Let’s say humanity has to go into underground shelters for decades or centuries. What would it look like?
How might the shelter be built?
Would the materials of life support all need to be stored? How much fabrication or recycling could be done, of what and how?
Would nuclear reactors be required for centuries-long sustenance?
What is the smallest group that could have enough genetic diversity not to lead to reproduction problems over centuries?
Note to mods: I am putting this here because I would like educated answers or at least serious stabs at determining what would be in the shelter. I am afraid that putting this in IMHO would lead to a lot of uninformative smartass answers.
Look at what goes into a submarine and extrapolate from there. A typical nuclear submarine carries a crew of 80, so there’s no reason to believe a similarly sized shelter couldn’t house the same number, given sufficient food and water. Electrolysis provides oxygen, CO2 scrubbers purify it, and reverse osmosis and evaporators provide fresh water. You would definitely run out of food before you ran out of air and water.
I once heard of a paper that mentioned the “50/500” rule. That is, 50 individuals for short term genetic variety, 500 for the long term. Other estimates range from 500 to 1000 for large mammals.
The big problems would be the same ones astronauts encounter in space: need for exercise and labor, resupply issues, fabrication, medical supplies and surgeries. Then there are the “mouse universe” experiments, which are no fun at all.
My take is that you would soon have a ‘Lord of The Flies’ situation. Discipline would break down and since there is no way to escape, the inmates would not survive for very long at all.
It really depends on what the threat is. Each threat needs a different form of shelter. Some threats would require that shelter be located on a different planet.
I wonder what the starter kit population was for somewhere like Easter Island?
The problem is the energy supply. Look now much hassle goes into creating a nuclear reactor for commercial use. you would need very strict controls on the material to not contaminate the living space… one long tunnel to store future fuel, another for waste, both with good sealed doors.
Would you store a limited amount of food, or run a grow-op? That comes with its own problems - a century supply of light bulbs or make your own? Artificial light will need even more electricity… and so on. Were you planning to filter air from outside? Is groundwater sufficient?
You can save a lot of issues with clothing by making it nudist. And, to ensure the survival of the human race, we would need about 10 breeding females for each male. To ensure survival, the females would have to be attractive, mien furheur, I mean Mr. President…
Basic fall-out shelters were designed to shelter from the short-lived nuclear fall-out, which would be most radioactive for about 30 to 90 days if I recall. Longer term is a whole different proposition.
If comfort were the goal rather than survival of the species, blow-up dolls of various configurations could be supplied for the occupants: goats, alpacas, sheep, etc.
You would not need men at all, just their sperm. Eventually some will grow back, but at first all women and a cyro storage unit and a turkey baster should do it.
The problem is supply chains and the difficulty of manufacturing complex systems.
If the shelter has to be completely underground, and cannot harvest some type of external energy source, then the only source of power that can work is nuclear.
The problem is that a nuclear reactor and all the ancillary components involve a huge number specialized, high tech parts. Moreover, just spare parts in general is a nearly intractable problem. You cannot fit manufacturing capabilities to make all the parts used in the bunker inside any reasonable sized bunker. I know that good machine shops and 3d printing and other tricks help, but it’s still nowhere near enough. So you have to stock spares, a century worth or more. That’s at least possible on paper, the problem is what do you do when a part wears faster than expected, or decays in storage? You’d have critical components failing before it is safe to emerge.
Also, if it has to be a self contained ecosystem, well. Biosphere 2 I think demonstrated that it was possible, just very difficult. This means the bunker would need to be on the scale of that habitat or larger, and with a complex internal ecosystem to provide the breadth of the web of life you need to make up for unexpected failures.
None of the above. Lets say you and ten companions build a shelter. Or dig one, whatever. Your all snug and everything is fine on the inside. Then one day 500 people show up and they are all thirsty. Do you A: Share what water you have until its gone B: Refuse to share and put up defenses. Lets say you refuse. 500 people are now outside your shelter dying of thirst. Some of them decide to try and take your water by force. Your defenses are too good and they all die. Now you have those deaths on your concience. And you have to bury 500 people or your area will stink and become infested. You have won, but wait, a thousand more show up. You hold out and win round two. Then 500 children show up. Are you going to sit back and watch 500 little kids die? How many of your group will be able to cope with all the deaths? My point here is that trying to hold out from whats left of civilization in some dream shelter is nothing but a fantasy. It will not work. We are all in this together and anyone that tries to seperate themselves and be greedy will end up being eaten, or will die by their own hands.
This is a good example of trying to be pedantic more than actually answering the question. If anyone is thinking of answering my question in the same way, realize that it doesn’t make you look clever or knowledgeable.
How to deal with moochers was not part of the question.
I imagined the scenario being something like Fallout: A virtually impenetrable vault completely sealed against the outside. Everyone on the outside is either dead or turned into some kind of radioactive zombie. If we are talking about the apocalypse, cutting off outside contact would probably be a mandatory step for maintaining your sanity.
And why should any of us care about burying the corpses? The scenario specifies that we are sealed off from the outside world, so disease and pests are irrelevant. Maybe in twenty years when the zombies and road warriors have mostly died off we can open the door and find some nicely fertilized soil.
This is really a difficult question to answer with any authority because workable solutions are so far outside of our current experience that we can’t really say with certainty which the limiting or co-interacting factors are. This is a case where the issue isn’t the technology per se–we certainly have technology to build shelters, stockpile resources, select skill sets, build nuclear reactors, et cetera–but rather the complexity of the overall system and our lack of empircal evidence for what happens in a closed system after decades. In other words, what fails first: hydroponics, air and water filtration, power, or psychology? Without outside resources and the natural hydrological cycle will toxins build up in the water supply until people start dying? While we encounter depletion of basic nutrients from the food cycle such that residents suffer from chronic malnurishment? Will the reactors that you’ve built to operate for decades (to operate for centuries you’ll have to have some system which either reprocesses the fuel or stockpiles of once-through fuel with an aging surveillance program to assure that it doesn’t suffer adverse effects while in storage) start to break down due to corrosion, neutron damage or activation, contamination, et cetera? What about your society, in which no one can leave, you can’t really allow for major shifts in power or control, people have to fit certain predefined roles, and the birth rate has to be tightly constrained? How will you manage this without becoming an oppressive authoritarian state which itself will seed discord and rebellion?
These are all questions for which we can only extrapolate answers from prior experience, and those extrapolations may miss critical effects that we’ve never encountered because we’ve never had a closed society for anything of this order of magnitude of duration. Comparisons to a submarine or Antarctic base break down because there is no end of tour or season respite. And consider that whatever planning or order you put into the system at the beginning will almost certainly have to change due to ongoing unexpected conditions. How will the leaders of the shelter consider and weigh the consequences of their decisions? In some ways, the smart thing to do would be to have multiple shelters and manage and equip them in different ways under the hope that at least one will survive and carry on the species (yes, this is the exact plot of the Fallout series of games) but even that is no guarantee if something mechanical like the reactors or hydroponics technology turns out to suffer from some kind of limit failure.