text
stringlengths 22
2.11M
|
|---|
[Question]
[
How would you design armour to be effective against wizards?
For simplicity's sake we'll have the only magic available to the wizards be elemental magic(fire, ice, electricity, wind, light), and they have to cast it as a bolt or stream from a wand or staff, where the wand can be fired off in quick succession but the staff requires a five second charge before the magic is cast, and where the wand produces bolts with the range of a crossbow but the staff produces a stream of typical flamethrower range for three seconds. The technology available to the people is the post-Maxwell european victorian era. Wands can hold 20 bolts while a staff can hold 5 streams, and they have to recharge on a 24 hour basis.
**Elaboration on the elements:**
1: Fire. The fire bolt would be able to cause fourth degree burns to a head-sized target while the stream would be the typical stream of fire produced by a flamethrower.
2: Ice. The bolt is an icicle the size of a gladius while the stream is the production of snow that can cause frostbite or hypothermia if stuck or stayed in for too long.
3: Electricity. The bolt is a typical lightning bolt but the strength is of second degree burns and muscle spasms, while the stream is like what I'd like to call palpatine shenanigans, portable weaponized tesla coil if you will.
4: Wind: The 'bolts' are strong enough to stop an average man in his tracks while the stream can make someone roll backwards if they don't hold on to something.
5: Light: Bolts are flashes of light capable of blinding someone like a flash bang while the stream is closer to a laser capable of igniting wood in three seconds.
[Answer]
## In a Typical Fantasy Setting, Use a Spiked Pavise
[](https://i.stack.imgur.com/OQ5jG.png)
A Pavise is a large wooden shield with a spike on the bottom. Shields create distance between your body and the attack; so, not only does the shield stop the attack, but unlike armor, it prevents radiating injuries as well from when the shield itself gets hot/cold.
1: Fire. Wood is actually a great thermal resister. It takes just as much total heat to fully burn a given amount of wood as it does to melt iron; so, burning through an wooden shield quickly is about as hard as melting though several layers of plate armor. It also does not conduct heat well; so, while metal armor would heat up and burn you long before it melts, wood takes a lot more time to feel heat though. Furthermore, most medieval shields were also faced with hide and/or treated with vinegar which made them more fire resistant than untreated wood; so, even if a fire attack is hot enough to ignite wood normally, it would not be able to sustain a reaction against a treated wooden shield. So, fire attacks might scorch the surface of your shield, but not catch on fire or harm the user through it.
2: Ice. Most historical shields could stop a gladius quite well; so, ice bolts are not that big of a deal. As for the cold spray, again wood is a great thermal resister so you will not feel any of the cold on the other side of your shield unless it has a lot of time to build up. Plenty of time to close range and cut down the troublesome caster.
3: Wind: This is where the spike part of your Pavise comes in. A Pavise is designed to be stabbed into the ground making it a sort of mobile wall; so, you can plant your shield in the ground to brace against the force of wind attacks.
4: Electricity. By using the spike to brace for lighting attacks, you can ground your shield so that the electricity goes down through the shield instead of through your body.
5: Light: All the same protection you get from fire also applies to light except for the blinding part. Blinding light is hard to deal with using medieval technology. Many helmets were designed to be tilted just before an arrow or lance strike to protect the eyes; so, the same training may apply to light spells.
[](https://i.stack.imgur.com/qzoaJ.jpg)
## But in post-Maxwell European Victorian era...
This changes things. The Victorian Era had sighted, riffled firearms that will decimate your wand and staff armies. Depending on the exact decade, you may also be looking at cartaged ammo, Gatling guns, revolvers, etc. While a Pavise may still be practical against magic, the guns of this age will cut right through them, and any other armor you try to field. They will also have a better effective combat range than staffs because they are better designed to be aimed. The average crossbow engagement was fought at 40 meters, with a theoretical max range of 300 meters. A crossbow is also easier to aim than a stick without a stock or handle; so, more like a longbow, your staffs will likely have a hard time hitting anything more than 20 meters away without significant training. In contrast, by the mid-1800s most battles were fought at 60-100 meters, with weapons that had a theoretical max range of 900+ meters. Even without the modern niceties of gas repeating mechanisms, the adage remains that [magic staffs are weapons of terror, and guns are weapons of war](https://www.youtube.com/watch?v=NjlCVW_ouL8).
So to answer your question, the best defense in this era is a better offense.
[Answer]
Armor. Faraday cage (metal wire cage, chainmail basically) to stop electricity, fire resistant materials like asbestos to resist fire, and chainmail to stop ice.
[](https://i.stack.imgur.com/56fYV.jpg)
[](https://i.stack.imgur.com/qnf7c.jpg)
Shoes. Spikes, to grip the ground in event of wind. Fire and electrical resistant as well.
Goggles. They could probably make some sort of tinted glass which would be resistant against flames.
With these defences the wizards won't be a lot more deadly than people with guns.
[Answer]
Apart from being produced by magic, there are already potential injuries which can be caused by fire, ice, electricity, wind, light, and we have protection against them. They are commercialized as PPE ([Personal Protective Equipment](https://en.wikipedia.org/wiki/Personal_protective_equipment)) and in many countries they are made mandatory by law.
>
> Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemicals, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. Protective clothing is applied to traditional categories of clothing, and protective gear applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit.
>
>
> The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it does not eliminate the hazard at the source and may result in employees being exposed to the hazard if the equipment fails.
>
>
>
Your armor has to be designed along the same lines.
[Answer]
/the only magic available to the wizards be elemental magic(fire, ice, electricity, wind, light/
**Magic armor!**
The magic armor uses the same 5 elemental magics. A given magic as defense would be more or less useful vs any given magic as offense. Fire and ice are both good against light and of course great against each other. Wind is good against fire, ice and electricity and also pretty good against wind but poor against light.
You get the idea. Fight magic with magic. Plus it is more fun to write than writing about people with lead codpieces to defend against electricity. Although now I think I need one of those.
]
|
[Question]
[
Imagine both humans uploaded into computer networks and biological humans exist in the same society. The uploaded humans have the normal range of human personalities (not an evil-AI-takes-over-the-world plot). For the rest of this question, I will refer to the uploaded human AIs simply as AIs. Because the AIs are running on computer hardware, they can think much faster than a biological human can and make decisions in microseconds. Some humans for various ethical, cultural, and religious reasons have chosen not to upload themselves and join the rest of the human species in becoming a machine civilization. They still try to live in society, with some of them forming their own societies ("human only" cities, a country which has banned mind uploading, etc).
Some extra details: The AIs have cybernetic bodies which they can enter which are physically superior to a human in strength, speed, and precision. A side note is that a poor AI may not be able to afford one and may just exist in a server. Mechanical bodies can also be specialized to be very adept at particular tasks. This means the AIs do not need humans to do general purpose labor.
Approximately 90% of the world population is uploaded people at this point, so biologicals are not unthinkably rare but are still the minority.
The strongest military players are controlled by AIs and defeating the AI nations in a war or uprising is unrealistic.
The question is this: what is the relative value (from a monetary sense) of a human compared to an AI in this scenario? I believe the humans would be comparatively poor, but it is hard to conceptualize just how much poorer. How much more money could we expect the average AI to have than the average human?
Edit: As pointed out by several people, the question of if the robotic bodies of the uploaded humans can self repair is important. They do not have self-repair capabilities. They could fix a broken wrist by replacing a motor, but they couldn't magically fix a fried circuit board. This means that robotic bodies require a large industrial complex to support while fleshy human bodies require relatively simple logistics to support (a fishing rod and a wheat farm).
[Answer]
**There seem to be some assumptions in your question that might not be realistic**
1. Apparently the machines are entirely capable of repairing themselves. That sounds obvious, but it isn't. Humans get a scratch and can all but ignore it and it heals by itself. Unless you have [Clarkean Magic](https://en.wikipedia.org/wiki/Clarke%27s_three_laws), when a machine gets a scratch, things seriously stop working (don't believe me? Scratch one of the copper traces on your computer's motherboard. Just one. Pick a small one.) This is a fairly massive assumption.
*Detection of hardware failures has been a nonstop effort in the computer industry. I remember working on JTAG Boundary Scan tech back in the day. You'd be surprised how difficult it is to distinguish between "that wasn't expected, but it was legitimate" and "whoa! Something's broken!"*
**Conclusion:** Humans are immensely valuable, possibly even revered to the point of enslavement, because they can fix things when they go very, very wrong.
2. Apparently this is a [post-scarcity economy](https://en.wikipedia.org/wiki/Post-scarcity_economy). It is, IMO, impossible to believe the idea of a post-scarcity economy. Unlimited energy, unlimited resources, unlimited opportunity, and all basically *free.* In a word: boring. From this perspective, the creation of the hardware necessary to house an uploaded intelligence, the cybernetic body for periodic use, the repair and recharging solutions (infinite battery? That's even more boring), are all incredibly cheap.
*In reality, [gallium is really rare](https://www.livescience.com/29476-gallium.html), as are a great many other technologically useful minerals. Things will be hard (aka "expensive") to build. Frankly, the **cost** of shifting someone to AI will be (and should be) very non-trivial.*
**Conclusion:** Humans are cheap to create and cheap to maintain. That's valuable in a world where if anything goes wrong, the cost of fixing it technologically could be very high. Besides, mewonders how many of the Cyborg Overlords will want to dig in the mines. ([Relevant Star Trek TOS episode](https://en.wikipedia.org/wiki/The_Cloud_Minders))
3. Finally, I think it's a whomping big assumption that people would actually *want* to "live forever." We all think about it during our lives, and it's a truism that the people who want to live to be 100 are usually the 99-year-olds, the the truth is much more *interesting.* What would happen to human sanity, morality, and ethics, once uploaded to an AI that lives, theoretically, forever? It's jumping quite a long way to the isle of conclusions to assume *nothing.*
*In reality, people get bored. Very few people want to do the same thing for decades on end. Most people, I suspect, want to retire. And then they get bored again. That leads, methinks, to either of two things: stupification or madness. And the only thing I can think of that's worse than an expensive AI that has the cognitive and social value of a tomato is the evil-AI-takes-over-the-world madness you appear to not think would happen. I'm not even sure madness would be required for that. Sociopathy and psychopathy should be thought of as dials every human has. For most people, those dials are set within what society calls "normal" ranges. For a few, they're off-center. For (thankfully) fewer still, they're turned way high. And you just gave **all** those people massively powerful bodies that can live forever. Remember that Facebook bully you hated so much? That person gets to live forever in a very difficult to destroy condition. I'd sure hate to see the legal system of your world.*
**Conclusion:** More people will avoid becoming cyborgs than you might think. Unless forced to it, I suspect many if not most will remain human just because they enjoy intercourse. And beer.
4. You're assuming that because computers can perform arithmetic faster than humans, that the proverbial positronic brain can "think" faster than humans. The only problem is that computers are really, really, really, really bad at doing anything *associative.*
*Yes, neural network hardware and programming has come a long way, but unless you once again invoke Clarkean Magic, the problem you face is that computers can **manipulate** data very quickly, but they come to **conclusions** very slowly. In fact they're bad at it. Look how long it's taken to get even basic facial recognition, and it's still beaten regularly by people growing beards, wearing makeup, or puffing their cheeks when the image was captured. Humans are incredibly good at visual and auditory pattern matching and we're amazing when it comes to putting the proverbial 2 and 2 together.*
**Conclusion:** Jumping into the AI pouch isn't all it's cracked up to be. There are pros and cons to being an AI just as there are to being human. You loose something, becoming a computer simulation. You lose a spark of intuition that lets you realize you're in danger when a computer's "judgement" based on protocols and statistical profiles disagrees. Some call that having a soul. Computers don't have them.
---
**And Finally:** From a certain point of view, this question is a bit erroneous. You did not completely explain all the rules of being an AI (its advantages and disadvantages) and, therefore, we really can't tell you what a human is worth in comparison.
The trouble is — it's *your* world. If you want humans to be valueless you can always come up with rules to force that to be. You literally could tick off the entries in my list and say, "yeah, my robots are better than that...," in which case, humans are worthless.
But that's a really boring story. It's just another kind of godlike character that your average reader can't relate to. One of the most brilliant moments of dialog from the *Matrix* trilogy was this:
>
> Did you know that the first Matrix was designed to be a perfect human world? Where none suffered, where everyone would be happy. It was a disaster. No one would accept the program.
>
>
>
Neither will your readers.
We already know that computers are flawed and that it's impossible for imperfect humanity to create a perfect machine. So, the real questions you should be answering yourself are, "what are the limitations and restrictions of being an AI in my world? What is the price people pay for cybernetic immortality?"
And if you keep finding roses, you haven't found the right answers. If you have not done so, I strongly recommend reading Asimov's *[The Bicentennial Man](https://en.wikipedia.org/wiki/The_Bicentennial_Man).*
[Answer]
Context.
Believe it or not mere speed is nothing. If you are cooking on a 4 eyes stove and you are using them it matter little of you have an Olympic athlete behind the thing or your 90 yo gramma. In fact I would take the gramma because she probably knows
more about cooking that the pure speed guy. I mean the 2 extra second he saves with his speed in moving the pots is nothing compared to babushka's tasty meals
## How does this translate into the job market and life?
Intelligence based job are dominated by AI. 100%
Less demanding jobs? Why waste money?
Think of a tech company CEO and a taxi driver, no insult to either or anything.
You need your CEO to be very smart to stay on top now and 10 years in the future.
So. That CEO as long as he or she is doing well then the CEO is getting paid well.
How well? A crapton of money.
Now a taxi driver? I don't care if my taxi driver is the smartest person in the world. I want him to drive the taxi from point A to point B and most of us prefer him being silent.
But the taxi driver is AI enhanced which costs money. The AI enhancement which costs money he has to pay somehow, so he wants a higher wage. But as a company he brings me **nothing** extra to justify giving him more money and it's just better to hire an average guy for an average job. Why throw money away?
So. Believe it or not you want the cheapest labor that does the job.
**In complex jobs you want intelligence true. But in other it does not matter.**
## Art
>
> I'm extremely quick at math
>
>
> What is 15\*8
>
>
> 13
>
>
> That's not true.
>
>
> Yes. But it was **fast**
>
>
>
Not only playing the piano faster is not big of a deal as there is speed to be kept. But also Speed or well playing is nothing compared to composing a piece let alone a symphony.
Now I'm certain it would be fun listening to 4 hours of deathmetal, or classical, preform by your AI with CB bodies as they don't tire.
But my neck will be dead, metal has this thing called headbanging, and even in classical people want to take a break.
So. To recap: the ability to create art is very prized.
Speed and repetition is good for certain things. Acting, musicians, painters...etc with CB bodies and AI brain will do better to a certain extent, true.
## Cybernetic bodies with AI cores are the big thing
I don't mean to just say look your idea is wrong. But the way I see it so far is that a cybernetic body, CB for short, give you all the good stuff of human labor while the AI cores provides the intelligence all without having to worry about human rights.
Think of it this way. A CB + AI core is better than humans but do **not** follow human laws. Which is perfect. Sell perfect servant suits to people.
They drive, clean, used for sex, protect, cook...etc for you and if you are angry enough to just destroy a bunch of money you can get a sword and decapitate one without any loss expect financial loss.
## What is the relative value (from a monetary sense) of a human compared to an AI
So we are back to it so say: Whatever that human, AI, CB + AI, alien, intelligent bear, angel, demon, god, devil, amoeba, transformer...etc brings to the table.
When you are paying money to people you do not give a toss about anything but what they give in return. Sure loyalty and keeping good morals and good fame is nice. But companies are built on you do X we give you Y and all is well.
[Answer]
I believe human capital and human-run operations would have a much larger monetary value than that of artificial intelligences.
Although your question addresses that the AI bodies are far superior to humans, you did not specify the state of software in your world.
It is much easier for terrorists to hack into AI and create AI computer viruses (just as some do with regular computers in the current state of technology) than to biologically engineer genetic or viral weapons against humans. AI are still based on code and programming that can be (relatively) easily modified. This would especially apply to first responder - type jobs where immediate action is required.
When an immediate, reliable, guaranteed response is needed in a job position, humans will dominate.
[Answer]
Frame challenge: one could turn this on its head.
Robot bodies just lack a certain something - they don't have the same intensity and quality of emotions. But being a human is much more tedious, one needs to take care of all those biological needs, and it requires space.
In that future, space is a premium, as is organic material, and all of the knowledge and medicine to grow and keep the human body alive, provide backups in case of accidents, etc.
So only the very rich can afford to be in human form - others have to make do with a little bit of storage space...
[Answer]
## Maybe Start at Relative Cost to Find Relative Value
Digital existence isn't free. The human mind has roughly $1 \times 10^{15}$ synapses, and they fire at a rate of around 60 Hz. That's $6 \times 10^{16}$ unique firings in the human brain, per second.
If the technology of your uploaded human beings takes the same amount of processing power, it will require $6 \times 10^{16}$ hashes, or about 60 petahashes per second to simulate a human mind at NORMAL speed. [Current technology](https://medium.com/luxor/energy-consumption-kwh-to-hashrate-ph-s-guide-for-bitcoin-mining-b0c02872c089) gets you about 100 terahashes (0.1 petahashes) for about 3 kilowatts (3 kilojoules per second).
For some references, a human body (mind and all) typically consumes 2,000 kilocalories (8,368 kilojoules) per day. A machine mind, at current processing efficiencies, would require $3 \times 3600 {{seconds} \over {hour}} \times 24 {{hour}\over{day}} = $ 259,200 kilojoules per day (259 megajoules).
A machine mind requires a little over 30 times as much energy to maintain, compared to a person.
At current energy prices (14 cents per kilowatt-hour), a machine mind costs 3.36 dollars per day (about 100 dollars per month) to maintain.
## Faster Than Real-time
If the mind is making decisions taking seconds in microseconds ($1 \times 10^{-6}$ seconds), then the costs scale up by a factor of $10^{6}$. It would cost 3.36 million dollars per day, just for the power to run such a mind, which comes in at a whopping 259 terjajoules per day (2.87 grams of mass-energy per day, per mind).
## Other Costs
As anyone in a nursing home can tell you, living with nothing but the four walls around you becomes very boring.
Each mind is probably going to want a simulated environment to work in. They will probably demand, at minimum, a digital "real" world which includes up-to-date feeds of what is going on, in all five senses (sight, sound, touch, taste, smell).
This will require you to build and maintain a comprehensive sensor network at least covering a large town -- and possibly covering the world.
But, there's a maybe unexpected benefit to this cost. With augmented reality, digital persons and real persons could interact in the same shared space.
## What Value Do Your Digital Persons Generate to Justify Their Cost?
[Answer]
**Evolution**
Only Biological humans can have children, which means they continue to evolve, It also means all humans are the offspring of those few biological humans so whatever makes them want to be biological will win in the long run, as only people with it get to reproduce, they will literally outbreed the mechanicals. It also means if you want kids you have to be biological, and most humans do.
**Independence**
Earths biosphere can support biological humans perpetually, small groups of humans can survive without outside help, this can't be true of mechanical humans, they will need society to keep them alive. Look at how many humans move off the grid now, those same kinds of people will favor biological bodies. This applies to skills as well, I can train my body for a new skill and it will adapt to preform them better, I am not stuck with whatever it is built for.
**Better biology**
If technology has advanced enough we can upload human minds we have likely solved most of the short comings of human biology, we will have certainly reached the point we can drastically change the human genome, so it is not super machines vs modern humans it is super machines vs super humans. Aging, disease, amputation, and a whole plethora of other current problems will likely not be a problem for your biological humans. So it is **temporary mechanical bodies vs biologically immortal biological bodies**. So do you want a body that will last forever as long as you feed it or a mechanical body that will wear out in a few decades.
]
|
[Question]
[
I have some isolated ice age civilizations in a setting I'm working on and there's one thing I'm not quite sure about; rapid sea level changes.
[](https://i.stack.imgur.com/1XXLh.png)
Sea level during the last 10,000 years or so of the ice age was absolutely not stable, unlike recorded history, changing quite a bit even before the big Meltwater Pulse. Civilizations tend to stick to rivers and coastlines for all sorts of good reasons, so this is not something to be ignored. Any civilizations that existed back then would likely be on the continental shelves or on rivers leading to them (which would also make them not evident in modern day). Prior to the Meltwater Pulse, the rate of sea level increase looks to be several cm/year. Year-to-year not so bad, but it adds up over time.
[](https://i.stack.imgur.com/7cuMQ.png)
On the one hand, that's kinda gradual, but continental shelves have gentle slopes, so an increase would cover land area faster than, say a steep volcanic island. Not to mention storm surges reaching even higher. How manageable is this? Cities, villages and farms could be built higher up over centuries, but I've mostly I'm wondering about sea walls. I've seen those depicted in numerous sci-fi franchises around coastal cities. Is a "Great Sea Wall of China" doable with stone/concrete? Such a wall would need to also run up any rivers a ways up too, I imagine, turning them into something like The Los Angeles River. I know there are dams holding back some pretty big lakes, but this the ocean we're talking about.
Am I missing something? Underestimating the problem? Or do I have the basics down and I'm just second-guessing myself?
[Answer]
### Nomadic <-> settled is a sliding scale.
There are, shall we say, "levels of settlement". Moving a modern city 10m higher up the coastline is a massive undertaking, but moving a few tents is pretty easy. Moving a town of mud huts with thatched roofs and preparing new farmland is somewhere in between on the logistics scale. I'm guessing your civilisation has wood or mud brick houses, thatched roofs, and hunts for food with a mostly meat diet (not a lot of farming in an ice age). Dismantling and rebuilding that architecture is annoying, but not impossible.
There will be warning the seas are coming, depending on how frozen the water is at that particular location.
If it's mostly water: king tides, storm surges reaching the town, and then submerging it. (Kinda like what's happening to us now). Thered be some rule of thumb devised - eg When the water touches the town twice in a year, time to move.
If it's mostly ice, frozen very thick, the ice will literally approach the villages, knocking trees down as it comes like a slow motion villain. They'll have plenty of warning to move when the ice is hundreds of metres away.
So your society will need to move, say 5m up every few generations. After a few repeats and it gets into the culture they'll become pretty good at moving, dismantling, and rebuilding.
[Answer]
You are not overestimating the problem. There have been humans around for 300 000 years.
But only after the coastal regions became usable and reliable, we were able to start our civilization, some 30 000 years ago.
This is a huge one.
* Walls don't work eternally. The sea water will come into the city through the ground and inject salt into the drinking water reservoir. That's a problem northern Europe will have to face in the coming decades, Jakarta already today.
[Answer]
There were very few cities more than 10,000 years ago and those that did exist were located on rivers such as the Tigris and Euphrates. Up until 10,000 years ago most of humanity lived as hunter gathers so would not have noticed the sea level rise - their lands would simply have shifted over time.
Even 8000 years ago the number of cities was still small and by then most of the flooding had already taken place so the issue is limited.
A Great sea wall of China might well have been possible. Looking at what the Egyptians did with the pyramids, the technology would have been available to build a very considerable wall. However the difficulty is why? How valuable is the city and a bit of farmland? It would almost certainly have been easier to abandon the city and move further inland.
Or more likely some sea walls would have been built, but eventually the effort would have drained the local economy. People (especially the younger ones) would start to leave to make a fresh start elsewhere. In the end salination would have started to contaminate the ground water and that would rapidly accelerate the process.
[Answer]
### Look to New Orleans for a Reference
The city sits on the mouth of the Mississippi River feeding into the Gulf of Mexico. Only the old city is above sea level. The parts of the city below sea level form part of the brackish swamps in most of the region. You might rightly call the old city a high spot in the swamp, located on the river. Expansion of the city has been with fill dirt or building on top of old buildings, sea walls, and pumping out isolated lowlands.
### Or look at Venice
You could choose not to fight the ocean. There may be enough (118) high spots in the new lagoon created by water incursion, and they may be close enough together, that personal boats can conduct a person from place to place. Most of the city however will grow along the new coastline.
[Answer]
Let's get some numbers here. The sea level change was 120 meters over 20,000 years. Now, the bulk of that was in the middle 8 thousand years of that range. So the peak rate was something like 2 meter per century.
[Tides](https://en.wikipedia.org/wiki/Tidal_range#:%7E:text=The%20typical%20tidal%20range%20in,16%20m%20(52%20ft)) range from 0.6 meters per day (twice a day) up to several meters (16.3 m at largest) in unusual places like interesting shaped bays and such.
So each century, the semi-nomadic folks would need to move five times as far inland as the tides moved up the beach each day. Not counting the distance from the water they would keep due to storms, ice, etc.
So the result is very obvious. /sarcasm They would of course be taken entirely surprise by the alarming inundations of monstrous flood waters and be utterly destroyed. /end\_sarcasm
But seriously, most of the folk living by the ocean at this time would be building structures that would be very unusual to last as long as a century. Even as recently as 2K years ago, a structure built to last that long would be highly unusual. Especially within a few meters of the edge of the ocean. They would simply build new buildings a few meters further inland about once every 4 or 5 generations. It might be interesting to have a look to see if there are settlements that this has happened to.
It would be complicated in some places by [rebound](https://en.wikipedia.org/wiki/Post-glacial_rebound) of the land after the ice melts. So, probably the best place to look for such settlements would be somewhere not too far from the equator, with lots of ocean front. Central America possibly.
]
|
[Question]
[
Usually "space battle" posts want to achieve some particular fantasy aim (like, realistic where fighters still exists), or they are focused on aliens and whatnot.
I am instead trying to figure out how space battles work when it is humans vs humans, sometimes even having friends on the other side, people DON'T want to wipe out the other side (but still want to win).
The goal of the battles, after breaking through enemy lines ("spheres, planes" ? since this is space...) is to land troops on the enemy planet and take it. (why not throw asteroids in it? Well, because you want the planet intact, including you want to live in it. Also people will object to you being a genocidal commander mass murdering your own species)
So far what I came up with:
Opening salvo with lasers, then you stop using these to avoid charged capacitors getting hit and exploding.
Then both sides do burns to approach each other while dodging kinetic projectiles, smaller lasers might be used (ones without big capacitors), missiles (with solid warheads, not explosives) too.
Eventually the fleets will be near each other enough that dodging kinetic projectiles is hard without splattering your crew with the acceleration, thus both sides start firing their cannons.
Then people might attempt boarding, to kill enemy commanders and keep their ships.
EDIT: Just to clarify, you can kill people on other side or even destroy a few ships, you just don't want every battle to turn into a complete bloodbath with one side 100% dead and the other side 95% dead.
[Answer]
# Spacecraft are fragile
Let's look at things that have imperiled real life space missions. I'm skipping a *lot* of detail here.
* Apollo 1: Damaged wire caused spark in command module. Resulting fire killed all crew members. Rocket undamaged and used in later mission.
* Apollo 8: Jim Lovell accidentally pushed the wrong button, which screwed up the guidance computer. After some tense troubleshooting, the computer was restored and the vehicle returned to Earth.
* Apollo 10: Guidance computer problem caused loss of control. Astronauts took manual control.
* Apollo 11: Misconfigured radar setting overworked the computer. Resulting error messages almost resulted in scrubbing moon landing.
* Apollo 13: Oxygen tank explosion nearly killed the crew.
* Soyuz 11: Mechanical problem resulted in depressurization of command module. Loss of crew.
* STS-51-L: Launch in cold temperature contributed to failure of O-ring. Total loss of crew and vehicle.
* STS-107: Damage to heat resistant tiles caused total loss of crew and vehicle on reentry.
I could make this list a lot longer. The point is that spacecraft have weaknesses through all of their systems. Even military craft will have critical systems. You could attack these systems. Following the examples of Apollos 8, 10, and 11, you could attack the computers or the sensors. If you wanted, you could even use a computer virus to effect a [Stuxnet-style](https://en.wikipedia.org/wiki/Stuxnet#Iran_as_a_target) attack. Or you could fire a small laser or kinetic projectile at the sensors that the ships need to be able to navigate. That would knock them out of commission quickly without destroying them.
[Answer]
Two weapons systems come to mind:
Lasers, aimed at things like engines. If you can disable an enemy craft it drifts out of the battle area. If the other side prevails convention dictates that it surrender (as the alternative would be to drift on until it's life support was exhausted.)
Sand guns. Given normal battle speeds this hits hard enough to do serious damage to exposed things, but it's not enough to punch through the hull. Blind a ship and it's out of it and must surrender if it's side loses.
As for why these weapons are used--this is a universe where point defense trumps missiles and kinetic weapons. These are the sorts of weapons that get through point defense.
If you'll accept some handwaving, I'm thinking of the Langston Field from some of Jerry Pornelle's work (collaboration with Larry Niven??) Most incoming energy gets absorbed, but the field heats up in the process. The hotter it is the more of the ship's power must be used to keep that energy away from the ship. Convention is that a ship surrenders when it's field gets too hot--it has no combat options at that point but is likely unharmed. No surrender, the enemy can destroy the ship at will.
[Answer]
**Drones**
Both sides fight capital ships sit at very long way from the actual battle. They launch swarms of drones at each other and allow the drones to do the attacking. Once one sides drones are defeated they surrender as they are now defenseless to the remaining attackers drones. The human crews never get near enough to each other to be shoot at, while the drones are cheap and disposable and do the dirty work.
[Answer]
**Overheating**
Getting rid of waste heat in space is hard. To radiate heat, spaceships need to have huge radiators. And combat-capable ship would need to have super-huge radiators. Possibly much bigger than ship itself. But those radiators are extreme weak spots. And they radiate away way too slowly to be used in combat.
At the same time, ships have such advanced defensive and evasive capabilities compared to attack capabilities of their oponents, that scoring hits is rare occurence. And during combat, both sides are constantly producing heat. But once spaceship is overheated, it needs to shut down it's systems not to damage itself or it's human crew.
So space battles are not about destroying the other side, but battles of attrition where each side is trying to cause the other side to overheat while staying 'chill' enough to function itself. Added bonus is that it is easy for your oponent to see if you have overheated from your infrared emmisions, so if they so wish, they will stop firing at you, knowing you won't be able to attack. And if you did try to attack, you will be retaliated against in a way you cannot defend against, because your defensive system is down due to overheating. So it would be suicidal to do anything funny while overheated.
[Answer]
Your ships have weapon systems mounted on modular pods outside of the vessel's main habitable areas for various reasons: easier to repair and replace depending on the enemy fleet's composition, lower risk of catastrophic damage from compromised weapons systems, and in an emergency (or once the weapons are expended) you can cut them loose to increase your thrust/weight ratio and boost away from trouble.
This means that it's relatively common for a ship to lose multiple, even all of its weapon systems, without its hull being compromised at all. In that case, it's considered honorable to allow that ship to withdraw, since it can't really hurt you anyway. Ships that lose their long-range weapons early on and are facing a completely hopeless rush to the target might disengage likewise.
Eventually, of course, you reach the point where the crew (via boarding) *are* the primary weapon, and at that point it's rather late to expect any mercy; ships have little choice but to go for the throat. Therefore, the closer you get to boarding range, the more serious the engagement: a probing attack or simple skirmish might be conducted entirely at long range, with ships only moving in closer when they're fully committed to an attack.
And, naturally, there's a "gentleman's agreement" aspect to it: if you don't target my ships' crews directly, and allow my damaged ships to withdraw in good order, I'll extend you the same courtesies. If you're constantly rushing to boarding range, focusing fire on my crews, or emplacing your weapons in your crew areas, then I have less obligation to let you escape.
[Answer]
**Pirate tactics**
First off you can send emps to fighters to disable controls for a little while.
Then if the mothership can be docked easily enough if it can't you may want to create a ship that spears into a ships walls then air locks. this drill ship opens and your pirates run in start taking prisoners and taking out guards you pirates fight through the ship to a main control center capture the commander and by that time if the fighters radio come back on demand a surrender of you blow the command ship if they refuse just kill everyone inside and retreat with their main ship using more emps escaping with teleportation or whatever. If the enemy ships come back on before you're done infiltrating the command ship use guerilla tactics basically camp around the command ship shooting mines to make more difficult to get to you. That would be my strategy.
Landing on the opponent planet
If you want to land on a opposing planet if theres a single place in the skys of the planet with slightly less craft barge in there using mentioned tactics from earlier bomb only the artierly and land using the same hostage tactics to get them to surrender.
Tl;DR: use hostages
[Answer]
**EMP**
EMP shuts down electronic systems. While damaging all electronics, it leaves everything else intact. It can cause fires etc., but as this is a great concern anyway, it isn't a stretch to say the modern spacecraft in your story are well protected against an EMP strike causing fires. An EMP would just shut everything down, at which point a clock starts ticking for the inhabitants. Yet it can take hours before they die if the whole craft is disabled, depending on several factors.
As you can shield things from EMP, it requires sufficient damage of the protecting material, or simply an overwhelmingly large EMP strike to disable systems. This way battles can happen with more regular guns etc. as well. Tactically disabling your opponent is very well possible, after which you only need to replace the damaged systems.
[Answer]
**Target their Weapons and Jam their Targeting Signal**
The goal is to take out your opponent's weapons. These are located on the extremities of the ship, so can usually be destroyed without killing everyone on board. Once the weapons are gone the enemy is harmless and you have won.
Some comments on your ideas:
>
> *Opening salvo with lasers, then you stop using these to avoid charged capacitors getting hit and exploding.*
>
>
>
Okay but then why fire them in the first place? You might hit the capacitors with the opening salvo.
>
> Then both sides do burns to approach each other while dodging kinetic projectiles
>
>
>
Okay but why are kinetic projectiles safer than lasers for not blowing up capacitors?
On a different note, the idea of dodging projectiles from short range is unrealistic. I don't believe *real aircraft* ever do this, except maybe by trying to outspeed the projectiles. In space it's MUCH MUCH harder to do precision movements since their is no air to push against.
Perhaps if the fight happens from light-minutes apart the ships could move around slightly to make them harder to target. You don't have to *dodge* per se. You just have to make sure you're somewhere else by the time the enemy laser arrives.
>
> smaller lasers might be used (ones without big capacitors), missiles (with solid warheads, not explosives) too.
>
>
>
Solid warheads is a good idea. I believe some anti-ballistic missiles work this way.
>
> Then people might attempt boarding, to kill enemy commanders and keep their ships.
>
>
>
Boarding also requires high precision movement.
[Answer]
**Lasers!!**
Lasers are mostly always the solution for precision work. They move at the speed of light so they are impossible to dodge. Because they can be so precise you can target vital enemy systems such as weapons, engines and sensors leaving the opponent disabled and open to boarding or surrender. Children of a Dead Earth is a great example for these things and so it has a mission where a ships crew have mutinied but the captain is an important political figure and so you must disable it.
Anyway Children of a Dead Earth fanboying aside, lasers would be the most effective weapon to disable without killing an opponent in space.
]
|
[Question]
[
Suppose, for instance, you lived in a world filled with nasty monsters and other creatures of the night, all of whom wanted to kill you and eat you in various ways. Now, the good news here is that we all know such creatures cannot cross running water. So, if you're in danger, all you need to do is hop over a running stream and you're fine.
Now, if we take this to it's logical extreme, the best thing to do is to build a city on a river so that it'll always be surrounded by running water. Or, (because this is going to be in a fantasy novel and what's the point of fantasy novels if they aren't fantastic) build your city between twin gigantic waterfalls.
To clarify, this is how the waterfalls works. They are both fed by a single gigantic river, the river itself it incredibly wide and deep and has hundreds of tributaries making it up. At a point, the river splits into two equally sized smaller rivers, both of which split off and then curve around after about a few mile until they're parallel to the original river's course. At that point they continue on for a good ten miles until they reach the twin waterfalls. Thus you have a nice square patch of land to build a decent-sized city, at least by Dark Age standards, cheerfully protected from all the nasty things that go bump in the night thanks to your waterfalls.
There's only a single problem here, and that is sound. You see, waterfalls can get very loud by nature - Niagara Falls, for instance, has a sound level of around 90 dB, equivalent to that of a lion's roar. Now, no matter how loud the falls the people living in the city don't care - a little noise beats dying. But they're definitely going to want to make a few adjustments to day-to-day life to make living around the waterfall easier.
Assume a Dark Ages level of technology, and assume a noise level similar to that of Niagara Falls. What kind of adjustments would you expect the inhabitants of this city to make to cope with the constant noise of the waterfall?
[Answer]
Niagara Falls is only loud up close: it might be 90 db from a few meters away but it's not that loud at any distance. Certainly not enough to bother local residents. (I was there a few years back).
Even when you go 'behind the falls' its not THAT loud.
Also, it's much noisier at the bottom than the top.
You can hear it from a very long way -- low frequencies carry well -- but it's not loud until you get very close. At the viewing areas you can talk normally.
A lot depends on the exact layout and how big the 'island' with the city is and how far from the falls. Properties closest the falls might be cheaper than those further away. Certainly, as has been suggested, those most affected will, like metalworkers etc, develop sign language and lipreading skills. Rich folk will have wax earplugs and insulated quiet rooms in their cellars where they can enjoy the luxury of peace and quiet conversation.
[Answer]
One possibility, especially if the people are a species that evolved in a running-water environment (rapids and lesser falls, specifically), is for the people to have evolved a very narrow-band voice at a high frequency, and hearing that filters other sounds but selectively amplifies the frequency band used for speech.
Waterfall noise is extremely broadband, but it's "pink" -- that is, intensity drops off as frequency increases. The deep roar can vibrate your chest, but the high hiss is far softer.
Narrow band voice is fairly easy -- use a whistle tone and resonate it in the sinuses rather than the lungs. Instead of a larynx, they'd have a sort of biological chiff and fipple. Hadrosaurs used this kind of sonic apparatus, and (based on simulations and reconstructions) could make themselves heard in a "normal" environment for literally miles.
For hearing, all that's needed is to have a tuned resonating chamber in the ear -- this will selectively amplify frequencies close to the its resonance. For compactness, this chamber could be half or a third the size of the vocal resonators, and the voice use a second or third harmonic, like overblowing a flute. As a bonus, the hearing apparatus need not be especially sensitive to sounds outside the amplification band; it might even incorporate a sort of bandpass filter with the resonator.
End result: people who don't hear especially well in general, but can hear each other speak with amazing range and accuracy.
[Answer]
I would expect some minimum level of ear protection would be called for. In Greek myths, Ulysses put wax in the ears of his men to protect them from the siren's call (he, himself, had to hear it, so he had them tie him to the mast and ignore his orders until they were at a safe distance).
The bigger issue would be that the 90dB noise would drown out communication. Speaking loudly is very hard on our biology, so we would likely not rely on it at all. The obvious result of this will be the spontaneous invention of sign language.
To see what that would be like, one can look to deaf communities. As a hearing person, I find it incredible to see just how many things they can do that I naively assumed required hearing. For a lesser experience, one could look at the TV show "Switched at Birth." The deaf community has very complicated opinions about the show (especially since the actress playing the lead deaf girl is not actually deaf), but it's the first mainstream show which prominently featured the deaf community and ASL, so they generally admit that it's a good introduction for those of us who know little about their world. It definitely functions to shake up misconceptions!
[Answer]
I'd imagine that they'd build double skinned shield walls to deflect the noise from waterfalls. The most expensive parts of the city would also be the quietest, while the slums would be where the sound protection is weakest or right by the walls where there is less light.
I'd also imagine that the Palace would be built on the spar of Rock that causes the river to split as both a status symbol as well as providing a fortified position at the most vulnerable place for the city (a creature could be carried down steam onto the rock with minimal stearing by a minion).
As others have suggested, the local language will probably also include large components of sign language for use in the louder parts of the city.
[Answer]
First off: brainstorm
* higher ranking people would be in the middle of the city
* lower on the edges
* thick walls not only to keep monsters out but for sound suppression
* cotton would be grown to make earplug like things
* communication wise they would use sign language
Making sense of it:
the first 2 bullets are straightforward, quite would be a luxury in a place like this. the 3rd is also straightforward. the 4th is stretching it a bit but the civilization would be forced to make it. the 5th is also straightforward although i suppose it wouldnt be needed everywhere.
]
|
[Question]
[
Let's imagine a society X. Society X is at a modern, 21th century (Information Age) level of development. Society X is run exactly like any modern, free, developed, and democratic society (ex. modern day Germany, Japan, USA). However, within 100 years, a caste system develops:
* People are assigned to one of four inherited castes:
+ *Monarchy (only the royal family):* works like feudal kings, the Saudi Arabian monarchy, or the line of succession in North Korea (dictators)
+ *Ruling class (1% of population):* equivalent to modern-day bureaucratic government officials and CEOs of high ranking companies--only people in this caste can perform these jobs; claim a salary roughly equal to $700,000 in 2020
+ *Specialist class (9% of population):* lawyers, doctors, scientists, engineers, product designers, ect.; claim a salary roughly equal to $215,000 in 2020
+ *Working class (90% of population):* clerks, technicians, miners, farmers, ect.; claim a salary roughly equal to $40,000 in 2020
* People are allowed to get education only corresponding to their caste determined by heritage and intermarriage between castes is outlawed
* Unemployed people in the ruling and specialist castes can claim 40% of the salary that they would have made had they been employed
* People in the working class facing unemployment receive only basic welfare and healthcare benefits, *unlike* unemployed people in the ruling and specialist castes
**So how could a hereditary caste system develop within 100 years in a modern society?** People in higher castes **do not** have any abilities or magic powers different from people in lower castes.
[Answer]
There are a few moving parts to make the society desired here. Overall, it's a cascading effect where the super rich and ultra rich will do what they can to preserve their wealth. Some cynics might call this the end result of Capitalism
Note: I have tried to keep this general where I can. Wall of Text ahead
### Step 1: Establish a Ruling Dynasty
This is the easy part for societies that have it and a bit more difficult for those that don't. Regardless, this will be a transfer of power that will be highly objected without a global disaster going on or the plutocrats deciding it's a good idea to instill a puppet dynasty and throwing money at the idea.
Regardless of the how, it will be resisted as people do not like to give up their power. In some societies, it would require a change to their constitution (or similar document) to make such a concept even remotely legal in the first place.
Now as to the why we do this: Overall the reason is stability. Something, be it somebody actually blowing up the houses of Parliament/Congress, a pandemic, or war, some trigger event causes enough chaos and mayhem to warrant setting this up. It will be touted as a way to keep the country running, but really be a way for the rich to fully consolidate their power.
For countries that already have a monarch, well this part is technically done. Said monarchs might need to take back some of the power they have given away over the decades.
### Step 2: Just in Caste
Well, now you have a ruler with enough power to make the laws. But how to handle the caste system? Well, typing for North America, it's handling itself quite fine already. The rich basically spend money specifically to separate themselves from the poorer folks already. All some people need is a push in a certain direction to land squarely in a caste, and to change the system to keep them there.
**Working Class**
Enough people here are essentially the Working Poor that they cannot afford a sick day unless it is a paid one. With rising costs of everything and a paycheck that cannot keep up with those costs, many are stuck poor with no chance of rising out barring a miracle. That is the current reality for many.
Keeping them there is simple in the sense of first never letting them own property. Without the ability to own their own home, they will forever have to pay rent to a higher caste in order to live there. A rent that can be tailored to take enough of their income to keep them poor, but without making homelessness a better alternative. It will be a balancing act.
The second big way to keep them from rising up the caste system is to prevent them from getting any form of loan or financial help that would help them ascend the ladder. This is easy because it will be the Ruling Class that has the money and a simple lookup will show them what class a person belongs to.
The third way is to only allow the Working Class enough education to do the jobs of the class. Most jobs you have listed in for the class only require a high school diploma (or equivalent) to attain with some of those jobs needing some manner of college level education. Put the focus on practical/applied classes and apprenticeships as opposed to classes heavy on theoretical content that they aren't really going to need. It's less keeping them uneducated as much as it is tailoring their education to their needs.
Separation is achieved by physically relocating people to higher density neighbourhoods. Apartment buildings that the Ruling Class owns will be the primary housing here with a handful of small bungalows that the wealthiest of this caste can potentially own with the infrequent duplex/triplex that the Specialist Class owns for extra income.
By offering a very basic healthcare and unemployment funds for this class, it keeps them from doing things that threaten the integrity of the class. The Ruling Class does not want a pandemic to cut through the streets because they can't go to a hospital, and they do not want people in agonizing pain due to disease. But overall, the Working Class is expendable and it is that overall thought that will guide healthcare decisions.
Side note: The big item you are missing for jobs here is Servant. It is not inconceivable for the Ruling Class to have servants or servant families to attend to them.
**Specialist Class**
Specialist jobs require a university degree on average with others needing further education on that, so that covers the education part of it. On that front, only approved schools can offer the degrees needed for Specialists to pursue their jobs. Not only that, there will be less of them in order to centralize them into one easy to track place. They will, of course, be priced such that the Working Class will never be able to afford it unless sponsored by a higher class (for personal retainer purposes likely)
They will never rise to the Ruling Class just because they lack the money to do so, and even if they do accumulate the money, they will never gather the appropriate influence. They are also kept down there by limiting what they own property-wise.
With a base 2020 salary of $86,000 unemployed, there might be some layabouts that cruise through because they are inept, relatively speaking. However, the class is designed to look good, but really keep them just as poor as the Working Class, just a prettier poor.
By not extending basic healthcare to the Specialists, it forces them to either tie up a portion of their money into a savings (held by the Ruling Class' banks) in case something happens, or suffer and be an example to others. By allowing them property in the form of houses, their personal office/stores, and the occasional property to rent, it ties up further income into maintaining those properties. However, they will be limited in how much they can own.
Expect small businesses to be owned by Specialists and have the Working Class work for them.
The Ruling class allows them loans to further deplete their money in the form of interest, and allows them highly limited investments into their ventures, perhaps as a reward for services rendered.
**Ruling Class**
Well, this class already exists at least in part. Multi-millionaires and billionaires that can throw money and influence around to get what they want and avoid paying taxes they do not want to spend. They are already segregated in part by large mansions with high walls, security guards to enforce their privacy, and the ability to pay more to access things that poorer people cannot.
For the Ruling Class, it is all about money and influence. Their life will revolve around networking, making connections, and expanding family fortunes. Since these are most likely the people that can access the ruler, some will also jockey for influence with the ruler. Others will be the people that administrate the lands.
To keep the lower classes out, the Ruling Class' children will attend an expensive boarding school, with the fees ensuring that they have the best of everything along with a superior experience, and that only they could afford it. This institution will be one part day care, one part school, and one part networking with each class making their life-long connections here. Children will be groomed for their roles, picked for the one they will have the most competency at for the most part. For those that cannot make it for reasons, an unemployment salary of 280,000 dollars (700,000 x 40%) will allow them to be comfortable, though not able to exert much influence.
These will be the people that can afford to own the large corporations and entire apartment buildings that the Working Class live in should they want to own them. They will have servants to attend to them. They will buy up the promising businesses that the Specialist Class start in order to prevent their rise and to keep the profits flowing to them.
The Ruling Class will also control information as since they are the administrators of the realm. It is their job to make sure that people stay in their roles and that people cannot ascend the class ranks. How they do it will depend on what kind of world feel you are going for.
### Step 3: Enforced Separation
Now the hard part: enforcing the separation of the classes. Laws brought down by the leader are a start, but there are still a ways to go.
First minor thing: Eliminate the big prize jackpot lotteries/gambling. Dumping multiple millions on a Working Class person allows them to move up, if only virtually because they can afford the Specialist schooling. Once enough get that education because of a lottery win, then the idea of separation starts to break down. Prizes should either have a monetary limit or be non-cash prizes, such as a bungalow or vehicle.
Second: The punishment for intercaste marriage will be a demotion to the lower of the two spouse's castes as dictated by law. The Ruling Class counts on this to be both a deterrent and to provide informants into the lower castes without having to go there themselves when they need to know something.
Third: Jail is for those that cannot pay for their crimes with money and/or influence. This keeps the jails free of the Ruling Class, though their own mansions may serve as a gilded jail in those situations. Sure, it looks like the rich can buy their freedom, but that's just privilege (and it happens now to an extent). Demotion might be the boogeyman's sentence.
Fourth: Ensure that your entertainment is consistent with the reality you want to present. TV shows should not have a Working Class man rising through the classes without either consequences or a clear indication that it is fantasy. The goal is to ensure that the idea that they could realistically move up is never taken seriously.
Lastly: The changes need to be applied subtly or in small increments. Some will need laws to fully enact while others will just be a matter of convention. This is more about nudging things into the directions wanted as opposed to just dropping a new world order on people.
[Answer]
*Disclaimer: any resemblance to currently existing societies is coincidental and not intentional* (scout honor, cross me heart...)
Simple
1. a certain president announces a skyrocketing deficit for 48 years and lower all the taxes in single digit range (because, why not? the central bank has negative interest rates anyhow, borrowing means earning money now). By presidential order, because a certain near-pandemic is hurting the economy, the country needs to be made great again and what better way than to take one for the team and encourage everyone else to spend or invest.
2. the same president convinces his voters (now a majority, due to cutting taxes) to pressure their representatives to pass the 28th amendment to the Constitution lifting the limit on the number of terms a president can sit
... a while passes, like 1-2 years ..
3. the govt cuts all the red tape and sides with the "employers" in regards with anything re workplace relations - because jobs! By a swear-to-God-is-only-a-coincidence, this affect absenteeism for whatever reasons (voting included. Oh, election happens on Tuesdays? How unfortunate!)
4. the govt don't guarantees student loans anymore
Done! Inflation ensues and erodes the finances of the lower classes and banks decline high risk loans anyway, student loans included. Whoever can pay for their kids education now, is likely to fall into the specialist class.
And all within a single electoral term or two. Because of course the income tax will be restored after, just not all the other taxes.
[Answer]
Establishing the working, non-specialist class:
* Funding cuts in public schools reduce the quality of free, public education. Gang activity compounds the problem. Pretty soon there are more [school resource officers](https://en.wikipedia.org/wiki/School_resource_officer) than teachers.
* Children being children, pretty soon anyone at a public school has an arrest record in addition to poor academic credentials. In private schools, the same offense would yield a stern talking-to by the principal ...
* Either legally or just in practice, this *arrest* record bans those children from specialist jobs.
---
Establishing the ruling class:
* Forget [STEM](https://en.wikipedia.org/wiki/Science,_technology,_engineering,_and_mathematics) degrees. Possibly even law. To really get ahead, you need a MBA from one of the really prestigious universities.
* In both commercial and public administration, ignore the inhouse experts. Those [external consultants](https://en.wikipedia.org/wiki/Management_consulting#Criticism) might not know what they're talking about, but they know all the current buzzwords to impress executives who went to the same schools.
* There is a glass ceiling on salaries *and influence* for non-consultants who don't have a certification from self-proclaimed management gurus. Those certifications cost a lot of money, but in this future they almost guarantee an income to afford the *next* course.
---
Making it hereditary:
* Dumb down public primary schools as well. The only way to give children a decent education is to pay for an expensive private school. Having a good nanny who reads with the kids instead of parking them in front of the TV also helps, which perpetuates the line between the 9% and the 1%.
[Answer]
The society could develop a breakthrough, but wildly expensive, genetics technology that allows them to begin splintering classes along genetic lines. The more initial wealth you have, the better your augmentations, the more entrenched your position in society becomes.
Once the ruling and specialist classes can point to an "intrinsic" difference between the classes, it would be easy to pass the laws necessary to create the system you described. It would also be very easy to make lower classes vote against their best interests with the promise of opening up the genetic therapy to more people -- which never comes to pass, of couurse.
>
> People in higher castes do not have any abilities or magic powers different from people in lower castes.
>
>
>
This may break this requirement. A way around it could be that the tech doesn't actually work and it's all a ruse to consolidate power.
[Answer]
## Just like in the Roman Empire.
Here's a (somewhat condensed) history of Rome until the time of Constantine:
1. Rome is founded by Romulus after he kills his brother Remus in a power struggle.
2. It gradually grows into a thriving city-state, ruled by an elected senate.
3. The four Punic wars cause Rome to become a major power, ruling the Mediterranean coast.
4. **Rome becomes somewhat decadent, with ~~Congress~~ the Senate descending into a state of constant squabbling and power-grubbing, unable to come to decisions.**
5. **The Senate, desperate for time to get their act together, declare Julius Caesar their emperor.**
6. **After a few years they manage to get their act together, only discover that you can't take away what has been given, and thus murder Caesar.**
7. **Riding on public outrage over his father's death, Augustus Caesar takes over the crown, and dissolves the Senate.**
8. After Caesar Augustus dies, his son takes over the throne, starting the Caesars' dynasty.
]
|
[Question]
[
How effective would it be to use [fusion scoops](https://en.wikipedia.org/wiki/Bussard_ramjet) as an actually effective method of interstellar travel? How quickly could you generate thrust? How much fuel would such a thing need, and would it work in deep space? What sort of procedures would be needed for a starliner using this strategy?
[Answer]
Bussard ramjets have a bunch of major and probably insurmountable problems.
The principle issue is "scoop drag", caused by interaction of the ramscoop's magnetic field with the interstellar medium (ISM). This quite sharply limits the top speed of any ramscoop driven ship... I don't have the figures to hand, but they top out at something like .16c to .2c even with some clever techniques to minimise electron and ion drag, and without those you might only be limited to the speed of a plain old fusion rocket exhaust which can be as low as 0.04c, and who would bother with that? Not that such speeds are to be sneezed at, of course, but it doesn't necessary compete well with the limits of alternatives.
The secondary issue is that there's a minimum speed, or at least a minimum mass flow rate into the scoop in order to develop thrust. This means you need a pretty serious rocket (or non-rocket propulsion alternative) in order to kickstart your ramship. This isn't a showstopper, but it presents an issue if you want to stop somewhere and then start again.
The third issue is the *type* of fusion you're going to be doing. Most of the stuff you find in space is going to be plain hold protium (1H) and helium (most likely, 4He) neither of which are at all useful for fusion recipes that work under sane temperatures, pressures and timescales.
The fourth issue is ionisation of non-ionised stuff in the ISM. You'll be needing big, powerful lasers to do this usefully, and that will sap power from your already fairly tenuous system. Even with such things (which are likely to be inefficient, and massive heat generators as a result) it is no easy task to ionised the ISM, and if you can't do that efficiently you'll suffer from low fuel flow and potentially greater scoop drag, too.
The fifth-ish issue is that the ISM is not created equal in all places. The Sun, for example, sits inside the [local bubble](https://en.wikipedia.org/wiki/Local_Bubble) where the density of the ISM is particularly low. This is good news from the point of view of shielding your spacecraft against radiation caused by high-speed travel, but bad news if you want to fuel a ramscoop.
The list probably goes on, but I don't have all the relevant papers to hand.
---
So, yeah. Basically, Bussard Ramjets are dead.
Some odd alternatives do exist, like Whitmire's [catalytic ramjets](https://ui.adsabs.harvard.edu/abs/1975AcAau...2..497W/abstract) where the incoming proton stream is used to ignite carbon or neon fusion, a fuel cycle that allows the "catalytic" part (the carbon or neon) to be regenerated so as not to run out. Such reactions are vastly harder to spark off than any of the types of fusion being considered today, though. Alan Bond also suggested the "Ram Augmented Interstellar Rocket", which uses the interstellar medium as reaction mass but not fusion fuel. Variants also use a finite supply of lithium or boron fuel which is fused with incoming ISM protons to generate energy. In all these cases, the designs are still subject to scoop-drag losses
there is some scope to go a little faster if their reactions are suitably energetic and clever engineering is used to help mitigate electron and ion drag.
Rocket-driven interstellar travel is a bit of a dead end, to be honest. If you can't manage beam propulsion or at least fusion runways, you may as well stay at home...
]
|
[Question]
[
## Premise
I was inspired by [Karl Niklas](https://en.wikipedia.org/wiki/Karl_J._Niklas) who used computer modeling to simulate the ideal structure for a tree when different traits were favored. Here is a chart summarizing his work:
[](https://i.stack.imgur.com/llkgX.jpg)
**Explanation**
* L (light): horizontal branches
* M (mechanical stability): fewer horizontal branches
* R (reproduction): taller to spread seeds further
When he combined them all, his model yielded trees that closely resemble trees in the real world, with enough of each trait to survive and reproduce.
**A new tree shape**
From this point I wanted to take things to a more extreme angle. I want to have trees that are shaped like a dodecahedron:
[](https://i.stack.imgur.com/xg8ug.png)
## Question
If we take the point from Niklas' research that trees take a shape that helps them best survive given what the environment deems favorable traits, then what kind of a world do I need for a dodecahedron tree to be deemed favorable?
**Further Clarifications:**
* Roots: as pictured
* Foliage: configurable
* World: configurable (Earth-like or non-Earth like), we just assume no matter what the world, evolutionary theory, as we understand it, holds to a reasonable degree
[Answer]
Trees are remarkably bloody minded in their growth patterns, since their greatest influencing factor is the presence of other trees, the classic requirements indicated in your question override almost anything else.
So we shall not have a tree, instead we shall have a shrub.
Here we get a lot more flexibility as we can spread the driving influences around a little.
We should also talk about [coevolution](https://en.wikipedia.org/wiki/Coevolution). A classic example being bees and flowers. Flowers need bees, bees need flowers. Take away one and the other is lost. The two have coevolved to be largely dependent on each other.
Your pattern of the branches rejoining to form such a shape is highly inefficient and would not happen without some sort of secondary influence driving it that matters more than that inefficiency. What you've created is a distinct inside and outside to the plant, importantly it's an inside that can only be accessed by creatures of a certain maximum size. We shall define it as a coevolved trait.
You have options here:
* flowers and pollination
* seeds and fruit
* protection
* trap
The first is reasonably common, normally it appears in the form of very long flowers matched by hummingbirds with very long beaks or some other similar form.
Fruit are usually designed to be attractive as widely as possible so that they get the best chance of dispersal. Colour schemes are designed to stand out to creatures with colour vision such as birds, monkeys and apes.
Protection could be an interesting one. Some creature finds a safe home in the bush and in doing so protects the bush from other creatures. Acacia Trees and ants sometimes have such a relationship.
It could be a carnivorous tree, the branches and thorns allow small creatures in, but don't allow them out again.
Any or all of the above in combination also works, perhaps in flowering and fruiting season creatures can come and go easily through the branches, but out of season the gaps allow inward movement only.
[Answer]
Since the structure defines an inside and an outside, it might be useful for situation where the nutrients are not absorbed via the roots but via the branches/leaves, while being carried by the medium. More or less what sponges do in water.
Such a tree would therefore have the outer leaves being the photosynthetic ones, while the inner ones would be the absorbing ones.
The roots would be used only as supporting mechanism, to anchor the tree to the substrate.
The environment could, for example, be:
* Highly windy, with nutrients carried by the wind. The hollow shape allows for the carried particles to precipitate.
* Liquid, like for the sponges.
[Answer]
Make the light come from every direction. That changes the first form so that instead of horizontal branches perpendicular to the average sun location, you get a more spherical shape.
Then make stability (the second form) important. Perhaps there are high winds. This helps keep the branches short.
The high winds could occasionally rip the plant from the ground so that it roams like a tumbleweed. The flat surfaces may optimize the chance that the plant can root again later. The optimal shape for this would be a tetrahedron, but a tetrahedron doesn't have the spherical shape to maximize light. The dodecahedron shape is a compromise between the sphere and tetrahedron.
You could amplify the compromise by creating reasons why particular orientations are important. Perhaps light doesn't come from every direction but only in certain places. The dodecahedron maximizes the likelihood that some of the branches will be in the right orientation.
[Answer]
The reasons trees grow upwards (for the most part) is because of their need to photosynthesize to create food for themselves. Different trees have different adaptations to acquire the maximum about of sunlight, while also protecting themselves from other threats.
One reason to have a dodecahedron shaped plant is if there is something on the faces or edges or corners of the dodecahedron that prevents other animals from eating it, thereby protecting it. Another thing could be to minimize the amount of itself an animal can eat. If the plant's main feeder is a larger animal that needs to bend over to consume it, it would help to be a small, stocky plant without any external protrusions and smooth faces to make it hard for an animal to eat.
Another reason could be that the plant's in-built 'factories' to absorb and process its food requires it to be that way. Much like why solar panels are flat, it helps to have an even and flat surface to acquire sunlight (or whatever it needs). Being many-sided allows it to have a direct interface to sunlight from any and all angles at all times. Sunflowers, in order to maximize how much sunlight they get, actually turn their 'face' towards the sun. Maybe this is similar?
[Answer]
The other answers are great, so I'll go a slightly different direction: imagine a [carnivorous plant](https://en.wikipedia.org/wiki/Carnivorous_plant) which folds and unfolds (you can [see an animation of a folding dodecahedron here](https://www.youtube.com/watch?v=Pcbjholy55A)).
If the center edge which stays fixed to the ground (with the roots) has some type of substance to stick or trap prey (or if they folding is fast and reflexive enough), then folding around it as this shape would be a strong force down (making it difficult for prey to escape), and would aid in the digestion process. As an aside, a plant that can eat a lion is creepy.
The challenge is to explain - why a dodecahedron? Why not a circle? Complex shapes do occur in nature, but usually only at very, very small sizes, not at all in plant-and-animal sizes. Perhaps a planet did have a more simple shaped plant or shrub, but as @cyber101 mentions in his answer, over time a shape which prevents grazing, has more structural force, etc, might slowly evolve.
Point is, anything trapping prey in a way which requires the entire inner area to be closed-off with force would inevitably require symmetry. The specifics of why this shape could be happenstance as to the nature of the planet and the creatures around it. I don't see why this wouldn't be *possible* in some theoretical planet, although I admit it would be extremely unlikely.
[Answer]
A permanent tumbling plant may evolve a shape that as closely resembles spherical as possible, while using minimal mass. Natural objects also tends to respect symmetry as this reduces the necessary genome size. Like the icosahedral viruses which only have to code for a protein that forms a pentameter of trimers for its capsid.
I imagine a world with constantly blowing high winds, which will uproot anything that is not adapted against it's force, but will also give any plants that can harness it's force plenty of opportunity to disperse and thrive. For example, plants that can tumble in the wind and put down roots where ever there is plenty of water and nutrient supplies, and have a shape that can always photosynthesize no matter which side it lands on.
For a given shape, the fewer the faces it has, the less amount of edge length it has for a give surface area. Of course, there will also be tetrahedral, cubic and octagonal plants, but they are unable to roll due to having acute to right angles on their edges and vertices.
The plant needs to roll or tumble, so therefore it have to have leaves on all sides, and needs to be rounded for rolling. It also have to be the lightest for its given size. A tree's mass is largely concentrated in its trunk and branches, therefore: any higher fullerenes or spherically symmetric structures will be less mass-efficient for it's cross section, and any lower symmetric structures won't roll because of the angles, therefore a rolling plant optimizes to adopt a dodecahedral shape, to both maximize it's surface area and minimize it's mass, while still being able to roll with the wind.
As for growth, I imagine the tree grows as a trimer of pentamers, I.e. having individual seedlings being a simple bent shape with a bend angle of 108 degrees, every five seedlings locks together to forme a Pentagonal face, then the outside of every three seedlings adheres to each other, forming a vertex. This naturally self assembles into a dodecahedron when high winds jitters the field of newly sprouted seedlings around, causing them to be stired up and bump into each other. As each seedling sprouts roots at the bent point, the dodecahedral structure can always take root nomatter which side it lands on. Also, The leaves will be on the inside of the seedlings, forming the face of the dodecahedron. This ensures the plant always have photosynthetic tissue facing the sun/light source nomatter which face it lands on.
]
|
[Question]
[
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
As I was thinking about space flight for my world, I thought about how they would need to know a planet's gravitational force before they could land, and found that humans figured out the moon's gravity using its orbital period, tides, etc.
*However*...the situation that native astronomers find themselves in is an interesting one, as the "moon" in question is actually the home planet's binary twin. Since the two planets are similar in mass, both planets are tidally locked to each other which means that, from a stationary point on land, *the moon would not move in the sky* and there would be *no tides,* thus our human methods are useless.
**Would it be possible for pre-space age astronomers to figure out the "moon's" gravity?**
In my mind, a really easy way would be to send a satellite to the planet and find how long it takes to orbit at a distance, but this question assumes no such technology is possible.
Also, if anything here is important, the data of the planets are as follows:
*Home Planet:*
* ~0.7x Earth mass
* ~0.9x Earth radius & gravity
* \*\*density of both planets are the same as Earth
*Moon Planet:*
* ~1.84x Earth mass (technically this makes Home planet the moon, but unimportant)
* ~1.26x Earth radius & gravity
* Distance between planets is about 129,000km
* Day length (both planets) is 79.9 hours
[Answer]
### 1. Tides
>
> the moon would not move in the sky and there would be no tides
>
>
>
Wrong. The [sun provides tides too](https://oceanservice.noaa.gov/education/tutorial_tides/tides06_variations.html) (albeit smaller ones than our moon), so the sea still rises and falls on a regular cycle. You'll even get variations in tide height depending on the relative angles of the sun and your "moon", though not to the same extent as spring tides on earth. This means that it may still be possible to use tides on your planet to calculate the mass of the moon in the way that was done historically here (see the [quora answer](https://www.quora.com/How-is-the-mass-of-the-moon-calculated) linked by AlexP above) though as I am not a mathematician I couldn't tell you the exact technique or how precise it may be.
### 2. Parallax.
Establish the distance to the "moon". Our moon's distance can be judged using [lunar parallax](https://en.wikipedia.org/wiki/Parallax#Lunar_parallax). You'll have to observe your moon from two different places on the surface to see the effect, of course. This'll also get you the size of the moon, so you can see that it is about the same size [as your own planet](https://stardate.org/astro-guide/faqs/how-was-size-earth-first-measured), another big clue.
Determine where the barycenter of your "moon"-planet system lies. I believe you can do this using [diurnal parallax](https://www.eso.org/public/outreach/eduoff/vt-2004/Background/Infol2/EIS-G4.html), only in this case your planet doesn't rotate itself, but it *does* rotate around the two bodys' barycenter which will cause visible [parallax](https://en.wikipedia.org/wiki/Parallax) effects. Not big enough to see the stars wobble, I suspect, but it should be enough to cause other planets in the same solar system to show some movement.
Now you've determined that the barycenter of your system lies at more-or-less the midpoint of the two worlds, that's a *massive* clue that they mass about the same, assuming you've got some idea of the nature of gravity.
### 3. Tidal locking
There's a big clue in the tidal locking, of course... I'm not certain on the history of understanding of tidal forces on solid a objects, or how the idea came about, but you'd still get tides on your world so it wouldn't require a huge leap of logic. If tidal forces *were* understood, it may well be seen that bodies will become tidally locked if they have similar masses, or if they have existed long enough to lose their rotation to tidal effects.
First, determine the mass of your planet (there are various ways to do this, [see this earth science SE answer](https://earthscience.stackexchange.com/a/523) for example, but I won't go into them here). Next, establish the [age of your planet](https://en.wikipedia.org/wiki/Age_of_the_Earth) (again, left as an exercise to the reader). It should be possible to determine that insufficient time has passed for your planet to become locked to a much less massive body, therefore the mass of your moon must be pretty similar to the mass of your planet.
I think. There are a lot more leaps of logic here, but it wouldn't do to underestimate people's ability to figure stuff out!
### 4ish. Meteorite Impacts
Meteorites will sometimes hit your moon. They sometimes hit the earth. There's good reason to believe the meteorites may be made of the same material. Given that you know the size of the moon and how far away it is (see parallax above), it is possible to [estimate the height of the craters](http://astro.physics.uiowa.edu/ITU/labs/observational-labs/studying-the-moon/measure-the-height-of-lunar/). Assuming your "moon" isn't made of something particularly bizarre and scifi-y, it'll be possible to make estimates of the density of its surface given the sizes of the craters and the spread of ejecta, given some understanding of gravity and ballistics.
I'm not *totally* certain that this will provide a useful estimate of the mass of your moon (because you have to make assumptions about density of subsurface layers), but it is certainly a contributing piece of evidence, *especially* when combined with assumptions about a common origin of the "moon" and the observer's planet.
(note that this does make some assumptions about the nature of the "moon". One with a thick atmosphere, or a liquid surface or whatever else may make this bit of analysis impossible)
(note 2: there's a related useful thing here if the "moon" is a rocky world, because you can use impact cratering to [help estimate its age](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JE005094), which is a pointer towards a common age and common origin of the observer's planet and the "moon")
[Answer]
*"Can early astronomers determine the gravity of their planet's “moon” without ever going there?"* Of course they can. Our Earth-bound astronomers did, and we know how they did it.
1. The distance from the Earth to the Moon and the size of the Moon were known since the Antiquity. The Moon is close enough that the [parallax method works well enough](https://hsm.stackexchange.com/questions/6869/how-did-ptolemy-calculate-the-distance-to-the-moon) with the naked eye instruments of the ancients.
For example, [Ptolemy](https://en.wikipedia.org/wiki/Ptolemy) in his [Almagest](https://en.wikipedia.org/wiki/Almagest) gives the average distance between the Earth and the Moon as 59 Earth radii; the correct value is 60.06 Earth radii. I'd say that Ptolemy's measurement is quite good for the 2nd century CE.
2. The mass of the Earth was measured in the 18th century; by 1798, the famous [Cavendish experiment](https://en.wikipedia.org/wiki/Cavendish_experiment) (performed by [Henry Cavendish](https://en.wikipedia.org/wiki/Henry_Cavendish) applying an idea by [John Michell](https://en.wikipedia.org/wiki/John_Michell)) came within 1% of the true value. (The same experiment measures the gravitational constant.)
3. Because the Earth-Moon system rotates around their common barycenter, astronomical objects seen from Earth show a monthly parallax. Towards the end of the 19th century, by measuring the monthly parallax of the asteroid 12 Victoria, British astronomer [David Gill](https://en.wikipedia.org/wiki/David_Gill_(astronomer)) determined the position of the barycenter and thus the ratio between the mass of the Earth and the mass of the Moon was determined with great accuracy.
4. Since the mass of the Moon was known and its size was known, the gravitational acceleration on the surface of the Moon could be easily computed.
[Answer]
Other answers have discussed the methods used by ancient, medieval, and modern pre-spaceflight astronomers to discover the distances, sizes, and masses of various astronomical bodies, from which the surface gravity and escape velocity of those bodies could be calculated once Newton published his laws of physics.
Here is another type of answer.
Any large library should contain astronomy, space flight, & science fiction books written before the space age.
I have read enough of them to know that popular books said that the surface gravity of the Moon was about one sixth that of Earth, while textbooks would give the actual scientific value of the Moon's surface gravity and of it's escape velocity.
Because of the Moon's low surface gravity, it was common for artistic depictions of the Moon's surface before the Space Age to show very steep mountains, unlike the ones actually photographed there during the Space Age.
The first Earthlings landed on the Moon in 1969, and the first space probe from Earth was sent to the orbit of the Moon in 1959. And if the astronomers of that era could not use data from Earthbound observations to provide the space agencies with reasonably accurate figures for the distance, orbital speed, size, mass, density, and gravitational attraction of the Moon, how could space flights to the Moon have been planned well enough for space probes to reach the Moon, and sometimes go into orbit around the Moon, and sometimes make soft landings on the Moon?
The first soft landing on the Moon was *Luna 9*, and the first lunar orbiter was *Luna 10*, both in 1966.
And I have read enough non fiction and science fiction from before the Space Age to know that the low surface gravity on the Moon was well known by amateur and professional astronomers, spaceflight enthusiasts, and science fiction fans, even in the remote and prehistoric era before 1959.
The lower surface gravity of the planet Mars was well enough known that Edgar Rice Burroughs, in *A Princess of Mars* (1912) had his hero from Earth, John Carter, discover that his Earthly muscles grave him a great advantage on Mars:
>
> Carter finds that he has great strength and superhuman agility in this new environment as a result of its lesser gravity and lower atmospheric pressure.
>
>
>
<https://en.wikipedia.org/wiki/A_Princess_of_Mars>[1](https://en.wikipedia.org/wiki/A_Princess_of_Mars)
Added August 4, 2019. The answers to this question should be interesting:
<https://scifi.stackexchange.com/questions/216975/earliest-story-to-mention-the-different-surface-gravity-on-the-moon>[2](https://scifi.stackexchange.com/questions/216975/earliest-story-to-mention-the-different-surface-gravity-on-the-moon)
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
Distance and size to our own moon were calculated with a surprising accuracy by the old greeks. That should make it fairly simple to calculate gravity relative to your own planet assuming the same density.
It should be noted that the moon is tidally locked to us because it has a bulge on one side, that caused it to slow it's rotation (by interaction with earths gravity) untill the bulge is permanently pointed towards earth. A similar formation should probably exist on both your planets if they are tidal locked to each other.
[Answer]
The planet's inhabitants are going to need, at minimum, to understand Newton's law of gravitation. Once they have that, there are many viable ways to calculate the mass of the moon. Here's one involving pendulums:
First, measure the distance to the moon using [lunar parallax](https://en.wikipedia.org/wiki/Parallax#Lunar_parallax). Then, set up identical pendulums at 2 points on the planet's surface and record the number of ticks that occur over the span of a day (either via a clockwork mechanism or by tedious counting, depending on how early you want people to have figured this out). This, effectively, measures the strength of gravity at 2 points on the planet's surface.
If you picked 2 points with the same elevation, almost all of the differences in gravity that you record will be due to the different distances from the Earth-moon barycenter. There will be a term from [centrifugal force](https://xkcd.com/123/) and another from the gravity of the moon. Both depend only on the mass of the moon and known parameters (the mass of the Earth, radius of the Earth, distance to the moon, and the rotation period / length of a day), and so the moon's mass can be readily calculated from there.
]
|
[Question]
[
In my world a space civilization is colonizing a massive solid planet.
The planet has an extraordinarily fast rotation.
The gravity is severe at the poles, making life impossible, but life flourish within a wide belt at the equator.
This “green belt” is possible thanks to the extreme rotation - the centrifugal force greatly reduces the high gravity.
Is this concept purely fiction or would such a planet (in theory) be possible?
[Answer]
**Yes**
**Example**
Let's assume we have a planet with the gravitational acceleration of Jupiter and want to reduce it to earths gravitational acceleration.
**Edit**
This is meant as an in practice example of how fast a planet with the size and mass of Jupiter would need to spin to experience same forces as on earth.
**Example continues**
[According to Wikipedia](https://en.wikipedia.org/wiki/Jupiter) Jupiter has a Gravitational acceleration of $24.79 \;\frac{m}{s^{2}}$. And as we all know Earth has a gravitational acceleration of $9.81\;\frac{m}{s^{2}}$. So the rotation has to cancel out the difference between gravity on earth vs gravity on Jupiter ($24.79 - 9.81 = 14.98$). This means our centripetal acceleration has to be $14.98\;\frac{m}{s^{2}}$.
With this Formula we can determine the speed at which the Planet has to rotate: $a = \frac {v^2}{r}$, where $a$ = acceleration, $v$ = speed and $r$ = radius.
If we take Jupiter as an example again, $r$ would be $71 492 000\;m$. So when we plug in our values we get this: $v^2 = 14.98\;\frac{m}{s^{2}} \cdot 71492000\;m = 1 070 950 160\frac{m^{2}}{s^{2}}$. Because we have $v^2$, we have to take the root of it which gets us to $32 72\;\frac{m}{s}$ speed. Which is about 3 times faster than Jupiter is actually rotating, but possible.
[Answer]
If you put a high spin on something squishy like a planet it's going to bulge at the equator and the poles will descend (to keep the volume constant)
Both re-shaping effects themselves reduce surface gravity. At the poles you have less mass beneath you, and at the equator you're further separated from most of the mass
I don't think my calculus is strong enough to guess the shape, but this guy has some ideas.
<https://www.science20.com/robert_inventor/so_you_thought_you_knew_what_spinning_planets_look_like_surprising_shapes_of_rapidly_spinning_planets-155538>
[Answer]
>
> the centrifugal force greatly reduces the high gravity.
>
>
>
Yes, this is a physical concept, and in fact how orbits work. Any small mass $m$ orbiting a large mass $M$ has its centrifugal force balancing gravitational acceleration exactly, so that
$$g = \frac{v^2}{r} $$
and the gravitational acceleration $g$ is the result of the planetary mass $M$, gravitational constant $G$ and distance $r$ via
$$g = \frac{G M}{r^2}$$
so that any velocity that fulfills the force equality is $v^2= \frac{GM}{r}$, also called Keplerian or orbital velocity. Therefore this is the velocity at which centrifugal force can balance gravity. This velocity is only a function of the planet to be orbited and nothing else, particularly no other planet, like @Soans confused answer might suggest. It is $8 km/s$ for Earth's low orbit, and will be much higher for OP's rapidly spinning, high-mass planet.
This has now several important implications:
1. A planet rotating with Keplerian speed at its equator, will not be a stable structure. Its surface would lift off into space.
2. A planet rotating at less than Keplerian speed will feel a reduction in gravity. This reduction will become less and less as one goes from equator to the poles, so the concept in OP's question is also real, but the 'centrifugally assisted life' needs to develop at the equator, otherwise there is always an unstable region on the planet.
The fine-tuning required for this effect to be viable (also we don't know at which gravity life can function) might make the setting unbelievable.
]
|
[Question]
[
I'm writing a story that will eventually escalate from being focused on one planet to the entire star system that planet belongs to, and finally to a big story involving the two nearest star systems to the one the Original planet is located in.
So what I would like to know is what is the minimal distance these different star systems will have to be apart from each other? (I don't want them so close as to be binary star systems but the 3 different systems should not influence each other with gravitational pull either)
P.S. If it matters what type of stars we are talking about, if we call the Original star system A and the others B and C then A has a Main Sequence Star (basically our sun), system B has a Blue Supergiant, and system C has a Red Dwarf.
Any advice will be greatly appreciated.
[Answer]
What makes a couple stars a binary system is the both of them having a stable orbit around a common barycenter. If they don't share that, then they are not a binary no matter how close they are. They will be doing a flyby on each other and will spend years to millenia close, depending on relative speeds.
As Alex said in the question comments, any star closer than a couple light years to the sun would disturb the Oort cloud. The practical consequence of that is a comet bombardment on every planet. Other than that, check this table of the closest stars to the sun and their distance to us over time:
Source: <https://www.explainxkcd.com/wiki/index.php/2062:_Barnard%27s_Star>
You can use this for inspiration. Those stars are probably the ones we are going to visit first if humanity doesn't destroy itself before we go interstellar.
Take into account that stars orbit the galactic core just like planets orbit stars; but their orbits are much more varied. Think about the timespan of your story. Over dozens of millions of years, stars have moved so much relative to each other that you don't get to see the same constellations. A star that is close today may be too far in the future and vice-versa. But for a timespan of millenia they should stay put, figuratively.
[Answer]
If you give a look at the [list of the closest stars to Earth](https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs) (from where the image below is taken), you see that the closest is at a few more than 4 light years.
Since our planet has been not significantly disturbed by neighboring stars to the point of being ejected from its solar system, and considering ours is the only system we have been able to investigate in such fine detail, you might take that as a reasonably upper limit for a safe distance.
[](https://i.stack.imgur.com/gBwrN.png)
[Answer]
## It Depends on Your Stars
Escape velocity, $V\_{escape}$, = $\sqrt{{2 G M}\over{r}}$.
G is the gravitational constant ($6.67 \cdot 10^{-11} {{m^3}\over{kg \* s}}$),
M is the mass in kilograms of the primary body ($1.989 \cdot 10^{30} kg$ for the sun) and
r is the distance.
Typically (for stars near our sun) stars are moving in our part of the galaxy at speeds of about 10 to 20 km/s. Which is 10,000 to 20,000 m/s. However, only the relative velocity counts, since we are looking at everything from the perspective of one of the two stars. That being said, I think you are looking for the distance at which an escape velocity is under a kilometer per second.
Plugging in different values for r, I get these values for $V\_{escape}$ from a star as massive as the sun :
* 1 light-second : 665 km/s
* 1 light-hour : 11 km/s
* 1 light-day : 2 km/s
* 1 light-month (30 light days) : 413 m/s (about the outer edge of Sol's outermost comet cloud)
A blue supergiant, like Rigel, has 23 times the mass of the sun. The escape velocity at different distances would be -
* 1 light-month (30 light days) : 1.9 km/s
* 9 light-months : 660 m/s
* 1.5 light-years : 463 m/s (would not be surprised to find the edge of a comet cloud here)
And a dwarf, like Proxima Centauri, has a smaller mass of 0.1221 Suns. The escape velocity at different distances would be -
* 1 light-hour : 3.8 km/s
* 1 light-day : 790 m/s
* 3 light-days : 456 m/s (expect some sort of comet cloud edge here)
This is additive, so your blue supergiant could be no closer than 1.5 light-years + 3 light-days to the red dwarf
[Answer]
The Traveller RPG assumes star systems are approximately 3 light-years apart (one *parsec* to be accurate, about 3.2 light years). The wiggle-room is roughly plus or minus a light year. This allows sufficient buffer space to (1) fit the interstellar "jump" drive scheme for the game itself, and tangentially (2) not interact with others' gravitational fields.
[Answer]
Here is a link to another question and answers with a similar topic:
[How close could another solar system be without adversely affecting our own?](https://worldbuilding.stackexchange.com/questions/135568/how-close-could-another-solar-system-be-without-adversely-affecting-our-own/135592#135592)[1](https://worldbuilding.stackexchange.com/questions/135568/how-close-could-another-solar-system-be-without-adversely-affecting-our-own/135592#135592)
You could get other stars quite close, within a tiny fraction of the distances of the nearest stars to our solar system, without disturbing the orbits of planets.
But a nearby star at the distance of the Oort Cloud of a solar system would disrupt the orbits of millions of comets and send some of them into the inner solar system to bombard planets causing multiple extinction events. Intelligent life on a planet would have to have a very active defense against incoming comets. So they would have to develop advanced interplanetary travel before the comets started arriving.
And if the stars were packed as close as in globular star clusters or the galactic core, any habitable planet would have been irradiated and sterilized by a number of nearby nova and supernova explosions during the billions of years it would take for intelligent life to evolve on that planet.
Perhaps super powerful aliens created a force field generator to stop the dangerous radiation from nearby novas and supernovas and then seeded the planet with life that eventually evolved intelligence. And perhaps the natives find and accidentally turn off the generator and then their astronomers say a nearby star is about to go supernova.
]
|
[Question]
[
Imagine a large room, perhaps 50 metres in length and 35 in width, with its ceiling 40 metres above the floor. On this ceiling, there are LED lights, rendering the brightness of the room to look something like this:
On the floor, there's a large pool, stretching 10 metres deep below the floor, and occupying about 60% of the floor area. The remaining 40 percent is covered in a few-inches-thick layer of dust. Now, imagine that the lights on this room would somehow stay turned on for all eternity, and the walls would never break. Some kind of device regulates the gases in the room, so that it stays 78% nitrogen, 21% oxygen, and the remaining 1% of Earth's other current gases.
**If we were to deploy a strain of aquatic bacteria into this hypothetical room, and waited billions of years, would it be feasible for things like sexual reproduction, complex multicellularity, and eventually air-breathing fauna to evolve?** The major differences here from the real world are:
* The confined space
* The lack of change (Same space, same light, same air etc.)
So, do these prohibit the likes of bacteria evolving into as complex organisms as we see on our Earth? Can extremely complex ecosystems exist in a 40 m x 35 m x 50 m space? A further clarification: imagine this room is on Earth, so the gravity will be Earth-like.
Bonus question: could macroscopic flying animals evolve in such a small, windless, thermal-less place? Feel free to ask more questions on the conditions of the room if I've left any out.
EDIT: the founding bacteria will be photoautotrophs, and once they have reached a stable population, heterotrophic ones will be introduced.
[Answer]
I will begin from the same argument as Roger above:
**Cyanobacteria**
These bacteria are useful due to (direct quote courtesy of Roger):
* Carbon fixation. They can pull CO2 out of the endlessly-refreshing atmosphere and convert it to something useful and cumulative.
* Nitrogen fixation. They can also pull N2 out of the atmosphere and give us ammonia and other useful compounds.
* Colonies. They can form sheets, which is useful for helping our body of water stay heterogenous, with a well-lit aerobic zone on top and a dark anaerobic zone at the bottom.
This gives us a good starting point. We have a form of life than is generating basic organics, as well as stratifying the environment into useful layers. This will become important later on. If we assume the "dust" is moderately nutrient rich, we also have an initial biomatter to allow normal reproduction (as even asexual reproduction requires some nutrients to be present).
Over time, this will introduce evolutionary pressures. Ammonia concentration in the water will increase over time, as will the presence of complex organics.
**Ammonia and Nitrogen Compounds**
The increasing concentration of nitrogen-containing compounds will apply an evolutionary pressure as it builds from harmless to caustic levels. This will also have the effect of slowly increasing the volume of the liquid present, while compressing the "atmosphere". We have assumed that the walls will never budge or burst (and are completely non-porous), and that the atmospheric concentrations are kept uniform. This then is a isochoric process. This implies that atmospheric pressure will increase over time. This will increase the levels of dissolved gasses in the liquid, as well as the overall temperature of the system. This is where the system diverges one of two ways in the short term.
If the device also extracts gasses that aren't "normal", gaseous ammonia, water vapour, and other compounds will slowly leave the system. Let us assume that the device operates at some flow rate K litres per minute (STP). If this flow rate exceeds the rate of nitrogen production and evaporation, the atmosphere will stay approximately earth-like indefinitely. We can call this the **well-regulated system**. Conversely, if the rate of gas generation and evaporation is greater than the flow rate K, then "seasons" will form. This can be the **badly-regulated system**.
**The well-regulated system**
In this scenario, temperature, pressure and atmospheric gasses will all remain at roughly starting levels. This scenario is "less interesting" in that it has lower evolutionary pressure. I will discard this scenario as we are specifically trying to force evolution.
**The badly-regulated system**
In this scenario, gasses are regulated, but poorly, or not quickly enough. This is the more interesting scenario. Temperature, pressure, and concentration of nitrogen compounds (especially ammonia) will increase until it reaches critical levels and begins killing the cyanobacteria. This will purge any members of the population with low ammonia, pressure, or temperature tolerance, leaving only the strongest members. The purge has two useful effects:
1. Evolutionary pressure. The purge ensures only the "fittest" survive.
2. Self-regulation. The sudden decrease in bacteria will slow the nitrogen production, and should allow the atmospheric purifier time to re-adjust the atmosphere.
I will designate the less hostile season "summer", and the more hostile season "winter".
The system will start in summer, and the first winter will take a long time. Despite this, it will probably be one of the largest purges in this system. Conditions will become violently hostile in multiple ways, and very few bacteria will survive this. It is also entirely possible that the first winter is a 100% extinction event. In this case, the experiment can be restarted. If we have no way of observing the system, the experiment should be run in parallel to maximise the chance of a successful set.
The survivors of the first winter will form the base population for the second "year". These will be the most chemically and physically resistant of the initial population. Thus, population growth will begin again in a more toxic environment than their predecessors. This will specialise the bacteria with each winter, and encourage mutations that enable survival in the hostile environment, as well as rapid population growth once summer rolls around.
Now that we have a system that encourages mutation, we can begin to answer the question.
>
> If we were to deploy a strain of aquatic bacteria into this
> hypothetical room, and waited billions of years, would it be feasible
> for things like sexual reproduction, complex multicellularity, and
> eventually air-breathing fauna to evolve? The major differences here
> from the real world are:
>
>
> * The confined space
> * The lack of change (Same space, same light, same air etc.)
>
>
> So, do these prohibit the likes of bacteria evolving into as complex
> organisms as we see on our Earth? Can extremely complex ecosystems
> exist in a 40 m x 35 m x 50 m space? A further clarification: imagine
> this room is on Earth, so the gravity will be Earth-like.
>
>
> Bonus question: could macroscopic flying animals evolve in such a
> small, windless, thermal-less place? Feel free to ask more questions
> on the conditions of the room if I've left any out.
>
>
> EDIT: the founding bacteria will be photoautotrophs, and once they
> have reached a stable population, heterotrophic ones will be
> introduced.
>
>
>
Let's break it down.
**Multi-cellular life**
It is possible for multi-cellular life to form here. The ocean will eventually be home to many nitrogen-based compounds, and the high pressures of winter may encourage complex molecules to form, including amino acids. Decomposing bacteria will also add biomatter to the equation. This will take many "years". However a "year" here is a summer->winter->summer cycle, not a year as we understand it. The main thing that hinders complex life is that as a being's complexity increases, it's energy efficiency decreases. This provides a practical upper bound for complexity (and size) within our mini-ocean. We could see the evolution of macroscopic life (after all, 1cm^3 is still tiny in the scope of the "world" it lives in), however, it will most like either (de-)nitrifying, or photoautotrophic as light and nitrogen will be the most abundant resources to consume.
**Macroscopic fliers**
The ability to fly (or jump really far) might be developed, however there are few evolutionary pressures to force this. The system will develop thermal currents and winds as during "autumn" and "spring", but there is little food in the air, and little benefit if a lifeform can fly. However, airborne bacteria that can survive on just ambient moisture and nitrogen gas may well form.
**Sexual Reproduction**
N.B. This is not my specialty, so I will defer on this point if I am incorrect.
The system I have posited becomes extremely hostile periodically. While sexual reproduction may form, it would not be particularly desirable from my baseline knowledge of evolutionary selection.
**Air-breathing Fauna**
This one depends on what you mean by fauna and what you mean by air-breathing. A multi-cellular organism that consumes nitrates, and produces nitrogen gas (like a more complex de-nitrifying bacteria) would be perfectly at home in this environment, and it would be "air-breathing". If you mean oxygen-consuming specifically, then it is possible that a fauna may form that is photosynthetic during summer and nitrogen-breathing during winter (when the "sun" is covered by clouds of nitrates). I'm not aware of any physical or chemical limitations that would prevent this from happening, however, the mutation may simply never occur.
**Conclusion**
It is entirely possible for you to generate complex life and force evolution in a number of interesting ways in your mini-world. However it does require rigging the process a little bit to maximise evolutionary pressure, while not going so harsh as to kill everything. Additionally, the physical bounds of the world (Watts of sunlight, volume, presence and type of atmosphere, nutrient presence and replacement) have to be carefully calibrated to prevent mass extinctions, or failure to evolve at all.
[Answer]
## Macro Evolution and Fauna, No.
You might be able to get amoebas and some basic algae but that's it. If this counts as 'macro' to you then your scenario fits the bill. However the reason you won't see anything larger than this comes down to two key constraints of your system, and several honorable mentions.
1. **The rate of energy entering the system is constant, and is too low** to accommodate large life forms. The only source of energy in this system are your lights. The total energy emission from your lights is going to be pitifully low compared to the energy requirements of almost any multicellular organism. Also keep in mind that these lights first have to be captured by photosynthetic organisms ([with less than 100% efficiency](https://en.wikipedia.org/wiki/Photosynthetic_efficiency#Typical_efficiencies)). Then anything that eats said photosynthesizers is going to have to convert the organic matter and get an even smaller percentage of that energy. So the actual energy entering this system is going to be a fraction of the ceiling lights output, which is already very small. Simply put there is just not enough energy to maintain anything but the most sessile, minimalistic organisms ([Algae](https://en.wikipedia.org/wiki/Algae), [phytoplankton](https://en.wikipedia.org/wiki/Phytoplankton), but probably something more like [Prochlorococcus](https://en.wikipedia.org/wiki/Prochlorococcus)).
2. **There is not enough space for a population to grow** and escape extinction from [random chance](https://en.wikipedia.org/wiki/Extinction_threshold#Stochastic). You may get sexual reproduction but in such a small space, with limited energy intake, and the strong prevalence of inbreeding anyway, asexual reproduction seems like the clear winner. The limited space will be the driving force for; favoring asexual reproduction, capping your population size, and capping your maximum organism size.
Population size is limited because [as organisms get bigger they require a bigger cut of the energy pie](http://book.bionumbers.org/how-does-metabolic-rate-scale-with-size/) to survive. Since the total energy available is not much the point where an organism's average size becomes too big for a sustainable population will be reached very quickly. This is because they have to divide the available energy amongst themselves.
Now a population needs at least a certain number of member in it in order to avoid the high risk of going extinct by accident. An example of spontaneous extinction would be every member contracting a lethal mutation, disease, or just dying from stochastic influences. An example of a stochastic event is if every member of a species just happens to not eat today and dies.
This low population size is going to be one of the barriers preventing organisms from getting too big. This is because if they get bigger they will inevitably go extinct, eventually, even if only by chance. So evolution will favor keeping them small at the point where they are stable. What this size is in your system I don't know, but it will be very small.
*Honourable Mentions:*
A. There is a fundamental lack organic material. Presumably the only materials available are the air, dust, and bacteria already present. This doesn't give a bacterial population much to work with in order to expand. Sophisticated life might never occur because crucial elementals and substances are missing.
*An interesting idea:*
If you can find someway for the organisms present to take advantage of the infinite amount of oxygen, nitrogen, etc available in this room (the ratios never change and are always refreshed) you may find a possible energy source for large multicellular organisms, by virtue of energy from chemical reactions.
[Answer]
Let's start with the most obvious inhibitor - lack of change.
While evolutionary change is fundamentally random at the organism scale, natural selection isn't. Natural Selection is basically the process whereby the 'best' random mutation or change is selected for the given environment. That is important because in an environment where nothing is changing, evolution can expect to occur at a very slow pace, especially after the initial adaptation has taken place.
Why? Because once the organism has adapted well enough to reproduce on a regular basis, nature is going to 'prefer' organisms that maintain the status quo. Admittedly, very occasionally (and at an increasingly lower level of probability for every time it happens) a random mutation will 'improve' surviveability in some way that actually improves reproduction likelihood as well. When that happens, there will be a subtle shift, but could take thousands of generations to propogate through the majority of the population because the existing model is 'good enough'.
What change in the environment introduces is new imperatives to adapt. In other words, once the organism is 'good enough' for the current environment, it has to adapt to the changes in the environment.
When you get right down to it, what this means is that life on the Earth has evolved so much because the environment has been constantly changing.
To put that in context; we currently believe that photosynthesising plant life originally evolved on an Earth with much less oxygen than it has now. There was also no food, after all life was very young, so photosynthesis allowed plants to create their own oxygen and food.
Moving on to nutrients.
In your artificial environment, there's plenty of oxygen, so you might not need photosynthesis to survive. Also, depending on what's in your 'dust', there may actually not be all the nutrients in the environment to support wholesale biomass increases that could occur through a species becoming successful. The nutrient (rather than energy) balance of the room may actually be the limiting factor here. Sure, chemical energy like sugars would be useful, but you are introducing a constant amount of energy and maintaining an environment in which your initial bacterial species can thrive, but if there are not the basic elemental building blocks available for DNA and biological replication, your species still can't grow.
Even in a nutrient rich environment, as has already been said in other answers there is a constant flow of energy into the system and the atmosphere is preserved, so your bacteria may well grow to accommodate the existing nutrient base. Unless that somehow changes the environment however, you may well just run the risk of a flame out; life growing to a point that's unsustainable in the environment causing your own mass extinction. The balance will be interesting to maintain, and in so doing you also remove the chance of environmental change and we're back to the original problem.
Finally, let's look at the issues with atmospheric control.
Maintaining your atmosphere may well end up being the most toxic thing you can do for your organisms. Remember that these are carbon based life forms, meaning that for the most part (this is an over-simplification, but bear with me) you can expect your organisms to breath in oxygen and release carbon-dioxide. But, that carbon is important to the eco-system. You can't just filter it out of the atmosphere and NOT return it to your closed environment. Ultimately, you'd end up with a critical shortage of carbon in your environment, and life would again not have the building blocks it needs to reproduce.
Ultimately, you *want* the closed system to create its own oxygen. If you don't, then you are not creating any form of equilibrium that balances itself depending on the current needs of the environment. You want plants to thrive from a lack of predators when oxygen wanes, to increase the oxygen. You want animals to eat the plants when the oxygen reaches sufficient levels and you don't want to over-produce.
It's these kinds of equilibria, on a massive and complex scale, that keeps the checks and balances on life that forces it to change and to evolve on Earth. In your artificial environment, you don't actually want to keep things too 'ideal'. In point of fact, that's the most destructive thing you can possibly do. What you want is for life to figure itself out, find the niche elements of shortage that it can exploit to survive and balance against itself.
As for scale, other answers are correct in saying that you're not introducing enough energy or providing enough area for variation to occur, especially around procreation. If all your organisms can reach or come into contact with all the other organisms in the tank during their lives, it means that your DNA homogenises. The moment that happens, not only do you no longer get the variations you need for evolution, but you also lose the ability to adapt to the changes that may occur in that environment in the future. In practice, that means that if (say) your lights go out for a couple of years until maintenance arrives to change the bulbs, your ecosystem is dead because it didn't have the ability to adapt in time.
Summing up, you need a balance of nutrients, sufficient energy being put into the system, sufficient space for different colonies to form, sufficient variation in the environment for those colonies to have different evolutionary needs, and an environmental control that ensures that the environment is never truly ideal (albeit in different ways at different times). If you do all that, you have a far better chance of seeing the evolution you seek in such an environment.
[Answer]
**possible but not likely**, the major problem is homogeneity and how small it is. There is little variety in standing condition and not much space so you will not have much variety in the life that is there. Sexual reproduction is the easiest that is about competition withing the same species which exist in this scenario.
Multicellularity is also possible although we do not fully understand what initially drove the evolution of multicellularity, but it is possible and maybe even likely, but we just can't say for sure.
The catch is air breathing fauna since there is no reason to evolve it, earth fauna evolved air breathing because they lived in oxygen poor water, like estuaries and swamps, no such environment exists in your scenario. Thuw evolving air breathing is not going to happen.
to be clear you are still going to end up with a variety of life in your pool but none will not be large, likely not even visible, and the small size of the pool will result in very limited diversity if you have a few dozen species across the entire pool I would be surprised.
[Answer]
**Probable.**
I'm basing this mostly on the characteristics of our starting lifeforms, the photoautotrophic bacteria.
Of particular interest to me is the humble cyanobacteria. This little dude is capable of three important things right out of the box:
* Carbon fixation. They can pull CO2 out of the endlessly-refreshing atmosphere and convert it to something useful and cumulative.
* Nitrogen fixation. They can also pull N2 out of the atmosphere and give us ammonia and other useful compounds.
* Colonies. They can form sheets, which is useful for helping our body of water stay heterogenous, with a well-lit aerobic zone on top and a dark anaerobic zone at the bottom.
That solves some of our biggest problems immediately -- we're getting a good mix of basic organic compounds, and we're changing the chemistry in our aquatic biome.
**Is the rate of energy entering the system too low for large lifeforms?** I don't think so -- the largest living lifeform on Earth is a fungus. Our new lifeforms might be slow, but I think they could be big enough.
**Is the space too small?** I don't think so -- bacteria are, well, pretty small. The smallest multicellular life is pretty small.
And a couple billion years is a really stupendously long time.
**Is the space too heterogenous?** I don't think so. Even if it starts out that way, life itself is going to differentiate that.
[Answer]
Some of the answers have mentioned that evolution will only happen slowly, if at all, because the organisms do not have to adapt to change. Really, that is the biggest inhibitor to life getting anywhere in this scenario.
To create diversity, you can introduce a reason for organisms to evolve. Here are two:
# Virus
Add a bacteriophage to the room. The selection pressure will kill off similar organisms.
Viruses evolve over time. Take for instance the flu. Each season, a new strain of the flu unique from every other strain emerges. A [bacteriophage](https://en.wikipedia.org/wiki/Bacteriophage) is a virus that infects bacteria. The bacteriophage in your room will evolve along with the bacteria. Eventually, a mutation will give one bacteria a cell membrane that the virus can't attach to. Immune to the predation that the other bacteria are undergoing, this bacteria will multiply and spread throughout the population. A random mutation in the virus will then create a strain of bacteriophage that is able to infect those bacteria. So begins an evolutionary arms race, with bacteria and virus constantly evolving to stay one step ahead of the other. Whenever a large amount of one strain of bacteria forms, the bacteriophage will decimate that population because it only needs one mutation that enables it to infect all of the organisms in that strain. Now your bacteria doesn't have a choice of whether or not to evolve. If no one group can stay dominant for long, diversity will be high, and that diversity will ensure that the bacteria will evolve.
As the bacteria evolves and some bacteria become multi-cellular organisms with immune systems, the virus will keep evolving to infect eukaryotic cells and circumvent the immune systems. In this case, I see large blob-like organisms with specialized immune cells evolving first, and when other bacteria evolve to prey on them, then both of these organisms will develop locomotion along with brains and nervous system in increasing complexity.
# Radiation
Radiation can create mutations in DNA. If you have some material that emits DNA-altering radiation, such as UV lighting or a some radioactive material, it will cause mutations in the bacteria that are potentially helpful, causing the gene to spread due to natural selection. Radiation will also introduce selective pressure towards radiation-resistant membranes and walls. The best way for bacteria to avoid the radiation, which will kill them, is to develop locomotion to move to an area of the pool with less radiation. Bacteria that remain near the source of radiation will have to evolve methods to prevent death by mutation. The bacteria can evolve to fix damaged DNA, or have an outer shell that blocks radiation. Now, there are at least two different strains of bacteria in the pool, so you have diversity. Keep in mind that radiation does not travel far through water, [this XKCD What-If](https://what-if.xkcd.com/29/) says the amount of radiation is cut in half every 7cm.
# Conclusion
Both of these options create a selection pressure that favors diversity. With diversity comes predation, and with predation comes evolution to avoid getting eaten. Predation results in complex life and a food chain. Without selective pressure, your bacteria will settle for good enough and won't evolve.
]
|
[Question]
[
I have this protagonist who has has the ability to magically nullify newtons of force when they would harm him. Functionally speaking, this makes the character immune from most forms of damage, both external and internal. While extremes of temperature, suffocation, and starvation can definitely kill him, the character is bullet resistant, knife proof, and can walk off a sledgehammer like it was a Wiffle bat. Furthermore, while the amount of force cancelled can be increased by concentrating, the process is largely automatic. Most people reflexively finch when they're about to get hit, this dude reflexively turns bulletproof.
I've thought of side effects of this trait, such as the character having a surprisingly devastating punch via breaking Newton's third law and possessing a lot of confidence, but there is something I am still worried about. How would this affect his physical development?
This character has been quasi-invincible since he was four and the effect is more than skin-deep, so to speak. With that in mind, what would his physique look like? He's most likely never pulled a muscle or overextended a tendon, but does this also mean he's never been able to build up muscle?
I'm interested in any physical ramifications of this character's kinetic-cancelling in terms of his appearance and physique, but any psychological ramifications would be appreciated as well.
Possibly relevant detail: This character's kinetic-cancelling defense can be overwhelmed with sufficient force and takes time to "recharge". Hit him hard enough (or very frequently very fast), the shield will break, and he becomes a normal human for an hour or so.
[Answer]
I recommend you look up the Marvel Comic's character of Butterball, who has this power with this immunity. He was overweight most of his life and when his powers manifested, it prevented him from ever losing weight. He could run any distance without a break, but never lose an ounce. And he was still physically unfit for superhero life. As he appeared in a series that was basically about a superhero boot camp, his drill instructor and camp staff were at a loss of what to do with him, and when he got his team in trouble, they homages the unit punishment inflicted on Private Pyle in Full Metal Jacket... and Butterball slept through it.
All in all, I don't think natural growth of a human violates invulnerability of this type, so I would imagine he would look like a normal teenager, albeit one locked into his body fat percentage of of his four year old self and muscle tone... as muscle growth is the result of small tears. As for the punch power, I think you could do a faux-conservation of energy by saying that his punches would impact with the same total kinetic force of the action. So if there is parked 18 wheeler and he punches the grill, he would hit with the force of an ordinary human punch... but if the same truck was on an interstate traveling at 65 mph and this guy times his punch so that it impacts with the grill, than the truck would be hit with it's full force plus the force of the punch... essentially it would have a head on collision with itself driving at the same speed... which as far as accidents go, is the one that is the most devastating for a vehicle to have.
[Answer]
**Why would this guys physique be any different than anyone else's?**
He's immune to damage, not super strong. If he wants to lift his girlfriend he needs to press iron like everybody else. This means his physique is no different than anybody.
What he would be is careless... the most accident prone person on the planet because it's irrelevant to him if he's accident prone or not. He wouldn't take particular care to watch when cars or coming, or whether he's grabbing the wrong end of a knife, or walking around with the safety off his cocked pistol...
**He'd be the most dangerous person to stand next to on the planet**
[Answer]
**He should be four.**
For purposes of narrative this makes him much more interesting than just super-dude. Because "damage" is how the brain grows, and how the body grows - and maybe also how memories are laid down. If he has the body and mindset of a four-year old and also has little to no long term memory, you can get rid of the "overwhelmed" piece - he is absolutely invulnerable. But he might not remember that he is invulnerable because his invulnerability suppresses pruning of neurons. He might not remember who you are, or what you want him to do and he might have a fussout when things get stressful. And he is not very strong at all.
But he thinks guns are cool and he can walk through a hive shooting monsters. Be careful though - he might still be able to drown and he cannot swim.
[Answer]
((i know i'm not supposed to ask a question to answer, but does him power only make him invulnerable or does it also prevent him from feeling pain as well?))
If it's the former, I don't think his ability would affect his growth much if you ignore the whole muscle-growth-requires-muscle-damage part of it (assuming his power would gloss over this as non-life-threatening injury).
He might be a little overconfident in the ability, or even more violent or trigger-happy seeing as he would suffer little consequences for his actions. He might have a god complex as he might think he's above physical harm, or be needlessly reckless to test the limits of the ability.
On the other hand, if he can't feel pain either, there's some pretty big consequences that would happen because of it.
According to this website (and several others),
<https://www.independent.co.uk/life-style/health-and-families/health-news/the-people-who-cant-feel-pain-scientists-discover-cause-of-rare-inherited-condition-that-turns-off-10274604.html>, the sense of pain is essential to our sense of self-preservation.
If he can't feel pain, there's the consequences I mentioned before, but in addition to all that, he might accidentally hurt others as he won't be able to judge how much force to use when touching, poking, or play-fighting with people; he would ignore any signs of fatigue or warning signs his body gives him that something is wrong; and in the event that he's actually in danger he won't be able to take it seriously as he believes he can't be harmed. While these effects are more prevalent in cases where people aren't immune to harm (they'd constantly accidentally hurt themselves without knowing), the hurting others part applies even more here because you've mentioned he can use his ability to become stronger.
[Answer]
**Psichological issues**
I don’t want to repeat the very interesting physical arguments already stated. So I will better go to his mind: He knows he is “physically invulnerable”, but he can be poisoned, and a virus or bacteria still can kill him.
So I imagine he will develop some sort of obsession for cleanning and desinfecting everything. If he gets sick, no injection can go through his skin, and no surgeon can operate him.
Additionally, he never eats something unless he is totally sure it is not poisoned (his enemies know he can be killed that way).
Besides, he is alone. No girl wants to sleep with him because everybody knows that story of the last girl that spent a night with him. He had a nightmare, and unwittingly sent the girl to the hospital with more than a few broken bones.
[Answer]
The answer is 100% up to you, because you get to define things like "what does damage actually mean?" Is the natural growth process damage? Is the fundamental process of building and repairing bones damage? When [ostioclasts consume bone](http://sciencenordic.com/when-bone-eating-cells-gain-upper-hand) as part of the natural balance of the body's operation, what happens? These are all up to you. Some of the answers may lead to absurd body shapes. Some may leave your character looking like a four year old (see *Interview with a Vampire*). Others may have less extreme effects.
If you intuitively define it with terms like "bullet proof" and "knife proof" you invoke an intuitive concept of harm, which I think most people would find very meaningful. If you are using that concept for what "harm" is, then there's a very clear answer: he'll look just like anyone else, with a build equivalent to anyone else.
I've never been shot. I've never been in a knife fight. These are simply not part of my growing up. However, lifting boxes and tightening lug nuts and trying to jump to reach the bottom branch in a tree all were part of my life. My body got enough exercise from these operations to develop into its physique. In fact, I would argue that *vast* majority of people developed their physique without grievous bodily injury. There's plenty else to do which affects the body.
[Answer]
## It entirely depends on his upbringing, genetics, and choices
If all he's done for 14 years is play GTA, his physique sucks. If he's into the outdoors, he's utterly fearless and very, very strong and fit. How muscular is his father? How about his mother? Does he live in a rural area, or a tiny urban apartment?
]
|
[Question]
[
**Closed**. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Add details and clarify the problem by [editing this post](/posts/111451/edit).
Closed 5 years ago.
[Improve this question](/posts/111451/edit)
Say that there is some mega-sized space tech that was developed to shoot a spear like object at a planet, and had enough power behind it to pierce the core. Perhaps something along the lines of a super huge magnetic accelerator that shot a metal pole.
If such a weapon was used on an earth-like planet and the spear pierced the core, but became lodged there, what would happen to Earth?
Would the magnetic field dissipate? What if the spear was able to pass all the way through earth?
I am thinking of an object no more than a mile wide as far as the spear is concerned.
[Answer]
No. The energies involved here are just too great.
First of all the "spear" would be gravitationally unstable, it would collapse upon itself and fold into a ball of metal, you couldn't make it strong enough.
Even if you solve that problem, then in the collision with the planet a lot of energy is released. This would be enough to vapourise the spear and the rock. If you get the rod moving fast and it is long enough you begin to dig a larger and larger crater, but before you get to the "impale" the planet, you have released enough energy to completely melt the planet, and in the process, completely melt the spear.
So no impaled but inhabitable planet, if you want to maintain realism.
If you magic away the impaling process, then there is not so much to change. The internal heat of the Earth melts the rod, the dynamo that powers the magnetic field would continue to operate. The rod would not be able to support its own weight (and if it broke up and fell to Earth, the damage would probably wipe out all complex life) so you will need more magic if you want to keep it sticking out the ground.
With sufficient application of magic almost anything is possible.
[Answer]
In order for the spear to pass into the planet without vaporizing it from the sheer force of the impact, it would have to be relatively slow moving and use some other process than impact to dig it's path into the planet. Then you're drilling into the planet rather than shooting something at it.
On a side note, throwing something heavy at high speeds at a planet (an artificial meteor impact essentially) will destroy it which is why the star wars death star is such a silly idea. Why go through all the effort to build that monster when you can just put a rocket on a rock and get the same effect?
]
|
[Question]
[
In a hypothetical scenario humans have discovered a new material that is decently expensive (not antimatter levels). Let's say it's slightly cheaper than gold. What properties would it need to have to make things like bullets, tanks, and gases obsolete during war? It would be preferrably if it replaced them in the form of melee weapons and armor.
[Answer]
It can't be done with a material, there is just nothing that does what you are looking for.
Imagine a human wearing armor hit by an RPG. It doesn't matter how much the armor holds its shape, the shockwave and acceleration will kill you.
What you need is some sort of reasonably cheap and efficient force-field generator that a person can wear. It would filter out poison gasses and stop incoming projectiles but would allow slower moving things to penetrate. To prevent remote controlled drones/seeker missiles/etc then maybe it would also be able to detect and neutralize those - basically nothing self-propelled or moving faster than X can penetrate the force shield.
Melee weapons can now be used since they are swung slow enough to penetrate the shield but then used to stab or slice the person inside.
In fact this was a concept used by the Dune novels and films. The special effects are very dated but here it is:
<https://www.youtube.com/watch?v=RkQFhPJuxgk>
[Answer]
>
> (...) a new material that is decently expensive (not antimatter levels). Let's say it's slightly cheaper than gold.
>
>
>
That's a poor comparison.
In 2006 antimatter cost [25 billion USD per gram](https://en.wikipedia.org/wiki/Antimatter#Cost). Gold around that time cost [20 USD per gram](https://goldprice.org/gold-price-history.html).
---
What you need is some **magical** material that can:
* **Stop gunpowder and other explosives from working -** so that firearms as we know cease being a thing. It has to affect things simpler than gunpoweder powered weapons otherwise spuds become the norm.
* **Stop compressed air from working -** otherwise paintball guns will be fitted with modified ammo.
* **Stop electricity from working -** otherwise the vacuum left by firearms will be filled in by lasers, tazers and [sound guns](https://worldbuilding.stackexchange.com/a/108398/21222).
* **Quench fires from a distance -** so as to stop flamethrowers also.
* **Breaking cord and rubber at a distance -** otherwise people will just resort to [bullet crossbows](https://en.wikipedia.org/wiki/Bullet-shooting_crossbow), or just regular bows. I make PVC bows for a hobby. Some of my friends have wooden ones as well. We have tested them against some materials and I believe that the strongest bows would be able to pierce chain mail. If not the ones we own and make, then the composite ones that use carbon-fiber arrows would sure do it. The latter might even pierce harder stuff. You don't bring swords against archers in formation, so unless you prevent bows as well, most battles will not be melee.
There are just so many alternatives to guns for long range killing that, rather than inventing a new material, you would be better served by a global disaster that would drive humanity back to the stone age.
[Answer]
You just need a material where the more force that is used against it, the stronger it gets. This material doesn't exist in the real world, but you can make it exist in yours, and it's manufacture is a trade secret that no one knows.
You can make swords even more attractive by giving them some property that neutralizes the armor that can't work with a bullet.
Take Black Panthers vibranium armor. It's immune to all impacts, and even stores up the energy to be used later, but it is weak to specific sonic waves.
Your armor could be immune to all damage, but be weakened when vibrated at a certain frequency. The vibration has to be in contact with the suit (no transmitters), and it's too bulky to fit into a bullet (guns are useless).
But it would fit into the hilt of a sword. So the blade of the sword vibrates at the right frequency, and so when it hits the armor it can cut through instead of bouncing off.
[Answer]
A cheap shot would be graphene-based compounds and assuming large-scale production is decently expensive. Alternatives would be a skin with lots of high-grade spider silk woven into it (high-grade can be 40x tougher than Kevlar and make you virtually immune to getting the skin cut).
Everywhere you read that graphene is between 5 to 300 times as strong as steel (although they usually don't mention which property of steel). So assuming a weak form of graphene used as an exoskeleton (Grahene is light after all, although I haven't found any Kg/m^3 mentions yet). Even a 2cm thick exoskeleton would rate as 10cm of steel. Using pure graphene instead of graphene with specific deficits (deficits that make it stiffer for a skeleton) allows you to make skin out of it, skin well capable of withstanding cuts because pure graphene has the highest strength ratio's while still being flexible.
The result would be that everything becomes a blunt instrument (Except overkill like a .50cal anti-tank machine gun most people wont be bringing to infantry fights). If bullets cant cut through your body they need to damage you with the shockwaves they create. Consider the recoil you feel when your weapon goes off and that this is the same force the bullet will apply to your opponent, this means blunt melee weapons will become viable.
[Answer]
How about a custard filled ballistic vest?
What you may be looking for is a non newtonian fluid, something that stiffens when sudden kinetic force is applied to it (like custard).
So you might imagine a vest made of sealed sections (pockets or cells) & each of these sections filled with such a fluid.
You couldn't shoot the wearer (through the vest) but you could stab him (through the vest), if you stab slowly enough (this is almost exactly the effect of the shields in Dune).
For the actual material of the vest you probably can't beat Demigan's suggested spider silk, but I wouldn't know which of our currently available non newtonian fluids is best to fill it's pockets with.
It probably won't stop the effect of a bullet completely but it will take some of the kinetic force out (redistribute it sideways) & the forward force that's left (probably most of it?) will be spread over a much larger area of the body so it'll be (a little bit) more like being hit by a flat plank of wood than shot with a bullet (so sort of a full body airbag for bullets), a lot less lethal.
On the down side I'm not sure we have anything right now that would provide sufficient stopping power for what you want to it's own weight in ratios that would make such an armor even slightly reasonable for a person to wear & move in though.
**Edit: rereading your question, my answer will only fit the bullets in your question.. if you really mean to include tanks & gas & weren't just getting a little excited & giving way to a touch of hyperbole as you typed then there's nothing, you want magic.**
It seems this idea was already very much in the design stage if not in production as far back as 2006 (see [Liquid Bullet-Proof Armour](https://www.youtube.com/watch?v=LlEo5MbcaX0)), and it seems much lighter & more flexible than I thought it could be with currently available materials (while still retaining adequate utility).
[Answer]
I'm going to assume you don't need bullets, tanks, and gases to be completely ineffective, but as you've said, just obsolete – by which I assume you mean not used in any significant amount, so that you can have a melee weapon setting.
You need a material which is extremely strong against impact, but weak against cutting. Kevlar fills these criteria, I believe – it's (somewhat) effective against bullets, but early kevlar jackets were susceptible to cutting – one demo I saw showed it was *easier* to stab through kevlar, as the fibres lubricated the blade.
Unlike in films, swords do *not* slice people in two by hitting people with them hard and fast – they kill by *cutting* (sure, or stabbing, if you've got a rapier, but we'll consider weapons which can cut, such as the sidesword). I practice sidesword, and one of the key things we're always reminded is that you have to *pull through the cut* to be effective. You don't cut a steak by hitting it with a knife fast; you cut by placing the knife on it and drawing it back and through. So impact resistance is meaningless against cutting. It'll probably stop stabbing, but there's whole schools of swordsmanship based around cutting.
So an impact-resistant but cutting-vulnerable material like kevlar is the starting point.
But you need that effect *much* more pronounced (kevlar can't protect against larger calibres, and the impact can still break ribs etc), and you need it to be in a form you can wrap a person with so there's no (or sufficiently few) weak spots, without harming mobility (or swords are also useless). So some super-kevlar or non-newtonian fluid type thing could work.
Now you've got a soldier invulnerable to small-arms, but not swords.
Now larger stuff... Tanks aren't used much against infantry. They're used against tanks. Sure you *could* use tank rounds to kill infantry with the shockwave, but it's gonna cost you - a single round for an Abrams tank apparently costs $8500. Most large weapons (bombs, etc.) for use against infantry rely on shrapnel, but shrapnel will get blocked. Shockwave and fire will still kill. Making your armour fire-proof is certainly plausible.
So, sure, you could use shockwaves from larger weapons to kill, but it's probably not the most practical, especially when you can just give infantry sharp sticks.
Gas – for this you either need your armour to be airtight, or you provide antidotes to bio/chemical weapons, or you rely on bans (it doesn't have to be impossible for gas to kill, just not used – Gas is very effective today, but it's basically obsolete because of the international backlash; similarly atomic weapons aren't used. No-one's asking "how do I invent a world where people use guns not nukes & nerve agents in wars?").
The problem with this is that it's relatively easy to add a cut-proof layer of armour, so swords would become useless. This really blows a hole in Dune – why didn't they wear some armour as well as their shields?
[Answer]
Rather than a new material, perhaps a change in the world? In the tv show Revolution ( <https://en.m.wikipedia.org/wiki/Revolution_(TV_series)> ) two things happened to bring swords back into the mainstream, no more electricty and loss of knowledge (no one knew how to make gun powder, so no more bullets). Change the world so that current weapon tech is no longer viable.
If you go with a shield technology (Dune is the best example I know of) give it an effective range so that, for Reasons, stops all attacks outside of melee range but cant stop attacks closer. (Because of tech limitations, the field must be 6 feet circular or if it was any closer to the user it causes cancer within eight seconds or Reasons).
]
|
[Question]
[
I had a thought last night about how to build a more efficient furnace in a fairly low tech society. (I build Games, so this is part of my world mechanics)
My question is: How feasible is this idea - could it actually be done?
So I had a thought, "Lodestone" or more precisely "Magnetic Lodestone" has been around for a long time (people have known about it for a long time, and magnetism was understood~ish).
If you could get hold of enough Magnetic Lodestone, and you attached all the pieces to the inside of a barrel. If you were to spin that barrel around a metal object would you induce enough heat to forge that metal object?
Lets say I want to make axe-heads, so 2kg? (that's a big axe)
And I have iron in the form of bog-iron (pretty pure I believe, but not exactly sure)
Could I do this? How much lode stone would I need? Would the lode stone wear out (lose magnetism?) Would I have to spin the barrel at an accomplish-able speed? Or would I have to spin the ore instead?
I've done some research, but my understanding of inductance and the finery of the field means I'm struggling to understand or search the right things.
Thanks for any help :)
[Answer]
It is possible to use induction heating to generate temperatures capable of forging metal (with relatively low power consumption).
<https://www.youtube.com/watch?v=HMYtTO8LIAw>
[](https://i.stack.imgur.com/zXKgm.jpg)
Unfortunately, although lodestones were great for compasses, they're relatively weak and have too low of a magnetic coercivity (resistance to demagnetization) to stay magnetized for long. Even the strongest, manufactured magnets would be insufficient (and would quickly lose their magnetic property).
Generators use electromagnetism (magnetism generated by electrical current) to operate.
This was true even with the first generator, the Faraday disc generator, in 1831 (by Michael Faraday).
[](https://i.stack.imgur.com/GJbom.jpg)
Even if you were to introduce a fictional mineral, it would still be the process of generating electricity -- and once technology reaches that point, your world would be on the verge of entering a Victorian equivalent era.
[Answer]
There are a few issues with your idea:
1. magnets lose their magnetism when they are heated above their Curie temperature, which is lower than the melting temperature of iron. Your lodestone would heat up by radiation.
2. To have a decent effect you need to be able to align all the magnetic fields in a somehow coherent way. Just stacking various cobbles will be less effective.
3. To melt iron you need to produce a good amount of power, which means a pretty high induced current in this case (order of the hundreds of Amp at least). Not so sure you can achieve it with such a simple design.
[Answer]
If you're looking for a low-technology, low-cost means of working iron, have a look at history. As other posters have noted above, any naturally-occurring magnetism will not be strong enough or persistent enough to be able to heat metal the way you're thinking of. But a simple wood-charcoal fire can be sufficient to not just forge metal, but even smelt it.
<https://www.google.com/search?q=viking+iron+smelting>
And if you can smelt iron, you could take the next step and cast it -- which might work a good deal better for getting the initial form of a 2kg axe head than trying to simply soften a lump of bog iron and then bash it into shape.
]
|
[Question]
[
Say that an apocalyptic even takes place, a genetic disease wiping out most of humanity in a matter of years. So, there are no bombs, nuclear winter, or any sort of event that messes up the environment.
**60 years have passed after the event.**
Leftover people live in small independent settlements, several hundred people most, self sustaining, growing crops and animals, fishing, hunting the abundant wildlife. Cities are overgrown and deserted.
There is no organized industry, mining, any sort of government, etc. Scavenging the ruins is the only possibility of getting certain resources.
Technology and knowledge is **not lost**. There are books to be found on a lot of subjects (chemistry, engineering, physics...), manuals, even knowledge is passed down.
The **QUESTION** is - would it be possible that those small settlements produce electricity, and, how would they do it? One thing is to make a wind or water turbine, but how would they store the energy (electricity)?
Maybe its better to ask how would they make batteries for storing electricity? Functioning light bulbs? Only with the materials they can get from scavenging the ruins.
Take in consideration that most of the stuff made by a pre-end society has decayed in 60 years time. They can't just find a car battery or a light bulb, connect it to an energy source and voila! Or can they?
[Answer]
Firs things first. Yes, the batteries charged 60 years ago would by just junk. They could salvage parts from it but not use as designed. Same as you can't charge fully depleted car battery.
BUT batteries not charged for the first time or with not started chemical reaction could be used. Or you could make your own battery. Here is (in Polish) a quick guide on how to make such battery. The article (and whole magazine) is targeted to teenagers so it's so simple a child could do it. [Young Technic battery maker](https://mlodytechnik.pl/eksperymenty-i-zadania-szkolne/chemia/5785-akumulatory)
Light bulbs would still work after 60 years. We have light bulb that have been WORKING for 117 years. [Centennial Light Bulb](http://www.centennialbulb.org/).
In the modern ones you even can switch bases so you can use it on E14, E27 or halogen nodes.
Led and Halogen are even more robust as their dome is harder to break.
My main concern in those types of setting is "Why would they need the electricity?". You see, the longer light cycle needed for work was created from industrialization need. To operate cow udders you don't even need to see them. Just find the head, go down and in back (check if it's not a bull).
To operate milling machine at 6 o clock in the winter you need some good source of light.
Yes, of course, people in rural areas use lighbulbs and electricity but it's kind of spin-off of industrial production.
Just imagine that this "post-apo" is just XIX century with a sprinkle of repossessed vehicles.
In Polish we have this saying
>
> Going to sleep with chickens
>
>
>
Which means that you go to sleep at the dusk because you don't need to do much things in dark. Apart from milking the cows in the early morning. But the cows will wake you up and you just need a knot and some fat to make a lantern.
In the 1930's in Poland most villages and rural area were not electrified. My grand grandparents used tallow lamp because kerosene was to expensive.
So the main question would be why they want to have electricy and now how they would make it (because you can make it with wool and amber).
[Answer]
I'm going to take advantage of the fact that you've asked about ENERGY storage and not ELECTRICITY storage by saying that perhaps the best way to handle this is to store the kinetic energy you generate first, and then feed it into an electric generator in a controlled manner that supports your electrical grid.
To do this, you need [Flywheels](https://en.wikipedia.org/wiki/Flywheel_energy_storage). These devices allow you to store the kinetic energy you create via rotational momentum, and then feed it back into a generator (or mill, or pump, etc.) as you need it. Before you get to lead acid batteries and the like, this may be one of the simplest ways to store energy for use around your new environment.
Remember, just because technology isn't lost, doesn't mean that your access to resources has also been preserved. electricity is relatively simple to make, but takes specific resources to build storage devices like batteries. Rotational kinetic energy on the other hand is VERY easy to create, and requires less specific resources to 'store'. That said, the lead acid battery is more effective than a flywheel at preserving energy over a longer period of time unless you've built something very fancy in terms of flywheel technology.
[Answer]
**Windmill and water tower.**
Here is a time tested way to store the energy you generate. Store it as kinetic energy by raising water.
[](https://i.stack.imgur.com/5KmPL.jpg)
<https://www.pinterest.com/pin/475763148113695491/>
Then when you want electricity, let the downflowing water turn a generator.
<http://www.micro-hydro-power.com/micro-hydro-power-Stream-Line-Kenya.htm>
[](https://i.stack.imgur.com/ZJL4f.gif)
During the Bosnia war, the populace of the besieged city Gorzade made little homebrew electrical generators out of electrical appliances and tethered them in the river. I have always wanted to see a picture of those and I found one. It must be purchased but here is a link to look.
<http://www.alamy.com/stock-photo-war-in-ex-yugoslavia-emergency-electric-power-generators-set-by-gorazde-89327869.html>
One could make a homebrew generator like these out of any old electrical applicance that has intact copper windings and the ability to turn. Hook it to your water tower. You have electricity.
[Answer]
It really depends on what you use the electricity for. Lights can come from lamps. Water can be gravity fed. Hot water from wood or solar.
Many people today live without electricity so why do they need electricity? What are they using it for?
Simple lead acid batteries are easy to construct to store it. Whilst car batteries have degraded, the old lead could be smelted down and new batteries made.
Simple generators can be made from copper wire and powered by wind, water or even human power.
Radio communication is the most obvious use for electricity I can think of.
[Answer]
Aqua power is going to be the easiest to harness, especially with the (Personal opinion: Ridiculous) restriction of no mining.
Without any organized industry (Opinion the same as the above), you can't make anything remotely like a steam engine or internal combustion engine. They're just too complex and require tools and equipment that can only be had by industry.
I'm not sure you could get electric lighting without industry, as incandescent light bulbs require the filament to be in a vacuum - And without industry, a vacuum is hard to make. Not to mention, without industry you can't really have the glass for the bulbs either.
Tim B II has a good method for storing the energy, which can work for even non-electrical things - Smothing out the gearing of a water mill to provide constant power for things like looms or grain grinding. Lead-acid batteries, as mentioned by Thorne, are also fairly easy to make.
Thorne also mentions Radio. Basic radio is possible, but would require, again, some amount of industry.
I would recommend that you allow *a small place* to have some industry, some mining, etc. In one of your other questions, you mentioned a University as maintaining knowledge. They would also be the prime location for small amounts of industry - As they know how to make things, how to maintain them, and as you've mentioned they can and do trade out knowledge of things, they could also be the source of things like radios and electric lights.
Additionally, *small* industry of the sort you would need is fairly straightforward to accomplish, especially given your time frame. A University will have many, many experts on many things - And, more importantly, it'll have exactly what is needed to learn about other things. A bio-plague is also more gradual, so it could have started on the opposite side of the world. It wouldn't take much of a leap for someone at the University to think "Hey, we're going to need to hoard these tools" and "We're going to need to make X, Y, and Z." There's also the fact that, at 60 years post-apocalypse, you can even have some people still around that were young (20-30s) when the apocalypse happened. Old Greg might be 80, but he's the one that set up the light bulb factory and still makes the best ones.
Also, to address whether things can be found and be functional after 60 years: This is all based on my *expectations* and *basic knowledge*, and **not** on any research, but the primary killer of incandescent light bulbs, and a lot of other technology, is vibration. The lights in the ovens at work are *constantly* dieing because they're right inside the door, on the latch side. A different store has ovens largely identical, except the lights are on the hinge side. Those lights last *significantly* longer than ours. How is this relevant? Well, it goes back to how your apocalypse happened. Meteor impact? Lots of vibration. Tsunami? Vibration. And water. Bad for tech. Nukes? Vibration and radiation, both bad for tech. And that's not even counting the EMP. Yours? Well, it's a bio-plague. Significantly less vibration caused *in specific areas* means things are more recoverable.
[Answer]
Why couldn't some relatively industrious people decide to settle in/on a hydro electric station? Some of the local maintenance and operational personnel survived and taught their progeny how to fix and run the thing. Those turbines last for DECADES, and they only need to run one of the generator stations to serve their needs, the other 3 or 4 generators and turbines could be taken apart for replacement parts to keep the one sluice they are running operational. After things get more figured out and organized in follow on decades they could export their excess power to nearby settlements in exchange for resources (even just one turbine running would produce waaaaaay more power than they could ever need).
It would be a heavily protected and fortified settlement on top of and inside the dam with access to both water and power, and pretty much could charge anything they wanted from anyone else in the region to export power.
[Answer]
If you only want light, check out gravity lamps: <https://en.wikipedia.org/wiki/GravityLight>
They were specifically made to replace kerosene lamps in third world countries and work by having a ballast fall (slowly) to power a generator which then powers a led.
]
|
[Question]
[
I just thought of something. Carnivorous and dangerous monsters are often depicted as common and dangerous enemies in fantasy, especially things like RPGs, but in real life herbivores far outnumber their predators. But what if some boost in prey levels caused their numbers to increase enough that they attacked a settlement to get more food, and the defenders slew enough to get the population back down? If that happened enough times, over a long enough period, might monsters start breeding faster, in general, to keep their populations going, creating a vicious cycle where the monsters breed quickly enough to justify being such a common threat?
Assuming normal nutritional needs (the monsters are not supernatural, for example), could this situation sustain an increase in the breeding of monsters and thus an increase in monsters?
[Answer]
1. You can have an increase in the population of prey animals. Maybe the weather is good. Or there are few predators.
2. More prey animals will lead to an increase in the population of predators that feed on them.
3. If the population of prey animals then crashes (probably because they ran out of food; possibly because of too many predators) then the predators will go hungry.
4. Hungry predators must "emigrate or starve."
<http://www.nature.com/news/2000/000601/full/news000601-10.html>
>
> To understand the reasoning behind this, one needs to think through
> the population cycles. When a prey species is rare, food and space are
> plentiful, and its population increases rapidly. Meanwhile, the
> population of predators that feeds on it grows only once the prey
> population is big enough to fuel expansion. When this happens, numbers
> shoot up.
>
>
> Eventually, there are so many predators that the prey population
> crashes. But by then, the number of prey has spent several years at or
> near its peak -- leading to a rounded curve.
>
>
> Faced with this dearth of prey, the predators must emigrate or starve
> -- either way, their numbers see a sharp decline.
>
>
>
@Lee Leon is correct in the comments. Nothing breeds faster in the absence of regular food. Lack of food makes it difficult to be a young animal because you are outcompeted for whatever food their is.
But a boost in prey, leading to a boost in predators, followed by a crash in prey could definitely lead to the starving predators moving to new areas and taking more risks. One reads about hard winters where the wolves come into town hoping to find an unwary human. Unless these predators find a new food source their numbers are going to crash whether adventurers take them on or not. But a cyclical burst of predator numbers driven by environmental factors is very realistic.
[Answer]
**The idea that killing things makes them evolve is wrong.** The cause-effect flaw in your premise is here:
"If that happened enough times, over a long enough period, might monsters start breeding faster, in general, to keep their populations going…?"
**MUTATION**, not genocide, is what makes a species change it's breeding habits. It would be pure coincedence that a happy mutation comes along just as your monsters were being driven to extinction, but fewer surviving adults means it's far *less* likely the mutation will find its way into the general population of your monsters.
In the lab when scientists talk about "forcing" evolution in a petri dish, there are hundreds (if not thousands) of more experiments where the organisms simply die. Scientists are excited because they were able to observe one *beneficial* mutation under a controlled environment but that was just chance, and the reason they use viruses and bacteria is that new generations come in hours, not years. Mutations are happening all the time, but of course the vast majority are not beneficial to the individual, much less the species.
Imagine a different environment, resources are scarce when the same mutation to breed faster happens. This causes physical stress on the mother who can't feed all the babies, competition among siblings who now compete for food and care, and leads to higher infant mortality and probably a shorter lifespan for the mother. In this situation, the same mutation is probably NOT a benefit to the species.
[Answer]
Over any amount of time that a civilization would still be living in more or less the same place doing more or less the same thing, evolution does not explain this fantasy trope. There is simply not enough time for any species to substantially change and adapt during the (let's be generous) five thousand years one fantasy city is still in one place battling local populations of monsters.
This is even not taking into account the totally correct answer already provided here which pointed out that random mutation is what causes adaptation, not wiping out large numbers of a species (thus reducing the chance of that mutation).
What you might be looking for is the underlying assumption of a fantasy world. In our world, we are the absolute apex predator. Nothing can possibly threaten a population of humans except potentially some microscopic organisms, but even that would probably be temporary, since we have adapted to plagues before. In a fantasy world, this is not the case. Monster species are monster species because they naturally do not accpet mankind as the apex predator. They may see us as food, or they may see us as competition for the top spot, but in either case, they are more than willing to kill us because there just isn't enough room for TWO totally dominant apex predators on any given world.
Why would you have creatures like this mixing with human populations? Inevitably is would be because someone (either us or them) had moved from their natural habitat into someone else's habitat. In many fantasy worlds developed for RPGs, there are either ancient stories of humans arriving on the world they are on, or some kind of catastrophe that leads to widespread travel by various monsters from wherever they naturally occur to the planet in question. This is because it just doesn't make sense to have that many apex predators in one place at one time. Basically, you can think of this kind of like the demographic mechanism that led to the Viking invasions. Small pockets of fertile land filled up with people, there was a shortage of new land and an excess of young, ambitious sons, and expeditions started to go out to find new areas to colonize, settle, or just loot. Some similar mechanism could be forcing both the humans and the monsters into the same area from their natural habitats elsewhere. This would also explain the constant supply of new monsters when the existing ones are defeated.
[Answer]
>
> If that happened enough times, over a long enough period, might monsters start breeding faster, in general, to keep their populations going
>
>
>
This question implies a teleological conception of evolution, where animals evolve to fulfill some sort of purpose. Neither animals, nor evolution, act with survival of the species as a goal; species moving towards higher fitness is simply an emergent property. Thinking of species "trying" to survive is, in some cases, a useful abstraction, but you need to avoid taking it literally.
>
> Assuming normal nutritional needs (the monsters are not supernatural, for example), could this situation sustain an increase in the breeding of monsters and thus an increase in monsters?
>
>
>
You're asking two completely different questions, and treating them as the same. Increase in breeding and increase in monsters are completely different things. If the increase in breeding is in response to higher mortality rates, then you can have the first without the second.
As else being equal, evolution favors traits that increase breeding. So animals will already be "trying" (again, this is just a metaphor) to breed as much as they can. It's not like in a world without adventurers, predators will be "holding back" their breeding because "there's already enough". Whatever forces that limit their breeding without adventurers, will also limit their breeding with adventurers.
It is possible that excessive killing of predators will decrease their numbers to below carrying capacity, and there will therefore be an excess of food that supports increased breeding, but this will simply allow the predators to rebound to carrying capacity. It would not explain a sustained excess above carrying capacity.
[Answer]
If the primary diet of monsters is adventurers then the number of monsters would increase with the number of adventurers.
One may initially assume that all adventurers come back alive, but if that was true then there'd be no status to the role as there was no risk. Insufficient adventurers to maintain the monster population would cause monsters to venture into farms and towns to feed causing a surge in the number of adventurers hoping to clear them out. Restored to their traditional diet, monsters would no longer attack towns.
[Answer]
Yes, this can happen. The coyote does this. When members of the pack are killed, it can trigger the females to increase the size of their litters, thus increasing the number of coyotes.
This graphic from the [humane society](http://www.humanesociety.org/assets/images/photos/coyote-killing-infographic.jpg?credit=web_id169097269) illustrates how it works
[](https://i.stack.imgur.com/Rmj3c.jpg)
Obviously this is a very specific organism and it implies that the environment, food supply, etc are relatively undisturbed, or at least not so much that the coyote can't adapt (which they do extraordinarily well). But it could serve as a model for a monster that increases in population due to adventurers killing some of them off.
[Answer]
Habitat destruction.
Most fantasy worlds have large areas of wilderness. As humans expand and tame this frontier, they would push all the beasties out, creating an artificially high density of monsters in the wilderness areas.
Some of these monsters might prey upon others, creating a surplus of prey and a population boom.
[Answer]
First I would clarify that a mutation for increased breeding occurring in response to increased predation by adventurers IS NOT NECESSARY for our premise. Rather, it is acceptable to assume sufficient variability already exists in the monster pop. For evolution to act on. So the question is, in the presence of increased predation, will genes for rapid sexual maturity and breeding rate outperform genes for slow sexual maturity and breeding rate? The answer depends on the nature of the monster, but the point is that if breeding faster improves survivability in a certain circumstance, then we would expect to see an immediate trend in the monster gene pool toward rapid breeding. We don't need to wait for a lucky mutation, variability already exists in the population and selection will act on it immediately.
[Answer]
You've got a big problem here: Evolution will have an opposite effect!
Adventurers generally kill monsters because those monsters are a threat to civilization. (Yeah, they want loot but that loot came from civilization in the first place.) If adventurers become a serious threat to monsters the logical evolutionary result is monsters avoid civilization. Any low-intelligence monster will evolve to run away from humans.
High-intelligence monsters may choose to raid civilization but they will live in locations very well concealed (probably quite remote) from anyone they are raiding.
[Answer]
What could explain increase in predator attacks on settlements is increased hunting of prey by people (we mostly eat herbivores, after all). This would leave less food for predators, and make them desperate enough to attack humans.
Also, expansion of human agriculture, mining or other ways to reduce habitat for prey.
Finally, hunting of large trophy predators (e.g. wolves) can lead to explosion of smaller and less prestigious predators: foxes, wolverines, etc.
]
|
[Question]
[
*This is question is related to the medieval world from [my earlier question](https://worldbuilding.stackexchange.com/questions/101214/what-qualities-could-a-hominid-evolve-to-make-it-a-better-farmer) in which several types of intelligent hominids evolved in isolation, until they were rediscovered, conquered, and [bred](https://worldbuilding.stackexchange.com/questions/99806/how-long-would-it-take-to-domesticate-humans?noredirect=1&lq=1) into a biological caste system by a dominant species.*
## **BACKGROUND**
To go with my [farm-laborers](https://worldbuilding.stackexchange.com/questions/101214/what-qualities-could-a-hominid-evolve-to-make-it-a-better-farmer) I'd like a warrior hominid that can run incredibly fast. Ideally, they might end up in a military role comparable to light cavalry; moving rapidly over the battlefield, skirmishing where needed, and then breaking off. (Edit: They would prioritize speed over endurance, while still being able to run and fight long enough to be useful before tagging out.)
But first there are some obvious problems with this that need working out, which is why unlike the last time I'm devoting this entire question just to the issue of speed. First, bipedalism and a faster-than-human running speed isn't a common evolutionary strategy, so I need to justify that. Second, they also still need to be viable as close combat soldiers, so I'd like them to be tall and strong. Depending on the physique, this may not be conducive to speed.
I don't have a good grasp of the mechanics, but I anticipate one solution might be for them to drop to all fours while running. If so, that would be an workable but imperfect fix, because it creates all kinds of problems for holding weapons, especially large ones like spears. Happily, there are two large, fast, and 100% bipedal runners I can think of from the animal kingdom: the ostrich and the kangaroo. But I'm not sure what lessons there can be applied to a recognizably hominid physique.
## **QUESTION**
* **How fast could a human sized or greater intelligent hominid evolve to run? How would its physiology differ from our own?** As a bonus: In what circumstances might such a creature evolve? Could they become fast enough to be a feasible competitor in a world with cavalry, or would I have to remove fast-moving mounts like horses from the world to make them more effective?
[Answer]
Ever wondered what the difference between red meat and white meat is?
Animals like cows and sheep are herd animals. Their survival strategy for attacks by predators is to be able to out-run them. Not run faster, just run for longer than the predator. This means that their muscles can be saturated with hemoglobin for longer; they can't fill the muscle with blood as quickly as an ambush predator so they have to build up to their top speed, but neither does the blood leave the muscle quickly, so they can maintain that speed for longer.
Predators and some other animals on the other hand don't need endurance, they need the ability to sprint from a standing start. These animals have muscles that are designed to be flooded with oxygenating blood very fast, providing massive amounts of energy quickly, but they drain just as fast meaning that the speed cannot be maintained. Very much a 'light that burns twice as bright lasts half as long' kind of thing.
So; sprinters are more likely to be predatory in their nature so that's a start. The first thing that would be needed for their adaptation is longer legs.
Longer legs mean larger muscles, but also larger 'levers' in the form of the bones. That means for every contraction the muscles make (especially quads and hamstrings), the further you go distance wise with more or less the same energy. The tradeoff here is that your hominid would lose a little agility in this so they can charge an enemy line, but they're less likely to be able to dodge fast spears or swords. They would be taller though, so perhaps they'd be able to see further into the enemy ranks and anticipate attacks better, making up for the reduced capacity to react. Balance would be another weakness in this case because of the long legs and lack of agility when running.
If their arms were also longer and they had strong upper body strength, they could wield larger swords and maces, making them quite dangerous in melee situations against smaller foes.
Your hominids would have evolved from ambush predators who work in groups to take down larger prey. They would have larger reserves of blood in their system to maintain a powerful sprint even for a short distance, and that would mean larger lungs to fuel the energy conversions. This probably means faster metabolisms (they'd have to eat more than a normal human, probably by a lot) and they'd tire easily after their short stint in combat.
They'd probably live a shorter lifespan than a conventional human. Faster metabolism is one thing, but using all that energy in a single burst would put a massive strain on their systems, just as it does with [Cheetahs](https://en.wikipedia.org/wiki/Cheetah) for instance. You can also see the longer, more spindly legs on these creatures by comparison to other cats.
For the record, horses are endurance runners, especially when they are fully mature (say around 6 years old). That means that they have good speed, but not the acceleration that a Cheetah is capable of (although they can run for a very long time).
So; I'd be using your hominids as cavalry hunters. Ambush them, kill the horses (or preferably the rider) and then get out. They would make great neutralisers of enemy cavalry ranks if deployed correctly, whereas against a line of pikemen and other infantry, they would be less effective.
In short, you use your cavalry against infantry, and your hominids against cavalry, and your infantry against hominids. Very much a scissors, paper, rock scenario in my humble opinion.
How would these hominids evolve? They're ambush hunters, pure and simple. They band together to take down larger prey, but use speed and weapons instead of strategy. They rely on overwhelming their prey rather than herding it into a difficult terrain or trap like the neoliths. I'd imagine that these hominids would evolve in large sweeping savannas, where the terrain can't be used to advantage and where stealth and teamwork are the answer to hunting. Much like modern lions.
Obviously I don't have hard data available, but with the right metabolism, blood and hemoglobin volumes, lung capacity, limb length, etc. you should be able to get your hominid up to around 80 Kph; fast enough to just outrun a horse over a short distance (again based on the Cheetah). This though would inhibit many of the other traits that you want for melee combat, which is why I suspect they would only fill niche tactical roles.
[Answer]
**Let's talk about [Usain Bolt](http://www.guinnessworldrecords.com/news/2016/8/olympic-legends-usain-bolt-fastest-man-on-the-planet-438787)**
...Who ran the 100 meter dash in 9.58 seconds. Or, as we Americans like to say, 23.35mph. That's whomping fast for a human. What are some of the reasons?
From [this source](http://www.bbc.com/news/magazine-34089451):
* A top sprinter takes longer and more powerful strides.
* They spend 60% of their time in the air.
* They naturally have more "fast-twitch" muscles.
But what's really cool is this statement:
>
> "Bolt is a genetic freak because being 6ft 5ins tall means he shouldn't be able to accelerate at the speed he does given the length of his legs," says former Great Britain sprinter Craig Pickering. "At the beginning of a race you want to take short steps in order to accelerate, but because he's so tall he can't do that. But then when he reaches top speed he has a massive advantage over everyone else because he's taking far fewer steps."
>
>
>
And from [this source](http://www.telegraph.co.uk/usain-bolt-worlds-fastest-man/0/built-for-speed-what-makes-usain-bolt-so-fast/)
>
> This raises the much-discussed phenomenon of fast-twitch muscle fibres, which are boosted by possession of the ‘sprinting gene’ - ACTN3. Studies have found that 75% of Jamaicans carry this gene, compared to 70% of US international-standard athletes. It has also been suggested that the aluminum-rich soil of Jamaica increases the activity of this gene; Bolt’s ability could be attributed to the very earth upon which he was raised.
>
>
>
* Sprinters have longer muscle fascicles (bundles of muscle fibres)
* Sprinters have shorter Achilles tendon ‘moment arms’ (the perpendicular distance from the tendon to the centre of the ankle joint).
* Sprinters have been shown to have longer toes, allowing them to apply force to the ground for longer.
**So, if you want to have a true hominid (not something that drops to all fours to run like mad), you want to genetically breed your warriors for:**
* Height
* Long legs
* A high percentage of [fast-twitch muscles](https://greatist.com/fitness/what-are-fast-and-slow-twitch-muscles)
* Long muscle fascicles
* The presence of the ACTN3 gene
* Short Achilles tendons
* Long toes
*And always remember, in the words of the [Great Sage](https://genius.com/Charles-wright-and-the-watts-103rd-street-rhythm-band-express-yourself-lyrics), "It's not what you look like, when you're doin' what you're doin', It's what you're doin' when you're doin' what you look like you're doin'!"*
[Answer]
I would imagine for a human to achieve Kangaroo like locomotion there would be several changes.
Firstly, their feet would be huge and pretty long. This would allow them to act as springs similar to the way a kangaroo moves. However, we would be incapable of balancing ourselves with a tail. Instead the human would probably have longer arms which it would use to stop itself from tipping over and face planting into the ground.
I would imagine it as people with rabbit like legs, and really long creepy arms. They would move by pushing out with both legs, support themselves momentarily with their arms, which keep their body horizontal before pushing out with their legs again. For slower motion, I imagine they would sort of skip or bounce around, as their large feet would make moving small amounts difficult, and with a lack of tail, the would need to be upright and move slowly.
To evolve this way, they would probably have to travel very long distances to get foot and water, so the more efficient method of bouncing, rather than running is used. As for speed and distance/time I would use [this](http://www.speedofanimals.com/animals/kangaroo). They might end up faster since there is a clear lack of tail and they use arms to run, but that should also translate into less distance as its more of a mix between hopping and 4 legged running.
For the fighting part, They would probably carry their weapon on their back, and if there is a need to use it. For a spear like weapon, They would leap up and use it, attempting to end the fight in one blow, but for normal weapons they would need to slow down. or have it attached closed to their forearms.
[Answer]
About 40 mph (64 km/h), [based on research published in 2010](https://www.livescience.com/8039-humans-run-40-mph-theory.html).
The main limit is to how fast the muscles can react: if you could increase the response speed of muscles, you allow them to put out force in briefer period of time while contact with the ground.
If you can get your fast-twitch muscles to be faster, however, then at around the above speed you hit another limit, namely how much force the human leg can take before bad things start happening.
]
|
[Question]
[
This question is related to [Deadly, Heavier than Air Gas](https://worldbuilding.stackexchange.com/questions/14792/deadly-heavier-than-air-gas), and [Is a world with two different types of air possible?](https://worldbuilding.stackexchange.com/questions/61663/is-a-world-with-two-different-types-of-air-possible/61669#61669) but has several different criteria. I've also looked at <https://chemistry.stackexchange.com> and not found anything
I'm building an alternate Earth in which, some time in the 18th or 19th century, the world was covered to a depth of ~100m by a certain gas.
**I need a gas with the following properties:**
* Denser than air (**necessary**)
* Will remain separate from the air above it (**necessary**, with a few metres of interface)
* Gaseous down to at least 0°, preferably -50° or less (**semi-necessary**,would need to be gaseous at the very least in the daytime)
* Not flammable (covering the planet in a flammable gas sounds like it would bring a whole new meaning to the phrase*Great Balls of Fire* (**optional**, would settle for only flammable with difficulty - I don't want to watch the world burn)
* Relatively safe (would only kill you by asphyxiation, unlike say Chlorine) (**optional**)
* Contains Hydrogen or Helium atoms, which can extracted with c19th technology (alternatively, something else which can be extracted and burned as fuel) (**optional**)
* Opaque or visible (**optional**)
Unfortunately, it's been a while since I last did any Chemistry and I can't think of any gases that quite fit the bill. The noble gases are out because they don't help with the fuel element, while gases like Benzene fail the 'not flammable' test.
**Is there a real gas with the above properties**, or will I have to go with *Handwavium*?
[Answer]
I have been pondering this one and I think I have a candidate. **Fog.**
• /Denser than air/ – water as a gas is not denser than air, but can exist at earth temperatures in equilibrium with its liquid phase. The presence of microscopic droplets of liquid condensing from and evaporating back into the gas makes the fog more dense than air. Additionally (as below) liquid/gas water will stratify out with cooler, denser air.
• /Will remain separate from the air above it / Gases are all miscible but still air will stratify by temperature. Cool air is denser than warm. Cool conditions are necessary for the above described equilibrium of liquid and gas phase. If the air is stratified by temperature, the water vapor will stay in the lower cooler layer. This is a **ground fog.**
[](https://i.stack.imgur.com/0xxzO.jpg)
• /Gaseous down to at least 0°/
Sure. Gaseous water can also exist in equilibrium with the solid form: ice. On reading I learned the difference between [ice fog](https://en.wikipedia.org/wiki/Ice_fog) and [freezing fog](https://en.wikipedia.org/wiki/Fog#Freezing_fog). Ice fog is suspended crystals of ice in the air that just hang there. Freezing fog is supercooled water that turns to ice when it touches anything, like the road.
[](https://i.stack.imgur.com/8nktW.jpg)
Don’t go out driving in the freezing fog, worldbuilders.
• /Not flammable/ - water excels at being not flammable.
• /Contains Hydrogen or Helium atoms/ – plenty of H in H2O and extractable with primitive electricity tech.
• /Opaque or visible:/ Both!
I am liking this also because fog is ok for earth. Fogworld would be spooky and surreal. I could suspend my disbelief for a world where fog moved in to stay.
[Answer]
No, sorry. Gases *by definition* are miscible. There are no gases which (in the absence of a gravitational (or possibly electric) gradient will separate. On Earth the gravity is insufficient to even get CO2 to concentrate below the O2 and N2 (molecular wts 44, 32, 28 respectively).
Also, your desire for a gas which is a source of energy but is "safe" is another oxymoron. If it can be readily converted to another state and provide energy, it is quite unlikely to be "safe". Are you able to give a counter-example? (Keep in mind that wood, as saw dust, is quite explosive).
Two gases come to mind which are dense and fairly inert SF6 and NF3. Both are big time greenhouse gases but not too toxic, iirc. You might be able to get some energy from them, I'm not sure what the reactions would be, possibly by reacting them with water...just a speculation.
[Answer]
**Sulfur Hexafluoride [SF6](https://en.wikipedia.org/wiki/Sulfur_hexafluoride)**
[](https://i.stack.imgur.com/JNYy7.png)
* Denser than air (it is used as invisible water trick to make small objects float)
[](https://i.stack.imgur.com/fXmcq.jpg)
* non toxic
* non flammable
* invisible
Funny side effect:
>
> As with all gases, the density of SF6 affects the resonance frequencies of the vocal tract, giving the voice a "demonic" quality when SF6 is inhaled
>
>
>
[Answer]
Your alternative Earth would have to have a radically different material composition from our Earth. There is a gas that might fit the bill. It is rare on our Earth, but if on yours it is very abundant then it could work.
The candidate gas is [xenon](https://en.wikipedia.org/wiki/Xenon).
>
> Xenon has atomic number 54; that is, its nucleus contains 54 protons. At standard temperature and pressure, pure xenon gas has a density of 5.761 kg/m3, about 4.5 times the density of the Earth's atmosphere at sea level, 1.217 kg/m3
>
>
>
But let's look at the density of air.
>
> Air density, like air pressure, decreases with increasing altitude. It
> also changes with variation in temperature and humidity. At sea level
> and at 15 °C air has a density of approximately 1.225 kg/m3 (1.225
> x10−3 g/cm3, 0.0023769 slug/(cu ft), 0.0765 lb/(cu ft)) according to
> ISA (International Standard Atmosphere).
>
>
>
Source: [Density of air](https://en.wikipedia.org/wiki/Density_of_air)
Air's density is 1.225 g/L. The density of xenon is 5.881 g/L. Xenon has approximately five times the density of normal air. Therefore, if xenon was an abundant gas in the atmosphere of a planet it could accumulate at lower altitudes. However, the miscibility of gases would tend to counteract the probability of a denser layer of up to one hundred metres (100 metres).
For more [information](https://en.wikipedia.org/wiki/Noble_gas_(data_page)) about the [noble gases](https://en.wikipedia.org/wiki/Noble_gas).
[Answer]
There are a few elements in your specifications that don't make sense.
* **Gases mix with each other.** The only way for you to have only a certain gas on Earth's surface (whether it's only the 100m the closest to the surface or not, it by not having other gases on the planet. *Which is kind of hard to imagine in Earth, since most of the land surface is covered with lifeforms which emit various gases (O2, CO2, Ch3, etc...) and water evaporates all over the Earth - especially above oceans and seas.*
* *You said you wanted a not flammable gas, that is also safe (only kill by asphyxiation) separated from air with a few meters thick interface between both layers.* If there is a 100m thick layer of your gas devoid of any other gas, then whether it's flammable or not, **it won't burn**. **Combustion also needs oxygen, without it there is no fire. There is no breathing either, so everything asphyxiates to death**.
* I'll live the density part aside. A gas density depends on its pressure, which depends on the amount of gas, the volume it's in and its temperature. What kind of gas it is isn't very relevent here.
]
|
[Question]
[
Let's say there's a planet with 18 times the radius of Earth, but has the same density as Earth. If so, how would it be possible for a big planet to such a density of Earth? Would it have the same gravity as Earth?
[Answer]
# That's no planet!
Let's say that the radius is $18R\_{\oplus}$, where $R\_{\oplus}$ is Earth's radius. The volume will then be
$$\frac{4}{3}\pi(18R\_{\oplus})^3\bar{\rho}=5832\left(\frac{4}{3}\pi R\_{\oplus}^3\bar{\rho}\right)=5832M\_{\oplus}$$
where $M\_{\oplus}$ is the mass of Earth and we assume the same mean density $\bar{\rho}$ for both bodies. That's roughly $18.4$ times the mass of Jupiter. Something this massive isn't a rocky planet, and it isn't even a gas giant. It's like a decent-sized [brown dwarf](https://en.wikipedia.org/wiki/Brown_dwarf).
Brown dwarfs generally have higher densities than gas giants; [their central densities can reach anywhere from $\sim10$ to $10^3\text{ g/cm}^3$](http://www.scholarpedia.org/article/Brown_dwarfs), much greater than Earth's density of about $5.5\text{ g/cm}^3$. The brown dwarf is less dense towards its surface, and there's not really a clear boundary (as is the case with stars, as they're gaseous), so some parts will be more dense than Earth (on average), while others will be less dense.
I see that Mormacil's answer mentioned [a question](https://worldbuilding.stackexchange.com/q/9948/627) I answered two years ago and have, I think, cited a couple of times since. An important takeaway is that you can't simply add more and more mass to rocky planets and expect them to stay rocky. One group ([Lammer et al. (2014)](https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/mnras/439/4/10.1093/mnras/stu085/2/stu085.pdf?Expires=1490555590&Signature=XZaZrpulMCo2Rbdq8tvTfHWApOwB9vKsfpBuBGDC6N%7EAxa1%7Ehxcq6yorCtzuOhA%7EUEMtyhLbWHTKFtoZbX-GLuntWBG2hbZr-zGcwq2ui9lgJPuyA-FO%7E24lgN7P%7E33uduAL73w8EJV5ASLXv8zVzbeV5LxaCrcaS4qywW5ME8Ac17u0FrmJCUWEqHs98RmRnsSwpjcfxspioYgdmsNwW1fI4zO6hVciMK5Q1z5GalLIUHUfaBID7WAHPi0j%7EJQdj2UK23C%7Euo4CY8neauqpkBBwgPYaipjJ4souLdgX-tJc25%7EeuiM-VYujutldV2-iajEAek%7Euz0kRYuQueirvLA__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q)) found that at around $2M\_{\oplus}$, rocky bodies will retain hydrogen/helium envelopes, entering a class of objects that are more like gas planets than rocky planets. Your $18M\_{\oplus}$ "planet" certainly won't be terrestrial in nature. Based on [Seager et al. 2008](https://arxiv.org/pdf/0707.2895v1.pdf), the maximum achievable radius for a terrestrial planet is, optimistically, $4\text{-}5R\_{\oplus}$, assuming a pure ocean world (which should be less dense than a silicate Earth-like planet of the same mass).
# Surface gravity
The surface gravity $g$ is related to the radius $R$ by
$$g\propto\bar{\rho}R$$
Given that $R=18R\_{\oplus}$, the surface gravity will be 18 times that of Earth. Again, though, it's not clear where the surface of a brown dwarf actually *is*, so take this figure with a grain of salt.
# Life
Life on brown dwarfs has been discussed in [Can life arise on a brown dwarf?](https://worldbuilding.stackexchange.com/q/65023/627), among other places. Essentially, there are some *big* problems you'd need to overcome, including high temperatures and possible radiation.
[Answer]
* If the planet is $n$ times bigger, then it has $n^3$ times bigger volume.
* But it has the same density as the Earth, thus it has $n^3$ times bigger mass.
* Its $n^3$ times more mass would produce $n^3$ times stronger gravity, but...
* Its surface is $n$ times more far away from its center, thus this gravity feels $n^2$ times lesser.
The result is that the surface gravity is $\frac{n^3}{n^2} = n$ times stronger!
Thus, on a planet having 18 times bigger size, but the same density as Earth, it would have $18g$ surface gravity.
---
If somehow it has similar surface parameters as the current Earth, then life is possible, although it would be highly different as ours. We would be most probably some "turtle-like" lifeforms.
---
About the physics: in general,
* if you make the density $n$ times bigger, the surface gravity will be $n$ times bigger
* if you make the planet $n$ times bigger, the surface gravity will be also $n$ times bigger
* but the mass of the planet will be $n^3$ times bigger and its surface area will be $n^2$ times bigger.
* also the escape speed will be $n$ times bigger, but note: to get anything to this $n$ times bigger escape speed, it requires $n^2$ times bigger kinetical energy.
Typically, in the atmospheric evolution of the planets, there are two effects:
1. The star heats the planet and blows it with stellar wind, and these try to evaporate its atmosphere
2. The planet's gravity tries to get the atmosphere on the planet.
The overall result — now, after knowing some [hundreds of exoplanets](https://en.wikipedia.org/wiki/List_of_exoplanets), too — is that around Jupiter-sized planets can keep their atmosphere even if they are near to the star. Maybe even the lighter gases. This is why the large planets are mainly gas giants (≈ the atmosphere is so dense that the majority of the planet mass is built up from it).
If you want this planet not be a gas giant, instead to have a planet-like atmosphere, then the star have to be able to blow the the hydrogen and helium away. If the planet is in the near of the star (or it is a very big one), then it is possible, but it causes such a heating that the surface temperature will make it impossible for the life.
For example, large exoplanets, close to their star were found, with around 2000°K surface temperature. Their atmosphere is from gaseous sodium, and they may have liquid iron rains. Even oxygen couldn't remain on them, despite their high surface gravity.
[Answer]
According to the answers on [this](https://worldbuilding.stackexchange.com/questions/9948/is-there-a-theoretical-maximum-size-for-rocky-planets) question that size won't be possible for an Earth like planet. They say about twice the radius/10 times the mass is the theoretical max.
Density is based on composition. If it's similar to Earth so should its composition. It will not however have the same gravity. If you scale up the liquid core the same amount as the rest of the planet it stands to reason its gravitational pull would similarly increase.
Higher gravity would dictate life that's shorter, closer to the ground and more dense in general. Things like grass would be rare but moss and short bushes would not. Animals likely have four or six limbs, very few bipedals. Flying would be much harder and birds would likely be smaller.
Life will probably favor the oceans that much more. As the water would nullify some of the crushing gravity. Regardless it will be impossible for humans to visit I think.
[Answer]
Some good answers.
Another consideration: Atmosphere: With 18 times the surface gravity and a much slower taper off of gravity. (Will go down by a factor of 4 at 2 R from the center. But your big planet is now 18 R, so you hve to get out to 36 R from the center to get that same lower gravity. This makes for a much much thicker atmosphere. Thousands of times more atmosphere.
Light is not going to reach the surface.
Escape velocity is $v=\sqrt{2GM/r)}$
But with $18^3$ times as much mass, and only 18 times as much r, escape velocity will be 324 times as great as earth's or about 3500 km/s. Not counting what you lose to atmospheric drag.
[Answer]
Yes it is, kind of, a planet that big with the same average density as Earth may be possible but it won't be a rocky, terrestrial world and it won't fit well in our existing planetary catalog. As HDE 226868 mentioned such a celestial object is heavy enough to be a [Brown Dwarf](https://en.wikipedia.org/wiki/Brown_dwarf) Star but it won't be, the composition can't be right.
It's 1.65 times the radius of Jupiter which is too big to be a Brown Dwarf ([measured Brown Dwarfs](https://arxiv.org/abs/1304.1259) are in the 0.63-1.13 Jovian Radius range) and only 4.1 times the average density (Brown Dwarfs are normally twice that [dense](https://en.wikipedia.org/wiki/Brown_dwarf#Theory), or more), so it's got to have a big, but relatively low density, rocky/metallic core (probably composed primarily of high pressure Carbon [allotropes](https://en.wikipedia.org/wiki/Allotropy)) with a thick atmosphere of light gases (Hydrogen, Helium and Hydrocarbons). It's a weird elemental mix for "modern" stars but you might find such a world in a younger universe where the heavier elements were much rarer, possibly such worlds might still exist around the very oldest [Red Dwarfs](https://en.wikipedia.org/wiki/Red_dwarf) but I don't think one *could* form in the modern universe.
]
|
[Question]
[
One hundred years into the future, humanity colonizes the first planet in another solar system. A big ocean world! Yay!
But there is a problem: Most of the flora is toxic for consumption, so the only option is to hunt the animals for meat. Most of the aquatic animals on this planet can be used as food, but those animals are mostly leviathans, and they are very aggressive.
There are several species of leviathan. The smaller species are twice as big as Earth's blue whale; the largest is 6 times bigger [than the blue whale].
**How can we catch these giants without major risks?**
[Answer]
**"You're Gonna Need a Bigger Boat"**
Using the wise words of Brody "You're Gonna Need a Bigger Boat". You can't use anything too destructive or lethal to kill and collect your giant leviathans because you want to maximize food collection in what is already a risky process.
The largest blue whales are [around 100 feet long and 300,000 pounds.](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=13&cad=rja&uact=8&ved=0ahUKEwjZgv69h8rSAhWHMGMKHWCQCcIQFghRMAw&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FBlue_whale&usg=AFQjCNFMi2XiMth3oDHoRj4eu_UDi51q0Q) If the largest leviathans are up to six times the size of our blue whales then you're going to scale a modern day whaling ship up that large. Then to be safe since these whales are aggressive you're going to want to scale it up again.
**How to kill the leviathan**
My first thoughts were a poison to slow them down or incapacitate them, however we can assume that their system already filters most toxins as they live in such a toxic environment yet have edible flesh .You could use similar harpoon methods as we have with whales on our own planet. This would also be a matter of scale however I think that such a large aggressive beast would be tougher.
**Submersible Homing Drills**
I would use submersible drones which would target a location above the animal's brain or other vital areas. They would latch on and begin to drill towards the vital area until death. This will allow you to remain situated a safe distance from this large aggressive beast. Drones can be retrieved during the butcher process and also act as a method to locate your food when it dies. This also allows you to potentially go after multiple targets with the ship just acting as a mobile butcher shop.
[Answer]
Forget boats - use **helicopters**. Or whatever the high-tech equivalent is in your universe. Read up on submarine-killer helicopters, and adapt some of their techniques to finding and killing your leviathans. Basically:
* You attack the leviathan from the air, where it can't reach you to attack back. Fire missiles at it. Or do a scaled up version of 'grenade fishing'. But with depth charges!
* If you don't need the body intact, then blowing it into messy chunks is a perfectly acceptable tactic.
* Once it's dead, 'hoover' the bits off the ocean surface and take them to market. The tech level of your society will determine how you do this. If you have tractor beams and anti-gravity, you just levitate them into the sky. (Actually you could levitate the leviathan into the sky when still alive, and then drop it onto dry land - splat). If you have more realistic tech, then harpooning bits of corpse and winching them up is what you are after.
* Remember to keep your hunter-killer helicopters patrolling to kill any 'pod mates' of the victim who might attack your 'chinook' helicopters as they collect body parts.
Or stay at home and use a 3D bioprinter to make steak?
[Answer]
No large animal can survive our extraordinary killing skills and weapons. The ordinary harpoon solution would work also in their case. Maybe it would need bigger ships. Building a little bit larger ships wouldn't be a problem for us. Actually the size of the whale hunting ships is determined by their container room and on-site meat processing capacity (essentially, they are also meat processing factories). They would be probably usable also in the case of the 6x whales.
The toxic atmosphere would result probably also toxic whales. It is unclear, what could be done with toxic meat. We could simply throw it out, and eat something non-toxic instead, but these newcomers probably don't have this option.
The whales have to eat something. Our whales eat [krill](https://en.wikipedia.org/wiki/Krill), like this:
[](https://i.stack.imgur.com/AN5DSm.png)
You have to find a way, what these whales eat.
If they eat some unicellular thing, you have to answer, why there are unicellular life-forms in the ocean, and also whales in the oceans, but nothing between them.
The toxic atmosphere would mean probably also toxic oceans, it would make our task much more hard.
The newly arrived colonists probably don't have the building capacity to produce large ships on the spot (possibly before they get hungry).
[Answer]
# Lampreyvilles
[](https://i.stack.imgur.com/HmpKp.jpg)
*Catching* something doesn't mean you have to drag it onto land. You said it's an ocean world - *is* there land?
No, you want to have a nice slimy submarine with sharp, grabby teeth. Not necessarily exactly like [this lamprey](https://www.boreal.org/2018/06/16/175277/scientists-target-sex-pheromones-to-control-bloodsucking-sea-lamprey-in-great-lakes-), but I wouldn't dismiss this arrangement out of hand.
The humans probably stay in the submarine at first, enjoying protection from excesses of pressure as their host dives, and anchoring or burrowing against the shock as it breaches. (If protected from impact with the ocean, they should suffer no more acceleration than the creature does, and with its weight I doubt it can take very much)
Their food supply may consist at first, like the lamprey's, of ingested body fluids that may need considerable processing for flavor. Over time, they may learn to be bolder, carving deep into their whaley host in pursuit of the choicest muscles, carefully sealing off and sterilizing their tunnels to ensure they don't prematurely damage the organism.
With a little effort, they can learn to interact with the host's cellular differentiation process, sealing up passages through the muscles and body cavity in tough integument for easy blood-free pedestrian travel. Luciferins in the walls provide ample illumination, all thanks to the host's boundless metabolic energy. Modified flame cells provide fountains of purified hypotonic fluid to nurture the hydroponics along the corridors and the recreational field where ball games are played where the creature's mighty uterus once heaved.
Home ... is where the stomach is!
[Answer]
What we do now but with more firepower. Fire a harpoon with an explosive head that also injects a lot of gas into the creature. That way, if you hit it in the right spot, you kill it, you make it buoyant so it floats and, if you are lucky and the harpoon stayed in, you have a tether.
If the fish never surface, use torpedoes instead of harpoons to carry the payload.
[Answer]
One wonders if these leviathans are just very cranky herbivores, or if they're preying on smaller, more abundant animals that might be more easily caught.
If you're determined to face such monsters, **harpoons may work**. Simple harpoons would be very risky, since they don't so much inflict mortal injury as let the hunters latch on long enough to tire the animal out. Basically being strung onto a very large, very powerful, and very unhappy creature is going to be dangerous no matter what kind of vessel you're in.
There is such a thing as **explosive harpoons**, which could do more damage. But even with our small earthly whales there's historically been some trouble with the dead animal sinking before it can be retrieved.
If you want to use an up-close attack, **it will probably be best to go after young leviathans in some way**, like orcas hunting a humpback. Depending on the species' reproductive cycle, this might also be a slightly more sustainable option, since there would still be adults left to reproduce. The only issue here would be that this would make Mama very unhappy, assuming she sticks around to raise the baby. The hunters would have to separate the baby from the mother.
Another thought: is the planet entirely water? If there are some landmasses, and if your leviathans use a whale-like sonar, or an eel-like magnetic compass, the hunters could conceivably **create a device that could confuse the animal's navigational ability and drive it towards land**, beaching it. When whales are beached naturally on earth, they become massive, readily available sources of meat for all kinds of animals. And there's some evidence that manmade technology may contribute to whales beaching. With your leviathans, this kind of hunting would let the humans hunt from a distance, conserving their resources, minimizing the risk to themselves, without damaging the animal or risking the loss of any part of it. If there are no natural landmasses, perhaps the hunters could construct some other large, reusable trap to drive the leviathans onto/into.
Ultimately, the best option will the one with the least risk to the hunters, the least amount of resources lost in the process, and the least amount of damage done to the animal being hunted.
[Answer]
I propose an electrified harpoon. A shock of electricity will stun the leviathan. Once stunned the next step is to attach more electrified harpoons at the proper sites along the body. By activating the harpoons in sequence the hunters will induce contractions in the leviathan's muscles which will recapitulate its swimming action. You could then swim your live leviathan back to the factory for processing.
[Answer]
I have one immediate idea:
Have a fleet of powerful drones, controlled from a remote location. I would use some kind of weapon that, once fired from a drone, revolves in the air like a drill bit. This spear-like-weapon would be designed to penetrate the skin of the leviathan. It would have to be aimed at a weak point on the leviathan, such as at the gills/blowhole (depending on its anatomy), eyes, or any point on its head. The harpoon would be designed to detonate five seconds after impact.
Have your entire fleet of drones fire at the leviathan's head, at one of these specific areas. This explosion would kill the leviathan, or at least severely cripple it, allowing for a second wave of harpoons to be fired. Then these drones can fire several rounds of spears into the leviathan, spears attached to synthetic cords. This would allow it to be towed to shore by the drones.
This ultimately depends on how many drones you have in the fleet. If you have 3-7, you'll have difficulty dragging the corpse to shore, but if you have 50-60-70...it becomes a lot easier.
This is by far the best method because it ensures that no human lives are placed on the line.
[Answer]
**Balloon Drills**
[](https://i.stack.imgur.com/qictjm.jpg)
Small robots dive through the water, drill into the monster's hide, then open a tank of compressed gas to inflate a baloon. When enough baloons are inflated the monster is pulled to the surface. This takes days or weeks until the creature cannot resist anymore. The robots then inject a non clotting serum so the creature dies of bloodloss as well as exhaustion.
Like the above but more horrific. This is the nature of whaling.
]
|
[Question]
[
I've built a magical world. In this world, mages crop up one of two ways.
1) Genetically passed down.
2) Through exposure of magic, for example, growing up in a magical forest.
I would also like the folks who get their talent from environment to be able to pass down their talent genetically to the next generation. So the environmental factor would have to necessarily change the genetics of the person and be heritable.
My question is this: **how can the genetic variant be expressed differently from the exposure variant? would there be a difference and how would it work?**
I don't know if there is a real-life analogue for a human trait that can become present through exposure but also genetically. I'd like to model this after any real-life traits (if there are any) that have this particular quirk of being switched on by environmental factors and that can then be passed down. Even though this is magic, I've also tagged it science-based for that reason.
[Answer]
## Epigenetics
[Epigenetic structures](https://en.wikipedia.org/wiki/Epigenetics) are structures that cover genetic structures, i.e. DNA, and govern how the genes of the DNA express themselves. DNA only changes over the course of millions of years through evolution, or suddenly through mutation. However, organisms need to be able to adapt to daily changes in their environment, and epigenetic structures turn genes on and off on a day to day basis to allow organisms the ability to cope with daily challenges and needs.
## Experiences Passed On To Children
Not only are genetic traits of DNA passed on to subsequent generations, but so too are epigenetic traits. The [Överkalix study](https://en.wikipedia.org/wiki/%C3%96verkalix_study) showed that children whose grandparents had lived through either a feast or a famine season before giving birth passed on the symptoms of starvation or gluttony to subsequent generations via epigenetic structures:
>
> Among the 1905 birth cohort, those who were grandsons of Överkalix boys who had experienced a “feast” season when they were just pre-puberty—a time when sperm cells are maturing—died on average six years earlier than the grandsons of Överkalix boys who had been exposed to a famine season during the same pre-puberty window, and often of diabetes. When a statistical model controlled for socioeconomic factors, the difference in lifespan became 32 years, all dependent simply on whether a boy’s grandfather had experienced one single season of starvation or gluttony just before puberty. It appeared that Överkalix grandfathers were somehow passing down brief but important childhood experiences to their grandsons.
>
>
>
([Source](http://io9.gizmodo.com/how-an-1836-famine-altered-the-genes-of-children-born-d-1200001177))
## Magic Passed On Via Epigenetics
So, even though some of your characters may not have genetic predispositions for magic, if their parents gain powers via environmental exposure, such experiences can easily be explained as being passed on to subsequent generations via epigenetics.
## Magical Ability Via Genetic Mutation
Sudden changes in genetic traits can be effected by mutation, allowing brand new traits to be gained in one generation and subsequently passed on to offspring. Perhaps your environmental exposure to magic causes benign, useful genetic mutations giving parents fully functional, beneficial genetic traits for magical ability.
Normally mutations are not always beneficial, since mutations are generally random in nature, but perhaps exposure to magic by it's very nature causes specific, beneficial mutations to DNA that grant magical abilities. These abilities would then be passed on to subsequent generations in the newly mutated DNA.
## Differences of Genetic vs Epigenetic vs Mutated Traits
Essentially there is no difference, so far as I'm aware, between how normal genetic traits and mutation-caused genetic traits manifest themselves in offspring--so far as I'm aware, they both are treated as genetic traits, i.e. traits manifesting in the DNA itself.
However, traits manifesting due to epigenetics are significantly different, as I understand them--epigenetic mechanisms allow existing genetic traits in the DNA to be activated or deactivated on an as-needed basis:
>
> Epigenetic factors are compounds that attach to, or "mark" DNA. These factors interact with genetic material, but do not change the underlying DNA sequence. Instead, they act as chemical tags, indicating what, where, and when genes should be "turned on" or expressed.
>
>
>
([Source](http://www.nchpeg.org/bssr/index.php?option=com_k2&view=item&id=99:epigenetics&Itemid=132))
So, this makes me wonder if epigenetics can carry and manifest a brand new trait **not** found in the DNA, or whether epigenetics can only effect traits already existing in the DNA. I've researched this a bit and cannot find an answer. Epigenetics is a much newer field of research than genetics, so this question perhaps would make a good question for [Stack Exchange's Biology site](https://biology.stackexchange.com/questions).
Nonetheless, the idea of epigenetics giving magical abilities due to parents having environmental exposure to magic can still be valid: you could say the parents already had the genetic traits for magical ability existing in their DNA in an inactive state, and their magical abilities didn't manifest until the magical environment caused their epigenetics to activate the magic genes.
[Answer]
Hate to go midiclorian on you, but have you considered making your magic sentient?
Consider the possibility of magic being an intelligent extra-dimensional life form with a playful, loyal and loving disposition. Sort of like a golden retriever puppy in a household which loves it.
This magic does not care one way or another about human events, except when those events effect the humans which it is loyal too. Sensitive and skilled humans can train their magic to perform tricks, but whether trained or not, sometimes the magic responds on its own initiative to the assistance or frustration of its' favorite humans.
One more thing is necessary to make this work. We need these magic creatures to breed as their human families grow. That way, a human woman who attracts and earns the loyalty of a magic during her youth in the enchanted forest, can pass on magic to her children as they arrive. To resolve this, let's make the magic capable and inclined to spawn baby magic whenever their hosts make babies in the human way.
If the humans remain unaware of the magic being alive and see it only as some mystical source of power, they might easily overlook the relationship aspect of the human-magic pairing. This could lead to diminished power, total loss of power or even the power (in the form of a magic's loyalty) moving from one person to another.
Meanwhile, the genetic scientists would be going nuts, comparing the genes of the gifted to those of the mundanes. Despite all their technology and scientific rigor, those scientists will never figure out the mystery of magic because that mystery comes from the heart, not the genes. They may however, while studying the gifted, attract the attention and loyalty of a newly spawned or disenfranchised magic, throwing their whole genetic explanation into even more turmoil.
[Answer]
Similar to Ryan, I would argue that you can't have "magical talent" just from your genes. In doing so, I'd like to point out that many things that we consider to be part of our "genetics" are really learned skills which are made easier by our genetic heritage.
As an example, consider mountain climbing. The tools we use to climb mountains are built into our genetic code, right? We have amazing legs and lungs that we use to power ourselves up to positions of greater gravitational potential than anywhere else in sight! There's even some sense of this ability being genetic. The Sherpas which haul gear on Everest are known for being "barrel chested," capable of breathing in far more of the thin mountain air.
Here's a mountain climber that one would argue climbing is *not* in his genes:
[](https://i.stack.imgur.com/RvpYo.jpg)
[Kyle Maynard](https://en.wikipedia.org/wiki/Kyle_Maynard) is a quadruple amputee. He suffered from congenital amputation, where fibrous bands restricted the development of his limbs. He's been this way since birth. Clearly his genes are not in his favor. Well, tough cookies. **The dude decided to go climb Mt. Kilimanjaro, so he just went out and [did it](https://www.youtube.com/watch?v=LuH4sK25AwE)**.
Your magic could be just like mountain climbing. It's so much easier if you have a genetic heritage supporting you, but you can learn it from interacting with your environment with enough dedication and heart. This is really true for any skill we have, if you think about it, but it's a bit more obvious if you pull in such an inspiration like Kyle Maynard first.
The real trick is the language you use within your body to describe what you are doing. That language would be shaped by whether you are trying to learn has genetics to help it along or not. If you are talking about a genetic trait, you will see the language we choose is not just based on how to make that genetic heritage work, but it's also founded in how to pass this information to the next generation (so they can use their genetic heritage). If you develop it from interaction with your environment, you are less concerned with how to pass it on and more concerned with how to just make it in the first place. Your language will be more focused on how to identify some capability and "misuse" it to leverage it for magic.
Our environment affects our language, and our language affects how we act. If you have a genetic heritage of magic and a language to match, you will see the social structure mirrored in the way magic is used. Perhaps spells are classified by "level of difficulty," relating to how we progress through life. Or perhaps only certain individuals are permitted to know certain spells. On the other hand, a non-genetic magic will be more haphazard, based on what works.
These linguistic differences could lead people to assume that the different magics actually work differently, even though it may have some unified force behind it. You, as an author, could choose. You could only ever show this linguistically colored viewpoint, in which case the two magic approaches would feel jarringly different. Or you could choose to show characters digging beyond the language they use to describe the magic to realize that they're all climbing towards the same peak.
[Answer]
Not all mutations can be passed down to Future Generations. One way you could distinguish them is by having the original Parent have multiple mutations brought about by being exposed to Magic that he can't passed down to his children. ( I'm not talking about the mutation that allows him to use magic as that obviously must be able to be passed down to his children, however it's possible that being exposed to Magic can it cause additional mutations that are not passed down to his kids).
Another way is to have the original mutated human have difficulty controlling Magic, generally speaking is easier to learn something as a newborn child then it is as an adult. Assuming he was adult when his exposure to Magic take place it's possible that he will never be able to master it as well someone who was born with it will.
[Answer]
Magic is normally not something trivial to control. In most stories, it can take years of practice to get just the basics, and in some cases the only ones considered masters are ones with decades of experience.
So, your specific magic system is one that is moderately complex, something that is not intuitive for normal humans. Some humans however, do find it fairly easy to understand. Their genetics mutated how they think ever so slightly so that they can figure it out easier. There are numerous examples of real life people who can think in ways other humans find unimaginable. If one of these people had a child, that child is likely to have a similar mind, and similarly have a talent for understanding how to use magic.
That is not the only way to get really good at something though. Mastery as a child frequently will carry on through adulthood. Speaking, and writing are primary examples of such things. We learn these basic functions as a child, and then as adults, they are trivial to us. Children's brains are built for learning and understanding new things, So a child growing up in a magic rich environment would likely have their brain molded by that magic. They too learn about magic intricately without even knowing its magic, and being children will try and discover what it is. This will lead to these children naturally discovering magic, giving them a base knowledge and understanding far beyond what any adult could ever learn, because they were literally raised by it.
Both systems are fundamentally different. While both will find it easier to grow, those raised by magic will start off at a higher level, and will more easily learn the basics/intermediates, but later on the Genetics will likely catch up and surpass them. Raised by magic individuals will also likely find it far easier to manipulate their magic, conserve stamina/magic power, and otherwise have more fine control of it. They would be more Jack of all trades kind of users. Genetic individuals on the other hand would be better One trick pony kind of magic users, Mastering only a few things, but they would be more creative in their useage, as well as better strategists.
Of course, Those ideas are not set in stone, and certainly can be mixed and matched based on the individual.
[Answer]
One example of genetic trait that is passed down vs. acquired trait is skin color. Cultures from areas with intense sun have adapted a darker skin tone to deal with harsh solar rays. Light skinned people that move to areas of high sun will eventually become tan (after a few burns perhaps). However, if they remove themselves from that environmental condition they will eventually revert back to light skin tone.
A problem you may encounter with making magic "genetic" is the eugenics aspect of it. People with "natural" ability (like mutants in Marvel comics, or witches/wizards in Harry Potter) have an edge over everyone else and may be viewed as superior. This has the potential of getting political and socially contentious. It puts focus on one's race/genes/lineage rather than hard work and study. Perhaps that is your intent to draw attention to this social issue.
You would also need to define what the limits of "magic" are in your world. Are they very limited, like slightly affecting probability in one's favor, or are your characters shooting fireballs from their fingertips? In the natural world genetic environmental conditioning takes time (many, many generations), and usually the results are subtle. People would also need to be a racial isolates, and not have an a constant influx of genes from elsewhere.
You may want to look at your "magical forest" as a form of magical radiation. Similar to how plants/animals living around Chernobyl have genetic mutations that are passed to their offspring, only in your story I would assume these are beneficial mutations.
Good luck!
]
|
[Question]
[
The money a country spends in defense is usually really high. There are many countries in a world like ours where the army is hardly ever used. Could it be possible for a country that is surrounded by allies to drop its army and use the money for something else? Would their allies see this as an opportunity for invasion and find any excuse to attack? Would it automatically trigger a coup?
[Answer]
## From Ally to Freeloader
One immediate problem a country would have from dropping its army is that it is now a big fat freeloader. An army is expensive, so immediately the allies could ask - why should we be paying all the cost of defense and allow you to enjoy the benefits? The well-armed countries could move for trade sanctions, demand payment from the country to help pay the cost, or just generally insist on bigger benefits on all future deals and treaties to help cover the cost of defense.
Humans also have a funny tendency to be willing to join others in punishing someone who has violated norms like reciprocity, people who want to take advantage. Psychologically it wouldn't take much for all the allies to join together to make the undefended country suffer - financially or otherwise - to "even the score".
This has happened and is actually a part of [NATO](https://en.wikipedia.org/wiki/Member_states_of_NATO) agreements, and there a number of Polandball comics like this:
[](https://i.stack.imgur.com/ZMzWA.png)
This doesn't necessarily mean revolution, but it could easily become more costly than actually having an army if your allies want to push the issue.
## Who's Going To Stop Us?
There is an old saying, along the lines of "one honest gun keeps two in the holster", or more famously: "Speak softly and carry a big stick." One reason that countries don't use their army is precisely because they have one, or simply the deterrent effect.
Also note that, while you mention a scenario with no outside threats (assuming alliances hold strong), note that armies are often used as an internal deterrent against revolution from within. If you don't have a military, then martial law isn't exactly an option, and this lack of opposition could make rebel forces quite dangerous (if you have any).
Finally, note that history has long recorded that few countries have allies forever. England and France were allies in the world wars, for instance - yet there were many hundreds of years where they were bitter enemies. Alliances tend to last precisely as long as both countries involved find them useful, and no longer.
[Answer]
They say you never need a gun until the moment you do. The same can be said about armies. governments don't really need them in good times, but when it's people began to revolt or another country decides to invade then suddenly the country needs an army, but army take time to build and time to train that way most country through out history have found it safer to have an army already available in crises situation instead of try to train an entire new army from scratch. At the very least they will a small group of elite warriors at the read backed up by local militia army that can be formed to support them if need.
Also something to consider sometimes disbanding an army can be more expensive then keeping one. If a large military of hundreds of thousands suddenly disbands then that s couple hundred thousand people that are suddenly unemployed. While some military jobs can build marketable skill that can be used out of the military. This is why are government put some much money in to paying for the education of ex vents, so that they can be reintegrate into society. Do this on gigantic scale could be very expensive.
[Answer]
A country without a military has a large number of problems, as other answers already described.
In many cases the outcome might be bad (or at least bad for those people or groups that are currently in power in that country)
All kinds of threats from the outside can be countered with enough military. But there is also a different way: Don't be a target.
Admittedly, in most cases that also means: don't have anything worth taking. Most of all no oil or such.
So, if you have natural ressouces, you need to find a way to make sure you can keep at least enough of them to support your population. Still, that, too, can be handled without an army, especially if you remember that there is always a bigger fish.
But then there are threats from the inside.
An army can be used to impose martial law. This is alwasy some kind of "lender of last resort" in any country where the government managed to screw up so badly that large parts of the population can no longer be kept peaceful by just threatening them with laws.
Such a government might either do the wise thing: remember what their job actually is, and improve the situation of the people. Or send the military to beat the hell out of protesters.
So, what does that all mean:
**Unless you have nothing left to lose, you would need a really good government to be able to afford not having a military.**
[Answer]
The answer will have to be "it depends". I'll speak of NATO since it's the most obvious example, assuming when you say "average country" you mean "average developed nation". The alliance requires members having a mutual investment in collective defence - if one party is attacked we all come to their defence, and we can't very well do that without a standing army.
However, there are exceptions. [Iceland hasn't had an army for yonks](https://en.wikipedia.org/wiki/Military_of_Iceland), and doesn't want to have one. Of course they aren't "average", but that term is pretty amorphous right now. Iceland however wanted in NATO. Problem is NATO requires one to have an army, the compromise was that Iceland would provide NATO with bases instead of troops. In the above link it details other military commitments Iceland provides, like radar bases it maintains. So it's possible to be armyless and still to contribute.
It's worth noting that NATO recommends (requires?) a 2% of GDP defence spending, which is really not very much at all. Armies also have utility to help in a crisis like a natural disaster, so they're not completely useless in peace time.
It would probably be possible for say, a country like Portugal or Britain or France to do away with their armies because they are not in immediate threat, surrounded by allies, and in a stable political situation. Their nearest rivals also simply don't have the logistical capability to invade and hold their territory. But a country like Finland, Estonia, Latvia, Lithuania, or Poland, with direct land border with historic rivals who are becoming more aggressive in recent years ([see Ukraine](https://en.wikipedia.org/wiki/War_in_Donbass)), needs a military. They also need allies because they are too small to survive on their own.
And while it would be risky for Russia's western-focused neighbours to decommission their armies, it would be downright suicidal for others like Israel, Taiwan, South Korea, whose militaries protect them from very real threats. If South Korea gave up its arms today and kicked out their US allies, you can bet North Korea will unify the peninsula tomorrow (in fairness the opposite is also true, though a better outcome).
Life outside of a military alliance however is riskier, and for example; countries in the Middle East usually spend a lot of money on defence ([Saudi Arabia spends a whopping 13.7% of GDP on their military](https://en.wikipedia.org/wiki/List_of_countries_by_military_expenditures) and America in comparison spends 3.3%), because they are surrounded by threats, both from neighbouring states and internal strife. Then again, perhaps a Latin American state could do away with its army and not have to worry too much, so long as they had a sufficient police and border force to handle any issues. Again, it depends on context.
[Answer]
Let's see what happened in Europe in 1940. While the Dutch, Danes, Belgians, and Luxembourg had some armed forces, they were woefully inadequate, underfunded, and very poorly equipped.
Other countries (Germany in this case) who were on paper friendly to them saw this as a golden opportunity to do a bit of expansion of their territory, gain new workers for their industry, and new raw materials as well.
And yes, these countries were not in any way hostile to Germany, non-agression agreements were in effect that had stood for something like 50 years in case of the Netherland, Denmark, and Germany.
There was a lot of trade, exchange of arts and science, etc. etc.
No reason to believe the same wouldn't happen in other places.
[Answer]
Supplementary answer about a special case, an **Island Nation**
Such a nation may not need much of an army to stay secure. What army it has, is to deal with internal security, and it might well go by a different name.
What it needs is a good navy and air force, and (in the modern world) excellent shore to ship missile defences.
It's then pretty much invasion-proof. If it maintains a policy of strict neutrality and provided it is not blocking any major sea route or global resource, it will be left alone. 15 miles of water kept the UK safe in WW2. (That was a close thing). 150 miles of water would have been 100 times safer, rather than 10.
New Zealand is the closest real world example I can think of. (About 1000 miles of water? And Oz is another island nation).
Switzerland, being land-locked, needs and maintains a good army, but it is very different to most other ciuntries' armies. Switzerland also follows the policy of neutrality, and geographically it is far easier to move armies around Switzerland rather than through. The Swiss army is trained for guerilla warfare in alpine terrain, should any other army ever invade. The alpine passes are death traps for any invader.
[Answer]
Costa Rica [abolished its military](http://articles.latimes.com/2013/dec/15/opinion/la-oe-barash-costa-rica-demilitarization-20131208) in 1948. It seems to have worked out fairly well for them.
[Answer]
Most nations need a military to defend them from foreign militaries.
But they also face a threat that their own military will take over the government in a coup and run the place for themselves.
There have been around 296 coups and coup attempts since 1945, which I believe is considerably more than the number of foreign wars. Of course, you might lose more in a foreign war.
[coups](https://en.wikipedia.org/wiki/List_of_coups_d%27%C3%A9tat_and_coup_attempts)
2% of GNP is nothing to sneeze at, either. If you can put an extra 2% into development each year, if you can grow your economy 2% faster, in 35 years your GNP will double compared to what it would be otherwise. But if you get a coup and a junta puts a lot of your resources into their offshore bank accounts, you might lose far more than 2%.
It's a question of relative risks. And it depends a lot on your neighbors. Particularly if you have border disputes and reasons they can use as an excuse to attack, that's an issue. They can always make up reasons later. But a lot of the excuses they can make up, depend on you having a military. They can't argue you're a threat to them if you don't have one.
The devil is in the details.
[Answer]
Attempting to not retread too much ground here, a simple side effect of disbanding one's army would be internal problems. Not even so much as a rebellion but the relative flexibility an army can provide. Engineering units can prove to be very useful economically as well as during disasters where a dam or bridge needs fixing, as well as a national guard/reserve can help during evacuations or searches for lost people. Amphibious assault ships have come to the aid of sinking civilian vessels, and a carrier i believe, to some extent, during hurricane Katrina. You also have the political value of joining the army and the nationalism, etc.
]
|
[Question]
[
>
> The term "middle class" has had several, sometimes contradictory,
> meanings. It was once defined by exception as an intermediate social
> class between the nobility and the peasantry of Europe. While the
> nobility owned the countryside, and the peasantry worked the
> countryside, a new bourgeoisie (literally "town-dwellers") arose
> around mercantile functions in the city. In France, the middle classes
> helped drive the French Revolution.[5] Another definition equated the
> middle class to the original meaning of capitalist: someone with so
> much capital that they could rival nobles. In fact, to be a
> capital-owning millionaire was the essential criterion of the middle
> class in the industrial revolution.
>
>
>
[Wikipedia](https://en.wikipedia.org/wiki/Middle_class)
The setting is Medieval, vaguely European. The setting has several kingdoms. The kingdoms aren't (resource wise, politically, geographically, and economically) positioned to thrive on trade. Further the industrial revolution, in any material form, hasn't touched these kingdoms yet.
Nevertheless I'd like to justify a prosperous middle class. I'm willing to be flexible (in either way) on terms of hygiene, exact mechanics of nobility/royalty, education, and religion, but I do not want the justification grounded in a specific religion/religious philosophy, or a culture so radically unique to abandon "medieval, vaguely European" from the ten-thousand foot view.
How can I justify this prosperous middle class?
[Answer]
# You don't need THE Industrial Revolution, just AN industrial revolution
The middle class grew in Early Modern Europe due to the increase in productivity caused by technological advances. While the steam engines and industrialization associated with THE Industrial Revolution were important, they are only a piece of the overall puzzle. A society without gunpowder or fossil-fuel driven machinery could achieve several of the productivity related technologies needed to create a prosperous 'capitalist' middle class while still maintaining the ten thousand foot appearance of 'medieval European'.
1. [Agricultural Revolution](https://en.wikipedia.org/wiki/British_Agricultural_Revolution). An un-appreciated cause of the Industrial Revolution. The reason there was so much labor available for factories is that farming in England in the 1700s became much more productive. By shifting the 'goal' of farming from peasant self-sufficiency to commercial market-driven production, much more food could be made with much less labor. This means increased population, larger cities, and thus larger markets for other goods
2. [Putting Out System](https://en.wikipedia.org/wiki/Putting-out_system). This developed in Europe in the early modern period and largely replaced the peasant's self-sufficient cloth production before mechanization took hold. Allows a low density suburban network of in-home 'manufacturers' to generate higher quality clothing by specializing in various tasks. Higher agricultural output from 1. would allow more people to specialize in cloth-making; and clothes are always in demand.
3. Hydropower. This [excellent book](http://rads.stackoverflow.com/amzn/click/0060925817) argues that the [higher productivity of Western European workers](https://en.wikipedia.org/wiki/List_of_regions_by_past_GDP_%28PPP%29_per_capita#World) by the end of the Middle Ages (compared to India, China, the Middle East) was due to extensive use of hydropower. Europe is uniquely suited to using hydropower, with many steady streams that do not freeze in the winter and do not have large seasonal fluctuations. Extensive use of hydropower for milling, sawing, stone polishing, forging (driving both hammers and bellows) would increase productivity and help create a prosperous class of mill owners, builders, and operators.
4. Infrastructure. One of the things that Early Modern Europe generally failed at was large scale infrastructure. But never fear, there were an even earlier group of Euros who did a much better job. Take medieval society and add Roman road and aqueduct building skills. Also, canal building could have advanced faster. Some pretty impressive canals ([like Canal du Midi](https://en.wikipedia.org/wiki/Canal_du_Midi)) were built before the 1700s; the technology level used to construct the canals wasn't much more than the Romans could have accomplished. With your kingdoms investing in infrastructure, intra-city travel and trade would be relatively cheap, and clean water supplies (and sewage disposal) would increase public health.
It is important to note that none of these points involve technology that wasn't demonstrated before the year 1500. All it takes is a little social re-organization into forms that didn't develop until later (commercial farming, putting out manufacturing, capitalist-style investment in watermills, kingdoms that could tax and spend on infrastructure). Also, not having a war every few years would help too.
In conclusion, if you take Medieval Europe, add some peace and infrastructure investment, maintain the economic and civic freedoms already enjoyed, and allow for some developments in civic and business organization, you can get the society you are looking for.
[Answer]
The simplest answer, I feel, is that your story is set in the immediate aftermath of something like the black death. During that era between 50-80% of the population of various places around Europe died. Whilst horrendous, it did provide a boon for those left behind.
Suddenly their labour became considerably more valuable, and they could negotiate generous wages and even indeed roam about looking for a better lord. The cost of land went down too; allowing them to gain and hold far more wealth in the long term. This also allows them to bargain for greater legal rights and opportunities, and the elite are at this point not in much of a position to ignore them.
[See here.](https://eh.net/encyclopedia/the-economic-impact-of-the-black-death/)
>
> Moralizing exaggeration aside, the rural worker indeed demanded and
> received higher payments in cash (nominal wages) in the plague’s
> aftermath. Wages in England rose from twelve to twenty—eight percent
> from the 1340s to the 1350s and twenty to forty percent from the 1340s
> to the 1360s. Immediate hikes were sometimes more drastic. During the
> plague year (1348—49) at Fornham All Saints (Suffolk), the lord paid
> the pre—plague rate of 3d. per acre for more half of the hired reaping
> but the rest cost 5d., an increase of 67 percent. The reaper,
> moreover, enjoyed more and larger tips in cash and perquisites in kind
> to supplement the wage. At Cuxham (Oxfordshire), a plowman making 2s.
> weekly before the plague demanded 3s. in 1349 and 10s. in 1350
> (Farmer, 1988; Farmer, 1991; West Suffolk Record Office 3/15.7/2.4;
> Harvey, 1965).
>
>
>
Main problem with this is inflation, which often cancelled out the gains in wages. So perhaps you'll have to implement an anti-inflationary something or other to deal with that side of things.
Another possibility is that your rich people have just won a war against someone else, looted and enslaved them; turning them into [Helot equivalents](https://en.wikipedia.org/wiki/Helots) and thus allowing themselves more free time, if nothing else. Time is money!
[Answer]
## **Step 1: Use an exaggerated [Hajnal line](https://en.wikipedia.org/wiki/Hajnal_line)**
The idea is that your country would have women marrying late. Late marriage means that both partners go in with a relatively large resource endowment, and then distribute it across relatively few children.
Having relatively few children would prevent a **[Malthusian catastrophe](https://en.wikipedia.org/wiki/Malthusian_catastrophe)**, where the popluation expands into a pauperized class living at the limits of what can be supported by the land and then falls due to war or disease.
## Step 2: Good property rights
Have a early and wide-sweeping **[Magna Carta](https://en.wikipedia.org/wiki/Magna_Carta)** or an Icelandic-style **[Althing](https://en.wikipedia.org/wiki/Althing)**, which is to say political representation of all property holders. Bonus points if you include women, either as widows or as pre-marriage freeholders.
Having a strong political voice by the plucky freeholders will serve to slow or even reverse the encroachment by the richer landholders against the commons or individual farms.
## Step 3: Early life insurance
Widows and orphans rely on a **social safety net** based on insurance payments. This prevents people from slipping into poverty due to the unavoidable medical disasters of a pre-antibiotic world. There is literally *nothing* about this that could not have been done as far back as Sumeria, it's just that nobody thought about it [before the 1700s](https://en.wikipedia.org/wiki/History_of_insurance) in Europe.
[Answer]
To me sounds like you could model things after Roman citizen soldiers or the early American freeholder middle class. One of the most prominent reasons peasants were so poor so they didn't for the most part own there own land. I think it would be reasonable if you were to have a society with still nobles and large estates, but also a significant number of small independent land owners. For the most part I think this would still resemble a medieval society
[Answer]
Who collects the taxes? Who manages the estates of the nobility? Who creates art, sculpture, or music for the nobility? Who are their elite fighters? Who builds siege engines and weaponry? Who tutors young nobles? Do the nobility tithe money or land to the clergy? If bastards can't inherit and are not considered nobles, do they still get some kind of position or income from noble parents? These kind of people are your potential middle class.
Basically anyone who has the patronage of the wealthy nobles but is not noble themselves is going to fall into the middle class. This middle class won't be as large as what we see in other types of societies but would still have a reasonable presence anywhere where there are wealthy nobles. However, it wouldn't be as large a presence as in other scenarios where other factors take part in the rise of the middle class. This middle class could be prosperous but is probably not incredibly stable.
]
|
[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'd like my (very well funded) group of scientists to conduct an important excavation, in-situ with fully breathable air and comfort. I realize a pipe down to the surface would require a pump and could cause issues.
What I'd like is a cylinder wide enough that there is natural ventilation, and they can continue their excavations, dry, and breathing naturally without any automated pumps, etc.
I'll handle the depth of the cylinder into the seabed later, and of course this is an expensive prospect, but basically want to have a perfectly breathable seabed at 500m depth. **How wide would it need to be?**
PS - It's about the elevation of the dead sea.
EDIT: I am looking for an open space that allows for the free-breathing of the excavators. Specifically the width of the air-space (I allow a conical shape of course as well). The structural, safety and financial features are a separate question. This is purely about breathe-ability.
[](https://i.stack.imgur.com/Ij9dy.png)
[Answer]
## Size of Site?
One important factor you have not yet provided us with is the known diameter of the excavation site. Is it miles wide, like a submerged ancient city, or is it a small ship wreck? That information can greatly effect the answer.
However, given the drawing you provided, I'm assuming it's a small site, and hence this is my thought:
## Cylindrical Tower with Ventilation Shafts in Walls
You could have a relatively narrow total radius of the tower if your cylinder's walls were hollow with wind-catching vent openings at the top and vent openings at their base:
[](https://i.stack.imgur.com/AU5NF.png)
The amount of wind caught by the ventilation shaft's openings at the top would depend on their [height above sea level](https://en.wikipedia.org/wiki/Wind_gradient), since [wind speed increases as elevation increases:](https://www.classzone.com/books/earth_science/terc/content/investigations/es1702/es1702page09.cfm)
[](https://i.stack.imgur.com/p3Q0e.png)
[(NOTE: 1 knot = 1.15078 mph)](https://www.google.com/search?q=convert%20knots%20to%20mph&oq=convert%20knot&aqs=chrome.2.69i57j69i64j0l4.4495j0j7&sourceid=chrome&ie=UTF-8)
In order to achieve a constant influx of wind, you need to make sure your tower is tall enough to catch a constant breeze--basically a skyscraper. For this, you need to know the atmospheric properties of your site. Although you have stated it will be in the Dead Sea, the amount of wind will be influenced by any nearby geographical features, so you will have to know your exact geographical location.
Once you have this information, you can use [wind engineering formulas](https://en.wikipedia.org/wiki/Wind_engineering) to determine how high the tower would have to be to achieve a sufficient constant influx of fresh air. You could then calculate:
* tower height
* number of ventilation shafts
* opening size of each vent mouth
[Answer]
## Convection-Based Ventilation
This idea would allow you to have a tower only as wide as your dig site. The main concept is to have a solar-heated element running down the central shaft of the tower, heating the air and causing a [chimney effect](https://en.wikipedia.org/wiki/Stack_effect), sucking fresh cool air in from the side ventilation shafts:
[](https://i.stack.imgur.com/eSylZ.jpg)
Here is an alternate design that doesn't require hollow walls, just a simple partition down the middle of the tower:
[](https://i.stack.imgur.com/Fix8t.jpg)
The principle of the solar-heated element is basically the same as that used in [solar power tower plants](https://en.wikipedia.org/wiki/Solar_power_tower), where an array of mirrors focuses sunlight on a central collection tower so that the collection tower becomes quite hot:
[](https://i.stack.imgur.com/6w3gX.jpg)
I think this type of design would be much more effecient and simple to design than the wind-catching skyscraper idea I proposed earlier. It also allows you to keep the tower quite small, only the size of your excavation site, hence keeping building costs low and increasing real-world feasibility.
[Answer]
Thermal convection is your friend
[](https://i.stack.imgur.com/jwg45.jpg)
By heating air in the center you can draw air down from the sides.
Because of thermal stacking, thermal power generation towers can be as tall as 1000 meters.
[Answer]
just use mine airflow as guide. For heavy exertion humans need a bout 65 liters of fresh air a minute. if they are just walking around they need only 14. the most important factor is what kind of activity level are people doing and how many people are there.
But in short no matter what the answer they are probably going to need a few fans.
<http://www.molecularproducts.com/pdf/technical-library/A%20Guide%20to%20Breathing%20Rates%20in%20Confined%20Environments%20Technical%20Article.pdf>
<https://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/bul589.pdf>
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
Really a comment but it won't fit:
1) You're missing a big problem here--you have 5 megapascals of pressure trying to push under your cofferdam. Water is going to seep in pretty quickly playing havoc with your request for dry. (Oops, I originally goofed up and said 50, a zero placement error.)
2) Temperature. It's going to be awfully cold down there, can you say "fog"? And "dew"?
3) Your cylinder need to be at least 540 meters, not 500 meters--it needs to be tall enough to keep the largest rogue wave from going over the top. (Edit: Thinking more about this you need even more height but I don't know how much. The 40 meters was to cover the highest of rogue waves but this isn't a ship designed to cut the water, when the water strikes a wall that wide some of it goes up.)
4) Can you say "sea spray"? Waves are going to hit your cylinder, some of the spray will fall inside. You asked for dry.
Finally
5) If you want your workers comfortable you will need to heat the work area--and that combined with a simple baffle in your cylinder will substantially cut the needed size.
Edit: Why did I get the warning about hard science? This is an oversize comment showing more of the problem, not an attempt to answer it.
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
As I understand it, you want to work on the seabed, 500 m down, without using either a [caisson](https://en.wikipedia.org/wiki/Caisson_(engineering)) or divers, so you opt for a [cofferdam](https://en.wikipedia.org/wiki/Cofferdam).
You will have to pump the water out (compare [this picture](http://www.americanbridge.net/experience/experience_detail.php?prj_ab_id=PortCorl20102004081129581)), so pumping air in will be the least of your problems.
If air circulation was your only worry, consider open pit mines like this one in [Bingham Canyon](https://en.wikipedia.org/wiki/Bingham_Canyon_Mine) as an upper limit on the necessary diameter.
---
Follow-Up: With a bit of googling I found [this article](https://www.researchgate.net/publication/305985993_Closed_coal_mine_shaft_as_a_source_of_carbon_dioxide_emissions) about CO2 emissions from mine shafts. Obviously the shafts have no air scoops, and the emissions depend on outside air pressure. That gives you a lower limit on the diameter of a feasible shaft.
]
|
[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/55149/edit).
Closed 7 years ago.
[Improve this question](/posts/55149/edit)
In my story, back in around 3000BC , a secret organization was formed with the smartest of scientists and inventors. They developed technology many years ahead of their time. Every 'Invention' or 'Scientific Discovery' was in fact developed hundreds, if not thousands of years ago, and every inventor is a member of this society. However, nobody outside the group, not even governments know about this group, and all children will become a part of this group. Anybody showing misdeed will be executed.
**But Why?**
Why not give these discoveries to the public as soon as you get them?
[Answer]
Regarding **why**, in 3000 BC stepping forward could have been unhealthy for the scientists in question. King, priests, and peasants might have decided to burn the scientists for practicing witchcraft. Kings and priests might have forced the scientists to work for the existing power structure, with priorities imposed from the outside and unreasonable deadlines.
*"You healed my advisor, now heal my wife. If you fail, your head will roll."*
*"Never mind crop rotation. Make gold."*
And if that had been true at any one period in history, the scientists' cabal would have been forced underground. The pattern would reinforce itself. The cabal leaders *believe* that going public is a bad idea. The security officers gain more and more power. Newcomers are trained in secrecy and cell structures long before they are trained in science.
Of course I do not believe that this will work for millenia, or even centuries. Some of the children (and the children's children) will be unsuitable. Some will want to use technology to help people. Some will be careless. Some will want glory and worldly power for themselves, *now*.
[Answer]
Power.
Knowledge is power. More specifically knowing **more** than others is power. If your organization expects to have a certain level of power over society that translates directly into having a certain knowledge gap to the general public.
The real question is why they would be obsessed with having their power in the form of knowledge instead of leveraging knowledge to more direct forms of power such a military, political, and financial.
I am guessing they are the conservative belt, suspenders and healthy dose of glue type of people. They have lots of conventional power behind the scenes that they actually **use**, but rely on superior technology as the hidden trump card to guarantee their power.
This would naturally lead to mind set their the public would be allowed only the direct of technology that is at least two steps of development from being able to challenge the tech the organization has access to. You can compare this to the old British policy of the Royal Navy being stronger than the next two fleets combined.
This way even if they need to use their technology they can use tools that pose no direct threat even if a hypothetical enemy gets access to it because they still have superior tech available.
This kind of mind set would have implications to how the organization works and operates, but that is really beyond the scope of this question.
[Answer]
Because [Einstein](http://quoteinvestigator.com/2012/10/25/tech-exceeded/) said so:
*Our world faces a crisis as yet unperceived by those possessing power to make great decisions for good or evil. The unleashed power of the atom has changed everything save our modes of thinking and we thus drift toward unparalleled catastrophe.*
We learned to split the atom, potentially giving us limitless energy, and the first thing we do is build some bombs and destroy two cities.
According to this [article](http://www.thenewatlantis.com/publications/the-agony-of-atomic-genius), When Fritz Haber, the presiding genius of German chemical weaponry, was implored by his wife, herself a chemistry Ph.D., to give up his work on poison gas in World War 1, he replied that in peace a scientist serves mankind but in war he serves his country. His wife killed herself that night.
I'm governed (in South Africa) by a president who didn't even finish high school. Do you really want to give my president a technology he could use as a super weapon? So I think highly advanced 'fringe' science technologies would be hidden by a secret society for the simple purpose of preventing us from destroying ourselves.
[Answer]
Because they're an elite class that will someday develop space travel and escape from the hordes of Morlocks.
The guarantee of saving the cream of the species against a future apocalypse is probably worth the secrecy of technology, so self-preservation would be a valid reason, I think.
If you knew that there was a huge asteroid heading toward the planet and you didn't have access to Bruce Willis or Aerosmith, then you want to do something about it. It's reasonable to assume that you can't save everyone on the planet, but you would want to have the most capable people possible to ensure survival of the species.
[Answer]
This implies a slight modification of your premise.
The members of the secret organization are time travelers. The technologies they develop centuries ahead of their due time are there because they visited the future and learnt about them. So, here's your answer: they must keep the inventions absolutely secret to avoid a paradox, the results of which, as you know, would cause a chain reaction that would unravel the very fabric of the space time continuum, and destroy the entire universe.
[Answer]
Because they are peaceful people who fear that other people might try to misuse their inventions for selfish or evil purposes rather than for the good of mankind..
For example, a man who discovers how to make perfect clones would be worried about villainous organisations using it to clone themselves or the government using it to create an army of clones.
Someone who created an early version of the internet might fear that it would be used to spread messages of hate or used by armies to arrange fights instead of its intended uses as a means of communication and a repositry of knowledge accessible to all.
---
In addition, the organisation might choose to only accept other people who seek knowledge only for the love of knowledge, not for selfish means such as gaining fame, wealth or power.
They may also seek to some day develop the technology to leave the planet behind so they can start a new world with a utopian society that follows their ideology of pacifism, self sufficiency and science.
[Answer]
As per my view sometimes its more dangerous to share an new invention of inventor with public.as we know both types of people live in this world..bad or good.we cant judge anybody.i just found this on Internet <http://listverse.com/2009/07/19/10-useful-inventions-that-went-bad/>
u can check it
]
|
[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/34947/edit).
Closed 7 years ago.
[Improve this question](/posts/34947/edit)
NOTE: This doesn't imply the lack of any society whatsoever. Imagine all the modern conveniences and technology of today, except instead of someone being 'American' or 'German' they merely identified as members of a single world civilization under a global government.
Succinctly speaking: it's a global nation-state, in that all peoples are united under a single global nation which is ruled by a single world government. To add some specificity, I'll narrow it down to a few key issues (answer in a few sentences or less):
1. What are the main advantages of such a system? The disadvantages? List 2-3 for each, but very concisely (a short phrase describing each).
2. Does this eliminate any societal wrongs present in our current world? Touch on one with more detail or name a several with 1-2 sentences each.
3. Does this add any additional sociopolitical issues not currently present in our own? Again, elaborate on one or briefly mention a few.
4. What would be the main concern(s) of this government? Expanding the human empire to the stars? Solving world hunger? etc. (same rules apply as before.)
5. *Superman: Red Son* envisioned a Utopian global government composed entirely of artists, philosophers, and thinkers. Is this depiction realistic? Would 'government' as we know it exist in this world, or would it be fundamentally different? Explain a few (brief) reasons why.
6. John Locke once wrote that the existence of man in organized society was an inevitability of human nature. Is the existence of individual nations an 'inevitability'? Explain why in a medium-sized paragraph or less.
[Answer]
Honestly, it probably wouldn't work all that well.
The simple facts are that there's only so much that an individual person can do in a day, and there are a lot of different places on Earth. Those two things combined kind of ruin the idea of a unified world government that runs everything. Let's run through things a bit to see what I mean, but on a smaller scale.
Congratulations! You've just been elected President of the United States! You've had a few minutes to sit behind the desk in the Oval Office and laugh maniacally at your newfound power, but now it's time to get down to business. The budget calls for a tax increase to pay for hurricane recovery on the Gulf Coast. However, the legislators from North Dakota are fighting it pretty hard. Their constituents don't like the idea of having to pay more taxes for problems that they don't face. They're willing to vote for it, though, if they can secure additional wildlife funding, which would have to be taken from California. California doesn't like this, so in return they want....
It would be like this on a much larger scale. "Americans" paying extra taxes to help with "Japanese" tsunami recovery, "Uzbekistan" losing funding to "Argentina".... The countries may not exist, but the parts of the world are still there. And sadly, many people don't really care about people 12,000 miles away that they'll never meet.
It doesn't help that even without countries, culture will still exist. Things are different in different parts of the world. I myself recently moved from Wisconsin to California for work; as a child in the Midwest, we had tornado drills on a regular basis, but I realized on moving that I have no idea what to do in case of an earthquake. And that's only within the same country. Subsidies on corn work great for Nebraska and Iowa, but aren't so helpful for the rice farmers in Southeast Asia.
The fact of the matter is that when it comes to governing, one size does not fit all. The world is too big for one government to be able to govern effectively. In order to be effective, it would have to basically do what the US has done, and have smaller governments that work under the bigger government -- take a certain area and say that governmentally it is distinct from a different area.
But at that point, we might as well call those sub-governments "countries" and be done with it.
[Answer]
The big catch to one world government is: What happens to people who don't like the laws of that government?
In the present world, if you don't like the laws of the U.S., you can move to Canada, or Iran, or wherever. But if there was only one government that ruled over all human beings, that if you don't like it, you're stuck.
What happens when this government becomes tyrannical? With many nations, if one nation gets too oppressive people start fleeing to other countries. If it's bad enough that people decide to rebel, they can often get support -- sanctuary, weapons, etc -- from other countries. But if there's only one nation, then presumably it controls all the police and all the military. Any rebellion could be ruthlessly crushed.
And please, don't tell me that you'll ensure that this country remains free and democratic by having rights protected by a constitution. Words on paper do not enforce themselves. Governments violate their written constitutions all the time.
Less dramatically, many countries means that there are many laboratories to try out different laws and customs. We can see that, for example, Greece's approach to taxes and spending didn't work. Germany's approach to green energy didn't work. Of course some results are endlessly debatable. Which is working out better, Denmark's approach to drugs or Singapore's? Etc. If there was one world government, the leaders could enact a policy that sounded like an obviously good idea to them, maybe even to a majority of the people, and if it turns out to be a disaster, the whole world goes down the tubes.
[Answer]
I will separate my answer in two questions : can a single *nation* exists and can a single *government* exists ?
## Nation
Humans define their identity relatively to something else. If I consider myself as a Swiss, it make sense because lots of people are not Swiss. However one ask me, in Switzerland "where are you from ?", I will not answer "Switzerland", I will answer "Valais" (my native region).
Why ? Because if everybody (in a given context) is Swiss, affirming that I am give no differentiation, it has no interest to identify myself as such. To have a common nation, you need something outside, for the definition to make sense in the hearth of the people.
However, having wide difference inside a nation is not an absolute problem against a common nation. Kurds often describe themselves as a nation, but do not share a religion, nor a state ; Swiss do not share a language ; and I am pretty sure I can greatly offence half of the United-States by saying "You are all just New-Yorker". Of course, the closest you are from the other in your nation, the easier it is to identify. Well, the closest you are, relative to how different are the others from not-your-nation, once again.
So yes, it is possible to have a unique nation for all humans, but you need to drop aliens for us to compare.
If you want to pick a nation, however, and force everyone to "convert" to it, it will just fail miserably. My point here is that a wider concept of nation can emerge, not that you can force everyone to live the same way without an Orwellian scenario.
## State
There is actually no reasons that we can not scale our current governments up to the size of the world. Of course it will be a multicultural government, but it is possible. India is an actual example, and pretty much any empire or kingdom before 1800 also were (for the latter not democratic, but still multicultural).
Obviously, you can not just scale up any of our government with their problems and hope they will suddenly disappear. My point is that by building a world government, you do not face any problem that can not happen in a small scale government.
Dictatorship ? No respect for minorities ? Corruption ? Too much job for the head of state ? Too high concentration of powers ? People unhappy with the government unable to go away ? Different laws in different parts of the country ?
All of that have dozens of real examples, that's not new stuff.
## Conclusion
Can we have a common nation ? You need something outside (in our case aliens) of it, otherwise the concept of nation makes no sense.
Can we have a common government ? Hell yeah ! (if you do not ask how to get there)
Would the problem of today modern society still exist ? The only difference is that the human wars will all be relabelled "civil wars".
[Answer]
If Individual nations did not exist, The World would Live in Peace.
This is a very Evolutionary and Enlightened Question/Thought.
Much praise to Ken H for posing this one.
This is actually a great way to solve world peace but what is not mentioned and very important is the other important variables of such a society, as what monetary and form of government and social control systems exist.
If individual nation states didn’t exist in the sense that there are no borders, let us go a bit further and clarify that we can assume that there are no individual governments, no individual political parties, no individual armies. No borders. Just 1 Human race. Of-course each country, community, culture, race etc. will always maintain their unique identities but without borders we would allow for Free roaming without unnecessary hindrances. This would surely create a more harmonious society for the unnecessary suffering that borders create is endless.
As soon as we unite as 1 World and 1 Human Race, borders would no longer exist. Separation is the same coin as divide and conquer. The system has the Human race separated, focusing on futile and hollow judgmental details about each-other. We are all One. More than one Race, We are one Energy.
Years ago, when I would propose to folks that we could actually unite as the One World and People we know we are and act as one together in Unison and Peace and create as much as a Heaven on Earth as is possible with current technology and resources, the reaction used to be one of disbelief. I now thankfully and amazingly find that most folks are in agreement and I realize that has to mean that it has officially become common universal Human Knowledge and Logic. If I’m not mistaken, that might be because a big majority are aware and awake that things do not have to be this way and should not be.
The next step after realization is action. I think the best plan may be to decide on a date that we will change the system. Best time is a New Years day like Jan 1st 2020. Most of Humanity as the belief in starting the new year with a new Year with a positive resolution or plan. We can decide that on that on the 31st of Dec 2019 everyone is fired. We must in reality do a Mass Reset. Everyone is fired. Especially Politicians, Government workers, Police and military and money is abolished including all written laws. I have come to realize that the majority of Humanity has in their hearts what is fair and just. Seems like the best Judge is the Holy Spirit that is within us. Our hearts and minds are all connected to the Collective Human Conscience.
We must live as if the major, governor and president is God, Jesus Christ, Buddha
No Borders, so no need for Military either because their only purpose is to defend the nation against foreign armies, which would no apply.
No Police, the local People are the best Police, Judge
No Goverment, this does not mean we would not have structure, we would and could and will live much more intelligently and harmoniously without the outdated system of social governance.
No Poitics, No Politicians, No Bureaucracy, No Class (just 1st Class)
...Namaste...
Utopia or Death
[Answer]
**If a single world government does exist, then clearly the issues keeping that from happening have been solved.**
It's a presupposition that if the world is united under a single government, then it's not at war with itself. That world government would still be made up of humans and would therefore almost certainly have a whole set of different problems.
It's enticing to think we'd be better off in such a situation, but it's not clear that things would actually be all that different. We could still have staggering poverty and wealth gaps, poor healthcare, regional tensions, and many of the other big issues we face today. In fact, I think a single government being responsible for all the people on Earth would be worse off than many nations today.
Or, on an optimistic note, you've torn down the borders that keep people apart. A world government leads more easily to mixing and averaging human cultures. This could have a beneficial effect of increased understanding and less radicalism between different peoples.
[Answer]
**Get used to Big Brother or put up with sectarian violence. Your pick.**
Yes, it's pretty problematic, because there are different social climes in different parts of the world.
Different people look different, speak different languages, have different customs, follow different religions, and so forth. It would be nearly impossible to construct a government that is sympathetic to all the different cultural groups in the world.
A big issue here is religion. Some countries are strongly ruled by religion. This is problematic in this scenario, because some religious laws in Country X may violate secular laws on Country Y - or worse, religious laws in Country Y. You'd never be able to unite them, because the two ethnic groups would push for different laws that could never be combined.
This government would soon dissolve into partisan disputes and, I suspect, secession by various countries. It would not last long. If it did manage to stay together, though, and politicians from everywhere were able to agree to this, you'd still have sectarian violence not condoned by the government. Paramilitary organizations would start fighting wars with each other.
The solution? Take away personal freedoms. Freedom of speech, freedom of the press, freedom of religion, and freedom of assembly all lead to sectarian warfare as different people disagree with one another. Big Brother needs to arise and develop very tight control over people.
It's not enough to *win* the hearts and minds of the people. Here, you need to *control* them, to save them from themselves.
[Answer]
I'm going to suggest that we have already seen this situation before, and if you accept that *not* having a powerful global government is a good thing it might even be workable.
The modern nation-state isn't all that old, coming into being in Europe in 1648 after the Peace of Westphalia brought an end to the 30 Years War. This treaty brought together several ideas, including the idea of a sovereign territory under the rule of a singular Prince. Before that, most territories were under overlapping control of various power and efficiency, ranging from guilds to "Empires".
If your global order reverted to the situation that existed after the fall of the Roman Empire when theoretically all European people's were united under "Christendom", then you have a start. A pan global culture united by a common idea provides the foundation, with perhaps a "spiritual" sort of guidance from the head of the global order. Perhaps less like the Pope and more like the Dalai Lama.
Under this spiritual or cultural guidance, we would need various levels of local governance to deal with things like law enforcement, contract enforcement and the resolution of disputes by neutral arbitrators. The reason we need the unified spiritual or cultural structure is so everyone agrees on the meanings of laws and contracts. Looking at today's world, there are many distinct ways of seeing similar terms, which is one of the reason we see seemingly intractable conflicts arising between the Western world and Islam, Russia and the "Orthadox" world, the Sinic world under China and so on. Samuel Huntingdon wrote about this in "The Clash of Civilizations".
Local governance is best, simply because it is closest to the people and the people have the ability to interact and influence the government in ways that are less and less possible as the levels of government rise from the people (compare writing a letter to city hall to writing a letter to the Provincial Premier or State Governor, to writing to the Chief Executive of your nation. Now imagine writing a letter to the world Emperor...).
Of course this also exposes the weakness of the idea. As you move throughout the world, different cities and counties will interpret the cultural or spiritual ideas of the global culture differently. In some cases this will give you distinct regional cultures and practices (much like visiting someplace in the other part of your country), but eventually the differences will become great enough to provide difficulties (in region "x", a certain practice marks acceptance of a contract. This didn't happen in region "y", so they argue the contract is invalid...). An overarching cultural guidance can provide a certain amount of leeway, but ultimately there may have to be an overarching enforcement agency as well.
The overarching enforcement agency is, of course, the objection to the idea of a one world state, especially since it will be remote and generally unanswerable to the people. We would see something like the Inquisition appear, with all that implies.
[Answer]
Let us assume the world government is federal is form. Each member state retains the right to its own laws and customs etc. and it is clearly demarked in some sort of world constitution. Each states rights and obligations clearly set out and generally seen to be fair.
If a state has a gripe against another state or a minority population had a beef against its state of residence they could take it to court and get a binding decision. Most purely nationalistic issues like those of ETA, Palestine, the Kurds would vanish. Why fight for a homeland when your immediate concerns are being met? As would the wars of the Powers regional and supers. The struggle for Russian, U.S. or Saudi supremacy could lead to civil war with literally the rest of the Earth and would be avoided by pragmatic sociopath leaders.
We would still have terrorism by Xtian and Muslim extremists that feel that the whole thing is the work of the antichrist/devil. The Islamists could be appeased if we allow a Caliphate over the Muslim world who is bound by good will and a commitment to peace to follow international law.
If a person or group doesn't like the laws of the state they live in they would have freedom of movement. Freedom of migration would be in the constitution Economic border effects would be lessened. Trade wars / Tariffs would be counterproductive as would outsourcing jobs as local job markets would have to compete on wages.
We would definitely put the capital in San Francisco and start exploring space in earnest. A fleet of starships that would go where no one has gone before if you will.
[Answer]
In theory Yes it is possible but there are many implementation problems
In order of severity ...
* Single point of failure. In our current world if a government does something stupid or evil it doesn't doom us all. If you gov refuses to adopt electricity, or starts an internal genocide you can flee to a neighbor country and get away. In this case your doomed. Even very smart leaders can make dumb decisions. Napoleon famously reacted to the steam boat by saying "You wish to power a ship against the wind and waves by lighting a fire under its decks. I have no time for this non-sense".
* Protecting the minority opinion. In a democratic government you have minority and majority opinion groups that disagree. How do you balance the needs of the few against the many? A small number of people want protection from volcanos but most people don't want to pay for it. If we only do things a majority wants then a large amount of good things will never be done. For this reason large countries have smaller provinces that let them split voters into smaller and smaller groups so the city government next to the volcano will have majority support for protection, but what about minority groups that are not geographically isolated? How would you convince people to join if they know they will share a minority opinion.
* the leader's time. a single leader can only deal with so many problems, we would need additional layers of government to reduce the load on upper layers, so we could have city, county, state, "national" and global levels of government to spread the load.
[Answer]
I'm less pessimistic than most of the other answers. Think of the "global mobile professional class" these days. Someone born in Denmark might have gone to a boarding school in Switzerland, to an university in the US, and work in Dubai for a London-based multinational company while a Filipino nanny cares for their kids. Until the job in Dubai is over and they go "back" to London. Or perhaps Singapore. Or Hong Kong.
So far this is just a small part of the global population, but it doesn't have to stay that way. First you get a global culture. In some ways a loss, in other ways a gain. As multiple passports and residency permits get more common, the birth passport gets less important. And what really matters is where one got the MBA. A few generations of that, and nations might be quaint parts of your heritage.
The question is if this applies only to people in the top income brackets or to everybody.
]
|
[Question]
[
Two planets rotate each other and are tidally locked. They are where earth is around a star nearly identical to the sun. One planet is much wetter, featuring oceans, swamps, jungles, and forests. The other is much dryer with plains and deserts. Both are about earth-sized and have similar atmospheres. They are close, like, 3,000 miles surface to surface. A moon about the size of ours orbits the two. This system orbits a sun at he same rate as earth. On one lives a race of lizard-men and on the other lives a race of electric eel-men. I'll let you pick which species belongs on which planet. Anyway, they are both extremely sensitive to radiation. Other than that, you can pretend they are human.
---
Both planets have futuristic technology, so they have all the modern conveniences of earth, and more besides. The lizard people issue an ultimatum. The inhabitants of the other planet must evacuate to their moon colony or face all out war/extinction. They have 1 year, then the lizards will invade their planet and kill everyone. However, the eel-men have prepared for this...
---
So, how do the inhabitants of one species kill the other ones without destroying the other planet? If one planet is destroyed it throws the other out of its orbit with potentially disastrous consequences. **Also, radioactive weapons are impossible to manufacture, because it would kill all the aliens who would make the bombs. Not only this, but these species are similar enough that they are affected by the same diseases.** So, how would one civilization wipe out the other and leave both planets habitable? The moon doesn't have to survive, but the planets' orbit must be left mostly unchanged.
Edit - The moon could be unnatural, put there by these alien species. I don't care about the stability of the moon's formation, but there is a sizable body of something that orbits these two planets.
[Answer]
## The Moon IS the weapon
The Eel people agrees immediately, which confuses the lizard people. '*We're their betters, and they know it*', say a Hawk lizard in triumph; the Dove lizards aren't so sure, but can't put a finger on it.
The Eel people asks for more time - there's a lot of eels to move around, you see. given the swift acceptance, the lizards add another year out of 'condescending acknowledgement'. (Or maybe that's a condition: '*If you give us two years, we'll accept your terms.*')
The Eel people starts moving to the moon. One day before the 2-year period expires, they issue an ultimatum: The Lizard people must now pay tribute, or face consequences.
The lizard people laugh it off in disbelief. A couple of hours later, their military centers are vaporized. At the end of the day they capitulate, with minimal loss of civilian lizard life. The Eel people now rules the system.
How, you ask?
They cut hundreds, maybe even thousands of large chunks (10-tons or more) of moon-rock and put it in orbit around the Lizard planet with the help of rockets, or a highly precise [mass driver](https://en.wikipedia.org/wiki/Mass_driver) build on the moon's surface. Less gravity means less fuel to move things around, and you have two years to position them. Using simple ballistic calculation, they can make them drop over military bases, cities and other strategic points. Once these enormous kinetic projectiles start falling, they can't be stopped.
(Just as a comparison, a 10-ton falling rock from around our Moon's orbit (384,400km) would carry the energy equivalent of roughly 627 Hiroshima atomic bombs.)
Disclaimer: Idea totally stolen from ['The Moon Is a Harsh Mistress' by Robert A. Heinlein](https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress).
I used [this calculator](http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html) for kinetic energy evaluation.
[Answer]
The first thing you need to do is change government and apologise. There's no point going into a war having already threatened a war, they're expecting you. It's going to take a good solid grovelling apology, preferential trade agreements and promises of investment to get out of the situation.
The first thing you're going to invest in is a decent spaceport at the nearest point on the other planet. This is to make sure all your other trade agreements go through more smoothly. Buy the land, buy the land around it. Make a point of offering good money for the inconvenience and noise that people living nearby are going to suffer. Promise jobs to locals but make the working conditions so shocking that they'd never take them, fill the vacancies with your own people, you need to run the place after all.
Try to work out the difference between a military base moving millions of tons of goods and a secure spaceport doing the same. Not a lot. You now have a foothold on the planet. You've also created a trade imbalance on the target world. They're going to want more spaceports spread around the planet to allow other regions in on the goods without planetside longhaul freight.
Given 20-50 years you'll have established military facilities near all their major population and industrial zones.
Next make low bid offers to run critical but risky and dirty industry. Power stations and the like. I know you're against nuclear power but it's a perfect option for this, as are water treatment plants and comms infrastructure. It'll take a couple of decades at least before you're sitting on a solid chunk of critical industry.
When you're ready, pick a nice juicy target, like every major city, shut off power water and comms and bomb at your leisure. They'll be used to your ships in the sky and it'll be too late before they work out what's going on.
[Answer]
# Option 1: Super Deadly Eel-Killing Plague of Swift Deadliness (Which is Deadly)
Develop super deadly eel-killing plague of swift deadliness. Simultaneously immunize lizards with a vaccine and/or make super deadly eel-killing plague of swift deadliness the super deadly to eel-only plague of swift deadliness to eels but not to lizards. Seriously, there has to be *something* different about these two species that a deadly plague can leverage! It could be a virus, a bacterium, [a prion](https://en.wikipedia.org/wiki/Prion), or a parasite. It just needs to be highly infectious and highly deadly!
The plan goes like this:
1. Develop disease and immunize lizards.
2. Issue ultimatum.
3. Upon failure to conform, send lots and lots envoys with plague and infect them until most of them are dead. Go to several of their major transit hubs and disperse them there. [Eel WHO](http://www.who.int/en/) can only do so much.
4. [Then the lizards make like the Europeans and clean up the rest](https://youtu.be/JEYh5WACqEk).
Upsides: Most eels are dead, the lizards didn't do the actual killing of most of them, their armed forces are diminished. Most of the resources are intact.
Downsides: they could develop a cure, and foil this plan. Takes a lot of mad science and lots of secrets.
# Option 2: Big Space Rocks
I'll call this the "big space rocks" because you just take an astroid, do some orbital mechanics, and send a modest asteroid at those eels. You'll need to guard the rock, but after a little bit, it'll kill those eels [like the dinosaurs](https://en.wikipedia.org/wiki/Dinosaur#Impact_event).
Upsides: A rock kills most eels, unless they survive in bunkers.
Downsides: Rock can be destroyed prematurely. Math can be done wrong and the asteroid hits the wrong planet, letting the eels colonize the lizard world. Can be survived if eels dig deep enough bunkers. Eel world could be uninhabitable and/or most natural resources are unusable.
# Option 3: Brutal, Brutal War
Upsides: you gain the planet with most natural resources likely intact. (Well, as intact as the eels had it.)
Downsides: brutal warfare with heavy losses for everyone. Lizards may lose. Takes forever.
[Answer]
What do the Eel-iads need to survive?
**Water:**
* Poison the oceans, lakes, rivers, major aqua-repositories.
* Turn their water into ice with that instant water to ice formula (forgot the name of that movie...)
* Vaporize their water. This might be a setback for colonizing the planet by the Lizardians but it'll win the war.
**Sunlight:**
* Simpsons did it. Matrix did it. Block the sun and laugh your maniacal lizard laughter.
**Food:**
* Poison/disease that targets the food sources, be they plants or animals (might be safer with poisoning plants, for re-colonization purposes)
Basically, you have a lot of options that largely depend on what you're willing to lose.
[Answer]
The basic way to kill off the other planet is to bathe it in deadly radiation. A powerful beam of charged particles is sent from one planet (ideally from a giant orbiting station, since you don't want to irradiate your own planet) and sent to bath the other planet with ionizing radiation.
There are a few complications in the scenario you have given, however.
Since the planets are tidally locked, only the facing hemisphere will be affected, unless you go to the additional expense of making a mobile firing platform (AKA space battleship) and send it into polar orbit around the other planet to start irradiating the planet below. Here you run into the issue of having a very expensive asset in range of enemy countermeasures. In low orbit, they could be as simple as firing rockets into orbital space and discharging buckets of ball bearings. The enemy ship flies into them with a minimum relative velocity of about 7 miles/second, which will turn anything less than a "death star" into confetti pretty fast.
The second issue is that while the surface will be bathed in deadly ionizing radiation, anyone who burrows underground will be safe from the beam. Submerging under enough water (about 5m) will also attenuate the radiation to the normal background level. While the biosphere above will be destroyed, so long as you have either stored supplies, or a functioning closed life support system, you can remain below ready to exact revenge.
Finally, for the people who want to conquer the planet, there will be a wait ranging from years to centuries as the induced radiation from activated materials on the surface decays. Since you went to a great deal of effort to totally destroy the biosphere of the planet, you will have to essentially terraform the world in order for you to start living on it (several centuries without plant life will change the composition of the atmosphere, for example).
So the risk is pretty high ( they are at the same technological level so they can do the same to you), the rewards uncertain (are there survivors lusting for revenge hidden under the oceans or mountains?) and the end result if everything goes right will be a dead planet that you have to terraform. Is it really worth it?
For more details see: <http://www.projectrho.com/public_html/rocket/spacegunconvent.php>
]
|
[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/32850/edit)
So the next next President of the USA has just got in his position, and by electoral estimates and the power of the status quo maintenance, he knows that he will win his re-election, so he is sure that he will be in this position for the next 8 years.
But our President has a problem: he doesn't want to be a career politician, and so he wants to retire after his term. He has dreams he wants to pursue, and such dreams are costly. On the other hand, our President wants to make a lot of money using his presidential salary, investing in whatever profitable activity he can put his money to be use of, so whatever he wants to do, he must do it in this gap of 8 years. And on top of that, our President is someone who wants to be as righteous as possible, as he cares about his reputation and he cannot allow himself to do anything bad.
It's obvious that being a politician is to be inside a system that allows and sometimes even coerces the representatives of the people in doing bad acts, and that's why our President wants to do only the 2 presidential terms and then get out of it. To finish it, let's a put an "easy" mark here: **1 billion of dollars** (or more if possible, maybe 10 billion, who knows).
Of course, we have some restrictions to limit our financial options, and these are the rules:
**1. The President cannot receive money from illegal actions or dubious representatives.** Our President is a man who cares about doing the right thing, and so he doesn't want to do anything that can harm his image or give potential ammunition to the opposition. Because of that, no money or service that came as a result of bribery, lobby or any kind of corruption will be accepted or expected. If our President receives any anonymous donation, he will investigate and, if he found that it came from an illegal or bad source, he will return the money and report it to the responsible authorities.
**2. The President cannot be director, chief, manager or hold any corporate title, and he also cannot found or manage a company.** It's obvious that, if our President has any high position in a company, any political action that could change the economical environment would be criticized as a "one-sided" or "biased" action that has the growth of his own capital as a goal. In fact, it's even illegal in some countries. A warning here: can our President be an anonymous investor in a company? I sincerely don't know. Is it illegal, or is it bad for his reputation? I guess that is the rule that could be the most discussed, because it's the rule that stands most in the "gray area".
**3. The President cannot engage in illegal activities.** The President wants money, but not a criminal record. Slave trade, trading weapons or uranium in the black market, selling federal secrets to other governments, ... that's all activities that our President will not do.
**4. The President cannot engage in activities that are not compatible with his presidential activities or that could go beyond his available time.** The President is, you guessed it, the President, and so he must work, because he has political things to do and a country to worry about. Because of that, his economical activities must be possible to be executed in his spare time. He cannot spend the entire day checking the ups and downs of his assets in the stock exchange.
P.S.: After writing all of these laws, I guess that the second one is the hardest to have an absolute position about it. The President could have a lot of stocks, which are anonymously in his hand. If such a thing was discovered, how bad would that be to his reputation?
On the other hand, let's say that the President has invested in Bitcoins. He could openly tell that to the public, and even create laws to make it more accessible to the people to invest in it. Such action would be criticized by some, but would it be bad for his image? Or maybe not that bad, because it doesn't affect him directly, although he has a relation with it as an investor. Any clue or discussion about that would be very welcomed.
In short: **how could a President become a billionaire without doing anything illegal, and using only his salary?**
[Answer]
**Short of immense luck, the President will not be able to legally make a billion dollars off of his salary and position alone. He should write a book instead.**
The President of the United States makes a yearly salary of 400,000. Over an eight year term that will give him $3.2 million to work with in total, but he’s only going to have a fraction of it up front when he gets started.
Unfortunately for this President’s wealth aspirations, he is unwilling to break the law. As a result, he will be limited to the same avenues of wealth acquisition as the general public. Between this and his extremely busy schedule, it’s almost impossible for him to turn a yearly salary of $400,000 into a billion dollars over eight years. It might be tempting to think that the president’s position would afford him a greater opportunity to invest, but his chief advantage is insider knowledge or relationships that would be dubious, if not downright illegal, to leverage. The only chance he could possibly have would be gambling, most likely via lotteries.
If, instead, the President merely wants to retire comfortably after his term, he’s better off writing a book. Popular politicians can easily make millions of dollars in book sales, and its an activity that feeds specifically off of his position and unique experience. A successful book can also continue to reap profits for many years.
[Answer]
**He can engage in insider trading.**
Now, you may say, insider trading is illegal. But actually this is not entirely true for politicians. For instance, it was not illegal for members of Congress to sell or hedge their portfolios before they passed TARP in 2008.
Furthermore, while you say the POTUS has to spend most of his time doing his job and doesn't have time to actively play the market, it doesn't really require much time to transact a trade here and there. There are plenty of mobile apps out there for various brokerages which will even allow you to initiate a buy or sell order from anywhere you have cell coverage. You can spend less than 5 minutes a day doing it, say during a restroom break before you make a speech.
Now, how will this work? As President of the United States, you have a great deal of inside information not only on what laws are likely to make it to you, and input on what laws you want to reach your desk, but veto power over laws, and even executive orders which bypass the need for legislation. Many of your acts as President can radically change the value of various publicly traded companies. Making a billion dollars is quite doable using highly leveraged instruments such as options and futures - things which normally would have very high risk if not for your inside knowledge of how your policies and legislation would proceed.
And you don't even need to compromise your ethics: for instance, you could buy cheap out of the money puts in a certain large oil company having significant interests in a remote Alaskan oil field (betting the price will fall) and then while nobody is expecting it, sign an executive order banning drilling in this region due to the environment impact it will have on native wildlife. Conservation organizations will praise you. Or you can position your money so you will make a killing when you announce your new health care initiative.
And you don't even have to limit yourself to local concerns. The actions of the President of the United States can even affect the value of the dollar. Invest heavily betting the USD will fall, and then announce policies to be taken to devalue the dollar to increase the competitiveness of American made goods abroad. (Unions love you) Or vice versa if you feel imported goods should be cheaper and benefit from a stronger dollar (consumers love you). Your views are not important to achieving your goal, whatever you believe in and whatever policies flow from that can facilitate your making a great amount of money. It doesn't really even matter if your goals are ultimately unsuccessful, because you can cash out after your initial announcement moves markets in the desired direction.
While you can make your positions strategic to benefit a large part of the population which will in turn re-elect you, you probably won't even actually need to be re-elected to a second turn. The combination of geometric returns on your initial investment combined with the power of what you say to move markets should take much less than 8 years. For a large part, your salary is not even a big part of this. As an illustration of leverage, in under two years, [Hillary Rodham Clinton turns \$1000 into nearly \$100,000 in cattle futures](https://en.wikipedia.org/wiki/Hillary_Rodham_cattle_futures_controversy). You are going for these kinds of moves, but overnight. The fact that it takes you a year take make $400k will pale in comparison.
[Answer]
There's **no reason** for a President to become a billionaire while in office because being an ex-President is itself immensely valuable. Just look at the Clintons. They were, by some standards, pretty poor when Bill Clinton got elected. Now they are worth hundreds of millions, if not billions. Just do what Bill and Hillary did.
This is because once he leaves office, he becomes very desirable to do business with. Once out of office he'll get paid $50,000 or more per **speaking engagement** - all over the world. He'll be invited onto the **board of trustees** of major world-wide corporations, and receive equity in them. This is because having an ex-President on a board makes the company more attractive to investors. He'll have as many **book offers** as he wants, and will get millions in advanced payments. He will have insider access to the best **investment opportunities**. Also, as an ex-President he'll have a lot of influence with the right people, and will be paid handsomely to **lobby** for industry.
So basically, why bother trying to get rich while President, when it will be that much easier to do - and far less controversial - after he leaves office?
[Answer]
## Run a meet-and-greet lottery.
The president's **time is extremely valuable**, but as a human being and citizen of a first-world country, and one with a high-stress job, it's generally accepted that the POTUS should get vacation time. How they use this time off is at their own discretion.
The president could hold the lottery, say, once a month, with each meeting lasting several hours -- perhaps styled like Seinfeld's [Comedians In Cars Getting Coffee](http://comediansincarsgettingcoffee.com/). Eight year's worth would be 24 meetings -- \$42 million apiece would net a billion dollars. A large sum, but the [average Powerball jackpot](https://www.lotterypost.com/game/4/jackpot) is ~\$80 million, so not inconceivable. Many people would be willing to pay a large sum for a chance to have an audience with the president, especially if it was publicly aired -- so to pay only a few dollars for a chance to meet them would be a bargain.
**Transparency would be key.** The POTUS would ideally release an accounting of the time spent in proportion to work duties, to avoid accusations that they were taking advantage of a public office or not doing enough work. The same goes for funds spent on Secret Service security during the meetings. For PR's sake, a portion of the proceeds would likely have to be donated to suitable charities.
[Answer]
Did I miss something in the question that said that doing what real presidents do doesn't count? Assuming I didn't, the president just has to wait until he leaves office and then make a fortune on the speaking circuit. It's certainly legal. It does attract a little criticism, but so would literally anything an ex-president does in public. It's true that he can't *immediately* retire, but at the [rate an ex-president can command](http://politicalticker.blogs.cnn.com/2013/05/23/first-on-cnn-bill-clintons-106-million-speech-circuit-windfall/) he should be able to make his pile in mere months. The only investment he need put into this while he is still in office is to keep a detailed diary from which he can later extract nuggets of folksy wisdom. This could also be useful for writing his autobiography, as suggested by [Avernium](https://worldbuilding.stackexchange.com/a/32859/9207) above, and for ensuring his anecdotes are actually true, as the question specifies that he does not want to find himself [under fire](http://www.telegraph.co.uk/news/worldnews/1582795/Hillary-Clintons-Bosnia-sniper-story-exposed.html) from critics.
[Answer]
**He can mine, trade, and own/co-found a fast growing digital currency.**
He's the president, so it's not like he can't get access to some very powerful machines or an array of them. It's not illegal to trade digital currencies, mine them, or sell them. Their characterisation is a bit grey, and really only Bitcoin has a bit of a nebulous negative reputation from The Silk Road, which would address your concerns with that.
There's nothing stopping him from being the sole owner of it or collaborating with a creator, either. The creator of Bitcoin, Satoshi, was rumoured to have over a million bitcoin which isn't too unrealistic. Its value rose to over 1,500 dollars which is over a billion dollars in total.
Owning so many and having an arrangement with the creator of the algorithm, blockchain / ledger wouldn't really be unrealistic. Its value could easily go over 2,000 or more as long as people give it that value. This isn't the same as owning a company, and it's not considered gambling if he managed to come across it with minimal resources. It's not even a company investment.
Since a lot of it is so virtual and has very little to do outside any sort of negotiations for ownership, he can maintain anonymity like Satoshi did. It wouldn't be costly to his time or interfere with his role as President. A lot of digital currencies are indeed anonymous so there's no reason he would have to disclose it. And even if he did, people would only criticise him because he has a position of power. However, it would be no different from the people who complained about Satoshi (which was quite the minority) simply because he had money.
He could even be the sole founder if he learned computer programming to a good degree.
[Answer]
How does a person become a billionaire? Either by inheritance, or by founding or investing in a corporation that achieves market capitalization in excess of $1B times his equity stake.
Speaking fees, investing his salary on mutual funds, writing books, etc. will not work. At 100,000 USD per speech, you would have to give 10,000 speeches that would take 192 years at a rate of one speech per week. At $2.5M per book, you would have to write 400 books. Would the 400th book by "the most interesting man in the history of mankind who also was the president of the USA" really sell?
His sole chance is to invest in start-up companies and then use all the powers of his office to make sure that those companies are hugely successful. Whether this is legal and ethical under your requirements 2 and 3 is ***highly*** questionable. Before 2017, I would have said this is clearly illegal but ethics rules regarding presidential business interests seem more murky under the current administration, so you may have a way out. Perhaps a family member can invest on his behalf. Think of it this way, if it was easy, every president would have done this. Who doesn't want to be a billionaire?
So, what start-ups is he going to invest in? Things that almost every other investor sees as non-viable but a president could potentially *make* viable.
* Human germline genetic manipulation, the designer baby company.
* Reckless gene therapy for every illness. The 21st century cures company.
* The cognitive enhancement company. Free, legal stimulants for everyone (competition from mainstream big pharma is an issue).
* The Mars colonization company.
* The green energy company
* The bog peat burning company
* The armed drones for civilian home defense and big game hunting company (competition from current defense contractors would be an issue but you could pass a law to the effect the same corporation cannot produce both military and civilian drones)
* The US affiliate of the one and only North Korean company and bank allowed to do business in the US
* The one and only US company allowed to export dual-use technology to Russia
Basically anything that he can strong-arm the NIH, State department, EPA, Department of Energy, NASA, etc to make unexpectedly profitable.
]
|
[Question]
[
After I asked [what language the Anglo-French Empire would use](https://worldbuilding.stackexchange.com/questions/29720/what-language-would-the-anglo-french-empire-use), I got a few comments that made me realise that I haven't really thought about how this would arise in the first place.
For starters, as pointed out by David Richerby, the British [had](https://en.wikipedia.org/wiki/Bill_of_Rights_1689) [laws](https://en.wikipedia.org/wiki/Act_of_Settlement_1701) that prevented a monarch from being Catholic. Another point of contention is that the French were an absolute monarchy during the late-17th to mid-18th Century, and the British were a parliamentary monarchy during the same time period. Finally, the Seven Years War and subsequent wars caused both to generally despise each other.
Obviously, the above would have to change, or it would have to happen in *spite* of the above. So, how would France and Britain merge into a single entity, given the following:
* It happens in the early to mid-18th Century, i.e. before the American War of Independence, and long before the French Revolution.
* It starts as a political and possibly military alliance, and by the early-20th Century has been a formal union for at least one generation.
[Answer]
[**Two words: The Hapsburgs** (or Habsburgs)](http://www.encyclopedia.com/topic/Hapsburg.aspx)
The Spanish branch of the Hapsburgs was behind the infamous Spanish Armada, defeated in 1588 by the plucky Sir Francis Drake. That was the high point of Spanish Empire. After that, everything was in slow retreat.
The Hapsburgs didn't just rule Spain at the time. It was also what is now Germany, Austria, Hungary, Czech Republic, Romania, The Netherlands, Belgium, Switzerland, and parts of France and Italy. [Click for a nice map from wikipedia.](https://commons.wikimedia.org/wiki/File:Habsburg_dominions_1700.png#/media/File:Habsburg_dominions_1700.png)
Ok. So, lets do some more history editing to get you where you want: Lets say England did turn back the Spanish Armada in 1588, but at a high cost and with the Armada largely intact afterwards. Lets also say that The Hapsburgs soundly defeated the dutch revolutionaries in the 17th century. Not only is the Netherlands still in their possession, there's no Dutch Golden Age where they became, for a while, one of the dominant sea powers globally. In fact, lets say they managed to hang on to everything, including Portugal - so another future global sea power is not on the international stage.
Bonus points if your Hapsburgs also figure out how to avoid all the inflation from the silver and gold which flowed in from the new world got dammed up by their mercantilist policies, and the genetic corruption from inbreeding.
So, all these bullets dodged taught the Hapsburgs a lesson on strength and avoiding decadence. So, they spend the rest of the 17th century unifying their family's two branches and developing a world class system of government bureaucracy - think mandarins - to keep all these far flung territories under their control and operating smoothly.
Meanwhile, Britain, the only other possible sea power, is struggling to build the navy and colonies they had in the real history. They're butting up against Spain all the time, and Spain is having a jolly time depriving England of the best colonies and chasing down her privateers. France attempts to build up sea power & colonies as well, with similar results. France is also happens to be surrounded on all sides. So, France has the motivation of the Hapsburgs, and their example, to unify and rationalize their own political structures; including equalizing the hated gabelle -- the salt tax that was mindlessly absurd in its implementation, and was a major source of grievance leading to the French Revolution in its own right.
So, no French revolution in sight, and the country is operating efficiently and has the same goal as Britain: take more colonies from the Hapsburgs.
Ok, so by the mid 17th century, you have a Hapsburg super power, and two great powers that are struggling for every advantage against the Hapsbug Empire, and thus are internally unified and militarily developed. Then a new Hapsburg emperor ascends the throne, and decides that the best way to end all this annoying chipping away at Hapsburg colonies and looting Hapsburg shipping is to solve the problem at its source -- in the French and British homelands. He invades...
So there ya go. One tailor made scenario for Anglo-French alliance. :)
[Answer]
The best way to have an Anglo French Empire is to go even farther back in History, during the 100 Years War. The English had a claim to the throne of France, and while they lacked the military and financial resources to actually conquer France, there were a few occasions where the French were ready to throw in the towel, and at one point had offered a French Princess to Henry V.
If the French had collapsed due to their internal feuds, or Henry had taken the French Bride and crown (and the rebellious French gone along with this), then there would have been a Lancasterian Empire in the late 1400's joining the two lands.
The contrafactual history at that point becomes rather murky, since so much would have changed. The English lords and merchants would probably have gone wholesale to France, as it was richer and had direct access to the continental markets, leaving England to be more of a backwater. The incredibly powerful Lancasterian kings would probably have squelched the development of a Parliament, along with many other institutions that we take for granted as part of our English inheritance. The reformation might not have happened either, or the Thirty Years War become a much shorter conflict, since the Catholic Lancasterian Empire could have provided many well trained armies to ravage the German principalities and crush Protestantism.
We also would never have herd of the Stewarts, Tudors or other royal houses in England (no Henry VIII or Elizabeth Gloriana, for example), while the French royal houses would also have been extinguished. The conditions for the French Revolution would not have taken place, and Napoleon would be, at best, an artillery officer in the Lancasterian Army. Of course no Dynasty lasts forever, but the replacement dynasty would probably not include figures like William of Orange, the Hanoverian "Georges" or anyone we would recognize in our timeline. As well, the conditions for the Glorious Revolution or the settlement of the American Colonies would also be different or extinguished; certainly an more land based Lancasterian Empire would not have developed along the lines England did, nor would there be any modern United States.
Cobbling together an Anglo-French Empire in the 1700's would be a much more difficult proposition, but Patches has done a remarkable job, so you have at least two contrafactuals to work with.
[Answer]
I think you should get around the issue of trying to arrange a *natural* alliance between England and France. They were at each other's throats for **centuries**. Not very likely in a *real world* scenario.
Instead, consider this:
**1. The one country conquers the other.**
The victorious king takes a queen from among their nobles to gain legitimacy (forced marriage). Then that monarch can impose all sorts of rules:
```
- Create a single kingdom
- Ban one language, etc.
```
**2. A mutual enemy**
An alliance (that did not historically happen) is forged between the Turks and nation X (Spain, for example?). They support a military Turkish campaign in the East, while their armies - with Turkish janissaries fighting beside their own troops - attack France and Italy (Rome is laid to waste, etc).
The French & English decide to ally in the face of their powerful, common enemy. They overcome the threat, but at a great cost: a large number of nobles from both countries are killed, including one of the monarchs. In the power-vacuum that ensues, a political alliance is forged, and a new kingdom is born, sworn to overcome their past differences in order to safeguard the Christian world.
(this could have happened in the past from where your story starts, so that you would be able to forge your own story from there on).
**The possibilities are endless.**
]
|
[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/26794/edit)
**Background Story**
Steve Gwa, a native American serving in U.S. special forces, one day wakes up to find himself in a very unlikely place. He is laying on the ground, near a village that appears to belong to some Mayan tribe in Mexico. He is extremely surprised but as he meets people coming out of huts and sees their skin color and facial structure, he remembers they are *somehow* familiar. More strangely, he is not wearing his shorts and vest that he wore last night, but instead is wearing a deerskin loincloth only ... just like other people.
In a few days he gradually recalls that all his life (he is 28 years old) in 21st century USA was a dream. A very long, very elaborate dream. His real name is Mumbini and he is a member of one of the Blackfoot Tribes. For several weeks he is unable to adjust to his wakeful *normal* life, always thinking whether all his life as a US spec ops member was a dream or a reality. He is exceptionally good with the use of tomahawk and empty hand combat where he uses the skills he learned in US armed forces training, but his fellows tell him that he was *always* good with these and that he was trained by his father, who was a renowned combatant.
Mumbini continues his life perplexedly, recalling bits and pieces of his life as a Blackfoot young man as days pass, but he just cannot shake away the thought of his life as a spec ops agent. He wants to know if history would continue as he had seen and lived it. What keeps bugging him is that he cannot find out what time of history he is living in. One day a group of other Indians, living on the shores, bring fish for barter to his tribe and then he learns that a strange large boat (ship) containing strange paleface men had landed on their shores 4 months ago. A little inquisitive questioning reveals (to him) that the incoming party was none other than Christopher Columbus!
He is feverishly excited by the news. Now is his chance to save his peoples from falling to the European invasion!
**Question**
Native Indian tribes are separated and are located far off. They are also divided into alliances and hostilities. How can Steve (Mumbini) unite them together against this overwhelming enemy? For a start, how can he convince them all not to partake in *any* friendly dealings with the newcomers and form an allied war party to immediately dispense of any and all invaders who land on their shores?
Edit to add: Eow means Edge of the World
[Answer]
**Mumbini needs to sink the Nina, the Pinta, and the Santa Maria.**
**Step One**
Alert all nearby tribes of the presence of the strange newcomers. Invite “delegates” from each tribe to come and see them with their own eyes. It’s important that each tribe have trusted sources who can verify the invaders’ existence, and even more important that they relay very specific information that Mumbini is about to feed them.
**Step Two**
Mumbini should make predictions that he remembers to be true from history to his own village elders and the foreign delegates. Major things to point out are the power of European weapons — swords and muskets may look foreign, but their danger must be communicated whether he is initially believed or not. Disease is another big one — trade, especially for foreign and unknown trinkets, will seem tempting. By creating a fear that interaction with European items or even extended proximity with European people will kill the tribespeople and their loved ones, Mumbini will create a disincentive to trade.
**Step Three**
Urge all tribespeople to stay away from the Europeans. This will not be obeyed, but it will add to Mumbini’s list of correct predictions in the future. The most important thing is to convince his own tribe to stay away and, critically, not to touch European items (even those being traded by other tribes). If any tribes are hit by unusual sickness, be swift to loudly proclaim that the Europeans brought the disease. Abusing the superstition of the local tribes will be valuable.
**Step Four**
Sink all three ships. Mumbini’s special ops training is going to be the absolutely perfect asset for this situation. From among his tribe he should select 5-8 others that respect him enough to follow his lead and undergo brief “training” in stealth and basic sabotage. Fire is going to be a great weapon to sink these ships and the gunpowder on board will help even more. Mumbini needs to coordinate three groups (he should lead the group sinking the larger Santa Maria) to ignite fires on all three ships at the same time. Reaching the hulls under the cover of darkness should be straightforward, though starting enough fires that the crew loses control will be harder. Attempting to infiltrate the ships to get to gunpowder is possible, but risky.
It’s critical that he sink all three ships. If one survives, it will return to Europe and more men and ships will arrive to supply and reinforce those left behind. By accomplishing this goal he not only destroys most of their resources, but he guarantees they will be stranded.
**Step Five**
At this point, Mumbini needs to kill the survivors. The sinking of their ships will make the crew much more desperate. It will take them quite some time to build a new ship (if they’re even capable of the feat) and their resources will likely be seriously thinned. This is going to make them more likely to forcefully seek to interact with the local tribes and very likely to use violence to survive. Over time Mumbini's correct predictions made at European arrival will earn him political favor that hopefully spans multiple tribes. This should open more opportunities for inter-tribe dialogues and give him an opportunity to suggest a combined effort to drive back the white invaders.
In the event that uniting the tribes initially proves difficult, he can begin attacking without them. Guerrilla strikes by Mumbini and a select few from his tribe should be possible — even against superior weaponry — due to his substantial experience. As he adds European scalps to his belt he will gain a reputation as both an effective warrior and someone worth following. Attacks, famine, and the elements will slowly whittle down the remaining European survivors.
[Answer]
*For a start, how can he convince them all not to partake in any friendly dealings with the newcomers and form an allied war party to immediately dispense of any and all invaders who land on their shores?*
Your story is a tragedy. He can't. How many thousands of miles of coastline would he have to patrol, and keep patrolling forever? How would he even *communicate* the danger to every settlement in a whole continent, let alone get many bitterly hostile tribes and nations to agree on a policy. (Remember that in real life Cortés and Pizarro could not have brought down the Aztec and Inca empires without allies motivated by a desperate desire to throw off the rule of those empires, especially the Aztecs.)
Maybe Mumbini can kill Columbus and sink his ships - but if reaching the Spice Islands was so desirable an objective that the Spanish Crown would even finance a crazy attempt to sail *west* to reach them, then either Spain or another European power would eventually finance another. And it would only take one man going down with a European disease to land somewhere for the great dying to start. According to your scenario they have already been there four months, and this is Columbus's second voyage. It is too late.
All Mumbini / Steve Gwa can do is to mitigate the horrible consequences somehow. Mikey's answer has already suggested formalizing Central America in a way that Europeans can understand. I would suggest that whatever his personal beliefs Mumbini should aim to convert the peoples, or at very least the rulers, of Eow to Roman Catholicism, so that when the conquistadors arrive they are greeted as equals by a Christian king graciously willing to open peaceful (and potentially profitable) relations with his fellow Christian king in Castile.
That won't be enough to make gold-hungry men like the conquistadors into advocates of peaceful coexistence. No one then living, European or Eow, held to our modern liberal notions in that respect. But it would remove the main justification for conquest.
And get working on vaccination or [variolation](https://en.wikipedia.org/wiki/Variolation).
[Answer]
*Nice storyline btw...*
# Buy Time
**Step 1: Address the Palefaces**
In addition to uniting the tribes, Mumbini should approach the ships. He knows that CC's third voyage bounced all along Central America within 10 years from hearing about the first, second or third voyage. Now he waits.
He likely doesn't know (archaic) Italian, but he does know about culture and history. He knows the names of prominent Europeans from their Renaissance, and a cultured man, such as CC likely knew Italian, Latin, and Spanish.
**Step 2: On the day of their arrival**
Mumbini puts on the "clothes" he had made (something like how he guessed they wore during the renaissance), he pulls out a *detailed* map he made of the coastline of the Americas, and he writes in English on rudimentary paper. He addresses the interlopers, and they understand that he knows of European people, he knows how to write, and he knows a vast amount of the area: and where to find gold and spices.
**Step 3: The map**
The map is a very accurate, albeit drawn from memory, map of the coast of Americas, but with one exception: a vast area filled with gold far, far to the south of South America. It is okay that the map is rudimentary, so was CC's! This buys him and his people potentially a hundred years, but not those at what is now USA, including Florida. North and South America were [inundated](https://en.wikipedia.org/wiki/Exploration_of_North_America#Age_of_Discovery_and_the_search_for_the_Northwest_Passage) in just a few following years by exploratory missions. It's too late to try to help those in Nova Scotia, Florida, or Brazil. But his people have time.
**Step 4: Formalize Central America**
This is going to be difficult; Mumbini will need to formalize Central America in a way that is understood by Europeans. This will not be done in a single lifetime, due to the enormous overland distances between tribes. A common, written language (English is a good start, for structure), and a common goal, which other answers here have hinted to. This is a broad, long-range, plan for the future, including formalized borders, to allow some tribes greater autonomy.
The United States of Central America.
**Step 5: Pit Nations Against Each Other**
Mumbini's long-range plan includes an oral history (or rather, future prediction) of how to gain influence with Portugal, Spain, and even England for when Central America is 're-visited.' Then begin promising or even delivering on trade and getting Portugal to compete with Spain, for example, to be allied with the USofCA.
**Step 6: Hope for Innovation**
After establishing a culture of innovation over warfare (use other peoples' answers for this), prepare schematics of things like trebuchets or catapults, and fortifications. Include the idea of soaps and how to wear a bandana or mask over the face when talking to future white-faces, to avoid contraction of diseases.
**Step 7: Hide Yo Gold, Hide Yo Spices**
Usher in an age where rich soil, or a rare tree are more important than gold for decoration or religious symbolism. Good luck with that. As a contingency if this doesn't work, always have a secret person in each tribe prepared to hide the things precious to Europeans when they approach. It won't be easy to pull off, but hopefully it will buy time: European race for colonization came long after exploration and declaration of ownership. Cross your fingers that they will be un-interested in 'colonizing' your land for a while, buying you more time.
Mumbini is really going to miss wi-fi and air conditioning...
[Answer]
The biggest problem with this scenario is that you have located the hero as part of the Blackfoot tribe, which is located in the heartland of the American continent, while Columbus landed in the Caribbean. Without horses (introduced by the Spanish many years later) the news would travel at the speed of foot, so learning about the landing 4 months later is actually astoundingly fast. More likely a very garbled version of the story might have arrived in his location years after the event (at which point it is far too late).
The environment also works in the favour of the invaders. The tribes are not united and (as we know from real history) it is easy for the Spaniards, Portuguese, French and English to gain favour by becoming allied with one tribe or confederation against another, offering the products of a much more advanced European culture in order to gain favour and provide some advantage over the "enemy". The hero may be a SpecOps operator, but he will be one man going against a culture which has developed mass warfare into an art, has reliable firearms, sophisticated logistics and a totally invulnerable base of operation (what is he going to do, invade the Kingdom of Castile and Aragon on the other side of the Atlantic?).
In fact, the ONLY way he could possibly change the outcome of history would be to go to the coast, convince the tribes there to lear the art of shipbuilding and oceanic navigation, develop an army and sail an expeditionary force across the Atlantic to convince the European monarchies that the Americas are far more trouble than they are going to be worth.
[Answer]
Being able to speak English, crudely (it's different from modern english) and possibly other European languages will make a difference. Knowledge of European things in general can make him seem to be some kind of prophet.
As well as advanced combat skills, he also has influence of 21st century Madison Avenue, Phycology, Cults, Telemarketers, etc. He might have read "how to win friends and influence people" or the like.
He *knows* it is important. So even if others may have had skills, nobody was really motivated to work toward an alliance.
He should set himself up as a prophet with future knowledge, which is the actual thing. A small number of followers is enough to get started, and then use *writing* and modern organizational skills to expand efficiently.
]
|
[Question]
[
Let's suppose we have found a new human colony today, somehow populating Pluto. They have good technology, much like ours and we don't want to slave them. We want to establish a communication link between us and them. How could we do it using our technology?
Ok, let's assume some things first.
* Wormhole, superdrive, novadrive, etc. was not invented yet.
* We are at 2015.
* Pluto is at 4,6 light hours from Earth.
* We have a big budget to spend.
* Our goal is to establish a 1Mb/s link (2,25 GB/5h).
With this, I think we could have some rudimentary communication established. We may send and receive videos, documentation and knowledge with a good speed. Within this scenario, we will never have a real time communication, since we can't break speed of light.
So, how do we address this issue?
[Answer]
Your question is misleading. Depending on the bandwidth allocated in the radio spectrum to such communication, we can very well have gigabit links to pluto and back. Major problem in deep space communication is latency, not bandwidth.
The limiting factor for digital bandwidth is signal to noise ratio (so, power alone wont cut) and bandwidth (this is the [in]famous shannon-hartley-nyquist theorem afterall), bandwidth here is the size, "width" of the radio spectrum allocated to transmissions. When you say "my FM transmitter uses the 100mhz frequency" you are not saying it all, because no transmission occurs in a single frequency, but on a continuous spectrum of frequencies called 'a channel', the size of such channel in MHz is the aforementioned bandwidth. Digital bandwidth is then a consequence of this channel size and the signal to noise level. Usually, the ammount of information you can inprint on a signal is half as much as the size of the channel in hertz (so 0.5 bits/hertz of bandwidth). For example, FM radio uses a ~200khz channel (this would mean that the 100mhz station mentioned earlier occupies from 99.900mhz to 100.100mhz contiguous spectrum). This size holds the guard bands between channels, two audio channels and a pilot tone that allows decoding the stereo arrangement. This same 200khz band would mean a ~100kbit/sec digital bandwidth using a first-order modulation scheme like PSK, by virtue of the nyquist limit. This cannot, however prevent second-order or higher-order modulation schemes (like QAM etc). Using higher order modulation schemes the same 200khz band can carr more information per second (called symbols per second) than the normal first-order modulation. But, as the symbol density of the modulated signal increases, the signal loses the capability to survive noise. This is where the signal to noise ratio comes into play. (The shannon part).
Another factor to be considered is the Friis equation, that allows calculating the signal power at the receiving end of a transmission/receiving system. Following this equation, a system with a low gain antenna and a very powerfull transmitter, will usually have a poorer performance than a system with low power but a very high gain antenna. Both characteristics (transmitter power and antenna gain) are expressed as decibels. The path loss (free space loss) is calculated as the sum of the gas loses (the energy that gases in the path convert to thermal energy) and the geometric loss (the decoherence of the beam, inverse square law). In space you should care only with the geometric loss. At such distances, the geometric loss is huge, so, a low directivity antenna pair will have bad performances, even if operating with very high power. The way to go is to have very very directional antennas. The Friis equation (also called radar equation) sums all gains and all loses on a system, like Rpower = AntennaGain1 + AntennaGain2 + Power1 - Pathloss. In decibels (a logarithmic scale) the difference between a 1w signal and a 1000w (1kw) signal is circa 36db(w). A parabolic antenna can usually have 36db gain over the isotropic transmitter. This means that a system transmitting at 1000w of power but using an isotropic antenna (theoretical) will reach the receiver with the same power as a transmitter with mere 1w of power but a 36db parabolic antenna, and cheaper too. Higher power transmitters tend to emit a lot more noise than lower power ones, so, in the end of the day, lower power is usually better than too much power (Your priority goes from finding the bigger gain antenna possible, to the lower noise equipment to the largest power, in that order).
Summarizing both poins above, the bandwidth is limited by the capability of the system to send a large bandwidth signal across space while maintaining a good signal to noise ration, and using very directional antennas. But, you asked about bandwidth, and there we have no big problems. Like I said earlier, major problem for space communications is latency, the time that a wave takes to go from pluto to earth will have a major impact on protocols like TCP/IP. We will need better protocols. If error rate is too high (your latency will prevent simple acknowledge protocols to work satisfactorily) we do have some forward error correction protocols which may prove good enough. TCP/IP does not use forward error correction protocols due to the best effort nature of our networks and the low latency usually involved. But, nothing prevents someone from using a error correction protocol at the physical layer of the network.
Forward error correction protocols go a step further from error detecting protocols, in that they allows not only to detect errors, but to use aditional information in the packet itself to correct a certain maximum ammount of errors induced by the propagation media. This why you decrease the need for acknowledge packets (wich are limited by the very high latency of the network). Its right at the aknowledge system where latency might become a bandwidth limitation, becase to transmit the next packet the network might need to wait for the aknowledgement of the previous packet sent. TCP/IP uses a sliding window protocol to prevent this, but, the size of the windows involved in such a case are too small to be used in huge latency situations like those in the question. So, you might use bigger, FEC-protected packets and go away with acks altogether.
tl;dr
Bandwidth is not a problem. Latency is the real problem and we dont have a way to break the speed of light limitations but we can mitigate that problem with forward-error-correction protocols.
(This question is right into my professional area (networks).)
[Answer]
**Get them a powerful directional transmitter and you shouldn't have any problems.** New Horizons is transmitting at 20 Watts in our direction and we can receive data just fine. Increasing the power output of the Pluto transmitter along with a larger transmitter should radically improve the signal to noise ratio thus granting higher bandwidth.
If the Pluto antenna doesn't point towards us we won't receive much, if anything at all. If the Pluto signal is too weak, we will have difficulty picking up the signal from the cosmic background noise. If we pick a too-long carrier frequency then there's bandwidth we miss out on that could be had with a shorter wavelength.
Terrestrial TCP/IP protocols are poorly adapted to the unique constraints of deep space data transmission. Proposals have been made for TCP protocols, one called [TCP-Planet](http://www.cs.ucsb.edu/~ebelding/courses/595/s04_dtn/papers/TCP-Planet.pdf) that should prove interesting.
Any kind of interaction that requires rapid interactions, such as AJAX and Web 2.0 will obviously fail.
[Answer]
Related: <https://www.nasa.gov/content/disruption-tolerant-networking/>
As @Green said, getting a giant transmitter will ensure that the message gets across more often than not.
The other problem is the protocol. Again, as @Green mentioned, TCP/IP is rubbish in this instance. As an alternative, NASA are working on and testing sometime called "Disruption Tolerant Networking". This new protocol recognises that messages transmitted across space will contain errors, and that it won't arrive immediately. Here's a quote form their page:
>
> Information processing nodes, satellites or ground stations, need to be able to store the data that they receive until they are able to safely send it to the next node in the network.
>
>
>
[Answer]
Easy: use x-rays!
Radio and even visible-light lasers diffract too much to get good efficiency. At the frequencies that *New Horizons* uses (about [7 GHz (pdf)](http://www.uhf-satcom.com/amateurdsn/Paper-969.pdf)), even a huge antenna like [Goldstone's 70-meter dish](http://deepspace.jpl.nasa.gov/galleries/goldstone/) are [diffraction-limited](https://en.wikipedia.org/wiki/Diffraction-limited_system) to a beamwidth of about:
$$
\theta \approx 1.2 \frac \lambda D = \frac{1.2c}{fD}=\frac{1.2c}{7~\text{GHz}\times70~\text{m}}\approx0.04^\circ\approx 2.5'
$$
This may not seem very big, but at Pluto this translates to a spot about:
$$
w\approx \theta d = 2.5'\times 33~\text{AU}\approx 3.6\cdot 10^{6}~\text{km}
$$
in diameter! On the other hand, if we use soft x-rays with an energy of about $1~\text{keV}$ and a much smaller "antenna" (say, one meter):
$$
\theta \approx \frac{1.2hc}{ED}=\frac{1.2hc}{1~\text{keV}\times 1~\text{m}}\approx 0.3~\text{mas}
$$
That's in milliarcseconds, or one one-thousandth of one thirty-six-hundredth of one degree. The spot is now only:
$$
w \approx 0.3~\text{mas}\times 33~\text{AU}\approx 7.3~\text{km}
$$
across! Of course, the small wavelength of x-rays mean that x-ray optics are in practice not diffraction limited. However, as long as we can achieve sufficient pointing accuracy we can pretty much make the beam as small as we want, achieving amazing link efficiency.
I'll assume that we can achieve a pointing accuracy of $0.1''$. This gives us a spot size of about $2400~\text{km}$. With a receiver diameter of just $2~\text{m}$, we get a total loss of about $120~\text{dB}$. Assuming that our detector is fairly sensitive and needs only about 100 x-ray photons per bit, then the transmitter power must be about:
$$
\begin{align}
P&=E\_\text{per bit, transmitted}B \\
&=E\_\text{per bit, received}L\_\text{free space}B \\
&= 100\times 1~\text{keV}\times 10^{-120~\text{dB}}\times B\\
&\approx 16~\text{mJ}\cdot\text{bit}^{-1}\times B \approx 16~\text{kW}\cdot\text{Mbps}^{-1}\times B
\end{align}
$$
In practice our pointing accuracy can get much better, and we have detectors capable of sensing individual photons, so the power usage could go even lower.
---
The only trouble is that soft x-rays don't penetrate through the atmosphere at all. This is not so much a problem at Pluto, but here at Earth we'd need put our x-ray transceiver in space. However, communicating at high data rates with spacecraft near Earth is not a problem, plus a spaceborne transmitter affords us the pointing accuracy that we need.
[Answer]
I can't cite the specific example, but this is a classic communications/information theory problem. Basically the lower your signal to noise ratio the less bandwidth you have, but the easiest way to increase your signal (with minimal effect on noise) is power. The only reason New Horizons is so slow is its power budget.
A solution I consider worth looking at is a laser based link, it can have incredibly high bandwidth, and a very tight beam.
[Answer]
We should very quickly be able to get TCP/IP (the core protocols of the internet) running on such a link- though it is likely to require some modification of the Data Link Layer (see [OSI Model](https://en.wikipedia.org/wiki/OSI_model#Layer_2:_Data_Link_Layer)) and probably those higher up the stack, to allow for massively increased packet and connection timeout durations.
The OSI Model, upon which TCP/IP is based, describes a standard way of handling communication between two points and deals adequately with packet errors, packet timeout delays, out of sequence packets etc.
Obviously this assumes we have:
* made contact
* have established a common language
* have physically transmitted the comms specs to the other end (or vice versa!)
Having done that, all that would remain would be to introduce the aliens to Facebook, Twitter and Instagram et al :)
]
|
[Question]
[
I have been reading on Wikipedia about [cloning](https://en.wikipedia.org/wiki/Cloning) and am considering it a possibility for reproduction in my world. I am finding it slightly difficult to find all of the cons and pros associated with it. I have these:
* Pros
+ Faster reproduction is theoretically possible
+ Get one good "template that has not inherited any genetic diseases and you effectively cure these diseases in a few generations
* Cons
+ easily susceptible to corruption-choose the wrong template and everyone born has a specific defect of the template
+ Moral and ethical reasons (nonexistent in my world but still thought to list it)
This list feels relatively complete but I want my world to be screaming detail and it feels like I am missing something important.
My question is this:
**What are the main, scientifically-backed reasons cloning is or is not an efficient method of reproduction for complex life?**
[Answer]
This is a well studied question in biology, often covered under the benefits of sexual reproduction. I will only explore the points with direct relevance to a clone army, you can explore the rest of the reasons in the link if you are interested in learning more.
## Advantages of cloning
* Clonal organisms are very good at taking over a new environment for
which they are suited. This is due to the intrinsic [twofold cost of sex](http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction#Two-fold_cost_of_sex) which ensures that clonal organisms will reproduce much faster than non-clonal ones, ceteris paribus. In the case of your example, a clonal army will be able to reach much larger sizes in the same amount of time as compared to a normal army (which you have already explained).
## Disadvantages of cloning
In contrast to the advantages of cloning, there are far more disadvantages for cloning.
* The genetic uniformity makes them extremely [susceptible to new
diseases or parasites](http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction#Increased_resistance_to_parasites). If a disease or parasite could target one of
the members of the clonal population, the entire population could be
easily wiped out due to the lack of genetic variability. In a clone army, this means that enemies can easily design a bioweapon to wipe out your clone army.
* Once a bad mutation occurs in a clonally reproducing organism, it is highly likely to be stuck in the gene pool of that organism, and this accumulation of bad mutations will damage the gene pool over time. This is known as the [Mullerian ratchet](http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction#Deleterious_mutation_clearance). If you are cloning an army using biotechnology from a single known-good soldier (such as in Star Wars), this point may be mitigated by always cloning from the originals.
Overall, if you are using the clonal army for very large short-term campaigns, it may be superior to standard armies. Under most circumstances though, a non-clonal army (or a clonal army drawn from a pool of genetically diverse templates) may be a better idea.
[Answer]
Cloning has one significant problem: **lack of genetic diversity.** In a clone army like the one in Star Wars, if the clone template is genetically susceptible to a particular disease, or if a disease evolves that targets the clones, everyone is vulnerable. If enemies of the army know this, it would be trivial to develop a disease to infect the whole army.
While we haven't seen this happen with people, we have seen it with another thing that our society has heavily cloned: bananas. The [Gros Michel](http://en.wikipedia.org/wiki/Gros_Michel_banana) banana was the main variety of banana eaten in the united states until around the '50s. Because it's tough to grow modern cultivated bananas from seeds, most bananas are clonally propagated, so all of the Gros Michels had the same resistances to disease, or lack thereof. Inevitably, a fungal disease wiped out the banana plantations in South America and Africa, after which the Gros Michel was replaced as the import banana of choice by the Dwarf Cavendish. The Dwarf Cavendish is another clonally propagated banana, because learning from past mistakes is for chumps.
Cloning also isn't inherently a faster way of making people. In modern cloning technology, a cloned embryo is produced which must then be implanted in a host mother to develop. Plants can be quickly clonally propagated through cuttings, but unlike plants, you can't cut someones foot off and plant it in the ground to grow another person.
In most sci-fi settings, of course, cloning is paired with technology for growing complete human beings ex-utero. Instead of coming out of mothers, clones come out of tubes. This tube-growth technology is what allows so many clones to be grown quickly, but it would probably be improved upon if we *removed the cloning aspect*. If you grew people in tubes, but instead of growing clones, grew a genetically diverse population, you would have far more resistance to disease. Embryos could still be line-bred to select for the best possible traits while maintaining genetic diversity. With this sort of diverse approach, you could also develop different lines of soldiers for different tasks. A tank driver and an infantryman, after all, have very different job requirements.
Of course, people are probably going to call you an immortal monster and accuse you of planing god. Those are just words, though. Words don't hurt people. Know what does hurt people? Giant armies of unstoppable super soldiers. Vat people 1, nay sayers 0.
[Answer]
The major problem that other sci-fi universes touch upon (the Asgard from Stargate SG-1, most prominently) is the Law of Diminishing Returns. Generation after generation of cloning can see flaws start to develop - essentially, when you're making a copy of a copy of a copy, all the little folds and niggles begin to add up. Continue to copy the flawed copies and eventually you can't copy any more, because the template has degraded so far as to be destroyed.
[Answer]
you answered it your self. Our sole means of surviving viruses is our difference, that someone out there is immune or resistant to a virus. If everyone had the same genetic materials it would be a global whiteout at the next epidemic
Lets evolve the idea
What if we had a genepool - like literally - a huge tub where people added genes to then create a clone, add more genetic materials - so everyone had their own genetic material. But then we are back to square one except without the fun part.
Accelerated growth is not a good idea. Many experiments about the human brain along with raising one as a person, somewhat indicate that a human mind will not be able to evolve it's brain and personality fast enough to support an accelerated growth.
So now we are back to a place where doing it the old fashion way is the best idea.
Unless you want a bunch of fast evolved maniacs, that will perish at the first biological attack that will hit them.
[Answer]
Your "raising a clone army" has an entirely unsupported premise: "Faster reproduction is theoretically possible". Why? How?
You are aware, I hope, that human clones are successfully raised all the time: they are called "identical twins". They are not notably quicker or cheaper to produce than regular singletons. Furthermore, if clones can be raised as cannon fodder, and apparently have no legal rights as individuals, which one of a pair of identical twins is the real person, and which the disposable clone?
You are presumably thinking of using artificial wombs, or something similar, and you must be assuming that clones can be subjected to forced growth rates in order to reduce their production time. Why is this not true of non-clones? Admittedly, the fast production of clones would be a great boon to geriatric medicine and oncology as a way to provide replacement parts, but the ethics seem a bit dodgy.
Assuming the existence of clone armies, and obvious countermeasure is biological warfare. Such armies would have all the problems inherent in any monoculture, and an enemy which creates a devastating plague which is restricted to the clones could use it with impunity, since the usual limit on such research is the need to protect your own population when the weapon gets out in the wild.
]
|
[Question]
[
What sort of circumstances would allow for a parasitic relationship between two dominant species of an Earth-like planet? The criteria for an answer is as follows:
* The relationship must involve no more nor less than 2 separate species
* Both species must be dominant, ie. independent, intelligent and capable of recognition of the existence of the relationship
* The relationship must **benefit** one of species whilst **harming** the other
* The relationship must be evident throughout the species, not only in a select sample
* The relationship must be ecologic or biologic, ie. a war between two dominant species, where one species is more advanced and clearly will win, does not qualify
Criteria aside, the question is how would such a relationship naturally develop whilst both species, especially the harmed species, remain dominant. The second point states that both species must be aware of the relationship; if this is not possible, this statement may be omitted.
[Answer]
I don't think you have to go outside of Earth's history to find a situation close enough to your criteria that minor modifications wouldn't satisfy. For example take one population being supplied with alcohol from the second population.
More explicitly, we have group Alpha and group Beta, each dominant civilizations of differing phylogenies. Secondly, we have a resource highly sought after, but destructive to, Beta. Alpha has a constant supply of this resource that Beta can't access on its own for whatever reason. Alpha could make whatever demands they want for the supply of this and Beta would likely comply within reason. It could be a fairly stable relationship on the order of centuries or millennia. Beta would likely eventually evolve out of a situation like this, but the volatility of civilization and politics probably means that this wouldn't be the constraining factor (in terms of time).
A few possible examples of the resource:
* Alpha secretes nectar similar to aphid's honeydew that gets Beta
high.
* Alpha can create a light show similar to cuttlefish that
puts Beta into a sort of trance that they love.
* Alpha and Beta are closely enough related that there is significant overlap in terms of
sexual desire but reproduction is impossible or offspring is sterile (eg. horses and donkeys). Beta prefers Alpha mates over Beta mates (donkeys prefer horses but horses don't like donkeys). Alpha supplies Beta with mates or prostitution, significantly retarding Beta's reproductive rate.
Some more examples that don't fit the bill for "resource" but could still plug into the equation:
* Alpha has clear, strong mathematical intuition, Beta does not. Alpha hustles Beta in gambles.
* Alpha is persuasive and Beta is gullible. Alpha constantly talks Beta into doing Alpha's bidding and Beta only figures out later what happened.
* Alpha has properties Beta had long considered properties of their deity. The lay Betas are always worshiping Alpha despite the educated Betas knowing better.
* Beta is altruistic. Alpha is opportunistic.
[Answer]
I think about humans and rats, which found a niche in human agriculture and followed us everywhere. Why are rats, roaches, and other pests *dominant* (living off our success) rather than killed off? Not for lack of trying!
So the only difference you want is sentience. Would it still work if rats or roaches were intelligent?
A big issue, I think, is the size difference. If another life form was similar in size we'd call it *war*. Pests need to find rich environments in our incidental infrastructure.
It is reasonable that being *clever* is a benefit, to keep ahead of the host. If the host is intelligent so can eliminate niches, create traps, and otherwise counteract the parasite using brain power which is much faster than biological evolution.
Pests solve that in real life by evolving rapidly (germs) or fast enough (roaches), but for non-microbes a main property is hiding so any attempt to kill the population will miss some; and fecundity so will bounce back if only a few are left.
If fecundity was strongly selected against, cleverness might take its place. Rats are already smart in some ways, with social behavior and learning, but the layout of the brain is the Mammal, same as ours but much smaller.
A bird has a different brain structure and some birds are surprisingly intelligent for such a small size, and smarter than previously thought. Point is, *very* unrelated species means the brain can be more different, not similar to ours but too small.
It's also noted that hive insects are like an extended organism and lots of fiction posits intelligent ant hills, when individual ants are not. That brings me back to cockroaches: a distributed many-body creature could be intelligent with a long life and low reproductive rate, while the component bodies are quickly replaced, tiny, and specialized. But that does not physically evolve as the units are produced by the fixed organism, not descendants with variation.
We might not realize that the pests are intelligent! But a hive-being could live off our productivity and co-evolve with us, the whole time being a pest. Our continuous attempts to wipe it out would only drive its evolution toward being a better pest.
An interesting story might be the discovery of the intelligent hive, and coping with its world-view.
[Answer]
Leaving aside the sentience part, there are very few examples of **accepted parasitic relationships** in nature. The only one I can think of is how some trees deliver drugs to ants in exchange for them protecting the tree, [like acacias do](http://sci.waikato.ac.nz/bioblog/2007/10/ants-drugs-aphid-slaves.shtml). I do think that sentience could be a deal changer in one of a few ways:
* The host specie is extremely altruistic and decides to allow the parasitic specie to live off them out of a moral decision (I mean, some humans are already altruistic to the extreme, even to other species, like [Grizzly-Man who got eaten by a Grizzly](http://en.wikipedia.org/wiki/Grizzly_Man), probably because he didn't want to fight it).
* The host specie is voluntarily blind to the harm done by the parasitic specie and prefers to live less long than to live without the parasite. In this case, the parasitic specie has to provide some addictive or high value material. We could think of drugs/alcool, socially enforced aesthetics, mental/physical enhancements... All the things humans are already ready to sacrifice a bit of their life for. This could also work the other way around, where the parasite allows for a longer life for its host, but with a lower quality of life.
I believe that even in these two cases, unless the parasitic specie as a control over the host that is unknown to the host, some (and maybe a lot of) hosts would refuse the parasites.
* The host specie *needs* the parasitic specie (this could almost qualify as a symbiotic relationship, see below, except that here, the parasite still *harms* the host). You could imagine the parasite being the only solution against a very deadly disease for which no cure was found, or maybe food sources for the host specie are depleted and only the parasite is able to generate enough energy from other sources...
---
On the other hand, you could consider a **mutual symbiotic relationship** — which could still fit your narrative as *some (more or less rare) combinations of host/symbiont could lead to harm to one or the other*. Mutual symbiotic relationships can be separated into two main categories:
* [Endosymbiotic mutual relationships](http://en.wikipedia.org/wiki/List_of_symbiotic_relationships#Endosymbiotic_relationships), where the symbiont lives inside (or attached to) the host. It is often the case of bacterias/pluri-cellular host, fungi/plant, virus/pluri-cellular host. The host usually provides mobility and protection, the symbiont provides a useful function (energy production, protection from some diseases...).
* [External symbiotic mutual relationships](http://en.wikipedia.org/wiki/List_of_symbiotic_relationships#Other_symbiotic_relationships), where the host and the symbiont are separate but cannot (or won't) live without each other. Most common examples are flowers/bees, whale sharks/remoras, leafcutter ants/fungus, anemone/clown-fish... In these cases, the two species provide an array of useful functions to each other. This is the most equal relationship.
I believe that in these two cases, almost all of your host population would host a symbiont.
[Answer]
I would say that nobility and peasants had a parasitic relationship in many societies in the history of mankind. This relationship was certainly acknowledged by both sides. It also wasn't a question of military might. After all soldiers beating down a revolution were peasants themselves and a united people could have gotten rid of the nobility at any point.
The way to perpetuate this relationship, even if it is clearly harmful for one party, is religion. "We all have our place in this world … and if god put parasites into our midst, who are we to remove them?" There could be some alleged spiritual benefits from suffering the parasites. Or possibly the parasites could function as a priest caste.
[Answer]
In the Star Trek universe, the relationship between the Founders and their genetically-engineered creations the Jem Hadar has many of the qualities you describe. The Founders created the Jem Hadar race (I can't remember if they engineered an existing race or created them "from scratch") as soldiers, bred to be loyal, however like most intelligent underlings they were smart enough to wonder why they had to take orders. In answer, the Founders tweaked the engineering so the Jem Hadar are addicted to a substance, ketracel white, that can only be produced by the Founders and is controlled by the Vorta attaches (another genetically-engineered race, much physically weaker and thus much more naturally subservient to the Founders). Ketracel white withdrawal is a combination of the worst aspects of heroin withdrawal, alcohol withdrawal, dehydration and starvation, and is ultimately fatal.
Thus, the Founders more or less rely on the Jem Hadar to do their fighting for them, while the Jem Hadar have little choice but to fight and die for ketracel white. Very unbalanced on the part of the Founders; they provide very little and get a lot, so one could say the Jem Hadar are subject to a parasitic relationship with the Founders.
There was an episode of DS9 involving a Jem Hadar who inadvertently broke his addiction to the white by being stranded on a planet away from his chain of command, and convinced other warriors to come back to that planet with him to try to free themselves as well. The attempt ultimately failed, in part because Miles O'Brien saw the inherent danger of a race as powerful as the Jem Hadar being a "free agent" in the galaxy. Bashir, also part of the same episode, was trying to help them, believing that freeing the Jem Hadar would deprive the Founders of their primary and really only weapon.
[Answer]
It sounds like a predator-prey relationship. Smart wildebeests being eaten by smart lions. The wildebeests have no choice but to migrate to where the good grass is. In stone age times they got picked off by lions along the way.
Now everyone is civilised and it is done as a 'tithe'. The wildebeest can choose to swim the Masai Mara river and get eaten by crocodiles and shot at by local hunters. Or they can hand over a tenth of their children and cross safely on this lovely bridge the lions have built.
Alternatively you are into brainslug or Stargate Goa'uld territory - the parasite species needs host bodies for part of its life cycle. Perhaps to take over the body. Perhaps to incubate their eggs in a live body, like a parasitic wasp does with a caterpillar. Though to be honest in both those situations it is a whole lot less trouble to possess a monkey or incubate your eggs in a cow. Monkeys and cows don't tend to have uprisings and rebellions.
]
|
[Question]
[
Centuries ago, the world was locked in a three-way cold war scenario between three large empires with nukes. The tech level was roughly equivalent to 2000's technology in our world. Runaway climate change occurred as the three superpowers doubled down on fossil fueled development in an attempt to get an edge up on the others, various natural disasters and minor wars ended up escalating, and around 500 years ago, a large-scale nuclear war broke out, destroying all but minor remnants of the nations that fought it.
The rest of the world didn't fare much better -- the planet was ravaged by nuclear winter, agriculture could no longer support most of the remaining population, disease and conflict was rampant. Within 30 years, 95% of the population was dead, for one reason or another.
Things were tough for a while. But, as it nearly always does, life went on. Today, civilization has finally been restored to what it was before the fall. Technologically, think near future -- say (very roughly) 2050.
Okay, exposition over, here's the question.
There are basically two big landmasses on the planet. For illustration, imagine a huge continent like Africa + Eurasia together with the Americas glued alongside them, and then a smaller continent like Australia around where South America would be. So: huge diverse continent, and small, mostly desert continent, separated by huge stretches of ocean. The three empires inhabited the large continent. The small continent was mostly spared from the destruction simply by virtue of being a remote desert colony of one of the three powers that no one really cared about enough to nuke.
After the nuclear war, I want there to be almost no communication between the big and the small continent up until recently. Why might that be? Being spared from the war, the smaller continent recovered faster, so they were the first to launch a satellite after the apocalypse about 150 years ago. I want this to be a dramatic moment when people on the other side look up and see an unexpected sign of life, as well as advanced technology that they were quite far from recovering themselves. Problem is, presumably radio would have been reinvented before then, or they could simply build a ship. The desire to communicate *was* there on both sides, but it just was not possible for some reason. What reasons could there be?
[Answer]
Considering long wave radio transmission be pretty much 1910s, see Popov's experiments, and the fact that long wave radio signal can wrap Earth, it's pretty possible that if one side rediscovers radio, the other side would be technically able to receive those transmissions. Also the ability to transfer orders *fast* is what actually makes empires stand and not crumple under their own weight, thus reinventing radio communication is desired by all states, perhaps they could even coordinate research for the benefit of all sides, as this tech is pretty fundamental. The same applies to the leftover community on the other continent, so if *both* sides manage to initiate technological revolution, they are bound to eventually come into radio contact with each other.
The possibility is there that they have too differing languages to not being able to *understand* what does the other side transmit, yet locating the source of a strong radio signal is possible with a little advance past initial discovery (modified radars), thus in a matte4r of decades either side would find out that the source of transmissions they receive is off their charts, so an expedition would ensue by either side, whoever thinks that contact with the outsiders would benefit them.
Also you pretty much forget that there was an epoch of Great Geographical Discoveries, that sufficiently predates inventing radio. In case the re-emerging states would desire expansion, they will commence a task to their fleet together with local shore control, in order to find any lost artifacts in the ravaged wasteland *elsewhere*, those that would embark on an expeditions to seas unknown might hit the forgotten continent as they collect maritime data on currents, winds, islands left etc.
**To answer your title question**
You asked "Why might there be no communication between continents for centuries after a civilization collapse?" - the answer is pretty simple, it took more than centuries for the remaining population to reach medieval tech level, as people were concerned with survival primarily. Having electric artifacts left over from pre-war times doesn't help unless you've regained knowledge of electricity, yet the supply chain on any modern power plant (even solar, even water-based) would not survive the nuclear war, thus there will be only remnants of stuff that was using electricity, without means to power them. (Some machines would be reworked into being powered by horse etc, yet these deteriorate too, and most easily accessible resources would be excavated, leaving no easy access to copper/iron/coal/oil aka energy sources, thus eventually all artifacts would become dust)
**Seeing a satellite launched? Likely won't be noticeable**
There are quite a lot of satellites in orbit currently, and while those that are on LEO would descend by drag while the civs would recover from post-war apocalypse, those that are located on SSO, let alone on geosync, won't, and those on SSO are visible at night as moving star-like objects. So people would get accommodated to seeing some moving stars, perhaps would use them to measure time, provided they would differ one from another and there isn't too many of them, and seeing another moving star might well be missed, unless the satellite would go "beep beep" and trigger radio receive across the globe. Astronomers of the mainland might be able to detect a new satellite and initiate a global outrage of "HUMANITY IN SPACE ONCE AGAIN!", yet should the mainland still be in 1500s due to technilogical drop, they won't really bother.
**Also a frame challenge**
"Being spared from the war, the smaller continent recovered faster, so they were the first to launch a satellite after the apocalypse" - since the pre-war civ was at least at 2000 tech level, there have to be major levels of goods transfer, at least for the power that had that colony on the small continent. As colonies usually go, the high-level industry was moved off the colony, leaving them dependent on mainland's production, in order for them to not revolt and gain independence. There might be other methods of keeping the colony in line, but all involve inducing dependency on the mainland and transfer of goods and personnel both ways. Then the war boomed, the mainland gets bombed, the colony gets abandoned, and then nuclear winter struck, leaving people in the colony without tech support for whatever installments of high-tech (power plants, computer centers, energy grid) they had, making them too go black. And getting out of black would prove very hard, especially with reduced population and deteriorated agriculture and general nature crippling. Even spared by war actions, the colony might get extinct instead of remaining afloat and with electricity.
[Answer]
Typically, such reasons are made by people, not so much limited by technology. There is basically always a way to deliver a message if someone wants it badly enough. If communication was not blocked actively, the two continents would eventually be talking to each other in one way or another.
The major reasons why anyone would block it are: taboo and crime. They can coexist, and they can reinforce each other.
If it was crime to do anything with the enemy, and the other continent was an enemy, communication with them would be outlawed. If this practice continues long enough, even thinking about such communication can become outlawed.
Of course, there will always be people who break the laws and taboos, but that is another story.
[Answer]
Oi! Those limey bogans blew the bloody world to the dunny. We're cross as a frog in a sock at em 'cause we've had a gutful. What makes ye think we would yak with the mainland? Most of them carked or gone walkabout anyway. Who here wants a mob of crooks and nippers shipping in to get on the dole? I say rack off and Hooroo to you.
In all seriousness, a grudge could be held and become a cultural touchstone/taboo. Keep the radios quiet lest the jerks who blew up the world find out we (on the smaller continent) don't have it as bad.
[Answer]
>
> civilization has finally been restored to what it was before the fall. Technologically, think near future -- say (very roughly) 2050
>
>
>
-- in which case the ability to sustain contact between distant landmasses depends on what technologies remain available in 2050, which cannot yet be known. It's 27 years away; enough time to discover *as well as to lose* quite a few technologies. You don't even need a world-shattering calamity for this to happen; all it would take is for them to become unaffordable for long enough to cause the supporting industries to go bankrupt, and the associated supply chains to be redirected to other parts of the economy (or go bankrupt too), and then they won't be coming back due to lack of both supply and demand.
So, **perhaps the technological level of 2050 is lower than today's, and restoring only to that level is insufficient to establish contact with a distant landmass.**
[Answer]
#### Decadence
China shortly after [Zheng He](https://en.wikipedia.org/wiki/Zheng_He) expedition began to close and self isolate the country. That was pushed by the necessity to keep under control a big population while preserving a strong pyramidal hierarchy. In short a decadent society. Similar examples can be found in other decadent societies. The late Ottoman empire was not so much isolated because the push by its neighbours was too strong, but it was not so open after all. Europe began its expansion shortly before the beginning of the renaissance and that expansion boomed during the renaissance. The internal structures of a society has a strong effect on its otward looking attitude.
What happened after the war? The destruction took out the tools to rebuild the machinery, but not the memory of the past abundance. The sense of loss pushed the people to rely heavily and put all their trust on few leaders and the world society fragmented in many small groups with a strong hierarchy. This pushed the few with a free attitude to rebel and flee, forming pirate groups at the borders.
Mind you, decadence might slow down the technological development, but it won't stop it completely, especially if the old books keep alive, at least in part, the old scientific knowledge.
To resume a combination of inward looking societies further isolated by barriers of pirate lands redeveloping slowly the old technology will make a good reason for the isolation.
[Answer]
Main problem is that Your small continent is close to big one. If understand You correctly then less than 1000km water gap between. That can be sailed even by canoe. Can move Your continent more far avay? Like to point nemo? and remove all islands who are beetwen Australia and Asia? If can then have 10 000 km gap. it is a big problem for ship, even big one to sail and for planes - need big fuel tanks and big plane. It will be easier to fire satelite than go by ship or plane. Then most people on small continent think that on big one is no life at all - killed by nukes and then by radiation. Go there to empty land only to die from radiation - noone will spend a peny for that.
Another thing - distance can explain why not nuked - it is lots cheapier to make 5k km range rocket than 15k range one. And is much easier defence against rocket if have 2-3 hours to intercept than when have 15-30 minutes. Even can use orbital detonted nukes to stop them.
Then have nuclear fallout - big continent will be wiped but smal one - can even not be affected at all. Hardly, but in theory can make currents and winds that way. Ofc after years backround radiation will rise 2,3 even 10 times but not to deadly level. Next that can lead to almost no dop in population. And if that continent was mostly food suply one then have good start.
If can add no fossil fuels like oil and gas but give them carbon and You have reciepe for no combustion engines, only electric and steam ones, and no planes at all. Only trains and small electric cars in cities. If want - big steam trucks and farm equipment(if You are steampunk fan :))
Ice age can be hard on big continent due to continental climate. Will be harder and last longer. If have it then need good explanation how people even survived on big continent. And if survived then they maybe have simple telescopes when satelite was fired. Maybe not even that. Think more about medieval level there.
[Answer]
**Autonomous hunter-killer marine drones, and radically different human languages.**
Frankly, the scenario is pretty unlikely, but this might not require too much suspension of disbelief.
They don't attempt to cross the ocean because the previous war left behind large numbers of nuclear-powered marine attack drones. These were reprogrammed by some suicidal or nihilist commander in the dying days of the final war, to simply destroy anything that strayed out of sight of land. So in the past, mariners simply set out and were never seen again. Today, the technology to fight a way through once again exists, but there would be significant cost in lives as well as money to create an armoured and weapon-bearing fleet ... and what reason to go up against an unknown but deadly threat? Might it trigger some doomsday weapon to even try?
They don't communicate by radio because they have absolutely no idea what the people on the other side are saying. In an analogue in our world, the survivors in the Americas are now all speaking Navaho. A language with absolutely nothing in common with Eurasian languages, so much so that native speakers could be an effective "encryption" technique during WW2.
Also old wartime propaganda has mutated during the dark ages into religion and legend. The other side aren't human any more. They are demons, or cannibalistic mutants. Isolation, and radio silence, were seen as the best hope to avoid the fate that the large continent suffered for its sins.
The small continent may now have developed to the point that they use low-power frequency-agile microwave radio, which can't easily be distinguished from noise and which can't propagate far over the horizon. (This is omnipresent in our civilisation: mobile phones work this way!) Historically they avoided high power broadcast radio in favour of developing the "telegraph" and had something like an internet rather earlier in technological history than we did. (Maybe they also got steampunk computing: their "Babbage" worked out binary and logic using electromechanical relays).
The big continent for its part has most of the world accessible by land transport, and knowledge that "Australia" exists was simply lost in their dark ages. They have the same problem with the hunter-killer drones, and very little motivation to do anything involving the deep seas because there is still a huge amount of land at hand to explore and colonise.
Bear in mind that in our world, when the Chinese started building ocean-going ships, the perceived threat from the unknown and from other cultures was perceived as so great that a new Emperor ordered that the fleets be destroyed, and made navigating out of sight of the Chinese mainland a capital crime. So its not unbelievable that something similar has taken hold where there is far greater evidence of what may be a deadly threat.
[Answer]
Superstition? Possibly spread by those in power whose power depends on there not being contact because of some big THING they know, or fear, would happen if there were contact.
Possibly in the war there was some bioweapon that some victims had immunity to, and they were the ancestors of everyone on Other Continent now. So people on the other continent would give you a lethal disease, maybe even deliberately, the way smallpox was weaponised in early America.
The other continent people think that everyone on your land is dead, and the place is radioactive slag? So they don't want to risk coming, and dying. Or the "dead" people don't want to tip off the others that they're alive, in case they come over and start a war that "we" don't have the resources to win.
Worst case tear up some paper and chuck it in a bucket, and draw out ideas til it makes sense. Really think about what you get.
[Answer]
During the nuclear war someone launched satellites that scramble whole electromagnetic spectrum and they are still operational. No long range radio transmissions are possible.
Seas are heavily mined and too dangerous to cross.
Why noone explores with aircraft that's harder to explain.
]
|
[Question]
[
If humans die out tomorrow the two most likely candidates to achieve sapience after us are our closest genetic relatives. One of these, chimpanzee, has been discussed quite thoroughly in stories such as 'Planet of the Apes', but chimps have been done and are boring. We have another relative, just as closely related to us but rarely remembered, the Bonobo. These poor apes are fascinating with many uniquely 'human' traits not shared by any other species and some other rather unique aspects such as being arguably more peaceful and empathetic then humans and being a society run by the ladies. I feel one could make a really interesting species and culture by extrapolating what happens if bonobos reached sapience and these poor apes really deserve more love.
Of course speaking of love one can't really discuss the bonobo without discussing their unique conflict resolution strategy, commonly cited as a 'make love not war' policy. Put simply they have sex, lots of sex! It's used far beyond reproduction, as a means to mediate conflict, to build stronger social bonds, as something to trade for food or other resource, I could go on. They do it in every possible combination of sexes and positions you can think of as well, about the only thing off limits is reproductively mature adults mating with opposite sex relatives due to the risk of inbreeding. One could hardly write about sapient bonobo's without at least touching on their conflict resolution method.
Of course such a strategy is prone to spread of sexually transmitted infections (STI)s. Right now Bonobo survive mostly by having small enough numbers to make the odds of an STI evolving a bit lower and being isolated in troops enough that even if an STI shows up and ravages one troops it may not successfully spread to others.
As humans have discovered though as civilization grows so to does the risk of threatening diseases, at least until you have a good understanding of sanitation and how diseases spread. If bonobos started to move past troops to larger social organizations, and further more as trade and interaction between such groups grew, the odds of spread of STIs would likewise grow. It would be reasonable to believe Bonobo's would evolve (either physically or culturally) away from such heavy sexual activity to mitigate the risk of STI spread once this became an increasingly likely outcome of growing civilization.
Now I wouldn't be that upset if the amount of sexual contact was lowered in an evolved sapient bonobo population, in fact It would make it a bit easier to write them without the obvious complications of trying to write about such a sexually active species. However, many of the more fascinating aspects of bonobos, their heavy empathy, the female dominated social structures, how they interact with each other etc., all derives from their conflict resolution strategy. If it goes away then lots of the other interesting aspects will fade away as well and you just end up with a species that is effectively human.
So how could the bonobo evolve in such a manner that they keep at least some of their conflict resolution strategy, enough that we don't lose all the aspects of their psychology and culture that makes them unique, even as the risk of STIs grows within their civilization?
[Answer]
Your bonobos evolved sapience? Great. They manage STIs the same way humans do.
**Step 1: They use protection**
As others have pointed out, condoms are a pretty primitive invention. If your bonobos have decent intelligence, they will realize pretty quickly that STIs spread through sex and will take steps to protect themselves. In fact - you say they are a female- dominated species? Let the women insist on them. No condom, no sex.
**Step 2: Good hygiene**
They wash themselves before and after sex. Where? In the river, doesn’t matter. They have indoor plumbing? Excellent, the shower then. They also use soap. Oh, and wash their towels before and after use. I assume they have towels. Everyone knows civilized beings must have towels. Even [Douglas Adams](https://www.goodreads.com/quotes/24779-a-towel-the-hitchhiker-s-guide-to-the-galaxy-says-is) agrees.
>
> A towel, [The Hitchhiker's Guide to the Galaxy] says, is about the most massively useful thing an interstellar hitchhiker can have…
>
>
>
**Step 3: Testing**
They test for STIs. Often. There are actually government-funded STI pop-up testing sites on every street. As a matter of fact, there are even bonobo-urologists and bonobo-gynecologists, and most bonobos go for regular doctors visits every month.
**Step 4: Antibiotics**
Horror of horrors: a bonobo gets an STI. It’s a good thing they’ve discovered antibiotics. Stole the idea from that extinct human species, actually. Doxycycline, azithromycin, penicillin… you name it, we make it. Turns out those humans were good for something, after all. Ah, the disease is not curable? It’s lucky we have medications to manage the symptoms.
**Step 5: Vaccination**
You want your teenage bonobo to stay in school? Don’t want to lose your job? Intend to go into politics? Make sure you and your children are STI-vaccinated. Oops, bonobo vaccines haven’t been invented yet? Well then, there’s always the smallpox method: get them exposed while their young. Preferably to the not-chronic, completely curable type of STI. This way they will be immune to those when they grow up.
On second thought, why not make all bonobos immune? They can’t get STIs because they’ve *evolved to be resistant to them.* How convenient.
[Answer]
**Prophylaxis**
Either natural "built in" mechanisms, or artificial ones.
A naturally occurring fold of skin in a strategic location could allow interactions of some kind without transferring bodily fluids. Perhaps this is enhanced by secreting various fluids that are anti-biological in nature. Many viruses, for example, are quite effectively killed by soapy water. So it would not be all that difficult to evolve something that kept the fluids where they could be neutralized by the right "wash."
Artificial prophylaxis was known at least as long ago as the Ancient Greeks. They used sheep intestines as condoms. We know this because we have found the "cast off detritus" in garbage dumps.
**Non-touching Ritual Completion**
The two individuals appear face to face and perform various activities in each other's field of vision, but without actually touching each other. "The smallest deed is better than the greatest intention." [John Burroughs](https://www.brainyquote.com/quotes/john_burroughs_120946)
This ritual could be completed in the presence of official witnessing personnel from each tribe or kingdom. This could cement the peace treaty.
**Third-party Ritual Completion**
[Round up the usual suspects.](https://medium.com/@h27kim/round-up-the-usual-suspects-ad123d348b62#:%7E:text=To%20me%2C%20%E2%80%9CMajor%20Strasser%20has%20been%20shot!,line%20from%20the%20film%20Casablanca.) The king wants to cement a treaty with a neighboring kingdom. The ritual is completed by designated performers from each kingdom who ritualistically perform the designated act. They do this in full view of the embassy staff from each kingdom, in order that it be clear that the ritual is complete. Should children result, they might obtain a particularly high status in each country, representing as they do the physical manifestation of the peace between the kingdoms. It might be a fragile status that would suffer drastically if the two kingdoms went to war despite the treaty.
This is not all that different to marrying a prince from one kingdom to a princess from the other.
[Answer]
## Ruthless punishment of STI carriers
Gonorrhea is as welcome to a bonobo civilisation as a sewage leak in a restaurant.
Anyone with a serious STI is summarily executed, with a brief interrogation to facilitate contact tracing. Having an STI is a strict liability offence.
Very, very minor STIs are dealt with in a non capital but incredibly draconian quarantine/banishment scheme.
That sounds harsh, but if sex is at the heart of an economy as well as all social institutions, politics, and even international diplomacy, it'll be seen as justified.
Enforcement is fairly easy; as you need to flash your genitals just to buy your groceries, so to speak, it will be impossible to hide an STI for very long, and sudden abstinence will be very suspicious.
[Answer]
**Bonoboism IS an STI**
Bonobos are not a species of their own. They are humans that have been infected with the Bonobo virus. In late stage the body becomes small, the back legs shorten, and vocal cords wither. They also get furry.
This is why Bonobos ride everything in site. It helps spread the virus.
The one advantage of the Bonobo virus is it does not let other STIs take hold.
[Answer]
## STDs are part of what makes Bonobos different than Humans.
Bonobos have very few STDs compared to humans. In fact, they appear to be immune to all of the strains of Bacterial STDs that afflict humans like Gonorhoea, Syphilis, Chancroid and Chlamydia, and have no known bacterial STDs of thier own. What viral STDs they do carry are generally not fatal or debilitating. In short, they are able to use sex the way they do BECAUSE their species has so few STDs to worry about. They would have never evolved these sexual practices if it were as dangerous as it is for humans.
Just because Bonobos begin to form larger societies does not mean that brand new, highly deadly STDs will automatically evolve. As thier populations increase, the real danger will be from the diseases that they already have to worry about spreading out of control like Ebola, Monkeypox, and Trypanosomiasis. None of these are STDs specifically; so, any fear of plagues they suffer from would not automatically make them avoid sex as a specific countermeasure.
So sure, they'd probably have thier own equivalents of things like HPV or Herpes... but so what? For most Bonobos, these STDs will have little to no symptoms and will be so common that any symptoms they do carry will just be considered a normal part of life for those who have them.
[Answer]
We have airborne diseases. Never did we stop talking, and only recently did we start protecting ourselves (masking up)
Their STIs have evolved very differently from ours. They spread about as quickly as airborne diseases do for us, and have thus evolved in a pretty similar fashion. Long incubation periods and very harsh symptoms were not favored (because worse for transmission).
Some of them come back every year (like the flu does for humans). Every few hundred years, there is a really bad pandemic, a significant chunk of the population dies, the rest evolves to resist it.
[Answer]
1. No ancient condoms is not the answer Condoms are primitive but comfortable condoms are not. There is a reason the condoms where rarely used before the invention of rubber.
2. Leper colonies for the infected. STDs are treated the same way they treat lepers back in the day. isolation of the individual and any they could have infected, marks on the clothing or even face as a warning to all who might approach.
3. Natural immunity. If every time civilization develops its destroyed by STDs, then eventually given enough time the only badoons left to reproduce will be those that have mutated a natural immunity to STDs.
While you still have to explain why they never switched to a alternative conflict resolution method before this, this could be a way for you to explain away STDs in your world.
]
|
[Question]
[
I was bouncing ideas off the wall about empires that could've plausibly existed in Asia if certain things went differently, and I stumbled across the very physical barrier of the Himalayas.
So my question is this: how great a physical obstacle is the Himalayas, exactly? Is it totally impossible for a political entity in say, Tibet, to rise and unite both East and South Asia in a single Empire? I'm aware that this is possible to a certain degree: the Tibetan Empire that emerged in the 7th century managed this to a certain extent. It was a big thorn in the Tang Dynasty's side, and some maps show its suzerainty over territories as far south as Bengal in the Indian subcontinent. However, that was as far as it got, while what I'm envisioning is more like Qing China and Mughal India combined, territorially speaking. Is that totally implausible due to the Himalayas?
(Later edit: removed a more speculative part of the question)
[Answer]
I think the main problem you've set yourself here is having *any* empire control all the territory of east and south Asia, regardless of where its core territory is situated. While China and India may look like territorially stable countries today, historically these regions were constantly splintering apart, then being united under a new strong government, then splitting apart again, over and over and over.
One possibility to get to something close to what you're after is to imagine Genghis Khan was born, (and the conditions that made him were present) in Tibet instead of Mongolia. This would be a flash-in-the-pan kind of empire, one built very quickly from the martial prowess of a single talented leader, taking advantage of weak and decaying governments to the south and east. But empires that rise quickly tend to fall quickly, and once your Tibetan Khan dies, there's every chance the lands they conquered will quickly reassert their independence. At best, this Himalayan Empire will leave successor states behind, but even these will quickly "go native" - case in point, compare the Mughal Empire in India and the Yuan Dynasty in China, both direct descendants of the Mongol hordes, but not particularly very similar to one another in any other ways.
[Answer]
**Yes, Mountain Empires are Possible**
While mountain ranges, especially very expansive and high altitude ranges such as the Himalayas are considerable barriers for human movement and settlement history shows that they are not an insurmountable barrier.
As mentioned in your question, the Tibetan Empire was a Himalayan Empire that had considerable geopolitical power at its height, and was mostly constrained by its more powerful eastern neighbor than any failing of geography. Pastoral nomadism is a very adaptable life way for empire building, as demonstrated repeatedly by the steppe tribes of Central Asia. Pastoral nomadism negates many of the problems with running a montane empire, and would be conducive to force projection over a large area. The biggest problem for such an empire is projecting into terrains where the nomads cannot function (see the Yuan Dynasty’s failed invasions of Vietnam and Java for two South East Asian examples)
Another Mountain Empire to consider is the Inkan Empire. The Inka controlled an empire stretching for over two thousand miles of the Andes mountains, and also extended into parts of the Amazon basin and the Atacama desert. The Inka domesticated crops that were highly tolerant of the severe climate, such as the potato.
[Answer]
Most of the successful nations and empires in history were founded on lowland river deltas. What are the reasons for this?
The primary answer aside from the obviously challenging matter of large scale food production, sanitation, and resultant ease of population growth, is that economies and militaries rely on ease of transport and access.
Mountains are notoriously difficult to mould to human needs. A group might take many years to carve a single, narrow mountain pass to allow treacherous passage in single-file. To carve that wide enough to allow an army to pass safely - never mind all the mishaps that can happen during construction due to natural seams and fault-lines in the stone - requires modern technology. Never mind robust bridges across steep gorges etc. None of this was easily possible until the 19th c.
There is a reason that it is difficult for most of us to think of many mountain empires in history: there really weren't any (that lasted long in the face of competition from more conveniently placed kingdoms and empires).
Mountains are easy to defend from, it's true. But lacking a large population and the ability to make them mobile in short order, kind of limits your options in terms of taking over the rest of the world. This could be mitigated by moving your capital out of the mountains into a captured lowland city, but then... well... you're no longer primarily based in a mountainous region, are you? Remember that administration in former centuries relied very much on physical proximity, so again, having a mountain capital severely limits such administration.
It is conceivable in a fantasy world, that dwarves or trolls with great strength, great stoneworking skill, magical picks and countless existing tunnels (such as the network built by the Viet Cong, but in stone) might be able to forge an empire with its administrative centre in a mountain range.
]
|
[Question]
[
In Dracoriri, I plan to have a species of small dragon called a Malidge (by small, we mean about the size of a human). These dragons are red, shiny, and covered in plates instead of scales, a natural armor fitted so well together that it is virtually impenetrable, much like on a Mesmerake.
They are also solitary creatures, bipedal too, standing on reptilian talons but possessing a pair of clawed fingers at the ends of their forelimbs, which are used to cut up and collect vegetation for food. In fact, their entire body is like this, with a vaguely humanoid torso, reptilian limbs and tail, and a neck and head that is very clearly that of an insect's.
Typically, this spadelike head is held pointed down, the three horns protruding from the back of its head standing up, possibly for sensory reasons-these horns are tough but flexible and have been observed moving when a Malidge is agitated, curious, looking for something....you get the idea, and holding the head down would allow it to see the ground....
**TL;DR: To a casual observer, Malidge may appear to be dangerous predators. They are in fact rather aggressive toward humans, almost unnaturally so, and they possess sharp fangs and claws, but they are herbivorous, eating wood and vegetation. Why would a herbivore be armed and aggressive?**
**The Best Answer Will:**
* Take into account a Malidge's traits and use them to glean information on what they would act like, as while I like biology, I am no expert and would like to fine-tune my creatures to make them at least somewhat realistic. Basically, I'm asking you to use what I have and what you know and be creative in answering this.
* Focus on the point of the question; there is a lot of weird things going on with Malidge, like the wood-eating and the mixed biology, but the focus here is on the fact that this is a herbivore with the aggressive behavior (yes, I know herbivores can be aggressive too, but only a hippo is aggressive like a Malidge, or in other words, acting like a predator) and weaponry of a predatory animal. I would like a biological explanation for this behavior.
* If possible, I would love it if the answer could include why Malidge are so aggressive toward humans and basically just humans-others they just remove or scare off, but humans they outright attack on sight. But, this is not necessary.
**Finally, let me know if there are problems, I appreciate feedback and new perspectives!**
[Answer]
Your description of a biped with claws for tearing vegetation makes me think of another creature that isn't a herbivore but is just a disinterested in attacking large animals as a typical herbivore: the giant anteater.
[](https://i.stack.imgur.com/oqR1o.jpg)
Their claws are designed to rip through termite mounds, which are comparable to concreate in terms of hardness, and are known for winning fights against jaguars with their powerful swipes. Basically every animal gives them a wide berth because, just like your malidge, they can kill anything that disturbs them without discrimination.
This indiscrimination is because they have terrible vision. If they sense any large moving object they might take a swing at it just because it *might* be a predator. Black African Rhinos also have awful vision and will likewise will charge at any moving object just to be on the safe side.
In summery, the malidge could be an armored herbivore that tears into specific trees to get at nutritious wood inside (as apposed to the nutritionally poor bark). To avoid driving their food source to extinction they have huge territories they roam so that more trees can grow while they are away. However, their faulty eyes, small to avoid splinters and insect bites, means that they can't tell creatures apart and so attack indiscriminately. This roaming behavior combined with their aggression makes them seem like they are hunting.
The three pronged sensory apparatus could be chemosensory organs, aka noses, that are positioned on the back of the head to keep them away from the trees while they are eating. They move to better triangulate smells and are how the malidge find ripe trees to eat. This might also be a weakspot for them and why they can attack so aggressively even though their armored. With out their smelling horns they would starve, doesn't matter how tough they are.
As for why they go for humans specifically . . . I'm not too sure. My gut says that humans are more pungent that other animals and therefore more noticeable to malidges. Or maybe malidges mark their territories with scents that humans can't smell and therefor tend to trespass where other creatures know to avoid. Or maybe our sweat and natural odor is similar to the trees malidges eat so they wander to human campsites and villages by mistake. Or maybe those same trees are used by local humans as building or crafting materials and Fred's knife handle is inadvertently enticing malidges as he sleeps.
[Answer]
Q: *"I would like a biological explanation for this behavior"*
**Territory**
Armed agression takes place among many herbivores and herbivores can act hostile to intruders, when territorial bounds are not respected. Gorillas are known for it, American Bison as well. Herbivores that want to keep their territory will attack animals that tend to steal territory. Humans especially. Some intelligence will help to let your creature know that.. and act accordingly.
**Mating competition**
In a herd, there is hierarchy, when it comes to procreation. Some males have the privilege, others have not. The hierarchy is determined by fights. That's why evolution provided them with arms in the first place.
[](https://i.stack.imgur.com/n3Bsc.png)
[Answer]
>
> Why would a herbivore be armed and aggressive?
>
>
>
Have you ever seen an [hippopotamus](https://en.wikipedia.org/wiki/Hippopotamus) with full open jaws?
[](https://i.stack.imgur.com/AhPbP.jpg)
There is plenty of footage of these herbivores, well known for being extremely aggressive, mauling crocodiles who didn't properly evaluate the risk when messing up with them.
Did I also mention the elephants, rhinoceros, the now extinct aurochs? All of them again pretty known for being aggressive and well armed with various body protuberances.
Be armed and aggressive is a way of putting in action the old saying "attacking is the best defense".
[Answer]
**They mistake humans for other malidges.**
The overall body shape is right and some of the movement, auditory and olfactory clues given off by humans match those of the malidge. Occasionally the reverse is true and at a distance or with limited visibilty a human can mistake a malidge for another human. Humans figure it out quick once up close. Malidges not so much.
The malidges are fiercely territorial. Another malidge that shows up outside of mating season will be chased off. A malidge will generally avoid its own kind unless it is spoiling for a fight and so when one shows up that is presumed to be what is going to happen. WHen a human shows up that is exactly what happens.
Inside of mating season is a different story. Humans misidentified as malidges during this period may receive a different reception.
[Answer]
Maybe in the past or even present, their main predator / competitor was human shaped (or, drawing from another comment, scented)? Thus, like the hippo that is aggressive towards crocodiles, the Malidge attacks humans.
The claws themselves could be purely for defence or for cutting up some secondary food source.
]
|
[Question]
[
If we consider a planet with the same characteristics as the earth, (diameter, mass, rotation period) what would be the maximum possible diameter of a moon on a geosynchronous orbit? Considering the Roche limit and other considerations of which I have no clue. This moon would be made of the same materials as our moon.
Context:
The fact is that a lot of things are due to chance, for example, in our reality, seen from the earth, the apparent size of the sun and the moon are similar, and this is absolutely due to chance.
In the same idea, an alternative earth could very well have a geosynchronous moon orbiting at 36'000km, whose apparent diameter would be (or not, hence the question of the upper size limit) the same as our moon.
If the configuration is stable and life appears despite the absence of tides, a sedentary civilization\* could be born, evolve, and even reach great astronomical knowledge, without even knowing that the second most luminous celestial body after the sun, is simply not visible, unless you sail far enough to find it.
In a way, the moon could, by pure chance, be discovered after the other planets of the solar system.
Here is the idea behind the question.
\*A civilization that does not feel the need to leave its island or continent.
[Answer]
Simple answer within the parameters you have specified.
The Earth's rotation is not changed from its current rate. It must remain 24-hour(~ish).
The moon must be geosynchronous.
The moon must be a moon not a ring.
The solution depends slightly on your definition of just what a "Moon" is.
**Definition 1:** The fluffy definition of "Moon" defined as an object orbiting around another, larger object. Preferably a planet.
It must be a *moon*. I.e. smaller than Earth.
**Solution: put a second Earth at exactly 53219km distance** (center-to-center).
To ensure the moon is smaller than Earth, remove one atom from it.
Sanity check: Yes, both planets are outside each other's mutual Roche limit.
**Definition 2:** The stricter definition of "Moon" which precludes a binary planet like above, requires that the Barycenter of the system be within the body of the larger object.
In this case, it would occur when the Barycenter is *at* the surface of Earth.
Earth r = 6371km
**Solution2:
Moon orbit R = 44484km
Moon mass = 0.168 Earth**
Sanity check: Yes, the Moon is well outside the Roche limit for Earth.
This places the barycenter right at the surface (ok, about 650m above sealevel), the Moon will have an orbital period of exactly 1 day.
**Appearance:**
Your big geocentric moon will be 8373 km in diameter (taken as direct scale-up of our current Moon, no regard for increased density due to higher self-gravity, sorry)
From the closest point on Earth below it, it will show as a circle some 9.55 degrees wide. 19.1 Times wider than our moon, 366 times the surface area.
It will 100% guaranteed undergo a very entertaining lunar eclipse every single night, and the Earth under it will undergo a matching solar eclipse every single day, at least in the equatorial regions.
[Answer]
As stated by others, your orbit does in fact depend on the mass of the moon as well, since it is not negligible with respect to Earth. As Starfish Prime said in his answer, the Roche limit for a rigid body ends up at about 9500 km assuming Earth and Moon properties. I wanted to go a little bit further and calculate the orbital separation for such a body in an orbit with Earth.
We can calculate this from Kepler's third law, and inserting the now known variables:
%20*%20%5Cfrac%7B(%5Ctext%7Bsidereal%20day%7D)%5E2%7D%7B4%5Cpi%5E2%7D%5Cright)%5E%7B%5Cfrac%7B1%7D%7B3%7D%7D)
Where the sidereal day is 23h56m04s, G is Newton's gravitational constant and we use the mass of the Earth and the Moon's density as given. I plotted this with some of the involved quantities indicated, see figure below. The value at R equal to the Roche limit is about 9.55 Earth radii, or 60800 km.
[Edit] However, if you want the moon to stay a moon in the sense that the centre of mass of the orbit (barycentre) is still within the Earth (answer by PcMan), we get a lower limit. I included the measurement of the barycentre from the centre of Earth and from the intersection with 1 (R\_earth) I find a maximum radius and orbital separation at that radius of:
R\_moon\_max = 0.65 R\_Earth = 4150 km
a\_moon = 6.97 R\_Earth = 44400 km
[](https://i.stack.imgur.com/yuDAX.png)
[Answer]
Orbital period doesn't depend on the mass of the orbiting object. The orbital velocity dictates the height of the orbit and its period.
The only limit is that the mass of the object has to be smaller than the one of the main body, so that one orbits the other and not vice versa.
To answer your question, the upper limit for the mass of something in a geosynchronous orbit is the mass of Earth.
]
|
[Question]
[
Humans are terraforming what they believed to be a barren planet when they encounter a new species of bacteria. This species is exobacteria (bacteria of extraterrestrial origin), but the human scientists can't immediately tell. The species should be sufficiently biologically similar to be able to pass for terrestrial under a microscope and to biologically interact with the terrestrial ecosystem the humans are building. The exobacteria have some surface proteins that are new but identifiable as proteins. The exobacteria are nitrogen-fixing bacteria able to fill a role in the terrestrial nitrogen cycle (or at least fill this well enough to cause trouble).
But the exobacteria DNA can't be sequenced using future-standard DNA sequencing technology because they don't actually have DNA! What do the exobacteria have instead DNA that sill allows them to synthesize proteins?
As an alternative formation of the question, which if the following is most plausible?
* The exobacteria has a pseudo-DNA with isomers for all four base pairs (A, T, C, and G), such as uracil instead of thymine. I'd find it acceptable that the a future DNA sequencer is sufficiently specialized at reading terrestrial DNA that it ignores isomers.
* The exobacteria assembles the standard amino acids into chains using some mechanism other than DNA (or at least not strictly isomorphic to terrestrial DNA).
* The exobacteria assembles proteins using something other than terrestrial amino acids.
[Answer]
[Xenonucleic acids](https://en.wikipedia.org/wiki/Xeno_nucleic_acid)
[](https://i.stack.imgur.com/XiRtE.jpg)
Xenonucleic acids are artificial structures that can substitute for the natural nucleic acids.
>
> The molecules that piece together to form the six xeno nucleic acids
> are almost identical to those of DNA and RNA, with one exception: in
> XNA nucleotides, the deoxyribose and ribose sugar groups of DNA and
> RNA have been replaced with other chemical structures. These
> substitutions make XNAs functionally and structurally analogous to DNA
> and RNA despite being unnatural and artificial... While DNA is
> incredibly efficient in its ability to store genetic information and
> lend complex biological diversity, its four-letter genetic alphabet is
> relatively limited. Using a genetic code of six XNAs rather than the
> four naturally occurring DNA nucleotide bases yields endless
> opportunities for genetic modification and expansion of chemical
> functionality.[9]
>
>
>
Your alien bacteria uses DNA for its genome but sequencing attempts fail because the tech hangs up on the xenonucleotides. I envision your alien organism as fundamentally similar to earth life - maybe because of some sort of [panspermia](https://en.wikipedia.org/wiki/Panspermia) event. Maybe it is life descended from the RNA world. Maybe its unusual nucleotides are borrowed from the [modified nucleotides of transfer RNA](https://www.mun.ca/biology/scarr/tRNA_unusual_bases.html).
Or maybe it is an engineered creature and the xenonucleotides are synthetic. Your people find it first because it is the most common engineered creature. There are others.
[Answer]
## XNAs (done)
Willk's answer is a good one, though for some reason he left out [PNA](https://en.wikipedia.org/wiki/Peptide_nucleic_acid), the very first of the alternate backbones.
## Alternate nucleotides
There are other nitrogenous bases that appear in our biochemistry as nucleotides (notably flavin and nicotinic acid/nicotinamide)- I have a [question](https://biology.stackexchange.com/questions/98544/were-nicotinic-acid-amide-or-flavin-nucleotides-ever-part-of-primary-rna-sequenc) up on biology.SE about them.
## Panspermia
Recent work showed that the [zodiacal light](https://phys.org/news/2021-03-serendipitous-juno-shatter-ideas-zodiacal.html) is dust from Mars that stretches all the way to Earth, in such quantity that the Juno probe detected it serendipitously and people can see it with the naked eye! Also note the prevalence of interstellar objects, which may actually be the majority of objects in the region of the Oort cloud, including interstellar comets and asteroids. (See [Paul Gilster's recent article at Centauri Dreams](https://www.centauri-dreams.org/2021/03/23/thoughts-on-acceleration-nitrogen-ice-the-local-standard-of-rest/)
## Convergence
The most impossible idea is the one that instinctively appeals to me. What if life, originating somewhere else, simply follows a very similar path? That may seem implausible, but let's go with the model that the formose reaction on a hydroxyapatite substrate creates phosphate-bound sugars, including actual ribose. ([ref](https://pubs.rsc.org/en/content/articlelanding/2017/OB/C7OB02051A#!divAbstract)) Basically, formaldehyde from a geologic source reacts on an inorganic calcium phosphate mineral, perhaps doped with a few interesting metal ions. This has the potential to form a phosphoribose or related sugar backbone, with which amines could react at the aldehyde position. That reaction has a three-carbon intermediate, and phospholipids adhere to hydroxyapatite to this day, causing struvites and clogged arteries. Last but not least, the calcium might chelate dicarboxylic acids, as are seen at alternate ends of the Krebs cycle (oxobutanedioic acid and 2-oxopentanedioic acid). Add NH3 to make glutamate and aspartate, then glutamine and asparagine - that's four amino acids right there. A huge part of our biochemistry might have been established right on the rock, with a patch of hydrophobic products on the way to becoming phospholipids to act as a chemical "filter feeding mechanism". It is conceivable the same could have happened elsewhere in the universe, leading to life forms compatible enough that, with vigorous defenses against toxic compounds, they might be able to view us as prey.
]
|
[Question]
[
I'm designing an alien race with limited points of articulation, and it got me thinking what is the minimum number of phonemes needed for a language to function? That would help me determine their physiology?
I've seen [Is a Language with Two Phonemes Feasible?](https://worldbuilding.stackexchange.com/questions/156565/is-a-language-with-two-phonemes-feasible) but that seems too limited, and the idea of speaking in binary doesn't mesh with my idea of this alien race.
[Answer]
Depending on how you count phonemes, the *"minimum number of phonemes needed for a language to function"* is obviously either one or two.
In real-life linguistic descriptions, [Polynesian languages](https://en.wikipedia.org/wiki/Polynesian_languages) feature small phonemic inventories; for example, [Tahitian](https://en.wikipedia.org/wiki/Tahitian_language) makes do with five vowels and nine consonants (/a/, /e/, /i/, /o/, /u/, /p/, /t/, /m/, /n/, /f/, /v/, /ʔ/, /h/, and /r/) and [Hawaiian](https://en.wikipedia.org/wiki/Hawaiian_language) makes do with the same five vowels and only eight consonants (by having no use for /f/). The Hawaiian alphabet has only 13 letters: a, e, i, o, u, h, k, l, m, n, p, w, and ʻ (which is called *ʻokina* and is used to write the glottal stop /ʔ/). (And yes, that is the alphabetical order.) (Depending on who's counting, that can be *ten* vowels, because each of them can be short and long.)
Attentive readers have noticed that in the preceding paragraph I spoke about the number of phonemes in *linguistic descriptions*, and not in *languages*. Languages do not have phonemes; phonemes are elements of the *models* we make of languages. In the physical reality, all we have is (allo-)[*phones*](https://en.wikipedia.org/wiki/Phone_(phonetics)): phones are the physical realities, phonemes are the abstract models. To a large extent, the number of phonemes depends on the principles behind a specific language model.
To give an extreme example, how many vowels does [Mandarin Chinese](https://en.wikipedia.org/wiki/Standard_Chinese_phonology) have? Well, that depends on who is counting. The minimum number I have seen is zero ([Edwin Pulleyblank](https://en.wikipedia.org/wiki/Edwin_G._Pulleyblank)'s model). The maximum is 25 (counting /a/, /ə/, /i/, /u/, /y/, each with one of the four tones or with the "zero" tone). Or, for a maybe better known example, how many vowels are there in classical Latin? Is it five, each having a long and a short version, or is it ten, or is it eleven? How many vowels are there in [BBC English](https://en.wikipedia.org/wiki/English_phonology)? The usual description (for the use of us foreigners who learn English) gives 19 (nineteen!) vowels and diphthongs, *plus* 4 quasi-diphthongs.
So for the purpose of creating a mock-up of an alien language, I would say that you cannot go wrong with three vowels (a central vowel /a/, a front unrounded vowel /e/, and a back rounded vowel /o/), two glides (/j/ and /w/) and a small set of consonants. Which consonants, that depends on the set of articulation points you accept; on whether you accept distinctions of voicing (as between /p/ and /b/ or between /k/ and /g/) or not; on whether you accept nasals or not; and so on.
[Answer]
## In theory, any number from 1 to infinite phonemes would work for a language.
Here is a run down of the lowest numbers, and how they would work
### Unary Language
Assuming you can pause between words (in a way that doesn't encode it's own data), unary works, although it likely very highly impractical:
>
> The unary numeral system is the simplest numeral system to represent natural numbers:[1](https://en.wikipedia.org/wiki/Phonotactics) to represent a number N, a symbol representing 1 is repeated N times.[2](https://www.wolframalpha.com/input/?i=solve+%28x%21%29%2F%28%28x+-+3%29%21%29+%3E+y)
>
>
> In the unary system, the number 0 (zero) is represented by the empty string, that is, the absence of a symbol. Numbers 1, 2, 3, 4, 5, 6, ... are represented in unary as 1, 11, 111, 1111, 11111, 111111, ...
>
>
>
-[Wikipedia](https://en.wikipedia.org/wiki/Unary_numeral_system)
So in this language, 1 sound would reflect the first word, 11 the second word etc. The complication come when combining words in a sentence to reflect more complex concepts:
The sentence related to "1 11 111 1 111 1", could encode enough complication if, for example "1 11" and "1 111" encode more information than their parts alone.
Without pauses
### Binary & Ternary
As the [Q&A you found](https://worldbuilding.stackexchange.com/questions/156565/is-a-language-with-two-phonemes-feasible), it goes over in good detail how binary works, as well touching on ternary.
>
> you can even compress those words by frequency of usage simply by adopting the same trick that saved Unicode
>
>
>
As you can see there's a similar conception of encoding more than the sum of it's parts.
On ternary:
>
> Tri-state let's you scrap the UTF-8 "extension bits", or gives you another symbol to play with (log(26)/log(3) now). Speed or compression gains either way.
>
>
>
This is the most 'efficient' number of phonemes, if we make an analogy in terms of [radix economy](https://en.wikipedia.org/wiki/Radix_economy#Radix_economy_of_different_bases), however as we see below there are other considerations. This is not a perfect analogy.
## More than 4 phonemes
With more than 4 phonemes, we can start to consider smaller words and even how combinations of sounds work together. One could safely assume, the most common words are also the shortest
For instance if you consider any combination of the 4 phonemes in a 3 phoneme word (assuming [simple Onset, Nucleus and Coda](https://en.wikipedia.org/wiki/Phonotactics)), you get
$$ \frac{4!}{(4-3!)} = 24, \text{words} $$
Is this enough for a language? Yes, in theory. Bear in mind that this assumes that, say `a, s, d and f` represent our phonemes, that `fff` is a valid word, which may not actually be distinguishable from `ff` (note, two phoneme words aren't part of our calculation, but may and most likely will still exist in the language!).
How many words are required in a language to convey basic concepts? If it's more than 24, we will need more phonemes. Thankfully we have the [Swadesh List](https://en.wikipedia.org/wiki/Swadesh_list) for this very purpose, which claims that there are for example 100/207/35 words needed to convey basic concepts.
Given these restrictions, we can use [wolframalpha](https://www.wolframalpha.com/input/?i=solve+%28x%21%29%2F%28%28x+-+3%29%21%29+%3E+y) to tell us the minimum phonemes to make enough 3-phoneme words to convey these concepts:
$$ \frac{x!}{(x-3!)} > 100, \text{x = 5.7 or ~6 phonemes}, $$
$$ \frac{x!}{(x-3!)} > 207, \text{x = 6.9 or ~7 phonemes}, $$
$$ \frac{x!}{(x-3!)} > 35, \text{x = 4.3 or ~5 phonemes}, $$
This gives a ballpark region for the minimum number, given the above constraints. Given that words longer and shorter than 3 phonemes can and do exist in languages, this is not an absolute limit. So you may have only 5 phonemes, which gives 60 3-phoneme words, and then 40 words with 1,2,4 or more phonemes. Or more minimally with 4 phonemes, 24 3-phoneme words, and at least 11 with 1,2,4 or more phonemes.
$$ \frac{4!}{(4 - 3)!} + \frac{4!}{(4 - 2)!} + \frac{4!}{(4 - 1)!} = 24 + 12 + 4 = 40 \text{words} $$
As you can see, including the shorter words means we can round down instead of up with 4 phonemes to get the smallest list (35). Doing the same with 5 phonemes puts us [15 words short](https://www.wolframalpha.com/input/?i=%20%285%21%29%2F%28%285%20-%203%29%21%29%20%2B%20%285%21%29%2F%28%285%20-%202%29%21%29%2B%20%285%21%29%2F%28%285%20-%201%29%21%29) of 100, but including 4-phoneme words puts us [3 words short](https://www.wolframalpha.com/input/?i=%20%285%21%29%2F%28%285%20-%204%29%21%29%20%2B%20%285%21%29%2F%28%285%20-%203%29%21%29%20%2B%20%285%21%29%2F%28%285%20-%202%29%21%29%2B%20%285%21%29%2F%28%285%20-%201%29%21%29) of the **longer** list. If we're assuming far fewer combinations are valid words, even longer phoneme combinations are needed.
### Conclusion
Any number of phonemes works, but depending on if you pick 1,2, 3 of more changes how you construct the language itself.
[Answer]
**Tones and inflection**
Theoretically you need *one*.
A letter can have multiple meanings by just Inflection. It exists in many languages. A different inflection of the same phoneme can distinguish a word from another. With a language that is limited in phonemes it's likely they'll express the differences in other ways, of which inflection is one of the first that comes to mind. Yet you can even potentially just have them wistle.
You might think it's impossible or too difficult, but an alien race grown up with it can distinguish the differences of tones at a much deeper level. It is the difference between a tone deaf person or a highly skilled musician, only instead of learning they have thousands if not millions/billions of generations of evolution. They could distinguish such minute details in the tones that would seem impossible without electronics. This can mean that a single phoneme can in theory convey more information than all phonemes in the human languages.
Even if you require a human like language you can put inflection or tones into it. Depending if you want a human like language or completely alien the answer is two or one respectively.
]
|
[Question]
[
What kind of footwear would be worn by a race of anthropomorphic cats in a fantasy setting? They live as a roughly medieval society in a temperate climate, and their feet have the same shape as cat paws.
[Answer]
Cats are digitigrade, they'd be better off without shoes.
# Crocs
Claws are important to cats, the holes in crocs would allow them to use their claws even while wearing shoes.
# Moccasins
Cats are quiet walkers, moccasins would allow them to keep moving silently. Claw holes can be allowed for.
# Clogs or other hard shoes (wood, leather or otherwise)
These are civilised cats, they make a point of being nosy as they walk to distinguish themselves from their wilder cousins who need to stalk their prey silently. Moving noisily is a symbol of status. Claws are not allowed for as again they're a sign of wilder times.
[Answer]
Sandals. Cats back legs claws don't rectract and hide like the front ones. So the footwear would need to allow them moving out when running or climbing. Also having 4 claws in the "foot" would allow to wear Ninja like footwear with a thong in the middle.
[Answer]
### Will they wear shoes at all?
Wild cats don't wear shoes. Not all *humans* wear shoes. Poorer individuals, and ones living in the country (where they aren't walking on rocks and possibly sharp bits of discarded metal or glass) probably won't wear shoes at all, if indeed *anyone* does. Shoes will make it harder for your felinoids to use their claws. (OTOH, you can play that up as a social status thing, per [Separatrix' answer](https://worldbuilding.stackexchange.com/a/165252/43697).)
So... why *might* they were shoes? Aside from pure ostentation, shoes are useful for protecting paws (which are *not* as tender as you think if they aren't pampered) if your environment is unnaturally hazardous, which might be the case in cities, especially as industry starts to develop. It might also be occupation specific, e.g. I could see the blacksmith wearing boots (at least while working) even if no one else does. Shoes can also help keep water, or worse, off your paws. Part of the reason humans wear shoes is for "hygienic" purposes (although I wonder about this, at least in cultures that don't tend to take their shoes off indoors), although if your cats are still obligate carnivores, this is probably less of an issue for them.
In your setting, I would consider not just *what* shoes are worn, but *when* and *by whom*, because you will most likely have a mix of shod and unshod cat people.
### Okay... so what kind of shoes?
We make shoes for dogs in a wide variety of styles, from [very simple](https://rads.stackoverflow.com/amzn/click/com/B00GHTGTR6) to [ones that are just as complex as human shoes](https://rads.stackoverflow.com/amzn/click/com/B07WNPQVQP). (Cat shoes aren't as popular, but probably because a) it would be hard because of cats' smaller size, and b) indoor cats don't need shoes, and outdoor cats don't tend to get the same sort of completely unnecessary attention as dogs. Keep in mind that dog shoes are as much *or more* for the owners' benefit as for the dog's.)
There's no reason to think that a race of felinoids wouldn't be equally capable. Of course, you specified "a roughly medieval society", so leather moccasins and wooden clogs/sandals are more likely. Deliberately limiting use of their claws as a status symbol seems entirely plausible; this would be seen in more "gentrified" people, while those "closer to the land" (farmers, ranchers, hunters, trappers, etc.) will want to be able to use their claws.
p.s. Yes, you'll have farmers. They grow the stuff that food eats üòâ.
[Answer]
**Depends on the season**
In mild or warm weather, cat people would were shoes that expose their claws, or wear no shoes at all (although the latter may be viewed with disdain). Other answers had suggested a number of options for that, like sandals.
In cold weather, or when the roads are particularly dirty, shoes with openings are becoming a trap for water and dirt, making them very impractical. If dirt is the only issue, very open sandals might do, but as the temperature goes below freezing, closed shoes is the only option for a "civilized" individual. Cat people would have to sacrifice their ability to use claws and wear human-like boots with no openings at the bottom.
[Answer]
Instead of using their own claws, as the other Answers suggest, I would think they would want to protect their claws and project a more pronounced claw.
# City dwellers
If these cats are anything like humans, they will have some sort of inferiority complex, which of course extends to every part of them, including their claws. They would wear large faux claws on their shoes to hide their "inferior" claws, just like when a guy crotch stuffs or a woman wears a padded/lifting bra.
Because the claws wouldn't get wore down normally, they would require regular pedicures, which would also go to enhance their claws. This includes male cats, too. They'd have them filed down to sharp points, painted wild colors, and even have fake ~~nail~~ claw extensions.
>
> Want substantial claws, go for the eagle talon. Or for those who want real class, our silver, gold, or platinum line claws are an absolute must!
>
>
>
FYI, gold, silver, and even platinum were used well before medieval times.
<https://www.providentmetals.com/knowledge-center/collectible-coins/platinum-history.html>
# Rural folk
Just like the city people, these cat-folk would have the fancy go-to-meeting shoes that everyone else wears. However, they would generally have more rugged shoes to prevent accidents, for more padding, and for more actual grip.
These shoes would be considered work boots, which would include steel claws, rough leather, straps, water proofing, and hard rubber soles. The steel claws would not only protect against dropping things on their feet. They would also provide better traction, without wearing out or breaking so easily, and with the ability to be resharpened and replaced. The straps would allow for better binding to the leg, so the shoes don't strip off when needing the extra grip of the steel claws. And water proofing, because blech, water.
>
> Our boots offer the latest in grip technology, which reacts to your own claws extending, shooting out an extra inch of claw to give you better traction when you need it. Get them in stainless steel, to prevent corrosion and to make cleaning easier.
>
>
>
Steel was also available before medieval times. Sure, stainless steel wasn't available until 1920's, but this provides a possible bridge to modern times.
<https://en.wikipedia.org/wiki/Ferrous_metallurgy>
Rubber was first invented in 1600 BCE, in Mexico, but who says the Americas weren't discovered earlier by the cat people? This is a fantasy story.
<https://quatr.us/science/rubber-history-rubber.htm>
# Design
The shoes would be designed to hold each toe independently, so they would maintain the flexibility and balance a cat-person would require. Taller boots would include a cutout/spacing or pouch for their hind claw. Some shoes may include customized faux fur to blend in with the fur of the individual.
Of course there are small cats and large cats, so there would likely be heels and platform shoes, since some cats are just as vain humans and of course could care more about their height than their balance, just like humans.
>
> Our Tigger(R) brand shoes give you the extra bounce and vivid colors you need to bring all the toms to your yard. You meow, girl!
>
>
>
[Answer]
Probably something like ballet shoes, with slits for the claws. As others have said, their back claws don't fully retract and they do use the claws for improved traction etc.
If your cats are anything like RL ones though, they will *hate* wearing them!
]
|
[Question]
[
If the right requirements are met, could bacteria survive on the Sun?
The bacteria would spend most of their time in hibernation and reproducing, and when the time comes, they spread out on plasma concentrations and fly towards the nearest celestial bodies.
* They are like [water-bears](https://en.wikipedia.org/wiki/Tardigrade) and are nearly indestructible.
* They survive on radiation, through an extremely complex form of photosynthesis.
[Answer]
## Some simple molecules can exist in stars - but not the right ones.
Contrary to popular belief, [many different types of molecules can exist in stellar atmospheres](https://en.wikipedia.org/wiki/Molecules_in_stars), especially cool stars like red dwarfs. Some are even helpful spectral diagnostics; [TiO bands are very common in stars cooler than 4000 K](https://physics.stackexchange.com/a/345463/56299), which actually encompasses most of the stars in the galaxy, and thus serve as a possible surface temperature indicator, as they are dominant from 3000 K to 4000 K.
Now, many of these molecules - TiO, MgH, CaH - are simple inorganic molecules, and rather unhelpful for life. They may be useful as steps in chemical reactions, but those reactions require other molecules likely to dissociate under the typical conditions in stellar atmospheres. Of course, there *are* some simple hydrocarbons; CH comes to mind, lending its name to the [CH stars](https://en.wikipedia.org/wiki/CH_star). Though unlikely to help life survive on its own, it appears to be [a part of a process for making more complex hydrocarbons](https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process) - perhaps useful if ejecta into cooler portions of the interstellar medium, but not a stellar atmosphere.
## Amino acid dissociation
Let's talk about more complex organic molecules - the kind these bacteria would use. [Amino acids](https://en.wikipedia.org/wiki/Amino_acid) are key compounds you might have heard of; 20 of them are used in protein. As you might expect, these amino acids are unstable even at reasonably low temperatures. [Recent work on eight major amino acids](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807855/) concluded that they tend to break up around 200-300$^{\circ}$ Celsius, or roughly 500-600 Kelvin. That corresponds to atmospheric temperatures in some brown dwarfs, but it's substantially lower than the surface temperatures of the stars you're interested in. No amino acids mean that carbon-based life is a little bit unlikely - at least life as we know it.
## The building blocks of the building blocks of life
The majority of molecules used by carbon-based life are very likely to quickly dissociate, even in late-type red dwarfs - and so I think a simple answer to your question remains a no; these bacteria would be unable to survive. However, it *is* interesting to note that some stars may be able to form the building blocks of the building blocks of life. [Polycyclic aromatic hydrocarbons](https://en.wikipedia.org/wiki/Polycyclic_aromatic_hydrocarbon) (PAHs) remain a hot topic of research, and are extremely common the cosmos. It seems possible that [they are formed in the atmospheres of carbon-rich stars](https://ui.adsabs.harvard.edu/abs/1998IAUS..191P.304F/abstract), which then eject them into the interstellar medium. Given the right amount of time, and a bit of luck, it's possible that they could form the basis for complex interstellar molecules.
So perhaps you could find bacteria around stars, their constituent molecules created thanks to PAHs forged in a star's atmosphere. But the bacteria themselves certainly couldn't survive in such a hellish furnace.
[Answer]
Plasma is made by a soup of atomic nuclei and loose electrons.
As such no molecules exist in a plasma.
Life is based on (complex) molecules, therefore no life can exist in a plasma like the one present in stars. It's like trying to make a castle of cards in the middle of an hurricane.
]
|
[Question]
[
I have a specific idea to draw out an alternate society. My plan is to design propaganda prospects or posters. Do you guys have some tips how I could show/tell most through-out this medium to understand the alternate society I'm trying to create?
Which information would be essential to show?
[Answer]
What is most important is that in real first world countries political parties rarely publish political posters and prospects outside of election campaigns. Why would they? They cost money and changing the oppinion of the voters is only relevant in the time before a vote.
On the other hand in times of political unrest, that fact changes, as you want everyone on the street to prostest for or against something. What this does is showing presence. You are living in a currently suppressing policital system and you see a poster of the resistence, you know you are not alone in your discontent.
So if you describe that there are posters and other propaganda year round, that would mean something is off. If only one party ist posting those, you know its not about the vote, its about something they want. They want you to keep in line, join the military, take your pills etc. Or they show you - like levitime said - that there are other in better condition than yourself to make yourself conform to the state and life a better life.
Alternativly if there are several posters yearround by different parties maybe the political system is diffent in your alternative world. Like a world where megacorps rule the world, then this propaganda is more like ads. In this case, the parties dont need votes, they need the consumers money.
So what you need to convey is:
* Who is posting this, are there several parties posting?
* Why are they posting? Just for votes, to keep you in line or to manipulate you?
* How does the propaganda change? From "Join the military" to "New Settling grounds" or "Families, we need more young boys"
[Answer]
I've produced "props" as a Game Master in pen-and-paper, tabletop RPGs.
Some of these were *supposed to be* more or less objective, like the printout of a map generated by starship sensors in orbit. Both the **player characters** and the **players** could trust them to show the truth, within understood limitations. Of course the world map did not have a big X for the villain's hideout even if that was the most significant feature on the continent, and so on.
Some were *supposed* to be subjective and to represent the opinion or propaganda by certain non-player characters. This could be a very good thing when the **player characters** and the **players** thought they were aware of some aspects of the fictional world, and suddenly a non-player character *contradicts* that. That's a big clue. In both Classic Traveller and GURPS Traveller, the Imperium is sort of benign but distant and careless. A character handing out pro-Imperial propaganda leaflets is *strange* and interesting times make good adventures ...
But that only works when the players or the readers have an understanding of the supposed truth to put the propaganda into perspective.
* Imagine a poster "let's all work together for the common good," the way you'd see in Communist or Nazi propaganda.
The setting could be a repressive police state, where government goons crack down on any dissent and [brain-wash the masses](https://de.m.wikipedia.org/wiki/Datei:R%C3%A9alisme_socialiste_(Vilnius)_(7622118328).jpg) with their propaganda.
Or it could be a society under outside thread, heroically coming together to [fight the enemy](https://en.wikipedia.org/wiki/We_shall_fight_on_the_beaches#Peroration) on the beaches, on the landing grounds, in the fields and streets.
* Imagine a public service announcement on healthy eating habits.
The setting could describe a prosperous and [increasingly overweight](https://health.gov/dietaryguidelines/) society, with do-gooders in government to keep obesity in check.
Or perhaps a [famine](https://www.theatlantic.com/business/archive/2011/12/how-kim-jong-il-starved-north-korea/250244/), seen through rose-colored glasses.
[Answer]
Propaganda conveys information in a biased and idealistic way, in line with a political view. This political view often does not open itself to scrutiny. Fictional propaganda posters are a good way of telling about your society, both by what you show and what you don't show. This way of story telling can work as black humor, because your reader knows better and looks critically. This way of storytelling is often satirical to governments that employ propaganda. The coined term "fake news" shows propaganda is a danger for all democratic institutions as well.
If the propaganda poster shows laughing people of a certain color feasting on an exorbitant amount of nice nourishment with the text underneath *Have you thanked our leaders for your feast today?* then this may show that wealth is not fairly distributed in this society.
So in short:
**By showing the extreme idealistic government view of the world conveyed through propaganda, the outside observer will notice the unjustices of the world.**
[Answer]
Propaganda strives to depict things which are not true as having already happened. The things which are actually true and obvious to the reader are not worth wasting the poster space.
So, if the propaganda poster depicts happy farmers with their hands full of grain and a caption like "To abundance!", this means that the food situation is rather dire, and it concerns both the people and the government. 
If it shows a mighty soldier crushing cowering enemies, this means that the situation on the front lines has reached a stalemate (or that there's no war at all, but the state insists that the enemy will strike soon).
If you see a poster condemning the brutality of the enemy, this means the state cannot stop them, is frustrated about that, and tries to, at least, portray them in a negative light.
In other words, let your posters convey the goals of your government that it can't achieve, but still wants people to think something is being done.
Upd.: posters about enemies can generally mean two things. Either the state wants you to believe it's winning against whatever (when it's not), or it wants you to believe there's an enemy (when they're not a reason for concern). This depends on the composition of the poster: whether or not there's someone to defeat the enemy there.
[Answer]
You could have a character working for or against this propaganda, and have them describe it in the way you want to.
I don't know if it fits in your story, but they would be an infinite ways to actually make it work.
i.e : an artist chosen by the goverment to draw the prospects
A rebel whose mission is to rip off from the city all the prospects
Someone distributing the news paper in the streets
[Answer]
>
> Advertising Propaganda shares techniques with advertising and public
> relations, each of which can be thought of as propaganda that promotes
> a commercial product or shapes the perception of an organization,
> person, or brand.
> <https://en.wikipedia.org/wiki/Propaganda#Advertising>
>
>
>
Rather than government propaganda (which seems to me to have a uniformly earnest tone) I propose that you use **movie posters.**
Pick a year that suits your world and google image the movie posters. They are funny, sexy, scary, zany, serious, weird and everything else. Many have serious artistic merit. They are all propaganda because they want you to pay to see the movie. It would be easy to adapt movie posters for your use. and you can lift the layout and format of the ones you like and so get some of that artistic merit for your own endeavor.
]
|
[Question]
[
### Background
The concept of an old and dying red planet is common in [pulp novels](https://en.wikipedia.org/wiki/Barsoom), [comics](https://en.wikipedia.org/wiki/Krypton_(comics)), and [gaming](https://en.wikipedia.org/wiki/Dark_Sun). What I am interested in is a world dying under a sun that has turned red and is expanding. The increasing luminosity of the aging sun drives water off the planet, where live is short and cheap, and men are desperate and cruel.
### The Problem Statement
But the confounding problem with the dying red planet genre is that the timescale for the environmental changes is immense. Stars take hundreds of millions of years, at the least, to grow from friendly main-sequence stars to menacing red giants. The time it takes a watery, verdant world have have water vapor sputtered out of its atmosphere is in the millions of years as well.
So how does society survive from the verdant world to the dying one? It must be stagnant, technologically. There are plenty of questions on this site addressing that aspect ([here](https://worldbuilding.stackexchange.com/questions/59588/how-to-explain-centuries-of-cultural-intellectual-stagnation/59591#59591), [here](https://worldbuilding.stackexchange.com/questions/104587/how-to-keep-my-colonists-primitive), [here](https://worldbuilding.stackexchange.com/questions/84231/how-could-i-justify-medieval-stasis), more if you want to search). But in this case, the society must be stagnant for tens to hundreds of *millions* of years.
Our current society, as is, won't make it. We rely greatly on stored hydrocarbons, and those won't last long on geological timescales; one way or another our society *will* change. But, plenty of older cultures were not sustainable in their own ways. The Sumerians poisoned their fields with salt after thousands of years of irrigation; the Ethiopians lost the topsoil on their fertile mountains after cutting down the trees. Early modern Europe would have lost most of its tree cover if wood burning had not given way to coal.
Finally, there is the issue of space travel. A society cannot be trapped in too advanced of a state, or some group of survivors will be able to escape the planet completely (even if it is only [one survivor](https://www.imdb.com/title/tt0177267/)).
### The Question
**Assuming that technology is already stagnant for whatever reason, what is the highest technological level that a society can achieve and still survive, stagnant, on the order of a hundred million years on one planet?**
### Considerations
* The obvious, and trivial answer, is zero technology. If intelligent life never develops on the planet then technology is at exactly the same level 100 million years from now.
* This doesn't have to be Earth, and it doesn't have to be humans. The question is only about the state of technology.
* The question isn't about evolution. The biological species can change all it likes, so long as the technology remains stagnant.
[Answer]
**Near future.**
Your society is governed by an artificial intelligence. Policy and technology decisions are all decided by the Benevolent AI (Ben for short). Ben does not innovate, but in an enlightened way it rearranges and redeploys the very adequate known technologies to cope with changing circumstances over the years such as drought, salinity, increasing UV and so on. The code of Ben is inviolate and not to be updated, amended or changed in any way for fear of introducing bias. Governed by an angel, humanity does very well over the eons.
Innovation / new technology is suppressed as dangerous, chiefly because Ben does not know about it, cannot use it and it is anathema to update Ben's program. Technology parks at the level it was when Ben was started. That does not necessarily mean Ben uses all the tech it knows about at any given time but that tech remains available for use as circumstances warrant. Life is good.
[Answer]
Before even thinking about society, we have to think on a more basic biological level about the scenario you are asking about. **In order for a society not to change on a high behavioural level, the species itself must not change evolutionarily on a basic biological level even though the world the species lives in changes a lot from friendly habitable to lacking in water and quite inhabitable.** Any species which is highly dependent on its environment is therefore ruled out to fulfill your requirements, as not only their society but even their biology would have to change to adapt to the changing environment. As examples look at polar bears as the 'big losers' in current climatic change, as they are very specialised in their habitate and food sources. Also consider human evolution itself within only a few million years - a much smaller time scale than you are asking for - where races developed based on the amount of pigments required in different environments or the body mass and size optimised for different climatic side conditions. Our current level of technology allows us to converge biologically, as races mix and physical requirements are less prominent due to technology being able to make up for environmental requirements.
We can also observe how only a few degrees of temperature rise cause havoc among humans, causing floods, draughts and in addition mass migration which is the most radical kind of societal change possible.
Thus, I see two possible options:
First, your species must possess a **sufficiently high level of technology** which can completely make up for any physical changes in their environment and is advanced enough to have sources of food, energy or living space completely unaffected by any environmental changes, e. g. because they migrated several 100s of metres below the surface and completely maintain their society by not moving out of their underground bunkers where the live so completely maintained by their technology that any further research is unnecessary and unacceptable by the society itself, because the technology can automatically adapt to the long term changes without active maintainance or intervention by the people. Likely a species living under such conditions would not be the species originally having developed and built the technology, as such amounts of research require a high enough number of peole driven by curiosity and the wish to learn about and change things in the world. *A species driven by the wish to change its environment and constantly improve itself and its technology through research would never just 'stand still'.* Thus, one can imagine that the people living in this unchanged technoloigcal environment without any drive or wish of even a single individual in millions of years to change somenthing could be that they are scavengers without much drive towards change or improvement having found and nested in the high technology environment and as they get all that they need from the technology itself they degenerated much like some overbred races of pets who would be unable to maintain themselves under any circumstances which do not involve someone feeding them.
Second, your species is **optimised for survival under conditions** in an environment which is **not greatly affected by global changes** as much as others, yet still flexible enough to survive minor changes. We have a few examples of such 'old' species: sharks and crocodiles as more advanced species, bacteria, amoeba on a more basic microbial level of life. *Sharks* and *crocodiles* show a 'group'social behaviour, however defining a school of sharks as a type of society might be far-fetched. They did not have to change evolutionarily, because they are already optimised as successful predators in the seas who can survive in warm as well as cold waters that any changes in shape or skills do not make much of a difference any more.
[Answer]
*I was originally going to leave this as a comment, but realized it was more of an answer, so...*
The inability to escape the planet could be the result of exceptionally high gravity. So long as whoever goes/lives there cannot devise a solution to escape the gravity well, they're stuck.
At that point, you can advance your technology all you want and still be on the one planet.
---
According to [this NASA site](https://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html) (emphasis mine):
>
> If the radius of our planet were larger, there could be a point at which an Earth escaping rocket could not be built. Let us assume that building a rocket at 96% propellant (4% rocket), currently the limit for just the Shuttle External Tank, is the practical limit for launch vehicle engineering. Let us also choose hydrogen-oxygen, the most energetic chemical propellant known and currently capable of use in a human rated rocket engine. By plugging these numbers into the rocket equation, we can transform the calculated escape velocity into its equivalent planetary radius. That radius would be about 9680 kilometers (Earth is 6670 km). **If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport.**
>
>
>
[Answer]
When you start talking about timescales like this, you have to shift the way you think entirely. The *meaning* of "surviving" starts to become tricky. You're operating on timescales where evolution of species starts to become a meaningful issue. Indeed, it forces us to recognize that "species" isn't even a natural concept. It's a man made one used for categorization. The genomes in question flow fluidly from one generation to the next. DNA from bacteria finds its way into human genomes. Nature doesn't care about our boundaries.
The same issue arises with societies. Was there really a transition from Confucian China to Daoist China? Or was it just a fluid series of events which we call a transition in retrospect? Should we say the Confucian society "died," and a new Daoist society was "born," or should we say that the Chinese society "evolved?"
Is the Voyager probe an "escape?" Or do we need a person on board for it to be an escape? What about just a vial of H. sapiens DNA?
To deal with these questions, I find it is most meaningful to look at individuals as a reflection of the universe around them. They're a fixed point, mirroring the world and themselves within the world. This is why "escape" is such a big deal. If just one reflection of a society gets free, that society can be mirrored once again upon whatever grounds the escapee lands in.
Have you ever pointed a video camera at a monitor displaying its own feed? The pattern dances around, but often there are single points on the screen which remain constant, black or white, because the camera is looking at the exact same pixel that it is outputting. Those are the fixed points in question. And, being reality, they're imperfect. One lone survivor of Nazi Germany may not be able to carry a perfect enough image of the Third Reich to rebirth it. That society may indeed die with its last individual. The image may simply lack the fidelity to resonate in the new landscape, and die out like so much thermal noise.
So when you start asking about how advanced a society can be and still be trapped like this, its a curious one to explore. You don't actually have to trap all of the individuals, you just have to trap the ones who mirror society with sufficient fidelity. Consider a society where religion and technology are entertwined. The technology fuels the success of the religion, and the religion passes down the skills and knowledge needed to manage the technology. Let's say this religion has a rule that you never leave your planet. It happens. The only potential "escapees" are those who are insufficiently indoctrinated in the religion to have this mindset. But then they also lack the knowledge to reproduce the technology. An escapee cannot bring their society with them.
You could also have a species that has made a fatal mistake and all they are doing is stalling for time. We see this in the Asgard of Stargate SG-1. They accidentally made all of their species sterile. They live a long time, but as they die, their society dies with them. They are an ironic twist on your question. They are spacefaring, traveling the stars, and yet they cannot save their society. Their society spans planets, yet is dying.
The universe can also be terribly inhospitable. Consider the extremophiles of these societies, the ones which buck up against the limits of the heat death of the universe. You can have FTL, but it won't do you a lick of good once you exceed the half life of protons, and there are simply no planets outside of your protective technological spheres to colonize. This is explored in Stephen Baxter's book *Manifold Time*.
Or perhaps the mistake is in our definition of a dying planet. If we look at a planet, we may see death, when they see life. Consider a tree in winter. It's easy to say the tree is dead, but any gardener knows that there's still life there when you know where to look. The deserts of the Australian Outback are famously dead, but the aborigines native to the area know exactly where to look to find food and water when they need it.
Going back to Stargate SG-1, we also have the Nox. The Nox inhabit a planet which we felt was dying because the Gua'uld were coming, and no planet survives that. But the Nox were some of the most technologically advanced species in the galaxy, and they saw no threat from the Gua'uld. They felt their planet was more than lively enough.
So where does that leave us? Anywhere we want, really. You're really only limited by your imagination, and any artificial limits you may place such as species boundaries. in 1883, Nietzche wrote *Thus Spoke Zarathustra*, we find The Last Man, a society which spends all of its energy just continuing to be a society. It slowly decays, never once looking to the stars to escape. We've had over a hundred years since he wrote that, and so many technological revolutions that we don't even track them any more. Surely there's room for imagination more!
[Answer]
I think that your approaching this with the wrong mindset. I don't see why a super advanced civilization would leave a planet they have the technology to survive on. As long as they have the means to do so, and get benefits from it, then why not.
Firstly, I want to address the society part. Society doesn't need to refer to the entire race or civilization it could be a very small part of it (relative to the species). For example a small town of only a couple hundred people might consider themselves a society, or a university group of 10 people could form into a society.
As the species advances and heads to space, they don't bring everyone with them. This is due to costs and unwillingness. Firstly, going off planet means relocation. Leaving your current life for a new one. You need money to get off planet and money for a new house. If you don't have this money, then you have to sell your life away to get sent off planet (this is a pretty common reoccurring theme). So the people who don't want that stay behind. The technology they had is still there and will get upgraded slowly over time as the tech becomes cheaper, more widely produced. Even if the star disappeared, people would try and find a way to survive. Because they can't afford to leave.
So the Technology level could be anywhere from a super advance 100% self sufficient space faring species to the stone age.
[Answer]
Related to Willk's answer: Far future.
The last real creation was a limited AI that could run things, providing a life of leisure for everyone. In time, the skills actually needed to accomplish useful things were lost--there was no reason to learn most practical things.
The AI is good at adapting but can't actually do research, it's trying it's best to keep things working. Since the survivors can't do anything meaningful in that regard there is no incentive to redevelop such learning. All innovation goes into fighting--something the AI doesn't do and so can't provide any help in.
[Answer]
The hard part here is not where is the technological ceiling, but "how does a civilization have any technology and be so stagnant for so long". The benevolent AI previously listed is one good solution to this problem because no man has the drive or intelligence to become more than it. Once people hit that climax, man itself goes into a sort of idiocracy that is wholly reliant on that superior intellect.
A second solution is Genetic Intelligence. Perhaps your species is not intelligent in the way people are, but more in the way ants are. Since this world is much older than Earth, a few billion extra years of behavioral evolution could make a species that creates things as complex as cars and planes and cell phones, not because they are innovative, but because their instincts have evolved to that point over time. Picture an ant hive, but instead of 4-5 genetic specialties, if there were 1000s of genetic specialites, that are each born knowing how to perform a needed vocation of this society.
In either case, the limit to your question is as you defined, just short of interstellar travel being viable. Otherwise, there is no theoretical limit to how smart such a static civilization might be.
[Answer]
>
> Assuming that technology is already stagnant for whatever reason, what
> is the highest technological level that a society can achieve and
> still survive, stagnant, on the order of a hundred million years on
> one planet?
>
>
>
They can be super advanced way beyond us. So we have the formula e=mc^2, but we can't actually implement. That mass can be converted to energy and vice versa freely and at will. At this point not much else matters.
I want a glass of water, but there's no water around. Picks up rocks, drops them into a Star Trek replicator. Deconstuct, and now you have energy. "computer glass of water 58F please. Now you have a glass of water.
Therefore as long as you have access to mass or energy either can be converted into anything you need.
The people on my planet wouldn't need to be desperate, cruel, or life be cheap for a very long time. Even then advanced technology may still save them. They maybe able to tractor beam asteriods,debris, who knows maybe even other planets close enough to absorb the material and convert it to energy.
Further, a primitive tractor beam may not even be needed. Maybe they can "beam" chunk of other planets directly onto there planet for absorbtion.
Maybe they actually open worms holes to anywhere and suck matter through for absorption.
In fact the super dense core of there dying star might be the very thing that saves them. They could keep ripping off tiny chunks of there dying star (and/or planets) for hundred of millions of years easy. Open a worm hole and suck through a chunk large enough to power there planet for a 1000 years plus the energy to pay for the wormhole.
In this case the only limit would be the range of there worm hole, and scientifically speaking there are no limits besides, maybe energy consumption to create said wormhole might increase over distance.
The Q on star trek are kind of an example of this type of thing, except they're not trapped on a single planet. They are essentially omnipotent. With a snap of their fingers they can do anything. Yet they are bored and a society stagnant because literally every person has experienced everything ever. There is no record of any of them ever dying of natural old age. Member of there society have literally volunteered to take up being a scarecrow in a field for millions or billions of years because they're "bored". This is demonstrated with Picard and Janeway.
[Answer]
# Technology has *never* been stagnant
Through all of recorded history, technology has *always* moved forward. The very act of recording history was itself a new invention, as writing is one the most fundamental of all technologies. Technology was probably moving forward before the invention of language, but it's hard to say for sure.
Necessity is the mother of invention, and technologies evolve much the same as species. Witness the gradual evolution of medieval weaponry. The rise of effective armor changed warfare. In response, anti-armor features were invented and new weapons adopted them. Armor compensated for the existence of armor penetration. The dance continued until the invention of weapons so powerful no armor could stop them, making armor obsolete.
You have a survival pressure in the form of this gradually shifting environment. This pressure is going to induce innovation to cope with the problems of the dying planet. You also have a problem in that technology breeds the creation of new technology.
It basically is not possible to make technological progress cease, and have everything stagnate, with a real population that's around for a hundred million years. In less than six thousand years our society went from inventing writing to working out how to *build stars*. (Not very big stars, mind, just big enough to blow ourselves up with.) That is more than four *orders of magnitude* shorter than the timescale you're talking about.
You'd have to force people to remain stagnant. That is going to be very hard because of the strong incentive to cheat: the rewards for finding a way around any 'no new technology' prohibition are power and prosperity. You're probably going to have to go all the way down to an extreme Orwellian society or something even worse, like actual mind control chips or [Friend Computer](https://tvtropes.org/pmwiki/pmwiki.php/TabletopGame/Paranoia).
# Proposed alternative: The population moved there but is now stuck
Instead I'd recommend looking into how Anne McAffrey solved this problem for Pern: A bunch of, well, basically space hippies wanted to recreate a lower-tech world, went out and bought themselves a colony world, then things went pear-shaped and things Went Bad. Similarly, you may want to check out the backstory of Trigun.
Find some reason for a population to settle on this planet, then cut them off from interstellar society at large, then have disaster strike leaving them stranded.
]
|
[Question]
[
Cryomancy is cool, ice is cool and ice mages too. But does it actually hold any utility other than keeping your food fresh, specially martially wise(?)
How could an individual with ice magic powers be able to use his magic in combat, a life or death situation where fleeing is not an option ?
The magic works like that : You can activate a part of your brain that enables you to turn air into liquid then solid ice by manipulating pressure or at least to drop it's temperature at the cost of calories, only the air you are able to directly ''see'' so freezing people to death from within is not an option.
Dropping 100 liters of air down by 10 C° costs 500 Kilocalories and causes extreme acceleration in breathing if this magic is abused it can fatigue or even kill the user.
[Answer]
**Internal damages**
How about creating a lot of really small, sharp and pointy needles of ice ? Use the cryomancy to create them from thin air, then as stated in the comment, use air pressure to project them through your opponent skin (if some body parts are not protected by armor, etc...). This could lead to :
* Damaged organs (possibly vitals).
* Haemorrhage.
Moreover, as stated in one of those [Quora's answer](https://www.quora.com/What-happens-if-you-inject-water-into-your-veins) :
>
> [], any kind of water is extremely hypotonic relative to blood serum, so
> you can expect immediate hemolysis of red blood cells (RBCs) —
> bursting of the cells due to osmotic swelling. RBCs are little bags of
> hemoglobin, and when free hemoglobin is released into the circulation
> it’s toxic to kidneys and can cause renal shutdown. You might even
> need emergency renal hemodialysis.
>
>
> In addition RBCs are little bags of potassium, so serum K+ levels will
> rise and could cause cardiac arrhythmias including fatal ventricular
> fibrillation or ventricular tachycardia.
>
>
>
Add those symptoms to the pain and the numb cause by the cold of being pierced by dozens/hundreds of needles, and you'll have a pretty dangerous mage capable of disabling and killing its foes from a secure distance.
[Answer]
Since there is a major energy drawback to using this power, one route for maximum combat efficiency would be to focus on Precision and/or Set-up.
**Precison**
Instead of forming huge chunks of ice and hurling/dropping them on your target, what about forming spikes from walls/ceiling, and simply creating a slippery surface to slide your foe into their own deaths / major injury?
It doesn't even have to be that complex, freezing the eyes of your enemy is another option, as well as freezing the air right at the opening of their nose, and when they breath/speak, freeze that as well and suffocate the target.
Defensively, the concept is the same. If you know where your opponent's attacks are aiming for, instead of completely stopping that force, redirect it using angled ice walls or simply liquid in the air. A Martial Art Style like Aikido would work well with this train of thought.
The whole goal here is to not exert a lot of effort, which could kill the user, but rather deliberately use precise force strategically.
**Set-Up**
Another, non-exclusive thought, would be to set-up your fights in a way that plays to your magic/strengths. Fight near a large body of water or a cold environment that minimize the energy you need to consume to drop the temperature farther.
Tools, like a bottle of water, liquid nitrogen cartridges, Water-filled vest, water balloons are all examples of how a smart user of this magic could prepare themselves for combat before it even happens. If given enough time before a fight within a set location, setting simple water traps could be lethal with the right circumstances.
All of these answers are only pertaining to dropping the temperature of the surroundings, if pressure were an option like suggested, there are a slew of other principles that could be applied depending on the circumstances.
[Answer]
Combat styles can't be defined simply. They involve thousands of tiny features coming together. However, what you describe does seem to be sufficient to create weapons out of thin air and to direct them.
What you probably want to train in is a rope-like weapon, such as a metor hammer or dart or chain whip. Here's a [video](https://www.youtube.com/watch?v=8IPl2tFNihc) of what can be done with one by a mere mortal.
Now one of the major limits of the chain whip class of weapons is that you have a very limited set of things you can do to the weapon. The masters spend a lot of time honing these so that they can increase and decrease the length of the chain by wrapping it around their body. Your ice master would have one additional capability: the ability to slow it down and guide it. By summoning mass in front of the weapon (in the form of snowflakes?) you can change its energy and momentum in ways that normal masters of these weapons cannot. Thus, in a fight, nobody will be prepared for what you can do.
For example, an opponent might grab the chain. They think that they now know the length of the weapon (it extends from their hand to the end of the chain). They *should* know what directions the chain can travel. But if you can put a ball of solid ice in the way, you can half the length of the chain, causing it to whip around and strike the opponent right in the hand they used to grab the sash.
This would also be very effective for diverting opponents off balance. This is both physically adjusting them off balance like a Tai Chi or Akido practicioner would, and simply making a slipery surface under their feet.
[Answer]
Cooling a air requires means reducing its energy, and that energy has to go somewhere. Heating up something else can be a useful attack if it is controlled, or a side-effect if not controlled, or it can be handwaived that energy is used to power the skill, or counter its effects, or is directed deep undeground, into alternative dimension, etc.
Time for Physics: <https://home.howstuffworks.com/humidifier1.htm>
A cubic meter of air at 100% humidty (and 25C) contains 22 grams of water.
At 20C, it can contain 18grams.
So dropping temp by 5C gets you 4 grams of liquid water per cubic meter, and your example of cooling 100m^2 of air by 10C gives you 800grams of liquid water (less than a kilogram). Turning it into ice will require sucking more energy out of it. I do not know enough physics to say how much, but I will assume 400 grams of ice, i.e. about a pound.
Simple combat use of 400g of ice is to drop it onto enemy from some height. If you have control, you can form the ice in some vulnerable location, e.g. over face to interrupt breathing and vision, or render their gear useless.
PS Freezing eyeballs like @Gene suggested is an excellent strategy if it is possible. Also freezing fingers. Do not have to completely freeze either, I bet a drop in temperature will hurt enough.
[Answer]
I am assuming the mage attracts moisture from a large area around him, both air, ground and potentialy a little from plants and animals nearby or this is going to be one bad magic.
Remember the ice bucket challenge? It is a method to simulate the ALS affliction. Just launching a large amount of ice water at an opponent could at the very least give you enough time to pass them by and flee, or give you time to retaliate and stab a knife through their helmet for example. Probably the easiest thing would be to have a mace, as a good hit at an essentially slowed or stunned enemy will at the very least incapacitate anyone on the receiving end even if they wear a helmet.
1 question though: where does the energy go? You could say that the energy extracted lowers the energy needed to draw water from your surroundings.
[Answer]
**Attrition**
In addition to more refined methods, just brute-force cold could be very effective. Apply as much cold as you can to somebody's immediate vicinity, then attack as normal. Cooling to even [as warm as 2 C](https://www.ncbi.nlm.nih.gov/pubmed/21466095) (~36 F) can have significant impacts on motor skills. If your cryomancer can get it much colder, and has at least average martial combat skills, this will swing any fight to his advantage within minutes.
[Answer]
If the basis for calling the magic user an "Ice Mage" is that they can rapidly lower the temperature of the air that they can see by manipulating the pressure down. I will assume that they can only decrease pressure and that they do so at great cost.
Non-lethal
Lowered temperatures have not been found to have notable effect on stimulus evaluation. [Integr Physiol Behav Sci. 1995 Jan-Mar;30(1):34-45], However, the temperature drop is only a byproduct of the real action- rapid pressure drop. Imagine someone charging at the mage, if they were to rapidly drop pressure, directly in front of the face, you could leave them winded at a fairly low cost.
The mage might, at relatively low cost, flash freeze the hands of the opponent.
Lethal
As @Gene mentioned, targeting the eyes would be a low cost means of really hurting the target.
Dropping ice from above might be a little too difficult and cost inefficient, but if they use the environment to their advantage, they might turn rain to hail.
If you were to continue dropping the pressure and lowering temperature near the face, I imagine you could also suffocate your opponent.
Disarm
Provided the target is using a metal weapon, iirc most metals are susceptible to risks of "brittle fracture" when exposed to rapidly changing temperatures. After rapidly changing the temperature of the metal on their weapon, it may fracture if you were to block with a weapon of your own.
If an Archer were targeting the cryomancer, a rapid drop in the temperature of the bow could cause the bow to break and split when it's drawn, possibly hurting the archer.
Regarding firearms, lubricant would become thick and the weapon may jam or at the least, become sluggish. Freezing a magazine may prevent the spring from feeding up into the weapon.
Hope this helps
[Answer]
You could condense air and use it as a cryogenic liquid, propellent or explosive or even augment fire with pure oxygen. You can be a silent killer: just displace oxygen with CO2 or N2. Possibilities depend on the level of technology & support and what enemies you are fighting against. Cryomages don't have to limited to just ice.
[Answer]
You could do a lot of crowd control with a small amount of water or ice. Like freezing surfaces creating slippery surfaces. If you are looking for direct damage then maybe try decreasing the temperature of anything on them. freezing a small surface of skin even a thin layer at 5 cm or so diameter at lets say -40 c can be very painful and cause quite a bit of shock and saps heat from surrounding areas causing more damage.
[Answer]
For a cryomancer i would say a fighting style of either ranged attacks or something a bit closure involving alot of grappling and holds so as to freeze the enemy while touching them.
]
|
[Question]
[
**Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers.
---
You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49).
Closed 5 years ago.
[Improve this question](/posts/119519/edit)
I would like to know what would be the best strategy to survive and prosper in the roman empire for a time traveller?
Let's say that the time traveller is a 30-year-old Italian from the XXI century with no particular expertise (i.e., basic knowledge in sciences, history, ...) and a typical modern italian culture. He does not speak latin or greek and does not know much about roman empire history.
He falls in a space warp and arrives in Rome during the course of the 2nd century (roman empire apogee) with only his clothes. He has no hope to come back to the present time.
[Answer]
Average Guido will have very little hope of surviving in 2nd century AD Rome. He has no skills that would be useful to him in that time, no knowledge of the language (although he'd have a slight advantage over, say, Average Joe American in that regard) and no knowledge of the culture, history or politics of the time. So, can pretty much forget about ingratiating himself within the upper crust. His clothing will be useless and uninteresting: they'll be considered outlandish and barbaric. The contents of his pockets will not likely prove to be much better. If he has a cell phone, it'll be dead in a couple days and useless. A pocket knife might prove handy, and a pen might be marginally interesting to a particularly inquisitive mindset. His money will be meaningless and worthless to the locals.
Being a product of the 21st century Rome, he will have no chance to withstand the many dangers ancient Rome will face him with: he might be mugged or murdered or sold into slavery. If he eats the food he'll probably end up with salmonella. If he drinks the water, he'll probably end up with something nastier still. Even a skinned knee can prove fatal: there's no soap to speak of and no antibiotics. Medicine is rudimentary at best, outright quackery at second best.
Good Catholic that Guido undoubtedly is, I think his best overall bet for anything like long term survival will be to find a Christian community to hook up with. There's always the risk of martyrdom, but that's how times were, and it will be among the Christians that he will find people most like him in world view. They will actually help him, whereas society at large would really have no interest in an ignorant, skill-less stranger.
[Answer]
It's probably not going to work out for your "typical" Italian man. He won't have enough knowledge of 2nd century Roman culture to navigate successfully, and his understanding of 21st century Italian culture won't translate very well to a totally different setting. The wonders of modern science and culture are great, but a typical person probably won't know enough of the details to reproduce them in another setting. I agree with the difficulties as outlined by elemtilas, but see a couple of other options:
His best chances may lie in mathematics. And depending on what you count as typical knowledge, he may know mathematics well beyond what is available in the 2nd century but that would still be useful if he understands them well enough (basic statistics, or basic calculus and some real-world applications, or a bit of classical physics would be hugely interesting). He could potentially find work auditing records or something, but it's hard to imagine an opportunity for him to demonstrate this skill in a way that would persuade someone to give him a chance at such a job.
But if he could demonstrate it, it's not unimaginable that he could capture the interest of mathematicians and engineers of the time. A numeral system which would make calculations much easier to do and check would be interesting and valuable to professionals, though once learned (and it wouldn't take long) I don't know how much else he would have to offer. But if he thoroughly knows even high school level physics and calculus, he could carve out a more-than-decent place for himself.
Otherwise... farming. It's the kind of position that doesn't require a ton of skill with language, knowledge of culture or current events, or anything like that. There is a good chance that he would end up farming as a slave, or else as a very low-status non-citizen. But he could eventually pick up the language well enough to get by, at least, and he could build some kind of life for himself.
**EDIT**
After discussion in comments I've removed a section about Arabic numerals being an advantage over the Greek system used at the time.
[Answer]
You might read the excellent [*Household Gods* by Harry Turtledove and Judith Tarr](https://rads.stackoverflow.com/amzn/click/0312864876) where a woman from modern LA finds herself in late 2nd century Carnutum. They're both SF writers and both historians and in this one the fantasy element is *just* enough to get her there and give her the language -- the rest is realistic. @elemtilas says it well.
[Answer]
Since elemtilas mentioned disease in his answer, I should point out that it was possible to live a long time in ancient times. In fact Pliny the Elder mentioned a number of people who claimed to be well over 100 years old in a Roman census, and an actress whose career started as a child and lasted for 90 years or something.
But it should be noticed that disease germs would mutate and evolve a lot in 1,900 years. So the 2nd century Romans would be resistant and partially immune to 2nd century germs, and the future Italian would be resistant and partially immune to 21st century germs. Thus he could get sick and die in 2nd century Rome and he could spread terrible plagues in 2nd century Rome.
[Answer]
It depends on what you mean by "prosper". Your character will be extremely tall and strong by the standards of the time, due to better nutrition in childhood. Maybe also quite fat. He will not have any money, land, or property except a few trinkets that could be valuable to trade (a pocket knife, glasses, sunglasses, maybe a watch). He won't speak the language. He would be in a similar situation perhaps to many foreigners who arrived in the empire at that time.
The first couple of years would be rough. He might have to beg a few meals, but I guess that pretty soon someone would notice his size and potential as a laborer. As a farmer, builder, or apprentice to an artisan he would earn his room and board, and more importantly learn the language. Completely immersed in the culture, if he's not an idiot he should be speaking quite fluently within two years.
Then I think the real fun begins. Even if he has "no particular expertise" he will every day be noticing things that could be improved upon, like the design of houses (no chimneys!) and the way the fields are planted. If you are willing to have him change history in this story, he could introduce simple inventions like the flush toilet or the printing press and become wealthy indeed. If not, he could still prosper as, say, a carpenter or blacksmith. His products would have better designs than the competition (drawing on his knowledge of modern day tools and furniture) so he would attract plenty of business, make money, obtain a wife and family. What more could you want?
[Answer]
Your guy can read and write, though not with usual tools of that time. He may not understand latin, but he knows the alphabet. Italian is close enough that he can probably decipher a lot of the content, if only phonetically. Give him a month and he'll be a useful scribe, and most likely a great accountant, using the arithmetic techniques taught in high school today.
Medicine in those times was usually really atrocious, even an average 21st century man probably would be able to teach *a lot* of things about infections to physicians of that time, or even how the body works at a basic level.
]
|
[Question]
[
It's easy to imagine how would a water-breathing aquatic race outfit its spaceship - take a normal spaceship, insulate it, fill it with oxygenated water, possibly add some enhanced turbines to pump water so that users will be able to stay at the consoles without having to swim all over all the time.
But what would air-breathing merfolk do? They can't just be thrown into water or they'll drown. Having a mix of water and air would appear to be very problematic in an interstellar environment.
I initially conceived the problem when trying to come up with a mermaids' starship, but it would also concern anthropomorphic otters, dolphins etc. - in general anything that feels the most comfortable when swimming in water but requires gaseous air to live.
[Answer]
Assuming some sort of "Dolphin with hands" type of creature, and no artificial gravity, the simplest way to arrange this is to have a rotating torus half filled with water.
The rotation of the torus keeps the water "down" in the "floor", while there will be an airspace between the surface of the water and the "roof" of the torus.
An added bonus of this arrangement is that water already provides an effective shield against cosmic radiation and other threats, as well as provides a thermal buffer. In "[The Millenial Project](https://infogalactic.com/info/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps)", the author considered a water shield 5m thick would keep radiation inside at a level similar to sea level Earth. For humans, this would mean a set of structures 5m apart filled with water surrounding the living space; for your aquatic creatures they would actually be living inside it, making some of the engineering easier. Since much of the life support would be living in the water as well (creating a closed ecosystem), in some respects the aquatic species might have an easier time of building a functional spacecraft or colony.
[Answer]
I like this question, space mermaids don't come up often enough. Your astronauts can breathe the same stuff the divers in *The Abyss* breathed: [perfluorocarbon.](https://en.wikipedia.org/wiki/Liquid_breathing?wprov=sfla1) It's not without problems IRL; human lungs can't circulate PFC fast enough to remove carbon dioxide. But if you're not doing hard scifi that can be handwaved away easily enough: your mermefolk aren't human and their lungs don't have to have the limitations human lungs do.
[You can read more about liquid breathing here.](https://gizmodo.com/can-humans-breathe-liquid-1156138301)
[Answer]
This is probably not so hard as you think, and the natural answer would lead to the development of the 'right' form of space propulsion technology insofar as it would be scalable beyond interplanetary flight full on into interstellar. That said, it's not all as simple as it sounds in the OP. There is a*fatal* flaw in your original assumption.
>
> It's easy to imagine how would a water-breathing aquatic race outfit its spaceship
>
>
>
This actually *isn't* the case. Air breathers have the benefit of needing a gaseous atmosphere, and that atmosphere has one crucial advantage over liquids; it's compressible. This allows the body to take a much higher level of G force in that atmosphere because the gas doesn't actually add to the problem (actually it does (Boyle's Law) but not in quantities that significantly contribute to the problem).
As an experiment, put a hamster in a cage and shake it. Check your hamster; it'll be bruised, sore and more than a little angry, but it'll most likely be alive. On the other hand, put a lid on a fishbowl containing a goldfish, and then shake it.
There's a VERY good chance your fish will be dead.
(When I say 'Experiment' by the way, I'm not actually recommending you do this. Please don't try this at home and if curiosity persists, please consult your mathematician.)
The reason for this is that water isn't compressible and therefore transfers the full brunt of all its kinetic energy into whatever IS compressible in its path, and in this case it's the goldfish. Water is also very dense, meaning that the mass striking the goldfish with every shockwave of the shake is phenomenal by comparison to its normal environment. The goldfish won't survive.
You can actually remove a cork from a wine bottle by repeatedly knocking the base of it against a wall or a tree. I don't recommend this either because it bruises the wine, but my point is that any living thing taking massive G force stresses in a liquid is unlikely to survive.
Even your Merfolk will be in the same boat, but the answer (provided you can get out of the planetary gravity well somehow) is simple; some form of constant acceleration engine.
NASA is already working on two possibilities in this space; [Ion](https://en.wikipedia.org/wiki/Ion_thruster) and [Plasma](https://en.wikipedia.org/wiki/Plasma_propulsion_engine) engines. These are designed to provide constant, relatively gentle thrust by comparison to conventional chemical rockets. These would be far more efficient for long distance travel than chemical rockets (although they're not powerful enough to get out of the gravity well) and the constant thrust ALSO provides for that simple answer for your merfolk; gravity.
Well, not really gravity, but the constant *acceleration* is going to gently push everything to the back of the spaceship. This will mean that all the water is going to drift to the back of the ship. If the ship's internal chamber is only 80% water, then the front of the spaceship is 'up', and your merfolk swim that way to breathe. You recycle the atmosphere at the tip of the ship, and the water gets filtrated et al at the bottom.
You will probably need space suits of some form for those short term attitude changes or at the half way point when you turn the ship around and start to decelerate, but for the vast majority of the trip, you have a natural chamber of air at the 'top' of the ship for your merfolk.
You still have the problem of getting out of the gravity well, but that could be done with a space elevator under the circumstances. So; you have a space elevator to get you out of the gravity well, then a continuous thrust engine to provide light gravity and orient your ship. For exploration, this is perfect. For combat, you're in trouble because rapid changes in velocity or impacts on the side of the ships don't have to breach your ship to be fatal. But, that's the price of being a water borne species I'm afraid.
[Answer]
**Who says you need the water at all? They could move through an air-filled ship same as a human astronaut: by pushing off the walls or climbing ladders.**
You're assuming they absolutely need to swim to move, but humans don't get to use our natural method of locomotion in space, so we've adapted. So can they. In fact they could do the same thing we do.
Mermaids could probably navigate the ISS as it is. They have two arms, and that's enough. Otters have two arms but they'd need miniature ladders (dawww). Dolphins as they currently exist would have trouble because they can't grab things, which is a necessary part of climbing ladders or re-orienting yourself for the next push. However you said they were anthropomorphized, and if they're space-faring then they must have some 'hands' either evolved or technological.
There is the problem of discomfort or even drying out like a beached whale. The solution is to keep the air humidity high and also have a dedicated saunas or pool rooms where they can go rejuvenate. The pool room could simply have a nozzle on the wall they can suck air from.
In case the simplicity and safety isn't convincing enough: consider that this would require no re-designs of systems to make them water-proof. No lifting huge quantities of water into space. And land-dwelling air-breathers can inhabit the same spaces as their aquatic friends.
[Answer]
For short missions ([Vostok](https://en.wikipedia.org/wiki/Vostok_(spacecraft)) to [Apollo](https://en.wikipedia.org/wiki/Apollo_program)-type) it has be an air-filled ship with water-filled spacesuits (similar to @Christian's suggestion).
For medium to long-term missions ([ISS](https://en.wikipedia.org/wiki/International_Space_Station)-type) ships can have separate air and water-filled compartments, and astronauts can split their time between them for their convenience.
For more advanced long-term missions, rotating spacecrafts (similar to @Thucydides' suggestion) can be used.
[Answer]
Spacesuits filled with water. Seal and compress the helmets, or have face masks to provide oxygen. Maybe the helmet stays water filled for a set period of time, followed by a purge to provide air (if being completely submersed for some amount of time is required for survival).
]
|
[Question]
[
The relationship between the *distance*, $d$, of the event horizon from a black hole's center and the *tidal acceleration*, $a$, experienced by an object near a black hole allows for scenarios in which a human could - assuming no other forces than gravity - cross the event horizon un-spaghettified.
In fact, the tidal acceleration experience by a 2 m tall person near (100 km from) the event horizon of a black hole of 100 million solar masses is only:
$$a =2\cdot(6.67\*10^{-8})\cdot(1.9\*10^{-41})\cdot{200}/{(2.95\*10^{13})^{3}} = 0.00020 \text{ cm/s}^2$$
(The event horizon has a radius of $295$ million km)
---
**My question is the following**:
Given the black hole at the center of [S5 0014+81](https://en.wikipedia.org/wiki/S5_0014%2B81), with an estimated mass of $40$ billion solar masses, **would it be feasible to have a spaceship survive, for a time, in a
decaying orbit below the event horizon**?
If so, **what would it be like to be inside that spaceship, and how long would that orbit last?** (in their FOR)
*I want this spaceship to be an ULTRA high security prison where there is no hope of escape due to the laws of the universe.*
---
Fun fact,
This black hole is estimated to live to be somewhere around $1.342\*10^{99}$ years old before it dissipates by the [Hawking Radiation](https://en.wikipedia.org/wiki/Hawking_radiation). (wow!)
[Answer]
# Calculations
In [this question](https://worldbuilding.stackexchange.com/questions/60520/how-structurally-strong-would-an-object-need-to-be-to-survive-a-trip-through-an/61400#61400), I solved for the stresses on an spacecraft passing close to a black hole's event horizon. There isn't some magical barrier that you go through around an event horizon, you just can't get out; you probably [wouldn't even notice](https://physics.stackexchange.com/questions/187917/thought-experiment-would-you-notice-if-you-fell-into-a-black-hole). I can use the same process to calculate the stresses that a prison slightly inside the event horizon would face.
### Event horizon of a black hole
The event horizon is the distance from a black hole where the escape velocity is equal to $c$. Escape velocity is
$$v\_e = \sqrt{\frac{2GM}{r}}.$$
A black hole with 40 billion solar masses will have mass $8\times10^{40}$ kg. Solving for r when $v\_e=c$ gives
$$r = \frac{2GM}{c^2} = \frac{2\cdot6.7\times10^{-11}\cdot2\times10^{38}}{\left(3\times10^{8}\right)^2} = 1\times10^{14} \text{ meters}.$$
### Gravity as a function of distance from the black hole
A person is 2 m tall, and 'orbiting' just inside the event horizon at $1\times10^{14}$ m from a black hole of mass $8\times10^{40}$ kg.
The tidal acceleration between the head and feet of a 2 meter tall person due to the gravity of the black hole is $$\begin{align}a &= \frac{m\_{hole}G}{(r+2)^2}-\frac{m\_{hole}G}{r^2} \\
&= 6.7\times10^{-11}\cdot8\times10^{40}\frac{1}{\left(100000000000002\right)^2}-\frac{1}{\left(1\times10^{14}\right)^2}\\
&=-2\times10^{-11} \frac{\text{m}}{\text{s}^2}
\end{align}$$
### What would that do to a 1 km long cylinder?
Conveniently, in my other question, I calculated the tension on a 1km long cylindrical object. Conveniently, this could be a pretty reasonable prison space station. Near the ergosphere of a black hole, the tension forces would destroy any known object, but what about at the even horizon?
Following the same math in the other question, and with the same structural assumptions, I get the differential stress on any slice of the prison/station:
$$\frac{dF\_{slice}}{dl} = \frac{2\times10^{35}}{(1\times10^{14}+l)^2}.$$
Total net force on the rod is $2\times10^{10}$ N, and maximum stress of about $1\times10^{12}$ N. Working backwards using the equation for gravity, we see that the assumption is that the station has a mass of 40000 tons. Depending on the cross-sectional area of the load bearing parts of your station, we can calculate the stresses. If your station is a cylinder 100m in radius, and 1/10 of the available area is taken up by load bearing structures, then the maximum stress on the 3000 m$^2$ of load bearing structure is about 6 MPa. A common structural steel has a [yield strength in tension](https://en.wikipedia.org/wiki/Yield_(engineering)#Typical_yield_and_ultimate_strengths) of about 250 MPA, so this isn't too much. If you have the technology to build space stations inside a black hole, then it is reasonable that you could construct it out of materials that won't fall apart.
The second question is how long you can maintain your orbit. Using simple Newtonian mechanics (Warning! Not valid near a singularity!) the gravitational pull of $2\times10^{10}$ N will have to be counter-acted by thrust. Now, that is a lot of thrust, about three orders of magnitude greater than a Saturn V. I suppose it really depends what sort of propulsion system you have. Thrust as a function of mass flow rate is given as $T = v\frac{dm}{dt}$. Assuming exhaust at the speed of light from some magical propulsion system, you still need 70 kg tons of propellant passed every second to keep from falling into the black hole.
# Conclusions
Given the small tidal acceleration, even a large object (1 km long, 25000 tons) could reasonably be kept together with known materials at the event horizon of such a large black hole.
As for keeping such an object in orbit, for any propulsion system with reaction mass, the propellant usage would be very large (about 250 tons per hour, as calculated above). Given that the mass of the whole station is 40,000 tons, you would burn through the entire station's mass in a week. Just like the tyranny of the rocket equations, the tyranny of a black hole's gravity is oppressive: the more propellant you keep on board, the harder you are pulled in and the more propellant you need. I suppose you could be refueled with propellant, but that is a lot of money to be literally throwing into a black hole.
For some sort of reaction-less system, well, I don't know how to measure that. You can't gain momentum out of black hole, so I don't know how you could calculate the thrust given off by a photonic engine. In any case, the 'not falling into the hole' part seems to be the catch, with any propellant based system. Doesn't seem very reasonable, given relatively hard science constraints.
[Answer]
It is not terribly *plausible*, but it is mathematically *possible* for a ship to survive indefinitely in the proper sort of black hole.
If we're talking about a basic Schwarzschild black hole--uncharged and non-rotating--then no orbits are possible. Once you cross the event horizon, you will hit the singularity in finite time. Now, that in and of itself is not *necessarily* a problem--after all, if the fall time were longer than the inmates' expected lifespans, such that they'd all die of natural causes before hitting the singularity anyway, that sounds like a perfectly good deal. And it turns out that, the bigger the black hole, the longer you have to live, and furthermore that [there are things you can do with rockets to extend your subject time](https://arxiv.org/PS_cache/arxiv/pdf/0705/0705.1029v1.pdf).
Unfortunately, the maximum lifetime you get even with supermassive galactic core black holes is on the order of hours, not decades.
So, we need a different kind of black hole. Black holes that are charged, rotating, or both contain a second inner horizon, where the radial coordinate switches from timelike back to spacelike again. As a result, while you will inevitably cross from the outer horizon to the inner horizon in a finite time, once you have crossed the inner horizon you can in principle *avoid* the central singularity. It is well established that photons can have stable (spirally, non-circular) orbits in this region, and [work by Russian physicist Vyacheslav Dokuchaev](https://arxiv.org/pdf/1103.6140.pdf) indicates that there is no fundamental reason why massive particles--including spaceships or even whole planets--could not also maintain stable (non-equatorial, non-elliptical) orbits around the singularity, below the inner horizon.
Of course, those predictions are based on idealized cases; actually adding extra massive particles to the universe besides the black hole singularity itself complicates the metric, and the inner horizon is not particularly stable. As such, not everyone agrees with Dr. Dokuchaev that an inner habitable region *would* actually exist within any real black hole. But, it's good enough for sci-fi!
So, your prison ship's orbit can theoretically last indefinitely. What would it be like? Well, if you have windows, the exterior view would be trippy. Space is pretty warped in there, to the point that you don't *just* get "normal" gravitational lensing--photons follow weird spiralling paths, so where you *see* other objects through the window bears very little relation at all to where anything actually *is* outside. On human scales, inside the ship, however, space would still be geometrically flat enough not to cause any real problems. The inmates would experience tidal gravity that would pull them towards the ends of the ship pointing towards and away from the singularity, the precise strength and direction of which would change over the course of the non-planar orbit; but, those forces would be weaker near the center of gravity of the ship than towards its extreme ends. If the ship rotates to provide spin gravity, and controls it orientation so that it's rotation axis is always aligned with the line towards the singularity, those effects could be almost entirely eliminated. And, you can make them as small as you want anyway by just picking a suitably heavy black hole, rotating suitably quickly, so that the inner horizon is at a great enough distance from the singularity to allow for *orbits* at a great enough distance to make the tides negligible on the scale of the ship.
[Answer]
In order to maintain an orbit you need to be going fast enough to not plummet towards the singularity. Orbiting after all is basically just falling so fast you miss the planet(or given celestial body).
Now in order to be *below* the event horizon and not be sucked into the singularity you'd have to be orbiting extraordinarily fast. You'd probably have to go faster than light in order to maintain such an orbit considering not even light has the capability of escaping the event horizon. And light doesn't even have to with the mass that you're having to drag up! I'm sure you're aware that objects that have mass cannot achieve the speed of light. E=mc^2 and whathaveyou.
So in short, no, it's not really *feasible* to have even a decaying orbit below the event horizon.
But let's say for a second you've invented faster than light travel and are somehow able to not immediately fall towards the center and also everyone on the ship isn't dying for some reason.
What the crew would experience is something called Gravitational Time Dilation. What it says is that the amount of time that has elapsed differs between two observers depending on how far each of them are from a gravity well. The closer one is, the slower time passes. Now this doesn't mean the crew and prisoners would feel like they're going in slow motion, it means that if they could see outside somehow, time would appear to be passing faster. This would only be exacerbated by the fact that they are going faster than light which would itself cause its own form of time dilation. The end result is that what could only be an hour to the people in the prison could be eons to the people outside.
As for the laws of the universe, well, if the only way of having even a decaying orbit is go faster than light then hypothetically the prisoners could riot, hijack the prison ship, and high tail it out of there.
My final notes would be that however long the orbit lasts depends on how wide the orbit is and how much fuel you have to maintain it. Although since a singularity takes up no space at some point the ship will just appear to be spinning around the center for an eternity before it hits the center.
<https://en.wikipedia.org/wiki/Gravitational_time_dilation>
<https://en.wikipedia.org/wiki/Time_dilation>
[Answer]
It is generally agreed that crossing event horizon by itself should be harmless to the traveler. However, conditions inside the event horizon are very much up to the debate. Physical equations point to some very weird results, like space inside the event horizon starts to behave like time, and time starts to behave like space.
So, the spaceship can possibly cross into event horizon without immediate destruction. But it is not possible to tell what would happen to it inside, and how soon something can happen to it, either from outside observer's or traveler's point of view.
Our real knowledge of the conditions inside a black hole is so limited, that the depiction of them in the movie "Interstellar" can very much be true. "Why not"?
[Answer]
The answer is your own hands. If you can calculate the tidal forces experienced over two metres at a distance of one hundred kilometres above the event horizon. Surely you do a similar calculation for the tidal forces over a distance of two metres, say, one hundred kilometres below the event horizon.
In which, you would know the situation for persons on spaceship orbiting the centre of mass of the supermassive black hole. Remember spaghettification only occurs when the tidal forces are capable of rendering people and things asunder over short distances.
One thing about supermassive black holes often overlooked is that a spaceship can pass through the event horizon without realizing it had done so. The event horizon isn't a physical barrier, it is a surface of gravitational potential where escape velocity is equal to the speed of light. Spaceships should be able to orbit just inside the event horizon as if it was a normal orbital vehicle. It's just that it can never escape from the interior of the black hole.
One caveat: This would be an excessively expensive method imprisoning anyone. It would be a major expenditure for a galactic economy. It would have to be more of a grand symbolic gesture than an effective prison system.
[Answer]
I remember sth that time and space are so dilated the traveller would never get very far in the black hole. Not sure if that was a scientific opinion.
Anyway most black holes are small, so the gradient in gravitation between someone's head and feet could be large enough to rip him into pieces long before he reaches the event horizon from the outside. *Inside*, I guess this problem will grow worse. Although that could take a long time if what I say above is correct. Cruel and unusual? :-/
]
|
[Question]
[
Throughout history we've seen that governments which expanded far and wide all ended up today controlling just one area on the map. I was playing Civ 6 and realized it can be tough even in a simplified game environment to control territories far away from home. A popular story line in movies and games lately has been colonization of our solar system where the colonists break off and rebel against their original government. The very country I live in (USA) went through almost the same exact scenario except the distance was an ocean, not interplanetary travel.
What factors govern this phenomenon? Can civilizations overcome this barrier, or are they bound to this pattern indefinitely?
[Answer]
There are two major factors that limit the ability of central government to exercise control:
1. Speed of communication
2. Frequency and dependability of travel
Fast and frequent travel makes it easy for central government to know what is going on in distant province, make quick adjustments to policy, or send troops, if necessary. Genghis Khan's empire owns its success to flat steppes and mounted riders. On the other hand, no one could keep unified rule over Southwest Asia or Western Europe for long time because rivers, forests and mountains did not allow for fast travel.
For the actual independence movement, there is a whole lot of other factors that may push parts of empire together, or apart, like:
* Common language
* Common religion (or secularism)
* Citizen's rights
* Lucrative trade or need to supply essential goods
* Taxation
* Ongoing war or threat of war from neighbors
[Answer]
Alexander's answer is, IMHO, the best answer and should be upvoted and accepted. I am only adding to it.
That list of "other factors" he mentions is, as a whole, equally important when compared to communication and travel. For example, if a widespread society "trusts" or "has faith in" their government, then that government is stable pretty much by default. But, what makes this true (or not true)?
**Law & Order**
Not to rob [Mr. Bellisario](https://en.wikiquote.org/wiki/Law_%26_Order) too much, but, "In the criminal justice system, the people are represented by two separate yet equally important groups: The police, who investigate crime, and the district attorneys, who prosecute the offenders." Without those two groups (aka, the police and judicial prosecution) you don't have a government. At best you have a services provider (the guys who fill in the potholes).
>
> We trust our government because it has sensible laws and a sensible way to add, remove, or modify those laws. We trust it because those laws are enforced in a reasonable and timely manner. We mistrust our government when laws are unbalanced or inadequate, or when enforcement is corrupt or undependable. The moment the majority believes they have no choice but to take the law and its enforcement into their own hands, there is no government.
>
>
>
**Services that Benefit the Whole**
Governments usually benefit us more than just by creating policy. Whether it be local governments providing roads and emergency services or national governments providing resources (usually money, but managing things like land, too), regulation, and centralization of knowledge and culture.
**Common Defense**
Finally, we trust our government because it provides defense for us in the form of a military.
---
Obviously, these are all to one degree or another dependent on communication and transportation. The simpler and less invasive the government, the less it must depend on C&T. However, people are people, so there will always be greed and lust for power.
* Fleets would likely be required to have a diplomatic corps and a judicial corps to handle planetary issues not the least of which are appeals. The threat of force would be necessary to impose the order needed to permit these actions to occur. A triumvirate of power (lead judge, lead diplomat, fleet admiral) would more-or-less hold the checks and balances needed per-visit.
* Planetary governors need to be kept in check. Ideally, no planet should be allowed to build a local defense that competes with the visiting fleet. Here is one of the most critical variables: if the time between visits is long enough to let the planets build fleets, well... that's a world of pain.
* The fleets likely need regular visits either with the homeworld or with other fleets to ensure (as much as possible) their loyalty. The triumvirate should have some kind of ability to lock everything down if one thinks the others aren't playing by the rules... but a rogue fleet is a problem.
* Finally, one of the best solutions is to export children from the planets to the governmental core for training in (*ahem*... *cough*...) civics. These become your loyal adherents that fill the middle-management positions that make a takeover fairly difficult. You want some of those kids to conscript into the fleet (possibly mandatory conscription, which wouldn't be a bad idea) to help instill the idea that the greater whole is more important than the local leadership. The U.S. military actually does this kind of thing, shipping enlistees to other states than their home states to, among other things, create a bit of separation between nation and state. When the military needs to step in for an emergency, it's common that people from other states are sent.
[Answer]
One more significant factor to add to the already good answers here:
**Bureaucratic technology**
We think of bureaucracy as a bad thing because it means a lot of red tape and boring stuff we don't want to deal with, but in history, it is the invention of bureaucracy that allowed for the development of very large empires. The Chinese did it very well quite early, with a class of people dedicated to be civil servants by a government-oriented religion that reinforced the authority of the Emperor with "submission to authority" ideology. They were able to maintain a very large and very stable empire for a very long time.
Bureaucratic technology was key to ancient Rome's success, and in fact is likely a major reason Rome was able to maintain a large empire after the Greeks had failed to keep Alexander's empire (or it's parts) together. Romans were very good at standardizing things like measurements, communication protocols, weights, even the layout of towns. It wasn't just their extraordinary road system that facilitated communication and commerce, but a very carefully organized system of civil servants and delegated authority to local governors and cities, all meshing together in a bureaucratic apparatus.
After the end of the middle ages, technology had made armor outdated, but it took warfare a while to transform. Napoleon really forced the world to adapt to the new technological paradigm, but he did it not so much through his knack for tactics on the battlefield as much as his radical use of bureaucratic machinery to create the modern nation state. Napoleon realized that since muskets were cheap and simple to learn, and very hard to defend against, the new paradigm of warfare wasn't "who has the best army?" but "who can replace their expendable army the fastest?". He weaponized the huge mobs of starving French peasants by drafting them, throwing together massive armies faster than his enemies could organize. To do this, he turned France itself into a massive machine for churning out badly trained cannon fodder. That is where everything from the modern census to public education comes from: the Napoleonic paradigm of warfare seen most clearly in World War I. By the 20th century, bureaucracy was the most important weapon of war on the planet. WWII was won entirely on that basis.
So my three factors I would say are ABSOLUTELY critical to determining the possible expansion of an empire are:
1. Speed of communication, as mentioned previously.
2. Dependability of travel, again, as mentioned.
3. Sophistication of bureaucratic systems.
The largest land empire in history was that of the Mongols, and it hinged entirely on the organized nature of the governing body, which was capable of coordinating effort across thousands of miles of territory. Loyalty of state agents, incorruptibility of functionaries, reliability of emissaries of the Imperium are all units of measurement for how well bureaucracy functions. In a case where travel requires years of time to cross vast distances in space, you need systems in place to ensure the long term loyalty of representatives of the state as well as the incorruptibility of your communications.
It is worth noting that the more efficient your bureaucratic apparatus, the more resistant to change your society becomes. This is because the entire point of bureaucracy is to guarantee rigid loyalty to the original intent of the central authorities. It has a natural dampening effect on innovation, change, and adaptation. This is why Rome declined, why China had multiple crises, periods of chaos, and eventually stagnated technologically until it was WAY behind the rest of the world, and why the USSR fell apart. The more territory you can control from one central point with one small group of people, the less room for independent thinking there is for everyone else. That's how you get left behind by the innovative, creative "barbarians" outside the imperium.
]
|
[Question]
[
Magic is drawn from an alternate dimension and used to alter reality in the world around you. It generally involves three steps.
* The first is tapping into this other realm and drawing energy from it into your body. This is a slow, arduous process that cannot be rushed. Every spell has its own time frame. The analogy is compared to cooking: too slow and nothing substantial will happen, too fast and there will be a "flaw" in the spell.
* The second step involves holding the energy in your body and keeping it stable. This energy tends to leak out of pores or fizzle away, so the more stable and controlled it is, the more effective the spell.
* The final part involves directing the energy outside your body to perform the actual spell. You must activate it by performing the incantation and envisioning the spell that you want to perform, such as starting a campfire or speeding up the growth of crops.
All of this requires much concentration and focus, and can be the equivalent of physical activity. Spells can take several minutes to hours to perform, depending on how powerful it is.
While regular magic is almost slow and patient, attack magic is the opposite. It requires aggressively forcing energy from the dimension and imposing your will onto the world. Creating fireballs and throwing lightning are some of the ways this form of magic is used to attack or defend. Although much quicker and more powerful, it is highly dangerous.
Drawing energy this way can be painful. Holding it inside yourself, without the right amount of control, can cause the energy to damage your internal organs, or make you combust, infect you with a disease, age prematurely, etc. Directing it out of your body without the right amount of control can also cause you to hurt yourself, like blowing off your own arm, losing control of the spell and causing collateral damage.
Would these drawbacks be enough to constrain usage of attack magic among people? Is more needed to control the use of this brand of magic?
[Answer]
The short answer is: *You'd better honking believe it's enough.* But, just to be sure, let's look at a comparison.
If I ask the question, "What would it take to constrain the use of a gun as a means of attack among the population," the value of your proposition becomes remarkably clear. Guns are relatively cheap. Bullets even more so. The method of holding a gun can cause discomfort (I wish I could remember the show and episode that pointed out that holding a modern semi-automatic pistol sideways "gangsta style" resulted in the slide cutting your hand), but, ultimately, it causes no pain, no fuss, no problem at all to use a gun to attack, for example, a neighbor.
So, why don't we see the use of guns gone rampant in our society? I mean, it's bad, but it's not *[The Purge](https://en.wikipedia.org/wiki/The_Purge)* bad. Why isn't it?
Because our society has, over the course of millennia, established rules of conduct about how you can legitimately "attack" your neighbor and what happens to you if you circumvent those rules. Your world would have rules just like this (if for no other reason than there's always somebody who wants to impose rules on other people).
Then, add to this the fact that it's painful, even fatal, to use attack magic and your society would, frankly, almost never use it. You might see small "attacks" like spells that mimic pinching the girl next to you (you know, 6-year-old stuff) — small "offences" that lead to spanking which reinforces the more complex stuff later on — but the big stuff? It's use would become a huge taboo... if only because the first thing anybody's going to do is look around to see who's doubled over in pain, then point their finger and scream, "That dude did it!" Cue the police.
So, considering you're imposing something more than our own society has done for the purpose of social order: Yes! it's plenty. What would make interesting stories would be the tales of how people circumvented the weaknesses for their own gains (much like we love crime mysteries today).
[Answer]
I like your system. It has a lot of promise.
It even offers a very simple argument to limit the use of attack magic: "it requires aggressively forcing energy from the dimension and imposing your will onto the world." When you impose your will on the world, it imposes its will on you. And you will find the world is a very big place.
One approach to this I have used is to say that the actions of your magic work perfectly, in the world you believe you are living in. However, if the world does not exactly match your model (and it rarely does), then the effects are not exactly as you want them to be. And they are *really* close to you. 99.9% of your lightning bolt spell may go to the intended target. However, if that 0.1% hits your own heart instead... well... let's just say this qualifies as a really good reason to not use attack magic unless you have to.
[Answer]
>
> Would these drawbacks be enough to constrain usage of attack magic among people?
>
>
>
I think this is just authorial choice, scale it to the needs of your plot. You can ramp up the fear factor among the other characters in the book; to the point the reader fears for the life of the hero using it (or is glad the villain must resort to it).
This is akin to the story telling technique of corroboration: If all the characters **treat** Cindy and talk about Cindy as being the most beautiful girl in the world, then in the eyes of the audience she is. On "The Big Bang" series, all the characters pretend Sheldon is one of the greatest physicists ***of all time,*** even other academics (except for Stephen Hawking), so the audience accepts that Sheldon is a world class brilliant physicist.
The danger of attack magic can be similar, and fun to write about the failures. Campfire stories abound about heads exploding and magicians being mysteriously diced into perfect fingernail sized cubes. The heroes about to use it go through elaborate rituals preparing to die in the effort, receiving the blessing of the King and an embrace and Kiss on the cheek from the Queen before they depart, since they will almost certainly die for the Kingdom at some point in the battle.
Or you can make it less dangerous than that; rig the odds (and the outcome) to fit your plot. Maybe a turning point is the hubris of your best Attack Magician, the one that never fails and knows it full well, the one superstar everybody is cheering for, saunters to the hill above the battle, casts his spell and is split in half and turned inside out by his spell, killing half the men around him and causing the loss of a pivotal battle that makes it seem all is lost.
[Answer]
# Yes, with a few exceptions...
You describe a process that requires patience, concentration, and focus.
*Combat allows none of those things.* Combat is fast-paced, requires you to be keenly [aware](https://en.wikipedia.org/wiki/Situation_awareness) all the time of what's going on around you, and rarely gives you the opportunity to sit down and work on something that is complex and nuanced like [baking a souffle](https://www.quora.com/Why-is-making-a-souffl%C3%A9-considered-difficult-What-are-some-tips-for-a-first-timer-attempting-a-chocolate-one) but with the possibility that messing up will blow your arm off.
**Think of it like this:** In society, people will use ready-to-hand weapons in non-military fights. Knives. Guns. Random blunt weapons like pipes, baseball bats, etc. But they very rarely use something that requires the finesse you describe. And never in heat-of-the-moment fights -- which is most of them. Just as you rarely see people use nitroglycerin or [IEDs](https://en.wikipedia.org/wiki/Improvised_explosive_device) in typical fights.
You are setting up a situation where combat magic might exist and be used in **mass-combat** events. Armies clashing somewhere might have at least a few trained combat wizards around. But they'd be used carefully, early in the fights, and would have to be ready to bug out fast if the combat didn't go according to plan. They might be a first strike force, firing the opening salvos of a battle. But they would not be front-line forces like cannon. Maybe rear forces like artillery.
Combat magic might also be used in similar ways to today's [IEDs](https://en.wikipedia.org/wiki/Improvised_explosive_device). Bombs that may be risky, but are perceived as worth the risk by their users (terrorists, revolutionaries, etc.).
And because of magic IEDs, you might have the equivalent of **bomb squads** in some cities, magicians trained to counter combat magic -- and therefore trained to perform combat magic. They might also serve within your world's equivalent to SWAT teams, trained to perform precision combat magic in rare but extreme situations.
[Answer]
The sheer effort of practicing as well as the imposed social taboo of it, (why are you trying to learn how to hurt people and nearly kill yourself..weirdo) would be enough to move it to the fringe elements of society, however with a thing like magic it will be used by lone groups, scientists and professionals because its still a fascinating area.
In this world because of the dangers this kind of magic practice would have to be tightly regulated and controlled by authorities, because a tiny bit of knowledge could lead to a massive explosion killing hundreds - this has probably happened before hence the laws around such use and would be enforced by the public informing on people who are practicing. Hopefully detectors can easily identify if magic has been used by the person recently to avoid any witch hunts and false positives.
]
|
[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/71714/edit).
Closed 6 years ago.
[Improve this question](/posts/71714/edit)
Based on [this question](https://worldbuilding.stackexchange.com/questions/71638/how-would-fembots-change-society)'s answers, for "fembots" not causing a Singularity, they need to be "primitive".
Physically, they are weak, sluggish and not that dexterous. They can carry around objects, but they cannot clean nor cook. They can easily be knocked down, even by a kid. Their surface texture has distinct "artificial" feel to it and their "sexual" abilities are "acceptable" for most (single) men. Intelligence-wise, they are no better than modern virtual assistants. They can hold simple conversations, but anything more complicated will confuse them. Something like more advanced chatbot. So best they can do is to remember when their owner returns home, know his favorite food, and order that favorite food so it arrives right after he returns home.
The question is same : How would this artificial companion change society? How much would they cost, so that manufacturer can gain profit?
[Answer]
## This could potentially solve an impending disaster
**Sex-ratios should be close to 1/1**
The sex ratio at birth, if there is no manipulation1:, has been stable and near 1/1 male/female for all populations for centuries. There are usually slightly more males than females born, but it naturally varies up and down (and it is often hard to obtain accurate numbers). Reports as far back as 1710 have been verified to show ratios as high as 1.07 and the European median was [1.059](http://www.pnas.org/content/103/36/13271.full#sec-1) between 1962-1980, a number which often is used as baseline in studies. We are "currently"2: at a ratio of [1.018](https://www.wolframalpha.com/input/?i=sex+ratio) world wide among all living (i.e., not only birth), if one instead look through [CIA's fact book](https://www.cia.gov/library/publications/resources/the-world-factbook/fields/2018.html#203) from 2013, then the birth numbers varies between 1.03-1.08 for most countries with some extremes both below and over.
**Extremely skewed ratios**
However, several countries have [preference for boys](http://www.popline.org/node/359060) meaning that, with the introduction of gender assessment during pregnancies, girl fetuses have a higher risk abortion and the child mortality for females have been reportedly higher than for boys; an estimated [67-92 million girls](http://www.pnas.org/content/103/36/13271.full#sec-3) were missing in 2001. The fact that many girls are lost at an early age means that the sex ratio skews even more later in life for many countries (something which can be seen in the CIA fact book). In addition, China had a [one child policy](https://en.wikipedia.org/wiki/One-child_policy) between 1979-2015 which, in itself is not affecting the sex ratio but together with the preference for boys, has led to an extremely skewed sex ratio.
All in all, the skewed ratio for people in marriageable age exceeds 1.1/1 male/female in many countries and the prognosis is that it will get worse in the future if we do not take action3. Millions of young men will be without a wife and majority of them in countries where having a wife and family is [essential in order to be accepted in the society](http://www.pnas.org/content/103/36/13271.full#sec-4).
**Consequences of a skewed sex ratio**
The exact consequence of this is very hard to predict. For the women who reaches adulthood in those countries, there are two potential paths: Either they will have their status massively improved and they will be highly pampered in order to select the "right" husband (if they have the option to choose partner) and/or they will have the chance to [switch partners](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3244803/) as to not get stuck with a bad first choice; or they risk being married at a much younger age than before (if they do not have the option to choose partner), something which most likely will lead to reduced education for women and increased gender based inequalities. In short, the rights and possibilities for women will either increase or decrease significantly, but which direction it will take is hard to say; with the history in mind of how their status has been in most of the areas, it is likely that it is not going to be for the better (although one can always hope).
History suggests that for those men who do not manage to get a wife, they will be social outcasts and have reduced happiness. Studies largely show that most of the crimes is caused by [unmarried, low status, young men](http://www.pnas.org/content/103/36/13271.full#sec-4). It is believed that there will be increased violence, both sexual and non sexual, and increased homicide rates. In short, if we thought terrorism is bad now, just wait and see how easy it will be for radicalist groups to recruit when there are millions of angry, under-educated, young men around.
**Gynoids4 as solution**
Introducing robots as companions will not solve all of the problems. For those males living in societies where it is highly important to have a family to be accepted, this will likely not be seen as an acceptable alternative of marriage - but that perception will probably change if enough men cannot obtain a wife. The improvement is that they will not feel as alone and under-stimulated if they have a partner, even if the partner is artificial, meaning that it will be a possibility to postpone most of the prognosis that suggests disaster; hopefully this will postpone the problem until the sex ratios are evened out, something which will take several decades. This could be a solution to prevent crimes, suicide and potential radicalization - provided that they are affordable. As most of the men lacking a wife will be from poorer areas, the dolls will either have to be subsidized or made really cheap.
**Effects in other areas**
In areas where the sex ratios are not as skewed, the effect of gynoids will be tricky to predict. I sincerely doubt that it will lead to any situations where we will have several females who cannot find a partner as men will prefer sex robots; most people will want to have a human partner. Most likely, it will be a sex toy or something those men who currently cannot find a wife would go for. Should it ever happen that men would prefer gynoids over real females, then there will be an increased market for android sex dolls (something which there likely will be anyway, there is no reason to believe that no women at all would ever want one). Worst case scenario would, of course, be that our species die out due to everyone getting a sex doll partner, but that is highly unlikely. We might simply end up on a fraction of people with sex dolls as partners, which can lead to that our numbers will stabilize at $\leq$10 billion people, which is deemed as an sustainable number.
---
1: Such as selective abortion or infanticide of children with unwanted gender.
2: The Wolfram data is from 2011-2013, which is relatively current but might have changed for the past years. Data from 2004 say 100.8/100, suggesting that it has been a slight increase.
3: Something far easier said than done.
4: While many argues that android can be used for both, the word [andro](https://en.wikipedia.org/wiki/Andro) means "male" and [android](https://en.wikipedia.org/wiki/Android_%28robot%29#Etymology) means "male-like". Gyno is the prefix for females, which would make female-like robots gynoids.
[Answer]
The way you describe the product makes clear they will be a niche thing, for real "tech must have".
Being a fairly new product its price will be still high. As reference, think how expensive and "dull" were the first mobile phones in the late '80s.
In all honesty, why would an average single man spend so much for something like what you describe?
So, if the manufacturer manage to survive on the market, I don't foresee any real impact on society from this "primitive" gynoids.
Maybe later on, if they become a more mature and affordable product, there might be concerns raising from the conservative parties that gynoids, freeing males from the search of a female companion to reproduce with, endanger the civil society by reducing the number of newborn citizens.
[Answer]
Note: I’ll be referring to the Gynoids/Fembots just as “machines”, out of personal preference (or lack thereof).
---
**Features**
Let's break down these machines by "features":
>
> They can carry around objects, but they cannot clean nor cook.
>
>
>
This means, it lacks the fine dexterity to handle a hand tool.
>
> They can easily be knocked down, even by a kid.
>
>
>
It either lacks strength or lacks balance. Definitively of little use as a guard.
>
> Their surface texture has distinct "artificial" feel to it
>
>
>
So touch give it away, it won't pass as human if skin contact is required
>
> and their "sexual" abilities are "acceptable" for most (single) men.
>
>
>
This is probably one of selling point for this product.
>
> Intelligence-wise, they are no better than modern virtual assistants.
>
>
>
So, there exists technology that's better in the market. The designers didn't go for the most intelligent solution, either because it wasn't needed for the intended task or because it would have made it too expensive.
>
> They can hold simple conversations, but anything more complicated will confuse them. Something like more advanced chatbot. So best they can do is to remember when their owner returns home, know his favorite food, and order that favorite food so it arrives right after he returns home.
>
>
>
This is the other selling point, they could be marketed as artificial companions.
While they could be useful to assist elderly people or even as baby watch... The fact that they have sexual abilities suggest that the market is single lonely male adults wealthy enough to pay.
Men with a bad job, that don't have time to date or don't earn enough to sustain a family could be the main market.
---
**Employment**
When introduced, as an expensive item, one of the first business models to use them is to rent them. The legitimate use would be to greet people in events, that would be expensive and sporadic.
Whoever considers that business will want to increase income by renting by the hour instead of days, adding an insurance fee, and a no-questions-asked policy... because we both know we don't want to ask what people actually do with these machines.
Note: below I use the word "programmed" loosely. Programming doesn't have to mean to write in an artificial language, it could be just setting configuration (like programming an alarm clock), some programming may mean to interface with a server elsewhere which is doing the actual work, or in some cases it could also mean to mod the device. Edit: perhaps it can be better to think about it as installing an "app".
The next stage is where people start to give more permanent tasks to the machines:
* As receptionist/secretary: it can greet people to buildings, manage appointments, and it could even work as security camera and be programmed to trigger an alarm on unexpected behavior (e.g. unknown person entering without appointment, person entering with weapons, any activity after work hours, etc...).
* As a teacher/lecturer: it could be programmed to repeat a speech, and even be able to answer a set of predefined questions.
* As waiter: it could be programmed to deliver orders from the tables to the kitchen and to carry the dishes back to the table. They could recognize customers, be able to recite portions of the menu, and even answer simple questions about the dishes or do recommendations.
* As guide: it could be used to make tours, to show people around a building, or even tours of a city if somebody or something else is driving (autonomous vehicle?)
* Others: Cashier, Bank-tellers, Librarian, and other similar jobs could get a similar treatment.
---
**Disruption**
I'll assume that this product becomes popular in some areas where it is a good deal for business. All the impact will be local to those areas.
It will take a while since the introduction in the market to become popular... if at all. Some business will have to step up and take the risk to see how viable is to use them, and they will face the most opposition... if that goes ok, others will follow.
Addendum: Perhaps it doesn't become popular with the first bussiness that tries it, it just means that the product or its production will have to be improved so that it provides a better cost/benefit scenario. After about a generation (20 to 25 year) it probably will be good enough, and there will be new people willing to take the risk. Think [Virtual Boy](https://es.wikipedia.org/wiki/Virtual_Boy) vs [Oculus Rift](https://es.wikipedia.org/wiki/Oculus_Rift).
---
Under the assumption that at the point where these are affordable and attractive for the single man, that person probably wasn't going to get a STD or cause an unwanted pregnancy... so, any effects on that is negligible. Although it may improve quality of life and even cut suicide rates in regions where those are problems.
On the economy, they are just another step toward replacing jobs with robots. We can model the effects using the Kübler-Ross model (a.k.a the stages of grief):
* Denial: A) people don't see a threat in these products. They are just a novelty or a thing for weirdos that won't affect the economy overall. B) buying these things is seen as waste, and whoever does it is seen as a loser.
* Anger: Some people start losing their jobs to be replaced by these machines, and people don't like it.
* Bargaining: some people are willing to pay more to be attended by a real person, and some people are willing to earn less to keep their jobs. Labor unions negotiate ways to keep people employed, and laws are made to restrict the use of these machines. Soon, they need to be audited periodically by the government to check they are working correctly, adding extra cost to their use in business.
* Depression: The jobs that were lost were lost, the times where you could get a human being at the counter were better. It is all mechanical now, no need for manners or respect. Just give up, machines win, humans are useless.
* Acceptance: I'm unsure how this looks like, but people got to find another source of revenue. They have to accept that they have lost a portion of the job market to these machines.
Not really all jobs can be gone, it is easier to disrespect these machines than human being, and people need income, so there will more crime. Which means that security guards are in good demand.
The time frame for those stages isn't clear, although "bargaining" may last a few years just because bureaucracy and law making isn't exactly the faster industry.
---
Rural and industrial areas would have a lesser impact, because most if not all of the applications of these machines are in urban service and commercial areas. That would suggest that there has been no impact in traditional food industry.
Stores and markets may be cutting prices, after all people aren't earning as much and they are saving in payrolls. In some areas, it could also be a push for local food production (e.g. neighborhood farm).
So, I don't expect starvation or anything like that, people will settle to something else.
The value of the land will initially go down, as the affected areas are places where it could be hard to get jobs (people may want to move out to other areas where they can get job easily, so they may willing to sell cheaper). But it will eventually go back up.
Note: I did consider that there could be less new families in urban areas where these machine are popular, not because male prefer the machines as sex partners... but because income would have gone down due to lost jobs and human interaction would have gone down. Although I thing this effect is negligible too, because it won't affect all areas and because people will find solutions soon enough.
[Answer]
Sheri Tepper's novel [The Companions](http://www.curledup.com/companio.htm) has something like this with "concs". They had no defined sexuality, so were equally applicable for both sexes.
The main effect of concs in the novel is to dramatically reduce the birthrate. Tepper's view from then is that there would be no such thing as an "unwanted" pregnancy, because people only wanting sex would have their needs met by their concs. Being Tepper, of course this is somewhat idealistic and the only people with sexual needs are clearly evil, but the concept is still interesting.
Tepper's concs were produced by benevolent aliens with a view to improving human society. (Tepper consistently imagines an overpopulated world, but she was writing at a time when birthrates had not yet started falling below maintenance levels in Europe.) As such, production cost was not an issue.
]
|
[Question]
[
Welcome to Nottonmap, a small village in Whateverdrivestheplotland! The entire village has an impressive total of 500 inhabitants and doesn't really have more to offer than a smog-free and peaceful environment. Because the village is so small everyone knows each other, and often get together on holidays or sport events.
Eight years ago this village gained two new residents who moved inside the village's old abandoned mansion: A man in his early forties together with his daughter of seven. Being a single dad is hard enough, but the poor guy also has various health problems: photosensitivity, eosinophilic gastrointestinal disorder, as well as numerous other allergies for various foods. This means he can't go outside or eat anything solid without throwing up. Regardless of these weird quirks he got accepted into the community and is still, after 8 years, one of the most likable neighbours in the village.
...But why?
Vampire-dad is back from my [previous question](https://worldbuilding.stackexchange.com/questions/69149/how-does-vampire-dad-keep-the-masquerade-to-his-daughter)! This question mainly focused on keeping the masquerade to his daughter, who doesn't know that her dad is actually a vampire. The reason why convincing the village's residents wasn't that important is because he already is an accepted and respected member of the community. "Stop calling that poor man a vampire, he's really conscious about his health issues!"
The problem here is that vampire-dad can't go outside during the day. May sunlight ever hit his skin he will painfully combust into flames - no sparkles or rashes, just instant death. To make matters worse he can't eat 'human food' either, or he'll throw up. This kills most of his options to socialize with the villagers. I could just say that the residents are empathetic of his issues and wait till dusk so he can join in events, but would a close-knit community like that really refit its schedule for the new creepy-looking stranger who just moved into the local abandoned mansion?
**How do I justify vampire-dad being an active and liked member of the village community?** Assume modern day age with nobody knowing about the existence of vampires while still aware of popular vampire-tropes from fiction.
**A few things about vampire-dad:**
* He can't stand sunlight. UV or any other light doesn't bother him, but a single ray of daylight will lead to a flashy and painful demise. While he *technically* can go out during the day he really shouldn't risk it.
* He is seriously allergic to garlic. Even the smell seems to cause rashes.
* He can't eat normal 'human' food. If he does he'll throw up after an hour or so.
* He needs to have his daily blood-fix, which he gets through a weird fruit he cultivates in his own backyard. He jokingly calls them 'blood-oranges'. They hold no nutritious value to humans and taste absolutely horrible.
* He has super strength, super senses, super reflexes, can fly and turn into black mist. But only during the night.
* Sleeps like any other person, but during the day because of his job. The real reason being, of course, that he really can't afford to go outside during the day even when it's cloudy.
* He has a lot of money, but still works night shifts at the hospital in the nearest city a reasonable drive distant away. He does this because he likes the work and to create some routine in his day. The real reason is to keep up the charade, of course.
* He is on good terms with his daughter.
* He does have a reflection. I removed this rule from the original list because it was too much of a hassle.
* He told everyone that his vampire quirks are all medical conditions for which he feigned the proper documents through his job at the hospital.
* He does not have any mind-controlling powers.
* He is very tall and looks really intimidating if you don't know him.
* He's a really nice person and wouldn't think of deceiving anyone about anything other than his vampirism.
* Just wants you to give him a chance.
**Vampire-dad's daughter**
* was 7 when she arrived into town, and is now 15.
* has no clue her dad's a vampire, and will defend him when someone puts his medical issues to question.
* is diurnal unlike her father and goes to school, but always on her own as her father can't go outside during the day. She is used to this and still sees him often enough during the morning and evening.
* Is not showing any vampire-traits. Yet.
Bonus points for the person who can think of a proper name for the village.
[Answer]
He can participate in the village activities (lets say some local fair), since most of them have duration of a full day. So, when the sun sets down, our vamp-dad can make an appearance, talk and interact with normal humans, etc.
He attends the school meetings of his daughter regularly, since these happens after school hours (sunset again), although for a brief time due to his working hours/shift.
He can invite neighbors to watch a game on tv on his day off, of cook some diner for them (he cant eat, but he is a descent cook since he must cook for his daughter).
He can meet with friends in local bar/pub and have a beer or two (he can drink i assume, since you mentioned only that he cant eat human food).
He attends meetings in mayor's house to vote/talk about local problems.
Once he beat up couple of punks that were harassing one elderly couple (improved physical attributes), but only after he tried to talk to them and only when they attacked him first - this gave him extra points.
Once he got drunk (faked it of course) and do something stupid. The next day he made amends and ever since he tries to behave (for example, he paint black the local statue of . Ever since, he takes good care of it, clean it, in a regular basis.)
In general, you can be very social in such a small community, despite the limitations, and be very likable only by performing one or two memorable deeds.
[Answer]
The fastest way to win a starting amount respect of the people in small village like this would be a heroic deed.
For example, if your vampire-dad is resistant to fire, make him save a person or two from the burning house:
>
> It was a dark and calm night a few years back when all'o the sudden
> Joe's gas pipes blew sky high. I told him a million times to fix the
> damn pipes, but "no-o-o, it's too expensive, they are fine as they
> are..."
>
>
> Anyway, Joe's ball'n'chain got out of the house in a nick
> of time, but Joe himself was trapped in this bloody inferno. The whole
> village came to try and put down the fire, but we couldn't do a damn
> thing. And then this new guy, thin as a stick, comes in and runs into
> the house like a crazy.
>
>
> "Well, damn, now we'll have to bury two of them" - I thought.
>
>
> A minute passed and then this new guy jumps out of burning window with
> poor Joe on his shoulders. Like a bat out of hell, I tell ya.
>
>
> Well, turns out this new guy wasn't that bad after all. Sure, he is a
> bit weird and if he had a dime for every illness he has he'd be rich
> as... as he is, I guess. He helped the poor Joe to rebuild his house.
> And he is a great doctor too, he helped me to get rid of that damn
> blister that had been bugging me for last twenty years. He is a good
> guy, I tell ya.
>
>
>
*(Sorry for the poor grammar, English is not my native language)*
[Answer]
* *he can not eat* - but can he drink? if so, he can definitely gather sympathy points at the bar - maybe even being the barkeepers favourite because he's the only one *not* getting blackout-drunk because of a super-human liver capacity
* he is regularly winning his team a bowling competition with a competetive, neighbouring village - which is only carried out late in the evening because the lane doesn't open earlier... there are many other potential activities that can be moved into the night for non-outlandish reasons.
* how succeptible to sunlight is he - does he really instantly die at the first ray? does a ray reflected by a mirror hurt him (and if yes, why can he stand moonlight)? can he go outside while staying in the shadows?
+ last scenario could open some geographically based options for the story, maybe a mountain village with less "direct sunlight"-hours than usual
* art. make him a great (or at least decent, but lovable) artist of some kind, perhaps photography? if the technology is available, perhaps he even has an obsession for photographing sunrises/sunsets (via remote/time-controlled cameras). if that's too weird, let him paint instead.
* art again, specifically performing art. he could regularly perform standup-comedy, which is usually done at night, anyway.
* how modern are the telecommunication habits? nowadays, thanks to internet messaging, most people wouldn't necessarily have to go outside to become popular, anyway
]
|
[Question]
[
The Utopians are a wise and benevolent civilization with Ancient Rome-like technology. Unfortunately, they are so peaceful that they are constantly on the verge of being conquered by the neighboring and envious barbaric tribes.
So the Utopians prayed to their gods and they looked with favor to the poor mortals. And the Utopians were all raptured to the skies on Tolkien-like eagles and were given the magic substance: Handwavium.
When Handwavium is dropped on a cloud, the cloud becomes solid. It doesn't change shape anymore and you can walk on it and build with it. It also becomes fertile with handwave fruit trees and eddible handwave cereals. However, it still keeps afloat somehow.
The Utopians rejoice and start building their new city up there on a cumulus on the lowest étage (ca. 1.900-2.000 m high).
Unfortunately, they soon find the gods' blessing to be a curse. Even though they built their city on the lowest étage, it seems that all the rain falls from below their altitude, not from above them (I may be wrong on this one... if I am, please tell me, for I would like to be wrong), so they can't collect rainwater.
Handwavium, OTOH, has poisoned the water on the cloud they built in, so they can't collect water directly from their own cloud.
Also, as a roman-like civilization, they were very savvy on building aqueducts... but water doesn't flow upwards, as you all know. Using Archimedes' screws or drums lifted with cranes from that altitude is impossible and would never be able to supply a whole city.
The gods, when questioned, just shrug and say: "You can't wish for more wishes".
Is there any way to save Utopia from abandonment or catastrophe, all by the Utopians own devices?
Some help: There is a slight possibility that Handwavium may make the cloud a little heavier and so the city could drop some meters... how much of a drop would suffice?
[Answer]
**You are wrong.**
Your civilisation is far from doomed.
Clouds don't follow a strict layering system. Even though you are correct that precipitation generally occurs at lower elevations, cumulus clouds (which are one of the principal type of clouds that give rise to rain) and which do indeed exist at the lowest part of the cloud layer can quite literally fly on top of each other when pushed by complex wind currents (which often cause rain to be produced at the same time).
Being that the surface of the cloud presumably wouldn't be absorbing much of the water, even if this wouldn't happen that often, depending on the size of your population, this could be enough to account for all your water needs.
In addition clouds, (including cumulus clouds) often "bump" into each other (especially with cumulonimbi, because you know, they are massive). You could quite easily collect part of these clouds, with technology no more sophisticated then a bucket. If you want this to be more efficient you can simply have a system of thick cloth sheets blowing in the wind, being controlled by pulleys to harvest the water content.
Because of all this, being able to provide enough water for your city is not an actual issue (I mean we are dealing with cities of antiquity, usually having no more then a few hundreds of thousands inhabitants).
[Answer]
I thought they'd be getting snow from higher clouds, not so? Even if no snow, all's not lost. **If the solidified cloud moves relative to the air around it, then local humidity could be condensed out of the air.** (I'm not saying they'd figure out how, without lots of help or lucky accidents, but still possible.
Three key conditions:
1. Source of power to condense ambient humidity. Extracting liquid water from ambient air takes power, and lots of it. From
<https://en.wikipedia.org/wiki/Enthalpy_of_vaporization>
we have just over 40 kJ per mole; and a mole of water masses just 18 grams (just over a tablespoon.) They can't use water power (irony), nor can they dig coal. Burning biomass is one option, but relative wind (see below) would IMHO be cleaner/nicer.
2. Relative motion is needed to access a steady supply of (still somewhat humid) air to de-humidify. So long as there's even modest (few Km/hour ?) motion of the solidified cloud, relative to its enclosing air layer, then we're in business, at least air-supply wise. But if the cloud moves right along with the local air (essentially no relative motion), then the local air will soon be stripped of moisure, making it much harder to get any more (modulo diffusion of gaseous H20.)
3. Do they have enough metal and metal-working skill to make something like a steam engine? (Actually an air compressor plus a few more bits.) Off hand, all the feasible heat engines I can imagine them building -- at the power levels they'd need -- would need either metal or exotic ceramics.
If they can't address 1 -- 3, I think they'd better start working on growing fiber for a long, long descent rope.
Although solar cells plus Peltier-junction (solid-state) refrigeration
<https://en.wikipedia.org/wiki/Thermoelectric_cooling>
would work very well indeed, up there above the rain clouds, the high-tech/green energy option just doesn't fit with this culture and would be *really* improbable.
[Answer]
You say they have fruit and plants. Where do these get water from? If it's magic water, they can squeez it from the fruit and plants and have an unlimited supply. If not, then their water problems should also extend to food.
Lowering a bucket during a rainstorm might get them a bit if water. The ropes wouldn't have to be all that long. Lemme do the math and get back to you...
OK, buckets are hard. Average global rainfall is ~1m, so 1 square meter bucket will collect ~35000 oz of water per year. Average American drinks 7000 oz, and that doesn't count bathing, etc. Crops can probably be watered with urine so at least that helps the crop watering problem. But yeah, every square meter of hanging bucket area allows about 5 people to survive (more if your world has more rainfall, less if they like to shower). Not impossible, but difficult.
[Answer]
You could try to "harvers" the cloud directley. Because the cloud is made from water.
Move you're cloud close to an other one and try to extract the water from it.
This way, you have access to water, without having to lower your vloud ore have it rained on.
]
|
[Question]
[
Most members of my species are fairly human-like and can communicate using speech, but many of them possess mutations that make normal speech impossible. These mutations can also significantly change their limbs and digits, so a shared sign language won't work either. So that everyone can talk to each other, they have invented a way to communicate by tapping or clicking, but I'm not sure if it would be too slow to be practical for everyday use.
Some information:
* Members of the species are about as intelligent as humans.
* They have not evolved to communicate using taps- it's a modern invention.
* They tap on small, simple devices they carry with them, personalised to the individual so that their taps sound unique. For this reason there is no standard on how the taps sound, except they are approximately the same length.
* They can produce two different-sounding taps with the devices. Of course, the absence of a tap can be used for communication too.
* I'll assume they can make up to 12 taps per second, and a listener can distinguish different taps at the same speed. [Humans can tap 10-11 times per second](http://www.kent-engineers.com/codespeed.htm), but because the species communicates this way constantly they're a little faster.
* The tapping language doesn't necessarily need to be similar to any spoken language.
* The tapping language must be able to communicate concepts just as complex as in English or another spoken language.
The obvious real-world parallel is morse code, but it's pretty slow to tap out each individual letter. Instead, my idea was to have each series of taps represent a different word, where each word's meaning is highly context-dependent (somewhat like the way Chinese characters work). However, I'm unsure of how fast communicating this way could be, and I feel that it might be easy to miscommunicate. Is there a better way? How fast could they communicate compared to real-world languages?
[Answer]
Use Huffman coding like language. If a word is used more often, it has a shorter tap duration. For instance, if I do a low tap (l), it would be "be" most used essential word in English. If I do a high tap (h), this means it will be followed by another say hhl would be "to" and hll would be "of" and continues like this. I tried to find the relation to regular human speech. At 2 levels, a document containing 50000 words could be spoken by your species would take 19 hours while it would take around 8 hours for a regular human. If you include silence and double tap it would take half of it, 9.5 hours. With small changes to the language you could easily get it down to regular speech. Note that this document contains many names, numbers and the like.
[Answer]
Well, let's see.
>
> Edit: my post was written when the Op still went with 6 taps per
> second. It was now changed to 12, so you can half all times and double
> the amount of sentences per minute... which makes this a VERY fast
> language in comparison.
>
>
> But arguably... 12 per second is SUPER fast, that's almost the rate of
> fire of a machine gun... back to original answer:
>
>
>
There are three possible stati for each "tap": no tap, low tap, high tap. You said each individual can make two different sounds. Can they make both at once, like a double tap?
So, my first tap has 3 different possibilities. My second tap also has that many, making it 9 possible tap-combinations. (3²). The third tap has 27 different ones (3³). After 1 second, and 6 taps, i have 729 possible combinations. After 2 seconds, i reach 531441 possible combinations.
>
> Edit: to put that into relation: UTF8 can code 1.048.576 characters, which we can reach with just one tap more.... and most of UTF8 characters aren't even used.
>
>
>
According to several sites, there are 50,000 chinese kanji characters, of which there are 2136 commonly used. So 2 seconds are MORE than enough to code all known characters and more.
But how effective is communication this way?!
Using taps, we could reach the usual 2136 after roughly 1,17 seconds. (3^7=2187). That's nice.
Let's assume the double-tap is possible. That will increase the number of possible combinations per second to: 4^6=4096. Sadly, that only reduces the amount of time we require for the minimum set to 1,0 seconds, as 0,83 seconds only give us 1024 characters.
Wow, that was a lot of math. As we can see, the double-tap would be nice to reduce "talking times", but is not necessary, so i will not further investigate here. Let's assume everything without doubletapping from here on.
So, we can communicate 1 word per 1,17 seconds. An average sentence length in english is 15-20 words. In asian languages, as i speak a bit japanese (weeb alert), i assume the word count is a bit less, as at least japanese has a fairly easy grammar, and allows to omit words, if the context is clear to the listener.
So, our tapping aliens would need 1,17 \* sentence length in seconds for each sentence... lets say the average is 12-15. So it takes them 14-18 seconds to tap an average sentence. That makes 3-4 sentences per minute. in english, you can speak roughly 5 per minute, 8-10 maximum. So it sounds like it can actually enter the competition.
overall, it sounds not like the fastest way to communicate, as i can probably type much faster, but it still sounds feasible and possible. Especially if the language offers a very simple grammar.
But how about those extra chinese characters? The ones above our 2000? Well, maybe the aliens have two ways of tapping: fast-tapping, and long tapping. If they want to tap a word that is not one of the usual characters (that are all the same length!), they start off with a special sequence, and then they tap the word for 12 taps (2 full seconds), giving them enough room to tap everything they want, all known chinese, japanese, greek, latin and farsi characters and some smileys, too.
That't it for my answer, and here are some links i used for sources:
<http://www.sljfaq.org/afaq/how-many-kanji.html>
<https://strainindex.wordpress.com/2008/07/28/the-average-sentence-length/>
<http://www.urch.com/forums/tse/16887-how-many-sentences-do-you-speak-one-minute.html>
<https://de.wikipedia.org/wiki/UTF-8>
[Answer]
In pure information content, as Andreas Heese noted above, tapping 12 times a second is more than fast enough to code data considerably faster than English. But remember - at a very conservative estimate, English has 7 different vowel sounds (a/e/i/o/u plus diphthongs) and 15 different consonants (p/t/k/b/d/g/s/z/sh/zh/th/l/r/n/m plus some more that can only be written in IPA), and packs upwards of eight separate sounds into a second. In pure information content, if we have to alternate between consonants and vowels, that should put us in the neighborhood of $7^4 \cdot 15^4 = 121,550,625$ possibilities *per second*. The English language only has about a million words (according to a quick Google search). If we're speaking at a rate of about one word per second, why are we leaving *one hundred and twenty million* possibilities open?
The best answer I'm aware of is redundancy - a language that relies on using every one of its possibilities is too vulnerable to getting misheard or misunderstood. Let's assume that English is about as efficient as it gets in that respect (not an entirely unrealistic assumption, after ten thousand years of linguistic evolution) but that the artificially designed language these tap-people will speak can do a bit better. So let's say we have to waste about $50$ times as many options as we use. Three options per tap, twelve taps per second, gives us $3^{12} = 531441$ options per second. That gives us about ten thousand usable options per second, comparing with English's million. Looks bad, right? But in two seconds that gives us a hundred million options, more than enough to handle English. In fact, we should be able to express one English word in $1.5$ seconds. So this tap-language should take about $50$ percent longer than English, which puts it neatly in the "workable" category.
[Answer]
The beings in question can tap 12 times per second and have a vocabulary of 2 sounds for this purpose. Let's call one . and one - for the simplicity of notification. There is also not tapping as a way to split information chunks. To efficiently transport information, the message should be short. So the best method of packing the information is to use an algorithm, that sorts the characters of the alphabet in a way, that makes often used characters very short but has the downside of making seldom used characters longer. The method of storing is a tree diagram, and the result for the English language is pretty much [Morse Code](https://en.wikipedia.org/wiki/Morse_code) - the most common 2 letters are . (E) and - (T). The sentence "to be" could be transferred as "- --- -... .", which would be exactly 12 taps, bringing it to the same speed of spoken language. It would be even faster than spoken language when telling numbers: the Morse encoding uses 5-tap chunks for each number, meaning 2 numerals per second. However, the encoding is still not the fastest:
Let's assume any character is 1 byte of information. So that makes at best (a message only made from T and E, maybe it was teetet) 6 byte per second and at worst (2 numerals) a 2 byte per second. If the tappers would use the average speed of the current world record holder, conversations would be held at 230 bytes per minute, so 3.83 bytes per second. That is ok for a somewhat slowed down conversation in English (which has an average word length of 5.1 letters).
It could be sped up if there would be no vowels in the alphabet used (because it would cut the average word length and the character length - 5 less!) so the information tree is only 21 characters tall. If we cut out close homophones, the information tree could be trimmed to as small as 16 characters + 10 numerals. 16 characters encoded as . - and combinations means one needs 2+4+8+16=40 possible combination of at worst 4 taps - that would pack the language better than current more, but it would read more like the transcript of ancient Egypt.
Now, they could also speak ASCII encoded. Of the 255 characters that the system allows, only 2x 26 are letters. Let's cut the 31 control taps from the front and just tap continuously with 26 characters + 10 letters encoded in same-length chunks. Each letter would need a chunk of 5 taps so we get all of them encoded, that would put us at exactly 2 byte per second... better use morse tree encoding with the gap than this. But if we use non-sound as an encoding method, our alphabet is down to combinations of 3 taps for 39 possibilities - that speeds us up to 4 characters per second, a bit better than our morse!
Now, one could ALSO encode the text in something like Katakana, which uses 73 syllables - while the average Japanese word uses something between 2 or 3 of these per word. Not using the no-sound as a possibility but only . and -, the 73 characters need a tree of depth 6, while only 11 characters (+ the 10 numerals) are in the 6th layer. So the standard tap length for a word is probably below the 12 taps. That would give us a speed of slightly over 1 word per second!
[Answer]
You say that "[m]embers of the species are about as intelligent as humans." All the other answers have only addressed the possible maximum speed of sending information through tapping, but none have addressed the question of how much information can be mentally processed by a being of average human intelligence.
Many people can speak pretty fast, if they say the same word over and over again. But if they have to actually form meaningful sentences that are relevant to the context, they usually have to slow down.
And many people can hear words coming in very fast, but they won't understand what is being said unless you speak slow enough for them to process the words.
So what you need to determine is maximum verbal processing speed, both for the production and the understanding of language.
There is a lot of literature on this, but you can find out yourself. To measure the maximum speed with which an average human (i.e. you) can understand language, simply use an audiobook that you are unfamiliar with and play it on your computer using a software such as VLC that allows you to change playback speed. Speed it up until it is as fast you can follow mentally for longer than a minute. Now use a printed version of that book and count the number of words you have heard in that minute. That's the maximum amount of verbal input processing.
To measure the maximum speed with which an average human can produce language, use your computer's built-in microphone to record you talking. Now do any speaking task your like (e.g. "Explain to me what you do at your job.") and then count the words. That's the maximum amount of verbal output processing.
[Answer]
comparing this to morse code, experts can read/hear at [140 words per minute](http://www.arrl.org/news/morse-code-at-140-wpm) and transmit at around 40-45 words per minute.
That's using morse code, whilst a language entirely made up of taps including slang could be even quicker.
[Answer]
You did not specify a tech level, so i will assume it comparable to our moderrn day.
Your species will quickly discover that the tapping device is the limiting factor.
If you replace it with something resembling a smartphone, you do not only gain a lot more tappable surfaces, you might also get autocomplete-features, "smart" layout of tappable surfaces and whatnot. This will multiply the information density per tap.
Obviously, you also gain the possibility to overcome range limits, since you could display the result either on the device for your partner to read, or send it over a network to a remote partner.
Broadcasting, locally or remotely, will also be simple.
A side effect is that audio signals are easier misunderstood or obscured by noise than written signals, so they may even communicate with a lower loss rate.
[Answer]
As you've said they are capable of making both types of taps (High and Low, they've been called) simultaneously, and the lack of a tap can also communicate information, this means there are four possible taps:
High
Low
High + Low
No Tap
You've specified they are capable of making and distinguishing 12 taps per second, which means every second there are 16,777,216 ($4^{12}$) potential combinations (including repeating the same tap 12 times) per second. This is essentially a [quaternary system](https://en.wikipedia.org/wiki/Quaternary_numeral_system). In comparison, binary (tap or no tap) communication at 12 taps per second would produce only 4,096 potential taps per second.
The smallest unit of information is a single tap lasting 1/12th of a second, but the largest would last multiple seconds maxing out at the limit of the human attention span. Since we're prizing speed above all other qualities, let's assume the longest tap-word is three seconds long. That's over 50 million potentially valid word formations (4$^{12}$ x 3 = 50,331,648).
With over 50 million twelfths-of-a-second slots to be filled, it's entirely possible for this language to compress more meaning into a three-second word (or shorter) than most natural languages manage in complex sentences. Consider that English has roughly a *tenth* the number of words that your tap-lang could contain.
For an example of a constructed language pursuing higher info density, look at [Ithkuil](https://en.wikipedia.org/wiki/Ithkuil). It is a constructed language designed to convey complex meaning without ambiguity.
>
> The many examples from the original grammar book show that a message, like a meaningful phrase or a sentence, can usually be expressed in Ithkuil with fewer sounds, or lexically distinct speech-elements, than in natural human languages. For example, the two-word Ithkuil sentence "Tram-mļöi hhâsmařpţuktôx" can be translated into English as "On the contrary, I think it may turn out that this rugged mountain range trails off at some point".
>
>
>
So it's entirely possible that in a span of a few seconds your tappers could have conversations that would take us a minute or more. The difference of a few taps (each a twelfth of a second long) could completely change the meaning of a tap-word or phrase, meaning this would be a [synthetic language](https://en.wikipedia.org/wiki/Synthetic_language) if not [polysynthetic](https://en.wikipedia.org/wiki/Polysynthetic_language):
>
> Polysynthetic languages typically have long "sentence-words" such as the Yupik word *tuntussuqatarniksaitengqiggtuq* which means "He had not yet said again that he was going to hunt reindeer." The word consists of the morphemes *tuntu-ssur-qatar-ni-ksaite-ngqiggte-uq* with the meanings, reindeer-hunt-future-say-negation-again-third.person.singular.indicative; and except for the morpheme *tuntu* "reindeer", none of the other morphemes can appear in isolation.
>
>
>
In conclusion your tappers would "speak" faster than the general population, and in short bursts, in my opinion.
[Answer]
**Why tapping?**
There are quite a few humans in the world today who cannot communicate by speaking. The problem is usually not with their vocal apparatus, but with their ears. They are profoundly deaf.
They have solved the problem of "speaking" between themselves, and with normal humans willing to learn how to "talk" with them, many times over. Many sign languages. A simultaneous translation from speech to sign language is perfectly possible, so there is clearly no bandwidth problem.
So why use a click language which is likely four times slower? Unless this species has some strange anatomy or neurology which makes them unable to sign. A click language might briefly be of use during the technological era of sound-only telephony. But once video phones become widely available I'd anticipate signing would take over.
[Answer]
Have you read about [Tap Code](https://en.wikipedia.org/wiki/Tap_code)? I remember hearing a radio interview of a former Vietnam POW who claimed they could send 25 to 30 words per minute using it.
[Answer]
Just to throw some simple math in here, you basically have a language with 3 units (High, low, and none)
Assuming that everything in the language is just long hyper-overloaded words, this means that you can express 3^n different ideas with n taps.
So a 1 second word (12 taps) is 3^12 = 531,441
And a 2 second word (24 taps) is 3^24 = 282,429,536,481
So assuming they have some form of edict memory, They can easily communicate a lot of information quickly. And if you want to reserve no sound as a word-break, than it just becomes 2^n (and for sum x^y for y= 0 to z, (x^z)\*2 is roughly close enough)
And similar any other language, the most commonly used words/phrases would make up the shorter tap portion of the language.
On another note, Humans can only remember roughly 7 things at a time, but can artificially increase that with grouping (say remembering 4 clicks as a 'syllable'. So you max word length would probably be about 3^(7\*4)
Hopefully this should give you some numbers/formulas to play with (and adding a wider verity of clicks, like scratching, rolling tap (with bumps on the device), or increasing the recognizable volume range; would greatly improve the language's communication)
Also a note, people who use languages with subtle pronunciation differences are better at picking up those subtle differences, so even with personalized devices, they could easily learn to recognize a wider verity of clicks. ^w^
And for the language itself, morose code would be a good starting reference with Huffman encoding (Which pretty much was the practice of using code words that have little meaning alone, like book, to mean whole phrases like "come ASAP")
]
|
[Question]
[
As part of a story idea, I'd like to create an alien civilization that colonized different solar systems in a manner similar to how European nations colonized other continents here on Earth. This civilization would have the technology to make travel between solar systems feasible, though certainly not without risk. At the same time, their political and economic systems resemble those prevalent in 16th century Europe. In particular, institutions such as democratic republics and corporations would be in their early stages while concepts like consumerism and environmentalism would be completely unheard of.
There are many works of fiction where alien civilizations have similar discrepancies in technological and social development. However, none of the works I'm familiar with providing a plausible explanation as to why; if any explanation is provided, it's due to some dramatic device or extenuating circumstances; I'd prefer an explanation that seems natural and logical.
The alien species needs to resemble humans in most respects, both physiological and psychological; humans would be able to interact and relate to them on a meaningful, personal level.
Any suggestions on plausible explanations? Are there any works that I could refer to for inspiration?
EDIT: To clarify, my chief concern is that I don't want this space faring civilization to have conceived of (or at least remember developing) many concepts that are essential to modern life. Here are some the concepts that I definitely don't want this alien civilization to be familiar with:
* Corporate person-hood: The idea that a business can be an entity separate from those operating it.
* Mass Marketing & Advertisement: The idea of promoting and selling a specific item to a broad national or global audience instead of catering to a niche market.
* Specialization: The idea that individuals learn very specific skills and work in professions that tackle very specific needs as well as the idea that individual businesses would only produce part of a final product or only play a limited role in providing a service.
* Automation: The idea that technology could be leveraged to perform tasks without direct interaction or oversight.
* Conservation & Sustainability: The idea that a civilization can consume resources at such a pace that it could exhaust them and that special measures are needed to prevent this.
Though the political and economic systems of the 16th century aren't necessarily *inferior*, I fail to see how they could support the sophisticated industrial complex needed to for our current space programs, let alone intergalactic travel. Even if the aliens eventually develop the necessary technologies, would they be able to put it to use? Also, how would the new opportunities and challenges associated with more sophisticated technology not inspire them to explore more modern concepts?
EDIT 2: Thank you everyone for your responses. I've selected rideoutcolin's answer because I feel it best addresses how to maintain technological progress without dramatically changing the social order.
[Answer]
It's fairly simple. Just have political ideologies evolve along different lines than they did in our history. Technology may progress in a similar fashion, and corporations could even develop (think East India Company instead of Apple or Ford).
The thing that drove Monarchs out of business was the set of ideas promulgated by thinkers like John Locke et al. These drove the American and French Revolutions, and later the revolutions of 1848. Now, it's not so simple as a linear correlation between those ideas and the fall of monarchies, but it certainly influenced the direction that they toppled in, so to speak.
Economic stagnation will usually lead to political upheaval, and the revolutionaries were there with their new ideas to fill the void in the late 18th century. However, there is plenty of room throughout human history for scientific progress that is compatible with aristocratic pomp and circumstance. For example, look at the Northern Rennaissance in Europe as contrasted with the Italian Rennaissance. Two different political environments both undergoing rapid adoption of the scientific method and artistic creativity.
Simply have your society of aliens develop political philosophies more based on those of Plato and Thomas Hobbes than those of John Locke and Thomas Jefferson.
[Answer]
There is some preformed bias in your question, which I would like to address here in my answer. You are considering the political systems of sixteenth century Earth inferior to the political systems we have active today. Then you are making an assumption that technological and political evolution must always occur at the same speed as it has occurred here on Earth.
Neither of the assumptions is correct. For the first, a political system is required by a state in order to:
a- protect it against foreign invasion
b- provide a socioeconomic framework for the state so that all parts of the state can be compatible to one another
c- provide a judicial system for the citizens so that disputes can be resolved
# Is One Political System Better Than The Other?
While a political system is necessary for a state, it would be utter ego and ignorance to claim that the current western form of *democracy* is somehow superior to a well balanced monarchy or aristocracy. In fact India has had a more prosperous time under monarchies such as Ashoka and the Mughals, instead of now or under the british rule. China is no different. When we think of monarchies today, many of us immediately think of a megalomaniac emperor with a huge inflated ego and disregard for his people. That is an absolutely incorrect generalization. Just like people of a democracy can elect a supremely dumb and idiotic head of state (watch America's forthcoming elections for a live example), so is the case with monarchy, too. However, a state will function much, much better under a wise, considerate monarch instead of a group of wise considerate ministers. Take the case of Islamic caliphate in the days of first four caliphs (Abubakr to Ali R.A.). While not technically *kings*, their reign does fit under monarchy as they alone were the heads of Muslim states. And the standard of life for their citizens was much higher than the citizens of those states today (economically, that is).
Hence it is a ghastly erratic approach to think that the political systems in effect now are somehow better or more sophisticated than those of the 16th century. The only important point is, monarchs of 16th century Europe were the egotistical, disregarding lot, otherwise the region would have lived happily under monarchy.
# Are Political And Technological Development Interrelated?
The second fallacy in your question is that you are assuming that political and technological advancements are somehow interrelated. This is incorrect. While a safe, economically stable society is a prerequisite for long term technological advancement, a change from one type of government system to another (while the prosperity of the people remains the same) has little effect on the technological evolution of the state.
Just consider how many advancements were made by the Chinese during their years of peaceful monarchy. Also consider the technological advancements of Arabian Muslims during their golden ages. The evolution of technology in Islamic world was stalled because of a series of political upheavals and change of priorities. If the political system in Islamic world had remained stable, Arabian peninsula would probably have been the technological hub of today's world. In China, the technological advancements halted time and again as a result of the economic crisis produced due to civil wars as the monarchs gradually lost authority.
In short, it is highly erratic to assume that the political evolution of a state is related to its technological advancements. If there is economic prosperity and security in the state, the technological development would continue, regardless of which political system is in place.
# Conclusion
Yes, a spacefaring race **can** have highly advanced technological status with 16th century political system in effect. There is nothing erratic or incompatible in the scenario.
---
**Edit To Add**
>
>
> >
> > *Though the political and economic systems of the 16th century aren't necessarily inferior, I fail to see how they could support the sophisticated industrial complex needed to for our current space programs, let alone intergalactic travel. Even if the aliens eventually develop the necessary technologies, would they be able to put it to use? Also, how would the new opportunities and challenges associated with more sophisticated technology not inspire them to explore more modern concepts?*
> >
> >
> >
>
>
>
The error here is not in your question, but your approach for the answer. The question should not be *how they could support the sophisticated industrial complex*, rather it should be *how they could **not** support the sophisticated industrial complex*. As in, what is the flaw in the political system of 16th century which would hinder the development of industry and technology?
Maybe you are thinking that 16th century European states at all did not have the wealth or resources required for developing major industrial complexes. That is correct, they definitely did not have. But that is because the technological progress back then was almost zero as compared to the technological progress of modern times. Those states did not have the technology to mine and refine aluminum. Modern types of steel were unknown. Ultra-strong alloys of titanium were unheard of. Even electricity and internal combustion engines were not discovered/invented. Remember that all these are technological prerequisites, not political or economic.
The main point is that it is technological advancement that power economical development and not vice versa. While huge funding is indeed required for ground-breaking research projects, the economical advantages of those projects are far, far greater than their funding. That is what keeps the technological progress running.
[Answer]
You say that you want a 1600s sort of society and government. So let's get into a little bit more detail about what exactly European empires did in that time period, and how this can apply to an interstellar empire.
I would call that system of government in this time period "colonialism and the economic system ["merchantalism"](https://en.wikipedia.org/wiki/Mercantilism). The general idea was that empires would look for resources around the world and then ship them back to the homeland. First, an empire would take control of an area. This could be done by bringing their own settlers or by bringing the existing inhabitant into their empire, either diplomatically or by force. A colonial government would be set up to manage that area and the inhabitants would be put to work harvesting resource. The empire would then connect the colony to the rest of their empire through trade companies that were owned by the state.
The usage of trading companies is particularly interesting. These companies were indeed separate from those operating them, but they were owned by the government, not privately. They didn't just move goods around either, they did basically everything. These companies were very vertically integrated: they owned everything it took to make a product from the mines to the factories to the stores. They were so large, in fact, that they could even make their own currencies and wage war. However, it would be a bad idea for them to act against the interests of the empire that owned them. The [Dutch East India Company](https://en.wikipedia.org/wiki/Dutch_East_India_Company) is a fascinating example as is the British East India Company.
The reason these companies made sense is the same reason your space empire could work: it was difficult to travel large distances. Maybe only a colossal empire-owned company can afford to travel between system. Even if the civilization makes advances in economics, such as banking and holding shares in a company, it would be in the empire's best interest to only allow their companies to take advantage of them.
Another question to direct your thinking is: how empty are the planets this empire is taking over? If they are starting from scratch, their methods will involve settlers and North America provides a (mostly) good example. If they are invading existing civilizations, look to Africa and India for examples.
To wrap up, I'll address your points:
* Corporate person-hood: Technically this idea did exist in colonial times, but large companies were not considered something that regular citizens could make on their own.
* Mass Marketing & Advertisement: Advertisement did exist in colonial times, but it was limited by the technology of the time. Presumably your space empire would have television, internet, etc. However, if these colonies can't communicate with each other easily, it would be hard to develop global advertisements.
* Specialization: Individuals have specialized in specific skills since the invention of agriculture. I'm not sure why they wouldn't do so under colonialism. You could probably prevent specialized companies from existing since anything of value would be gobbled up by the empire's company.
* Automation: This is an interesting point of contention. The industrial revolution didn't happen until late in the life of these empires. However, it would be pretty strange for a space-faring civilization to not have automation. I don't see why you can't have the two but you may have to come up with some way the empire keeps control on automation.
* Conservation & Sustainability: If space travel is difficult, but possible, I could see the civilization developing a pattern of: settle a planet, take anything good from it, trash the place and move to the next. They can simply leave a waste heap behind and not have to worry about it.
[Answer]
>
> Are there any works that I could refer to for inspiration?
>
>
>
Obligatory [short story where FTL travel is super simple](https://scifi.stackexchange.com/questions/33341/short-story-where-ftl-travel-is-super-simple) question. If the technology is so simple that it is discovered early, an "earlier" (assuming similar development to our timeline) socio-political paradigm makes more sense.
If you'd prefer not to have a unique scientific breakthrough (or super simple FTL), then my suggestion would be a culture hearkening back to an earlier "golden" age. An example from Western civilization would be homages (architecture, toga parties, scientific nomenclature) to Greco-Roman culture. If this were taken to a further extreme, you might see a civilization that simple does things the "old way" - but better (in their minds).
[Answer]
Simple answers...
* Fashion. If a culture simply wants to look like it's from the 16th century there is no reason they couldn't live that way without a problem.
* Some people LARP or go to Renessaince fairs or do re-enactments. Some people, that's their entire life.
* Or maybe some people live as close to a certain life style as possible like the Amish.
If any of these are true and then enough time passes or something happens it easily can result in a culture that has interstellar travel while living generally in the 16th century. This is especially the case when you have machines that do everything for you which may be a common thing for advanced cultures. We might develop robots to run everything and then a majority of us might want live in a living RPG which would result in us appearing to have a lower tech level. Now if the robots get destroyed and enough generations of people are removed from the technological civ they might not even realize it and just continue on as a 16th century civ with a 22 century civ technology in some places.
[Answer]
What about if advanced space travel was given to them by an alien race. The alien race is not into conquest and more into trade and has no qualms with trading ships and technology.
[Answer]
There are some important assumptions of the human condition that would need to be significantly altered in your aliens in order to discourage the developments you specificied.
The way I look at it, all of the modern developments you mention are modern responses to the same old problem of limits that has faced humanity since its inception. Just how much can any one human being reasonably perceive or achieve? It's little secret that the scope of the answer to that question relies largely on humanity's intensely social nature, which is largely responsible for our species's (sp?) success in survival and reproduction (<http://www.nature.com/nrn/journal/v4/n3/full/nrn1056.html>)
Corporations and specialization are highly efficient forms of cooperation that (usually) foster group cohesiveness and survival, enhancing group strengths while covering individual weaknesses. Mass advertising is also an efficient method of social communication. Automation answers for some of the limitations of human cognition by taking over mundane tasks that would otherwise cumber limited human attention and energy. Sustainability is a response to the limitations of Earth's ability to sustain a large, modern society.
Most of these would be difficult to avoid in some form, given that a spacefaring society would face similar limitations and require similar sophistication. However, if you were to find a way to tweak these parameters (increasing cognitive capacity and optimal life spans, giving them telepathy, or decreasing the sophistication necessary to sustain a spacefaring culture) then you might be able to project the renaissance into space. A race of telepathic Da Vinci-like polymaths might be a fun concept to explore.
[Answer]
If their space travel came from something natural that developed on their home world e.g. Something like [Moya from Farscape](https://en.wikipedia.org/wiki/List_of_Farscape_characters#Moya). Then they don't need to have developed space travel and can get to other places with almost any level of political development from Viking clan, through 16th century expansionist, corporations, to futuristic dictatorships. Their planet happens to be the spawning ground for these "space turtles", and with just enough tech you can find a way to piggy back a ride and even control their direction.
[Answer]
remove karl marx. and britain.
or better said, remove the thought base of the ideology known coloquially as socialism or leftism.
i think you are telling about late 17th to early 18th century culture. e.g. 1600s. which is 17th, not 16th century. e.g. 1500s.
what you don't want your alternative humans to have can be described as being of the leftist ideological doctrines, better known as cultural marxism. <https://en.m.wikipedia.org/wiki/Left-wing_politics>
a right wing, libertarian world resembles 16 to 17 th century culture is primarily because of the french revolution, <https://en.m.wikipedia.org/wiki/French_Revolution>
which have happened in late 18th century, which was orchestrated by socialists, sent the history of later nations constant leaning to leftism, giving the illusion of libertarian and right wing being old or outdated.
in reality, a late 1600s culture is just a world before socialism.
without karl marx, there will be no socialism, therefore no communist/liberal ideas like corporate personhood or environmentalism, nazism would be nonpresent , therefore no propaganda/mass advertisement.
<https://en.m.wikipedia.org/wiki/Nazism>
<https://en.m.wikipedia.org/wiki/Joseph_Goebbels>
remove marx, then you remove the soviet union and the idea of "alienization of man", therefore there will be no liberalism directed act of directed marketing, globalization or automation replacing workers (which require political materialism)
<https://en.m.wikipedia.org/wiki/Marx%27s_theory_of_alienation>
generally, the post 18th century suicide of the intellectual populace to progressive thought and behavioral sink
<https://en.m.wikipedia.org/wiki/Behavioral_sink>
is primarily related to marxism, communism and the rise of a malvolent, neoauthouritarian political idea, which have striped humanity this present timeline of nearly all potential for space expansion, or expansion in general.
a world where socialism never developed would be honest, henst no corporate dirty jobs or bogus mass advertising, little exploitive specialization/slave labor, and with concept the human soul not broken by the materialist doctrine of socialist evolution, artificial intelligence will be distrusted, hence no unsupervised automation. and definitively no environmentalism or conservation whatsover, which the nonpresence of conservation ideas is necessary for true spacefaring civilizations, as leaving planets unexploited or protected is indifferent from suicide when you always need maxumum amount of matter to continue the move or proliferate, an given fact that the useful lifetime of a key resource is normally less than the time it needs for it to ne depleted.
be careful marxists, because whatever aliens up there that would come to earth, probably would not be happy with you, or be friendly at all.
[Answer]
The other possibility:
Merchantilism associated with 16 to 17th century culture is related to the availability of new land and resource outside of europe. which negated much of the Enlightenment, and delayed the advant of socialism and all it's ires.
therefore, it's perfectly concievable, that once a civilization have reached space, the abundant resource would result in a second colonial rush, reviving merchantilism and colonialism. therefore quickly removing any trace of Enlightenment cultural phenomena from the culture, returning the civilization to the 17th century cultures.
Who need specialized market when more resources is easier than designer products? who need corporate personhood when endless colonial possibilities exists for everyone? who need complicated automation when one does not face too much competition nor large stock market? and why sustainability issues would exist if there is literaly 100000 earths worth of resources just in the solar system?
so even when a culture initially starts with 20th century ideological doctrines, it quickly resumes 17th century culture once it have reached it's own solar system.
]
|
[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.
Guests of this large space station enjoy Earth-like gravity (80-90% minimum).
How? Well the space station is so massive it has its own gravity. The disk shaped "core" is made with ultradense materials with an overall of 20-30 g/cm3 similar to Iridium or Osmium (the densest elements).
I thought that working with material with such density could provide decent gravity with relatively little amount of material so I tried crunching some numbers...
Turns out I suck at math. How massive/large does a disk with these density have to be to provide similar gravitational pull close to its surface?
(Ignore edge effects and the core does not have to keep its own atmosphere, even if you can just provide some formulas it would be great since right now I don't have much time for this)
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
A disk won't really work in the sense that you want it to. Supposing that your material was massive enough to create an appreciable gravitic field, a body would be attracted to the centre of the disk. The centre of mass needs to be directly below your astronauts; they need to walk on the edge of the disk, not the flat dorsal or ventral surfaces.
Additionally, the increase in density is only a four-fold increase, while the decrease in volume will be exponential by going from a sphere to a disk. Logically, your prospective disk will have to be an order of magnitude larger in radius than the earth in order to achieve earth-like mass (and therefore gravitational attraction).
You need some fantastic substance to make this idea viable, either to take the associated interstellar punishment and associated integrity issues that would be dealt out to a disk sized like an enormous net spread out across a solar orbit, or to have some fantastically hyperdense material that will give you the gravity you want. In the latter case, this fantastic substance is entirely under your control, and you can handwave its required properties away.
EDIT: This doesn't even address the problem of how you would prevent your disk from collapsing in on itself. There's a reason celestial bodies are shaped roughly like spheres.
EDIT: @TLW points out that for a [sufficiently large disk](http://en.wikipedia.org/wiki/Alderson_disk), the gravitational field changes so that gravity can no longer be approximated by a point. Very cool, but nevertheless huge, and prone to all the problems of a system-sized megastructure.
[Answer]
I believe the space station would induce nausea due to the changing distribution of the amount of gravitational force in different directions as the astronauts walk over the surface. In the center of the disk, for example, I imagine the astronaut would not feel pulled downward as much as they would feel pulled to the edges of the disk. Any effort to fix this likely results in a space station that is spheroid.
To simplify the math, let's set aside the disk shape idea and just think about a spheroid space station made entirely out of material at the upper end of the density range you provided, 30 g/cm3.
The earth has a mass of $5.972 \* 10^{24} kg$. $80\%$ of this is $4.778 \* 10^{24} kg$, or $4.778 \* 10^{27} g$ because there are $10^3 g / kg$. To get this much mass with a $30 g / cm^3$ material, you need:
$$ \frac{4.778 \* 10^{27} g}{30 g / cm^3} = \frac{4.778 \* 10^{26} g}{3 g / cm^3} = \frac{1.593 \* 10^{26} g}{1 g / cm^3} = 1.593 \* 10^{26} cm^3$$
In a cubic meter, there are $100^3$ cubic centimeters, and in a cubic kilometer, there are $(10^3)^3$ meters or $10^9$ meters. We end up with $1.593 \* 10^{11} km^3$. The earth is approximately 1 trillion $km^3$, so our space station, if spheroid, would be about $16\%$ the size of the earth.
Smashing that sphere into a disk does things to the gravitational field that I am not qualified to answer; I can only imagine it would be very disorienting to walk across.
[Answer]
Gravitation on the surface scales linearly with radius and density. The earth has a radius of 6,400 km and a density ~ 5g/cm3. Irridium and osmium have densities about 20g/cm3, thats 4 times earths density.
Therefore the radius of the sphere is 1/4 that of earth to produce normal gravity.
1,600km radius ball of osmium might be hard to find. If you want 80% gravity then 1,600\*80%=1,300km radius.
4/3\*Pi\*r^3 tels us that the volume is 9.2 billion cubic km and as 1 billion cubic m is 1 cubic km and 1 cubic m weighs 20 tonnes. The volume is 9.2 billion billion m^3 and the density 20 million g/m^3. That gives a weight of 184 million billion billion gram's.
Iridium costs £10 per gram and osmium £5 per gram. (ballpark)
This makes the project cost in the region of £1 billion billion billion or £10^27.
With a world gdp of £50 thousand billion this project could be paid for in 20 thousand billion years(assuming all funds are devoted to it and osmium prices and gdp remain constant) About when the last stars are dying out.
[Answer]
Given a disk of radius $R$ and thickness $T$ made out of a material of density $\rho$, the gravitational acceleration a distance $h$ directly above (or below) the center of the dist is given by the integral $$\int\_0^T\int\_0^R\frac{2\pi\rho G}{\sqrt{x^2+(t+h)^2}}\,dx\,dt.$$ The solution is lengthy, but what really interests us is the limit as $h\to 0$, which is $$a=2\pi\rho G\left(R \log \left(\frac{\sqrt{R^2+T^2}+T}{R}\right)+T \log \left(\sqrt{R^2+T^2}+R\right)-T \log (T)\right)$$ If we assume that the thickness of the disk is very small compared to the radius of the disk, We can make some simplifications which reduce this to $$a=2\pi\rho G\left(R(1-\log 2)+R\log(R/T)\right).$$ Anyway, here are the equations you asked for.
[Answer]
*If* you can stabilize neutronium, or something equally dense, this will work.
Big if, however.
Otherwise, it won't work - the density simply isn't high enough to build it on a sane scale.
Build the flooring of your station out of a sheet of neutronium ~58nm in thickness and ~100m in diameter.
A cautionary note: this will mass somewhere on the order of three-quarters of a quadrillion metric tons (~7.5 \* 1014 kg) - somewhere in the range of a decent asteroid (several km in radius, depending on the density of said asteroid). You had best ensure that it is safely bound to the station, lest it tear the station apart. Remember, it's 60nm thick.
Also, one had best hope that said stabilization is stable, lest it explode. That much evaporating neutronium would release on the order of 5.6\*1028 J of energy. (That's somewhere around the amount of energy required to stop the Moon in its orbit around the Earth, just to give you a comparison.) That's enough to melt a cm of aluminum at 45 light-seconds away (!), if I did my math correctly.
This will give you a difference in acceleration of something like 20cm/s2 between head and feet, which may be annoying. Though you can mitigate this by making it larger.
In actuality, you'll want to vary the thickness depending on the radius, as well as spin it slightly (which reduces the total material required). Otherwise you'll get weird effects anywhere but the center of the disk. But with the spinning and thickness variation you can get something like 90
% of the disk's radius to be locally flat, which is good enough for most purposes.
Note that you could accomplish much the same thing with an array of small black holes - although they would have to be rather small in order to not have a noticeably "bumpy" field, and the required stabilization would be even more absurd for them than for neutronium (among other things, the Hawking radiation would mean that they would decay almost instantaneously unless stopped)
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
Robert L Forward wrote about using ultra dense materials for controlling and manipulating gravity, but when *he* was speaking of ultra dense materials the subject was the sort of degenerate material from White Dwarf stars or neutronium as you would find in a Neutron star. One example in his book "Future Magic" suggests that to nullify a 1g field you could take a 4 million ton mass and compress it to a sphere 32cm in diameter, or a disc 45cm in diameter and 10 cm thick.
Forward was always a bit playful, so some of his suggestions included supporting a disc of degenerate matter with massive diamond pillars to counteract the gravity of Earth under the disk. This would make for an amazing amusement park ride (although the ticket price would be a bit steep). Small matters like how to keep degenerate matter or neutronium from expanding at close to the speed of light outside of their environments were conveniently overlooked.
At any rate, many other posters provided the mathematical tools, so simply plug in the desired "g" field to find out what unnatural material the gravity disc will have to be made from.
]
|
[Question]
[
And I'm not talking about insects. In what kind of environment could a large number of different species all develop six legs/limbs/appendages the same way most vertebrate species on Earth have four? Could it just be up to chance or is there a reason all animals on Earth have =< 4 limbs?
[Answer]
I have vague memories of a biology lecture back when I was a student which said:
* The most efficient way for a fish to generate thrust when swimming is to curve its body into a sine wave. Or some whole number of sine waves. So 2 is fine, but 1.5 or 2.5 is not.
* The most stable arrangement of paired fins on a sine wave curved fish is 2 pairs of 2 (4 fins total) for a *single sine wave*. By paired fins it means the pectoral and pelvic type which stick out sideways from the body, not the dorsal or anal fin.
* Hence our fishy ancestor had 2 pairs of fins for efficiency reasons... and land vertebrates ended up with 2 pairs of legs. (Presumably by this logic 8, 12 and other multiples of 4 are also stable configurations?)
Apparently [Manta rays](http://www.arkive.org/giant-manta-ray/manta-birostris/) are the only living species of fish with three pairs of fins: pectoral, pelvic and cephalic. The cephalic ones are the ones which stick out at the front and are used for feeding.
If you can figure out a reason for a manta ray to come out onto land, perhaps its descendants would have 6 legs. But it would have to evolve another way to feed if it stopped using its cephalic fins for that.
[Answer]
While not directly related, a couple of the answers [here](https://worldbuilding.stackexchange.com/questions/48913/anatomically-correct-sleipnir) relate to your question.
To paraphrase, I think it has a lot to do with evolution. If you assume it takes hundreds or thousands of generations to evolve a functional limb, its pretty unlikely that it would happen (unless you're selecting for it while breeding). As a result, there's practically no chance for a new limb to be added via evolution.
I have no background in biology or evolution, but given the large # of generations needed to add a limb, vertebrates having 4 limbs +/- a tail is probably related to a common ancestor that crawled out of the sea. (even dinosaurs tended towards this)
Invertebrates appear to have a few more ancestors, but given the general presence of an exoskeleton and weight limitations on land, their overall size was limited and depending on the specific configuration they concentrated on a few body types.
So if you want lots of things with 6 limbs, tie it to a common ancestor. You may also need to show why it was beneficial to keep 6, as humans have less useful feet as compared to a lot of other primates. A couple examples might be -
Terrain - using 4-5 hands to hang onto terrain features and 1 or 2 to harvest resources might be better
Other animals - If most things have 6 limbs and can fight with 4+, you will probably survive better if you can also fight with 4+
Specific resources - you might have 2 legs, 2 large arms to do 1 thing and then 2 small arms for another thing if that series of actions is required to access your food source. This could also be a justification for something like 1 set of human hands, 1 of human feet and 1 of cat/dog paws.
[Answer]
Tetrapod lifeforms on planet Earth have four limbs (that's why they're called tetrapods) because they evolved from fish with four fins. See DrBob's answer for more details.
If the lifeforms that colonised the land on planet evolved from benthic or bottom-dwelling ancestors instead of free-swimming fish, then it is probable that instead of adapting four fins of a fish into four limbs of a tetrapod that the six appendages of a bottom dweller developed into the six limbs of a hexapod.
If the planet had a higher gravity than Earth's then the presuption would be that this further weighs the evolutionary dice in favour of six-limbed lifeforms. Since the OP's planet has low gravity, but there's no reason why that benthic creatures might not be able to make the transition to land dwelling lifeforms with lower gravity. Perhaps being able to do so with greater ease than on higher gravity planets.
Interestingly octopuses are known to come out briefly on to land. There are stories of them climbing trees. Octopuses are well known for escaping from their tanks in aquaria and research laboratories and invading nearby tanks full of fish which then become less full of fish. The cunning blighters return to their own tanks and act innocent.
The best explanation is [here](http://blogs.scientificamerican.com/octopus-chronicles/land-walking-octopus-explained-video/). Any organism capable of feats like this is a probable ancestor for land-dwelling creatures. While the octopus has eight limbs, it is an easy step to imagine the same thing happening with a six limbed sea creature.
]
|
[Question]
[
Glass has been around since 3500 BC, and since then, it has been one of the many everyday materials of choice. We pretty much see them everywhere nowadays--our windows, our windshields, our mirrors, our fancy wine bottles.
But now, it seems, glass is going to suffer some stiff competition from something that, until quite recently, exists only in science fiction: **transparent aluminum**.
But before finding out just how stiff the competition is going to be, let's look up the basic pros and cons of glass, in no particular order:
* Glass lets light through, so that our houses don't look like caves on the inside.
* Glass also focuses light, which makes for deadly heat-based weaponry.
* Glass is transparent, so that we can see how we look.
* Glass breaks easily, so unless you have a floor full of good, thick carpeting, you'd best find yourself another mirror.
* Glass can't react well to pressure, which is why deep-sea submariners like *Alvin* have only very small windows.
So let us assume that in this alternate scenario, glass fell out of favor during the Industrial Revolution after an anonymous inventor accidentally discovered "transparent aluminum" (the name itself being a 20th-century last-minute addition). Would TA improve from the list above, or should we just stick with good ol' glass?
[Answer]
[Aluminium oxynitride aka ALON](http://www.surmet.com/technology/alon-optical-ceramics/) is the real world transparent aluminum. It's four times harder than glass, 80% transparent, and bulletproof up to and including a 50 caliber round. You can get it up to 18" x 35", a bit small for a [window in a US house](https://www.andersenwindows.com/products/400-series-tilt-wash-double-hung-window/), but acceptable. Sounds great! Why are we still using glass?
***It's expensive***. How expensive? The manufacturer, [Surmet](http://www.surmet.com/), never gives a price. An article in [*Stars And Stripes* from 2005](http://www.stripes.com/news/air-force-testing-lighter-transparent-alon-armor-1.40353) says:
>
> Glass costs about \$3.25 per square inch, while ALON runs between \$10 and \$15 per square inch
>
>
>
The article goes on to elaborate why it wasn't being used in Humvees in 2005.
>
> But in the long run, the new transparent armor could save money, La Monica said.
>
>
> Because it is lighter than glass, it would put less wear and tear on Humvee engines and would save on gas, he said.
>
>
> However, ALON has not been shown to be effective in large panels and is currently only suitable for small windows, a Defense Department spokesman wrote in an e-mail.
>
>
> “ALON use in large windows will require significant investments in manufacturing technology and test and evaluation to demonstrate the required protection factors, especially against a multi-hit threat,” the spokesman wrote.
>
>
> Countering the spokesman’s comments, La Monica’s supervisor at Air Force Research Laboratories wrote in an e-mail that “large size” is a relative term.
>
>
> “ALON can be fabricated in 25-inch lengths, and it can be tiled to larger sizes,” wrote Ondercin. “In the opinion of this office [Air Force Research Laboratory Materials and Manufacturing Directorate at Wright-Patterson Air Force Base], the reason that ALON is not being used in Humvees is its cost. It can be fabricated in Humvee sizes, but it is costly compared to bullet-proof glass [layers].”
>
>
> Ondercin wrote that Air Force Research Laboratories are trying to reduce ALON’s manufacturing costs to equal what it costs to put bulletproof glass on Humvees.
>
>
> “This accounts for such items as wear and tear on vehicles due to the added weight and needed replacement due to permanent clouding of the glass in service due to sand abrasion from the use of the current glass product,” he wrote. “These issues would be greatly alleviated by the use of ALON, not to mention its greater ballistic protection.”
>
>
>
Why is it so expensive? It cannot contain any impurities, the crystalline structure must be perfect, and it must be polished for hours. If you're flying or driving in a combat zone this price might be worth it. But it's prohibitively expensive for your home or car.
[Here's a great video about ALON](http://www.surmet.com/video/engine/swf/player.swf?url=../../data/video/surmet2.m4v).
[Answer]
What you are talking about already exists: It's called Aluminium oxynitride. It's a ceramic made of aluminium, oxygen and nitrogen
**However, glass is still widely used (And will remain so) because of how easy it is to produce it.**
Glass is made of sand, which is extremely easy to obtain in large quantities. Aluminum, however? Much less easy to obtain in large quantities. Don't forget about the work it takes to to treat your aluminum and make it transparent, which drives the cost up.
[Answer]
Hundreds of years ago Aluminum was worth more than platnum. What you asking is like "If we could make glass out of rhodium (2x the value of gold) would it phase out making glass out of sand?". Others have already mentioned that despite modern technology, aluminum glass is still 5x the price of normal glass.
To answer your question, yes "TA" would beat out glass if it were the same price, a similar price, or cheaper. Unfortunately that is not the case now, and certainly not in the past. TA would have amazing thermal conductive properties and may be easier to work with in many cases. Granted you would never see any TA stained glass artwork, I would bet having all the heat wick away from the solder joint would be super fun when trying to lay solder joints as big around as your little finger with an old fashioned torch.
One thing that I think TA would be really good for is 3D printer build plates. Invar would be better for its self releasing properties, but it would be so cool to set something up where you used a rear window defroster on a TA plate and 3D printed on the underside of the plate so you could look through the top of the plate and see the underside of the first layer. Then again rear window defroster style heaters rely on a non-conductive substrate so perhaps it may not work so well
[Answer]
It's not going to work for kitchenware.
I was checking out the various grades of glass bakeware a few years back. I decided to email the company that makes ALON and ask. Their reply not only mentioned the expense, but also pointed out that a drop of cold water hitting a piece of oven-hot ALON would probably break or shatter it.
Perhaps some later formulation will overcome this limitation (and be cheaper to make), but for now it's not practical or safe for use on stovetops or in ovens or microwaves.
I'm still sad that I can't (yet) have transparent aluminum kitchenware. üò≠
]
|
[Question]
[
[Food for thought from /r/worldbuilding:](https://www.reddit.com/r/worldbuilding/comments/4j61hl/do_separate_races_not_species_automatically/) If the dominant race (typically human) of a given world, without any other context, has a huge cultural diversity, then is racism **surely** going to appear?
If this question is answerable, what are the general factors that contribute to the racism?
[Answer]
There's something I talked about in one of my [previous answers](https://worldbuilding.stackexchange.com/a/11502/6781) that goes a long way toward helping you understand when you should expect to see racism in some form - [Dunbar's number](https://en.wikipedia.org/wiki/Dunbar%27s_number). To quote myself, this is
>
> the size of the average person's ["monkeysphere"](http://www.cracked.com/article_14990_what-monkeysphere.html) (from Cracked, so language is somewhat crude at times). In short, the monkeysphere is the group of people with whom you associate and readily consider as people.
>
>
>
From the cracked article:
>
> Remember the first time, as a kid, you met one of your school teachers outside the classroom? ... Do you remember that surreal feeling you had when you saw these people actually had lives outside the classroom?
>
>
> I mean, they're not people. They're teachers.
>
>
>
So how does this relate to racism? Simply put, races develop in situations where there is physical separation between groups for a significant period of time. For a person in a particular group, this means that not only are the members of another group outside of their monkeysphere, they are *significantly* outside of it. If the groups meet up when under competitive circumstances (which is almost always going to be the case) then you're going to choose the members of your monkeysphere over those outside it.
I'd suggest that this is the most basic source of racism. When cultures clash, it's likely that the stronger (or eventually victorious) culture will paint themselves as the "good guys" or superior in some way, and this will leak into how individuals treat each other.
In short, in order to believably not have racism in a situation with diverse races you need to have an unusual way in which the races are brought together. A common enemy, such as an invasion of monsters, is one such way this can happen. If you think back to the monkeysphere idea, you can see how this scenario is so different - you won't feel like the other races are a threat to the members of your monkeysphere. This also works best if the common enemy survives long enough for the races to mingle enough that it's very common for members of other races to be inside your monkeysphere.
[Answer]
>
> then does it imply that racism is surely going to appear?
>
>
>
No. Racism as we understand it today is a result of specific history (transatlantic slave trade, racial pseudo-science, mass media, etc) which established and propagated stereotypes. Racism isn't just xenophobia. It isn't inevitable just because you have races, because racism as a prejudice requires negative interactions between peoples to create negative beliefs, which isn't always going to happen. People are not guaranteed to think in racial terms either.
The Greeks and Egyptians for instance considered themselves superior to their rivals, indeed the Greeks regarded the people to their north as barbarian degenerates. But this didn't take the form of the racism we know.
The Romans offered citizenship through military service to the men of conquered peoples. The empire was a melting pot unified not by racial identity, but by Roman culture. Septimius Severus was a Roman Emperor who married a Syrian woman, and was born in Libya to a Carthaginian/Libyan father and Roman mother.
There also appeared to be something more of an enthusiastic exchange between peoples back then. The Persian empire's military couldn't be supported only by ethnic Persians, so they used their wealth to hire a lot of mercenaries. Persian nobles were especially fond of Greek bodyguards, even during Persian invasion of Greece.
In your context, there may very well be a great deal of different cultures and "races", but if the movement of people between cultures is slight then there simply aren't enough people being exposed to the other side to establish stereotypes. Foreigners are at first a curiosity, and if there is an equivalent level of technology and military power between these cultures there's no reason for one side to think as they did at the height of European imperial power; that this must be because their subjects were inferior creatures.
The history of European colonialism offers an insight into the fact people weren't always racist. Initially European traders in India often fell in love with Indian cultures. There are stories of young English traders, having made their fortune, marrying a few Indian women and settling down to immerse themselves in local culture. Unfortunately it wasn't long until this changed for the worse, and the establishment enforced rules to ensure that the British and Indians both knew their place. But that wasn't organic, cultural cross pollination is arguably the natural way people interact upon discovering exotic peoples.
It's also worth noting that prejudice between "whites" and "blacks" is a limited way of understanding prejudice against other groups. Feudalism justified serfdom by saying the aristocracy were superior. Peasants were not regarded as equal by any means. Even by the time George Orwell was writing prior to the second world, was he was putting considerable effort into confronting class stereotypes in Britain: that the elite and middle believed the working class were actually a lesser sort of people. So perhaps you should consider the issue of racism more broadly as issues of prejudice along different criteria.
If people are predisposed to view those outside of their Dunbar number unsympathetically, then that means they are going to disapprove of everyone outside of a small tribal group. And that prejudice doesn't explain racism because it's not specifically about races.
I would go as far as saying that colonial racism in the Americas was a reflection of, and required, the feudal social system of the old world, based on prejudice between people of the same "race". In the new world the Spanish replaced the upper, middle, and lower feudal classes with Iberians, Amerindians, and Africans respectively. Without the old world's feudal conceptual framework, and the experience of colonial conquest and slave trading in the new, why would people think in racial terms?
[Answer]
This is a bit of a flamebait from reddit. The answer is simple:
>
> If there are races, there will be racism
>
>
>
Likewise, we can generalize:
>
> If people can be divided into groups, there will surely be actions which act differently upon each group.
>
>
>
Beyond that point, you're going to have to decide what the term "racism" means to you, and then you can answer the question for yourself. The real issue is that "racism" is a *far* more complicated concept than most people give it credit for. Not only is it not black and white, but shades of grey don't even cover it. Color might not cover it either... maybe full spectrum color plus polarization?
The factors which contribute to it are also equally complex. Societies are tremendously integrated feedback loops, so very often "We do A because we do A" is a valid statement. If you asked what factors contribute to racism in the right places, you could probably get enough differing responses to write 4 PhD theses on the topic and give a few TED talks without repeating yourself!
[Answer]
Humans are naturally predisposed toward discrimination of some variety or another, for the reason outlined in Rob Watts' answer - our small tribal village brains simply don't have the capacity to handle the thousands of people we encounter in our daily lives, forcing us to come up with shorthand methods of discriminating the "us" from the "them".
However, using race as that means of discrimination is an artifact of the way our society evolved, where people of different races generally hailed from more distant regions and therefore had different cultures and were harder to understand. As worldwide communication and travel becomes more widespread, this particular means of discrimination is likely to become less relevant over the next few generations.
What form of discrimination we replace it with depends largely on what kind of society becomes widespread. Classism seems likely in a capitalist society, while a religious society tends to discriminate by religion rather than race. Another society may discriminate by career, or one's physical or mental capabilities.
Granted, not all discrimination needs to be negative. A more enlightened society may view members of other groups as having their own distinct and valued skillset and may appreciate them for this, instead of viewing each other with hostility. But as long as we are living in a society with more people than we are capable of viewing as individuals, we will always need to take shortcuts to judge someone before we actually know them, and we will always act in accordance with that judgement.
A world without discrimination of any kind would require us to view every individual we encountered as an individual, which would mean either living in a smaller society or being a species capable of storing this much extra information.
[Answer]
What is origin of racism? We can consider it from two different viewpoints:
1. It justifies differences in society (for example, USA with large poor black minority):
Of course, nobody is going to say that you are jobless because you belong to minority, but common racial stereotypes will still be applied to you. Ideology (as explained by Slavoj Žižek and Marx) is our subconscious interpretation of the world. Before our conscious brains take over everything around us is already interpreted by our experiences and yes, stereotypes. Even if we know, that racial minority is equal to us, we still see them as stupid, violent, etc. In this way it serves as an excuse for maintaining the difference between wealthy and poor. But how do the stereotypes form? Their source is fear, and this leads us to second viewpoint.
2. We fear the minority. There are many kinds of fear, and the dominant one here is fear of losing something we now have and the fear of the unknown. From this fear stereotypes form, which are a way of justifying the fear, rationalizing it. We fear the refugees, because we are afraid of losing our jobs, of losing our culture, etc. From this stereotypes form, and ideology consists from them. Thus racism is born.
But there is still a potential for a racism-less society. The first reason is made irrelevant, if the society has no classes, no differences. The second is irrelevant, if we understand the concepts of racism, if we know and understand their culture and if we don't have nothing to lose (all property is mutual or there is no property at all). One example of such a system could be Aragorn 1936 (however they had no racial minorities, so we can't be sure).
Also, it should be noted that race isn't a biological concept, in biology separation of human species in races was refuted long ago. Today it is only sociological concept. There is bigger difference (in DNA) between a redhead and blonde than between white and black person.
Sorry for bad English.
[Answer]
As race is only a social construct with no scientific basis then it is certain that if someone uses the concept of race then that individual is actually automatically and with no doubt racist.
Not knowing the difference from race and real taxonomy is also a sign of ignorance and as you know racism roots its existence on ignorance.
No wonder why Humans are the only living organism in the whole universe to ''have'' races.
But we as well as anything else on this universe don't really posses races but only species and we have only one species. There isn't such thing as Homo Asianus and Homo teutonicus: every living person on earth today descends from the same tribe of African people. Race is as real as the magical invisible borders dividing rock and dirt into nations or as real as religions.
[](https://i.stack.imgur.com/ST2Lu.png)
[Answer]
Race is a pretty much just a lineage. If you have family lines you have races, simple as that.
With the correct and scientific usages of the word racism is simply believing the above is true.
With the coloquial and "wrong" usage of the word that most people use racism is believing that one person is superior or inferior or another based solely on race and act on it.
If you mean the former, which I doubt you are, then racism naturally will come about because it's a pretty obvious thing. We have a natural predisposition to kin grouping which makes people group and associate with those closer to their own lineage which sharpens these divides the longer they go on.
If you mean the latter, no, that form of racism came about largely due to 2 happenstances and revisionist history. The first of these is that Europe and Asia simple had animals that they could exploit in a city setting leading them to improve cities and technology where as Africans and Americans did not have this so they didn't need to advance technologically so they didn't. Eventually, because people are dumb, this cultural inferiority was shifted to biological inferiority in people's minds and this is the start of what you likely mean by racism, however, this wasn't this vile, toxic, thing that many people think of it today. It was just a mild, "well kids are dumber than adults," type thing. The racism that you're talking about started to set in due to African slaves flooding the slave market which meant slaves from other races were pushed out of the market and slavery became associated with Africans which lead to the deeper engraining of, "Africans are inferior, why else would they be slaves?" This started happening at the same time Americans were dying off in great swathes and being pushed around in terrible ways. We then get to the US civil war and the freeing of slaves which was a very nasty blow to the wealth of the South and we have freed slaves being taught that slavery was awful while disposessed slave owners be wrecked in several ways. Both groups turned their feelings to the other, viewing them as the cause of the problem. Further, people of the same race but not of either group were targeted as part of the other group's animosity which. At the same time as this we have feminists rewriting and lying about the history. As time passed the Northern moral crusaders started teaching that Americans were slaughtered wholesale by Europeans, Africans were enslaved by Europeans, and being that women were now said to be opressed as well we have the various races believing that Europeans are super racists and everyone was discriminated against throughout US history so we now need a bunch of racial organizations to be watchdogs. If you mean this level of racism which is just barely there, largely misinformed by a revisionist history, but largely ignored, then the answer is revisionism + generalization = racism. For racism to exist there needs to be set of things that make a racial divide originally for whatever reason, in this case Market forces, for it to have a cultural impact on how things seem to be.
Despite what many people believe, generally people aren't racists. So what's up with this recent spat that is going on? Simple answer is miseducation, believing things because they feel good or let them feel ok about doing terrible things, and a whole host of a lot of issues that are combining into one big storm. If there isn't something else feeding it, then racism dies away.
Racism as we think of it today isn't inevitable, but the factors that lead to it are more or less inevitable. Change a few things about the overall world and you'd never get it, but those factors that could lead to it are always in play on greater and lesser scales.
[Answer]
Will they have prejudice, yes, that is inevitable, the brain literally can't handle the myriad of facets that make up other people so it has to simplify, being X means this, being Y means that, If X then A,B,C. we need to be able to group people based on characteristics in order to predict behavior.
do those devision need to be along "race" or physical characteristics, No\* it appears that what we divide people on is whatever is both easy **and** perceived as reliable. if you repeatedly tell someone X=Y people tend to believe it, esspecially if you tell them as children. We could create a culture based of sterotyping based on other characteristics. instead of Dave is black therefore also X, Y,and Z, it could be Dave is a Labor Party therefore... Or Dave is an accountant therefore... Or even Dave wears plaid therefore...
most of us don't predict people's behavior by hair color becasue there is no perceived reliability to doing so. The reason we do by race in modern societies is becasue of a combination of historical baggage and the fact that it is kinda reliable for some things in modern society due to ghettoization, national history & language, and cultural identity. ( example: if you meet a large blonde man in kilt you would not expect him to speak with a jamaican accent, becasue you're brain is making predictions about his past based on his appearance and it doesn't match the generalization of Jamaican, and that would be a fairly accurate prediction based on living right now anywhere except perhaps on jamaica. We have been taught, often accidentally, to associate certain things with "race" so we do. We wouldn't if we had not been repeatedly shown these things together, if we had not been give reason to think of races as reliable means of grouping and thus prediction . For example most cultures don't predict behavior based on height or hair color even though it is easy to identify, becasue we we never taught to associate those things with anything else.
The hard part is colonizing a world without bringing the cultural baggage with you, but if you can think of a way around that they no racism is not automatically going to happen, at least as long as your new world doesn't break up into individual nations.
\*(other than minor ones like Tim is short so Tim can't reach thing on high shelves, or Bob has the complexion of fresh snow so Bob probably doesn't spend much time outside.)
[Answer]
Most definitely not. Look at cats for example. You can have a litter of kittens that are all sorts of different colors, all coming from the same parents. Yet are they racist to one another?
To say that "different colored people" implies racism is to unnecessarily project the dynamics of the real world to your constructed world.
There are so very many situations when people of different races interact without racism being an issue. Would you be surprised if in some discussion of disparate races interacting, racism wasn't mentioned? I would suspect *no*.
]
|
[Question]
[
In *Halo*, there are large mechanized suits called [Mantises](http://halo.wikia.com/wiki/HRUNTING/YGGDRASIL_Mark_IX_Armor_Defense_System). These are heavily armed and bipedal (kind of like the the AT-ST). There is no doubt that they *can* be built, but why would they? What would the advantages be of a bipedal mech suit?
[Answer]
The page you linked says that they're about 5.7 meters (18.8 feet) tall. My immediate thought is that this height advantage should be used. The operator of the drone would need to use it to face enemies that are pretty big.
Potential victims:
* Large aliens that could rip a human in half
* Large military/armored vehicles
* Other large mech suits
* Large animals (maybe we're waging a war on elephants)
A human - even a heavily armed one - would have problems taking one of these enemies down. A mech suit would have it easier.
[Answer]
Mech suites are great, but bipeds are a bit iffy
Three reasons why:
* Use tools built for humans: A human shaped mech suite with human shaped hands would not require redesigning tools or weapons for the mech to be able to wield or use
* Intuitive to operate for complex actions: Human drivers have years of experience operating human shaped bodies so it would be more simple to teach them how to do very complex moves in a biped.
* Move through human shaped spaces: The stairs, doors and ladders of our world are shaped for easy use by humans, not mechs on tank treads maybe the need to move in human shaped spaces is enough.
Why not:
* Bipeds are slow: The record speed of mechanical or [organic bipeds](https://en.wikipedia.org/wiki/Fastest_animals) is 60 mph, the current record speed for [wheeled vehicles](https://en.wikipedia.org/wiki/Land_speed_record) is 763.035 mph. You are 10 times slower for being a biped.
* Bipeds are unstable: A quadruped or a hexapod can walk in a statically stable manner. If frozen at any time it would be balanced and upright. A biped must be constantly leaning or stepping to keep balance. For examples, look at the recent [DARPA robotics competition](http://www.theroboticschallenge.org).
[Answer]
The number one answer is they would be super cool especially in animation.
Another reason would be fast movement over unpaved terrain. Obviously, our tech is not there but if you wanted to get up and over bombed out buildings and what not being able to climb over them would be a boon. A better design for this would include hands or be a goat-bot. If the desire was to Run Ostrich style across broken roads guns a blazing the mech shown could be a solution.
But looking cool would be the best reason.
]
|
[Question]
[
Assuming fission thrusters as described here:
[Would a nuclear fission thruster with continuous fuel injection be possible?](https://worldbuilding.stackexchange.com/questions/21596/would-a-nuclear-fission-thruster-with-continuous-fuel-injection-be-possible), and assuming drilling for the planet's molten mettle core as discussed here:
[Could you cool the earth's mantle and then bore into it?](https://worldbuilding.stackexchange.com/questions/21601/could-you-cool-the-earths-mantle-and-then-bore-into-it), and also assuming that people have built self-sustaining environments underground, and won't instantly freeze or starve to death the second the planet moves further from the star, would it be possible to add thrusters to a planet and travel to a different star system by using the unstable elements in it's own core for fuel?
Maybe the main thrusters would be built at one of the poles so that the planets spin is not such a problem. The spin would have to be gradually reduced to make navigation and guidance easier.
Is the star's gravity a major problem or can you just gradually widen your orbit?
How far would a planet get given its own fuel reserves?
[Answer]
So, your question faces two physical problems, even given your assumptions:
* The energy requirements to move a planet; and
* The time it takes to get to other planets.
I'll address the former for now.
## Could your engines do anything useful?
I found a number online that says how much uranium we mine every year. This number is not accurate (no unclassified number would be!), but I'm going to use it anyway: `50 Gg` (giga-grams; or mega-kilograms; how's that for a unit?).
So, let's say this number represents your quantity of uranium for the fuel (to use for the reactor). I'm also assuming the 90% UTB from the linked page. Note that this is an over-estimate because there will be losses and you'll never achieve this, but it'll help this problem.
With that fuel, the 90% UTB reactor can thrust for `1633986.928 seconds` (or `18.9 days`) on one-year's worth of mined uranium.
Burning for that long with the specs in the link provides `5e19 J` of kinetic energy (theoretically). Note that this is also an overestimate because losses will occur.
So, using the 1/2\*m\*v^2=energy equation and the mass of the earth (thanks, Wolframalpha), this translates into a whopping...
...wait for it...
**4.313 mm/s change in velocity!**
Woo!
According to another link I found (which is right up your alley! and is pasted below...), the escape-velocity from the sun's gravitational field in the vicinity of earth is...
...wait for it...
**42 km/s**
You'd have to be 10,000,000 more productive than we currently are to reach escape velocity.
In terms of joules, it requires `4.457e32 J` for earth to escape.
Nuclear fission is particularly good at turning mass into energy (`E=mc^2` and all that), but it's still not really good at it. However, if you assume you instead have an engine that **IS** perfectly good at this, and you were to convert a year's worth of uranium into pure energy to propel earth, you'd get a whopping...
...wait for it...
**4.949e24 J**
So it would still take almost 100,000,000 more energy than that to get earth to escape velocity.
So no, it is not particularly realistic to move earth to travel between star systems.
But here's the link, which you'll want for some light reading: <http://www.quora.com/How-much-energy-would-it-take-to-shift-the-Earth-from-its-orbit-around-the-Sun-and-propel-it-out-of-the-solar-system-and-are-there-any-processes-natural-or-otherwise-that-could-achieve-this>
*(Also, that's a ridiculously long link.)*
One final note: it's amazing how many of these numbers are awfully close to starting with a 5...
## Some fun number comparisons:
`5e19 J`, the amount of energy produced by these engines, is...
* 38% the energy released by the 2004 Indian Ocean earthquake
* 48% the energy consumed by the United States in 2001
`4.949e24 J`, the amount of energy it would take to propel earth to escape velocity, is...
* 1.3% the energy output of the sun per second
* 10x the estimated energy released by the Chicxulub meteor impact *(whatever that is)*
## What if...
What would happen if you converted 10% of the earth's mass into pure kinetic energy (`E=m*c^2` again)?
Firstly, **earth wouldn't survive**. But assuming it did...
You'd be traveling at `0.222 c` (22% the speed of light).
The nearest star is `4.22 ly` away. This means that, after turning 10% of your planet into energy, it'd still take you `19 years` to get there. Note that this is **NOT** a renewable energy source, and is *definitely* not green.
[Answer]
This is most certainly possible and technically feasible, if we slightly change our first assumption and ignore cost. Particularly if the race is highly cooperative and possesses great ingenuity!
I will address each of the concerns raised in the first two links mentioned above and of course the concerns raised here.
Lets start with building a massive, distributed nuclear fission thruster system; actually, lets not. Trying to move massive objects over great distances with propellant based system is a pipe dream. Instead, let's use our massive, distributed nuclear reactor to sustain our energy needs for millions of years. We will need it.
Since we still need to move the planet, what can we use? Well, we can use one of those shiny RF resonant cavity thrusters, or any kind of quantum vacuum plasma thruster.
sciencealert com/independent-scientists-confirm-that-the-impossible-em-drive-produces-thrust
On multiple parts of the planet, with the main thrusters being positioned within diametrically opposed bore holes (we've got to slow down too!). Only the opposed bore holes need to reach the core. The other thruster bore holes can settle for scaled down geothermal and nuclear power. We can use the smaller thrusters for thrust vectoring.
Using @iAdjunct 's 50 Gg of Uranium and the geothermal heat we have available will provide us plenty of electrical power to sustain our operations for at least a few millennia.
We will need to use @Thucydides suggestion of patience and interplanetary momentum transferring to get started. But once we've started moving, we will rely only on our thrusting mechanisms.
Since it will take some time to actually get moving (and for our engineers to invent these exotic thrusters), let's work on getting to the core. And while we're at it, let's consider some of the other challenges/opportunities we will face:
1. Losing the atmosphere
We can start our work by bottling up the entire atmosphere. This will reduce the massive amount of pressure that would be on our thrusters & our underground systems. This partially removes the pressure problem raised in the second link above. Once we start moving, we will lose this atmosphere either way, so this is absolutely necessary for our long term success. And it will take some time.
2. Surviving the conditional extremes
We need something to survive the extreme temperatures coming from below the thrusters, within the underground system (via the planet's mantle, core, etc) and from without and above (i.e the cold gas of a nebula, the heat from a near by star).
We need something to survive the extreme pressure as we build structures deeper into the planet, and as we travel closer or further away from massive objects.
Can we address all of these problems and the concerns raised by @D. Elliot Lamb and some of others in the second link? Turns out we can! We have our unobtainium: Aerogel composites!
Sufficient research could yield a host of aerogels with the necessary properties for most of our engineering needs:
Today's aerogel is already capable of maintaining functionality under extreme temperature differentials.
Aerogel's porosity gives it the mechanical properties necessary to bear high loads. Creating a composite with the right formula could allow our engineers to create a sort of planetary spring/sponge. This will be particularly useful for absorbing the forces created during acceleration and from tidal forces from other large planets.
As a bonus we can also store our atmosphere within the aerogel, killing two birds with one stone. Closer to the bore hole walls, the aerogel structures can absorb some of the steam produced from continuous wall cooling, using the aerogel as a thermoelectric catalyst to produce hydrogen and oxygen necessary for our chemistry and survival respectively (producing ammonia for food, breathing).
And while we're at it, let's grow things micro-organisms our aerogel pores :)
Eventually our scientists will figure out how to evolve a collection of organisms which can regrow what will become our symbiotic planetary host.
2a. The serious issue of building large structures
Even after removing the atmosphere, we still must support the pressure of our entire system as we move closer to the planet's outer core. Using Earth as an example, that's a 2,890 km (1,800 mi) overhead we have to deal with.
The composition of the mantle is locally a solid, but essentially a fluid over time. And its temperature (using Earth as an example) can range from between 500 to 900 °C (932 to 1,652 °F) at the upper boundary with the crust; to over 4,000 °C (7,230 °F) at the boundary with the core. [shameless copy pasted from Wiki]
Can we provide an anchoring solution strong enough to withstand the heat and pressure of geological time?
I think so, in the present moment we have (predicted) Hafnium Carbide superalloys with of melting points of about 7,460 degrees Fahrenheit:
<http://journals.aps.org/prb/abstract/10.1103/PhysRevB.92.020104>
And Hafnium superalloys are already known to be excellent an neutron moderators, to shield us from the neutrons produced from nuclear reactions in the planet.
Scientists are already pursuing Hafnium Carbide aerogels!
<http://sbir.gsfc.nasa.gov/SBIR/abstracts/98/sbir/phase1/SBIR-98-1-19.02-5058B.html>
Having strong, porous materials along with an abundance of atmospheric gases can allow us to making floating platforms which withstand the large pressures from above. Technology like this also already exists:
aps org/units/dfd/meetings/upload/Weinbaum\_DFD03.pdf
In conclusion, by simultaneously constructing a planetary spring/storage system, a geothermal/nuclear energy system, and all the other planetary scale systems you'd need included, you could satisfy all of the requirements of creating a traveling planet which could sustain its own needs and survive the internal and external forces of traveling intergalactic space :)
[Answer]
Moving planets can be done, but this requires a lot of patience and playing a long game of interplanetary billiards.
When a spacecraft like New Horizon "slingshots" around a gian planet like Jupiter, there is a momentum transfer; the spacecraft gains energy, while the gas giant loses a corresponding amount of energy. Given the mass differentials, you will have a very hard time measuring the reduction in Jupiter's orbital velocity.
However, early in the evolution of the solar system, billions of small bodies, asteroids and comets filled the protoplanetary disk. As the gas giant planets passed through this mass of bodies, some were accelerated away into deep space by the gravitational interaction, slowing the forming gas giant down and moving its orbit closer to the sun. It is equally possible for more of the protoplanetary material to be decelerated, speeding up the growing gas giant and causing it's orbit to move outwards from the sun.
So if you want to move a planet today, you would have to start in the Oort cloud or Kuiper belt and start sending bodies on carefully calculated orbits to trade momentum with the planet you want to move. There are some advantages; since the momentum exchange is done through gravitational interaction spread over a long period of time (it would take millions of asteroids passing the Earth to change its orbit), the physical effects on the planet would be minimized, and you have plenty of time to adjust the biosphere through genetic engineering and so on the match the new solar constant.
The disadvantage is since the objects have to fly through the entire solar system, orbital calculations would be insanely difficult, to account for the perturbations of the other planets as the objects passed, and also to ensure these bodies didn't hit vital space infrastructure as they moved past the planet who's orbit you are changing. You also have to account for the bodies after they make their momentum exchange passes, are you going to reuse them or do they settle down in a new, highly eccentric orbit around the sun?
So moving a planet of any size *is* possible, given enough time and resources. The amount of effort will be so huge that there would have to be a very compelling reason to do so.
[Answer]
My physics are weak. But wouldn't some kind of magnetic field be required to keep the planet's structure intact as the gravitational forces on it shift (zipping by other solar systems, gas giants, passing by black holes etc)? On a long enough journey who knows how many different and unexpected gravitational influences might test the planet's structure?
Running a continuous energy field through the planet's structure would be a huge fuel cost. Unless some kind of mechanical reinforcement could substitute. But installing steel meshes inside the planetary structure sounds like one hell of a project.
]
|
[Question]
[
This question is intended as a follow up to this one: [Naturally occurring wheels - do the 'mech' vs. 'tank' comparison apply to organics?](https://worldbuilding.stackexchange.com/questions/20664/naturally-occurring-wheels-do-the-mech-vs-tank-comparison-apply-to-organi)
I agree with the arguments against wheels evolving in place of hoofs/feet in the answer, however, I was wondering if there was a way to make a creature that uses wheels, without sapience or reasoning to build them.
My idea was to have a species which evolve naturally feet, or something similar. However, which then adopted a way to optionally choose to use some naturally existing item as a wheel analog in addition to walking. I'm specifically thinking of a creature that does not have wheels of it's own, but instead an adaptation that allows them to coveneintly use an existing object as a sort of external wheel when it would prove useful; but does this out of instinct rather then reasoned use of technology.
For instance, perhaps there is a species that often travels plans that tend to have long smooth slopes. When at the top of one of these hills if they find a fallen long they (armored) front limbs into either side of the log and push off to roll down with the log (okay, that example doesn't really work, but you get the idea).
Can anyone come up with a credible way with which a species may have evolved to instinctual use 'wheel' technology? Any example where they benefit from the 'wheels' and could plausible evolve the adaptation works is fine, no specifically how or how frequently they use the 'wheels'. For instance maybe the 'wheels' are only used for carrying food stuffs or newborns. However, it must be an example of adaptation, not intelligent use of technology.
[Answer]
There is an example in the "His Dark Materials" trilogy (I think the last book) where creatures use seeds of a plant as wheels.
That sort of approach seems the most probable to me. Lets say a species of animal evolves on a tropical island, where coconuts are common. Being tropical the coconuts are available year-round. The place they evolve is in a sea with a multitude of small islands and a lot of open beaches.
The species evolves special claws designed to pierce the coconut so that it can drink the liquid out from inside, while keeping the coconut fresh. At first it carries the coconuts around but then it starts using them as flotation aids to help with crossing sections of water and it starts rolling them for easier moving on beaches.
Over time this evolves to it attaching a pair of coconuts to its rear legs using the special claw evolved there and then using the front legs to roll the coconuts. This is used both for rapid travel over sandy beaches and to cross sections of water.
Over time this method of locomotion can improve upon and grow more efficient until it becomes their primary means of moving around. They start to secret special oils to lubricate the joints, and favouring particularly round or well shaped coconuts. This actually helps those coconuts as they get widely dispersed by the roaming animals so a symbiotic relationship grows, with coconuts becoming as attractive to use as wheels as possible while the creatures themselves become better and better at using them.
Soon these animals are found zooming around the beach and across the water between a multitude of tropical islands.
[Answer]
I can think of very few possibilities for this to happen. Primarily because while round things can be found in nature, to really use them you need an axle. or you're just a bear performing on a ball.
However, one other example that I can think of that sort of fits is a hamster wheel arrangement. Say something like large bamboo grows on hillsides but when it dies the sections fall apart leaving large empty tubs. the lowlands are wet marshy areas difficult to walk or swim through.
Now a smaller animal like a hedgehog or something that uses the pieces of bamboo to try and hide from predators. Running up a wall will roll the 'home' one way or another. They also float across the marshes. The hedgehogs can run across the marshes using these 'hamster' wheels and can escape from land predators and the wheel also protects them from those living in the marsh, large fish and reptiles. they can even do rudimentary turning by run near one end or the other to tilt the tub for turning.
[Answer]
So let me preface this by acknowledging that it's pretty fanciful, but:
What if you've got some pangolin-like species that rolls into a ball for defense. From there it develops a technique to roll downhill into a prey animal. This technique not only surprises the prey but gives it a heck of a wallop to boot. One downside is that it's impossible to see when you're rolled into a ball, which makes aiming difficult. The prey has a good chance of dodging this attack, increasingly so once they start evolving to avoid it.
Eventually, mated pairs of these pangoloids develop a behavior in which they grasp hands before rolling up, so that they make a dumbbell shape--two spheres connected with a bar between them. The increase in mass, along with the inherent advantage of numbers, allows these pairs to bring down bigger targets. One disadvantage is that, if both parents hunt, there's no one's guarding the young some of the time.
Flash forward a few million years. Consider a mated pair of pangoloids and their baby pangoloid. They're all out hunting together. The parents hold hands and then roll into balls. The juvenile grasps the parents' arms with his specially greased paws and hangs down from them.
The parents start rolling downhill toward their prey. The juvenile, along for the ride, keeps an eye on the prey and communicates its current position to his parents, either through touch or through sound. The parents adjust their angle of attack accordingly. The end result is significantly increased accuracy, which results in increased survivability.
Maybe from there, the child evolves the ability to act as an engine, by actively running instead of just passively hanging on. This would allow the attack to work with shallower slopes or even flat terrain.
Like I say, pretty fanciful.
[Answer]
Maybe not what you're after, but does the wheel have to be an object? I could imagine a hive-like species (think ants) to develop routines which involve *turning into a wheel* as a group. Think like [bivouacing](https://en.wikipedia.org/wiki/Bivouac_(ants)). They might have discovered that the can form such a wheel (or ball) to travel downhill faster. Or, by turning the wheel develop higher speeds at the periphery to "throw" things. Or they could reach out to form temporary "sails" at the top of the wheel to catch wind and use it to accelerate or decelerate.
[Answer]
Assuming you have something that makes a convincing wheel, you can create a creature that will grasp random objects to quickly move downhill between two long appendages, or four for two wheels, keeping balanced atop. The why is important: perhaps the organism migrates through hilly areas and uses the wheels, which it basically just grabs with revolving wrists, to get from one place to another cross-country, but not as a tool, just as an evolved way of using revolving "wrists" to grasp circular objects and move faster with them than without. They don't "build" anything this way.
[Answer]
Imagine a species of mice or bugs which likes to climb inside [Tumbleweeds](https://en.wikipedia.org/wiki/Tumbleweed). On dry, windy desert plains, this might be quite an efficient method of traveling long distances with little energy usage as well as a bit of shelter from sun and predators.
]
|
[Question]
[
In the novel Alien Influences by [Kristine Kathryn Rusch](https://en.wikipedia.org/wiki/Kristine_Kathryn_Rusch) an alien species is presented with no concept of past. In the novel they have some other way of accessing older knowledge, but let's assume some intelligent alien species have no concept of past and concrete memories are fading fast (while learned things like language or work routine is kept). Could such a species develop a civilization and which problems it would face?
EDIT (influenced by some comments): While they have no concious concept of past, they may have one on the subconcious level. They have a consept of the future. They can finish work or conservations they started, so enough short-term-memory for such tasks is available. They may learn to seed crops at certain times (maybe if the stars indicate it).
To clarify on the learning aspect: everyone of us has learned his native language, but no one (I assume) remembers directly the learning process. That way it would be for this species. They can learn stuff, and keep processes, but will have forgotten tomorrow what happened today.
[Answer]
Society? quite probably, as Vincent points out in the comments above. However, civilization I find very unlikely. I think a civilization needs to be based on (at least a few) individuals thinking, especially new thoughts in new ways and being able to spread those thoughts to others.
If you don't remember what happened yesterday, how can you know that next week is the time to plant crops. Or that following a set of animal tracks will lead you to prey, or even that animal tracks were MADE by prey?
Learning is a form of remembering the past, both the rewards and consequences of previous actions. If you can't actively remember, then you are operating completely by instinct, and that can form a society, but not a civilization.
Civilization needs planning and you can only plan for the future if you can remember the past. (Those who don't know history are doomed to repeat it)
[Answer]
This will be a serious impediment to societal or individual development for them to work around.
I'm honestly not sure you can have a self-aware, conscious intelligence with the IQ to develop any kind of society or language but with no concept of past (or time passing) and no memory of past events.
The concept of the past naturally follows from having memory. If you can recall a memory and compare it the current situation, it follows that there is a what-is and a what-was. If you have continuity of memory, you can follow the chain from a given what-was and see how all of the previous moments led up to the current moment.
Do you mean that they don't even have a moment-to-moment working procedural memory? I'm not sure how you could avoid them having an abstract concept of the past without one—even if it's just the recent past—but I'm not sure how you can have conscious intelligence without one. [Object permanence](https://en.wikipedia.org/wiki/Object_permanence) is out, and that's something humans develop as infants. Most of the smarter [animals](https://en.wikipedia.org/wiki/Object_permanence#In_animals) manage it just fine, and none of them have anything we'd call a "society" much less language or abstract conceptualization.
I guess they can learn things by rote conditioning, like animals can, but without a concept or memory of the past, they have no way to direct it, and thus no way to learn anything on purpose. They lack any way to have purpose at all. Even if they make a decision, how do they carry through on it without being able to remember that they made it? They'd constantly be like the guy who walks into a room and forgets what he came in there for, except on a complete and existential level. The guy in Memento had it easy compared to them.
How would they even develop speech, writing, or record keeping with no way to compare the symbol they see or the sound they hear with the memory of learning what it means? How could they become tool-users if they don't have a way to remember what problem a given tool can be used to solve?
Without a concept of the past or memory of it, you can't really have a personality, habits, purpose, learning—not even by trial and error—the ability to assign meaning to events, or the emotions that follow from those meanings (except maybe surprise), or any sense of individuality. Experimentation is out, and so is the development of the scientific method. They can't predict the future based on past events. They can't generalize a solution to a current problem if they can't remember how they solved similar problems in the past, so they're forever reinventing the wheel. Literally. Fire's really convenient for warmth when lightning happens to create it, but they're darned if they can recall how to get some more of it when they're cold.
They're really missing the basic tools to get a society off of the ground.
I'm also not sure how they could have any idea of the future without an idea of time that includes the concept of the past. Without the ability to conceive of things that don't exist but could in the future, how could they act so as to make that future goal a reality?
I'm not saying there couldn't be some alien species that meets your requirements but still has intelligence, but I think they'd be so utterly alien that we'd have a very difficult time interacting with them or even recognizing them as intelligent. That intelligence would have to be some kind of emergent, group-based property that doesn't exist at an individual level.
Maybe the individual aliens are just nodes in some kind of larger, possibly planet-wide, neural net or groupmind? Alone, they're just animals, but enough of them together can form a hivemind that can do abstraction, learn, make a decision, and then split up into its component parts to execute those decisions, leaving the individuals (albeit, without any concept of themselves as individuals) with no real concept of why they are doing what they are doing but just doing it by rote anyway.
I think you've really got to fudge or fuzz at least a few the usual concepts of "memory," "the past," "intelligence," or "individual" to manage this.
[Answer]
I'd imagine the society would be quite robitic in their forms of tasks. They'll just continue doing their daily routines and would struggle to make any advancement to things that they do.
Depending on how much of the past they can remember, experimenting wouldn't be their greatest achievements. If they quickly forget what they've recently done, there would be no "trial and error" experiments.
However if they successfully discover something new without testing (playing around with pieces of flint and creating fire) and use this newfound knowledge in their daily routines then they'd slowly start to develop.
This all really depends on how much of the past they can remember and how significant an event has to be for them to actually memorise.
[Answer]
Lets say yes and go from there.
With no concept of Past, they probably wouldn't have a real concept of Future like we know it, but they could/would have goals and instincts, at least on a society level if not personal level. Some kind of hive mentality like bees or ants.
With the addition of sentience you would probably have some level of personal goals too, but it would be instinctual as much as anything.
>
> "I don't really know why, but I need to have a large amount of food stored up while it's plentiful, because something is telling me it might not be later."
>
>
>
But really some kind of genetic memory like some insects/animals have would be key. Instinct again... This instinctual knowledge could be passed on to others verbally:
Day 1: subject A eats the purple berries, has bad reaction.
Day 2: subject A sees subject B reach for purple berries and instinctually knows they aren't good, and so warns subject B.
Day 3: subject B sees purple berries, and instinctually knows they wouldn't be good, and so passes them.
They could still have memory with no sense of past. I know something happened, but not when it happened because there is nothing before this moment... Cause and effect might be hard to develop in this system.
Civilization could be difficult, but depending on the level that instinctual knowledge is communicated it could be possible. It would form around societal/hive goals, and may be unrecognizable to us, but that doesn't mean it wouldn't be a civilization.
[Answer]
This method of living is extolled by many Earthbound groups, under the phrasing "live in the moment." We can look at how they do it, and extrapolate to aliens.
Why do we need the past anyway? After all, we have senses that can tell us what the present is like, and we have effectors like muscles to help us shape what the future can be, why not simply look at the current situation, and act accordingly? The answer is that some things happen faster than we would choose to act. If we did not prepare for them, they would affect us too fast for us to adapt to them. A conscious concept of the past is one way to solve this issue.
The other approach is to craft a world around you with sufficient harmony that you are never forced to act faster than you can sense the world around you. You subconsciously nurture the environment around you to be your protection and gather energy for you. Any hostile intentions must come from outside this harmonious environment, so it must plow through layer after layer of it. If this act of plowing through layers causes you to shift your position to simply not be where the hostile thought you were, there is no need to remember complex histories to identify that hostile as hostile. You simply react to the world around you.
[Answer]
You might be interested in the story of [Henry Molaison](https://en.wikipedia.org/wiki/Henry_Molaison) as a model. After extensive brain surgery to prevent epileptic seizures, he lost his ability to form new episodic memories (remembering specific events) but still had the ability to create implicit (intuitive memories), especially through repetition.
I think the ability of the brain to form very strong learning based on intense emotional information (primarily the Hippocampus, I believe) would also be intact. I could see that an extended childhood, perhaps teaching through repetitive songs, stable multi-generational families and long lives that would promoting the transmission of knowledge.
[Answer]
On a different tact, consider the [Pirah Trab of the Amazon](https://en.wikipedia.org/wiki/Pirah%C3%A3)
>
> As far as the Pirahã have related to researchers, their culture is concerned solely with matters that fall within direct personal experience, and thus there is no history beyond living memory. Pirahã have a simple kinship system that includes baíxi (parent, grandparent, or elder), xahaigí (sibling, male or female), hoagí or hoísai (son), kai (daughter), and piihí (stepchild, favorite child, child with at least one deceased parent, and more).[4] (pp86–87)
>
>
>
What's really interesting is that they share many similarities to what Anthropologists believe to be early hunter-gatherers: belief in spirits as opposed to gods, no means of counting or numeric system, and engaged in primitive, non-coercive form of communism.
[Answer]
There was a [Star Trek episode revolving around a species who communicated only through references to past events](http://en.memory-alpha.wikia.com/wiki/Darmok_(episode)).
It makes me wonder if a society could emerge without history by weaving or developing their language from, essentially, shared memes that embody history without really considering it history. Thus cultural knowledge and experience could be passed on without having explicit stories - it's the only language they have and know, so the knowledge is obvious, even though the reasoning or history behind it is long gone.
]
|
[Question]
[
Two nations are at war over something rather trivial, but offenses have been perpetrated here and there such that the conflict has escalated from a couple of guys shooting each other to massive bombing runs by both sides which can kill thousands.
The bombing runs are *a la* the strategic bombing campaigns of Britain and Germany during World War II:
* Wings of bombers set out in groups of four, flying four abreast. They're not quite heavy bombers, but more like the [Heinkel He 111](https://en.wikipedia.org/wiki/Heinkel_He_111):
[](https://upload.wikimedia.org/wikipedia/commons/c/cc/Bundesarchiv_Bild_101I-343-0694-21%2C_Belgien-Frankreich%2C_Flugzeug_Heinkel_He_111.jpg)
There are a few squadrons of heavy bombers, though, like the [Avro Lancaster](https://en.wikipedia.org/wiki/Avro_Lancaster):
[](https://upload.wikimedia.org/wikipedia/commons/5/55/Lancaster_B_MkI_44_Sqn_RAF_in_flight_1942.jpg)
* The bombers are protected by fast, single-seat fighters armed with four front-facing machine guns and two rear-facing machine guns. They're similar in speed and size to the [Supermarine Spitfire](https://en.wikipedia.org/wiki/Supermarine_Spitfire):
[](https://upload.wikimedia.org/wikipedia/commons/3/31/Ray_Flying_Legends_2005-1.jpg)
There are about ten fighters per four bombers - enough heavy defenses to hold off most attacks.
Technologically, all of the aircraft have systems similar in technology those of the 1960s. The one significant difference is that the engines are not jet engines. On this world, electric engines have been developed, making anything running on oil obsolete. The jet engine was never developed.
However, one side has developed technology that can emit [electromagnetic pulses](https://en.wikipedia.org/wiki/Electromagnetic_pulse). Concentrated pulses can travel about fifty feet before dissipating. Each of the enemy fighters has been modified so that it only carries two (forward-facing) machine guns but has turrets above and below the cockpit that can fire an electromagnetic pulse. The one below the cockpit is weaker so that it can be fit in without causing inconvenience to the landing gear.
With proper aim, one of these fighters can render part of a bomber useless. Targets depend on the bomber type; on two-engine bombers the main target is one of the engines, in an attempt to knock out the power and control. One four-engine bombers, the strategy is to take out the rear gunner with the machine guns, then fly overhead and deliver two pulses in the general area of the cockpit, hopefully destroying instruments and potentially killing crew members.1
The *other* side (non-EMP guys) are not too pleased about this, and they'd like to figure out a mechanism that can protect all the critical components (e.g. engines, fuselage, bomb bay, etc.) of the bombers from EMP attacks. They've hit on the idea of a [Faraday cage](https://en.wikipedia.org/wiki/Faraday_cage), which can be really effective . . . but it's been found that holes from bullets can inadvertently cause considerable damage to the cage, which drastically reduces its ability to stop the EMP pulses (hence the strategy used when attacking heavy bombers). They've also read [this pdf](http://www.zmne.hu/aarms/docs/Volume3/Issue3/pdf/13vass.pdf), but they're not at all convinced that any of the shielding ideas could remain uncompromised after machine gun attacks. Bullet-proof walls have proven to be ineffective, because of certain (as-yet unknown) characteristics of the enemy's bullets.
What can the bomber crews do to protect themselves and their airplanes?
---
1 Bombers now are designed with escape routes and landing gear doors that do not involve electricity and can be operated manually. Same goes for fighters.
[Answer]
Of the two bombers you mention, one is fuel-injected and the other is carbureted. Neither of them use sensitive electronics (the first fly-by-wire/ECM system appeared in the Concorde in the late 60s). To see how much protection they need, let's look at some real-world examples of EMPs.
[These guys](https://www.youtube.com/watch?v=oT5EJYY_6HQ) have developed a car-stopping EMP 'gun' that, at first, seems to operate like you describe. However, the video neglects to show you the (undoubtedly large) capacitor bank used to power the EMP. They also pull the car up to point-blank range, suggesting that the impressive-looking helical antenna isn't able to focus the broadband pulse (they certainly have no qualms about firing it out towards the parking lot!). Lastly, they mention that they are disabling the car's microprocessors, which is not a feat, since without their protective circuitry, complex integrated circuits can be destroyed by accidental static discharges far too small to feel. Also note that their claimed timeframe is five years: but it's 2015 and no one's using EMP cannons on cars.
[This video](https://www.youtube.com/watch?v=Aj54FcI7_dE) shows another example of disabling a car with an EMP. The important thing to notice is that the electric windows still work. The alternator, starter motor, and spark plugs are built to handle far more current than the window motor, so they are undoubtedly still working too. The reason the car doesn't start is most likely that the computer is damaged. An engine without a computer (see 1960s planes, above) would be undamaged.
Even if your EMPs are powerful enough to cause damage to an unprotected alternator, shielding such a small target is relatively simple. The only other target is the spark plugs (the starter could be external to the plane), which are already well-protected due to their placement between the head and valve covers, which form a very thick shell.
All the other parts can be mechanical, and in fact on WWII bombers like the ones you mention (developed in the 30s and 40s), they were! If powerful, long-range EMPs were developed in the 60s, likely the only change the Air Force would have to make is to switch from the B-29 (which used, among other things, electronic fire control) back to the B-17.
Finally, unless your EMP fighters are equipped with some really, really heavy shielding, they're going to fry themselves when they fire. Since they're closer to the focal point of the pulse, their shielding requirements scale faster than the defender's requirements, meaning that an offensive, non-kamikaze EMP is wholly impractical.
[Answer]
Using aircraft technology as in World War 2, I believe EM weapons wouldn't actually do much damage. The controls are complete mechanical and work without electric power and I think the electronics in the engine spark plugs are so simple that they can deal with pretty strong EMP before being damaged.
Radio and gun turrets are probably the most vulnerable components on a bomber of that era and lightbulbs might fail, but otherwise I think they would be fine.
The damage of EMP is caused by the wires experiencing an energy surge that is high enough to cause the components to heat to a point where they are destroyed. The efficiency of EMP depends on the length of electronic circuits and the diameter of the the wires. Modern electronics have microscopically thin circuits that are very sensitive to getting too hot and their total length can be many kilometers. Especially when connected to power grid landline the length of circuits become mind boggling. An airplane is not connected to the power grid so all the cables to be affected are limited to those on the plane itself. And 1940s electronics are very primitive with comperatively thick wires and not actually a great length of wires. The strength of the power surge would be pretty low and the equipment be quite robust to withstand it. I wouldn't be surprised if a bomber of that era would be unscratched by an EMP that completely fries a modern cell phone.
And no, bullet holes don't actually have any effect on a Faraday Cage.
That is not to say you can't get ahead with your idea, but it probably needs to be handwaved sci-fi magic and does not actually work with real physics.
[Answer]
EMP works against electronics, by inducing electric pulse of voltage far exceeding the flimsy ratings of 5V or so in wires nanometers thick, breaking through diodes, transistors and capacitors, damaging the components. It's a very low power, capable of micrometer scale damages, but applied to microscopic structures the effect destroys them.
High-power electronic and electric circuits experience a short surge of high-voltage current, but the power delivered wouldn't change a thing.
In internal combustion engines you might experience a minor glitch, the spark going off at a wrong moment etc, the engine skipping one cycle without a burn, but they would not be damaged. Diesel engines would be entirely unaffected; once started they can run without any electricity at all.
If the bombers have some on-board electronics: radio, radar etc, these would possibly be damaged, though if made in discrete parts and not in integrated circuits, that's a rather low possibility.
The worst that could happen is triggering a spark in the ignitor of a bomb on board. They vary in construction, but some may use wire constructions that could spark with enough voltage induced. Of course that would be fatal for the airplane, and of course constructing an ignitor entirely immune to EMP is perfectly viable, providing they realize the requirement.
Also, though quite improbable, some construction quirks (e.g. of fuel level sensors) may cause a spark in the fuel tanks of the airplane.
[Answer]
What about changing the design of the aircraft instead?
Rather than protecting against it directly - which as you've noted is somewhat unfeasible - you could decentralize your systems and add additional redundancies. The enemy's tactic only works if they can disable the bomber in a fairly short period of time, so anything that makes it take significantly longer to disable your bombers makes the EMP fighters less useful.
Use 8 smaller engines instead of 4, and insulate them from each other. This mitigates any single attack, and isn't incredibly hard to do with electrical engines. Have two cockpits, with parallel controls. The second cockpit will still be connected to some systems and can do most of what a co-pilot normally does, and in the case of an attack on the primary cockpit they can hit a manual control and connect fully to take over. Do something similar with your bomb bays and other critical systems.
Another tactic presents itself - controlled shutdowns. Design your bombers with the *expectation* that they'll need to glide for significant distances. If a fighter gets close (and 50 feet is **really** close), go into a special shut down mode and glide for 20-30 seconds. This mode completely isolates all electrical systems, putting the controls back on a temporary, manual setup and cutting all power. EMP attacks may do some damage, but that damage can't spread and will be reduced and contained. I find it unlikely that a fighter will be able to stay close for a long period, so you don't need to stay that way for long.
[Answer]
Well, unless the EMP plane is a suicide plane, it needs to have protection from EMP just to stay up and use its weapon more than once.
So the other side just needs to steal that technology itself.
[Answer]
You could use a redundant electronic system, one of its part is normally on while other(s) is(are) off keeping "well-grounded" to an accessible "mass". In the case of a success EMI attack, the first part will be dis-operated (got harmed), after that, the second part (so called cold reserve) could start to operate that give your plane a second chance.
This is a real technique, the [Satan ICMB](https://en.wikipedia.org/wiki/SS-18) used such a surviving concept in each of its warheads.
[Answer]
EMP isn't magic. It's little more than what is experienced by a generator. The plane is passing through a dense magnetic field just as the generator's wire is passing through a (locally) dense magnetic field. The theoretical threat of an EMP is that it carries so much energy that things are damaged.
But that doesn't change the physics of delivery. If the plane is sheeted in conductive metal, then the fusalage skin is getting all (100%) of the energy. That's what's passing through the field first, and it has by far the largest conductive path to absorb the energy.
So the real question is, what is the skin connected to? Modern automobiles, for example, connect the chassis, frame, skin (if metal), etc., to the negative pole of the battery. It makes the car's electronics easy to reference (voltage reference or ground reference). I'd be surprised if airplanes didn't do the same thing for the same reason.
This means the first (and likely only) thing damaged is the battery. And the easiest way to protect against EMP is to add more battery, or to create some electricity-consuming device (like an arc generator) that could dump overvoltage energy.
I have not looked into the effect of EMP on automobiles, but I'm willing to bet that cars that survive are metal-skinned cars and cars that don't are fiberglass/plastic skinned cars. Further, the chassis/frame, motor, etc., are all so large that they'll absorb the energy long before wires or computers. The only way the computers would be damaged is if they're not begind something large and metalic (referenced from the direction of the emp source) or not shielded (encased) in metal.
**Solution: build the planes with metal skin, connect the negative post of the battery to the skin with thick cables, use a lot of batteries or design an over-voltage shunt that dumps excess energy to an electricity-consuming device like an arc generator.**
]
|
[Question]
[
Is it possible to have a major trade city built on the edges of a lagoon?
For a city I'm designing it is situated on a lagoon but if there is a small strait/canal so that ships can move in and out of the lagoon does it still qualify as a lagoon?
I ask not only for geographic understanding but also because the name of the city means lagoon.
[Answer]
A good example would be the city of [Venice](https://en.wikipedia.org/wiki/Venice), which is built on the [Venetian Lagoon](https://en.wikipedia.org/wiki/Venetian_Lagoon).
This is, in fact, [where the name lagoon comes from](https://en.wikipedia.org/wiki/Lagoon#Etymology).
Historically, from the 9th to the 12th century, the city was a hub of trade between Western Europe and the Byzantine Empire and the Islamic world.
So clearly it's possible to have a major trade city on a lagoon, the name itself comes from a real world example.
[Answer]
Lagos, Nigeria
It is situated on a lagoon and its Yoruba name, Eko, means lake or lagoon.
]
|
[Question]
[
When traveling at fast speeds through the galaxy, would it be possible to identify where all the black holes were on your path? I know most black holes are identified by their affect on other nearby objects. But what would happen if it was all by its lonesome?
Would we be able to 'sense' it somehow before getting to close to be adversely affected by it? Or would we fly by, maybe getting close enough for it to deflects our course? And how much could it deflect a course (assuming you stay out of the event horizon)? Would it warping of space allow for Alcubierre drive like properties?
I guess I'd hate to get thrown into a sun because of a course alteration from a black hole, though getting caught in the event horizon wouldn't be much better. Can we detect these masses to avoid them at distance or do we need to take first trips much slower so we can scan for these anomalies and mark them for safe 'shipping lanes'?
[Answer]
Barring the presence of an accretion disk surrounding these black holes - unlikely, in the absence of a compansion object - our best bet is likely to exploit **[gravitational lensing](https://en.wikipedia.org/wiki/Gravitational_lens)**, the bending of light from distant objects by a massive object in front of the source. Typically, the massive object is a foreground galaxy, a massive star, or - in this case - a black hole.
The angle of the light bent can be calculated as
$$\theta=\frac{4GM}{rc^2}$$
where $M$ is the mass of the black hole and $r$ is the closest distance a light ray passes from the black hole. For stellar-mass black holes (on the order of a few dozen solar masses), $\theta$ is likely going to be small because the angle is only linearly dependent on mass. When we reach masses of $\sim10^4M\_{\odot}$, lensing seems more easily detectable, but at that point, we're talking about intermediate-mass black holes, which should have strong effects on the kinematics of their surroundings.
We have yet to detect lensing from an isolated, low-mass black hole, but it's not out of the question. If we did see it, it might look like this:
[](https://i.stack.imgur.com/pAxux.gif)
Image credit: Wikipedia user Urbane Legend, [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/deed.en)
[Answer]
[Black holes](http://en.wikipedia.org/wiki/Black_hole) are called "black" only because light does not escape from beyond the event horizon. However, they are typically not what we would call either black or invisible.
A black hole was typically once a star, and so is highly likely to still have orbiting bodies - it may have lost some mass in its supernova explosion, but not so much that it would have lost all of its satellites, though it is probable that their orbits would have been significantly altered.
Also, black holes *appear* to emit EM radiation as matter falling in toward them is torn apart by the gravitational tidal forces. Some black holes have very bright accretion disks.
Finally, the powerful gravitic field of a black hole would cause gravitiational lensing, that could be used to detect it, given that this effect will distort the image of the rest of the universe as the black hole passes between the observer and the rest of the universe.
[Answer]
I think unmanned scouts could lead the main craft. Besides other hazards, the gravity would affect the course and let you map all kinds of dark bodies, including more prevalent sub-brown dwarfs. Having them not only ahead but off tomthe side gives you a long baseline for viewing your destination as well as Earth in the rear. It could be a LIGO system for detecting gravitational waves.
[Answer]
Another idea: Black holes shadow the cosmic microwave background. This might be used to detect them. Given that with high speeds, the microwave background in movement direction (that's the direction that's relevant if you want to avoid them) will be at higher frequencies due to the Doppler effect, I can imagine detecting them by their shadowing would be simplified.
[Answer]
Black holes tend to have high relative velocities, you couldn't mark out permanent safe routes regardless of detection flights. If you're heading directly towards a particular star you should be able to see the gravitational interaction between a black hole and the star light you receive from the target, this will either be in the form of [occultation](https://en.wikipedia.org/wiki/Occultation) or [gravitational lensing](https://en.wikipedia.org/wiki/Gravitational_lens) but if you *can* see these effects you're probably far enough away that the transitory mass causing them won't get near you, it's passing ahead of your course at galactic speeds. Of greater concern is near lateral detection and that's likely to be spotty because it depends on what the background around the ship is like in terms of visible object density. Black holes and other non-emitting bodies coming in at high velocities roughly perpendicular to the direction of travel are going to be the hardest to spot before they cause disruptions.
]
|
[Question]
[
I am trying to imagine a terraformed solar system in the late 3rd millennium to early 4th millennium AD. As a result, I am curious if plants on this Mercury, which would have all the oxygen, CO2, soil nutrients, and water they need to survive the sunlight intensity on Mercury. Also, this Mercury has had its day shortened to 20 hours. MANDATORY EDIT: This Mercury has a magnetosphere that is strong enough to block a similar percentage of UVB and A that Earth's does, or what I mean is, only an Earth-like amount of radiation reaches its surface. It has a surface pressure of 96,879 millibars.
[Answer]
It seems unlikely. Ultraviolet will basically kill anything we know of at that intensity. We use it to purify water as even microscopic life can't survive it. It definitely damages plants even on Earth as anyone involved with hydroponics can attest, too much will kill them in short order as it messes with their chemistry in a myriad of ways.
Our plants have evolved for the amount they receive on Earth, too little or too much is bad for them.
One of the main things plants get from UV light is that it stresses them, and therefore causes important protective mechanisms to combat the stress. These things are great for the plant, kind of like stressing muscles to make them grow for body builders. Overdoing it will cause irreversible damage.
[Answer]
**Frame Challenge: Why expose them to full direct sunlight?**
If you have the technological capacity and resources needed to Terraform Mercury you must by default also have the capacity to basically just 'green house' it. The gravity on Mercury is only about .4 of G BTW so it would have a thinner atmosphere than Earth by default and the intense radiation would strip that away very quickly.
Better to invest all your efforts in constructing a planet spanning network of giant arcologies (well as much of it as you want to anyway). You still end up a habitual planet without the hassle of dealing with the issues I raised above. Hundreds of thousands of square kilometers of the surface covered in sealed domes and towers (or any other shape you want) each stretching kilometers upwards into the sky and/or downwards into the crust. All of them with their own controlled ecosystems with Earth like air pressure, oxygen levels and weather as well as all the other comforts of home. Think rivers and seas, forests, hills, valleys and even mountains if you want. Just like the kind of thing you might see on larger space habitats only on a far grander scale. The planet would sparkle and glitter in the harsh sunlight when seen from space.
[Answer]
Rainforest trees often grow high, wide leaf canopies to gather as much sunlight s they can in the jungle, simultaneously blocking most light from reaching the forest floor.
Additionally, in real life, there are many plants that grow branches or leaves that die, but remain attached to the plant. This happens with plants that live in dry areas such as deserts, so it isn't a far stretch to imagine plants on a brightly lit planet doing the same.
Your plants could combine the traits above to quickly grow a dense canopy after being planted, which then shrivels and dries up. then the plants could grow at a more reasonable pace under the shelter of the canopy, like grass sprouting up under a tree in dry areas. To accomplish the canopy growth, the plants could grow from large seeds that contain plenty of stored nutrients so they don't need the sun until after they have assembled their canopy. the disadvantage of this method would be that the canopy would be dry tinder on a baking planet. it would probably be wise for the plants to fabricate some type of flame-retardant chemical on the canopy leaves.
There's another option: the plants hide from the sun.
again, this is similar to what many real plants do, like morning glories, which open their flowers in the morning and close them later, or sunflowers, which move their flowerheads throughout the day to follow the sun during the day. your plants could have tough leaves that shield them during the day, then blossom at dusk for the plants to grow. They could even employ a hibernative state like some plants and animals, where they practically dry up in the day, perhaps storing all their water in their roots, then when the worst of the heat is gone, they could rehydrate themselves.
Third option: If your planet follows a normal spin pattern, there is probably somewhere like our poles that gets less light than most of the planet for at least part of the year, meaning that plants without to many special adaptations could survive there, especially if they have shelter from rocks, mountains, or other natural formations.
Fourth option: Water plants. Plants that live in swamp-like or even fully submerged environments.
Apologies for the length of this answer, your question really got me thinking. Thank you!
[Answer]
>
> "... Also, this Mercury has had its day shortened to 20 hours..."
>
>
>
If your future-science civilization has the technological power to alter the very spin of an entire planet... then surely they have the ability to build a [sunshield](https://en.wikipedia.org/wiki/Space_sunshade) or two.
]
|
[Question]
[
I was thinking of a story I wanted to write, but I had a legal question.
It involves a war story, and a group of around 12 soldiers. Members of a regular armed force, with the authority of the head of state legally behind them, have taken a position in an armed conflict and have in the process captured some of their enemies, who haven't actually said they gave up nor did they raise their hands but were physically overpowered. Those enemies are not part of another country, but are members of a designated terrorist group – some of their members having been convicted of it, even having had their death sentences commuted years before.
The allies of those enemies are coming back and are clearly going to take the position back, imminently, within a minute or two, and there is only room for the soldiers to retreat back to safety.
One of the soldiers asks their commander if it would be a good idea to kill the ones they captured before they leave, given that they can't take the captives (who are about to rejoin their enemies) with them. **Does the commander have the right to do this?**
I am planning to add a dialogue with one of the soldiers who is brilliant and is legally trained, and I want to know what this advisor should legally say in accordance with the laws of war in effect today.
If it matters which conventions have been ratified, I would like to know which ones are relevant.
The municipal laws of a country aren't important; the story will invent that later. I am interested in what the international treaties would say on this.
---
OP comments added for clarification and posterity:
>
> This is more like a far future event, hundreds of years from now, with a long era of peace, and this is basically completely ad hoc to create a militia, as for why nobody remembers precisely what is in these conventions, not even the king. Don't worry that this is a real scenario.
>
>
>
>
> This isn't really like an army of any real country. The idea I had was futuristic and a little magical in the literal sense, although then again, Thor is noted for having said in the Avengers movies with advanced technology being indistinguishable from magic. It would be centuries, maybe over a thousand years, into the future where war has been essentially absolute for that time. This scenario involves no vehicles, little prep (like maybe 5 minutes max for capturing and being forced out), no fortifications, no evac this way, just running or flying the way that Iron Man flies.
>
>
>
[Answer]
The relevant [Geneva Convention](https://ihl-databases.icrc.org/en/ihl-treaties/gciii-1949/article-4?activeTab=undefined) talks about persons who have
>
> fallen into the power of the enemy
>
>
>
The convention explicitly prohibits
>
> the passing of sentences and the carrying out of executions without previous judgment pronounced by a regularly constituted court, affording all the judicial guarantees which are recognized as indispensable by civilized peoples.
>
>
>
So while it may be possible to haul those presumed 'terrorists' before a court, the killing you describe would clearly be an illegal order. Military forces have issued and obeyed illegal orders, time and again, but they are not *supposed* to do that.
The officer would be expected to know that, the other character just has to remind her.
---
*Follow-up, because this has been migrated to Worldbuilding:*
* *Good troops do not* argue *with their commanding officer when the bullets fly. They do their best to understand the commander's intent and to make it happen.*
* *Good staff do* provide options *while their commanding officer is planning. They evaluate them from as many angles as they can, to advise on their strengths and weaknesses, and they argue with each other while they do that.* "If I were the enemy, my countermove would be ..."
*So either there is a bad apple, undermining the chain of command when the leader has made a decision, or they have a bit of breathing space and they leader is running through an abbreviated planning session with an improvised staff. Even a minute to talk through a plan can make a difference.*
*In the former case, the officer says* "because I say so" *and all good soldiers should obey. In the latter case, what is the question? I cannot see the officer asking* "I want/I do not want to shoot the prisoners, find me a legal loophole to do what I want." *It might be something like* "we need to deny as much of these supplies to the enemy as we can with the demolitions at hand, what should we blow and in which order?"
[Answer]
This was written when the question was on Law StackExchange and pertains to *contemporary* law. However, human rights law tends to run hand in hand with a technological society, because first, it's hard to get humans to innovate when they're treated like meat... and second, tech components like petroleum, lithium, rare earths, (or for that matter tea) tend to only be accessible when you have a world peacefully trading under rule of law. Yes, there's aluminum and lithium in your garden soil, but it is much more costly to extract than the rich ore bodies in exotic places in the world.
## The soldiers blew it. Now they eat the loss.
They should have pushed the captives to the rear *immediately* when they had the chance, especially if they are high value. Now it's too late.
If they never had the chance, then they never really held the position, they were just raiding.
Once the enemies are rendered unable to actively fight, they are *hors de combat* and you cannot harm them under civilized laws. I mean, you could arrange for an "accident" like unshackling them and letting them overpower one of you and reach for some weapons you carelessly left lying around. At that point you could shoot them. *However, not the best idea. If you follow Ryan MacBeth on social media, one thing he says, when you go to combat, you're gonna be haunted by the experience for the rest of your life *even if you do everything right*. If you did stuff that was wrong, it will be much worse.*
## However, you may have a narrative gold mine
One very interesting option would be give the prisoners some seats in the transport **by leaving some of your soldiers behind**. And then, they "exfil" (leave the area) by other means.
It has the merit that the enemy *would never conceive of you doing that*, because if they're experienced at fighting your army, they're familiar with your very strong "Leave No Man Behind" morality, and may regularly exploit it.
[Answer]
## International Law Does Not Apply
>
> Those enemies are not part of another country
>
>
>
Unless an International Organization like the UN recognizes the terrorist group as a sovereign nation, then the Geneva Convention, and most other international treaties do not apply. POW laws apply to the treatment of Prisoners of War as fought between countries who have by treaty agreed not to mistreat each other's POWs.
But since this is an internal conflict, the only laws you need to worry about are at the national level, and different countries would treat this sort of behavior very differently. In many parts of Asia or South/Central America, there would likely be little-to-no consequence. In North America or Europe, there tends to be a lot more red tape when it comes to restraining and then killing your own citizens. But even some Westernized states offer very little protection to someone once they've been declared a terrorist, because that means that they have been declared enemy combatants and have no citizenship left to fall back on when it comes to protection of thier rights as POWs; so, a prosecution would have a had time finding jurisdiction to actually punish the soldiers on, even if they found the act morally reprehensible.
]
|
[Question]
[
I am thinking of adding an element to my world that is primarily desert that consists of a semi liquid sea of possibly high silica sand that's inundated with salt water. Would such a mixture have the effect of a sea like body of sand?
Thank you for your time
[Answer]
# Two words: "Gassy ground".
You might know that the idea of a desert that works like a sea of liquid has been used in various games and movies. What you may not know is that that can actually happen in real life. It's called [sand fluidization](http://colgatephys111.blogspot.com/2017/12/sand-fluidization-by-jon-delman.html), and it's basically about having gas coming from the ground in regularly space openings and with enough pressure as to generate a force that essentially counteracts gravity, making the sand behave much like a liquid, or rather like a fluid.
[](https://i.stack.imgur.com/gRTqW.gif)
The main problem really is to get this to work. It's been done artificially by us and up to [hot tub size](https://m.youtube.com/watch?v=My4RA5I0FKs) as far as I'm aware, but for it to work on a desert scale would require a very specific type of ground and **A COLOSSAL AMOUNT** of gas coming out of it at all times. You might want to add this landmark to the handwave bill, as such a terrain probably shouldn't last for long unless very specific conditions are kept. You might even have portions of the desert where the flow of gas and composition of the ground creates islands.
I'm not exactly sure how this would work for wildlife, but given how we have creatures adapted to swimming on non fluidized sand (such as sandfish), it's not impossible for something to adapt to living in this conditions by developing traits similar to bony fish or other adaptations that enable them to change their own buoyancy. Boats also may be able to float properly under the right conditions depending on their size, weight and volume.
[Answer]
There is one problem you simply can't overcome: the density of sand is greater than the density of water. For something to float, it must have a density *less than* water. Because sand's density is greater than water, it will always sink.
**Condition #1: A lot of sand, some water.**
Yours is a desert world, but even desert worlds have bedrock. So let's assume an area of bedrock shaped like a bowl but filled with sand. As you add water, the sand gets soggy. If you don't fill it too fast, you eventually get a bowl full of wet sand. You can have life in this condition, but not fish. "Swimming" (as we traditionally think of it) isn't possible.
**Condition #2: A lot of water, some sand.**
Consider the same bowl full of sand, but this time we'll add water fast enough that erosion can occur. Eventually you have a bowl full of water with some sand on the bottom. Even if we consider this like a sea (no outlet), you'll have salty water, but it's still water with a sandy sea bottom.
**Condition #3: We take advantage of surface tension**
A finely ground sand (a small grain) can float on water! It's not that the density is lower than water, it's that the mass of the grain is insufficient to break the surface tension of water. You can make the surface absolutely opaque in this way. However, as the amount of fine grain sand builds on the surface, you'll occasionally get globs of sand that fall beneath the surface and sink. How thick can the sand get? Not very. While the thickness varies greatly with the nature of the sand and the salinity of the water, etc., I'd be surprised if you could get a consistent thickness much more than a millimeter or two.
**Condition #4: Sand... made of igneous rock.**
We can circumvent some of the problems of sand density using igneous rock. What is igneous rock?
>
> Igneous rocks (from the Latin word for fire) form when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. ([Source](https://www.usgs.gov/faqs/what-are-igneous-rocks))
>
>
>
The beautiful thing about igneous rock is that it's common for air to be trapped inside the rock's porous interior. The *rock* has a higher density than water, but the *aggregate density* of the rock (due to the buoyancy of air) is less than water! Now we're cooking with gas! You can get a LOT of rocks floating in water this way.
For a while...
The other problem with igneous rock is that they're, well, porous. Which means the water will eventually seep into the rock, displace the air, and the sand will sink.
**Condition #5: Pumice Stone**
But there is one option: pumice stone. Pumice stone is a specific type of igneous rock. It can float for a long time... but not forever.
>
> When Havre erupted in 2012, it produced a large amount of floating pumice so we know the eruption was explosive. Ocean currents swept the floating pumice along, some of it as far as the eastern coast of Australia. Pumice doesn’t float forever—water seeps slowly into the holes in the pumice, making it heavier and heavier until it sinks to the seafloor. ([Source](https://web.whoi.edu/mesh/what-is-pumice/))
>
>
>
**Conclusion**
There are temporary ways in Real Life to get what you want: a sea of soggy sand that's mostly water. But Real Life is against you and no permanent solution exists. You can get closer using biomatter (swamps, peat bogs, etc.), but even that might not be quite what you're looking for. There is, of course, nothing stopping you from declaring that your world has exactly the kind of sea you're looking for and ignore the explanation. But if you need the explanation, I believe temporary is the best you can get.
[Answer]
I'm going to throw a hard no on this if you're talking about silicates. Any significant thickness would crush the lower strata together, making sandstone. It gets even worse if you add salt water. Silicates are very slightly water soluble, causing the salt water to act like glue under pressure over geological time periods.
Since this is science fiction, however, let's consider a small ocean of [fullerenes](https://en.wikipedia.org/wiki/Fullerene). These are very low density (1.56 x water), has negligible solubility, and little reactivity. The one problem would be that it's flammable, so you probably couldn't put your fullerene desert near volcanos.
[Answer]
## You need flocculants. Make sodium silicate slip
Sodium silicate (waterglass), as well as some other chemicals, is a flocculant. You can use them to make clay into slip, which is semi-liquid and a dilatant, like quicksand. Potters use it to make high fired ceramics.
Take some toothpaste and squirt it out of the tube. While it moves it goes thin, but when it ceases to move it becomes almost solid.
I once poured a few litres of waterglass into some soil in my garden thinking it would eventually dry out and turn hard. It took about a year before that spot became normal again.
Now, sodium silicate can dry out (and go incredibly hard and strong) ; you'll need to ensure some minimum water content. Over time CO2 will decrease its pH and cause it to drop out. So you need some reason why the pH stays high, or to use some other neutral pH flocculants. Extremophiles? Ammonia? Who knows?
]
|
[Question]
[
I want to design alien plants in which wood and cell walls are not made of the lignin/cellulose mixture wood and plant cell walls on Earth are made from, but I don't actually know what materials would be suitable. On it's own, I admit, this isn't a very helpful thing to say, as what counts as "suitable" could be almost infinitely variable, so I have a list of criteria for my definition of suitability:
1. Its strongest form must have a ratio of compressive strength to weight at least 75% that of average Earth wood
2. It should be sufficiently rigid that tall trees made of it would remain upright
3. It should be composed entirely of carbon, hydrogen, oxygen, and nitrogen, with no other elements as part of its core chemical structure
4. It should not be so reactive that it would be significantly more unstable than flammable wood in an oxygen-rich atmosphere
5. It should be possible to biodegrade but not so easy to digest that it cannot form fossil fuels; If it cannot biodegrade at all, it is not viable for use by living things, but I would also like the planet these plants to inhabit to experience an industrial revolution at some point, which requires at least coal, so it must be plausible for it to take long enough for biodegradation of it to evolve that something like what happened in the Earth Carboniferous era could take place whereby it could trap enough carbon before biodegradation evolved that large amounts of carbon-rich material derived from it could be fossilized
With all that out of the way, what materials meet the above criteria and, therefore, could comprise the wood and plant cell walls of an alien world, and what interesting uniquenesses do these have?
[Answer]
The space of possible structural chemicals, as AlexP observed, is Quite Big.
Cellulose is a [polysaccharide](https://en.wikipedia.org/wiki/Polysaccharide), for example. [Chitin](https://en.wikipedia.org/wiki/Chitin) is another, and is used for the cell walls of fungi. You don't have any cell walls, but various bits of you are held together or held up by [polypeptides](https://en.wikipedia.org/wiki/Peptide) like [collagen](https://en.wikipedia.org/wiki/Collagen) or [keratin](https://en.wikipedia.org/wiki/Keratin). Various things can synthesize [silk](https://en.wikipedia.org/wiki/Silk), another protein based material.
And terrestrial life's building blocks don't even end there... [lignin](https://en.wikipedia.org/wiki/Lignin) is a different kind of polymer again (a [polyphenol](https://en.wikipedia.org/wiki/Polyphenol)). For a non-polymer example, corals use calcium carbonate, though that's perhaps a little less convenient above the water's surface and not quite so suitable for a fuel, but other minerals could substitute. Styrene, the monomer from which polystyrene is formed, can be [extracted from the resin of a particular species of tree](https://en.wikipedia.org/wiki/Polystyrene#History). Latex rubber is a natural product, and although is isn't used as a natural structural material it clearly *could* be.
And that's barely scratching the surface of structural compounds. There's plenty of carbon in all those things (apart from maybe conventional corals), and so plenty of scope for forming fossil fuels given enough time and suitable conditions.
The point is you can handwave in pretty much anything you like, given your relaxed and plausible requirements. You're not asking for supernatural properties, so you can just declare your material to exist and you can't really be "wrong". There's no need to go into any detail... just make up a name. It'll be fine. This isn't like inventing a new element, or natural superconductor, or nuclear fuel or whatever. Don't overthink it, and use your limited and valuable brainwidth on other parts of your story and setting.
>
> It should be possible to biodegrade but not so easy to digest that it cannot form fossil fuels
>
>
>
Lignin was obviously undigestible for quite some time, hence coal, but under the right conditions all sorts of organic matter can turn into fossil fuels. The precursors to oil and gas would have been very much digestible under normal circumstances, but dead stuff sinking to the bottom of an anoxic abyssal plain isn't going to be broken down in the same way as the same material sitting around in a damp, temperate, oxygenated location. Wood free plant matter can form peat, and peat can turn into coal too; its about the environment of decay as much as the materials involved.
Remember also the existence of [nylonase](https://en.wikipedia.org/wiki/Nylon-eating_bacteria)! Just because something might seem unbiodegradeable *now*, does not mean it is intrinsically immune to all forms of digestion.
>
> an industrial revolution at some point, which requires at least coal
>
>
>
It isn't a fundamental requirement, merely a very convenient thing to use. Oil and gas are more awkward to work with, but they can do all the necessary things.
That said, there's nothing to stop you using your authorial fiat to say that your xenolignoid polymers can undergo coalification (which is a real word, apparently).
[Answer]
**Chitin or Keratin**
From [Wikipedia](https://en.wikipedia.org/wiki/Chitin):
>
> Chitin $(C\_8H\_{13}O\_5N)$ is a primary component of cell walls in fungi, the exoskeletons of arthropods such as crustaceans and insects, and the radulae, cephalopod beaks and gladii of molluscs. It is also synthesised by at least some fish and lissamphibians.[1] The structure of chitin is comparable to cellulose, forming crystalline nanofibrils or whiskers. It is functionally comparable to the protein keratin.
>
>
>
Chitin is structurally similar to cellulose and suitable for uses ranging from cell walls to shells to exoskeletons, and presumably everything in between. It would work for tree bark too.
[Answer]
**Polycarbonate.**
[](https://i.stack.imgur.com/3BhM6.png)
<https://en.wikipedia.org/wiki/Polycarbonate#Construction_materials>
[](https://i.stack.imgur.com/W7EIfm.png)
[lexan sheets](https://www.indiamart.com/proddetail/polycarbonate-sheet-thickness-3mm-23752508873.html)
There are many types of plastic. Above is polycarbonate; the stuff is strong, light and durable. There are other kinds of plastic. Probably you are sitting on some. You are! And that button on your pants is plastic. You can leave it buttoned for now.
Plastic I am reminded sometimes has nonorganic interlopers but polycarbonate is just C H and O. There is no reason biology could not make it. It would be easier than making diamonds which was my initial idea. I like the idea of Gaudiesque organic plastic structures comprising the plants of your world. In a world of plastic plants there would of course eventually evolve things that could eat the carbon in the plastic. Our world is not quite there yet, and so plastic accumulates the way cellulose did before fungi evolved the ability to eat it.
---
Skeptical Mark. Luckily I have a love of learning!
>
> Its strongest form must have a ratio of compressive strength to weight
> at least 75% that of average Earth wood
>
>
>
[Polycarbonate properties](https://www.azom.com/properties.aspx?ArticleID=2008)
Compressive Strength 121- 159 MPa 17.5496 - 23.061 ksi
1 ksi = 1000 psi. 23.061 ksi = 23061 psi.
[Southern red oak wood](https://www.matweb.com/search/DataSheet.aspx?MatGUID=ea505704d8d343f2800de42db7b16de8&ckck=1)
Compressive Strength 3.79 MPa 550 psi Green, perpendicular to grain
6.00 MPa 870 psi 12% moisture content, perpendicular to grain
20.9 MPa 3030 psi Green, parallel to grain
42.0 MPa 6090 psi 12% moisture content, parallel to grain
Oak = 0.52g/cc compressive strength / weight = 11711
[Polycarbonate = 1.22g/cc](https://www.jiga.io/calculator/density/polycarbonate/gml)
compressive strength / weight = 18902
Polycarbonate has a little less than 400% of the compressive strength of the strongest oak. Compressive strength / weight exceeds oak.
>
> It should be sufficiently rigid that tall trees made of it would
> remain upright
>
>
>
I think this has more to do with the 3dimensional structure of the trunk than the stiffness of the material. But for your viewing pleasure here is a polycarbonate dome measuring about 3m.
<https://vikingdome.com/en-be/products/auradome-60-standard-geodesic-dome>
[](https://i.stack.imgur.com/eE5kF.jpg)
>
> It should be composed entirely of carbon, hydrogen, oxygen, and
> nitrogen, with no other elements as part of its core chemical
> structure
>
>
>
Yes but no nitrogen. You can add your own when you are done with it, if no-one is watching. This is supposed to be a tree after all.
>
> It should not be so reactive that it would be significantly more
> unstable than flammable wood in an oxygen-rich atmosphere
> Yes.
>
>
> It should be possible to biodegrade but not so easy to digest that it
> cannot form fossil fuels
>
>
>
Yes. They are just carbon carbon bonds. No funky halogens to make the molecule indigestible. In an oxygen atmosphere they would provide good energy.
]
|
[Question]
[
(Before I begin, I would like to assure everyone present that, yes, I'm fully aware of the lunacy of this idea.)
Let us assume this takes place on a parallel Earth sometime in the early 1900s, during the dawn of the great age of airships. You, an aspiring aerostat engineer of great creativity and little self-preservation, have been approached by a organization with (relatively) limitless funding and are told that to create a better airship with better lift than what is previously had by everyone.
Now, there's an issue - you can't just create lift out of nowhere for an airship. Sure, you can keep making the envelope and the gas sacks bigger and bigger, but *anyone* can do that. Suddenly a flash of inspiration hits you - you *can* make a better lifting gas than anyone else, all you need to is simply fill it with the lightest lifting gas known to man (hydrogen) and then **heat the hydrogen cells**. I mean, it works for air, right? And hydrogen is lighter than air, right? So it stands to reason that *heated hydrogen* is the going to be the greatest lifting gas of all time! ...Once you work out the kinks of figuring out how to heat it without killing everyone onboard, anyway, anyway.
**The Challenge: Figure out a way to build an airship that *safely\** uses super-heated hydrogen cells instead of normal ones.** Any technology up to 1920 is considered fair game, and alternate technology that *could* have been discovered but haven't (i.e. metal alloys) are also permitted. The airship dimensions preferably should be modeled after the [LZ 104](https://en.wikipedia.org/wiki/LZ_104_(L_59)), though if a smaller airship / larger airship is needed, that's fine.
Now, conventionally, this is probably considered to be a "foolish" idea given hydrogen's *[incredibly flammable](https://www.airgas.com/msds/001026.pdf)* (and explosive) properties, but in theory, this should be fully possible, even with early 1900s technology. Now, some people would argue to use helium instead, but those people [clearly don't understand science](https://www.youtube.com/watch?v=VPpIjhtgGj0) - we aren't trying to be safe and go for second best. The *only* acceptable solution here involves heated hydrogen cells.
Some people would also point out that the increase of lift would be marginal at best (probably no greater than 3% over normal hydrogen under normal conditions, this depends heavily on how much you can heat the hydrogen) and that whatever methods used to heat the hydrogen would consume all that weight, and to that I respond that it just sounds like an engineering challenge to me.
\*For some, but not all degrees of safe. Ultimately, you're flying an airship while attempting to heat giant sacks of hydrogen. Things can go horribly wrong, but the goal here is a design that you can be reasonably sure won't spontaneously ignite.
[Answer]
I got your hot hydrogen right here!
**Roziere Balloon**
[](https://i.stack.imgur.com/BoRnD.jpg)
<https://balloon.hu/new/balloons/roziere-balloon/>
>
> The Rozière balloon (or simply Rozière) is a type of hybrid balloon
> that has separate chambers for a non-heated lifting gas (such as
> hydrogen or helium) as well as a heated lifting gas (as used in a hot
> air balloon or Montgolfière). This type of aircraft takes its name
> from its creator, Jean-François Pilâtre de Rozier.
>
>
> The advantage of a Rozière is that it allows some control of buoyancy
> with much less use of fuel than a typical hot air balloon. This
> reduction in fuel consumption has allowed Rozière balloons and their
> crew to achieve very long flight times, up to several days or even
> weeks.
>
>
>
It makes sense. There was a problem with Roziere's balloon, chiefly that he died when it crashed and so I guess other people were chicken to try again. People make them today with helium.
Your character can surely make them. I like the idea of heating the hydrogen internally with a resistance wire powered by a handcrank that the pilot turns. Your character cramps up at the prospect of physical labor (and also the prospect of falling from great heights) and so hires out the job to pair of brawny pilots.
More reading along more speculative lines and a scheme by the inimitable bungston...
<https://www.halfbakery.com/idea/Internal_20flame_20hydrogen_20balloon#1232972746>
---
addendum - balloon schematics. The Roziere does not heat the lift gas directly but heat is conducted to the lift gas balloon from the external hot air balloon.
[](https://i.stack.imgur.com/8QRiD.png)
<https://twitter.com/balloonarchives/status/1348562796674502656>
[Answer]
# Oxygenation
Burning things requires 3 things. A material to burn. Sufficient heat for that material to readily start a reaction with oxygen. Finally you need oxygen. The fire triangle. You have two out of three, namely heat and a material that can start an oxygen reaction. Now we *just* need to prevent oxygen from touching the heated material and no fire reaction can start!
That means that if we contain the hydrogen with no or too few oxygen, we can heat it to very high temperatures without starting a fire.
Of course there is the crux. How do we store the heated hydrogen safely inside the cells? Short answer is we can't. It would have been used if we could. But what gets us close enough?
The problem with hydrogen is that it's the smallest element in existence. It is hard to contain even with modern materials. In 1920 it'll get out anyway. It doesn't go terribly fast, but if heated hydrogen ignites the moment it leaves the containment and touches oxygen you'll have a fireball. The envelope would heat and deteriorate, giving more and more chance for hydrogen to escape and ignite.
What we can do is compartmentalise. Make a heated hydrogen cell. Surround the hydrogen cell with a non flammable material that is still light enough. A thin layer of helium for example. This allows for some cooling of the hydrogen if it escapes the first layer and if it finally diffuses to the outside it can be so little it's not a problem anymore. Maybe you can pressurise the helium enough that it becomes very difficult for hydrogen to leave the internal cell as well, but might defeat the purpose (being light).
The biggest problem is that such technique is most likely offsetting your gains of heating the gas. You need extra stuff to make it safe. However, you might be able to sell it as a more safe alternative. Making multiple compartments for the gas is a good practice anyway, so compared to a similarly structured airship you have an advantage. Damages and ruptures will not instantly damage your hydrogen cells, so safer! We'll campaign so hard the population doesn't realise that if any rupture occurs they are this much closer to heated hydrogen touching oxygen.
[Answer]
Your engineer needs an **indirect heating element**. That is, a thermal conductor which is itself not flammable, and can heat the hydrogen in a diffuse way so that no localized part of the hydrogen reaches ignition temperature. Willk's answer is correct in that, but it seems that using a significant volume of regular heated air is distastefully conventional for such an avant-garde and reckless inventor.
Hot oil heaters and steam heating systems are a couple conventional examples of such thermal conductors, but would add significant weight. Perhaps thin sheets of a thermally conductive solid within the cells could act like the fins of a processor heat sink. Copper would be the best choice because silver doesn't grow on trees. Beryllium oxide deserves a notable mention for being both highly thermally conductive and electrically insulating (non-sparking for safety!), with bonus idiot points for being carcinogenic when crumbled and generally poisonous.
My best recommendation is that your engineer concede to using a minimal amount of **helium, heated and circulated** through a narrowly enveloping balloon outside the hydrogen cells, and/or a web of tubing within the cells. As a side benefit, this design will also mitigate the loss of hydrogen, which more readily diffuses through materials - at the heating location, any hydrogen that has diffused into the helium will combust with oxygen impurities and further heat the helium.
Side notes: Inducing a convection current in the hydrogen would improve heat diffusion as well as provide another wonderful point of failure. And finally, with this level of ingeniousitude, it behooves one to at least attempt burning some of the hydrogen to heat the hydrogen. Bringing other heavy fuel along would be pointless! What could go wrong?
Sources:
* [Wikipedia: List of thermal conductivities](https://en.wikipedia.org/wiki/List_of_thermal_conductivities)
* [Wikipedia: Beryllium oxide](https://en.wikipedia.org/wiki/Beryllium_oxide)
[Answer]
I'm going to build off of BoomChuck's answer. They note that a steam heating system would add considerable weight, which of course is true. However, the LZ 104 used water-cooled engines. We still need to carry those radiators somewhere, right? What if we put them *inside* the hydrogen cells?
I would assume that airship engines of the time used non-pressurized cooling systems; but I'm not aware of a technical limitation that forces that to be the case, since there clearly were pressurized steam systems at the time. (I'm invoking the "alternate technology that could have been discovered" clause here.) If we seal and pressurize the cooling systems, we can run that cooling water over 100°C.
As far as practical (hah!) considerations go, the distributed radiator system would certainly be heavier than a conventional radiator, but would allow us to reduce or eliminate the conventional cooling system. (Let's just eliminate it entirely, because that gives us the great story opportunity of potentially having to decide whether to reduce engine power or overheat the hydrogen.) In addition to the fact that the piping would have to run the entire length of the Zeppelin, you'd also probably want some sort of valving so you could increase or decrease the heat in individual cells, as well as being able to shut off flow entirely if a pipe or radiator broke. (...assuming that spraying steam all over the inside of your hydrogen cell somehow didn't just send you to a flaming death anyway.)
You'd definitely have some engineering questions as far as how quickly the heat dissipated given the large surface area of the Zeppelin. It's possible that the cooling water alone wouldn't be enough to heat things up sufficiently. No problem! We have another heat source with us, after all: I mean, that engine exhaust has to go somewhere, right? In fact, let's just use it anyway—the more heat, the better!
In case you're wondering if I'm suggesting what it sounds like I'm suggesting, the answer is yes: take the cooling water from all five engines, superheat it with the engine exhaust, then run that superheated water through radiators in each of the hydrogen cells, where we hopefully dissipate enough heat to keep the engines from overheating when we run that water back into them. (...thus drastically increasing number of points of failure and potential ways to die, all for a maybe 10% lift increase that is partially offset by the weight penalty for the whole system.) What could possibly go wrong?
**Edit:** Halfthawed's comment made me curious, so I did some searching and found some numbers, so let's try some back-of-the-envelope calculations.
An engine with a liquid-cooled exhaust manifold produces about 645W/hp; the LZ 104's engines were rated for 240hp; so about 154,800W per engine or 774,000W total for the five engines. We want to maintain a temperature of 100°C, so let's call that 85°C warmer than the ambient air (cruise altitude for a Zeppelin was only around 200 meters, so you're close to sea-level temperatures). LZ 104 was 23.9m diameter, 226.5m long; let's approximate it as a cylinder, so we have 17,000m2 surface area. (An overestimate, of course, but close enough for the accuracy we need here.) To maintain the 85°C difference across 17,000m2 of surface area, we need an (SI) R-value of 1.87, which is about an inch-pound R-value of 10.6, so to maintain temperature we need to wrap the whole Zeppelin (or, more accurately, its hydrogen cells) in R-11 fiberglass. Modern R-13 fiberglass is about 1kg/m2, which is a nice round number, so let's just use that figure... and we need 17,000kg of fiberglass insulation in order to gain less than 2400kg of lift. Looks like we do, indeed, need moar boosters.
(BTW, I'm once again invoking the "technology that could have been discovered" clause; fiberglass was discovered by accident in 1932 when a jet of compressed air was directed at a stream of molten glass, so there's no fundamental reason that couldn't have happened a few decades earlier.)
I have to wonder, though—could we heat the hydrogen less and still produce a usable amount of additional lift? Maybe only a 35°C temperature difference? That would still be ~1000kg of extra lift, and would require a low-enough amount of insulation that the basic construction of the Zeppelin might suffice. (After all, you don't have perfect conduction from the hydrogen cells to the skin.) Also, the figure I used for engine cooling was for a liquid-cooled exhaust manifold, not for a design intentionally trying to capture as much heat from the exhaust as possible, so it's possible we could push the heat output of each engine a little higher. (Ultimately, though, the total heat you're getting out of each engine is the amount of energy in the fuel burned, and some of that energy is going to, y'know, actually *moving* the thing.)
One more complicating factor arose while doing research for this. It turns out that actual dirigibles would try to limit their heating because otherwise the gas cells would exceed their pressure limits—there were safety valves for that. I have to wonder just how much heavier the cells would need to be to hold the higher-temperature, higher-pressure gas. I wouldn't even know where to start to calculate that, though.
[Answer]
There would be no significant difference in lift.
There was a question just asked on a vacuum blimp,
[Would a "Ridged" balloon "filled" with a vacuum work better than a hydrogen balloon in an earth atmosphere?](https://worldbuilding.stackexchange.com/questions/230786/would-a-ridged-balloon-filled-with-a-vacuum-work-better-than-a-hydrogen-ball/230790#230790)
A vacuum gives 88 milligrams/litre better lift.
For hydrogen at 0°C to 100°C, (273 kelvin to 373 kelvin), the mass of 1 litre of hydrogen would decrease by 100/373, or 26%.
1 mole of a gas occupies 22.7 litres at 0°C. One mole is the molecular mass in grams. Thus one mole of hydrogen weighs 2 grams, and one mole of air is (28 \* 0.8 + 32 \* 0.2) = 28.8 grams. Therefore a hydrogen blimp at 0°C gives 26.8 grams/22.7litres lift (1.18 grams/litre) and a hydrogen at 100°C blimp gives 26 grams/22.7 litres (1.14 grams/litre), a difference of 35 milligrams/litre.
<https://en.wikipedia.org/wiki/Molar_volume#Ideal_gases>
]
|
[Question]
[
Post-Apocalyptic modern world, a group of civilian survivors about three dozen in number find themselves trapped in a military base. They have no way out except by air.
The military base has a dozen helicopters but none of them knows how to fly the damn contraption. Assume they have endless food, fuel, and time, and access to training and operating manuals, video, etc, for the helicopters.
What is a reasonable time frame for at least one of them to learn how to pilot that on their own, assuming they are of average intelligence and ability?
EDIT: I'm not looking at exceptional cases, stroke of luck, or Hollywoodian handwavium. I asked for a reasonable, realistic timeframe.
[Answer]
# Frame challenge
If they have a PC, a joystick controller and a copy of Microsoft's Flight Simulator (specially versions 9 or later), they can play for weeks until they are comfortable with the basics of some helicopter model close to what they have in the base.
Then they can try their skills on the real thing, maybe crash a couple helicopters along the way (killing half of the survivors in doing so). Then finally a few people can fly out of the base and have a very bumpy and painful landing somewhere else.
**But flying the helicopters is just one thing they would need to do. Aircraft are very complex machines with very complex maintenance routines. Learning how to keep such machines in good shape takes years when you have a proper education. They won't learn it in a military base during the zombie apocalypse.**
It would be much more realistic to salvage parts and hack them into an [autogyro](https://en.wikipedia.org/wiki/Autogyro) for just a couple of survivors to escape, but being realistic this would require everybody to be an engineer and still would be borderline a ticket to Darwin Awards.
It would be even more realistic and efficient to scrap the metal to build a makeshift armor for a van or truck, a la *Dawn of the Dead*/*Left 4 Dead*/*Army of Darkness* and escape by land.
[Answer]
You ask "how long till X" but your actual problem is that X is undefined. Without an instructor there would be no way for them to tell if they actually learned anything or just got lucky so far. And if they got unlucky they die.
With enough luck, they could read/watch everything and fly away with (extreme caution) on the first try. As Daron said, surviving the first landing is the hardest part, so never training for that seems to be the most plausible option. If there are parachutes in the base my bet would be to learn the theory, fly away and jump.
I think the most believable option would be to use unmanned delivery vehicle, something like [K-MAX](https://en.wikipedia.org/wiki/Kaman_K-MAX). I don't know how autonomous it actually is, but assuming the best, your protagonists probably could program a route for it, climb onto a cargo pallet and get delivered. Or jump out of the pallet. Kaman added some remote-control capabilities so something like flying a drone while swinging from it comes to mind. If there are many such delivery drones in the base, they could practice remote controlling them without risking lives. However, even the Wikipedia article highlights how complex it is, when unforeseen wind caused one to crash.
[Answer]
The legend is that, unlike the movies, a non-pilot landing a plane is impossible, even if there is someone giving them verbal instructions, even if the non-pilot is familiar with other types of planes.
With that in mind it is hard to believe someone can teach themself to fly a helicopter. Perhaps if they had a simulator at hand to practice landing and crash landing they could do it.
In that case you should start researching the process by which one gets a helicopter license. How much training is required. I imagine you don't have lessons every day. So you can smoosh all the training together. Then multiply it by two or three times as long.
---
**Extra:** As The Square-Cube Law points out, there is one case of a [non-pilot landing a Cessna 208](https://www.bbc.com/news/world-us-canada-61416384) while on the phone with a flying teacher.
[](https://i.stack.imgur.com/9P49r.png)
The Cessna is very unlike the passenger airliners in the movies. But perhaps that is a good thing because it is more like a helicopter. **Note:** According to the pilots in the comments this is a load of bull honkey and there is almost nothing in common between a Cessna and a helicopter.
[Answer]
I see you have already acceptd an answer, but i'd like to propose a number. The others are right with the maintenance problem though.
I'm thinking about myself. I like plane, i've nevered flew one but i enjoy playing flight simulation. Been playing "DCS World" on and off, and some time ago i tried my first helicopter (KA-50). What i've learned, it's that helicopter are hard to flight, and they can kill you in plenty of new way compared to plane (did you know about vortex ring state for exemple ?).
So if i was in that situation, I think it would be at least 50 hours before i try starting the engine (no flying yet), and a good 100 hours before i try some "real" flying, away from the base. Most of the time would be reading the manual (note: if no manual, i don't even try), and flying on simulator if there is. And then, i'm talking about "flying". Not "safe flying". Any kind of unexpected thing (mechanical failure, bad weather, ...) would probably end very badly.
For reference i took a quick look at getting a license pilot, my first link says :
* 45h briefing
* 90h theoric course
* 35h flying with instructor
* 10h flying solo
So, my 100h are really a minimum. With some previous basic knowledge. If your guys don't know shit, they'll have a very hard time. Or a rude awakening in their first flight.
[Answer]
The question isn't time. It's their approach (yeehaw or careful) that would determine who If any survived.
The next question is what kind of helicopter we are discussing. Controls are more or less identical, but responsiveness might be different and the amount of instrumentation (lights, sounds and buttons) and procedures can vary greatly. A military helicopter would have more difficult procedures, more instrumentation that would distract a learning pilot, and sluggish throttle response then a trainer helicopter with a reciprocating engine.
Considering they have training materials and literature, they can takeoff within a few minutes of reading the manual on a trainer helicopter. Up to a couple days on a military helicopter. Next - it's much easier to crash a turbine helicopter than a reciprocating one, by simply cutting throttle at the wrong time and the turbines taking too long to spin up afterwards. But basically the next maneuver is landing. Start by hopping around - take off and land immediately. Then hovering higher and higher before landing. Then maneuvers.
The big things to watchout for are - wrong input (especially if nerves get the better hand), too much input (just be gentle), overcorrection.
I've never flown a helicopter myself, but I am familiar with the controls, but the more difficult part for md would be the startup sequence.
Someone absolutely oblivious to helicopters? I'd give them a week or two.
]
|
[Question]
[
The fluff:
As part of the world I'm building there is modern technology of firearms. However there is a problem: there are some categories of creatures (from some of my previous questions) that just keep comming until the ammo is depleted, and then swarm the fireteams with what is left.
The biggest problem category would be the archetypical biological swarm attackers like the Flood, Zerg, Tyranids etc. In my world the lionshare would be medium dog sized (up to the knees) and not actively organized. These would attack in small bands with total combined populations of tens of thousands. For various reasons that arent important things like artillery, air support and heavy vehicle power are all limited.
To have a higher chance of survival these fireteams are equipped with melee weapons as backup.
The question:
What melee weapon(s) would be best as backup for fireteams?
Additional information:
* the most common enemy will be between 0.4m and 1m tall and be the target of the melee weapons. Both quadrupeds and (unarmed) bipeds will be present.
* the fireteams consist out of 4 individuals who have to be able to support one another in defeating the enemies. Each is allowed to carry a different melee weapon to synergise with one another.
* a quarter of the enemies is lightly armored.
* the enemies are spread in groups of 8.
* the melee weapons when stowed away in the gear are a maximum size of 70cm. With access to modern materials you are allowed to use things like telescopic hafts to increase the length once the gear is used, assuming it does not weaken the weapon too much.
Constraints:
* this question is NOT about finding alternatives to carrying melee weapons, so no answers similar to "they would carry more ammo instead".
[Answer]
# Kopis (and scutum!)
 
The ideal weapon should have decent reach, but not be useless in close quarters if an animal gets within their guard, as a collapsible spear would be. I recommend a Greek-style kopis, (essentially a longer kukri). The general Xenophon recommended the kopis/machaira for mounted combat:
>
> because from the height of a horse’s back the cut of a machaira will serve you better than the thrust of a xiphos [a double edged straight short sword]
>
>
>
and being humanoids fighting 1m tall creatures, you’re essentially cavalry in terms of height advantage (but not speed / momentum of a horse charge, therefore, no cavalry sabers). The heavy leading edge is made for cutting meat, and is unlikely to get caught or stuck. Thrusting, which is important to counteract heavier armor armor, is not as essential here. A kopis grants the power of an axe while not losing edge closer to the body, and has no head to get lodged inside a rib cage.
While electroshock weapons like batons have their place in herding cattle and less-lethally subduing civilians, they are neither reliable enough nor permanent enough to be a practical solution, and will be much less useful against even lightly armored foes. Like maces and clubs, they also lose much (though not all) of their effectiveness when an enemy gets within the wielder's guard. As @KerrAvon2055 notes, a spear, while excellent against single targets, is not an ideal solution when outnumbered, because it is easily fouled by the corpse of the first slain beast.
I also recommend that your troops should each carry a tall, and somewhat broad shield, ideally of polycarbonate, like the Roman scutum or the modern riot shield to pair with their kopises. Despite weighing just 6-7 pounds, a riot shield is virtually impregnable to teeth and claws. I recommend a scalloped or sawtoothed bottom edge, enabling it to be planted in the ground and used as a barricade.
A squad of four should be able to make a sort of miniature pike square / testudo, protecting each other from every side.
The combined weight of two items will be ten pounds or so, and while a significant addition to your kit, are not imposssibly cumbersome.
[Answer]
**Buckler, shock baton and steel capped boots**
First - shields are good. With access to modern materials and a handwaved requirement to go into melee, a clear riot shield is preferable but a small transparent buckler can be carried more easily on the belt. (Which is why rapier-and-buckler was the go-to combination for impromptu duelling back in the bad old days, the young toughs could stick their instruments of violence on their belts to wander around town looking for trouble without being overly burdened by physical weight.) Note that the way to use a buckler is held in the off hand, not strapped to the arm. So if a beastie lunges forward to bite a soldier they punch their buckler-protected hand out to block it, no wild swinging of the arm.
Second - electroshock weapons are good for incapacitating an enemy immediately. Forget the scenes in the movies where the tough guy grits his teeth and keeps fighting through the shock (eg the elevator fight in Captain America - the Winter Soldier). The way an electroshock weapon works is to disrupt the messages from the nervous system to the muscles. It does not matter how tough, pain resistant and/or hyped on drugs the subject of a hit is, they are going down until their nervous system can do a reboot. A 70 cm long shock baton is just what the (evil) doctor ordered to take out attacking beasties. No need for wild swings that may endanger friendlies, just a quick jab-and-shock to disable a target.
Speak of a "reboot" - give the soldiers steel capped boots and use them to finish off the opponents twitching on the ground. Minimal additional weight (although it will slow down running speed somewhat) and some protection if something does bite them on the boot.
Given the specification that soldiers are expected to fight in groups of 4 against swarm attacks, it may be worth having one or two soldiers carry extendable spears. If the fireteam is desperately (and probably futilely) fighting back-to-back in open ground then they each need to hold their own quarter of the circle, requiring the same weaponry. However, if they are able to take advantage of buildings and hold one or two doorways then it would be preferable to pair up - a buckler-and-shock baton trooper simply stuns each attacker while their buddy reaches past them with a spear to administer the coup de grace to the twitching beastie. (Spears and other stabbing weapons are not feasible as primary weapons against swarms of suicidal non-sapients - the first beastie will impale itself on the spear and its buddies will be all over the wielder before the spear can be freed.)
[Answer]
If you're fighting things that attack in packs, and are so bloody-minded that they'll just keep on coming even while you blow their pack-mates away wholesale just so that they can run you out of ammunition, you really don't want to be stuffing around with them.
Whatever you use to protect yourself should be as quick and effective as possible.
So, for when your supply of ammunition is exhausted, I propose not merely simple melee *weapons*, but an entire melee *system*.
Firstly, each soldier should be wearing head to toe body armour capable of resisting whatever natural weapons that these critters possess. If they're small, there must be a corresponding limit to their weight and strength.
Secondly, each soldier should have a large transparent riot shield. If you have advanced materials tech, make it a folding shield that can be expanded when necessary. Being shaped so that a fire team can form a [testudo](https://en.wikipedia.org/wiki/Testudo_formation) is important, and if the shields can physically lock together so that they can't accidentally come apart or be pulled apart by enemy action, all the better. There should still be gaps through which a melee weapon can be thrust.
Next, each soldier should carry a collapsible single-handed [morningstar](https://en.wikipedia.org/wiki/Morning_star_(weapon)) style mace. This would not be a simple metal weight with spikes and a handle, this would be a sophisticated modern weapon. The head would have an Osmium core for added weight, a non-conducting layer over the core, and a high-voltage source attached to the spikes like an electroshock weapon. The spikes would also be hollow, capable of injecting a toxin, and the haft would contain a large supply of this toxin.
Such a weapon would be useable very quickly. It need not be aligned to the direction of a swing in order to be effective. Mere contact would result in a disabling shock, a scratch would inject a lethal poison, and a solid hit might be immediately disabling or fatal even if the power and toxin runs out.
However, that's not all. The armour would similarly be equipped with spikes on the toes, heels, knees, knuckles, elbows and head that are both electrified and envenomed, so in the event that a soldier gets swarmed under, every movement that hits a critter can be immediately disabling and eventually lethal. The batteries for the shock weapons should be [charged by body movements](https://www.universal-sci.com/article/textile-capable-of-charging-electronics-using-body-movement), so as long as the soldier is moving, the shock weapons should be functional.
In addition it should be possible to electrify the exterior of the body armor so as to be able to shock any critters that are clinging to the wearer.
As for the toxin, it should ideally be something that is rapidly lethal in microlitre quantities, and would be carried by the soldiers in litre or greater quantities. While the OP's question wasn't about these soldiers' firearms, I'd suggest using the toxin in their ammunition too, just in case a shot isn't immediately lethal.
[Answer]
If they have rifles they can use it as extensions for the melee weapons, and use something that can be attached to their end.
Instead of, or combined with, the bayonet they could attach an axe or a hammer, and swing it around. Something like an halberd or a pole axe.
[Answer]
* Multi-purpose axe: You could have an axe blade on one side of the head for hacking and slashing soft tissue and limbs; a hammer or spike on the opposite side of the head for crushing armor and exoskeletons. Additionally, you could mount a spike on the top end for precise stabbing of vulnerable spots (e.g. the eyes)
* Entrenching tool: Chances are your soldiers are carrying short fold-able spades as part of their standard equipment anyways. Sharpened spades have seen widespread and effective use as melee weapons in the World Wars. Using a tool in dual roles like this can reduce the overall weight and bulk of equipment a soldier has to carry.
* Even with a dedicated weapon in place, I would still issue multi-purpose survival/combat knives as a last resort weapon and rifles that can mount them as bayonets. Even though your soldiers have access to better melee weapons, these might get lost or break and a knife is better than no weapon. Plus, knives can be used as survival tools as well.
* If your soldiers are exclusively fighting critters like that, consider issuing chain mail instead of regular body armor. Shark divers use chain mail for protection, as do some present-day police forces when they expect knife-wielding assailants. While somewhat heavy, chain mail does not leave any gaps like a ballistic west would (e.g. under the arms) and a hauberk also protects the neck and head from critters that crawl/jump up or when you have been dragged to the ground. Complement this with chain greaves to protect the legs and some face/eye protection.
[Answer]
## Katara
The Katar is often criticized as a terrible battlefield weapon, but that is because they were not made for fighting humans. It was historically used in pairs for hunting quadrupedal predator's like lions and tigers. The Katar is not nearly as good at parrying as a more traditional knife or sword, but against an animal that fights with tooth and claw, the advantages they do have can far outweigh the disadvantages.
* It does not have great range, but since the OP put a 70cm cap on the weapon, the same will be true for all other options as well. (Collapsing weapons break way too easily.
* It is bad for slashing, but this is okay because some of the monsters are armored which means you need to focus on thrusts to get between the joints in its armor.
* It is easier to deliver a deeper and more precise thrusts than a sword of similar size which makes it further useful at dealing with the monsters with armor.
* Some Katara had armored hoods which gives you a perfect bite zone. When fighting humans, wild animals will generally bite whatever they think they can get ahold of first to try to take you down before moving in for a more fatal bite. So, when humans fight quadrupedal predators, the first place you get bitten is normally the hand or forearm. The hood means that you can let the monster bite your hand, and then use that to manipulate the creature exposing its neck or chest to be struck by your second Katar.
* You can keep two enemies on point at once. Several answers so far have suggested a shield in the offhand, but this is not a great idea with only 4 man firesquads. Not only do shields long enough to protect you from shorter attackers, not fit the size requirements given by the OP, there is no way you can line up with only 4 shields to form a proper shield wall against 8 enemies unless you are in a hallway. Given the rules of this battle, a second weapon will offer a much bigger advantage. Also, at 70cm or less, 2-handed weapons are not going to be optimal either; so, 2 short weapons gives you the best coverage.
[](https://i.stack.imgur.com/FU46s.png)
## How to Improve on the Katar
While the katar works well for killing a quadrupedal predator, it suffers the same vulnerability that most other melee weapons have: draw time. If you run out of bullets and don't have time to reload, there is a good chance you also don't have time to draw a sword, axe, club, or fix baronets. That said, a punch blade does not need to be a hand-held weapon, it can be integrated into a gauntlet or bracer. This means you can fire your last bullet with that one last monster just a few feet away and leaping at you full force. With just a slight twist of your hand you go from holding your gun to pointing your punch blade at the monster without having to return your hand to your body somewhere to draw your weapon.
Also, by fixing the katar to an armored gauntlet, you can get much better armor coverage on your bite zone than you could with a hooded katar.
[](https://i.stack.imgur.com/HUEVC.png)
[Answer]
(for the purpose of this answer, I am assuming that the enemies mostly bite)
The first thing you need to do is protect the legs. You're fighting waist high enemies, so they will want to grab your legs, drag you to the ground, and tear you apart. For that, you would ideally want some spiky armour. If you can make your lower half relatively safe, that radically simplifies melee combat. Covering an entire soldier in spikes isn't exactly practical (mobility would become an issue), but waist-high or even knee-high armour would make a big difference.
Next, the non-dominant hand would be used for protection. People who train attack dogs will wear thick, padded sleeves that a dog can safely bite into. You want your soldiers to carry around something like that. They can't wear it all the time because it's stiff and doesn't allow full use of the fingers, but when it's time to affix bayonets, they put on the sleeve. The sleeve is used as a shield. A bad guy lunges at you, and you swing the sleeve straight at his mouth or whatever other sharp thing he's using.
In the dominant hand, a machete. Stabbing weapons are nice, but you need to be able to attack downwards, so hacking is the priority. If an enemy gets a hold on the sleeve, you can use the machete to chop at it until it's dead.
Assuming these enemies are sort of animalistic, they will fixate on the sleeve. Once they get their teeth in, they will not let go, and you can attack them relatively safely.
Optionally, you can put a katar-type weapon on the end of the sleeve, but you don't want to risk exposing the hand, so don't think go for a second machete.
[Answer]
**Fist weapons**
Humans are more adapted to use our hands in combat than tool-like weapons. Yes, we use tool-like weapons to great, if not amazing effect, but a lot of weapons require a great deal of training to use well. There's a 'method' to cutting or piercing well with a sword, while every Tom, Dick, and Harry knows how to throw a passable punch intrinsically.
Yes, getting the most out of the mass drivers that are our arms require training just like any weapon, boxers being case in point where the PSI delivered differs by an order of magnitude compared to a typical person, but that almost doesn't matter anymore once you introduce force amplifiers such as spiked knuckles. Smaller creatures can easily be punched to death by normal people without protection or force amplifiers, just imagine how much more dangerous a trained combatant with armour and spiked knuckles will be. If metal spikes won't work against the creature who're 'lightly armoured'(chitin-based perhaps?) then blunted force amplifiers like brass knuckles would work just as well if not better.
Another pro about fist-weapons are that they're less likely to catch or get stuck on/in something, allowing more attacks without such concerns and allowing you to deal with the swarm at a greater rate.
]
|
[Question]
[
Lately, I've again pondered how mermaids could move on land. I know certain fish, like frogfish, devilfish, and even batfish, as well as mudskippers, have developed fins that work as feet.
However, I'm pretty sure that would be ineffective, as seals do something similar and they are painfully slow and lack the agility they have in water. This is without the added problems of a human torso that must be held up in order to not hamper movement, which would ironically add an awful lot of weight in one place, which would also hamper movement!
Long ago, I pondered the idea of mermaids standing up on their fishtail, using their strong tailbones and fins to hold themselves up. However, the positioning required for this to work may make the tailfins less effective for swimming, and such a walking arrangement would be slow and awkward compared to our own, as well as incredibly exhausting. It just doesn't seem workable.
Then we get to slithering. Snakes do this, but guess what else does? Eels! It's been well established that eels can and do go on land, absorbing oxygen through their moist skin and gills, and can survive for extended periods out of water. It's possible that slithering mermaids could move quite well on land, but the aforementioned issues with a human upper half could prove me wrong.
Finally, the only other options seem to be:
1. Manipulation-If a mermaid can manipulate men as a siren does, then she can get someone to carry her around. Alternatively, some smart thinking, pheromones, or magic could enable them to influence or control something for a free ride.
2. Crawling-It's not the best, but it works.
3. Gliding/flying-If they can glide like flying fish, or maybe even fly, it would allow them to circumvent the troubles of land travel
4. They just don't bother-They live in the sea, they eat in the sea, why would they go on land?
My question is, **How Could Mermaids Feasibly Move Effectively On Land?**
**Specifications:**
1. Feasible methods of transportation should be adaptations, specifically physiological or behavioral adaptations. The former would be like a mermaid developing fins that can be used as feet, the latter would be utilizing
2. By 'effectively,' I mean the mermaid moves in a timely manner. The main problem mermaids and seals have on land is a lack of speed and agility, which makes them vulnerable. The transportation methods should thus account for this, as otherwise they are extremely vulnerable on land. However....
3. Feasibility is key. Some of the possible methods mentioned above are outlandish, sure, but when it comes to effective locomotory methods on land I understand being half-fish would be a severe limiting factor. If a method wouldn't work, or if it could work but would almost certainly never develop, or if it would work just fine, I would appreciate that the best answer say that and explain why.
[Answer]
Slight frame challenge here, but...
# Fins (really flippers) that work as feet.
Yes, I know you discounted this in your question, but I suspect you haven’t researched that as much as you think you have.
You specifically call out seals as an example of this. There are two issues with this:
* True seals don’t have flippers that work as feet (they have to just kind of hop or scoot along on land, and look absolutely pathetic while doing so), so they’re not a good example.
* Sea lions (the stereotypical ‘circus seal’) and fur seals, who *do* have flippers that work as feet, actually have almost none of the issues you mention.
Addressing your specific concerns in order:
### They’re slow on land.
They won’t set any land speed records, but sea lions are by no means ‘slow’ on land. They’re more than fast enough to avoid most predators, and absolutely fast enough to be predators themselves. The exact speed varies by species, but the average sea lion can actually run *faster* than the average human (average human running speed is roughly 10 miles per hour, if we’re being generous, while the average (across species) for sea lions is roughly 15 miles per hour) over short distances (we still win at endurance running, but humans beat essentially *everything* at endurance running, so that’s not a great point of comparison).
See <https://www.youtube.com/watch?v=5-TkUOvuuNE> for an example, the sea lion easily keeps up with the zookeepers walking alongside him. You can find similar videos with search terms like ‘sea lion running on land’, though that’s the best I’ve found on Youtube that really showcases their terrestrial mobility.
### It would impact their agility in water.
Actually, not really. At least, not any more than putting a human torso on top already does (humans bodies are *horribly* inefficient for swimming, and replacing everything from the waist down with a fish/cetacean/pinniped body doesn’t really help). Sea lions, despite being better on land than true seals, can actually *outmaneuver* true seals in the water in some cases. This is because sea lions rely on their robust, muscular flippers for propulsion and control, while true seals swim more like cetaceans or eels do, relying on movement of their whole body.
### The human torso would add too much weight.
Maybe. This is not really that different from any other centauroid (or pseudo-centauroid) body plan. THe front limbs would have to be more robust, and more musculature would be required than for a normal quadruped body plan (yes, sea lions are quadrupeds), but that shouldn’t matter much, because a normal sea lion weighs *600 to 800 pounds*, while the human torso is maybe 150 pounds.
In practice, the solution to this is to make the upper body as light as possible, which would actually improve agility in the water as well. Realistically, this will become an evolutionary balancing act, as hands without sufficient strength are just a waste of energy while growing, but too much strength would impact weight too much. The example of the development of birds is probably a decent parallel here (too much weight, and they can’t fly, but they need strong enough bones to not be killed outright just from someone sneezing in their general direction).
[Answer]
Presuming a mermaid weighs about as much as an adult female human, they can be adapted to walk on their hands:
>
> The Guinness World Records world record for the Walking on hands -
> farthest distance in 8 hours was set by Sarah Chapman (UK) who walked
> a distance of 5,000 m (16,404 ft) on her hands in an 8-hour period at
> Glastonbury, Somerset, UK, on 3 June 2002.
>
>
>
Sarah Chapman walked 3.1 miles on her hands, without any special adaptations.
For adaptations, the most obvious would be help in walking "forward" on your hands; our tendency is to walk in the direction our back (and back of our head) is facing, which makes it difficult to see where you are going. Being able to comfortably turn your head 180 degrees (like an Owl can) would be a useful adaptation. Stronger arms would be useful. Also, arms that can rotate better to put the hinge of the elbow facing the other direction might be useful.
I would give the mermaid the ability to flip to a tail stand on land, to get the height to see a decent distance, and to easily, without strain, walk on their hands and be able to see in the direction of travel; for hand-positioning (where they are "stepping".)
Given the adaptations; this could be as fast as walking, and there's no particular limit on distance; just like there isn't for walking.
In fact, if you want sensible limits, adult well exercised arms are about the same as the legs of children of some age. Aboriginal children can and do walk 20 miles a day.
It might seem weird for them to walk on their hands, but it probably would not seem weird to the mermaids. It's just what you do. They can even make themselves good gloves designed for hand walking, to protect their hands.
(Edit: I originally said "with strain" when I meant to say "without strain")
[Answer]
# Legs
Legs are a very effective way of getting around on land, which is clearly seen by the fact that it is the main method of terrestrial locomotion among both vertebrates and arthropods
Mermaids are nothing new. Ichthyocentaurs are a clear example of mermaids with legs, as are many depictions of tritons
In terms of realism, there are many aquatic animals with legs, such as salamanders, beavers, and penguins. Penguins are also quite humanoid in posture, so it seems like quite a good comparison
[Answer]
Walking on their hands is certainly the easiest explanation on the face of it. You could simply say that's how they do it and leave it at that; it's fairly logical and quite suitable if you don't want to get into it.
However, if you want to be precise, there are some issues with that. While some people are obviously very good at walking on their hands, it takes a lot of practice and a lot of balance. I, for example, cannot walk on my hands, nor do I need to. The average mermaid, as you said, lives in water, eats in water, and has no need to go on land. Unless your mermaids are habitually traveling over land, there is no reason for them to have the adaptations necessary to walk on their hands. Besides the adaptations mentioned in regards to head rotation and elbow position, extensive shoulder modification would be necessary for habitual hand-walking. The human pelvis is highly specialized for bipedal walking, including proper support and carriage of internal organs. The human body is not designed to be inverted for long periods or on a regular basis, which doesn't mean that it can't be, but it does mean that you need a good reason for the mermaids to go that route. See these pages for info on the human pelvis and on the risks of being inverted (just hanging, not including joint issues from reversed gravity)- <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5545133/> <https://www.healthline.com/health/hanging-upside-down#whats-the-max>
The other problem with hand-walking is in terrain. There is a reason that no land animals have their heads between their legs. If your mermaids have human proportions, their heads will hang to about the level of their elbows when walking on their hands, meaning that even something like stairs would be challenging for them simply because their heads are in the way. If your mermaids are simply walking down the road, that's not much of an issue, but if they live in semi-wild areas, they're going to have trouble. Living in the water, they are also going to face much more sand, mud, rock, and marsh than most people do. Even with our advanced balance (which I'll come back to), our long legs, and our high vantage point, humans generally avoid traversing loose sand, slick mud and rock, and deep marsh because it's a pain in the behind to get through. For a mermaid walking on her hands, these terrains would be incredibly difficult, both because she can't well see what's coming up or how to navigate it and because her head is already in danger of being whacked on the topography or lost below the surface.
Balance is another factor in both rough and fair terrain. Humans, besides having specially evolved features to assist in bipedal locomotion, have arms we can windmill wildly to help us keep our balance. Even when we walk on our hands, we can use our legs to help steady us. A mermaid cannot. Even if she has incredible balance from years of practice, she's going to have a terrible time remaining steady on anything but a flat road. Additionally, because she doesn't have independent legs, she'll have to have abs of absolute steel just to get herself upright in the first place. Humans, when getting up on their hands, will usually swing one leg up first, to create the momentum to lift their other leg into position. Unless a mermaid has assistance, she's going to have to lift her entire body off the ground in a plank position and then raise it with the sheer force of muscle power, or do some kind of worm dance to heave her back half up into position. Not impossible, but again, not a first-time sort of thing.
If you want a realistic, effective, biological means of land locomotion for your mermaids, the best way to go about it is probably to modify them to account for all these limiting factors and just go with hand-stands. It will require physiological alterations that would have taken a very, very long time to develop (and so must have been selected for over millennia) and which might change the appearance of your creatures though. Since, however, this is a work of fiction, you could simply ignore or hand-wave any or all of these concerns.
I think the most realistic way that mermaids would move over land, given that they should have no regular need to, would be for them to slither like eels and octopods, and would do so for roughly the same reasons. If, for example, a mermaid got caught in a tide pool or needs to get from one lake into another. It would be slow and probably ungraceful, but it would also work better in the areas it is likely to be necessary. While hand-walking doesn't work well in wet sand and mud, belly-slithering is perfect for those conditions.
In a world with mermaids, it's also very possible that those mermaids have some kind of magic or siren song that would make outside intervention possible. Maybe they cloud men's minds to do their bidding, carrying them across great distances. Maybe they have an ancient kinship with another mythical beast like the centaur, the unicorn, or the dragon, which they are able to leverage for aid. Maybe they have a mystical connection with wild beasts and can call on them in times of need. For a semi-biological explanation, the mermaids could have a sort of tranquilizing venom they use to stun large animals like moose, bison, or horses, then drag themselves up onto the backs of these stupefied beasts and ride them like zombies. Heck, maybe they have giant frogs as pets and can ride them about whenever they feel like it, or have sleighs pulled by crocodiles.
In terms of a classical mermaid- ie, one without wings, without four legs, and with a single-column tail- there just isn't a good way for them to move on land. That's why there aren't myths about mermaids on land. If you are willing to modify the basic mermaid body, or if you are willing to simply say "magic" and move on, the options are limitless.
[Answer]
**Dance like a ballerina**
[](https://i.stack.imgur.com/KypTr.png)
The merfolk merged their legs, to put a nice smooth skin on them, to be able to swim faster. The feet however are still in there.. when the tail fins developed, the foot was pushed to the middle of each fin and narrowed, but the ankles remained separated and their muscles were preserved, even strengthened, to enable flipping movement.
All your mermaid needs to do is trim her fins a bit.. order a pair of tailor made ballet shoes and go practice. Arms are still present, so balance will be no issue. You can't run on spitzen, but it looks elegant ! Merfolk should be beautiful, making them dance on land would preserve that beauty.
[Answer]
Why not crutches? A mermaid could easily find and fashion reeds into rigid crutches suited to her body size, and she could use them similar to how a team walks in a three legged race. Middle leg first. Made up of fin folded in one direction to make a kind of landing surface with grip. Then using some clever balance and strong arm muscles, swing one or both of the outer crutches.
Barring magic like Luca where a mermaid just forms human legs, she could have two legs that join together to form a fish half. They could have scales on all surfaces but those that touch, giving the illusion that they are one limb when held together. Some clever joints or muscles that grab scales or hold the legs together could make a rigid structure of two legs similar enough to the central fin without losing the mermaid vibe totally.
[Answer]
## Why try to walk without legs when you can roll?
I’ve said this before about seals and I’ll keep saying it until the end of time: just roll. **Seriously! Why do they waste so much energy bouncing on their belly to cover a short distance when’s they can just roll on their side.** Seals have no excuse for being unable to roll, I’ve seen them spin in place in the water!
**Your mermaids are no different.** They even have a human torso which means they have the muscles and flexibility for it. Sure the fins might get in the way but if they’re foldable there should be no problem. In fact, rolling might even be better for mermaids that have been dry for too long. By rolling themselves into water (even a puddle) they will make themselves moist again in no time. No need to crawl into the water until they are submerged.
Now, you might say that rolling isn’t terribly comfortable. Well neither is crawling or walking on your bare hands. Mermaid scales would even make this more bearable. It’s not that elegant of a method of locomotion but it’s efficient. Mermaids planning to move on shore might want to take a few classes and exercises in rolling. Something to think about.
[Answer]
**They ride.**
[](https://i.stack.imgur.com/N1RcCm.jpg)
<https://www.oldbookillustrations.com/illustrations/horse-sea/>
They ride side saddle. Their mounts come down into the shallow water to get them and then go back in to drop them off. The mermaids do not come down off their mounts on purpose. If one falls off, the mounts will kneel like a camel and let the mermaid pull herself back on.
]
|
[Question]
[
I have the idea of a fantasy civilization based around shifting dunes. The idea is that the land is largely uninhabitable except for the coasts, but there are large dunes that function as habitable "islands" in this wasteland. Blown by the wind, these dunes slowly drift across the land at the speed of several metres per year, like the somewhat famous [Råbjerg Mile](https://en.wikipedia.org/wiki/R%C3%A5bjerg_Mile?wprov=sfla1) in Denmark.
Maybe the soil on this continent is toxic due to pollution by a past civilization so that little can grow there, whereas the dunes carry with them not only sand but also fresh, healthy soil (maybe [loess](https://en.wikipedia.org/wiki/Loess)) - and there's plenty of rain, so lots of plants can grow on the dunes.
These dune-dwellers are somewhere between settled folk and nomads, since it can take years for a dune to move a distance equivalent to its own length.
There is a problem, however: Råbjerg Mile only keeps moving because of conservation. You can arrest dune drift by building fences and planting the right plants.
If my dune dwellers can just stabilise the dunes, that's no fun. Then they'll soon be just like any other settled folk. This is only fun if there is a good reason why they cannot lock down the dunes.
Having a superstitious taboo against stopping the dunes is not good enough. It's not satisfying for me to have a culture built on stupidity. That also sounds unstable. I need a better reason than that.
It's important to note that this is fantasy, not science fiction. Supernatural explanations are acceptable.
Thanks in advance!
[Answer]
Small dunes can be stabilized. Large dunes do what they want without caring of what those little furless ants say.
I remember my Earth science book in high school with two photos of the same dune taken few years apart: a road that once went straight in front of the dune had been swallowed by it and had to curve around the dune front.
If fencing would have been effective at protecting that road, why would have they moved the road?
[Answer]
**The ground isn't uninhabitable, it has hostile inhabitants.**
The ground has hostile mutated animal swarms that attack anything loud. You can avoid them, but you can't avoid them if you are building walls to hold in your wind blown homes, as the animals come in, knock down your walls, and kill your workers.
**There's a cultural taboo against blocking the movement for good reason.**
The movement helps refresh the resources of the dunes and regenerate them. Cultures that do manage to kill enough worms and overcome the challenges to anchor their dunes in place tend to die out, as they run out of resources. Then their walls collapse in time, and the dune moves on. These graveyards are a great place to explore and colonize for bold explorers.
[Answer]
I suspect you need the right kind of plants, not just any plants. Wikipedia has an [article on sand dune stabilisation](https://en.m.wikipedia.org/wiki/Sand_dune_stabilization) which seems to confirm this:
>
> **Overview (as you stated)** - Planting vegetation reduces the impact of wind and water. Wooden sand fences can help retain sand and other material needed for a healthy sand dune ecosystem. Footpaths protect dunes from damage from foot traffic.
>
>
> **Detail summarised**: The location of the dune limits the types of plant that can thrive there...... Plants that thrive on the foredune must be tolerant to salt spray, strong winds, and burial by blowing/accumulating sand.... Plants which thrive on the broad dune plain and backdune grow together into dense patches ("Dune mats") that hold the dune together.... Then shrubs can develop.
>
>
>
You aren't on earth (you're okay with the supernatural), so it would be easy to handwave that on this world, the types of plant that would work, don't exist, or died previously.
Maybe they never evolved. Maybe a past civilization genetically engineered a "better something" or an improved something else that accidentally led to.a chain of events that killed off all plant species with certain features, leaving the deserts as well as everywhere else, bare of them. Could be some part of biology needed just got wiped out, could be parasite ecosystem or defences, could be ability to absorb nutrients. Food production and other plants unaffected. (That makes quite a strong and topical backstory, fwiw, and explains nomadism too). Maybe predators ate them, infections got them, or they were overgrazed till they died out.
(Note - my gut feel is that overgrazing seems unlikely to fully destroy them, so its mentioned for completeness. Maybe it accelerated things, as the plants dwindled, those remaining because more needed for herd fodder?)
You don't seem to need much. You need plants to.simply not exist that tolerant sand burial, or strong winds; or plants on this planet spread by spores or seeds to form individual spread out individual plants that can't stabilise sand, not by growing their ground level roots or rizones or other mat-like structures.
Earth was like that for quite a while (grasses are quite a late-comer, and I haven't researched other plants in the Wikipedia article but I suspect the same applies - they could simply not have evolved, or have died). So both different flora, and/or accidental or natural loss, would cover it easily.
Without suitable plants, fences are useless anyway, and if the only wood is from fruit trees near water sources, nobody in their right mind will chop them down for wood, and the occasional fall or imported wood from a trader, will be too low level or costly - and would get buried quickly anyway
[Answer]
When the plants roots grow too much they reach the polluted underground and they die, but before they pump part of the pollution to the upper layers. People don't know why, but they see that if they stay in the same area for too long everything begins to die and they must move.
[Answer]
It is simply impossible to have moving dunes with buildings, soil and plants on top of them. That's because dunes do not move as a whole, they move because the dominant wind is constantly pushing the sand on top of them forward. You can say that the wind move them grain by grain.
If you plant something on top, you will stop the dune... or the sand will cover ("swallow") whatever you have there, be it a tree or a building.
[Answer]
## Living Dunes
The dunes are not made of sand by tiny living organisms. The dunes move in the same way caterpillar rolling swarms moves or like a moving army ant bivouac. They don't move with the wind but with intent, possibly some kind of feeding migration.
[](https://i.stack.imgur.com/dIVPv.gif)
Note your creatures will have to be largely sustained by "mana" or some other handwavium as otherwise the central part of that mass would starve. Actually having them feed on something in the air like mana would also explain the movement as the ones in the rear try to get the the front where the fresh mana is, this constant turn over will create movement as a side effect. we actually see something like this in cooperating animals like penguin, fish schools, grazing herds, they stay together for protection but each individuals is trying to get to the optimal point (front) of the swarm which creates movement of the swarm as a whole.
Maybe much of the center of the mass is the larva. You should probably make the creatures magically tough or strong so the ones on the bottom are not crushed. Maybe the "sand" is actually a hard spherical shell they grow, with holes like a whiffle ball for them to poke limbs out for movement but much of the weight is taken by the shell.
things stay on top of them because they "float" in the mass of living things and are at the same time anchored deep in the mass, and are thus carried on by the mass movement. that way even if the surface of the "dune" is moving the deeper currents act to counteract that force on the stilt buildings.
Perhaps some plants have evolved to stay anchored in the same way and that's where humans got the idea.
[Answer]
Let's postulate a different biology. Instead of plants which are stationary, postulate a different type of organism that takes water, sunshine, and carbon dioxide to produce sugars and oxygen - perhaps a different kind of lichen that can live on top of the shifting sand. Each year, it falls apart and regenerates in a new place. If it can grow fast enough to support other animals living off of it, then you have the basis to build a civilization. Imagine something growing an inch a day. That rate of compounding would be sufficient.
As long as the inhabitants can find a food source, they can live in shifting sands. Something that can grow in that environment would work.
Why don't we have something like that already in our world? Because shifting sands here are in an arid environment. Water holds the sand grains together preventing them from being blown by the wind. Sufficient water stops sand dunes from moving. Sufficient water also allows plants to colonize the dunes. Thus, our planet has not had a situation where dunes had enough water to allow the evolution of such organisms but not been invaded by existing plants. Any place that could have allowed such evolution got invaded by plants.
Edit Add:
To keep the dunes able to drift, have alternating super dry and wet seasons. The dunes move during the dry season. The inhabitants store up food and water during the wet season to survive the dry season.
[Answer]
maybe if you consider that the dunes don't "slowly" shift position but it happens in bursts. So whatever happened before, we now have raging recurrent storms that regularly pass, and typically grabs the dune and shifts it by a couple meters (shifts sand from the wind facing front to the back).
Since the storm always comes from the same direction, waiting out the storm is a matter of orienting the house openings correctly, but there is no fighting the movement of the sand, the storm *rages* it does not care about barriers or plants on the windward side, and anything on the other side gets buried by the storm.
[Answer]
Maybe they *want* to travel? It takes decades, but there is no safe alternative.
They build a big dune on the north side of the west coast, where the winds blow to the east. It would take the wind a thousand years to roll it across the continent, but the people nudge it along much faster.
And people on the east coast build dunes in the south, where the wind is westerly. This is the only way to keep trade flowing across the thousands of miles of deadly wasteland that separate them. They start preparing to celebrate a "dunefall" as soon as an incoming dune appears on the horizon.
[Answer]
## It's not About the Dunes
The actual hard question is: how does a society survive in a land covered in sand? They need to eat.
Maybe we can find a way to eat that requires the society to drift with the sands...
## Sand Creatures
Pick some creature that lives beneath the sands. Maybe Sand Worms, in a nod to *Dune*.
This creature move **very slowly** through the earth, and somehow produces a resource that the desert dwellers can use to create food.
It could be that the Sand Worms produce actual soil and that after a few years of use it is covered by sand or exhausted.
It could be that the Sand Worm waste is edible to some other creature that the desert dwellers herd.
Whatever the resource, the desert dwellers follow the slow motion journey of the Sand Worms across the endless wastes. They don't stabilize the dunes because... why would they? They have to follow the Worm to eat.
]
|
[Question]
[
I am writing a story with a world of sentient animals (equal rights to humans), and some of my main dog characters are part of a police department.
Now, in a world like this, I'm kinda thinking that if your K-9 partner is just as smart as you are, you might want to arm them too so they can back you up with their own pepper spray, taser, or gun. However, a trigger would be a tad hard to reach and pull with paws, and the recoil of even a relatively small 9mm pistol could probably break a canine leg easily. I was thinking maybe a mouth bite trigger and grip, but am also thinking that could be really hard on one's jaw and teeth.
So, I'm here to solicit you folk's help--how could a gun, taser, or pepper spray can be adapted for holstering, carry, and use by an animal with paws?
*Note: Dogs have been sentient since the 1790s*
[Answer]
Dog's teeth and head are tough. If it isn't an extremely bred breed like a chihuahua (also Devil's Spawn) then you have to imagine a dog running at maximum speed teeth first into their opponent. I have a 27 kg dog who can be lifted off the ground pulling a rope and slung in a circle with just the front teeth holding the rope (although I don't recommend this).
I would place the items on the Dog's head so he aims by looking at them. "Hand"guns are places beneath the head as far away from the ears as possible with the muzzle sticking a bit out from under the Dog's nose to prevent the muzzle flash from burning the fur or the hot air from burning the sensitive nose. [Ear protectors](https://images.app.goo.gl/UCDf4tuvfDTVLQCo6) are used to help protect the ears. With technology available you could electronically sync a noise cancelling with each shot, helping protect the ears from at least their own gunshots. The guns themselves are modified for the dog specifically, there wont be a literal human handgun sticking out from under their chin. Reloads have to be done by someone else or they use a belt-fed system from their back, but it is likely the dog would disable an enemy with one clip due to how they can operate. If a military dog can get close enough to bite they can shoot you as well. Things like pepperspray and tasers can be placed on top of the head. In case of pepperspray a metal tube would extend a ways over his head and stick out a ways from the nose to prevent eyes or nose accidentally getting sprayed as well. Possibly a few flaps will fall into place and protect the nose when the pepperspray is used while the eyes could use goggles all the time.
Trigger mechanisms are electronic and activated with the tongue. Dog's tongues have a high strength and agility behind it, and a sentient one would be able to learn how to control it to a greater degree. Lethal fire would be on one side of the mouth, non-lethal items on the other to prevent accidents. A double-trigger mechanism that requires for example the clenching of the jaw and a tongue press can reduce accidental firing. You could also use sound triggers, a growling dog is already warning you that he could go off at any second, so growling could be the first trigger and a tongue press the second.
[Answer]
**Pepper spray and guns both hurt people (and dogs) not in the line of fire**!
## Gunfire near a dogs head will deafen them
The gun needs to be near the dogs head for aiming. Either harnessed to an arm, mounted on side, or strapped to head somehow. All of these will damage the dogs hearing substantially after a few shots.
### Pepper spray passing a dogs eyes will blind them
Pepper spray is a similar issue. A dog can extend its front paw a decent distance while unbalanced on hind legs, but when balanced the pepper spray needs to come from a similar location very close to their eyes. Tinyest variation in the wind, or if it gets in their coat, they're suffering too.
### Taser? Could work
I'd suggest 2 mounted to a harness on either side of the neck. Button in the front middle of the collar to fire them. Can press it twice before he needs to reload.
[Answer]
It would require a more elaborate setup than a human's gun.
Probably the safest route would be a gun mounted on its back or sides via a secure harness. This is triggered by a lever that the dog can manipulate with its mouth -- jerking it down hard. Then, the harness takes the force of the gun's firing, and so the entire body absorbs it.
Back vs. side will be influenced by the size of the dog and the position of its head. Obviously, it doesn't want to shoot itself in the head, but especially for small dogs, the back helps make it easier to balance without putting equal weight on both sides.
[Answer]
This is how I think it can go.
* Lower calibers have lower recoil.
* The overall structure can be made to reduce the recoil.
* Sub-sonic ammunition exists already.
* Many weapons in the real world can achieve the whosh sound of fiction. Many silenced weapons are very low and can be used without ear protection. Forgotten weapons features many.
* So a long well designed silencer can reduce the sound to safe levels.
* The overall structure of the thing does not have to be similar to human weapons. Think of it as a platform of a gun. Not a normal pistol.
* You can also reduce the noise effect by having the whole firing part further from the animal. Remember special ops guys want to reduce the total noise while you only want to reduce the damaging part.
* A paw or jaw level can be made and easily engineered to be easy to pull and be very reliable. Yes the longer the firing group is, I mean the wires and all that, the more it is likely to have trouble but that is just things.
* Aiming is a bit of a problem but we can start solving it. One word: LASERS. Well zeroed laser can be excellent for an animal as the dog does not have the same control of humans so lasers can be very useful.
* Another solution is to create the entire platform, again this is not a gun, extent to the head of the animal and goes over their eyes with a sort of iron sights that the animal can use and with time and zero it. You can see something similar with those backup titled sights that you see in movies. YouTube videos exist.
* Another is to use shotguns to solve the problem of aiming.
* Ejection can be easily solved as well as you can control it.
* Reloading however is out of the question. I'm not including this as a frame challenge or anything. I just can't think of a single way for anyone to come up with a system that allows dogs to reload their platform. Maybe a genius can.
* You won't have larger calibers like ever. But again even a 9mm can still kill at more than a 100 meters. And this is obviously a backup not an actual army or anything.
* Even without reloading this platform is still viable and can work. I mean engineering, I'm not engineer but it breaks no laws and only mixes stuff that exists already, so if you really need it I think it can be made.
Now I can write a frame challenge to why this will not work or at least have a huge amount of setbacks to the effect of it not being used in any setting like ever.
But I'm not sure you want that. Though if you are interested I can do so.
[Answer]
Even though they might be smart, these dogs don't have the same experience as human adults, they can easily be shot if they stand still to aim, because armor would be too heavy for them, they'll need big calibres if they want to harm animals they'd actually need guns against, they won't have a way to aim a gun as precisely, they won't be able to reload, they won't be able to let go of their gun as a sign of peace, they won't like how the gun feels, etc. I'd stop thinking of them as equal to human officers. Rather give them completely different equipment.
Build it around the natural strengths of dogs: Most taller dogs are faster than humans and have a stronger grip. Let them coordinate in packs, because it will probably feel more natural to them. Have a human throw a flashbang before the dog unit gets sent in, because dogs just aren't as good at throwing things. Dogs would be sent out to rather narrow crime scenes, where humans have problems moving around, e.g. when there's trouble in cat town.
Maybe come up with some kind of mouth taser concept for them. If a dog bites you, you'll get zapped by 500-50000 volts, depending on how strong the bite is.
**off-topic below**
I'm not sure if you'd even want sentient dogs as officers. 1. because I don't think other sentient animals will respect them. It might feel similar to them like whater is going on in america, with the white cops shooting black people more often than white people in similar scenarios. 2. because there's no need for a dogs natural intelligence or loyality, if all animals have the same intelligence as humans. You might be better off using other animals for skills like flying, climbing, digging, etc. 3. As an example: Patas monkeys are faster than most dogs, they have no reason to feel sympathy for humans, they are harder to hit with weapons that are effective against humans, in nature they don't harm other animals besides insects, they can wrestle animals down without biting them, they don't need a lot of space, they can climb and they have fingers. Give them a harpoon-like taser and a few grenades in a backpack and you are ready to go.
[Answer]
**Dogs are weapons on legs**
Dogs are natural experts at close combat fighting. They have evolved from wolves and wolves are death machines.
You could provide the dog with hydraulically enhanced, tungsten-coated teeth so they could bite through a plaster wall or bite someone's leg clean off instead of merely grasping and holding.
Instead of giving dogs weapons that were designed for use by bipeds with opposable thumbs, a much better "weapon" would be strategic planning.
The humans and dogs would attend a pre-raid meeting where roles would be assigned. Dogs would be excellent at listening at doors and sniffing out suspects as well as drugs and other substances. Because they are intelligent, they could do this without human aid and would be a hundred times more efficient than current police canines. They would of course have police radios fitted to their collars.
**Speed**
A German Shepherd can outrun Usain Bolt, in fact a *cat* can outrun Usain Bolt!
[](https://i.stack.imgur.com/sb3YG.png)
In terms of strategy, use humans for what humans are good at - handling weapons. Use dogs for what dogs are good at - being weapons and running, sniffing and hearing.
---
## **Answer**
Dogs could be fitted with all sorts of jaw extensions. Crocodile-type jaws, bolt-cutters, disarming jaws that literally remove an assailant's arm. Clamping jaws that painfully cling onto someone's leg while anaesthetising them or giving them shocks to slow them down while the dog lets go and attacks separately.
**Don't adapt human weapons - make lots of jaw adaptations that require a biting motion to operate.**
]
|
[Question]
[
The high fantasy world I'm building is loosely based on 10th-century Scotland, under threat by Viking-type raiders. There's a small group of not-Scots with supernatural gifts that an ambitious chief of not-Iceland would particularly like to get his hands on for his own power-hungry purposes, so the gifted folk have built a secret community in a fertile but difficult-to-access highland valley to hide from him and his goons. They leave the valley seasonally and take a boat downriver to trade goods, so they aren't totally isolated, but they don't tell anyone where they come from.
What conditions could I introduce to the entrance or surroundings of a valley capable of growing enough crops to feed <50 people and an appropriate number of livestock that would make it extremely difficult or impossible for strangers to find the place unless someone shows them the way?
My best idea so far is that the valley is accessed through a narrow, rocky pass that's hard to see from the outside, which could be further concealed with brush and other obstacles. There's also one gifted villager who can alter what other people see, so he could deliberately conceal the entrance if he knew enemies were looking for it -- but I think it's a bit much to propose that he could do so without conscious thought and effort, so I'm hoping for a plausible way to hide the valley that doesn't require supernatural intervention 24/7.
Any ideas?
ETA: I don't need the valley to stay safe from the raiders - in fact they're destined to find it eventually. I just want to explain why they can't find it unaided even once they start looking, and need somebody on the inside to lead them (inadvertently or deliberately) to the entrance.
[Answer]
**There is no (direct) passage. They climb.**
Your 'valley' is actually the caldera of a volcano that went inactive eras ago. There was enough time to build soil and it is minerally rich, hence fertile. Rain gathered in the caldera and there is a nice little lake at its center. Water flows away by underground streams.
**There is no direct passage to access the crater**
Your smart not-Scots have found a way though (maybe someone had a vison?).
The outside of the crater has a forest. If you climb high enough on a tall fir growing close to the outer side of the crater you can reach a natural terrace from where you can easily pass to the inner side.
With time they have improved the way with well camouflaged wooden walkways and ladders. They have also installed a pulley system to lift and lower the goods they want to carry with them. Elderly people can safely use them too.
Of all the outside trees only that fir allows a way into the steep crater.
You also mention livestock. It's possible to bring in only small animals. But of course some could be brought in when sitll young and grown inside (like piglets). Horses and cows would not be suitable.
Imagine something like this but with a thick forest around and inside the crater and a small lake at the center. And no taller mountains around to have a view of the inside of the crater.
[](https://i.stack.imgur.com/QYyj5.jpg)
[Volcanic craters](https://www.zmescience.com/other/great-pics/11-volcanic-craters-to-blow-your-mind/)
Edit: Upon thinking about it I think a fir tree is not adequate (the branches would hardly carry anyone). I suggest instead beech, because am partial to it. But oak is fine too.
[Answer]
Social engineering
Pose as poor, tattered wood-dwellers. Use your guy who can alter what people see to make them look scrawny and ill-fed. It limits your ability to buy and sell unless you do it secretly with trusted merchants who won't betray to traveling strangers that those "poor" buy quite a bit -- but then, it's hard to get things back, so they would limit outside purchases anyway.
Vikings aimed their raids at rich locations. Cities. Monasteries. They would time them for festivals in order to maximize their haul of slaves for capture. The point of this is to make them think "slim pickings."
[Answer]
To stick with your narrow, rocky pass idea, you could block off the pass. If you have someone who can move rocks easily, you could set up a barricade or make the pass look (if you'll pardon the wordplay) completely impassable. This would bring any would-be invaders to an impasse. This would work especially well if they only need to leave infrequently. If they leave once a year for trading, you wouldn't even need anyone with special gifts to do it---you could just have everyone work together to clear the pass, leave the person who can conceal the opening as a guard, and then have everyone seal it up again when they return. You could do that even if they leave more frequently, but it seems like a lot of effort to go to on a regular basis.
[Answer]
Surround the village with a forest of highly poisonous plants like [Heracleum sosnowskyi](https://en.wikipedia.org/wiki/Heracleum_sosnowskyi). I know there is no such thing in Scotland, but it could be. Any warrior in medieval armor will get terrible burns if they'll try to go through debris.
And there can be a secret tunnel (or even trench) that leads to the village. Or maybe once per year villagers put on some special closed clothing (like plague doctors) and carefully chop passage through the forest.
[Answer]
**Crypt.**
[](https://i.stack.imgur.com/PvXLI.jpg)
<https://www.pxfuel.com/en/free-photo-jadol>
There are ruins up on the mountain. They were there when the first settlers came to the lands below. The ruins extend back into the mountain, merging with natural caves. It is easy to get lost in the caves. They were built to make it easy to get lost. In some parts of the caves there may be other things.
Your hidden people know the route. They are descended from the ancients who built the ruins originally. You can traverse the cave systems and emerge into the light on the far side if you know what you are doing. There are patterns etched into the wall so you can go through in the dark with one hand on the wall. These patterns don't look like much by torchlight.
The raiders are afraid to go into the cave and rightly so. They try once and then back out. Then they catch a child and make her lead them through the cave. Of course the builders expected this and the child falls down a hole, deep in the cave. The raiders are not sure if this was an accident or a planned escape route. They don't want to follow her.
This would be fun to write. The ruins and cave will be exciting and scary. Perhaps a few raiders make it through. They probably will not have much fight left in them. When the girl makes it thru first and lets the people know who is coming (maybe), these survivors could be met with psychically augmented super creepy finale. They then wake up by the river, to return and tell the story.
[Answer]
**Consider the [Debre Damo](https://en.wikipedia.org/wiki/Debre_Damo) monastery**
the Debre Damo Monastery is located on a flat-top mountain and can only be accessed by rope lowered from someone above. [The monastery is self-sufficient](https://www.lonelyplanet.com/ethiopia/northern-ethiopia/attractions/debre-damo/a/poi-sig/1425204/355293), growing its own crops, etc., for about 300 people.
But would this stop a raiding party?
Nope.
While the difficulty accessing Debre Damo is legendary, the reality is that a good free-style rock climber could get on top without a lot of trouble. Your valley has the same issue. A good climber can climb any slope, any cliff, anywhere along the circumference of the valley, then lower a rope for everyone else. There is no such thing as "impenetrable" in any believable way.
And all it would take is one enterprising person wondering, "huh, where'd those dudes come from?" to follow them and discover the hidden trail. It would take a LOT of concerted effort to keep the secret if people are leaving the valley for any reason.
Finally, keep in mind that the harder you make it for a raiding party to discover or get to the valley, the harder it is for the people living in the valley to leave it (and get back).
[Answer]
**Use a decoy road**
The real Scotland is big and wild. Even the invading Romans were unable to conquer it. In fact they built a wall to keep the Scots out of the rest of Britain!
Build a nice road that bypasses your people's encampment. Make it look old and little used. Make sure that there are no paths leading from it to the hideaway. Instruct your people never to use the same path twice so as not to wear a track. Definitely tell them not to use the road, except annually when heading to the river. There aren't many of them so their annual passage will just help keep the weeds down.
The invaders will be grateful for the existence of a road, however worn, and will just see the usual mountains around them that are ubiquitous in this sparsely populated land. They will march past without a second glance. They will assume that the road leads somewhere important that is worth looting.
Ideally a fresh water spring crosses the road so the invaders will have no reason to search for water in that vicinity. If you are really nasty, always leave a dead sheep in the water upstream of the road. This will make travellers very ill but only after a delay. They will not want to go back to somewhere with bad water.
[Answer]
Pretend to be raiders of another - even more violent gang marking your territory. Strip your dead, put the on poles to rot, let the sound of the tortured echo down the canyon, make a huge charade and ocassionally send patrols out to hunt for the "weaker" gangs - if you run out of farm labour.
Turns out that engaging in gang wars - is not actually a substainable buisness.
]
|
[Question]
[
In various science fiction works, we see our plucky heroes beaming down to, or flying down to planets other than their own. They meet with the inhabitants there, be they human or otherwise and then they just go back on their way without incident.
Given the situation the world finds itself at the moment, this has me wondering what would be the mechanism that would allow travellers to visit other planets (or countries?) without becoming infected, infecting those they meet or otherwise without suffering the consequences of infection/quarantine etc?
Imagine right now, if a human from (say) the ISS beamed down to the surface, met with a few people for some intergalactic peace conference and then beamed back up again. There's a reasonable chance they'd take Covid with them, with all the consequences that entails.
Should they have some sort of tox-screen in their teleporter that filters out the bugs whilst in transit? Such a solution might mean they infect the locals with something they already have (and possibly need). Should they wear some sort of bio-forcefield that blocks the bugs but still lets them breathe the air? Should they have some sort of "universal immunity" before they travel? What about the locals?
How might some future people solve infection issues when visiting strange new worlds, or seeking out new life? I realise we're talking about future-fiction here, but which would be the most practical/socially acceptable/physiologically acceptable etc?
[Answer]
If you wanna be smart, you do it like we do in real life: send a probe instead of a person.
Probes are more resistant than humans to:
* Radiation
* Dehydration
* Extreme temperatures
* Extreme G forces
* Hard vacuum, or even mere oxygen deprivation
* Tide pods
* Concussion
* Starvation
* Loneliness
* Infectious diseases, such as salmonella, COVID-19 and syphilis [citation needed]
They are also cheaper (they don't unionize), and generally won't require a visit back to their home every once in a while.
If you really must shake a friendly tentacle, make the probe humanoid and able to sync with someone else's movements. That someone else may stay in an orbiter for low latency of the signals involved.
---
Per Willk's request:
>
> There are billions of worlds
>
> In the Milky way alone
>
> But getting to any one of them
>
> takes just way too long
>
> And if you go you are prooooone
>
> To get [redacted] by
>
>
>
Try to sing the next part as fast as you can
>
> Radiation
>
> Dehydration
>
> Loneliness and starvation
>
> High G forces! Asphyxiation
>
> By oxygen deprivation
>
> Each challenge a tribulation
>
>
>
Back to regular tempo
>
> So what is an explorer to do
>
> If I want to claim a new planet or two?
>
>
> Send a probe! Send a probe! Seeeend a prooooobe!
>
>
> Send a probe, send a probe
>
> To Uranus and to Jove
>
> Send a pretty little drone
>
> And it gets your job done
>
>
> Send a probe, send a robot
>
> It can go where you cannot
>
> You can do some exploration
>
> Through the joy of automation
>
>
> Send a probe! Send a probe! Seeeend a prooooobe!
>
>
> Send a probe, send a rover
>
> You don't have to come over
>
> If the landing you get to botch
>
> Well no human life is lost
>
>
> Send a probe, send a lander
>
> From the station, be a commander
>
> And when the mission's done
>
> There's no need to bring it home
>
>
> So send a probe! Send a probe! Seeeend a prooooobe!
>
>
>
[Answer]
**Full body suit with filters or canisters for respiration**
While filters that can science-finction-nally detect any and all pathogens and immediately remove them from the body might sound cooler, a more practical, cheaper and less risky (preventing rather than trearing) would be to invest in less bulky protective suits, which can create a flexible, yet resistant force field a millimeter away from the user's skin, thus isolating them from the external environment, as well as having a special apparatus that either filters the nearby air or uses a pressurized cannister to allow for breathing sounds like the best approach. While it doesn't sound as cool, it'll protect the user from any possible infections/pathogens transmitted by air and contact, without being as bulky as modern protective suits (at best a small-backpack-sized device to carry the cannisters and mask, as well as to create the force field, since we're going full science fiction here). It won't protect against contaminated food and water though, so offerings of food and water would likely be less common, as they'd be denied until proven safe and served in a sterilized environment (it might sound like too many measures, but remember that, in case any alien virus is compatible with your biology, you'll have no antibodies to fend it off whatsoever, meaning that even what's considered a normal flu might kill you if not treated properly).
But all of this is assuming all lifeforms you're interacting with are somehow so biologically similar to your species that there's an actual risk of their diseases being compatible with your body, and that's a whole different story.
[Answer]
It will be necessary to ware a protective suit and filter the atmosphere to remove chemical and physical contaminants, however it is unlikely in the extreme that there would be a serious biological risk as the planet would have had an entirely different biogenesis and presumably billions of years of evolution that would produce a very alien biochemistry.
It might not involve amino acids or if it did not the same ones we use. The sugars might not be the same or have the same handedness. All the biochemical pathways would be different or hopelessly garbled and the genetic code would undoubtedly be different. So any alien virus would be out of luck trying to hijack our biochemistry to make copies of itself. In fact it would be so different that a good analogy would be trying to get a gramophone record to play on a VHS video recorder. Different technology, different substrate, different coding. Not going to happen.
[Answer]
Standard pre-first contact protocols require that sterilized flying saucers containing equally sterile biological clones (with gray-skin, thin arms and big black eyes) isolate and kidnap a sample of the indigenous life of any early space flight capable species, for the purpose of taking a full biological inventory of the target biosphere.
This is done so that the first klaatu model replicants who openly visit the planet will already be immunized against all planet-borne pathogens and equally freed of any of our pathogens which might threaten the indigenous life.
[Answer]
Why actually bother going in person?
Use remote controlled drones/robots or other type of machines that can collect samples, interact with the locals, make field tests and repairs to the machinery, build stuff for the locals...etc until you get all the relevant information you want.
All that is controlled from the safety of your ship in orbit. No need to worry about anything at that point.
Also handling sterilizing and disinfection in machines is much easier that doing that for humans.
Especially having rigid protocols about it and the machines being programmed to actually follow them.
You would be surprised at the number of doctors who might be a bit careless with themselves let alone other types of people.
Also this saves money and people.
Say you land on planet A and then the populace decide to burn your guys and gals alive. Well good luck getting replacements.
But machines are less difficult to make, we are assuming a civilization capable of intergalactic travel, and even more resilient and non emotional.
It even saves resources on your ships. Say a group of 30 people don't need as much resources as a group of 200 people would.
And the group of 30 people can use machines to do a lot of their work for them meaning that, at least, they are as effective as the larger group.
And gain training and maintaining such a group of people is way more difficult that having machines do it.
And after you are certain of the intentions of the locals and that there are no chance of infecting either group of anything then you can make contact with them if needs be.
Anyway a rule of story telling of mine is this: "Think lazy"
A lot of human advances are just people being too lazy to do something the hard or right way.
[Answer]
## Nanomachines
If you want to be able to truly play the part like Captain Kirk, you can't be having to deal with clunky protection or reliance on the mishap prone teleporter. The solution? Nanomachines that have been already programmed to recognize the usual inhabitants of your microbiome. Any unexpected intruders would be swiftly dealt with.
The system would also work the other way around, killing that last 0.1% of sanitizer resistant germs on your skin. To ensure complete protection of your interspecies pals after you leave, they would also wipe out any lingering traces of your microbiome before self-terminating.
]
|
[Question]
[
I'm designing a world where people and dinosaurs exist at the same time. I'm making it realistic (in the sense that it is more like *Jurassic Park* and not like *The Flintstones*).
Supposing you could tame an adult male triceratops, is there a way to estimate how much load it could pull/carry? I'm envisioning a cart with wheels, but if the tail is too much of a blocker for that then stowing stuff on its back and sides would do nicely too.
[Answer]
So a triceratops would mass about 6-12 tonnes, according to wikipedia.
Draft horses that weigh 1 tonne can pull carts of 2 tonnes. Elephants working in logging drag 2t logs (about half their weight) in the course of their work.
So for a 6 tonne triceratops, that suggests a 12 tonne cart, or 3 tonnes of dragging. (Despite many cars being only about 2t, I don't think a triceratops could drag one if the parking brake was on. Too much friction.) For the 12 t, that's a 24 t cart, or a 6 tonne drag.
As far as actually carrying something by strapping it to the side or putting it on a harness, for horses it's recommended to not exceed 20% of body weight. A triceratops is a bit more stocky, but because of the square-cube law I don't actually think there would be improved specific capacity. So 1.2 to 2.4 tonnes carried.
As far as pulling the cart goes, one option is to have two smaller carts on either side, just behind the legs, and use that. Another option is just to have a really long shaft between the harness and the rest of the cart. (It'd probably need to be 3-4 meters long)
[Answer]
*Triceratops* is an example of a very large mediportal animal: an animal that is large, but adapted for relatively rapid locomotion. This can be seen by the structure of its limbs, which unlike an elephant or a more contemporary sauropod, are not columnar, but semi-flexed, a design that allows rapid acceleration. This would fit with its horns: when defending against a predator, it would need to be able to turn quickly and lunge quickly in order to stab at its foe with its horns. The robustness of the leg bones even in comparison to an elephant or sauropod suggests that this is likely. A side effect of being able to accelerate quickly is being able to also run quickly.
Now, we must consider that *Triceratops* is estimated to have a body mass of 6 to 12 metric tons.
If we consider modern horses, it can be seen from their skeletons and lifestyle that they are a large cursorial species, adapted to running. However, being cursorial does not necessarily equate to maximal load-bearing or -pulling capability: horses' legs are slender at the bottom and relatively far up the limb, and then bulk out near the body, which are classic adaptations to minimising the mass of the limb in order to maximise the rapidity of the gait cycle.
However, *Triceratops* has *far* more bulky, robust limbs that are proportionally shorter than a horse's. Despite its longer legs in absolute terms, it is unlikely that it would have been anywhere near as fast as a horse. As I have pointed out, *Triceratops* seems evolved for making rapid turns and lunges, probably so that it can use its horns as weapons.
So, if a 1 metric ton draft horse can pull a 2 metric ton cart, scaling up the creature to a 6 to 12 ton *Triceratops* would naively give a hauling capacity of 12 to 24 tons... but this does not take the creature's musculature into consideration.
If we compare a horse with a *Triceratops*, the comparison is similar to that between a marathon runner and a weight lifter. Even if they weighed the same, the weight lifter would run less quickly and for a lesser duration, but could pull a much greater weight.
A human Marathon runner might be able to lift his own body weight, or perhaps a bit more. However, his training has been more toward lightening his body and increasing his endurance. This is in contrast to a weightlifter, who might be able to lift 2.3 times his own body mass. The comparison between a horse and a *Triceratops* is that extreme, perhaps even more so.
So, with *Triceratops* being one of the weight lifters of the animal kingdom, we can expect that they could pull a much greater load than an equivalent-sized horse. If we go with a not unreasonable figure of 2.5 as the greater weight-pulling capacity of a *Triceratops* as compared to a horse, then we must conclude that a *Triceratops*'s pulling capacity would be on the order of 5 times its body mass... so for a 6 to 12 metric ton *Triceratops*, it might be able to pull a 30 to 60 ton wagon, provided that the friction of the horse-sized and *Triceratops*-sized wagons was equivalent.
I mentioned elephants in passing. Elephants have relatively slender limbs for such a large animal, and they are also relatively slow, despite their relatively long legs. A rhinoceros of the same mass has shorter, stronger limbs, and is also faster, as it can gallop, bringing all of its feet off the ground for part of its gait cycle, while an elephant cannot gallop at all.
So, since a *Triceratops* is equivalent to a physiologically even stronger rhinoceros rather than an elephant, the pulling capabilities of an elephant are a poor example for comparison.
Now, having said that a *Triceratops* can likely pull vast masses, I would not expect that it could pull them particularly quickly, but it is likely that they could pull a load for a considerable amount of time. Lunging with its horns at a predator would require anaerobic fitness, rather than aerobic fitness. However, *Triceratops* has a deep, broad rib cage which would be able to house a large heart and a large set of lungs, so it is likely that it could keep up a fairly decent walking pace for a considerable amount of time.
*Triceratops* dentition consists of around 800 teeth arranged to slice up very fibrous food. This would mean that their preferred diet may have been something like fern fronds or even tree-fern trunks. They would need to spend a considerable amount of time eating in order to meet their energy needs.
The fact that *Triceratops* has a vast battery of teeth implies that its digestive system is more reminiscent of a horse than a cow, in that it must chew its food thoroughly before swallowing it, and that it does not have the opportunity to re-chew its food as cows do. Cows are forgut-fermenting herbivores, while horses are hindgut-fermenting herbivores.
The significance of this is that a *Triceratops* could likely eat rich, high-energy food (as can a horse), while a cow cannot, lest it suffer from a digestive imbalance that can be lethal. This would tend to make domestication of *Triceratops* for purposes of haulage feasible in that eating rich food gives it the ability to gain the nutrients it needs in less time than eating its usual poor-quality food, therefore increasing the time that it can spend working.
On the matter of carts, ball- or roller- bearing axles would reduce the friction of the wood-on-wood bearing surfaces of pre-modern carts, as would having carts with flanged steel wheels running on metal rails, as both these measures decrease rolling resistance. Rubber tyres would have the effect of providing a smoother ride, but at the cost of increasing rolling resistance.
However, as typically happened in pre-modern times when the only power was muscle power, if more power was needed, more animals were added. However, with a single *Triceratops* likely being able to pull a 30 to 60 metric ton cart, it would be difficult to build a cart that could carry that much, let alone *twice* that much.
In fact, the extreme strength of a *Triceratops* would suggest that the more likely arrangement of animal and load would be a *train* of carts pulled by a single animal, since the individual carts may need to be able to be moved by lesser beings on occasion, as well as the cost involved with producing a single 20 to 40 ton capable cart as compared to the cost of 10 to 20 two-ton capable carts.
[Answer]
**Frame Shift Challenge: You might want a hadrosaur instead of a *Triceratops***
Ceratopsians don't appear to have been particularly fast dinosaurs or have a lot of endurance. They appear to have been slower than big predators like *Tyrannosaurus*, who wasn't very fast in the first place (speeds of 40 km/h). The semi-sprawling forelimbs of *Triceratops* are really bad for long-distance running or walking, but are really good at helping the animal turn. By using its hips as a pivot, *Triceratops* could rapidly swivel around and make sure its horns were pointed at a potential threat at all times. This also means it's really hard to put a saddle or harness on them, as a *Triceratops* can rapidly turn around and either gore a would-be handler with its horns or [maul them with its beak](http://markwitton-com.blogspot.com/2015/02/controversial-ceratopsids-revisited.html).
By contrast, hadrosaurs were in [some ways faster than tyrannosaurs](https://palaeo-electronica.org/2009_3/180/index.html) (speeds of ~50 km/h have been suggested) and [may have had more endurance](https://www.ualberta.ca/newtrail/featurestories/who-is-faster-tyrannosaur-or-hadrosaur). Hadrosaurs like *Edmontosaurus* are also known to have [migrated as much as a modern African elephant](https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2019.0930), which suggests they were better at the long-distance endurance locomotion necessary for a pack animal.
Another problem with the posture of a *Triceratops* is it's hard to put a saddle or harness on them. Their backs are strongly sloping and your field of vision could easily be blocked by the large frill and horns. By contrast, hadrosaurs have a nice place to put a saddle at the back of the neck (regardless of whether it's curved and saddle-ready like in some reconstructions or horse-like as in others) which would remain stable even if the animal assumed a bipedal posture.
Ceratopsians also come with some behavioral challenges that make them less appealing candidates for cart animals than. *Triceratops* is unusual among ceratopsians in that [it was rather solitary](https://www.tandfonline.com/doi/abs/10.1080/02724634.2009.10010382?casa_token=Vdbm-jPZFkoAAAAA:q0OZU0k0LkWMZkC79zksDcAyuxJdir873lc06vmPKgW9rlelb8Fc7CDRO34a5Hmf8j-7pkRjZ6Z0Nw), whereas other ceratopsians like *Centrosaurus* would form herds measuring in the hundreds. Even in the cited example you have only three *Triceratops* at one site, which is a lot lower than is usual for ceratopsians. Solitary behavior means it is a lot harder for humans to impose themselves at the top of the dominance hierarchy and make the *Triceratops* do what they want. Many, many hadrosaurs, including *Edmontosaurus*, live in large herds which would make them easier to domesticate.
Hadrosaurs also get a lot bigger than ceratopsians, and therefore can pull bigger loads. [The largest known individuals of *Edmontosaurus* got bigger than *T. rex*](https://sauriangame.squarespace.com/blog/549), and *Hypsibema* and *Shangtungosaurus* frequently grew to similar sizes.
[Ceratopsians also can't swim](https://archosaurmusings.wordpress.com/2018/03/21/ceratopsian-horns-and-frills-what-drove-their-evolution/). Their heads are so heavy they would drown if they went in the water, which means one bad flood and you've lost your draft animal. Compare this with horses or elephants, who can swim. Hadrosaurs are land-adapted animals similar to ungulates, but at least they wouldn't drown if they went through a river.
Realistically speaking, there isn't much a domesticated ceratopsian can do as a draft animal that a hadrosaur couldn't do better, aside from the cool factor and maybe using its horns as a war animal. Ceratopsians may have some advantages in eating higher-fiber woody vegetation.
[Answer]
Based on weight and the fact that things don't scale , your (?5-?10 ton) triceratops will have the pulling power of a team of 1-ton heavy horses, so it could pull the largest conventional cart.
Their size creates some interesting issues with harness. Getting them geared up for the ay may require a team of people and some scaffolding.
What makes it more interesting it is metabolism. I would envision them as placid grazers more like oxen, so like oxen or bulls capable of a fast charge at need but generally moving slowly. You may be in for more of an ox-cart lumber than a horse-like brisk trot.
You would also have to consider temperament and intelligence. Obviously they will be bred for domestication, but not all animals have the right qualities to start with. Something that large and powerful will be extremely dangerous if startled or provoked. (What are they like during mating season....?)
Suddenly I see all the advantages of something smaller and horsier.
[Answer]
Pulling a cart might not take full advantage of the triceratops size and strength. Moreover, you have to deal with the logistics of delivering food and water to its current location and removing the resulting fertilizer.
A track or road wide and strong enough for a triceratops, as well as its carts, would be very expensive to build.
I suggest as an alternative a cable railway system. The goods would be moved in trains running on tracks, and pulled by cable loops. The cables would be powered by strategically placed stationary triceratops. The railway system would carry carts full of grain and dried ferns to power the system, in addition to payload. The triceratops locations would be selected for being close enough to a spring or river to keep the triceratops supplied with water.
[Answer]
Because of the locomotive range of a *Triceratops,* a light cart would naturally bounce up and down (like with horses)[1](https://chimacumtack.com/blog/2019/05/14/tuesday-tip-two-wheeled-cart-balance/). As a result, we will want to make the base of the cart heavier by using tungsten (a dense material).
Second of all, we will create a cart slightly shorter in height than the *Triceratops* and equally wide (it will topple over if too tall or wide)[2](https://www.ponyandcarriage.co.uk/horse-and-carriage-sizing-guide.htm). Since *Triceratops* is thought to have measured 2.9-3 meters in height, we will create a 2.5 meter tall and wide cart[3](https://www.dimensions.com/element/triceratops).
In addition, it would be difficult to turn such a large animal using conventional wheels with tires without causing excessive friction between the tires and the ground. As a result, we will use Mecanum Wheels™ with opposing angles on each side[4](https://www.core77.com/posts/47205/Wheels-That-Permit-360-Degree-Movement%E2%80%94Without-Turning) to allow for a 360 degree range of motion. (Image source: <https://s3files.core77.com/blog/images/lead_n_spotlight/410006_title__47205_te6iK5WZJ.jpg>)
[](https://i.stack.imgur.com/4rGY9.jpg)
The cart will be 10 meters long to allow for a larger volume in carrying capacity without creating excessive length that could lead to collapse. The sides of the cart will be made out of wood to decrease upper cart weight.
As a result, a cart for a *Triceratops* would look like this:
[](https://i.stack.imgur.com/83fN7.jpg)
Finally, we will need a method of attaching the triceratops to the cart. A *Triceratops* is somewhat similar to an elephant, so we will use a modified elephant harness, but scaled up in size to meet a triceratops' dimensions plus a tail holder. (Image source: <https://i.stack.imgur.com/Dm79U.jpg>)
[](https://i.stack.imgur.com/Dm79U.jpg)
An elephant harness is based on an elephant saddle (as shown below), but with wood compartments that attach the saddle to a cart/carriage. (Image source: <https://i.stack.imgur.com/xCsoc.png>)
[](https://i.stack.imgur.com/xCsoc.png)
**P.S. A *Triceratops* should not carry any more than 1,500 kilograms in its cart as calculated by @Itmauve.**
1. <https://chimacumtack.com/blog/2019/05/14/tuesday-tip-two-wheeled-cart-balance/>
2. <https://www.ponyandcarriage.co.uk/horse-and-carriage-sizing-guide.htm>
3. <https://www.dimensions.com/element/triceratops>
4. <https://www.core77.com/posts/47205/Wheels-That-Permit-360-Degree-Movement%E2%80%94Without-Turning>
]
|
[Question]
[
In my narrative I have these aliens that don't experience time, they don't remember and don't predict events, which makes them completely reactionary. This is supposed to make them alien and difficult to understand. They are in a sense a physical metaphor that not everyone experiences the world in the same way. However the challenge I face when creating these aliens is how it would affect other aspects of their lives. They are not supposed to be a civilization but rather a native species of life-forms. They are not human-like either but since they are carbon based they have the same needs.
**So the question is: how does no perception of time affect a species?**
My initial assumption is that they respond in programed ways. They only look for food when hungry, they defend themselves automatically, they wonder around when they have energy to spare etc... Not much else comes to mind but do tell me what you think.
[Answer]
I think you have several options for your exceptional Zen creatures.
One is that they are most similar to terrestrial vegetables or bacteria - which can only mechanically react to their environment. They are restricted to this because they have no memory. They turn towards the light that feeds them — plants — because of evolved mechanical properties that made their ancestors more survivable. Their jaws close and trap food because the presence of something in their mouths — as with a Venus fly trap — triggers a chemical release that circulates through their bodies systems, causing ‘muscles’ to contract.
Or your creatures are like jellyfish, flowing with the breeze or current, with filter feeder tentacles swanning about snaring the nutrients that they require.
Or, your creatures have a central nervous system that collates sensory stimulus from its perception components, into a motor neuron impulses triggering muscles and contract and relax. Its a lot like having a doctor tap your patella and seeing your leg kick. No learning, not sense of time, involved, just reaction. Similarly, scalding heat will cause the muscles to pull back — the pain sensors send a powerful signal and the spinal cord tells the arm to move as its transmits the pain towards the brain.
Without an awareness of time, your creatures exist in a perpetual now, and have no capacity to compare one experience to any other experience. Without memory, they can’t learn. 100% of their actions would need to be either random events or knee jerk responses.
Its difficult to conceive how any creatures besides bacteria, vegetables, and jellyfish could survive and reproduce with this kind of constraint. But, they seem to okay, having survived and competed against all kinds of creatures that do have a sense of time integrated into their consciousness and can remember things and, more or less, learn — animals and insects.
[Answer]
## Perhaps they discovered the true nature of time: and exist independantly
All biological process have a 'concept' of time - ie. even a stimulus and response within an individual, or evolution of an organism from one to a more adapted one.
So for your question how indeed could an organism exist truly without a 'concept' of time? We need to look at the underlying physics to see what time is to answer this.
Time is indeed a concept that seems easy to grasp. Past present future. Could one exist without the need for it, or for indeed a [simple classical aspect like causality](https://en.wikipedia.org/wiki/Causality)? How can an organism exist even without perceiving simple cause and effect (without the obvious alternate answer is it does not perceive at all)?
We need to have a look at the Quantum realm - Einstein, Feynman and Wheeler concluded that time at a 'quantum' level (ie. the scale of the very-small) is 'symmetric'. ie. It could flow in both directions. In particular this relates to electrons photons and particles that can interact with a historical particle, or is a 'reversed' particle flowing backwards in time. [Feynman developed the infamous Feynman diagrams](https://en.wikipedia.org/wiki/Feynman_diagram) that demonstrate this concept - the 'time' axis flows both ways, and the diagrams for interactions could be 'rotated' for particles to travel in the 'time' axis, but also in the reverse of this axis. And interestingly, interactions could occur with no time - ie. perpendicular to a time axis meaning it exists both forever and in an instant.
This indicates time is not nearly as easy to comprehend as we used to think it was. Even Special and General Relativity bends our 'concept' of time - ie. time being different for observers travelling relative to each other or being closer to mass - our primitive standard 'concept' of time being simply a consistent past present and future is starting to look shaky indeed. Indeed, photons travel at light speed, and experience truly 'no time'. Even that classical truth is difficult for us to grasp, and it is [demonstrably true](https://phys.org/news/2014-05-does-light-experience-time.html).
So perhaps your aliens are smart, and have researched what time actually is: and they have made true discoveries that do not align with our primitive understanding of what time is, being the consistent march of regular intervals from past to present to future. Perhaps they 'evolved' beyond the limitations of time, and now exist on an axis of quantum existence that is perpendicular to the Feyman 'time' axis, or at least warps or bends it so much it no longer relates to our primitive inexorable march.
But how do they relate to each other? The answer is they already did, and did so in an instant, and will do so again. How do they perceive the world? Again, they already did, are doing it, and will do it forever, in an instant. Time is independent of them, like the humble photon that truly does not experience or perceive time, so do these creatures. They perceive the universe in an instant, and forever, and spatially everywhere.
How do we detect them, and interact with them? The same we catch and detect light, with detectors and materials that absorb them, [collapse their wave function](https://en.wikipedia.org/wiki/Wave_function_collapse), to which we can see evidence of them, in 'our' time.
[Answer]
### A Turbulent World of Chaos
There are many living organisms conceivable without a concept of time. Plants, jellyfish, single-celled organisms...automatic life forms that operate on pure reaction and instinct, with no ability to plan.
The hard part is, these organisms generally cannot learn, and certainly aren't intelligent - which makes them rather boring as an alien race. How could humans relate to or communicate with them?
What we want here is a species that is capable of *complex learning* - at the very least, remembering who its allies and enemies are, and extrapolating from things it is familiar with to things it is unfamiliar with - but cannot *plan*, since planning, by its very nature, implies an understanding of time. What kind of world would learning be useful, but planning would not be?
One possible answer is a world that is so turbulent and chaotic that planning for the future would be completely useless - anything set up in one moment would be gone in the next. Perhaps this species evolved in the upper atmosphere of a gas giant, a world of powerful winds and ceaseless storms. The creature was a predator that would have to learn to either attack or flee from every organism it happened to encounter, but it could not do things like build a home, collect tools, or travel towards a destination, since the landscape was constantly changing none of these things would have any meaning to it.
With thousands of other species also being blown around, it would be very useful to learn patterns. What could be eaten, what was dangerous, what had defenses and how to get around these defenses. It could even learn the concept of alliances - not in the sense of a "long-term partnership", but in the sense of "it is a good thing to remain with a member of this species, because it is a food source or protects from enemies".
Such a creature could understand the idea of "humans are good" or even "this human is good and this one is bad" but would be unable to comprehend "this was bad but now it is good". Its opinion of someone could be sophisticated, but would be completely constant - it would be happy when its friend was present and would forget they existed when they were not.
[Answer]
So basicly you are creating a Turing Mashine-life form. Interesting. I see two chances here:
They might be incomprehencable workers of some kind of meta intelligence that's intelligence is observable to humans (like most ants who are as dumb as it gets but put human architecture, logistics and what not to shame). The individuals neither learn nor plan but a group of them just might. You could even have them communicate with somthing pheromonish that influences their reactions (state of the Turing Mashine). If they don't remember, the air does. This way, through the pheromon mix in the air they can know when the time for a certain activity comes, are able to mate after they solved a difficult problem thus spread favorable genes and so on.
On the other hand when you do not remember things you would want your body to remember them for you, right? They could be highly susceptable to environmental influences and their (physiology and) neural system could slightly change over time. They would form more or less random patterns that lead to reactions to any given situation. Successful or otherwise favorable patterns get reinforced (only minor changes occure) while injuries, hunger, etc. result in considerable, possibly random changes to the patterns. This is basicly the AI-scientist's wet dream. An AI that can be trained on life data while operating on it life. There are some systems that try to achieve this life training but non that would be mighty enought to run an organism. Maybe you can take some basic mashine learning pattern and "what if?" it up to a cool dream. [**Edit:** This kind of learning or at least something similar exists in humans. Amnesiacs that are unable to gain any new memories are proven to be able to learn new skills even thought they don't know they ever trained them. "Have you ever seen this maze?" "No" "Than how do you explain that you just solved it with zero mistakes? By the way, your first try last weak took four times as long."]
The first model aims for a unrelatable dumb individual, that reacts to basic impulses. They might form insect-like states that outsmart even mankind or just chill out in their cave/swamp/desert/primeval forst like any other animal does. In any way, tickeling the right nerves will make them behave in a certain way though it might be a too complex system to study so one can't trigger reactions on purpose but ony mess with them in extreme and unpredictable ways.
The second idea could produce an surprising intelligent life form that might even be able to learn language or anything else that can be achieved by classical conditioning and a healthy rapid mutation here and there. Yes, not being able to remember anything might result in a strong tendency towards clasical conditioning. These individuals might behave similar to calamary. When hold captive, they prove to be smart and quick to learn but hard to communicate with and easily bored. Unlike with dogs, horses and so on, we don't chare a natural environment with them, we don't know how their mind (or even body) works and we can train them if they want but it won't work like with our usual pets. [**Edit**: In case you wander how mastering a language is possible without memory: In language theory there are several types of languages with more or less strict formal requirements. These languages need no memory to process but the state of the "automate". Unfortunately natural languages here on earth don't follow these formal requirements. Their language must be strictly structured and when teaching them human languages one should reduce complexity at least by allways using the same word order. Turing Mashines are able to process every (even natural) language but it would be super inconvenient and takes (at least potentially literally) forever.]
[Answer]
Given the universe as we are able to perceive it, I postulate that it is impossible to develop sapience without first understanding causality (that is, understanding that certain things cause other things to happen). And time is irrevocably correlated with causality. Could there be organisms that exist without a perception of time? Sure, as others mentioned, some of them already exist here on earth. However these creatures cannot be described as "sapient" - at best, they operate at a level of strict biological programming, following instructions hardcoded into their DNA. Such creatures would be impossible to meaningfully interact with (at a level that we consider meaningful, at least).
This gives you the answer you're looking for. Biological evolution would give you a concept of time before (or at best, simultaneously) with sapience. *Artificial* evolution wouldn't. What you need for your story is a race of cyborgs, machines whose sapience is hardcoded into them. These beings do not need to understand causality or time because they do not possess true sapience - yet it is possible to have meaningful interactions with them, limited only by the robustness of their code.
Now, if you want to ask why would someone create artificial intelligence without giving it a concept of causality and time - both core concepts for a being, biological or otherwise, to achieve continuity of existence - then that's a different question. Thought experiment, perhaps? Maybe they had the same questions as you, wanted to experiment with it, and the idea worked great?
]
|
[Question]
[
In the world my friend and I are making, the dark lord makes one of the planets uninhabitable by causing a moon, about the size of our own, to fall on it. About 7000 years later, it is unnaturally cooled down via deus-ex-machina. What would be the impacts of this event on the planet itself? The planet is about the size of Earth.
I am asking what effects the impact would have on the natural terrain of an Earth-like planet and how that would look when the land in and outside of the crater is cooled down and oceans re-form 7000 years later, unnaturally. Note: I am asking about how it affects the planet, I would understand it more easily by considering how the planet would look because of the moon-fall after 7000 years when the oceans re-form. Don't worry about how the oceans re-form, its deus-ex-machina and that part doesn't matter. I am asking specifically about the terrain and what it looks like.
Edit:
I recently found a similar question [here](https://worldbuilding.stackexchange.com/questions/148000/how-could-a-very-strong-impact-on-a-planet-create-deformations-on-the-opposite-s?rq=1), but just like the question that this question I found references, it's answers don't help me and aren't specifically the same question since we are really focusing on opposite sides of the planet. He is focusing on the area opposite the area of impact, and on a much larger time-scale, while I am focusing *on* the area of impact.
Edit:
I just decided that my world is in the process of becoming a Q-ball world before the moon-fall. Ie. it is tectonically inactive, though it hasn't entirely lost its magnetic field, erosion hasn't washed away it's mountains yet either. I don't know how this will work, but I am wanting to make it really cold deep-down before the moon-fall (though there is an iron core and it does hold a relatively high density). I don't know if this detail matters.
[Answer]
What you are asking is basically the [giant impact hypothesis](https://en.wikipedia.org/wiki/Giant-impact_hypothesis):
>
> The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact suggests that the Moon formed out of the debris left over from a collision between Earth and an astronomical body the size of Mars, approximately 4.5 billion years ago, in the Hadean eon; about 20 to 100 million years after the Solar System coalesced.
>
>
>
As a consequence of the impact the whole planet would be turned into a molten body of rock, orbited by debris. Being basically a liquid it won't retain any shape present prior the impact.
Upon cooling down you would find no visible traces of the old planet.
[Answer]
Depends on size of impactor and speed of collision. The giant-impact hypothesis has a **Mars sized planet** hitting the proto earth at **high velocity**. The energy was enough to remelt both planets, throwing a good part of Earth and Theia into orbit round molten earth. This debries formed moon.
A smaller impactor would leave a crater, have a look at the moon, particulary either Mare Oriental, or Mare Imbrium for what a large but not quite catastrophic impact looks like.
The base would fill with lava making a plain (fill with water later), surrounded by a ring (or rings) of mountains. Note impact would trigger a cold period (dust in air and forest fires), look at scenarios for killing off the dinosaurs from Chicxulub crater.
If it was an existing moon orbiting planet that was de-orbited, the moon would break apart before reaching surface at the Roche radius, forming a thick ring. You could then have these debris "rain down" on planet say forming a heavily cratered belt around equator of planet. The last step is a bit artificial, because the ring would probably be made up of fairly small bits, and getting the rain requires ongoing de-orbiting, say by gas in ring ... but you have a super-powerful being anyway.
[Answer]
After the impact, the entire planet would be covered by fire and lava. Once it cools down, the surface would be changed dramatically.
There would be a giant crater, about the size of the Indian Ocean would take most of the scene, with **bordering mountains around the crater**. **The wind from the blast wave would create hills, crevices, and mountains around the general area.**
From the ejecta, there would be several small craters all over the planet, along with a satellite ring around the planet.
The mountains likely wouldn't be that big, but they would be significantly taller than their surroundings, and would cause a weather/climate difference,specifically a colder climate, around the crater. They would also be rather tilted, due to the blast that formed them also having blown them sideways.
]
|
[Question]
[
A scientist is resetting the clock on his microwave one day as he considers the hopelessness of keeping the time exactly right. Not for the reasons we worry about like power outages and daylight savings times, but because in the back of his head, he knows that Earth's movements through space are not properly standardized for good time keeping system.
This makes him unreasonably mad, so he decides that the best way to correct for this aberration is to simply alter the spin and orbital period of the earth so that a day is exactly 86400 seconds and a year is exactly 365 days based on caesium frequencies so that he never has to worry about converting units again.
>
> Although the historical definition of the unit (seconds) was based on this
> division of the Earth's rotation cycle, the formal definition in the
> International System of Units (SI) is a much steadier timekeeper: it
> is defined by taking the fixed numerical value of the caesium
> frequency ∆νCs, the unperturbed ground-state hyperfine transition
> frequency of the caesium 133 atom, to be 9192631770 when expressed in
> the unit Hz, which is equal to s−1.[1](https://en.wikipedia.org/wiki/Double-precision_floating-point_format)[2] Because the Earth's rotation
> varies and is also slowing ever so slightly, a leap second is
> periodically added to clock time[nb 1] to keep clocks in sync with
> Earth's rotation. ~ <https://en.wikipedia.org/wiki/Second>
>
>
>
So, our mad scientist devises a two step plan to unify metric and traditional time once and for all! The first stage it to use a series of powerful explosions to speed up/ slow down the Earth's movements to make days and seconds the right lengths, the second it to install propulsion systems on the Earth to keep it moving at these speeds indefinitely.
**The Question:** How much force (and in what directions) does the scientist need to exert on the Earth to achieve his goals?
*Bonus points if new seconds actually = scientific seconds when rounded to the level of a [double floating-point number](https://en.wikipedia.org/wiki/Double-precision_floating-point_format), but I would be surprised if anyone could actually find measurements on the Earth accurate enough to do this, so no pressure.*
**Caveats based on Comments:**
>
> How long is indefinitely?
>
>
>
If additional thrust needs to be added over time, the scientist trusts future generations (assuming he hasn't killed everyone) to continue his work. His initial thruster just needs to be strong enough to make sure that he doesn't start seeing desync start creeping back in before his own end-of-life. If thrust needed decreases over time, assume his thruster can throttle down to compensate.
>
> the explosions and "propulsion" would probably devastate the biosphere at worst it might even generate enough energy to melt the crust and boil the oceans to a significant extent.
>
>
>
Devastation does not necessarily need to be addressed for purposes of this question unless it involves there not being an Earth left to have a day/night cycle.
[Answer]
Lets first think about how much energy this needs. You've asked for spurious precision, but I'll save that til the end because no-one wants to see all the tedious decimal places in the workings (and if they do, they can repeat the process themselves).
You want an orbit with a period of precisely 365 days, each 24 hours long. Via Kepler's third law, we can see that this will need to reduce the semimajor axis of Earth's orbit by about 71950km.
At its perihelion of its current orbit, earth has a velocity of about 30.2868km/s. In its new orbit, with the same perihelion (and hence a reduced aphelion) it will have a velocity of more like 30.2797km/s. Given Earth's mass, that will require its kinetic energy be changed by a bit over 9.02 x 1031 joules. I'm not really certain where you'd get this much energy from... it is nearly two orders of magnitude more energy than the kinetic energy of Mars if you crashed it into earth at 4km/s (about the speed of the hypothesized [Theia](https://en.wikipedia.org/wiki/Theia_(planet)) impact), and more energy than you'd get from all the solar radiation falling onto Earth in about 16 million (old-style) years. If anyone has any suggestions on where to source 500 billion tonnes of antimatter, that'd be great.
It is also about 2/5ths of Earth's [gravitational binding energy](https://en.wikipedia.org/wiki/Gravitational_binding_energy), meaning that it if it were not released carefully over an extended period of time you'd reduce the planet to a ring of gravel orbitting the sun. Releasing the energy slowly and carefully *enough* will probably take entirely too long for *anyone's* attention span.
(energy change would be ~9.015096928089181 x 1031 joules)
---
So much for the year. What about the day?
The [angular kinetic energy](https://en.wikipedia.org/wiki/Rotational_energy) of the Earth (using the Lambeck 1980 figure for the Earth's moment of inertia about its polar axis from [here](http://scienceworld.wolfram.com/physics/MomentofInertiaEarth.html)) is about 2.136 x 1029J. Speeding up the Earth to give it a nice round 24 hour day requires an angular KE of more like 2.124 x 1029J, giving a required oomph of about 1.165 x 1027J, a much more manageable figure as I'm sure you'll agree. Please use caution releasing this much energy in the atmosphere all at once, because whilst it isn't quite enough to *vapourise* our oceans, it is more than enough to *boil* them, and the clouds of hot steam will spoil the view.
I did have a look at imparting this energy using a train of carefully aimed asteroids, with trajectories in the Earth's equatorial plane, hitting the equator at an optimal 15 degrees angle. Unfortunately the plan started to resemble a re-run of the [Hadean era](https://en.wikipedia.org/wiki/Hadean), and the inefficiencies of using explosions or rocks to change the Earth's rate of rotation resulted in a lot of waste heat and seemed lamentably inefficient. There may or may not be any oceans or atmosphere afterwards, but the clouds of dust and debris and subsequent re-entry probably preclude any appreciation of a day-night cycle for some time (possibly thousands of years).
(energy change would be ~1.1648246454801083x 1027 joules)
---
So much for the day. Can we just deal with the changing day length, if nothing else?
Turns out that no-one can seem to say anything useful about exactly how much deviation you'd need to correct for... the state of [ΔT](https://en.wikipedia.org/wiki/%CE%94T) is woefully confusing. The day length only changes by [milliseconds per century](https://en.wikipedia.org/wiki/Leap_second#Slowing_rotation_of_the_Earth), but the leap seconds keep on coming.
Lets just look at a system that can manage to change earth's day length by a second (because I'm despairing of getting *anything* to work).
This requires adding ~4.96 x 1024 joules of angular kinetic energy. By a happy coincidence, this is a little *under* the total amount of solar energy that strikes the Earth every year (more like 5.5 x 1024 J). Using a rocket to do this needs 1.57 x 1017W of useful thrust. Given efficiency issues, it will not alas be practical to resurface the Earth with solar panels and use the Earth's own oceans as reaction mass, but it is *soooo close*.
I have a final alternative plan for you. A lot of our problems are caused by the moon. It takes ~7.62×1028J to throw that rock into deep space, where it will never offend your eyes or your day length again. Just say the word, and we'll draw up a plan for you...
(rocket thrust power would be ~1.571089676036397 x 1017 watts)
[Answer]
Explosives on the Earth's surface, no matter their power level (short of ejecting significant chunks of the crust) will never change the Earth's rotation rate or orbit. Nor will a reaction drive of any kind -- with the exception that if its exhaust, after exiting the atmosphere, is still above Earth's escape speed, some tiny fraction of its thrust will act to change the Earth's velocity.
Modern times changes in Earth rotation rate have been attributed to changes in the amount of water captured behind dams (hence further from the Earth's centroid than its natural height average), melting of glaciers or ice caps, and (very rarely) land movement due to tectonic events (major eruptions and earthquakes). Your mad scientist need "merely" alter the proportion of water trapped in the polar ice caps relative to the oceans in order to take and maintain very fine control (on the order of microseconds alteration in the day length) of the Earth's rotation.
Now, to change the orbit will require going off Earth. The most likely way to accomplish this (to cut around a quarter day off the period -- ideally without changing the eccentricity or ecliptic plane) would be to attach large mass drivers to a biggish asteroid (Vesta, perhaps), use them to drive it around the Solar System, and then use the asteroid as a gravity tug to subtly change the Earth's orbit.
Whether the mad scientist can gain the required precision in altering either the Earth's rotation or its orbital period is up to him/her -- but with good enough computers and software, and a willingness to spend multiple decades on the project, he can quit having to deal with messy numbers of seconds in a day or year -- at the expense of making every astronomer alive an enemy. If he's careful, he could probably accomplish the whole project without a single (attributable) casualty. If not, he might kill a few million with the mass driver exhaust, and a hard-to-count number due to climate changes produce by or required to manage the ice cap project.
[Answer]
The Earth is rotating too slowly for our scientist's liking, and it's also getting slower all the time due to gravitational tidal drag and other factors. This is currently happening at a rate of about $\mathrm{7.3×10^{−13} day/day}$, which is also the fraction by which the Earth's angular momentum needs to be topped up. Let's specify the propulsion system to be able to compensate for drift up to $\mathrm{10^{−12} day/day}$ for proper redundancy and future-proofing.
The Earth's total rotational angular momentum is
$L = I \omega = \frac{2}{5}MR^2 \times \frac{2\pi}{86400} \approx \mathrm{7.2\times 10^{33}\ kg \ m^2 \ s^{-1}}$
And we need to be able to change this by one part in a trillion. In order to get on to torque we need to decide how long the scientist is willing to wait to apply this correction. Let's say he's moderately impatient and wants it to apply over 1000 seconds, or $\mathrm{10^{−15} day/day/s}$ (yes those units are getting a bit crazy now). We must therefore be able to apply a torque to the Earth of approximately $\mathrm{10^{19} N \ m}$. As noted the best way to do this is actually to move large masses of water closer or further from the Earth's rotation axis, but you've specified explosions, so let's go with that.
We do our explosion on the correct place on the equator and somehow manage to focus it so that all the debris is ejected directly backwards. It's really important that all the debris reaches escape velocity or it doesn't actually contribute a net change to the angular momentum, just sloshes it around in time, so let's say all our debris ends up moving at $\sim \mathrm{10^4\ m \ s^{-1}}$, so from our launch site at $R \approx \mathrm{6.4 \times 10^{6}\ m}$ each kilo of debris contributes $\sim \mathrm{10^{10}\ N \ m}$, meaning we only need to launch $\sim \mathrm{10^{9} kg}$ of material at each correction. Simple, that's just a lump . Handling the collateral damage from that is left as an engineering exercise.
[Answer]
Simply put, sane or not, if he were any scientist worth his salt, he'd understand that he cannot make a day any closer to the 86400 seconds that it currently is defined as.
**How precise can we be?**
The length of the year is ~365.2422ish days. This is the oft-cited duration of a tropical year, the "mean time between between vernal equinoxes", but is in fact arguably wrong (see <https://www.hermetic.ch/cal_stud/cassidy/err_trop.htm> for the drama inherent in this issue). The time to orbit the sun is ~365.2564 days, and now you're already deeply into the weeds and your scientist is going mad asking himself "so what IS a year? What do I want to align TO?"
And you can't get more precise than those four significant figures (well, five if you're optimistic, some use 365.24219, to specify it to the nearest second, but then it depends where you measure from). Any more digits simply aren't meaningful, because it varies by a few fractions of a second each year, due to chaotic atmospheric effects, geological effects (mantle convection, glacial rebound, etc), the rotation of the earth slowing (due to tidal friction, etc), and more.
This is why we occasionally get leap-seconds.
**How much energy do we need?**
The rotational kinetic energy of the planet is around 2.138 \* 10^29 Joules.
To convert 365.2422ish days to to 365.0000 precisely, would require about a 0.066% change to that energy. We need to find 1.4186948 \* 10^26 J, and apply it to slow down the rotation of the planet.
**Can we do it with a gravity tug?**
A gravity tug seems to have the same problem as moving the earth using mass-drivers to eject mass: it requires more energy than we have either on the earth or on the tug.
**Can we do that with a solar sail?**
Sunlight hits every square meter of our planet at ~1000 Joules/second, so mirrors placed around the equator so that there was always a 1m square mirror reflecting the sun on the side seeing the sunrise, you'd get a retardation force of that much. Over a year, that'd be 3.1536 \* 10^10 J per year, which means you'd have it to the right speed in 10^14 years. If you made the mirrors 10km square, or 100,000,000 square m, it would still take a million years. OK, solar sails aren't the answer.
**What about orbital bombardment?**
The problem there is that, sure, it's easy to drop rocks onto the planet. Well, OK, actually it's quite hard, they have this bad habit of falling down but continuously missing, which terrible habit we give the less embarassing name "orbiting". But we need to get it to only-just-fail-to-miss. To collide with the most glancing blow possible, to impart as much of its energy in the direction of rotation and as little as possible downwards towards the crust. It's impossible to do that 100% efficiency, but I'll assume you can get close.
But the problem is that Chicxulub, the dinosaur-killer, imparted only 4.20 \* 10^23 joules. That means you'd need a thousand dinosaur-killers hitting at just the right angle to change the world's spin enough.
Everyone dies! A thousand times over.
]
|
[Question]
[
I have an Earth analog that is nearly completely covered in ice and glaciers. I want to have oases of warmth scattered across the planet. These oases aren't tropical by any means, having just enough heat to support soil temperatures warm enough to allow tree growth. However, geothermal heat often seems dangerous due to poisonous gas releases, sulfur compounds, and other dangers. Are there any other possible ways to warm these oases?
[Answer]
So, first of all, there's no particular reason that geothermal heat has to be dangerous. Scandanavia makes VERY extensive use of it and always has. The use of geothermal heating for exactly the kind of purposes you're describing [goes back to the paleolithic era](https://en.wikipedia.org/wiki/Geothermal_heating#History).
Ultimately, there are only two sources of thermal energy available to a planet. Radiant energy from the sun, and Geothermal energy from the molten core (assuming it has one). An ice planet can only be that way because it's not getting enough radiant energy to keep water liquid at the surface, so I'm really not sure what other alternative you have BESIDES geothermal.
[Answer]
**Telluric iron fires.**
I was thinking about the underground coal fires, which are natural occurrences, can burn a long time, and produce a lot of heat. And also a lot of poison: the landscapes over these fires are spectacularly dead. Plus it has been done.
But what else could be underground, gradually oxidize and give off heat? What about metallic iron? Native non-meteoric iron is super rare. I did not think there was any in the crust until I researched this question.
<https://en.wikipedia.org/wiki/Telluric_iron>
Metallic iron exists. The oxidation of iron is what makes those pocked hand warmers heat up. Your world has underground places where metallic iron has become exposed to air - maybe by the action of glaciers, or some sort of crustal upwelling. Or maybe these are ancient meteorites, not telluric iron. In any case: iron, and oxygen loves it. In your world, underground caves of iron breathe the air and gradually oxidize, exhaling warm and and heating up the crust - without a lot of tar and sulfur as part of the reaction.
I made this up as far as I know. Maybe it happened long ago during the Great Oxidizing. Not currently as far as can tell.
[Answer]
## Use Earth crust and volcanoes as an analog
Just having a hot core would do it. If there is liquid water under the ice (or slush under the ice), convection can occur. That would make areas where the warm, deep water is brought to specific areas under the ice crust. Those would slowly melt the ice in those areas providing a route to the surface.
Also, the pressure of the warm water convection may push the ice crust around. That may form cracks and other weak spots that allow the up welling warm water to push through to the surface.
The hot crust can come from an Earth like core or it can come from tidal stress like happens in several of Jupiter's and Saturn's moons.
[Answer]
Geothermal heat does not have to be dangerous there are many places where springs exist that provide warm water that is not dangerous only a few are in active volcanic zones like Yellowstone.
One example are the hot springs that provide the waters for the Roman Baths in the city of Bath in England.
<https://en.m.wikipedia.org/wiki/Roman_Baths_(Bath)>
Water percolates through limestone aquifers to a depth of upto 4km in the Earths crust and returns to the surface through faults and fissures under pressure. Whilst the water is mineral rich it is safe to drink, I have it does have a slightly strange taste.
Other similar springs exist in many other places England has several Droitwich Spa, Matlock are just two others, Baden Baden in Germany is another famous example.
[Answer]
Option 1: Giant Rings: The planet has huge sunlight blocking rings. Except, at a few specific angles and specific times of day, some spots get direct sunlight, creating warm habitable zones.
Option 2: Global warming: The planet is warming up, over the next 200,000 years the glacier will be gone. But right now, only small patches are visible.
[Answer]
## [Natural Nuclear Reactors](https://en.m.wikipedia.org/wiki/Natural_nuclear_fission_reactor)
While this is certainly a plausable option at least if we tweak some some basic planetary parameters, unless your planet has been terraformed by low tech humans the native flora and fauna will have successfully adepted to the dangers of life near geothermal oasis. Adaption to a radiation and heavy metal poisened environment might be more difficult. Biological radiation resistance can be found in the [Tardigrades have evolved an natural radiation resistance](https://www.newscientist.com/article/2106468-worlds-hardiest-animal-has-evolved-radiation-shield-for-its-dna/) by shielding their cells, having az lot of redundant information and repairing their DNA. Adaption to heavy metal poisened environments might be mor difficult, but as some guy said; life always finds a way.
# Oklo Reactors
In the former colony of France, Gabon in Africa,
[](https://upload.wikimedia.org/wikipedia/commons/9/9c/Location_Gabon_AU_Africa.svg)
uranium deposits with a lower than expected U235 (the fissile isotope which reactors require) fraction where found. This lead to an investigation which discovered that the special geological setup of the region had created a number of natural nuclear reactors.
[](https://upload.wikimedia.org/wikipedia/commons/9/9f/Gabon_Geology_Oklo.svg)
At the time when the reactors where active groundwater filled the uranium ore veins. Since the the fissible U235 made up 3% of the Uranium 1.7 billion years ago when the reactors where active the water acted as a moderator and the setup became critical, i.e. produced energy.
Water was needed as a neutron moderator, because while neutrons are given off by every U235 fission event, they are usually too fast to be absorbed by other U235 nuclei. Only hen they are slow they can be absorbed and cause further fission.
In the Oklo setup ground-water flowed into the vein and was cooked by the heat its fission produced. After 3 hours all the water had been cooked out of the vein, escaped into the rock and possibly to the surface and the cycle started again. Your oases would essentially be the places with the highest uranium concentration on the surface. This would also create the possibility of huge glacier lake caverns where the fission does not produce enough heat to break the ice shild. To be fair this setup could also be found with geothermal vents.
# Setup
[](https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Nucleosynthesis_periodic_table.svg/1024px-Nucleosynthesis_periodic_table.svg.png)
Uranium is generated almost exclusively in neutron star mergers.
[](https://i.ytimg.com/vi/PoqQ_-GkLCQ/maxresdefault.jpg)
Having a few of these occur in the region your solar system formed would be a plsusible statistical fluke. This and having complex life develope faster than on Earth will ensure that there will be enough U235 to keep natural reactors running fpr a long time.
A few things must be considered in this setup. Firstly natural nuclear bombs might be an option in the early history of the planet. I'm not 100 % certain about that, asking a nuclear physicist is the best way to clear this up. Secondly the planet will have a **lot** radiogenic heat, so it might transitioned into a plate tectonic setups from its original lid tectonic setup much later than Earth, which did it about 0.5 byr after its formation. The planet will also jave a very thin crust and a lot of vulcanism due to this. Thirdly the abundance of U235 will not come in isolation, just look at the other elements formed by neutron star mergers. The system and the planet will be incredibly valuble mining worlds.
]
|
[Question]
[
So I was surfing this [website](https://www.writeups.org/) which gives rpg stats for various fictional characters in various media, when I came across this character called ["The Frenchman"](https://www.writeups.org/frenchman-global-frequency-comics-ellis/) who apparently uses biofeedback to boost his performance to superhuman levels. As the site points out:
>
> Biofeedback is using tech to monitor certain biological indicators such as an ECG, then using concentration exercises to change those. It is primarily explored to compensate for damaged biological functions.
>
>
>
Which was interesting to me and made me wonder, what if we implanted the tech used to monitior these biological functions via cybernetic implants?
We already have similiar devices like pacemakers [artificial pancreas](https://www.healthline.com/diabetesmine/artificial-pancreas-what-you-should-know)
Or outright replacing organs like [kidnies](https://www.healthline.com/health-news/implantable-artificial-kidney-moves-closer-to-reality)
How far could we take it? Why type of implants are possible to give us full self'control of our biological functions? Would we be able to perform superhuman feats like the Frenchman?
[Answer]
**No.**
The reason why human athletic levels are where they are have nothing to do with control and everything to do with tolerances. This is actually a similar reason to why being in a car accident or falling off a cliff is so dangerous; the human body is not designed to go at those speeds or 'jump' that high. For one thing, our bones are designed to be strong but still relatively light. They support us perfectly well in running, jumping, dancing, lifting some heavy things, but they can't take stresses that occur at driving speeds or from falling off high buildings or cliffs.
The same is true of your tendons; they are designed to hold your muscles to your skeleton and in normal use are more than up to the task. But, try to lift a car and assuming you get it up, there's a very strong chance that you'll tear a ligament. Athletes are constantly doing this and anterior cruciate ligament (ACL) tears are a common injury that they suffer even now.
Your Frenchmen won't be able to run super long endurance events like 10x marathon distances because this requires extra energy that has to be stored somewhere in the body and released in a constant manner to the active muscles and there's some evidence to say that even regular marathons can be damaging to a body over the long term because of the way the body stores and supplies energy.
Your Frenchmen also won't be able to run sprints in a tenth of the time Usain Bolt can do it because the muscles can only twitch so fast and accelerating that, even if possible, is only likely to tear the aforementioned ligaments; essentially the muscles would tear themselves off the bones.
Your Frenchmen also won't be able to lift cars or jump buildings or the like because the skeleton won't be strong enough to support the weight or take the impact of landing. Alright, that's not strictly true; it may be able to do it for a while but the price you're going to pay is that your body is going to give out a lot earlier than it otherwise would.
Even tradesmen and athletes today, without emulating super powers, suffer from a range of health problems in their later life. Many have worn cartilage, joint (especially knee) issues, arthritis and a stream of other wear to their bodies that limit their ability to perform basic tasks in their later years.
Put simply, your Frenchman still has a standard body that can only be pushed so far in its lifetime, regardless of how much control you may have over it.
[Answer]
I would assume that "superhuman" means "one that cannot be achieved by humans without supply of performance enhancers".
Because that what those implants would be. First remove that such implants would release hormones ON THEIR OWN. But they could stimulate release of such by owners body. Because you can always supply such with a needle and syringe and you don't need to implant anything to do that.
So in terms of power/strength/endurance those implants would work slightly worse than injections BUT much faster. Monitoring of "wearer" body stats would stimulate hormones at best times, giving most efficient training in best window. It could also provide exact feedback to maintain best performance. For example "right now eat exactly 50g of carbs to replenish glycogen in muscles for peak performance for 30 minutes".
No more guessing, trial and error kind of stuff.
But even with those some feats wouldn't be available without proper, long-term training. So if Frenchman muscles don't have the power to rip arm out of the socket it wouldn't be possible with implants. And I'm talking about "maximum power with adrenaline rush".
What does implants could do is stimulate that adrenaline rush on demand. Block "flight" part of "fight or flight", block pain receptors or intercept pain signals but find workaround for disabled parts of body. So to use secondary muscles if primary is damaged. Or to use some muscles exclusively to support broken bones while maintaining highest level of movability.
So in terms of "**how much power/strength**" such implants could provide the answer is "**similar to taking steroids or SARMS (in long-time)**".
In "**how much endurance**" such implants could provide the answer is "**as much needed or until wearer dies**".
You need to remember that pain is a biofeedback. If you ignore it you end up hurting yourself more than it's needed. There are stories about marathoners that had broken all bones in their feet's because they ignored the pain "there is nothing cushioning your feet". There are examples of strongmen ripping their muscles/hamstrings doing lifts they done in safe gym environment. Look at latest Arnold Classic. On 10 contenders 2 of them received injuries. Brian Shawn tried to compete with one but his performance was sub par.
If you consider using implants like pancreas or pacemaker you are considering introduction of outside stimulus. Artificial pancreas is (in very simplified terms) injections of insulin. Something people do manually everyday. Just like everyday they inject themselves with growth hormone. So instead of carrying syringe with hormone you have it sewed in your body.
]
|
[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/143020/edit).
Closed 4 years ago.
[Improve this question](/posts/143020/edit)
The demon king Sparda had an affair with a mortal woman. This union produced a set of twins named Dante and Virgil. However, a peculiarity occurred between their forming. The one called Dante was born a half-demon, with access to demonic powers from his father. These include, among other things, super strength, speed, and immortality. The other, Virgil, was born completely human, with no trace of demonic heritage or abilities.
Identical twins develop from one zygote, which splits to form two embryos. These twins are supposed to have the same genetic origins and therefore the same DNA. How could one twin be born a hybrid with demonic abilities, while the other is born a worthless mortal?
[Answer]
# X-Men solution
Mutations can happen in the embryo after it has split in two.
# Discworld solution
Most beautiful quote from his works:
>
> *"Some genetics are passed on via the soul."*
>
>
> -Sir Terence David John Pratchett
>
>
>
The latter has been used in Shaman King, for example, to justify why the antagonist is a very powerful being while his identical twin is only moderately more powerful than a human.
[Answer]
**Mono-allelic expression**
Your identical twins might have the same DNA, but that doesn't mean they have to use it the same way (assuming that human and demon genetics are close enough, that we can apply 'normal' mechanisms).
Lets postulate that the activation of demonic heritage genes in hybrid species is not 'on' by default, but needs a certain activator (this is important because many species don't cope well with demon traits, who'd have thought ...).
This (potential) activator gene is both present in the human genome and in the demonic genome, however only the demonic version actually activates all other demonic genes - and one of these two is *chosen at random* during zygote maturation.
Such mechanisms exist in nature, the most prominent example being [X-chromosome silencing](https://en.wikipedia.org/wiki/X-inactivation) in female mammals, but it can also happen to [other individual genes](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4037383/) (couldnt find a wiki link here).
[Answer]
Chirality - these are not technically [Identical Twins](https://en.wikipedia.org/wiki/Twin#Monozygotic_(identical)_twins), they are [Mirror Image Twins](https://en.wikipedia.org/wiki/Twin#Mirror_image_twins). However, since people are generally symmetrical, it is hard to tell the difference at first glance. Demonic Heritage boosts this symmetricality to make the host supernaturally [more attractive](https://www.scienceofpeople.com/symmetrical-face), making it even *harder* to differentiate that these are not classical Identical Twins
In real life, this leads to differences like one twin being left-handed and the other right-handed, or their hair naturally parting to different sides (due to the placement and direction of the [crown](https://en.wikipedia.org/wiki/Hair_whorl)).
The demonic powers that Dante develops are somehow dependant on physical structures in his body - when mirrored in Virgil's body, these structures are inert and no abilities are observed.
*"But wait! If they still have the same DNA, and these structures, how can Virgil be completely human?"*, your Devil may cry. The answer is, Demons are metaphysical entities - demonic heritage is not strictly a product of the DNA, but rather of the Soul. They are both just as human, and just as demonic as each other - but it can only be detected in (or passed on by) Dante.
[Answer]
## [Fraternal Twins](https://en.wikipedia.org/wiki/Twin#Dizygotic_(fraternal)_twins)
If you are willing to use *fraternal-twins* instead of *identical-twins*, this difference can explained away very easily. They would be siblings, that didn't inherit the same genes.
>
> Dizygotic (DZ) or fraternal twins ... usually occur when two fertilized
> eggs are implanted in the uterus wall at the same time. When two eggs
> are independently fertilized by two different sperm cells, fraternal
> twins result. … *(they are)* essentially, two ordinary
> siblings who happen to be born at the same time, since they arise from
> two separate eggs fertilized by two separate sperm, just like ordinary
> siblings.
>
>
>
## [Otherwise Epigenetics:](http://footnote.co/epigenetics-reveals-how-environment-shapes-gene-expression/)
[If they have to be identical, then you will need epigenetics to explain the difference.](https://www.whatisepigenetics.com/fundamentals/) [Epigenetics](https://en.wikipedia.org/wiki/Epigenetics) basically explains that what happens to us in our life, can affect the way our bodies choose to express our genes. For example if you are susceptible to certain diseases like psoriasis, if you have a stressful childhood you may develop the disease, but if you have a stress free childhood you may never develop it (even if your later adult life is stressful).
[In a famous dutch example, mothers who experienced starvation during pregnancy, caused changes in the gene expression of their children.](https://www.nytimes.com/2018/01/31/science/dutch-famine-genes.html) These temporary changes to gene expression have been noted to even [last several generations](https://www.sciencealert.com/scientists-observe-epigenetic-memories-passed-down-for-14-generations-most-animal) in some cases.
[So differences in the situation both these children were raised in can affect their gene expression as adults.](http://footnote.co/epigenetics-reveals-how-environment-shapes-gene-expression/) Assuming that the demon power gene is some aspect of the twin's body that can be activated by certain conditions during their youth (and only then), you can have one twin that has demon powers and one that doesn't.
[Answer]
Identical twins are not identical. They will ALWAYS have slight differences and these differences are usually caused by variances in the physical environment. For instance, one twin gets sick while young and the other does not. If something like this were to happen during a critical stage of their development say, during the limited time when demonic powers develop, then it's feasible that one twin could have demonic powers while the other does not.
[Answer]
# Demons are not animals, they don't have DNA.
The heritability of demonic attributes is not governed by their genetic code. It's something else. You make up what the something else is, or just don't explain it at all. They're demons, there has not been a serious scientific inquiry into their procreation, let alone a hybrid demon-human, which shouldn't be possible anyway.
# They procreate magically using their demonic powers
So the demon king procreated with the human using his demon powers to make such a union capable of producing a child, and imbued his spawn with powers, but after that, the zygote split, but there was only a single imbuement of power, so one got it and the other didn't.
[Answer]
**Twin to twin transfusion syndrome**
[](https://i.stack.imgur.com/yFspl.png)
When you share a placenta, it is possible for the blood supply in utero to favor one twin over the other. One winds up huge and red, the other pale and stunted.
<https://en.wikipedia.org/wiki/Twin-to-twin_transfusion_syndrome>
>
> As a result of sharing a single placenta, the blood supplies of
> monochorionic twin fetuses can become connected, so that they share
> blood circulation... This state of transfusion causes the donor twin
> to have decreased blood volume, retarding the donor's development and
> growth, and also decreased urinary output, leading to a lower than
> normal level of amniotic fluid (becoming oligohydramnios). The blood
> volume of the recipient twin is increased, which can strain the
> fetus's heart and eventually lead to heart failure, and also higher
> than normal urinary output, which can lead to excess amniotic fluid
> (becoming polyhydramnios).
>
>
>
They are identical. Your demon twin gets the lions share of in utero resources. The human one gets much less But hopefully over the course of the story it will become evident that the human twin is not entirely normal either.
]
|
[Question]
[
Heyo. Well this is my very first question here so it might be a bit, I guess crude/blunt or unpolished. Anyways!
This is for a world I've been building set in the nearish future (around 200-300 years) in the Solar System, called Warlords. So the belt in this universe is populated by three main groups of people:
Corporations: Usually Terran or Martian based who make money in one of two ways: mining like everyone else. Or controlling the space stations (ex: renting out property to businesses, selling fuel, and tariffs on shipping goods to the other colonies)
Clans: The Clans are large groups of mining families that have banded together into a couple of fleets for mutual protection. They are usually only considered a proper 'Clan' if they are able to demand tribute or 'bump' (knocking another ship off of an asteroid) smaller families.
Free Miners: This one is pretty vague. Free miners can be anything from small families with a few ships, a one ship operation, or migrant workers that go the stations to be hired out by guilds or larger clans.
Now the Hegemony (government that controls the inner planets) is the official ruler of the belt, but lacks direct control for the majority of the belt only controlling major population centers(Ceres, Vesta, etc are under their control). The Hegemony has also set prices and regulations on certain materials and businesses (ex: fuel, rations, and water) to prevent economic abuse by the clans or companies and to minimize conflict in the belt. Finally the Fleet patrols the belt dealing with piracy and other threats, but the patrols are spaced out and rare.
To actually control the stations not under their direct control the Hegemony uses their fleet and economics. They threaten stations that don't comply to their standards with occupation (which means less profits). They also make special deals with corporations and clans that cooperate giving them under the table financing inexchange for the groups helping to maintain order in the belt.
Would a system built around those three groups and the government work/does it make practical sense?
note: (been edited so some of the comments below may look out of place or look like I repeated something already said)
[Answer]
## Summary: Yes
* Space is a big place. Really big. The Hegemony may well control just enough activity in the Belt to be an important player, but probably lack sufficient boots on the ground to make themselves an effective imperial force in the region. The Hegemony may "object" all it wants to powerful Clans bumping off smaller outfits, but really, law enforcement out that far is largely a game of whack-a-mole. The Hegemon is smart enough to realise this and will tolerate a certain amount of Clans throwing their own weight around. Perhaps the principal Clan chiefs even have an Arrangement with the Hegemon? They provide regional "law" enforcement and in exchange enjoy a certain amount of legitimacy of action.
* The tripartite system you've outlined has historical precedent. Back on Old Earth, the Hegemony could be likened to the distant and waning power of the Emperor: a force to be reckoned with, but not of immediate consequence; the Corporations could be likened to smaller regional powers, outposts of the Empire, dangerous to cross directly, but not really powerful enough to enforce their authority everywhere; the Clans could be likened to the various Barbarian kingdoms ever on the periphery of the civilised world, sometimes allied with the Empire, sometimes working for their own ends, sometimes settled, sometimes on the move; the Free Miners could be likened to small unaligned tribes, fleas in the imperial ermine. I see these guys as part-time miners, part-time free-loaders, part-time freelancers and part-time freebooters / pirates.
* The system works simply because the volume of space involved is too large for even a powerful central authority to rein in. There are something like 200 asteroids larger than 60 miles in diameter. If all the resources of every country on Earth could be pooled to build and launch a large mining vessel every year for the next two centuries, we'd be able to set up shop on those largest planetoids. That's a lot of energy & resources that the Hegemony must expend *just to get out there!* There is plenty of opportunity for smaller industrialists to fill in the gaps and thus give rise to the smaller Clan operations. The Hegemony will just about be able to outfit, supply and protect maybe half the stations on those two hundred asteroids. They'll have to, eventually, rely on the services of sub-contracted Clans to protect their other interests.
* The one piece of the puzzle you don't bring in is criminal syndicates. Surely, 300 years from now, there will be some kind of criminal activity out there in the Belt? Possibly controlling one or more Clans and hiring the services of some of the Free Miners?
[Answer]
# Summary: No
* A central government (your Inner Colonies) with enough power to fix prices on fuel and rations must have enough of a presence that it would object to Clans 'bumping' smaller outfits. Either there is law and order or there isn't, it is extremely difficult to have control only in some sectors of the economy.
* Corporations by and large believe that contracts should be fulfilled. Sure, they might try to wiggle out of unprofitable ones, but general lawlessness will hurt their bottom line.
Those two factors will make life hard on your Clans.
* The Asteroid Belt is not territory where one can easily draw boundaries for territories. It is a slightly-more-dense-than-average collection of rocks on different orbits. Two major asteroid settlements may be close to each other today, far apart a decade from now.
* The idea that the owner of an asteroid also owns, say, a sphere around it with 1,000 km radius also gets problematic when two asteroids pass closer than 2,000 km. Who is entering whose 'exclusive' space? What in the improbable case that three claimed asteroids meet?
So the idea that somebody holds a "stretch" of the Belt does not work. Perhaps somebody can own one or more asteroids, but not the volume in between.
[Answer]
**Summery: Plausible enough to work**
Let's see if I understand this:
The organizations with the most power (i.e. money) are the Corporations stationed on Earth and Mars. While they have a lot of influence due to their resources, like everyone else, they lack the manpower to control the asteroid belt in any meaningful way. I'm guessing they can hire private military contractors to perform specific operations, but mostly have to negotiate with the clans to get things done. Still, they would likely be responsible for selling the mined ore outside the belt.
Clans are a combination of mob and union, likely formed in response to the Corporations forcing unfavorable conditions. By unifying, the Clans developed the ability to go on strikes and rally against the Corporations' mercenaries. Of course, not only does the money and power lead to corruption (tributes and extortion), but the Corporations would put a lot of effort to keep the Clans from unifying further. That's why there would be a lot of Clans that hate each others guts.
Free Miners would have it very rough. At best, they would be independent contractors that operate in less profitable zones sense the Clans would call dibs on everything else. In this system I'm describing, Free Miners would be the mom-and-pop grocery stores across the street from Walmart (the Clans).
The Hegemony would likely be underfunded and hated. The Corporations wouldn't want any authority over them and the Clans would see them as just another corporation to deal with. They might have more influence in older/larger territories, but even them they might be just figureheads. I wouldn't count of them to be able to fix prices, so the free market might rein unchecked in the asteroid belt.
Lastly, space is kinda weird for borders. When it comes down to it, territories would be determined by what the organization can control and protect, which would fluctuate a lot. Rather than actual borders, there would be contested/demilitarized zones where two or more Clans both claim as theirs. This would be a lot of fighting goes down and would probably be avoided by travelers whenever possible.
If I am understanding this right, I think the political system makes a good amount of sense (assuming there aren't any technological wildcards I don't know about) and I'd give it a go as is. Oh, but avoid mentioning robots, cause drones are a hell of a lot cheaper and more effective than paying a bunch of human miners.
]
|
[Question]
[
I am working on a sort of alien contact story in a fantasy world, where a society would be completely isolated from the rest of the world and thus develop the idea that there is no outside world as a way of coping with the isolation. And soon this myth gets carried down and is eventually considered to be fact. That is, until a group of humans with more advanced technology makes contact with the isolated ones, and thus the idea of an outside world is reborn, sparking the stories beginning.
But under what conditions would this society need to be under that forces them to resort to this idea? Remeber that humans are a curious species so these conditions, whatever they are, would have to be brutal, but not too brutal as to let the humans live (food, water, shelter, etc). Also remember that this is fantasy medieval, meaning that the isolated people's technology is not equivalent to ours. I would say that their tech would be around what the Roman Empire had at its hight (between 96 and 180 B.C.). Lastly, other humans would have to be able to make contact with these humans too, who have the technology equivalent to that of the American Civil War, from 1861 to 1865.
[Answer]
Obviously you require physical isolation, which is accomplished even in modern times by some tribes in remote jungles.
Typically isolations are accomplished by two elements. The first is physical barriers: Too much water, too much ice, the mountains are too high, the jungle is too thick and they are dozens of miles into it.
An alternative to a physical barrier is a ***cultural*** barrier: Your tech may be fine, but you do not wander far because you have been trained from childhood to know it can be lethal. This works in some extreme northern tribes where being caught alone at night could mean freezing to death. Members travel in groups for self-preservation and "innovation" striking out on one's own into new territory is frowned upon. So nobody gets a rebellious impulse and runs away; there is literally nowhere to run. They are taught and believe that there is nothing but ice outside their society, and that is how the gods intended it.
The second necessity is self-sufficiency: The remote tribes in the jungle can hunt and fish and have all the food they need, they don't wander out into unknown territory because it is dangerous for THEM too. At home they have their trails and shelters, with water and food nearby, and that becomes all there is to see and do in their life.
[Answer]
I agree that a good source of ideas is native peoples. Specifically, look at the Yanomami people of the Amazon. They were completely isolated until the 1940s and their experiences with missionaries, anthropologists, and industrialists have been extensively studied. Most interesting are the personal accounts provided by shaman Davi Kopenawa. (Be wary of Napoleon Chagnon's studies as they're controversial and quite probably corrupted by questionable data and tainted observations.) Two sources:
<http://www.nybooks.com/articles/2014/11/06/davi-kopenawa-voice-shaman/>
<https://sites.duke.edu/amazonindigenousculture/yanomami-and-the-evolution-of-a-culture/>
Consider animism and the connection to the land as major aspects of this developing culture. <https://voices.nationalgeographic.org/2011/04/01/uncontacted-tribes-the-last-free-people-on-earth/>
One thing to keep in mind is the notion you've put forth that your people are "coping" with their isolation. That presupposes they're aware of and missing an outside world. It undermines the very foundation of your idea. Also, presenting the outsiders as "more advanced" negates the value of this "native" culture. I suggest you think of these people as KNOWING they are the only "humans" to exist in their world and consider the considerable merits of their "less advanced" society as you're developing your contact mythology.
[Answer]
Low oxygen levels would do it. One of the explanations for the Permian-Triassic extinction is a severe depletion of oxygen. After the extinction there was a "Coal Gap" where no coal was formed for millions of years, which may be because oxygen levels were too low for forests to burn.
In this scenario, it may be that animals became trapped in valleys, which they couldn't leave because the air wasn't breathable at higher elevations. This would explain the divergence of species at this point, since they were evolving in isolation of one another.
It would take fairly high-tech to be able to leave one valley for another. You'd need oxygen tanks and probably re-breathers at least. People might think "there is no one beyond our valleys because only the valleys have air". And sure enough, people who make it to the valley's edge will note that there are no animals as far as the eye can see.
[Answer]
A world view is a piece of a political view. Liberal humanists and conservative evangelicals have different world views, which comprise the foundation of their political thoughts and also serve to bring individuals in a group holding shared beliefs.
Getting a little more extreme (I want no flame wars here!) there are Flat Earth believers. Theirs is a radical world view to use as an example, and has some similarities with that of your society: in the Flat Earth view there are not other worlds and stars, etc. It is just us and Heaven and Hell. Check out their website. They have internally consistent theories about the edges of the earth, the nonexistence of satellites and so on. Good stuff! Given all this evidence, why would anyone state the earth was round?
<https://flatearthscienceandbible.com/2016/02/10/flat-earth-frequently-asked-questions/>
>
> 8) Q. Why would they lie to us about the shape of the earth?
>
>
> A. The number one reason is a Biblical and gospel related reason. The
> ball earth is the foundation for evolution and the Big Bang, which
> both put God completely out of the picture. If the world is run by the
> Satanic elite (which it is), then their primary goal would be to
> discredit and hide God, making us believe He doesn’t exist. In order
> for evolution to work it needs the Big Bang and the Big Bang needs
> outer space and the vast nothingness and the planets and galaxies and
> the giant sun and hurtling through space. The globe earth is the
> foundation for Atheism, the Big Bang, evolution, the New World Order,
> the alien deception, many false religions, and Satanic control. So if
> Satan hides God through his deceptions then he can convince people
> there is no God. He wants to be God himself. Without the globe earth
> lie, all of Satan’s deception are blown out of the water.
>
>
>
So too your no outside world people. The myth (of no outside world, or yes outside world; your choice) is perpetuated by persons who derive political power through the myth, and keep opposing factions out of power.
[Answer]
Your isolated people need to be in an area that meets most of the following guidelines:
1) It's very hard to get there. High altitude, lots of natural barriers, or some such. If it's an island, It needs to be way off of the shipping lanes and preferably in a place where there are contrary currents that will take others no where.
2) It needs to be a bit beyond just self sufficient. If you live in the perfect place, why go anywhere else? Especially if leaving means your survival is unlikely. You are going to fall off of that cliff, or you will end up in the doldrums off the coast and run out of water. More than adequate resources will suppress, to an extent, the curiosity of the locals. The community needs to be large enough to keep going with a small amount of genetic diversity. If curiosity is the only reason to leave, not many will want to go. The very curious get selected out, because if they leave, they die. Or they never get back, which is the same thing. Think about Bonobos and Chimps. Chimps are in resource poor areas so they roam about and are aggressive. Bonobos are in a resource rich environment, so they just hang out. Otherwise, the two species are extremely similar.
3) They have nothing of value to the Modern Peoples. At least they have nothing that is worth braving whatever barrier surrounds them. Lets face it, most of the exploring in history was a search for resources. It might have been arable land, food, metals, coal, spices, tea.... you get the picture. If there is no real reason to go to that empty area of ocean that has claimed other ships before, they won't go.
That gives you your basic setup. So long as these conditions remain fairly static, The unknown people are going to remain unknown until Outside technology progresses to the point that it can both overcome the barriers AND for it to be cheap enough to attempt the barriers just to satisfy curiosity. Now we can see evidence of super remote amazonian tribes because we have satellites that can take high resolution pictures without it being too expensive in the big scheme of things. I can use google earth to cover a huge amount of the planet without even putting on pants! Now if I put on pants and decide to go there, I can, but it will still be very hard to get there to be face to face with the remote tribe.
This should be sufficient to keep the isolated community isolated until at the very least, powered boats. Maybe even powered flight.
]
|
[Question]
[
Halite, or rock salt, is a rock formed by salt deposited in past and then undergone geological processes.
My question is: provided that enough (how to get that much sugar is not in scope of this question) white sugar is deposited in a suitable location in a earth like environment (enclosed between clay layers so that no water can pour through and dissolve the sugar), is it possible to have it follow a rock salt-like path, leading to the formation of a rock? Or will it simply convert to coal?
[Answer]
# Not very likely, no
The big problem for you is that saccharides are yummy food for everything from fungi, to bacteria, to insects, to animals, to big hairless apes of the species Homo Sapiens. You will need a place that is pretty much **sterile** in order to not have living things eat all of that delicious sugar.
Another big problem is that sugars are water soluble. You would need to have a Dead Sea like situation where sugar water is running into a basin and then evaporating away.
[](https://i.stack.imgur.com/1Vbn5.jpg)
*Sugar flats?*
And then of course you need something that produces all of that sugar in these conditions. Can this be done?
# Well... maybe
You would need...
1. Something that produces sugar. Honey bees would be the obvious choice.
2. A way of moving the honey from the bees' nest
3. A way to sterilize the honey and everything around it
4. A way to let the honey recombine into crystals
So... suppose that on a volcanic island on the equator, lush with many different exotic plants and fruits, there is a cave. In that cave there is this *huge* bee colony.
The cave is not entirely water proof. As the daily tropic rains fall on the island, water does leak in and leech honey away from the colony.
The honey-water drains into cracks and crevices that takes it deeper into the cave. These streams pass over rocks that are heated by volcanic activity. The honey-water is brought next to boiling.
The now [pasteurized](https://en.wikipedia.org/wiki/Pasteurization) honey-water reaches deep recesses of the cave, where it goes no further but instead drips, pools and evaporates due to the heat. The leftover steam vents out upwards, leaving the sugar in huge crystals of [rock candy](https://en.wikipedia.org/wiki/Rock_candy).
So who knows... one day you might find that [Big Rock Candy Mountain](https://www.youtube.com/watch?v=JqowmHgxVJQ). ;)
[Answer]
## Are you looking for these?
[](https://i.stack.imgur.com/5zrJnm.jpg)
It's popular here in Indonesia. We call them "Gula Batu", literally translates to "Rock Sugar". You call them ["Rock Candy"](https://en.wikipedia.org/wiki/Rock_candy).
You can even [make them at home](https://www.thespruce.com/rock-candy-521016). Lucky for you, the process does not require the heat and pressure needed to make diamond from carbon. You just need supersaturated sugar solution and a crystal nucleation (similar to a grain of sand to make pearl) like a grain of sugar.
---
What actually happens **depend on the temperature** of the site. Sugar begins to "melt" at 130-160 degree Celsius. If the melt sugar can be maintained within the temperature range without burning, it will be slowly caramelized at 170 degree Celsius. If the heating stop, the sugar will crystallize into a big chunk of candy. *Not exactly a rock.*
However, if you put the sugar deeper with hotter temperature, the sugar will turn to carbon, which in turn may become coal, or further diamond. [A simple experiment](https://www.education.com/science-fair/article/heating-sugar/) produces carbon residue. In a process called [pyrolysis](https://en.wikipedia.org/wiki/Pyrolysis), the hydrogen and oxygen will degrade and leave the carbon behind.
>
> **Q:** If you put it in a vacuum and heated it very hot (to the point that something would happen), how would some common substances that usually burn react? (wood, cotton, paper, cork)
>
>
> **A:** Well all of those materials are 95+% one compound: cellulose. And they would all oxidize, degrade, and eventually turn into oxygen, carbon dioxide, water, and char (carbonaceous crap, i.e. various unsaturated carbon compounds)
>
>
> Source: [reddit.com/r/askscience](https://www.reddit.com/r/askscience/comments/1muwva/when_subjected_to_heat_why_do_some_objects_melt/)
>
>
>
[Answer]
Sugar (or better sucrose) is an organic compound (a substance that contains carbon -C-) as you can see in its chemical formula:
My best guess is that the same chemical and physical changes that would happen if the material was another "thing" containing carbon (a tree for example) will happen, removing the oxygen and hydrogen, thus leaving a deposit rich in carbon, which in time would transform to coal.
Salt is an inorganic substance (NaCl), so i suppose you can't get the same result with salt and sugar.
[Answer]
Since crystalline sugar is a manmade substance, someone would have to manually deposit the sugar in place, or leave the sugar somewhere, in order for this to even begin to work. Likely what would happen is it would just be spread throughout the mud too sparsely to form a continuous crystal, as it is individual grains, as opposed to salt, which when deposited forms a crust.
]
|
[Question]
[
I am writing a rule system for a homebrew space sci-fi tabletop RPG. As part of this process I also need to come up with gear to give my players.
My setting, with two major exceptions that don't affect melee weaponry, my setting is set in very hard science. I like things like carbon nano-tubes, and megastructures, and fusion that are understood now or theorised now but hard to do. Basically, I don't want anything that requires new science.
Other questions on this site have already dealt with the question of whether or not melee is ever viable and proven that it is in many cases. Just not usually warfare. This will be reflected in the guns being mostly superior but, due to roleplaying situations, sometimes the guns will become less viable or unavailable. Therefore, I need to give players the option of carrying, and being skilled in, melee weapons. (Or martial arts)
How would melee weaponry (like knives, brass knuckles, and shock batons) be improved in the future? And what about defences? Could we see retractable perspex-like shields? A Folded Graphene Katana? Or a shock glove that works at short ranges?
Ideally it would be something already in the works, but any idea that's plausible *enough* is very much appreciated.
[Answer]
I study Historic European Martial Arts and Material Science, so I consider myself smarter than the average bear when it comes to melee weapons and how to improve them. I also authored several bits about medieval warefare in the Universe Factory. [Check out the first one here](https://medium.com/universe-factory/fight-earnestly-ceb0eccc117f)!
**A Side Note:** There is no ideal melee weapon. I dislike it when people think that one weapon or another is best, and the katana is often that weapon. Katanas are not special: they're too stiff, short, and terrible at thrusting compared to many other kinds of swords. What you're using a weapon on is just as important as the weapon (and the techniques used), so I'm not going to talk about individual weapons, but some technologies that can change current melee weapons into super-sweet future melee weapons.
# Improvements To Existing Weapons: Materials and Manufacturing
**[Graphene-Infused Rubber](http://www.businessinsider.com/graphene-unbreakable-rubber-bands-2017-8)**: this should be used in grips and to absorb impacts, like in the handle of a shock baton. The graphene reportedly increases the durability of the rubber. Sneakers that never wear out, armor that will always absorb impacts but still have amazing durability.
**[Functionally Graded Materials](https://en.wikipedia.org/wiki/Functionally_graded_material)**: these are materials that are assembled so that one or more properties change with location. They can be used in blades, for example, to keep a very hard edge but then have the blade not be brittle, so you can use it to block attacks without it shattering. These could be found in a shock baton which is graded like a [mantis shrimp's club](https://youtu.be/LXrxCT0NpHo?t=4m51s) to greatly increase its strength and durability.
**[Memory Metals](https://en.wikipedia.org/wiki/Shape-memory_alloy)**: If you make a blade out of a memory metal, you need to only heat it up to allow it to re-form into it's ideally sharpened state. While this won't give you an edge in combat, it certainly would increase the durability and life of such a blade.
**[Graphene](https://en.wikipedia.org/wiki/Graphene)**: This has an incredible tensile strength. If it's produced in sheets and paired with something to increase its stiffness, it can be made into weapons and armor.
**Highly Ordered Materials**: better manufacturing techniques could let us have better products, like [abalone-inspired armor](https://youtu.be/LXrxCT0NpHo?t=4m51s). Abalone-inspired armor would be amazing against bullet strikes: maybe even rendering low to mid powered guns totally useless! That is, until someone walks up and simply hits in the gaps of the armor.
[Answer]
Attack and defence weapons and armour have been around for all of recorded history, and long into prehistory (the Palaeolithic era gets its name because hominids of various species were making tools out of rocks). You can always postulate that things can become better with improved material science, technology for manufacturing and so on. A Katana was made by folding steel in feudal Japan because the iron ore was of a fairly low quality, today we could make a katana using high quality alloys and computer controlled machines to ensure the temperatures in the forge, the pressure of the hammers etc. were controlled to a high degree of accuracy.
Similarly, armour can be made using various high strength materials, and using modern computer simulations and mapping to make the armour fit and move accurately to each individual person.
But this isn't very futuristic at all, rather updating age old ideas.
Perhaps the most advanced idea for a universal weapon/armour is the idea of "[Utility Fog](https://infogalactic.com/info/Utility_fog)"
[](https://i.stack.imgur.com/ykxhg.jpg)
*Individual unit of utility fog*
The person has a cloud of "fog" surrounding them at all times (alternatively, if the local laws and customs discourage this, they could keep the "fog" in a bottle or container on their person). Under normal conditions, the foglets are spaced far enough part they don't impede vision, but when an attack or threat is detected, they can close up to form a shield. If it is an incoming projectile, they may form a sponge like shield, gradually increasing in density and hardness towards the person being protected. This sort of shield also dissipates energy from swords, clubs, ASP batons and other striking or piercing weapons.
Froglets can also spring into action and link together to create a weapon for the person to use. While it is unlikely they could assemble an automatic pistol in a reasonable amount of time, they could create a single shot Derringer type pistol. or the obligatory sword, knife or other hand weapon.
[](https://i.stack.imgur.com/FAk1U.jpg)
*A 4 shot derringer. It is the future, after all*
The other advantage of a cloud of utility fog is it provides early warning, and can also be used to provide first aid, build a radio or antenna to help signalling people and even join cooperatively with your friends and allies "fog" to make larger zones of protection and weapons.
YMMV
[Answer]
For weapons relying on cutting, you may want to have swarms of nanobots crawling their surface and taking care of the edge of the blade being constantly sharp, something like osteoblasts and osteoclasts do with our bones.
After each fight you wouldn't have to worry about sharpening the blade, it would be taken care by itself.
The same nanobots could also take care of the geometry of the blade, i.e. a non lethal configuration with flat edge (for stunning only, not for cutting) to be used in certain situation and a lethal configuration when needed.
[Answer]
Hmm ... can we expect people to be largely unarmored? I'm getting a visual of desperate brawls in back alleys; starveling cast-offs of the magical technic civilization fighting savagely with whatever tech scraps they can find.
If so, how about sonic weapons [1]? There are weapons which can hurt, can kill, or can incapacitate. Just make sure all *your* guys are over here, and all *their* guys are over there.
You might have some kind of nanowire ... can cut through anything. If you can put handles on it (heh) you have one heck of a garotte. If it's cheap enough, string it up at calf level as a trap.
You might imagine that there is some kind of handheld device which can alter mental states by induction on nerves. Originally intended for medicine, it quickly became used for vice, and then murder. Only defense is to more or less have a wire-mesh faraday cage around your head.
In this no-armor scenario, I think you'll find that the old fashioned stuff works pretty well, too. A good uppercut can still knock a guy out. A knife will still cut (okay, you can have it be a reciprocating blade ;D). Heck, a baseball bat to the head will still get 'er done. I think martial arts will be viable on these streets.
Imagine that the odd piece of technology is a game-changer on the streets -- for as long as its charge lasts. A gangster might fuel his entire rise to power off a stolen police body armor vest. A madam might protect her House because everyone knows she has a laser pistol, and nobody's *quite* sure how many charges.
So your RPG heroes might be expected -- if they're fighting on the Law's side -- to be better equipped than their foes, and can afford better training, but will always be outnumbered.
[1] Ref: <https://en.wikipedia.org/wiki/Sonic_weapon>
]
|
[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 6 years ago.
[Improve this question](/posts/78723/edit)
My first thought when I read [How can I hide my island?](https://worldbuilding.stackexchange.com/questions/78611/how-can-i-hide-my-island) was that if the villain is being tracked by satellite imagery, they should just go to the island via submarine. But then I realized I don't actually know how easy it is to hide using a submarine.
So, **how hard would it be to track someone who is trying to disappear using their own submarine?**
I can think of two technologies for tracking off the top of my head (as well as questions about their limitations):
1. Satellites. How deep would they have to go before satellite imagery wouldn't show their submarine? Are there different kinds of satellites that might force them to go deeper in order to remain undetectable? How far would they have to travel at depth in order for your satellites to have very little chance of being able to find them again?
2. Sonar. Is there a maximum range for sonar? Are there any submarine-tracking systems in existence, such as an array of sonar detectors spread out over a large area? If none exist, how expensive/difficult would it be to set one up?
What other technologies are there that could be used to track a submarine? What limitations do they have?
I would appreciate hard-science where possible (such as how deep to avoid satellite imagery). I don't expect classified-info levels of accuracy, but we should be able to narrow it down with non-classified info. For example, light doesn't reach to the midnight zone (1000m deep), so if the sub could travel there it obviously wouldn't show up on a satellite image. I'm sure we can do better than that number, though.
Near-future tech is also okay as long as you are clear that it doesn't exist quite yet.
[Answer]
# Magnetic Anomaly Detectors
[](https://i.stack.imgur.com/CP2e4.jpg)
[MAD](https://en.wikipedia.org/wiki/Magnetic_anomaly_detector) devices detect the interaction of a moving submarine's hull with the Earth's magnetic field. As such, they can be used to track a submarine underwater as long as it stays on the move and doesn't go too deep (although MAD works pretty deep, deeper than sonobuoys I can tell you from experience, though specifics are obviously classified). A regular diesel submarine would probably not have the diving capability to avoid the P-3's, so the only way your villain gets away is if he has hijacked a US or Russian nuclear sub (possibly a Chinese one; I don't really know how good those are).
MAD booms can be mounted on patrol aircraft with very long times in the air, such as a [P-3](https://en.wikipedia.org/wiki/Lockheed_P-3_Orion) that can do an 8 hour patrol easily. A pair of P-3's and bases to refuel at, and you could track a submarine all the way around the world.
So basically, the US Navy can track him all the way...if they found him in the first place. The thing with MAD is that it is relatively easy to track the movement of someone you know is there, it is relatively hard to find someone just by running the plane back and forth across the ocean. If the goal is for the villain to get away, then he just needs to escape notice for a few hours, then he will be as easy to find in the open ocean as a needle in a haystack.
Regarding satellites, a satellite will never find a diesel submarine that is either underwater or snorkeling on diesels. You have no reason to be on the surface if you are trying to hide, so a satellite will not find you,. Regarding sonar, a passive sonar will never find a submarine that is running on electric. Since I assume your submarine has its own sonar, the solution is simple: run snorkeling on diesels when there is no-one else around, and run submerged on battery when there are other ships nearby.
If you did that, the chances of being found are close to nil, and totally random. The ocean is huge, and the chances that an aircraft would randomly fly over head while you were snorkeling *and* spot your snorkel (they are small) is not very big. The chances that a passive sonar having ship will sneak up on you close enough so it get a range on your diesels is also not very big.
Conclusion: it is pretty easy to hide in a submarine, and as long as you don't get tracked right out of the harbor it should be fairly trivial to get to your secret island/[resort](https://worldbuilding.stackexchange.com/questions/78611/how-can-i-hide-my-island/78670#78670) undetected.
[Answer]
* Satellites.
Satellites can detect submarines in various ways. Commonly they are used to detect the *wakes* of moving submarines; going deep will help the submarine avoid this, but in many places of interest the sea is just not that deep. For example, the Taiwan Strait is only 70 meters deep. Water is also pretty transparent; going deep will help here too. There are also rumors of other methods, such as ultra-sensitive gravity gradiometry or magnetometry, but they seem more science-fiction than practical. But then, a lot of military tech seems more science-fiction than practical until it becomes ordinary.
On the other hand, various powers spend a lot of money and effort in detecting submarines from aircraft, which are much closer to the sea than satellites.
* Is there a maximum range for sonar?
Yes. Hard numbers are hard to come by, but [active sonar](https://en.wikipedia.org/wiki/Sonar) is commonly thought to be limited to a few kilometers (say, maybe 6 km or at least on this order of magnitude). Passive sonar performance depends on many many factors, so that sometimes it can detect noisy submarines at hundreds of kilometers (see [SOFAR](https://en.wikipedia.org/wiki/SOFAR_channel) channel), and other times it will miss modern submarines at 5 kilometers. If the passive sonar is aboard a moving submarine or surface ship it may even miss modern submarines at closer range. Modern submarines are very very quiet when they move slowly.
On the other hand, detection techniques are evolving fast. See the article "[Transparent Sea: The Unstealthy Future Of Submarines](http://breakingdefense.com/2015/01/transparent-sea-the-unstealthy-future-of-submarines/) " by Sydney J. Freedberg Jr. at [Breaking Defense](http://breakingdefense.com/) (2015).
* Are there any submarine-tracking systems in existence, such as an array of sonar detectors spread out over a large area?
[SOSUS](https://en.wikipedia.org/wiki/SOSUS) (short for sound surveillance system) is a chain of underwater listening posts located around the world in places such as the Atlantic Ocean near Greenland, Iceland and the United Kingdom—the GIUK gap—and at various locations in the Pacific Ocean. The United States Navy's initial intent for the system was for tracking Soviet submarines, which had to pass through the gap to attack targets further west. It was later supplemented by mobile assets such as the Surveillance Towed Array Sensor System (SURTASS), and became part of the Integrated Undersea Surveillance System (IUSS). (Wikipedia)
Japan has a [similar system](http://www.jstor.org/stable/j.ctt13wwvvt.10?seq=1#page_scan_tab_contents) too.
Hiding a nuclear submarine long-term is obviously easier than hiding a conventional submarine which needs must come to the surface to recharge its batteries. On the other hand, on a shorter term a conventional submarine can hide better than a nuclear submarine because it makes much less noise and it is (or can be) much smaller. If you want to be amazed at the state of the art in conventional subs, look at the German [Type 212](https://en.wikipedia.org/wiki/Type_212_submarine):
>
> In 2013, while on the way to participate in naval exercises in U.S. waters, the German Navy's U-32 established a new record for non-nuclear submarines with 18 days in submerged transit without snorkelling. Also it got through all the defence of a U.S. carrier strike group, unseen, and shot green simulation torpedos at the carrier. (Wikipedia)
>
>
>
[Answer]
The answers by AlexD and kingledion both assume that the submarine is a modern state of the art military boat, but there is much more to it than that.
The Soviet era [Alfa](https://en.m.wikipedia.org/wiki/Alfa-class_submarine) submarine had a Titanium hull, which is non-magnetic and much harder to detect with magnetic anomaly detectors, effectively making them useless. However, as submarines go, while very fast, it was also noisy, which is the last thing a naval submariner wants.
So, if MAD is rendered irrelevant, and since optical observation - either visible or infra-red - by aircraft or satellite is dependent upon the submarine remaining above the [Secchi depth](https://en.wikipedia.org/wiki/Secchi_disk), which [at sea](http://www.dtic.mil/dtic/tr/fulltext/u2/a164420.pdf) is between 1 and 50 metres, most typically around 20m in the deep ocean, but less in more coastal and disturbed areas, any submarine capable of submerging below 50m or whatever the local Secchi depth is can go unseen.
Similarly, water attenuates radar severely at the frequencies typically used for surface search and tracking, making these radar sets useless for underwater search. Low frequency radar *can* penetrate water effectively, but even aboard a ship the antennas required are impractically large.
This leaves only sonar. Water transmits sound extremely well - but *all* sounds, not just those of submarines. There is a constant background noise into which a submarine may vanish if it is quiet enough. Modern submarines detect each other using waterfall displays, where the width of the screen represents the unwrapped 360° space around the sub, and the vertical axis represents time, with the current time at the top. With no contacts, the waterfall display shows random dots, but a noise-emitting contact results in a line, vertical if it is at a constant bearing, otherwise it is slanted from the vertical. The sonar operator can select a contact and use a frequency spectrum analyser to split the sounds emitted by a target into discrete frequencies over time, and finally, the sonar operator can listen to the contact.
Man-made objects such as ships and submarines have distinctive sounds that separate them from geological and biological sounds. Ships and subs usually have propellers, and sonar can - when close enough - detect the individual blades as the screw turns as a kind of beat. The faster the screw is turning, the louder and easier it is to detect, as the blades cause [cavitation](https://en.wikipedia.org/wiki/Cavitation) once the blades are travelling through the water fast enough. A vessel can be tracked by guessing its type from its sound, calculating a blade-rate, guessing (or hearing) the number of blades based upon the probably type of contact - if the propeller is worn or damaged, determining the number of blades can be achieved from observation since each blade takes on a distinct sound of its own - and then guessing (or knowing from prior experience) the speed-per-RPM and calculating the probable speed. From that, and knowing the movement of one's own submarine, a reasonably exact course can be determined for the contact over a period of time, perhaps 15 minutes, since the bearing at each moment will be known, and the probable speed can be used to fit the course with time markers to the observed bearing to the target at those times. By moving the proposed course around until its time markers match with the bearing at those times, the actual course can be determined. Choosing an inappropriate speed can be detected using this method, since it will usually result in the appearance of a curved course, while most ships travel in straight lines for the most part.
So, in a break-away contest, we have the villain's submarine and we can assume the pursuer's. The villain would want as quiet a sub as he could manage - let's hope he hasn't gone with a noisy soviet-era nuclear clunker unless he's spent a fortune refitting it. Nuclear subs are actually noisier - they sound like a kettle on the boil - whereas diesel-electrics are much quieter except when snorting to recharge their batteries. Some modern subs only emit sound below ambient when running silent and at low speed, these would include US missile submarines and some new diesel-electric subs. However, at close range, even emitting below ambient isn't necessarily going to help against a pursuer with experienced sonar men and state-of-the-art sonar transducers - they can see the shadow the fleeing sub makes in the background noise, as well as hear the distinctive mechanical sounds.
However, that isn't all there is to it. A fleeing sub can use decoys to produce the sounds that the pursuer is expecting to hear in a place other than that where the pursued is, or to simply fill the water with bubbles that mask the sounds beyond it. The water temperature typically decreases somewhat as depth increases, but there are also strata of temperatures within the seas, with thinner strata across which temperature changes rapidly, known as [thermoclines](https://en.wikipedia.org/wiki/Thermocline), which - because they refract sound - can be used to hide from an enemy. Some locations have multiple thermoclines, or there may be only one, or none at all in shallower areas. Consider the confusion caused upon the pursued dropping a moving decoy above a thermocline, then ducking beneath that thermocline and changing direction. Some sonar crews may fall for the deception, and continue to report the incorrect course that the decoy is taking rather than reporting that the target has changed depth and released a decoy.
Changing depth has its own acoustic signature - a creak or groan as the pressure upon the hull changes, resulting in it expanding or contracting. Launching a decoy or torpedo may be heard, since these devices are loaded into dry tubes that are then flooded - with a sound like that of a toilet flushing - the tube doors opening, with associated mechanical sounds, and then a shot of high-pressure air to eject the device, again with a distinctive sound, much louder in the case of torpedoes than decoys. Some torpedo-tube launched mobile decoys are "swum" out, being launched without the shot of high-pressure air to keep things quiet.
In detection and evasion exercises between submarines, a sonar telephone is typically used to announce the administrative launch of a torpedo, but it is also known for a torpedo tube to be fired empty, particularly where the participants in the exercise are not all that friendly, to wake up a negligent ally, or to flush out a lurking enemy. The distinctive sounds of a torpedo tube being flooded, opened and fired are much like the sounds of a pistol being cocked are to a land-dweller, or even worse, since they represent not just the weapon being armed but actually fired, and it takes an experienced sonarman to be able to tell the difference between a loaded tube and an empty tube being flooded and fired. Also, since the firing of a tube releases a mass of bubbles, the torpedo engines won't be heard for a second or two, and any decently-trained sonar man will report a torpedo launch on hearing the first sounds without waiting to hear the torpedo, since seconds can make the difference between life and death when attempting to evade a torpedo.
Evading a torpedo is possible by going to maximum speed, releasing a decoy (often static) and then changing direction, hoping that the torpedo sonar will acquire the decoy's bubble cloud rather than the sub while the sub heads in another direction. A counter-attack shot down the line of bearing to an enemy torpedo may be useful to get the attacker to cut the guidance wires to their own torpedo in order to maneuver - an unguided torpedo has to rely upon its own limited brains rather than those of a human crew while its guidance wire is stall attached, and a miss is more likely when unguided, since a crew can both listen through and manually control the torpedo while on the wire.
So, a torpedo launch, whether real or dry, is cause for a submarine to go to full, noisy, power, and it takes experience to know if the launch might be a bluff which can be ignored, or is a potentially deadly attack which must be evaded. An evading submarine can be made to reveal its presence by going to full power, but on the other hand, an evading sub may also launch a live torpedo or dry-fire a tube in order to get their *pursuer* to go to full speed, since at higher speeds, flow noise degrades sonar performance, giving the pursued a chance to vanish into the background noise while the pursuer is running and can't hear.
It is of interest that drug cartels are now building single and multiple-use submersible craft to smuggle drugs. These [narco-subs](https://en.wikipedia.org/wiki/Narco-submarine) are increasing in sophistication, but have also led to laws - in the US at least - outlawing the use of an [unflagged](https://en.wikipedia.org/wiki/Maritime_flag) submarine in international waters, so the OP's villain had better have a pretty good sub, or at least have a registered sub and a good excuse to be using it in the event of capture.
If we're talking about a James-Bond style villain with heaps of ill-gotten gains and global contacts in the right places, his submarine could well be an all-up torpedo-armed sub of a quality equivalent to the best in the world, something that even the US authorities would have difficulty tracking and capturing, or it may be a more improvised affair, a-la the Columbian narco-subs.
So, as I've shown, the "range" of sonar depends upon all sorts of things, and can't really be expressed as a hard number. An advanced submarine evading a poor pursuer may not be detectable at a few hundred metres range, or the other way around, may be detectable a hundred kilometres away. Given technical parity, a realistic detection range might be ten to thirty kilometres, and even that depends upon the skills of the respective crews. Also consider that detection and capture are different things - when we're talking about armed subs, a single torpedo is a game-changer - if our villain launched just one real torpedo, with a decent motor, range and sonar seeker, it would scare the opposition into handling the situation far more conservatively regardless of wether the torpedo did any actual damage, and potentially allow the villain to escape.
On the other side, many first-world nations have emplaced sonar networks. The G-I-UK SOSUS net that runs from Greenland to Iceland to the UK was emplaced to detect soviet submarines, and while effective, was never infallible. Local sea conditions can reduce sonar performance, the sub captain's patience and knowledge could lead him to creeping past the sensor net so slowly that the sub just isn't heard, or the sub captain could use a convenient merchantman as a hat, travelling beneath it in order that the sub's signature be lost amongst the merchantman's noisier signature.
[Answer]
If competent authorities know WHEN and WHERE the villain starts his escape in his submarine, AND has resources in place, then it is extremely difficult to stay hidden, even in a submarine.
1. Passive sonar systems are very good and widely distributed across key parts of the ocean floor, or can be dropped via aircraft. It is highly unlikely that a villain would have access to a super-stealthy submarine, although the new non-nuclear AIP subs from Germany can be extremely stealthy without all the trouble of needing a nuclear reactor.
2. Satellite and airborne systems can track subs via several methods, IF they know where to look. They can detect the phosphorescent wake left by a passing ship through plankton swarms, use blue-green lasers (which can penetrate water) as a LIDAR system, and measure the water displacement of the sub on the surface, even if it is deep. The MAD system is already described here.
3. They can place hunter/killer subs AHEAD of the villain, at places he is likely to cross. The faster he goes, the more noise he makes, the easier it is to detect him if you are already in an intercept position. They could even place nuclear mines in these places, set to depths far below other marine traffic, to deny the villain the ability to escape.
4. Hiding amidst commercial traffic only works if the villain can get into the traffic flow at an unknown time and place. Otherwise the most likely masking vessels (which are usually not very close together out in the open ocean) can be easily tracked and diverted into places where the hiding villain can be easily flushed out and captured/destroyed.
So, in short, a submarine escape is actually rather difficult, if the good guys have resources in place. Obviously escaping from the shores of Africa, far from airbases, ASW forces, and pre-positioned naval assets would be much easier than escaping from a well defended place such as New York City. Much of the stealth value for a sub comes from not knowing when and where they may be, not in the inherent camouflage nature of the vessel itself (although the technological bar to detect a sub is fairly high).
[Answer]
In addition to the perfect answers from [@AlexP](https://worldbuilding.stackexchange.com/a/78727/28789) and [@kingledion](https://worldbuilding.stackexchange.com/a/78757/28789) there are some options to hide the submarine:
1. Go underneath the ship.
* The noise from its engines hide the submarine from any sonars
* Satellites and airplanes can't see the submarine too
* You could do this only for several hours - and it's almost impossible to track your submarine.
2. Use the ship as a base.
* The submarine re-fuels and the crew takes a rest on the ship
* Secret passengers and cargo could travel mostly by ships: submarine->ship->submarine->another ship.
So nobody could track the route and nobody could say `Definetely he went to the secret island`. At most someone could say `we don't know where he is`. At least anybody would think `He's on the sea travel`.
These ways are real and have been used during the Cold War.
---
It's almost impossible to track someone **everywhere** who has proper organisation and enough money. Note that somewhere (like the Panama channel) you can't escape the tracking.
[Answer]
It is the very mission of a boomer to disappear at sea. To some extent they can be trailed when their location is known (for example, when leaving base) but noise in the water can be used to confuse a sub trying to chase them.
If the boomers weren't able to do this we wouldn't consider them a very important aspect of our nuclear deterrence.
Magnetic anomaly detectors have been mentioned in other answers. You have to get close to use them--and they work very poorly against titanium-hulled submarines.
About your best bet is a fleet chasing him with a bunch of helicopters but even that isn't anything like assured if he's got a nuclear sub, especially if he's willing to be obvious about getting away. (For example, jettison a large explosive device, detonate when he's far enough away for safety. Every sonar in the area is temporarily jammed.)
[Answer]
Depending on your flexibility with timeline and such, it is believed that a sufficiently sensitive **neutrino detector** would be able to track the location of any nuclear reactor on earth.
With current tech, this method is not possible since neutrinos are notoriously hard to detect since their interaction with "normal" matter is extremely weak. Experiments have been running for a few years and they've only detected a handful.
This article elaborates and shows what such detector might see:
<https://www.technologyreview.com/s/541146/map-of-the-worlds-neutrinos-exposes-nuclear-activity-wherever-its-happening/>
]
|
[Question]
[
In an Alternate Earth timeline, round about 1200 AD, we have the Great Alchemist and Philosopher Bob. Bob, being from a wealthy family has a handful of older brothers, so he's not likely to be an heir. He was raised with a rather eclectic variety of tutors and he did have an indulgent father, so when he came of age, he was allowed to travel extensively.
Bob is unusually open minded and curious, so during his travels he noticed something. Cultures that were more fastidious about hygiene tended to have people who lived longer (as long as they didn't die violently, or from starvation). He also noticed that places that had lots of fast moving water and few swamps also tended to have more people living to old age. He also found that deep wells in mountainous regions had much better tasting water.
Bob has the gift of original thought and comes to the conclusion that cleanliness is a key to longer life. He gets home and demonstrates to his father that water from a fast moving river tastes better and that a good bath feels good. He also shows his mother that the forest smells better than town, and asks if she would be happier if he could help the town smell better.
Bob embarks on a series of public works, funded by his father and enlisting a great number of craftsmen and nearby alchemists. He wants to:
* **scale up a number of alchemical tools to purify and distill water**
* **build a centrally located system of water storage**
* **find ways to remove waste from the city**
* **improve agricultural output**
Bob also figures that things that keep people healthy will keep livestock healthy. This is in addition to any sort of plant based agricultural improvements.
So I ask you, how far can Bob get in his lifetime (he's about 27 when he gets back from his travels)? Assuming he's going to live the proverbial 4 score and ten years (70) and he will be resetting the city up to and including demolishing areas of the city as he needs to. Only the main castle needs to remain, but with improvements. The city wall needs to be maintained, but can be altered to fit whatever.
The only real limitation is that methodologies be related to making things cleaner (filtration etc.), healthier, and known somewhere in Europe and Asia by around 1200 AD.
Assume Bob's dad is extremely wealthy, so money is no problem. Bob can also enlist at least one master craftsman from just about any discipline. It's a peaceful time in the region. The city itself is landlocked, near a fairly swift but navigable river, and is pretty sizable for anything other than a major port or capital city.
The goal is to get to industrial revolution within 4 generations. Is this enough?
I'll be happy to add details for specificity or to refine restrictions as necessary.
**Quick Edit:** It's understood that Sanitation alone isn't going to turn the trick. I'm looking at the increased lifespan and increased agricultural output being the foundation when combined with the increase in knowledge from multiple disciplines working together.
**Edit 2:** Perhaps this is more about finding underpinnings of technological advancement that are not directly related to massive armed conflict. To work through rough logic: better sanitation means reduced disease. More agriculture output means more base wealth. These both mean longer lifespans. Master craftsmen being encouraged to work together should mean increased and more broadly distributed knowledge and as a side effect, creative thought goes up.
[Answer]
I agree with the other answers that sanitation on its own is not likely to spawn an industrial revolution. *However*, I'll offer the somewhat divisive opinion that it could create an environment that promotes technological development.
A little context:
For most of human history, cities have been a pretty crappy place to live. Even for developed countries like the US, its only been for [the last 100 years or so](https://www.cairn.info/revue-annales-de-demographie-historique-2001-1-page-33.htm) that city mortality rates have not outpaced the rural. There are a number of reasons for this, but one of the big ones is (lack of) sanitation.
This is unfortunate too, because Cities are really good for creative types. It's where they're most likely to find wealthy patrons and investors and being in close proximity to other creative types allows for collaboration. This is the middle ages after all. If you're not within walking distance to someone, the odds of you working together with them are pretty slim. More funding for inventors and more inventors collaborating (or competing) are both pretty big deals.
It is also worth considering the technological advancements that might be made in trying to build a sanitation network in the first place. Even a marginal improvement to building techniques would have a huge impact on a project of this scale. [Most of Chicago was raised on Stilts to build its system](https://en.wikipedia.org/wiki/Raising_of_Chicago). Finding methods to move all that sewage, to dispose of it or to clean it, to say nothing of all the other varied waste? What about water delivery? Trash collection? Soap Production?
Well, there's a lot of room for improvement by entrepreneurial inventors.
Now, to play Devil's Advocate somewhat, I'm not totally confident that this is what would happen. This wealthy, well traveled and presumably well-read man has no doubt heard about miasma theory at some point in his life. Bob's observations do not refute it and he would naturally want to study the theory and look for a solution that improves health as informed by its claims. This is not entirely a bad thing. A robust sewer system would be all but a necessity to ward off miasma. But it does mean that you are not addressing every cause that you need to address for the results we're looking for. Sewage is going to seep into *someone's* water supply and pretty much everyone in the city is downstream from someone.
I suspect that Bob is clever enough to conclude that just become you've covered up a sickening smell does not mean you've fully protected yourself from it, but the theories of his time are ill equipped to deal with transmission vectors other than touch and air. Further compounding issues, just because Bob has had this revelation doesn't mean that the city's inhabitants agree with him. Training and educating the populace is no small feat, as is evidenced by the [preventable health disasters that plague us today](https://en.wikipedia.org/wiki/Measles).
[Answer]
Sanitation won't spark an industrial revolution. It is neither necessary nor sufficient.
A modern understanding of sanitation is unnecessary to start an industrial revolution. Given that the Industrial Revolution was considered to have ended sometime between 1820 and 1840 and the [Broad Street Cholera Outbreak](https://en.wikipedia.org/wiki/1854_Broad_Street_cholera_outbreak) happened 1854 in London we can safely assume that adequate sanitation did not exist throughout the Industrial Revolution.
The capabilities to build a system of piped water and covered sewers existed as far back as [Rome](https://en.wikipedia.org/wiki/Sanitation_in_ancient_Rome). Building the system would promote economic growth and improve the quality of life for the inhabitants of the town but would not lead to any of the innovations iconic to the Industrial Revolution.
[Answer]
When the industrial revolution started, the city habitants were still used to leave their leftovers (feces, urines, organic residuals) pretty much in front of their door, then rain or animals (pigs and crows are good at cleaning from organic wastes) would have done something to get rid of it.
So sanitation is not going to start industrial revolution.
Bob can maybe try to investigate why fields enriched with organic waste, like cow dung, are somehow more fertile and come with a way to boost agricolture production. The increase in population following this can increase the demand for goods and so on and so on...
[Answer]
Sanitation no, the sanitation scheme itself may give you some of the underlying ideas and ideals you need though. This scheme is going to be a huge undertaking, it is going to require a vast supply of components many of which need to match up perfectly. This means that you have to have an industrial scale production of interchangeable parts to make the scheme successful and achievable in Bob's lifetime. It sounds like he's also liberating a labour surplus from the fields by creating a greater calorie surplus which will let him throw a lot of unskilled labour into production tasks. He's doing a lot of what the Industrial Revolution did but not widely enough or to great enough degree to get full industrialisation going, the Romans industrialised a good number of the tasks involved in feeding Rome but they didn't have the non-human, non-animal, powered technologies that it took to get true mass production going in the late 18th early 19th century. The most important factor in the Industrial Revolution is a hotly debated topic but most sources agree that without efficient water power, and increasingly steam power, it would have been impossible to get the work per individual ratios that were necessary.
[Answer]
No, it can't. The two are completely separate things. One, the industrial revolution, was focused on mass production of goods by unskilled laborers, which displaced the previous "cottage industries" and skilled workers who produced the same goods at smaller scales. This really has no direct connection to sanitation.
Furthermore, we have at least one very famous counter-point to this idea - the Roman empire. They had public baths, plumbing, running water and were very hygienic compared to Europeans even a thousand years later. Yet, we know the industrial revolution happened in Europe over a thousand years after the fall of the Roman empire.
]
|
[Question]
[
Various sources consider heat emission and heat management a major issue when it comes to setting up "realistic" space battle scenarios.
I have a few questions in regards to this:
* Heat is a byproduct of creating power via various means. Say my starship is powered by a central reactor, the reactor will transform some kind of fuel/material into energy to power its various systems. And it will likely emit a ton of heat as a byproduct of said process.
Does this mean the reactor heat emission is the primary source of heat, or would, for example, firing a laser gun, also emit a sizeable amount of heat which would have to be take into consideration? Would firing some kind of rail gun or mass driver emit heat, as compared to a laser?
* If I need energy and my reactor emits heat while creating something like electricity, why can't I simply surround my reactor with something like a mantle of solar sails, so I could harness the heat and transform it into power, in effect circumventing ANY heat issues in the process?
I'm thinking what you consider heat management would in this example simply lead to a smaller reactor with less heat and power output, but the heat would be converted into power, setting off the smaller initial reactor size / efficiency.
* Do conventional, chem engines emit heat or is this a moot point since the heat is generated outside of the starship, i.e. at the thrusters, and hence of no issue to the starship?
[Answer]
There are multiple questions in this one question, so I'm tempted to close as "too broad", but I can answer one of your questions, so I'm going to:
>
> If I need energy and my reactor emits heat while creating something
> like electricity, why can't I simply surround my reactor with something
> like a mantle of solar sails, so I could harness the heat and
> transform it into power, in effect circumventing ANY heat issues in
> the process?
>
>
>
Ever heard of a Matrioshka Brain?
<https://en.wikipedia.org/wiki/Matrioshka_brain>
An even deeper description is found as [part of the Orion's Arm archive](http://www.orionsarm.com/eg-article/4a48cf99d24c8). *Warning: I've lost friends in Orion's Arm. You start reading one article, and you just lose yourself for days amid the awesome visions of possible futures. PACK A LUNCH before clicking on that link.*
This is basically a Dyson sphere, then another sphere that lives off the heat output of the inner sphere, then another sphere around that, and so on. There's a lot of material out in the world about ways of harnessing the heat output of one process to fuel the next process that needs energy. **So, at its heart, your proposal is a sound one.**
The problem is that ultimately, at the end of the shells, the last shell has to actually bleed heat off to space or the whole system melts down. So while you can use your reactor for thrust and then use its heat for making tea for the crew (to use an easy example), at some point, you're going to have to seep heat to space.
Note that even the biological processes of your crew are adding heat to the system that will have to be vented. Every active process on your ship adds to the heat. Sure, this pales in comparison to the heat of your engines, but it has to be addressed or your crew will bake.
[Answer]
@SRM addresses the question of reclaiming heat as power. You need a heat differential to do that. Your hot thing gets cooler and the cool thing gets hotter. Space does not count as the cool thing. On a spaceship, you have a limited supply of cool things that you can heat up to generate power.
"Venting heat" as steam involves losing mass to space; @Sherwood Botsford proposes using steam for that. If you have plenty of mass that is fine. If mass is precious, less so. With current tech, mass is expensive because you have to push it up off of Earth first.
If you are not jettisoning hot mass somewhere else your option to ditch heat is radiation. Other methods useful on earth entail transferring heat to handy mass - convection (gas mass) or conduction (nongas mass). Neither is available in space. Satellites have things like increased surface area from which to radiate, and maximize reflectiveness (minimizing heating from incoming radiation).
You have a spaceship. Unless you have a <https://en.wikipedia.org/wiki/Reactionless_drive>
you will need to throw mass of some sort behind you as propellant. Hot things have just as much mass as cold things. Maybe your engine could serve double duty and also serve as a heat exhaust? If you are a lover of steampunk space scifi you could use Sherwood's idea and push your ship along on a plume of superheated steam.
[Answer]
To address your indirect question...
The reason people bring up heat is cuz it accumulates and it's very visible. Heat radiates very slowly away because it needs a medium to disperse through and there isn't much in space. So you end up holding it with little being disapated, however, so long as you are moving you can just dump it out through venting gasses. If you're not moving you just create a gas cloud around you that continues to keep the heat around you.
The other issue is that ideally, if you're in a military craft, you'd like to not give away your position, but due to heat issues you light up like a christmas tree. This is why a lot of sci-fi stories use heat sink to collect all the heat and then just eject it periodically, rather than radiating it or expelling it via gas. Then you can use the Heat sinks as decoys if you really wanted to. Of course the issue with the heat sink method is that it means you keeping all the heat in a given place and causing it to become very hot, which if you're in that place or have electronics that can't stand high heat, you probably don't want to do, but it is a tactic that could be used for short periods of time.
The other answers give you the direct answers... Basically, every process generates heat. Even the coldest functioning process generates heat. Heat is movement. If you're doing something, you're moving. Everything that is doing something is heat. It really is that simple. You can mitigate heat to a certain extent with knowing that. Every little bit helps and so a ship would be designed with as few moving parts as possible. Of course that practical engineering too. Everything that moves has a high chance of failing. In this case you just have an extra-critical reason to do it, due to the heat.
[Answer]
You have two sources of heat:
* The generation of heat to power. The theoretical limit comes from Carnot.
(Temp in -Temp out)/Temp In.
For hydrogen fusion, in theory you can have very high efficiencies due to the initial reaction being millions of degrees.
Postulate superconducting coils for the reactor, and a small fraction of your energy is lost to heat.
* Waste heat from weapons and the activity within the ship
Lasers are notoriously inefficient at present. Something like 10%?
I would suggest using waste heat to boil water, pressurize to super heat temperatures, then vent it to space. It would cool very rapidly, and condense into fog. Water and heat management would be coupled. If you have enough pressureized storage to keep it for a while, then radiate at leasure, you save water.
Note that if a high pressure tank ruptures, it is sudden death for people in the area. Read up about high pressure steam safety.
Another useful tool for moving heat around are heat pipes. Take a tube, pump all the air out of it. Put a wick and suitable liquid in it. This becomes almost a superconductor of heat. The wick moves liquid to both ends of the pipe. The hot end evaporates the liquid, the cold end condenses the liquid. For water it works well from 0C to about 120 C assuming under 60 psi pressure. Propane works well for lower temp ranges. CO2 has a very wide range. The max range for a given liquid I think goes from its freezing point in vacuum to its triple point.
Some variation on a heat pipe can be used to radiate waste heat into space.
Remember that heat runs downhill -- from a higher temp to a lower temp. You can 'pump' it out but this also generates more waste heat. Space ships will have large radiators operating at around room temperature. This will produce large quantities of far infrared radiation. This radiation will be one of the ways to detect the enemy. Shielding this radiation, and beaming it in directions where there are no enemy detectors will be part of the game. Radiation goes up with the 4th power of the temperature. Double the temp, and you need a radiator only 1/16th the size.
You will need at least a conceptual understanding of thermodynamics to pull this off plausibly. (There is reason that engineers refer to ThermoGodDamnics. I suspect this is one reason why most space opera just ignores the problem.)
[Answer]
>
> If I need energy and my reactor emits heat while creating something
> like electricity, why can't I simply surround my reactor with
> something like a mantle of solar sails, so I could harness the heat
> and transform it into power
>
>
>
**It is all about Power Density**
Military ship needs high power density (HUGE!!!). It needs it for:
1. **manuevering** as thrust $F = P/I\_{SP}$ ($P$ is power, $I\_{SP}$ is specific impuls). You want to have very high specific impulse, because that's the only way how to achieve high velocity using limited storage of propelent (see [Rocket Equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation) for details). So yur power requrement is $P = F I\_{SP}$ where both $I\_{SP}$ and $F$ you want to have as high as possible. But if the ship should be maneuverable it should be also very light, because maneuvering is about acceleration $a = F/m = P/(mI\_{SP}) $. So $P/m = aI\_{SP}$ ... and $P/m$ is your power density.
2. **weapons** obviously you want to have as much power for weapons as possible, not only because you want to deposite as much energy to the target with your laser (and ablate its armor), but also you want to reach the far distance target fast with your railgun, which means your projectile must have high muzzle velocity. And muzzle velocity scales $v\_{muzzle} \approx P^3$ (I don't want to derive it here, but believe me). Yet, you still want to keep the weapon light for the same reason as the whole ship should be light - it must be manueverable!
**You can use waste heat as power source for next-process, but ...**
Clearly you can e.g. use waste heat irradiated from engine of [Daedalus Project](https://en.wikipedia.org/wiki/Project_Daedalus) to heat some watter, produce steam, than use turbine to make electricity. It is Molybedenum sphere of 1000m radius 1600K hot, that is a lot of waste heat! (According to [Stefan-Boltzman law](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law) it is 2\*pi\*1000^2 [m^2] \* 1600[K]^4 \* 5.6e-8 ~ 2.3 TW of power (i.e. like 2000 decent nuclear powerplants ) or half of current humanity electricity consumption). =>
I guess you would need some sort of heat engine (biler, turbine etc.) of size of these 2000 nuclear power plants. Perhaps you can miniaturize it a bit (using better materials, like steel instead of concrete), but **still it would be HEAVY**.
**Run, It is a Pyramide scheme ! :-)**
all this only illustrates general picture which is a cascade ([Djoser pyramide](https://en.wikipedia.org/wiki/Pyramid_of_Djoser))
* every step of this cascade (pyramide) is at lower temperature (using waste heat from cooler of previous step)
+ Therefore it needs more heavy machinery and space (e.g. area), because **heat engines operating at lower temperature needs to be bigger for the same power**
**Why it is so?**
One problem is [Carnot efficiency](https://en.wikipedia.org/wiki/Carnot_cycle#The_Carnot_cycle) $\eta = 1-T\_C/T\_H$, so in order to have high efficiency you need high difference between Heater temperature $T\_H$ and cooler temperature $T\_C$. If you have low efficiency you need to both produce and cool lot of heat, but you gain just little work.
More importaint problem is [density of Heat flux](https://en.wikipedia.org/wiki/Heat_flux). Heat flow differently in different environment/setting. But everywhere **heat flows faster at high temperature**. This makes sense, because Heat is transfered by some particles (e.g. moleculers of gas, electrons of metal, or photons from radiator). The higher temperature the more energy there is per particle, and the faster the particles are (=> higher flux or current of particles). It is loosly connected to [3rd law of thermodynamics](https://en.wikipedia.org/wiki/Third_law_of_thermodynamics) but not very clearly, so I guess my explanation whit speed of particles is more clear.
The difference is sometimes HUGE, just consider how much area of radiators you would need to cool your steam powerplant (using waste heat from Daedalus main engine). So you have 40% Carnot efficieny, threfore you gain 0.92 TW of useful work and 1.38 TW of waste heat in form of hot watter (Assume T~100C=400K), so using Stefan-Boltzman law from above you need ~1e+9 m^2 of radiators ( that is **square with side 33 km** ) ! => You can do that, but your space-ship will be significantly heavier.
>
> in effect circumventing ANY heat issues in the process?
>
>
>
You cannot. you always need cooling, because every usefull device on the ship need to do ***work*** and work can be only created at the expense of dissipating some heat (=cooling). This is absolutely general and essential [2nd law of thermodynamics](https://en.wikipedia.org/wiki/Second_law_of_thermodynamics). It has something to do with information (you don't have full information about position and velocity of every particle of photon, so you cannot employ them exactly as you want), seem [Maxwell Daemon](https://en.wikipedia.org/wiki/Maxwell%27s_demon) (but I don't want to go to much into theoretical physics). The best what you can do is expressed by Carnot Cycle and Carnot efficiency mentioned above. You may think this is something specific for steam engine (as I was thinking when I was young), but It is not, Carnot efficiency is absolutely general law for any device which turns heat into work.
]
|
[Question]
[
**This question already has answers here**:
[Order of Solar System Colonization](/questions/56243/order-of-solar-system-colonization)
(2 answers)
Closed 6 years ago.
To live on another planet, we have deal with its environment. Let us assume that terraforming is not a near-time, realistic option, so we have to deal with none-or-thin atmosphere (pressure), with missing oxygen, with too hot or too cold temperature, with low gravity, and even with too long day/night cycles.
To colonize Mars, for example, we would need pressurized (and heated) domes, underground cities, or something like those. To leave those enclosures, we need suits. The low gravity we will not be able to do anything about, so we will have to adapt. On rock/ice balls without any atmosphere (like our or some Jovian moons), the effort will even be higher.
On the other hand, we could instead built space stations. Cylindrical designs with rotation would give us even a possibility to get Earth-like "gravitation". While Mars' thin atmosphere will give some protection against radiation and while Mars' temperatures are not so low/ high as in space, rock/ice planets without atmosphere seem not to have any advantages compared to a space station, except material structure.
So assuming that we can get the needed material into space (for example, by mining asteroids), what colony would be the easiest to begin with? Space stations? Rock/Ice planet without atmosphere (e.g. our moon or Jovian moons)? Or something like Mars?
Edit:
From the comments I take that I have to define what I mean with "easiest".
So assume for this question that we have to establish human colonies for some reasons and we have plenty of time. Transportation may not be a serious issue if the colony can sustain itself after it is established. We will not have artificial gravity nor will we be able to terraform a planet in the time scale.
What I really want to explore is if it makes any sense to colonize other planets, or (with the same technology that would be needed to colonize planets) it would make more sense to build space stations instead. My theory is that if we have the technology to colonize even the promising mars, it would be more feasable with the same technology to build space stations to give new homes to humanity.
Edit 2:
I already accepted an answer. But I also want to explain why I think it's not a duplicate.
The other question asks about a feasible order in which we colonize our solar system. While there is many information there that helps me in my question, the difference is that I am not interested in a step by step plan what is easiest first and then next, but what would be the easiest if we have all the technology for every of the choices and start from the scratch.
So, think we are able to transport materials into orbit quite easily. We are able to do space flight to the other planets. We are able to mine asteroids, built mass drivers etc. Maybe even we have someday artificial gravity. So let us say we made the evolution that is described in the "order" question. Now we discover a stable wormhole that gives us easy access to another solar system, similiar to or own with similiar planets (except an earth).
In this situation and with all the technology at hand able to make a free choice, would it make any sense (other then scientifically) to build colonies on a mars equivalent, or on some moon equivalent or on some other (except earth) equivalent to some body of our system? Or would it make more sense to say "We can build giant space station colonies with paradise like environments as much as we want, and it's much harder to achieve something nearly similiar on any body, so we explore the other system for science reasons but we don't colonize it (except perhaps by building space stations also there)."
Perhaps this in the end explains what I was looking for. The accepted answer seems to indicate my assumption that with any given technology it is easier to go with space stations.
[Answer]
# Stations are better for sure.
## Gravity well
In both cases, to be able to inhabit another planet or to build a space habitat humans have to leave the gravity well of their planet Earth. The challenge is the same in both cases in terms of transporting humans and their initial supplies.
Systems like [SpaceX ITS](https://en.wikipedia.org/wiki/Interplanetary_Transport_System) can be used to solve the problem of exporting humans into space and it can do it for any purpose - a planet, a moon, a space station.
## Building material
A planet may offer some advantages by offering building material for the price of energy of extraction of those materials(and transporting, and processing and ...). A planet as a source of such materials - is a big source of them, but not infinite or super good.
As an example, if we use a layer 1km thick on a planet like Earth for our constructions it will be 486'922'800 cubic km of materials - a number of materials which is equivalent to a dwarf planet with a diameter of 990 km.
But as we can see there would be problems in doing that on a planet if people live close to the surface(or on the surface).
On the Earth, a human can live under a rock and call it home - so we may say on Earth(and only there) a human do not need a lot of materials to build a home.
On a planet like Mars, material demands are higher than on Earth, everything (especially first few thousand years, for those who would like to terraform the planet, until they wait for the results of terraforming) have to be built as an enclosed system, the same way as a space habitat.
### On a planet, materials are laying around...
That is kinda true, but when we take look closer at the problem, as for example Mars, things begins to be not so good, still probably in favor of the Mars, but how much in favor it depends on, and we can't say so about any planet, or even about Mars, just because we do not know yet for sure.
Mars have water on its pole, but the problem is where it have water it means not good solar insolation, the whole Mars have a problem with that, but some places are worse than others. Some suggest solar to be the source of energy for the Mars colony, and for reason of solar to be more efficient, strategically it makes sense to place the colony near the equator. But it may be more efficient to place the colony in the middle, energy station on the equator, make power line from the equator to the station, from the station to the pole etc(because of transportation problems, because of other factors which have to be optimized).
The point is - to be on the planet it does not mean all needed resources are under the feet. Planets are usually relatively big, Mars circumference is about half of the earth (21'280km). Not all resources colonists may need will be in one place and it does not necessary mean only materials, energy, but also seismic stable region as an example, or better landing place or better relief etc, the list goes on. So even a small colony may need relatively long routes of transportation.
Real world example, with good roads a tesla car uses about 500 Wh per km to pull about 1.5-ton trailer(and its weight is about 2.3-tons), it is about 2 times of its typical consumption. Useful payload there is the trailer, so we need to spend 500 Wh on towing 2 tons per 1 km on a relatively good road(Norway). It means 900J to transport 1 kg per 1 km on a road. (On mars it is hard to use fossil cars, for obvious reasons.)
The Moon escape velocity is 2.38 km/s, and it have no atmosphere, so we may have a mass driver launch system there, and to launch 1kg from the Moon with a mass driver we have to spend 2'832'200 J per kg, to Earth orbit or to an orbit around the Sun(!). The energy is equivalent to transport the 1kg over a distance 3146 km. And I would not say that such transportations will be an unreal case for a Mars colony, I think such distances may easy have a place there. (Saw suggestion to use ITS for transporting stuff at the begin of colony building from one place on the planet to another, makes sense actually)
### But on a planet, they do not have to transport all their material
True. To build a space habitat one has to transport all needed materials into the orbit, where the construction will be.
But how much? O'Neill estimation for the first colony are
>
> The nominal values for the first model colony are taken as: construction force, 2000 people; population, 10,000; total mass, 500,000 tons. When the design and cost analysis are done in detail for the entire enterprise, the need to fit a budget may force some reduction in size. The initial estimates have been aimed at holding the cost equal to that of one project we have already carried through: Apollo. The choice of 10,000 as a target population ensures that, even with some reduction, Model 1 will be large enough to obtain economies of scale and to serve as an effective industrial base for the construction of Model 2. A much reduced colonization project would be little more than a renamed space station, perhaps able to maintain itself but incapable of building the larger models that are necessary if the program is ultimately to support itself. It is an essential feature of the colonization project that Earth should no longer have to support it after the first two or three stages.
>
>
>
[O'Neill, G. K: The Colonization of Space, Physics Today, vol. 27, no. 9, Sept. 1974, pp. 32-40.](http://www.nss.org/settlement/physicstoday.htm)
50 tons per human for the construction and I would say it is pretty realistic. It is ISS mass proportion, but as volume grows proportionally to the cube of linear sizes we get more results for a bigger colony than we have with ISS.
For those 50 tons per human you get:
* Earth-like gravity
* radiation protection
* Earth-like climate
* Earth-like ecology (potentially) without the need to wait for the end of terraforming a planet, which may take some time, and have some bad planetary scale consequences.
* Most important, we will get an environment over which we have full control, and that is not possible to achieve at our current level of technologies on the scale of a planet, even with partial-limited terraforming(some kind of big dome) it might be close to what we may have on the space station but not quite the same, not 100%(planet soil, tectonics, winds, dust etc).
* We also get the ability to choose the orbit for the space habitat, where to build it - on an orbit around the moon, on an orbit around the Earth, Lagrange points, an orbit around the sun(closer to the sun, closer to asteroids). We can't do that with the planets. Different places/orbits have different advantages. Closer to Earth, less delay in everything (connectivity, supply, help, human resources, teleoperating, services(buy/sell)). Closer to asteroids - matter in shallow gravity wells. Earth-Sun L1 - plenty of energy 24/7/365, 1360W/m2.
ITS projected to be capable of delivering 450 tons payloads to Mars surface, with the price of 140'000\$ per ton - so even if we do not think to make the building easier by establishing a manufacturing base on the Moon, the project(O'Neill cylinder, 10'000 population, 500'000 tons construction) may cost 70 billion for material delivered by SpaceX ITS.
### A planet is not the Earth
We tend to think that we know how to live on planets because we live on a planet right now. The fact is, a planet it *not* the Earth. Surviving each planet or moon in the solar system needs the same amount of technologies as to get there.
With space habitats, we can't say we did that, especially at such scale, and it is obvious for us we have to reinvent and adapt our technologies for the station, and that is true, but the same thing we have to do with any other planet, and the only planet where we do not need to do the adaptation of technologies is the Planet, the Earth.
Inhabit a planet or build a space habitat, problems are overlapping in 90% cases if not all 100%. And the difference is in result we get after our efforts.
With space habitats, we get highly scalable and tunable system, with a planet we get a very inertial system where is hard to implement things and almost impossible to undone the things, hard to predict the results, etc - all sorts of problems. The inertia of a planet as a system might be a good thing, for sure is so for Earth(because we do not have to change things here, we have to preserve them as it is), but for all other planets it is exact opposite, we have to change them almost in every aspect of their presence(if it possible at all) and only real thing they may offer for our efforts is gravitational mass.
The Mars with a 1 million colony for research of the planet, or even 10 million for the task(or 100 million or whatever number is needed) - not a problem, welcome and get us the science. A second new home for humanity - no, I do not buy that.
## Microgravity and Energy
Microgravity is a big advantage of space, especially near Earth orbit(let's say L1), especially in terms of producing energy and converting it to useful work.
Near Earth, there is a constant flux of 1360 W per square meter of energy, 24/7/365 - no clouds, no wind, no weight, no so much dust, a little bit of meteorites, constant angle of sunlight(if our solar station makes 1 revolution per year), no birds to preserve.
The system like [a real example](http://www.solarreserve.com/en/technology/molten-salt-tower-receiver) of a solar plant which works with molten salt as a heat carrier. Its life cycle intended to be 30 years, and it gets at least 4 times less energy than it would get at near Earth orbit. It is more massive(and it means more energy was spent to build one of such) because it has to be robust to its own weight, winds and all forces which would be applied to it during those 30 years.
It could be replaced by just a top of the tower and energy producing machinery and with aluminum foils floating nearby the system guided by such [ion microthrusters](http://news.mit.edu/2012/microthrusters-could-propel-small-satellites-0817) or another light weight tether-like, umbrella-like construction, which could significantly reduce the time it returns the energy spent on its construction, even with lifting materials from a gravity well.
### Notes
Another reason why people think about planets, they think they will deliver colonists, and after that will be a business as usual, and we do not need rockets anymore. But why not. SpaceX works on reducing the price trough re-usability. But it is not the only way to reduce the price of rockets, cheap energy is also one of the ways to reduce the price of the production, automation of the productions is also one of the ways to reduce the production price. Energy in space is cheaper, resources may be cheaper if we deliver them from the moon, so why not to produce them in orbit. It is not something which is impossible to do (as note - micro-gravity actually will help with precise machining, less distortion of machines, no need to be bulky, less energy to produce such machines, no vibrations from ground) - and if we do their production, why not to continue to use them - build a mass-driver on Ceres and it will supply with water -> LOX-LH2 millions of those rockets - why should we discontinue their use.
Materials. Production of aluminium costs us 54MJ per kg, and launching aluminium ore from Luna costs 8% of the energy we should spend to make actual aluminium from it. So the cost of launching it might be not a major factor in the cost of making something from aluminium, but the cost of the energy where it is processed is the major factor. This molten salt tower, if such will work on mars (it probably will not) it would probably work for 50 years to make some profit, and that do not helps with reducing the cost of converting raw ores into useful materials and production.
[Relative concentration of various elements on the lunar surface](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Composition_of_lunar_soil.svg/500px-Composition_of_lunar_soil.svg.png)
[Answer]
Although the topic is controversial, seemly the easiest off-world base to build and maintain for large amount of humans is a baloon base in Venus.
First, filling it with breathable air will make it float in Venus dense atmosphere.
Second, since it floats, you can make it fly around Venus every 24 hours, keeping our day/night biological expectations met.
Third, Venus gravity is about 0.9g, less than Earth, but not much less, thus probably not ruining the settlers health (settling in gravity-less places is expected to make Earth-born settlers weaker over time, and space-born settlers might end with some weird shape, maybe extremely tall, due to lack of gravity).
Fourth, the atmosphere in Venus, although dangerous (specially its stupid-high pressure and temperature near the ground), isn't THAT dangerous where the colony would float.
The only major challenge that showed up about this plan, is how to handle the sulfuric acid clouds, we would need materials that resist them very well, including for "space-suits", for maintenance colonists that need to step outside, and probably to handle ship docking.
As for resources, it is expected that the colony would use some kind of hook, to grab stuff from the ground in Venus, this is also a big unknown, we never build such thing before, and we don't even know how we would mine in Venus surface in first place, since the mining equipment would be forced to survive some extreme environment.
Thus the ultimate obstacle, might be just the transportation of the materials, since we have no idea how to mine in Venus surface, we will have to ship all the materials to build and maintain the colony from other places in the Solar System, it is an easy feat, but very expensive, like I noted earlier, Venus gravity is 0.9g, meaning space-flight inbound and outbound from Venus isn't much cheaper than on Earth.
[Answer]
The "easiest" space colony to build would be a free space colony much like the ones proposed by the L5 society back in the 1980's, although using much more modernized materials and assumptions.
[](https://i.stack.imgur.com/vngWh.jpg)
*Island 3 structure*
I'm thinking the adjective "easiest" is being applied to the physical structure of the colony itself, as well as making that structure inhabitable for all people. Any colony on a planet or moon needs to be essentially custom built for that particular environment, and there will be a lot of things which your simply cannot change such as local gravity or the day/night cycle.
Free space colonies, on the other hand, can be "factory built" (one can imagine a "Willow Run" like megastructure cranking out habitat modules) since factors like gravity, day/night cycles, amount of insulation or radiator surfaces and so on can be constant. Depending on the distance from the Sun, you will have to adjust things like the external mirrors to provide enough light and solar energy, but even then platoons of external mirrors in co orbit can provide the additional light without changing the "factory standard" mirrors if you desire.
People can move in right away without any sort of adjustment from Earth's gravity or day night cycles, and getting raw materials or exporting finished products can be as easy as installing a mass driver down the central axis or a free flying one nearby, while asteroid mines and robot miners on various moons shoot "cans" of raw materials to the colonies.
The colony could be as simple as creating two huge "plastic" bags (some 22nd century super material) that fit one inside the other then filling the space between them with water to provide radiation shielding and thermal buffering, not to mention allowing light into the structure (about 5m of water would be needed for radiation shielding, according to [Marshal Savage](http://rads.stackoverflow.com/amzn/click/0316771635). As a bonus, you could actually grow algae in the water as part of your food and air recycling systems. If you are not keen on using water, then 5m of regolith distributed in the space between the bags will also do.
Factory built free space colonies will be by far the easiest way to colonize space.
[Answer]
# The problem with planets is gravity
A fundamental problem with a long-term colony on a planet or moon's surface is the unknown effects of long-term low gravity conditions on humans. Astronauts, who are generally in good physical condition, suffer a [variety](https://en.wikipedia.org/wiki/Weightlessness#Human_health_effects) of negative effects from prolonged weightlessness. Attempting to live and entire life in such conditions could result in even worse health problems. We just don't know how much gravity is enough. Is Mars' 38% surface gravity enough? What about the ~15% on Luna, Titan, and the Jovian moons? We don't know.
# The problem with space is radiation
The long term effects of radiation in space are also poorly understood. No one on earth is subjected long-term to the amount of radiation that someone outside of a magnetosphere will endure. Apollo astronauts did get short term exposure on their trips to the moon, but again, they were in good health and their exposure was brief on a scale of lifetimes. In particular, the effects of low level lifetime radiation exposure on human reproduction are completely unknown.
There are very few radiation safe zones. The Earth and Saturn's magnetospheres are safe zones, Jupiter is not since it produces its own, much higher, radiation levels. Venus' atmosphere is thick enough to provide protection, as is Titan's (Titan may or may not be within Saturn's magnetosphere at any given time, depending on orientation with the sun). Under the ice sheet on Europa or Ganymede would be safe, as would places far from the sun.
# What is best?
The answer depends on the gravity and radiation problems, and if either one is limiting to long term human life. If neither gravity or radiation turns out to not be a big deal, then the best option would be the surface of Mars, which has lots of valuable space and minerals for growing food. If radiation is a concern, but gravity isn't, then the surfaces of well protected moons might be good, like Callisto, Europa or Titan. If gravity is a concern, but radiation isn't, then space habitats that simulate near 1g would be best. Finally, if both gravity and radiation are limiting, then the best options are space habitats within Earth's or Saturn's magnetosphere, or a cloud colony on Venus.
[Answer]
On the surface is much easier because you have a supply of resources, whereas, if you colonize in space, you can only have the materials that you put in space (or maybe mine from an asteroid, but such asteroids are not found in likely locations to build a space station).
Also, planets with an atmosphere would be easier to colonize than planets without an atmosphere. There are plans to [colonize Venus's upper atmosphere](https://en.wikipedia.org/wiki/Colonization_of_Venus), which can be done because the air that we breathe provides lift on Venus (like Helium here on Earth) and Mars which, while it lacks that benefit due to its thin atmosphere, its atmosphere is enough to aid in slowing down from orbit. And both of these have the same benefits as colonies on atmosphere-less objects.
]
|
[Question]
[
**Proposal:** a world where people have a form of telepathy that enables them to see what is seen by anyone else.
In this world, people would have difficulty hiding any complex task from other persons. For example, Person A can see what Person B uses for the combination of a lock unless Person B closes their eyes while opening the lock. Person A could see when Person B hides a key under the doormat, etc.
Basically this telepathy allows spying on someone through their own eyes.
In this world...
1. ... what would people not bother hiding?
2. ... what would people still try to hide?
3. ... and what actions could they take when they wanted to hide something?
[Answer]
In this world you propose, privacy of any sort more or less goes out of the window. But people would grow up with it and so it wouldn't really be noticeable to them. Tinted windows would never get invented, nobody bothered developing encryption for personal use, James Bond is out of a job, etc. So, with that in mind:
**1. What would people *not* hide:**
Most things, really. As stated above, growing up without any real privacy would make people pretty open about everything.
**2. What *would* people hide:**
Anything illegal, obviously. State secrets and sensitive weapons. All the things with an obviously massive negative impact if revealed to the wrong people.
**3. But, how would they do it?**
For criminals, simply not looking at stuff is really their only choice. Serious career criminals may take the time to learn to read braille. Taking someone somewhere? A blindfold won't do it, you'll have to use chloroform so they can't see through your eyes either. Making drugs? You'll have to have all your equipment assembled separately by separate, unrelated people in "black box" style units so you can't see what's in them. Counting money? Hire blind money counters, or blindfold the seeing ones.
For states, it's much more complicated. How can professor N assemble super top secret weapon X without anyone seeing? How did he develop it in the first place? They would probably spend a lot of money on trying to build a telepath immune workspace. Would a Faraday cage work? What about heavy water? Can we signal jam this stuff? Failing all of that, they'd probably spend all their time developing highly functional automated robots to do everything, then have Prof. N pass on instructions via a braille computer, with no visual feedback. Make every visible user interface visually confusing to someone who doesn't understand it, random numbers with seemingly no place unless you know where they go.
And everyone everywhere would presumably have a strong culture of doing anything by speech instead of visually.
[Answer]
## Who would hide things
Everyone who already tries to hide things.
## How would they do it
By not looking at what they are doing and relying on their other senses. If you are going to try to hide your key under your doormat, then pick up your key without looking at it, close your eyes and go place it under your mat, then go back inside and open your yes again--no one will know where you put it.
[Human echolocation](https://en.wikipedia.org/wiki/Human_echolocation) and other non-sight-savants might become more common amongst those who make their living via hiding.
## Augmented reality encoding
Lets say you want to grab a key and hide it somewhere. You put on your [augmented reality glasses](https://en.wikipedia.org/wiki/Augmented_reality) and without ever looking at a key, you assign any key to look like something that is not a key--let's say you assign it the shape of a small lump of clay. You could assign this shape via voice commands, so you never see a key. Then, whenever a key comes into your field of vision, the augmented reality glasses change the apparance of the key into a small lump of clay. You can then pick up the key, feel it in your hands, but as far as anyone who happens to be watching through your eyes is concerned, they only see a lump of clay. Naturally they think nothing of the clay and you are free to do whatever you want with it.
## Blind people become sought after
Blind people might become highly sought after by clandestine services like the CIA, KGB, mafia, etc, to perform handling of sensitive objects or performing secretive tasks when other methods of not looking at the object or area are not possible.
[Answer]
# Q3: Don't Give People A Reason To Look Through Your Eyes During Most Hours
To avoid being seen, one of the biggest defenses is to avoid suspicion. If I can look through the eyes of anyone I want, I'm going to want to look through the eyes of those that are worth looking through. That's almost self-evident, but worth explicitly stating. If I am boring, if most of the time people look through my eyes they see the driest texts and most humdrum surroundings, people are going to stop looking through my eyes.
When I want to do something private, I'm going to wait until most people are asleep, to minimize the chance of random surveillance. I will encourage other more interesting things to be happening at the same time. I will chose locations that people don't have a reason to look for a random set of eyes to borrow.
Lots of audio conversation -- vocal commands to computers, telephone conversations with people. Braille also becomes useful. Foreign languages in written communications. Imagine a custom language for some corporations, like government spy agencies.
Q1: What would we not hide?
Most of our home life, just because it is inconvenient to do so.
Q2: What would we still hide?
We probably still want to hide our home finances, just to prevent thieves from targeting us. We probably hide R&D work in businesses.
[Answer]
## Invisibility Cloak
Recent research suggests we may be getting close to making a [real invisibility cloak](http://www.cnn.com/2016/07/20/health/invisibility-cloaks-research/). By coving up what one is doing with one's body, you could provide yourself with a certain amount of secrecy.
]
|
[Question]
[
Or would any alien megastructures humanity discovers have had to enter our solar system from interstellar space? Basically, what is the likelihood that an alien megastructure like a space station, spaceship, or some remnant of planetary engineering (a space elevator or a moon-sized supercomputer perhaps) could have remained undetected by astronomers up to the present day? It has to be many kilometers in size, at least as big as an asteroid.
[Answer]
The size limit for such an alien artefact depends mostly on where you want it to reside in the solar system and how much it is concealed.
The main methods by which we detect asteroids and moons is reflected light (not restricted to visible wavelengths). If the object is near earth and a few kilometers is size it is likely it would be discovered (by hobby astronomers, or by coincidence observation). But if its surface properies were within the range expected from asteorids, nobody would suspect its alien origin.
Larger installations could very well exist inside large asteroids or under the surface of the many moons. For the sake of plausibility, I'd keep the size of such an artefact well below 400km - thats about the size were hydrodynamic forces would be strong enough to pull it into spherical shape.
Some activity (read: excess heat emission) could be inconspiculous enough to be not recognized as artificial. For example if a subsurface installation on a jovian moon produced a few gigawatts of excess heat, raising the surface temperature by less than a kelvin, we would most likely not notice it as artificial. Instead scientists would assume tidal friction at work, or a bit higher than average amount of radioactive elements in its core.
The farther out you place the object, the less likely it is we would even detect it. Most sky surveys looking for minor planets focus at the plane of the ecliptic; objects with high inclination are less likely to be found; unless they are very large (big KBO-sized).
Considering there are still a lot of fairly large bodies we don't even have images that allow to discern large surface features there is a lot of room to hide alien bases. If it were a sub-surface base, it may well be undetected until (if its large enough) a probes orbit deviation detects it as a gravity anomaly. Even then, we would not suspect it as alien immediately. A set of subsurface tunnels could remain undetected for a really long time. Even unknown cave systems on earth are still found in this day an age (and fairly large ones, too; sometimes by geological survey, sometimes by accidentially digging into them when mining).
An inactive artefact that is covered with asteroid rubble could possibly be overlooked even when humanity already is expanding into the solar system. If the density is not too peculiar and its orbit inconvenient for exploration, nobody would take a second look.
So all in all, there is a lot of room where you can hide your alien station/base. Just make it not too large and too active and it could very well remain plausible for many decades or more into the future. If, on the other hand you *want* it to be found, you probably want to take above into account to give it a property that allows it to be found (e.g. excess heat emission, u**nu**sual surface features etc).
It might help to read a bit into minor planet detection and the intricacies of their size estimation to get a better grip on how much telescopes can do and what they *can't* do.
[Answer]
How big do you want it to be?
Until the Dawn probe came close enough, this was our best picture of Ceres, the largest object in the asteroid belt:
[](https://i.stack.imgur.com/WYLuI.jpg)
1 Ceres is 965 km across, much larger than either Death Star.
This is 2 Pallas, the third most massive body in the asteroid belt:
[](https://i.stack.imgur.com/PnRyt.jpg)
Pallas is around 550 km across, again much larger than either Death Star.
If a Death Star was in the asteroid belt, we could theoretically have missed it.
Further out, you have even more room to play.
This is the best picture the Hubble space telescope could capture of Pluto:
[](https://i.stack.imgur.com/2m5KZ.jpg)
Prior to the images provided by the New Horizon's mission, we knew next to nothing about what Pluto looked like.
We're only beginning to explore our solar system. We've hit the big targets, but the small ones are still fuzzy blurs in our telescopes. To be sure, it's very unlikely that any of them could hold *active* technology - the infrared signature of the waste heat would be easy to spot - but cold, silent, inactive technology is certainly not impossible.
[Answer]
There is believed to be a ninth planet in the solar system, a bit smaller than Uranus or Neptune, that has thus far evaded detection (except as the result of a chain of inferences based on the orbits of trans-Neptunian objects). If there's room for an undetected planet ten times the mass of the Earth, there's room for as big a space station as you want, provided you put it sufficiently far from the sun.
More information about the search for Planet Nine:
<https://en.wikipedia.org/wiki/Planet_Nine>
Many indicators of the planet were found during the year 2016.
[Answer]
There are many possibilities, here are some:
**Perfect deception:**
A whole moon is, in fact, an alien structure, covered by rocks and dust to conceal it's true nature.
**Aerostatic Station:** A huge station, hidden into the atmosphere of a gas giant, well beneath the cloud layer (assuming that it's shielded or a remnant it emits no energy so it's really hard to detect)
**Solar Base:** Aliens are so technologically advanced that they can build bases on the sun (thus masking any emission)
**Deep space base:** A base so far from the sun that it's almost impossible to find (unless you know it's exact position) - See [Sedna](https://en.wikipedia.org/wiki/90377_Sedna)
**Underground Base:** on Venus. We don't even think that something or someone can build a base on a so hot planet (and with such atmosphere pressure).
**Asteroid Base:** an asteroid base, built inside the rings of one of the solar system planets. That would be really hard to spot.
I could go on and on, but the truth is that we know little of our solar system. We explored even less, and finding even a 10km cube would be really hard, in the right conditions.
[Answer]
This question has attracted many good answers. There are two "places" where alien megastructures could be located and be hard to detect.
Firstly, if they were located out of the plane of ecliptic. Most searches for objects in the solar system take place by looking in directions confined to the plane of the ecliptic. An alien megastructure could be in orbit around the solar system and there be very small windows of opportunity to detect it as its orbit carried it close to the plane of the ecliptic.
Secondly, any megastructure might be located a long way from the centre of the solar system. In this case, their angular resolution will be miniscule and therefore hard to detect. Objects out as far as the orbits of Uranus and Neptune could be difficult to spot. Remember Clyde Tombaugh had an extremely difficult task in finding Pluto and he knew he was looking for something, in this case, a ninth planet. Astronomers might easily overlook something a few pixels wide if it was something they weren't looking for.
Of course, structures pumping gigawatts of energy could be readily spotted. However, any technological civilization capable of interstellar travel may be able to avoid dumping large amounts of waste energy into its surroundings. Thus adding to its difficulty in being detected.
[Answer]
**An energy-using thing, be it large or small is a much easier thing to detect than a turned-off or otherwise totally passive device** -- and competent searchers would take advantage of this.
Thermodynamics still apply, so a powered device (unless it's perfectly efficient) must eventually reject waste heat into its environment. Perfectly directional heat rejection is hard to do, if for no other reason than diffraction limits (e.g. for a highly efficient IR 'flashlight' always pointed away from all observers, as a tactic for covert heat rejection.) This is why militaries have thermal cameras and heat-seeking missiles.
Power use is easier to hide/mask near substantial existing power sources, especially concentrated and/or varying ones. I suspect that the varying volcanic activity on some of Jupiter's moons could usefully mask the energy use of a considerable base or small city.
Generally, we'd have to search for some feature or signal that is unlikely to come from natural processes. Lots of straight lines, or flat surfaces other than planetary/asteroid 'ground level' are things I'd look for.
[Answer]
Stretching the definition of a megastructure a bit, a truly advanced alien race could hide by creating a "basement universe" and only using a narrow wormhole to enter and exit this universe.
[](https://i.stack.imgur.com/XJgbf.jpg)
*DIY universe*
Since the effects of a "basement universe" might still be felt through gravitational interaction or leakage of heat energy from the wormhole, the construct would need to be a considerable distance from the Sun, possibly orbiting in the Oort cloud or at a considerable angle to the plane of the ecliptic.
[](https://i.stack.imgur.com/AMM7p.png)
*The Oort cloud*
Of course, this would lead to some interesting questions about the motivations of the aliens in the first place. If they have the ability to create their own universe(s), why are they anywhere near the Solar System, unless they had tapped the energy of the Sun at some point in the very distant past to create this artifact. If they can create their own universe, why would they not adjust the various physical constants to make it even *better* than this universe for life, and if it is *better*, then why wold they want a connection to this universe, unless it is actually a sort of vent to dump entropy from their universe to our own....
]
|
[Question]
[
I am trying to make an original character who is blind
and hunts with bow and arrow from a flying mount.
(Obviously, no existing animal can fly while bearing the weight of a human,
so let’s assume that the mount is a mythical/fantastical species;
for instance, a dragon or a gryphon.)
What physical qualities (internal/external)
would enable and enhance the archer’s feasibility and hunting prowess?
[Answer]
Very acute hearing, like that of a barn owl. Barn owls can hunt in complete darkness and without an active sonar like bats.
All owls have one ear pointing up and another pointing down so they can pinpoint sound sources more accurately. Their disc-like face also acts like a parabolic antenna for sound. The ears are hidden beneath the facial feathers, one aimed forward-up and the other forward-down.
Your hunter may wear an owl-mask to help them locate prey, or it may be descended from owls somehow.
Failing that, an active sonar like that of bats and dolphins would be a way to go, too.
[Answer]
Yeah, her/his other senses would need to be heightened, either by natural or unnatural means. Think Daredevil for instance. Other than just hearing, his heightened sense of touch allows him to feel variations in temperature/pressure/humidity, his heightened sense of smell/taste allow him to smell/taste particles in the air. These could potentially be factored into your characters story.
Like I said, it could be natural through training and adaptation, or unnatural through magic or technology.
This is all assuming the character is human. If the character is another species/race such as one with larger ears or longer fingers it might bode well for his archery capabilities. And if the character is not human, you may consider giving the character a creative new organ. Think birds who can "see" magnetic fields which allow them to traverse the globe easier.
[Answer]
Some sort of ESP-like ability, which would allow the protagonist to either pinpoint another being, or possibly permit them to see through the eyes of another creature. Note that if they've been blind from birth, the ability to see through the eyes of another probably won't help unless they've had a lot of experience hunting this way.
[Answer]
This is somewhat generic
(i.e., it goes to support the feasibility of a blind rider
controlling a flying beast, and not so much the archery aspect),
but, since telepathy has already been mentioned:
a psychic link between the rider and the steed would be very useful.
Even if it doesn’t go so far as to allow
the rider to see through the mount’s eyes (as [suggested by James](https://worldbuilding.stackexchange.com/questions/45212/#comment127266_45257)),
it would be very handy if the mount could alert the rider
to upcoming maneuvers, or if the rider could direct the mount,
all without making a sound.
Compare to the [neural interface](http://www.avatarmovie.com/index.html) between creatures
(including the bond between rider and steed) in James Cameron’s [*Avatar*](https://en.wikipedia.org/wiki/Avatar_(2009_film)).
Also, you might want to look at the [Nazgûl](https://en.wikipedia.org/wiki/Nazg%C3%BBl)
(from *The Lord of the Rings*) for some general inspiration.
While they are not totally blind,
they [do not see the world of light as we do](https://scifi.stackexchange.com/q/14876/30482#14880 "Lord of the Rings – Are the Nazgûl Blind? – Science Fiction & Fantasy Stack Exchange").
(They may use a sense of smell when on the ground;
it’s not clear whether that would be useful when they are airborne.)
[Answer]
How about ability to see/detect minute alterations of Earth's magnetic field or electricity? That might allow him to detect live beigns from a distance. I assume a medieval background due to the presence of mythical creatures so no radiowaves everywhere to drive him crazy, though his perception of a thunderstorm would be interesting.
Can't imagine the kind of organ which would allow, I can only think it would have to be duplicated to allow triangulation for distances. Maybe replacing the eyes?
[Answer]
# Hidden power
Your character has a hidden power that permanently allows them to see into the future. Hence their current eyesight has been traded for one out of sequence with time. They know where the arrow will be once they let go for they see it already having arrived.
To make sure this is not OP this could be limited to an enhancement / curse given by the bow they wield and only bestows the future location of arrows potentially fired from it.
]
|
[Question]
[
My NASA-like scientists in a system far, far away, but otherwise similar to us today, understand that their nearest sister planet, *Sunev*, is habitable for mankind.
With one exception: it is almost pure oxygen. My space program really wants to get a scientist out there, but the likelihood of entry and landing could ignite large pockets of combustion.
**Is there any way for my-NASA to land astronauts on *Sunev*, conduct studies in their gas filter masks, and return?**
If it's too hard, I'm happy to leave my scientist astronauts there forever. We don't think there's any life on the planet, but they volunteered the possible eventuality that there might soon be death on the planet.
[Answer]
Another answer is good, but a bit too narrow. So let's talk about it one by one:
# Atmosphere itself
Will not burn. There is oxygen in it, but no fuel
# Engines (working)
One might be concerned about afterburner-like effect. That's not a problem. It's a benefit, if anything. Afterburners work because not all oxygen is used up by main engine. Fuel is used up completely - because carrying fuel is expensive and oxygen is simply there. Thus, engines are designed to avoid fuel waste, not oxygen waste, On a spaceship you may be sure atmospheric oxygen would be taken into account. You will get normal engine exhaust, with less massive rocket (because you don't need to carry oxygen). If your rocket scientist can send rockets to orbit, they will be able to calculate that, no problem.
# Breathing
Oxygen for breathing is already there, isn't it? So nitrogen tanks and mixers will suffice - for about 21% to 25% lower mass. OR lowered pressure somehow. Was good enough for astronauts of Apollo program.
For details, [see this answer on Space Exploration](https://space.stackexchange.com/a/5694/11639).
# Interior & clothing
[Apollo 1 fire](https://en.wikipedia.org/wiki/Apollo_1#Fire) was a big tragedy. But it set a foundation. Nothing in space craft interior will spark again. Nothing in space will be flammable in pure oxygen. Not again. OK, maybe something will, but it really shouldn't. NASA did a huge job to make sure it won't happen, and rules against fire are set high, **meant to be suitable** to pure oxygen. Other space agencies plan for that as well - better safe than baked. Of course pure oxygen atmosphere is not used anymore, but precautions are set in place.
# Exterior
## Engines (structural)
Rocket engines work with pure liquid oxygen and other strong oxidizing agents. So conditions would be pretty much normal for them. Of course jet engines do not, and that's what you want to use with free oxygen readily available, but materials and knowledge are there. No problem. Just some testing and engineering to match two already related technologies.
## Fuselage
This would be a main issue. Stainless steel is brittle. Painted steel is not safe, there is to much risk of scratching it on a planet. Ceramic tiles can be knocked out. For interior it was figured out - but in conditions with moderate temperatures and low risk of scratches.
Composite materials for lander would probably work. Few layers with different properties. And very limited time dirtside. I'm pretty sure it can be done with modern tech. I'd go for steel or aluminium covered with fiberglass covered with ceramics for parts under heavy load, and fiberglass + ceramics for the rest, but I'm no space engineer. Just give them two years, funds and reason and they will make it, sure bet.
[Answer]
**Pure oxygen won't combust.**
Oxygen is an oxidizer, not fuel. As long as they're not landing in a ship made of fuel, or otherwise easily oxidized, they should be alright.
For the most part, any exposed fuel sources (which is a bigger list in a pure oxygen environment) will oxidize in a non-explosive-oh-god-why kind of way. For instance iron will oxidize (commonly known as rusting) and the rust (iron oxide) will form a [protective layer against further oxidation](https://en.wikipedia.org/wiki/Passivation_(chemistry)).
[Answer]
When I saw this question I was immediately reminded of the [fire triangle](https://en.wikipedia.org/wiki/Fire_triangle):
[](https://i.stack.imgur.com/ZgsYF.png)
The [Mythbusters did an episode](https://en.wikipedia.org/wiki/MythBusters_%282011_season%29#Bourne_Magazine) about one of the Bourne movies, in which the hero sets up a diversion: natural gas from the stove, and a magazine stuffed into a toaster oven. The idea was that the eventual ignition of the magazine would trigger an explosion for the pursuing bad guys.
They utilized principles from [stoichiometry](https://en.wikipedia.org/wiki/Stoichiometry) to determine what the best ratio of gas was for an explosion. Basically with the wrong fuel mixture, objects burn more or less intensely, but an explosion wasn't possible.
I agree with the other answers - as long as you're not providing fuel and heat, having an oxygen-rich environment isn't necessarily a fire or explosion hazard.
]
|
[Question]
[
If Mars was vaporized by aliens, how would it affect us? Assume that the core of Mars exploded, sending the debris flying in all directions, and that some would pass close by, but not hit, Earth. How would it affect Earth's orbit? Would it cause another planet to diverge from its orbit which would then affect ours?
Mars isn't blown up, it's vaporized, and all of the particles are sent flying outward in a sphere, so the chunks of Mars are irrelevant. it's just the absence of it's gravity you need to take into account.
[Answer]
The effect of Mars on Earth is negligible. The total force between the planets is — at their closest approach —
$$F\_{\text{max}}=\frac{GM\_{\text{Earth}}M\_{\text{Mars}}}{r\_{\text{min}}^2}\approx8.6\times10^{16}\text{ Newtons}$$
This produces an acceleration of . . . well, [pretty much zero](http://www.wolframalpha.com/input/?i=%28gravitational+constant%29+%2A+%28mars+mass%29+%2F+%28%28mars+periapsis%29+-+%28earth+apoapsis%29%29%5E2). Mars does not affect Earth much, and so its absence will not affect Earth much. In the long-term, there will be effects, as the Solar System is chaotic (i.e. the orbits cannot be predicted well) over a couple hundred million years. However, there aren't important resonances between Mars and Earth, and in the short-term, the effects will be minimal.
The same goes for the other planets. The only affected bodies will be Mars' two moons, Deimos and Phobos. Even so, they'll most likely continue to orbit the Sun on Mars's current orbit.
[Answer]
In the short and medium term, it will cause: absolutely nothing.
In the long term, astronomically speaking, it will result in a slight increase in the number of asteroids coming close to and eventually hitting Earth. Mars does play a (very minor) role in herding the asteroid belt into its current extent. The extreme vast majority of this is handled by Jupiter, of course.
There will be long-term effects on both the exact shape of Earth's orbital ellipse and on the Earth's rotational axis. [Both of these are affected by the other planets](https://www.sciencedaily.com/releases/1997/12/971218090305.htm), but virtually all influence (99%++) is linked to Jupiter and Saturn, not Mars because even though it is closer, the planet is just such a weeny compared to the Giants of the solar system.
p.s.
Astronomical "long-term" means not tens or hundreds of thousands of years, but millions. Many of them.
[Answer]
Other answers covered the negligible direct physical effects well.
I'd like to mention the effect on *humanity*. This was alluded jokingly in the question's comments, but is a very serious matter.
If a planet suddenly disappears, we'll want to know why, and particularly if something similar may happen to Earth. Expect new and revitalized space programs surpassing even Apollo in ambition and resources.
If we find out about the aliens, much further work will be directed towards contacting them and staying on their good side.
[Answer]
As was noted, in the short term there will be no visible effect, but in the (very) long term the solar system will probably change, since now the planet orbits are the result of a balance between the various gravitational forces.
If you wipe out Mars, you alter this balance and the solar system will need to find a new balance and this can affect Earth, giving her a new orbit, not necessarily in the habitable zone. But here we are speaking of million years time frames.
]
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.