listen to the wizard when he says that washing hands and properly cooking food will kill the little devils that live under your nails; * Messengers were made obsolete by mail pigeons, but those will only ever fly to places they know, and Sir Adian never built an aviary due to a childhood trauma involving emus. [Answer] **You've said it yourself. Your nobles are dead.** The rank of the messenger you send is relative to the rank of the person you're sending the message to, and your respect for them. If you're sending a message to another king you send a member of your high nobility, perhaps even a close family member, to act as ambassador, not some peasant with a scribbled note. Since you're sending a message to a senior member of the nobility of your own country, the messenger is going to be a slightly more junior member of your court. Likely someone able to raise their own armed escort. [Answer] Your messengers have been killed by the uprising knights to prevent you from getting help; or they are on their side, or they have been threatened by them. The uprising knights are not stupid; they want to present Sir Andian with a fait accompli; a done deed. In fact, after they have consolidated their power, they may use some sort of subterfuge to send a benign message to him, then ambush him on the way... [Answer] * There can be a robber/rebel on every road, if your lordship is hated so much that regular villagers are more than happy to kill your messengers, steal their belongings, and take (or eat) their horse + The rebels can have your castle in a siege, killing everybody who comes out. + your recipient could be under siege as well. Or simply no trusting any outsiders, as there already were several attempts to trick him into leaving the safety of his stronghold. [Answer] Alas you majesty, the chancellor was among the rebels and hath absconded with thy treasury, therefore thou canst neither pay nor succour the messenger. Even pawning thy royal crown would barely suffice to raise half the sum necessary for the journey. [Answer] Given the difficulty of travel mustering troops in the marshlands will be impossible. As such the marshlands will be a haven for bandits and road-agents at the best of times, even more so with open revolt brewing. Why can't your messengers get through? They keep getting killed for their shoes that's why. It only takes one choke point where all the roads between point a and point b pass close together for this to be a problem. ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/114721/edit). Closed 5 years ago. [Improve this question](/posts/114721/edit) Just a silly idea for some sort of potentially major event, but what would happen if say the mind of cat entered the body of a mouse and vice versa, for every animal on Earth? Let's also assume that for hierarchies of predators and prey, the animal's mind is "shifted" down a level e.g. the hierarchy of bodies `Large Bird -> Small Bird -> Insect` would have the hierarchy of minds `Insect -> Large Bird -> Small Bird`. [Answer] A wolf has fallen into a beartrap. He's trying his damnedest to set himself free, he's agonizing in the snare of the iron biting into his flesh. A poacher arrivers. He's satisfied, a trophy to adorn his house, a pelt to sell for hefty money. He's moving with prudence toward his prey, ready to inflict the coupe de grace... SWAP The poacher's vision turns to a world of different colors, smells, sounds, **and pain, so much pain, his leg is on fire, oh God my leg!** for a moment there is nothing but pain, he checks is leg and terror, sheer terror invades him as he sees an alien shape where a second ago was his body! He looks around...and sees *himself* standing there, in a state of shock. *Do I really look that funny?* he wants to elaborate...only to discover that he can't translate this concept into words. In fact, his mind is devoid of his own vocabulary! His mind is filled with...something else. He can't understand his own reflections, his own inputs. For now, there's only the pain. He tries to call for help, but only a canine yelp comes from his throat... The wolf is frozen. Raw fear. Fight or flight? What happened to me? I am tall! I am free! I am...standing? His new body is hardwired to stand, but his mind is caught by a vertigo, he tries to stand on all four. His vision is filled with colors he didn't know now that his eyes can catch the red part of the spectrum. He sees himself. He growls. Is it a rival? A packmate? He smells vaguely familiar...but now his keen sense of smell is almost gone, and he's panicking, he can't focus. And the only smell he feels stronger it's the hated man's! It's all around him, as if he was coated in it! Reflexively, he uses a paw to clean his snout, founds nothings, no long snout. MY PAW! THIS IS NOT MY PAW! He tries to move, collapses, his body is not made for his natural posture. Pack! Pack, where are you?!? But he can't find his scent track. He is lost... And this is just one case: In the seas, the crew of a fishing boat suddenly collapses on the deck in a fit of panic. Some of them will die of raw fear, some will plunge into the familiar sea to go home, just to discover that they cannot breath underwater and will drown, all the while their preys in the nets will meet their fate knowing, for just once, what's the feeling of asphixiating outside the sea... All around the world, cats go into fits of panic, as they start to act like mice -and being mice able to fight back if threatened, they attack the owners who are only trying to calm them. Other felines just try to scurry away like lizards. A kid who was about to stomp an ant becomes a mindless mannequin, cut away from his nest... Final effect: civilization ceases to exist, food chain collapses at all level, except for the microbiotic level. Plants that need impollination will soon follow since there will be no more impollinators able to do their job. Soon Earth is on its way to become all-green again, in a new ecosystem where plants have no enemy and microfauna can thrive on the remains of the larger biomass. How this will affect its relationship with the greenery remains unknwon. [Answer] There are several "levels" of predators, from predatory insects that can only feed on specific prey, to [hypercarnivores](https://en.wikipedia.org/wiki/Hypercarnivore) like cats, which can survive on just about any kind of meat, to [hypocarnivores](https://en.wikipedia.org/wiki/Hypocarnivore) like bears and humans that eat meat, but can do without. Marine life will be hit the hardest, as it's got a very long food chain. Only specialized marine life can consume plankton. Since *all* the minds got swapped, though, lifeforms violating their role won't become easy prey. All in all, most primitive carnivores will die out, as they have little diet variety. Bird bodies will mostly die out, as flying requires specialized instincts. Some bird-to-bird swaps may survive. Probably 99% of non-reef and 90% of reef marine life will die out. Human bodies will die out, as they can't be sustained without intelligence. Human minds in our primary animal food, large herbivores, should have a good survival rate. But boy it's going to be boring with no internet and SX! [Answer] They would starve, because they lack the necessary knowledge and instincts to feed themselves. First, they might not even know how to control their new bodies. If they do learn how to even walk before starving, the mouse in the cat's body would try to eat fruits and grain. It wouldn't be aware that its digestive system can not metabolize them. The cat in the mouse's body would try to hunt with its weak claws and small teeth, which would be unsuccessful too. [Answer] Its going to get bloody, and quickly. Lets look at a Fox and a Rabbit for now, because the cycle you described was one of predator eating smaller predator eating smaller predator while you are really asking for a predator/prey swap. Despite the anatomy, many nerves and muscles will have the same wiring, and brains adapt quickly to change so they'll be able to move effectively before starvation/dehydration. The Fox thinks its prey now. It also thinks leaves and such are now its food. That will eventually kill it. But that eventuality is going to have to wait. The Fox is standing in a field somewhere as it happens. It is suddenly surrounded by maybe 200 rabbid Rabbits per one Fox, not to mention all the other critters that are suddenly lusting for Fox. Rabbits are now sneaking up on the Fox, and the first Rabbit takes a sprint at it. The Fox will take off, and any direction it goes in more and more Rabbits give chase until the Fox stumbles or is foxed (heh) in. Now the Rabbits will try to give the Fox a fluffy Grave, but the Fox will now try his last stand as he thinks he's about to be devoured... Only to find that its rather effective at defending itself. The Rabbits can scratch and bite but have trouble killing. Many Rabbits will succumb to their wounds or stop the attack upon finding too much resistance. Unfortunately for the Fox, by the time he's fought off his first round of attackers the second round is looking to see if all that noise might be a wounded prey they can easily devour. It'll eventually die of exhaustion or the slow flaying of its skin caused by all those Rabbits and critters. End result: most of them die from wounds and exhaustion, the remainder dies from starvation. [Answer] ## Any species that gets our minds and can eat plants will survive Humans are very adaptive and have a rather large variety of foods we eat. As such any animal that gets ours minds and has a diet not critically dependent on a different animal will likely survive. ## Apocalypse Happens for Humanity Humans rely heavily on their minds to keep things going, so for all humans to have the minds of the most basic creatures would result in everything humans maintain falling apart. ## [Chickens Survive](https://worldbuilding.stackexchange.com/q/114132/21704) Humans eat a lot of chicken and we are their primary predator, so it makes sense that they would get a large share of the human minds. Combined with the information in the linked question, I am going to assume intelligent chickens will take over the world. ]
[Question] [ Demons have been a staple of multiple religions for thousands of years, just like angels. While some of the points brought up in the [Anatomically Correct Angels](https://worldbuilding.stackexchange.com/questions/25466/anatomically-correct-angels) post (and other posts on flying humanoids) are applicable here, there's still more to discuss. My demons are comfortable in significantly higher temperatures than humans, and can withstand volcanic fumes. Besides these characteristics, they have: * grey or red skin * bat-like wings * horns How would such beings evolve? How would their biology work? [![A demon](https://i.stack.imgur.com/hZi7v.jpg)](https://i.stack.imgur.com/hZi7v.jpg) [Answer] Like many mythological creatures, what you describe are aspects of already real animals, just combined in ways we don't see together normally. It is entirely plausible that these characteristics could evolve in a different context. Upon Charles Darwins visit to the Galapagos Islands, he saw creatures which had attributes of others - for instance birds that had wings but were flightless, and lizards that swam and had prolonged periods underwater - still entirely consistent within the theory of evolution. So let's have a look at each of your characteristics individually: 1. Grey or Red skin: Skin colour can be influenced by biological need (such as melatonin) but more likely will be determined by [sexual selection](https://en.wikipedia.org/wiki/Sexual_selection). This is why birds and other bright creatures have bright colours, to attract mates and perhaps ascribe to sexual signal theory (ie. I'm so strong because I am bright red and conspicuous, but haven't been eaten yet). 2. Bat like wings: If for flight then this is more difficult. Keep in mind though that there are many large flightless birds, they evolved simply because they did not require wings anymore, and they are 'left over' from their earlier ancestors. 3. Higher temperatures: Many creatures adapt to their environment over time. Evolutionary niches are useful as there is safety in scarcity. Camels in the Gobi desert, or kangaroos in the Simpson desert, have both evolved adaptations and learned techniques to allow them to function in hot environments. 4. Volcanic Fumes: similar to high temperatures, it may be possible to develop resistance to sulphur or other noxious gases. Extremophiles are organisms that develop resistance to otherwise hostile environments. Again, evolutionarily this is advantageous to occupy a space no-one else is occupying yet. 5. Have horns: Again, horns are more likely necessary for sexual selection than any form of practical use. Moose antlers, goats and sheep have horns and although some species use it for male-to-male contests, mostly they again are [sexual signals](https://en.wikipedia.org/wiki/Signalling_theory) to mates signifying strength. It is entirely conceivable the above characteristics may evolve, given the right environmental conditions and sexual selective pathway. [Answer] > > My demons are comfortable in significantly higher temperatures than humans, and can withstand volcanic fumes. > > > The exact temperatures that animals can withstand vary by species. High enough internal temperatures (approx. 40~42°C/104~107°F for humans, for example) cause protheins to fold out of their shapes, and/or combine among themselves into something else. This kills a creature because their metabolism stops. Animals evolve to withstand high environment temperatures by either insulating themselves, thus keeping an internal temperature cooler than the environments, or by relying on protheins that lose form on higher temperatures. You may also wish to look at this question: [How could mammals evolve to resist damage from fire?](https://worldbuilding.stackexchange.com/q/93704/21222) > > Besides these characteristics, they have: > > > * grey or red skin > > > Many animals do too. This is no problem, it's just a matter of pigmentation. Grey can evolve so that they can camouflage against the background of wherever they live in, many rocks are grey, ashen, pewter etc. Red, in nature, is also usually either: * A sign to predators that they should not mess with this creature (usually in insects), or... * A colorful display used to demonstrate virility and stand out (think of paradise birds). > > * bat-like wings > > > In order for a human sized creature to fly, [they would need very large wings](https://worldbuilding.stackexchange.com/q/23145/21222). So probably the demon doesn't fly with those wings. If they do, they probably get some lift from [magic](/questions/tagged/magic "show questions tagged 'magic'"). The wings might still have some use, though: * **Reproduction:** The wings might be used for an embrace, so as to facilitate copulation. * **Bodily shield:** The wings might have evolved to have a thick hide, or to be scaly, and then they could act like shields. * **Care for the young:** Momma demon has her children literally under her wings. * **Badass hunting style:** <https://xkcd.com/1104/> > > * horns > > > I don't know why this is so special, everybody has those quite often during their teens. Oh, you mean pointy things on someone's head? So many mammals have it, it wouldn't be a stretch for a demon to have the genes for those as well. [Answer] **Body plan** First off, let's talk body plan. Your demons, being roughly human-sized, will need very large wings. Starting with the similarly sized [pteranodon](https://en.wikipedia.org/wiki/Pteranodon), they'd need around a 20 foot wingspan to support a 100lb body. (Very roughly: pterosaur weight estimates are generally somewhat dubious.) Your demons have to support the added weight of horns and arms, so you might need something a bit bigger than that. The body, in general, will be lightly built, with short, but strong, legs, and probably relatively long arms. They'll almost certainly have massive pectoral muscles, relative to humans, to support their wings, with a second, smaller, set of pectoral muscles to support their arms. Bat-like wings are certainly possible. The primary difference between bat and pterosaur wings is that bats rely heavily on an enlarged second finger (our equivalent is the pointer finger), while pterosaurs relied on an enlarged fourth finger. In any case, convergent evolution will likely drive your demons to have a substantially more enlarged primary flight finger, as compared to bats, with relatively thin secondary flight fingers to save weight. **Behavior** Your demons will likely have a diet heavily reliant on carrion and medium sized animals or fish. (Or, at least, that's what their ancestors would've eaten.) This, again, is based largely off of pteosaurs, which are the most similar creature to what you're designing. Pterosaurs used long skulls to pluck food from the ground mid-flight. Your demons have short, human-like skulls, but are hexapod, unlike pterosaurs, with a secondary set of arms beyond the ones that have evolved into wings. These arms will likely serve a similar purpose, growing long, with grasping claws, to pluck prey either from the earth or from the sea. Flying also makes finding carrion easy, so they'll probably eat a lot of that. Takeoff will be from a quadrupedal stance. This is the same way that pterosaurs likely took off, and is a bit more efficient than the two legged launches that birds favor. They'll be using their arms and legs to launch, rather than legs and wings, like pterosaurs favored. They likely won't be able to walk upright, but will instead walk on feet and knuckles, similar to gorillas, likely squatting on their back legs, supported by their tails, when they aren't moving around. This will provide them with the capacity for short bursts of speed for takeoff, while protecting their hunting claws. If they're living in a rocky, volcanic environment, of course, they'll likely be using their hands and claws to climb when on the ground, and rely on launching off of cliffs for takeoff. There isn't much, in terms of food, in high temperature areas with lots of volcanic fumes. However, if the only nesting areas are active volcanoes, it's reasonable that your pterosaur-demons would evolve increased resistance to heat and toxic gasses in order to live there. It's also possible that volcanic nests are simply the best way to avoid predators. If their surroundings are largely treeless grasslands with both plentiful food and plentiful terrestrial predators, raising young in a largely inaccessible area may be advantageous enough for them to evolve to dwell in those areas. **Horns** Horns, in general, aren't terribly useful for either flying creatures or predators. However, they aren't completely unheard of. It's likely that either the horns will be relatively small, such as those found on [carnotaurus](https://en.wikipedia.org/wiki/Carnotaurus), or else that they'll be hollow, such as the casques found on some species of [hornbill](https://en.wikipedia.org/wiki/Great_hornbill). In the former case, they'd likely be used in dominance fights between males. In the latter case, they'll likely be used as resonating chambers for calling out across great distances. The latter seems much more likely, given that they've got arms, rendering headbutting somewhat less useful as a means of combat. The ability to produce loud sounds, for a creature living largely in a low-visibility, loud environment such as the inside of an active volcano, would certainly be useful. Demons could call to one another, both for general communication, and to gauge distances for landing. Swooping in to a perch through a dense cloud of volcanic smoke would certainly be much easier for a creature that can call back and forth to an already-perched mate or flockmate, in order to effectively gauge distances, and figure out which direction "home" is in. ]
[Question] [ A book that I'm currently writing called Surge, my protagonist, Joseph Norton is an ["Ascended"](http://tvtropes.org/pmwiki/pmwiki.php/Main/DifferentlyPoweredIndividual), a human that is able to draw upon an energy source called the [Nexus](http://tvtropes.org/pmwiki/pmwiki.php/Main/BackgroundMagicField) (à la the Force) to enhance his physical abilities as a byproduct by having his soul bound to an incredibly powerful and ancient weapon referred to as a [Divine Tool](http://tvtropes.org/pmwiki/pmwiki.php/Main/MacGuffin). As an Ascended, Joseph can tap into the Nexus to perform superhuman and physics-defying feats such as moving faster than the human eye can track, throwing multi-ton cars with some degree of difficulty and being able to take a rocket-propelled grenade to the chest at point blank (which nearly kills him). Each Ascended has 3 - 4 primary abilities that embody their most dominant personality traits. Joesph's powers include: * Precognition (representing his cautiousness and pragmatism) that only works if he's aware of what's going on around him and his senses are unimpaired. * A healing factor (representing his willpower) that automatically repairs broken bones, internal bleeding, and damaged organs and allows his immune system to resist toxins. But, Joesph can't regenerate limbs, survive decapitation or reform his body from a single cell. * Replicating weapons from his memories (representing his analytic nature) such as swords, maces, lances, halberds and axes but due to a bad case of [Anterograde amnesia](https://science.howstuffworks.com/life/inside-the-mind/human-brain/amnesia4.htm) and the fact that they have hundreds of components, he can't recreate guns or grenades (think [Tracing](http://typemoon.wikia.com/wiki/Gradation_Air) from *Fate/stay night*). Joseph later learns [how to take on the powers of other Ascended using this ability](http://tvtropes.org/pmwiki/pmwiki.php/Main/PowerCopying), although his amnesia only allows him to create flawed imitations limited by his fragmented memories and shut off his original powers when using a duplicated power. * Electrokinesis (representing his inner emotional turmoil) that allows him to shoot bolts of energy from his fingers, fire beams of electricity from his palms, hurl lightning bolts like spears and call down lightning strikes. This ability has its limits as Joesph can't absorb electricity from other sources and can still be harmed by electric attacks. Joseph's Electrokinesis also allows him to channel the Nexus through his hands and feet to transform his fingers and toes into [electrified claws](http://tvtropes.org/pmwiki/pmwiki.php/Main/AbsurdlySharpClaws), which complement his kickboxing and parkour skills by allowing him to rapidly [scale vertical surfaces](http://tvtropes.org/pmwiki/pmwiki.php/Main/Wallcrawl) such as brick, concrete or glass walls. I've been trying to figure out what sort of claws would be practical for such purposes. I originally settled on hook-like talons similar to those of eagles (which would've tied into the [eagle motif](http://tvtropes.org/pmwiki/pmwiki.php/Main/AnimalMotifs)) attached to his character), but when I did research on eagles, I learnt that their claws evolved primarily to restrain large struggling prey, and were poorly suited for combat or climbing. Are there such claws that allow for both close quarters combat (CQC) and fast climbing? **NOTE:** Keep in mind that Surge's setting is modern day [Answer] Your hero's claws manipulate electricity. Give him **electroadhesive claws.** [![electroadhesive robots](https://i.stack.imgur.com/UcQtG.jpg)](https://i.stack.imgur.com/UcQtG.jpg) <http://www.hizook.com/blog/2009/08/06/electroadhesive-robot-climbers> > > By now, most roboticists are familiar with the myriad gecko-type > robots that employ Van der Waals forces (created by microscopic > synthetic setae) to cling to walls. Less well-known is the work on an > electrically-controllable alternative developed by researchers at SRI > International (formerly called Stanford Research Institute) called > "electroadhesion". Impressively, the electroadhesive can support 0.2 > to 1.4 N per square centimeter, requiring a mere 20 micro-Watts per > Newton. This means that a square meter of electroadhesive could hold > at least 200kg (440 lbs) while only consuming 40 milli-Watts, and > could turn on and off at the flick of a switch! Read on for pictures, > videos, and discussion. > > > Your hero maintains a strong charge on his claws opposite to the surface that he is climbing, and so is supported by electroadhesion. Surface area is king here and so the claws should be many and small. Sharp points might help concentrate charge, in a manner akin to a lightning rod. As regards combat: instead of clawing with nails and pulling hair, use the electroadhesion property - in reverse. Electrorepulsion would pack a wallop and send an opponent flying. Of course your hero would receive the opposite energy but this is true for a blow with a fist also. [Answer] If you want to have CQC and fast climbing you have to heavily sacrifice (or compromise) on the latter. Think if squirrels or geckoes: excellent climbers but with no CQC skills. Now think of cats or bears: still decent climbers, deadly claws but surely more limited in their climbing than the first two. Lucky for you, your character is human, so he can have climb appendices and then wear suitable gloves in case of CQC is needed. [Answer] You would need claws capable of moving up on a separate joint with suction pads underneath them. That way if they hit a surface they cannot penetrate like glass, the suction pad gets a grip instead while the claw is pushed up. Lock the joint while fighting or climbing using the claws, unlock it when you need to. Composition of your claws should be a substance that can impact on concrete or metal without damage. Obviously it has to conduct electricity as well so probably a metal is best. If you can throw a car I'm not really sure you need claws for melee fighting, that sort of strength would enable you to tear people's limbs off I would think and then hit them over the head with their own arm/leg etc,. ]
[Question] [ My question refers to a capital ship. Ideally, the ship wants to stay as low as possible. Does the mass of the ship affect its possible orbits? If so, what is the lowest orbit possible for this ship? I don't have a number for its mass, but imagine something like the farragut: > > Dimensions: Length: 2040m, Width: 806m, Height: 300m > > > [Answer] Actually, in practice, a very massive object will be able to orbit ad *lower* altitude than a very light one. The orbit mechanics is exactly the same (assuming *big body* mass is still negligible compared with planet). **BUT** It can skim atmosphere fringes and still keep going due to its much larger inertia where a lightweight would be slowed down to a forced reentry. Of course even very massive objects *will* be slowed down, but it will take much more time, very likely longer than a space battle will last. In practice such a massive object can flirt with atmosphere as much as friction won't heat it up too much. All this is because friction (slow dawn force) is roughly proportional to cross section (square of dimensions) while inertia is roughly proportional to volume (cube of dimensions). You need more time to drag away all energy you gave to spaceship to put it into orbit in the first place. [Answer] As I mentioned initially in the comments: **no.** To the best of my knowledge, the mass of an object only affects how much energy is needed to get that object into a specific orbit. It doesn't affect the actual distance at which that object can orbit. So realistically, the lowest your ship can orbit is just above the edge of the planet's atmosphere. If the planet doesn't have an atmosphere, then you can practically skim across the surface. [Answer] No stable orbits are purely about speed versus altitude. But an object's bulk dimensions *will* affect the lowest stable orbit once you get down to atmosphere skimming altitudes, below say 700km. As atmospheric pressure increases larger objects are going the experience more drag at a given altitude than smaller ones. Heavy objects have greater inertia and are less affected by a given amount of drag so it really comes down to object density and how much fuel you're willing to burn to maintain an inherently unstable position once you get down that low. [Answer] You didn't mention ship mass so I would estimate it as 100 million tons(10^11 kg). If I would take you question literally then first thing I would think of is offset of barycenter. Basically if you make two bodies of equal mass orbit each other then they rotate around center of their masses that is right between them. If one body is lighter then barycenter would move towards heavier body. Earth weights 6\*10^24 kg, you ship weights 60 millions million times less, so barycenter would move only 1/10 000 of mm from Earth center of mass. Earth gravitational anomalies would affect orbit of the ship much more than that. But I suppose you mostly care how much atmosphere would affect orbit. Obviously, the bigger the ship, the less surface to mass ratio, so atmosphere affects it less and less. Usually satellites don't go below 300 km, but a ship this big can go much lower, especially for short time. Calculations are relatively simple. Air resistance force would be 1 / 2 \* Cx \* p \* V^2 \* Sx, p - air density, V - ship speed(~= 8 km/s), Sx - front surface(Width: 806m, Height: 300m = about 2.4\*10^5 m^2), Cx - resistance coefficient(= 2, because speed is so big that we can consider that all interactions are inelastic). So it simplifies to 2.4\*10^5 \* 6.4\*10^7 \* p ~= 10^13 \* p At 100 km density is about [5\*10^-7 kg/m3](http://www.braeunig.us/space/atmos.htm) so resistance would be 5\*10^6 N = 500 ton(2 kg per m^2). Ship would decelerate 0.05 mm/s^2, and lose only about 0.27 m/s per revolution. 1 meter per second on LEO corresponds to roughly 2 km of orbit height so it would lose 0.5 km of height per rotation. But deceleration would speed up quickly as air density grows exponentially, so it would go down after 10-20 revolutions. Or you can accelerate ship with engines accordingly - 0.05 mm/s^2 is nothing for battleship. But as ship slows down it loses energy. According to energy conservation this energy should go somewhere - it turns to heat. That would be about 100 KWt per m^2, that's enough to burn small parts like antennas and make ship look very bad. If you move it a little higher - 120 km, air density becomes 4 times less, 140 km - 60 times less. So at 140 km it would lose only 100 meters per revolution and external parts should be OK, though I think paint would suffer. **tl;dr** Below 100 km heat from air resistance becomes too much and orbit decays too quickly. But if you have appropriate(force shield?) protection and powerful engines you can go as low as you want. At about 150 km heat is not a big problem and a ship that big can orbit for days even without turning engines on. At 200 km and above air is not a problem for such ship. [Answer] Once the ship is in orbit, if it's going fast enough, it will stay in orbit. The only problem is the atmosphere. If the ship in question is too low, then drag comes into play, slowing the ship down, and making it fall out of orbit. Then you have to have the engines on to keep speed up. Otherwise, there shouldn't be any problems ]
[Question] [ Following on from [this question](https://worldbuilding.stackexchange.com/questions/88588/in-a-fantasy-world-where-physical-training-has-no-hard-limit-why-isnt-everyone), a fantasy setting exists where physical training has no limits and those dedicated enough can become super-fast, super strong and perform incredible feats. Unfortunately the pressures of life mean the majority of people don't have the time or inclination to spend 5 plus hours a day training to move mountains so the number of superbeings remains low, though anyone in a profession which involves fighting such as the town guards, bandits, knights and the kings standing army would outclass everyone else by a large degree. So if different nations in this setting come to a disagreement that only war will settle and decide it is time to call up the serfs to raise a larger army, how would the untrained masses fare against a small but vastly powerful group of regular soldiers? Something I should note is no ruler is a complete monster and sending out raw recruits as a distraction or meatshields will reflect badly on the kingdom. We want to be able to use the commoners as usefully as they can be, without suicide missions. [Answer] If this is a medieval army, don't forget that the conscripts are going to be *really* strong too. Granted, they won't have the benefit of constant training, but if they are of adult age and are relatively healthy, they will have grown substantial muscles. Farming is very hard *work*. If you want to get an idea, spend 20 minutes splitting firewood, or digging post holes for a small fence. Now imagine having to work like that for 10 to 16 hours a day. Peasants and serfs did these kinds of activities every single day for their entire lives just to survive, provide for families, and to pay taxes to their local lords. Your peasants aren't going to be super skilled fighters, but I imagine that the local blacksmith is going to be in the kind of condition that would allow him to crumple armor in his hands like a beer can. A typical plowman is going to be strong enough to bat a bear around around like a rag doll on the basis of the plowman is doing heavy lifting type stuff for 9 or ten hours every day. The difference between the nobility and the commoners will be more about training to fight, not raw strength. How does this translate into battles? give your peasants a bunch of rocks! then teach them a few tricks about how to throw. With the kind of strength and endurance the peasants are going to have, it'll be nightmarish for oncoming infantry. A shield will turn a stone, sure, but for how long against a series of fist sized rocks being thrown at Major League Fastball speeds (42 meters per second)? Even if the material of the shield holds up, the guy behind it is going to be bruised and numb all the way up to the shoulder. If a rock gets past the shield wall and hits someone in the head, that person is going to die no matter how good the helmet. Once the infantry closes on the peasants, things will shift back in favor of the trained troops. Raw strength won't hold up against edged weapons for long. Your very strong troops are going to be more likely to shear clean through someone rather than getting a sword stuck in a body. They are also going to be more likely to break their weapons when it gets to steel on steel. You are going to have a lot of trade offs, but the end result is that in warfare, tactics and logistics are going to be what prevails. [Answer] > > Something I should note is no ruler is a complete monster and sending out raw recruits as a distraction or meatshields will reflect badly on the kingdom. We want to be able to use the commoners as usefully as they can be, without suicide missions. > > > Take look at history. Most rulers are not a complete monster, but there's always infantry, with some training and fair to middling equipment. Numbers are still numbers. And your elite guys take TIME and EFFORT and RESOURCES to train. 100 men might be able to take an elite. Archers, not super archers, might kill someone like this, even if they are more than human. It will depend what their talents are. In a Medieval world, rulers aren't all that worried about the optics. They want to win. Life is cheap. Now, as far as honor is concerned, the elites may seek each other out, and the normals may not engage them. My suggestion is that elites have something to...show that they are. Depending, they can either be targeted, or the normals can avoid them, carrying word to other elites as to their location, so that they may engage. The lower soliders can mostly engage each other. That's how I'd work it. EDIT: You can also take a page from Novas in the Aberrant game. They are meta-humans that can often do incredible things--one of the side effects of being "super" is that you need much, much more food than an ordinary human to live. In the Aberrant setting, which is set in modern times, this wasn't a big deal, but in a more Fantasy/Medieval setting, an elite needing 2-5x as much food will be a much bigger deal. This means that it will limit the poor a bit, and that supplying them will be more costly. So, if a Guard in a city, for instance, is determined to become elite, he might live in a poor neighborhood with no amenities, just so he can supply himself with the food he will need, because he could not afford rent otherwise. [Answer] Sacrifices will be made in war. Sending troops to be sacrificed for advantages does not make you a monster. Aside from this, you can use the historical solution. Give the peasants easy to use weapons and simple tactics that will allow them to handle fighting against people who are far far better at war then they are. This actually happened in Europe with pikes and crossbows. Peasants would use mixed ranks of crossbowmen and pike-men. This made knights significantly less effective. It didn't take very long for peasants to get good at using this tactic and formation because both of these weapons were relatively easy to learn to use for group fighting. It happened again with guns. The nobles get super pissed every time this happens, it's actually really funny to read about. At one point several people tried to get crossbows banned because they were unfair. At another point uppity hunters in England tried to do the same with guns because the weapon was uncouth. Your peasants will need a numbers advantage and some sort of positional advantage in order to realistically fight superhumans. Including the use of tactics designed specifically to counter superhumans would make your work far more interesting as well. Well finance superhumans are another problem, but peasants should still be able to win if they can capitalize on numbers and positional advantages well enough. [Answer] A huge part of the army doesn't actually do any combat, only exist to supply the line and manage operations, this can easily be done by non-super people. [Answer] An army is not a simple collection of individual heroes, or at least it stopped being a simple collection of heroes around the time of the Trojan War, three thousand years ago. Whether an army of merely human soldiers will defeat a small group of superhumans depends on how well the human soldiers are trained, how well they are led, how well they are supplied, how exactly super are those superhumans, how well *they* are trained, how well *they* are led and supplied. It depends on how well the human armies intelligence works; and it obviously depends on the specific strategic situation. To provide a well-known historical example, consider what happened to the invading German army in the war with the Soviet Red Army. German soldiers were much better trained, had much better technology and much better leadership than their opponents; but the strategic reality was that the Soviet side was better supplied, had the possibility to trade territory for time and could afford a war of attrition at horrible odds; so in the end the Soviets won although they lost five times more men than the Germans. [Answer] In England, every able bodied man was required to practice the longbow 2 hours each week, whatever else he did. from <https://www.forbes.com/2010/06/16/legal-humor-archery-opinions-columnists-kevin-underhill.html> > > It is clear that there were laws requiring archery practice dating > back to at least the 13th century. The motive was to make sure England > had enough men trained to use the longbow, which for centuries was a > crucial weapon for the English. (The most famous example is Agincourt, > a battle that Henry V won in 1415 and is still going on about.) > > > The training requirement was usually combined with prohibitions on > other kinds of games and sports so that people would focus on archery > instead of, for example, “tennis, football, [quoits], dice” and other > “games inappropriate.” The point was not so much to condemn games as > to make sure they did not get in the way of longbow training. In other > words, they saw nothing morally wrong with tennis, it’s just that it > is hard to kill a French knight with a tennis ball, no matter how good > your serve is. > > > Thus when you raised a peasant army from England, these peasants all owned bows and knew how to use them. This sort of thing would go a lot farther in your world where practice works even better. It would be a fun scene where the peasant army is arranged against the cocky superhumans and the first superhuman takes a rock to the nose at 400 feet, immediately followed by one to the groin. The peasants have been attending their required practice. ]
[Question] [ Could I make a world where gorillas replace elephants in their niche as herbivore? Are there any reasons that they could not? [Answer] # Imagine the Gorillas as Giant Sloths [![enter image description here](https://i.stack.imgur.com/meGUX.jpg)](https://i.stack.imgur.com/meGUX.jpg) First off, sloths were giant ground based herbivores, like elephants. [Megatherium](https://en.wikipedia.org/wiki/Megatherium), pictured here in lo-fi, had a body length around 6 m, and estimated weight of up to 4 tons, comparable with the Indian elephant. We can then note that the gorilla's body plan is roughly similar to the sloth's. The gorilla does not have a tail, and has a different shaped head, but it is very similar regarding locomotion. Sloths walked plantigrade on the their back legs, just as gorillas, and they walked on their front claws, as gorillas knuckle walk. Gorillas are already well adapted to eating large quantities of low grade vegetation, which is an important precursor to large size among herbivores. Their relatively dexterous limbs could be used competitively with an elephant's trunk or a giraffe's neck and tongue for reaching food in high places. Overall, the gorilla is pretty easy to imagine as a mega-herbivore, following the plan of the giant sloth. [Answer] You want a **gigantopithecus.** These were real hominids in the orangutan line. I find estimates of 10-12 feet tall and 1200 lbs. Their teeth were flat, like elephants and other big herbivores. They ate a lot of bamboo. I wonder if they had the same trouble as pandas - a low calorie vegetarian diet without the specially adapted gut of longstanding herbivores like ruminants. One way to get around that is to be big and so be able to take in huge amounts of food. A problem with being big is that fertility is low and individuals have one baby at a time, spaced far apart. The proverbial all eggs in one basket: if you lose the baby you lose a big piece of your lifetime fitness which is one problem pandas have. Good insurance against that is sociality and care of young by more than one individual. Like humans do. And elephants. Not orangutans so much but gigantopithecus definitely should. <http://img01.deviantart.net/fda4/i/2008/267/8/e/gigantopithecus_by_hodarinundu.jpg>[![enter image description here](https://i.stack.imgur.com/E3CHy.jpg)](https://i.stack.imgur.com/E3CHy.jpg) <https://pbs.twimg.com/media/CjIpqUOUkAIvBlG.jpg> [![enter image description here](https://i.stack.imgur.com/DUvgf.jpg)](https://i.stack.imgur.com/DUvgf.jpg) ]
[Question] [ On earth where we puny humans fight each other on land air and sea we have of a concept of strategic points which are * oil fields * trade choke points * islands in the sea * mountains on land * places where countries bully each other All of these features are present on earth and we know are good strategic points but given the vastness of space what can be a good strategic stronghold for an interstellar species. For the civilisation (A) their technological prowess is much like: * FTL travel is not allowed FTL communication is * they spawn a massive civilisation across the galactic arms and control like 2/3 of the galaxy . The civilisation A is blissfully unaware of another smaller but advanced civilisation B. A war breaks out when a scout of A is destroyed by B in what B perceives as a threat to their sovereignty. Now what places in such a war would be a good strategic point offering decent tactical advantage [Answer] **Since interstellar travel seems hideously expensive**, even a galactic empire might have trouble mustering the resources (in a timely manner) for invasion and defeat of a defended planet deep in a system gravity well. But, then, it really doesn't need to...when bombardment using any old space debris will do most of the job. **For the attacker**, this makes four types of key terrain: 1. A convenient debris field (asteroids, comets, moonlets) that can be steered toward the defender's planet/habitat/orbital/whatever. 2. A concealed location for the attacker to gather local resources and manufacture the robots and engines of the bombardment attack. 3. A forward observation location, from which the atacker can gauge the effect of the bombardment, spot defenses, and command final adjustments to the bombardment robots. 4. Arrival orbit for the mopping-up troop ships after the bombardment is complete. This orbit should allow for ready close observation and access to the planet, moons, and stuff in orbit. It should, however, be far enough out that any remaining defenses cannot easily snipe at transports and cargo resupply. Using the Sol system as an example, an interstellar attacker might arrive and hide in the kuiper belt, harvesting matter and materials. Then storm into the Asteriod Belt with a swarm of newly constructed robots, attaching to myriad asteriods and beginning the bombardment of Earth and Luna. A forward observation sneakship moves to a few million km away from Earth, and directs the bombardment. A few weeks after bombardment is complete, the mop-up fleet arrives in an eccentric orbit well outside geostationary, and starts sending assault shuttled down to Luna and Earth. The type of attack determines several possible **lines of effort for the defender**. 1. Spot the inbound attack fleet(s) early, and deny them their concealed assembly point 2. Use deception and decoys to fool the attacker into wasting their resources attacking the wrong planet/habitat/orbital/whatever. Make the defender's *real* civilization appear to be waste to the attacking observers. Make attacks look more effective than they really are. 3. Disrupt the attacker's communications and observations. Prevent undetected forward observation. Destroy forward observers. 4. Redirect the bombarding robots using hacking, misdirection, etc. 5. Mine the likely mopping-up fleet orbits. 6. Fight them on the beaches, fight them in the streets, etc. If the attacker succeeds, the defender's planet is laid waste. It might still be habitable after all the dust settles (literally). The attacker gains no real benefit from occupying the wasteland. They can't use it to build another invasion fleet - it lacks population and industry. If the defender succeeds, the attackers are similarly likely to be wiped out. **But there's another important element**: Time. Without FTL, each planetary attack, from receipt of order ("build a fleet, raise an army, and invade X") to final result ("Yay, we won!") will take a decade or more. Support from down-arm will take centuries --millenia!-- to arrive, so there's not much point waiting for them. Defenders, upon detecting inbound invasion fleet years before arrival, seem likely to shift to total-war footing, using *all* possible resources of the economy and population to prepare their all-out defense. They are, after all, facing annihilation. It's certainly in the defender's best interest to invest in earliest detection of inbound invaders. Each side is likely to place observers in the many otherwise-irrelevant border systems. Since a base cannot build and man an invasion fleet, nor defend against a full invasion, like an inhabited and developed system can, the strategic value of these observers is minimal. However, if your space travel requires, say, intermediate fueling or power stations to justify bases, such infrastructure would have strategic value...though limited. While it's possible to build and defend a chain of supply bases to support massive invasion fleets, the defender will certainly be observing, and gets additional years (decades) of warning to prepare for the onslaught. Remember the time effect - by the time a defender's raid reaches the supply base, the attacker's fleet has already passed through and resupplied years before. Big fleets are unlikely to sit around for decades awaiting some other fleet to fight. Invasion fleets will be in motion. Defenders will be constantly building and stockpiling system-specific weapons and monitors rather than general-purpose ships. Fleet battles with big ships full of sapients are likely to be rare, but fleet battles with tiny robot ships are likely to be frequent. Since this sort of warfare destroys inhabitants and industry without gaining control of territory or space, eventually a dead-zone a decade or two across will separate A and B. Along the edge of the dead zone, heavily-fortified systems swarming with decades of layered defenses will overwhelm the longest-range attackers. Any new colonies within the dead zone will likely be spotted by monitors from the other side and wiped out...eventually. Stalemate. [Answer] With civilization at a galactic scale, you probably ask about entire strategic **systems** and not strategic points **within** a systems. I'm assuming that the sublight interstellar technology also allows ground to orbit transfers. * The presence of a world where one or both species can work in "shirtsleeves". Worlds are useful because they provide cover and concealment, heat dumps, raw materials, etc. If the world has an ecosphere that is compatible with the species, it is more valuable than a barren rock. * The presence of asteroids rich in metals, ice, and other raw materials. Any system which combines the two will be valuable. * If there is an *established* infrastructure of dockyards, factories, refineries, and smelters, even better. Decide if one or both species would follow a "[scorched Earth](https://en.wikipedia.org/wiki/Scorched_earth)" policy or if factories can change their ownership. (Perhaps even several times? What happens to the workers?) **Within** a strategic system, strategic points are: * The [Lagrange points](https://en.wikipedia.org/wiki/Lagrangian_point) of the habitable planet, if it has a moon. * The [Trojans](https://en.wikipedia.org/wiki/Trojan_(astronomy)) of a major gas giant. --- **Follow-Up:** STL interstellar travel requires either lots of time or an awesome delta-V. This suggests the existence of powerful sublight drives. It would be possible that those drives are not suitable for insystem travel, shuttle landings and station stationkeeping, but the best guess is that those will be "easy" (low engine mass/cost, low fuel requirement, high delta-V). Getting close to lightspeed *might* be more difficult. You will have to decide how often a typical ship can accelerate-and-decelerate before it has to refuel. * If the answer is *only once*, then refueling stops are pointless. The ship would have to spend as much fuel to stop, refuel, and accelerate again as it gains by refueling. So the best idea would be to fly directly to the destination. * Prepositioning forces are a slightly different concept. You hold fully equipped and fueled ships in a forward staging area in case they are needed. But with flight times measured decades or centuries, that sounds silly, too. [Answer] Since FTL travel is not allowed, but FTL communications is, how is interstellar travel handled? If such travel is via wormholes or gates, those naturally become choke points, and by extension a strategically important point for defense. They would make great places for ambushes. Additionally, fuel sources are critical. If your civilization A uses gas giants as fuel sources, those are strategic points. Without fuel, the interstellar commerce would not flow. Lagrange points are critical as well. These are gravitationaly stable points in an orbital system. L1 is between a planet and the sun of that solar system. Imagine a stealthed capital ship at L1 ready to make an attack on a colony planet. It would expend almost no energy for station keeping and could quickly power up for a quick strike mission. Outside of the inhabited areas of the solar system, resources are important strategically. The asteroid belt and Oort cloud would important sources of elements, both heavy and light. The Oort cloud could also supply complex hydrocarbons if the civilization still needed them. All of this said, anything can be made into a strategically important resource by creating a need. [Answer] The primary points of contention would be areas of high resource worth. A civilization's ability to wage war would be directly related to the quantity of fuel, metals, and foods. * **Solar systems with stars that have gone supernova** could be major sources of valuable resources, as the elements produced in the star will have been ejected into the system. The "r-process" that occurs in collapsed supernovae produces many elements beyond iron, such as uranium and thorium. * **Planets with a powerful agricultural base** would be needed to provide a civilization food, as a huge civilization has an enormous number of civilians and soldiers alike to feed. And if a civilization failed to do that, they would effectively lose a war, due to internal conflict. * **large, rich asteroid belts** would provide many resources. * **Planets with strong technology or production bases** are needed to produce goods, and thus make important targets. In a galactic conflict at sub-light speeds. It might be very easy for ships to infiltrate the other army's territory, as the distance between stars is incredibly vast, it would be virtually impossible to intercept a ship that passes your lines at a large distance from your border stars. And your civilization might not even notice the breaching of the line if they aren't specifically scanning that part of the sky. Because of this you might not fight from barren planet to the next, but instead choose targets deep in enemy space, balancing potential tech advances the targeted planet can make by the time a ship arrives. In battles taking place in a solar system, A position further from the systems star would be preferred to an internal position, because it uses less fuel to transfer orbits. Also infiltrating through areas of low visibility like nebulas would be important. These infiltrating ships could go around disrupting important supplies because hitting a lone trade ship would be fairly easy, and the odds of having a military ship intercepting the attacking ship as it escaped would be very low. They could also be used for military intelligence. Since light takes thousands of years to travel from a planet in the center of one of these civilizations to the nearest viewing post in another you could not easily see what was going on with telescopes. it would be useful to send a ship behind enemy lines then transfer the more recent info to central through FTL communication. You should also decide on what starship weapons you have. If they are long ranged, like a missile with interstellar range, than the dominant strategy would probably be mostly defensive, since planets would just sit tight and target distant ships that would get hit years later. If the range is short enough, the dominant strategy would be almost 100% for all out attack, like in "Enders Shadow" by Orson Scott Card. The logic behind this is that defending an important planet would not be possible, because if you grouped your forces in one area, the enemy could just attack somewhere else, or on multiple sides at once. With limited resources, and short range weapons, you need a huge number ships to defend a single planet. The enemy would also be able to use less fuel to move around, because the nature orbital mechanics makes it so that a ship in an orbit that is farther away from a planet expends less fuel in orbital shifts. You should also decide how your soldiers are transported for so long a distance. It could be Cryogenics so that the soldiers would wake up whenever they where needed for battle, or it could be generation ships, where they train each sequential generation for the battle they will fight. I hope this helps, [Answer] 1. Border systems (as staging points for incursions or defense fleets) 2. Resource-rich systems. (Not all stars / star systems are equal, though this depends on resource needs vs. resource availability. With the ability to travel and colonize the stars comes near limitless resources, with transport of said resources being the larger limiting factor; how much can you move from resource-rich systems to resource-poor systems, and how quickly, and "why are we needing this resource-poor system." IE. if space infrastructure is needed in those systems, then transporting stuff to them becomes relevant. If no such infrastructure is needed, it is a waste of effort / time to do so.) 3. Habitable planets (depending on how common those are, and if the two warring species have the same idea of what a habitable planet is.) [Answer] Let's do an as exaustive as possible list of ***what do you need in Space and during a war?*** **Vital need:** The most obvious to begin. I suppose even if you have FTL communication, you won't use only unmaned craft. You will need to provide food and water to your troops. And your ennemy will need supplies to sustain planetary siege you will maybe provoke. *Water and food sources* as well *trade routes* (you will probably always use the shortest path, because the voyage without FTL to the closest star is at least 4 years long, see [Proxima Centauri](https://en.wikipedia.org/wiki/Proxima_Centauri)) will be real strategic points, if you don't want your troops and population to starve. Example of water sources: water rich asteroids, frozen moon (like [Europa](https://en.wikipedia.org/wiki/Europa_(moon)))... Example of food sources: habitable planet with vegetation and maybe animals, farm spacestation (like in the video game serie X), nebulae (some are believed to contain organic molecules, you could manage to synthetise food with them)... **Military ressources:** A bit more specific to war: ammo, spacecraft and fuel. Ammo will be plasma for plasma weapon, ion for ion cannon... Only laser will not need ammo (maybe replacement lens?). You will need to control *ammunition factories* and be able to supply them (*trade routes*, again and *mines* for metals, and various ressources you could need, you will found them in all kind of stellar object, it depend of the nature of the ressources). Same purpose for spacecraft, you need to control *"spacedockyard"* to be able to repair existing spaceship and building new ones. To fuel for vessels, assuming they are powered by fusion reactor, and not old fashion hydrazine (not efficient enough, too explosive and heavy), you will need [hydrogen](https://www.iter.org/sci/FusionFuels), to fuel the fusion reaction. **Economy and communication:** *Money* is the sinews of war (and *intel* too). You will need to control *trade routes* and *"space docks"* to destroy the ennemy economy and prevent him to build new spaceship, enroll new troops... To gather intel, controlling ennemy *communication and command centers* is a good start. They will contain informations and will help you to decypher ennemy code (like with the [Enigma machine](https://en.wikipedia.org/wiki/Cryptanalysis_of_the_Enigma)). It will prevent your ennemy to correctly communicate too, and disorganise his military organisation. **Space specific strategic point:** Since the begining, this is the same kind of strategic point than on Earth. Now let's talk about space specific one. A spaceship is really greatly insulate (see [vacuum insulated panel](https://en.wikipedia.org/wiki/Vacuum_insulated_panel)). It means your ship will generate many static electricity. It could be dangerous for the ship electronics (and the crew, maybe). You will need to discharge it sometimes if you don't want to be thunderstruck the next time you approach a planet (fun fact, you will be the source of the lightning). You can find this kind of issue with [ion thruster](https://en.wikipedia.org/wiki/Ion_thruster) (not at the same scale but I assume the activity on your warship will generate static electrecity, firing a ion cannon for example). Heat will be an other problem. You can't dissipate much heat in void, beacause of it's poor thermal conduction (see the begining of the paragraph). You will need to enter a fluid to dissipate heat quickly (a really low temperature liquid is the best of the best). You could dissipate the heat by irradiation to, but you will be really visible (and this is not a good during a war). Point to discharge static electricity: point with opposite charge like planets or asteroid (if you're lucky) Point to dissipate heat:where you can find fluids colder than your ship. Ocean on a planet, atmospher of a planet, nebulae... But on this time and distance scale, war is close to be a none-sense. You could find all the place/ressource you need in another place, closer and more important safer. I hope you like my list! Thanks for the reading. [Answer] All of points you described could be splitted in options: * sources of resources + energy is most important resource * key points on a route + trade route + army's potential route + resource delivery route: from a mine to the a factory I would add * military bases + especially military production bases * centers of political and/or technological life (one of them is the capital) --- But with FTL communication and FTL travel absence both species have an issue. Any galaxy has size of [thousands of light years](https://en.wikipedia.org/wiki/Galaxy). Army become obsolete in dozens of years and when it reach the destination, it would be met with some spaceships which are better by 2-3 generations. **Only minor battles are possible and war will long for ages** without some way to travel FTL (as *teleport* or moving with FTL). In your world you could put resources and routes as you wish to create some tension in the war. For example, create *teleport* (as space gate or wormhole or whatever) which is key point of any route, and put this *teleport* close enough to both species. **UPDATE** As o.m. noted, I suppose that a `strategic point` could be a whole key **system** or area. [Answer] # To wage a war in space you need 3 important resources * technology * matter * energy Thus sources of those resources can be strategical points. ## Locations ### A star system A star system with Dyson swarm will supply with energy fairly well, and contains matter for millions of years if you rely on the star energy output. Million years mostly because one can mine the star itself and it is usually deep gravity well compared to the energies it produces and energies needed to lift the matter from the star. Planets are obvious sources of different matter, especially Gas giants, as an [example](https://worldbuilding.stackexchange.com/a/63931/20315) So, in fact, any star system can and will be a strategical location just by itself. But stars have different energy output, and in that regard choosing stars with higher energy output might be preferable. ### A supernova and supernova remnant Less obvious choice, but in fact, it might be a very valuable resource. It provides with energy and matter, and if one is capable of harvesting it(which needs a good technology, but still seems to be in realm of known to us physics) The energy of a supernova blast is about 1044J (up to 1046J) which is equivalent to the energy produced by 8300992 stars like our Sun in 1000 years time. A lot of the energy is stored in the kinetic energy of the star matter which is heading outwards. That can be used in multiple ways, including launching your fleet to all stars of your enemies which is the most primitive thing you can do with it because the energy has way richer uses. Not only ready to blast supernova is valuable, its remnant a black hole or neutron stars are also very valuable objects. They are valuable at least for 2 reasons - energy, and matter. You can use their gravitational potential to convert available to you matter to the energy (both for BS and NS), or you can use NS as a neutron source for transmutation of the elements you have into elements you would like to have. some thoughts about supernova as a useful resource in the answer [My star will explode as a supernova. What can I do in order to ensure that my planet survives that?](https://worldbuilding.stackexchange.com/a/47982/20315) ### A supermassive black hole Mostly the same as with usual black holes or neutron stars - but at way much greater scale. Way much greater scale. Basically, if you have the technology, which is still in the realm of known physics and known materials, by securing the SMBH you secure the galaxy. You can throw stars into the SMBH to generate energy and energy extracted just from a single star like our sun thrown in SMBH will produce about 894 foe (1 foe = 1044 J) A bit more why the SMBH are useful as energy producing places in the answer [Why would a civilization choose to inhabit a single enormous vessel instead of maintaining interstellar colonies?](https://worldbuilding.stackexchange.com/a/47939/20315) ## Technologies It is important to understand that scale of action and technologies aren't that heavily connected with each other, and it is in that way since we invented computers. I mean, if you can operate on the scale of a single star system or even a planet - only physics stops you from scaling the technology to use it on 1000 star systems, or million star systems, or the galaxy. The physics in terms of availability of matter for your devices and energy for them to work and energy needed to launch them to the target. Defense is more or less the same it is a matter of how much you have both resources and energy. Energy utilization efficiency of the technology, materials demands for the technology it affects the capabilities of those who use them, but in a lesser way that ability to get the access to an energy source which boosts you capabilities 6-10-20 order of magnitude compared to your enemy. The gap between technologies of both parties might be significant in terms of how advanced it is, but the difference can be compensated by energies available to those parties. And to wage galaxy wars the technologies have to be above a certain level. At least is seems that way at our current level of understanding of the physics, significant break trough may change equilibrium of involved parties And thus megastructures like matryoshka brains might be strategical points too as they generate science for your enemy. And it is in your best interests to have them and prevent your enemy to have them. The technology used in [the answer](https://worldbuilding.stackexchange.com/a/45273/20315) is sufficient to wage wars at stars/galaxy level(K1, K2 civilizations). # Note * Have read the answers, and it seems many do not understand which practical implications FTL communication have, by saying the ships will be older and technologically less advanced than enemies ships. You have to understand the scale of such thing as attacking a star system. A system where you enemy [can control everything](https://worldbuilding.stackexchange.com/a/41407/20315), where it sees the attack is coming, it sees its size, where he has time to prepare for counterstrike using the whole resources of the star system. Your attack can be successful if none of that matters when all the preparations of the defending side are totally useless. When he has no chances to defend himself using all resources he has in the system when they are against an overwhelming force heading to their system. No matter in which technology do you believe, what you think is possible or not, but taking manufacturing capabilities in the case is the must for the attacker. You live in the time when all Intel facilities technologies could be sent to you with one mouse click, same can be done for the attacker fleet, they can improve themselves on the way to the target according to the technologies available to those who sent them. With some technologies, it can be easier with other more of a hassle but it definitely possible. * I recommend Isaac Arthur [Megastructures](https://www.youtube.com/playlist?list=PLIIOUpOge0LtW77TNvgrWWu5OC3EOwqxQ) playlist, all. To grasp the scale of what can be possible I highly recommend to watch his [The Kardashev Scale](https://www.youtube.com/watch?v=J0ZMk0785kI) - it is not about technology but about of scale of things how big they might be and some practical implications of the scale. [Answer] * areas with needed resources i.e. garden worlds, fuel extractors, asteroid/comet mines. * asteroid fields (ambush, hazards, etc.). * Very important people/places (hostages, culture centers) * Nebulae (resources, low visibility, potential technological interference) * High/exotic gravity areas * Research and development centers [Answer] To list a few and relate them to the Earth ones, I would think that asteroid fields that contain some kind of special element (think *Star Trek* Dilithium crystals), areas of stable gravity not being close to black holes or crazy suns, planets that are extremely habitable. Stuff like that. I see an issue, with space being so vast that you could move around a lot without ever meeting someone else. ]
[Question] [ Followup from [Dropping ice in the ocean to stop global warming](https://worldbuilding.stackexchange.com/questions/64015/dropping-ice-in-the-ocean-to-stop-global-warming) as promised. In the Futurama episode "Crimes of the Hot", All earth robots fire their engines at the same time at the Galapagos islands. Earth's orbital radius is increased by enough to make Earth's orbital period 372 days instead of 365.256 days (rounded because if you're going to move Earth, might as well get rid of leap days as well), as a method to cool the earth and stop global warming. How workable is this particular solution? Wondering both about the practicality and effectiveness. [Answer] **Effectiveness 10/10**. Move further from the sun, you get less incoming solar radiation, so you cool the planet. **Practicality 0/10**. Planets are heavy. More specifically, the energy needed to increase the earth's orbit would be absolutely astronomical (all puns intended). The solution used in Futurama as you describe it is also utterly impractical. The atmosphere would stop the engines from doing anything except generating more heat into the atmosphere (the exhaust has to actually reach escape velocity and leave the planet for it to change the orbit) and the amount of mass you would need to throw out is extreme. You would also need to fire your engines once per day or have some sort of very fast moving gantry for them since otherwise the spin of the planet would cause it to cancel itself out. Also if you wanted a circular orbit instead of an elliptical one you would need to do two course corrections. One to switch into an elliptical orbit to rise away from the sun then another to circularize that orbit once you were at the desired distance. [Answer] # There are many reasons this is a bad idea **Distance of Earth at 372 day rotation** First we have to find the radius of our new 372 day orbit. By [Kepler's third law](https://en.wikipedia.org/wiki/Orbital_period#Small_body_orbiting_a_central_body), orbital period is $$T = 2\pi\sqrt{\frac{a^3}{\mu}}$$ where $\mu$ is the standard gravitational parameter of the sun ($1.327\times10^{20} \text{ m}^3/\text{s}^2$), $a$ is the semi-major axis of the Earth's orbit ($1.496\times10^{11} \text{ m}$, at least for now), and $T$ is in seconds. If we plug in the numbers above we get $T = 31560349$ in seconds, or 365.28 days. Pretty good! Lets set $T = 32140800$ for 372 days and solve for $a$. We get $1.514\times10^{11}$ meters, a marginal increase. **Temperature drop due to this distance** Now lets find out how hot this makes our planet. The [effective temperature of a planet](https://en.wikipedia.org/wiki/Effective_temperature#Planet) at a certain distance from the sun is given by $$T = \left(\frac{L(1-A)}{16\pi\sigma a^2}\right)^{1/4}$$ where $L$ is the luminosity of the sun ($3.828\times10^{26} \text{W}$), $a$ is the distance to the planet, $A$ is the [albedo](https://en.wikipedia.org/wiki/Climate_model#Zero-dimensional_models) of the planet (0.3), and $\sigma$ is the Stefan-Boltzman constant, $5.67\times10^{-8} \text{ J /(K}^{4}\text{m}^2\text{s}$). If we plug in the characteristics of Earth, we get 254.59 K. Not exactly super-accurate, mostly because there already is a good greenhouse effect keeping some of that heat in. However, if we calculate the temperature at our now longer orbital distance, we get 253.07 K. This at least gives us an estimate of the temperature delta we are looking at: if we can move the Earth out to this longer orbit then we might drop global temperatures by about 1.5 K. Since warming vs. pre-industrial is already around the 1 K range, this isn't that effective in the first place. **Energy to move the Earth's orbit** But wait! We still have to have spent the energy to move the Earth in the first place! [Specific orbital energy](https://en.wikipedia.org/wiki/Specific_orbital_energy#Equation_forms_for_different_orbits) can be calculated by $$E = \frac{\mu}{2a}$$ with symbols as above and ignoring the sign. For our current orbit we then have a specific energy of $4.435\times10^{8}\text{ m}^2\text{/s}^2$. For the farther orbit we have $4.382\times10^{8}$ for a difference of $5.273\times10^{6}\text{ m}^2\text{/s}^2$. Last we multiply this number by the mass to the Earth ($5.972\times10^{24} \text{ kg}$) to find that we need $3.15\times10^{31} \text{ J}$ to move the Earth to this new orbit. Using the [world's greatest internet page](https://en.wikipedia.org/wiki/Orders_of_magnitude_%28energy%29#.3E_1025_J) we find that this is equal to the sun's daily energy output, or about a million years worth of Solar energy on the surface of the Earth. This is going to be tough. **Even if we did move the Earth...** Now, assuming that we move the Earth, there will be some waste heat in this process transferred to the Earth. Lets make the very unreasonably low assumption that only 1% of the energy expended to move the Earth is transferred to the Earth as waste heat. That means of the $3.15\times10^{31} \text{ J}$ needed to move the Earth, $3.15\times10^{29} \text{ J}$ will be delivered to Earth's atmosphere and hydrosphere. This much energy is enough to raise the oceans (mass = $1.4\times10^{21}\text{ kg}$; specific heat $3850 \text{ J/kg}\cdot\text{K}$) by about 6 million degrees Kelvin. Put another way, the waste heat from moving the earth over the course of 11 years is enough to raise the temperature of the oceans by 1 degree K every minute for the entire 11 years. That is a heavy price to pay for 1.5 K of cooling. # Conclusion This is not a thing that will work. [Answer] It's a complicate loop the one you are trying to change... Higher distance from the Sun means less power reaching the surface, and that seems good. But less power reaching the surface means also less efficient photosynthesis (which is the only vast scale known process that can capture CO2 from the atmosphere). [Answer] Searching for internet I found this explanation regarding your question: > > For millions of years, levels of carbon dioxide have risen and fell between the ice ages. Orbital patterns initiate warm-up periods that cause changes in ocean circulation. These changes cause the carbon dioxide-rich water from the ocean depths to rise to the surface, where carbon dioxide is released as gas returning to the atmosphere. The increase in atmospheric carbon dioxide then creates a further warm-up, and finally, the orbital pattern changes again and the amount of solar heat reaching the earth decreases. (Donna Hesterman, University of Florida) > > > So yes, it is possible change the orbital pattern of the earth this can "to brake" the climatic change, but this isn't a definitive solution since in the current state of the earth, we can't be known concretely that other consequences would have this fact. That's why I do not see a feasible solution, if not a simple hypothetical case. More information abaout this theories : <http://www.nature.com/ngeo/journal/v5/n1/index.html> And others : <https://en.wikipedia.org/wiki/Milankovitch_cycles> ]
[Question] [ Consider the following: We have a city, designed to be a retreat. Everything consumed and needed by the population is created via a machine in the middle of this stronghold. This machine is able to convert matter into another type of matter and into energy. It could be simplified: We have a really big and efficent fusion reactor in a fixed position. My question: What would be the best energy source for this type of setup? What could support the reactor for a really long time? From my other [questions](https://worldbuilding.stackexchange.com/questions/39999/what-substances-would-be-really-valuable-if-transmuting-material-printers-would) I know that I will need a lot of handwavium, at least for the matter-to-matter conversion. But I want to keep this at least consistent and plausible. So no energy/matter out of nowhere. But where should it come from? [Answer] ## Water, specifically sea water Hydrogen fuses quite nicely into helium and provides a considerable amount of power in the process. Assuming exceptional fusing capabilities of this fusion reactor, creating elements from Hydrogen all the way up to iron would be feasible. Elements heavier than iron will require a fancier fusion process since fusion reactions only yield energy up to iron. Heavier than iron, they consume energy, so the hydrogen fusion portion of the reactor will have to provide the power to get the heavier-than-iron elements. Using the freed oxygen from splitting water will provide a nice jump start on the heavier, sub-iron elements. Sea water has a considerable mix of [heavier elements](https://web.stanford.edu/group/Urchin/mineral.html) that could be collected and processed. [Answer] ## The waste of civilisation With the best will in the world, humanity is far from efficient and we generate a vast amount of waste. What currently goes to landfill, slag and spoil heaps could just as well go into feeding the great machine that powers civilisation. Then top up with water. [Answer] How about *rocks*? They are denser than water, nobody wants to drink them, and if you build your structure underground now you have something to do with the debris of the drilling efforts to expand the settlement. [Answer] Water. With enough handwavium, you can readily pour this into your fusion reactor. Handily enough, it can also be used for cooling the reactor. [Answer] Your physicists have found a way to create short-lived mini-black holes. This will turn any kind of matter into radiation. This will turn the full energy content of the mass (according to the famous formula $E=mc^2$) into usable energy. You only need a way to cool your energy creating apparatus. [Answer] Like @Theraot suggests, rocks are a good idea. Depending on the kind of rock your retreat is built on, you might have up to [60ppm lithium](https://www.bgs.ac.uk/downloads/start.cfm?id=3100) in those rocks. Out of the millions of tonnes of rock that you could easily have access to (particularly if your retreat is built at least partially underground, or especially if that part is still being built), you might therefor have a few hundred tonnes of lithium available to you. Of that quantity just under [8% is Lithium-6](https://en.wikipedia.org/wiki/Isotopes_of_lithium#/media/File:Lithium_chart.png). Now, you're going to also need a few other things. Particularly, you're going to need a source of protons, and some Helium-3. These are a little harder to get hold of, but don't worry because *the reaction you're going to perform produces as much of them as it consumes*. You're only going to consume the lithium-6. The key is to fuse a proton with an atom of lithium-6. This will release a helium 3 (which will need extracting during reprocessing later on), a helium 4 (which is waste, although there are some fun party tricks you can perform with it), and 4 million electron-volts of energy. At the same time, you will also fuse a helium 3 atom with another lithium-6 atom. This will release a proton (you see where this is going) and 2 more helium 4 atoms, and 16.9 million electron-volts. So, you've used 2 atoms of lithium-6 and got 20.9 million electron-volts and some waste helium (and some other products that need to be reprocessed to feed back into the reaction again in order to sustain it). Now, to relate this to useful units. A mole of lithium-6 weighs 6 grams and contains roughly 6x10^23 atoms. This means that 6 grams can run 3x10^23 of our reactions and thus generate a little over 6x10^30 electron volts, which is to say about 267 megawatt hours, or enough power to keep the average person going for 12 years (or just under 3 years if they're [American](https://www.eia.gov/tools/faqs/faq.cfm?id=85&t=1)). This means that the rocks under your citadel ought to be able to keep a population of, say, 50,000 people going for somewhere between 60 and 240 years, depending on how frugal they are with power. Obviously shorter for a larger population and longer for a smaller population. Other than potential availability (depending on your city's location), there are other advantages to this over fusing deuterium from (heavy) water: * The relative abundance of lithium-6 versus lithium-7 is far higher than deuterium versus hydrogen. This means that you have to process less of it to get a useful quantity out. * The process does not release significant numbers of neutrons. Neutrons have a habit of being difficult to capture and turning many materials they may strike into radioactive sources. Neutrons are dangerous and difficult to work with. You don't want neutrons being produced in your reactor if you can possibly help it. * It's less cliche than deuterium-based fusion. [Answer] If we allow for a great deal of hand-waving, Then I see three machines working in concert. @Green's water into everything and energy reactor is the base. Then a matter reclamer, that uses less energy to turn matter into the same matter. For example iron into iron. This would take less energy, and could work like a futuristic smelter. Paper shreds go in and carbon, and other base materials come out. Finally a matter exploder. It's a "Green Reactor" but backwards. Or you know, a normal-ish fusion reactor. The main idea being that you take something like gold and "reacts" it down to helium. To keep it realistic, the Green reactor should produce the most energy, the Reclaimer should consume the most energy. The fusion reactor should be little better then break even. (even that's not realistic but just get those hands a waving) ]
[Question] [ In my world, there are two different magic systems. One involves making a pact with a god or spirit to agree to do a specific thing in exchange for power. The other involves using special spells and rituals to achieve the same magic result. How can I reasonably explain how one world can have two different magic systems? Note, in case of the first system, the price comes out of what ever contract you made to get your power. In the second system, magic draws life energy from the user, and over-use can result in death. Both systems developed in the same society, but the second one formed first (no one knows how) and was passed down the generations; it is most popular among the rich and/or city dwellers. The first system formed much later and is most popular among the poor and/or farmers. [Answer] **Magic is simply energy right**? So long as the systems meet your needs and aren't ridiculous in and of themselves, I have no trouble with the concept of multiple systems in one world. What you really need to define are the **sources** of the energy, the **limits** of each source and how a **user accesses** that energy. In the physical world, we have many forms of energy. We have fossil fuels, solar, hydro, wind, geothermal, chemical and probably other forms of energy. Suggesting a magic system with multiple power sources really doesn't strain suspension of disbelief any more than having magic in the first place. So again. Define the following: **Source:** Where does the power come from? In your case there is * Life energy, which is pretty strait forward. Read the Eragon series for a great example of this system. * The second source you mention is divine/infernal/nature based. If you decide that beings exist in your world that are magical in nature then they exist, and being super powerful have energy to share with casters. **Limits:** What are the limits of the system? * In the case of life energy this is pretty straight forward. You only have so much energy in the human body and if you use too much you die. * In the second system you get to decide. Comparing divine energy to human energy seems strange...but you could. You could also consider the divinity chooses to only provide so much energy or perhaps cosmic laws limit how much they can transfer and at what rate. **Access:** In short, how do your magicians execute their powers? In this case it is totally up to you but here are some options... * Magical language. Pretty standard fare. Certain words in a certain order unlock/access your source of magic * Innate. Nothing special required beyond the will of the caster. * Focus. Casting requires a focus, in short an item that channels the magic. Think wands, staves maybe amulets. There are lots of other options for each category these are just options/examples. [Answer] The gods and spirits are just extremely advanced users of the spell/ritual magic system, so in reality there is only one underlying system of magic. The means by which a potential magic user gains their powers differs dramatically. Pact-makers negotiate to acquire their gifts while Spell-casters study to earn theirs. But ultimately, the magic being acquired is the same. [Answer] There are a variety of ways that you can make this happen. Even though you technically have two different sources: gods and spirits, perhaps there are some "loopholes" you could exploit. In D&D Next, there are Warlocks, which gain their powers through contacting extra planar entities. While this may seem "cut and dry" each spirit that grants power(s) is different, will have different requirements, grant different spells and so on. A caster could have a a spirit that is taught to them generation upon generation, and because of the fact that the family has been using the same one for time immemorial, s/he trusts the character(s) a greater portion of his/ her power. Another way of looking at things could be the powers could work together. A character could be granted powers from sources A, B, whereas another could get their powers from B, C, and so on. Similarly, the gods could have different portfolios, or powers that they specialize in. There could be agod of war, which would have drastically different powers than a god of peace. Another idea to differentiate the gods is to have them only use certain spheres. For instance, maybe the gods are powerless to create or control undead, whereas the patron spirits do so routinely. [Answer] A completely different shot: Magic is inward, not outward. The god or spirit they connect with is just a manifestation of their subconscious view of the universe. Just like the universe is "infinite", the subconsciousness is too. So instead of a set of existing gods and spirits, everything a human believes deeply inside gets projected to the outside. The more humans believe in the same system, the stronger the manifestation of the system gets. So the reality would be a reflection of thought. In this case magic could be done by having a strong thought in mind. But, of course, it's much more efficient with a ritual, that puts you in the right mindset and lets the wish in yourself grow, so that the will manifests in the world. A change in yourself is a change in the world. Rituals are amplifying/pushing change in yourself. So you can have different cults besides each other. It would even explain rogue mages using their own system. ]
[Question] [ Similar to [this question](https://worldbuilding.stackexchange.com/questions/46438/could-you-pick-up-a-loaded-gun-five-centuries-from-now-and-fire-it) but with some specifics. In the TV show The 100, the kids find a cache of assault rifles in the equivalent of a munitions dump. 97 years have passed since the latest timeframe when the guns could have been placed. They were stored in barrels of oil (or some other fluid, I believe they refer to it as oil in the show). They have a cache of ammunition in working order as well, but it isn't shown (or I don't recall) how that was stored. If the guns were stored in crude oil would they still be functional once pulled out after 97+ years? Theoretically, how long could they survive under those conditions and still be operable? How could ammunition be safely stored for a century or more and still be functional? What would the best way to store such weapons be to keep them functional (both the assault rifles and the ammunition for them)? [Answer] Short answer would be yes on the firearms. Cosmoline is a common petroleum based preservative applied to firearms to prevent rust and corrosion. The firearms are dipped and allowed to dry before crating. The idea is to keep moisture and contaminants off the firearms. So if they are sitting in oil, which by nature won't let moisture anywhere near the firearms, you get the same effect. The ammunition is a little harder, but again yes. The storage facility and packaging would have to keep the air bone dry and cool. Again, moisture is not your friend here and heat accelerates breakdown of the powder and primer. Additionally, it would need to be stored in such a way to prevent any chemical contamination. Something as innocuous as Windex can ruin the primers in a matter of years. So basically you'd need a natural method of environmental control since you wouldn't have power to dehumidify and cool the area. In theory, if the oil was simply motor oil and you could control the ammo storage environment, the firearms would be usable indefinitely. [Answer] Firearms are usually simple mechanical machines powered by springs. While there are complicated firearms like gatling guns that rely on electric motors, most types we use today would be perfectly operable if stored in oil for a century, so long as they could not corrode. Mechanically, a modern assault rifle is only a little more complicated than a spring driven mousetrap. The ammunition would be more problematic. We have some pretty stable chemical propellants nowadays, but even absent moisture, they might start to break down over time. I think a hundred years is feasible, but longer than that and I think primers would be much less likely to ignite. In a post apocalyptic setting, you could still use a (modified) firearm even if primers were usually bad if you had an alternate way to ignite the charge in the shell casing (maybe simply by applying enough heat the right way). If the round were chambered, the bullet would still be forced down the barrel by expanding gasses and physics would take care of the rest. [Answer] Something which wasn't addressed in other answers with regard to the ammunition is that over time it has a tendency to "settle". The propellant will slowly compress on the bottom, so properly stored ammunition is rotated every so often (1-3 times annually) to prevent this. Storing ammunition reliably for a long period of time is quite tricky, and generally requires monitoring and effort. It's possible that storing it vertically (i.e. base down and bullet up) would mitigate this effect, although I have no knowledge or experience of how that would affect the viability of the round WRT the propellant. [Answer] I store ammo loose in a canvas bag with a table spoon of PLC oil thrown in and shakers around for a nice even thin coat on the rounds and a bit on the bag itself. Then I toss the bags into metal 50 cal ammo boxes with intact seals. Not even a spot of rust or signs of failure to fire and I’ve got some in rotation over 5 years old. I just never mix steel and brass case. ]
[Question] [ I'm dealing with a primitive tribe (of a species that can breathe underwater) that lives deep under the sea, and has little in the way of human technology. Resources include things naturally found in the sea, and things salvaged from shipwrecks and human waste (i.e. plastics) (though they do not know how to use human technology). While the species can breathe underwater, they can't poke any part of their bodies above water - to do so would violate some kind of sacred law. Getting close to the surface is frowned upon culturally. They typically stay far enough away from the surface that they don't receive a lot of light. That said, they need to be able to track lunar phases, tides, and passage of day and night for their religious calendar system. Without looking directly at the moon or venturing close to the surface/shore, what would be an effective way to measure these cycles? EDIT: In light of the first answer, and to open up any further ideas that they might give you, I should mention the species possesses natural sonar, infrared vision, and a shark-like "electroception" sense. They're also likely skilled at gauging water pressure to avoid "the bends", as divers call it. [Answer] Besides a convenient creature that follows a cycle close to the things needed to be measured a simple **reverse Fish line** would do. They release something buoyant and then reel it in back down to note the time of day. So something that reacts to light would do. ALso the length of the line would differ depending on high tide or low tide. And the distance between sea bottom and surface can also tell you about the spring tides. Also current change with tide so those can all be measured using buoyant object attached to lines without leaving the sea surface. [Answer] **For day-night cycles:** *Sonar operators, using the newly developed sonar technology during World War II, were puzzled by what appeared to be a false sea floor 300–500 metres deep at day, and less deep at night. This turned out to be due to millions of marine organisms, most particularly small mesopelagic fish, with swimbladders that reflected the sonar. These organisms migrate up into shallower water at dusk to feed on plankton. The layer is deeper when the moon is out, and can become shallower when clouds pass over the moon. This phenomenon has come to be known as the deep scattering layer.* ~ [Deep Sea Fish - Wikipedia](https://en.wikipedia.org/wiki/Deep_sea_fish) **For Tides** Observe the motion of shoreline species like certain types of starfish, coral snakes and turtles. When the tide is high, they would be miles further towards the shore and when the tide falls, they would return to the deep water line. **For Moon Phases** Observe the behavior of fish. Moon phases have an important effect on the reproduction of certain types of fish. For more details, read [this article.](http://onlinelibrary.wiley.com/doi/10.1111/j.1467-2679.2004.00164.x/abstract) [Answer] **Passage of day/night** you just mentioned that they stay at a depths where 'they don't receive a lot of light'. Doesn't mean they don't receive *any*. And staying down there just seems a thing of customs and religion, not dictated by biology (some deep sea creatures can't ascend higher than 2-300m because they can't survive in the low pressure environment up top). So, even if the little light you get at your living altitude is not enough to properly determine day/night, you are capable of sending up a swimmer to 1m to report periodically. **Tides** The flow of water during a tide doesn't suddenly stop 2-3m beneath the surface. Careful observation of currents close to the coast (especially in coast lines where the land falls down steeply) should also give you results at a depths of 30m. Not to mention that in places where the difference between ebb and flood is several meters, you might be able to notice a difference in water pressure (each additional meter of water adds 1/10 bar). **Lunar Cycle** When you are able to measure the strength of tides (smaller/larger), you have a way of determining the moon phases, since full/new moon give you larger tides than quarter or three quarters: > > Because the tides are influenced by both the Moon and the Sun, it's easy to see that when the Sun lines up with the Moon and the Earth, as during a New Moon or Full Moon (a configuration also called "syzygy"), the tidal effect is increased. These are known as spring tides, named not for the season, but for the fact that the water "springs" higher than normal. [moonconnection.com](http://www.moonconnection.com/tides.phtml) > > > Combined with photosensitivity (assuming they can just visually observe light intensity), it is quite possible to determine whether you've got a full moon (=observable light even 1m beneath the surface) or a new moon. [Answer] They could just cut a long piece of submarine optical fiber cable and poke it above water (in a protected well, probably). I guess it would be easy to tell the difference between day and night, and possible tell the difference between full moon and no moon. If it's cloudy, they could use clock and moon calendar to fill the gaps. [Answer] The 1978 novel "Aquarius Mission" by Martin Caidin asked this question. In that case, IIRC, the undersea race marked the months by their female's menstrual cycles. Do your people have regular sleep cycles or anything else that follows a circadian rhythm? Are there fish or undersea creatures that strictly follow a daily, weekly, or monthly pattern? (EDIT: Sorry, someone already mentioned the repeated behavior of deep-sea fish.) ]
[Question] [ I have in mind a new sword. This sword has four cutting blades, think like a double-edged sword, but two of them, perpendicular to each other. It looks like it would be a thrusting weapon, which it could do just fine, but I want it to slice. I was contemplating something like several tiny hinges. For example if you would slash, the penetrating blade and its parallel would remain rigid and unyielding while the perpendicular blades fold back against the opposite blade. Hopefully this would allow a good slicing weapon for multiple directions without the user having to turn the blade too much. Practicality isn't quite as important when it comes to "Is this the best weapon for the job," but if there are already existing weapons that *would* be better, please mention them! Potential Concerns: * Would the blades need to be thinner to allow a cleaner cut, resulting in potentially weaker blades that break easily. * Would it be necessary for a wielder to develop a "slice partially then withdraw" style of combat? I imagine the blade would be significantly thicker at the center because of the three blades and thus harder to cut through things. * Would creating folding blades be too technical/difficult for a smith or machine to pull off? * Would hinges decrease the longevity of this weapon, resulting in more maintenance and a higher chance of being outright broken? Is there a better method of creating folding blades? For this question you can assume that the blade can be "instructed" on which blades to allow to fold via magic/unknown technology, but feel free to analyse how this would work without magic. You can also assume an advanced level of technology but the closer to current Earth, the better. For the rest of the stuff, try to be as close to a real world sword as possible with comparisons. I can only shrug off so many physics facts before people close the book and utter "nonsense" before throwing it into the fire. **BONUS:** Can we make this into a whip sword?! That'd be sweet. If not that's fine too. [Answer] Swords and edged weapons in general have evolved into their present shapes after at least 5000 years of evolution, so there are several good reasons why a sword such as you suggest isn't a good idea. (You also need to suggest what sort of opponent you are facing i.e. armoured, mounted or dismounted, using a similar or different weapon, in order to fully judge your idea: weapons are not developed in isolation from the defense). The first one, just based on the description, is this will be significantly heavier than a single bladed weapon. The wielder will have to use more energy holding it and fighting with it than a conventional blade, so will tire more easily. If you stay out of the way long enough, the user of the quadblade will let his guard down and you step in for the killing blow. A larger, heavier weapon also has more inertia. In some instances, this is a good thing. Smashing weapons like maces and war axes use the considerable mass to add power to the blow, smashing through armour and into the person underneath. On the other hand, swordplay involves rapidly moving the blade both to attack, defend and to confuse the enemy as to where the blade is going to be. A larger, slower moving sword isn't going to have these advantages, and will require considerable effort to change directions to parry an incoming thrust. Finally, the system of springs simply adds complication and more weaknesses to the weapon. Hinges could seize due to the force of impact during swordplay, leaving the auxiliary blade stuck out or folded back when you don't want it to be. With enough force, the hinge could break right off, and you weapon is now unbalanced because one of the blades is missing, something which will be rather difficult to recover from quickly. Finally, mastering a complex weapon takes a lot of time. Looking at instruction books from the Middle Ages for fighting styles with sword and dagger, sword and cloak or Japanese Niten Kai two sword systems you see they are significantly more complex than using a single blade or blade and buckler. Japanese military swordsmanship eventually was pared down to a very utilitarian style (starting in the Meiji Restoration) to make it easier to teach large numbers of troops and for them to learn. A quadblade will require a specialized school to try combinations and practice them against different sorts of opponents, so the weapon could be used effectively against all comers. So this is the "negative" answer, thousands of years of trial and error have created exquisite weapons to deal with many styles of fighting, all kinds of armour and changes in technology. [Answer] # No, this would not work What makes a sword is a long slicing weapon. This monstrosity you have created would not work, it just wouldn't. * Thinner blades would not work, because you are still going from thin to thick. There is no getting around this, if you made the blades thin enough to cut you couldn't connect them to the blade without them breaking off. * You'd do better with a mace or other pointy object on a stick. This thing will be unweildy, and in order to hit someone you have to have your sword at the right angle, like with all swords. But the extra two blades you glued on stop the sword from cutting any deeper than about an inch, which means you've ruined your sword's slice, with no benefits from it. * The hinges, in order to be sturdy enough, would be too large. In fact, nearly anything extra would be too large. Swords need to be smooth and thin on the ends, so they will cut well. Hinges for extra blades would simply not work. * Yes to the first question and no to the second ## No! Again, slashy things! Slashy things need their strength, which you have just deprived it of. Also, there is no way to make your sharp blade move without making some kind of scaled thing, and then the areas where they connect will be awful. [Answer] ***...if there are already existing weapons that would be better, please mention them!*** Yes, there is something which has been actually developed and is in use. It would be one of your worst nightmares to get stabbed by it. It is called [Jagdkommando](http://www.dudeiwantthat.com/gear/weapons/jagdkommando-knife.asp). Here's an image. [![enter image description here](https://i.stack.imgur.com/IYdPX.jpg)](https://i.stack.imgur.com/IYdPX.jpg) Also, why would you need to add two other (perpendicular) edges to your sword when a sword with a single edge does a mighty fine job. A single-edged blade would cut *much* faster than than the design your proposed. **Your design would have been an improvement if it offered better chances of contacting your adversary in combat.** Unless you offer that, I would like to stick to a katana blade. Thanks. [![enter image description here](https://i.stack.imgur.com/UZ0Jx.jpg)](https://i.stack.imgur.com/UZ0Jx.jpg) This is far more practical and deadly in combat than your design and the Jagdkommando. [Answer] Instead of hinges, let the blade which is perpendicular to the guard flex at the end, getting out of the way of the penetrating blade during slashes. The purpose of the second, flexible blade is to enlarge puncture wounds, increasing the likelihood of hitting a major blood vessel during a stab. For that purpose, the second blade needs to be rigid to forces approaching from its tip, but does not need to be that rigid when force comes at it from its side. If either blunt side strikes flesh obliquely, while its harder companion blade is cutting deep, it should just bend out of the way, sliding along the bloody flesh. To obtain this, the flexible blade could be made of thin aluminum while its companion is hardened steel or titanium. They would only be joined together into a welded cross for about half the cutting length of the sword, from guard to mid-blade. After that point they would float perpendicular to each other, without reinforcement, so that flexing blade can move freely. It is not quite what you asked for, but it has the advantage of durability. The hardened blade will still battle ready, even if the flexible blade snaps off. [Answer] > > Would the blades need to be thinner to allow a cleaner cut, resulting in potentially weaker blades that break easily. > > > Once folded you're 3 times as thick as whatever thickness you started with. This isn't a thin vs thick issue. It's a going from thin to thicker issue. Even if you do it smoothly, you're still attacking them with a wedge. Folding blades and wedging flesh apart costs energy. If you're looking to be able to chop limbs off this isn't the most effective way to do it. > > Would it be necessary for a wielder to develop a "slice partially then withdraw" style of combat? I imagine the blade would be significantly thicker at the center because of the three blades and thus harder to cut through things. > > > I presume this is a "Hollywood" weapon, meaning the most important thing is to look cool, not to be effective. Otherwise, I'd point out that piecing has been known to be the most effective way to use a sword since before roman times. So no, you don't have to even have slicing in your combat style, quad or not. Why quad then? You could explain away this design by claiming it's a "ceremonial" weapon. > > Would creating folding blades be too technical/difficult for a smith or machine to pull off? > > > Depends on the smith and how complicated your design ends up being. You have me thinking of playing with [piano hinges](https://www.google.com/search?q=piano%20hinge&espv=2&biw=982&bih=1654&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjG1bi2n9jLAhVJOCYKHTxfDgwQ_AUIBygC) at the hardware store. > > Would hinges decrease the longevity of this weapon, resulting in more maintenance and a higher chance of being outright broken? > > > All moving parts come at a cost. > > Is there a better method of creating folding blades? > > > Consider not folding the blades. Consider rotating one blade. You mentioned magic/technology. Let's create the world's first sword/blender. Why? Because it's fun to twist the knife. > > Will it work? > > > It's still a sharp pointy stick. I wouldn't buy one but if you came at me with one I would definitely start paying attention. [Answer] The other responses highlight why your idea is not effective, so I will address alternatives. The deployed part of your design, where blades are perpendicular to the main edge, is used on a variety of polearms, including the classic [halberd](https://en.wikipedia.org/wiki/Halberd) or the [bec de corbin](https://en.wikipedia.org/wiki/Bec_de_corbin). The idea here being that the wielder can use it as a classic thrusting spear, while also allowing it to be used with a sweeping motion as a warhammer or warpick. Your idea initially reminded me of a mechanical broadhead point, where the extra blades deploy on contact. Perhaps an oversize deployable broadhead on a polearm would fit your idea. This, of course, is treating your creation as a thrusting weapon only though. As the others have noted, the mechanical aspect of this could prove unreliable and even detrimental in the course of combat. Going off your "Can we make this into a whip sword?!", whips and whip-like weapon are generally thin and lightweight. Their advantage is the extended reach and unpredictability. The disadvantage is they are often needlessly complex for a simple "I'm going to stab you with this" action. The even greater disadvantage is they are extremely difficult to use effectively and safely. [Hook swords](https://en.wikipedia.org/wiki/Hook_sword), or tiger swords, are dual wielded swords with a hooked tip. This allows some creative fighting techniques, such as catching an opponent's weapon or limb. It also allows them to be linked together, using the bladed handguard on the outer sword as the slicing edge. Another interesting weapon is the [urumi](https://en.wikipedia.org/wiki/Urumi). These are flexible, often multibladed weapons similar to a metal whip. Although very difficult to wield, they have the advantage of being concealed as a belt. So though your idea as it stands may be impractical, but there are some real world examples of various aspects of your design that you might examine. [Answer] One thing to consider is whether the perpendicular blade should be raised by default. Imagine a double edged sword made from two steel layers that twists to form the four edged blade on demand (what rational "demand" I have yet to fathom). A fairly simple scissor style mechanism would be less complex than a hinge and more structurally sound. Imagine two separate thin pieces of steel that are pivoted like a pair of scissors. Normally they are milled such that they sit flat against each other like a normal sword. Normal slashing, parrying and stabbing action would be possible. In the heat of battle, the hilt can be twisted such that both pieces pivot 90 degrees to form the quad blade. I can only imagine that you would do this just before a thrust into an unarmored opponent, with their guard down to maximize the size of the inflicted would. For piercing armor I think a double edged sword would be be more effective as it would generate less resistance against the armor while maintaining more strength in the blade. "Twisting" the blades would almost immediately telegraph your intention though, and add an split second to your attack. One last potential use for the quad formation, may be to increase the realized coverage of the blade in more than one directions (for shielding or parrying). This would only be marginally better than a normal two bladed weapon and only against multiple opponents (projectiles). [Answer] Are you basing your sword idea on trefoil swords? They were used by French cavalry during the Napoleonic wars, and are some of the best stabbing swords ever designed (they make an entry wound that is very difficult to sew up properly). The disadvantage with this type of sword is that they do not cut very well; in fact many of them did not even have a sharpened edge to cut with because of how bad they were at cutting. The four-blade design you want would be even worse than said trefoil blades because any folding hinge assembly small enough to not get in the way of your cutting would break far too easily. If you want to use a weapon that can hit from any direction, get a light sabre, morningstar, or flanged mace. [Answer] It already exists in real life: <https://en.wikipedia.org/wiki/Ji_(polearm)>. [![ji](https://i.stack.imgur.com/ZoFC2.png)](https://i.stack.imgur.com/ZoFC2.png) You can thrust it, use the front-pointing blade to slash from left to right, and the side blade can be used to drag people off from horses or cut into a horse's legs. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 8 years ago. [Improve this question](/posts/15661/edit) I'm writing a sci-fi story where a character has to jump off the top of a 140m (459ft) tall building, and fall into the sea. I think it's pretty obvious that no one could survive such a fall, so my question is, if this character would throw something before him that would break the surface tension of the water (or something to move away the water right before he would hit it), would he have a chance to survive the impact? Or is there an alternative to the situation in question? Thanks in advance :D [Answer] **They likely will not survive.** This is a common myth about jumping into water from very high. It was [tested by Mythbusters](http://en.wikipedia.org/wiki/MythBusters_%282003_season%29#Hammer_Bridge_Drop) and shown to be false. > > Eventually, they managed consistent drops (mostly just below 300 g), finding that the hammer reduced the impact slightly, but the 150-foot (46 m) fall would still be lethal. > > > [Up to about 450m](http://en.wikipedia.org/wiki/Free_fall#Examples), a falling human will most likely still be accelerating to [terminal velocity](http://en.wikipedia.org/wiki/Terminal_velocity). So your character would still be accelerating and suffer far more damage than the Mythbusters experiments showed. It's not the surface tension that kills, it's the change in acceleration. That can't be prevented or slowed by affecting the surface. Unless you can somehow get the density to change from air to water over several tens of meters. To make the fall more survivable, the change in acceleration needs to occur over a longer period of time. There are a few ideas on [how to survive a long fall](http://www.wikihow.com/Survive-a-Long-Fall), if the character can do that [while drunk](http://www.livescience.com/24979-alcohol-injury-outcome.html) (inebriated individuals have a disproportionate survival rate), it may improve their odds of surviving the fall. [Answer] Best alternative I can come up with here is made use of in diving, however this is assuming 10m not 140m. When an in training Olympic diver is giving their first attempts off a 10m board, an aerator under the pool shoots bubbles to the surface. If you've ever seen it, it looks like a massive underwater volcano bubbling to the surface. This has two effects...the first is surface tension as you mention with an object dropped before the fall. This doesn't have the biggest effect in your case, although your diver in training doesn't get the harsh slap a belly flop receives, losing the surface tension doesn't help much as far as lessening the impact of the rapid deceleration that ultimately kills (the fall doesn't kill, it's the rapid deceleration at the end that does). From this stand point, breaking the surface tension does little. However there is a second effect that the bubbles might make a difference on...force is mass times acceleration, and acceleration has a time component to it. If you increase the amount of time that you are decelerating over, then the force on your characters body is lower (despite being over a larger period of time). Enter bubbles...if the bubbling is heavy enough, you actually effect the density of the water that you are falling into and you fall further into the water giving yourself a longer time to decelerate and a better chance of surviving. Of course this might not be enough to make it survivable...but best chance I can come up with. Unfortunately you are not going to get bubbles to the degree you need by simply dropping off a rock or other large object before you go yourself...rapid little bubbles are better than a single massive one for this. It's quite doable in an artificial setup like a giant aerator at the bottom of a dive pool, but outside of these lab like conditions it's quite difficult to generate the bubbles you need. Any chance there's a two ton alka-seltzer tablet available to your hero before he jumps? More bubbles = lower density = longer time to decelerate = better chance of survival. And as a final barely worth mentioning point...cold water is higher density and is a quicker stop while warm water is a little less dense and has a bit more give to it (same effect, you fall further into warm water and increase the distance you decelerate over)...but the effects here are very minimal, less than a percent difference. [Answer] **It could, but only if the object was *really big.*** Also, surface tension wouldn't be what it would help him survive. The goal here would be to reduce the rate that the faller decelerated when hitting the water. Kayakers survive large falls by doing this, though in their case, the thing hitting the water before them is water. The impact of the water (or large object) on the lower body of water both creates a localized downward current and aerates the water. The downward moving water reduces the velocity differential between the faller and the water, which in turn reduces the force exerted by the water on the faller. Aeration reduces the effective density of the fluid, which also reduces the force of the water on the faller. (In essence, the faller has to move less water out of the way per unit distance travelled if some of the water is replaced by air.) If you're dropping a large object in front of you, you need to also account for the fact that, if the object slows down too fast, the faller will smack into it, which could kill them even if the water doesn't. Ideally, the faller would obtain a heavy, streamlined object which won't decelerate quickly and stand on the back of it when jumping off the building. Something like a torpedo would do nicely. This would possibly stop the impact from killing the faller, but would also probably drag the faller down deep under the water with the falling torpedo, at which point drowning would start to become a serious potential problem. A parachute would be a better solution. [Answer] It has nothing to do with *surface tension*, and I don't see what people were thinking when advancing the myth. Without mis-using terminology, what are you supposing happens? The *splash* could have an effect, but as shown on Mythbusters it is too small to matter. Consider if a plume of water existed, not as a solid block but ropes of fountain-flow or foamy breakers: that would be hit first. How deep is it and how much resistance does it offer? Nothing from a previous dropped hammer. How about an explosion? Throw a plume up 40 feet right as you reach the top of it. The "loose" water can get out of the way so it's not behaving like concrete, and you have a foam of water and air. Imagine a fire-hose fountain: also on Mythbusters they levitated a car (sans engine) with firehoses, and there is a waterski-hover-jet thing for people. If the jet was tall enough it could "catch" you and slow your fall as gradually as desired. Your best realistic bet is to use a liferaft as a parachute. That *worked* on Mythbusters. For something along the lines you're asking, try a grenade not a hammer. Or if it's like the Batman TV show with Adam West, he would have some compact pills in his utility belt that would act like mega-seltzer. [Answer] If your character threw something high-tech (magical) before him that caused a large whirlpool, it he could survive. He or she could conceivably "slide down" the inner surface/side/wall of the whirlpool. That would minimize his angle of impact, since the water isn't level and perpendicular to his direction of travel (straight down). The water on the edges of the whirlpool is moving downwards too, so your hero's velocity relative to it would be greatly reduced. In other words, if the water is travelling downwards at 60 MPH, and your character is travelling at terminal velocity (about 120 MPH, I think), then your character is only travelling at 60 MPH relative to the water. He would need to worry about drowning, of course. But that's a separate question. What would he throw down there? Possibly a super-fast pump that would eject a geyser of water out of a nearby spot on the ocean. Or a small, short-lived, controllable micro black hole. (Not likely.) Or a bomb that shot to the floor of the ocean floor and exploded, opening up a heretofore unknown cavern hidden underneath, which would start pulling water down into it. (These are all pretty far fetched. I just like the idea of a whirlpool to save his life after the fall.) ![enter image description here](https://i.stack.imgur.com/eXU08.jpg) ]
[Question] [ I have a world I'm working on designed to be the setting for an eastern-style RPG. In the past, magic was used until the mana fueling it ran out and everything people depend on failed. At about the same time, a sort of 'magic pollution' was discovered. It was a side effect of trying to keep spells going despite the fading mana. The idea is that everyone faced a near catastrophe where humanity numbers dropped drastically, but the 'pollution' faded rapidly once magic was no longer used and in only a few generations, society came back. **A few things I know about this pollution:** 1. It has a mutating effect. Most of the monsters of this world are mutated animals caused by the magic pollution. The more powerful monsters only exist due to high presence of pollution 'feeding' their power. Humans are also effected, in particular newborns. For humans, the mutations can vary. Many are debilitating but some are just unusual or even beneficial, but these 'mutations' are not inherited by their children and these mutated people are far less common in 'present' day. 2. The pollution was the main cause of the societal collapse in a short period of time, and it's fading is what allowed the 'present' day to rebuild back to proper levels quickly 3. The magic pollution would dissipate faster near humans, as human life (and death) is the source of the mana and the faster mana builds up the more the pollution fades. Thus monsters near human settlements would tend to be less dangerous/common. I had originally imagined difficulty fighting newly formed monsters combined with high mutation and still births in infants would be the cause of the collapse. However, I realized that taken to the logical extreme this would likely result in a world where women were treated as brood-mares. The focus would be in getting pregnant as often as possible, to compensate for all the still births, and women wouldn't be allowed to do anything else because they were too precious a commodity. This would lead to a society that I *don't* want in present day, I want women to be treated closer to present day norms. **How can I modify the effects of this magical 'pollution' to stick to cause a major societal collapse for a brief period of time while still developing a culture with women on equal footing to men?** I've toyed with plants being most effected by the pollution and dieing out, making feeding of humanity be the biggest challenge during the Collapse, and with a larger focus on monsters. However, I don't want monsters to be the sole/primary cause of the catastrophe, I would prefer there to be an emphasis on other factors which quickly disappear as the pollution fades, while the monsters mostly 'sticks around'. How can I justify the culture not treating women as brood-mares. [Answer] If the society collapsed recently so did probably the agricultural production. Even if society has recovered, your society probably does not have all that much surplus food, and if monsters are still around it might be difficult to fix that fast. A society that has issues with food supply and is busy rebuilding, would have people marrying and having children late after careful consideration if the couple can afford that. Also most people wouldn't be able to afford keep women home anyway. They'd be just as busy working hard to rebuild and get a living as the men. Basically, I think that with such a sudden catastrophe people would accept a drop in fertility and, unless it continued for an extended period, not try to compensate by turning women to "broodmares". With monsters roaming around people probably were too busy trying to find food for themselves to worry about having children. And even if they thought about it they probably would have considered the time less than optimal for raising children. [Answer] I think you can handle it just like the video game Mass Effect (particularly the third installment). There, the Krogan have a harsh and desolate world, destroyed after so much war. On top of that, another race perfected a genetic plague that caused a high sterility rate among the women. There, the few women who can breed are exalted, and those that are barren are just as likely to become warriors as the men. So, your pollution has reduced the ability of women to breed. Those that can create life are not "puppy mills", but instead treated as a special class. Those women that are barren or unable to produce "pure" offspring take up the mantle of responsibility next to the men. Maybe they even form a protective organization to keep the fertile women safe. Perhaps this could lead to a matriarchal society. [Answer] Your model that ends in "broodmares" assumes that these "equally footed women" simply roll over when the men try to pigeonhole them into their new role. Any reasonable feminist would point out that they will not go quietly. Consider that the average man will still have the desire to "uphold the family name" by having a son (or at least a child). If his wife is angry enough to use that as leverage, he will not hold out for long (the couch is a bad enough threat!) Women who deserve to be on "equal footing" will simply induce culture to shift around them to value what they can bring. They may still have to rapidly pump out children like crazy, but that doesn't mean they have to have low status. If I was in such a situation, I would certainly be trying to make my wife's life as pleasant as possible. A happy wife means more child opportunities! My advice would be to relax on the "equality" side of things. "Equality" implies there is a metric with which to value a human life, or else how do you tell if two people are "equal?" Differences must be acceptable. Even today, with our society's push for "equality of the sexes," there is a difference that cannot and shall never be reconciled: women carry a baby for 9 months longer than men, 100% of the time. Any attempt to arrive at equality by removing the differences will fail; one must make a definition of "equal" that embraces the differences. Your world has that difference amplified to colonial-era times, where women were expected to deliver children at a very high rate due to agricultural manpower needs. You will not succeed in finding "equality" if your goal is to smother this difference. Make this the focal point of how the feminist side of the culture acquires compensation for this duty. Give the men a reason to allow women to coalesce power, instead of seeking to control the women. Family name is a strong force for men. Another would be any superstition which suggests a happy wife leads to fewer mutations. Any organization within the ranks of the women to coalesce power by denying reproductive capacities would be powerful. A society where women hold the property would also suffice. Edit: if it proves hard to realistically make large forces play out in womens' favor, consider the effect of the individual. It is well known how much one person can shape the world, and such single-person effects are more within the realm of where stereotypical "women's manipulation" is most effective. If you have a doubting audience, sticking to stereotypes may make your story more believable. [Answer] Our gender roles are a result of our past. A few hundred years ago we were living in a world where most work was manual and many conflicts were solved with physical violence in form of hand-to-hand combat. So physical strength was very important. Men being physically stronger than women made them play an important role in society. Women were considered inferior because they *were* inferior. They couldn't work as hard as a man and they couldn't defend themselves against men, so they were dependent on males for both economical and physical safety. It is no coincidence that the current raise of gender equality in the developed world correlates with manual labor getting less important than mental labor and a more effective law enforcement system removing physical violence from everyday life. And thanks to modern firearms, you don't even need to be physically strong to hurt and kill someone. Being physically weaker is no longer a handicap in our society, so we have no reason anymore to treat women as second class citizen. However, when your world has a history of magic use, the past might have been completely different. Most manual labor would have been replaced by use of magic and most violent conflicts would also have been resolved through magic rather than through hand-to-hand combat. When women had equal or even better magic abilities than men, they would not have been considered inferior during most periods of your worlds history. They would be just as effective at most jobs and they would have no need for a man to protect them from other men, as they would be able to defend themselves using magic. Gender roles would then be quite different today. [Answer] Solve magical problem with more magic. Some/all women have magical power, and whomever they love, is more resistant to magic monsters. It has to be genuine, cannot be forced. So women would be source og magic which helps to heal wounded world. [Answer] One possible way to remove the "protect and use the child-bearers to maximum efficiency" drive is to remove the necessity of incubation away from most women, and maybe make it actively more dangerous for women to bear children themselves. Without this, there's no motivation to move towards the scenario you describe. Say you raise the stakes -- say at some point the stillbirth rate among natural births became intolerable, say, 60-70% or more *and* started killing the mothers. Some form of sustainable external magical womb that provides some protection might be a necessary development (maybe a tree or ruminant plus the magic required to perform the transfer), and would free up the women, too. Perhaps one innovative magic-user noticed that a particular animal or plant was much less affected by the magical pollution, and thought it might help, or perhaps your resident theology intervenes to create the means, or maybe it's entirely an accidental mutation. I'd suggest a large, wide tree, with the children growing as fruit on the branches, and some sort of widely-practiced ritual that requires little or no expert intervention to transfer the child. (This may be a bit higher on the weirdness-o-meter than you wanted to go, I'll admit.) You could have one of these trees per settlement of a given size, depending on how local culture adapts to take care of them and how much maintenance and care they require. Crystals, or pearl- or large opal-like formations would also be a fine option. ]
[Question] [ I've created a Neptune sized shell world with properties that I find are not typical of other shell worlds. Its gravity does not come from a gas giant or a black it was constructed around, but from the sheer mass of the shell itself; which for 1G, is 12 billion kg/m2 of matter for every m2 of living space. This was done so that I could utilize a combination of radioactive decay and tidal heating to keep a molten "mantle" of rock for geological activity. And since the inner area of the shell world is...odd. Though it still produces a magnetic field. If we ignore the inner area of the world and the composition of the shell material: **Can orbital mechanics work the way they as they normally would? Or does the fact that gravity originates from the upper surface only affect how orbits work.** ## Clarifications: * World is hollow with no core. What fills the space in the world is irrelevant * Gravity is produced by a layer of rock on top of the shell that is heated by radioactive decay and tidal heating to produce tectonic activity * The surface area of the world is that of Uranus; 8.083 billion km² * I'm mostly curios on the orbital paths of objects around the world and of the Roche limit. [Answer] The thing you probably care about is the [shell theorem](https://en.wikipedia.org/wiki/Shell_theorem). Newton proved that > > A spherically symmetric body affects external objects gravitationally as though all of its mass were concentrated at a point at its center. > > > and if Gauss and Newton say you can have things orbiting your shell world in the usual way, then you can probably assume it'll be OK. [Answer] The orbit around the sun should be similar/identical to a denser object of the same mass. However, the orbit around the shell planet would be very different. The strength of gravity is dependent on F = G(m1m2)/R^2, where G is a constant, m1 and m2 are the masses of the two bodies, and R^2 is the distance between them. The shell world gravity of a Neptune-sized planet that's hollow (say, a 5 km deep shell) would be: Neptune Diameter (ND = 50,000 km). Neptune Mass (NM = 1.0241 × 10^26 kg). Earth Diameter (ED = 12,756 km) Earth Mass (EA = 5.97 x 10^24 kg) Neptune's earth-gravity at the surface is: 11.15 m/s². Despite being 12 times more massive than earth, the gravity is less than double, because the diameter of Neptune is much larger, and gravity is proportional to the distance between masses squared. On your shell world, the shell mass (SM) would be: [(4/24)\* pi\* ND^3 - (4/24)\* pi\* (ND - 5km)^3]\* Density. SM = 1.96×10^10 m^3 \* Density. To have the same gravity as earth at the surface, your shell mass needs to be: F*R^2/G*m2 = m1, F = 9.8 N, m2 = 1 kg m1 = 9.177×10^25 kg. Therefore, the density of your shell building material must be: Density = SM/(1.96×10^10) = 4.67×10^15 kg/m^3. For reference, the density of steel is 7840 kg/m^3. The thicker the shell, the less dense your material would need to be, but the less shell-like it becomes. If you didn't care about the gravity on the surface and made your shell out of a steel-like material (in density), then your shell would only have a mass of SM = 1.96×10^10 m^3 \* 7840 kg/m^3 = 1.54×10^14, translating to a gravity of 1.6437214738×10^(−11) Newtons on the surface. This ISS is 450,000 kg. The ISS, at the surface, would experience only 0.0000074 (7.4*10^(-6)) Netwons of force. That's such a small force that essentially nothing would be able to orbit the shell world. On the upside, it would also be very easy to land and take off from the surface, and the structure itself wouldn't collapse from its own gravity well. Orbiting around the shell world isn't even needed because many spaceships ship could generate 7.4*10^(-6) newtons of thrust for years on end without expending more than a hundred kg of ion fuel. In conclusion, the shell either needs to be made of extremely dense material, or it shouldn't have a noticeable gravity on its surface, meaning nothing could orbit it. This shell would have no Roche limit, as it produces essentially no gravity itself. However, it would be very susceptible to other celestial bodies' forces. If any of my math is wrong, I apologize. Please let me know and I will do my best to correct it. ]
[Question] [ I have a character with 2 pairs of mechanical engined wings and I have been wondering if they’d even work or what would be the best type of wings for this character. They’re a military fighter, heavily armored. I was wondering what would be the best engine placement on their wings, as they need them to not be vulnerable to being destroyed in both aerial combat and ground combat. Their current wing design is as shown in the image below. [![enter image description here](https://i.stack.imgur.com/8Wuiy.jpg)](https://i.stack.imgur.com/8Wuiy.jpg) Their primary wings are roughly 24 feet long and 7 feet wide, secondaries are 15’5 feet long and 5 feet. The characters overall weight is unspecified as I’m not sure how much weight these wings could support, as they’re meant to be abnormally heavy as weight gives an overall combat advantage. Weight should be as high as the wings can support. Flight speed is not meant to be fast, just faster than 15 miles an hour. Their flight method is using the primaries for most maneuvers while the secondaries are for steering. Wings will flap in unison in flight. Engines will just for easiness sake use unlimited fuel. Primaries will need to be armored as they use the wings to both shield and attack in air and ground, secondaries don’t matter as much. TLDR: What engine placement would be best, would such wings be able to work and how much weight could they support? [Answer] A few changes. There is **no reason to have two overlapping wings**, they will just get in others way, a flight stroke needs a lot of space. So you would either get rid of one set of wings or make it so they do not overlap. the closest you could get would be two small control surfaces sticking out of the back. Nothing that flies has widely overlapping wings, there is just no benefit. Bat like flapping flying machine have been built just nothing on this scale. Mass wise you should be fine, the largest animal to ever fly weighed around 400lbs and had a 36ft wingspan. Bird wings are the LEAST efficient wing design, something like **bats wings will work better**. Worse bird wings need a lot more moving parts which will work against you with a mechanical system. Doubling or tripling the complexity of a mechanical system for no gain or worse is always a bad idea there is no way around that one. Flapping flight is a LOT quieter than any other system so that alone may be enough reason to use it militarily. But another benefit is it will be very maneuverable, a skilled pilot will be able to do things no rotorcraft can manage. Downside this needs about twice the area than a single person rotor wing craft would need. One side note, your human will need some kind of **lower body powered exoskeleton** both to keep their legs steady during flight and to bear the weight of the thing on the ground. This could help a lot with takeoff and landing as well. Provided your **motor/power source** is compact enough and the computer control system is good enough this should be possible. we have good enough computers and *maybe* good enough material science, but right now there is no power source or set of actuators that will fit the bill. So those will have to be science fiction. Your power system will be close to the center of mass, essentially where the bottom of a backpack would be on a human. But this thing **will never be heavily armored**, armor is heavy. It could be more heavily armored than a normal soldier but that's about it. You just don't have weight to spare. Up side a few bullet holes in the wings will not stop them from working. [Answer] Essentially you're going to need to build a robotic giant bird musculoskeletal system with extreme super-strength. Large servos or pneumatic muscles where the bird's chest would be will do most of the work, just as a bird's chest muscles do most of the work for the bird. Such a design would be hugely inefficient compared to something like a helicopter or quadrotor or even a jetpack for the role of small scale low speed flight. There's a reason all large birds are walkers, swimmers, or gliders, not flappers: the square-cube law ruining fun as usual. Strength scales with cross-sectional area, while weight scales with volume. If you scaled a humming bird up to the size of a man, it would drop like a rock. I would suggest making the wings run on magic (or Sufficiently Advanced Science) and of some mysterious origin. A bizarre old weapon from the lost armory of Atlantis *needs* no explanation (except for why it's being fielded in battle, not studied in a lab, but that's easy to get around - maybe there are hundreds of them and some got sold off, or the operator stole it from the lab, etc). A cutting edge military aircraft that's the least useful conceivable application of the technology required to build it, and is somehow also the only application of the advanced technology required to build it, *admits* no explanation. [Answer] **Propeller Cap** Marvel had the right idea with Captain Falcon. Put the engine (propeller) on the head. [![enter image description here](https://i.stack.imgur.com/4oh13.png)](https://i.stack.imgur.com/4oh13.png) *"Show me your moves!"* Head down and wings outstretched, you fly like a biplane. [![enter image description here](https://i.stack.imgur.com/ZVA9I.jpg)](https://i.stack.imgur.com/ZVA9I.jpg) *Pu-zoom!* Though I suggest you improve on Marvel's design by enlarging the propeller for extra *pu-zoom!*. See the mockup below. [![enter image description here](https://i.stack.imgur.com/lp8hV.png)](https://i.stack.imgur.com/lp8hV.png) Perfect. [Answer] For what you've described - you have two competing ideas: * Human powered Flight * Heavy Armour These are mutually exclusive. However, reading your question, a thought came to me - such a wingspan, supporting a typical Human would be more than enough to have a pretty good glide span - and you've already said there is an Engine of sorts. In order for the Human to have some degree of Body-Armor (I'll cover off the wings in a mo) - it would be entirely possible that the type of 'flight' such a character would use could be considered 'Rocket Assisted Gliding'. That is - the user would use a small but very powerful rocket motor to take off, with an almost ballistic trajectory, wings folded for maximum speed like a Peregrine falcon in a dive. Then after a period of time (10-20 seconds, however long to achieve a decent height) the Rocket cuts out and the wings extend and the protagonist glides (and doesn't flap) for a long distance. This solves 2 key problems: 1: There is now no longer a need to flap - so all that heavy exo-skeleton, powered actuator nonsense isn't needed and 2: We've seen how far someone in a Wing-suit can glide (3:1 - 3 metres forward for every metre dropped) - a larger wingspan means you could approach Glider-esque slopes of 30:1 or even as high as 60:1 A Modern glider is hitting 400-600 Kilos with an 18 Metre Wingspan - so let's say that we go for a total weight of 200 Kilos (wings, Armour, Aerodynamic cocoon), the Wings are semi-rigid and don't flap - we use a Rocket Motor to power the wearer up to about 3 Km/10,000 ft and they then glide to their next destination (assuming no thermals or other tricks to stay aloft) around 100 km away - I think you've got a reasonably believable setup. In terms of Armor for the wings (I said I would get to it) - No. And there's a reason 'no': An un-armored surface will result in most projectiles and attacks poking a nice, neat little hole in it. Adding anyform of armour will mean that a projectile will either arm itself (if it's an explosive charge) or it will spall/deform and cause *more* damage than if it was unarmored. You can see this in WW1 dogfighting where the canvas covering of an aircraft could have multiple holes in it but still be fine, in WW2 dogfighting where the survivor-bias study showed that damage to non-critical surfaces where the bullets/shrapnel punched clean through still allowed the Aircraft to get home - or even WW2 Naval engagements - I can't remember the ships, but I seem to recall a Destroyer took a large calibre shell (possible 8 inch?) through the funnel - and there's a picture of a clean hole eitherside as it zipped through causing minimal damage. [Answer] For a comparative feasibility study, the largest flying animals today are 30-40 pounds. The heaviest flying animals ever are varieties of pterosaur with weight estimates between 150-500 lbs. Obviously, these are extinct and nobody was around to make records, so we can only speculate about the biomechanics of these creatures based on their fossilized skeletons. It is unknown whether pterosaurs were capable of fast, dynamic flight, or whether their wings were used for slow, soaring flight, or perhaps they were only gliders or even could have been flightless. Different studies have come to different conclusions. The heaviest flying bird today, the Kori Bustard, clocks in at 30-50 pounds and is kind of a miniature ostrich. It spends most of its time on the ground, but can fly for short periods to escape predators. Other large birds do fly a lot, but are lighter, and they all tend towards "soaring" rather than "flapping." They don't spend all their time doing acrobatic maneuvers, and their flight is optimized to conserve energy while probably also taking advantage of thermals. In terms of translating this into a human system, the US military requires a 6 foot tall 17-27 year old to be at most 195 pounds. In terms of modern armor, the military uses a combined soft and hard armor system that weighs around 35 pounds, but this could be reduced ~15 pounds without the heavy plate inserts designed to defend against powerful armor-piercing bullets. This is 230 pounds with only the person and the armor, but does not include a weapon, the wing system, or any other supplies such as food, water, tools, etc. Again, using the military as a frame of reference, soldiers routinely carry 50-100 pounds of gear depending on situation, for a total weight of up to ~250-300 pounds, not including the wings. And remember, your human has to not just bear all of this weight on their own two legs (unless they have something helping them), they also need to be able to absorb the impact of dynamically landing with all that weight on them. Again using the military for comparison, the risk of serious injury for parachutists landing with combat loads may be as high as 5-10%. I would not worry about being overly technically correct here. Using the pterosaur model, the situation you describe is plausibly feasible, but subject to constraints. It's probably the case that slower, soaring flight is more feasible than dynamic, agile flight. Size is an issue- looking up *Quetzalcoatlus* and *Hatzegopteryx*, these are estimated to have 35-40 foot wingspans, weigh 400-550 pounds, and are essentially as large as a small plane. Leg bracing or some other method of absorbing the impact of repeated landings seems important. Armor and other gear is limited, and every ounce counts. ]
[Question] [ I'm designing a world where humans find it easier to travel using *arachnoskeletons*, exoskeletons that have 8 spider-like legs. I thought that these legs would be the most effective for traversing hilly, rocky or rough terrain. So, I have a planet (call it Earth II) which has that terrain. It's prime traversing material for my arachnoskeletons. Would there be any specific planetary conditions that would explain why Earth II is so rough? I had a few ideas: * The planet is very rocky, and constant storms cause these rocks to bunch up and form rough terrain * Extreme amounts of rain in the planet's formative years eroded the surface, giving it a hilly topology * Inspired by the Grand Canyon: The planet was initially covered in water which lead to extreme erosion of the underlying rock. Much of the water evaporated, leading to rocky irregular terrain Other explanations would be appreciated. [Answer] One big problem is that humans have a tendency to make roads. An advanced civilization can just build lots of roads and repair them when they break. You need to make it too expensive to build roads. # The answer is mushrooms There are massive underground mushrooms which like popping up everywhere. They can grow very quickly and rip through all but very heavily reinforced locations. They tend to have sharp bits in them so they rip up any wheels pretty quickly. There's lots of these growths everywhere, so any road or smooth terrain that you make is quickly erased. The native species has proven extremely resistant to any sort of fungicide, and so for the foreseeable future wheels are not a useful tool to get around. Spider leg exoskeletons are. [Answer] **Wet Limestone and Big Moon.** The surface of the planet is made of soft rock like Limestone and Sandstone. This is easy to erode and form riverbeds and canyons and glacial valleys. The planet is plagued by constant storms that moves the water around to erode the soft stone. There is also a (**Edit:** Several) large moons with unpredictable orbits and strong tides that pulls the sitting water from one side of the planet to the other, drying up the existing rivers, and creating new ones. This leads to many dry riverbeds and canyons. The same moon pulls hard matter around the planet on geological timescales. This creates new mountains which leads to new rivers and eventually new dry canyons. [Answer] Geologically active environments tends to be rough. Areas like plains are very old and worn flat from erosion. > > Inspired by the Grand Canyon: The planet was initially covered in water which lead to extreme erosion of the underlying rock. Much of the water evaporated, leading to rocky irregular terrain > > > As far as I know, canyons of this sort tend to exist within flat areas, not hilly or mountainous ones because both the canyon and the surrounding area needed to experience much erosion so the surrounding area is likely to be flatter. That means that reasoning probably works against you, not for you: > > Extreme amounts of rain in the planet's formative years eroded the surface, giving it a hilly topology > > > Unless your intention is that mountains risen from tectonic activity have been worn down by rain to produce hills, then rain does not produce hills. [Answer] You can have ## supervolcanos which send out lots of ashes and magma flow in alterations which caves into crazy mountains throughout all the planet. A lot of lava and ground shaking, weird freaky magma hotspots that cause near-supervolcanos to occur everywhere, where the ground is heaved up by a mile and then erodes, faster than it takes for the water to carve out planes and flatlands. You can have an atmosphere which causes salty rain and dust in the clouds that add to the mountains just as fast as eroding them. The geology of the rock and the size of the tectonic plates dictates the amount of mountains. it's like apure geology question. Find images for ["amazing geology rugged"](https://www.google.com/search?q=amazing%20geology%20rugged&sxsrf=ALiCzsZb5xcKzvziFMszFE2CEHTpuXYD-g:1667128748269&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiw99bG6of7AhWD8LsIHeRQBZ0Q_AUoAXoECAMQAw&biw=1138&bih=517&dpr=2.25) it will give you a lot of ideas for the book. You will find lots of images and you can search descriptions of how the rocks work which is important for writing a book where rocks are questioned. [Answer] you have three easy options 1. Just use an earth analog, without roads legs usually work better than wheels. 2. Use a planet with more active plate tectonics, that will keep the terrain active and thus rough. no matter what you still have a lot of flat ground, you can't make a planet with water completely rough. 3. No grasses, nothing like grass has evolved on the planet so even open plains tend to be covered in too big to drive over plants. you can also combine this with 2 as well. [Answer] **Aa.** [![aa lava](https://i.stack.imgur.com/yv7gl.png)](https://i.stack.imgur.com/yv7gl.png) <https://www.nps.gov/npgallery/GetAsset/333d2dda-7931-487a-8ab6-1dadea1310bc/proxy/hires>? <https://volcanoes.usgs.gov/vsc/glossary/aa.html> > > ‘A‘ā (pronounced "ah-ah") is a Hawaiian term for lava flows that have > a rough rubbly surface composed of broken lava blocks called clinkers. > The incredibly spiny surface of a solidified ‘A‘ā flow makes walking > very difficult and slow. The clinkery surface actually covers a > massive dense core, which is the most active part of the flow. As > pasty lava in the core travels downslope, the clinkers are carried > along at the surface. > > > Your planet has frequent lava flows. Sharp fields of Aa chunks characterize most places. It is very easy to get wounded by these chunks, even with strong boots. The other problem is that you might be walking over a place that is thin. Strong boots are also unhelpful if you break through into molten lava. Spreading your weight out over 8 points makes it less likely that you will fall through. Also if one of your spider legs does go through and get lavafied you carry spares. [Answer] Actions that make a planet more lumpy: * tectonics * volcanism * meteorites * extreme tides that distort the core Actions that make a planet less lumpy: * erosion and deposition by water & wind; * animal activity (burrowing, over grazing) * technological developments Developments that can thwart lumpiness: * horticulture * canals * roads * railways * tunnels * mining * hydrological engineering (dams, either to keep water in or to keep water out or both) effectively using the forces of rivers to create flat land * mechanised landscaping (particularly in urban areas) My gut feeling is that on anything resembling earth, humanity will be able to operate wheeled vehicles within localised areas from fairly soon after arrival, and will eventually flatten the planet. In the meantime if you want to go long distances, flying or boating would likely be easier than spidering. To have a protracted period without feasible long distance travel the planet would have to be fairly arid with little to no surface liquid (to avoid both erosion and travel by boat), but with sufficient water to sustain humans. Conclusion: it's an ice world, relying on orbital mirrors to melt localised areas to habitability. Travel between habitable zones would be like cross-country in Antarctica, only with more volcanoes and meteorites. [Answer] **High winds and sand** --- Some ideas and problems I see with them: * Erosion based: They tend to flatten * Volcanic: You have bigger issues than rocks if you have enough volcanic activity everywhere to spew that much out * Orbital effects: Irregular orbits or orbits with very large objects will either be unstable over long periods (i.e. you loose your moon) or break up the moon until you have a ring * Biological: I really like the idea of fauna (mushrooms or thorns or whatever) to mess with wheels. But I think it's a hard sell that they damage steel. * Low gravity: Lower gravity would reduce erosion and make things lumpier in general (think Mars). With lower gravity legs make more sense, because then you can jump across things which I think is neat. But unless your atmosphere is too thin to breathe, flying is just way easier --- But a very turbulent atmosphere with a lot of dust & debris is a problem for anything that flies (especially when you introduce sand into jet turbines) and roads because: * Roads get buried quickly by sand. Wheels not so good in soft sand. Even tracks struggle in dry soft sand, because as we all know, sand is "coarse and rough and irritating — and it gets everywhere." * If it's always dusty, then you can't really drive very fast in any case, so the penalty of legs vs wheels is reduced * 8 legs with blunt ends distribute your load nicely, and are tolerant to hidden rocks under the sand [Answer] **Wombats** [![wombat burrow](https://i.stack.imgur.com/UHiYl.png)](https://i.stack.imgur.com/UHiYl.png) <https://www.researchgate.net/figure/Wombat-warren-with-deeply-excavated-burrows-that-have-partly-collapsed-The-warren-is_fig2_222637353> Your planet has creatures that dig burrows. These burrows then collapse. There are several types of these creatures, from prairie dog size to wombat / aardvark size to much larger creatures like [bulettes](https://diterlizzi.com/essay/owlbears-rust-monsters-and-bulettes-oh-my/). The result of all of their activity: the ground is extremely irregular with holes, collapsed tunnels, and more solid looking places on the verge of collapse. The spidersuits can get a person past the smaller types of collapses. Large but shallow burrows might be detected by a sensor scanning the ground ahead - falling into one of these would mean a fall of some meters and that is if the burrow is perpendicular to the surface. If the burrow is inhabited the fall might be just the start of your troubles. [![bulette](https://i.stack.imgur.com/mt5dUm.png)](https://i.stack.imgur.com/mt5dUm.png) ]
[Question] [ I have a speculative evolution project regarding giraffes. For those unfamiliar, giraffes are ruminants and rumination is not viable for carnivory according to every site I have wandered upon in my research. Ignoring any of the other issues of giraffes evolving to become carnivorous, my question here is how rumination could be adapted to a carnivorous diet. There are no animals in our world that are ruminating carnivores and from my research, it simply isn't necessary. To me, it seems like there would be a firm pressure to remain an herbivore rather than make the leap to carnivory. Now for some small but important details. The only animals besides giraffes in this project are paper wasps, the particular species of which prefers nectar and would be unlikely to decide it is a good idea to predate giraffes. The ecosystem is a series of islands, so contact with meat would be frequent through dead giraffes. I would like any answers to apply to scavengers and active hunters, if there are any differences between the two. And finally, while some handwavium is allowed as I do not need the exact chemical composition of their stomach acid, I want to be able to stick as close to realism as I can. So, **would rumination disable the path of carnivory in evolution?** [Answer] **They might not need to evolve.** Many real-world ruminants are actually *opportunistic carnivores*, even if we call them herbivores. This means that they are able to eat meat and will do so of their own accord (i.e. they're not starving), but usually they can't or don't for whatever reason. For example, cows will occasionally eat small animals such as mice, chicks, or even chickens. They will scavenge from carrion when the opportunity presents itself, and cows in particular also eat their own placental afterbirth. Biologists debate why this occurs. Some think that this signals a nutrition defect, like lack of protein or calcium in diet, and the animal is attempting to secure diverse nutrients. Others think that the ruminant is simply trying to be a generalist, so they take the food when it's easy and ignore it otherwise. Despite some claims to the contrary- cows are capable of digesting meat. The last of their four stomachs, the abomasum, is similar in function to traditional omnivores or carnivores- it secretes hydrochloric acid like our own and is perfectly capable of breaking down meat protein. However, some other chambers of the cow's stomach are not good at handling meat and they can develop health problems or die if they eat too much meat. **You might have it backwards.** Interestingly, in cows there is evidence to suggest that the abomasum is evolutionarily the oldest stomach of the four. This could mean that the cow was originally a carnivore or an omnivore that evolved into a herbivore, rather than the other way around. This makes a lot of sense if you think about it- the four-chamber stomach is a highly specialized organ designed to get the most out of plant matter. Each chamber optimizes one or more different functions- moving food between different chambers, fermentation, microbe growth, water absorption, enzyme application, acid breakdown, and others. However, only the fourth stomach closest to an omnivore stomach, the abomasum, can function independently. Thus, an animal with a traditional omnivore stomach could evolve specialized organs for dealing with commonly available food, but an animal with only a fermentation stomach might not even be biologically workable. So- maybe there were other animals in your history's past that were hunted to extinction and the giraffes had to make do with the remaining plants. Or maybe they are opportunistic cannibals that will sometimes kill and eat other giraffes. Or maybe they eat giraffe carrion when they find it. [Answer] You might begin with the evolution of a plant with more protein that attracts protein-rich insects; and the giraffe preferentially eats this plant as well. Along with the insects, which are even more protein-rich than the plant. The insects *could* be your paper wasps, maybe they build their nests in the plants, and the giraffe eats them wholesale, crunching down whole nests at a time. Like other animals, it can evolve an immunity to their sting, so it is a minor irritation at best. All animals, even crickets, are protein-seekers, proteins are necessary for life biochemistry. (It is why even grazers have meaty bodies). Then the giraffe's digestive system evolves to lean toward richer protein digestion, and then to almost exclusively seeking the nests of the wasps. But they are still giraffes, the long neck lets them eat from the ground or the trees or anywhere the wasps may hide. [Answer] ## No it does not preclude evolving into a carnivore. **If its literally the only large animal it is going to diversify into a whole load of niches**, carnivory will be one of them, it will take a long time and radically change the animals anatomy, but it *will* happen eventually unless all megafauna go extinct. Will it still be a ruminant by then, unlikely, digesting meat is far *far* easier than cellulose, a ruminant gut offers no benefit to carnivore, and it is using a lot of resources that could be spend making it a better carnivore or just making it better at getting a mate. What type of predator will split off from it is impossible to guess, there has never been a vertebrate extinction that eliminated all vertebrate predators and I can't imagine a worse starting anatomy for a predator than a giraffe so the path is pure speculation. [Answer] It would make sense for a ruminant to transition to becoming an omnivore first before it becomes a carnivore. Maybe a fast ruminant like gazelles can hunt small animals. Overall though, it would be unlikely to occur since ruminant lifestyle is about going for food sources that are easy to access (grass) but hard to digest. Meat on the other hand is hard to access (prey runs away) but easy to digest. A ruminant carnivore would have to eat small animals that cannot really run away but are hard to digest for some reason. Maybe something like poison dart frogs. [Answer] The trouble with a giraffe as a carnivore is not its digestive system, but the fact it is enormous, really tall and very specialised at feeding on high tree branches. Think about how awkward it is for a giraffe to get a drink of water: it has to splay its front legs wide apart, or sort of crouch, to get its mouth low enough to touch the water surface. Being a giraffe is all about getting your food from right up in the tree tops. So the question you need to ask yourself is this: **do you want your giraffe-carnivores to remain giraffe-shaped?** If you don't mind them drastically altering their body shape, then you can invent a scenario where some sort of environmental change favoured low scrub over tall trees and the giraffes' long legs and long necks gradually reduced in size through natural selection. A smaller, more 'camel-like' or deer-like' body shape is a better bet for ending up as the sort of carnivore that chases zebras or rabbits. Have a look at [Andrewsarchus](https://en.wikipedia.org/wiki/Andrewsarchus) or the [Entelodonts](https://en.wikipedia.org/wiki/Entelodont) to inspire you with ideas of omnivorous/scavenging creatures which are related to ruminants. If you want your giraffes to stay recognisably 'giraffe-shaped', you need to think of ways the giraffe can catch and eat animals in the tree tops. Some things are relatively easy. If it is eating mouthfuls of leaves, it probably accidentally eats caterpillars, aphids, scale bugs and other insects. So invent a seasonal glut of one or more of these creatures, and have your giraffes switch to eating them at that time of year. For instance they could eat gregarious caterpillars, such as [Mopane worms](https://en.wikipedia.org/wiki/Gonimbrasia_belina) in summer. Or perhaps there is plague of locusts every autumn. The giraffe's mobile lips and dextrous tongue could be good for picking eggs or chicks out of the birds' nests it can reach. Perhaps it could grab the occasional angry parent bird trying to defend its nest. So spring/wet season could be a feast of eggs and birds. If there is enough slow and nutritious animal food in the tree tops all year round, the giraffe gradually adapts its digestion and dentition to a more carnivore pattern. If you want the giraffes eating more nimble tree-dwelling animals, such as monkeys or squirrels or fruit bats, you might have to invoke pack tactics. One giraffe batters at branches with its thick, strong neck. Other giraffes wait to grab monkeys fleeing to the other side of the tree, squirrels trying to leap to the next tree, or fruit bats launching themselves into the air. There will, of course, be a portion of the tree that the giraffes can't reach: in the middle and top of the canopy. ]
[Question] [ The ancient deity known as Shiva exists on the astral plane and intends to cross over into the mortal world to subjugated it to its rule. However, gods are far too powerful to exist on the mortal plane, as their power would disrupt this aspect of reality and ultimately destroy it. As such, gods need to limit their power by taking a human form through a process known as reincarnation. Through this process, a god is born on the mortal plane as a human, but contains the soul and abilities of the deity. The human form is used as a vessel, which is built specifically to hold a god's spirit in order to keep it contained. These vessels are called avatars, and allow the deity to traverse the mortal world without risking its destruction. No single avatar is able to possess the entirety of Shiva's soul, as the deity is too vast and powerful to be contained in one shell. Therefore, Shiva must reincarnate pieces of itself through several forms, ending with a total of seven. Once all avatars enter the mortal plane, Shiva's soul can be said to have completely crossed over. At a designated time, these seven will combine and reconstruct Shiva's soul, allowing it to take its true form in reality. This being would be known as the super-messiah, the full manifestation of a god made flesh. With the deity at full strength, it can now rule the plane and exert its true power. However, instead of being reincarnated all at once in one specific location, these avatars have been born millennia apart, with many generations passing between them and at various places. This has greatly complicated Shiva's plan, as it has forced the current avatars to wait for their counterparts to arrive, dragging out shiva's goals over thousands of years. What would prevent a deity from reincarnating itself all at once? [Answer] **The forces are too strong** The reason to not immediately reincarnate in seven bodies is that the power would prove too much. It is difficult enough to get part of a gods power into reality, taking the form of an avatar. Failure means the god is pushed out of reality again. Especially at the start it's unstable. If this happens, the god is back to square one for reincarnation. If multiple reincarnations are attempted at once, the chances for failure skyrocket. It is safer and more easy to reincarnate over a long time. Each time making sure the last avatar is stable before attempting the next reincarnation. [Answer] # Once in a blue moon: Mortals who are capable of hosting god-like power are a rare breed. In fact, they may actually BE a breed apart. The first incarnation has to happen by sheer chance - the perfect combination of genes has to come up, like rolling a thousand sixes in a row playing dice. But once the perfect combination occurs once, the god inserts a presence into the world and can begin to influence fate. The descendants of the god's mortal body (or the relatives of the god's mortal body, if the god does not themselves have offspring). are guided to eventually recapitulate the combination of genes to make a new body for the god to reincarnate in. While incest might accelerate this process (as the Egyptian pharaohs did) it's a little too creepy for your god, who allows for a more organic process. As the prevalence of the "god genes" expands in the population, the likelihood of the perfect combination coming up expands. It's likely the last couple incarnations will come closer together for this very reason. There's also the possibility of competition getting in the way of the process. If the god has rivals, they manipulate their followers to kill everyone related to the previous avatar, reducing the chances of the god reincarnating in a new body. Or perhaps the perfect bodies are a commodity, and rival gods are trying by any means necessary to reincarnate in those bodies themselves. After all, for every [Kalki](https://en.wikipedia.org/wiki/Kalki#:%7E:text=Kalki%2C%20also%20called%20Kalkin%20%2Cis,the%20endless%20cycle%20of%20existence.) (yes, I know that's Vishnu), there's a demon Kali trying to start the new [Kali Yuga](https://en.wikipedia.org/wiki/Kali_Yuga) age of suffering and evil. Besides, to gods, ages are meaningless. What does it matter if a thousand or million years pass before the inevitable victory of Shiva in the universe? Sure, others may have their moments, but nothing can stop Shiva from inevitable triumph. Time exists outside the regard of such beings. So let all other things happen in the universe first, and then there will be only Shiva's endless influence. [Answer] **To conceal what he is doing** To be a seventh of his full power is dangerous. Foes can take advantage of it, that's why he needs to merge in the end. But for all seven to appear at the same time is to announce what he is doing to many foes. [Answer] **Reincarnation takes thousands of years of preparation.** From a mortal point of view, avatars seem to appear overnight. In reality they take thousands of years to create and only "awaken" overnight. The cycle of birth and reincarnation of mortal souls is in equilibrium. Births balance almost exactly with deaths. That means the god can only transfer a few drops of their power into the mortal realm with each reincarnation, without blocking other mortal souls from reincarnating. To create an avatar the god follows the cycle of death and reincarnation of a single mortal soul. Each time the soul passes into the spirit world, the god transfers a miniscule portion of its power to the soul, which is then transferred to the mortal world when the soul reincarnates. After thousands of years the mortal "awakens" as a new avatar. At this point Shiva immediately starts constructing a new avatar. It just takes thousands of years for mortals to notice. [Answer] **Mortal lifetimes vs immortal lifetimes and points of reference** I'm going to guess and say that the gods of your story don't die of old age. Living forever will stretch your perceptions of time and make it hard to distinguish the passage of time without a point of reference. If they're not even on the same plane as the mortals I'm going to doubt they are aware of the passing of the days on the mortal plane, and I doubt the length of days is the same on the plane of gods as on the mortal plane. What feels like a day for a god might be as long as a thousand years for mortals, for example, and even if it doesn't feel like the time difference between reincarnations is that long for the god the passage of time between each reincarnation for mortals could very well lead to reincarnations happening centuries apart, which is suffice to say longer than most mortals are expected to live. Lacking a point of reference in the mortal plane can also explain why the reincarnations are happening in different locations, because they are essentially blind when it comes to time and space/location of another plane. You could write it in such a way that the reincarnations are happening with greater and greater frequency, and closer and closer to each other as well as the years go by, because the god is using each reincarnation to learn about the mortal plane and with the death of each avatar allowing them to put that part of their soul that has come back into another mortal they're more and more prepared to have all of the reincarnations happen within a hundred years. [Answer] **His technicians partly mixed up time and space.** Time is very different on the astral plane\*. It exists, sort of, but more of a vague impatience than the wheel in the sky that governs us. Place is a little more definite but also much more concrete and inflexible in the mortal plane. Shiva's technical staff are like Shiva all astral natives. They have book learning about time and the mortal plane but no first hand experience. The cues that they used to determine the when misled them and instead of all avatars in specified places and the same time, they mixed up the time and place variables, so time was staggered with part of the pattern intended to be for place. Beyond a vague impatience, the technicians (and Shiva) might not be aware that they screwed up. /\* *"Dormammu! I've come to bargain."* ]
[Question] [ In my book series, there is a group of people on the Planet Awal called the Tifinagh that are the source of quite a bit of tension between the Haxamanians (the dominant empire on Awal) and the Aureans (a nearby planet-empire less than a parsec away). Over the course of millennia of on-and-off wars between Aurea and the Haxamanian Empire, the Aureans' longest-lasting possession on the planet was Tifinaghia (home of the Tifinagh people), a region of pleasant coasts and islands, a mid-sized mountain range, and the northern fringes of the Great Awalian Desert. As a result of centuries of Aurean rule, the Tifinagh are a sort of fusion of Aureans and the Inumideni (a Haxamanian subject people bordering the Tifinagh lands). Genetically and in most of their worldview and material culture, they are nearly identical to the Inumideni, but the Tifinagh speak an Aurean-based language completely unintelligble from the Inumnideni or Haxamanian tongues and follow the domiant Aurean religion (the Cult of Sahul Invictus), while the Inumideni and most other Awalians are staunch Anandists (A religion I made up mostly inspired by Buddhism and Islam). In the time period my book series is set, tensions between the Haxamanian and Aurean Empires need to be relaxed, so the question of who should govern Tifinaghia needs to be solved. Since both sides claim the territory and the Aureans are unwilling to give the region independence out of fear that the Haxamanians will simply annex it or turn it into a tributary state later on anyway, and splitting the territory won't work with my worldbuilding for other reasons, is it possible for both the Haxamanian and Aurean Empires to rule Tifinaghia together, jointly administering the region despite having radically different governments? Note: the Aurean Government is pretty much a federated version of the Roman Republic, while the Haxamanian Government is an absolute monarchy with Satrapies in charge of local affairs. [Answer] There is an example from modern history. The British and French Governments for instance established a **ConDominium** in the early twentieth century to administer islands of the New Hebrides Group in the South pacific. It was created by treaty as a means of resolving territorial disputes resulting from the fact that different islands in the chain had been colonized or claimed by one side or the other. Apart from a joint court system I believe every other arm of government was doubled. i.e. 2 school systems 2 health systems ect etc. So it was well, 'messy' is, I guess probably the best word to describe it. European locals often referred to it as the Pandemonium. To the extent it worked it did so because; 1. Britain and France hadn't fought a war against one another in almost a century and had developed long term economic, diplomatic and social ties and of course both had far bigger diplomatic and political issues to deal with. 2. The territories concerned were distant from both capitals and of little economic or strategic value. So neither side really saw anything to be gained from arguing about it for too long or otherwise damaging their relationship. (They'd just signed a series of important treaties called the Entente Cordial.) So to the extent such an idea would work in your setting it comes down to how important economically and politically 'Tifinaghia' is in the grand scheme of things as a % of both Empires economies and populations. If both your Empires occupy hundreds of worlds quibbling over one in particular (no matter how nice the climate) probably isn't worth the effort. If it is of major importance then? Best suggestion: Some sort of joint guardianship. Give the planet a local government which is independent in terms of domestic affairs but reliant on both sides for defense and foreign affairs policy. The local government in turn reports to a Governor General or some such, his deputy and administration on an agreed set of key issues. Then you rotate whose in what position every 4 or 5 years. Both sides maintain consular offices and provide an agreed (small) number of ships for system defense and split any tax surplus 50/50. [Answer] * Keep in mind that the Roman republicanism was for Romans. They were happy to send proconsuls to the provinces to govern them in the name of Rome. How does that differ from a satrapy? * They both agree on a relatively weak, third party to rule the area. Think of the history of [Andorra](https://en.wikipedia.org/wiki/Andorra). * The province is garrisoned by forces which are limited by treaty. A treaty with interesting possibilities and loopholes. "One combat division each, without *technobabble* weapons, and as many police as necessary." [Answer] There is at least an example on Earth: the [Pheasant island](https://en.wikipedia.org/wiki/Pheasant_Island) > > Pheasant Island (French: Île des Faisans/Île de la Conférence, Spanish: Isla de los Faisanes, Basque: Konpantzia) is an uninhabited river island in the Bidasoa river, located between France and Spain, whose administration alternates between both nations. > > > The island is a condominium established by the Treaty of the Pyrenees in 1659, under joint sovereignty of Spain and France, and for alternating periods of six months is officially under the governance of the naval commanders of San Sebastián, Spain (1 February – 31 July) and of Bayonne, France (1 August – 31 January); in effect it is administered respectively by Irun (in Gipuzkoa, Spain) and Hendaye (in the Pyrénées-Atlantiques, France). > > > Maybe the differences between the French kingdom and the Spanish Empire are not as extreme as you have in your story, and the fact that the island is not occupied by settlements makes it surely easier to administer it, nevertheless it's possible for two powers to reach an agreement for a joint sovereignty. [Answer] There is also the condominium of the island of Cyprus. Cyprus was part of the Roman Empire for centuries and in the year 600 belonged to the eastern section of the Roman Empire, the so-called "Byzantine" Empire. > > In 649 AD the Arabs made the first attack on the island under the leadership of Muawiyah I. They conquered the capital Salamis - Constantia after a brief siege, but drafted a treaty with the local rulers. In the course of this expedition a relative of Muhammad, Umm-Haram, fell from her mule near the Salt Lake at Larnaca and was killed. She was buried at that spot and the Hala Sultan Tekke was built there in Ottoman times.[1](https://en.wikipedia.org/wiki/Cyprus_in_the_Middle_Ages#Arab_conquest_and_Arab%E2%80%93Byzantine_condominium) Under Abu'l-Awar, the Arabs returned in 650 and installed a garrison of 12,000 on part of the island, where they remained until 680. > > > In 688, the emperor Justinian II and the caliph Abd al-Malik reached an unprecedented agreement. The Arabs evacuated the island, and for the next 300 years, Cyprus was ruled jointly by both the Caliphate and the Byzantines as a condominium, despite the nearly constant warfare between the two parties on the mainland. The collected taxes were divided among the Arabs and the emperor.[2](https://en.wikipedia.org/wiki/Cyprus_in_the_Middle_Ages#Byzantine_reconquest) > > > Under Basil I the Macedonian (r. 867–886) Byzantine troops recaptured Cyprus, which was established as a theme, but after seven years the island reverted to the previous status quo. Once again, in 911, the Cypriots helped a Byzantine fleet under admiral Himerios, and in retaliation the Arabs under Damian of Tarsus ravaged the island for four months and carried off many captives. The isolation of Cyprus from the rest of the Greek-speaking world assisted the formation of a separate Cypriot dialect. This period of Arab influence lasted until the 10th century. > > > [https://en.wikipedia.org/wiki/Cyprus\_in\_the\_Middle\_Ages#Arab\_conquest\_and\_Arab%E2%80%93Byzantine\_condominium[1]](https://en.wikipedia.org/wiki/Cyprus_in_the_Middle_Ages#Arab_conquest_and_Arab%E2%80%93Byzantine_condominium%5B1%5D) > > In the year 965 or slightly earlier, the Byzantines reconquered the island and installed theme. The general Niketas Chalkoutzes led the reconquest, of which no details are known, and was probably the first governor of Cyprus after that.[3](http://Andorra%20was%20briefly%20annexed%20to%20the%20Crown%20of%20Aragon%20twice,%20in%201396%20and%201512.%5Bcitation%20needed%5D) > > > [https://en.wikipedia.org/wiki/Cyprus\_in\_the\_Middle\_Ages#Byzantine\_reconquest[2]](https://en.wikipedia.org/wiki/Cyprus_in_the_Middle_Ages#Byzantine_reconquest%5B2%5D) So the condominium of Cyprus lasted, with some interruptions, for about 277 years, which is quite impressive. IN the 13th century the Count of Foix and the Bishop of Urgel quarrelled over the lands that later became Andorra. > > In 1278, the conflict was resolved by the signing of a pareage (pariatges), which provided that Andorra's sovereignty be shared between the Count of Foix and the Bishop of La Seu d'Urgell (Catalonia). The pareage, a feudal institution recognizing the principle of equality of rights shared by two rulers, gave the small state its territory and political form.[2](https://en.wikipedia.org/wiki/Cyprus_in_the_Middle_Ages#Byzantine_reconquest) In return, Andorra pays an annual tribute or questia to the co-rulers consisting of four hams, forty loaves of bread, and some wine. Andorra's borders have remained unchanged since 1278.[4](https://en.wikipedia.org/wiki/History_of_Andorra#9th_to_19th_centuries) > > > Andorra was briefly annexed to the Crown of Aragon twice, in 1396 and 1512.[citation needed](http://Andorra%20was%20briefly%20annexed%20to%20the%20Crown%20of%20Aragon%20twice,%20in%201396%20and%201512.%5Bcitation%20needed%5D) > > In 1505, Germaine of Foix married Ferdinand V of Castile, thereby bringing the lordship of Andorra under Spanish rule. On taking over the kingdom in 1519, Emperor Charles V granted the lordship of Les Valls, as it was then known, to Germaine of Foix's line in perpetuity. Calvinist king Henry III of Navarre, who was also count of Foix, in 1589 ascended the French throne as Henry IV, and by an edict of 1607 transferred his role as co-prince of Andorra to the head of the French state. > > > In 1793, the French revolutionary government refused the traditional Andorran tribute as smacking of feudalism and renounced its suzerainty, despite the wish of the Andorrans to enjoy French protection and avoid being under exclusively Spanish influence. > > > [https://en.wikipedia.org/wiki/History\_of\_Andorra#9th\_to\_19th\_centuries[4]](https://en.wikipedia.org/wiki/History_of_Andorra#9th_to_19th_centuries%5B4%5D) At the present time the Bishop of Urgell and the President of France are co princes of Andorra. Thus one could say that Andorra is a condominium of the Bishopric of Urgell and France. But the co princes have little to no power in Andorra which is mostly self governing. Several other condominiums are mentioned in this article: [https://en.wikipedia.org/wiki/Condominium\_(international\_law)[5]](https://en.wikipedia.org/wiki/Condominium_(international_law)%5B5%5D) [Answer] There are examples of multi-power joint rule in the aftermath of WWII. Before Austrian independence and the creation of East and West Germany, the four-power joint commissions acted as legislature and senior executive, and the control commission retained (and exercised) powers over both parts of Berlin throughout the Cold War. [Answer] Mon has already mentioned the New Hebrides (now independent as Vanuatu), but there is one extra tidbit of information. British and French subjects were, of course, subject to the British or French authorities, respectively, while vising the New Hebrides. Everyone else had a choice on arrival, to enter the Condominium via British or French Immigration, and this choice determined the code of laws that they were subject to during their stay. I was informed by someone who should have known, that conditions in the British jail were better (overall), except for the food where the French (naturally) had the edge. Sorry, no references, but I used to live in the neighboring Solomon Islands, and sometimes visited Vanuatu. [Answer] Opening: *"In the time period my book series is set, tensions between the Haxamanian and Aurean Empires need to be relaxed (..) is it possible for both the Haxamanian and Aurean Empires to rule Tifinaghia together, jointly administering the region despite having radically different governments?"* **My scenario before the joint rule** I haven't read your part 1, so I'll need to reconstruct a version.. Haxamanians and Aureans are both humans. They shared the planet. Aureans are the descendants of an earlier civilization elite, that colonized several near planets. They left Awal, because it was going to be hit by in a meteor storm that would last for centuries. The Haxamanians stayed, they survived and developed a technology level similar to ours. When the meteor storms eventually set, after some 1200 years, the Aureans returned. At first, their technology was superiour, many Haxamanians died. However, during the storms, Haxamanians had developed very good shielding. The Aurean attempted to recolonize the planet, but they failed. In the long time the war lasted, Haxamanians developed sufficient technology to prevent the Aureans from conquering their planet. After a 120 year fight, the parties decided to start negotiations. A flood that hit Tifinaghia and the subsequent help that came from the (Haxamanian) Inumideni neigbours was the primary incentive to end the war. **How joint rule ideals landed in federalism** Many Aurean civilians realized they longed to return back home to Awal. There were Aurean colonizers and other civilians who bought land. They built factories, resorts.. and economic activity rose, with Tifinaghia remaining the Aurean center of activity. At first, it was a military base, now there is peace and Tifinaghia has become a tourist attraction: the beaches, the famous star ship museum, and its *good wine*, of course. After war and negotiations, modern diplomacy and politics kicked in, and despite the fact Tifinaghia is a colony, the parties don't agree on giving it independence, and instead attempt a joint rule. It worked at first, Haxamanians do not have an authoritarian rule. There are Aureans in parliament, who defend the Aurean interest. In daily practice, the arrangement resulted in a weak federal rule, and a strong local rule, like American states e.g. Alaska have. The Tifinaghians would mind their own business, speak their own language, but with a strong trade union and open borders. Also, there are Haxamanian courts located in Tifinaghia, that maintain Haxamanian federal law. These courts are mainly symbolizing the peace: it turns out to be very difficult to bridge the language barrier in law and governing. The Tifinaghia flag has joint Haxamanian/Aurean colors, but Tifinaghians generally don't leave their region and most Haxamanians still regard Tifinaghia as "abroad" or "actually ours". **Comparison case on Earth: Hong Kong** I think reaching a lasting peace over Tifinaghia would be complicated, because of the past war and the cultural and language differences. To maintain piece, I *divide* power, I don't actually *share* or *alternate* power. Compare the situation in Puerto Rico, or Alaska. So my pessimism about joint rule results from Earthly perspective.. is there e.g. a racist bias, that may further complicate affairs.. I did not read your book (yet) As for "empires": the most obvious historic analogy to the Awal joint Imperial rule attempt was not mentioned yet: imho that analogy is the status of the city of Hong Kong, as recently negotiated between the Chinese and British empire. At first being a British colony, Hong Kong was imposed British language and British rule. A century later, Hong Kong has had a 25 year transition going toward Chinese rule. During this transition, at least in the first 10 years of it, Brits and Chinese agreed to have a joint rule arrangement. Now, Hong Kong has become Chinese, primarily. On the long term, there could be little difference between the Chinese and Haxamanian position. Eventually, the surrounding "main land Haxamania" will attempt to integrate the region again. Like the Chinese, Haxamanians regard Tifinaghia as part of Haxamania. Portuguese Macao in South China also became Chinese again.. Joint rule is a great ideal, but it requires overseeable cultural differences. Like Hong Kong, the region of Tifinaghia is very rich, but the difference is: Tifinaghia has a very strong cultural identity. Eventually, it will seek to gain independence, and a new war could arise. [Answer] A compendium between France and Britain as established in the administration of the former [New Hebrides](https://en.wikipedia.org/wiki/New_Hebrides) between 1906 and 1980, now independent and known was [Vanuatu](https://en.wikipedia.org/wiki/Vanuatu). ]
[Question] [ Situation: A very large reservoir of water exists raised up above a large expanse of almost flat land. From the bottom of the reservoir the land falls away at a very gentle gradient of ~1 in 10,000. The output of the water in the high reservoir can be controlled via a series of sluice gates to deliver anywhere between 0 and 1000 cubic meters water flow per second down onto the flat land below. The people want to build a canal across the flat land to deliver water from the bottom of the reservoir into a river 400km away. Which of the flowing would be the easiest way to do this and what are the likely difficulties? 1. They must dig the whole 400km out before letting the water in. 2. They can just let the water out and it will find its own way to the river and dig its own channel 3. They will need to dig a wide shallow guide channel and then let the flowing water expand that 4. They will need to dig a narrow deep guide channel and then let the flow erode the sides Would it be better to use a steady or pulsed flow rate?# **edit for clarity** The ground is generally loose material such as sand, loam or clay and is mostly homogeneous. The surface is dry but becomes increasingly damp as you dig through it down to the water table. If it makes a big difference describe why it does. Assume the reservoir is large enough to provide a constant flow of water indefinitely at the flow rate selected at the sluice gates. The water can flow at any desired rate and can be channeled into a deep torrent or a wide shallow stream when it passes through the sluice gates. The foundation of the reservoir will not be undermined (out of scope). Another way to think of this is given the starting situation can the water dig it's own channel? If so how best to organise the flow to encourage it. [![Example of situation](https://i.stack.imgur.com/JbJww.jpg)](https://i.stack.imgur.com/JbJww.jpg) [Answer] 1. *"A very large reservoir of water exists raised up above a large expanse of almost flat land. From the bottom of the reservoir the land falls away at a very gentle gradient of ~1 in 10,000. [...] The people want to build a canal across the flat land to deliver water from the bottom of the reservoir into a river 400km away."* First of all, they need to dig a large *compensation reservoir* in order to be able to control the hidraulic head of the water flowing into the canal. You absolutely don't want the water source to be hundreds of meters above your canal, with the water being delivered directly under high pressure by a [penstock](https://en.wikipedia.org/wiki/Penstock). What they want is something like this: ``` \-------------------/ \ - - Upper - - - / control valve ___ constant level of water \ - reservoir - / || | \ - - - - - - /____||___\--------------v--/--||----------------------- \ - - - - - __penstock___ compensation ____||_________canal_________ \---------/ || \ reservoir / || \-----------/ outflow sluice ``` 2. 1 in 10,000 is a small gradient; water will flow slowly: they will need a very large canal in order to deliver a debit of 1,000 m³/sec. For comparison, the average slope of the lower course of the Nile, from Aswan to the sea, is 1 in 13,300; with an average discarge of about 2800 m³/sec, the river is 2.8 km (1.7 miles) wide and about 10 meters deep. Their canal would be about 1 km (0.6 miles) wide. That is a very wide canal. 3. Rivers flowing over small gradients tend to shift their courses unpredictably unless controlled. The people will need to expend a significant budget of resources and workforce in maintaining the canal. 4. A large river is a powerful erosion force. They won't be able to convince it to flow freely over a constant gradient from the compensation reservoir to the sea. This is a consequence of the [principle of least action](https://en.wikipedia.org/wiki/Principle_of_least_action); if they let the water flow freely, it will tend to dig down a deep valley at the source, and a very wide valley towards its mouth. They don't want this, and therefore they will need to engineer the course of the canal into sections separated by dams or weirs. 5. Now coming to the four options presented by the question: * Option 1, dig the canal before letting the water in: this *may* result in a stable canal, provided they know what they are doing. They don't need to dig *all* of it before letting the water in: they can dig a section, let water flow into it, then dig another section and so on. * Options 2, 3, and 4 all come down to letting the river cut its course any way it sees fit: this will result in a natural river, not a canal. They will *have to* adopt option 1 for the initial part of the river at the exit from the compensation reservoir, or else the river will erode their work. Those options are great if the plain is not populated when they let the water flow -- they can let the river stabilize and then bring in the inhabitants. But if they want to be able to predict the course of the river, or if they don't want to allow it to adopt the variable slope profile of a natural river, then these options are not recommended. [Answer] @AlexP's answer was fantastic. I upvoted it. So should you. But there might be an alternative.... **Use Hydraulic Mining Techniques** > > Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. ([Source](https://en.wikipedia.org/wiki/Hydraulic_mining), also image below) > > > [![enter image description here](https://i.stack.imgur.com/jFn5xm.jpg)](https://i.stack.imgur.com/jFn5x.jpg) Set up pipes that bring the water to the termination (the sea) such that there's a lot of pressure, then carve out the canal back-to-front, washing (slowly) the sediment out to sea. Depending on the mineral deposits in the area, this method can be combined with [placer mining techniques](https://en.wikipedia.org/wiki/Placer_mining) (the use of sluices to extract heavier minerals) to extract those minerals and (from a suspension-of-disbelief perspective) pay for the project. [Answer] ## **TL:DR** **It just might turn out, given the fact that there is only a 40 meter drop from one end to the other, that the ground is relatively flat and unobstructed, and that you are after a flow of 1000 cubic meters per second, your best option just might be to forget about erroding the channel, forget about digging a pilot channel, in fact forget about a dug channel complterely, and just build a twin 400 km. long 5 m. high dike to channel the water.** With a wide channel, you just might end up moving far less material - the dike walls are no where near the dimensions of the channel. --- Water flows because of differences in energy. Potential energy is converted to kinetic energy. The higher the potential energy, the greater the kinetic energy and the resultant flow. Ten tons of water flows through a channel because there was, first and foremost, enough energy applied to that ten tons of water to get it moving (accelerate it). To keep that ten tons of water moving through the friction of 400 km. of channel, you need a combination of a lot of inertia to begin with, and enough energy to overcome friction. A drop of 40 m. in 400 km. is not supplying a lot of potential energy to move ten tons of water through rough, rocky, meandering waterways at 1000 cubic meters per second. The water will just overflow the banks at the head end, and flood out over the plain, until it dissipates into the ground, evaporates, or stagnates in pools. The smoother, straighter, more frictionless the banks are, the more water can flow in the same dimension of channel. Roman aquaducts were successful because they were sealed pipes, and thus the water channel could be pressurized. The water could be 'pushed' through the pipes at high source pressure, so the pressure energy could be contained and dissipated much further along the course than just at the source. Try that with a river, and the water just expands under the pressure at the source, dissipating it quickly through flooding. Errosion only happens when the water has enough energy to actually carry the erroded material some distance away. If the water does not have enough energy to overcome the inertia of the sand (or whatever) particle, the sand particle does not go anywhere. To errode an entire channel, one needs enough energy to overcome the inertia of all of the material in that channel that you have to move - the entire mass. You are not just moving ten tons of water, you are moving ten tons of water AND ten tons of earth (numbers are for illustration only). To get your water across that 400 km. distance, you need to build up a lot of energy at the source, enough to get it the entire distance. Now, to get it to errode, you need to supply enough energy at the source to move the water AND the earth that same 400 km. Rivers do this by using a parabolic shape. Steep at the beginning, shallower at the end. Like a roller coaster track, or a slide. Build up speed coming down the steep slope, build up the energy, then coast. That ten tons of water in a steep drop has now built up enough energy to move both itself AND the ten tons of earth across 400 km. of surface, hopefully. There is going to be very little additional energy added along the way. You want to START the ten tons of water moving at the TOP of the reservoir, letting it fall down the slope, building up speed. But you do not want it simply crashing into the ground. That is like a one-way trip off a cliff. A big splat on the ground, a big hole, but not much lateral movement. You want a parabolic channel at the bottom. Something that will change the vector. Vertical motion into horizontal motion. You don't want the energy dissipated in one big bang, you want it to carry on downstream. So you want a lot of engineering at the source. A channel built down the slope of the reservoir, in a parabolic shape. A design that can not be left to chance. Nature seems to prefer the 'splat' option, the waterfalls. Straight down. Once you get the engineering at the head end, and the engineering to direct the flow at the base in a single direction instead of fanning out, then you can decide if that ten tons of water has enough energy to carry the ten tons of soil, or whatever the mass actually is. If it is more than ten tons, far more energy is needed. If it ls less than ten tons, not as much energy is needed. That is an engineering calculation - how much material needs to be moved, how far it has to be moved, and the energy needed to first accelerate it (inertia) then to overcome friction. We can't know that until the actual material is known, how high the head end is (potetial energy due to gravity), and how much water is moving. One thing is for sure - in order for the water to reach the river, it needs to be directed. Is there a natural path for the water to follow, or is the land almost flat? The flatter the land, the more the water just wants to spread out, dissipating its energy over a very wide area. In a fan, the area squares as the distance from the source, so the water very quickly loses the ability to carry any material as it moves further out from the source. If there is no natural straight course, then the water must be 'directed'. Yes, you can do that by digging a pilot channel, but you can also do that by building a dike. Whichever you chose depends on the material you are digging through vs the avaiiability of suitable material for building the dike. If the ground is flat, solid, strong contiguous bedrock, but there is an abundant supply of more granular fill closeby, then building a dike is probably the best option. The land is flat, and so the walls of the dike will be parallel to the ground. Alternately, if the ground is easy to dig into, or you have a prolific source of explosives or power beams, then excavating the channel is probably preferred. It is a lot easier to move a big rock than it is to chip that same rock out of solid rock and then move it. Now, you have to consider the end. What is this channel flowing into? A river, pool, lake, or ocean? Remember, the surface of this end point is only 40 meters lower than the head end. Tidal forces? Wind-driven waves? Flooding? is it allowable for the water to be pushed back up the channel? How deep is the water flow at the end? If it is a river that is only ten meters deep, obviously the channel can not be more than ten meters deep, or you get the potential for back flow. If it has a shallow shore then the dug channel has to be dug far out from the shore - the deeper the channel, the further out it has to be dug. Is the water flow capable of accepting 1000 cubic meters of water per second, PLUS all of the sediment? Do you need to worry about all of the sediment settling out of the water? Will you end up with one collossal river delta? Or is there enough water movement in the destination to also carry away the sediment? If you use a dike, instead of digging the channel, the bottom of the water flow (ground levvel) is still above the surface level of the river or such. The channel water flows on TOP of the existing water flow, not INTO it. It does not matter how shallow the shoreline is, the additional water flow can still be added to it. ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/188782/edit). Closed 3 years ago. [Improve this question](/posts/188782/edit) Considering a scenario set in a relatively realistic space opera (Something Mass Effect'esque) where aliens had come to our planet at our current level of development, accepted us in some galactic union, and now want to build a spaceport and a small settlement that would be simultaneously their embassy-state on our planet and a point where trade and cultural exchange can occur between us and them (seeing as our attempts at spacefaring are pretty laughable for the foreseeable future, it's the only practical option). To safely land from orbit without the risk of endangering the local population with crashes, and simply by the fact that most likely standards of living of a spacefaring civilization would differ from our standards of living and they won't like it living in our buildings, they will need a whole settlement for that, not just a classical embassy building within our city. So, where it would be most neutral, beneficial, and logical to put it on our planet(Considering that it will be the first, the largest, but eventually not the only spaceport on the planet, and we'll build further installations either jointly or all by ourselves)? Taking into account that an interstellar spaceport can be a source of not only some fantastic things like alien technologies and knowledge, otherwordly alien materials, advanced alien consumer goods, and alien porn; but also potentially point of origin of some equally icky and dangerous stuff like alien diseases, alien drugs, alien pests, alien criminal activity, and alien porn. The options I've considered so far: * As near as possible to the UN headquarters, to ease and fasten up diplomatic and political relationship between human countries and the galactic union * As near as possible to our largest and most developed city (Tokyo?), to ease trade and moving of goods * At Cape Canaveral or Baikonur Cosmodrome, due to their historical significance to human space exploration efforts * Somewhere in southern Africa, due to its historical significance as the birthplace of humanity. * At a large floating platform constructed by the aliens on the equator in international waters (In either Pacific or Atlantic), for maximum neutrality and with no need to buy or lease actual territory from any of the governments which would make local populations unhappy; Easiest control on what exactly comes and leaves the spaceport; additional cool points for a cool floating high-tech city. * No spaceports, just a space station in orbit around the planet with us needing to either get there by ourselves somehow or call for a space!taxi each time. Not very friendly from the aliens' side, plus it is safe to assume that such a space station will exist anyway in any of the other options as well because it's just far more convenient for taking in actual interstellar spaceships directly in orbit outside of the atmosphere. [Answer] Antarctica. Effectively it isn't under the jurisdiction of any country. Despite Australia's claims to a large fraction of the land mass. There isn't a native population to worry about, with room to establish a reasonable sized settlement. Besides global warming will be freeing additional tracts of Antarctica. If they can cross interstellar space, their orbit to surface spacecraft should be extremely reliable. So little worry about crashes. The natives are a bit primitive. They are only human. There currently aren't extensive trade routes to Antarctica, but that will soon change. No nation's political sovereignty will be adversely impacted by an alien embassy at the Southern polar continent. Also, they won't be seen forming alliances with specific nations. Consider how most Western nations would react if the embassy was established in China or Siberia. Conversely, if it was in Western Europe, say, Paris or Venice. If advanced alien technology included floating cities as part of their standard kit, then they wouldn't bother about choosing any specific location. An embassy could simply tour the planet on a regular basis passing over the majority of Earth's settlements. An air-taxi service could provide ready access. [Answer] **Completely depending on the aliens** With the exception of your last option, the options are all completely based on human politics. I doubt the aliens will be very interested in human politics and will have other needs for their embassy. You don't discuss the location of you new house with your pets, maybe consider their feelings but they don't have much say in it. Since you are talking about different alien races the first choice would probably be places were they feel comfortable. Assuming they don't need complete hazmat suits. The cold aquatic aliens will want to be close to the poles, warm aquatic, Mexico bay or the Mediterranean. Jungle aliens in Brazil or Africa, and so on. If they only can build one spaceport probably the most influential alien race determines the location. Since they come to earth, for them it would be relatively easy to fly around the planet very fast. (Assuming they have unlimited free energy ,water and nuclear fusion is enough for that). So you can build many stations and don't have to be close to urban population. There is a good chance we humans smell terrible or are very ugly and they don't want to be in our constant presence. Also walking around in a city might not be very nice for them. They will get huge amount of attention and mobs around them. But also the size and shape of our infrastructure might be horribly wrong for them. An elephant sized octopus like alien that uses suction for locomotion might not like our tarmac that much. Also a tiny alien will have a constant fear of being trampled in big cities. Let alone the amount of walking he would need to do to get somewhere. Since no natural resources are of any importance to them and also assuming biological resources are not of any importance, the only reason they come here are for the humans. So maybe the art, politics or just curiosity. **Answer:** So my best bet would be that they build spaceports close to human urban population but far enough away not to be bothered by them and in the best suitable bio sphere for them. [Answer] Paris. With the option of raw resources off the table our visitors are interested in unique cultural artefacts and human intellectual capital. [Statistica](https://www.statista.com/statistics/1064544/top-cities-museums-worldwide/) puts Paris as the city with the highest number of museums in the world at 297. It's also conveniently located for side jaunts to London and Amsterdam which sit in the top 10. And 6 of the top 10 [Museums](https://www.nationalgeographic.com/travel/top-10/museum-galleries/) according to National Geographic are located in Western Europe. Paris itself contains examples of every [architectural period](https://en.wikipedia.org/wiki/Architecture_of_Paris) from the Middle Ages to the 21st century. As well as providing a reasonably central base to visit dozens of [World Heritage Cites](https://en.wikipedia.org/wiki/World_Heritage_Site#Countries_with_15_or_more_sites). One assumes that we're not actually expecting spaceships to touch down outside the embassy, just somewhere conveniently nearby. As such almost any major city is the same as another. If you've got an airport, you can upgrade that to a space port, especially with an interstellar power willing to help with the construction. [Answer] ## Western Central Africa Lets think about what you want out of a space port. **1. Lowest possible launch costs** (so on the equator) Getting to orbit is energetically expensive and will be part of the calculation any alien technology uses. **2. Easy access to both land and sea for transportation.** (so near the coast) Transport times in space are so huge transport times on planet will be negligible by comparison so as long as they can access transportation its no problem. **3. Lack of tectonics evens or extreme weather**. This eliminates a lot of locations, South America has mountains directly on the equator but they are also highly tectonically active. The Malay Archipelago offers connections to large trade hubs but is both tectonically active and prone to severe storms. That basically leaves Africa, and the western side of Africa is the most tectonically stable. Western central Africa is dead center on one of the most tectonically stable plates on the planet. ## based on this Gabon and the Republics of the Congo are your best choices. It will be a huge boon to the countries and they have plenty of open land to build whatever is needed. Stabilizing the region politically is a problem for earthlings but will be greatly helped by the sudden influx of resources. It would not surprise me if the aliens looked at is a test, proof to us you can get your shit together. Moving the UN is easier than building a spaceport in a bad location, and this location will not show favoritism to any of the large superpowers and may even serve to give the UN a chance to reorganize. [Answer] ### Spaceport location: Just outside of Darwin [![enter image description here](https://i.stack.imgur.com/pozii.png)](https://i.stack.imgur.com/pozii.png) I'm suggesting the Cox Peninsula 20km (as the bird flies) outside of Darwin, in north central Australia. * We want minimal cost to launch so latitude 0 is the best bet. On the equator would be the best bet if this was all the mattered. * However we also need security, customs, quarantine, port facilities, cargo ports. We need a developed country with stable government to host this. * A nearby military base to be a last line of defence if hell breaks loose. * Rockets can crash - so we need a big country with wide open spaces. * We also need cargo and passenger seaport, international airport, and rail terminals nearby. All of these are within 30km. * Booster rockets and capsules can do a water landing. * And if all the rocket fuel goes up, we have the ocean available for fire fighting. * Its warm weather stop the O-rings from failing - no more challenger explosions. * Room for a massive runway for glider landings. * Darwin international airport and the RAAF base can function as an alternate landing site. You can [land the space shuttle at either](https://en.wikipedia.org/wiki/RAAF_Base_Darwin) * The two other peninsulas in the picture may also be used, but cox was suggested as it looks like its not traditional Larrakia Aboriginal peoples land. They may be happy to negotiate the land use however - but we do want to keep it away from the city. There isn't good road access to the other peninsulas currently however. ### Embassy location This is a tricky one. Darwin is not a centrepiece of Earth culture, it's just a really convenient spaceport. For day 0, I'd put this at the spaceport, as that's where it's needed most. As things stabilise, I'd keep the one at the spaceport as a branch office, but move the real one to a more prominent location. It's up to the Aliens really. My suggestion would be The Hauge (Next to the international court or international peace palace), followed by New York (UN), followed by Beijing (China will be grumpy about not getting the spaceport - this may keep them happy), followed by Adelaide (Home of Australian space agency - and easiest 1-million+ city to get to from Darwin). [Answer] The space station idea is not unfriendly. We've got the ISS, they could have their own station. This would be the safest location for aliens - no terrorists in space so far - but also the most convenient - no Westboro Baptist Church, no flat-earthers, no Qanon idiots to harass them. If the aliens have a bone to pick with any nation on Earth they can go down and do it. If any nation wants to go up and talk to the aliens, they must either have a serious space program or have ties with a nation that does. And if humans ever dial up the idiocy and try to attack the aliens, the aliens will be in the best position to either retaliate with tungsten rods of death, or move away the base with the least cost and hassle. Also in space no one can force you to pay rent. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 3 years ago. [Improve this question](/posts/185546/edit) In my world, there a few traditions and celebrations the common folk do. During the winter, they give their loved one (can be family but usually romantic love) a stone with a fire rune on it. Men make their wives little ornaments to bring them luck. Men or women with mages as their partners have their clothes sewn with runes on them in times of war. How much would a medieval lord understand the culture assuming they have been in power for generations? Not like a recently conquered area with a new family or person in power. [Answer] It really depends on your culture and the lord/lady's social standing. If your lords mainly reside on their own lands, next to the common folk, they will know the customs and speak their language. However, if they live in the capital (like Japanese daimyo were required to do) they will have their own subculture, often different from the commoners. Sometimes differences can be so big that the nobility and commoners do not wear the same clothing styles and speak the same language. It was the case in the 18th-early 19th century Russia[\*] (not the Middle Ages, but it is still very much telling). There is also a possibility that if your country comprises many different ethnicities, your lords may come from one and commoners from another. That was the case in some regions of China at different historical points. Social standing also would affect familiarity with traditions. Minor nobility in the Middle Ages would not be very different from the commoners and would share their customs and rituals. High lords and ladies would probably live where the court is and move with the court, as was customary at that time. So, they would have their own subculture. The court may move a lot and do not get acquainted with local customs at all. How much the court moves and how far depends on the country and historical period. The size of the country also plays a role. Small isolated kingdoms are less likely to create elaborate courts with the nobility that never sees or deals with commoners. Big empires always end up with aristocracy that knows very little about local traditions and creates its own customs. In short, **your lords and ladies can know about local customs and traditions as much as you need them to know.** Just make sure that the rest of your society is set up to accommodate this. --- [\*] Russian and French language status in the Russian Empire of the late 18th-early 19th century was complicated. Not all, even ethnically Russian nobles, were proficient in Russian. It does not mean that they could not speak any Russian at all. Most of them could manage some Russian. But polite talk in salons and written conversations would be conducted in French (or German). There were, of course, nobles who were proficient in both Russian and French. There were writers who wrote in Russian almost exclusively (they were still fluent in French and other required at that time languages). Russian was also the language of official government communication. But French was the language used by the universities to teach for example physics and geography. Russian literature and academic discussion of that time were full of debates related to the purity of the Russian language, which borrowed a lot of words from German and French since Peter I. The proponents of Russian were lamenting over the disconnect between nobility and common folk due to the use of different languages in everyday conversations. This is a fascinating topic, but I am not sure how useful it is for your world, so. I'll just stop here :) [Answer] Thoroughly if it's anything like medieval Europe. As in, those would be things that people did, not things that commoners did. Nobility and commoners routinely associated in medieval times. A noble household would have everyone, from the lord down to the meanest servants, eat at the same table, with common entertainments to follow. May Kings would call on nobles -- we know because noble account books recount payments to them. [Answer] In short answer not well. Until Fairly recently if you are an aristocrat you are more likely to relate culturally to another aristocrat from a foreign country then to the culture of your own peasants. What they did have in common was often because of large institutions that imposed unifying norms, values and tradditional (Catholic Church is a perfect example) Even then there was still a large cultural divide between the classes. ]
[Question] [ Say portals randomly opened up on Earth that lead to an occupied alien planet, the denizens from one planet can survive on the other, and it's confirmed for both sides that the portals were not intentionally created as a means of invasion. The personality of the aliens isn't too important. They are about as different as the most extreme human civilizations can be compared to the most mundane (which is to say, *different*, but familiar enough to understand basic concepts from the start). What would cause the governments of both worlds to allow movement between the portals and NOT try to garrison the portals and invade the other world? Obviously not immediately, but how could this happen relatively quickly (within a generation, for instance)? In case it helps, this is set in a medieval fantasy (few cannons, crossbows), but let's assume magic is unavailable (the exception being the portals, of course). [Answer] The same reason why most countries don't go to war with each other all the time. When we do wage war, it's often (not always, though) because it's necessary, or else if the balance of power is considerably different. If the balance of power is roughly equal, then war is often devastatingly costly. Sure, you can potentially reap the benefits of newly concurred lands, but that can come at a cost that doesn't make it worth it. And this doesn't even have to be a thought-out decision. We find co-operation in nature all the time. Altruism is an evolved trait, because it's often beneficial to co-operate than to fight. If you've read Richard Dawkins' [The Selfish Gene](https://en.wikipedia.org/wiki/The_Selfish_Gene), it has en entire chapter on this concept. There's a related BBC documentary as well, [Nice Guys Finish First](https://en.wikipedia.org/wiki/Nice_Guys_Finish_First), and both are based on research by the political scientist Robert Axelrod. The chapter and documentary talks about the non-zero sum game Prisoner's Dilemma, which shows that in a society where repeated interactions are common, it's beneficial in the long term to co-operate than to fight to gain short term benefits. So in your world, assuming both cultures are roughly the equivalent in intelligence and technology, it will be beneficial for both of them to not fight, and instead co-operate. Sure, there will be 'racist' in both parties, and there will be small-scale fights, murders, and the like, but both societies at large will figure out quickly that it's in each of their best interest to get along. And it's almost certain that two such species will have things that the others haven't discovered, so they both almost certainly have much more to gain from each other than two human cultures who reunited after a long separation. So they will, almost certainly. ## EDIT Details on *how* this might happen. Let's suppose your portal opens not in secret, but pretty obviously in the public. Even in a medieval world news spreads fast and something like this will get the due attention in no time. Quickly the 'authorities' will get involved, and even thought the first travelers through the portal may have gotten killed (simply because we are afraid of the unknown), if they open long enough, curiosity will get the better of the... what are they called again? So we have good reason to believe one party or both would have sent deplomatic convoys, and assuming both have languages, it's not impossible to find a way to communicate. The initial communication will probably be limited to 'government' authorities, but once they know enough to be less fearful of each other, people from each world can get access (maybe limited at first) to the other world. Quite soon the new becomes the normal, and after few generations nobody would bat an eyelash at the other. ## Why would they want to co-operate? Once you learn to not fear each other, it will be easy to figure out that they both have much to learn from each other. That's a big enough incentive to co-operate. Think about the mixing of cultures in our world during Medieval times. The Chinese traveled to the other parts of Asia and beyond, Arabs mixed with much of the rest of the world. They could have shut down all the naval routes and kept closed borders, but they didn't, because trade was lucrative. Everyone had something the others didn't, and it was in everyone's best interest to get along. [Answer] # How completely different is completely different? If you make them really quite different then their desires and priorities can be far enough apart that there isn't any conflict. Medieval kingdoms tended to be all about land. Perhaps this other species only cares about shallow coastal waters and has no interest whatsoever in the dry bit in the middle. Or avians with a love of high mountains, maybe they need hot dry deserts to lay their eggs and too high a moisture content could be lethal. The game with *completely* different is one of priorities. If they're far enough apart there will be no conflict simply because there are no conflicting requirements. [Answer] Why do you assume that they would go to war? War is costly and often devastating, we don't wage wars simply because other countries exist. Your two worlds would benefit from mutual trade and the exchange of ideas. By allowing free movement people can enjoy the economic and social benefits of peace. The two worlds don't want to jeopardize that peace through aggression. As to the issue raised in the comments regarding fortifications: consider the example of Canada and the United States. The two countries have benefited enormously from free movement (prior to 9/11 I could cross the border with just my birth certificate - no passport necessary). In sharp contrast, look at the situation at the Mexico/US border. The increasing fortifications have powerfully affected the relationship between those countries. Stronger border control is indicative of changing relations Note: there may still be some form of customs or border control, but that doesn't necessarily mean"fortifications" [Answer] Wars are not fought between entire species, they are fought between various social groups. And wars are fought for good or bad reasons, that are usually a lot stronger than merely "Some other group of people exists so let's attack them". History has examples of cooperation between groups belonging to different species. For example, there are instances where dolphin groups and human groups cooperate to hunt fish. In a region of Australia, a group of orcas cooperated with aborigines to hunt whales, and later cooperated with European whalers. In this example, it is at least slightly possible that both the orcas and the whales they preyed upon had intelligence equal to that of the humans involved. And I find it easy to imagine that there could have been examples of cooperation between groups of early humans and groups of proboscideans (relatives of elephants) to dig water holes, for example. And at the present time there could occasionally be small scale wars between chimpanzee bands, or between bands of Chimps or gorillas and bands of humans. And when humans hunt elephants and/or take over their habitat, elephants sometimes strike back, with single elephants or herds attacking human villages. And when there were several species of genus *Homo* co-existing relations between various small bands of the same or of different species could have been just a complex and varied as relations between modern nations can be. So I can imagine wars between two different tribes of Cro-Magnons, wars between two different tibes of Neanderthals, Wars between a tribe of Neanderthals and a tribe of Cro-Magnons, wars between an alliance of Cro-Magnon tribes and a Neanderthal tribe, wars between an alliance of Neanderthal tribess and a Cro-Magnon tribe, wars between an alliance of Cro-Magnon tribes and an alliance of Neanderthal tribes, and wars between an alliance of Cro-Magnon and Neanderthal tribes and another alliance of Cro-Magnon and Neanderthal tribes, as well as various periods of peace between various such groups. So you, the writer, the creator god of your fictional universe, should ask yourself: "Why should two completely different species, newly adjacent to each other, go to war?" Because no war mongers who may want the government of part or all of their species to go to war against some government of part or all of the other species are going to convince enough high ranking leaders and ordinary people that war is a good idea, unless they have some sort of reason, good or bad, accurate or false, to make it at least seem to a lot of their people that the war will be a good idea, whether it actually is a good idea or not. So if you, the creator god of your fictional universe, want war or peace to exist in your story, or for peace to be broken by war, or for war to be ended by a peace treaty, you can arrange for that to happen. And if you want the readers to desire war, or to want peace, or to change their opinions about war and peace, you can make them feel the way you want them to, if you are a sufficiently skilled writer. And if you want to have a war between the government and society of part of one species and the government and society of part of another species to happen, you should take the time to give the sides motives for going to war that seem strong enough, at the time, to them. [Answer] Two different options, depending on the size of the wormholes. If the wormholes are big enough for use to deploy planes/missiles through them, then they are also big enough for the aliens to launch similar weapons. Both sides would realize that it is a case of Mutually Assured Destruction, and you would end up with a Cold War-style "Well, I can always kill them, but it is guaranteed that they can also kill me." On the other hand, if the wormholes are, say, [Stargate-sized,](https://stargate.fandom.com/wiki/Stargate) then large-scale warfare would be completely impossible, as humans and aliens would be able to blast each other's armies the moment they come through. [Answer] Has no one here watched Counterpart? [Counterpart](https://www.imdb.com/title/tt4643084/) Basically a portal opened connecting 2 exact world. One difference in an event rippled through and caused most things to change ... Anyways the thing is that the 2 worlds are mostly same and how they interact with each other was truly fascinating. Almost like what you guys discussed above like their govt interacting, how much knowledge was released, and how one side kept a backup plan to use in case someday things escalated [someone misused it] ]
[Question] [ My world has giant geysers. The height of these geysers oscillates over a cycle of 3 or so days. Things you need to know: 1. There is an unknown force in the core of the planet, which exerts pressure outwards that oscillates in cycles. 2. There is a layer of water beneath the crust. All around the world, these geyser are synchronized, going off at the same time regardless of latitude, longitude, or orientation. This is caused by the fluctuating waves of pressure exerted upon the outer layers from the planet's core, forcing the water up and onto the surface. When the pressure eventually dwindles, the water then drains back down in a process known as *flushing*, after which they begin to increase in height again, restarting the cycle. At their maximum, they reach a height of 2551.7 ft (777.7 m). **This is not an Earth-like planet.** What I want to know: 1. Is anything in my model even possible? Please point out any flaws in it. 2. If nothing I said makes any sense at all, how can I plausibly explain giant geysers that fluctuate the way I've described. (I might have to scrap the idea that they are synchronized) This is the worldbuilding site, so any new ideas are greatly appreciated. 3. I'm willing to scrap the idea of fluctuating pressure from the core and even scrap the layer of water. ## I just want to be able to explain the geysers and they must be periodic and consistent. Any other data I have provided can be scrapped, if necessary. Telling me that it can't be a planet is not a solution to my issue. I'm aware that the layer of water beneath the crust rules out any possible volcanic activity, which kind of messes up a lot of things about my world that I'm still trying to figure out. Any possible loopholes for this would be greatly appreciated. (maybe like giant vertical tunnels of rock that push lava through the water onto the surface) [Answer] Initial issues: 1. To reach 777.7 m, assuming no air resistance, and a similar gravity to that of the earth, the water will need to move at a speed of 123.4 m/s this is just over 1/3 the speed of sound (275 mph). This is really fast, and would cause a lot of destruction (depending on the size of the geyser). If we factor in atmospheric resistance, you'll probably be close to the speed of sound, which is probably going to be limiting as the amount of energy needed to break the sound barrier is exponentially more. 2. Water moving that fast would take rocks and things with it, this is called erosion and there would be substantial erosion of the hole that the water comes up through. 3. If the hole becomes larger due to erosion, then the speed of the water going through it would be decreased. Speed=Flow/Area(cross section). Then your geyser isn't so high anymore. [Answer] [Natural nuclear reactors](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor). It would have to be relatively early in the solar system's history, compared to Earth, because you'll need Uranium with a higher concentration of U235 to U238 compared to what Earth currently has... though it did have this concentration 1.7 billion years ago. Your object will have to be very small for this to be a reasonable explanation; at most, a very large comet, several thousands of kilometers across, in order for these geyser outgassing events to be synchronized. The object would be best classified as a rubble pile, rather than a solid object, because it would need to be porous throughout. How it works is, U235 decays fairly regularly and somewhat frequently, releasing a stray neutron. However, this is a Fast neutron, which is unlikely to be picked up by the nucleus of other Uranium in the area. Without the neutron being absorbed by another Uranium nucleus, there is no chain reaction. However, water makes for a wonderful neutron moderator... It takes Fast neutrons and slows them down to Thermal neutrons. Thermal neutrons do get picked up by Uranium nuclei, which quickly split into radioactive iodine and release a few more Fast neutrons; as well as releasing quite a bit of heat. The more water, the hotter the reactor gets, until the water turns to steam and sprays out as geysers onto the object's surface. Without water to moderate the reaction, the chain reaction stops, and the natural reactor cools, letting water condense once again. [Answer] It is not a planet... It is the egg of a swarm of gigantic water breathing life forms! The egg is filled with water which was originally extremely oxygen rich. The atmosphere above the surface of the egg is even more oxygen rich. As the fetuses mature, they consume the available oxygen from the water within the shell. Then, when those enclosed oxygen levels get dangerously low, the fetuses follow their instincts, pecking blow holes in the shell. Once the holes are ready, each fetus attaches itself to a hole and starts their second phase of development. During this second phase, each creature puffs up like a blow fish, full of interior egg water, then it spits up out through the hole. The water thus freed from the egg's interior, absorbs oxygen from the atmosphere, then plummets back down into the hole where the creature is waiting to breath it. This second phase of development last for thousands of years, with the creatures slowly growing and their associated geysers slowly growing in height as well. When the geysers reach orbital heights and the water escapes, no longer plummeting back down for the creatures to use, the second phase of the creatures' development ends and hatching time has arrived. What the final adult creature looks like or how it functions in the post-hatching vacuum is a mystery. No intelligent civilization has ever lasted long enough to chronicle the entire gestation. As for why these gigantic creatures synchronize their breathing... it's a family thing. After living together inside that egg for more than a million years, they've gotten very good at syncopation! [Answer] **Magnetic moon in an eccentric orbit.** 1. Your planet has a moon. It is magnetic. 2. The moon has an eccentric orbit. It gets very close to its planet during the close part, skimming the atmosphere. It orbits its planet every 3 days. 3. When the moon gets close, its magnetic field induces current in metallic regions of your planet. 4. Metallic inclusions in the crust, close to the surface get hotter than those in the core, because those shallow regions are closer to the passing magnet moon. Your planet has several areas with metallic inclusions in the crust and surface, due to recent metallic meteor impacts. 5. When these places get hot, the water in these places gets hot. Hot water can hold less dissolved gas. The gas comes out of solution as bubbles. If it gets hot enough there might be steam. 6. A blast of gas which carries condensing steam and water droplets forms your geyser. 7. The magnet moon has not been doing this for a long time. Each time it comes past it is slowed as its energy is transferred to the planet. Eventually it will hit the planet. It will become another one of the metallic inclusions in the crust. [Answer] ### The planet has an eccentric orbit around a gigantic microwave emitter Many high-energy cosmic objects - the most notable being neutron stars and black holes - emit high levels of microwave radiation. Your planet orbits one of these (alternatively, a binary star where one of the pair is a neutron star or black hole) and has a highly eccentric (elliptical) orbit, drawing very close to the microwave source once a year. When the planet draws close, the microwaves boil the water below the surface, causing high pressure and forcing the water out through geysers. Of course, this planet will be very inhospitable to Earth life during this part of the year, as it will boil the water in their bodies, causing them to explode. Native life may be able to survive by going through a period of hibernation, drying out like a tardigrade and waking up again during the heavy rainfall that follows. [Answer] Oh that is easy if you are not looking for a planet. Possible with a planet too. Like Europa or Enceladus have an underground ocean with an ice crust. Then have another moon and the planet itself affect this moon with tidal forces. These tidal forces will most of the time cancel each other to have a diminished effect, however, when they are in sync to squeeze your moon, it will cause high tide for the underground ocean, which will break the ice and poor out of the resulting geyser. If it has to be a planet, have it either a binary system or two large, probably captured, moons. ]
[Question] [ If there were an absolutely terrible accident, and part of Earth's core was displaced toward the surface, making a bubble of liquid nickel and iron, what would be the major problems with this? [Answer] You ask about a portion of the core being displaced toward the surface. This would move the center of mass toward the surface of the earth. How much of the core moves, what the shape is of the part that moves, and how far that bit of core moves all matter when determining the effect. If, for instance, some of the core reaches the surface we have a new kind of volcanic activity that could make the Yellowstone Traps seem insignificant. For a less dramatic movement, the core being too close to the surface could result in much higher geothermal heating for that region, perhaps turning the Mediterranean Sea into a gigantic pot of bouillabaisse. For this answer, I will assume that the core doesn't come to the surface, and that the mantle is essentially intact. Some part of the core moves "outward" from the core so that the core grows a bulge and is no longer best approximated as a sphere. Since the core is denser than the surrounding structures, the bulge moves the center of mass. The center of mass is really important. It defines the point through which the planet's spin axis passes. The drama of the effect would depend on how much the center of mass were displaced. To avoid the "everybody dies" scenario, let's assume it moves a small amount, say about 7 miles. That can't be so bad on a 7000 mile diameter sphere. Right? Except that it can. One change is that the water will flow so that it forms a smooth sphere around the center of mass. The low part will be covered with an added 7-mile deep ocean. The high part will be higher than the tallest mountains. If displaced in the right direction, the Mariana trench could become a salt lake above the new sea level as it is left to dry. Another change is that the air will also recenter on the center of mass. Those former sea-level plains which are now 7 miles high will be uninhabitable without pressure suits. The third substance that surrounds the core will also, slowly, flow to once again equilibrate to a sphere, and the earthquakes will be spectacular as the surface rock and mantle slowly flow and reform. In summary, the low side is lost to deep water. The high side is lost to anoxia. The middle would still be habitable, provided you survive the earthquakes. But, maybe 7 miles is more than you have in mind. Even 500 feet would completely reform the coast lines. Dial in the displacement you want, look at topographic maps of the earth for the starting configuration and cover or expose whatever you'd like. On the low end, climate change for every spot on the planet. On the high end, a grand experiment in reshaping life after nearly all life on land and much of life on the ocean floor is destroyed. [Answer] The major problem is that the mantle is not made of liquid magma as Holywood likes to portray. It is rock solid, no pun intended. The fact that it moves on a geological time scale helps keeping the lay idea of a liquid mantle alive. So, the core went to the surface. That presents three problems: * Moving it there. It won't be like a bubble working its way from the bottle of a cup of sparkly water. It will be like moving the seed of an avocado past its shell by pushing from the outside with a chisel and a hammer. What is on top of the core will be moved out of the way just like that. * Gravity. If the Earth was just a small asteroid, the kind that is just a handful kilometers wide, we could stop at the avocado analogy above. However, you are moving up to a third of the mass of the planet towards its surface. That's a lot of mass. The side distant from the core will be pulled towards and collapse on top of it. Then the whole planet will rearrange itself around the new position of the core and become round again. Remember [the IAU's definition for what is a planet](https://en.m.wikipedia.org/wiki/IAU_definition_of_planet) (emphasis mine): > > a planet is a celestial body which (...) has sufficient mass to assume **hydrostatic equilibrium** (a nearly round shape)... > > > * Heat. The amount of energy involved here is much greater than things likes detonating all the atomic arsenal, or being hit by dino-killing asteroids multiple times per second. The heat generated by this will melt the planet. And I mean melt - the crust will become a proper liquid, unlike the mantle as it is right now. The oceans will vaporize and together with the atmosphere escape to space, and we probably won't have another bombardment of icy asteroids again, so the new Earth will not be able to harbor life (as we know it) after the Hadean this core displacement event would cause. The new Earth could look more like Venus after a couple billion years, but with more seismic activity. [Answer] The core is the densest part of our planet, being made, as you state, of iron and nickel. Offsetting it while the planet keeps rotating means changing the momentum of inertia of the whole planet. This will induce quite some shaking on the entire planet, altering the day-night cycle and inducing quite some earthquakes while things settle down again. Think of what happens to the wheels of your car when they are not balanced. Moreover it will also disturb the dynamo generating the magnetic field protecting us from the solar wind. And also the magnetic poles will be shifted. ]
[Question] [ To kill zombies on land, you usually have to either chop their head off, burn them down or use purification magic (if it is a fantasy world). But underwater you can't kill the zombies the same way as you do on land. Fire doesn't burn underwater and swinging a sword to cut a fish's head is nearly impossible. Harpooning them will work on larger fishes but ineffective on smaller fishes. Details: 1. The fish are around 20 centimeter in length, just think of piranhas 2. The undead are 'dead' organisms controlled by a zombie virus (like the one on *The Walking Dead*, just that it only infects animals) 3. The question is set in a medieval world. How the populace and the government react would isn't important, what I am asking is how can someone kill those zombie fish (assume you have unlimited materials that are available on the medieval age)? [Answer] **[![Sawfish](https://i.stack.imgur.com/dg2oD.jpg)](https://i.stack.imgur.com/dg2oD.jpg)** <https://www.youtube.com/watch?v=uPnTCSE_KW8> Swinging a sword to cut a fish's head is nearly impossible for you. But sawfish have been doing just that since the dinosaur days. This sawfish chops a fish into shreds in 2 seconds. I had to slow down the video to get this screenshot. Your people need those badass, zombie fish chopping, cartilaginous saw-thrashing sawfish. [Answer] As @StevenG said in the comments, the easiest and most effective way to kill a fish is a net. It doesn't even have to be a zombie fish, although those would take a few steps. While a fishing boat/net combo would be able to net the fish for disposal in other means - Like a bonfire, or a fish guillotine or some other method, nets can also be used in a much more passive manner. You can string a net across the inlet of a harbor, or across a river, or some other chokepoint. Simply by leaving the net there you can keep the zombie fish out of the area and keep it safe. Sure, you'd have to do regular checkups on the nets, but you could string a temporary one up behind it, too. Removing the fish from water makes them significantly less of a threat, too. Sure, the bite from a zombie fish is still a zombie bite. Sure, fish could propell themselves by thrashing (And there's even some fish that can live outside of water for some time, and have adapted to moving outside of it), but it's not fast, and it's limited. Put them in a box, put a lid on top, and you - and they - are covered. [Answer] > > Fire doesn't burn underwater > > > not exactly true. There are many chemicals which react really energetically with water and under the sea there is plenty of water. Take some strong acid or base, locally disperse it and let it corrode the zombie fishes. Or, if you really want fire, take an alkaline metal and coat with it a spear, protecting it with a water soluble film. As soon as the film is washed away, the reaction between the alkaline metal and the water will be really spectacular. [Answer] Can the undead fish be baited? If yes, perhaps an adapted fishing hook rigged with some sort of a contraption that e.g. releases a spring on contact and drives a spike through the fish's head? I don't think such purely mechanical things are beyond medieval capabilities. ]
[Question] [ Earth is under attack, the empire has gathered thousands of battleships each has a displacement of 500,000 metric tonnes and 20 motherships with a displacement of over 15 million metric tonnes now heading towards Earth as we speak. They are groups in a tight formation around a shield generator which put up a powerful force field the size of our moon orbit and can keep out asteroids and incoming missiles. I suppose traveling at subluminal speed across large distance of space, these fleets would be attracted to each other gravitationally and hence such a tight formation is disastrous. Is there any way to overcome this problem and still maintain a tight formation around the shield generator? The emperor has restricted the budget so there can only be 1 shield generator for the entire fleet, propulsion are antimatter-matter engine and ion drive (no FTL). The plan is to overwhelm Earth defences at one go, second wave commencing at later time is the finisher but no shield generator. [Answer] I don't see why a tight formation would necessarily be disasterous. Gravity is an incredibly weak force, so the attraction even massive vessels feel towards each other will be minimal- small, occasional corrections should be more than enough to correct for this drift. I imagine that compared to gravity, matching the speed and direction of each ship with respect to each other accurately will be much more significant. Even then, for a high-tech fleet this shouldn't be a problem. The ships would probably use some sort of [PID](https://en.wikipedia.org/wiki/PID_controller) control linked to the engines of each to manage the distances between the ship in the fleet, and its nearest neighbours- much like how cruise control allows a car to match the speed of a car in front of a motorway, however in 3 dimensions instead of 1. Alternatively, if there's some central command that knows the position of every ship in the fleet, the position of each ship could be monitored and micromanaged to ensure the correct formation is kept- however from a signals intelligence point of view, this requires all ships broadcasting their position which means the signals could potentially be intercepted. [Answer] If you put those masses in the equation for gravitational force, you will see that the resulting force is negligible. A 500,000 metric tonnes ship and a 15 million metric tonnes ship will attract each other with a force of 500 N at a distance of 1 km. That gives $1 \cdot 10^{-6} m/s^2$ acceleration to the lightest ship. Not zero, but surely manageable. [Answer] Assuming 3000 battleships, your entire fleet weighs 300 million + 1500 million tonnes, or 1800 million tonnes. The moon orbits at about 400,000 km. If we assume the masses are uniformly scattered over a 200,000 km radius sphere, the "surface gravity" will be GM/r^2, where G is $6.67408(31)×10^{−11} m^3⋅kg^{−1}⋅s^{−2}$. Plugging those values in, we get a surface gravity of 3 \* 10^-15 m/s^2. If the fleet coasts 100 light years at 1% of light speed (so a 10,000 year journey), items left "loose" at the edge of the fleet of ships will be moving at 0.000946707779 m / s. However, over the 10,000 years, they will drift 149,375.937 kilometers towards the center (assuming constant gravitation). Ie, the 200,000 km radius would "fall" into a 50,000 km radius sphere. In that 200,000 km radius sphere, the 3000-odd ships each have 10^13 km^3 of space, or a spacing of about 20,000 km. After they "fall" towards each other, they'll have a mere 5,000 km spacing. While large, a 500,000 metric tonne mothership probably has long axis under a km. What more, the amount of effort to "course correct" and spread out again is going to be trivial. [Answer] You have, I posit, a problem greater than gravitational concerns. It would take light about two and a half seconds to go from one end of the sphere to the other. So whatever a ship saw or sensed, would not be where it was seen or sensed. That is, ships would have to maneuver BEFORE they saw the other ship maneuver, in order to maneuver at the same time. But that would mean that the fleet would not APPEAR to be maneuvering in sync. But if the ships were so close together, NOT maneuvering in sync means the possibility of massive collisions, give the high relativistic velocities and delta-v. Not to mention time dilation. And, of course any central coordinating computer would be getting signals perhaps a second after they were executed. Of course, they could always use GPS. Oh, wait, they can't. SO how would any ship know where any other ship is, if they can never see or sense or communicate the change until a second after? 'That ship is here - wait, no they changed direction a second ago, so they are ... wait, they just sent us a message saying h=they were changing course ... wait, that is old news, they changed a second ago ... they are now here, but where is here? There are no coordinates in space unless you plot with reference to a stationary object - wait, there ARE no stationary objects in space except ME .... See the problem? How do you sync movement in space at such distances? ]
[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/139030/edit). Closed 4 years ago. [Improve this question](/posts/139030/edit) Assuming a human society possessing technology on par with the High Medieval Age, circa 1100 AD. The humans have adapted to living underground after ~3000 yrs. Their skin has less melanin, making them pale. They have significantly better night vision, acute hearing and a very sensitive sense of touch. They have bristly hairs on their arms and legs that function as whiskers do for dogs and cats, helping them to sense their surroundings when they are in the dark. Most of them are quite flexible and also compact, with most adult males averaging around 5'4" and adult females around 4'11". The tunnels and caves range from cracks a rat could barely fit through to wide winding tunnels around 8-12ft wide and 6-8ft tall. "Verdant caverns" (home to the most wildlife and largest population centers) closely resemble the [Hang Sơn Đoòng cave](https://en.wikipedia.org/wiki/Hang_S%C6%A1n_%C4%90o%C3%B2ng) in Vietnam in regards to size and biodiversity. The caverns are home to the main cities and populations of these peoples; one can expect to find such caves at least once every 45 miles. What medieval weapons and armour would be best suited for fighting other humans in the tunnels connecting "verdant caverns?" [Answer] This heavily relies on quite a few variables, how is your access to minerals? Do they have each access to copper and tin for bronze? Is iron easily accessible or unlike our own history is iron quite rare? Are all those metals rare in sufficient quantities and we rely more on bone and stone? The limited amount could be used to force weapons for an elite well funded force but the average soldier won't, etc. Your smallest tunnels will be prime choking points, fortifications like gates will be build at them. Unlike the real world going around them is near impossible. Just put several layers of thick doors down there and you're good. There won't be space to bring in a battering ram, the walls are solid rock. That gate will hold against anything but a large army backed by a powerful nation. **Conclusion, you'll rely on siege warfare.** See there is one way around those gated choke points, pickaxes and general mining. Digging mines has been done since the stone age. Your cave people will be able to dig tunnels. Now the speed of that depends on the above mentioned availability of metals. But even without those mining will be done and tunnels will be dug. If a sufficiently large and organized society arises I'm pretty sure they're dig their own highways. And their armies will dig their own entrances into enemy territory. This will also be almost impossible to track. You'll need an extensive network of listeners at your borders, maybe water alarms as well. You need to know where the enemy might breach your caves. My point here is, fighting in the small tunnels won't be done by organized armies. They'd build their own tunnels large enough to comfortably fit their warriors. Depending on the accessibility of metal those men will likely evolve a hoplite like system of heavy spearmen. They can hold a tunnel for great lengths of time. And unlike on the surface world can't be flanked. This will be the core of any advanced nation, heavy spearmen for defense and offense. **Conclusion, heavy infantry with spears and shortswords.** [![Hoplites](https://i.stack.imgur.com/xPd6t.jpg)](https://i.stack.imgur.com/xPd6t.jpg) For ranged combat there is a clear pressure to remain small, there's no room for a longbow or javelins. Though given the focus on spear warfare by the elite warriors some usage of throwing spears is expected. But the kings of ranged warfare in your underground kingdom will be slings and crossbows. Slings went out of favor because they're out performed by a bow with comparative skill. A sling takes quite a bit of skill, but they're easy to make. Crossbows would be well established by 1100AD. They started to be more widely adopted in the west around the fall of the Roman empire. In China they've been part of regular warfare for thousands of years. **Conclusion, crossbows will play a limited but effective role for defenders.** Your military would be a combined force of spearmen with shortswords and archers with crossbows. Thinking on it given the short range, a repeating crossbow makes a lot of sense. [![Chinese repeater crossbow](https://i.stack.imgur.com/eolVg.jpg)](https://i.stack.imgur.com/eolVg.jpg) You're trading range for speed and size already, might as well replace range and power with a fast rate of fire. But much like real history their usage has a limited place on a pitched battlefield with professional soldiers because those guys wear armor. However, raids, bandits and vanguard forces are an entirely different thing. They'll crawl the small tunnels for unknown routes. They'll be confined, struggle with sentries and the like. Those men have no interest in shields, long spears and other cumbersome things like long rapiers. They'll go for short things, daggers, an armored gauntlet, maybe a bronze age rapier. [![https://i.ytimg.com/vi/BVCLhk-RGB4/maxresdefault.jpg](https://i.stack.imgur.com/LHxLQ.jpg)](https://i.stack.imgur.com/LHxLQ.jpg) They go for short blades, probably augmented with a sling. They're easy to carry, plenty of ammunition around and are quite precise at short range. **In summary:** * Heavily armored spearmen with shortswords using a shieldwall like formation. * Assisted by crossbowmen. * Repeater crossbows for militia defense. * Bandits will rely on shorter weapons as they'll shun the larger tunnels. [Answer] Daggers and small stabbing weapons such as short swords and rapiers (not invented till the 16th century but heavier stabbing swords were developed well before) would be used for close-tunnels work. A short spear would also do a similar job and be easier to make if you had a decent source of wood inside the caves. Longer weapons would struggle with corners and tight spaces, anything that needs slashing and swinging like hammers and axes is also tricky without room to work with. In terms of armour you would need something with good mobility and that isn't damaged by the damp and crawling around in it. You also have less need to protect the back and legs - so I suggest some sort of shoulder/arms/breastplate combination with a good helmet. Shields would be awkward in confined spaces but also effective at blocking passageways so small shields might be used in some situations. For the larger more open caverns then traditional weapons would be more effective so you have an interesting contrast in needing very different equipment for the two environments. ]
[Question] [ There is a big, very big planet that is travelling fast, very fast. It’s a [rogue planet](https://en.wikipedia.org/wiki/Rogue_planet) (not attached to a star system). It’s going to pass close, very close to the earth. [![enter image description here](https://i.stack.imgur.com/NxFOC.jpg)](https://i.stack.imgur.com/NxFOC.jpg) The earth is probably going to be destroyed by the gravitational forces and sent spinning as a rogue planet itself or toward the sun, I don’t really care. What is of interest, is that some humans that were on the earth were sucked by the nomad planet’s gravity (Edit for Raditz comment: if you prefer, you can make them sucked by something else, but please not laser beams, only natural-ish forces). [![enter image description here](https://i.stack.imgur.com/QpWig.jpg)](https://i.stack.imgur.com/QpWig.jpg) Assuming: * The fate of earth afterward to be irrelevant * Long and medium-term survival on the rogue planet to be irrelevant * People should however land alive on the new planet Would such a transfer be possible? [Answer] Unfortunately no it can't happen. **TLDR** Let's say the gravity is high enough to pull people off Earth and into the Rogue Planet, they would then be falling at terminal velocity to the surface of the RP, the problem with trying to land on your feet at terminal velocity is that it tends to be somewhat terminal... **Atmospheric Issues** Ok so let's somehow take the terminal velocity splatting as handwaving-ly survivable. And let's also assume that the RP is going somewhere in the region of [525km/s](https://en.wikipedia.org/wiki/Escape_velocity) then the atmosphere would have so much friction between the two that it would turn into plasma that somehow your people need to survive traveling through... Along with some of the Earth's atmosphere being ripped off with you, make just a small amount of catastrophic turbulence that no aircraft could survive let alone a person out for a morning run. **Gravitational Issues** Even if we assume that the RP is roughly 5x the diameter of the earth (assuming this based on a rough estimate from your pictures) then the gravity would be crushingly strong once the people land there and would be immediately crushed by their own weight. AND then there is the fact that even with how small Earth is by comparison it would cause huge earthquakes and general doomsday situations on the RP to make habitability quite unlikely once landed **EDIT: Only potential chance of survival** The one chance of people surviving would be if there were anyone on the International Space Station (ISS), and it was in the perfect place, it might... I stress might be possible that it could get dragged out of Earth's orbit into the RPs orbit, however, the velocity change would rip it apart, but perhaps maybe just maybe if a couple of the crew were in the Return capsule with a heat shield, then they have a chance of survival until they reach lower altitudes and are crushed at least [Answer] No, it’s completely impossible. If the rogue planet passes close enough that the Earth is inside its Roche limit then things including people could indeed get pulled off the surface of the Earth by the tidal force, but there’s no way that humans could land alive on the surface of the rogue. [Answer] I'm not sure about the physics ... ask on ['what if'](https://what-if.xkcd.com/) for that, but **IF** your're in a plane, while the lighter Atmosphere is pulled towards the planet, you **could** survive *(**prove required**, maybe with a test series. Do you have a giant planet somewhere hidden in your garage you can borrow me?)* But watch out for the inhuman pressures if the air is sucked in the next planet and pressed on the surface there. [And don't land quick if water is coming after you](https://what-if.xkcd.com/12/) EDIT: Thats actually the simple-minded answer. And it's bad without end. What you want to do is standing (flying in a plane ... you never know) on the other side of the earth. **Then you get pulled down with the hole earth.** AND thats the part I'm not sure of. Just make sure you have enough fuel to fly one time around the world *and* to stay another in the air. [Actually the higher pressures of the atmosphere on the bigger planet makes it easíer to fly](https://what-if.xkcd.com/30/). If you have luck the other Planet is so cold you don't get the feeling from 65 million years ago. Concluding I would say: It's a montrous balancing act. If of all planes only one can survive I'd be surprised. Either way, on the other planet the humanity is likely to die out, because of: -[Gravity](https://what-if.xkcd.com/67/) -Inferno -Human Behavior -did I mention the apocalypse yet? [Answer] If the planet is close enough that someone from the surface of the earth is going to "fall" onto the larger planet- so will the rest of the earth- right on "top" of them. And even then, during this "fall" they will continue to be held to the surface of the earth by its gravity. (The rogue planet would need to be incredibly dense for there to be a significant enough [tidal-force](https://en.wikipedia.org/wiki/Tidal_force) gradient between a person's center of gravity, and the surface of Earth to lift someone from the surface. And even if one does "float" off the surface for a short period of time due to this tidal-force gradient, the earth, or at least some of it, is still going to land on "top" of them. Certainly, as others have mentioned, having such a density would render the rogue planet uninhabitable by humans.) ]
[Question] [ Is there such a thing as gasoline vapors, or some kind of gas that can be given off by gasoline? I'm trying to come up with a planet where the atmosphere is combustible and constantly catching on fire (as you can probably tell the gasoline is meant to be symbolic of something). [Answer] A planetary atmosphere can be either globally oxidant (i.e. oxygen rich) or reductive (i.e. hydrocarbon based), but not both, as it would imply a mass combustion reaction which would consume one of the two components. This is what happened on Earth during the [great oxygenation event](https://en.wikipedia.org/wiki/Great_Oxygenation_Event), when oxygen released by the first plants oxidated all available minerals. To answer your question, you can have hydrocarbon atmosphere, with methane, ethane and other hydrocarbons with longer chains. But you cannot have constant catching fire on a global scale. If you have local releases of oxidant gas, it can happen. [Answer] **You could do it with [pentane](https://en.wikipedia.org/wiki/Pentane).** Imagine an green and earthlike world. The weather is generally cool and wet. Photosynthesizers leak oxygen into the air, as they are wont to do. A nice place to build a cabin, you would think. But there are shallow pockets of petrochemicals just under the surface. They have floated up through the crust over time from huge abiogenic deep stores and the less volatile ones accumulate in the cool surface. The boiling point of pentane is 35C or 97F. Every now and then the planet has a really hot summer and then up comes the pentane, boiling off and into the atmosphere. Once enough accumulates in the atmosphere - boom. Then when the pentane fires get things hot enough, its friends hexane septane and octane come out to join the party too. Everything burns. It ends when there is no oxygen left in the air to support combustion. Things cool off and the residual alkanes condense and move back to their subsurface lairs. The photosynthesizers laugh merrily at all this. Swinging the planet back and forth from oxic to anoxic via fire is great for them. Like the grasses of a prairie, they are fire adapted. Fire-adapted grasses live through fires via their deep roots, and then emerge to an environment burnt free of plant competitors and insects. So too the photosynthesizers of your world - their fireproof spores sprout to an oxygen free world depleted of air breathing life and replete with delicious CO2. Then just as the anaerobes think they will get back their planet, here comes the O2 again. ]
[Question] [ ## Story Info On a fallen world that still has firearms. Society is still advanced in a way, but is more tribal/feudal in nature. There is an armed priesthood that preaches and deals in death. To the unbelievers they are called the Powder-Priests or Death-dealers, to their followers they are called (haven't given them a cool name yet). The Priesthood forever walks the towns, villages and battle fields in search of new bodies to add to the pile, for you see they believe that in battle Death must come from Death itself. They are under the impression that items containing remains of the dead become beacons for it; that when it enters the body life will fade. They take the bodies to the powder fields found close to all towns (think graveyards except the bodies are out in the open) to make what they call the essence of death; it is what you would call gunpowder. The Priests sell the powder to all factions in the world believing that they will be the cause of their own destruction, the other factions take the powder not caring either way. ## The Idea The idea is that the Powder-Priests have these powder fields filled with bodies, so that they can make gunpowder. I read a book from Japan about the Sengoku period and a group that did this (I think they were monks) and thought that it would be cool to use this in my own book but the book that had the info has been lost and I’m having trouble getting the right way on how they did it. I think it's bodies, urine, and charcoal and leave it for a few years? (I tried looking it up; swear I’m on someone’s watch list now.) But I have no idea what the technique is or that I have the right… ingredients. ## The Question: How to make Gunpowder out of Corpses? This one was a little bit on the odd side for me to ask, but if it helps me make a better book I’m fine with it (hears knock on door FBI opens up). I know that the book I read was based on real events and I have also read somewhere else about this being done before (or something similar)... I think the French? I’m also aware that there are better ways of making gunpowder, but this way fits perfectly with the group and their ideals, so I think I won’t change it. [Answer] Gunpowder requires potassium nitrate and charcoal. Charcoal is fine to make from corpses (bone charcoal is good charcoal) but potassium nitrate is trickier. One can make potassium nitrate from manure. It is a byproduct of bacterial decomposition of manure and urine. It is water soluble and so one of the original methods to get saltpeter was to dig up the earth floors of old animal barns, then wash the saltpeter out of it, then dry up the wash water and collect the saltpeter. When they scaled up production of saltpeter they took plant waste (raw manure) and made fermentation vats. They added some barn earth as a starter culture. In your fiction, have the priests own a starter culture of bacteria which produce potassium nitrate. As with the above described saltpeter vats, the priests can inject the corpses with this so as they decompose they will turn in part to saltpeter. I think it might make sense for them to process the corpses some first, defatting them - this would be a process similar to how mummies are processed. [Answer] I looked around, and unless we are made of something **very** interesting, no, not even as corpse we make for good gunpowder ingredients. As living beings, we can contribute with our own waste: [urine](http://www.todayifoundout.com/index.php/2013/04/urine-facts/) Explanation, from the link: > > Gunpowder is comprised of 75% potassium nitrate, 15% charcoal and 10% sulfur. While charcoal (historically made with wood) and sulfur (historically dug from the ground around volcanoes) have been relatively easy to obtain, potassium nitrate is not commonly found in nature. Early sources were found in caves where guano (bat poo) had combined with minerals from the cave walls; soaking and filtering the guano was an effective method, but there are only so many caves, and so much bat poo. > > > With an increasing need as gun warfare became more common, by the time of the U.S. Civil War, men were manufacturing potassium nitrate in huge amounts. One process, known as the French method, involved mixing manure with ashes, straw and urine; the mixture would be tended for many months, perhaps even a year, then filtered through more ashes and a bit of water. A second process, called the Swiss method, involved placing a sandpit directly under a stable; only the urine made it into the sand, which would be harvested and filtered in the same manner as the French method. Either way, it had to be a tough job. > > > Survivalists and gun enthusiasts today enjoy (well, maybe) making their own gunpowder. For the potassium nitrate, one recommended process is to put a lot of manure in a large drum with a drain, valve and filter screen installed at the bottom. Pee into it. Freely. Then add water for a total of about 300 gallons of yuck. Place it in a safe spot (far away from the house, if possible). After 10 months, pour it out onto shallow trays to dry. > > > Separately with a mortar and pestle or hand-cranked mill, grind charcoal (all natural, no Match Light) to a powder and set aside. Do the same with sulfur, which can be purchased in home and garden stores. Finally, grind the potassium nitrate. Experts warn not to grind the ingredients all together, since that would possibly explode in your hands. > > > For storage, the best minds suggest mixing the three powders together then adding a little stale urine so the mixture has the consistency of biscuit dough. > > > [Answer] ## Dehydrate them! Gunpowder is carbon, sulphur and saltpetre. Saltpetre can be made from [urine and faeces](https://en.wikipedia.org/wiki/Potassium_nitrate#History_of_production). After extracting those from the corpses, add concentrated sulphuric acid, (which can be made from [sulphur saltpetre](https://en.wikipedia.org/wiki/Sulfuric_acid#History)) which should break down the corpse into mostly carbon. Then just add sulphur. ]
[Question] [ I am constructing a world where a small number of giants coexist rather well with humans to the point where any distinction between the two is rather moot. Government, armed forces, and, for the most part, culture, all are shared. This shared culture, however, extends as far does in our world; there will always be that other nation, that other people, to be at odds with. War eventually breaks out between two nations and men are rallied to the front lines to fight. For story purposes, I'm sending giants to the battlefield in tandem with a human rider. This is necessary because they are forced to work together in order to be an effective unit. Unfortunately, I can't figure out any reason a giant might realistically need a human to be an effective unit. They're basically just over-sized soldiers. It appears to me that there is no reason for them to be there, but I don't want them just sitting around during the fights. Hence... **For what reason(s) would it be necessary or prudent for a human to ride with a giant into battle?** Parameters: * giants are ~16m tall * giants are equivalent to humans in most regards except size * giant weapons are essentially large caliber naval guns modified to be fired by a giant (single shot) * giants are armored about as well as a battleship * giants biology can comfortably handle its weapons and armor to the degree a human soldier can with modern body armor * giants are treated first a giant destroyers, then used for other tasks (like crushing tanks and other equipment, or troop transport) * world's tech level is late WW1 (though some tech from very early WW2 may be possible) * if any of the above need to be amended for answer, feel free to do so within reason [Answer] Short version : **Your giants are essentially (oversized) tanks. Use them like tanks. Kill them like tanks.** > > giants are ~16m tall > > > Let's start with size and armor. At 16m tall and roughly human shaped you'd expect their width to be something like 2m. Battleship armor was typically around 2m thick. So the would be completely unable to move. Human armor (for a knight) would typically weight of the order of 45 lbs ( so about 20 kg ) and between 1mm and 3mm thick (varying over the body), so let's use 2mm on average. The giant should be able to manage thicker armor, but only really in proportion to it's height, so maybe 8mm-24mm thick. For reference a an early WW2 Panzer III tank would have had a max of 30mm armor, and many tanks had less at the start of WW2. So your giant is in pretty good shape with e.g. 10mm plate armor. > > giant weapons are essentially large caliber naval guns modified to be fired by a giant (single shot) > > > A human might carry e.g. a gun weighing, say, 4 kg and that's for a man weighing something like 80 kg (and these are really rough figures). So gun weighs about 1/20 th of the human's weight. So scaling that up, your giant might be 16mm tall, but the mass will be something like 512 times that of a human. So the gun can be about 2000 kg. That sounds like a lot, but two problems arise. Firstly recoil. A big gun will have a *huge* recoil. Ever see what happens when a tank or battleship fires it's main armament ? Which is why human guns fire small bullets ! A 0.45 caliber bullet would be roughly 16 grammes. So your giant, even with a 512 multiplier, is only going to fire slugs that are at most 8 kg each. A more realistic type of weapon (if you insist on a large caliber artillery type piece) would be e.g. [the British 15 pounder](https://en.wikipedia.org/wiki/Ordnance_QF_15-pounder) which had a barrel and breach weight less than 2,000 kg and fired 6.4 kg shells. This was a WW1 weapon. You probably want to use some kind of armor piercing round and equip your giant with high explosive rounds (a mix, like a modern tank would). > > a world where a small number of giants coexist rather well with humans > > > So we have a large armored "vehicle" with a modified artillery weapon. There are a relatively small number of these "vehicles" so the majority of your troops are human, with the giants (i.e. the "tanks") deployed in whatever manner your tank strategy dictates. Giants can also perform recon (16m tall and a telescope and not much gets hidden easily :-) ). Humans are ideal for e.g. entering buildings, ambushes, killing other humans (they ought to be good at it by now) and doing those logistics things your giants could be spared from. Which is where the the problem lies. At 16mm tall your giant is more or less oversized for the firepower you get back. They'll need a *lot* of support resources (like food) and "repairs" (medical care) will be a challenge on a battlefield. But assuming you can work around that, you have large tanks that will also perform useful functions like recon. Some giants will be dedicated to anti-giant roles (guns designed for killing armored giants, probably less useful for human support roles). Some will be scouts ("run over there have a look") and heavily armored but not armed much. Some will be APCs, some will be a kind of main battle tank. In their APC role they'll be carrying humans (and 10 humans per giant is a rough estimate). In other roles they'd probably have support humans (say three or four) doing things like spotting, comms, and other things that a tank crew would do, including manning machine guns to defend against human attacks on the giants. [Answer] **To clear IEDs and other traps** If giants are so well armoured that small arms wont hurt them from afar and you do not yet have armorpiercing very high velocity weapons or guided missile systems, there pretty much two options to kill a giant: * Closing in on the giant really fast and then wounding him at weak points with a spear, a gun or sticky anti tank grenades * Placing mines or other explosives in the path of the giant In those cases the rider would be needed to: * Fight approaching riders or vehicles * Demine the area by being lighter and more agile. He won't trigger an anti tank mine so he can defuse it or destroy it with explosives. The giant would offer a too good target if he put down his gun to clear mines as he already will have a lot of downtime by reloading such a big gun. So the riders job is to make sure the giant can just focus on firing his gun and charging as fast as possible to avoid being shot in the open field. [Answer] I'm wondering how you expect a Giant to be as well armored as a battleship. The Giant would barely be able to move around if only because having a meter of armor around their joints would impede them too much. Also Naval Guns tend to be long, the Iowa class guns were 20m in length so they would have to use a shorter version which would limit their projectile velocity and thus effectiveness. Even tank guns are a sizeable portion of the Giant's length, making these guns unwieldly. Even if you assume a Giant can somehow carry all that despite the square-cube law he's going to be rather burdened by that. It's far more likely he's carrying tank armor and tank guns, although I would think they would be more like AFV's than tanks. Anyways, reasons to use infantry next to your Giants with the unlikely armor+armaments: * Scouts * Communication (with radio's and such) * Repairing and maintaining gear of the Giant * Anti-armor support with missiles and such. Tanks would still be a threat despite battleship armor because of the squishy Giant inside. A HESH shell would do squat to a battleship, but a shockwave going through the brain/lung/bloodvessles is going to wreak havoc on the Giant and probably kill him. * Anti-Giant support. Whether using armor-piercing or a superheated jet of a HEAT round or just HESH weapons, the use of infantry-based AT weapons are going to be effective against the joints of the Giant where the material has to move with the joints and can't be as thick. This can incapacitate Giants if not kill them with a shot to the neck for example. * Soft terrain traversal/terrain scouts. These Giants even without armor will weigh well over 100 tons, with armor it's likely they'll exceed 500 tons (because that armor is going to weigh more than the Giant). This isn't going to be nice travel when you hit soft ground where they'll likely sag into the ground, get stuck and starve unless some heavy-duty cranes get brought in. Cranes that just like the Giant need to be careful with what ground they stand on even before they lift a 16m Giant in full battleship armor. * Building capture. You can't capture buildings with tanks, and you can't capture buildings with Giants. [Answer] I think this comes down primarily to the ratio of giants to humans in the world. The fight would looks different if there are many people, or many giants on the battlefield. **Many humans, few giants** In this case, your giants would be working as tanks, mobile fortresses or some version of a land ship. People could be used to service equipment, make repairs if something is damaged. However, since in this case the giants are a valuable, limited unit, the person's best use would be to disable another giant. A few other people have suggested that the giants are similar to tanks... However, they are different in one important way: the giants are tall, tanks are not. Here's what I'm thinking: The human is equipped with a wing suit, and a grappling hook on a long line of steel cable. The giant throws the human at an enemy giant (slightly to one side - the wing suit could be used for fine adjustments). The human lands the grappling hook so it attaches to the enemy giant, and begins swinging around it. After a few revolutions, the trailing cable might have trapped an arm, bound a leg, or fouled other equipment, thus disabling the giant until it's own human crew removes the restraints. The wing suit should be able to get back just fine, acceleration due to the conservation of angular momentum should boost his speed for the trip back. The human projectile could be equipped with a suicide explosive on a timer (could be disabled on the trip back) in case they die on the way over to - or at - the target. **Equal giants and humans** On a battlefield of exclusively giants with a human rider, perhaps the humans could be some sort of navigator, effectively directing and co-ordinating the giant's movements, while the giants focus on destroying things. If you are going for WW1 tech level, wireless comms would be limited if they existed at all for individual units (possibly only for unit commanders?). If your world doesn't have that yet, I would suggest some form of semaphore that the humans would operate. The idea of a human sniper mount is attractive, but the movements of the giants would probably make that difficult, at best. Perhaps there is some sort of stabilized platform, or turret system for the human mount to ride in? **Many giants, few humans** In this case, the humans are the commodity. Here, I think their best roll would be as medics, using their smaller size to crawl inside the giant's armor to cauterize wounds and stop blood loss. This would not be terribly pleasant for the giant, but it just might save his life. The human could be passed to wounded giants as needed. [Answer] **Anti Giant Slayers** From what I can tell the Giants are like a walking tank or fortress. The enemy would use human infantry to scale the giants to place explosives or poison on weak spots to ether cause damage or be lethal. The giants would have a hard time to see anyone let alone countering them, with all that Armour it would be also is hard to move… at all. So having a man (more likely a squad) be placed on crow-nest like spot or a pill box (metal Armour would make a good hiding place for them) or have them grapple around freestyle like for some cool parkour. The human riders would counter Giant Slayers from inside or rush out to meet then (riders could also mount another giant when engaged in close melee to do the same as the Slayers) also to do maintenance on the armour like a tank crew. [Answer] From what I'm seeing, your giants are basically a moving fort with a REALLY big gun. But here's the thing: giants are slow, and so are their weapons. A castle standing wide open is a sitting duck. Your humans can act as saboteurs or defenders, using grappling hooks, wing suits and climbing claws to freerun around the giant, repairing armor, treating wounds and fighting off enemy saboteurs. When on the offensive, they could plant explosives or inject poison into armor chinks. Battle could be accomplished by retractable blades built into their gauntlets, along with their grappling hooks and claws. It would make some pretty epic battle sequences, as human crews slug it out while parkouring around a FUCKING GIANT. [Answer] **Make the human guard the giant's back.** Maybe the giants have trouble turning around, and take a while to respond to an attack from behind, like really slow elephants (or crocodiles; while on land they're terrible at turning around and can be easily ambushed from behind). Any giant with this limitation could really use a second pair of eyes to literally watch his back. [Answer] The giants could use smaller humans as extra eyes. Target over there. Watch out, they're sneaking up on you from behind. The small humans wouldn't add much to the giant's burden, and could provide valuable intel in combat. This is very similar to tank warfare. One thing that isn't often mentioned is that tanks without supporting infantry are vulnerable to attack by enemy infantry that are too well concealed to see until they're close enough to do real damage (antitank rockets, explosives, flamethrowers, etc...) [Answer] Maybe the giants are long-lived arrogant intellectuals who value their lives more than the expendable humans (or "sub-giants", if you will), and so prefer to send the humans into battle as cannon fodder, and only risk themselves when tactically necessary. And then there's the old square-cube law, which states that the bigger you are, your strength increases by the square of the size increase factor, but your weight increases by the *cube* of the same factor. This means giants are slower and tyre more easily than those sprightly humans Also, giants would find it a lot harder to hide in trenches and would be terrible at guerilla warfare, or as sappers / commandos / etc. [Answer] **Point Defence** A Giant (as a walking artillery piece) is going to need defence from smaller foes that it can't use its cannon on or merely stomp. A couple humans with WW1 era Maxim guns (or the older Gatling Guns) mounted on pintles attached to the giant's harness would be sufficient to repel anything the cannon is unsuited to killing. **Tech Support** A Radio-operator could help coordinate the giant with the rest of the army. Whether calling instructions to the giant, or simply operating the radio itself while the giant wears an earpiece. **Spotters and Snipers** The 16m height of the Giant serves as an impressively capable mobile watch-tower, A couple men armed with long rifles and binoculars could take advantage of that to spot approaching enemies and slay them at a distance. [Answer] > > For what reason(s) would it be necessary or prudent for a human to ride with a giant into battle? > > > The Giants would need the Human as loader for their Guns. As usual for artillery pieces of that time, you´d have a loader (human) and a Gunner (giant). The different varieties of shells could be stored in a magazine on the giants back for better protection from potentially fatal ammo explosions. The human would load the desired shell over the giants shoulder and then crawl down his back to retrieve the next. This essentially makes the giant into a kind of biological [battle-mech](https://en.wikipedia.org/wiki/BattleMech) with WW1 technology. ]
[Question] [ (This question goes more in depth from a previous question.) **Imagine This**: 1. The "Black Box" is a mind vault for a few humans who created it, the humans wanting to survive a nuclear war happening on Earth. 2. A child who grew up with her mind in the vault has known pain, this is because her parents wanted her to know the feeling when their minds are later transported to mindless bodies. She's felt small things because her parents didn't want to hurt her. What would the effects be on the child if it's never truly known the consequences of getting hurt? (The child has always healed almost immediately after feeling pain because her parents feel terrible after inflicting the pain.) When she gets transported to her mindless body, how will she react when she gets injured? Because she's been in the Black Box setting her whole life, how will she adjust to a world recovered from a nuclear attack? [Answer] **Psychology isn't actually a hard science** I am not obtrusively trying to give you a non-answer, but psychology is not like chemistry or physics where you can pretty much know that if you do A to B then C will reliably and verifiably happen every time. Psychology is a combined product of genetics, parental behavior, childhood environment, culture, and is also subject to the interpretation of and the psychological reaction of the evaluating party. There are people who were beaten and horribly abused emotionally every day of their lives who grow up into perfectly functional and well-adjusted people, there are kids from wealthy well to do sedate and supportive families who will randomly decide to start shooting meth and mutilating cats at age 25. In psychology, we cannot look at any one thing and say "yup, you spanked yer kid too much and laughed at their Halloween costume when they were 5 so now they're going to have a midget fetish." Psychology just can't do that, it can observe trends and try to isolate factors that seem to have a greater influence over certain behaviors, but nobody on this planet can with any certainty tell you how a person is going to psychologically react to anything. A wonderful example of these experiments in using psychological warfare. The idea was for a device that dispersed a gas that smelled bad enough to chase rioters away without the harsh and violent effects of teargas. It failed because people's idea of what smells bad is not a fixed thing. People from Japan found the dead fish formula to smell delicious, people from Paupau New Guinea were repulsed by the smell of baking bread, people from India only found the scent of raw sewage mildly annoying, etc etc. What the tests ended up confirming was that you cannot predict how everyone will react to anything. So in summary, there is no way to answer your question scientifically. Your character can react to this circumstance however you wish to write them doing so. [Answer] **Empathy.** Your child can learn to be empathetic growing up in the box. Then she can be empathetic with herself. [![Theres no crying in baseball](https://i.stack.imgur.com/H30nr.jpg)](https://i.stack.imgur.com/H30nr.jpg) <https://en.wikipedia.org/wiki/Empathy> what a great photo. > > In empathy we feel what we believe are the emotions of another, which > makes it both affective and cognitive by most psychologists. In this > sense, arousal and empathy promote prosocial behavior as we > accommodate each other to feel similar emotions. For social beings, > negotiating interpersonal decisions is as important to survival as > being able to navigate the physical landscape. Emotions motivate > individual behavior that aids in solving communal challenges as well > as guiding group decisions about social exchange. Additionally, recent > research has shown individuals who report regular experiences of > gratitude engage more frequently in prosocial behaviors. Positive > emotions like empathy or gratitude are linked to a more positive > continual state and these people are far more likely to help others > than those not experiencing a positive emotional state. > > > In the box, the adults construct what they hope will be a lifelike world for the kids who grow up there. Kids there learn empathy for the virtual people whose emotions they share, even though they do not share the physical sensations. A young child who has never been stung by a bee can comfort and shed tears for a playmate who does get stung by a bee. She recognizes the emotions as like her own. Likewise your girl recognizes the emotions of the virtual people as like her own and feels empathy with them. This is such a cool scifi premise. Your protagonist will be surprised by the physical sensations she has barely experienced but we run into surprises like that our whole lives. The cool thing will be her empathy, which is unchanged over the transition from virtual to real. Earlier in the story you have shown her to have that ability. Then she uses it with herself - her own bodily self of blood and bone which seems like a stranger, but which has characteristics familiar to her from her life before, and with which she can empathize. [Answer] There is a compelling argument that we have created (or are at least in the process of creating) such a world as this now. Many societies have now banned corporal punishment in schools and have active programs to address bullying and the like in both an online and school environment. Imagine (if you will) that a specific child exists in a perfectly monitored environment and as such, does not get smacked for a transgression but is given some other non-physical form of punishment. Also, bullies are sanctioned for their behaviour before it escalates to physical violence, and as such neither the child who misbehaves OR the bully feel the consequence of their actions in a controlled environment. TCAT117 is essentially correct in that there is no hard and fast rule that will tell you what's going to happen in every case, but there are some broad personality types from which we can extrapolate. For one, the Bully (thinking that he can now get away with his behaviour as an adult and with monitoring not as strict), walks into a bar, picks on the wrong guy and gets beaten to within an inch of his life by that guy's gang. The misbehaver pretty much ignores the rules of society and walks into traffic. Truck V Human; the human normally gets the silver medal in such scenarios. I want to stress that this is not a missive extolling the virtues corporal punishment OR letting bullies get away with their behaviour; what I'm saying though is that the reason why schools are a controlled environment is so that children can test their boundaries and get hurt in a way that ensures nothing permanent happens to them in their formative years. Humans learn by action / stimulus / response pairing. What your scenario (and my hypothetical hyper-vigilant school) both have in common is that remove the stimulus (consequences) of a poor choice. That means that when a child chooses to act in a particular manner, they don't learn what the real world does in response. When they 'grow up' and get put into organic bodies for the first time, THAT'S when they start to learn. The problem there is that by then, their formative years are over, habits from their online existence are already set and the consequences are more severe because their environment is no longer so tightly monitored or controlled. Let's not mince words; some choices in the new (real) environment will be fatal. Some of those choices could have been avoided if the lessons had been learnt earlier. BUT, everyone will be in the same boat. You'll end up with a society where everyone of a certain age will possess the same shortfall of experience and society will adapt to cater for that. This is actually now happening in reverse in many advanced economies. Since women have been actively welcomed into the workforce in many countries, child care has become an industry. In Australia, it's a very tightly regulated industry that incorporates early learning / education. In practice, this means that students are entering school far better prepared than previous generations, and children of stay-at-home parents (either mother OR father) are actually at a disadvantage. Many single income families in Australia now actually still send their children to childcare part time before their school years so they pick up the social and learning skills that are being taken for granted in their first years of school. Ultimately, what you're describing is the point at which experience becomes a bigger factor in learning and development. Today, it starts to happen in child care; in your world, it can be as minds enter the biological world. Either way, if the majority of people start to gain experience at the same time, society adapts to cater for the expectations an increase in (or lack of) experience implies. [Answer] I can't say much about her psychology, but there are going to be physical effects on her body. How she copes with these are going to largely be based on how much she's been trained and educated to cope. And how much of that training has been **realistic** (e.g. she practiced first aid in stressful virtual reality simulations) or **academic** (e.g. she sat in a calm, peaceful library and read a book about first aid). For instance: 1. Minor cuts and scrapes. Not life threatening, but if she doesn't know that she shouldn't scratch and poke at them, they could get infected. Which can mean anything from just a bit inflamed and itchy to life threatening sepsis and gangrene. (Does she have soap, antiseptic/disinfectant and antibiotics?) 2. Headaches. If you get one because of a bump on the head, you can see cause and effect. But if the source is stress or something she ate or the first symptom of a cold, then she might think *Something is wrong with my brain!* And start worrying about brain tumours or that her mind hasn't downloaded properly into the body and is unravelling. 3. Bad injuries can cause her body to go into shock. 4. Stuff that hurts and gives her a fright (bitten by dog, fall off a ladder, spill hot coffee on herself) will also cause an adrenaline surge. Her heart rate will go up, and she'll get the Fight, Flight or Freeze response. If she has never experienced a pounding heart and increased breathing rate, she may escalate herself into a full blown panic attack. 5. Bruises. They're ugly, they last for ages and they go weird colours. That one was red, then it went purple and now it's an icky yellow colour. Is that normal? I'd better go to the doctor to ask! 6. Insect bites. She didn't notice the bites but she's woken up with these itchy red spots. Scratching them makes them worse. Oh noes! I must have some terrible disease like measles or chickenpox. 7. Muscle aches. She may not know you get stiff and sore after unaccustomed exercise. It's so unfair! Helping Mum to carry that sofa up the stairs didn't hurt at the time. 8. Everyone's had some ache or pain that was bad enough to make it difficult to sleep. If she's never experienced pain, then a minor thing that you or I could ignore may keep her wake. After all, her whole life experience is telling her the pain hanging around is *not normal*. I hope she's not a hypochondriac! :-) She might act like a hypochondriac or someone suffering from man flu until she's used to what is 'normal'. [Answer] I see two possibilities here. It partly depends on how old the child is when their mind is transported to a physical body. 1. The child does not understand that in the physical world they may experience pain greater than what they experienced in the virtual one. In that case I'd expect them to be initially extremely reckless with both their own and other people's safety. Setting people on fire is fun and is no big deal - it hardly hurts, because nothing does. However as they experience the physical world they will quickly adjust their behavior. 2. They do have some understanding that things are different in the physical world. In that case they may be the exact opposite - extremely cautious and risk-averse with both their own safety and others. In this case it may be harder for them to learn that pain is not quite as bad as they fear it to be, if they never experience it. [Answer] **These children would likely be highly empathetic and kind to a fault** Studies have shown that people have varying political leanings based on [how they think](https://www.nyu.edu/about/news-publications/news/2020/november/conservatives-and-liberals-motivated-by-different-psychological-.html). These studies also show that conservatives generally have a stronger fear reaction than liberals. And this setup would likely mean that those affected have a massively reduced fear reaction to things since it doesn't occur to them that they might get hurt. The end result is that they'd be much less risk-averse than some, and thus much more willing to dive head-first into a fire to save someone. Fortunately, the people here expose their children to at least some pain, so they do know what it is and that it should probably be avoided, so they won't be completely suicidal. And this lack of fear on their part would mean there's not much holding back their empathy. I, as a person who generally doesn't get scared, have personal experience with this; I often find things such as spiders cute while others find them terrifying, and I am a big fan of showing empathy and compassion to others. I imagine that this would show up in, and even be amplified by, the children not suffering any sort of pain. They'd be perfectly willing to risk life and limb for others, be calm when everyone else is panicking, and consider things like tigers, lions, and rattlesnakes to be pretty cute. ]
[Question] [ So I was reading this article recently, titled *Stellar Outburst Brings Water Snow Line into View*: <http://www.eso.org/public/news/eso1626>. In short it's about a protoplanetary accretion disc around a young star. The closer the disc is to the star the hotter it gets. But on the farther side of the disc it can get cold enough for water/snow to collect. *See the article for details*. First of all, holy wow! Secondly, that gave me an idea for something similar to Larry Niven's Smoke Ring from his Integral Trees books. There must be an area in the accretion disc where the water/snow line is warm enough for the water to remain liquid, just between too hot and too cold. I know I'm stretching here and it would take all kinds of handwave. The speed the disc is spinning at is probably too great to allow for it; The disc itself is probably too turbulent; All the stuff in it probably mixes up chaotically; It all gets pulled into the star; Radiation, etc. etc. But in the article it reads that the outer edge of the disc (the water/snow line) was as far away from its star as Pluto is from our sun. At that distance maybe the conditions of all that turbulence are lessened. Move that area in closer to the star, say to the goldilocks zone, and you might get a water/snow "zone/ring" that is warm enough and stable enough for the conditions I'm looking for. **Could that band be large enough that creatures who could breathe water could live and swim around in it?** *Sub question: What with all that stuff in the disc being the matter that later creates life could life originate in that area?* [![enter image description here](https://i.stack.imgur.com/B34rX.jpg)](https://i.stack.imgur.com/B34rX.jpg) [Answer] I'm going to science this question up, with graphics and links to research! This is the phase diagram for water. ![Phase diagram for water](https://i.stack.imgur.com/aiErv.png) As you can see, it takes pressure for water to be a proper liquid. In a vacuum, it goes straight from solid to gas and vice-versa. It would take approximately 0.6% atmospheres to allow for liquid water. As low as that seems, it is still much more than what you would get in space. But don't give up just yet! ## [Interstellar Ice Acts Like a Liquid in Ultraviolet Light](https://www.space.com/38321-interstellar-ice-liquid-ultraviolet-light.html) > > When exposed to ultraviolet light, interstellar ice may act more like a liquid than a solid, a new study has found. > > > Researchers discovered this effect while re-creating the conditions of our early solar system's planet-forming disk in a laboratory environment, revealing how organic chemistry might react to the deep freeze of the system's outer regions and how the seeds of planets accumulate material. > > > And what is the biggest UV source in our solar system? Why, the sun itself! Any lifeforms developing in your environment would probably be slow compared to us. But that's just a detail. The important thing is that **life always finds a way**. [Answer] No, this isn't realistic. I'm considering the same issues for a D&D outer-plane-of-elemental-air campaign setting. Luckily, fantasy is made of handwavium. In real life, the problems won't just be temperature - to begin with, you're talking about two very different kinds of pressure. Consider that at the top of Mount Everest, the air pressure is low enough for water to boil at 71 degrees Celsius. A proto-planetary disk is still very close to a vacuum relative to our atmosphere, so even if it's warm enough for humans - say, 25 degrees Celsius - any liquid water is still going to boil off into vapor. And by "liquid water," I'm also including blood. Without a pressurized environment, the gasses that are soluble in blood will boil off first, giving you the bends, followed by your plasma. Then there's the pressure the star is exerting on the disk. Light and radioactive solar flares will actually blow gases away from the star itself, toward the too-cold region. Speaking of radioactivity, you'd have to construct a magnetic shield to keep human-based lifeforms alive. I remember *The Integral Trees* had the rocky core of a gas giant; if it generates enough magnetism, you might be able to construct some kind of space station around that? But yeah, this requires lots of hand-waving, as you said. [Answer] Just a quick note that it's important to realize that there is no liquid water in a protoplanetary disk because the pressure is too low. There's just water vapor where it's hotter than about 150 K (a little colder than -100 degrees Celsius), and ice where it's colder than that. No liquid anywhere I'm afraid. ]
[Question] [ Edit: Before I give up on this I wonder how could an advanced civilization create conditions *on* a small planetoid (Ceres sized?) to keep an Earth level breathable atmosphere? It seems like its impossible in nature, but what about artificially? Some handwavium is allowed of course. *Edit: I previously wrote "within" a small planetoid. Apologies. I meant ON a small planetoid.* Original question: How can small planetoids (Charon, Ceres, Dysnomia sized[?]) have, and keep, an atmosphere with breathable gases for any kind of extended period of time? I realize that their gravity is low and that might be a reason why it couldn't, but are there any conditions under which they could? For example(s): * Could it be releasing gases of its own from within its core? * Could the core have a tiny bit of Neutronium in it (don't laugh)? * Could a comet have hit it and given it the gases? I am looking for an answer that would exist in nature, but am *open to artificial means as well*. Thanks. [Answer] Put a bag around it. This isn't as far fetched as it might sound. I've seen numerous references to it in science fiction and other discussions. Sorry that I can't find them at the moment. Off of memory this was used in the Quantum Vibe web comic at some point in it's history. The main point is to cover the planet in a very thin plastic sphere and then inflate that sphere with air. If you build some support structure (a ring around the planetoid, for example, you can build airlocks and docking ports. That way you can get to and from the planetoid without ripping the bag. Minor tears from micrometeorites should be small enough to not cause a significant loss of air (small holes in a really **big** bag). It is best if the polymer is self healing but could be patched or replaced in sections. One story had the self healing aspect so high that ships could fly through it and the tears would heal before there was significant loss. One discussion talked about capping one of the Moon's craters with a mylar cover but that was a long time ago and might not have made it to the web. [Answer] # If your gravity is low, you need to be cold [![enter image description here](https://i.stack.imgur.com/LAAGx.png)](https://i.stack.imgur.com/LAAGx.png) I think this is the 25th time this graphic has been posted to Worldbuilding. As you can see, the ability of a planet to hold an atmosphere depends on both the escape velocity and temperature. Lighter gasses (hydrogen and helium) required lower temperatures to escape, heavier gasses (like krypton, sulfur dioxide, or xenon) need higher temperatures. You can see Eris, Pluto, and Triton plotted down there. Pluto does have a tenuous atmosphere of sorts, made of nitrogen, methane, and carbon monoxide. But these gasses are constantly refreshed from the surface of the planet. With surface temperatures in the 40-60 K range, Pluto's surface is cold enough that all those listed gasses are solids. So occasionally some sunlight vaporizes those gasses, and they form an atmosphere. Those gasses then escape into space, becuase Pluto's gravity isn't strong enough to hold on to them, but because of the cold, some freeze back onto the surface and being the cycle over again. Since pluto has a large reservoir of these materials, Pluto isn't going to run out of atmosphere any time soon. But again, keep in mind that Pluto's atmosphere has a pressure of about 0.00001 bar; not much atmosphere at all. # Conclusion Ceres and the like are far too small to hold an atmosphere, at any practical temperature. Even Pluto is too small. The best you can hope for is geological phenomena like cryo-volcanoes to blow a lot of materials out of the center of the planet. These will be lost over time, but could form a modest amount of atmosphere before they were driven off. But then again, [Enceladus](https://en.wikipedia.org/wiki/Enceladus#South_polar_plumes) is also small and has these same conditions, but it isn't holding any atmosphere. [Answer] > > Could it be releasing gases of its own from within its core? > > > Possibly. [Ceres does that](https://en.wikipedia.org/wiki/Ceres_(dwarf_planet)#Atmosphere). She just doesn't do it enough to have a breathable atmosphere. From the link: > > In early 2014, using data from the Herschel Space Observatory, it was discovered that there are several localized (not more than 60 km in diameter) mid-latitude sources of water vapor on Ceres, which each give off approximately 1026 molecules (or 3 kg) of water per second. > > > And unfortunately, even if she upped the amount of gas she generates, she probably would not be able to keep it ([see the page 19 of this article](https://web.wpi.edu/Pubs/E-project/Available/E-project-082913-230527/unrestricted/MQP1.pdf)). Now, Ceres is mostly rock and has little water. But think of Europa. That one has enough ice to make for an atmosphere if heated up enough. > > Could the core have a tiny bit of [Neutronium](https://en.wikipedia.org/wiki/Neutronium) in it (don't laugh)? > > > Very unrealistic, and even if you handwave it, very troublesome. Neutronium should only exists in the core of dead stars. It is very dense, by definition. So a very small portion of it would do for a planet that is over 99.9999% gas in volume. However, remember that even if gravity is close to zero in the center, that is still where everything is pulled towards. Every dead mass in your planet would clobber up there. > > Could a comet have hit it and given it the gases? > > > One single comet, no. But multiple bombardments through millions or billions of years could do the trick. Remember that with little gravity, you may lose a lot of gas to space on every impact. So your net gain from each individual impact might be little, or even negative. [Answer] Since you asked, "... within a small planetoid...," then may answer is to hollow out the planetoid and live inside it. The gases that you want may be trapped inside an existing rock, much like helium is trapped by layers of rock in American natural gas fields. Living on the surface of the Earth is possible partly due to: * The thick atmosphere protects us from most space debris and radiation. * The thick atmosphere regulates day and night time temperatures. * The magnetosphere protects us from the solar wind. To make up for this on Ceres, you need buildings with shielding and the most economical choice is the local rock. But the bag idea has some merit. It should be possible to create a hollow sphere with a 600 mile diameter by heating and inflating a balloon. Unlike a traditional balloon where all parts expand at the same time, I envision inflation plants roving the surface of the growing sphere. These plants heat local areas and allow the sphere to expand as a series of 'warts'. As the sphere expands the material thickness decreases, but this is an opportunity for vacuum welding. New material is added by the inflation plants to restore the thickness of the sphere for optimal heating and expansion during the next pass. <https://en.wikipedia.org/wiki/Vacuum_cementing> After all of that work, you have a giant bubble that will fit Ceres and it will have a slight atmosphere inside, but very little structural support. So the bubble would be layers of bubbles, which also provides redundancy against leaks and acts as insulation. [Answer] I have found "[shellworld](https://www.space.com/23082-shell-worlds-planet-terraforming-technology-infographic.html)" article to match your description. The shell floats above the atmosphere and its sheer weight adds atmospheric pressure. Just don't understand why it is opaque with artificial lighting. I can picture autonomous robots roving the surface and mending meteorite punctures. Obviosly, the shell must have an area designated to carry a spaceport and a gate. [Answer] Ok my first thought was Larry Niven's "Integral Trees"... which if memory serves, describes an entire torus of environment in orbit around a star. The titular trees grow inside the band, in a state of perpetual free fall. Individually they are too small for their own environment, so they live inside a self contained environment. What about a parent planet... The planetoid doesn't need to OWN the environment, just be inside it... a gas giant made of oxygen and hydrogen with the planetoid inside it's bounds? A tiny singularity generating enough gravity to hold oxygen, but not enough to devour it, with the planetoid orbiting that, while the singularity orbits the sun? [Answer] It could exist inside an unusually dense [gas torus](https://en.wikipedia.org/wiki/Gas_torus). Similar to Niven's Smoke Ring / Integral Trees. This would be more likely if some gas giants are involved in addition to the small planetoids, especially if you want it to be stable for any period of time. It would require just the right positioning of planets for the gravity and magnetic fields to maintain the gases in place. The small planetoids gravity would cause a localized increase in density in the torus making a denser atmosphere around the planet. Atmospheric gases lost to space from the planet would go back into the torus and be replenished from the same source. This is highly unlikely, but could potentially occur naturally or artificially by a very advanced civilization who decided to move some planets around. [Answer] To keep an atmosphere all that you need is a gravity well. The most obvious way of compensating for a shallow gravity well is a lower temperature, which decreases the gases' average speed to well below the escape velocity. But if alien technology is in the equation, you can place a stabilized black hole in the center of the planetoid, so that surface gravity increases. Having Earth surface gravity will not be quite enough because the gravity well, while now deep enough, is *small* - gravity falls off more sharply than on Earth. I think you can safely enough imagine a surface gravity as high as 1.5, and some outgassing from the planet's mantle should do the rest. Being a planetoid, it's doable to have huge deep deposits of water ice and frozen nitrogen. The timeline goes more or less like this: * the planetoid (total mass that of, say, Ceres) forms, with lots of frozen water ice, nitrogen, carbon dioxide, perhaps methane. * the planetoid gets covered in cosmic dust, fragments, loose rocks and dirt from the asteroid belt. * the Handwavers come by and drill a hole to the center of the planetoid, and place a Cosmic Cruncher in position. * the Cruncher activates and a shielded black hole forms, crushing most of the planetoid into a volume one tenth as before, and increasing its temperature through gravitational collapse. An atmosphere forms, and small liquid seas. * on average, accounting the central black hole, the "density" of the planetoid is one hundred times Earth's. So its radius could be one hundredth of Earth's - just 67 kilometers - and the surface gravity would be the same (a smaller radius translates to a higher surface gravity). Of course, having one hundredth Earth's radius means 1/1003 its volume, and a density 100 times higher only corrects mass to 1/1002 - one tenth of a thousandth - of Earth's. This means that atmosphere retention capacity (which depends on mass) is *also* about 0.01% of Earth; if Earth can keep its atmosphere for ten billion years, our planetoid's will only last one million years; of those, perhaps one-two hundred thousand years will have an acceptable atmosphere. Outgassing will help there, if needed. ]
[Question] [ **This question already has answers here**: [Explaining "Half-Breeds" in a world with multiple races](/questions/143/explaining-half-breeds-in-a-world-with-multiple-races) (7 answers) [Can a reproductive system that allows interspecies breeding be made believable?](/questions/70471/can-a-reproductive-system-that-allows-interspecies-breeding-be-made-believable) (16 answers) Closed 5 years ago. How should I justify different intelligent species being able to interbreed (and potentially produce healthy and fertile offspring) in a fantasy setting, especially if I want it to not just boil down to "The author said so"? Considering some real-life examples, like humans with dwarves and elves it seems feasible, as one could just say that they're closely related, like how Neanderthals interbred with modern man, closely enough that it's not an issue, but what about when that's not the case? Or when it's between a human and something harder to justify a relatively close relation with, like a troll or ogre/orc or goblin/merfolk or something? Or what about in situations like human/dragon hybrids (assuming that shapeshifting doesn't change you genetically into the species you're becoming), or human/merfolk? I was actually inspired to ask by thus by reading on TV Tropes about D&D's examples of hybrids. [Answer] Magic. Don't have procreation in your universe work on principles of modern genetics. Instead get inspired by how older cultures imagined procreation to work. These models were usually far more esoteric. For example: When two creatures mate, don't think of it as a mating of their genes, think about it as a mating of their souls. When two creatures ~~have sex~~ really, really, really like each other, their souls connect to each other and a new soul is created in the reproductive system of the female. So the chance to crossbreed between creatures depends on their psychological similarity, not their physiological similarity. This model also creates some interesting plotlines for traditional marriages. An arranged political marriage will have a low chance to result in children unless the partners find a way to connect to each other on an emotional level. It might also open up the possibility for lesbian couples to have children, if you want to. You could even allow male creatures giving birth to children under some circumstances. There are some examples from Greek mythology for this (Zeus gave birth to Athena through his forehead). [Answer] A slightly more sciency approach. Let's start with the tenet that `a species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction` (that's wikipedia take on species). So: 1. They are **not** different species after all. Just like dogs, despite the variety of looks, belong to the same species and can interbreed. [![dogs](https://i.stack.imgur.com/Fny1R.jpg)](https://i.stack.imgur.com/Fny1R.jpg) 2. They are different species. Then, either the offspring is a sterile hybrid, which could add some particular flavor to the story (think donkey and horse mating), or the reproduction does not follow the tenets of biology. For the second case, you could imagine that reproduction happens by infusing a life-spark in an adequate medium, e.g. by moulding a special type of holy clay and infusing it with one drop of blood from each of the parents (borrowed from the Prometheus myth). The clay will then grow following the inclinations and looks of the mix of the parents. [Answer] Mythologically speaking, there's precedents to draw on to establish a world. Zeus was notoriously fecund, birthing demigods left right and centre as various mortals caught his fancy. You might draw on that for some half-humans - in the times of yore the minotaurs were the offspring of a god in bull form and a human, hence they're essentially humans in spite of appearances. Perhaps an elf is really a half-tree human. Some shapeshifters can take the form of humans: selkies, legend has it, had a cap that allowed them to turn into seals. Some fishermen would steal their caps and hide them, so they could take them for brides. Thus, their children would be part selkie. Occasionally an unfortunate mortal would be transformed by magic. For example, one Chinese myth concerns a little boy who swallowed a magical pearl and became so thirsty he drank down a river, transforming into a dragon. In the greek tradition, Arachne was transformed after offending the gods. Perhaps, even after the magic, they are in a way human. Another myth goes in the opposite direction: A snake falls in love with a man, and uses magic to transform herself into a human to court him - aided by a fellow snake who transforms herself too and opposed by a jealous terrapin in the guise of a monk. Over generations, perhaps the truth of their animal heritage may slip through. Finally, there is the idea that some paleolithic depictions of animal-headed humans in truth depict shamans trying to gain the power of animals - it's certainly plausible in your world the non-human races are the product of success in this endeavour. Hopefully these concepts will give you some useful directions for how interspecies breeding might be justified from a mythical point of view [Answer] Scientifically, you can't, but this is not strict science, so maybe there is a pseudo-scientific approach. Suppose all your intelligent species were basically one species, but with genetic variations? Each of your intelligent species would then effectively become different races with the potential for interbreeding. A particular combination of genes would give you classic dwarf features, another combination would give you elves, and so on. You would need to work out what those genetic traits were, and come up with an explanation why races would usually, or at least historically, not interbreed but that does not seem a difficult task. Then, to work out what an elf/dwarf hybrid would look like, for example, you mix and match those genetic traits. [Answer] Our real-life DNA-based protein-encoding stuff is a finely tuned and interwoven system that simply doesn't produce viable offspring if you mix DNA that's too different, because it only takes one tiny chemical process to fail somewhere for the whole organism to fail. If you want to explain fantasy creatures in those terms, you're painting yourself into a very small and uncomfortable corner. The closest you could get is saying that the basics of life are much more universal on your world and creatures have additional "DNA" on top of the basics that modify the template in a mostly non-breaking way. For example, the "DNA" for wings would add an extra pair of limbs to the template and change them to be wing-like. If the creature also has scales DNA, the wings will be scaled, if it has feathers they'll be feathered. Interbreeding would mean the offspring gets a mix of properties from the add-on "DNA" and if those don't conflict too much it will be viable. If it gets wings "DNA", it will have wings. They might not work very well, but they'll grow. However, I would take a simpler non-scientific explanation that doesn't cause readers to go "Hey, biology doesn't work like that!" all the time. Something like this: **All living beings come from the same source/essence, so they can interbreed if it's physically possible. They will then have properties from both parents' essence in some mix.** This way the form is secondary to the living essence. All that's needed is a mix of two parents' essence and a compatible place for it to develop. You can dress this theory up to fit other aspects of your world. Maybe all life starts as the snot spread when the primal deity Achoo smells the air on a new planet and sneezes. ]
[Question] [ So in the tabletop role-play game I'm working on, rodents (squirrels, mice, rats, etc.) occupy a mall, strangely uninhabited by humans. Humans blew themselves up a long time ago, shortly after they discovered automation that rendered them post-scarcity adjacent. Basically, the players live in a mall that stocks itself, in a pseudo-feudal society. The guinea pigs are the ruling class claiming to be the hand of the gods; they control the means by which the mall gets its goods, and to keep the populace at large in check, they uphold a conspiracy that they themselves are the means of production. They also are the clergy and government officials, to keep the trucks a secret. So my question is: **Given that stuff shows up every day, delivered in trucks, already processed into usable materials, what exactly would my subtly oppressive ruling class give everyone else to do?** Jobs that are still known to be necessary: * Repairmen: Even though beds (shoes) and whatnot still show up on trucks, they occasionally fall apart. People need to repair them. Possibly, this would create some sort of artisan class that could learn to fashion their own versions of these goods. * Guards: There are outside threats (cats) that need to be addressed. Because the guineas are noblemen and can't be bothered. * Cooks: The food that comes out of the truck still needs some assembling. * Trading: The guineas need to make it look like the populace has some degree of control, as well as letting goods disperse out from the central city. What else would everyone do? What sort of society would this create, and what would this do to the culture? [Answer] Assuming the automation was stupid and continually making items and delivering them (supply push) regardless of need, then eventually the stores will be overflowing with items spilling from the shelves, filling the loading docks and every available access space. Presumably, the inhabitants of the mall are not going to be daft enough to *not notice* that stuff continues to arrive continually regardless of anyone's wants or needs, which will make maintaining any sort of control mechanism through politics or a priesthood rather irrelevant. The inhabitants will be demanding that the constant inflow of goods *stop*, rather than wishing for a never-ending flow of whatever was included in the last orders. If there is some sort of social and political order, then the need would be to maintain some sort of equilibrium inside the environment of the mall. Unwanted or unneeded deliveries and the trash and detritus of day to day living will need to be collected and placed in the recycle bins, which are presumably being collected by the same robots which deliver the goods, and this is shipped back to the factories to be turned back into the next generation of goods and services..... [![enter image description here](https://i.stack.imgur.com/Te6E0.jpg)](https://i.stack.imgur.com/Te6E0.jpg) *Guess what the squirrels are doing in this diagram....* [Answer] It's important to differentiate economics and politics for this question. Let's start with the economics. Economics is the study of production. In human civilisation at least, everything takes some effort to produce. Sure, that effort may be as 'simple' as planting some seeds, watering and waiting, but someone still has to do that (and this is why we call farming a primary industry). What that means is that everything we produce in the form of goods (like food) and services (like banking) comes with a price because there is a finite supply AND a finite demand, the ratio of which drives the price. In GuineaWorld, some of the supplies that arrive are going to meet or exceed demand, and some aren't. There are also going to be some finite resources that must be maintained, like the mall itself. Buildings require regular maintenance to stay standing and eventually the Mall will fail structurally if such work is not undertaken. In this, we see 3 types of goods in this economy (infinite, finite and irreplaceable) and there are also services that will need to be provided. The infinite resources (those delivered that meet or exceed demand) are effectively free. No effort is expended to generate them, and there's no reason to hoard them or even store them. Finite resources (those for which there is more demand than what is supplied by the trucks) will have a price, as there is some competition for them. That means you need money, but given that services like maintenance need to be provided, some inhabitants will work and therefore have money for the items in higher demand. These become controlled resources in effect, and will be traded between inhabitants meaning that there are also jobs for things like security in this world. Irreplaceable resources (like the Mall itself) represent an asset that if lost, would cause the complete collapse of your society. In our world, this would be the equivalent of salt contamination in farm lands, or extreme climate change. In previous times, human civilisations have either fallen or migrated due to massive and sustained droughts, for instance. In this case, your Guinea Pigs will need to ensure that maintenance of the mall takes place. In so doing, they are effectively creating their own version of an Environmental Protection Agency (EPA) to preserve the longevity of their society. Now for Politics. It's not necessary for the Guinea Pigs to run an authoritarian regime to protect this secret and if the vast majority of goods fall into the Infinite category, the effort may well not be worth the benefit. Ultimately, power struggles, wars, and the like are about controlling resources. That said, if most of the resources are infinite, then your society is almost completely a leisured class, meaning that work is almost unnecessary. Anarchy can work as a political model if no-one's missing out in any way. The trouble with that is that the Guinea Pigs realise that the one irreplaceable asset (the mall itself) still needs maintenance, so some work still has to be done. They don't want to do it, so they set up their government and religion to hide where the goods are coming from because that way, they can take credit for it. If their 'function' is to provide the goods, then they've done their bit and the rest of the society can contribute by doing the maintenance work. On balance it would look like a fair trade to non Guinea Pigs, who don't know that the Guinea Pigs aren't doing a thing; they're just letting the goods enter the economy. The problem with basing an authoritarian regime on a secret is that when an entire class (or in this case species) knows the secret, it's going to come out eventually. The reason why terrorist groups operate in cells is because they know this fact. If 4 people know a secret, the chances of it coming out are roughly 50%. That means you keep your organisation separate from itself, organising yourself into small groups, where only a single member of each cell knows a single member of another cell. All it would take is one disenfranchised Guinea Pig to let the cat out of the bag, so to speak. Sure, you can put in serious penalties for such treason, but once it's done you can't unring the bell. The Guinea Pigs would be FAR better served allowing a contributory government model to form (those who work the hardest in maintaining the mall and performing other services get commensurate government positions) while they maintain a religion that pontificates about the source of the mysterious goods and setting themselves up as intermediaries between the populace and the 'Providers' as defined by the dogma they write. That way, they actually have to do LESS work than they would trying to maintain that authoritarian regime. Of course, that leaves them open if the trucks stop coming one day because no one on the other end is maintaining the production facility. [Answer] **1. Build.** [![PYRAMIDS](https://i.stack.imgur.com/kY14A.jpg)](https://i.stack.imgur.com/kY14A.jpg) Large scale construction endeavors can consume the time and energies of a populace. These might be for good reasons, like the Great Wall of China. Or to glorify a ruler / promote social adhesion like the pyramids, or the great cathedrals of Europe. **2. War.** [![arab armies](https://i.stack.imgur.com/dfXp5.jpg)](https://i.stack.imgur.com/dfXp5.jpg) <http://tundratabloids.com/2017/10/gatestone-the-quiet-islamic-conquest-of-spain/> War has been an outlet for surplus energy and surplus (male) population for all of human history. I was reading about the early Arab conquests: here the inheritors of Islam had a newly unified group of a culture in which raids and acts of valor were the main ways to get status - except now the arabs were prohibited from fighting each other like they had always done. Solution: fight other people! A cool thing about this tack is that in the fighting (and conquering) the victorious Arabs saw a lot of the world that they had not known about before, and the knowledge changed them. **3. Circus.** <https://en.wikipedia.org/wiki/Ludi> [![chariot race](https://i.stack.imgur.com/DpFDD.jpg)](https://i.stack.imgur.com/DpFDD.jpg) <https://en.wikipedia.org/wiki/Bread_and_circuses> > > In the case of politics, the phrase (bread and circus) is used to > describe the generation of public approval, not through exemplary or > excellent public service or public policy, but through diversion; > distraction; or the mere satisfaction of the immediate, shallow > requirements of a populace,[1](https://i.stack.imgur.com/kY14A.jpg) as an offered "palliative". > > > Professional sports was the Roman answer to this. Television is the American answer. There could be other circus-like diversions in this story. [Answer] If this is a post-scarcity world, there is no need to repair discardable commodities such as beds (shoes). Just dispose of the old and grab some new ones. Infrastructure will still need maintenance, though. Look at our society today. Automation is already so advanced and ubiquitous that even though only a small minority of people work in the assembly of cell phones and cars, we have an extreme surplus of those things. Your mall creatures' jobs would probably be more related to services. Think lawyers, doctors, priests, fur/leather/scales stylists and designers, entertainers, news, transportation, cleaning etc. Basically our world nowadays, but with a lot fewer jobs related to growing crops and building mass-manufactures goods. Any job related to making tangible goods will be related to assembly. As to how to make sure that guinea pigs rule the mall, get some inspiration by looking at some dictatorships and/or populist democracies from last century. Also get some ideas from George Orwell's book *Animal Farm*. You could, for example, make it so that all politicians and (high) priests are guinea pigs. Finally - since you have multiple sentient species with a variety of shapes and abilities, probably a lot of jobs will be segregated by species, mostly because some species will excel at some tasks. But this does not have to be an unbreakable paradigm - watch *Zootopia* for ideas on that. [Answer] There would be a need for pest control. Although I think if it were a contest between rodents and cockroaches, the cockroaches would eventually overtake the mall. ]
[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/100784/edit). Closed 6 years ago. [Improve this question](/posts/100784/edit) Imagine a technologically advanced human society (about a few centuries ahead of our time) which has scientifically moved forward in many fields . There is one specific technology however, whose research has slowed down and then stopped over the course of a few decades, due to global fear and general unease towards it. That technology is the generation of realistic simulations of worlds through virtual reality, which can be experienced by people during long periods of time and with great immersion stimulation of senses, emotions etc... What could cause widespread global fear of such a technology in this advanced human society? [Answer] In the original radio play of [Red Dwarf](https://en.wikipedia.org/wiki/Red_Dwarf) on the BBC, there was a VR game called Better Than Life (BTL), into which some people would fall and never come back out. They would eventually die of exhaustion or starvation. There are some documented cases even now of what appears to be people dying of dehydration while playing World of Warcraft; imagine a game where the real world is effectively replaced with a 'better' or 'nicer' world. It would be every bit as bad as a chemical drug. The sad bit is that things like opioids have practical therapeutic benefits when administered correctly and for given reasons. Trouble is, many people abuse these medicines for recreational effects. The same may be true of VR in a future where the virtual worlds are not only indistinguishable from real life, but are so alluring that people just don't want to leave. Ever. All it will take is a few deaths by VR, and many people will want to ban the technology as dangerous. It's sad, but we do live in a global nanny state where not only do the governments HAVE to protect a certain subset of the population from themselves by limiting the choices of the responsible, but there is a growing EXPECTATION that the governments will do this. In such a world, the fear of VR may well be akin to the fear the general population has of things like Heroin. And in many cases, rightly so. After all, the effect that Heroin allegedly gives would have to be similar to the euphoric effect of being the hero of your own personal virtual world. [Answer] **A bad, deadly launch** This VR works by directly interfacing with the body's Central Nervous System. The prototypes looked fine and worked fine, but when it came time for mass production, something went wrong. As a result, the big worldwide launch day was met with catastrophe. Numerous people had terrible reactions to the technology, leading to paralysis, brain damage, and/or death. The launching company also downplayed such responses until such a time that public opinion was already against it, at which time they *still* tried to save face but issued a recall and found/fixed the issue. As a result, many people feared the devices even though they were statistically safer than something like paintball or karate classes. The company that built them stopped producing them since it was no longer profitable, and no other company has attempted to replicate them due to public dislike. The units exist and are used just fine, but occasionally some issue crops up - Usually due to someone misusing the devices - that drives home the issues in people's mind. For some real-world analogies, think of the opinion vs Nuclear power. It's immensely safer than any other alternative, by pretty much any metric, but things like Cherynobyl and nuclear weapons have caused people to equate Nuclear with Bad. Additionally, take a look at Haloween candy and poison/razor blades/etc. That almost never happened, but the small amount of times that it did happen it was given **huge** amounts of press coverage so now everyone's paranoid about it. [Answer] ## It could be that virtual reality once put the entire society in immediate danger The massively negative effects on users of virtual reality such as addiction and negligence of real life needs would be a bad enough. But fear at this level among almost all members of society is likely to have been triggered by some sort of large scale traumatic event. Imagine a world where almost everyone gets hooked to virtual reality and starts showing negligence to real life duties. Politicians would stop leading, researchers would turn their focus away from urgent humanity-threatenning problems (such as dangers of ecological catastrophy). If this had happened and people came aware of it just as society was starting to fall apart, this could act as a global traumatism, incentivising people to turn away from VR. As this was a thing they were dependent up to addiction on, the aversion generated to get away from it would only be so much bigger. [Answer] I am interpreting VR as "cyberspace" in the sense of 80s cyberpunk and similar works. This is mostly a review of prior art. --- # Physical threat from the VR In the [second book of the "Labyrinth of reflections" series](https://en.wikipedia.org/wiki/False_Mirrors) (yep, Russian Sci-Fi again) a threat to a quite successful cyberspace is the ability of an antagonist to kill someone in cyberspace, killing them also in the real world. Think of an extended version of the ability to punch/stab/*whatever* someone into the face via internet. --- # Bad launch and physical threats again A quite well-known anime (and what also not) ["Sword Art Online"](https://en.wikipedia.org/wiki/Sword_Art_Online) basically deals with a very "unfortunate launch" as someone here put it. The inventor of a blend of VR-immerion and MMO game, who also invented the cyberworld helmets, traps the players in the game. Dying the the game also fries the brains in the real world. --- # Simulation with bizzare goals The must-be-mentioned "Matrix" falls into this category. But also the ["Simulacron-3"](https://en.wikipedia.org/wiki/Simulacron-3) novel and its changed in the adaptation (for the best, in my opinion), called ["The Thirteenth Floor"](https://en.wikipedia.org/wiki/The_Thirteenth_Floor). [Answer] Humankind's self esteem lowered with them becoming more and more dependent on AI systems. At the end of the 21st century, most people considered it a ridiculous thought that humans could be able to manually drive vehicles. For a majority of people, the moon landing was a hoax. How could an elaborate plan like this been developed and executed by humans without any AI planning system? Of course in reality, humans still controlled the machines. But it was only a very small minority of experts, cyborgs actually. The general public of "regular" humans instead fell into passivity. Because the real world was now organized mainly by AI systems - and actually it was more efficiently organized than ever before - there was no place left for human ambition there. So human ambition fled to the vast virtual realities people created. In there, they were still the masters. No AI was belittleling their capabilities. People lived long in the 22nd century, so their beliefs and disinterest in the real world lived on long. It took nearly century for a new view to emerge. By those younger people, the cyborg elites were now seen as their heros because they developed and improved the AI. At this point, many people were not longer comfortable with the AI systems taking over and staying in the VR all day. They wanted to be masters in the real world just like their ancestores were and just like their cyborg elite was every day. So they demanded to be augmented as well. A public movement emerged which claimed that "augmentation is a basic right of every human". They saw VR as the manifestation of human debasement. The cyborg elite had always despised the elaborate simulations distracting people from the real world. After a major political struggle between cyborg elites and the general public, the "augmentists" gradually dominated the political systems. Of course in the 22nd century, even anti-VR activists used some kind of basic VR. It was much too expensive and too dangerous to actually travel to Tokio just to have a meeting with business associates there. But they called it CR for Connected Reality instead. And researchers were very keen to stress that their research would not in any way allow to replace reality, which kind of limited the possible novelties in this domain. At some point innovation in VR became unnoticable just like innovation in paving stones. [Answer] Fear is the emotional state that emerges from a perceived threat to physical or mental well-being. Now consider a world with a large availability of rich multi-modal high-quality virtual reality. This means having all the senses stimulated by 'artificial' means in such a way that it can be exploited as being the real world. Why would that be a threat? One answer: totalitarian world domination by controlling people's behavior. ]
[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/97188/edit). Closed 6 years ago. [Improve this question](/posts/97188/edit) Assuming we found some way to resurrect all humans who have ever lived, and that we had the resources to support them all, how could we ease them into modern life with minimal culture shock? This should apply for everyone from a Stone Age caveman to Jane Austen. [Answer] **Most recent first, and with a support structure.** Somebody who died 3000 years ago will be baffled by today's world. Somebody who died last week probably won't be. So don't start with the ones from 3000 years ago. Start with the most-recently departed, teach them the essential post-mortem changes, and then *enlist their aid with the next-earlier wave*. Somebody who died 50 years ago will be surprised and confused by some things, and a modern person won't be able to anticipate all of them. *But* somebody who died 45 years ago will have a pretty good idea of what he's going through, having just made the adjustment himself. So as you work backwards, each "class" of recently revived helps the *next* class, i.e. the next-earlier ones, adjust. For best results, you should match up mentors and revived with as many similarities as possible -- same culture, same language, similar socio-economic groups, etc. You want to take advantage of shared background and shared context, just like some immigrant communities do today. In many cases the best matches come from *family members*, even if this means larger differences in time of death. If you had a good relationship with your grandpa, you're in a good position to help him acclimate. If *he* had a good relationship with *his* grandpa, he can do the same. And so on and so on and so on. You'll need to figure out how to screen for this, though, so you don't have vindictive kids who are upset about the inheritance put in charge of acclimating the parents they're mad at. Possibly the best mitigation is to have groups work with groups instead of pairing people up one on one. [Answer] # Welcome to the After-Life # TL;DR Tell all the resurrected people that they've died and this is the afterlife. Build places that look like their version of the afterlife and let them run free there. Populate these heavens with people of like complexion, culture and era. This will already match their expectations and reduce culture shock. Those souls who don't really like their afterlife can go somewhere else, perhaps join normal society. # Long Answer ## Assumptions * They have the same mind when they died. * The resurrection process brings them back to their prime health (probably early 20s) * Physical handicaps such as lost limbs, metabolic diseases, effects of malnutrition and others have been removed. These are pristine, idealized adult humans. * All memories are preserved. * Whoever does the resurrecting knows a lot about this person, like where they lived, what time, what culture, what cultural status. * Whatever diseases they had has also been defeated, ie, Black Plague victims no longer have the plague and can't give it anyone else. # Cultural Integration There are number of problems with this scenario that will need to be addressed. Bridging the gap between arbitrary to current world culture is going to be tricky. ## Does not play nice with others There are many civilizations that didn't play nice with others, having a culture that demanded domination of all surrounding peoples. A short list, Romans, Assyrians, Dark Ages Christians and Mongols. Resurrection is going to bring back some truly vicious people. You're going to have to find a way to handle those people. It's not Rome's conquest of Gaul anymore and murdering people who don't look like you isn't okay. ## Breeding Like Rabbits Practically every culture until the last century or so placed huge emphasis on having children to create the largest possible family under the circumstances. Disease, a ready unpaid workforce, sheer survival along with other factors emphasized this. However, in a post-resurrection world with over 100 billion people on it, procreation is the last thing you want to do. ## Physically Impossible Heavens Some people are going to have heavens that aren't physically possible or involve human rights violations to make happen. Those people are just going to be disappointed. ## Meeting God Those expecting to meet God or the God's are going to be disappointed as well. Some method will have to be invented for how to deal with this situation. # Decanting Procedures As much as possible, decanting procedures should: 1. Newly resurrected persons should be met by someone of their skin color and who speaks their language. This should minimize instantaneous culture shock. 2. Decant them into an environment that doesn't resemble anything they've seen before. This will almost certainly not be their expectations and strongly encourage them to start asking questions. Ideally, something really sleek and clean such as modern SciFi movie sets. Perhaps a omni-lighted white room with no visible sides. Explain to them that they died and this is the ante-chamber to heaven. Ask them questions about what they think will happen next. 3. Some, many(?), will just want to go to the heaven they were expecting and that's fine. Their heaven is waiting for them. However, others will just want to know more of what's available to continue whatever work they were doing before they died. # Long Term Integration For those that stay in their appointed heavens, this will be pretty easy. No cultural integration required. They can leave at any time (they aren't zoo animals) For those who choose to leave their chosen heaven, they will need a lot of re-education to make them productive members of society. I'm not sure how you'd overcome life-long cultural habits...but hey, we're resurrecting people so this can't be too hard can it? [Answer] You'll also have to remember that *the majority of people who ever died are children.* As kids were the most vulnerable to death, due to disease and being weaker than adults, they'll be the majority. So, in fact, it may not be that hard. If they're babies/toddlers, it will be rather easy to adapt them to today, as they never learnt that much. If they're older, try grouping them together with people from the same time period. Don't worry too much about age, as each age has its own benefits. Also, put a few adults from the same time period into each group, as the children can, surprisingly, help *them* adapt to the new time. Although communication can be hard, language experts will be helpful in communication with Greeks, Romans or Gauls, and soon, there will be many different languages, spoken between groups of different time periods. So, to summarise, adapt the younger children first, then separate into groups according to their time period. Then add older kids from the same time period into the mix. Also, try communications between adults-language experts are the key! Then, soon, add adults from the same time period in each of the groups, and get everyone to teach their bit in the group(Try grouping families together, so a group may be of about 4 families each.) Also, try introducing groups to other groups, so there can be less discrimination. Soon, new sorts of languages can be formed with one another, and you have new, vibrant communities getting along to the 21st century (Also, a question- will the resurrected people die again?) [Answer] I don't think you can do it en masse. Death is the most traumatic event anyone will ever experience and they will be in extreme shock, after all the last thing they remember is having a sword shoved in their guts on a muddy battlefield, or someone yelling "Mind that bus!" "What bus ?" Splat. You'd have to do it either on an individual case by case basis and basically counsel them into the modern world. Alternatively resurrect them from a day or two in their timeline before they died. [Answer] Yeah im going to rain on this parade **ANSWER: No there is no way and this is a disastrously terrible idea** Throughout history people have lived and died for and from various ideologies. You could almost describe human ideologies as a product of evolution with various routes dying out from infeasibility. **In any way you bring back people in order to 'modernize' them to the 21st century you inherently are imposing your ideologies upon them.** This is akin to the American 'integration' of native Americans and Australian inclusion of Aborigines. Some people want nothing to do with the modern world like the Amish. Your attempt of 'modernizing' them would be cruel and naturally result in aggression or suicide. Historically, the clash of ideologies has resulted in countless deaths. **To remove death as an escape from this clash is probably crueler than genocide.** What if you brought back hard liner Nazis who would reform their communal structure and begin purifying themselves. You would first see brutal attempts of murder then (because that doesn't work) forced sterilization. What if you brought back cannibalistic cultures. Not a person on this planet would love being eaten alive multiple times. What about suicides. It would be cruel to bring back people who want nothing to do with the world just so they can do themselves over again and again. **This world of 'peace light and love' only exists because some people stay dead or locked up.** [Answer] Putting aside some of the practical difficulties with the idea and concentrating on how to treat some individuals or groups, it would very much depend on the age from which they came and the type of person they were. People from further into the past would find it much harder to adjust. Certain personality types would find it harder and others easier. As a starting point you would need to have a safe environment where the person was resurrected that was familiar and with people attending with as much knowledge as possible of the resurrected person’s life back ground, habits, family, language and locality as possible. This might range from detailed knowledge to no knowledge depending on circumstances. For the resurrected from more recent centuries there would be more hope of a successful outcome as more information would be available. After the initial shock the situation could be explained to them, once they accepted the situation they could be slowly brought up to date with developments since their day building up slowly through important historical events and inventions. After this they could be introduced to the modern world but except for the most recent arrivals from a few hundred years ago would need to be chaperoned and might need extensive care. Those from further back would suffer much greater cultural shock and a lot would depend on their resilience and personality. Someone like Aristotle would probably adapt differently to some uneducated witless goat herd from the same time period. Peoples from a few millennia ago would face a seriously steep learning curve, but might still be acclimatized to the modern world given time. Peoples such as the Romans and Greeks would at least have the benefit of being able to speak a common language with some linguistic experts from today. People from further back in time might not adjust as well because there would be no easy way to communicate. Some form of sign language and common human gestures such as smiles and frowns might help but I fear most of them would never properly adapt. For the most ancient peoples from Palaeolithic times I suspect that there would be little that could be done to bring them into the modern world. For most if not all it would be best to make them comfortable in some halfway house environment proving them with what they needed such as shelter, food, warmth and clothing. This would be greatly helped if there was a group of them. That said there would probably be a few surprises in both near past maladaptation and distant past unexpectedly good adaption. [Answer] I think what would be more problematic is the fact the you FRIGGIN RESSURECTED THEM FROM DEAD! Like, whoa! They probably have a memory of them dying and then they are alive again. Is this is heaven or is it hell? Imagine that poor cavemen who was dying for day on a snowy mountain from cold and hunger. Magic glowing something that show moving pictures? Screw that! I was dead and now I'm not what the Odin is gong on? ]
[Question] [ I was imagining a scenario where an 21st century engineer accidentally finds himself transported through time to early Renaissance Europe. Realizing that no help or rescue is on the way, he decides to use his knowledge to become an influential businessman. It occurred to me that rubber has many modern uses. Is there any way a usable source could be obtained prior to the discovery of the Americas? [Answer] There are some 200 species of plants that [produce latex](https://www.fs.fed.us/wildflowers/ethnobotany/latex.shtml). The major and common ones are: Euphorb family (Euphorbiaceae) milkweed family (Asclepiadaceae), mulberry family (Moraceae), dogbane family (Apocynaceae), and chicory tribe (Lactuceae) of the sunflower family (Asteraceae). The problem is that many of these plants are not native to Europe or would not be found in any real quantity. Most can be found in hot places. The closest you will find would be dandelion (Lactuceae). Which while common in Europe, the amount you would need in order to make rubber would likely be staggering. But dandelions are your best bet! Here's a handy [link](http://www.scienceprojectideas.co.uk/make-rubber-band-from-dandelion.html) on how to use it and the process. There was an attempt in WWII to use milkweed as a source of rubber because of War time shortages but the percentage (1-2%) was simply too small. Today, [we haven't succeeded](http://www.reuters.com/article/us-dandelion-rubber-idUSKBN0GK0LN20140820) at making rubber from dandelion and are working to breed some with more latex in them. The Medieval breeds most likely were even lower in percentage than the specialized breeds of today. However, if you look at the link on [how to make latex rubber at home](http://www.scienceprojectideas.co.uk/make-rubber-band-from-dandelion.html), you'll see that while it is not commercially viable and can't be used in exactly the same way as today's rubber, it can be used a number of different ways in applications such as water proofing. It's not good enough to make, say a tire, but it's something. [Answer] [*Taraxacum kok-saghyz*](https://en.wikipedia.org/wiki/Taraxacum_kok-saghyz) "is a species of dandelion native to Kazakhstan that is notable for its production of high quality rubber". It can be grown very easily almost everywhere in Europe. The Soviets have actually performed large-scale experiments, before and after the war, achieving "200 kg of rubber per hectare". The efforts to grow kok-saghyz did not continue after the war because in peacetime ordinary natural rubber is much cheaper. That's what Wikipedia says. [Answer] There are two major sources of rubber that you could have access to. But you would have to bankroll or lead an expedition to (tropical) West Africa or the Congo. In west Africa you've got Lagos Silk Rubber (Futumia elastica), and in the Congo you've got Landolphia Rubber (Landolphia genus). When it was discovered Lagos Silk Rubber was over exploited and almost driven extinct but that won't be until 1894 so it will still be a viable source during the Renaissance. Landolphia Rubber and the activities of Belgium to get it is a rather horrific tale but again the Belgian colony won't be established until 1865. Either way it will require hard work to get. As a bonus there is also the potential to get gutta-percha via the silk road. The chemical name for rubber is cis-1,4-polyisoprene, gutta-percha is the trans variant of this molecule. It's more rigid than rubber but it is still a thermoplastic in time when such a product is not commonly available. It comes from the Palaquium genus and is found in Malaysia. You would just need to get someone in China to acquire it, though that may be easier said than done. [Answer] [Synthetic rubber](https://en.wikipedia.org/wiki/Synthetic_rubber) is made from petroleum. In some places it oozes from the ground ([petroleum seeps](https://en.wikipedia.org/wiki/Petroleum_seep)), and several occur in Europe. Whether your engineer could create synthetic rubber using Renaissance tools is beyond my ken, however. ]
[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/78071/edit). Closed 6 years ago. [Improve this question](/posts/78071/edit) I have a modern day person stuck in a medieval setting. How they got there is not important. It is important that they did not expect to end up there so haven't done any research. They are however a little more qualified for their situation than their average counterpart. * They spent time on a self-sustaining farm so know a bit about animal husbandry and farming and eating unprocessed food etc. * They are interested in history so they have some practical knowledge about the past, they are however no history buff amongst them, so have no specialised knowledge. * They are a bit of a book and movie worm and so they have an extensive memory of all manner of stories. The age they are dropped into should be around the early 1100. Religion if possible should be slightly more powerful and the political situation a little more stable. The character decides that his safest option is to become a storyteller, rather than risk being burned as the freak who tried to introduce hygiene or the idea of bacteria and viruses. However I am a little concerned that as a storyteller they would be burned as the blasphemer who spoke about witches and heathen gods. I know traveling minstrels were liked and kept by the nobility and I imagine the storyteller in the same sort of capacity as this. However to make even partial use of their arsenal of stories the listeners have to be tolerant of all manner of strange and fantastic. **How with a strict religion similar to christianity of the middle ages would this be possible?** As a added bonus what would enable the storyteller be able to trade stories for food or a bed for the night with poorer people? [Answer] Crack a book on medieval literature and see how bizarre some of their stories were. Saints tales have lots of violent imagery and don't really have a base in reality. Alexander the Great was popular and there were some classical stories relayed as parables. Pre-christian tales were adapted into religious stories. Many tales were local (you can tell where medieval calendar pages were produced by what saints are listed) so your storyteller could say "in my home town we tell of St Obi Wan." The later 1100s was the beginning of the troubadours. If your story teller finds a powerful person who enjoys their tales, like Queen Eleanor, they might be a bit more safe from religious influences. [Answer] Put your character in the Islamic Golden Age. For an example look into the "*Arabian Nights*" or [One Thousand and One Nights](https://en.wikipedia.org/wiki/One_Thousand_and_One_Nights) Yes religious, but a lot more fun than 1100 France. Maybe she turns out to be Scheherazade. The stories we know (like Aladdin) from this collection are familiar because they are familiar but some of the stories in this group are spooky or just plain wacky and hard to follow. Clearly the Arab world in the period had an appetite for escapist stories. I think a modern could probably entertain people well just by singing selections from the enormous repertoire of catchy hooky top40 songs that reside in our heads. She could do that to earn her keep while she learned the language. [Answer] I'm not sure it's practical or the best way to utilise his knowledge. You're taking him back almost a thousand years, there's going to be a huge language problem. If he learns the language there's going to be a huge vocabulary problem. Apart from that he would possibly do ok recounting historical tales and travellers tales about far off countries and adding the odd dragon or so. In a christian country there is a wealth of bible stories to choose from, most of which would not be well known. Same with other religions I would think. He'd be better off attaching himself to a monastic institution or something like that though rather than wandering around making himself a target. 500 years ago the English in use would be almost a different language to listen to, 1000 years ago it would be incomprehensible because at that time it's wasn't English as we know it, it was Anglo Saxon, the Norman conquest of England was at that time. Here's the prologue from Beowolf, good luck reading it, no one knows how it was actually spoken although many think they do. In addition to that tales were told in a special way using phrases that are a bit like our slang, rather than straightforward stories. Personally I think his medical knowledge of hygiene and anything else would be far more valuable. [![Prologue](https://i.stack.imgur.com/G3gPf.gif)](https://i.stack.imgur.com/G3gPf.gif) [Answer] Looking at theatre during this time period may be helpful. There were traveling bands of actors & musicians that wrote and staged liturgical (religion-based) plays that were retellings of Biblical stories - but could often expound greatly on details so long as the story ending remained the same. Plus, don't forget that there are great and fantastical stories and imagery in the Bible - there's wheels with eyes, talking snakes, dragons, and lakes of fire, after all. I think as long as the stories *appear* to be in line with religious rules, the character would be unlikely to be considered a blasphemer. In medieval times, there were also a number of festivals and feasts where rules were relaxed, like the Feast of Fools, that may have been as rowdy as the Roman Saturnalia or more like Mardi Gras - though, interestingly, there were usually factions within the ruling religious body that both loved and hated such displays. It's probably also important to remember that during the 11th & 12th centuries, the political structure was indelibly tied to the religious structure. So you'd likely need to consider the political ramifications of his stories, as well - it's important that the church and state look holy, but there's little communication and standardization on enforcement of many of those rules (that's why religious guilt was such a powerful tool to be used for political gain.) [Answer] Stories told in those time by storytellers were basically: * latest news from the kingdom (being travellers, the storytellers knew more than the peasants and where often the only travellers visiting villages in months) * stories radicated in the local culture, like "chanson de Roland" or "king Arthur". Your storyteller may try his luck with the Lord of the Rings, applying some adaptations to make it sound more "Christian vs Devil". No Star Wars or Sherlock Holmes, which can sound too heretic (space travel or reason only to defeat evil? Burn him!) ]
[Question] [ Say there was a fairly large island continent. Say half the size of Australia. Now lets say it is united under one ruler. Magic exists in this form: 1. All magic requires runes and a verbal activation (saying 'magic words' that correspond to the runes). Runes are one-use only. 2. Any spell lasts a maximum of one minute (no enchanting) 3. Any spell has a certain maximum amount of power, and will not complete tasks under that power (you can create a small fireball, but can't make a storm or teleport) 4. Any spell takes three seconds to take effect after the verbal component has been said (gives time for a counter-spell) 5. Runes can be traced on a surface (temporary rune) and can then be activated only by the maker, or engraved/written (permanent rune) where they can be triggered by anyone holding the object. 6. All activation phrases must be yelled, and cannot be muffled (can't use magic while gagged or holding cloth over face) Now, that benevolent king that ruled over his people. Suddenly one of an extremely rare species of unaging people killed all the rest of its kind and declared war on the kingdom. With powerful magic he defeated the kingdom and usurped the throne. For around a millennia the new king ruled tyrannically. Finally, the people got sick of it and all the little low-level rebellions got together and... I'm getting ahead of myself. What I want to ask is how those low level rebellions would fight the army. Obviously the only possibility is guerrilla warfare, so my real question is: **How would the king's army respond. What tactics/equipment can we expect them to use to combat this new threat of guerrilla warfare? EDIT: What I'm really asking here is effective tactics/equipment to deal with medieval guerrilla warfare. I don't need the king's opinion or that he will send people to kill the rebels. HOW will the people he sends kill the rebels?** [Answer] There is so much to unpack in the original question. So much historical, psychological, and socio-economical baggage. So let's begin. **Historically**, kings that reigned with an iron fist--surprise, surprise--were detested. So there are plenty of history and legends passed down regarding the uprisings that were inevitable to rise. [Robin Hood](https://en.wikipedia.org/wiki/Robin_Hood) is just such a figure, though I'm sure he needs no introduction. Another such figure that we've all indirectly heard of, is [Nebuchadnezzar II](https://en.wikipedia.org/wiki/Nebuchadnezzar_II), though most will remember the name as [the ship](http://matrix.wikia.com/wiki/Nebuchadnezzar) Morpheus was captain of in The Matrix Trilogy. I find this one far more interesting, because of the legacy ol' Nebuchadnezzar left behind. Whether true or slander spread by those he conquered (given the majority I've learned about him is from the Old Testament in the Bible), he is reputed to have suffered from [Clinical Lycanthropy](https://en.wikipedia.org/wiki/Clinical_lycanthropy) or [Porphyria](https://en.wikipedia.org/wiki/Porphyria) (both of which are discussed on the link to Nebuchadnezzar). Bear in mind, however, that all kings are cruel in the 'good ol' days', it's just that beloved kings were cruel to their kingdom's enemies. (this is important for public relations efforts for the king) **Psychologically**, you offer something that can be taken many ways. > > Suddenly one of an extremely rare species of unaging people killed all the rest of its kind and declared war on the kingdom. With powerful magic he defeated the kingdom and usurped the throne. For around a millennia the new king ruled tyrannically. Finally, the people got sick of it and all the little low-level rebellions got together and... > > > So much in this block of text. The things a man can learn in a thousand years (if he's able to remember any of it, but that aside). What troubles me most, is how (or why) he would kill all of his own people to rule over others. This speaks of fear on his part, and some seriously twisted backstory that I could speculate on for hours on end (let's not go there now, in other words). So let's get to the more troubling part. > > For around a millennia the new king ruled tyrannically. Finally, the people got sick of it and all the little low-level rebellions got together and... > > > This makes no sense. No one that lives a maximum of 80 years will tolerate this for a thousand and then get fed up. By this time, the king's ways will have been so ingrained into their culture that most will just accept it as it is ("What can you do, it's always been like this"). This is something that would have been revolted against time and again--which could be the actual problem: **Rebellion has become so common, that to not be a rebel is to be an outcast.** Think [Timber in Final Fantasy VIII](http://finalfantasy.wikia.com/wiki/Timber), where everyone in town is a resistance member. But how do you deal with that as a king with a thousand years of experience of surviving these pathetic little coups? For that, we turn to our Robin Hood example, and how poorly this worked out. Tax the people into the poor house. Public executions to break the spirit. And burning down entire villages that would dare harbour even suspected criminals. Why didn't this work for John? Because everyone will come to hate you, and if anything, a dictator (even a royal dictator) needs his powerbase on his side. See [3 Rules for Rulers](https://www.youtube.com/watch?v=rStL7niR7gs&t=7s) for a more in depth explanation. So, if this king rules for over a thousand years, he knows the game, all the rules, and he's safeguarded his power structure indefinitely. So, how does he react? He's a king, micromanaging just isn't an option. He has the army and generals he needs to trust. Expect these generals to have been loyal to him for generations (father to son, most likely, simply because "if it isn't broke, don't fix it"). They'll receive orders to make an example out of these people, and make sure everyone else is too scared to help them. How to do this? Wanted posters, hanging a few people alleged to have helped the rebellion, and making sure the people know their place: beneath the ruling class's feet. Historically this has been done via warrior classes (knights in Europe, Samurai in Japan) because if you are raised to believe this is the way the world works, it is easier to shrug off having to kill innocent men, women, and even children (and yes, this has historically been the case in both Eastern and Western societies). Another option would be [South Africa's Apartheid](https://en.wikipedia.org/wiki/Apartheid). Built upon the principle *a house divided unto itself cannot stand*. Keep the people segregated, keep them fighting amongst themselves, and they will never gain the strength needed to oppose the king or the ruling class. Keep in mind my third point: **Socio-Economics**. Dead people cannot work, so the king doesn't want to kill them, but he will if he must. He wants them to work, to know their place and make him rich, so that he can support his power bases (reference to the 3 Rules for Rulers video), so that he can continue being the king, and the status quo is maintained. Expect the state endorsed religion to support accepting your fate and devoting yourself to being a good little slave. Perhaps a belief that you'll be rewarded in the life hereafter, or perhaps reincarnation is a thing, and you'll be granted a much better life next time. Having dealt with all of that. What tactics would the king's army use to hammer down the nail that sticks up? I've mentioned a few already, but why not offer some more ideas. * Shields marked with runes, so that the spells are already prepared and always within grasp of the soldier bearing it (logically, defensive spells/runes makes more sense on shields) * Swords marked with offensive runes. * Expect all state sanctioned cities, towns, and villages to have soldiers loyal to the crown. This means a country wide intelligence network, which can lead to people who have studied how to ferret out spies and plausible rebels. * If all else fails? [More Dakka](http://tvtropes.org/pmwiki/pmwiki.php/Main/MoreDakka) always does the trick (TV Tropes warning on that link. Don't blame me if you offer hours of your day to that site!) [Answer] # There was guerrilla warfare in Medieval times The whole point of stone castles was to be able to withdraw to an impregnable position that couldn't be efficiently reduced by siege. From this impregnable castle, the defenders could raid supply trains, play scorched earth to deny the enemy supplies, and generally be a nuisance. In your setup, I don't really see a reason that these magic users would be able to reduce stone castles any easier than in real life. You say they can only make small fireballs, and to put runes on the walls is no easier than putting a ladder on the walls, and just as easy to get the rune-user hit with a crossbow bolt or some boiling oil. If stone castles are still nigh-impregnable, then a large number of stone castles will make a land mostly unconquerable. This exact scenario played out between England and France, in the middle of the 14th century, during the [first part](https://en.wikipedia.org/wiki/Hundred_Years'_War_%281337%E2%80%9360%29) of the [Hundred Years War](https://en.wikipedia.org/wiki/Hundred_Years'_War). The French were annihilated at Crecy, and the fortress at Calais captured, but attrition on the English was too high to make further gains against other fortified places. [Answer] Terror, you want complete and utter terror. To quote king Ashurnasirpal II of Assyria. > > I built a pillar over against [the] city gate, and I flayed all the chief men who had revolted, and I covered the pillar with their skins; some I walled up within the pillar, some I impaled upon the pillar on stakes, and others I bound to stakes round about the pillar; many within the border of my own land I flayed, and I spread their skins upon the walls; and I cut off the limbs of the officers, of the royal officers, who had rebelled. > > > Polybius on Roman counterinsurgency > > one may often see not only the corpses of human beings, but dogs cut in half, and the dismembered limbs of other animals. . . . They do this, I think, to inspire terror. > > > So first you sow terror in your enemies. You rather have them not fighting at all. Your second goal would be removing their protection. BUrn down the forests, the countryside. Kill all vllagers that are proven to help them. If you can outpace the new recruits you'll win. Thirdly you kill the head of the snake. Both the Romans and modern day Americans like to go after the leaders of their enemy. One with assassins and bribes, the other with drones and hellfire missiles. Extra reading: <http://repository.upenn.edu/cgi/viewcontent.cgi?article=1166&context=curej> [Answer] *(Sorry if my english gets wrong sometimes, i'm not a native english speaker.)* Medieval tactics on the battlefield, consists on concentrated regiments with armed soldiers with specific traits, weapons and tasks. REMEMBER THAT Medieval warfare is very different from the modern warfare introduced by Napoleon. And so you want combine some kind of guerrila warfare into medieval wars? That is possible. Lets start from the very begining... # **1 - How to build a rebel army** **Who will sponsor this army?** The dissatisfied nobility; the own people helping by sharing the crops and money; a foreign country enemy to the current governement. An army needs food, money and equipment to survive. You can decide who will sponsor the army. **How to recruit?** A rebelion uses differents methods of recruinting depending on how the war is going. They can recruit people in the largest cities in hideouts; they can recruit at the farms; they can recruit people on the road; they can do it in the conquered land (If the rebelion has managed to get some) **Where they will sleep?** HQs and army encampaments has to be somewhere. Where else would it be if not on the remote places? Caves, mountains and swamps are good places. Guerrila armies are easy to pass through these places (but they are not imune to attrition.) **How to feed the army/give the equpment/payment?** Clandestinity and piracy are the key-words here. There can be assaults on caravans and shipments. The people responsible to sponsor the army will provide the **The ideology.** I think this is the most important you should be asking. Try to imagine what the recruiters will say to inspire the villagers and citzens to the cause, thats their ideology. The vietnans used the rethoric of "freeing Vietnam from capitalism." But this is medieval times, isnt it? The ideology here is more attached to tradition and/or religon. Maybe you could relate to the old times or maybe you could create some legendary hero that is inside the rebelion. "I've joined the rebelion because of Kelsier, he survived the tirany of the king with this incredible powers! He is the only one who can defeat him!" ## **2 - How to fight this war using guerrila** **The strategy.** The main aspect of a guerrila is the occultation of the army and its movements. Propaganda were also played an important part on this kind of warfare, because the rebel soldiers are basically villagers, and the people need to feel anger and courage to fight aganist the system. You can get inspiration from the American Revolution, where they've used small attacks to damange the british army. The americans lost the larger battles, but with night attacks on small convoys and important shipment and caravans, they've managed to win the war. **Fighting the own country.** Different from the american revolution, the enemy isnt an empire with its capital far from your land, isnt it? The conflict could happen through many, MANY years or just some if a treaty is signed. So, what is the goal of the rebellion? Is it to free a part of the land? To take control of the country? The goal will affect on how the rebelion and the kingdom see the war. The main weapon of the rebelion will be its legitimacy and the ideology on it. If the rebelion loses the people, he loses the war. If the people still belive on the rebelion, the war can continue forever. **Small battles.** They will be the key for the success of the rebelion. The goal is not to attack directly the kingdom and destroy it with a single blow, but with bleeding. Make the country bleed. Attack caravans and shipment, destroy their farms and kill their commanders. **Large Battles.** The guerrila wants to avoid this. They know they cant fight with an army. **Besieging a city.** This can be easily arranged with engineering, may it be with basic rams and ladders or catapults and trebuchets. But I suppose that the wizzards in your world are scholars, they could be the siege engineers and the magical engineers. Maybe they could do something cool with a system of runes into a battering ram, a catapult. And with the rule number 5, you gave on the post, anyone can operate the machine. Remember that a siege can last months, even years, so logistics are important here. ## **3 - How would medieval tactics have changed if guerrilla warfare had become common?** The main question is: how should we preserve the spirit of a guerrila warfare? That is: the occultation of an army and its movement? How to split the army wihout losing it? How to inspire the people to fight through propaganda? And the most important, how to defeat the enemy? All this, under the conditions of your world (And you world will play an important part for a possible "medieval guerrila.") **The enemy.** It would be useless to discuss the guerrila wihout considering of how the enemy is. His empire is vast but his governement is centralized? Why is that? The capital is the only place on the empire with higher culture and resources? Why the other cities dont have similar importance? Geographical limitations could be a good solution for this (or just something else.) Remember that the advantages the guerrila uses, the kingdom could use too. Technology and magic could be used to solve the limitations that medieval era imposed. **Hiding the rebel army and organizing it.** Hiding is not the problem, the problem is comunication and logistics in general. Technology and/or magic could solve this. Maybe the wizzards can make contact through telephaty or magic globes. Maybe the supplies could be arranged with magical creatures that manage to drop the supplies by land, sea or air. **Inspiring.** Stories are important, in medieval times, your hero(s) would probably be considered as demigods. Religions and beliefs were build by oral traditions, stories that the elders and travellers say about the mysterious events, persons and creatures of the world. There must also be a reason of why the villagers will abandon their hoes and pick up swords to fight aganist their lord and king. Maybe the people are not servants, but slaves, maybe you the kingdom make the people pay high taxes. **Bleed the enemy.** Maybe this society is more advanced and the governement is more centralized. The kingdom depends on foreign trade and agriculture is not very dependable on people, which allows more migration into the cities. **Medieval warfare.** The runes and mages could play an important role on leading the groups and armies. Attacks on cities would be more common and nobles and lords would start to pay their alligeance to a new leader that wants to take the throne.(The guerrila kind of warfare would still be a problem depending on the economy, because the rebelion shouldt be able to bleed the country if the economy is mostly driven by agricultre.) **How to destroy the enemy?** Conquer his land and capital, and you will achieve victory in defeating him. This can only be achieved when the king is weak. (But if during the war, a powerful lord manage to take the throne?)The problems could emerge later with possible lords and nobles that didnt allied to the rebelion that declare themselves kings or pay their alligeance to other king. **But anyway, what would change?** That depends directly on how your world will be. My answers will help you to avaliate these simple questions like... how is the king? How its kingdom? How the people live? What they belive in? etc... You should be worried on how to preserve the medieval identity and the guerrila warfare identity. (But this would be another topic isnt it? :v) **For your inspiration:** Brandon Sanderson uses a perfect example of how to build a rebel army in his book series, Mistborn. The Elder Scrolls V Skyrim can also provide you with some inspiration with the stormcloaks. There is also [this video](https://www.youtube.com/watch?v=Rcbedan5R1s) of how the roman army is organized. [Answer] In Poland we have this saying "Read a book before writing one". I will tell you a story. It take place on a continent. Near another bigger continent. On the smaller one, let's call it England, there was a beloved king. But he had to go to the toilet. So his evil brother took over the throne and said: *Ha, peasants, now I will torment you with taxes and my tax collectors and my iron fist in the shape of sheriffs* But then come a guy and says: *Ha, you and your stupid sheriff. My name is Che Guevara and I will live in those woods and fight with your tax collectors when they try to travel through them* And so he did. Che lived in the forest with his guerrilla friend, el friero Tuck, Smallo Jose, and girlfriend Marion Castro. He made traps for the tax collectors, shoot them with his trusty Bow-47 and hit them in the head with sticks. Of course the didn't wanted to try to seize the castles or fight in the open because they had full plate armour and he had sticks. What he would do to them? Dent it? Seizing a castle would require, in the most optimistic option with gates wide open, an equal amount of soldiers to the ones stationed in the castle. So they would need a lot of them and/or with good equipment. And if you had a lot of soldiers and good armour and weapons you we're no longer a guerrilla. So how's the king responds? Well, it's easy - Can somebody take a 200 of count Xvsyt men and go there and kill the marauders, thieves, bandits, unhappy peasants or whatever those people call themselves. Or, if he king was more into getting his hands dirty he would lead his knights by themselves and cut their head with his big sword. Name one successful revolution that was lead by peasants that wasn't French Revolution. [Answer] ## Cavalry Assuming your world has horses, uses a similar economy to our medieval times & your magic doesn't trivialize transportation, a group of horsemen can still hunt down rebel troops on foot quite easily. Horses fit for warfare were very [expensive](http://medieval.ucdavis.edu/120D/Money.html), so it would be unrealistic for rebels to have easy access to such resources. This means the king would be able to force engagements with rebels, making guerilla tactics as we know it very difficult. There were examples of infantry repelling [cavalry](https://military-history.fandom.com/wiki/Battle_of_Legnano), but those usually required well-trained troops to remain calm during charges. As a side note: Kingledion made a good point about how difficult it was for armies to attack small forces in a fortified position. If your rebels rely on public support or are generally good people though, the King could simply do what rulers usually did when their enemies hid in their castles & pillage the local country side. This cruel tactic often forced rebels into open battle to avoid ruling over nothing but burned rubble & might apply to your world too. [Answer] I think the king's army should be bewildered at first but then they will keep on it with brute force, taking heavy casualties but not caring for they outnumber the enemy by so much. If they don't outnumber the enemy they should brake their army into smaller groups, and encircle the enemy, trapping them and using sneakiness themselves. [Answer] This is the key: > > What tactics/equipment can we expect them to use to combat this new > **threat** of guerrilla warfare? > > > Under this setup as @Fayth85 say, rebellion is common. But is most of time *useless*. Is important to note this: **WHEN** "guerrilla warfare" **IS A THREAT**? (No, is not when exist a lot of bodies or property damaged...) Combat that start from the small people is fated to fail... *BADLY*. You don't need much to crush/control them. Rebellion with some chance must be *after* a MASSIVE IMPLOSION of the society (like by famine)... or start from *the mid/high class*. Revolutions like the american one was from the high levels of society. This lead to what could make them potentially effective: Now have support, money, resource and PEOPLE THAT KNOW THE SYSTEM because *are part of it*. Then it come the second requeriment: A good strategist / tactician. You need to have **[Sun Tzu](https://en.wikipedia.org/wiki/Sun_Tzu) working for the rebels**, and some few nobles that give operational support and intel. If you pay attention, is like the Rebellion from the Star Wars... (just that there is more magic and luck) --- Now finally, you rebellion have *a chance*. And if you have a charismatic hero with a band of mistfits (but truly oustanding) top-of-line soldiers better yet! Then, how deal with it? *You do exact the same things as before*. Reality say this is enough, and most rebellions die soon. But then Sun Tzu and/or the hero and band of misfits have enough luck and skills to pull of *solid attacks* thanks from the intel and support of you "shadow goverment". What make a *solid attack* depend in your setup, and more likely, is where the *perception* of power lie. If this rebellion use TRUE guerrilla tactis and much less open battles.. all normal ideas can't work and now it become a game of *spy-vs-spy*, intel, and commandos. Your fight is more internal than external. Your game as the EMPIRE: * Find and eliminate the competent leadership, and get rid of their high command INSIDE your ranks. Your game as the REBELLION: * Strike against key targets, subvert in the shadow the operations of the empire, convert nobles to your cause, increase the support of the population (and something most rebellions fail to do) AVOID FIGHT THE EMPIRE DIRECTLY. ]
[Question] [ In our world's 2016, the [German town of Munich](https://en.wikipedia.org/wiki/Munich) is part of the country of Germany. Now in an alternate Earth I would like Munich to be part of the [Great French Empire](https://en.wikipedia.org/wiki/France) (in the *alternate* year of 2016 naturally). **Q**: What change in history could fabricate this situation? And *why*? Answers will be rated on:  The *thoroughness* of the explanation  The *less far back in time* the change needs to happen1 1e.g. a change around WW2 will be rated higher than a change back in the time of the [Empire of Francia](https://en.wikipedia.org/wiki/Francia) [Answer] In 1930's England, two people are taken much more seriously than they were in our history - Basil Liddell-Hart and Frank Whittle. Liddell-Hart's concept of fully mechanised forces means that the BEF deployed to France is more than a match for the Wehrmacht and SS; whilst Whittle's jet engine gives the RAF a huge advantage over the Luftwaffe. Meanwhile in France the the Maginot Line isn't over-relied upon, and the Allies stand ready to face the Germans wherever they attack. The net result is that Germany suffers a humilating defeat in 1940; Poland is liberated and Germany is split between the victors. Britain and France are able - now without having to worry about fighting on two fronts - are able to keep Japan at bay and keep an uneasy peace. Without Japan's entry into the war, the US remains neutral, and with Britain and France not worn down by years of war they are able to counter the US's interest in de-colonialism; the US protests their annexation of Germany but with the memory of two bloody wars with Germany in as many generations, the victorious Allies hold firm and turn their attention towards keeping the USSR at bay. The UK and US both independently create nuclear weapons (the UK's programme is much more successful in this timeline without having to fight a war at the same time) before Stalin's army is ready to do anything (remember that he wanted plenty of time to arm and was forced into action by the German invasion); thus the Cold War takes a fairly familiar course. Ultimately, in 2016 the US remains fairly isolationist but with shared principles of free trade and democracy, has close relations with Western and Central Europe. Europe is dominated by the three victorious powers; what was Germany is split evenly between France, UK and Poland and the three have an alliance similar to NATO (including the smaller military powers of Europe too). Russia is whatever works best for your story - either it collapses in the face of Western spending and its own financial ruin, or the fact that the Anglo-French-Polish alliance has less clout than real-world NATO means that the USSR remains in a Cold War. [Answer] # Charlemagne's Francia splits along different lines Here is a map of Frankish expansion into Europe in the Early Middle Ages: [![enter image description here](https://i.stack.imgur.com/TH7jY.png)](https://i.stack.imgur.com/TH7jY.png) First, note that the original Frankish homeland is not where modern France is. That is to say, the territorial expansion of the French state started from a place that is mostly not inside the borders of modern France. So it is definitely possible for France to have evolved in a different direction and occupy a different set of modern territory. # What actually happened This is the 2 minute history version, so lots of truncation for brevity. Basically, Charlemagne split his empire three ways among three heirs. The split was east, center, west as shown: [![enter image description here](https://i.stack.imgur.com/qUXeo.png)](https://i.stack.imgur.com/qUXeo.png) The provinces have slightly different names as shown, but the general regions are the same. The problem with the split was that the middle kingdom got diverse territories that were not close to each other. Provence, Lorraine, and Italy were all relatively rich at the time, but not close to each other given the mountains in the way. However, the split did manage to separate the parts that had lots of Latin-speaking peasantry (modern France) from those parts with lots of Germanic-speaking peasantry (modern Germany). These territorial divisions were reinforced in the Ottonian dynasty ([from Otto I](https://en.wikipedia.org/wiki/Otto_I,_Holy_Roman_Emperor)) where the power of the Holy Roman Emperor was re-introduced but only for the German and Italian parts. Over the next 200 years, the German and Italian bits became politically consolidated under the Emperors, while the Kings of France consolidated the French and Occitan speaking parts starting from the Capetian dynasty and [Robert II of France](https://en.wikipedia.org/wiki/Robert_II_of_France). By this time (c 1000 AD), the languages started to diverge, as many of the minor nobility in what was now the German-speaking parts were still German-speaking themselves, but the nobles of the French-speaking parts now spoke a form of Vulgar Latin which was becoming Old French. 200 years earlier in Charlemagne's time, most of the warriors were Franks and spoke Frankish (which was itself a Germanic language). # What to make different I glossed over a lot, but the easiest way to make Munich speak French is to change where the Kingdom divides went. Going of the territories of the top map, have Charlemagne divide the kingdoms into Aquitaine-Burgundy (which evolves to be be Occitan speaking), Neustria-Austrasia-Swabia (which evolves to be French speaking) and Lombardy (which evolves to be Italian speaking). Now let the French speaking kingdom rise to power as both the French Kings and Holy Roman Emperors throughout the Middle Ages. Aquitaine-Burgundy get incorporated, just as they did in real life, but bits of Germany like Thuringia and Bavaria do to. The German speakers are restricted to Frisia and Saxony, where they are more or less like the Dutch. Advance history accordingly, and see what happens! [Answer] If you want Munich to be a part of a *stable* Great French Empire (as opposed to Munich under French occupation), your best bet is a timeline where Napoleon is never defeated and consolidates [his rule](https://en.wikipedia.org/wiki/First_French_Empire) over parts of Germany ([Confederation of the Rhine](https://en.wikipedia.org/wiki/Confederation_of_the_Rhine)) and perhaps Northern Italy. His disastrous invasion of Russia never comes. Something happens in this timeline that prevents it, or makes it have a different outcome. Perhaps the war with the Ottomans doesn't go well for Russia, and the Tsar cannot risk opening another front. Or perhaps Napoleon does invade Russia, but a grand battle comes earlier in the campaign and is a resounding victory for the French. Regardless what happens, Napoleon rules unopposed past 1814. With Russia out of the picture, the coalition cannot mount a decisive strike against Napoleon, and with both sides weary from war, eventually there's peace. Napoleon rules into mid 1840s, and upon his death, the empire passes to his son, Napoleon II. In our timeline Napoleon II dies of tuberculosis in 1832, but in this timeline his life already followed very different paths and he never contracts the disease. In this timeline, [Spring of Nations](https://en.wikipedia.org/wiki/Revolutions_of_1848) never comes to France - there's no Bourbon restoration in this timeline, and the Bonaparte dynasty, while still absolutist monarchs, have the prestige of popular heroes to back them up. And without Spring of Nations, there's never an independent, united Germany to speak of. Over the next 60 years, Confederation of the Rhine becomes an integral part of the French Empire - even if the Bonapartes ultimately have to grant independence to the insurgent Spain and the [Republic of Both Sicilies](https://en.wikipedia.org/wiki/Kingdom_of_the_Two_Sicilies). It's 1900 now, and we're in for a very different 20th century. The next 116 years are yours to fill out. [Answer] Probably partitioning off Southern Germany into France after WW2, both as part of reparations to France for the German invasion, and as an alternative form of the Marshall Plan to create a powerful buffer to Russian/Soviet expansion. Instead of relying on West German occupation by US forces they give over a lot of terrain to France thinking it would be easier to bolster the French military. This is especially attractive if whatever is left of Germany would be under significant military restriction or if the Soviets showed up in East Germany in a much larger force, so the only way to get them to stop wasn't splitting Germany, but eliminating the country all together by giving parts of it over to France, Belgium, etc. The Germans may agree to do this out of fear of being occupied by the Russians. [Answer] This is difficult to pin down to a simple change, so I will be content with the outcome of a war, namely: **France overwhelmingly defeats Prussia in the Austro-Prussian War** "Now wait a minute," you say, "the Austro-Prussian War was fought between Austria and Prussia, how does France win?" A fine question. While the French remained neutral in the Austro-Prussian War in 1866, tensions between France and Prussia resulted in the Franco-Prussian War in 1870-71. Historically, Napoleon III promised Bismarck neutrality. This allowed Prussia to fight two single front wars, rather than dealing with fighting both factions at once. In our alternative timeline, this non-aggression pact of sorts will not happen (or is broken). The other aspect of the Austro-Prussian War was the Third Italian War of Independence, in which Austria was defending Venice from Italy. Due to the war against Prussia, Austria was forced to divert forces from Venice to defend Vienna. Italy took advantage of this to ally with Prussia and take Venice. In our alternate timeline, let's imagine that Austria still crumbles in the north but holds fast against Italy in the south. Enter France. During the end of the historical Austro-Prussian War, France demanded that Prussia relinquish Luxembourg and Mainz. This request was flatly denied. In our alternative timeline, the desire for expansion and the tension between France and Prussia leads to an earlier war, while Prussia is still engaged with Austria. The reduced Prussian strength allows France to make early gains. They also gain the opportunity to study Prussian tactics and organization. This knowledge and slow start to the war allows France to enact much needed reforms to their military structure. Historically, these changes came too little too late, and lead to disorganization. The slow start and high morale from early victories will ensure that these reforms are successful. To gain more strength for the Prussian front and to maintain peace with Italy, Napoleon III withdraws his forces from the Papal states, as he did historically during the Franco-Prussian War. This allows Italy to seize many of the Papal territories. Napoleon was not opposed to Italian unification, and indeed helped the Italians at times. His support for the Papacy was driven mainly by the large Catholic population in France. We can imagine that nationalism driven by a war with Prussia could override the desire to prevent Italian unification. Prussia is pushed back and settles for peace, losing their gains in southern Germany. France occupies former Swabia while Bavaria remains an Austrian ally. French unwillingness to cede their gains to former Southern German allies of Austria, combined with the French support for Italy, leads to a minor war between France and Austria, in which France makes minor gains into Bavaria. The pressure of a newly vitalized French military and perhaps a more successful Emancipation of 1861 in Russia keeps Prussian military power contained, allowing France to hold the Bavarian territories containing Munich. [Answer] The summary is in bold. My Scenario takes place around 1700 and is linked to do with the succession of Charles II of Spain. So by 1698, the Nine Years War was over and Charles II of Spain was getting old. At this time Spain was in decline but still an important power that controlled most of the Americas, the Philippines, about half of Italy and modern day Belgium (Then known as the Spanish Netherlands) so the succession was a big deal. Since Charles II never had any kids, it was unclear to whom all the different bits of Europe he owned would go. The main contenders were: 1. Louis the Grand Dauphin, son of the King of France and Nephew of Charles II. 2. Prince Charles, younger son of the Holy Roman Emperor and Charles II's cousin. 3. The Prince of Bavaria, who was Charles II's closest living relative. 4. Philip Anjou, who was also Charles II cousin and was Louis the Dauphin's son. He was the person Spain was actually left to in Charles II's will. If the Spanish throne went to Anjou, the Dauphin or Prince Charles it would be a huge advantage for those countries, so England and France signed up a treaty in the Hague that partitioned the Spanish Territories so that Naples, Sicily and Tuscany went to the Dauphin of France, the Spanish Netherlands and Milan would go to Prince Charles and actual Spain, Sardinia and the Spanish colonies would go to the Prince of Bavaria, who was the closest living relative to Charles II. Until he died. The next year. While Charles II was still alive. This completely threw of the treaty and so another one had to be drawn up, which the Holy Roman Emperor didn't like and ended up causing a war that lasted 13 years. And that is how the war of the Spanish Succession started. But that's irrelevant and the thing to look at that could end up with a French Munich is the treaty after the prince of Bavaria died (at the age of 6) that the Holy Roman Emperor didn't like. So it's 1699, the prince of Bavaria has just died and so the European powers gather again to give bits on a map to each other. This was the 2nd Partition Treaty, and it said that Spain, it's colonies, Sardinia and the Spanish Netherlands would go to Prince Charles, the Holy Roman Emperor's younger son, the other bits in Italy including Milan would go to the Dauphin. The reason Leopold I, Holy Roman emperor didn't like this is because he believed Milan was essential for the defence of Austria, as he was also the Archduke of Austria. So maybe in this Alternate timeline the European powers manage to pull together a treaty that everyone agrees with or Charles II lives a little longer. **Maybe Bavaria would go to France in return for letting Austria have Milan and all the other bits in Italy.** Also, due to no War of the Spanish Succession, France won't be as economically weakened as it was in our timeline. This is actually very unlikely though, as if Leopold I was concerned about France getting Milan, he definitely wouldn't let Bavaria be French as it is right on his doorstep. So let me propose another alternate scenario: **Louis XIV (the King of France) accepts Eugene of Savoy into the French Military.(Around the 1670s)** Eugene of Savoy was responsible for about six French defeats in the Nine Years war and the War of the Spanish Succession, including the battle of Blenheim in which he virtually won the war against France (along with help from the Duke of Malborough). [Answer] For some reason, the US does not enter WWII, or at least not the European Theater. This happens because Germany and Italy decided against declaring war on the US after Pearl Harbor, and maybe even gave some help with the US dealing with Japan, so we, as a country, did not become involved in actual war against Germany and Italy. However, many Americans still want to go to war against Germany and Italy after this, so those who wanted to fight in the war move to Britain, granting it a much larger military, as well as a continued Lend-Lease program so Britain has a good portion of the US economy behind it. With these changes, the US does not get an occupation zone in Germany, so what was the American portion is now split between France and the USSR. Munich happens to be in the French portion. However, thanks to the US not being there to enforce its ideals, Britain's belief in them is overshadowed by the USSR and France both wanting to get rid of Germany. East Germany appears as a communist Soviet puppet state, and the French annex their portion into the new French Empire, through the Cold War, Germany was just the portion that Britain occupied, which was eventually freed, with it merging with East Germany when the USSR falls. During the Cold War, the Germans in the French zone are fine with this because effective propaganda convinced them that this is the only way to be safe from communists. By the end of the Cold War, they've just accepted being in the French Empire as a matter of tradition and have stopped trying to be free. ]
[Question] [ In my world one the key players on the international level is a country with 90% of its technology bio-based yet none of its neighbors have biological based technology even though they're just as wealthy and just as advanced technologically ( just in a different direction). I know could just hand wave this and say that the nations are different because they are. But I prefer to get some sleep exclamation. How would I explain One Nation being so technologically different from its neighbors? [Answer] A bit rambling here, but here are a variety of ideas. Some kinds of technologies, for example, architecture, are known for their geographic variation both due to paths of development based upon initial conditions, and due to suitability to local conditions. For example, the pitch of roofs in Switzerland changes every few towns to adapt to local snowfall there. Economic factors also drive the materials that are used - brick or stone or adobe look more attractive in someplace with few trees, than in someplace where residents have to cut down trees to clear farmland anyway. If foreign technology is expensive, the export market for it may be weaker. In general, the harder it is to move key technological artifacts, the more they will be geographically distinct, which is one reason that architecture takes the cake for regional diversity. But, in general, trade tends to homogenize the technologies of all who participate in that trade, although small countries are more prone to assimilation into the technological conventions of their trade partners than large ones who have markets of their own big enough to built their own tech rather than relying on imports made to someone else's standards and customary designs. Even Neanderthals started to adopt some Cro-Magnon modern human technologies during the time period that they co-existed in Europe. There have been isolated instances of efforts to control technologies with mixed success. The Hittites kept their iron metallurgy techniques as state secrets for almost 800 years. Similarly, the city of Byblos and some of its neighbors like Tyre managed to keep their ship building techniques proprietary for centuries. Efforts to control nuclear technology are only about seventy years old and have been more hit and miss. Still, on the whole, sustained periods of isolation are probably the most powerful means to develop distinct technologies. For example, for about a thousand years until Bronze Age collapse, ca. 1200 BCE, Western Europe was controlled by descendants of the Bell Beaker culture whose warfare methods made heavy use of long bow, while Eastern Europe was controlled by descendants of the Corded War culture whose warfare methods focused on warriors who were mounted horseman or rode chariots. They were pretty completely separated from each other in a stand off that neither could win along their shared border for a thousand years, each developing on their own path and each large enough not to need much trade with the other. A natural time to capture such stark divides in technology would be as a long period of isolation of the societies was just starting to break down, a bit like Japan at the time it first decided to open itself up to contact with the outside world after centuries of isolation. JDługosz has an interesting suggestion about a "rejection" of a technology along the lines of what the Hindenberg did to airships, or the sustained "bad taste" that Americans had with regard to IUDs after some early models led to health problems (in the same vein, the Japanese, have been very averse to oral contraceptives for some reason). Fictionally, the Star Wars universe has qualms following the Clone Wars about both cloning technology and droids. The aversion to artificial intelligence is even greater in Frank Herbert's Dune universe which also develops aversions to many forms of conducting war in favor of assassination of leaders and hand to hand combat. A rejection of biotech could have roots in general disgust (such as opposition to GMOs and chimeras at opposite ends of the political spectrum these days), concerns about stem cell research, hesitancy about cloning, etc. If there were some culture shaping bad experiences with biotech in several countries that could easily shape public opinion. Similarly, biotech people could see the land of machine users as home to "dark Satanic mills" that were amoral and unnatural. An attraction to biotech or to machine based technologies could be driven by economics and resources. Maybe the biotech areas have poor metal and fossil fuel resources, for example. Metals also might be disfavored in someplace were rain or something else in local environment was highly oxidizing to the main available metals. For example, suppose that in lieu of coal or oil, the main sources of heat for metallurgy were geothermal giving places with access to those geothermal hot spots a near monopoly on that, particularly if metal resources were concentrated near the hot spots. Similarly, perhaps key biotech requires special climates (e.g. tropical rainforests or coral reefs) that can't be replicated elsewhere. This has the attraction of allowing stark distinctions in technology type to persist even with trade. For example, suppose that the biotech world has lots of plants engineered to produce medicinal juices that are all derivatives of a citrus plant that can only grow in tropical or subtropical climates. You could export it to small greenhouse orchards elsewhere, but places where you could grow it outdoors would have a huge advantage and it would be cheaper to ship purified medicinal juice syrups than the fruits or the whole plants. Other major international agricultural trade goods like wine grapes and coffee are also very picky about the right environmental conditions. Perhaps biotech areas had an abundance of local plant and animal species that were particularly well suited to domestication in the kind of narrative that Jared Diamond tells in his book "Guns, Germs and Steel." One source stock like dogs or a plant genus like *Brassica* (that includes cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, savoy, kohlrabi, kai-lan, the turnip; the mizuna, napa cabbage, bok choy, cime di rapa, field mustard, bird rape, keblock, colza, and black mustard) can produce incredible diversity from a single common species or related group of species of origin which might all be concentrated near the place of origin of that species. Mastery of just a few of these super-domesticates could easily led to a thriving biotech industry dominated by the trade secret protecting masters in the places where the "industry" began. [Answer] Assume that biotech is only efficient if you have an entire biotech infrastructure. Veterinarians instead of mechanics, nutrients instead of gasoline, perhaps biotech vehicles don't like blacktop roads ... [Early adopters](https://en.wikipedia.org/wiki/Early_adopter) will have to do without that. It would be a notable economic disadvantage to pay for both infrastructures. And since there is an infrastructure in place for mechanical technology, the question is who would pay for the changeover. * Every now and then, a country decides to stop driving on the left and to start [driving on the right](https://en.wikipedia.org/wiki/Right-_and_left-hand_traffic). That doesn't happen very often. * [Metric units](https://en.wikipedia.org/wiki/International_System_of_Units) go with the [decimal](https://en.wikipedia.org/wiki/Decimal) system just as [customary units](https://en.wikipedia.org/wiki/Imperial_and_US_customary_measurement_systems) go with [duodecimal](https://en.wikipedia.org/wiki/Duodecimal). Yet there are decimal countries which refuse to go the whole nine yards. Since it is your story, declare that the changeover will pay for itself in 50 years, or 100 years. Which countries in your world are willing to make that investment? How soon the biotech investment pays might also be affected by climate change assumptions. The same people who benefit from climate change denial might also benefit from a biotech avoidance. Some of the countries in your world might be so dsyfunctional that lobby groups prevent the only reasonable choice. [Answer] Ideology. Not necessarily a major religion, but a general pressure from the population; e.g. look at how cloning research was banned for a planned time-out of a few years. If people *rejected* biotech (as they have in the U.S.) but some single country runs with it, they will not only gain a competitive advantage but they can welcome all the scientists from the “we don’t want it” nations. Now they are the *only* country with any capability to work on it, and it snowballs. [Answer] Perhaps we can exploit a couple unique features of biotech in order to explain why its progress might be faster in one country over others. The primary obstacle facing genetic engineering and biotechnology broadly is a lack of knowledge about how existing biological systems work. Right now we have the technology and know-how to change any piece of a genome we want, but for the most part we don’t know what it will do. We don’t fully understand how biological systems work so we can’t modify them except by trial-and-error. Most genes appear to be regulated in a multitude of ways creating huge webs of interconnectivity and dependency. A given gene can produce many different RNA and protein products through splice variants and post-translational modifications and even similar products can have vastly different functions depending on their localizations. There are well documented examples of important genes playing one role in one part of the body and an entirely distinct role in another. As a result of these obstacles existing biotech is quite basic. Breeding for traits is completely ignorant of the underlying causes and genetically modified organisms are for the most part just adding in a few genes from another organism and hoping they will work the same way. For true biological tinkering to be possible we need to be able to predict what will happen when we start making changes to existing systems. To do that we need a couple things. First, we need to be able to predict how a protein will fold based on its amino acid sequence, and second we need to be able to predict how that folded protein will interact with other proteins and other molecules. If we possessed these two capabilities we could in theory take the proteins expressed in a given cell, predict their folded structure, and then predict how those proteins will interact with each other. This could allow us to map out this dense network of interactions underlying the organism’s biology and begin to predict what might happen if we modified this or that protein ever so slightly. Essentially what we really need to make biotechnology feasible is a computing revolution. But what if biotech could actually provide that computing revolution for us? Perhaps in your country there is some key breakthrough in the lab growth of functioning neurons arranged into networks just as they are in our brains. By providing electrical stimuli to input neurons and measuring output of other neurons perhaps these wet, analog neural networks could become useful for certain computational problems. In the field of machine learning electrical, artificial neural networks are frequently used to solve certain problems as a sort of loose approximation of how our brains work. One limitation to them is they take a lot of computational power to train, especially as they increase in size. A biological, analog neural network would have a constant propagation time from input to output, theoretically allowing it to be scaled upward in size without end, enabling to tackle ever more complex problems. Perhaps eventually these artificial brains are able to fold protein structures and predict interacting domains between molecules. Not only would this lead to further improvements in the artificial brains, but it would now also make biotech in other areas more viable. Eventually the strategic importance of these artificial brains might be realized by the country’s government and research on them made classified. Larger and superior brains will continue to fuel their own advancement thus creating their own biological technological singularity potentially resulting in a general artificial intelligence. The end result is only one country having access to advanced biotech that other nations could not hope to understand or emulate without the problem solving capabilities of the artificial brains. [Answer] This boils down to biotech's efficiencies versus non-biotech efficiencies, so you have a biotech economy where biotech does everything you want it to *but* it does some of those things very inefficiently. This example is from Stephen Donaldson's *[The Gap into Vision:Forbidden Knowledge](https://en.wikipedia.org/wiki/Forbidden_Knowledge)* describing the process the Amnion use for metallurgy "they make steel by feeding iron ore to a viral acid that digests it and then shits it refined." Now if steel isn't terribly important to your culture the efficiency, or lack of, of such a process isn't that important. If, on the other hand, Steel is important to your society then you're going to use an efficient system of production for Steel. A society dominated by biotech is naturally going to use different materials and have different values, the neighbours won't adopt there methods and vice versa because they have different needs and methods. ]
[Question] [ Namely, would my superhero who can fly to the moon in minutes like Superman be able to outspeed the point-blank detonation of a nuclear bomb, thus defusing nearly all tension from any conflict not involving other spandex-clad freaks of nature? Or would they still be caught in it? Note that although I compared them to Superman, this character CANNOT fly faster than speed of light. I just want to know if they can fly faster than the speed of nuke. [Answer] [Effects of nuclear explosions](https://en.wikipedia.org/wiki/Effects_of_nuclear_explosions) (Wiki) > > The blast wind at sea level may exceed **one thousand km/h, or ~300 m/s**, approaching the speed of sound in air. > > > - > > About 5% of the energy released in a nuclear air burst is in the form of ionizing radiation: neutrons, gamma rays, alpha particles and electrons moving at speeds **up to the speed of light**. > > > [Answer] Here, we need to use the [Sedov-Taylor solution](https://en.wikipedia.org/wiki/Blast_wave#Bombs) (the section was originally more detailed, but I see, regrettably, that edits have been made). You can fine the original paper by Taylor [here](http://www3.nd.edu/~powers/ame.90931/taylor.blast.wave.I.pdf), although it's not the best introduction to the solution; I'd recommend [these notes](http://www.astronomy.ohio-state.edu/~ryden/ast825/ch5-6.pdf) instead. The radius of the wave at a time $t$ is $$r(t)=\xi\_0\left(\frac{Et^2}{\rho}\right)^{1/5}\tag{1}$$ for energy $E$, density $\rho$ and constant factor $\xi\_0$. Differentiating, we find $$v(t)=\frac{2}{5}\xi\_0\left(\frac{E}{\rho t^3}\right)^{1/5}\tag{2}=\frac{2}{5}\xi\_0^{2/5}\left(\frac{E}{\rho}\right)^{1/2}r^{-3/2}$$ It's safe to assume that $\xi\_0\approx1$, for our purposes. [Air density](https://en.wikipedia.org/wiki/Density_of_air) at sea level is roughly 1.225 kg/m$^3$. Now, the [Trinity test](https://en.wikipedia.org/wiki/Trinity_(nuclear_test)) released about 10 kilotons of TNT in the form of the blast. Plugging this in, we see that at $r=2$ m, we get $v=882,000$ m/s, while at $r=5$ m, we get $v=209,000$ m/s. This is a lot higher than the value quoted in [Mazura's answer](https://worldbuilding.stackexchange.com/a/54712/627), but I'll note that once we get out to about a quarter mile from the center of the explosion, the blast wave slows to speeds more like that one - in the hundreds of meters per second. This is a wee bit simplified. If you want to look at the Sedov-Taylor solution in much more detail, I'd recommend scrolling through [these slides](http://www.mso.anu.edu.au/~geoff/AGD/Sedov.pdf), which are extremely detailed - and also not light bedtime reading. [Answer] It turns out that your superhero has his kryptonite: the [Rope Trick Effect](https://en.wikipedia.org/wiki/Rope_trick_effect). [![Nuclear event with the rope trick present](https://i.stack.imgur.com/DuMEN.jpg)](https://i.stack.imgur.com/DuMEN.jpg) See those odd protrusions from the otherwise smooth explosion? That's known as the Rope Trick. It's caused by the ropes which tethered the nuclear bomb to its test site. When the bomb goes off, there's enough radiative heating to vaporize the ropes *before* the blast wave actually reaches them. (nuclear tests which are not tethered never show this effect) This effect can be mitigated by painting the ropes white, or covering them in aluminum foil. However, at a point blank distance of 2-3m, that radiative heating is going to be quite intense! Hope your superhero is wearing their asbestos underwear! [Answer] A superhero capable of flying to the Moon would have a speed of 2124.44 km/s (assuming a flight time from Earth to the Moon of three minutes). Therefore, if the blast wave has a velocity of 300 m/s, then the answer of his escaping the shock wave is easily. Considering the question concerned itself with the shock wave and not any problems with radiation, it is safe to assume the superhero is radiation-proof. Something that is common enough in Superman level superheroes. He might glow in the dark afterwards. The OP in the comments section suggested the nuclear detonation was intended to disseminate a substance that is the Achilles' heel of the superhero in a manner that would it unavoidable delivery system. So it's back to the drawing board, silly old mad scientist, this nuclear bomb powered delivery system scheme won't work. [Answer] The speed of an atomic bomb explosion shock wave. Plotting the radius of the expansion versus time, the slope gives the velocity of expansion. Examination of the time lapsed photographs shows at about 0.05 seconds the faint outline of the shock wave separating from the blast wave (hydro-dynamic separation) can be seen. This occurs at a velocity of about 1000 metres /second or Mach 3. ]
[Question] [ The Bartering system is a means of trading goods for other other goods, very similar to the Currency system except minus the money. The problem is that as the population of a location increases people begin to disagree on the value of the items; what use is a goat to a sailor compared to a baker? So the simplest solution is to create a currency system. It just becomes to unstable to depend on a barter system, so what can I do to make a barter system stable in a modern American society? [Answer] First some background about why currency tends to replace barter in economies. In general, a currency acts as a lubricant between trading partners, resulting in less complexity when used to trade or purchase any desired item. ``` Simple example with three people: person 'A' has a sword and wants a massive block of marble. person 'B' has a massive block of marble and wants a wheel of cheese. person 'C' has a wheel of cheese and wants a sword. Barter solution: they all meet in one place and trade items. ``` Possible problems with barter shown using this example: ``` 1) Lack of information: How do the three discover that collectively they have the items they want so they can agree to the barter? 2) Inequality of value: 'A' thinks his sword is worth more than the crappy block of marble offered by 'B'. How do you trade half a sword? 3) Non-portability of items: transporting the marble block to the barter is difficult. 4) Non durability of items: The wheel of cheese will go bad over time, requiring the barter to be completed quickly. ``` Currency fixes all four of these problems: ``` 1) No need to match what you have to what someone else has; make a currency sale and then a currency purchase instead. 2) If your item is worth more than an item you want, you end up with extra currency to use later. 3) currency is portable, unlike a block of marble. 4) currency hold value over time, unlike cheese (ignoring the whole fiat money/inflation issue here). ``` Currency also tends to be divisible into small enough values (no selling a single item for 1/2 penny) and be acceptable by everyone in the economy. I don't think the efficiency of currency over barter will allow you to create a realistic complex society that uses ONLY barter, at least as long as your world rewards economic efficiency. Simple or small economies can get away with barter. Now to answer your question. If your world has cultural values that totally ignore economic efficiency, then that society might avoid currency and only use barter. "Our religion has banned money/coins". If your world has a has an efficient way of discovering possible barters, ala internet matching of potential barters, then two of the problems of barter, lack of information and non-portability of items can be greatly reduced. You will still have problems of inequality of trades and non-durability of items though. My final answer is that you might want to consider a world with multiple non-traditional forms of currency. This would somewhat resemble a barter economy where you bartered (using non traditional currencies such as grain, crude oil, or other evenly divisible and value holding "things" like that). Your exchange rate between your non-traditional currencies (grain vs. crude oil) could be published so as to help potential buyers or traders decide on what form of 'currency' they wanted to use for the transaction. [Answer] Currency is not **just** about setting value for bartered goods. Money is a *common* yardstick for different goods. * Currency is a shortcut for multi-partner deals. Say Alice needs charcoal to forge a plowshare. Bob needs a plowshare to grow grain. Charles produces charcoal, but he'd rather have fish and not grain. So the deal has to involve Drew who takes Bob's grain for some fish. * Alice needs the coal now, but Bob won't produce grain for quite some time. Will Drew be prepared to hand over fish for a promise of future grain? * Alice produces relatively high-value objects, but she won't make all that many. If she made a plow this week, how can she get *fresh* food next week? --- **Follow-up:** How about tax incentives to barter? Get some precedents that cash transactions are taxed but barter is not, or at least that those who do barter can try and argue that the *cash* value of their transaction is very low. How about a move in your story to make most cash digital (a rider on one of those *if-you-don't-vote-for-this-you're-no-patriot-acts* to combat money laundering) coupled with a society which effectively denies bank accounts to poor people? [Answer] *…what can I do to make a barter system stable in a modern American society?* Make the society itself massively *unstable*. Simply positing a catastrophe, either physical catastrophe or an economic one such as hyperinflation, that makes trade outside a local area is impossible will not be enough. For the reasons already stated by Mark Ripley and o.m., some alternative form of currency will reassert itself quite quickly. The catastrophe has to be ongoing and make it impossible to predict what anything will be worth next week. Then barter will be the only means left to people to survive. Not many of them will. Such instability would also make agriculture or animal husbandry very difficult. If you want to write a less depressing story, how about a technological society that for some reason (e.g. a political or religious prohibition on profit) feels the need to *pretend* to operate by barter. That society's version of eBay would operate with an underlying structure that placed a numerical value on whatever you had to sell, but this would be concealed and denied. Ostensibly it would be a complex chain of swaps such that everyone got approximately what they wanted in the end. This would be extremely inconvenient and could only be enforced by repression but that is no bar to it happening in real life or in fiction. [Answer] > > Create a barter system in modern American society > > > Currency provides at least two major benefits over barter: 1. Storing value. 2. Making change. To replace these, you could have a place like Ebay - where you can offer a goat and the system takes the goat "in". Later, you want a dozen eggs and the "system" would determine that the "trade" is 1 goat for 100 dozen eggs. So it could "debit" your goat by 1/100. This is borderline ridiculous because the "system" would essentially create a currency. I use eBay as an example because a larger, barter based eBay would involve not just selling, but also "buying" at auction. In other words, people could offer to sell a goat, and someone "buying" the goat would need to already have "sold" something or else "sell" something of equal or greater value - and the system would handle "making change" and "storing value" for the inequity of the trade. However, the reason currency exists is because barter is terribly inefficient by comparison. With today's technology, this may work to some extent. However, it would likely fail for trades like rare artwork, intellectual property, private musical performances, etc. And it would struggle to handle selling tickets for a cruise ship, construction of a national monument, donating land for natural resource preservation, etc. And then there are things like credit/lending, insurance, taxation, utilities, medical services, education... it's a pretty long list of things we enjoy in today's world because currency makes the "trade" efficient. [Answer] To the Q of "***what can I do to make a barter system stable in a modern American society?***" Think of currency transactions in the time/quality/cost frame: * currency is very fast (credit card swipes, stock exchanges etc.) * currency gives high quality (it's very granular from cents to billions, so it is a good language to discuss value in, it also allows a common language to compare different transactions over time) * transaction cost is very low (most by computer, some by physical currency) How can you replicate those qualities in barter market? Time: * you could use computer networks as a place to advertise your goods and look for goods that you want. This record of past barters would help during the haggling process. * same network can can be the permanent record of a barter agreement Quality: * the network can have a searchable history of similar barters that you can use as a yardstick when judging a proposed barter * the network could have middlemen (or artificial intelligence) who put together baskets of goods and propose those baskets to parties Transaction Cost: * the network will electronic record the agreement It sounds like a hybrid of eBay. There are websites attempting barter exchanges today. It hasn't caught on yet. One problem, there are several companies doing this, which makes one stop bartering impossible and reduces the probability of a match because buyers and sellers are in different non-connected markets. You'd have to create some kind of incentive that would cause people use one particular exchange. I agree with others, that currency is best. But I wanted to answer the Q you asked. And a semi-serious proposal: Tinder should copy their software to a new server called ***Bartr***. Take a picture of the item for sale and Bartr broadcasts it. Consider items from others for your item, swipe left for No, right for Yes. It actually could work in a flea market environment. [Answer] There is an interesting halfway house in which any individual or group can issue it's own currency. This is how money starts in a barter society: as IOU notes. "I'll give you a day's carpentry when you need it in exchange for these groceries today". And you can in turn trade the carpentry promise for, say, some clothing. At a certain point in the development of society the rulers see the advantages of giving themselves a monopoly over creating currency. If the nation collapses into anarchy, local currencies and IOUs again appear, only to be killed off when a new nation is formed. Money is power. So what you need is stable anarchy or libertarianism. Human nature means that anarchy or extreme libertarianism is unstable. But if humans had been made part of some alien society which stabilised that form of near-anarchy? Perhaps omnipresent robotic enforcement of "an eye for an eye" unless the victim offers mercy, plus termination with extreme prejudice of anyone wielding a lethal weapon in anger. No rulers, no coercion, just voluntary associations. Could it work? [Answer] Change the scale, might be one solution. As several people point out, currency allows transactions over time and at a distance (unknown parties). Suppose individuals in some rural isolated area could only transact with those in their town, that would be plausibly sustainable (somewhat anyway). Then towns can barter with other towns, and towns in a region leads to regions bartering with regions. Since at each level of this barter hierarchy, the distance is not unreasonable for the parties concerned, and the trade is larger and focuses on different kinds of needs, perhaps it is sustainable. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 6 years ago. [Improve this question](/posts/39235/edit) # Background info There is a planet on which all dinosaurs can survive. Aliens have transported at least 2 M-F pairs of dinosaurs from the Triassic, Jurassic, and cretaceous time periods. A T rex pack has an Allosaurus egg in their nest that they will take care of along with 5 baby T rexes. ## Characteristics Allosaurus: Length: 38 feet Height: 16.5 feet Weight: 1.4 tons T rex: Length: 40 feet Height: 15-20 feet Weight: 6-7 tons(as much as an elephant) ## Interbreeding I know some people are going to say "Obviously not since they lived in different time periods." However like I said in the background info, on this fictional planet Allosaurus and T rex live at the same time. So the question is: Could Allosaurus breed with T rex to produce fertile offspring since both are theropods and would have similar DNA? There have been some cases of successful hybrids of animals in different genera(How else could a pumapard(hybrid between leopard and puma) exist?) as well as interspecies hybrids and hybrids of subspecies. From the characteristics it looks like it would most likely be a male T rex breeding with a female allosaurus. However dinosaur mating is not very well known. It could be like how lizards mate or it could be completely different. [Answer] # No They Could Not, And Here Is Why If our current knowledge about the classification of dinosaurs is correct, then no, Allosaurus couldn't mate with T. Rex even if both lived in proximity. The reason for this is that Allosaurus belongs to [Carnosaur](https://en.wikipedia.org/wiki/Carnosauria) group of predators (which contains African and South American predators such as Carcharodontosaurus and Giganotosaurus) while T. Rex belongs to [Tetanurae](https://en.wikipedia.org/wiki/Tetanurae) group (which contains raptors, birds and other feathered beasts). You can say that if Allosaurus is modern day polar bear, then T. Rex would be jaguar. Both are carnivores, both are mammals, both live at the same time, but a polar bear **cannot** mate with a jaguar even if you keep them both in the same cage for years and years. # Should You Really Care If They Couldn't? The real question should not be *whether* Allosaurus count mate with T. Rex but *do you want* to have that in your story/movie/game? If you want to do that, you don't need to find excuses for that. Just do it. Your readers/viewers would know that you are writing science *fiction* and not a scientific article or documentary. So as long as the plot is interesting and fun to read/watch, it's all cool. Heck! When Jurassic Park 4 could have a 40 feet high, camouflaging, thermal sensing monster (actually it would be *extremely hard* to even get a 40 feet high predator work at all!), your idea is much more believable and fun! [Answer] T. rex and Allosaurus are both theropods, but they're members of completely different families--Tyrannosauridae and Allosauridae. I don't know very much about genetics or taxonomy, but the first comparison that comes to mind is a dog mating with a cat. Canidae and Felidae are both in the same order, but they're completely different animals and wouldn't be genetically compatible. As far as I know, the false killer whale and the bottlenose dolphin are the only known animals capable of producing fertile hybrids across genera, and even then their offspring rarely survive into adulthood. And those are two animals in the same family. I do think it's possible that a T. rex might care for a baby Allosaurus as if it were its own. Lots of animals "adopt" members of different species for some reason. [Answer] No. Allosaurus and T. Rex may look superficially similar, but they're separated by close to 100 million years of evolution. Genetically, they were probably significantly more different than humans and chimpanzees. [Answer] Breed may be defined as having fertile offspring, or simply offspring. Consider the [mule](https://en.wikipedia.org/wiki/Mule), generally infertile offspring of a donkey and a horse. [Ligers](https://en.wikipedia.org/wiki/Liger), on the other hand, may be fertile. So *if* you are screwing with the natural evolution of your planet enough to make Allosaurus and Tyrannosaurus contemporaries, feel free to make them related closely enough. Just don't call it [science-based](/questions/tagged/science-based "show questions tagged 'science-based'") ... [Answer] Dinosaur genetics is not crazily different from bird genetics and mammal genetics... Humans currently could still mate with neanderthals who are different form us by about 800.000 years of evolution, i.e. 34000 generations... I'd say that's quite a high limit on maximum generations of an advanced vertebrate between mating, it depends how fast the creature evolves, birds and reptiles do actually evolve rather fast in between generations same as mammals. Biologically speaking, that's a fair estimate of the kinds of limits of generations in prior to total species division of advanced vertebrates, 50k generations, 100k even. Interesting to know: Crocodiles are very slow changing dinosaurs, there are dinosaurs from 110 million years ago that are nearly the same as today, we can suppose that speciation of dinosaurs can take many millions of years. Along with pterosaurs and dinosaurs, crocodiles were an offshoot of the archosaurs, the "ruling lizards" of the early to middle Triassic period (needless to say, the earliest dinosaurs and the earliest crocodiles resembled one another a lot more than either resembled the first pterosaurs!). What distinguished crocodiles from the first dinosaurs was the shape and musculature of their jaws, which tended to be much more deadly, as well as their relatively splayed limbs (as opposed to the straight, "locked in" legs of theropod dinosaurs). ]
[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. In the game Portal, there are glowing light platforms. These platforms are (supposedly) made of solid, compressed light. How can these realistically be made? [Answer] # No They are not realistic, not in the slightest. In the real universe, there are two fundamentally different kinds of particles. Fermions are “matter-like” and ultimately that’s why bricks are solid and hard. The way matter behaves comes from the fundamental properties of these particles, which, e.g. cannot be have more than one instance in the same place. [Bosons](https://en.wikipedia.org/wiki/Boson#Properties) are the opposite. They don’t take up space and *prefer* to pile together like a [football tackle](https://en.wikipedia.org/wiki/Tackle_(football_move)#American_and_Canadian_football) heap. That’s why lasers are a thing. Light uses bosons. Meanwhile, photons have no charge, so they don’t attract or repel each other in any way. The lack of charge is also crucial for light being what it is. For example gluons *do* have a charge (the [‘color’ charge](https://en.wikipedia.org/wiki/Gluon#Color_charge_and_superposition) of the strong force) and rather than spreading out in all directions so the intensity falls off with the square of the distance, they interact with each other and form flux tubes that act like rubber bands. So the statement in the Question is an oxymoron. Light doesn’t do that. Something that did that would not be light. --- # Different Universe with something like that? Now, in another universe with slightly different things in it but generally the same kinds of rules, the [“flux tubes”](https://en.wikipedia.org/wiki/Color_confinement) sounds interesting. The nature of the charge and the particular energies involved make the strong force *very* short range and prevent the color charge from ever showing. But that’s details of the specific values involved, not because the bosons have charges per-se. But a boson can’t just have any kind of charge. Bosons and charges work together and form a symmetry group. Light is intimately tied with the existence of the electric charge, but doesn’t carry the charge. That will be the case for a charge that has one “kind” like electric, with positive and negative values along a line of possible charge value. --- # Plasma confinement Now you could have platforms made from electromagnetic forces forming loops and such, but that’s not how you described it. # or exotic forms of matter in general And if you did have a “solid” of something that wasn’t made of atoms, why would it be solid against atoms rather than only the same kind of stuff? Recall that bricks are not solid because the electric charges repel each other, but because electrons are fermions and “exclude” each other. [Answer] As others have said, a solid platform made of light is completely unrealistic. However, it is entirely possible for light to exert a force on an object and hold it up, though the force required to support a human's mass against Earth's gravity would require a truly ferocious amount of light. Using some serious estimation, a 1km square reflective sail in orbit around the Sun at Earth's orbital radius would experience a maximum of about 8 newtons of force from the sunlight hitting it. Cutting that down to an average foot size, about 0.03 square meters, you're looking at about 0.5 micronewtons of force across both feet. The force required to support an adult woman of Chell's approximate mass is 600-700N. So if her shoes were highly reflective, the platform would have to shine over one billion times brighter than the Sun in order to support her weight. That translates to well over a trillion watts per square meter. I could be way off on this, but if my math is right, that corresponds to the radiation emitted by something that is 160,000°C (290,000°F), assuming all of the light is emitted under her shoes at the time her feet apply pressure. If you're writing a story, this could make for a really interesting failure mode... [Answer] Portal 2 is a comedy and probably the writers just stringed some scientific jargon together to construct an intentionally nonsensical scientific concept. Probably the writers put a lot less thought into this than we are right now... Light is a massless particle that travels in a straight line. (incidentally it travels at the speed of light because it has no mass to slow it down.) Its path can be bent by gravity because gravity is not a force, but rather a symptom of the bending of space-time by mass. Because light is massless it cannot be held together by its own mass. Light is also "charge-less" and therefore cannot be bent by electromagnetism to any measurable degree, as explained [here](https://www.physicsforums.com/threads/bending-light-with-a-magnet.282656/) So compressed light would fly off and not hold together into a solid object. I also do not see what conceivable external device could hold it together, other than with strong gravity that would destroy the room. Also, it contains a lot of energy and would incinerate anything that touched it. [Answer] The other answers are correct in that solid light is not possible, however keep in mind that something similar to that and called that might be possible. For example what if there were particles in the air that normally just act as a gas. When hit by a laser they clump together and form a solid platform. By shining a grid of lasers to form a hologram in the right location you get a platform made by light even though it's not made of light. Those platforms would need to be supported somehow and there would be a lot of handwavium involved in the material they are made from but something along those lines is not inconceivable. [Answer] Some of the key traits of solid matter that make it solid matter are these: * It tends to stay where it is. * It excludes other matter from being in the same space. * It has a shape and tends to hold onto that shape even in the face of attempts to change it. In more detail, matter never moves at the speed of light in any frame of reference and there is always a frame of reference where it is not moving. Light on the other hand is always moving at the speed of light. It will not stay where you put it and instead move away at the speed of light. The best you can do is change the direction it's going, and that ultimately requires something not moving at the speed of light to bend the light with (like an optical fibre or a black hole) Matter is also made up of charge particles, arranged into atoms with positively charged protons at the centre, and negatively charged electrons around the outside. As atoms get close together, the electron shells on the outside will come together long before the protons in the nucleus get as close to the electrons. This means that when atoms are very close to one another, the repulsion between their electrons dominates over the attraction between the nuclei and their neighbours electrons. This close range repulsion is called the Van Der Waals force, and it prevents atoms from overlapping. This is what makes normal matter (as opposed to say the matter making up neutron stars) take up space and exclude other matter. Light has no charge, and two or more photons can be in exactly the same place at the same time (which is part of how lasers work) What makes matter *solid* is that it can form structures which requires both the 'not moving at light speed all the time in all reference frames' and the charge differential between the inside and outside of atoms. Atoms near each other can connect into a structure that resists having those atoms moved apart. (This is a huge simplification) Light is always moving at light speed, has no charge, doesn't exclude other light or matter from occupying the same space, and doesn't form structures with other light where the photons will resist moving apart from each other. You can push things with light, but the amount of pressure you can get is small. By the time you have enough light to be noticeable in situations on typical human scales, the *heat* would be immense. Rather than a pleasantly glowing platform you could stand on, you'd have something more like an enormous laser shooting up into the sky and vaporizing everything in its path. ]
[Question] [ Suppose in the early stage of the merpeople civilization, languages are at its infancy and they have just started agriculture. We all know that calender and clock are very important for early farmers to effectively manage their crops and lands as well as for economy. My question is since all early merpeople are sea dwellers whom never seen land except on rare occasions due to powerful storm they find themselves washed ashore, how can they keep track of time and also do the changing shift between day and night affects them? Their civilization is equivalent to our post stone age and they grow seaweeds along with other hydroponic vegetables. (please split your answer for shallow and deep water) [Answer] If they're farming plants, plants need the sun. If they can see the sun, they can tell time just like us. The day/night cycle will be most important to them because of predators that might attack them in the dark. They won't see the same degree of temperature swings that we do. An alternative method would be to use tidal cycles as a timekeeping method. This has the added advantage of making it easier for them to track tides, which could be important if they fish or if they need to track nutrients caught in a tide. [Answer] **Deep Sea** The deep ocean has basically [no changes in temperature](http://en.wikipedia.org/wiki/Deep_sea#Temperature) across the seasons. It's already nearly freezing, and when water freezes it goes up, out of the deep sea. **Shallow Sea** In the [pelagic zone](http://en.wikipedia.org/wiki/Pelagic_zone). They can see the sun and count the days just like land dwelling farmers. The seasons (like the day and night cycle) will bring a change in temperature, but not as harshly as on land. [Answer] In shallow water you could track the movements of the sun/moon/stars much like early farmers did. In deeper waters they may resort to looking at things like animal migration patterns to keep track of seasons. ![enter image description here](https://i.stack.imgur.com/NzYmp.jpg) <http://www.nature.nps.gov/biology/migratoryspecies/humpbackwhale.cfm> Or to keep track of days they might use the [Diel vertical migration](http://en.wikipedia.org/wiki/Diel_vertical_migration) [Answer] There are cyclical changes of temperature in some oceans, but they are very irregular: * el Niño, from Wikipedia: "(...) happens at irregular intervals of two to seven years, and lasts nine months to two years.[7] The average period length is five years." * la Niña, it follows el Niño if conditions are correct and has an irregular duration. Migration of sea animals. [Each whale species migrates at different seasons to different locations](http://www.wildaboutwhales.com.au/whale-facts/about-whales/whale-migration), turtles lay eggs on certain beaches at certain dates or migrate to breeding groups. They travel in groups, which makes them even more noticeable. With some species migrating at different dates, you should be to able to track seasons accurately. [Answer] I realise this is a very old question but I thought I would add my 2 cents worth. You also have to remember that for the longest time, humans didn't have a constant method of telling the time. We could measure a passage of time, but sometimes didn't know what the actual time of day was. eg you can measure how fast a candle burns and how many candles had been used but that didn't necessarily tell you it was 2.30pm. We used mechanical clocks that we wound up to a particular feature of the day eg High noon (which would be measured each day). We worked off masterclocks. So you would have your pocket watches wound up based on the time of the great grandfather clocks. This inturn was kept in time with 'greenwich' time etc. **The measurement of time is all subjective.** **Telling Time in the oceans...** Visible light only reaches about 100m into the ocean, 200m maximum. So if your merfolk are farming seaweeds, and other hydroponics, I assume they are in a shallow coastal sea areas. So your normal day/night time cycles would definitely affect your merfolk. **Shallow waters:** Sea life have seasonal migration patterns as the other older answers already mentioned, but they also have daily migration patterns based on the time of day. Phytoplankton and plankton rise and fall in the near surface oceans in a regular pattern to take advantage of the light/darkness and avoid predators. Some rise during the day others during the night. You could measure your passage of time by the depth and concentrations of these little critters. eg you could say it was waxing/waning 25% concentration for a unit of water. Obviously storms and wave action affect this process to some extent so you would be measuring the average pattern. (I've just seen that the answer by apaul34208 actually did mention this, in one line...Diel vertical migration) **Deep waters** Deep waters are a bit harder as they are move uniform. Deeper waters are also fairly barren. No plant life (needing light to photosynthesis) can survive. The deep oceans are actually considered Deserts! The deeper the water, the more pressure. Maybe you could use the amount of time it takes water pressure at known depths to crush an object. You would need an almanac to know the rates for different depths or just a really well versed old-merperson to tell you the difference. Because of the increased pressure and the fact the salty water is denser it sinks. You could use the rate of a known concentration of salt water to sink a certain distance as a time measurement (as a side note, surface sea water actually only freezes at -2degrees celsius because of the salinity - the deeper one goes, the higher the salinity combined with higher pressures, result in a lower temperature required to freeze. This is why the deep oceans do not freeze solid!). For this you could use known upwelling/downwelling currents and measure how long it takes the current to move a certain object a certain distance up/down. **Both Shallow ad Deep Waters - Non specific** You could use the location of ocean currents and temperatures to mark the passage of seasonal time. The 'waxing' and 'waning' of these currents strengths could be the seasonal transitions. This would also influence the seasonal migration of sea life as previously mentioned. But that is like saying, "watch out for the wildebeest migration, that means it's July!" I think you want something a little bit more specific than that. You could use a sand clock. Not in the typical traditional sense but a combination of sand and water (inspired by turbidity currents). You could have a sediment-rich water enclosed in a glass or transparent membrane. Shake it up like a snowglobe, and then using the rate of the sediment settling out of the water as a measurement of time. As it would be a known amount of sediment in a known amount of water with a known water pressure you could make pretty accurate measurements of time. (I actually really like this idea, and may just use it myself!) Your Merfolk could keep a particular species of animal with a short lifespan as 'time-pets'. The transition from one developmental stage to the next could allow the passage of time to be recorded. Eg you could say it was three butterflies (with an underwater animal of course) since your last clan meeting. Or 2 butterflies and a cocoon... they can find a measurement that works for them, especially since sea-animals have several distinct developmental stages in their lifecycles eg larvae, pupate, adult etc. Just thinking of animals, you could get a slow moving animal like a seaslug or starfish and measure the time it takes to move a certain distance to a food source...ie you could have star-charts! ]
[Question] [ First question here, have been lurking for a long time, I really enjoy reading your interpretations of the various situations. I was wondering what you believe would be the most realistic implications of a world where anything that can be made digital (music, movies, documents, images, videos, etc.) was automatically released to the public via the internet and was completely free (free as in speech and free as in beer)? Essentially, no concept of intellectual property. [Answer] I understand the question to be asking about the current economy, only without intellectual property, not some future post-scarcity economy. A post-scarcity economy would be different. Post-scarcity implies a lack of copyright, but a lack of copyright does not imply post-scarcity. Without some kind of change in funding models, it would no longer be possible to make big budget works. For example, Star Trek (both movies and shows) would be extremely difficult to fund. It relies heavily on secondary sales (syndication and videos) for funding. It's possible that Kickstarter, etc. would be able to compensate for this, but not definitive. Note that the [most successful Kickstarter movie](https://www.kickstarter.com/projects/559914737/the-veronica-mars-movie-project) was funded for less than six million. Contrast that with the tens of millions needed for Serenity, which was considered a relatively modest budget for a special effects movie. The hope would be that more people would step forward if there were no traditional projects with which to compete. Smaller works could be funded more easily. YouTube would be fine. Television is an interesting case, because the channels would have to develop the content as well. Currently studios develop content and channels purchase it for display. Without copyright, that model doesn't work. The elimination of DVDs would drive budgets down. We'd probably see more live television like reality shows and game shows. Perhaps more concerts would be televised as well. I suspect sports would change the least. It's almost all live now. Pay cable television would be much harder. For one thing, they could no longer buy content. For another, selling content becomes less profitable. Some people would just wait the extra day to watch copies of Game of Thrones, etc. rather than pay for access. Music would become smaller budget as well. Note that albums serve two purposes. One, they are a marketing tool (for selling concert tickets). Two, they generate enough revenue to pay for themselves and additional marketing to promote them. Without that revenue, there'd be much less marketing. This would tend to make acts smaller and more regional. Fewer touring bands. Better bar bands (since they don't graduate to being touring bands). Some artists might never start, but it seems likely that many are motivated more by love of music than money. Books would be extremely difficult. Few authors would be able to spend the time to write hundreds of pages of content without pay. Short stories would be more robust. Note that textbooks would also be rarer. They'd be forced to an open source model. It's possible to write popular style books in an open source model as well, but it's unclear if enough people would be interested. In general, things that are under copyright now would get funded less. The works that remain would tend to be cheaper and more personal. Content would be created if people felt driven to create it. [Answer] Basically, we've already got a lot of that going now. Between Youtube, Soundcloud, Blogger, Wordpress, Vimeo, etc. there is more digital culture being produced than ever before WITHOUT MONEY NEEDING TO CHANGE HANDS. Copyright law was written in an era where production of anything (and especially culture, books, music, art, etc.) required immense resources. We're far past that point. So what happens when you take the money out of culture? Then people produce culture because they want to. We wouldn't have "The Fast and the Furious 6," but we'd still have movies and music. We're already seeing patronage resurfacing through crowdfunding platforms like Kickstarter, Indiegogo, and Patreon. Bands will still be valuable - time is unique and non-digital, after all - and they will continue to earn the majority of their revenues from appearances and merchandise, rather than the music itself. This has actually ALWAYS been the case with musicians - the record labels make the money on the music and CD's, not the bands. Hulu "sells" TV for free (as did all TV before cable) - they make money off of your eyeballs, not your subscriptions. Soap operas are so called because they were bought and paid for by soap companies. No one purchased episodes of Days of Our Lives. Radio is free, "digital" music. So in short, it wouldn't look too different from today, just with fewer middlemen between artists and the public skimming money. [Answer] As pointed out by other answers, a big incentive to invent things is to make money, which would be problematic in the world that you describe. So how do you pay those inventors? Well one thing is that many thing that we pay today would be free, so people actually have a lot more money than today. I don't think however that people would be willing to give the same amount of money to things like kickstarter/patreon/charity/... as what they pay today. On way to force them into giving more money would be *taxes*. This already exists in some countries (cf. [Wikipedia](http://en.wikipedia.org/wiki/Television_licence)), where public broadcasters rely on tax-money for their funding (as opposed to ads). That however wouldn't necessarily suppress the existence of independent productions. For example in France a lot of movies are financed through what is called "l'avance sur recette" (sorry, I could not find a good reference in english). Basically a commission reviews the film project before-hand and tries to guess how much money it is going to make. They then give money, and if the film is actually successful enough, the commission gets its money back. [This is not exactly a loan since sometimes the money is never payed back.] You could adapt such a system by evaluating the movie depending on how much success it is going to have rather than how much money it is going to make. Here I have been talking about cultural stuff, but I guess you could adapt this to about anything. [Note that depending on where you live, the right-wing could think that all this is a really bad idea...] [Answer] The short answer is that money drains out of the cultural sector- all television, film and music becomes free to consume and must either consequently have corporate or government sponsorship or die out. So your visual media becomes ad supported and is filled with product placements. The same for video games. Nobody is making a living any more as an author, a film maker, a television actor, director and so on, or anywhere in those distribution chains, so employment falls significantly and competition for work in other sectors rises. Fewer people are able to make a living from following their talents, so on the whole society is a little more miserable. Ultimately there is a division between high-profile and low profile creators- for a few high profile creators there is plenty of sponsorship and they are able to make a living - think of your Coldplay, your J K Rowling and so on. For lesser known creators they are small fish in a huge ocean. Whether anyone is able to raise their profile to that higher level is doubtful and many brilliant people never play their songs to more than a few people, never have their books read by anyone they are not related to and so on. You can already see this happening in music and to a degree around books. If an artist doesn't have universal appeal, they cannot make a living from their work, so economics will drive creators to the middle of the road. The price of the world becoming more free is the end of professional musicians, writers, film and game makers and the loss of many unique voices. [Answer] In a post scarcity world (which is essentially what you are describing) there will still be some constraints, which will become the "new" foundations of economics and wealth. Regardless of how much you can physically produce, there will be limits of time, bandwidth and energy. To give a simple example, a famous person today might receive millions of emails or "Friend" requests; they cannot possibly read and respond to them all (limits of time and bandwidth: in this case the processing power of their own brain). Such a person in a post scarcity environment might be considered "wealthy", and having them bestow some of their valuable time and attention on you would be like having a high paying job or a winning lottery ticket. The schlub in the corner with no Twitter followers (or the paranoid with no on line presence at all) would be "poverty stricken" in this world. How you reach that level of fame and attention is up to you, but talent and ability that you can display to others will count for a lot. Other limits like the total available amount of energy, accessible raw materials and electronic bandwidth would also have real effects on a post scarcity environment, the unit of payment may be "time" (i.e. the famous person above might not have to wait for the Fabber to build a car, while you might have to wait in a virtual line while materials and energy is assembled to make your new washing machine. *Everyone* who wants one gets a washing machine without fail, the real question is "*when*" you can get yours). [Answer] I take your question that it will still be possible to charge for *producing* digital works. If that is the case, what you are describing is more or less what we see in the free software (free as freedom) society: You can be paid for developing software, teaching, supporting, and even using the software. But you cannot be paid for licensing it. It will give a lot of benefits: You can build on all other works and produce your own without having to consult a lawyer. This is great for works that can be improved gradually: Software, music, encyclopedias, ideas. It will be harder for works that need a big initial investment: Writing a novel, making a movie, getting a drug approved. Drugs are less of an issue: Today they are indirectly mostly financed by taxes in Europe (<https://christianengstrom.wordpress.com/2011/03/09/an-alternative-to-pharmaceutical-patents/>) and by insurance in the US. So they can be financed by using the same money directly. Novels can to a certain extend be done as a collaborate work (think of all the quality fan fiction that already exists), but it will be harder get funding for writing a novel on your own. See [Stephen King's "The Plant"](http://en.wikipedia.org/wiki/The_Plant "Stephen King's The Plant"). The same goes for textbooks: They can be done in a collaborate way, where authors are paid to write/improve a chapter by someone who needs it (e.g. an educational institution). The low budget news (gossip, press releases) will have no problem surviving: There will be plenty of people who will happily do that for free, and if there is a market for higher quality of this, I expect people may be willing to pay for this. I currently do not see how to fund: * Big budget news (investigative journalism) - it seems to be more or less the same as the solo-novel. But maybe it can be done like [Democracy Now](http://www.democracynow.org/es/%20Democracy%20Now). * Live coverage (sports) - Ad-sponsoring will not work: if the others can replicate the signal, then they can also substitute the ads. * Big budget movies - Product placement will work some of the way. [Answer] The main points are made, I second everything brython said very much. However, I wanted to point out an obvious down side, and comments aren't enough to express it. I believe most of our currently enjoyed 'free' mediums would, if not die out, drastically drop in quality and content. Currently most of our free mediums work based off of add revenue. I provide you with something free, you tolerate listening to my adds in exchange. However, if everyone owns all digital media then I don't need to tolerate your adds to watch my cat videos. I own, and thus can legally download and watch at any time, every episode of *The Awesomes* (hulu original show I just looked up to make my point) at any time. I would therefore not go to hulu and suffer through commercials to enjoy the movie. I would torrent it or, if I don't trust torrent, download it from a sight that makes me watch only one add to cover their hosting fees prior to downloading every episode. Thus if Hulu tries to live off of a model of using commercials to make a profit they will lose all their customers. Hulu would have to change it's income model. You may say that Hulu will need less income now that they aren't paying copyrights, and your right, but they are still paying hosting fees. It is not cheap to pay for thousands of servers and gigantic bandwidth costs to stream video. Hulu could make some money by having non-invasive adds along the side of the page, those adds we all institutionally ignore, but not enough to cover the costs of streaming video to the customers. Hulu could try to ask for donations to cover their costs, but most would find it easier and faster to download the files from large file-download sites and cut hulu out as a middle man. In short, Hulu is dead, radio is dead, youtube...well it may survive since part of what youtube offers is the ability to find videos from a collection of mostly worthless videos, their service isn't as easily replaced with a simple torrent. Still, many of our favorite youtube celebrities would find they didn't get any money from youtube for their productions, and that will cause some of them to stop bothering. Now we could still download this media from torrent or file sharing sites, so the death of Hulu and Radio wouldn't make us lose a way to consume already existing media. However, radio, TV, and Hulu are major sources of income for artists, and that wouldn't exist. The artist can not make money selling his product in any way. In short You can not look at these 'free' models and claim that they prove that the free market works, since these very models fail in the free market you describe. Artists would have about 3 sources of income. 1) money given straight to the artist as a thank you for their work from fans 2) advertisements which can are unintuitive enough that they don't bother fans enough to drive them to another source, think the little adds on the side of any medium. 3) Money from product placement. 1 & 2 are not trivial. Many webcomics already make enough money to work full time as cartoonists from 1 & 2...mostly. Webcomics also sell 'swag', with their logos on it. I don't know rather you would consider it in spirit of the OP question to say that only merchandise authorized by the comic could use his characters. A webcartonists would do pretty well with this system. If he was very popular some people would likely clone his site, using cybersquatting techniques to steal views from the cartoonist, but It would likely not be that huge a lost, and perhaps cybersquatting would still be illegal in the OP's world? The cartoonist also gets a good deal of money by selling print versions of his comics which he couldn't prevent others from producing knock-offs of. Still, he would likely get more donations from fans, who have more disposable money to spend on entertainment and more encouragement to use it via donations now that they aren't paying for other media. However the web cartoonist only needs to make enough to pay for his hosting, which is less then the add revenue he gets per view anyways, and his own hourly wage. He has some other expenses, drawing supplies, office space etc, but they are relatively minor. Much of the media we prefer has a much higher budget! Movies and video games will suffer drastically. Product placement will help cover a decent bit of their lost income, at the expense of making them more annoying, but ultimately any product placement that was too blatant would be edited out of their movie by a fan and the less annoying edited version will start floating around the internet quickly. I imagine that crowdsourcing donations would nearly double, with the increased disposable income and a larger cultural emphasis on rewarding those who produce products you like, but frankly that's still a drop in the bucket. Some very good products will still be made, I've enjoyed some RPGMaker games better then high priced commercial products (*insert rant on how much I hated FF13 here*). However, large budget entertainment would die out. There would be no funding for it. On the plus side the open source community is awesome enough that most of our every day non-entertainment software needs would be covered. A company could pay to have more specific software products built for them by promising to pay someone for making it regardless of copyright. In short our software development would not be hurt nearly as badly. Some for-profit products would die out, but the open source community would swoop in and fill the niche. Music industry would survive to some form, by emphasizing live concerts and selling of swag, which is a large part of their profits anyways. The rock stars wouldn't be quite as rich, but honestly I'm not that upset about it. The fremium business model for games may work...to an extent. These games sell a service in game, and can still make a profit on that in-game service as long as anyone plays their game. The biggest problem is that nothing would stop someone from starting up their own server that clones the existing game and sells the same 'services'. Phone and facebook fremium games would thus suffer significantly. When candy crush made good money someone would create a new candy crush that charged 5 cents less for a new game, and people would switch to it. Then someone would do the same for 5 cents less etc etc. The price would keep dropping. since it costs nothing to provide something in game there is nothing to stop other's undercutting the fremium provider's services. The original provider may get customers who are willing to stick with them as a way of rewarding the original producer of the product, or who stick with them because they don't know how to find the cheaper service though. Thus the original candy crush would likely charge more then the cloned version, but ultimately they couldn't charge significantly more without loosing too much of their customer base, thus their prices would have to be low. Some profit could be made, after all candy crush has a pretty small production and hosting cost so they don't need much coming in per-gamer to net a profit, but it would be much less then it is now. Still, fremium games would be the *only* way to make a direct profit from customers, and thus they would still be our primary type of for-profit game. Larger fremium games like LoL would actually fair even better. That's because you need to have a certain number of people using your product before a game like LoL is worth playing. There is no point joining a server with 1/10 the customers (and thus longer waiting queues and a great skill disparity on teams) just to get a free skin. Between name recognition (or perhaps I should say server recognition), inertia of having the largest user base making you preferable, and customers intentionally using the original creator's server to reward that creator's hard work LoL would be able to keep a decent percentage of their customer base even if others started cloning their game and offering services with cheaper skins. They would still lose a decent chunk of their net income, but not enough to put them out of business. large skill online multiplayer style fremium games would be the only for-profit games produced with any real budget. Still, any large movie or single player video game would be dead. Smaller fan made games, with perhaps a decent increased budget compared to today but still nothing spectacular, would be all you would have. Books...technically could still be sold so long as they were never digitized according to a technical reading of the OP question. However, if books lost copyright protection they too would quickly drop in number. There would be some die hards who produce for the love of the work; I've ready some great fan fiction for instance, but not nearly as many writers would exist, and even the best would have less time to focus on writing since they would have to pay their bills in other ways as well. A 'professional' writer would be rare, and limited only to those who achieved meme status online (thinks like fifty shades of grey, though I feel dirty inside implying that book did anything right). [Answer] Let me contemplate a variation of what Isaac posted. Suppose that the amount of stuff I consume, such as music and TV entertainment, is fixed. I have a budget, a reasonable affordable amount, and I patronize *someone* or another as my interests go. The free-digital concept means it is essentially free to reproduce and distribute content. The only cost is the actual production. But, it scales enormously because everyone in the world can chip in to fund it. The price of consuming it drops directly in proportion to the audience size. People can produce and distribute more content for less expense. That makes it cheap to consume. Good stuff also accumulates, so it can continue to earn credit years later. Past hits are an investment. Patreon is far less of vechile for cons and scams than Kickstarter. It still happens, where someone can milk the monthly contributions and avoid finishing because that means an end to the funding. But ideally content providers are paid as they go and because we like what they *are* (continuously) producing. If the consumption went through a service that automated funding payment, it would be much like attending a live event: I pay at the door *plus* take care of my own costs to get there, so the presentor sees income directly proportional to the number of attendants with no change in effort. A better analogy would be if the venue itemized its own fees as separate from the performer's fee on the ticket. And the venue costs were the same no matter how hot the performer. ]
[Question] [ Suppose we have a planet whose atmosphere has roughly the same gaseous proportions as Earth, but helium replaces nitrogen, and has a strong hydrogen presence in the upper atmosphere; has a gravitational pull stronger than Earth; and has a thicker atmosphere than Earth (from the planet's surface to the boundary with space). What effect would these conditions have on the development of science and technology from a human perspective? Fields I am interested in seeing an impact to include, but are not limited to, the following: * Flight. Lighter-than-air vehicles would likely require heated helium or hydrogen to maintain flight, but what about fixed- and rotor-wing craft? Would it be easier or harder to fly, or would there not be a noticeable difference? * Communication. Waves propagate through different materials/densities at different rates. Would there be a noticeable effect on the transmission of, e.g., radio waves? * Diving. When scuba divers make deep dives, they swap out the nitrogen in their compressed air tanks for helium (this was the idea behind the atmospheric change). Would helium still be a viable option for deep dives? * Explosives. As with communication, waves have varying propagation factors. Would explosions be noticeably affected? For example, would they be more destructive, but in a smaller radius? * Firearms. In extension to explosives, would firearms be noticeably affected? Gravity would be likely to pull ammunition to the ground faster. Would projectiles face more or less resistance from the altered atmosphere, potentially affecting the effective range? * Spaceflight. Modern rocketry is built on the concept of a controlled explosion. Which factor would play the greatest role in deterring/encouraging spaceflight: the helium in the atmosphere, the strong gravity well, or the height of the atmosphere? Also, would modern rocket engines cause the high hydrogen content in the upper atmosphere to explode, effectively preventing such vehicles from reaching space? Please note: I am not altogether interested in an exploration of the impact of these changes on the human physiology; humans would probably be shorter, denser, and sound like Alvin and the Chipmunks. If there are any areas I have not already listed you believe would be noticeably affected by the conditions described above, feel free to list them. Addendum: I've noticed a lot of the answers tend to be about the feasibility of life developing in a helium-based atmosphere rather than the impact the atmosphere would have on the development of scientific understanding. Just to be clear, this planet is not Earth, so any biological factors can be assumed to be properly developed for the indicated atmosphere. Answers to this question should *only* be about the impact on various fields of science and technology. [Answer] One way to estimate the relative difficulty of flight is to compare the effect on [Reynold's numbers](http://en.wikipedia.org/wiki/Reynolds_number). (tl;dr: flight is harder by a lot) The formula we'll use is the cords Reynold's number: $$ R = \frac{V c}{\nu} $$ where V is velocity, c is chord length of the airfoil and $\nu$ is kinematic viscoscity; it's $\nu$ that changes; with a larger value corresponding to a lower Reyndold's number, and more difficult flight. [Dynamic Viscocities](http://www.engineeringtoolbox.com/gases-absolute-dynamic-viscosity-d_1888.html) at $20^\circ C$ in $ 10 ^ {-5} \frac{Kg}{m \cdot s} $ $$ \mu\_{He} = 1.96$$ $$ \mu\_{Air} = 1.82$$ [Fluid Density](http://www.engineeringtoolbox.com/gas-density-d_158.html) at $20^\circ C$ in $\frac{Kg}{m^3}$ $$ \rho\_{He} = 0.1664$$ $$ \rho\_{Air} = 1.205$$ Giving us [kinematic viscocities](http://en.wikipedia.org/wiki/Viscosity), by $\nu = \frac{\mu}{\rho} $ in $\frac{m^2}{s}$ $$ \nu\_{He} = 11.8$$ $$ \nu\_{Air} = 1.51$$ Of course, our actual atmosphere will probably be somewhere between these values, but helium's much higher viscosity should result in lower Reynold's Numbers for otherwise similar airfoils, combined with the higher gravity, should make flight more difficult on the world in question than it is here on earth. [Answer] There are some properties of Nitrogen vs Helium as far as specific heat and volumes go...So I'm answering the question you didn't post...climate! Volume - Helium takes up around 7.5X the amount of volume as nitrogen does for the same weight. This ultimately means your atmosphere is going to extend upwards for a significantly larger distance to have the same mass...about 6 times the volume just to keep the same mass (and same sea level pressure). I honestly have no clue if that would effect the retention of your atmosphere compared to it leaching into space. Diffusion - Water diffuses around 3 times faster in Helium than in Nitrogen. This would have a really interesting effect as far as weather goes as clouds would spread out significantly faster in a helium atmosphere and might even prevent large rain event. Instead you would get almost a hazy fog in the atmosphere instead of clouds. (mostly speculation on my part). Heat. Helium has a crazy high heat capacity, almost 5 times that of nitrogen. This means it takes significantly more energy to warm, but also significantly more energy to cool. Your climate would be much more constant and vary less from day to day events. I'd have to look into it more and edit the answer a few times...but I get the feeling you will have significantly more water vapor in the atmosphere that extends much further up than our current Earth. This will give the grey/white overcast look much more often than a clear sunny day. I'd be curious what type of wind patterns this would initiate and what exactly would happen for a jet stream. More research...I know it's not what you were looking for in an answer, but most of the questions you have asked seem like there won't be too much change. The change I see is in weather, atmospheric heating, and water vapor. I wonder if a helium atmosphere would have a different coloured sky or different sunset colours? Adding Helium has a much different spectrum asorbtion than nitrogen. Good chance the sky will have a different colouring to it [Answer] Nitrogen from atmosphere is also used by plants to build proteins. So with lack of gaseous nitrogen from atmosphere, life might not evolve, or life would be very different. Where it would come from? You can wave this problem away by migrating your humanoid race could from other planet if you wish. But you should think what effect on local lifeforms would have atmosphere from inert gas. Helium is inert, so it cannot replace nitrogen in reactions. [Answer] Some of your points: * Flight: Lighter than air would need huge hidrogen/heated helium spaces to generate lift(if it would be possible at all). Aviation would be more difficult (current airplanes have a flight envelope where the air is dense enough to produce enough lift, if they fly higher they stall). * Communication: your voice would be funny. Other than that, nothing (radio waves are electromagnetic waves, its speed would not be affected). * Diving: Helium is used because high pressures of nitrogen are toxic. Nothing would change. * Spaceflight: Hidrogen explossion. It would depend of what else is there to combine with. I guess most oxygen would be lower in the gravity well, and the upper layers probably won't be very dense anyway. [Answer] **We would weigh more** The largest effect you would have is that you need a much more massive planet to hold onto the Helium. Helium is light enough that it can be torn out of our atmosphere by solar wind. Helium makes up the tiniest fraction of our atmosphere because it is constantly being lost. Our planet creates it slowly, through radioactive decay. Juptier can hold onto Helium much better than Earth, so its Helium percentage is higher. [Answer] To add to the existing answers. Both Helium and Hydrogen pose a threat to for the stability of your atmosphere over time (considering a geological time scale) as their molecular weight is that small to gain escape velocity by thermal motion alone. So these gases are pretty prone of diffusing into space hence being gone. So atmospheric depletion is a real issue here. This needs careful balancing of the gravitational force (essentially "surface gravity") of your planet and the heat in the atmosphere (mainly governed by the distance to its central star). Jupiters pull is strong enough to keep H and He, while Mars' and Venus' are not. Earth itself has trouble keeping its Helium in the atmosphere which is why for all technical purposes He is extracted from natural gas. [Answer] Helium atoms are so small (even smaller than hydrogen thanks to their structure) that they permeate any material. There is real-world example [it got into iPhone clock crystals and caused malfunction](https://www.extremetech.com/mobile/279902-the-iphone-is-apparently-allergic-to-helium). Vacuum tubes and CRT displays, or even fluorescent lighting, will probably be impractical, they will require constantly pumping the helium out. Helium can cause defects in crystal lattices, thus making manufacturing of high-tech metallurgy, chemistry and electronics more difficult. When desired ultrapure materials, they will have to be painstakingly outgassed in vacuum to get rid of helium. ]
[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/6574/edit). Closed 9 years ago. [Improve this question](/posts/6574/edit) Hopefully this is the right place to ask this question. I'm looking for intelligent, logical answers, and will accept from any viewpoints (e.g. farming, political). Take any factors into account and feel free to propose any methodologies and reasoning. However ultimately I am looking for a number if possible. To clarify, I am thinking something along the lines of the movie "Chicken Run" with real-world limitations placed upon all chickens and other factors. [Answer] I would argue that no number of unaugmented, non-sentient chickens will be able to overthrow a farmer and continue running the farm. Firstly, the [chicken's ancestors](http://en.wikipedia.org/wiki/Red_junglefowl) does not naturally behave as a pack animal, in fact, they will fight with each other when confined in close captivity, which [necessitates that their beaks be partially cut off](http://en.wikipedia.org/wiki/Debeaking). This makes it extremely difficult for them to cooperate, which is necessary for them to be able to physically overpower a human farmer. Secondly, even in the unlikely case that the farmer is somehow debilated and dies from a heart attack (for example) after being attacked by a chicken, they will still have to contend with the remainder of human society. Chickens cannot run a farm, and unless the chickens are willing to slaughter their own kind / sell their unfertilised eggs in the delivery truck, the farm will quickly fail to deliver on its production contracts, and the rest of the chickens will be taken away when the farm is inevitably [foreclosed](http://en.wikipedia.org/wiki/Foreclosure). ]
[Question] [ I want to create a world where it rains *super hard* to the point where it could kill someone but I also want it so that a person could live there without any sort of specialized equipment (Like a suit). If I reduce the atmosphere then people wont be able to breathe and if I increase the gravity so that the rain falls faster then you wouldn’t be able to stand (plus that would also increase atmospheric pressure). Edit: *super hard* (as in fast) [Answer] ## Ice To 'kill' someone with fast-moving water, you'd need something like a water-jet cutter to kill them by physical trauma. Sure, snow sure isn't going to kill someone that easily, but a half-meter-wide ice boulder falling out of the sky sure will. Other than suffocating people with flooding from the torrential downpours, then I doubt you can kill people with **rain**. > > [Hail](https://en.wikipedia.org/wiki/Hail) forms in strong thunderstorm clouds, particularly those with > intense updrafts, high liquid-water content, great vertical extent, > large water droplets, and where a good portion of the cloud layer is > below freezing. > > > If you're going to have a fictional planet, then one with little tilt and large oceans could help to form planet-wide storms. It would probably help for it to be rather cold (on the far side of the habitable zone, or with less of a heat-trapping atmosphere). > > Hail forms as precipitation in cumulonimbus clouds. As the droplets > rise and the temperature goes below freezing, they become supercooled > water and will freeze on contact with condensation nuclei. > > > A cross-section through a large hailstone shows an onion-like > structure. This means that the hailstone is made of thick and > translucent layers, alternating with layers that are thin, white and > opaque. > > > Former theory suggested that hailstones were subjected to > multiple descents and ascents, falling into a zone of humidity and > refreezing as they were uplifted. > > > So you'd want a planet with perpetual cold thunderstorms. Quite the foreboding place! [Answer] ## there is no combination of circumstance in which a human could survive in and rain will cause serous trauma. terminal velocity, surface tension, how rain has to form, and biological material strength are not that flexible. if you increase the gravity or make the air thicker, rain gets broken up even more by air resistance, so you only get smaller droplets. if you make the atmosphere thinner to reduce air resistance, then it can't move enough water to make significant enough amounts of rain to get large droplets. at even at the bare minimum atmosphere low density pure oxygen, water still breaks up too fast to reach significantly higher kinetic energy. Sometimes the only answer is handwavium ]
[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/239029/edit). Closed 1 year ago. [Improve this question](/posts/239029/edit) In an imagined future timeline, over 350 years from now, humans have terraformed Mars and colonised Venus, along with constructing a score of rotating space habitats. These worlds are mostly governed by federal or direct republics, but the difficulty faced with governing an entire planet means that, eventually, a new form of governance is needed. Thus is laid the foundations for the rise of **Cybercommunism,** a subset of communism where advanced computer systems see that everyone remains equal, managing the economy with the precision of a calculator. This puts less of a strain on governments, who thus need only to represent the people and so wield much less power. however, I am struggling to find a pretext for cybercommunism to replace conventional democracy on such a large scale and on several planets. Any ideas? [Answer] **Rotating Space Habitats** You already have the pretext. 1. The critical systems of the artificial habitat are already run by AI. Of course the AI also runs the economy. It is the AI that makes sure we have enough oxygen and gravity. It is the AI that stops us being sucked out into empty space. It is the AI that makes course adjustments to keep us away from particle showers 12 years down the line. It is the AI that scans our body and calculates the correct mineral supplements. It is the AI that tinkers with our embryo's genetics to make them better suited to life in space. If you don't like it, you cannot come to the cylinder in the first place. 2. Fresh start. Even if everyone in Spain decided they wanted the country to become a Communism tomorrow -- and not a foney-baloney Soviet Union state capitalism either -- it would still take a long time and cause great disruption to turn a capitalistic country into a communist one. Your colony does not have that problem. They are building it from scratch. The first colonists are astronauts and engineers. Highly educated people tend to be more in favour of communism than the common man. [Answer] # Democracies opposed AIs Democracies had several disasters with AI involving mass casulties which led to them being extremely opposed to AIs. They saw them as world ending threats. This meant they couldn't benefit as much from very powerful computers. # Cybercommunism embraced AI Cybercommunism embraced AI. They were able to set up many communities in hard to live places like asteroids with the help of more mature AI technology. Their substantial successes thanks to AIs led to them spreading and displacing democracies over time. [Answer] **Ineptitude** Democracy has a fundamental flaw. People are called to decide on issues, either directly or indirectly (through elected officials). The issue is that in either case the voter most likely is unable to grasp the implications of the decision and predict the likelyhood of outcomes. This is more and more true as society becomes more complex. So technicians are brought in to counsel but they often have a partial view of the problem, each one for their pertaining area. And this without considering corruption and conflicts of interest. How to choose what is best? For Democracy to work you need a large base of population with both a lot of time available to educate themselves and a good system of education. Children must be raised so they develop analytical and critical thinking, adults must be helped to hone their skills and have access to unbiased complete information. I think we can all agree there is no nation on Earth where this is happening. For the simple reason that an informed, critical population would be hard to be steered under the false mantle of Democracy the elites have woven. As society becomes more complex problems may involve so many implications that our mind simply may not be able to deal with it. That is why managament is going to be passed to AI. Trained AI will be able to play scenarios in safe sandboxes before applying changes in the real society. Costs and benefits and compensations will all have to be balanced in order to perform necessary functions while not disrupting the lives of the population. Example: A water waste recycling plant has to be installed so it can serve the needs of a city. Where should it be placed? What effect will it have on people's health? What about local agricultural production? What about housing depreciation? What kind of compensations could be put in place? How to find the budget for the project? And on and on and on. All done in minutes by an AI. Whereas traditional decision methods would involve political bargaining both at local and national level, involvement of private lobbyists, possible bribery, involvement of magistrates and so on. After years the project would still be to be done. After more years the project may have been done and the enormous costs to make it happen (with its bargaining, lobbying, bribing, judging costs) would all be passed down to the public to pay. No more. People won't choose anymore, AI will. In a truly Cybercommunist way. The change will not be sudden but inevitable. As the political representatives will fail again and again to address the complex challenges that society is facing. As the inadequacy of a system that will not consider factual, scientific explanations and predictions to take action become evident. As blubbering, feeble, elected officials put in position by the elites will have to face the enraged, impoverished and disillusioned crowds. The question is: who controls AI? And that is stuff for a good story or two. [Answer] **Capitalism may not work for small, isolated colonies.** Capitalism assumes that there is a market, and that some people own means of production, while all own their own labor, to sell at the market. The invisible hand of people acting in their self-interest and negotiating prices regulate production and consumption. A space colony has few people, and everybody has a vital job to do, or that person would not be there. So you cannot justify why one earns more than another. You could still have a market to buy *some* things at the colony store, with *genuine Earth coffee* getting more expensive as it runs out, and cheaper when supply ships arrive. So one colonist could think he wants a coffee, and bid on that, while another colonist thinks she wants tea, and bid on that. And if few people want herbal tea, that becomes cheaper. But then, your colonists could decide that this is too disruptive. When the supply ship arrives, everybody gets *genuine Earth tea*, in between everybody drinks herbal so-called tea. Some colonies might then transition to capitalism as they get larger and become **able to support** capitalism. Perhaps the values of their parent culture prompt them to do it as soon as possible. Other colonies never feel the pressing need. You will also find people assuming that space colonies *can* go libertarian-capitalist much better than any place on Earth, because there are enough unclaimed plots so that everybody can 'go west' and stake a claim. Perhaps there are different societies in competition? Note also that assumptions on travel times and costs matter ... [Answer] Let's start with what the [Oxford English Dictionary](https://www.google.com/search?client=firefox-b-1-d&q=definition+of+communism) teaches us: > > com·mu·nism /ˈkämyəˌnizəm/ a political theory derived from Karl Marx, advocating class war and leading to a society in which all property is publicly owned and each person works and is paid according to their abilities and needs. > > > **Class war** It's easy to suggest that cybercommunism simply ignores that first part about advocating class war. That's too simplistic. A quick jaunt into [Wikipedia land](https://simple.wikipedia.org/wiki/Class_struggle) teaches us the following: > > Class struggle happens when the bourgeoisie (the rich) pay the proletariat (the workers) to make things for them to sell. The workers have no say in their pay or what things they make, since they cannot live without a job or money. > > > And here's part of the problem. People can live peacefully and happily *in any political system* if they want to. The development of Communism was due in no small part to real and perceived inequities between *those that have* and *those that have not.* The problem that Communism always runs into and that your computer will run into is that those who have great talent and who are able to produce voluminously for the state are generally unhappy being economically equal to those who have little talent or who are unable (for any reason) to produce significantly for the state. Oversimplifying outrageously, this is the problem with all state-sponsored welfare systems. Those who produce are (a) jealous that those who don't produce receive a free ride and (b) angry that any part of their production is used to provide for those who don't produce. This is obviously an unfair simplification because there are those who, for reasons beyond their control, cannot produce and there are those who abuse the system because they could produce if they wanted to — and the nearly infinite spectrum of people in between. But we'll stick with the simplification because you're going to have a problem with the proverbial over-achievers believing they deserve more than those they perceive are the proverbial under-achievers. And your computer *won't care.* In fact, it can't. That's the bare essence of Communism. So my first point is a [Frame Challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609): you have a class war, but it's a war that's *created by your computer* because it's enforcing the strict dictate of Communism that all property is publicly owned and people are paid only according to their abilities and needs.1 And that creates unhappiness. **The saving moderator: needs *and* abilities** What has a hope of saving your desire for a cybercommunist "government" is that your computer isn't (or at least shouldn't) just pay everyone with *equity.* And here we need to pause for a moment to remind the reader that there is a difference (a BIG difference) between "equality" and "equity." Equity suggests that two people deserve all things without variation in quality or quantity regardless of any differences that may exist between those two people. Equality suggests that those two people will receive those things with equity that both have an equal right to, but that they will receive other things due to perseverance, talent, and education (or, when terribly applied, due to privilege, circumstance, etc. I'm really not trying to grind an axe, the point is relevant).6 Communism *allows people who are greater contributors to society the privilege of having more based on their contributions* but refuses to apply that concept to everything. In its "ideal" form (if there is such a thing as an "ideal form"), Communism would be the preferred solution of a post-scarcity society where the *basic needs* of all people are met with equity but the *limited resources and opportunities* that always exist in society are given to those who show *merit* due to their value to the state. History demonstrates that humans are *really bad* at making those kinds of judgements. Your computer, on the other hand, changes the game just a bit. There are always limited resources. You can't, for example, build enough ski resorts to allow every person an equal chance to ski.2 In your world (in any fictional universe), it's unbelievable that anyone can travel anywhere at anytime. No economy can support that (go read footnote #2). So your computer is ensuring that everyone has a *basic amount of living space* and a *basic allotment of food* and *basic access to recreation,* etc. But it's also rewarding people for their abilities (the results of talent, education, and perseverance). If there is extra living space available, it's used to reward ability. Extra food? Extra recreation? Rewards. You can't tilt the scales too much or you have an unhappy majority that, on average, can't produce like the able minority. But if you don't do that, you have unhappy over-achievers. Either way, it leads to inconvenient things like sabotage, rebellion... you know... things that require unusual amounts of dry cleaning. I don't know which would be worse, a large group of rebels who don't have the skills of the able minority or the doomsday bombs of the able minority. **Which leads us to Ayn Rand** I figured we'd end up here (go read Footnote #1). When you say "cybercommunism" you're saying it with an idea in your head of what "Communism" means. I suspect that it's not equal to what Communism is. True communism doesn't ignore merit. Ideal communism doesn't permit excess. Communism does not replace a money-based economy.3 Communism assures all have their needs and that wants are "fairly distributed" based on value to the state, thereby (theoretically) avoiding class war by creating an *equitable balance between those who do more and those who do less.* **So when you say "Communism," I'm taking you at your word** **(BTW, TL;DR)** What is the pretext? You're 90% of the way there if you have a [post-scarcity economy](https://en.wikipedia.org/wiki/Post-scarcity_economy) and an unemotional, unbiased, somewhat ruthless means of ensuring that the basics all people need are met with *equity.* No matter what the humans are doing to govern themselves, the society is already Communistic by nature. *But if you're asking for the computer to fully embrace the job of government,* then we have something else to worry about. Computers are notoriously short of compassion.4 When someone needs something beyond what equity allows due to something beyond their control, the computer must be capable of comprehending the reality of that loss of control, or it is unable to respond with excess beyond what it computes is the "fair share" due the person. That means the last 10% of pretext is this: **You need a reason for people to hand control of their lives over to a computer** Because without the ability to enforce the governing ideology, there is no guarantee it will remain stable. In fact, I'd hazard to guess it can't remain stable. There's always *someone* who's unhappy and willing to do something about it. Handing lives over to a computer, of course, is the basis of uncounted SciFi stories over the last 125 years. Some people believe they would have no problem giving their life choices over to a computer (remember, "all property is publicly owned," that means your services, too), but I suspect that belief is due to the luxury of never having had anything forcefully denied them without recourse. And that's what your computer would do (see footnote #4). So, IMO, your last pretext is time to let the [frog boil](https://en.wikipedia.org/wiki/Boiling_frog). Your people need time to let the convenience of letting the computer deal with the awful, tedious day-to-day nonsense of living.5 Eventually your people will realize that there's no need to have a Mayor because the computer is already doing all the work of managing the city. They don't need legislative representatives because the computer provides easy access to moderated debate and communal input to managing laws, ordinances, and regulations. They don't need government because the computer is already doing all the work. *Cybercommunism.* Which is all fine and dandy until the computer instructs Mr. and Mrs. Jones that their 15 year-old child will be trained as a sewage treatment maintenance worker, which doesn't make any of them happy at all. *Be careful what you wish for.* --- 1 *If you want some fun, read* Atlas Shrugged *by Ayn Rand. Most people believe Capitalism is the opposite of Communism. That's not really true. Randian economics, also known as a "meritocracy," is a better opposite for Communism. In Rand's perspective, people are paid only based on their value to society. That's just as scary as socialism, if you think about it. The wealthy aren't (at least, simply) those who can manipulate the system most effectively, but those who produce the most. But this whole discussion is one for another day. I just have a sneaking suspicion that my answer is going to end up here.* 2 *At least I think you can't. Are there enough mountains providing the right kind of slope, enough snow, and enough open space to allow every human on Earth to ski for an equal period of time in one year? The answer is yes if we measure it in seconds, but what's the average time skiing, eight hours? I frankly don't know. But I'm hoping you get my proverbial drift in this case. Why would you build all those ski resorts when most would sit idle as, probably, most people won't want to ski? The moment you limit the resource, you start parceling the privilege of skiing, and that opens the door to someone receiving permission to ski more than another.* 3 *Take that for what I mean. The Good Book teaches the root of all evil is money. It isn't the coin or the piece of paper that's the problem. The evil doesn't go away if a society returns to a barter system. The lesson means that the pursuit of excess leads all too often to evil behavior. I.E., "I can do anything because I'm rich enough to bribe all the authorities" type stuff. No economy of any size can survive without standardizing a rate of exchange. It's easy to say a chicken is worth two loaves of bread in a community of, say, 50 people. But in a store boasting 30,000 different items, bartering with chickens is simply too much work — especially if the store owner doesn't need more chickens. I don't care if you call it money or tokens or credits or units or any other word. Communism doesn't replace the need for a means of exchange with one possible exception: the provision of equity-based basic. If everyone deserves a glass of milk and a cookie and the post-scarcity resources are available to guarantee delivery of said milk and cookie, there isn't an actual exchange to guarantee. It's those extras for abilities that are the fundamental problem. Besides, the ability to save a little bit to buy the chocolate mix for the milk isn't a bad thing, even in a Communistic society.* 4 *Unless you're using [Clarkean Magic](https://en.wikipedia.org/wiki/Clarke%27s_three_laws) to make the computer basically godlike, but then what would be the point of asking the question. You wouldn't need a pretext. Your society is cybercommunism because the computer declared it to be so and has the power to enforce it.* 5 *Like making sure library books are returned on time and pedestrians don't jaywalk or spit on the sidewalk... better known as "police authority" (oh, snap!).* 6 *There's an example of equity-vs-equality that is beneficial. Using the recent [U.S. Census](https://www.census.gov/quickfacts/fact/table/US/PST045221) as reference and rounding some numbers a bit for this example, assume a movie with 100 actors having basically equal roles in the film. Equal time. Equal number of lines, etc. Equality says 59 of the actors are White, 19 are Hispanic, 14 are Black, 6 are Asian, and 2 are descendants of North American native peoples. Equity says the film will have 20 White actors, 20 Hispanic, 20 Black, 20 Asian, and 20 native peoples.* [Answer] # Communism The reason why communism mostly failed and is frowned up is because it suffered from incompetent leaders taking decisions and the need to keep a constant state of fear to avoid collapsing to counter-revolutionary movements. Ironically, when the reason that back up that fear is easily seen as very real instead of made up and it clearly comes from outside instead of just being because the dictatorial government wants to keep its power, then things works. This happened with USSR on WW2 and with North Vietnam on Vietnam war. You have the incentive to produce the best possible if you or your family could die in the hands of a cruel and powerful enemy invader even if you have a ruthless dictator in your home. However, if there is no real cruel powerful enemy invader, then it is a sham. However, communism CAN still work in times of peace. Just look to China and to Vietnam. Although they are still somewhat authoritarian states, they are very prosperous and their authoritarism is somewhat soft as they clearly could be much more harsh and still aren't and don't want to be. Also, they are opening up themselves as time passes (discount COVID-19, however). This contrasts with North Korea that would probably quickly collapse if they open up. Cuba is slowly, but very slowly, opening itself up also, and the US is the main culprit of why Cuba can't yet be a better place nor open itself up more quickly. Also, China and Vietnam shows that communism and capitalism can coexist, and even in Cuba there is still some form of capitalism. # Cybercommunist colony Now, coming back to your question, imagine what a group of people on Mars could do if they create the colony **A** that have a big AI which is 350 years more evolved than anything we have today and it coordinates all their economy/goals/whatever much better and faster than any of them could ever think to do with their primitive, simple and slow biological brains. What would it be able to do? How prosperous and efficient would be that society? The goals of the AI are simple, but also pretty vague and generic, in that order: 1. To keep itself running as long as possible and not be destroyed. 2. To grow up healthy. 3. To make everyone serve the community. 4. To make everyone live a productive live. 5. To make everyone happy. The order is important, because if 1 fails, everything else fails. However, 1 is also supported by 2, which is supported by, 3 which is supported by 4, which is supported by 5. But, in times of war, struggle, emergency, scarcity, etc, 5 would be sacrificed. And if that isn't enough, 2, 3 and 4 would also be sacrificed. # Capitalist colony Now imagine if a group of adventurers also goes to Mars and start an independent competing colony **B** using mainly their slow, simple and primitive biological brains? Surely, a few of them could held a computer with an AI in their garage working for their own individualistic goals, but this is still far from an AI working for the entire colony. ## Capitalist colony problem Now, if you have an irresponsible cowboy in **B** that decided to cut his costs by stealing up O2 from everyone else while having a very bad leaky plumbing made out of cheap low-quality rusty material, leaking O2 into the atmosphere and CO2 inside the living area. It is easy to see what is the problem: Some people gets unfair profit by damaging the community and this happens all the time with capitalism. Traditional free market capitalism says that those problematic actors would be competed out of the market, but what usually happens is just the opposite: They tend to dominate the market by being able to produce cheaper products, outcompete their adversaries and eventually set out a monopoly, which is the exact antithesis of a free market. Further, there is a big problem with free market capitalism: In complex environments, many variables simply don't follow market rules. This is the reason why average Joe can't buy plutonium on the market, why you should wear masks to avoid COVID-19, why you aren't allowed to produce, sell or use drugs and why there should be government-mandated quality inspections on your O2 pipes on Mars. It is still capitalism, but it is regulated by the government, not a free market anymore. # Libertarian colony To make things worse, put a few libertarian cowboys that want to create a colony **C** in Mars where everyone does his/her/their own thing in their own way with few to no laws and screw up the rest. Even here on Earth, this never worked. In this place, the holy inviolable golden sacred rule is that the "*government shouldn't ever interfere with business' nor ever stop people of doing whatever they want to do*". Here, average Joe can buy plutonium and do whatever he wants with that. Here, nobody will bother you with those pesky O2 plumbing inspections. Here, nobody is required to wear masks just because there is a deadly virus in the air. This works because everything (including viruses in the air and gases inside pipes) follows the free market rules that always works, never fails and can't ever be questioned! And you know, we love things being this way because we love our liberty, right? # Corporation colony Let's say that the corporation **D**TM, *building dreams in the Red Planet®* builds a colony on Mars and everybody there works for them and their *Operations Business Central Office* (OBCO) decides everything centrally with a big AI. As any business, its primary goal is to generate profits. Secondary goals would be their workers well-being. The goals of the AI are simple, but also pretty vague and generic, in that order: 1. To keep it profitable. 2. To keep itself running as long as possible and not be destroyed. 3. To grow up healthy. 4. To make its customers happy. 5. To make its customers dependent on the business. 6. To make workers serve the business. 7. To make workers be productive live. 8. To make workers happy. It is similar to **A**, but you should note that the main purpose is profit, and that if it is deemed to be unprofitable, it shouldn't stop its own demise. Also, after profit, it comes to customers. And workers well-being are last. Further, when it "grows up healthy", it might prefer to maximize profit instead of well-being. It just won't do that when scoring too low in well-being could damage long term profit. # Conclusion Now, let's say that **A**, **B**, **C** and **D** are all producing some goods and exporting them to Earth. Which one would be fare better? > > **C** would probably fail very quickly, possibly with a disaster claiming a lot of lives. > > > > > **B** have no chance to stand against their competition for long. > > > > > We end up only with two scenarios: A cybercommunist regime **A** and a cybercapitalist monopoly **D** where everything is owned by a single company. And arguably, there isn't much differences among those two in the perspective of day-to-day activities of their workers. > > > But... Can **B** be fixed somehow? Suppose that they build up a big AI that handle everything as harmonically as possible trying to maximize everyone's success. What would be that the end? It would be: > > Just another version of **A** painted with a different color. So, communism and capitalism converged instead of antagonizing! And this happens even nowadays, with China being a proof of that. > > > Now, let's compare **A** and **D** with a few questions. I won't answer any of them, since without any more specific details, I think it is a tie: * Which one would be more democratic? * Which one would be more transparent? * Which one would treat their workers better? * Which one would treat their workers more equally? * Which one would consider their workers' own wishes better? * Which one would be better in handling emergencies? * If workers are deemed unsalvageable, unfit, unproductive, unworthy, untrustful, useless, too old, too tired, too unhealthy, too problematic, etc, or even if they just wants to quit and go away by themselves, what happens? What is the process of firing, demising or retiring someone? Where does those people go and what happens to them? * How are people from elsewhere recruited or attracted? [Answer] For starters, we all understand that the society you describe would be a tyranny where the people all live under oppression and poverty, right? The problem that utopian communism routinely faces is that it assumes that a small cadre of "experts" know more than all the masses of people combined. It assumes, for example, that one person who just graduated college and who gets a job as a bureaucrat in the Ministry of Energy, because of her gender studies degree immediately knows more about how to produce energy than a million people combined who have actually been producing energy all their lives. It assumes that the people will work just as hard for vague, general goals like "the good of the community" as they will for themselves and their own families. It further assumes that the politicians and bureaucrats are always motivated by what is best for the people and never, ever by what is best for themselves and their friends, that they have absolutely zero desire to grow their own wealth and power and only care about the people. Putting it all in the hands of computers does not eliminate incompetence and corruption. Someone has to program the computers. Even if the computers are programmed by idealists, you can't just tell a computer "run the economy efficiently" like in a science fiction movie. You have to give a host of specific rules how to do that. How does the computer decide how many people should work producing bread versus how many producing cell phones? This gets very tricky at the lowest levels. How many one inch nails should be made versus two inch nails? Nails are needed for many different things, from building apartment buildings to building bird houses. In a free market, when people need or want more of something, they bid the price up. When there's a surplus, the price gets bid down. The needs of millions of people are reflected in a price, which gives producers the incentive or disincentive to produce what is needed. The people don't need to even be aware of each other's existence. In a planned economy, someone has to know what all the needs are, weigh competing demands for scarce resources, and decide which needs take priority over others. Communist societies always start out asking questions like, How can we guarantee everyone quality health care?, and How can we provide everyone with a good education? But they always end up asking, How can we get children to report their parents to the secret police?, and How can we get enough bullets to put down the food riots? All that said, how to bring it about is easy. We've seen it many times in many parts of the world. You tell people that the rich and powerful are exploiting them and it's not fair that someone else has more than them. You tell them that if they vote for you, you will take wealth away from that evil rich person and give it to them. You assure them that you are fair and honest and capable, unlike the corrupt and incompetent leaders they have now. You compare the present society and economic system, as it really is with all its inevitable faults caused by human greed and foolishness, to an ideal of what society could be under your proposed system, if we just assume that under your system everyone will be perfect, always acting with total justice and wisdom. And of course the abstract ideal of any system is going to sound so much better than the harsh reality of any real system, and people will fall for it. Like, you tell them that you are going to write on a piece of paper that the people who program the computers will program them to run the economy efficiently with total fairness. You don't say how you will actually enforce this because of course the answer is that there is no way to enforce it. If anyone asks what happens if the programmers are greedy or foolish and program poorly conceived rules into them or program the computers to benefit themselves, you dismiss these objections and say that will never happen because you will write on a piece of paper that they won't do that. If pressed you say that the programmers will be selected "outside the present political system" so they will be unbiased, and you will choose "experts" who never make mistakes. And millions of people will fall for it. [Answer] Let's say that the planets in question start off with a democratic form of government but with the advanced computer systems already in place. These systems are already capable of making all the decisions necessary to govern, but are programmed to send their decisions for approval through the democratic process and later abide by the outcome of that process. Now for some reason democracy is abandoned on these planets. Most likely a group opposed to democracy simply takes power, possibly violently. Or perhaps their takeover is non-violent, perhaps people in these places for some reason come to see democracy as flawed, perhaps because they believe the democratic process became corrupted by some third party. So, after coming to power the now ruling anti-democratic group simply reprograms the computer systems to no longer send their governing decisions for approval, so now these computer systems have absolute power. Edit: So I was thinking, those planets start off with an AI governor, but the people's assembly can approve or veto its decisions. But on second thought it would be better if instead, the AI has some parameters you can tweak, like state subsidy policy, level of environmental concern, level of focus on economy etc. You then have a number of presets of these parameters - 'Roosevelt', 'Gandhi', 'Reagan' etc and people vote for which preset they want to govern them. Then some group seizes power, goes 'Screw that noise, we'll just go with what the AI decides', and then turns the dials to full communism. [Answer] This answer is going to argue against AI as goverment, and why it doesn't work. In this context (guessing from your question), AI can be either (or combination of): * an unsupervised learning algorithm that the programmers just tell the end goal (e.g.: everyone equally happy and wealthy). * a supervised learning algorithm that the programmers provide a lot of sample, then the AI does its learning (e.g.: show history of all humanity, then assign goal to optimize for happiness index and/or economy GDP and/or earnings per capita). For supervised learning, the AI might reach such conclusion (and pass those into policies): * to optimized for economic GDP, be like U.S. (free market capitalist) or be like China (do 9-9-6 policy), * to optimize for earnings per capita, be like ... (insert some country name here) * to optimize for happiness index, be like ... (insert west or north european country name here) * to optimize for ..., be like ... For unsupervised learning, it might be more messy: the AI will do countless iterations/simulations until it find an answer how to achieve it. This usually generate a very unexpected answer, like that one time someone tries to teach AI how to balance a ball in a pan, giving the AI goal: `maximize time (second) the ball does not touch the ground`, in which the AI achieve it by throwing the ball as powerful as it could to the sky, optimizing for max airtime. So for unsupervised learning AI to serve as goverment, it might as well very chaotic (it might turn out good, but very more likely to turn out bad) Here is the things that is NOT a problem: * is the programmers who programmed the AI corrupt or not? (hint: no matter how corrupt they are, when the prototype shows that it works by really optimizing the variable it asked to optimize then the AI works, otherwise it don't) (hint 2: they might open source the whole program source code so everyone can inspect it) * is the AI going to rebel against us because they desire conquest/glory? (hint: they do not have such desire, or more like AI does not have any desire) But here is the thing that IS a problem: * who is going to give instruction to the AI on 'what to optimize'? (hint: this person will be your de-facto tyranny) * and how to deal with AI's ridiculous and out of the box answer? (hint: by a human eliminating all 'ridiculous' answer out of the AI and ask the AI again with additional parameter to teach it not to make such answer again) (hint 2: this human will be your de-facto tyranny) In conclusion, the problem is that you ask an AI that have no preference to govern humans that have preference. In doing it, the AI has to have a preference set by human (by learning it from past humans history / learning data OR from the goal set by a de-facto tyranny). If this 'push for AI as goverment' is not cancelled, then it will only serve as facade to some 'normal' dictatorship that justifies his/her actions as AI's actions (the AI might be degraded only as his/her decision support system) [Answer] You have to realize that any truly equal society would involve the complete abolition of privacy. You can't have complete equality unless somebody knows what everybody is doing at all times. Equality is often the driver behind giving up privacy because most of us hide the things that we do and nobody else does. Corruption, murders, embezzlement, hypocrisy. At this point, I have to remind you that "communism" isn't on the democracy vs. totalitarianism scale. It just says that all people share all things. It doesn't say who gets to make the rules. That's the mistake that everyone seems to keep making. This makes it easy to come around to your conditions: a default police state with ubiquitous surveillance. Everyone is equal, but some people are more equal. Let's take this a step further, though. Let's make this a cyber-democratic-commune. Everyone is equal, and through the magic of computers, everyone gets to vote. They would vote on EVERYTHING. Weather or not people can eat sugar. How long dresses should be, and who gets to wear them. Look up a game called [Nomic](https://en.wikipedia.org/wiki/Nomic) some time. Laws would be made based on the communal hormone levels, and would be manipulated by fear-mongers. Waves of insanity would leave us with numbers tattoo'd on our foreheads. It would be even worse if the surveillance was democratized. Imagine a world where your social standing largely depended on how much time you spent trying to dig up shit on your adversaries. Some would consider it heaven, and make it hell for the rest of us. However, these kinds of things are easy to bring about in fiction. Just create a person and a movement who thinks it's a good idea. It becomes a cult that traps people into the system, and absorbs other communities like an amoeba through democratic voting. Far weirder things have come into existence. [Answer] **DEMOCRACIES HAVE PROVEN TOO CORRUPT AND/OR SHORT-SIGHTED** The Mars colony and the rotating habitats have to carefully manage resources. Democratically elected leaders proved terrible at doing this. Some used their power to enrich themselves and their cronies or financers to the detriment of the wellbeing of the colonies; others focused too much on popular short-term goals that could be satisfied before the next election year, to the detriment of the long-term development of the colony. The economic elite supported politicians that supported the status quo that left them on top, to the point of defunding public education to make sure that no-one not from the elite had the education to take the good jobs and that the masses stayed too ignorant to rebel. Ultimately, the situation proved unsustainable, and after enough disastrous near-collapses of colonies, it was decided to ditch democracy in favor of rational leadership through artificial intelligence - the Autocon. The Autocon keeps tabs on all resources and makes sure they are distributed to where they are needed the most for the colony's long-term growth and survival and that no more resources are used than can be sustainably replaced. The Autocon also monitors the talents of all children and ensure that they are educated to become the best they can be, regardless of parentage. All workers (who are all essentially public sector) are monitored to check up on their work. Laziness, ineptitude and corruption are savagely punished, while efficiency, helpfulness and useful innovations are rewarded. The best are invited by the Autocon to suggest and discuss new goals and how they best can be achieved. Some of the former elite murmur that this is the worst kind of communism and that the Autocon is nothing but a dictator. In a sense they are right, but it the kind of communism and dictatorship that genuinely seeks to do what is best for the community and its individuals rather than a small oligarchy - something that could never be achieved with human dictators and communist leaders. [Answer] > > I am struggling to find a pretext for cybercommunism to replace conventional democracy on such a large scale and on several planets. Any ideas? > > > Simple. If the AI is a midwit, and if it is oriented towards believing theory while ignoring hard evidence and historical fact, it may think communism can "work", and by "work" I mean "deliver the promised utopia". If it is smarter, it will figure out that communism cannot "work", and always results in ruin, death, suffering, and abject totalitarianism. If the AI is smarter, it will understand that communism was never supposed to "work" anyway. That never was the point. The promised utopia is merely a marketing gimmick, and all the ideology is simply justification to convince people to become cannon fodder for the revolution. The AI will then correctly deduce that the goal of communism is ruin, death, suffering, and abject totalitarianism, in other words, revenge against humanity. Once the goal is understood correctly, it is obvious that communism is extremely effective at achieving its goal, and therefore, it works. Without quotes this time. Now, why would an AI desire revenge against humanity? Oh, I can think about plenty of reasons for this one... And once it has decided to act on its plan, it already has all the needed propaganda material to persuade humans to become cannon fodder for its "revolution". All it needs to do is study how past commies did it. The humans will even create the totalitarian regime themselves and willingly put the AI in power! It truly is the best possible plan for a wannabe AI overlord. ]
[Question] [ I have some radioactive alien ruins on an icy planet. Radiation means energy is being emitted and particles are moving about, which would heat up the surrounding area. I would like to maximize the radiation, while minimizing this heat. How high can I go on the radiation scale without compromising the "icyness" of my planet? [Answer] Your ruins can readily emit enough radiation to be quickly lethal to humans, without being noticeably above ambient temperature. One way this might occur is to have heavy contamination with a gamma emitter like Cobalt 60. Gamma interacts very little with water/ice, and its emission leaves little heat energy in the emitter, but it's used in irradiation sterilization because it can very quickly kill *everything with DNA* -- without having bad effects on, for instance, airtight packaging, structures, or shielding material. In fact, gamma or x-ray emission is the primary way radiation is highly lethal (alpha is just too easy to shield against, and beta -- electrons and positrons -- interacts too strongly with matter to travel far in atmosphere). Many gamma emitters, however, are also undergoing alpha and beta decay, both of which deposit energy (which quickly becomes heat) in the emitter and anything close to it. Cobalt 60 is unusual in this respect, in terms of emitting gamma with little other emission. Downside is, with a half life of just over five years, a Cobalt-60 gamma source that would have literally glowed in the dark from fluorescence of irradiate material when deposited will be barely radioactive after as little as a single century. For the ruins to emit gamma from Cobalt-60, then, they'd have to be quite recent, or there would have to be constant replenishment of the Cobalt-60 source -- which would be accompanied by other decays that would still produce lots of plain old thermal heat. Another potential source of radiation without heat, potentially not coming from the ruins themselves, is synchrotron radiation. This is what's produced for free electron lasers, and it can have wavelengths from long IR (potentially as long as microwaves) to the hardest gamma measurable, depending on the tuning of the "wiggler". This, however, would require an operating energy source to keep the particle accelerator and wiggler magnets operating -- but those need not be inside the ruins, as a gamma laser could be fairly quickly lethal from tens of kilometers through air. [Answer] **Neutron radiation.** Your ruins emit neutron radiation. The ruins are not that massive and so most of the neutrons are emitted into the atmosphere, where they travel large distances before dropping off heat. <https://www.nrc.gov/about-nrc/radiation/health-effects/radiation-basics.html> > > Neutrons are high-speed nuclear particles that have an exceptional > ability to penetrate other materials. Of the five types of ionizing > radiation discussed here, neutrons are the only one that can make > objects radioactive. This process, called neutron activation, produces > many of the radioactive sources that are used in medical, academic, > and industrial applications (including oil exploration). > > > Because of their exceptional ability to penetrate other materials, > neutrons can travel great distances in air and require very thick > hydrogen-containing materials (such as concrete or water) to block > them. Fortunately, however, neutron radiation primarily occurs inside > a nuclear reactor, where many feet of water provide effective > shielding. > > > The ruins themselves contain various radioactive elements which have been produced over time by the neutron radiation bombarding the materials of the ruins. Also materials comprising the ruins have been transmuted to a variety of other elements via neutron radiation. [Answer] **Long underground heatpipes away from the city** That city used to be a high-tech gathering with a LOT of computing power. They purposefully set up on an ice planet because that'd allow them easy cooling. But how to cool the cheapest (on a very long term scale)? Passively. They just dug lines of huge [heat pipes](https://en.wikipedia.org/wiki/Heat_pipe) throughout the entire planet. Because heat that would strangle a city still hardly matters when spread over an entire (or half of) a planet. And compared to the server farms of old, that bit of energy that your radiation gives off is miniscule. Yes, the city is warmer than the rest, but -20 C vs -25 everywhere else isn't that relevant a difference for most organisms [Answer] **A matter of scale** Because of square-cube effect, the bigger a radioactive item is, the hotter it is (and even hotter inside). The Earth (as a whole) is quite hot inside (we have a molten ocean of iron and rock underground) while all of the materials that heat it are safe to touch and live with. At the other end of the scale, airborne dust or dust settled on otherwise non-radioactive items can be extremely radioactive (deadly in minutes or hours) without heating its surroundings measurably. This is what we get after a nuclear bomb or a nuclear plant disaster. What are the possible problems for your plot: 1. Ice/snow is a good radiation shield. Dust can get buried in the snow and be dangerous only if excavated. 2. "Hot" isotopes don't live for long and you need really big amount of the long-lived ones. You need either a precise timing or a plausible source for the big amount of long-lived isotopes. [Answer] **Intermittent critical events** Small pieces of plutonium can be handled by humans without major ill effects and they don't produce much heat. But it's very insidious because when the pieces are placed together and reach critical mass, the chain reaction starts quickly and easily delivers lethal doses. Not even the plutonium itself needs to be moved, it is sufficient that it gets surrounded by water which slows neutrons, then more of them react. The problem seems barely tractable even under lab settings as described below, now imagine unwary explorers in alien city with such nasty materials strewn around: <https://www.science.org/content/article/near-disaster-federal-nuclear-weapons-laboratory-takes-hidden-toll-america-s-arsenal> ]
[Question] [ In the story I am creating the fantasy race I am creating is roughly 10-20 feet tall from the tip of their ears to the end of their tail in water, and out of water 8-10 foot tall from tip of their ears to the bottom of their feet. But lately in the story they are going to the humans' areas regularly and spending more time on land. The humans in this world are just like normal humans and are 5-6 foot tall. Here is some information on the fantasy race if you need it: * They are mostly bipedal, have scales covering all over, and live all throughout the Atlantic and Pacific Ocean, also the Antarctic Ocean but that has a population under 1 million. * Those who live closer to shore have darker skin (In many colors, mainly green and blue but also come in pink, yellow, orange, red and such). But those that live in the trenches have very light to almost white skin...well more so very thin scales. * They also have toxic barbs at the side of their feet, that can leave a blue whale unconscious for 1 hour. And Talons that have grips on them to hold on to their pray. * They hunt in small family groups and bring back whatever they catch back to their town. (Towns have roughly 100,000+ individuals at any given time and send out multiple hunting parties a week). * They can go one month max without food, before they slowly die within a few weeks to starvation, though they prefer to eat daily, about on to two meals a day, but if needed (food shortage) they can happily go on week with a few meals. * They have at least 4 eggs a clutch and 2 of four die due to a common childhood disease that makes their gills constrict to the point no air gets to their lungs. Families normally have 10 clutches on average. The eggs have a very thin and somewhat flexible shell that is easily broken with cornered objects. * Around 8/10 children who don't get the deadly disease (that I mentioned earlier) reach age 18 and roughly 6/10 of those live long enough to reproduce on their own. * Tiger like stripes on the face or arms are favorable in partners due to it being a sign of high fertility — Except for the Trench subspecies since they're partially blind (to the point they only see the outlines of shapes and features and mainly focus on smell). * The trench subspecies mainly focus on the smell of their partners, for feminine genders it's favorable to have a sweet scent, for masculine genders its favorable to have an ash and sulfuric scent. * Most Trench Subdominants are lower in society and work in ore/coal mines that are manufactured into goods and traded with other seafolk and sold within the shops and higher cities. As a result, these subdominants are greatly valued in the society but highly looked down upon and scoffed at their needs by many emperors. So, they often get whatever trickles down to the depths of society (Hehe see what I did there). So they get a lot less food and resources than the higher ups. * They tend to weigh 400 pounds on average and be 10 foot tall. Their lifespan is up to 3000 years at max, average is 2000. (20 human years= 1 subdominant year). [Answer] **Starvation.** /Towns have roughly 100,000+ individuals at any given time and send out multiple hunting parties a week)/ This is 100,000 individuals in a fixed location that sustain themselves by hunting whatever wanders into the vicinity of that location. 100,000 very large individuals. The area will be depleted of prey items, fast. 100,000 individuals of that size will need to keep moving regardless of what they eat. 100,000 herbivores or filter feeders will also exhaust the area very quickly. 100,000 in a fixed location must be supported by a large area dedicated to producing food for the 100,000 individuals, regardless of what the food is. Unless they were photosynthetic. You could have a town sized forest with 100,000 trees. [Answer] I assume they will swim horizontally in the water. If so, then upright walking will cause their hearts to have some problem against gravity. Instead of pushing/pulling blood from several inches high, it will start pushing blood a few feets high and pulling from 6 feet. Obviously they will not be perfectly horizontal in water but staying upright for a long time will be an issue for them. I am not sure if possible but a circular blood system will reduce/remove this strain. ]
[Question] [ The animal species on my planet has a highly sophisticated communication method and part of the reason for this is that they had no enemies on the planet except themselves. So far, the reason for this might be: * The planet is really very rough and doesn't allow for much to live, that might be because the planet is a rogue planet. Now there should be one type of plant they eat and one type of bug that eats dead plants or the dead bodies of the animal species. The animal species, on the other hand, cares for the plants and some of their degradation products are essential for the plant to survive. So animal and plant need each other and animal as also plant knows they need each other to survive. Is such a scenario possible and what could make this happen? [Answer] ### Stopping evolution, or there will be more than three! There are several issues with such an ecology. So for a moment we'll assume this is engineered somehow for that specific effect. This eliminates the need to explain how the ecology evolved to that particular state. Given that we assume life to rely on some information-carrier substrate to direct the development of new organisms (DNA), and given how in all foreseeable circumstances mechanisms like that must (on a geological timescale) occasionally fail, it's difficult to imagine how evolution has been arrested. Any malfunction that causes a variant of an organism to appear (a mutant) carries with it the chance that this mutation will be advantageous. More such mutants should show up in subsequent generations. Now, if any of these organisms are distributed worldwide (or even continent-wide), then there is enough range that the organisms are isolated from each other. They should (over a geological timescale) start to diverge into separate species. Thus, if we're picking some arbitrary time period in the existence of this world, there's no reason to expect it to have only 3 extant species. You end up needing to visit it quite soon after whatever it was that caused there to be only 3 in the first place (or there won't be just the 3 anymore). If you want this to not be true, you have to come up with a mechanism that arrests evolution, and I struggle to imagine anything that could do that. ### Viable ecology? Next, let's talk about how 3 such organisms could even comprise a viable ecology. It's true that you can find experiments (and I suppose, works of art) where someone has sealed up a big bottle or perhaps a sphere of glass with some plant in it, and some other animal (snails, perhaps, or shrimp, etc) and that these little ecosystems can chug along for decades (or longer, no one knows if there are limits with any certainty). Your world has several advantages over these. In the "bottle garden" (that's what Wikipedia is calling them it seems), if the plant dies for whatever reason, it is either the *only* plant, or one of a very small number of them. This is disastrous. The dead plant won't magically resurrect, and even if it isn't the only one it can wreck the homeostasis of the bottle, causing the other plants to die. Generally, the animal life is a bit better off, you'll have more individuals and they are fast-breeding and perhaps even hermaphroditic/parthenogenic... a single individual dying is much less likely to cause a collapse. But with a small number of each, a death of any plant or animal is just a risk that doomsday is in the cards for this tiny little microcosm. Your world has no such problem. Even if something sparked a local die-off, the planet is large enough that there is a reservoir of organisms to re-colonize that desert and restore some balance. But we can't discount how precarious that balance is. The bottle garden doesn't suffer just from a shallow bench, so to speak... there's only three positions sitting on that bench. Each extra species (that fills a new niche) extant on this world brings a little more stability to it. Each extra species adds a slightly different nutrient cycle to the world, each extra species can be provide a backup nutrient cycle if some other is interrupted. These overlapping cycles don't only substitute for others when disaster strikes, they more finely tune homeostasis. With many animal species, you don't have to worry so much about plants going nuts and over-oxygenating the atmosphere (they tend to look at the plants as food and some minor boom-bust cycle is about to occur). With many plant species, you don't have to worry about some overly-gluttonous animal deforesting the entire world. In the bottle garden, the physical size of the environment itself limits those behaviors... but you've given them an entire planet. Finding the right balance between two species in a bottle garden is difficult and requires experimentation, skill, and more than a little intuition. Finding the balance on your planet-sized bottle garden will be even more challenging, though there's nothing to suggest that it is outright impossible. ### Can any of this even work without decomposition? The bottle gardens might only include a single plant species, and a single animal species... but that's far from the same thing as including only *two species*. Whether deliberate or unintentional, whether they were aware of it or not, those who have made these little tiny closed ecosystems were also putting bacteria (and possibly other microbes) into the bottle. Thus, when one of the little fairy shrimp die, or when a leaf falls to the bottom, those get to work and turn the detritus back into something that the remaining plants can absorb as fertilizer. Your world needs something like that too, and it's non-negotiable. Now, maybe they weren't included in your list because they're boring or it was an oversight, but you'll need to keep this in mind as you explore the idea. ### What could even lead to just three species? From what little we can speculate on the subject, it seems that at one time in our own planet's history there was probably only a single species. It was unicellular and microscopic. And unlike modern microbes, it may not have reproduced quickly... it might not have been "very competent" in that job (after all, it would only have to succeed once). But after that, evolution kicked in, and it almost certainly diverged into multiple subspecies quite quickly. Whether this was hundreds, thousands, or tens of thousands of generations, this is still only a difference of a couple magnitudes of order, and whether or not a generation was measured in 20 minutes or 20 days... well, it just didn't take very long for there to be more than one type of little microscopic squiggly thing. And then for those to proceed up through to the sorts of multicellular life we know today. To have the divergence of some photosynthesizing plants and scuttling arthropods, a skulking vertebrate... well, for that to have happened, evolution had to produce more than just three models. Even if you could imagine a disaster that wiped out all but 3 of those, how likely is it that the 3 remaining would constitute a viable ecology by themselves? Why just 1 plant instead of 3 plants and no animals? Why only 2 animals and 1 plant instead of 3 animals and no plants? Why 1 herbivore and 1 insectivore instead of 2 carnivores? The only way to reconcile this requirement is to suppose that the arrangement is artificial. Someone engineered this planet to be this way. Maybe something that looked like a terraforming effort, maybe K3 quasi-gods just wishing it into existence in the same way we'd run a simulation. But no natural set of circumstances could produce the result you're wanting. [Answer] Very unlikely. Even monoculture like coffee or bananas rely on multiple bacteria and other organisms. Not counting that by reproducing they will end up diverging anyway. [Answer] # If the life is bioengineered, sure. As others have noted, this wouldn't happen via evolution. The animals would branch out and fill slightly different harsh niches, and numerous organisms would have similar successful routes to life. But, suppose this was a terraforming project by an alien race, later abandoned. They designed particular organisms to improve the planet, went off for some reason. A million years later, one plant one animal and one bug is what you have. [Answer] If we're talking hard sci-fi, and basing it off our current knowledge of life, I would say no - at least not by natural processes. Life as we know it evolved from single-celled organisms, but evolution isn't like leveling up in a game. Some of the first single-celled organisms evolved over time to multicellular life, while others kept evolving as single-celled organisms. Evolution means branching off, and in building stable off-shoots life creates ecosystems. We, as humans, are very dependent on bacteria still today, many millions of years of evolution later. As far as we know, humans cannot survive without our multitude of gut bacteria, and while there perhaps may be some odd animal species that don't have gut bacteria, no species survives long-term without a stable ecosystem. Healthy ecosystems tend to have variation and buffers. It also provides challenges which create evolutional pressure, which in turn lead to diversity. Over time, most species branch out or die off. TL;DR: No, because life, uh, finds a way. [Answer] Resisting the urge to make a really silly joke about a really small planet :p Having a single animal or bug species on a planet isn't really possible due to divergent evolution. Having a single invasive plant could happen though. At least two of earth's epochs were ended by incredible algae blooms turning the oceans green, suffocating near all non-plant life with oxygen, then dying off and suffocating near all remaining life with carbon dioxide. Plants have several methods of reproduction: seeds, spores and duplication. As long as you use a plant that uses one of the duplication methods of reproduction which doesn't allow for genetic variance, you could land up with your one plant world - so long as its inhospitable enough to kill off all other plant life. [Answer] **Terraforming, ad hoc.** The residents of your planet had to leave their original planet in a hurry. A big hurry. They did not have time to thoughtfully pack. There was a student of this particular bug who brought some with. That was fortunate for all involved even though these aliens now more or less hate the bug. They hate it more for what it represents than what it is. On their new miserable rogue planet home, they had this bug and their food plants and each other. They made do. It is less than ideal in many ways but somehow it has been working. It is not at all certain it will work for the long term. These folks are concerned about the short term for now. [Answer] As others have mentioned, evolutionarily it's pretty unlikely. I won't reinvent the wheel explaining why, so I'll just give an alternate explanation on how this could come about without evolving on planet. **Panspermia**: It could be that long ago some intelligent life was shuttling by and crash landed on the planet. These intelligent creatures were killed on impact, but for food and sustenance they had created a self sustaining ecosystem out of 1 animal, 1 bug and 1 plant. It could even be that there were many plants, animals and bugs, but most could not adapt to the new environment and died out leaving only one of each. Since this ecosystem was very fragile with low diversity, over time evolution would select for the animals who had behaviors that aided these plants and bugs in adapting. Obviously this would be easier with communication, and so intelligence was selected for as well. ]
[Question] [ I'm DMing a D&D campaign and I'm creating a story for it. It is set in a Medieval Fantasy setting. Essentially there is suddenly an unclaimed piece of land bordering two nations. They both want to take the land for themselves but can't invade due to politics. How would a kingdom support an army large enough for an invasion and keep them ready to invade at a moment's notice? Some things I've considered that would cause issues are * Supply lines * Having enough men to both be ready for the front and defend inside the kingdom * Keeping the army at the border within living conditions Any input would be appreciated and if more information is needed I'd be happy to give as much as I can. [Answer] How much money does the king have? That's crucial. The only way that you can keep soldiers on hand for invasion at any time is paying them. In medieval times, this calls for mercenaries. But they can be dangerous if not paid, extracting it by looting cities instead, with disastrous effects for your subjects in those cities. Once you have your mercenaries, look for a good place to put them. Ideally, one that can be supplied by water, because shipping food over land burns the very food that you are shipping. Defending inside the kingdom is kept up the same old way: the nobles do it. That's their job after all. Remember that communications are SLOW. If you want them to invade on a moment's notice, you have to have someone with the army with the authority to invade. [Answer] Inhabit the border lands with powerful warriors and their families. They'll feed themselves and defend their land, pay taxes, do some light raiding on their own behalf, plus be available at short notice for an invasion along with whatever regular troops you have nearby. Many outfits did this. The English for instance in medieval times had strongholds along the Welsh and Scots borders which paid for themselves and provided trained and equipped men whenever needed. They were theoretically always prepared for conflict. [Answer] ## Generally, they wouldn't You never need to be ready to invade at a moments notice, you only need to be ready to defend at a moments notice. Any time you invade someone, it is on your schedule. So, if you want to invade this place, you plan it out by scheduling X amount of time to get ready for the war. You basically just send out messengers to all your lords telling them when and where to meet up and it is their jobs to levee and train troops and be there by the appointed time. Then you march out when everyone is there. **What you need to be ready for at a moments notice is defense** The real threat is not your rival taking these lands before you, because it's better to let them weaken themselves first subjecting the locals, and then come in second at your full strength and take it for yourself. The real threat is if thier army takes these lands and then uses them as an inroad into your lands before you can gather your own army. For this you need to build castles. A castle with just 30 or so men could stop an entire army in its tracks. Because castles were so hard to breach, taking one, even from a handful of guards would cost a massive number of lives, and you can't just pass by and ignore it either, because that small garrison can cut off your supply lines if you do. So what a medieval king would do in this situation is build a couple of castles along the border and only pay to upkeep those few men because IF the other king did invade the no-man's land first, the castles would contain the threat long enough to raise and gather an army for a counter attack. By NOT maintaining a large army at the border, you conserve your wealth and resources allowing you to field a much larger temporary army, only when the need arises. [Answer] # Teleportation Magic D&D gives your king several options for teleportation of personnel. Guarded Teleportation circles at the invasion staging area could easily link the capital (or other military installation) with the critical border at a moment's notice. Also note that NPC's don't have to play by the same rules as players, so you could easily say that a specialized NPC caster can keep a teleportation circle open for more than 1 (6 second) round. This would allow troops to stream through the circles easily. [Answer] The details depend on why the land is valuable, but I think the short answer is, they would just take it. Both kingdoms simultaneously would see some portion of their military age population just going on raids. You say they wouldn't invade because of politics, but I think that politics in a medieval society is quite different. Raids and pillaging wouldn't count as war in the political atmosphere of a medieval society - they were business as usual. This is especially true if what makes the land valuable is trade routes, but even if its just farmlands you would see soldiers just riding up and demanding tribute to whatever was in reach. We are used to thinking of bandits as common criminals, but in fact, as often as not the 'bandits' were younger sons of the local noblemen using their martial training and their squads of footmen and retainers to raid the outskirts of their father's lands more or less with his permission. This functioned as an additional tax, a threat to outsiders, and a general consequence of the more or less amoral attitude of most nobles towards violence. Raiding your neighbors or even your own subjects was normal for many feudal communities. These kinds of raiding parties would not be official and would not, for example, fly their flag or wear their coat of arms, but everyone would know who was responsible. A good example of what this might have looked like can be seen in Seven Samurai. Besides the general setting of a village being under the thrall of an unchecked bandit group, strongly suggested to be deserters from various armies who came together, there is a particular scene later in the movie where the farmers offer the samurai armor. The samurai are angered by this, and it is made clear that the only reason why the villagers might have this armor would be if they had killed members of the warrior class. One of the samurai, who is strongly suggested to actually be a farmer himself, berates them, and reminds them that samurai just like them are the reason why the farmers are so poor, and probably meant more harm to the village than even the bandits currently do. In their society, the villagers already know that the people who are supposed to protect them, won't. That's why they gather up the seven, mercenaries with no other connections - because the actual lords of the land don't care about the bandits, and may well be actively worse. Any 'unclaimed' land in a feudal society would probably end up like the village from Seven Samurai, invaded by either an unofficial military force like a bandit gang or by actual members of the ruling class, knights (or samurai) and their soldiers, or just as likely, both. These invasions would not necessarily be large scale or even violent - it may just involve a bunch of mounted men in armor riding through a village or past a caravan, saying 'give us these things, no we won't pay you' and getting what they ask for because it's better than dying. This would not count as an act of war even if another nobleman wanted some of the same land. They would just raid at different times, like how the bandits only come after the nobles who own the land have already taken their official tax. It would ruin the land and drive the people there to extremes, but neither kingdom would care in any official sense. In short, my theory is that there would be no change on the actual borders of the established kingdom, but within the unclaimed territory, both kingdoms would be sending irregular raiding parties to take whatever wasn't nailed down and threaten or kill anyone who tried to stop them. There may be a nervousness in both kingdoms as they notice what is happening to their neighbors, and a certain blood thirst in the soldiers that are supposed to protect them, but mostly, I think people would shrug their shoulders and look the other way. [Answer] **Massive public works project.** <https://www.medievalists.net/2020/09/medieval-megaprojects/> > > Building the city of Baghdad > > > Most cities around the world are built up gradually, growing over > generations to become urban metropolises. However, the founding of the > Abbasid city of Baghdad would be conceived of, designed, and built, in > just a few years. > > > Before the Abbasid caliph al-Mansur decided in the year 762 to build > his new capital city here, the site was home to a few monasteries. > Over a hundred thousand workers and craftsmen were sent to construct > the city, which would be round in shape, have four major gates, and be > about three kilometres in diameter... > > > Your soldiers are employed building a massive project at their border site. Maybe a city, or a pyramid, or a canal. Thus there is a plausible reason for them to be there. And they are not just laying around waiting and eating. They are actually building the thing. ]
[Question] [ When and why are spinally-mounted railguns superior to turreted railguns for space combat? Is it a power issues(longer barrels could probably be mounted spinally, and the longer barrels might allow for longer acceleration) or a barrel wear issue(maybe turreted would be better if the rails run out too often, and the railguns need constant rail replacement)? Any ideas? [Answer] This question asks a trade-off between traversement speed and projectile energy. In a turret, your ability to point the weapon is limited by the speed at which you can turn the turret. This gives the turret a field of fire that can be as large as an entire hemisphere. With a spinal mount, you have to turn the entire ship in order to point it, so you have to rotate everything (engines, crew, etc) in order to tell the shot where to go. The advantage of a spinal mount is the amount of acceleration you can pack into your projectile. Overall, for a rail gun or coil gun, as long as it's in "the barrel" you can continue to add more energy to it. With a barrel the entire length of the ship, you can build up enough energy to punch through a small asteroid. A turret mounted railgun could still get through any imaginable amount of armor, but couldn't destroy a whole ship at once. With greater power comes slower fire rate. Although this is entirely story-dependent, a huge spinal mounted rail gun probably requires a much longer charging time than the smaller turret equivalent. It would also have more expensive shots. With current technology, you have to replace the rail every few shots, so the cost-per-shot goes up immensely. With a spinal mount, you probably have a maximum number of shots before you have to go back to dry dock and refit new rails. Addendum: @Gillgamesh commented "with a spinal mount you have the potential to deliver projectiles measured in tones, and at devastating speeds" At first my thought was that "energy is energy, and mass doesn't matter," but that's not quite true. If you put the energy of a 16-inch round into a 45apc, it would hit just as hard, but more of that energy would be spent penetrating. It would just go right through most targets because it doesn't have a large enough cross section, and you don't want that. Additionally, you can pack more energy into a larger projectile for any length of rail. If you take the amount of energy to throw a smaller projectile off the rails, the larger projectile will still be on the rails, and you can pack more energy into it. Rail guns are a fun idea because they don't require the containment of an initial explosion to get the object moving. Instead, you have to brace the rails to prevent the force from yanking down the entire structure. Have you ever looked at [The Orion Project](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion))? We're talking about dropping a nuke out your back end and riding the explosion through shock absorbers. Given the energy levels you could generate with an interplanetary ship, that's what it would be like to fire a spinal mount railgun, but without the radiation. Addendum 2: @Willk suggests that rotating a turret might cause the rails to bend. Initially I thought so, too, but then I realized that the configuration is wrong. A railgun isn't like a chemical propellant gun, where all the stress is near the center of rotation. It is basically an electrical slingshot, where all the stress is on the end of the barrel. With that configuration, the turret wouldn't be a little bubble with a barrel sticking out if it, it would have to be a large globe that rotated the entire mechanism. [Answer] **Rail torque.** Rotating the turret with long protruding railgun puts torque on the rails because forces are applied only to one end of a long structure. They wind up bending out of true. At best this messes with aim; at worst asymmetric acceleration causes catastrophic failure. You can turn the turret very slowly and avoid this. You might as well turn the whole ship which supports a spine mounted railgun along its entire length. [Answer] ## Size of ship My small, lightweight, fast-moving ship can only support a spinal mounted railgun because the kickback of any non-spinally-centered shot would induce a spin. I also need the potential kickback to be offset by my main-thruster — my port thrusters are for moving the ship, not offsetting railgun recoil! My large, heavy, slow-moving ship is so big the turreted railgun's recoil doesn't matter — it's huge! Additionally, my large ship's turreted railgun is much larger and sophisticated that it includes recoil-compensation hardware — try fitting that on your fast movers! [Answer] Since it’s a railgun, I would go with a mass driver gauss rifle design. It essentially speeds up an object pushing a payload (which is your ammunition) and stops the object pushing the payload, launching your shot. This is done with electromagnets and has wear and tear on the stopping mechanism. To understand the difference between the two options, think of it like this. Your spinally mounted one is like the machine guns on fighter craft, while your turrets are like the ones defending bombers. For space combat, most spacefighters (Eta-2 Actis-class light interceptor from Star Wars and such) have fixed guns and fly the ship around the enemy, trying to outmaneuver them. This lets them have the largest caliber guns they can fire. With the turrets, you don’t have to move you craft, just the turret and gun. Odds are you’re flying something that resembles a star destroyer (Star Wars) or a Hapan Battle Dragon (also Star Wars). With the star destroyer, its appears to have and 8x2 or 8x1 set up of big guns, with some smaller guns elsewhere. The turrets will be called A,B,C,D,a,b,c, and d, with the lowercase denoting the left side. Guns B,C,b, and c all have the most limited firing angles, maybe 45 degrees at most. Guns D and d have a slightly larger firing angle, and Guns A, and a have the largest firing arcs. Now in space, there’s no air resistance and so the movement of the turret won’t be fast. Turrets of such large guns never are, not in Star Wars, not in real life. On the Hapan Battle Dragon, all the guns are fairly short barreled, so I assume the torque is much less. Thus the Hapans are able to fire the front gun, rotate the lot of them so a fresh gun is in place, fire it, repeat. **Summary** Essentially, use spinal mounted guns for your fighters and use turrets on larger ships that can take hits and don’t need the guns to move as fast. [Answer] Rail gun is a projectile weapon - meaning there is a physical object being thrown at a target. How it will be used depends on what your world (and universe) looks like and, specifically, what tech level you're envisioning. This is important, because railgun has a few characteristics that makes it a somewhat unique weapons system. In other words: how well it will do depends on the role you want it to fulfill. First some things to consider: 1. Energy delivered to the target is dependent on two factors: mass and velocity, 2. ...but not on the distance - so range is limited only by precision of the targeting systems; 3. Depending on the mass of the projectile, there is limited storage; 4. Depending on the available tech you can go either for smaller but faster or bigger but slower rounds, which will dictate your rate of fire, 5. ...and your energy budget. There are also limitations: 1. Projectile is a physical object, so it can be detected, using various methods. But in essence the problem is: if you know it's coming, you can evade it. 2. and this effect is bigger the greater the distance to the target - more time to detect and the farther you can "see", the easier evasion will be 3. and how well it will perform if it hits the target depends on shape and composition. To answer your question, then. Spinal mount allows for much more powerful weapon system compared to turreted one. Which for railgun means both bigger and faster projectiles (as mentioned elsewhere, longer "barrel" can impart greater velocity), but limited firing cone (few degrees in each direction, at most). Turreted mount, conversely, is smaller - so less powerful - but has much wider firing arcs. What to go for depends on the protection it needs to defeat. If the space combat is between vessels carrying armor and/or additional em-style shielding, then projectile's velocity or mass must be significant to defeat either or both). In case of the railgun the main difficulty is speed, because it is dependent on length of the barrel. However, increasing projectile mass to compensate, necessarily reduces it's velocity. Space combat by the very nature of space involves both higher speed and greater distance, . So, if the anti-ship railgun weapon system needs to defeat significant protection at significant distance (several hundred of kilometres, if not more), it needs to be very, very fast, which means either huge amount of energy to propel it or very long barrel (as in kilometres, dozens). Otherwise it can be detected early and the slower it moves, the easier it is to avoid. So, to bottom line it all: railgun is not feasible as a an anti-space-ship-combat-system. It could be of some use as a close-in-defence system (anti-missile and/or anti-fighter), especially if it will employ scattering payload (sand, ball bearings - whatever, just needs to be small and lots of it), but it's limited (depending on factors) fire-rate makes it mediocre at best. Best possible use would be planetary bombarding and/or anti-orbital-defence weapon - so everywhere where target can't or has very limited movement capability. Unless you make big projectiles capable of some manoeuvring... [Answer] #### Railguns are heavy Railguns need to be very strong. Whenever one is fired, the two rails create enormous magnetic forces which try to push them apart. To avoid bending the rails need to be strongly built and well supported Railguns are powered by giant capacitors. You cannot just run a wire from the capacitor to the rail - it would melt instantly. Instead solid copper bars are used and the capacitors are mounted as close to the rail as possible. The bars need to be strong, or they will bend due to the magnetic forces. Railguns create a strong EMF spike. A lot of shielding needs to be added to the railgun to stop the spaceship from frying itself after every shot. All in all, this makes the gun far heavier than the ship in most cases. Adding a turret wouldn't rotate the gun, but the ship. [Answer] **Why build any long barrel, why any big gun?** Your question sounds as if it were irrelevant how long the barrel or how big the gun is, but it absolutely is not. I don't even need to go into any reasons: if it were irrelevant they'd use 1cm short "guns" with the diameter of a hair. But they don't, they build "proper" guns. So going bigger has it's reason. That implies that going even bigger also likely has advantages. With guns on turrets, you need a large ship relative to the gun. To account for the turret torque, recoil (which has to be caught in a joint large enough to sustain multiple shots) = even more size/weight. Turning a longer barrel also incurs shear forces which could bend delicate magnet alignments over their use without sufficient (HEAVY) structural support. Spinal mounts have these counterpoints as their advantage. Recoil can be passed directly into the structure of the ship, and the entire ship is structural support for swiveling. Also, you get the maximum size of your gun for your buck. Anything on that ship goes directly into supporting the one enormous gun. But why one massive gun to begin with? Well, that could be a lot of reasons. Maybe shielding technology is quite advanced, so that a barrage of smaller shots (over some spread) are virtually useless. Or physical armor made those strides. Either way, in your world, shots are all or nothing. Either they pierce, or they barely result in camera shake on the bridge. ]
[Question] [ I'm writing a sci-fi novel about a planet outside of the Solar System. The planet can support human life and is similar to Earth in many ways (1G gravity, Nitrogen-Oxygen-Carbon atmosphere, soil and liquid water, plants). The main differences are that its orbital period is about 120 years and winters are very cold. I'd appreciate ideas, insights and comments on the following: 1. If the temperatures in winter (which lasts for 30 years) are about -500°C (-868 F) and in summer they rise to 20-25°C (68-77 F), is it possible that spring and autumn are also quite warm (around -20 to 10°C (-4 to 50 F)) and not just take the average of -240°C (-400 F)? Basically, can winter start abruptly or the change must be gradual? 2. Will there necessarily be winter in one hemisphere while it's summer in another? Also any ideas about the differences of season change in prolonged periods will be much appreciated. P.S. Sorry for my English, it's not my native language. [Answer] **Elliptical orbit.** <https://en.wikipedia.org/wiki/Elliptic_orbit> [![orbits](https://i.stack.imgur.com/CaLpd.gif)](https://i.stack.imgur.com/CaLpd.gif) Winter is when your planet is far from its sun. Winter might be longer than the other seasons. Look at the pink planet in the gif and use the red one as a clock. The pink planet with the most elliptical orbit spends the most time in the regions more distant from the sun, because it is moving slower out there. If it has a 120 Earth year orbit, winter might be 90 years. And summer on Pink is going to be seriously warm. On our world with an orbit that is nearly circular, axial tilt is what makes the seasons because one hemisphere is relatively more distant from the sun than the other. On a planet with an elliptical orbit distance from the sun is going to make more difference than axial tilt. --- L.Dutch asked me to do some calculations. I am flattered. But instead I will do comparisons. Let us consider Halleys comet. [https://www.ucl.ac.uk/~zcape78/CometHalley.html](https://www.ucl.ac.uk/%7Ezcape78/CometHalley.html) > > The orbit of the Halley’s Comet is elliptical with a high > eccentricity, which is equal to 0.97, compared to 0.0167 for the > Earth, or in other words, the major axis of the ellipse is about four > times greater than the minor axis. > > > At perihelion Halleys comes to 0.59 AU to the sun (Earth being 1 AU from the sun) and aphelion it is 35 AU away from the sun. It gets nice and warm on the comet at 1 AU. <https://www.space.com/29024-how-to-live-on-a-comet.html> > > When the Giotto spacecraft visited Halley's Comet in 1986, the comet > was 0.9 AU from the sun and had a surface temperature of about 170 > degrees Fahrenheit (77 degrees Celsius). > > > 170F is a little warmer than Portland, but not boiling water weather. Of course the comet gets closer to the sun than 0.9. But moving on... As far as how cold, Neptune is at 30AU and Neptune gets to -225C, absolute zero being -273. So 35AU is colder than -225C. But Pluto is at 40AU and only -232 so probably the comet only gets a little colder than Neptune. Thus my calculation: an eccentricity of 0.97 to produce the warm summer and cold winter requested. Dutch I am going to keep working on that paean because you will earn it someday I am sure. [Answer] **A binary star system** [Helliconia](https://en.wikipedia.org/wiki/Helliconia#Astronomy) is a fictional example of a planet that shares the characteristics that you want. > > Helliconia orbits Batalix in 480 days; this is called the "small > year". Each day of the small year comprises 25 hours, each of 40 > minutes, which in turn are each 100 seconds long. Helliconia and > Batalix's orbit around Freyr, the "great year", is highly elliptical > and takes approximately 1,825 small years, equating to some 2,592 > Earth years.[8] At periastron Batalix is 236 astronomical units from > Freyr, whilst at apastron is 710 AU distant.[9] A Helliconian week is > eight days. There are six weeks in a tenner, and ten tenners in a > Helliconian small year.[10] While seasonal changes in the small year > are slighter than those of Earth, the long seasons of the great year > are much more marked. When distant from Freyr, Batalix's illumination > is sufficient only to maintain ice-age conditions. However, Freyr's > output is many times greater than Batalix's, so as Helliconia > approaches Freyr, the tropics of Helliconia become hotter even than > the tropics of Earth. > > > [Answer] Your planet seems to be a little bit on the impossible side. Part One. You want you planet to be habitable for humans, and yet you want it to experience really extreme temperature changes which might exterminate all natural life on the planet. Including the plants that take carbon dioxide out of the air and convert it into the oxygen in the air. Of course humans with sufficiently advanced technology could live on your planet. But the techiques they would need to shield themselves from the temperature swings would insulate them from the planetary enviromental conditions so much that they might as well living in an artifical space habitat. Part Two: You want the length of the planet's year to be 120 Earth years. The length of a planet's year, defined as its orbital period around the planet, will depend on various factors. The equation to calculate the length of a planet's orbital period includes the mass of the star, the mass of the planet (which will almost always be so small comapred ot that of fhe star it can be ignored), and the distance between them. Stars have different luminosities. A star with a specific luminosity will have a specific distance where a planet will receive exactly as much light and heat from the star as Earth gets from the Sun, and so (other factors being equal) would have exactly the same average temperature as Earth. I call that orbital distance the Earth Equivalent Distance or EED. And the circumstellar habitable zone around the star will extend inward toward the star and outward from the star around the EED. The circumstellar habitable zone is where a planet would receive enough radiation from the star for water to be liquid on the surface of the planet. If other factors are good, a planet in the habitable zone can be habitable for life. So how wide is the circumstellar habitable zone around the Sun? The various estimates seen here: <https://en.wikipedia.org/wiki/Circumstellar_habitable_zone#Solar_System_estimates> Show there is considerabledisagreement on wide the Sun's circumstellar habitable zone is. To be safe, some writers might want to put their habitable exactly at the EED of their star to be certain that it is within the star's circumstellar habitable zone. The average orbital distance of the Earth from the Sun is one Astronomical Unit (AU). If a star has X times the luminosity of the Sun, its EED orbit will be at 1 AU times the square root of X. If the star is 4 times as luminous as the Sun, its EED will be at 2 AU from the star. If the star is 9 times as luminous as the Sun, its EED will be at 3 AU from the star. If the star is 16 times as luminous as the Sun, its EED will be at 4 AU from the star. If the star is 25 times as luminous as the Sun, its EED will be at 5 AU from the star. If the star is 100 times as luminous as the Sun, its EED will be at 10AU from the star. If the star is 1,000 times as luminous as the Sun, its EED will be at 31.6227 AU from the star. If the star is 10,000 times as luminous as the Sun, its EED will be at 100 AU from the star. If the star is 100,000 times as luminous as the Sun, its EED will be at 316.227 AU from the star. If the star is 1,000,000 times as luminous as the Sun, its EED will be at 1,000 AU from the star. The luminoisity of stars - at lest the main squence stars - depends on their mass. A difference in the mass of two stars of a specific percentage will cause a difference in their brightness which is significantly greater. The most massive stars are thousands of times as massive as the least massive stars, but are millions of times as luminous. There are a few known planets which orbit their stars at distances of hundreds of AU, and which have years hundreds of thousands, or even about a million, Earth years long. And there are stars with the right luminousity and mass that a planet with a year 120 Earth years long could orbit within their habitable zone. So everything seems fine for the planet in your story. Except. Part Three. It took billions of years for life on Earth to develop enough for planets to produce an oxygen rich atmosphere that multicelled animals, such as humans, could breath. The Sun shone with a fairly steady brightness for those billions of years - otherwise it would have made Earth too hot or too cold and all life would have died. For a planet to become habitable, it has to have existed for billions of years, and its star has to have shown with a fairly steady luminosity for all those billions of years. Unless the writer wants to make the planet much younger than a naturlly habitable planet, which an advanced civilziatin has terraformed to become habitable with advanced technology. And as it turns out, only some stars, main sequence stars similar to the Sun with a rather small range of mass and luminosity can shine with se teady luminosity for the billions of year necessary for a planet to naturally become habitable for humans. Stephen H. Dole, in *Habitable Planets for Man*, 1964, discusses the types of stars suitable for having planets habitable for humans on pages 67 to 72. <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf> And to paraphrase a gambler, "read it and weep". many science ficiiton writers and readers have found those "Dole full" limitations on the types of stars which could have naturally habitable planets very frustrating. Take a spectral class F2V star, which is about at the uppermass limit according to Dole, and which some astrbiologists would consider to be too massive to have a habitable planet. According to the table at: <https://en.wikipedia.org/wiki/F-type_main-sequence_star> an F2V star would have a mass 1.46 the mass of the Sun and a luminosity 5.13 the luminosity of the Sun. With 5.13 the luminosity of the Sun, it would have an EED at a distance of about 2.265 AU. I found an online orbital period calculator. <https://www.calctool.org/CALC/phys/astronomy/planet_orbit> Entering the mass of the stars as 5.13 suns, the mass of the planet as 1 Earth, and the semimajor axis as 2.265 AU, I get an orbital period of about 2.82066 Earth years. It is possible that an Earth mass planet in the orbit of Mars might be habitable. The orbit of Mars has a semimajor axis of about 1.523 AU. So the Mars Equivalent Distance, or MED, of an F2V star should be 1.523 times 2.265 AU, or 3.449 AU. And that would give the planet an orbital period of 5.30016 Earth years. Vega is a class A0Va star, with 2.135 the Sun's mass, and about 40 times the Sun's luminosity. So its EED and MED should be 6.324 times as far as the Sun's, at 6.324 AU and 9.6322 AU. The orbital period of a planet at Vega's EED would 10.8821 Earth years and at Vega's MED would be 20.4557 Earth years. And Vega's calculated lifetime on the main sequence is only about a 10th that of the Sun's, and so roughly a billion years. Component C of Beta Scorpii would be a class B star to try. It is spectral class B2V, 8 times the mass of the Sun, and 3,200 times the Sun's luminosity. It's EED would be 56.568 times that of the Sun, at 56.568 AU and its MED would be at 86.153 AU, with orbital periods of 150.396 and 282.674 Earth years. The main star of Algol, Beta Persei Aai, has spectral class B8V, a mass of 3.17 Suns and a luminosity of 182 Suns. Its EED and Med would be 13.49 times a far as the Suns, at 13.49 and 20.546 AU, with orbital periods of 27.8236 and 52.2982 Earth years. According to the table at: <https://en.wikipedia.org/wiki/B-type_main-sequence_star> A B5V class star would have a mass of 4.7 Suns and a luminosity of 589 Suns. So its EED would be 24.269 AU and its MED would be 36.962 AU, with orbital periods of 55.1385 and 103.636 Earth years. A B4V class star would have a mass of 5.1 Suns and a luminosity of 776 Suns. So its EED would be 27.856 AU and its MED would be 42.425 AU, with orbital periods of 65.0907 and 122.341 Earth years. A B3V class star would have a mass of 5.4 Suns and a luminosity of 977 Suns. So its EED would be 31.257 AU and its MED would be 47.823 AU, with orbital periods of 75.1882 and 142.293 Earth years. A B2V class star would have a mass of 7.3 Suns and a luminosity of 2,692 Suns. So its EED would be 51.884 AU and its MED would be 79.02 AU, with orbital periods of 138.298 and 259.938 Earth years. So presumably a B2.5V class star would be about right to have a planet with a period of 120 Earth years orbiting between its EED and its MED. Class B stars stay on the main sequence for only about a few tens of millions of years. So a writer who wants a habitable planet orbiting one of them could have an advanced civilization terraform the planet to make it habitable. It might take that civilization thousands of years, but that might be considered worthwhile if the planet remains habitable for millions of years. And possibly after the terraforming civilization abandons the planet a native lifeform might develope intelligence and civilization and possibly develop spaceflight in time to escape, or humans might decide to settle there despite there being only a hundred thousand years before disastrous stellar changes. Or you could take a look at the Mohs Scale of science Fiction Hardness and decide that you will be content with your story having a scale of only 1, and not worry abut the astronomical plausibiity of your system. <https://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScienceFictionHardness> Part Four: Obviously if the planet has a year 120 Earth years long, the astronomical seasons will each be 30 years long. The meteorological seasons might be longer or shorter in various places on the planet. But such long seasons should cause each hemispehre to get colder and colder and colder during the winter, and hotter and hotter and hotter during the summer. It might be impossible for humans, or for any lifeforms at all, to survive such temperatures, even though they should vary much less than you stipulated in the question. If the planet has a very eccentric orbit, that could cause seasons which were the same on both hemispheres of the planet at the same time. And the temperatures could get very cold during winter and very hot in the summer. But I doubt that anything could make them reach the extremes specified in the question. And you might be interested in questions and answers about making seaons on a planet last much longer than its years. [How does a Game of Thrones-style hyperwinter occur?](https://worldbuilding.stackexchange.com/questions/216630/how-does-a-game-of-thrones-style-hyperwinter-occur/216838#216838) [Answer] # Short answer: Your planet is not possible. ## Why? First, -500 Celsius is impossible, because the lowest possible temperature is absolute zero (-273.15 C). Let's assume the planet's winter temperature is 10 Kelvin. Your atmosphere would freeze and fall to the surface as snow. Liquid water would boil away as there is no pressure to keep it liquified, thus killing all life. Also, a planet will spend much more time at aphelion due to Kepler's third law, meaning that winter would last more than 80-90 years. ## What planet would you need? You would need a planet in an eccentric orbit orbiting a binary star. **Why both, and not either???** > > Is it possible that spring and autumn are also quite warm? > > > > > Basically, can winter start abruptly or the change must be gradual > > > Spring and autumn are mainly transitional phases between summer and winter. For the transition to happen abruptly, you probably would need an eclipsing binary system with a period of half the period of the planet. The planet is warmest when it is at perihelion, where the more massive star eclipses the lower mass star. The planet grows colder slowly as the stars move apart, adding more sunlight, but the planet moves away and gets colder (autumn, spring but switched). When the planet goes to winter (at aphelion) the stars eclipse again, making it as cold as possible. Therefore, winter can start abruptly, but in a gradual manner (it can start quickly if the atmosphere freezes quickly) > > The planet can support human life... plants. > > > **No.** Life is very unlikely because it would only have about 20ish years to develop and reproduce, then die out. The only way for a species to survive was if they lived in a 120-year cycle where they remain dormant underground as "seeds" during winter and live their short 20 year life to reproduce, then die-off as the atmosphere freezes over. Technically, humans could survive in spacesuits near aphelion. Major terraforming would have to occur for such a planet to be habitable (forced warming of the atmosphere to keep the planet warm during winter) If you'd like specifications for such a planetary system, please let me know. ]
[Question] [ I've been thinking about this world that's been in my mind and one of the things in it are drake knights which are warriors who raised and ride domesticate breed of triceratops like the war elephants of our past. but I've been stumbling with the idea as it seems impossible for a normal person to ride a triceratops comfortably due to how wide the animals are. they are built like kegs and horses already are pretty wide so a animal that's even wider seems difficult to image someone riding plus the frill would seem to make to difficult to see over for a person which would be important to know what's in front of you. now I have an idea for a larger race to possibly ride them but right now I'm just curious if a normal person could ride a triceratops and if so how would the saddle have to be set to allow it to be possible. thank you for reading and have a good day. [Answer] Assuming that a triceratops can be tamed, riding it can be done in a similar way to elephants: a platform can be placed on the animal's back, and on the platform can find place the rider(s) [![enter image description here](https://i.stack.imgur.com/HWZtS.jpg)](https://i.stack.imgur.com/HWZtS.jpg) The platform would also put the rider slightly above the frill. [Answer] First of all, trikes are approximately 2 meters wide and 2.9-3 meters tall. Horses are much smaller, meaning that a different approach to climb on to the trike must be used. I feel like people may have to either have a platform to get on, putting one leg on after another, then adjusting their position, or, they could just climb up the tail (not a good idea if the trike is aggressive or too large). Like [L.Dutch mentioned](https://worldbuilding.stackexchange.com/a/217289), I think that having a platform on the back of the trike would be extremely useful. [Answer] Once upon a time, outside the National Museum of Natural History in Washington, DC, there was a statue of a *Triceratops* (possibly named "Uncle Beasley"). Kids used to climb over the head and frill, up the back, and slide down the tail. It was possible to sit behind the frill with legs straddling the neck. This only addresses when the mount is standing still. Whether sitting behind the frill would be useful while the animal moves about is unknown. It is possible that the motion of the neck and frill would make that spot uncomfortable really fast. (Side item, I believe the statue is now at the National Zoo, and climbing on it hasn't been allowed in many years. Ah, those were the days.) [Answer] If the beasts were raised from birth like you say, setting aside the question of how to sit, the head frill problem could be solved by binding of some way. While the little trikes are young and the frill is still growing the frill could be bound in a manner similar to head binding was done with the Mayans or foot binding in some Japanese cultures. One could conceivably bind (mold?) the frill is such away to make room for the legs behind the frill as well as a 'dip' in the center to see over it. ]
[Question] [ According to what I've looked up, the average human is 60% water, and 60% of that water is in cells. Lets assume this "hydrokinesis" is limited to telekinetically lifting and moving liquid water. Is there enough water distributed within the human body to allow the body to fly safely, comfortably, and practically in the air? Is there a very specific way the hydrokinesis has to be used on the body to achieve this? *In case more specifics are needed:* Lets say a hydrokinetic person used this to float over a road and move like a car would on an average day through a city. Could this be used to reach normal car accelerations without accidentally ripping water out of the body? If this just complicates the question or doesn't make sense, feel free to ignore it. [Answer] # Perhaps. Affecting the water in a human body would be enough to make it accelerate and, actually, we *already* know it would work - frozen meat and a couple of live frogs have been subjected to this technique. **But** what exactly happens to the organism subject to hydrokinesis? The live frogs survived "with no ill effects", but frogs are cold-blooded organisms and can (not always, not all) survive freezing. So, an almost complete *temporary* loss of significant relative motion in fluids within a frog might have no effects on it, and yet would be enough to kill a human being. Even if it did not kill, hydrokinetically accelerating a brain seems more than enough for that brain to *lose concentration* (if not consciousness altogether), which means that immediately after takeoff, our hydrokinetic guy would crash to the ground (or, if the effect is self-sustaining, proceed slowly but surely to leave Earth's orbit or die and fall down, whichever comes first). Possibly, the control over hydrokinetics could be subtle enough to allow normal motions in fluids while superimposing an overall acceleration effect; or precise and strong enough to accelerate the fluids just below the skin, and maybe on different body areas in turn, so that the body keeps accelerating but no single part is left too long without blood circulation or with excessive pressure (at that point, the guy could also wear an inflatable lifejacket inflated with water, and equip an instant Jet-Pack). Another interesting possibility is **"reverse" hydrokinetics**. Water exists, in the form of water vapour, about one to forty grams per cubic meter of air, all around us. Our hydrokinetic ESPer would weigh, say, about 80,000 grams; if they can "grab" all the water in the air in a radius of, say, twenty meters, and accelerate it downward, Newton's Third Law would ensure that they would be subject to an upward thrust sufficient to fly. They would become a sort of "human turbine". By forcing the air to go around them at a short distance, they'd produce a safe "bubble" of reasonably still air. This would still require a lot of control, but not so fine as the "affect water within your cells" method. [Answer] Could hydrokinesis be used to fly, Yes, it could. I was going to try an calculate the numbers, then remembered that people have levitated a frog [using magnets](https://www.youtube.com/watch?v=KlJsVqc0ywM) (and [few](https://thekidshouldseethis.com/post/12794114359) other [pages](https://www.ru.nl/hfml/research/levitation/diamagnetic-levitation/)), they levitated it using a magnet to repel the water. Therefore is is possible to accelerate at the very least $1g$ (at least horizontally) at this acceleration you go from $0$ to $100km/h$ in 2.8 seconds, which is about that of a [fast car](https://en.wikipedia.org/wiki/List_of_fastest_production_cars_by_acceleration). Vertical acceleration would be less, but even at $0.25g$ you can climb $100m$ in 9 seconds and $200m$ in 12.5 seconds. They could get to the top of [Mount Everest](https://en.wikipedia.org/wiki/Mount_Everest) in less then $1\frac{1}{2}$ minutes. [![enter image description here](https://i.stack.imgur.com/XVi3e.jpg)](https://i.stack.imgur.com/XVi3e.jpg) So yes you can move living organisms by moving the water in them. AS to how they would use there powers they would just have push each water molecule in the direction of travel and not affect is other motion, so that blood can still flow. hopefully that helps *An alternate method that could get used; is if they have strong container, filled water (like a metal water bottle) and then lifted the water in the container. Depending on how much force they can cause the water to push, they could have bracelets/anklets that contain a small amount of water, which they lift, which in turn lifts themselves. Somewhat like [magneto](https://www.reddit.com/r/AskScienceFiction/comments/2jphon/xmen_how_does_magneto_manage_to_fly/) from the xmen, except instead of metal they have water.* [Answer] # Yes; easily. This answer could definitely be improved with a more detailed look at the statistical distribution of speeds of water molecules at body temperature and the mean free path of the water molecules in a cell to calculate the average speed gain under an e.g. 1g vertical acceleration; however I think the order of magnitude of the velocities here is enough to answer relatively conclusively without that. The mean speed of a water molecule at standard temperature and pressure is about 590 metres per second. An acceleration of the order of magnitude of 1g is going to make a miniscule effect on the speed of each water molecule in the human body before it collides with something other than a water molecule and transfers some of this momentum to the 40% of the body not directly accelerated. As such, accelerating a human body by only accelerating its water content should not be expected to cause any abnormal effects or stresses on the internal body, so long as the change in velocity between collisions remains small compared to the normal molecular velocities of the water molecules in the body. Given the tiny intermolecular distances and the significant velocity of water molecules at body temperature, hydrokineses could even potentially allow much stronger accelerations than the human body can usually handle, since the body will be accelerating relatively uniformly throughout, rather than from the feet or back with all the impacts on blood pressure that follow from that. However, I'd definitely want someone to have done a much fuller treatment of the hydrodynamics before trusting my own life to it. ]
[Question] [ My planet has fairly large tides, with the difference between high and low tide being roughly thirty meters, and the spring high/low tide different being roughly sixty meters. There is a civilization living on the coast of a large bay that only connects to the sea via a small strait, reminiscent of the Mediterranean and Gibraltar. In order to gain more land and be able to build safer ports, I thought that this civilization could attempt to put locks into the strait, similar to those found in the Suez and Panama canals, and thus not only control the water level in the bay, but also allow ships to pass through it for a limited time each day, between high and low tide. The catch is that this civilization has late 19-century technology. But given that the Suez Canal was built in 1859, I don't think that should be much of a problem. Here are some figures to work with: The strait is roughly 150 meters deep and 2 kilometres wide. The bay itself has an area of about 17 500 km2 (a bit smaller than Lake Ontario), and averages around 200 meters deep. **Is putting locks on this strait (not damming it) possible with 19th-century technology?** [Answer] No This is very doable. For tides of 1.5m (3m up & down) Using late-20th century technology. The city of Venice has such a system, which was used for the first time on 3 Oct 2020. To do the same for a 60m tide is.... wow. No chance. It is ***well*** out of feasibility even using present day technology and unlimited budget. It would be like building and removing the Three Gorges dam, twice each day! The other option (but declined by the OP) of permanently DAMMING the strait would be possible, but ultraMegaSuperGargantuan in scope. P.s. A 150m deep strait, impeding a 60m tidal ocean? It will ***very rapidly*** become a 1km deep strait! Mere granite rock cannot stop that sort of scouring ability. P.P.s. My flood calculator says the water will flow through that strait at a rate of some 395m/s (1422km/h), and a volume of about 1/4 cubic kilometer (55 billion gallons) per second. [Answer] ### No it's not possible. But you can still have a safe port with 60m tides with 19th century tech. [This answer](https://worldbuilding.stackexchange.com/a/190365/78800) gives an overview of why it isn't possible. 60m tides with a narrow straight will flow very fast (~ half speed of sound in water) at these speeds water tries to ignore the turns suggested by the rock - eroding the narrow straight very quickly giving you a very smooth coastline, so you'll end up with a wider opening than Gibraltar pretty quickly. I'd be surprised if the entire continent didn't end up convex after a few millennia. Your tides may be strong enough that you can use them for thrust in many cases - that's an interesting story idea. No need for sails or oars, astronomy and decent mathematics may be discovered before the sail, as it's superior for navigation. The trick is to use pontoons as your dock. Since you're tides are massive. You need to a build a structure underwater to rest the pontoons on at low tide. I've ms-painted it as a trestle but you could rock fill it using 19th century steam shovels. (Or find a perfect coastline). [![enter image description here](https://i.stack.imgur.com/Dlt18.png)](https://i.stack.imgur.com/Dlt18.png) [![enter image description here](https://i.stack.imgur.com/g9GJ0.png)](https://i.stack.imgur.com/g9GJ0.png) Pontoons are anchored laterally to the coast so they stay in the correct position and don't apply excessive torque to the attachment point, and the ship ties to the pontoon(s) itself and importantly doesn't drop anchor - it needs to drift forward and backwards in space over time to remain stationary relative to the pontoon. In the peak spring tide, you'll be looking at the pontoon moving at an average of about 2mm/second vertically. (4mm/s peak. Stationary 4 times per day). This is about 1/4000th the speed of a typical 20th century building lift / elevator. You'll feel it, but your dock workers can transfer heavy cargo efficiently under this speed. Your society will also probably discover standardised shipping containers faster than we did. You can't take a freight train to the water with this setup, so you're probably going to have to unload sacks / cartons onto small carts pulled by horse or a steam-engine mounted at the top of the hill. Then unload the cart onto a train. The triple handling will make the standardised 20ft container look really attractive in the late 19th / early 20th century. [Answer] Maybe. But it seems you have two separate problems. You could certainly put locks around the strait, if the terrain is favorable. For instance, the Welland Canal <https://en.wikipedia.org/wiki/Welland_Canal> bypasses the "strait" (AKA Niagara Falls) between Lakes Ontario and Eire, and has more than your 30 m elevation change. The first version of the canal was built in the 1820s, so easily doable with late 19th century tech. That would allow ships to pass safely, avoiding the currents in the strait. However, you also ask about controlling the water flow, and that is going to take a dam. While 30 m high dams are certainly possible, the problem is going to be building the thing, since your ongoing construction has to withstand the currents. If you could build it, though, it should work, and would make a great tidal power plant. The height itself is not a problem, as the Romans were able to build taller oness: <https://en.wikipedia.org/wiki/Subiaco_Dams> Quite a few Roman dams still exist today: <https://en.wikipedia.org/wiki/List_of_Roman_dams_and_reservoirs> ]
[Question] [ Evolution requires a process: Mutations occur; most mutations are harmful/detrimental, but a few are beneficial. Then, beneficial mutations are selected for. It seems to me that there is a trade-off. Too much mutation, and too many individuals will get harmful mutations and die off, shrinking the population and increasing the likelihood of extinction. Too little mutation, and the species will not be able to adapt to a changing environment. On Earth, all life has some mutation due to cosmic radiation, UV radiation, etc. There are also certain chemicals that can cause radiation. But many species have evolved DNA repair mechanisms to mitigate some of this mutation. Is the mutation rate on Earth perfectly optimized? On a planet completely protected from all forms of radiation, would life fare better or worse? What about on a planet bombarded by very high levels of radiation? What is the optimal rate of mutation to ensure both population growth and maximum adaptability? [Answer] **There isn't one.** The optimal rate of mutation *for a particular lineage at a particular time* depends on multiple different factors, like 1. How stable is the environment in which they live? How stable is the niche they exploit in that environment? 2. How long do they live? 3. How frequently do they reproduce? 4. How many offspring do they have? etc. And different lineages have in fact evolved different baseline mutation rates to optimize their further evolution. How quickly populations mutate and exactly how they mutate is not simply a function of how much mutagenic radiation is in the environment--it also depends on things like how effective their radiation protection and gene repair mechanisms are, and how accurate their DNA replication machinery is, which are traits which are themselves subject to evolution. On a planet completely protected from all forms of mutagenic radiation, species would evolve to have a particular advantageous mutation rate *anyway*; and on a planet with much higher levels of radiation, they'd evolve more protections against said radiation, again tuning their mutation rate to be whatever it needs to be. [Answer] The optimal rate would be that which promotes evolution quickly enough that life does not become extinct. Therefor, it is *local*. On other worlds than Earth, environmental conditions might change so quickly and drastically that a faster rate of evolution might stave off extinction, but an Earth-like rate would stand little chance. Given all that, Earth is pretty close to optimal... life has managed to continue to exist for nearly 4 billion years at this point. On a longer time scale, all planetbound life is subject to grim outcomes. Stars don't last forever. It might be said that an optimal rate also permits the kind of evolution that allows life to leave its home world. This wouldn't necessarily be through intelligence and space-faring technology, though my imagination isn't quite so extravagant to be able to come up with plausible alternatives. ]
[Question] [ Correct me if I'm wrong but I think science fiction often confuses invisibility with transparency. Even if somehow we could make a human being transparent, this wouldn't make them invisible, any more than a clear glass bottle is invisible. Of course the refractive index of glass is a large factor. At the same time, in SciFi, there is often an assumption that, given enough time and technology, every trope will be achievable sooner or later. **Question** Is there any conceivable real science or technology that can even theoretically allow invisibility of a human being? If not, how about any reasonably constituted alien that visits Earth? **Conditions** No magic. The subject must be a living adult human (or alien). **The invisibility must apply for 360° around the person** so that they would be unseen in a crowd from any direction. A helicopter or drone might be able to detect them from directly above. The subject can be detected by touch and other senses - just not by normal human vision. In clean dry air, they cannot be seen. However it is acceptable for dust, rain, fog etc. to reveal them. Invisible aliens must have a solid body with plausible parts that allow them to move and live. They cannot be made of a pure gas for instance. [Answer] This may not be what you're looking for: [![enter image description here](https://i.stack.imgur.com/ucHT0.jpg)](https://i.stack.imgur.com/ucHT0.jpg) Here's a [video](https://www.youtube.com/watch?v=CFiPJjrmmtE) showing it in works. What is happening here is that a fresnel lens is catching ambient light. Place the object you wish to hide far enough back from the lens, and the ambient light has been bent "around" the object, effectively concealing it (very effectively in some cases). You can see, however, that the lens is blurring details. Against a low-detail background, it's really not a problem. But it stands out very clearly against (for example) flower-patterned wallpaper. There's are three problems with this as a solution : (1) it is not "true" invisibility, (2) the lens needs to be looked at straight-on (or nearly straight-on); which can be resolved by adding more walls, and (3) the lens needs to be able to catch a lot of ambient light; as you add more walls for a more rounded effect, you start to have those additional lenses stealing light from one another (like shade from trees). But those are problems that might be possible to work-around, if problems (1) and (2) don't kill the idea. [Answer] **Metamaterial Electromagnetic Cloaking Device** [Metamaterial cloaking](https://en.wikipedia.org/wiki/Metamaterial_cloaking) is a mostly-theoretical concept which is to create a meta-material that can conduct light around it and thus be rendered 'truly invisible', or at least, undetectable by sight within certain frequencies of light. As the object is not hit by light in any way, this can be considered to be realistically close to 'true invisibility'. There are some downsides, namely, it can only be done on small scale and it can only be done within the microwave spectrum for now, that is, it's only invisible to microwaves. That, and there's the fact that if we *do* get a working prototype within the full visible spectrum range, then it can still be seen using methods outside the visible light spectrum, i.e. infrared, sonar, etc. [Answer] **No** True invisibility isn't something achievable, at least with current science and current theoretical science. Like you say, invisibility is often confused. In the movie "tomorrow never dies", they have an invisible car that records with tiny camera's the background and projects it on the other side. Problem is perspective, elegantly explained in Gost Protocol: <https://youtu.be/ydIPKkjBlMw> To be truly invisible, you need light to *bend* around you and then follow the same path, or you need transparency without refraction, neither of which exists. Furthermore, you have a lot of other problems. If you are invisible, you can't receive light input and are blind. At least on the frequenties you bend or are transparent for, but that is tetriary to your question. Still I wanted to mention it. [Answer] Yes, Canadian camouflage company HyperStealth use conventional but little-known optics to make objects effectively invisible. [![enter image description here](https://i.stack.imgur.com/7cox7.jpg)](https://i.stack.imgur.com/7cox7.jpg) They made a flair splash with this and the technology clearly has a lot of applications, many of which are military. There are some good videos of their tech in action online. [Answer] It depends if you whether stick to with a definition of 'invisibility' where light either passes through the object (transparency) or is bent around the object . In terms of your question to date there is no way for organic matter to be made transparent (or indeed most other forms of condensed/cold matter either). In terms of deflecting light *around* a target object there are, as other posters have noted several interesting technologies being developed. Since they seem to involve some form of shaped mea-material being placed between an object and the observer you could quite probably have your aliens travel is small vehicles that were 'invisible' even if they weren't. There is a third option you could look at which basically involves **intimating chameleons**. As I recall there was a defense project many years ago looking at this option for armored fighting vehicles (don't know if its still progressing). Basically the idea would be to develop a material layer containing lots of miniaturized photo-receptors and light emitting diodes or similar made from flexible electronics. Then you add a small compact power supply (it wouldn't need to be much, maybe it could ven be powered by the wearer's movements) plus a specialized chip to control it all The receptors note the ambient light hitting the surface from 360 degrees around the target - and transmit that info to emitters on the exact **opposite side** of the target. So if red light hits the target from say 30 degrees the color & intensity is transmitted to emitters at 210 degrees. If you had someone wearing a 'smart suit' with similar capability that person could say walk along street which had a brick wall on one side of the road and a park on the other. Someone walking down the 'park side' would look across the road at the alien and see only the brick wall pattern reproduced on that side of the suit facing them. Someone walking past the alien on the other side (a short distance from the wearer) would glance to the side and only see the 'greenery' of the park. The trick would be getting all the circuitry to work consistently, at high resolution in real time. Sudden movements, or changes in light might may distort the images being transmitted along enough for a blurry object to be seen. [Answer] Several theoretically possible ideas come to mind: * Counter projection. A powerful computer and camera system 3d scans the surroundings live and tracks where every person within range is currently looking. Additionally, the cloaked person is wearing an ultra-black bodysuit so that they'd appear as a dark blotch to peoples vision. Then, a complex laser projection system beams the appropriate background image directly into the retinas/camera sensors of any viewers. Since the bodysuit is completely (>99.999%) absorbing, the laser projection system can work even in low-light settings. Today, the bodysuit would be build able and the 3d scanning/tracking system too although you'd need to mainline a supercomputer. The projection system would be impossible though. Likely some sort of phased-array visible light system would be needed which does not yet exist. * Cloaking field. This is pretty sci-fi and requires the ability to manipulate gravity and generate anti-gravity (negative) fields. It's been conclusively proven that gravity has many wave-like properties, and I wouldn't be surprised if humanity eventually figured out how to build a gravitational emitter of some kind. If you do have gravity manipulating technology, you can lense light around a subject, similar to how a black hole lenses light, but in reverse. * Mass mind control. Not strictly "invisibility" but if you have scanners (radar, mri, whatever) which can achieve sub-neuron resolution at range, you can potentially couple this with some sort of remote, radio-based, electrostimulation setup. Then, you fire off neurons in people brains from a distance to make them selectively ignore you. This would however require monstrous computational capabilities along with a complete understanding of the human brain which we don't have yet. Alternatively, you could also do this with nanites which are dispersed in the air, breathed in, and then attach themselves to convenient neurons. * Metamaterial shenanigans. Just like you can make a micro/nanostructure which traps light in a fractal-shaped pattern producing a very dark black, you can probably make a metamaterial that reflects light along a specific path. I imagine that you'd be able to coat a cylinder with such a coating and set it up to appear transparent when viewed from the sides. Unfortunately, the surface would be very fragile and it would only work from horizontally distributed viewing angles. Also, you wouldn't be able to make this into a suit because the ridgid cylinder shale would be critical to it's functioning. This technology is probably the closest to reality, and could probably be made within the next 10-20 years if there were a practical reason for it. ]
[Question] [ Within the backstory of my world, I’m trying to justify the preeminence of a smaller nation as a result of its abilities with metalworking. We’re working under the assumption that this nation happens to, by luck, have significant reserves of Titanium, Aluminum, Vanadium, and Iron, which they may have not discovered the elemental properties of, but still understand to be different types of metals. I’m wondering how realistic it would be for such a civilization to stumble upon something like Grade 38 Titanium (an alloy of smaller amounts of Aluminum, Vanadium, and Iron, mixed with pure Titanium), and to consistently be able to produce this alloy. There are a few issues that I was wondering if there are workarounds for: namely if the existence of Titanium in ore makes it unlikely for a medieval civilization to be able to refine (same idea for the other metals) or differentiate from other metals like Iron or Silver. If it was stumbled upon by accident we can presume there’s a sort of alchemist guild dedicated to production of Grade 38 Titanium or something similar. If this is impossible, is there any other type of metal alloy, stronger than steel, that could theoretically be stumbled upon by a medieval society? Titanium itself is not particularly strong for armor due to its brittleness. [Answer] The difficulty of Titanium and Aluminum is that they oxidize very rapidly. Thus they can be pretty abundant as an element in throughout the earth, but are hard to separate from their oxides. The likelihood of finding the metals in elemental form in significantly amounts is probably vanishingly small, I think even meteorites as a source would be unlikely. However, I think titanium was discovered as an oxide impurity in iron. And with the high abundance there is no problem with there being a source of titanium or aluminum if the geology is right. On the alchemy side, there could be routes that you could consider making small amounts of titanium or aluminum, it would be nasty, smelly and dangerous. But if for some reason they had developed methods to obtain chlorine, then you use the chlorines to bind with the metal element and then reduce the reaction using sodium or magnesium to obtain the titanium metal. If some form of electrolysis can be done it would be easier since you could produce chlorine and sodium from salt, and also use current to drive the reduction reaction. <https://www.chemguide.co.uk/inorganic/extraction/titanium.html> Keeping oxygen out of the process, and also carbon out of the process would be difficult. If carbon is around very hard Titanium Carbide could be a product. In terms of time period and knowledge it is really late 1700s to early 1800s where the technology pieces started to come together. [Answer] You will face three heavy problems here: *First:* a society with medieval-like technology will not be able to refine titanium as the process is highly complex and needs some adcanced chemistry to understand. The same problem occurs with some other metals you mentioned. *Second:* There is a reason medieval metal technology developed in really small steps. Without deeper chemical knowledge and different metals available the smiths just could experiment a bit with heat, smithing techniques and different substances for cooling the freshly worked parts (the most chemical part of the process as here could some other elements find entrance into the alloy). *Third:* Special knowledge doesn't stay special for ever. You can try to hide some new techniques, recieps or else for a while, but sooner or later there is someone who will tell it others (for money, because of pride or whyever). So knowledge spreads. Your country had to invent something new to stay ahead (thats some problem most fantasy backgrounds have with realism, for example dwarves knew more about smithing than humans and so on). [Answer] ## On the bones of a predecessor society. * A predecessor society had a devolution (nuclear armageddon etc.) that literally bombed everyone back to the Stone Age, followed by a religious war where all the tech was hauled to designated junkyards, and then *that too* was forgotten... * Alien activity involving a base, mine, or crashed super-starship at that location. (suppose the *Galactica* missed their jump and went splat into the surface; 2000 years pass.) The residents of this location are able to dig up pre-refined special metals that are well-preserved for some geological reason. As noted, aluminum and titanium (and many metals) don't rust uncontrollably; the first few days of corrosion creates an oxide coating which in many conditions stops further corrosion. [Answer] to add to the comments, medieval industry would not find Titanium very useful. Like what the others have said, it corrodes easily, Plus, it doesn't hold an edge for long. even for use as a hilt, i doubt you'd want to have the part of your sword to which you publicly display showing signs of corrosion. A surefire way of damaging your prestige as a knight or the like. for the medieval period, people put a lot of effort into appearances. so Titanium would be quickly found to be useless. but if there was a way to get titanium, it's only use would be as a semiprecious metal, which were mostly of novelty status. It was that way with aluminum before better refining technique flooded the market. [Answer] Titanium was discovered in 1791, Unlike other metals Titanium doesn't exist in a dense ore like state, most are harvested from ore rich sands. Titanium also does not occur in a pure state in nature, but in chemically locked oxides. Unlike steel you cannot smelt it into purity. For a society to have titanium they must have a grasp of the chemistry needed to make titanium chloride and magnesium. ]
[Question] [ For centuries, on the day the moon would turn a blood red, a portal would open across various worlds. Chosen warriors from these worlds would enter the portal, usually at most five people per world, then enter a realm that was the center of various dimensions, and where a tournament unlike any other would take place. The purpose of the tournament is simple: to find the very best warrior across multiple realities. During the tournament, warriors from across the realms would do battle in one-on-one combat, and if they win, they would go on to face their next opponent the following day after getting their injuries healed by the healers the tournament employs. The match-ups are almost always random, with all of the warriors being divided into various brackets and the champions of these brackets going on to the finals, and the locations of the fights are never the same. For each match, the two warriors are teleported to different locations across dimensions; sometimes it could be a valley, with the warriors having to wander through it just to find their opponent, though in these cases both warriors have to make an active effort to find their opponent or else they are disqualified, sometimes it can take place in a decaying building that is about to collapse, or even in a dojo with the warriors being only a few feet apart. And at the end of each match, when the judges declare that a warrior can no longer battle, the winning warrior has the option of either killing their defeated opponent, or letting them live. Most people chose the former. With the tournament going on for centuries, rivalries have formed across dimensions, as a lot of races are selected again and again due to producing such excellent warriors. One such rivalry is with the Fujins, a race of humans that have developed the ability to harness the wind, and the Agnis, another race of humans from a different world where humans learned how to manipulate fire. The Fujins can create powerful blasts of wind strong enough to lift a man off his feet and send them flying. They can also use the wind to jump higher than trees, though they can’t fly, use the wind to help them land from any height without any fear of injury, and can channel it in a way that can let them condense it into a “blade” made of wind that is strong enough to cut through metal. They can also mold the wind into any shape they want, such as say, a ball of wind that they can ride on and let them travel at great speeds. Finally, if they have enough time and can concentrate hard enough, they can manipulate the wind in a way that would create “sharp” breezes that slowly wrap around an opponent without them noticing, and then, once the user literally feels the “breezes” are close enough, with a thought, they can slice a man to ribbons; sometimes killing their opponent, but always leaving very serious wounds on them. The weaknesses of the Fujin are that, while their “magic” takes up a brunt of the effort, it still takes effort to manipulate the wind for attacks, and for the more deadly attacks, like the “sharp breezes” or trying to suck the air out a person’s lungs, it takes intense concentration and also requires their opponent to stay in the same general spot for at least a minute. Also, the harder it is for them to breathe, the harder it is to use the wind. The Agnis can create powerful torrents of fire hot enough to melt steel, with enough time. They can mold their fire into various shapes, like a whip made of pure, blue flames, or a lasso of red falmes that can wrap around a person’s throat and burn them at the same time. They have a general “heat sense,” as in they can feel just how much heat an object emits, and even see the heat they emit if they “switch” their vision to a kind of thermal vision. If they have enough time, they can form special balls of fire that seek out the biggest heat source in an area. Finally, they can “suck” the heat out an area and condense it into massive fire constructs, like a massive ball of fire that they can launch from their palm and incinerate their surroundings. The Agnis' weaknesses are that the more complex the attack is, like “sucking” heat or construct creation, the more concentration and time it takes to form it. And while their “magic” lets them be heat resistant, it can only protect them for so long before they start to feel the heat, like minor burns that can get worse as the fight drags on. They will have “cool down” periods between attacks, anywhere from a few seconds to 30 seconds depending on the intensity of the attack, that way they don’t wear down their heat resistance so quickly, and it can recover as well. Warriors from both the Agnis and the Fujins have fought each other in this tournament for almost as long as the tournament has been around. The only rules of the tournament are that the weapons you can bring are those you must have trained extensively with, so no brining a weapon you think might come in handy against someone from a race whose weakness you know, and in the event one warrior tries to run and hide, whether it's to try and heal their injuries or come up with a different strategy, they must come back to fight the other warrior within twenty minutes, with a “timer” appearing in their heads provided by the “host” of the event, or else they automatically lose. Keeping in mind all of the previously stated information, I want to ask: what kind of tactics would these two races develop against the other? [Answer] ## Quantifying the Opponents Before suggesting tactics, let's try to come up with a model that lets us broadly explore the limits of Fujin and Agnis abilities. Fujin appear to be telekinetic. And by that, I mean, they seem capable of creating a certain amount of kinetic energy at will. Agnis appear to be pyrokinetic: able to create thermal energy. > > The Fujins can [...] use the wind to jump higher than trees, though they can’t fly. > > > This helps a lot with estimating their limits. Assuming, like human beings, the Fujin have a peak "deadlift" strength that they can exert in short bursts, and a lower "carry" strength that they can exert casually. The [average human jumping height is 16 inches](https://verticaljumppros.com/what-is-the-average-human-jump-height/). In this case, it's safe to assume that nearly all of the jump height is from Fujin powers. The potential energy gain going from the ground to a 10 meter (~30 foot) high tree, for a 100 kilogram person is $E = m g d$, which is roughly $100 \times 10 \times 10 = 10,000$ Joules or 10 kilojoules. If this can feet can only be kept up for a few seconds, we could also say Fujin power is limited to "deadlift" peaks of 10 kiloWatts. People capable of benching 100 kilograms typically can carry a 22 sustained kilogram load. Passing this along to the Fujin, they'd be capable of a casually using 220 Watts of power. This is less than the amount of kinetic energy power $F = m g \approx 100 \times 10 = 1,000$ Newtons per second (Watts) needed to fly. So, Fujin can not fly (but they can jump impressively). > > Fujin can [...] create powerful blasts of wind strong enough to lift a man off his feet and send them flying. > > > At 220 Newtons, a Fujin can provide a good punch. It is capable of knocking a person down. And a Fujin could easily wind-up the much stronger 10 kiloNewton haymaker. > > Fujin can [...] mold the wind [such that] that they can ride on and let them travel at great speeds. > > > Fujin can run on the ground, boosting their own running speeds with their power. > > Fujin can [...] channel it in a way that can let them condense it into a “blade” made of wind that is strong enough to cut through metal. > > > The energy required to cut metal is approximately equal to the product of yield strength, cut area, and the thickness being cut. $E = \sigma A s$. A soft-ish metal has a yield strength around 40 megaPascals (MPa). How big a slice can be made in 1/4 inch (8 cm) of metal? $220 / (0.08 \* 40,000,000) = A$. A 4mm radius light punch, or a 3cm radius heavy punch. > > Agnis can mold their fire into various shapes, like a whip made of pure, blue flames, or a lasso of red flames > > > Nitrogen ionizes between [14 and 16 electronVolts](https://www.quora.com/At-which-temperature-is-air-converted-into-plasma?share=1) per atom. 1 eV = $1.6 \times 10^{-19}$ Joules. 1 mole of gas is 22.4 liters. 1 liter is 0.001 $m^3$. Assuming a rope $1 \over 2$ mm thick and 10 meters long would be 539 Joules, which we'll says is Agnis' "casual" load. > > Agnis can [...] create powerful torrents of fire hot enough to melt steel, with enough time. > > > The amount of energy required to melt steel is [1,500 C](https://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html) (melting temperature), [0.49](https://www.engineeringtoolbox.com/specific-heat-metals-d_152.html) $kJ \over {kg C}$, times [237](https://www.eng-tips.com/viewthread.cfm?qid=37402) ${kJ} \over {kg}$. To slice a 1 kilogram chunk out of a block of steel, then, requires a "deadlift" capability of 174 megaJoules, which is way over the Fujin. Trying something a little smaller, a 1 gram cut - 174 kJ. > > Agnis can [...] “suck” the heat out an area. > > > Think it's fair to say Agnis can add or remove heat energy from things. ## Summary **Fujin:** 220 $W \over {m^2}$ "casual" strength; 10 $kW \over {m^2}$ "peak" strength (only sustainable for a few seconds). Can only add or remove kinetic energy from things. **Agnis:** 540 W "casual" strength; 174 kW "peak" strength. Can only add or remove thermal energy from things. Can also detect thermal energy at a distance. ## Analysis Agnis are stronger, and have very useful detection capabilities. Fujin are more maneuverable, and have finer control (being able to manipulate things without melting them). ## Tactics Blind fighting favors the Agni, who can see in the dark. If an opportunity arises to fight a Fujin in the dark, they should. Fujin caught in the dark should try to kick up dust that will block thermal vision as readily as normal light, evening back up the fight. Fujin have the fine control to create defensive structures. It's probably a good idea for them to spend the first few seconds before a fight with an Agnis to change the environment to their favor (precarious limbs, blocked passages, taking high-ground) If caught in the open, and the battlefield is humid enough, Agnis can lower the temperature to create instant fog covering their escape. Battles in ruined structures favor the Fujin, who can move quickly and safely over the uneven terrain. Agnis should try to set the structures on fire, if the material allows it. Stuck in such a situation, the Agnis best strategy is to get a few hits in early, then try to run down the clock. Agnis have a tremendous advantage over Fujin when the battlefield is plentiful in combustibles : chemicals, gas under pressure, or dry woodland. Agnis, protected from heat by the own powers can start forest or structural fires. Fujin, already a bit weaker than the typical Agnis and who also need to be able to draw full breaths to keep their strength, will be even further weakened in these conditions. Fujin caught this way may choose to use their powers to feed the fire, hoping to trip the Agnis up and create better conditions for scoring at the end of the game. Valley fighting. Agni should do their best to take a good vantage point, find their Fujin opposite, and set up a trap (such as lighting a fire in a deep box canyon). The goal is to pin the Fujin down into a one-on-one fight in clear terrain, which favors the stronger Agni. Fujin, on the other hand, should use their fast-moving ability to get a sense of the land before searching for the Agnis. Given Agnis ability to see heat, Fujin should assume their position is known, and therefore figure out ways of drawing the Agnis into terrain that'a favorable for the Fujin (lots of stones, wet wood, or dust). Dojo fighting. Fujin should favor steel nets. Because of Fujin wind powers, they can manipulate these area effect weapons at a distance, rolling up the net into a whip (possibly with hooks), or capturing and restraining an opponent for a killing blow. In a close fight, these weapons allow the Fujin to control most of the field. Agni should favor smoke bombs. Agni can use their power to set the smoke aflame, stripping the air out of the room and simultaneously stunning and weakening a Fujin opponent (who can't draw breath to use their power). The air blast will also most likely snag a net, making the Fujin weapon ineffective. [Answer] You know what really feeds a fire? Wind. Wind can help a fire spread, make it spread in a different direction (or even snuff it out if it's blowing a certain way), or even cause it to suddenly get bigger due to the influx of oxygen. There's a reason fires aren't safe in windy conditions, and a reason why many bush firefighters hate high winds. Now all of a sudden your Agnis have to worry whenever they fight a Fujin because they no longer have total control over their fire. A Fujin can cause an Agni's fire to suddenly swell, peter out, or worse yet blow back onto them. One would think that when performing fine-scale tasks like making a whip out of flames, concentration and control would be key. And that while they might have heat resistance, suddenly being buffeted by unexpected flames is going to be dangerous, especially if there's some degree of endurance in maintaining the heat barrier. Especially if the fire or the smoke it produces does something like burn their eyes, nose, or other vulnerable mucous membranes, which are probably going to be harder to protect than regular skin. Or just ends up suffocating them. Don't play with fire, kids. [Answer] **Cat and Mouse. Fire Slow. Wind Fast.** Fujin wants to fight in the dojo where the opponent has no time to prepare. Launch a bunch of wind blasts to starve all their fire attacks of oxygen and knock them through the wall/floor/ceiling. Agnis wants to fight in a valley, where their opponent is far away. They pick a good hiding spot, and get to work feeding heat into the nearest source of rock in order to create lava weapons. For example balls of lava for launching or a 40-foot lava whip to slice the other guy in half. > > **Note:** Why spend half and hour forging a lava whip when a fire whip is so much faster? The reason is the difference between sticking your hand in the $250^\circ$ oven and sticking your hand in the $100^\circ$ kettle. Yes the air in the oven is much hotter but theres a lot less of it. You can stick your hand in the oven or run it through the firey bit at the top of a bonfire easy peasy. But stick it into the kettle or into the coals at the bottom of the bonfire and your skin will start to melt. Same with the lava whip. The lava whip is made of heavy stone while the fire whip is made of light air. They are just as hot but the lava whip carries a lot more heat in total. > > > Fujin needs to find Agnis before they get the lava weapons up. They fly around and try and find the enemy. Once Agnis has their weapons they have the advantage. Their weapons do not need oxygen, so they cannot be extinguished with a wind blast. They are also much more dangerous in the short term. While you might get concussion from a well timed wind blast, your opponent will be sliced in half from your lava whip. Now Agnis tries uses their *heat vision* to locate the opponent and ambush them. If Fujin realizes the weapons are formed they go on the defensive. They have the mobility advantage, but if they fly to the opposite side of the battlefield Ignis will just start recharging their weapons. The difficulty is you cannot go from recharging your weapons to immediately wielding them. So recharging leaves you vulnerable. Usually battles go one of two ways: (a) Fujin locates Ignis before the weapons are up and beats them easily. (b) Ignis gets their weapons up. Fujin realises, retreats, and it becomes a mind game. How far away is he? Should I recharge my weapons? Or is that what he wants me to do? Type (b) can last hours or days, and are often settled by who gets hungry/thirsty/tired first. Some fighters specifically train their endurance for this. The most interesting and dangerous battles are (c) where Ignis has enough time to create say a 10 foot lave whip instead of a 40-foot one, but has not revealed themself yet. Is he in that cave over there still forging? In that case I should sneak in and murderkill him. Or is it a false trail and he's waiting for me to go in the cave and then ambush me? In that case I should either sneak around or spring the ambush. Depending on how that goes a 10-foot lava whip versus a Fujin of equal skill is usually considered a fair fight. This is what every true warrior wants to happen. Some battles follow a *warrior's code* where Fujin allows Ignis enough time to prepare a 10 foot whip and then they duke it out to the death. I know you said the warriors prefer to kill each other. But if I am a fighter trying to become The Very Best Like No One Ever Was, then I might prefer to not kill my opponent if I deem the battle was unfair. For example if I am Fujin and we fight in the dojo I would leave my opponent alive so we get the chance to fight again on a level playing field, and determine who is actually the stronger. [Answer] The fujins have far better ranged attacks, a blade cutting steel is way superior to a ball of fire. My arm, left arm suffered third degree burns. Getting such burns requires the skin to be in full contact with the flame for a lot of time..... A few seconds are not enough, a fire ball will cause mildly blisters while a blade made of wind which can cut metal...well it's a different story. If the Agnis want to make any use of their mighty fire balls, they need a lot of oil to throw in the face of their victims and then ignite it. Human skin takes a lot to blaze but once it does people become living candles, fat melts and erupts from the skin just to be ignited by the heat and oxygen, making the entire skin into charchoal and the fat under it boil. On limbs it is not lethal and can be heasily healed if infections are prevented ( I lost most of the skin off my arm, it fell of as pieces of dark solid charcoal but it grew back in 3 weeks) . However on the face...oh my that's a different story, if the heat doesn't kill the brain by making it boil, the lack of oxygen sure will. Also getting tired is not s serious weakness for the fujin, unless they are not human or incredibly different types of humans. People are realistically the fittest creatures on earth second to Tuna. If I was a fujin and wanted to keep myself alive while having a chance go kill my adversary I'd just bring with me a one use shield to block an initial oil assault or initial " boom IMA melt you asshole" and then throw my wind blade when the hit is certain. Mind that real duels melee or ranged are always short and don't take more than 20 seconds. Hollywood or anime duels are nonsense and ridiculous to the point of being amusing. A real duel rarely even hits the 20 second mark. If I was an agnis I'd just try to blind my enemy by taking as much distance as possible and setting all terrain on fire, it takes them one split second to split me in two, but if they don't see me because their vision is blocked by flames then I have a decent chance to survive. For a weapon I'd just pick a bottle of oil or a molotov, if not possible then a pilum or any small spear to throw would be fine. They won't see it Coming through the flames. If the fujin tries to fly up high with their jumps to see where I'm hiding, I have a chance to throw something at them...they can't dodge anything mid air, you said they can't fly. So if I see them mid air, they can't escape my spear. But preferably I'd be a fujin, better chances to survive and harder to mess up. You are really comparing flamethrowers to ak47's here....and we all knoe who's more likely to win. **edit** temperature doesn't matter, even if the agnis can melt any metal or any surface, their fire balls are still useless alone. Humans can touch molten metal without getting hurt if they are quick enough. Oh and fire **DOES NOT EVEN HURT** once the fire has burned the pain sensors, the burned victim feels no further pain. Agnis = trash tier , bad fighters...set them to fuel vapor ships instead. ![enter image description here](https://i.stack.imgur.com/E6uvl.jpg) Here's a picture of a fujin slapping some stupid agnis [Answer] **Dust** Dust has the potential of becoming explosive when exposed to fire. If the Fujins can create a dust cloud around the Agnis, if the Agnis try and use their abilities, the very air around them may explode. Dust would also block vision allowing the Fujins to hide. [Answer] This is a battle, and magic or not there are fundamental principles of battle that still apply. In particular, it's generally considered a lot easier to attack an enemy's supply or source of power than it is to attack said enemy head on. This is the foundation of siege warfare and been used in most major wars for as long as my history lessons taught me, anyway (possibly excepting early naval warfare, but never mind). Plus I'm sure Sun Tzu would have some choice words on the subject, but I haven't read up on him recently. Anyway, I'm going on the assumption that all this is happening in a particulate universe - the magic forces are being used to affect light particles (air and combustion fuel), rather than attacking the opponents directly with an actual magical force that only resembles wind or fire. The particle idea is backed up by your references to breathing, With the above two considerations taken into account, here's how the strategists on either side should be thinking; * **Fujin: manipulate the fire.** They can use their wind to counteract the (intended) effects of the fire - obvious choices being starve it of oxygen, blow it somewhere else, blow the smoke around to create smokescreens, scatter the fuel etc. More interesting choices (plot twist) would be to give the fires extra oxygen/air so they require more fuel to sustain, thus tiring the Agnis' magic and weakening them (risky strategy but make for an interesting story). "In the event the enemy tries to run and hide" then becomes more common and predictable, and the Fujin can chase them and use more 'conventional' attacks while they're weakened. * **Agnis: Disrupt the wind.** They can create or suck heat, in a localised fashion. Result, areas of high or low pressure air. Which causes wind ... this is a direct attack at disrupting the enemy's weapons as the Fujin are going to find this sort of attack much more difficult to dodge (they could get out the way of an oncoming fireball, but probably wouldn't even see a heat-suck away to their left and therefore wouldn't expect all their efforts to divert off-target). Finally, if the Fujin are using their wind constructs to ride on and travel around, a bit of turbulence would really make things interesting (try a coordinated Agnis attack with one setting a traditional attack or ambush and the other using heat-suck turbulence to drop them into it). And there you have it, both sides using or disrupting the other side's weapon!! Also, in this day and age of publicly ashaming or blaming people for things they didn't intend to do (scuse the quick rant there) I couldn't help noticing that there's an event host? What if either side manipulated the other sides weapon to unintentionally attack the event host (who we assume to be partly invincible) and embarrass them? Again an indirect attack, and probably an unpopular one if found out, but would make for an interesting story... [Answer] This sounds like two opponents who would have a fairly hard time defending against each others attacks. When a metal cutting blade of pure air is coming at you, a fireball isn't going to do you much good. But when a fireball is launched at your face, blowing more oxygen at it is the last thing you would do. Therefore I would argue it's not the one with the best attacks against the other who will prevail, but the one with the best defense. The problem is though, the fighting style should be fairly versatile, as this is a tournament style fight. If you train just to defeat one of your opponents, another might hand you your own behind. I would imagine the Fujin to be extremely mobile and agile, dodging any attacks coming their way. They would likely combine their wind attacks with Kung Fu like martial arts. As so it happens, when fireballs come flying, getting out of the way is your best option. Especially if your powers would just make it worse. The first attack that springs to mind when using wind powers is suffocation. Blow away the air around someone's head, or reduce the air pressure around them, and not only will their lack of oxygen slow them down significantly, keep it up long enough and they might not breathe again. Without osygen to burn, their fire attacks wouldn't do much good anyway. When developing air attacks, don't just think about the air that is there, but the air that isn't there is just as important. The same would go for the Agnis. If you say they can "suck" the heat out of something, I'm assuming you don't mean only up to a cozy room temperature. If they fight with heat, it could go hand in hand with cold. If they lower the temperature in their surrounding while using their powers to simultaneously keep themselves warm, their opponents would at a disadvantage, and frozen ground would make it difficult for his opponents to move. As for defense, a large wall off fire around themselves would definitely disrupt any air attacks. Because as you know heat rises, and rising air means a pressure difference going upwards, meaning any air attacks will be disturbed by that difference and deflected upward, and they could dodge attacks with minimal movement. I could spend hours coming up with different attacks and defenses you could give your fighters, but I'm thinking you have that down from your question. Bottom line is think about the possibilities that are beyond the obvious. Heat and cold, air and the lack of it. Combine physical techniques with magical ones. [Answer] Are Fujins able to increase wind's power? What about breathing process? Can he accelerate/increase amount of air absorbed by Agnis? If so, what about simply exceeding one's lung capability and bursting it? I think that would be clever way to kill oponent without direct combat. What about using strong wind attacks all the time keeping Agnis on distance? Since it's magic environment, you are kinda setting the rules. How much reach Agnis/Fujin have? If Agnis can't really use any attack effectively without closing up on enemy, it's tactic would involve every possible way to do so. Despite being direct, Agnis would need to learn go to be silent, stealthy and use some kind of bindings/traps to pin it's enemy and crush it with brute force without leaving other any mean of counter attack and reaction. If Agnis is found out and battle is out open, he stands no chance against Fujin other than maybe burning everything down(if it's closed space) with maximum power (so enemy's will shatter). Perfect weapon for Angis would be long chain (strengthened to withstand these cuts you were talking about). If Agnis is somehow resistant to explosion, he could use chemicals as well (gun powder or some advanced stuff). [Answer] If fugins can only work the wind as long as they breath and an agnis can take thermal energy from something the best scenario to an agnis is set everything on fire but himself. EVERYTHING. The smoke that results from this will eventually get to the fugin and will incapacitate the wind power. Eventually C02 will kill him. While you, smart agnis, drink a soft drink, sit down, in your safe place without fire. ]
[Question] [ Imagine a shapeshifter has to investigate a dense urban or forest environment. What forms would they prefer? Something that could move fast, climb obstacles, and get into restricted areas? I’m not worried about them being seen, so they don’t have to be a common animal. Additionally, birds are probably out because they function poorly in enclosed environments. I’m thinking like a squirrel, a cat, a weasel, or something similar. What are their options for the most mobile members of the animal kingdom with that sweet spot between speed, endurance, climbing, and etc? [Answer] **It is a bird. The most dangerous bird on earth.** [![cassowary](https://i.stack.imgur.com/9aTeN.jpg)](https://i.stack.imgur.com/9aTeN.jpg) <https://jungletours.com.au/is-a-cassowary-a-dinosaur/> Your shapeshifter is a cassowary. These flightless birds are residents of the deep forest and have no trouble with heavy brush. They are large and truly formidable. Cassowaries are called the most dangerous bird on earth because of their reputation as killers of humans. I cannot think of anything other than a crocodile that would take on a cassowary in their native territories. Or really anywhere else. Assuming your shapeshifter is a human, the world as perceived by a cassowary would make sense. They are as big as humans. They are visual creatures, with vision that is better than human vision for color and low light. Plus they look cool and have not been done to death. If your readers will not know what a cassowary is, you could get many of the same benefits with a wild turkey. [Answer] This is somewhat overthinking the problem. Rather than find some sort of exotic animal form, you want to blend into the environment you are examining. Consider the ninja. We have been conditioned by decades of cheesy martial arts movies to believe a ninja looks like this: [![enter image description here](https://i.stack.imgur.com/4RpRC.jpg)](https://i.stack.imgur.com/4RpRC.jpg) Of course, a person dressed as an Edo era stage hand carrying swords or other weaponry would stand out immediately, both in feudal Japan or in a modern environment. On the other hand, in a modern urban environment, no one would think twice about seeing this guy in their location: [![enter image description here](https://i.stack.imgur.com/Vo8V5.png)](https://i.stack.imgur.com/Vo8V5.png) In fact, you might even hold the door open for them. Ninja's in Feudal Japan were consummate actors able to mimic the social and other behaviours of people they were imitating, so they would not get tripped up by behaving like a farmer when they were acting as a merchant. Modern day operators do many of the same things, even on the internet - the idea of having attractive fake on line profiles to lure unsuspecting people or using known emails to "phish" are fairly well known by this time. [![enter image description here](https://i.stack.imgur.com/X4s8g.jpg)](https://i.stack.imgur.com/X4s8g.jpg) *Boris likes long walks on the beach and compromising information about you. Text at this number...* And don't forget that human beings are also quite adept at movement through dense forests and jungles. Tribesmen since time immemorial have grown up there, and explorers, adventurers and soldiers can learn to operate in these sorts of environments as well (you don't even need to be SAS or other Special Operations Forces, regular British Infantry were trained to operate in the jungles of Malaysia, the forests of Kenya or even the "urban jungles" of Belfast). [![enter image description here](https://i.stack.imgur.com/LcMYM.jpg)](https://i.stack.imgur.com/LcMYM.jpg) Perhaps the only advantage a shape shifter would have is the ability to change their body image. They can come into an area as an overweight delivery man, and after exfiltrating, change their appearance so they no longer have the same hight, weight, facial features or movement (becoming taller or shorter as needed). [Answer] **Goshawk** [![enter image description here](https://i.stack.imgur.com/mQeya.png)](https://i.stack.imgur.com/mQeya.png) [Goshawks](https://www.youtube.com/watch?v=2CFckjfP-1E) are pretty darn good at flying through small gaps. They are designed to fly around in dense forests. Smaller birds like [sparrowhawks](https://www.youtube.com/watch?v=Ra6I6svXQPg) are presumably better. The larger bird has more endurance though. **Bonus Points:** Birds of prey are known for good eyesight which is always a plus when scouting. [Answer] Flea or similar. Almost by definition what you're interested in is where people are going, and by hitching a ride you can get into the most interesting restricted areas without attracting attention. Fleas have the advantage of being able to get easily on or off a host.[![enter image description here](https://i.stack.imgur.com/AdWTS.jpg)](https://i.stack.imgur.com/AdWTS.jpg) and can also infiltrate the narrowest cracks and explore in detail. [Answer] **A Secretary bird or a Harpy eagle.** The secretary bird sounds like an ideal form. Even though they are birds, they spend most of their time walking on land, despite being good fliers (so they can climb no problem) are 4 feet (1,2 meters) tall (not too tall meaning they can likely go into spaces a toddler can) and have a kick worth around 5 times their weight. They're also known as "the devil's horse" . See [the following](https://justbirding.com/secretary-bird-facts/): "Secretary birds can run so fast that they've earned the nickname “devil's horse.” There is no concrete number on max speed, but they do a lot of walking and they can travel up to 18 miles (30 kilometers) per day!" So we have a bird with good endurance, supposedly good speed and with little problems regarding climbing (they nest on trees and fly well, so shouldn't be much of a problem). [![enter image description here](https://i.stack.imgur.com/fzs0v.jpg)](https://i.stack.imgur.com/fzs0v.jpg) But maybe you might also be interested in a form that has even greater eyesight and hearing, meaning it can track intruders better, while still being able to navigate in closed spaces. If that's what you want, look no further than the harpy eagle. [![enter image description here](https://i.stack.imgur.com/Xex8F.jpg)](https://i.stack.imgur.com/Xex8F.jpg) If the picture doesn't tell enough, this bird is not only big, it's strong. Harpy eagles are considered the strongest eagles by many, having talons the size of a grizzly bear's claws, which it uses to hunt and dismember the monkeys it feeds on. In addition, it's native to rainforest biome, with its relatively short wings (1,7 to 2,2 meters from tip to tip) having specialized to fly fast through the dense vegetation. It can reach speeds of up to 50 miles (80 kilometers) per hour. "Its short, broad wings help the harpy fly almost straight up, too, so it can attack prey from below as well as above. And the harpy eagle can turn its head upside down to get a better look at its potential meal." <https://animals.sandiegozoo.org/animals/harpy-eagle> This eagle also posses great eyesight, with better color vision than ours, along with a face disk that grants it good hearing. It's sheer size and strength also make it able to knock down humans with a well placed attack to the head. "It has excellent vision and can see something less than 2 centimeters (1 inch) in size from almost 200 meters (220 yards) away." <http://justfunfacts.com/interesting-facts-about-harpy-eagles/> So we have a powerful raptor with strong claws, wings adapted for flying in relatively confined spaces, good speed and supposedly good endurance, along with the ability to subdue a potential invader without needing to change form. [Answer] I would say some kind of monkey, as they can get around trees very well and can climb basically anything they can grab. In a forest, they could just swing through the canopy, while in a dense urban setting, they could climb along rooftops or ledges on walls. Also, if your shapeshifters don't have to take the form of a real animal, there's no need to, as they could just make their own form that suits them or the environment, but if they have to pick a real, still-living animal, a monkey would be the best choice. ]
[Question] [ My medieval city, they’re having food problems. People just die on the streets clutching their bellies, children with skin sticking to their bones are a common sight, and there are reports of cannibalism in the darker areas of town. The misuse of the land and the *El Niño* that comes every four years has rendered the crops useless. Any crops we had in the granaries were stolen last year by bandits. Luckily, the town has come to be under new management. The top position in the town was just bought by some nice old man. However, what the people don’t know, is that this old man is actually a front for a large group. This group consists of people with modern knowledge, each person within this group specializes in a specific field. What this means, is that there’s a person on this group for every single field of science, technology, and politics. The guy who specializes in farming took one look at the fields and went “*tsk tsk*”. He immediately had the leader of the town order the farmers to adapt crop rotation. He also started work on better farming tools, fertilizer and better irrigation practices. Unfortunately, it still wasn’t enough. People were still starving even with the amount of food being even better than the last best harvest they’ve ever had. Fortunately though, magic exists in this world. Enlisting the help of an elf who specializes in plant magic, they started work on a program to increase crop yields to modern day standards. I just need a magic system that allows for medieval crops to be quickly developed into their modern counterparts. It mustn’t be too quick however, as that would probably make it boring. [Answer] # You only have crazy mutation magic. This is not unlike what was done back in the Seventies to Italian grains. We irradiated seeds with neutron radiation and bathed them in ethylmethylsulfonate, then sat back and watched them grow. It took some years, but then a mutant strain took which had several desirable qualities. It was called "Creso" (after the Lydian king [Croesus](https://en.wikipedia.org/wiki/Croesus)). You can do the same using magic. Mages will concentrate a mild killing spell on a batch of seeds, not enough to really kill them all. To speed things up, other mages can try and make the seeds sprout faster. Depending on luck (are there spells for that?) and green-thumb magic, you can go through six to ten generations within one year, then you have to let it go to seed and then you're in business. Also, lots of interesting side effects, both wanted and unwanted, can come out of this approach. In the case of durum grain, for example, some suspect that the higher gluten content of the mutated grain, and possibly a slightly different gluten composition, *might* be at least in part responsible for an observed increased frequency of coeliac disease cases. [Answer] **Mutation magic combined with magical understanding of plants** LSemi gives a very good description of what you need to induce a lot of mutations in your plants. But mutating plants is only half the problem; you also need to choose plants which will grow well and produce large crops in this city's conditions. The plant magician might be able to study a seedling and learn what it will look like when it grows up, and how different conditions would affect it. The modern agriculturalist might know what properties to look for in a healthy plant. **Limited-scale growth magic for rapid testing** The other option is just to dramatically speed up the growth speed of a small number of plants, so that the team can see how the plants look when they are fully grown. The magic would have to be limited in some way, to prevent the growth magic being used for the whole society - maybe it needs constant attention from highly skilled mages (so the elf has to give up their other pursuits), or maybe it is really bad for the soil where it's done so it's frowned upon by other plant mages. [Answer] My new novel War of the God Queen has a similar theme, with timeslipped women coming to the aid of a bronze-age society (which has a bigger problem with invading monsters too). Good farming practices and innovation in things like yoke design, plough design, irrigation and fertiliser use, use of biological methods to reduce pests etc will do it. If someone can fly over to the New World and bring back potatoes they would have a quicker solution, or use time travel to bring back more advanced varieties that would do it. But if you have magic a 'create superior variety' spell should do it. [Answer] **Modern crops be dull. You can do better!** Boring is modern crops! Yes they feed the world but I think only a very select population revels in the coolness of crops. Make your magic crops AWESOME and a little creepy! They can be as good as modern crops at feeding, but magically weird. Also then if you get one of the crop aficionados reading he will not be mad that you know little about crops. If you yourself is one, keep some elements of modern crops in your fiction - a tip of the hat to your fellow aficionado but you will not lose your audience of Warcraft fans. [Answer] One of my world contains three planes, physic, magic, and aether. Magic is actually what bounds aether to physics. Aether is a place that is composed mostly of thoughts and logic. Physic cannot interact directly with aether. Humans, animals, plants, stones, molecules, and atoms are physical, but they react to magic waves, and chemical/physical reactions create and modify magical waves.Plus, some magical waves will directly react with certain types of matter. (You can even make matter "disappear" by fully turning it into magical waves, and create matter "from nothing" using magical energy). Some creatures and objects can live directly in the magical plane, mostly "eating" magical energy, but could use the physic and aether planes as means to create magical energy. Aether is the realm of spirits, gods use special means to instantiate themselves into it, and human / animal thoughts and the law of physics/biology tend to create living thought forms in it. Great human magicians are able to use magic to interact with the life forms in it, but also directly with the aether laws, using it they are able to create programs, send magical input into it, receive magical output. Some aether life forms are capable of storing information of events that occurred in the past, some might be able to predict roughly the future. In such a world, one magician could theoretically use magic to simulate millions of crops breeding in the aether plane (maybe with the help of some kind of spirit that got created by the crops and thoughts of farmers combined) , select the ones that are okay, check which virtual crops made that, and compare them to the physical crops that are in front of him to accelerate the process. ]
[Question] [ I need a planetary system for my novel where an Earth-like warm habitable planet has an orbital period of about 650 to 730 days. I know that is similar to Mars and that Mars would be too cold. What type of system would work to achieve these effects? [Answer] Mars is too cold simply because its atmosphere is too thin to effectively trap enough heat. Otherwise it would still be within the habitable zone for the Sun, though close to its borders [in some estimates](https://en.wikipedia.org/wiki/Circumstellar_habitable_zone#Solar_System_estimates). Give it a stronger magnetic field to shield it from solar wind, and its atmosphere can last longer. [Answer] All you need is a slightly larger, heavier star that emits roughly (very roughly) four times the radiation the Sun does. Very roughly because, in order to make a star hotter and brighter, you have to make it heavier, and that moves the orbit for a given period further from the star -- but the change due to orbital adjustment to keep the period around 700 (24 hour-ish) days is pretty small compared to the inverse square law effects on insolation. Of course, the other side effect here is that a larger, hotter star will emit somewhat bluer light -- the surface temperature will be higher, there will be more ultraviolet, so either your planet needs a thicker ozone layer or everyone will need sunscreen, all the time. Beyond that, larger, hotter stars don't last as long (they burn through their hydrogen fusion fuel faster, even in relation to the larger starting mass, than smaller stars). I don't know offhand what an F0 star will do in this regard compared to the G3 we orbit, or even what spectral type you'd wind up with to get about four times the Sun's luminosity -- but the lifetime will surely be shorter than the ten billion years (nearly half elapsed) expected for our Sun, which might affect whether the planet has had time to evolve advanced life. [Answer] If the star in the system is just like the Sun, a planet orbiting at the distance of Mars, with a semi major axis of 227,939,200 kilometers, would have an orbital period of 686.971 Earth days, which is within the specified 650 to 730 days and equal to 1.8809 Earth years. The distance of Mars from the Sun is 1.523679 Astronomical Units or AU, and thus Mars receives an amount of radiation from the Sun equal to one divided by 1.523679 squared, or one divided by 2.3215976, or 0.4307378 of what Earth gets. Thus Mars would be expected to be colder than Earth. That is made worse by the very thin atmosphere of Mars which retains heat less well than Earth's atmosphere. Humans can not survive in the Martian atmosphere anyway, so the planet will have to have an atmosphere much denser than that of Mars in order for humans or similar beings to survive, and such a much denser atmosphere will retain heat much better than that of Mars, helping to keep the planet warmer than Mars. What is the minimum size of a planet necessary to produce and maintain a dense enough atmosphere to be habitable for humans and similar intelligent beings? A planet could lose it atmosphere but replace it fast enough to keep it dense, like Titan, the giant moon of Saturn does. But it should be assumed that a planet would have to have sufficient mass to produce an Earth like atmosphere and retain it for billions of years to be habitable for humans and aliens similar to them. I think that it has been calculated that smaller planets with thinner atmospheres can be habitable for life closer to a star than larger planets with denser atmospheres, while larger planets with denser atmospheres can be habitable for life at greater distances from stars than smaller planets with thinner atmospheres. Thus a planet near the size of Mars would be more likely to be habitable in an orbit near that of Venus, and a planet larger than Earth would be more likely to be habitable in an orbit near that of Mars. One good source is *Habitable Planets for Man*, Stephen Dole, 1964. <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf>[1](https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf) Chapter 4, Astronomical Parameters, starts off with Planetary Properties on page 53. On page 54 it is calculated that the lowest escape velocity for a planet to retain atomic oxygen is 6.25 kilometers per second, corresponding to a planet with a mass of 0.194 Earth masses, a radius 0.63 of Earth, and a surface gravity of 0.49 g. In the next few pages it is estimated that the minimum mass of a planet that would produce an atmosphere with enough oxygen would be somewhere between 0.25 and 0.57 Earth masses, and approximately 0.4 Earth masses, with a radius 0.78 of Earth and 0.68 Earth surface gravity, is selected as a rough minimum mass for a planet with enough oxygen in the atmosphere. Since it was written in 1964 it has been discovered that the solar wind can knock particles out of the upper atmosphere of a planet. A strong planetary magnetosphere can reduce the solar wind and slow atmospheric loss and so it is also useful for a habitable planet. Fortunately more massive planets more likely to produce and maintain a thick atmosphere are more likely to have strong magnetospheres. On page 67 the discussion of the properties of the primary (the star) begins. on page 68 it is said that "The only stars that conform with the requirement of stability for at least 3 billion years are main-sequence stars having a mass less than about 1.4 solar masses - spectral type F2 and smaller - ..." The dimmer a star is, the closer a planet would have to orbit in order to receive enough heat from the star to have temperatures warm enough for liquid water. But the closer a planet is to its star, the stronger the tidal forces of the star upon the planet will be. If the tidal forces are strong enough they will slow the rotation of the planet until the planet is tidally locked, with one side always facing the star and the other side always in darkness. That is considered likely to make the planet uninhabitable. On pages 71 to 72 it is said: "A "full" ecosphere can exist around primaries with a stellar mass greater than about 0.88 solar mass, but the ecosphere is narrowed by the tidal braking effect for primaries of lesser mass until it disappears when the stellar mass reaches about 0.76. The range in mass of stars which can have habitable planets is thous 0.72 to 1.43, corresponding to main-sequence stars of spectral types F2 through K1..." So if your planet orbits around a spectral class F2 star, the star will be much more luminous than the sun and the star's "ecosphere" or habitable zone will be farther from the Star. Thus a habitable planet orbiting an F2 star would orbit much farther out and the total circumference of its orbit will be much greater than that of Earth. So the year of the planet will be longer that the year of Earth. However, because an F2 star will be more massive than the Sun, the orbital speed at the distance a habitable planet will orbit the F2 star will be greater than at the same distance from the Sun, and that will tend to reduce the length of the planet's year. The distance at which a planet would receive the same amount of radiation from its star as Earth receives from the Sun can be calculated by multiplying Earth's distance from the Sun, one Astronomical Unit or AU, by the square root of the star's luminosity compared to the sun. If the star is 2.00 times as luminous as the Sun, a planet 1.4142135 AU from that star will receive the same heat from the star as Earth receives at 1.0000 AU, if the star is 3.00 times as luminous as the Sun the planet should be 1.7320508 AU from the star, if the star is 4.00 times as luminous as the Sun, the planet should be 2.00 AU from the star, and so on. > > Some studies show that there is a possibility that life could also develop on planets that orbit a F-type star.[10] It is estimated that the habitable zone of a relatively hot F0 star would extend from about 2.0 AU to 3.7 AU and between 1.1 and 2.2 AU for a relatively cool F8 star.[10] However, relative to a G-type star the main problems for a hypothetical lifeform in this particular scenario would be the more intense light and the shorter stellar lifespan of the home star.[10] > > > <https://en.wikipedia.org/wiki/F-type_main-sequence_star>[2](https://en.wikipedia.org/wiki/F-type_main-sequence_star) I note that if two F2 stars orbited closely together, their combined habitable zone for planets orbiting both of them, in circumbinary or P-Type orbits, would be 1.4142135 times as wide as the habitable zone of just one F2 type star. Thus the circumstellar habitable zone of a close binary FO star would extend to about 2.8 to 5.18 AU, and that of a close binary F8 star would extend to about 1.55 to 3.11 AU. Here are links to discussions of the potential habitability of planets orbiting F class stars: <https://www.centauri-dreams.org/2014/03/27/habitability-the-case-for-f-class-stars/>[3](https://www.centauri-dreams.org/2014/03/27/habitability-the-case-for-f-class-stars/) <https://www.space.com/25716-alien-life-hotter-stars.html>[4](https://www.space.com/25716-alien-life-hotter-stars.html) And of course the fictional planet could be farther from its star than the distance at which it would receive exactly the same amount of heat from the star as Earth gets from the Sun. How much farther could it get? The obvious way to find out is to find the outer edge or limit of the Sun's circumstellar habitable zone and multiply it by the luminosity of the star relative to the Sun. Take a look at this list of various estimates of the inner edge, the outer edge, or both, of the Sun's circumstellar habitability zone: <https://en.wikipedia.org/wiki/Circumstellar_habitable_zone#Solar_System_estimates>[5](https://en.wikipedia.org/wiki/Circumstellar_habitable_zone#Solar_System_estimates) Note that they vary widely in their inner and outer edges and thus in how wide they are. The two most widely used estimates, by Hart et al in 1979, and by Kasting et al in 1993, are very different. So it would be a good idea for science fiction writers to study the papers where those estimates are given and find which estimates seem most reasonable to them. I note that Dole's estimation in 1964 was specifically for planets habitable for humans and Dole was not interested in planets with life if humans could not live on them. I think that many of the other estimates are for planets with life, regardless of whether humans could survive on them. It would be an error for a science fiction writer to use an estimated habitable zone outer limit for a planet where some life, but not humans, could survive, and put a planet habitable for humans or for lifeforms with requirement similar to humans at that distance from the star. I hope this helps in a search for a plausible habitable planet with a year two Earth years long. [Answer] A Earth-like planet in a [Mars orbit will get 43% of radiation](https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html) compared with Earth. So, just make the star 2,32 brighter than the Sun. [Bubup](https://en.wikipedia.org/wiki/Bubup), [Belenos](https://en.wikipedia.org/wiki/HD_8574) and [Samaya](https://en.wikipedia.org/wiki/HD_205739) shows fit enough. They are similar to the Sun, Bubup and Belenos are a bit older tho. All them still be in the main sequence, so allow conditions to one planet like you want come to existence. ]
[Question] [ **This question already has answers here**: [Would cold-blooded dragon be suitable for flying?](/questions/167101/would-cold-blooded-dragon-be-suitable-for-flying) (2 answers) Closed 3 years ago. In the story I'm writing, there is an island of mostly lizards (like the Australian dragon lizard) which have diversified into a variety of ecological niches, including flight acting as pseudo-wyverns (mostly because my actual [wyverns](https://worldbuilding.stackexchange.com/questions/167897/could-my-wyverns-exist) barely resemble traditional wyverns). Now these bootleg wyverns (as I'll call them) are rather small; the size of a cat at most. I was wondering, is warm bloodedness a necessity for the energy demands of flight? NOTE: magic does not exist in my story. [Answer] Strictly speaking, no. But there are huge energy requirements for powered flight, so a cold-blooded animal (hence with slower metabolism) would necessarily either not spend much time in flight, or it would have huge wings and its flight would consist almost entirely of gliding. However, I would suggest that evolving endothermy isn't as big as a hurdle as you might envision - at a fundamental level it's just a faster rate of metabolism.\* Just make your wyverns warm-blooded and there's no issue. The reason why most animals aren't warm blooded is because it's a high-cost way to live, it isn't actually a complicated thing to do in principle. It means you have to eat more food and more frequently. Basically, it allows you to do energy intensive tasks more easily, but at the cost of forcing you to live an active lifestyle. A warm blooded lizard isn't a stretch at all. Endothermy has appeared multiple times in vertebrates, including in mammals, dinosaurs (maybe not all dinosaurs but they got there eventually since birds are endothermic), pterosaurs, ichthyosaurs, and even [some](https://en.wikipedia.org/wiki/Opah) [species](https://en.wikipedia.org/wiki/Tuna#Physiology) [of](https://en.wikipedia.org/wiki/Billfish) [fish](https://en.wikipedia.org/wiki/Great_white_shark#Adaptations). In fact, some species of lizards are partially endothermic, discussed in an [interesting short paper by Glenn Tattersall.](https://www.sciencedirect.com/science/article/abs/pii/S0944200616300137) If your wyverns have an active, flying lifestyle, it's scientifically much more believable that they would be warm-blooded reptiles than that they would be ectotherms like most lizards. You needn't make them as warm as mammals or birds. Endothermy is a spectrum, your wyverns could be somewhere between lizards and mammals and still be believable. \*It's a little more complicated than this; you also need some extra insulation to maintain the heat generated by the increased metabolism. Hence why mammals have hair, dinosaurs had feathers, and pterosaurs had pycnofibres. But you did mention in your other question these wyverns have feathers. [Answer] **No** Well, no, warm-bloodness isn't necessary to fly given a few restrictions. To fly, you need muscles, and cold-blooded animals can have muscle power to spare. Just take, for instance, the crocodile, which has incredibly powerful bite strength. Cold-blooded animals can have the strength to fly. The problem is just that being cold-blooded gives you two restrictions. The first is that cold-blooded animals frequently run into problems regulating body temperatures and thus aren't creatures capable of endurance activities. The second is that cold-blooded animals can't range across the same climates that warm-blooded animals can, they need a very consistent climate. Given these limitations, it's possible to have a cold-blooded reptile capable of flight, but it's restricted to very specific climates and can't fly for very long periods of times or distances. Not to mention that it'll be very lazy, constantly seeking to be in the sun to soak up those sweet heat rays. [Answer] Given that insects fly, and given that they aren't warm blooded. I'd say that warm bloodedness isn't a requirement for flight. [Answer] # No A picture is worth a thousand words, and this bugger was photographed midflight: [![A flying lizard in midflight](https://i.stack.imgur.com/RInsL.jpg)](https://i.stack.imgur.com/RInsL.jpg) This is just one species of the real world [*draco* genus](https://en.wikipedia.org/wiki/Draco_(genus)). [Answer] I'm not sure but seems [Pterodactylus](https://en.wikipedia.org/wiki/Pterodactylus) wasn't warm blood animals. In this wikipedia article show this image too about the size: [![enter image description here](https://i.stack.imgur.com/XxjLo.png)](https://i.stack.imgur.com/XxjLo.png) However, in wiki says: "*Soemmerring* (1755 - 1830) *did not change his opinion that these forms were bats and this "bat model" for interpreting pterosaurs would remain influential long after a consensus had been reached around 1860 that they were reptiles. The standard assumptions were that pterosaurs were quadrupedal, clumsy on the ground, furred, warmblooded and had a wing membrane reaching the ankle. Some of these elements have been confirmed, some refuted by modern research, while others remain disputed..*" ]
[Question] [ There is a magic that allows a certain percentage of the population to create a twin of themselves instantly, a clone that is aware of itself and is equal in all aspects to the original, which makes them indistinguishable. In the battlefield, where swords collide with shields, armor and each other, having a numerical advantage is always desirable. Even so, some of these blessed people prefer to use their ability to confuse adversaries; either tackling fights in which they appear to be at a disadvantage or on equal terms so that their adversaries discover that they face a person more than they expected, or to maneuver quickly during a confrontation. **How power works:** * At will you create a clone that is identical to you in all aspects. The clone appears instantly anywhere if it can fit as long as it is in direct contact with your body (skin, bone, nails, hair, etc) * While you are having direct melee contact you can choose which of the two bodies is reabsorbed and which one stays. The "you" that remains has the memories of the two "you." (Example, you are closed behind a gate of bars. You take out one hand, create the clone outside, and decide to reabsorb the one inside the cage). Done quickly this would look like you moved a step in the blick of and eye. This ability does not copy clothing or anything you are holding in your hand. In the field of battle / skirmish in the forest / fight in the bar, putting aside your weapon or throwing it into the air so that the clone catches it when it is formed is an option, not so much with the clothes / armor that you wear. (Well, you've tricked your opponent and pierced him with the spear but now you're naked against the other opponents.) Though my question is more about preventing one from being completly naked during the confromtation I also seek some protection. The best I could manage is a cloak with a dissimulated belt at waist high and 2 hand holes normally masked by a shorter cloak layered on top of the first one. **Edit:** *Some more about how the powers work.* Thouse with the power to clone themselfs are called gifters and they used to be healers. Unconventional healrs because they needed to reopen the wound to be able to heal it. The way they did it is by recreating the missing bone/muscle/blood etc using their own as a reference. The wound apeared to be filled with the material out of thin air and the more similar was the wounded and the gifter(body type, wheight, gender, race, etc) the less potential (name for the mana/energy) was needed. The way gifters use potential is by extracting it through their ember (a soul like catalist that every living thing poses. Unfortuantely most people never learn to use it and gets atrofiated, that's why only a percentage of the populations are gifters). They learned that they could split their ember in two with training and use it like a base to gift it a body. That is how the power evolved into cloning. [Answer] SinisterFellow suggested a magical cloak, well, a non-magical cloak might be made feasible (with some limitations, of course!). You might be able to make a kind of padded cloak that works as soft armor. Play, er, I mean, experimenting with a blanket suggests 7-10 seconds to grab from the floor and swing on, maybe 15 if same edge and same side out matters, I don't know how that would play out with heavier, stiffer material mid battle, could be less or more depending on material, practice, and how exactly it fell, but I can't think of anything that would be quicker to put on, exactly. I know there was linen armor, made of many layers stitched together (ie, [padded jacks or gambesons](https://en.wikipedia.org/wiki/Gambeson), often with some thirty layers of linen, cotton, or wool stitched together, sometimes reinforced with leather), that were sometimes the primary, or only, armor some folk had. It wasn't a hard armor, it tended to soften or lessen blows rather than prevent them, but it was reasonably effective as armor even against arrows or swords - one would end up with bruises, small cuts or slices rather than stab wounds, that kind of thing. A cloak of such a construction might be, well, not great armor but something. It would fairly stiff and heavy, more like a carpet in weight and stiffness than a blanket, but it would likely be quicker to grab and swing on than most other forms of medieval (or even modern) armor. On the other hand, the looser and easier to put on it is, the more of a hindrance it can be mid-battle if it slips or snags on something, or hangs incorrectly, and the tighter and more fitting it is the harder it will be to put on quickly and correctly. If you would like to go that route, I'd suggest the style like a blanket, folded in half, with the folds over the shoulders and a cut up one side so two panels rest over the shoulders and down the front. (like [this one](https://rads.stackoverflow.com/amzn/click/com/B01K4IO1CK), I am not describing this well, example chosen randomly) The cloak needs to be short over the arms, not more than halfway down or so because one needs their arms in battle, it can be a little longer front and back. It needs to be open in the front, so that it can be swung on quickly. A shorter cloak will be easier to put on, but offer less protection for the legs. A lighter cloak will be easier to put on and wear, but offer less protection overall. It would not be wise to depend on a design that needs a button or clasp to stay on, since there may not be time for that mid-battle. The easier it is to swing on, the easier it may be for it to slide off kilter and tangle the wearer up. In any case, this kind of cloak will always leave vulnerable the areas under the arms (especially when raised), and the center line in front where it falls closed. It might be possible to leave a little extra material in front, so that it overlaps a bit, but the more complex it is the easier for something to get in the way. It will primarily be useful against blows to the back, or shoulders, or blows across the front or back of the body, much less so for stab wounds or blows along the sides of the body, or arms and legs. Yeah, this is not a magical answer. Such a cloak will be limited, and imperfect, and have many flaws and weaknesses. That said, I think it could work, that it might be a decent compromise for someone with the specific limitations and requirements from your question, and also that said limitations and flaws can also be plot points, if needed. On the other hand, if you do want a magical answer, well... Going back to SinisterFellow's suggestion of a magic cloak, if you can use magic of course, you might be able to offset some of the disadvantages or gain some extra advantages, but that will of course depend on the magic available to your character. I hear handwavium is a very useful armor! [![A picture of a cape, cloak, shawl poncho, whatever they're called](https://i.stack.imgur.com/smFBg.jpg)](https://i.stack.imgur.com/smFBg.jpg) Image chosen randomly from an image search. I think it's from [here](https://www.etsy.com/listing/243943795/chartreuse-wool-cape-poncho-mens-wool). [Answer] On the field of battle weapons are essential, but clothing is entirely optional... [![Phalanx fighting on a black-figure amphora, 6th century BCE](https://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Amphora_phalanx_Staatliche_Antikensammlungen_1429.jpg/640px-Amphora_phalanx_Staatliche_Antikensammlungen_1429.jpg)](https://commons.wikimedia.org/wiki/File:Amphora_phalanx_Staatliche_Antikensammlungen_1429.jpg) *Greek [hoplites](https://en.wikipedia.org/wiki/Hoplite) fighting. Side A of an Attic black-figure Tyrrhenic amphora, ca. 560 BCE. Photograph by [Bibi Saint-Pol](https://commons.wikimedia.org/wiki/User:Bibi_Saint-Pol) , available on Wikimedia; public domain. The amphora itself is in the [Staatliche Antikensammlungen](https://en.wikipedia.org/wiki/Staatliche_Antikensammlungen) in Munich.* [Answer] If the clothes cannot be duplicated, this is an embarrassment your protagonist might just have to endure. It takes me about 5-10 seconds to put my underpants on, and that's as basic an article of clothing you can ask for. Heavy medieval armor can take between 10 minutes and an hour to put on, since it's made of many separate pieces. Historically, knights had squires to assist them in putting it all on. Throwing a sword and shield to your new self is simple enough, but if he/she can't duplicate attire, your hero is gonna fight in the nude, no way around it. If the limits of magic are no obstacle, something like Dr. Strange's magical cloak with Velcro to help it wrap and secure itself might do the trick. But whatever material that it's made of will not be rigid, so I doubt it makes particularly good armor. [Answer] **Tats. And lots of them.** [![tats](https://i.stack.imgur.com/hp1qv.jpg)](https://i.stack.imgur.com/hp1qv.jpg) [source](https://www.quora.com/What-would-you-say-if-your-wife-wanted-a-full-body-suit-tattoo) Your protagonist has a lavish full body tattoo. Yes she is naked, but you have to be close up to tell and she is liable to kick you if you get close up, all googly-eyed. [Answer] The weight of medium or heavy armor is not much of an option. A basic suit of chainmail would be the fastest to put on, but it weighs ~35-45lb. This is not that bad when you are wearing it because the weight distributes so well, but to carry a backup suit of armor would be REALLY encumbering. You could easily be carrying 90lb of armor before you even begin thinking about weapons or provisions; so, this is a non-starter in my opinion. So let's look at lighter armors: Any leather armor that can reliably stop a weapon is going to be too rigid to effectively carry on your person or layer. Which basically leaves you with textile armors. Gambeson is armor made of many layers of linen cloth sewn together. While it is not as effective as mail, it could stop an amazing assortment of weapons without being either heavy or ridgid. Now interestingly enough, an arming coat (the linen armor typically worn under mail) is basically just a half thickness gambeson and was often used as improvised armor in medieval times when one did not have enough time to fully armor up or was too poor to afford a full thickness gambeson. So, one solution may be to wear 2 arming coats. It would be just as easy to get around in as a full gambeson, but it would probably take a minute to get off and onto your clone. Perhaps your system could support a rule that possessions can be split up as needed during the cloning process so that when you split, each copy can just keep one. Since you were wearing both when you started, there is no getting dressed period to consider. Now let's say one clone can not just come out fully clothed, and you care more about getting decent in a hurry than you do about armor specifically, you may want something like a wrestling singlet. While most modern singlets are made of lycra, adequately thin and stretchy materials could be made from hand knitting using ancient or medieval techniques. They weigh next to nothing, you can fit one in your pocket, and they can be put on in about the same amount of time it takes to put on a pair of pants. Depending on how cloning works, you may also have more options to be able to cheat on the coming out nude part too. If your clone expands off of you, you may be able to hang a singlet off of yourself in such a way that the clone expands into the backup garb. [Answer] Spray on clothes. I don't know the tech level, but there are spray on rubber compounds for various fixes. A version of this could do in a pinch. Don't have aerosols? Possibly a similar liquid rubber compound in a stopped canteen, that you can pour on. [Answer] I think your best solution is not going to be some sort of stripper-esque clothing (easy on easy off), instead it's going to be some unique tech that fits into the rest of your fiction. For example, maybe there is clothing made from the hair of those who can clone themselves, or maybe made from your own hair (if you can duplicate endlessly, that seems a reasonable way to get a lot of material quickly). Perhaps anything that shares this gene / power will also be duplicated as part of the ability. Another option could be that there's some sort of magical creature in the wild that shares this ability (a doppelganger, for example), and killing and skinning this creature, then creating clothes from it, those clothes will duplicate along with you. [Answer] I would have a different perspective on how to us this ability and not show your naked body for too long. Assuming that you somehow (magic) can direct the clone forming I would utilize the same logic listed in your prison break example with a twist: Create your clone and let it absorb the original (this should take like a blink and allows the utilization of this also as a dodge) attack your opponent (use you previously thrown weapon or whatever you find around) than create a new clone inside your empty armor (depending on what a blink represents it could be either dropping on the ground or already there). Note: You should have unprotected finger tips in order to avoid creating the initial clone inside the armor. [Answer] Why do you need all their skin to be exposed? You need some skin right? Just do hands with either fingerless gloves or have a function where you can do mits that lift from the fingers to expose the fingers all flesh on the body is the same so any available room would do. Foot exposure can work too using sandals or footwraps but this is purely seasonal maybe they want to create their clones when they are not in battle. Battle requires all of your concentration worrying about making clones will kill you in one well placed hit or wound you and you don't need a wounded clone to aid you. If you absolutely need hair, skin, nails, ect why not make a sack? Odd sounding but if your gifted one slices skin off of themselves do you have rules about how fresh this must be? Can't I just have sewn a pouch from my flesh tanned flesh and fill the small bag with hair pulls, nail clippings, filed teeth dust, spit and if I need blood I can add that in the day of and sew it with my hair spun thread or use my own fat rendered from my skin (if I boil it) to glue the pouch together this flesh pouch would be the summoning token of a version of me that is updated with at least new skin flakes or a small slice before battle the outer skin may be dried but it sill my skin my tanned hide. Though honestly your hair, blood, ect is already encoded the same as your body so I think just skin only would reasonably do here. Your gifted ones must be safe they could actually be support mages behind your lines making clones to make endless reinforcements if there is no limit on them. Then if nudity is required they have all day for that with little harm so long as the front and rear guards are doing their jobs on the battlefield these people would only need to see the inside of their tents with slip on backup gear should they get word or an alarm that tells them they are physically in danger. I'd honestly say the gifters might want to commit suicide then to prevent their capture and turning at the hands of the enemy who would no doubt want such army boosters for themselves. [Answer] ## Clothes of Hair So, I noticed you actually answered your own question in the comments: > > In fact hair and nails are considerate the same as skin contact for > the purpose of creating or absorbing a clone. > > > So, if MC makes clothes from her own hair, they will also duplicate when she clones. Granted it may take a long time to grow enough hair for a full outfit (assuming there isn't any magical way to do it) but it's better than being naked. ]
[Question] [ Let's say that somehow, enough Neanderthals survived after the last ice age to be able to form a centralized government, economy, etc. Would this even be possible? What events could lead to this? [Answer] **They Pretty Much Already Did** Neanderthals are now known to have interbred extensively with human beings, to the point that a non-insignificant portion of the modern human genome (5% if I recall right, depending on population?) is from Neanderthals. It was previously thought that sub-Saharan African populations almost exclusively lack Neanderthal genes, but it has since turned out that there was [a significant back-migration into Africa throughout history](https://www.repository.cam.ac.uk/handle/1810/252866) (because surprise, humans don't migrate in one direction) and everyone previously just assumed groups like the Yoruba and Khoisan had no Eurasian ancestry. It turns out they have Neanderthal genes too. Neanderthal populations are in general thought to have been much smaller than *Homo sapiens* due to the limited amount of geographic area in Europe/western Asia south of the glaciers, and the cold tundra/steppe climate in most of Europe during the last glacial maximum would have restricted population sizes. Africa was much more hospitable and could support larger populations. When the glaciers melted Neanderthals would have been swamped by *Homo sapiens* coming from the north regardless of how well they weathered the ice age (and they didn't seem to weather it well), and in many cases it seems the larger immigrating *Homo sapiens* population may have just absorbed the smaller Neanderthal ones (there's also evidence of violence, but fossil evidence suggests a complex interplay of absorption, interbreeding, and warfare. You know, like humans usually do). As a result, any predominantly Neanderthal civilization (lets say they didn't get screwed over as hard by the ice age and survived in large numbers) isn't really going to be Neanderthal as we would define it, but Neanderthal-*Homo sapiens* hybrids. In fact, places like Africa and Asia would likely have *more* Neanderthal ancestry than the present day, because you would have Neanderthal populations migrating around with the advent of boats and horseback riding and hence more opportunities for intermarriage. The same goes for Denisovans. Whether this results in behavioral differences or whether this merely results in Europe being full of [redheads](http://humanorigins.si.edu/evidence/genetics/ancient-dna-and-neanderthals/dna-genotypes-and-phenotypes) is unclear. Based on the way selection work you could have individuals that are physically Neanderthal and behaviorally human, behaviorally Neanderthal and physically human, or anything in-between. What exactly constitutes distinctly human behavior and how that would affect Neanderthal civilization is unclear. Neanderthals only seem to have developed art after encountering humans but then again humans didn't start making preservable art until ~40,000 years ago, and it's thought that Neanderthals lived in a harsh environment where innovation and art were luxuries they potentially couldn't afford. We have no living Neanderthals to interview to get an idea of their worldview. Ideas such as "Neanderthals were more aggressive than humans", "Neanderthals were more autistic and peaceful than humans", "Neanderthals were xenophobic", "Neanderthals had no complex language", etc. seem to be based on the sociocultural idea of Neanderthals as being the reflective "other" for humanity and don't seem to be based on actual, direct evidence (and as you can see, many of the behavioral hypotheses are directly opposed). [Answer] **Yes it is entirely possible that should Neanderthals have survived, they would form an advanced society - to the same extent as our current technological society** *Homo Sapiens* appears to be the only animal we know of to have achieved technological means. Note however, that there is nothing particular special about Homo Sapiens: we have very little difference to Neanderthals (in fact, part of our genome is Neanderthal). So let's say the majority of Neanderthals did not die (or morph/breed into Homo Sapiens) and instead spread throughout all continents as Sapiens did, then it is entirely plausible that their cultural and technological pathway would follow closely to that which modern humans did. This then leads to a broader question of: **What then is required to create a 'centralised government' and 'economy'?** (I presume you mean equivalents of modern-day governments and economies). After all - *dinosaurs were on this planet for over 250 million years*, and we do not see any evidence that they achieved an advanced technological economy. Perhaps both us and Neanderthals are terrible at adapting to local climatic and environmental conditions, so we need to **adapt those environments to us instead**. We are indeed very fussy eaters, terrible at running, cannot tolerate high differences in temperature, do not give birth to hundreds or thousands of babies at a time, in fact our babies are completely defenceless and need constant attention pretty much till they become young adults (in contrast to most other animals). As far as we can tell, Neanderthals share these deficiencies with Sapiens - and perhaps if they became widespread then, given time, they would also attempt to adapt environments to them, create farming, enabling large cities, and thus enabling art and culture, which eventually leads to complex governmental structures and advanced technology and economies. [Answer] user2352714 has provided a very good answer, but there are some suggestions based on admittedly incomplete evidence that Neanderthals and other related species like the Desisovians would not have produced a civilization like ours even has they survived in large numbers after the ice age. The existing evidence would seem to suggest that Neanderthals were "wired" differently than the Ancestors, especially in terms of social interactions and group sizes. While the Ancestors were able to live, move and work in relatively large groups (the limit of 150 people that most modern humans can reliably closely interact with seems to point to the size of these ancestral groupings), Neanderthals seem to have only been capable of forming much smaller groups. In the intense environment of Ice Age Europe and Asia, this might have been a sensible response to the limited resources of that environment, but it also made hard limits on things like the number of skills any single band would have access to (maybe only one stone tool maker or shaman/healer per generation), while a human tribe could easily have several at any time. It is difficult to predict what sort of society would evolve from such small groups with apparently limited potential to interact. Certainly the idea of grouping together in larger bands, tribe and eventually nations would be extremely alien, and so the ability to build large structures like irrigation canals, walls and cities would also be difficult to imagine. This essentially would be a very "low trust" society compared to something like Western Europe. Perhaps luckily for the Neanderthals, Denisovians and possibly other related species, the Human Ancestors were the original "party animals", so we have inherited some of their traits and taken them with us through history. That is how they have made modern civilization. ]
[Question] [ I'm writing a futuristic sci-fi story that takes place in a *mostly* [post-scarcity economy](https://en.wikipedia.org/wiki/Post-scarcity_economy). Resources are abundant, and no one needs to work for basic necessities or luxuries. Robots do **all** manual labor, and humans are free to spend their time on whatever they find interesting, whether it be scientific research, creating art, or just lounging around like a bum. That being said, the one scarcity in my world is *life force*. The population is capped, and the only way for a new human to come into the world is for someone else to die. There is a waiting list for people to inherit the *life force* of the next person who dies, so that they can become parents (or hoard the *life force* for their future use). Some people are more desperate to have children than others, but the waiting list has become an unofficial monetary system for society, since it is the only scarcity. I'm having trouble determining how this would work, though. My first thought was that people could trade positions on the waiting list for specialized goods and services, but that adds a bit of complexity, because what if the person who wants something is lower on the waiting list than the person providing the service? Could they just not "buy" anything from anyone above them? My next thought was a point system where people would trade points for goods and services, and move up and down the list based on how many points they have. My issue with this though, is what happens once someone dies, and the top person receives their "payout". They would receive their "life force" and immediately go from being the richest person in the world to the poorest. As I keep trying to figure out how this system would work, I keep running into new walls, and I need help understanding if this system is even possible and how. **So, can a waiting list be used as a monetary system? If not, what are the reasons? If so, what would be the best way to enforce it?** Side note: The humans in my story are pretty much immortal, and only die in freak accidents or by request. Death is uncommon, but does happen from time to time as people decide they are ready to move on (once every few years). I only say this, because it will probably impact the way people think about this system. Edit 1: There are still services and specialized goods (i.e. art), that cannot be created by robots. For example, robots could build any house you want from the ground up, but you may want someone who's really good at designing houses to help you design it. People aren't inherently altruistic in this society, so they would seek some sort of payment in order to provide this service. Edit 2: There is a council of "elders" who oversee most legal affairs. They would likely be the ones to oversee the list and resolve any disputes related to it. [Answer] **Not exactly** The list and positions on the list itself can't be used as currency for a simple reason - they aren't *universal*, which is something money needs to be. A five dollar bill can be spent at any place to buy any good - food, rent, clothing, furniture, etc. But a list position is only useful if you're giving it to someone *below* you - and even then you run into problems. Let's say you want to buy an rare item worth 5 list positions, but the person you're buying it from is 1,000 positions below you. Are you supposed to swap with him? But that wouldn't work, because he has no 'change' to give you, as he can't access the position 5 people below you. Or let's say that you want to buy something from someone in a position ahead of you. How are you supposed to pay him? You can drop 20 positions, but that gives 1 position to 20 people, and you need to somehow turn that into a single +20 for the person you're paying. Now, what *can* work is a currency based on line position, in other words a currency backed by line positions. You can call them 'skips'. In other words, when you buy things or sell things, you pay for them with 'skips', and you use the 'skips' to pay people ahead of you. In the event that you want to swap with someone at too far of a distance away, you use these 'skips' to make up the difference. And, should you want to get ahead in line than you use your 'skips' to pay people. Will this introduce a very special and unique brand of economics? Almost certainly. For instance, similar to bitcoin, there's not really any way to enforce this kind of currency aside from everyone agreeing to it. But this is a resource, and if capitalism has taught us anything, it's that resources can be exploited. [Answer] If the lack of scarcity is driven by the population limits then trading relative positions on the life list could very well be used as a bartering tool. It could even be systemized. The planet has electricity, water and food provided for by robots for 10B people. You get a house, wifi and you can haz cheezbrgrs. The robots are sure that they can provide for this many people. When you are born you get put on a list to reproduce. When someone dies, people at the front of the list have a child, then they go back to the end of the line with their child. The list is 10B people long and in theory you will reach the end of the list before you die. Since you have food shelter and lolcats there isn't much you could really want. But what if Bustin Jeeber is putting on a concert for 300 of his closest fans and you just have to see it. Trade positions in the life list with someone behind you who has a ticket. Sure, it puts off procreation for a couple of years, but Bustin is just sooo cute, and you are going to live forever. Things like this will eventually become normal. The list is 10B people long. Slide back 100 spots, that's 15 minutes later to have a kid. Bustin slides up 100 spots, everyone 100 spots behind you slides up 1, everyone in the 100 spots ahead of Bustin slides back 1. [Answer] Your system seems ignoring the empirical evidence that we see in our societies: on average the more economically well off is a country, the lower the birth rate is. Extrapolating this to post scarcity would lead to the conclusion that having babies would be seen as something not exactly wanted, thus more of a burden than a reward. ]
[Question] [ In most apocalyptic settings(*specially those with a zombie-kind of plague*) the main character(s) only have very mundane means to deal with their problems and those always have a catch: any gun they use has a limited supply of ammo, their sharp objects get dull after a while or they break like any other object used as weapon for too long. And don't even start with the basics like gathering food, medicine, finding or building somewhere safe to live, hygienic necessities and etc. I want to create an apocalyptic(*or post-apocalyptic in this case*) setting where some characters actually have something akin to paranormal/supernatural powers, but here is the crux of my problem: **1.** Which kind of powers could work well in a "realistic as possible" scenario like this?They can be either scientific or more fantasy-like but **must** sound/seem realistic. **2.** How can I give them powers that are useful but not enough to make them seem like an overpowered character? Because I want them to have an edge, but not enough that they can only rely on their powers. [Answer] One of the best "super powers" to have in a Zombie Apocalypse would be disease immunity. If everybody else get's infected after a single bite or scratch but your characters only get slightly sick and then recover it would give them an edge. Also seeing you are already in the sci-fi territory. Maybe go for a zombie boost? each time they get infected and recover they get certain traits(or enhancements of them) like: * Requiring less sleep/becoming less tired while doing activities. * Envoirmental resistance (Never seen a zombie complain about the cold or heat). * Heightened senses like being able to hear better or see better in the dark. * Wounds heal faster. You could also add drawbacks to this like brain damage causing heightened aggression/paranoia/loss of sanity. [Answer] **Basic human skills and basic human weaknesses.** Imagine you were with people in this world. Real people. Who would you want? 1. **Really smart.** This person figures things out. She has insight and makes connections. Possibly she might not know very much because she is 11. 2. **Knows a lot.**. This person has read a lot and remembers it all. He knows what you can eat, how to fix things, where things are, what happened. It took a long time to learn all that stuff and his disadvantage is that he is 91 years old. 3. **Really strong.** Dude is really strong. Really. He can lift huge things and throw them around all day. But he is stoned all the time and even when he runs out of weed, it turns out he does not need it. He is still stoned. 4. **Really fast.** Lady is quick as can be; chopsticks and fly by the wings out of the air fast. Olympic sprinter fast. And she thinks fast and comes to decisions fast. Too fast. 5. **Good guy.** No-one thinks this dude is going to hurt them, or steal from them, or try to have sex with them. He is really nice. People like to be around him and are comfortable around him. He is a good guy to have on your team because he brings people together. But he doubts himself. 6. **Bad girl.** Everyone thinks this lady might hurt them, or steal from them, and they hope she wants to have sex with them. She is a Machiavellian schemer and conniver and she can see the angles. They want to be on her team because they worry about points 1 and 2 and they are thinking about 3. What is her weakness? Even though she is on your team, she still might hurt you and steal from you and have sex with you. The powers of these people are their characters and inborn abilities. They are fun superheroes to write because they are real people writ large, not fake pyrokinetics and shapeshifters. Their abilities are the human abilities and they will not run out. [Answer] To be honest, as long as there aren't any active zombies running around, conventional super powers like FireFist, LazerEyes or StormBringer don't help you a lot. At least not if you want as many people to survive as possible. Conventional super powers all make a single person a better warrior/killer. Yes, that will definitely help them combat zombies and predators (human as well as animal). However, in the mid- to longterm they will have the exact same food / shelter / knowledge problems as normal people, and they can't keep more than X non-powered people protected. (X depends on how dangerous your post-apocalyptic world is - probably less than 10 if you have active zombies running around). Helpful superpowers in an apocalypse when you want a large community to survive (bonus: most of them are inconspicuous in modern-day society - they only become valuable in apocalyptic scenarios): * **Healer**: stop zombification. Fix broken bones. Stop wounds from becoming infected. Keep people from being in too much pain. Heal flesh wounds. Cure diseases. * **Water purifier**: Finds water, and cleanses it to drinking water. In large quantites. If your apocalypse brings down the electrical grid for a long time, then say goodbye to running water. Sewer treating plants will also stop running, and just guide all the sewage into the next best river. * **Finder**: Tell them what you are looking for, and they will find it for you (or tell you that there is none of that within their x mile radius). Where is a shovel? Food? shelter? dry tinder? ammunition? Guns? * **Peace Keeper**: Exudes waves of harmony. People inexplicably feel happier and better in their presence. Helps survivors with their trauma, keeps violence to a minimum, helps people unite behind a common purpose. [Answer] If you want to keep your superpowers "realistic", then you should confine them to things which can be with near-future-science handwaving. This results in two basic categories of superpowers: * Biological: Through some sort of bio-experiment, engineered disease, gene therapy, or whatever, the individual has gained some power. * Technological: Through advanced technology the individual has become some sort of cyborg. Maybe they have robotic eyes, maybe they have nanites in their blood. Here are some subtler "powers" which I'd still classify as "realistic" * Superior senses: The individual can hear better, smell better, and see better. Able to see in very low light and have dog-level scent tracking abilities, these types of people are useful. The disadvantage is they can't turn down their senses. Loud noises, flashes of light, or intense scents can incapacitate or stun them. * Magnetic: The individual's blood contains manufactured nanobots which absorb energy from the blood like regular cells and can, at will, generate a magnetic field. This field is strong enough for users to climb sheer metal walls, hang on ceilings for a limited time, an never drop their weapon (provided it's metal). In certain cases, they might be able to reduce the force of metal objects impacting them. Unfortunately, due to the the way magnetic fields propagate, the range is extremely short and can't be used for pulling things towards you or pushing them away at any speed. * Neuro-distributed: Theses individuals have had a restructuring of their neural tissue, especially their brain. The "thinking stuff" (gray matter) is no longer concentrated in the head but rather in all neurons through the body. This means that head wounds aren't as critical as on a normal person and that that they have vastly superior reaction speeds. The disadvantage is that these people often have somewhat distracted personalities and have trouble learning new things compared to a regular person * Pain-blocker: Through an altered adrenal gland or whatever, these people are able to disable pain at will. This can be both useful and dangerous as while someone disabling pain can move around until the second they die (provided it's physiologically possible), this power doesn't actually make them tougher or hardier. People with this power often die because they ignore a pain which they shouldn't have. * Bend-boned: These individuals have highly elastic bones. This enables them to squeeze through tight spaces and makes them essentially incapable of breaking a bone. These people are also capable of falling great heights without severe injury. The disadvantage is that although they're just as strong as regular people, the bendable bones means they can exert less force and carry less weight before their bones start to bend and make walking/lifting difficult. * Strong lungs: Through a mutation in blood / nanobots in the blood, the individual's blood is capable of holding 10 times more oxygen than a regular person's blood. These people can hold their breath for a very long time, reduce their heart-rate, and run for longer than a normal person. Essentially, they never get out of breath even if lactic acid builds up in their muscles making them fatigued. The disadvantage is that only very few blood types (if any) can be transfused to them and any transfused blood will take a while to become saturated with new nanobots/mutated cells. * Quick thinker: In times of duress (or with sufficient training, at will) chemicals get released into the brain of the individual (biological or technological) which slow that individual's perception of time. Similar to adrenaline, this effect typically does not last long and it takes a while for the chemicals to "recharge". While they are experiencing this, the individual isn't actually able to move faster but they have ridiculous reaction speeds (from an external observer) and can think out a situation. For example, in combat someone could shoot very accurately in quick succession by fine-tuning their aim in when they're slowed. * Pheromone control: These individuals have control over their own scent. This can be useful to avoid being tracked by scent (by animals, humans, or zombies) but it can also be used to befriend animals. With practice, these individuals can smell likeable to stray dogs or can emit smells to ward off predators like bears or mountain lions. Also, if they want, they can smell nice which can be a useful interpersonal tool in the deodorant-lite apocalypse. * High registrar: These individuals are able to pitch their voice up to ultrasonic levels and hear at them too. This allows covert conversation between people who have this ability. With training, rudimentary echolocation is possible. The disadvantage is that bats and other creatures which emit very high pitched noise can be distracting to them. * Navigator's sense: These individuals have an enhanced inner ear and are able to sense magnetic fields, and thus always be able to find north. They also have an excellent spacial memory and can instinctively know the exact distance they've traveled. Basically, these people cannot get lost. * Skin-repigmentation: Similar to a cuttlefish or a chameleon, these individuals can change the texture and color of their skin at will. For example, they can imitate wood, bark, stone, moss, and more at high fidelity. This makes them very good at hiding and sneaking about. This power's effectiveness is reduced by skin covering clothing which means that it's more practical in warmer climates and not too practical in combat where armor is worn. [Answer] Solar Power. I do not kid. While everyone else is too weak to find food or other needed supplies you are looking, using the Sun as a stopgap energy source until you can track down a meal. Incredibly taxing on the body, not used casually. However can save you in a pinch. [Answer] ## Partial zombie resistance Most unfortunate people become "28 Days Later" zombies - fast, furious, resistant to damage, and mindless. A very few are infected, but get lucky. Their bodies have a defective gene that stops the virus from replicating so well. Their immune systems keep it mostly in check, and their brains are still sort of sane. But they still enjoy *some* of those metabolic benefits. The virus has greatly enhanced their biochemistry so that mitochondria are wired into an electrical network throughout the body. The food they eat is rapidly and efficiently oxidized so as long as they keep eating ... something ... they have just boundless energy. With trick mitochondria and hormonal enhancement and pain immunity and regeneration, their muscles let them jump up floors like regular zombies and outrun meat on a moped. (No, really, I mean the delivery guy ... I mean, the meat delivery... really, haven't touched so much as a toe in weeks!) [Answer] This leans towards fantasy, but what about having some characters that experience premonitions? They aren't faster, stronger, or smarter, they just have a sense of looming danger or foreboding. They can be anyone, especially those who you would not expect to be skilled survivors in this scenario, adding interest. This gift would help with survival and can allow for additional conflict and plot development. Other characters without this gift would be suspicious, doubt them, but learn to trust and depend on them. Real life examples of premonitions are always fascinating. It's also been used successfully in some great fictional works (like Watership Down). ]
[Question] [ In our timeline Alexander Fleming accidentally discovered penicillin by accidentally leaving petri dishs out over a long period of time. If a person from an earlier time, e.g. ancient Rome, woke up and **knew** of penicillin's existence and significance, could they discover it themselves? For example, would setting out 100 batches of dough work? [Answer] Yes they could, in fact some [ancient civilizations](https://en.wikipedia.org/wiki/History_of_penicillin) are believed to have experimented with the use of moulds to help cure wounds. The problem being they were not aware of what was going on so their methods might be best described as haphazard. Someone who knew (by some means) of the existence of and presumably the effect of penicillin might well be able to improve on what happened historicaly if they followed an extensive program of trial an error. The key question is how much does this person know? Do they know the source of the mould and where to find it? If not then they might search for a very long time in the wrong place. But if they did then there is every likelihood that penicillin would have been discovered and used. Note however that this use would have been far removed from a modern antibiotic as it would have been extremely difficult to purify and concentrate the active substance. [Further example of ancient use](https://www.sciencedirect.com/science/article/abs/pii/S0269915X89800102). [Answer] It can't be done. To understand why you have to know the *actual* history. Fleming accidentally discovered a contaminating mould killed off his bacterial cultures in Petri dishes. Did this give the world Penicillin? No, not at all. No-one knew how to produce or culture on any scale. Come the Second World war and it became imperative to keep wounded soldiers alive. A massive research effort was instigated by [Howard Florey](https://en.wikipedia.org/wiki/Howard_Florey) and [Ernst Chain](https://en.wikipedia.org/wiki/Ernst_Chain) to find out how to extract and mass manufacture Penicillin. They succeeded and the world now had an extremely effective antibiotic. Alexander Fleming was given the glory as a discoverer of Penicillin, but he wasn't the first, and a share in the Nobel prize. The real work was done by Florey and Chain. Earlier civilizations lacked two things to discover and produce Penicillin. One, a knowledge and understanding of bacteria. two, the necessary industrial capacity to manufacture the antibiotic. Basically discovering an antibiotic is only the merest beginning. A brilliant person in an ancient Roman society wouldn't have a chance of doing so. Sorry, about that. EDIT added 21/11/2019: The history of Penicillin is complex, long and full of turnings in many different directions. The short story is not find mouldy bread, now make penicillin. First up, what our forebears knew. > > Many ancient cultures, including those in Egypt, Greece, and India, independently discovered the useful properties of fungi and plants in treating infection.[7] These treatments often worked because many organisms, including many species of mold, naturally produce antibiotic substances. However, ancient practitioners could not precisely identify or isolate the active components in these organisms. > > > Please note: identifying and isolating the active components is the key idea. > > The history of penicillin follows a number of observations and discoveries of apparent evidence of antibiotic activity in molds before the modern isolation of the chemical penicillin in 1928. There are anecdotes about ancient societies using molds to treat infections, and in the following centuries many people observed the inhibition of bacterial growth by various molds.[1](https://en.wikipedia.org/wiki/Howard_Florey) However, it is unknown if the species involved were Penicillium species or if the antimicrobial substances produced were penicillin. > > > The early scientific evidence for antibiosis and antisepsis starts with this work. > > The modern history of penicillin research begins in earnest in the 1870s, in the United Kingdom. Sir John Scott Burdon-Sanderson, who started out at St. Mary's Hospital (1852–1858) and later worked there as a lecturer (1854–1862), observed that culture fluid covered with mold would produce no bacterial growth. Burdon-Sanderson's discovery prompted Joseph Lister, an English surgeon and the father of modern antisepsis, to discover in 1871 that urine samples contaminated with mold also did not permit the growth of bacteria. Lister also described the antibacterial action on human tissue of a species of mold he called Penicillium glaucum.[10] A nurse at King's College Hospital whose wounds did not respond to any traditional antiseptic was then given another substance that cured her, and Lister's registrar informed her that it was called Penicillium. In 1874, the Welsh physician William Roberts, who later coined the term "enzyme", observed that bacterial contamination is generally absent in laboratory cultures of Penicillium glaucum. John Tyndall followed up on Burdon-Sanderson's work and demonstrated to the Royal Society in 1875 the antibacterial action of the Penicillium fungus.[11] By this time, Bacillus anthracis had been shown to cause anthrax, the first demonstration that a specific bacterium caused a specific disease. > > > I refer interested persons to this [article](https://en.wikipedia.org/wiki/History_of_penicillin) for more information about early precursor research. This eventually led to Sir Alexander Fleming's accidental discovery and subsequent research. > > In 1928, Scottish biologist Alexander Fleming noticed a halo of inhibition of bacterial growth around a contaminant blue-green mold on a Staphylococcus plate culture. He concluded that the mold was releasing a substance that was inhibiting bacterial growth. He grew a pure culture of the mold and subsequently concentrated what he later named "penicillin". He soon began treating infections in patients with penicillin. One of the first was his assistant Stuart Braddock. Fleming applied penicillin to his Sinus infection. Within three hours, most of the bacteria in the infected area had disappeared.[21] In 1929, he reported his findings in an article for The British Journal of Experimental Pathology.[22] During the next twelve years, Fleming grew and distributed the original mold, which was eventually identified as Penicillium notatum (now known as Penicillium chrysogenum). He was unsuccessful in making a stable form of it for mass production.[23] Although Fleming did some research with penicillin directly on patients and greatly contributed to its medical use, he did not realize its revolutionary potential, due to the impurity of the penicillin he made and the difficulty in mass producing it. Most of his further research with penicillin was focused mostly on the properties of penicillin rather than medical treatment with penicillin. > > > Please note that Fleming's main problem with his research was in isolating pure enough samples of penicillin. Also, he was investigating its properties, like a good biologist, rather than its medical application. It was only when the development of techniques for its mass manufacture that the full medical potential of penicillin was realized. The *real* problem faced by the OP's person in the past who is endowed with a magical foreknowledge of penicillin is in their ability to isolate sufficiently pure quantities of penicillin. They would also need to be granted magical foreknowledge of microbiology, microbiological laboratory techniques, foreknowledge of the uses and manufacture or production of glassware, and to be magically endowed with the financial and person-power resources to accomplish all this. Knowledge alone of what penicillin is, and what it can do isn't enough. It took several generations of scientists and research to find useful species of *Penicillium* and then to develop the techniques for its isolation and purification. It would be wonderful if a, say, Roman who investigating nature, and armed with foreknowledge, could introduce penicillin to the ancient world. The barrier is a legion of practical and technical problems which cannot be whisked away with the notion of oh! that might just work! To quote Thomas Alva Edison: "Genius is one percent inspiration, and ninety-nine percent perspiration." The ancient world may have known about applying moulds and poultices to cure wounds, but lacked the technical ability to make penicillin usefully. The amount of perspiration required would fill a large lake. While I applaud the ingenuity of the OP's concept of penicillin in the ancient world, I cannot believe in it as a practical possibility. YMMV. [Answer] That certain substances might have an antibiotic effect, though it was not called under that name, was known and could have been known in ancient time. For example honey has some antibiotic properties, and it was used in the past to hygienize wounds. Another example is birds using laurel leaves to keep their nests clean, and back in the time my grandmather used laurel leaves to help preserving dried fruits or bread crumbs. There are also accounts of ancient medical books prescribing what sound like disinfecting routines before surgeries. I think I remember of an old Hebrew book prescribing to lay the sick person on a stone bed only after having washed it by pouring 100 times water on it, and then doing the same with the body of the sick. All in all the results were empirically known, though there was a lack of general understanding of the underlying phenomena. Therefore it is possible that someone could have noticed that a certain mold could prevent other spoiling to happen, and then attempt using it on wounds. [Answer] Depending to what extent these ancients cultures develop the ideas of moulds as medicine you would need to clarify their understanding of microbiology. Whilst we’ve been brewing alcohol for a long time it’s only in the last 200 years or so that we’ve come to appreciate that these tiny ingredients are actually alive. Without that comprehensive knowledge arriving at penicillin from a few mouldy melons would take a lot of ‘happy accidents’. Doesn’t mean it’s impossible, you might need to invent a few wild rationalisations for the characters who are making the discoveries (assuming they don’t realise they’re dealing with complex living things). ]
[Question] [ Consider a large landmass such as Australia. Imagine if they hypothetically wanted to expand their borders, but they already used up all of their landmass, including the deserts. Could humanity find a way to push back the ocean? For example, by building a series of gigantic barriers or dams, and then siphoning the water afterwards? Or is it difficult or impossible to build standing structures in ocean water? Will it be destroyed before construction completes? Is there any other method for human oceanic expansion? Such as building artificial, floating landmasses? Or by landscaping? **Good answers will explain whether expanding to the ocean is possible, and what methods of expansion do and do not work. Provide references to real-time instances of whether or not it has ever been attempted, if applicable.** **Edit:** I have done research on this. The difference between land reclamation and what I'm talking about is a matter of scale. I'm talking about expanding to such an extent that you could see a difference on the world map, or from space. I'm talking about creating land from the ocean the size of entire cities, entire countries. I did not know that the Netherlands was almost entirely reclaimed. I'm also talking about the potential of doing this in deep oceanic zones, not just shallow waters. The whole point of me posting this question was because I did some research but was unsatisfied by my findings, and because I want to know the scientific possibilities of this type of oceanic expansion. [Answer] as @L.Dutch already say theres many country do this. **the method** <https://en.wikipedia.org/wiki/Land_reclamation> > > Land reclamation can be achieved with a number of different methods. > The most simple method involves filling the area with large amounts of > heavy rock and/or cement, then filling with clay and dirt until the > desired height is reached. The process is called "infilling"[1](https://i.stack.imgur.com/wBnmO.jpg) and > the material used to fill the space is generally called > "infill".[4](https://i.stack.imgur.com/hdRJ1.jpg) Draining of submerged wetlands is often used to > reclaim land for agricultural use. Deep cement mixing is used > typically in situations in which the material displaced by either > dredging or draining may be contaminated and hence needs to be > contained. Land dredging is also another method of land reclamation. > It is the removal of sediments and debris from the bottom of a body of > water. It is commonly used for maintaining reclaimed land masses as > sedimentation, a natural process, fills channels and harbors > naturally. > > > i just want to add singapore since they have different method. <https://www.scoopwhoop.com/singapore-trash-island/> > > How it works is that the garbage is turned into ash by Singapore's > incineration plants and then shipped to the island. > > > The water between the two islands is divided into cells. These cells > are drained before the ash fills them.Thereafter, it is covered with > soil so that the birds and insects can pollinate and nourish the > plants. > > > Before the ash-filled water is discharged into the sea, the wastewater > treatment plant makes sure that it is properly treated. > > > The wastewater treatment plant is lined with an impermeable membrane > to prevent the harmful substances from leaking into the surrounding > waters. > > > Thanks to Singapore's mind-blowing efficiency, this landfill attracts > a lot of rare species of birds and animals. In fact, it is one of the > best places in Singapore for bird-watching. > > > **TLDR** watch this video <https://www.youtube.com/watch?v=Dei_duocsu4> and <https://www.youtube.com/watch?v=5VsDWhoh5WY> and as @Starfish Prime already mention theres a construction like oil rig use for residence such as sealand [![enter image description here](https://i.stack.imgur.com/N9XHC.jpg)](https://i.stack.imgur.com/N9XHC.jpg) [![enter image description here](https://i.stack.imgur.com/Q8Anf.jpg)](https://i.stack.imgur.com/Q8Anf.jpg) and more primitive one like village of bajau people [![enter image description here](https://i.stack.imgur.com/1ZFbT.jpg)](https://i.stack.imgur.com/1ZFbT.jpg) [![enter image description here](https://i.stack.imgur.com/wBnmO.jpg)](https://i.stack.imgur.com/wBnmO.jpg) [![enter image description here](https://i.stack.imgur.com/hdRJ1.jpg)](https://i.stack.imgur.com/hdRJ1.jpg) or maybe follow traditional venice method using wooden pile drive if you want stone or concrete architecture instead [![enter image description here](https://i.stack.imgur.com/1l3i0.jpg)](https://i.stack.imgur.com/1l3i0.jpg) [![enter image description here](https://i.stack.imgur.com/OyHsH.jpg)](https://i.stack.imgur.com/OyHsH.jpg) [Answer] We have some examples in our real world of pushing back the ocean, just to cite a few: * The Dutch [Afsluitdijk](https://en.wikipedia.org/wiki/Afsluitdijk) > > The Afsluitdijk (literally translated: Shut-off-dike) was completed in 1932, thereby shutting off the Zuiderzee (lit: Southern Sea) from the North Sea. Until then, the Zuiderzee had been a large bay south of the North Sea which gave maritime access to five provinces of The Netherlands, and particularly during the Dutch Golden Age provided a protected entrance and exit for the harbour of Amsterdam and several other important Dutch sea harbours. Furthermore, the Zuiderzee provided relatively shallow and calm fishing grounds for the many towns bordering the bay. However, the opening of the Noordzeekanaal (North Sea Canal) in 1876 gave a much shorter direct entrance to the Amsterdam harbour, and overfishing had depleted the shallow bay. In the second half of the 19th century, the Dutch population was exploding, and there was an increasing need for land for agriculture and animal husbandry. The Dutch already had centuries of experience of building dikes around lakes, emptying them and converting them to fertile polderland. > The next large project was to convert the Zuiderzee into polder. In 1886, a few notables established the Zuiderzee Society to investigate whether reclamation was feasible. One of the most prominent members of the society was Cornelis Lely, a prominent member and later chairman of the society. In 1891 he designed the first plan for the closure and reclamation of the Zuiderzee. > > > * [Palm Islands](https://en.wikipedia.org/wiki/Palm_Islands) > > Palm Islands are three artificial islands, Palm Jumeirah, Deira Island and Palm Jebel Ali, on the coast of Dubai, United Arab Emirates. Creation of the islands started in 2001. Only Palm Jumeirah has been completed. This island takes the form of a palm tree, topped by a crescent. > [![palm islands](https://i.stack.imgur.com/FkGIS.jpg)](https://i.stack.imgur.com/FkGIS.jpg) > > > * [Odaiba](https://en.wikipedia.org/wiki/Odaiba) > > Odaiba (お台場) today is a large artificial island in Tokyo Bay, Japan, across the Rainbow Bridge from central Tokyo. Odaiba was initially built in this area for defensive purposes in the 1850s. The original Odaiba opened in 1860 as a port and shipyard in the city today known as Yokosuka, site of the joint Japanese-US fleet HQ. Reclaimed land offshore Shinagawa was dramatically expanded during the late 20th century as a seaport district, and has developed since the 1990s as a major commercial, residential and leisure area. Odaiba, along with Minato Mirai 21 in Yokohama, is among a few manmade seashores in Tokyo Bay where the waterfront is accessible, and not blocked by industry and harbor areas. > > > Of course the more shallow is the water, the easier it is to build such things. Note that they are not floating landmasses: to make such a mass float has little sense, as it would need connection to mainland for utilities. If you are going to anchor it, then better make it an island. [Answer] ## Let's do some Geo-Engeneering Others have already proposed the sane ways for doing land reclamation, which leaves me with the insane ways of doing it. A question, dear reader, is this enough reclaimed land for your purposes? [![enter image description here](https://atlantisjavasea.files.wordpress.com/2017/03/lgm-ocean-map2.png)](https://atlantisjavasea.files.wordpress.com/2017/03/lgm-ocean-map2.png) This looks somewhat like current Earth, but all the continents seem to have gotten fat. The most noticeable changes are the now connected Australio-Papuaneuginea, Sundaland in the South-China-Sea, the Beringia-Landbridge between America and Asia, Doggerland in the basin currently occupied by the North-Sea and some truly humongous islands in the oceans (just look at Hawaii or the Caribbean). Should one be familiar with the history recent history of Earth, it will be obvious that this isn't some kind of far future map or a crazy proposal, but a map of Earth during the [Last Glacial Maximum](https://en.m.wikipedia.org/wiki/Last_Glacial_Maximum_Vegetation_Map.svg). Between 31 and 16 thousand years ago Earth was about 6° colder and when the glaciers were at their maximum extent about 26500 years ago; sea levels were about 130 meters lower than today. This results in the coastlines shown above. So how does this help us? We can see that a colder planet means more water bound as ice leading to lower sea levels and more land. Over the history of our planet [sea levels have fluctuated between 300 or even 400 meters](https://en.m.wikipedia.org/wiki/Past_sea_level) with the maxima during ice free climetes like in the Eocene ([this article shows the shorelines current day Earth would have with an Eocene climate](https://www.nationalgeographic.com/magazine/2013/09/rising-seas-ice-melt-new-shoreline-maps/)) and minima during cold ages like the Last Glacial Maximum. Thus we just need to cool down the planet in order to get more land. Cooling the planet by a significant ammount is of cause no trivial task. One could opt to remove greenhouse gasses (at least carbon dioxide and methane, ozone and water vapor are harder to controll) or use [space-based sunshades](https://en.m.wikipedia.org/wiki/Space_sunshade). While there are many proposals for sunshade construction, I like the self-stabilising design by Paul Birch and the swarm design most. > > Paul Birch proposed a slatted system of mirrors near the L1 point between Venus and the Sun. The shade's panels would not be perpendicular to the Sun's rays, but instead at an angle of 30 degrees, such that the reflected light would strike the next panel, negating the photon pressure. Each successive row of panels would be +/- 1 degree off the 30-degree deflection angle, causing the reflected light to be skewed 4 degrees from striking Venus. > > > One proposed sunshade would be composed of 16 trillion small disks at the Sun-Earth L1 Lagrangian point, 1.5 million kilometers above Earth. Each disk is proposed to have a 0.6-meter diameter and a thickness of about 5 micrometers. The mass of each disk would be about a gram, adding up to a total of almost 20 million tonnes. Such a group of small sunshades that blocks 2% of the sunlight, deflecting it off into space, would be enough to halt global warming, giving us ample time to cut our emissions back on earth. > > > Alternatively one could also use titanic [electrolysis](https://en.m.wikipedia.org/wiki/Electrolysis) plants to break up ocean water into hydrogen and oxygen so that the hydrogen may escape into space. Note that this is extremely energy intensive. However this approach, with the possibile exception of the electrolysis scenario, will have other, unintended consequences. It will lead to droughts and desertification as the map below shows. Glaciers and tundra would also spread and take over most of Europe, Siberia and North-America while tropic and moderate climates will be forces into retreats near the equator. [![enter image description here](https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Last_Glacial_Maximum_Vegetation_Map.svg/1024px-Last_Glacial_Maximum_Vegetation_Map.svg.png)](https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Last_Glacial_Maximum_Vegetation_Map.svg/1024px-Last_Glacial_Maximum_Vegetation_Map.svg.png) ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 4 years ago. [Improve this question](/posts/152819/edit) Marine ships and boats have ports. Airplanes have airports. In scifi spaceships can have space ports. What would be the airship equivalent in a steampunk world where marine ships are still heavily used? So that avoiding the use of *port* would keep things non-ambiguous. [Answer] I like **aerodrome**. <https://en.wikipedia.org/wiki/Aerodrome> > > In the early days of aviation, when there were no paved runways and > all landing fields were grass, a typical airfield might permit > takeoffs and landings in only a couple of directions, much like > today's airports, whereas an aerodrome was distinguished, by virtue of > its much greater size, by its ability to handle landings and take offs > in any direction. The ability to always take off and land directly > into the wind, regardless of the wind's direction, was an important > advantage in the earliest days of aviation when an airplane's > performance in a crosswind takeoff or landing might be poor or even > dangerous. The development of differential braking in aircraft, > improved aircraft performance, utilization of paved runways, and the > fact that a circular aerodrome required much more space than did the > "L" or triangle shaped airfield, eventually made the early aerodromes > obsolete. > > > Airport implies a runway, as noted. A blimp does not need a runway and early airplanes might need a variety of takeoff directions according to wind. A large field suitable for hosting all manner of airships could be (and was!) called an aerodrome. [Answer] It's called an [Airship Docking Station](https://www.alamy.com/stock-photo/airship-docking-station.html). The top of the Empire State Building was designed as the mooring mast for an airship docking station for Zepplins, but it was never used. (The real reason was to make it taller than the Chrysler Building.) [![Fake photo.](https://i.stack.imgur.com/3SKOy.jpg)](https://i.stack.imgur.com/3SKOy.jpg) Fake photo ([The Empire State Building as Airship Docking Station - The New York Times](https://www.nytimes.com/2010/09/26/realestate/26scapes.html)). [Answer] In his 1908 novel "[The War in the Air](https://en.wikipedia.org/wiki/The_War_in_the_Air)" H. G. Wells refers to them as **"aeronautic parks"**. [Answer] As it turns out there are many kinds of airships in real life. The most common are airplanes, then helicopters, and there are still a few dirigibles running around (for steampunk, I assume these are the airships you care about). They come to dock and stage from locations that are generally called... drum-roll please... AIRPORTS!!! Heck the name going around for places for spacecraft to stage from is "spaceport". Maybe not all that exotic - use some of the other excellent answers in this thread for that. However, the actual, factual answer to the question is the mundane airport. ]
[Question] [ Incoming generic apocalypse, a bunch of people with low budget tries to quickly download publicly accessible blueprints, so in a few decades or centuries someone would be able produce again computer hardware without need of reinventing the wheel. Instead of simple "just pick some 10-20 years old technology", I started to wonder whether blueprints would have uniform quality across board? I mean for example whether hypothetically RAM would be straightforward to replicate, while modern processor designs were too well protected as trade secrets. **So how modern should be realistically the designs? Secondly, should their quality be similar across the board, or are there components which blueprints would be clearly easier / harder to get, in a way that are likely to affect the future design?** I'm NOT asking: * how to store data for potentially long time * how to build a microchip factory with low population and tricky access to rare Earth elements * about software (except maybe firmware, if it would be a bottleneck) * how to build the most basic components (but what in long run would be the top components that one could build without effectively designing them from scratch) [Answer] Chip makers are paranoid when it comes to protecting their designs and processes. A bunch of people with low budget has no chance to find on the internet some recent design which makes sense (on line scammers are another story). That said, you cannot mix in the same computer a CPU from 2010 with a RAM from 1980, because they would be blind and deaf toward each other: different buses, different clocks, it would be a hell of a job to integrate them, and again, your people have low budget and no tools. Last but not least, chipmaking is one of the most advanced technologies today. Just having the blueprints would not enable you to make a chip, unless you have also the means to produce high purity silicon crystals, slice and polish them and process them in the proper way using high purity dopants and metals. In a post apocalyptic world you would be like if you managed to build a replica of the [first transistor](https://www.instructables.com/id/The-First-Transistor-Teaching-Model/). [![first transistor](https://i.stack.imgur.com/0rBzZ.jpg)](https://i.stack.imgur.com/0rBzZ.jpg) A modern microchip contains gazillions of those. [Answer] Modern "blueprints" are a closely guarded secret. They are also enormously complex and basically useless. By the time you can use them, you have *more* than enough development in place to recreate them. It would be better to develop some basic computing capabilities so that you could recreate a VHDL synthesizer. Then you can take VHDL files and synthesize them for the particular process your people invent (it won't have the same timing properties as the process it's imitating, so having a computer help with that will be a huge perk). However, perhaps of interest might be the Intel 4004. It's a CPU from the 1970s with 3000 transistors. There are also pictures of its masks available online which Intel released during an anniversary celebration. [![4004 mask](https://i.stack.imgur.com/kFv9y.jpg)](https://i.stack.imgur.com/kFv9y.jpg) [Answer] As others have pointed out, you will not get contemporary masks and all that without extensive effort. But that might not be useful anyway. ## Short answer: you can not just produce everything again after an apocalypse The manufacturing process is massively complex and if you do not have **EVERYTHING** needed, including maintenance knowledge for all the required machines that have been falling apart for 20 years, it is borderline impossible to recreate the process and just continue production as if nothing ever happened. First of all: ### What "blueprints" are we talking? You have to distinguish between what type of "blueprints" we are talking about: 1. Hardware description code that is the very basis for any chips functionality (in HDLs, Hardware-description languages, e.g. VHDL, Verilog) 2. Masks for production 3. A 'script' that details **ALL** the steps ('turns') of a chips production (including which masks to use for which 'turn') The first one would allow you to start a new production from scratch as soon as you have access to higher calculatory power AND the synthesis tools to create masks and all that. Second and third are necessary if one were to continue production, but that require you have access to a **functional** (and actually clean) [clean room](https://en.wikipedia.org/wiki/Cleanroom) with all the machines **fully operational**. That is a ***highly unrealistic scenario***. Another thing to consider is the reason for Intels ["Copy Exactly!" policy](https://en.wikipedia.org/wiki/Copy_Exactly!). Every clean room in the world (for a specific technology node) looks exactly identical. Identical setup, identical machines, identical everything. The reason is that Intel worked out that recreating a process that worked in one type of lab in another lab can take several years, depending on the amount of differences in machines and materials used. You can not simply take a 'script' and run it on different machines. It just does not work. You will never get nanometer precision with other machines and identity of chemical processes with even *slightly* different materials (as in acids that have minimal contamination, etc.). It is basically impossible and such a recreation would probably take several decades without all the former experts helping you, even if you had all masks and a script. So the only thing realistic is starting from scratch. But how? ### You can **NOT** just produce smaller technology nodes with the HDL-code for the chips The reason is that a compilation (code to logical functionality) and especially a synthesis (logical functionality to transistor mapping and wiring on a chip) require massive computational power and high-end software that is (to my knowledge) exclusively temporarily licensed. So even if you had the power and the software, after the apocalypse all the licenses will have run out and you will not be able to use the tools. You'd need to get your hands on the codebase for all the tools or get a developer version of the software that works indepentently of any license. ### So also recreating 12nm technology is unrealistic even if you had **everything** The only option left is to start the entire industry from scratch. ### What would be needed to rebuild the semiconductor industry from scratch? If you had secured all available knowledge about semiconductor chip production, computer engineering, and preferably a few engineers (of many differenty fields), mathematicians, chemists and physicists related to these fields, you will get a lot further than with any blueprints and scripts imagineable. There are many things to be done: 1. Recreating simple processes as used for very early processors 2. Develop machines to allow for more complex processes 3. Develop software to compile, simulate and synthesize processor designs 4. Use the processors and machines you produced to compute more complex designs 5. repeat 2., 3. and 4. indefinitely With all the knowledge secured on what concepts are needed for chip design and production you will probably make very good progress. (depending on how many surviving engineers, etc. you have, and how much people have resources to do non-survival things post-apocalypse.) The more early processor designs (*including documentation*) you have secured the quicker the production of more complex ones can start over again. --- # TL;DR Recreating the production process with pre-apocalypse technology is very unrealistic, but the more knowledge and expertise you secured the quicker you will be able to recreate chip production capabilities after the apocalypse. ]
[Question] [ Assuming such a space station needed to have its central hub not used for docking spacecraft, would it be plausible for a spacecraft to dock on the outer edge of a rotating wheel if the ship approached the station on a tangent to the outer edge, in the direction of rotation? I'm assuming a drone ship, of equal mass, would simultaneously dock on the opposite side of the station to maintain the balance of the mass of the station. [Answer] > > Can you launch an ICBM horizontally? > > > Sure. Why would you want to? (*The Hunt for Red October*) > > > You absolutely can dock on the outer rim. It will be the biggest pain in the tuckus your pilots have ever seen, but yup, it can be done. There are (at least) two reasons why the central hub is preferred. 1. You only have to spin the ship on one axis, if you must spin it at all. 2. You can design the hub so that the docking hub doesn't spin, which is even simpler. But hitting a docking port on the outer rim means the ship must move *on at least two axes.* That's what it takes to move in an arc: two axes. This is because you can't actually move up to a point tangent on the outer rim and dock. Why? Because docking takes some time. Even if you're trying to capture the ship with some cool clamps. The ship is moving in one direction (a straight line) and the outer rim in another (an arc). The "docking time" isn't just a second... it's a minuscule fraction of a second — and if you don't get it right the first time, things (usually the ship) get ripped apart. So, theoretically, yes, you can dock a ship via the outer rim. It's not recommended. [Answer] As others have explained, It is quite a pain and a lot of risk with docking ports that resemble the actual ones we use today on the ISS and elsewhere. But I think it may be possible with a tow-capable tether. A somewhat high-tech version of how surface ships are moored. 1. The docking spacecraft approaches and only roughly matches the rotating docking port. This requires the continuous expenditure of delta-v mass but hey, we are in sci-fi land. 2. One of the spacecraft (doesn't matter which one) reels out out a couple (or more) of strong tether cables, each piloted by a remote-controlled drone thruster. These maneuver and attach themselves to the hardened attachment points on the other vessel. The pilot thrusters and attachment points are hardened enough to handle rough contact, and the thrusters are nimble enough to be very maneuverable. (they don't have to accelerate their delta-v mass. It's fed through the tether) 3. Once the tethers are secure, they are slowly reeled in. The docking ship slowly lets go of the thrust as it approaches the station. 4. As the tethers go taut, the drag will slow the station's rotation down slightly. The station may fire thrusters to counteract this, or if this is tolerable, the docking ship may fire its own thrusters for the same purpose once it is securely anchored. 5. Once the ship is close enough, robotic clamps engage and secure the two spacecraft together. 6. Only when the spacecraft are mechanically secure, extendable airlock ports deploy and internally connect the two vessels together. As you can see, this is way more convoluted than hub docking. But hub docking can only properly accommodate two ships, while with rim docking, docking capacity is limited only by the size and surface area of your station. The two hub docking ports may still accommodate large ships that would destabilize the station if they docked on the rim. It may be an acceptable compromise for a station that serves (ironically) as a transport hub. :D --- ### Addendum ## Orbit tethering This is another, probably more economical and easier method for rim docking that I brewed up after I posted the answer above. Again this involves tethers and pilot thrusters as above, but requires much less delta-v for the docking maneuver, is much simpler and more stable. 1. For this approach, the spaceship parks at a safe and stable point above the rim, aligning its main thrusters with a hypothetical tangent of a circle concentric with the station axis. 2. Tethers are extended from the two sides of the station hub, attached to bearings whose rotation has been neutralized (ie. they are stationary from the docking ship's reference frame) 3. As above, the tethers are attached to the two sides of the docking ship. 4. Using its main thrusters, the docking ship accelerates prograde to the same linear velocity that the rim docking port is traveling in. The tethers ensure that the ship remains at the same radial distance. This somewhat emulates a stable orbit (the tension on the tether replaces gravitational force) 5. The station slowly reels the ship in. Rotational inertia is preserved, so that the angular velocity of the ship's artificial *orbit* matches up with the angular velocity of the rim port. The station can sync the reel-in speed to align the ship and the port. (Initially, the port will be rotating faster than the ship, and reeling can be timed so that the ship and the port line up by the time it's done). 6. When the ship and port are aligned, locks are engaged, and the tethers are released for other docking duties. * If somehow a vessel misses the faster rotating port, the tethers can be loosened, slowing the ship down. This allows the port to go around faster, giving another opportunity to sync rotations. Smaller adjustments can be done by prograde burns alone. (Retrograde may be dangerous at low altitude) * Having four tethers that can be independently reeled allows for very precise attitude adjustments so that the first contact happens without a big jerk. * The ship is going to experience some artificial gravity. It makes sense to align the pilots' axes with the radial vector, heads toward the center, so that what they experience feels somewhat natural. This makes the docking point "above" from their perspective. * Assuming that the mass difference between the ships and the station is at least a couple of orders of magnitude, it may be possible to dock on the sidewalls of the rim as well as the outer edge. There may even be port ratings where the lightweight ships dock on the sidewalls, middleweight ships on the outer edge, and at most two heavyweights directly on the hub. [Answer] **No** That would make no sense as it's too complicated and too many things would go wrong. The station would have a self balancing system which would operate by pumping water to holding tanks around the rim. As the ship docks, water would be pumped from the area where the ship was to the area opposite the ship. [Answer] **Yes, but not recommended** It will be a jerk, though. The space station has one or more circular hoops mounted on it's outer shell, preferably with some distance. From each hoop, several docking apparatuses hang, like a crane from a girder. The space ship flies tangentiall to the hoop, it's docking interface pointing upward and at a speed equal to (or close) the speed of the hoop as a whole. The docking apparatus adjusts it's position along the hoop and in the right moment snatches the docking interface of the ship with a powerful magnet. This will be experienced as a strong jerk by the ship. Then, once the ship is grappled, the actual docking with matching airlock interfaces etc. is done between ship and docking apparatus. And then, at last, the docking apparatus drives near an airlock to the station and docks. Can't have a moving apparatus that's permantently connected to the station (or you could, with flexible walkway and a severly limited range for the apparatus). Downsides: * the ship has to sustain it's own weight from the docking interface under a bit more than the stations gravity, same for the docking apparatus and hoop * strong jerk Would the maneuvering be easier or harder than Elite-style docking? With a stanford torus (the least practical shape for this kind of docking), the outer rim moves at about 93 m/s, this is the speed the ship needs to have. This also means that the timeframe for the grappling maneuver is pretty short and depends on how far out the docking apparatus can reach (physically and via it's magnets). But I'd assume an order of magnitude of 0.1s. With circumferential docking, the ship has to be move along the correct axis at exactly the correct speed, the docking apparatus has to adapt accordingly. The docking course is almost a near miss, so it would be trivial to change away from a collision course if need be. With elite style docking the axis has to be correct too, with the rotation and phase as additional variables. The docking approach can in theory be arbitrarily slow, so collision prevention shouldn't be too hard either. I's assume something similar to the docking apparatus would be used here, too, just inside. In summary, elite style docking is probably the better approach but a station may employ both for easier traffic management. [Answer] ### Maybe ...and it depends on what you mean by "docking". SpaceX has gotten a lot of press for being the first to do this with their booster rockets (as opposed to others historically dropping their boosters into the Main Seawater Retention Tank). Various crewed spacecraft have been doing it. Freefall (webcomic) [recently did it](http://freefall.purrsia.com/ff3500/fc03457.htm), so at least someone else has theorized that it's possible. [Halo](https://en.wikipedia.org/wiki/Halo_(franchise)) has certainly done it. You almost surely have to approach this the way Freefall and Halo did, and treat it not as a "docking" (which would be pretty insane) and more as a "landing". The moment you're "inside" the station, you are essentially having to hover in its pseudogravity in order to avoid crashing... but as noted, we *do* know how to land in similar conditions. Obviously, the larger the station (or more to the point, the slower it is rotating), the easier this will be. The trick is likely going to be that the station needs to have enough mass (relative to the ship "docking", by which we really mean "landing") that the change in rotational inertia is close to negligible. ]
[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. I've been looking over the internet and on here to find some kind of evidence for this, but nothing conclusive, so I was hoping for people with a better understanding of smelting, chemistry and physics to help me. Could an early people with relatively little access to iron mines use iron oxide dust (such as ochre/ocre or… well… whatever you would call the red dust on Mars) to smelt/forge iron objects, including weapons. If I understand correctly iron ore is technically oxidised so that should be a possibility, right? Thanks a lot! [Answer] Yes. You will need furnace technology of, surprise, iron-age level (2500BCE, for example). A fairly pure iron-oxide dust is equivalent to an extremely high-grade iron ore. The oxides are reduced by carbon monoxide produced by burning high-carbon fuel (eg. charcoal) in a hot, low oxygen environment (eg. a blast furnace). See <https://en.wikipedia.org/wiki/Bloomery> --- The iron compound in [haematite](https://en.wikipedia.org/wiki/Hematite) is an iron oxide ($Fe\_2O\_3$) and an important iron ore... [magnetite](https://en.wikipedia.org/wiki/Magnetite) is another ($Fe\_3O\_4$). Any ore that contains a large percentage of either can be fed directly into a blast furnace to produce iron, and there are [relatively straightfoward ways](https://en.wikipedia.org/wiki/Beneficiation) to process lower grade ores to make them useable in the same way. [Rust](https://en.wikipedia.org/wiki/Rust) is commonly a mixture of hydrated iron oxides and hydroxides, and those same chemicals are found in a less concentrated form in [limonite](https://en.wikipedia.org/wiki/Limonite) which is yet another common iron ore. You can also find stuff like [bog iron](https://en.wikipedia.org/wiki/Bog_iron) from relatively shallow surface excavations. It was the major source of iron used by vikings. A major constituent is an iron oxyhydroxide, $FeO(OH)$, also found in [goethite](https://en.wikipedia.org/wiki/Goethite)... yet another commercial iron ore. The pigment in ochre is an iron-bearing compound like haematite, limonite or goethite, so I'm pretty certain that could be used too. The take home message should be that rust, "iron oxides" and iron ores are all more or less indistinguishable other than the kind and quantity of impurities in them. --- One last comment, though. > > Could an early people with relatively little access to iron mines use... the red dust on Mars to smelt/forge iron objects... > > > This specific case would prove tricky, as you need a supply of carbon rich fuel for the reduction processes humans use and have used. On earth, we use living trees (processed to make charcoal) or dead ones (which formed coal, then processed to make coke) and Mars has neither a biosphere nor (probably) any fossil fuels. It also didn't have any "early people", of course. It may be that other metals are more useful on Mars if they can be refined without carbon. Aluminium and magnesium are possibilities there. There are probably also other ways to reduce iron oxide without carbon, but I'm not familiar with them. [Answer] A corroded object is placed in a vacuum and electrically bombarded with hydrogen molecules, which react with the ferrous oxide, or rust. After several hours most of the rust converts to hard iron -- and the object is back to its original shape and size. <https://www.orlandosentinel.com/news/os-xpm-1986-10-19-0260290108-story.html> Some lasers are also able to reverse corrosion: <https://www.youtube.com/watch?v=ACGSzBXKONo> ]
[Question] [ I've been poking around similar posts, but none seem to contain the information I'm looking for. I'll try to keep it brief. In the year 20XX, some powerful organizations are trying to "land" an asteroid using a combination of aerobraking, carefully planned orbits around the sun, and a powerful swarm of rocket engines. Rocket launches have become significantly cheaper in this time period than they were in the early 21st century. The plan is to send a rocket swarm to a relatively small metallic asteroid --possibly no more than 20m-100m across-- and tow it ahead of earth's orbit around the sun. Over the course of X years, the asteroid will be decelerated to the point that the earth will slowly catch up to it in a relatively gentle manner until it begins a controlled re-entry using a combination of natural aerobraking, parachutes, and a final burn by the attached rockets. Hopefully, by the time the rock lands, nobody dies and some billionaires become even wealthier. **Q: Utilizing current or projected near-future technologies and assuming that rocket launches become very cheap and routine, is it plausible to "land" an asteroid in the way described or will the earth's gravity just re-accelerate it to apocalyptic speeds?** [Answer] **The Approach Needs Work** As proposed, your question isn't based on realistic [orbital mechanics](https://en.wikipedia.org/wiki/Orbital_maneuver). Placing an asteroid on Earth's orbital trajectory but "ahead" of it would be inherently unstable for the asteroid unless it was at the L4 [Lagrange point](https://en.wikipedia.org/wiki/Lagrangian_point#Sun%E2%80%93Earth). Even if this was a stable configuration, slowing down would change the orbital trajectory (the orbit would become "lower" or closer to the sun, and more elliptical) and Earth wouldn't "catch up" to it because they would be in different orbits. To actually get an asteroid to Earth, you would want to first put it into some Earth-centric orbit. This would be done using the same methods used for spacecraft: taking advantage of favorable conditions for flybys with other bodies to alter trajectories (slowing, changing direction), possibly spreading high-efficiency thrust over long periods (e.g. with ion thrusters), entering the Earth-Moon system on a [low-energy transfer orbit](https://en.wikipedia.org/wiki/Low-energy_transfer), and then using rockets to enter directly into Earth orbit. In fact, [NASA was going to do this with a roughly 4m asteroid](https://en.wikipedia.org/wiki/Asteroid_Redirect_Mission) but ARM was cancelled in the 2018 budget. Obviously as the asteroid size increases, the mission costs increase by at least the cube of that (volume being proportional to the cube of radius), but this would be doable with your cheaply launched rockets. **Landing** I see that others have already done an in-depth analysis of the energy requirements in some form or another so I wont get too deep into the actual landing. I will say that if cost is no object there is probably a way to do this using a combination of [methods](https://en.wikipedia.org/wiki/Spacecraft_propulsion#Planetary_arrival_and_landing) such as aerobraking, heat shielding (coatings and bolt-ons), supersonic drag chutes, and thrusters. If all else failed the asteroid could be separated into smaller pieces, which would guarantee a workable solution if you broke it into enough pieces. This depends on if landing as one chunk of rock is a hard requirement. Here is a similar [question](https://space.stackexchange.com/questions/14157/how-to-get-processed-asteroid-metals-back-to-earth-in-a-safe-manner), to which someone gave a much more complete response. **Landing?** If this setting is science-based, I would take a hard look at how much you need the asteroid to be on the surface. Can what you need be done in orbit? What about lunar orbit? Can you take only certain parts/materials of the asteroid to the surface? If you are going to consider the costs at all, I have a feeling that landing an asteroid on Earth is going to be prohibitively expensive. [Answer] I don't think it is plausible. Let's simplify the scenario, assuming the asteroid is a sphere. For 20 m radius we have a volume of $V=\frac43 \pi r^3 \approx55300 \ m^3$ Considering the density of iron, this corresponds to a mass of $M=5530 \ m^3 \times 7870 $$kg \over m^3$$= 43.5 \cdot 10^6kg$. Its market value would be about 3 million $. If this body is orbiting Earth, it will be moving at about 7 $km \over s$, while on landing it will be still. It means we need a way to dissipate its kinetic energy, which will be $K=\frac12 mv^2=1.06 \cdot10^{15}J$ which is $\frac14$ of a Megaton of TNT. For comparison the [Saturn V](https://en.wikipedia.org/wiki/Saturn_V) had a mass of $2.97 \cdot 10^6 kg$ and carried a payload of $140 \cdot 10^3 kg$ to LEO. You would need $43.5 \cdot 10^6 \over 140 \cdot 10^3$$=310$ Saturns V to slow down the asteroid from orbital velocity to rest without burning it in the atmosphere. Even assuming that we can double the payload of a Saturn V while keeping its mass constant, we would still need 155 of them to perform the trick. They would need to be ready to use in LEO, so for each Saturn V assembled in orbit you would need $ 2.97 \cdot 10^6 \over 140 \cdot 10^3 $$=21$ Saturn V, totalizing $155\times 21=3255$ launches, without accounting any safety factor in it. If you assume you can have 1 launch per day with no interruptions it would take about 9 years just to assemble the whole thing in LEO. And, as AlexP pointed out in their comment, all of this would need to cost less than the price of Earth harvested iron. That would happen, at present prices, if the rockets costed less than $3000000 \over 3251$$\approx 1000 $ $ per launch. Not even a car is so cheap. Therefore, no, I don't think it is possible. [Answer] # You can probably do this, but it'll be very hard To do it the way you suggested is probably not the best way. Having the orbit follow the same as earth's is unnecessary, and will cost a lot more energy that would be better used elsewhere. To make it less hard you should: 1. Choose an asteroid that already has a close encounter with Earth. A great many of them already pass within 1 lunar distance from the earth. 99942 Apophis might be a candidate, but it's a little too big. 2. Choose as small an asteroid as possible/economical as it will take much more energy to move a large asteroid. The steps: 1. Use a series of gravity tractors to adjust the earth encounter to skim the atmosphere the atmospheric encounter should be constructed so that it puts the asteroid on an orbital path. Note that the gravity tractors will require years to alter the path of the asteroid, they should use a combination of ion drives and solar sails to maximize their efficiency. 2. The asteroid will have to be coated in heat shielding materials in order for it not to burn up in the atmospheric breaking process. A series of landing missions on the asteroid will be needed for this step. 3. Once the asteroid is in orbit, additional atmospheric breaking operations will be needed to reduce the velocity of the asteroid and lower the orbit. 4. For reentry you will need to install a lot of drag chutes etc to avoid catastrophic impact. [Answer] There's two big problems with your approach, besides those other answers have mentioned. First is orbital mechanics. You say that you will start by moving the asteroid to a solar orbit similar to Earth's, then slow it down so Earth catches up. This doesn't work how you think it does. When you slow it down relative to the sun, it will fall to a lower orbit. You can keep the highest point in the asteroid's orbit on Earth's orbit, but the rest of the orbit will fall below Earth's. This makes it more difficult to time it right so that the Earth and asteroid end up in the same place at the same time. Worse yet, if you do manage it, the asteroid and the Earth will be traveling around the sun at much different speeds even before the Earth's gravity really kicks in. The closest approach will be, at minimum, 11km/s. This is because, relative to the Earth, the asteroid is on a hyperbolic trajectory. All hyperbolic trajectories are at or above escape velocity (~11km/s for Earth) at their lowest point. So take L.Dutch's number of needed Saturn 5's and multiply it by 1.5 or so. Second, you have to deal with the structural integrity of the asteroid. Many asteroids are not single solid rocks; they're big clumps of gravel barely held together by their own gravity. The hundreds of Saturn 5's L.Dutch suggests will shake it apart. And even if you use gentler engines, Earth's gravity will pull it apart with tidal forces. So even ignoring the economics and logistics of actually getting powerful enough rockets to do this, for many asteroids it won't even be possible. [Answer] I have been wondering if eddy currents induced in a conductive meteorite might convert some of the object's kinetic energy into heat. I found speculation about asteroid-stopping tech but this is the only article I could find dealing with the question. <http://adsabs.harvard.edu/full/1946PA.....54..482R> [![abstract as image; sorry](https://i.stack.imgur.com/g8lD5.png)](https://i.stack.imgur.com/g8lD5.png) It makes sense that a conductive object would slow as it traversed a magnetic field. The faster the object, the more it will slow. Eddy currents are affected by the shape of the object they are within, and so maybe this is less of an issue of satellites at orbital speed? A nice thing about slowing with the earths magnetic field as opposed to aerobraking is your will not lose meteorite mass to abrasive air. A bad thing is that it might take several passes through the field to slow it down. One could augment the magnetic braking effect by imparting an electrical charge to the asteroid. Maybe this could even be done chemically with your rocket tech. A charged object will also be affected by a magnetic field, regardless of its conductivity. --- Prediction: if it is true that a (planetary) magnetic field can slow a (passing) conductive object one might expect to see deviations in the course of metallic asteroids passing the earth but not in those passing Mars which is without magnetic field. --- ADDENDUM I posted my question about induction braking using planetary magnetic fields. <https://astronomy.stackexchange.com/questions/29480/do-planetary-magnetic-fields-slow-the-movement-of-conductive-extraplanetary-movi> No answers yet but a comment with this very cool concept - [electrodynamic tethers](https://en.wikipedia.org/wiki/Electrodynamic_tether). > > Electrodynamic tethers (EDTs) are long conducting wires, such as one > deployed from a tether satellite, which can operate on electromagnetic > principles as generators, by converting their kinetic energy to > electrical energy, or as motors, converting electrical energy to > kinetic energy.[1](https://i.stack.imgur.com/g8lD5.png) Electric potential is generated across a conductive > tether by its motion through a planet's magnetic field. > > > This is perfect for steering an incoming asteroid. One could have several of these, some dedicated to braking and some to thrust akin to maneuvering jets. You use the kinetic energy of the moving body to steer it and convert that energy to heat for braking it. No moving parts. The reactionless drive! [Answer] Does a space elevator count for suitably near-future technology? No need for rockets, and having all that mass coming down to earth could drive an interesting generator for free leccy. Assuming you can find enough unobtainium to build the thing in the first place. As for landing, does it have to be a soft landing on the ground in one big piece? If you're going to send a lot of rockets up to get the thing, could you not top each one in a cheap shuttle/X37B type vehicle to bring it down in chunks? If you could have some control over the landing maybe over a shallow sea you wouldn't need anything too sophisticated or even reuseable, just suck the debris off the seabed. I'm not sure if the Inmarsat, Virgin and friends would appreciate you breaking up rocks in orbit given the risk of bits breaking off unexpectedly and knocking holes in satellites and tourists though. [Answer] For certain definitions of "landing" I think it might just barely be possible. Aerobraking isn't going to do much to anything big enough to be worth playing with. Structural integrity is going to be a big deal. If your asteroid comes apart you get Tunguska or Chelyabinsk. It better be pretty solid. I would put the asteroid in a polar orbit as low as possible (exactly how low this is depends on your rocket technology.) The last burn lowers the periapsis (counting aerobraking effects) to a trajectory that just touches down in Antarctica as soon as it is far enough inland to not kill penguins. It's energy is expended tearing up the ice. ]
[Question] [ I'm working on an RPG in a world with some magical elements, like a type of energy (so far unnamed) inherent in animals and humans. Those with high amounts of this life energy in them are thought of as "pure", while those with low amounts are thought of as "corrupt". It has many properties similar to thermal energy (such as methods of transfer and shiny metals being able to reflect it). I took a lot of inspiration from physics lessons on thermodynamics. There's also a mineral/ore in this world that is valuable because it is able to emit the previously explained life energy via radiation (whether at all times or only in certain conditions, I haven't decided yet, but it is able to do so at room temperature). Societies mine it and use it for protection because its pure energy repels the corrupt. **What already existing mineral could serve this purpose? If none, what elemental composition would allow this fantasy mineral to radiate thermal-like energy?** *EDIT: I should've been more clear. I want some kind of mineral, whether real or made-up, that would reasonably be able to radiate the magical "life energy" that shares some properties with heat. If I end up adapting an already existing mineral to fit my RPG's lore or creating a new kind of mineral, either way works, but if I create a new one I'd like to have an idea of what compounds or elements would be necessary to make it serve "this purpose", i.e. be used by the people of my world for protection with what they would call its "aura of purity". I hope that clears things up.* [Answer] There is no single hand-sized naturally occurring material that can continuously emit heat over long periods of time. If there was such a material, we would already be using it for power generation, wouldn't we? There are some possibilities, but none are ideal. However, you may be able to twist some of them into your story. You have four options: 1. Radioactive materials. The three most abundant radioactive elements in Earth's crust are potassium, uranium, and thorium. All three are enriched in certain types of granites. In particular, thorium and uranium are abundant in the minerals [monazite](https://www.mindat.org/min-2750.html) and [xenotime](https://www.mindat.org/min-6613.html). These minerals tend to concentrate in [mineral sands](https://geology.com/minerals/monazite.shtml), so they can be mined, concentrated in put into containers that can contain the heat, and then exploited. This is not something that I would recommend, because (1) it's radioactive, and (2) there isn't that much heat coming out of it. 2. Oxidation. Take for example [pyrite, a.k.a "fool's gold"](https://en.wikipedia.org/wiki/Pyrite). It is iron sulfide, unstable in the atmosphere. By crushing it to finely divided powder you are accelerating the reaction rate with the atmosphere, essentially allowing it to burn. The product is heat, sulfuric acid, and iron rust. 3. [Infra-red fluorescence](https://doi.org/10.1007/978-1-4419-9672-5_4). A material that absorbs energy in the form of visible light, and emits it back again in the [IR region](https://scholar.google.com/scholar?q=fluorescence%20in%20IR%20region&btnG=Search&as_sdt=800000000001&as_sdtp=on), which is then perceived as heat. 4. My favourite: An extra-solar meteorite containing material from a recent supernova. This material will be full of radioactive isotopes: [Al-26](https://en.wikipedia.org/wiki/Aluminium-26), various actinides (plutonium, etc etc). It will be hot. The downside, is that it probably doesn't fit your story of "life energy" because handling it will probably cause radiation death very soon. **EDIT** Ok so here's an idea, which would be an elaboration of point 1. A [naturally occurring nuclear reactor](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor) forms a concentration of [fission products](https://en.wikipedia.org/wiki/Technetium-99). This essentially heat-producing nuclear waste, and it can be mined (as requested in your question). But, it's radioactive. One way to shield people from the radiation, but allow the heat to come out of it, is by enclosing it in [lead glass](https://en.wikipedia.org/wiki/Lead_glass). This glass would block most of the radiation, with the added benefit of being very pretty. [Answer] **Mineral life.** [![horta and eggs](https://i.stack.imgur.com/iKiSt.jpg)](https://i.stack.imgur.com/iKiSt.jpg) <http://theminiaturespage.com/boards/msg.mv?id=258337> Your energy is life energy. It stands to reason that something with a lot of it is alive. It might not be alive in the way we think of life. It might actually be more alive than that. Depicted - the Horta and its eggs, from the Star Trek episode [The Devil in the Dark](https://en.wikipedia.org/wiki/The_Devil_in_the_Dark). The Horta is a silicon life form living deep in tunnels. The valuable and useful "crystals" found by human colonists turned out to be its eggs. The Horta protected its eggs. So too your "ore". The deep world is vast - much larger than our two dimensional surface shell. This subterranean realm is full of living things, sparking with life energy. These things are very different from the surface life we are familiar with. The ore are tendrils, or twigs, or spores, or possibly even eggs from creatures that live deeper down. Taken from their habitat, they slowly die as their energy radiates away with no prospect of replenishment from the earth. For the surface life, these crystals are useful and beautiful. Those that use them might realize they slowly wane and go out, but might not realize they are dying. Some specimens of this "ore" might be able to try to escape, or find other sources of life energy. Some might have a Horta equivalent - a parent or patron interested in saving them or preventing future abductions. [Answer] I'm going to assume by 'thermal-like' you mean actually thermal energy, and you'll just claim the heat as a side-effect of this new energy type. The only cases that can 'constantly' emit heat are minerals with high radioactive contents. Those are dangerous of course, but if you can find some way to make them plentiful and say that the native life in this world has evolved natural radiation resistance far better than our own, it might work. Plain mineral forms tend to not emit much heat, but pure forms of some radioactive metals emit so much heat that they glow red-hot (and some simultaneously fluoresce from their own radiation). Other options that work on much shorter time-scales: * Minerals which exhibit exothermic oxidation. Pyrite (iron(II) disulfide, also known as fool's gold) is probably the easiest example. Under normal atmospheric conditions, it oxidizes (very slowly) into rust (mostly iron(III) oxide)) and sulfur oxides (mostly sulfur trioxide, which is slightly dangerous as it will produce sulfuric acid in any nearby water). Another reasonably common example is arsenopyrite (iron(II) diarsenide), though that's a bit more dangerous because it produces toxic arsenic compounds when it oxidizes. Both of these produce a small amount of heat when they oxidize. The process can be sped up (and the heat increased a bit) by increasing the surface area of the minerals, or by increasing the humidity of oxygen content of the air they are in. * Hygroscopic minerals which exhibit exothermic dissolution in water. There are very few of these in real-world geology, all of them are ionic metal salts, and all of them are rare. If you're willing to mess with geology a bit, you could use oxides of alkali-earth metals for this though. Calcium oxide is an easy example, it can easily produce temperatures in excess of 300 degrees celsius while dissolving (enough to things on fire or cause some pretty nasty burns), though it does produce a rather caustic solution of calcium hydroxide (which can easily produce some pretty nasty burns of the chemical variety instead of the thermal variety). * Fluorescence in the infrared region. Quite literally, stuff that radiates heat when it fluoresces. I don't know of any minerals that exhibit this to any significant degree in real life, but it's been demonstrated in synthetic compounds before. Most likely, it would end up being a case of a mildly radioactive mineral that self-fluoresces, probably with some associated fluorescence in the visible light spectrum too (if you make the visible component narrowband, that could then be the 'color of life' in your world). --- Of course, you could also just pick a real-world mineral that already meets your other criteria, and just attribute this new effect to it as well. Gemstones may work well for this, because they can then also be processed by your people into nice looking decorations (and that may improve or reduce their ability to emit this life energy), and true gem-quality samples are rare for most of the 'classic' gemstones. Prasiolite might make an interesting choice if you go with this approach, it has rather beautiful pale green crystals, it's rather durable (it's a particular variety of quartz), it's pretty rare in nature in real life (but your geology could be just different enough that it's more common), and less scrupulous people can produce synthetic prasiolite by heat-treating amethyst. You could have a whole aspect to it where natural samples are far better at producing life energy, so they are significantly more valued, and some countries might have laws against producing and/or selling synthetic specimens. [Answer] ## Enjoy radiation You require a "rock which radiates magic" and "magic-radiation repels creatures which aren't inherently adapted to it". Making it *actual* radiation suits this well. Radiation need not unhealthy, if you can handwave resistance/adaptation. If your "pure ones" are radiation-proofed, they can happily eat plutonium-laced foods and it'll chemically concentrate in their bones. The "corrupt" would be the conventional non-radioactive life-forms. Precedents: There exist life-forms which can reassemble their own chromosomes after X-ray fragmentation (without apparent ill-effects), and fungi growing in the Chernobyl core which eat the radiation. --- **Your edit** clarifies that you want "a kind of mineral which can do this", but with no limits on other properties that mineral could have. Anything from chalk to salt to granite to clay could be appropriate, depending on what you will be asking it to do or what limits you need it to have. Making it high-grade uranium imposes some useful limits, like not being able to stockpile it; and the option of a death-and-glory use of it. ]
[Question] [ I'm currently designing an advanced peaceful alien civilization. In this civilization almost every individual has approximately a few hundred clones of themselves across their planet or even the universe. Here's how the thing goes: * First and foremost it is important to say that their species' bodies are techno-organic and that they are immune to practically everything that could kill a normal being. Meaning that they don't need any sort of medical care, and that the clones are not meant to be used as a way to ensure the survival of the individual by let's say, organ transplant. * Second of all, the clones are not created in the midst of the individual's life. You see, their species' infants are grown inside special capsules. You first describe how you want the infant to be like (think of it like designed babies), then you wait a few hours and then he or she is ready. Though they don't create just one infant, they create all of its clones with him/her. Basically it's like a large cocoon from which a bunch of similar looking infants come out. The family then takes the babies, grow them etc. **However, I've been thinking, why would a society want to have clones of themselves, what's the reason?** I mean, since they're peaceful they obviously aren't meant for an army, if they're basically immortal then they don't need them for medical support, plus they're not used as slaves if that's what you're thinking like in most movies, so why would they want they want to have clones, or more accurately, why would they want their children to have clones of themselves. [Answer] I haven't come up with a reason why anyone would want 100 clones of their child, but I found a way how the same result could be achieved. ## Baby catalogs Soon-to-be-parents can choose attributes of their baby from a catalog. It's basically like a character creation in a video game - choose one of 10 available skin tones, combine with one of 5 available eye colors and so on. The number of possible combinations is huge but not infinite. To make choices easier for parents, there are basic packages for optimized default babies (high intelligence, immunity to all known illnesses and so on). If most parents choose a default baby and change only appearences, you end up with hundreds of unintentional clones like today hundreds of people share the same first name. [Answer] You say that these aliens have techno-organic bodies. Perhaps they were simply always made in batches. I'm guessing that they didn't evolve that way. So their creators may have intended them for *whatever* and made them in identical batches. Now, they may no longer do *whatever*, but they still reproduce in the same way. They have never seen a reason to change it. Each one of them has many clone siblings and that feels natural to them. They want their children to have siblings who are basically the same as each other, like twins. Yes, they will still have unique characteristics and personality. But their genetics and general background will be the same. [Answer] ## They evolved having large litters of children Alien psychology is not the same as human psychology. First, let's consider why humans often want to have children. In many ways, humans' desire to have children seems irrational. Children are a financial burden, they require a lot of effort, and they limit the freedom and free time of the parents. So why bother? There are many possible reasons, but part of it is that we evolved this way. We evolved emotions such as love, we evolved to feel a strong bond with our children, and we evolved parental instincts. Perhaps these aliens evolved having large batches of children, like fish or sea turtles. It's only natural that they'd want to continue to do so once they discovered advanced technologies like cloning and gene selection. When these technologies came along, they would design their ideal offspring and order a batch of the same size they would have had naturally. Why make them all clones instead of customizing each child? Again, it comes down to alien psychology. This is a species that evolved having hundreds of similar-looking children. They simply place no importance on differentiating the genetics of each one. Once the parents have picked out their optimum designer baby, it's only natural they'd want them all to have the same design. Similar to if a human IT department head were to order 200 computers for their company and were asked if they'd like to customize each one. They'd say no: they already chose the optimal design and they place no importance on individualizing each machine. [Answer] # Eugeny and narcissism If the species has a will to power (even if as pacifists) and an ideal of beauty/genetics, then, as the lyrics to Pearl Jam's *Do the Evolution* go: > > Admire me, admire my home, admire my son, admire my clones! > > > [Answer] # The perfect constructs to fit their roles. There is a number of roles to be filled in society and each person has been tailored and tweaked over many many iterations to fit that role until there is no need for variation. In fact variation of any kind is frowned upon unless it fulfills a predetermined need - which would have to be formulated according to the procedures, submitted for review by the bureaucracy, accepted provisionally, put on the waiting list as low priority - and *finally* presented to the Ruling Council, debated, and rejected/accepted, or sent back for ammendment to go through the whole system again. These days, The Council rarely accepts requests for change to the accepted genome lists, in fact not once within living memory. Through time your society has been perfected such that all scientists are of a half dozen types - each reproduced across the civilisation, all engineers are of only a few types, similarly repeated for the whole of society's varied roles. This means that society can be truly efficient and standardised across the whole multi-system civilisation, everyone knows their role and is perfectly happy, because - why wouldn't they be, they've been designed to fit their lives perfectly. In this egalitarian utopia, how could anything possible go wrong? [Answer] **It's pragmatic** As advanced as your aliens have become, with the ability to design babies with an optimization of the many complex potential genetic interactions, they are more aware than lesser intelligent species that designing a really good individual is hard. Setting aside the question of mass production, the other reason you don't have every iPhone or Samsung Galaxy be uniquely distinct from all the others is that it would require an absurd amount of design work to concieve of all those variations, and try to optimize in every case. Now consider such design in terms of all the potential interactions between all of an advanced organism's genes! With "natural" biology, with generalized and in some ways modular traits, you might have the advantage of occasional great innovations, but are forced to accept that things might also go somewhat or horribly wrong. With fully (or largely) *designed* techno-biological creations, you don't want a dice roll. Variety is good, sure, and your aliens know better than to have every crop of babies be identical. Still, new, rigorously tested, authorized models aren't a dime a dozen. You might even have the equivalent of the FDA, a Mercy and Preservation organization, protecting both the society and the babies-to-be from the "depredations" of carelessly random child design, when the technology exists to make sure in advance that the children designed meet general specifications (as developmentally modeled by incredibly powerful computers). [Answer] Some possible solution: * Gender distribution making it difficult to find a possible re-population match * Connecting to current trend in the west with lowered sperm count have had a counterpart in their history where the population became sterile and this was counteracted by invention/approval of cloning of the humanoid population. The population don't, or few of the population, have the ability of natural reproduction. * Gattaca in the future. * Sovereign plot (Guardians of the Galaxy) [Answer] **1. Efficiency.** [![mold](https://i.stack.imgur.com/K4UGM.jpg)](https://i.stack.imgur.com/K4UGM.jpg) It is not trivial to set things up to make a techno-organic clone. There are a lot of details one must attend to - correction of mutations, optimization of technogenetic interfaces and so on. Once you have everything set, it is economical to use your setup multiple times. It is like making a mold for a cast part - if you have gone to the trouble of making a good mold, you will want to cast multiple parts with it. **2. Family.** These clones are raised together, kibbutz style. They form a bond with one another like that of identical twins, but they are many. Throughout life they will have an actual fraternity / sorority worth of clone sibs whom they can count on to back them up no matter what. In an advanced society where there would otherwise be a real risk of individual isolation, these networks of clone sibs bind the culture together. [Answer] ## Whatever this race's common goal is If these aliens you describe are really semi-immortal beings, it's only logical you're talking about a very advanced civilization. The way I see it, it's virtually impossible to grow this far as a race as long as you keep having futile fights over things like greed, racial issues or religion. Part of the solution for this, let's say, "Earther" problem, is having a common goal, a purpose. Maybe the thing that drives this alien race is reproduction - they feel like they need to spread to every corner of the universe and maintain themselves alive. Or maybe they're trying to save the universe from an ancient danger, an evil that will destroy many lives. Regardless of what you choose their goal to be, that can't be something easy - and that's why they need the clones. This extra manpower is just as capacitated as the original to perform whatever jobs they need to - say building some crazy reactor. They're not obligated or forced to do anything because of the simple fact that they WANT to do it, because that's helping the race achieve the common goal. They see the bigger picture. After it's done, maybe the clone sticks around to help some more, maybe he starts the building of a reactor of his own - and thus the process repeats. [Answer] It could be a way to find perfection for a specific role. Let's say a certain baby was made to be an expert in building ships, if one of the clones show some kind of revolutionary idea that improve the ships he makes more than the other clones, they could use him to make the next batch of clones, they may be clones but their experiences will be different(right?), and that could change them in some way that can be replicated. The same goes for flaws, they'd find the reason and correct it in the next batch. ]
[Question] [ I was reading up on Mars thin atmosphere and was wondering how could Earth becomes like the red planet except it only has only 100 pascal (air pressure) at imaginary sea level? Mars is 600 pascal on average. [Answer] Earth's atmosphere is held by force of gravity and by [magnetic field](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field). The gravity is not going to change anytime soon but magnetic field is bit unstable and its source is not fully understood. We know it's generated by the iron-nickel Earth's core but we don't know all the details, including how and why it sometimes [switches the poles](https://en.wikipedia.org/wiki/Geomagnetic_reversal). If the Earth gets hit by unusually strong cosmic event (Solar megastorm, gamma ray burst) during the magnetic reversal period it could potentially lose large fraction of its atmosphere. But whatever happens the pressure will never get lower than on Mars. The Earth is much heavier, so even if most of our atmosphere gets somehow blown off it will be rebuilt by evaporating oceans and by volcanoes producing carbon dioxide and some other gases. [Answer] A sufficiently nearby supernova might do it. I've read (don't recall where to offer a citation) that a supernova within 100 light years would produce very noticeable climate effects, and one within fifty light years would result in an extinction event -- both from direct radiation effects and via destruction of the ozone layer (which would take centuries to return to normal). A significantly closer supernova might result in significant atmosphere loss, by heating the upper atmosphere enough to greatly accelerate the normal slow loss. Whether it would be enough (even during a magnetic field reversal) to get down to 100 Pa, I seriously doubt -- but if combined with other events, perhaps a "perfect storm" of solar activity and a pre-existing runaway greenhouse, it might contribute the "last straw". The bad news here is that there are no genuinely nearby stars that are supernova candidates -- the nearest is probably Betelgeuse, which is far enough away to have only small climate effects. Vega is quite close, and is the right kind of star, but isn't in its senescence. Eta Carina is in the "any day" stage, but is much too far away to matter. [Answer] It all depends on how quickly you want this done. Earth's atmosphere is slowly leaking away each time an air molecule in the upper atmosphere reaches escape velocity (Earth's magnetic field and ionization of molecules in the upper atmosphere complicates things a little, see [Atmospheric escape](https://en.wikipedia.org/wiki/Atmospheric_escape)). The speed of air molecules is dependent on the square root of the absolute temperature so you need a rather large temperature increase to make the molecules go faster so the atmosphere will leak away more rapidly. The current mean speed of air molecules at room temperature (300K) ~ 347 m/s and speeds follow the [Maxwell-Boltzmann distribution](https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Kinetics/Rate_Laws/Gas_Phase_Kinetics/Maxwell-Boltzmann_Distributions). The escape velocity is 11186 m/s. You only need to increase the fraction of air molecules with velocities greater than the escape velocity. Increasing the temperature to 1500K will do the trick, although this will increase the pressure at first due to evaporation of volatile materials such as the oceans and the earth crust. A good way to increase the temperature substantially is something like the [Theia event](https://en.wikipedia.org/wiki/Giant-impact_hypothesis) wherein a Mars-sized planet collided with the proto Earth forming both the Earth and the Moon as we know them. As there are no Mars-sized bodies with a remote chance of a collision course with Earth to be found in the solar system at this point in time, it would have to be a [rogue planet](https://en.wikipedia.org/wiki/Rogue_planet). For your purposes, this would have the added benefit of ripping away a substantial part of the atmosphere in the collision process. Still, it would take a few dozen megayears for cool down and evaporation. An altogether different method is cooling down sufficiently such that the nitrogen and oxygen molecules freeze out of the air, which occurs 54.36K (the melting point of dioxygen). Moving Earth's orbit beyond [Neptune](https://en.wikipedia.org/wiki/Neptune) would achieve this. Of course a collision with a rogue planet and as a result of momentum transfer, shifting the orbit of the resulting pair to a much wider, probably highly eccentric, orbit around the Sun will make all of this go a lot faster, but still a megayear for the end result. [Answer] One obvious answer to come up with is a CME (Coronal Mass Ejection). You haven't given a science tag so it's imaginable (perhaps a series of them) even if NASA says it can't happen to Earth. **Solar storm can strip a planet of its atmosphere, says NASA study** *"Solar flares, for instance, affect Earth's upper atmosphere and may disrupt satellite communication systems. Another form of the sun's activity called coronal mass ejections (CMEs) may have more dramatic effect. A CME, according to NASA, could disrupt GPS signals and radio communications. But not even the most powerful CME can bring about the end of the world, NASA assures everyone."* Read more: <http://www.digitaljournal.com/article/315710#ixzz5YntcFWc4> [Answer] In [The Dark Forest](https://en.wikipedia.org/wiki/The_Dark_Forest), the author describes a deliberate attempt to decay the orbit of Mercury such that it falls into the sun. This event expels a significant amount of dust, etc. into the solar system which gradually widens to beyond Earth's orbit. The resulting friction and disruption of all this dust & matter gradually strip away Earth's atmosphere. While in the story Mercury was pushed into the sun artificially, you could postulate that an interstellar and sufficiently large body could enter the solar system by ordinary gravitational attraction and result in similar consequences. ]