Cryonics: Frozen Civilizations
This video is sponsored by CuriosityStream. Get access to my streaming video service, Nebula, when you sign up for CuriosityStream using the link in the description. It might sound pretty cool to be frozen for a century or two and then thaw out to see what the future holds. But of course if everyone did that, the future wouldn't hold anything. Today we’ll be examining the science and technology of freezing people and asking what the ramifications of it would actually be, if it became a regular and easy process.
Of course at the moment it’s neither regular nor easy. Even freezing people isn’t very easy and that’s supposed to be the easy part. Freezing people for later thawing and revival is a bit of a misnomer, what we’re talking about in modern times is taking the corpses of the already deceased and trying to freeze them before too much damage sets in and in a way that doesn’t cause too much more damage during freezing itself. Indeed the main process focused on these cases is vitrification, essentially turning the subject into a non-crystalline solid like glass, but we’ll treat that as freezing today too, as we’re not too interested in the specific procedures, just their impact on society if done successfully. For a given value of the word ‘success’. The procedures are utterly lethal to anyone still alive during it, and it frequently involves decapitation too. The intent is to preserve the brain well enough that we can repair or recreate it at a later date with access to superior medical technology. Since the alternative is death,
if that gamble is wrong you’re not out much, but it’s also probably a good gamble. Medical nanotechnology able to engage in cellular repair should be an invention in the 21st century. Of course, that’s the issue with cryonics, it’s a technology that depends on assuming the invention of a future technology and one that would render it redundant. Cryonics is likely to be a growing industry as we get better at the procedure for freezing brains and more confident that medical nanotechnology able to engage in cellular repair will be successfully developed.
Once it is though, your reasons for freezing dead people pretty much cease, as it’s more likely the nanotechnology will be developed on and for the living first, significantly shrinking the cryonics customer base. This episode isn’t too interested in the procedure itself, but the critical challenge for that is the complexity of cells. I think there tends to be an assumption that a biological cell is bigger than an atom but in the same way a tree is bigger than a shrub. I’ve occasionally asked folks how many atoms they think are in a cell and they tend to answer hundreds or thousands, and rarely hundreds of thousands or even millions. However,
even the smallest cells are composed of more like a trillion atoms and often a lot more, a human neuron can mass as much as a microgram, thousands of times more than a red blood cell for instance. In context, if we think of an atom as a brick, a cell is not a house made of bricks, rather a small cell would be a large city, while a larger cell would be an entire nation’s buildings and infrastructure. Each of our cells is essentially a world to itself. If you flash froze a city, you would not expect it to thaw out and be operational, but you would expect to be able to look at it while it was frozen and see what got damaged, like water mains exploding, pipes breaking, bridges and roads cracking and falling apart. You would figure you could repair that when it thawed out if you threw enough manpower at it, very different then if the city gets hit by an asteroid for instance. Key notion, freezing does damage but once frozen that damage ceases. You can put humpty-dumpty back together again after
he falls if he shatters into clean pieces and you don’t give those too much time to scatter or wear down, you can’t if humpty-dumpty was incinerated and his ashes scattered to the winds. This is essentially the notion of cryonics, each cell needs major repair, but you know what those cells should look like and they also aren’t rearranging their location relative to each other. The task of repair is huge but doable, though of course it has to be done at the microscopic level.
What you need is trillions of little workers who can get in and do the work, and that’s where medical nanotechnology comes into play. There may be ways to freeze people with minimal cellular damage and to thaw them and revive them so their own regular healing mechanisms can finish the job, we’ve had limited but growing success freezing and thawing out other organisms, but the core of current cryonics is the assumption we can eventually repair the frozen person with all those little robots. Critical thing though is that if you’ve got all those little medical robots that can repair cells, your society really doesn’t have nearly as many untreatable medical issues, so you don’t need to freeze many people. And it’s also a lot easier for such robots to fix existing living but damaged cells than repair ones frozen or vitrified, particularly since your cells already have very good repair systems. So cryonics might grow very popular as we get closer to that point and more folks feel like it represents a plausible way of extending life, but once you get to the point you can thaw people, you don’t really need to freeze them for that reason anymore. They should effectively be able to self-repair any type of damage which wasn’t overwhelming.
So what does that leave as a reason for freezing? Well interstellar spaceships is a popular suggestion, but we looked at that before in our Sleeper Ships episode. One critical note on that is that I’d have a hard time imagining us sending ships full of frozen colonists out unless we already had the revival technology well-developed. Space is immense, and while there may be a push to colonize quickly that might result in some risk taking, I can’t really see anyone trying to claim the best worlds by getting to them first by sending out frozen colonists without a proven way to revive them yet. Though you might do that if our solar
system was in imminent danger, as a last desperate gamble, and even then only if you thought the thawing process you already had would work, since no one would be around to continue researching. If you have that technology you don’t really need to freeze them as they’re probably biologically immortal, and that same sort of technology tends to fix most of your supply issues in terms of producing, repairing, and recycling material on an interstellar ship. You might freeze folks to avoid boredom or to lower power usage, but you might just put them all into some non-frozen hibernation, especially since for really long voyages you have to worry about radiation damage to the frozen body from the radioisotopes in your own body, like potassium-40, and if you’re frozen there’s no repair going on, certainly not biologically, but probably not by the little robots either. Indeed if you did have the robots working on your frozen body you would probably need to add extra cooling to make sure you stayed frozen, all that energy from them moving and drilling around your frozen cells is likely to thaw you out otherwise.
Right now we freeze people’s heads and discard their bodies in most cases. But You might do the opposite for ship hibernation, render the person brain dead or close to it while keeping the rest of the body pretty alive, so that they didn’t experience much time passing but their body was repaired and ready for rapid re-awakening. See the Sleeper Ships episode though for more discussion of using freezing or other types of stasis for interstellar travel. What about other uses though? Emergency medicine is a possibility, and it is worth keeping in mind those tiny little robots aren’t magic. A repair crew can fix a damaged
building, even rebuild it from scratch if needed, but they can’t do it in the middle of a fire or hurricane, and you can’t fix a dam when it just burst during a flood. Your cells repair minor damage as-is, but a majorly damaged cell is replaced by another dividing itself. Those little robots supplement the existing processes by augmenting or fixing the bits of our internal repair mechanisms or speeding some processes up. Freezing someone so you can prepare major replacements is an option, so too those bots can do repairs while you’re just very cold, to slow damage, and while the ones in the regular human body probably wouldn’t be designed to function at ultra-low temperatures, we probably could make some that were and put those in someone we froze. Or have some in a person already that could operate like that. This episode isn’t about
medical nanobots or self-replicating machines but a point I often make about those is that the same as we have tons of different species of microorganisms inside us of varying types, sizes and purposes, you can build your nanobots the same way and probably would. The notion of a tiny and universal robot assembler is a popular one but probably overly simple. There’s an advantage in specialized species of robots. Such being the case you might have some that existed especially for trauma operations or during freezing. We said such robots largely made cryonics irrelevant even as it made us able to revive the frozen, but at the same time it makes it far easier. You could potentially be putting yourself on ice for a long weekend vacation, depending on how good the robots are, but then if they are that good you’ve probably got easier stasis methods available in terms of avoiding boredom.
That again is one of the reasons we often consider cryonics, to leap frog through time and avoid boredom, but there are probably much easier ways to avoid boredom. For instance , given that a lot of what we think of as boredom is chemical, all those little robots able to repair cells can probably also play with the neurotransmitters responsible for boredom to just decrease it, one example of what we call neurohacking. Of course that presumably has its limits, the ability to remove the sensation of hunger doesn’t remove hunger, and presumably being able to dial down the sensation of boredom doesn’t alter boring circumstances, so this might be one reason why a civilization had large numbers of people go on ice, emerging every few years or centuries based on predefined triggers, like if that book series they loved was finally done. Hopefully they have a contingency trigger in case the author goes on ice too. We should also note that experiencing huge swaths of time beyond the normal lifespan is likely problematic beyond just figuring out how to extend youthful physiology indefinitely. I genuinely do not think anyone who had a full memory of having lived a million years could qualify as even vaguely human anymore beyond the biological sense. So why else might we use cryonics in mass? One example I’m fond of from fiction is the planet Hubris from Dan Abnett’s Eisenhorn series. The planet was settled by a colony
ship full of frozen colonists and they didn’t realize till after arriving that the planet was on a wildly elliptical orbit that left it an ice ball for eleven of its 29 month long year, so they adapted their stasis pods to keep 99% of their population on ice during that period. As a sociological consequence of that the caretaker population during the Dormant Season tends to live in places where the lighting is on all the time, a perpetual noon. I love the notion and the book, however it is not a terribly likely scenario for a planet, you could put artificial lighting and heating in place by many means, such as orbital mirrors around the world to add light when you need it, and that would seem a better approach than freezing your population. Though if your planet’s orbit is elliptical enough, you might try the other approach, and if life evolved on such a world it might do that naturally. Artificial lighting and heating would seem the better path for a technological species though. But not so much from a cost savings perspective.
Freezing people is rather cheap, in terms of the storage equipment and the coolant. It’s not terribly expensive even now and that’s with most of the cost going into research and into the efforts to get someone frozen on short notice after their death. If a culture has refined this process it might be about as easy as we often see in scifi, where you just get in the tube and pull the door shut after setting a timer. It might be the routine approach for ambulances to have freezers, or combat medics too, to just have some bag with an endothermic chemical in it ready to freeze an injured person. Folks might have them in their
own home and household robots ready to just haul you into your cryo-vault if you were injured. Indeed it’s quite possible such a cryo-vault might not only be no larger than a bed but no more expensive either. I really could imagine them as a standard feature on board spaceships or in people’s normal homes, the ice closet, as it were. There is a distinct cost
for keeping things ultra-cold but it goes down when you pack the stuff in together. At a minimum your cost drops with the cube-square law as heat exchange is about total surface area, so a freezer ten times bigger on each side, has 10-squared or a hundred times the heat loss on its expanded surface, but contains 10-cubed or 1000 times the storage space, so your coolant cost drops to a tenth in terms of cost per person. But it’s not really prohibitive even for individual pods in personal homes and with only modern costs for coolant, liquid nitrogen is dirt cheap.
Still not free though, except in deep space. Now any spaceship is probably going to need some active parts that are kept warm, but you can keep them frozen for free, it is heating them that costs power. This is part of their appeal for interstellar space travel. We recently discussed interstellar trade and one of the concepts we discussed was the Interstellar Cycler, giant spacecraft that are essentially on long circuits around a collection of stars that other ships rendezvous with. It would not be hard to imagine such ships having huge
sections of them that were powered down and frozen during those voyages. You dock with the Cycler, disembark, and check into your freezer, leaving a wakeup call for when you near your destination. Given the potential enormity of those vessels, they would qualify as civilizations all on their own, and ones that might spend much of their time dormant, like our example of Hubris only even more so, spending decades asleep and perhaps a year awake. This implies the crew might be awake and the nominal passengers engaged in the trade efforts or traveling would be asleep, but it might be the other way around sometimes too. The interstellar cycler is a trade ship that makes a circuit of centuries between its many destinations, but we have another vessel we call the Gardener Ship that visits many worlds but only to drop off colonists. The Gardener Ship uses the premise that any realistic interstellar colony vessel needs to be essentially self-sufficient and able to manufacture any spare parts it needs from raw materials, and that means it can keep producing colonial gear, not just ferry the gear to a single planet one time. And given the length
of the voyages, decades, they can breed up new colonists too. It is the opposite of the classic sleeper ship, you need your colonist awake for the journeys, living and manufacturing and having families, but the crew maybe not so much. Indeed a big part of the crew’s job is making sure the ship stays on the same task from beginning to end, and as we saw in our Galactic Gardeners episode, that end might be a million years down the road as some gardener ship leaves Earth and goes to world after world on its way to the galactic rim, settling thousands of new systems on the way. With a task that long, your biggest barrier to success is losing the will to continue, and that more than boredom might be why certain people or groups go on ice. They have a goal that will take a very long time to happen, and they want to be around for it to make sure it happens, so they go on ice for periods, waking up occasionally. Civilizations might sometimes do the same, after all it may be that the best way to achieve cultural stasis, if that’s your goal, is to put the people in stasis. However it is a dangerous play, which makes sense,
hibernation is always a risky strategy in nature. Isolated on a colony ship, your sleeping crew would still be very vulnerable to hijacking by anyone still awake, be it colonists or whatever bit of the crew was awake, and the risk of such hijacking may be nearly as great as what risks to the mission would be entailed by generational drift of goals and ideals by not freezing. On the other hand, freezing part of your civilization while leaving part unfrozen places the unfrozen portion in charge of it. We usually assume that’s intentional, the caretaker crew who hopefully were selected for stability and trustworthiness.
This is a gamble all on its own, but mutiny by your caretaker crew may be secondary to the risk of takeover from outside groups, rebels in the hills so to speak or a foreign invader. If the majority of your population goes on ice, for whatever reason, whoever is left unfrozen is in a pretty good position to have things their way. Assuming they don’t die anyway, after all if everyone is going on ice there’s probably a good reason for it and one of the more obvious ones is that normal life won’t be viable soon. Though why it would be viable down the road is unclear. A civilization that decided that it had damaged its planet and was continuing to do so might decide to go on ice while the world recovered but would probably be better off devoting efforts to figure out how to fix that damage or at least do less of it.
You don’t get much work done while you’re asleep, and little new work gets done if most folks are, so if your civilization is full of bored people hoping to leapfrog forward and see new things, not many new things will develop if almost everyone is on ice. I suppose if there was a set cost to staying frozen folks might opt to sleep for as long as their personal wealth permits. The very richest might be able to go on stasis long enough to go hang out at the Restaurant at the End of the Universe. This would be a rather bizarre economy that would give a whole new meaning to the phrase ‘Time is Money” Trying to skip ahead into a bright new future, or the end of the world, is one motivation for going to sleep on ice. Or to be a frozen corpse anyway, it's customary to call folks on ice asleep in fiction but they are thoroughly dead, and nowadays they are dead even before we freeze them. However, that might not be true either,
which takes us to our last and maybe most plausible example of a frozen civilization. In Alastair Reynolds’ classic scifi novel, Revelation Space, we have a faction of humanity that spends a lot of its time on near-light-speed vessels, called light-huggers, and spend most of its time in frozen stasis too. That may be a very common way to leapfrog forward through time and those interstellar traders might be their own civilization, and the longest lived one, and indeed we see an example of that in another of his novels, House of Suns, but I have a different example in mind today. In Revelation Space the captain of one of those ships, the Nostalgia for Infinity, is infected with a virus that causes severe and gross mutation in flesh and machine, indeed it's really machines it seems to go after, people’s cybernetic implants, and the captain is very much a cyborg. They put him on ice, and very cold too, down to below a Kelvin, whereas most cryonic freezing assumes to be more like 100 Kelvin. Incidentally there is no set temperature you have to freeze people to, the two key bits are the Arrhenius Equation, the formula for the temperature dependence of reaction rates, of which decay is one such reaction, and the desire to keep the temperature constant.
No fluctuations to cause cracking from repeated expansion and contraction. You could build a cryonic facility in Antarctica or Pluto but you still need some active equipment to make sure the temperature stays put, no seasonal variance. Anyway the captain is Ultra-Cold, appropriate since his faction’s name is the Ultra’s, and yet he is still able to be conscious because his brain is a mix of the organic and the computer. We often discuss the notion of replacing damaged neurons in our minds with something more synthetic, and that seems to be the most preferred approach to mind uploading and augmentation as well, to simply replace our billions of neurons and their connecting synapses gradually as each one starts wearing down. A person who went that path probably could be placed in stasis and remain conscious in whole or part if those synthetic neurons were able to keep firing at sub-zero temperatures and could function as a brain without the rest. Indeed there are many advantages to computing,
or thinking, at low temperatures, as we discussed in the civilizations at the end of time series. This raises an interesting option, not just that those on ice might be able to continue in some dream-like slumber, but that civilizations that decide to embrace cold-computing and post-biological existences, as we often look at in our Civilizations at the End of Time series, might make the transition by freezing themselves. I think a lot of folks would prefer to keep their body around if they went digital anyway, as opposed to the usual suggestion it be destroyed in the upload or discarded afterward, and so I could easily imagine finding some world full of nothing but frozen tomb vaults full of computers of minds expanded beyond their bodies, with a frozen body in the center of each one. Their inhabitants slumbering away in artificial virtual worlds, or very awake and possibly existing at a far higher subjective time rate. Such a frozen civilization might not be waiting around at all, not pausing out of boredom, but gone onto ice to gain the advantage of ultra-cold computing efficiencies and be very busy indeed.
One of the most common applications suggested for Cryonics is as a way to extend lifespans, and as we saw today it really only does that in a short-term context of potentially letting us take advantage of such technologies in the early 21st century when they will probably be more of late 21st and early 22nd century sort of thing, and outside this specific period of history we won’t see freezing people as a way to extend life. There’s an excellent video, “Waiting for Immortality” that does looks at Cryonics as well some other methods that might be more useful for extending life like cloning, age-reversal, and mind uploading over on Curiositystream. Curiosity Stream has thousands of fun and educational videos, but they’ve also partnered up with us at Nebula, our Streamy-Award Nominated streaming service, to offer Nebula’s content along with their own, if you sign up at the link in the episode description. That
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