This is my assessment on what may be the best way to cryogenically preserve a dead human in the hope that future technology would find a way to repair the damage to the body and bring the human back to life and why I don’t believe that the conventional method of cryogenic preservation of humans would work:
The usual procedure to cryogenically preserving a human body is to first cool the body then remove all the blood with the help of an ‘anticoagulant’ (which is a substance that prevents the blood clotting and, in this case, must be administered before the blood clots after death) and then, by pumping antifreeze solution through these blood vessels, replace the moisture in the body with an antifreeze solution designed to minimise the damage done through freezing and then, finally freeze the body down to liquid nitrogen temperature and keep it that temperature until if or when future technology can become so advanced that it can repair the damage and resurrect the person.
In the future, if technology ever becomes so advanced that it can perform the formidable task of repairing the microscopic damage done to the human brain as a direct result of freezing the brain then it must surely have become more than advanced enough to perform the comparatively much less formidable task of replacing every organ in the body with organs grown in a laboratory. Obviously, if future technology cannot repair the human brain then there is no hope of bringing the frozen person back because there would be no point in replacing the brain! Therefore, if we cryogenically freeze a human then there would be no point in doing so without the assumption that future technology not only would be able to repair the brain but would also be able to replace the whole body except the brain.
Therefore, it only makes sense to cryogenically preserve the brain of the person and not the body although, in practice, it would be easier to preserve the whole head of the person as attempting to remove the brain from the scull from a person would only make an unnecessary extra risk of accidentally creating additional damage to the brain. Even then, cryogenic preservation should only be all about preserving the brain itself and we must regard the preservation of the other parts of the persons head as almost irrelevant. We must only consider how well the cryogenic preservation preserves the human brain.
It is my judgement that the conventional method of cryogenically preserving humans is doomed to fail because, no mater how advanced technology becomes in the future, the laws of physics indirectly conspire to make it impossible for there to ever be a practical way of repairing the microscopic damage done to the human brain as a direct result the conventional method of freezing the brain.
As far as I am aware, the microscopic damage done to the human brain by conventional method of cryogenically preserving humans is mainly in three forms:
1, as ice crystals grow, they can pierce delicate structures such as cell membranes.
2, as ice crystals grow on the outside of a brain cell, they absorb moisture away from that brain cell causing that brain cell to be severely dehydrated.
3, as ice crystals grow, they expand and, as they expand, this inevitably leads to uneven expansion in the brain with some parts expanding faster than other parts. This uneven expansion as the brain freezes solid leads to tension building up which then leads to micro fractures. Each one of these micro fractures can sever millions of blood vessels, neurons and nerve fibres.
There are several reasons why this may mean that, no mater how advanced technology becomes in the future, it cannot repair the damage. I will only disuse some of these reasons here:
The ‘access problem’
One reason why future technology cannot repair this damage is because of what I call the ‘access problem’: suppose, in the far future with extremely advanced technology, we consider how we are to repair a particular brain cell that is located somewhere within the centre of the cryogenically frozen human brain and which is completely surrounded by frozen brain tissue. To physically repair that brain cell, one of the minimum requirements is that we must surely be able to directly physically access it by touching it with something solid such as some kind of tool or machine that is designed to repair it. I believe that it is a safe assumption that it would not be physically possible to repair it remotely without anything actually solid touching it -no mater how advanced technology becomes!
But in order to make something physically touch that brain cell, it would have to be made to pass through all the brain tissue that surrounds it and this is when the problems begin: with no way of making something solid pass through the surrounding tissue without doing considerable more damage to that tissue, by making something solid pass through the surrounding tissue and repairing that cell you would, in fact, be increasing the total amount of damage. So, metaphorically speaking, to even begin to repair the brain, you have to take a hundred steps back before you can make one step forward. Even with the most advanced technology, his would surely make repairing the brain a technical nightmare if not physically impossible.
I am tempting to consider, as a solution to this problem, slicing up the brain into extremely thin slices (so as to make the distance between any given brain cell and the outside a extremely short one) before repairing each slice and then somehow fix the slices back together again. But, obviously, this slicing process would do considerable more damage not least by severing brain cell connections/fibres.
Also, do you slice up the brain before or after thawing it? If you do it before thawing it, then it would be as brittle as glass and there would be the risk of creating yet more damage. If you do it after thawing it, then, as soon as you thaw it, chemical degradation will start to occur so you better then act fairly fast. And then there is the problem of fixing the slices back together again: how do you know which broken end of a brain cell fibre in one layer is supposed to connect to which broken end of the corresponding brain cell fibre in the adjacent layer? After all, nature does not conveniently give each connection a unique identification tag and one connection looks pretty much like another!
However, there is a solution to this access problem: why not pump fluid down the blood vessels in the brain that is carrying some tiny things, either tiny machines or genetically engineered cells, and these tiny things access each brain cell from the nearest capillary blood vessel to it? Without exception, all brain cells are only a very short distance from at least one blood vessel so it should be possible to make something go from the inside of the blood vessel to the brain cell while causing minimum or even no damage.
But, this relies on the blood vessels being unbroken and, unfortunately, the usual procedure to cryogenically preserving a human brain causes micro fractures that sever blood vessels (not to mention that they also sever nerve fibres). Because of tiny movements during freezing and thawing, the broken ends of the smaller blood vessels may not even stay in line. This would mean that if you attempted to pump fluid down those blood vessels carrying something, the fluid would just spill out where you would not want it to go and this may even cause yet more damage.
My conclusion here is that the only solution to this access problem is to find a way of preserving the brain without micro fractures and thus keep all the blood vessels unbroken otherwise it would be extremely difficult if not totally impossible for future technology to repair the damage no mater how advanced it becomes!
The ‘soft preservation’ of the human brain
One way preserving the brain without causing micro fractures is to fill the brain with the most powerful non-toxic but highly concentrated antifreeze mix that is designed to have a freezing point as low as possible and then, instead of freezing the brain solid, the brain is merely cooled to a temperature just above that freezing point, and then keeping the temperature permanently at that temperature and never actually freeze the brain solid. I personally like to call this ‘soft preservation’ as opposed to what I like to call ‘hard preservation’ because his would leave the brain with a soft rather than a frozen-hard consistency.
This idea has some advantages and disadvantages:
Its advantage is that it would certainly solve the access problem as the blood vessels would not be severed by any micro fractures. It would also stop ice crystals from forming and thus doing microscopic damage. There would also be the interesting advantage that, if, later on, a better antifreeze mix is invented, perhaps one that allows the brain to be frozen solid without micro fractures, because the blood vessels would still be unbroken, it would be perfectly practical to pump the blood vessels with the new improved antifreeze mix to replace the now old obsolete antifreeze mix.
But there is a serious disadvantages with this ‘soft preservation’ : it may result in slow chemical degradation of the cryogenically preserved brain though centuries of storage. There are two reasons for this:
firstly, I think it is unlikely that a non-toxic antifreeze mix that it fully soluble in water can be made to have a freezing point as low as liquid nitrogen temperature (although I would really like to be proven completely wrong!). That would mean that the brain couldn’t be ...
...This post does not allow me to add the rest of the words I wont to post because the article that I wont to send contains too many words. Can anyone tell me how I can send my article in the form of a compressed attachment? If not, can anyone tell me how to delete this post?
Originally posted by Andrew HamiltonYou have a problem with some of your conclusions. You think it impossible to repair a brain cell without touching it, but you are forgetting about the possiblities of nanoengineering. The right kind of nanoengineered say, virus, or bacteria, could do the job by bringing a brain reconstruction kit with it and no machine would touch a brain cell. I think the best hope for cryogenics on humans is to figure out how to stop the ice crystals from forming in the first place. I think that will be the future of cryoresearch, if not already.
This is my assessment on what may be the best way to cryogenically preserve a dead human in the hope that future technology would find a way to repair the damage to the body and bring the human back to life and why I don’t believe that the conventional method of cryogenic preservation of humans would work:
The usual procedure to cryogenically pre ...[text shortened]... icle in the form of a compressed attachment? If not, can anyone tell me how to delete this post?
The real question is whether some advance future civilization will be interested in attempting to revive your corpse.
It might be more important to leave a note with your body saying you know the secret to the location of some vast store of wealth than how to you about preserving your brain.
Originally posted by twhiteheadLike "I know how to revive cryo people! Wake me up and I'll tell you how!"?
The real question is whether some advance future civilization will be interested in attempting to revive your corpse.
It might be more important to leave a note with your body saying you know the secret to the location of some vast store of wealth than how to you about preserving your brain.
Originally posted by FabianFnasWhat about a cryo sauna? I've been to one and it's quite refreshing. The idea is that liquid nitrogen gets sprayed on one's skin and after that, the muscles feel very relaxed. This is especially good after big physical tension, for example playing basketball all day. One important thing is that one's skin must be completely dry, otherwise, a liquid on the skin can turn into a solid state and cause injury. Anyway, I recommend trying out this cryo sauna if you get the chance.
I would never step into a cryo chamber. Not in my life!
Originally posted by kbaumenI dunno, I was REALLY REALLY cramped after I tried it.
What about a cryo sauna? I've been to one and it's quite refreshing. The idea is that liquid nitrogen gets sprayed on one's skin and after that, the muscles feel very relaxed. This is especially good after big physical tension, for example playing basketball all day. One important thing is that one's skin must be completely dry, otherwise, a liquid on the sk ...[text shortened]... tate and cause injury. Anyway, I recommend trying out this cryo sauna if you get the chance.
Originally posted by kbaumenCryo sauna? We, in the Nordic countries, have it already every winter.
What about a cryo sauna? I've been to one and it's quite refreshing. The idea is that liquid nitrogen gets sprayed on one's skin and after that, the muscles feel very relaxed. This is especially good after big physical tension, for example playing basketball all day. One important thing is that one's skin must be completely dry, otherwise, a liquid on the sk ...[text shortened]... tate and cause injury. Anyway, I recommend trying out this cryo sauna if you get the chance.
In Swedish we call it 'utomhus' (English: 'outdoors'😉.
Originally posted by sonhouseI was coming to the problem of nano-engineering but the post would not let me send any more words of the article I have made about it so that I could not explain my reasoning. I have sent the next part of my article below from the paragraph where the first part I sent ended but it is still very incomplete:
You have a problem with some of your conclusions. You think it impossible to repair a brain cell without touching it, but you are forgetting about the possiblities of nanoengineering...
...firstly, I think it is unlikely that a non-toxic antifreeze mix that it fully soluble in water can be made to have a freezing point as low as liquid nitrogen temperature (although I would really like to be proven completely wrong!). That would mean that the brain couldn’t be cooled to as low a temperature as with conventional cryogenic preservation and that would mean that there may be slow chemical degradation of the cryogenically preserved brain though centuries of storage. Still, if the temperature can be made cold enough, perhaps this slow chemical degradation can be made so slow that, even after several centuries, the damage done would not be too significant.
The second reason why there may be slow chemical degradation is that, because the brain would not be frozen solid, the brain cells would be constantly exposed to a liquid media. Because the soluble organic molecules in the brain cells would be immersed in a liquid and not a frozen solid, even though the temperature would be vary low, they would still inevitably move and drift by diffusion. After a century, a soluble molecule could have slowly moved quite a distance from its original position. I would guess that all the soluble molecules in a brain cell would eventually end up on the outside of that cell after a century and probably much less time than that. Perhaps it is possible to design an antifreeze mix that is so viscose at that low temperature as to make such movement of molecules insignificant but I seriously doubt it. What could be just as bad is that this movement of molecules would make them regularly meet with each other and one of the minimal requirements for a chemical reaction to take place is for molecules to meet. This could mean that they could sometimes chemically react when they meet and that would inevitably mean slow chemical degradation. But one thing chemical reactions also need is sufficient temperature and if the temperature can be made to be cold enough then perhaps this could stop all significant chemical reaction -but I doubt it.
My conclusion here is that what I call ‘soft preservation’ of the human brain would be less than ideal and, again I conclude that we desperately need to find a way of freezing the brain solid without producing micro fractures.
The ‘nanobot delusion’:
Some people have the wildly optimistic delusional idea that technology will eventually solve all these problems because they assume that eventually technology will somehow eventually create so-called ‘nanobots’ (robots that are only a few nanometers across) that are so small that they can squeeze between the brain cells and brain cell connections and be programmed to repair the microscopic damage. Unfortunately there are several reasons why this will always be pure science fiction:
Firstly, and most importantly, I believe that it not possible for any ‘useful’ ‘nanobots’ to physical exist without subtlety and implicitly braking the laws of physics. Don’t misunderstand me here; I am not simply saying that nanobots could not physical exist per se. I just believe that, despite the tremendous hype surrounding nanobots, no ‘useful’ or ‘practical’ nanobots could physically exist and certainly not useful enough to perform the extremely complex task of repairing some microscopic damage in a human brain.
There are a number of reasons for this but first we must clearly understand the distinction between a ‘nanomachine’ and a ‘nanobot’. Obviously, all robots are machines but not all machines are robots. Strictly speaking, what distinguishes a ‘true robot’ from a mere machine is that all true robots have three extra things:
1, they all have ‘sensors’ that can measure some aspect/aspects of their external environment.
2, they all have what are called ‘activators’ which are devices that allow the robot to perform physical movement by exerting a force that pulls or pushes or rotates something such as a leg or arm or wheel etc.
3, they all have some kind of ‘brain’, that may merely consist of a tiny circuit, that can take in signals from the sensors, analyse them, and then, depending on that analysis, send some appropriate signals to the robot’s activators to make the robot perform the appropriate movements.
There is no doubt that nanomachines can physically exist. After all, nanomachine already exist throughout nature! For example, the structure called a flagella on sperm that wipes around and propels sperm forward can be considered to be one of natures nanomachine. There are many other examples: structures called ‘microtubules’ that exist in all living cells including our own human cells pump around chemicals around the cell and can be considered to be another one of natures nanomachine as they are just a few nanometers across. So, obviously, as nanomachine already exist in nature, it must be possible for them to be artificially created.
However, the problem here is that all these ‘nanomachine’ are essentially ‘dumb’ and each type of nanomachine blindly and crudely performs only one repetitive task. But what would be required to repair the microscopic damage in a conventionally cryogenically frozen human brain would be something with intelligence for it would somehow would have to work out and ‘know’, for example, which broken end of a nerve connection belongs to which other broken end of the corresponding nerve connection along a micro fracture. No ‘dumb’ machine could do this, hence, if nanomachines are to do the job, what would be presumably required here is that they must be ‘nanobots’.
But for a robot to be nano-size, it would have to have nano-sized sensors, nano-sized activators and a nano-sized brain. It would be possible to make nano-sized activators without too much problem and we can be sure of this because such activators already exist in nature (e.g. flagella on sperm). The problem is creating nano-sized sensors and a nano-sized brain; especially a nano-sized brain. That is because anything that is nano-size can only consist of a very few molecules at most and this severely limits the sophistication of what it can do.
It must be possible to make nano-sized sensors because such a thing already exists in nature. But each kind of nano-sized sensor that exists in nature can only detect only one narrow kind of simple stimulus such as the presence or absence of a particular bandwidth of light or the presence or absence of a particular kind of molecule or class of molecules. One thing that is physically impossible for a nano-sized sensor to do is to act as a complete camera that can take a visual picture of its environment. That is because, implicitly, according to the laws of quantum physics, no lens can effectively focus an image to the back of a camera film (or, indeed, a retina) if the lens has a diameter that is less than half of the wavelength of light it is supposed to focus. But, in practice, it is generally agreed that the lens would have to be at least several times wider than that to be practical because otherwise the image produced would be blurred anyway. Visible light has a wavelength between about 390 to 740 nm so any robot with a practical camera lens would, at the very least, because of the size of that lens, have to be more than just a ‘few’ nanometers across but then it would be too large to be described as a ‘nanobot’. Even if a ’nanobot’ can somehow be built with super-intelligence, how is it supposed to repair the microscopic damage in a cryogenically frozen brain if it has no camera to give it a clear picture of exactly were the microscopic damage is and how to fix it? For similar reasons (related to wavelengths), you can rule out the possibility of a nanobot using ultrasound-sonar as well as radar to give it a clear picture of exactly were the microscopic damage is and how to fix it.
I suppose it could use a sense of touch so that it would be like a blind-man feeling about with a walking stick. But, on that scale, you could not even make a robot use a walking stick with nearly the same skill and sophistication as a blind man can. There are a number of reasons for this; a blind man has a sense of touch vastly more sophisticated than what can be achieved by a bunch of touch sensors consisting of just a few molecules. And, even a blind man has a sense of direction and orientation because he has such sophisticated things as the movement of fluid within a balance-organ in his middle ear. But on a nano-scale virtually all liquids and even pure water behaves as if they are thicker than treacle so how can a nanobot have such a sense of direction? I had thought of equipping each nanomachine with a molecular-sized magnet and placing the whole of the brain in a powerful magnetic field but this would, at best, give it a crude sense of direction; it may tell it which way is ‘north’ but how would it be able to distinguish ‘east’ from ‘west’? And, more importantly, how would a ‘nanobot’ be able to ‘sense’ exactly where it currently is in the human brain? I don’t see how it is physically possible for something that consists of just a few molecules to have such an amazingly sophisticated senses that it can ‘sense’ exactly where it is in something as complex human brain or were it is in relation to some molecule just a few micrometers away from it. So how would a ‘nanobot’ be able to intelligently navigate through a human brain? The answer is it couldn’t.
You can rule out the possibility of making nano-sized sensors that can see in X-rays and can be used to see the microscopic damage in the human brain because, although they have shorter wavelengths than visible light, X-rays ionise orga...
I have sent the third part of my article below from the paragraph where the second part I sent ended:
...You can rule out the possibility of making nano-sized sensors that can see in X-rays and can be used to see the microscopic damage in the human brain because, although they have shorter wavelengths than visible light, X-rays ionise organic molecules and, as a result, illuminating the brain with X-rays would slowly chemical degrade the brain tissue.
But, the biggest and most fundamental problem with the concept of ’nanobots’ is the problem of how something so small that it consists of just a few molecules could have any ‘useful’ amounts of intelligence. For a ‘nanobot’ to have useful intelligence it presumably would need a nano-sized electronic computer brain. Such a computer would need to store as well as process information. To store binary bits of information (each one can have a value of either digit 0 or 1), even the most advanced computer memory would need at least one molecule to store each binary bit of information. In addition, for the ‘nanobot’ to access this memory, there would have to be connections to and from these ‘memory molecules’ which would consist of yet more molecules. You cannot squeeze in many molecules in a nano-sized computer so, therefore, a ‘nanobot’ could only store a pathetic amount of information in its memory; perhaps about one hundred bits of info at most which I don’t think is not even enough to store a really useful picture let alone any really useful computer program. How could such a pathetic amount of information in a nanobot’s memory tell it how to repair something as immensely complex as a human brain?
Then there is the problem of how much a nano-sized computer can process information; To process information, that information would have to be represented as physical signals (presumably electrical signals) in the computer that must interact at electrical switches (transistors) for the information to be processed. Each electrical switch must be represented by at least one molecule. The signals would also have to physically move around between these electrical switches else these electrical switches would not be able to ‘communicate’ with each other and the computer would be ineffective. This means that there has to be electrical connections between these electrical switches. Each one of these connections would have to be at least a few atoms thick (including the electrical insulation around each wire).
Taking all this into account, a crude calculation to estimate the number of connections you could fit into a ’nanobot’ would show that, even ignoring the room taken up by the electrical switches, it is barely possible if not impossible to fit in as many connections in a tiny brain just a few nanometers across as exists in a typical nematode brain. You would be lucky if you could squeeze one hundred such connections in such a computer. Even your average pocket calculator has vastly more connections than this. Judging from this, and assuming the number of connections is fundamental to the theoretical maximum possible magnitude of intelligence, you probably could not even give a nanobot an intelligence close to that of a nematode and a nematode cannot do very much! You certainly could not give a nanobot the intelligence of a honey bee with the same impressive ability to navigate. As for the idea that some people have that nanobots can have human-like intelligence, this is a pure absurdity.
Now some people would counter these arguments by claiming that ‘nanobots’ can work together to have a kind of collective ‘swarm intelligence’. The idea here would be that, although each nanobot would, by itself, have a tiny intelligence just like a single brain cell by itself has a tiny intelligence, they would communicate with each other, like brain cells communicate with each other, to act as a large brain that has a collective intelligence considerably more than each individual nanobot. But, a brain cell communicates with other brain cells by being static and by using static electrical connections that are in physical contact with them. If ‘nanobots’ are to navigate through a human brain, they cannot be static but must be mobile and self-propelled so they could not be constantly connected to some kind of static electrical connections between them that would allow them to communicate with each other.
So how would such nanobots communicate with each other to give rise to this ’swarm intelligence’? they would have to communicate by sending signals through the space between them without being in direct physical contact with each other. Large-scale robots can easily be designed to do this by, for example, using radio communication. But what about practical communication between robots when each one is so small that it consists of just a few molecules?
In order for a communication network to give rise to some sort of collective intelligence, one of the minimum requirements is that each part of the communication network must somehow discriminate between the different signals sent to it from the other parts of the network. This is because if each part of the network cannot discriminate between the various signals sent to it from other parts of the network then that would leave no other option but for each part of the network to respond to each such signal in a totally arbitrary or random way. But for a communication network to have ’intelligence’, it must surely be able to process information and, to process information, it must not respond to the signals within it in a totally arbitrary way but in a orderly way. And, to do that, it must be able to discriminate between the various signals sent around within it.
So in order for a swarm of nanobots communicate with each other to have a ‘collective intelligence’, each nanobot, which, remember, is just the size of only a few molecules, presumably even while it is moving around, would have to discriminate between the various signals sent to it from the other nanobots. But can something that is just the size of only a few molecules and which is mobile do this?
The most obvious ways each nanobot in a swarm could discriminate between the various signals sent to it from the other nanobots is either simply on the bases of which direction each signal came or from the identity of the nanobot that sent each signal.
One reason why practical communication between robots on a nano-scale would be virtually physically impossible is that, even if you used visible light which has a much shorter wavelength than radio waves, the laws of physics implicitly conspire to make it very hard indeed for a nano-sized sensor to tell which direction a signal is coming from. You can rule out using X-rays for this purpose because, although they have shorter wavelengths than visible light, X-rays ionise organic molecules and this would slowly chemical degrade the brain tissue. Without the ability to know which direction the signal is coming from, how would a nanobot know, for example, which other nanobot sent the signal? Or where the signal came from? And, while the nanobots are constantly moving around to navigate through the human brain, how would they keep track of each others position in order to maintain communication links that allow non-arbitrary discrimination between the various signals?
Perhaps each nanobot can be given a unique name and, every time it sends a signal, the start of the signal always consists of that name so that every signal has info on which nanobot sent that signal. But for that name to be meaningful to the nanobot that receives that signal, it would surely have to have a memory of a list of names of nanobots that send it signals and some kind of information of the distinguishing characteristics between those nanobots or, at the very least, info on how to treat the signals from each nanobot differently. But, as already has been explained, a nanobot could, at most, store only a pathetic amount of information in its tiny nano-sized computer brain so it is doubtful that such a tiny computer memory could store even that much info.
Sending the signals chemically would give rise to the same problems and would be hopelessly inefficient because all but a tiny proportion of the molecules that make up the chemical signal would be wasted by randomly defusing into the wrong direction and totally miss their intended target and the greater the distance that needs to be covered by the chemical signal, the greater the wastage. Besides, how many molecules to be used as chemical signals can something as small as a nanobot, which is just a few molecules across, can store? -the answer is not very many.
To compound these communication problems further, the laws of physics conspire to make it extremely difficult for something as small as a nanobot to send a signal in one and only one direction only. This makes it hard for a nanobot to send a signal to only the nanobot it wants to receive the signal. This is because if a nanobot sends a signal, it would tend to spread in all directions and it would be received by all the nanobots in close proximity to it. How would a nanobot that receive such signals be able to know which ones are intended for itself and which ones are not? It may be just possible to make a nano-sized laser that can be attached to a nanobot and sends a light signal in one direction only but, as already has been explained, something as small as a nanobot would, at best, have a very crude sense of direction and, in addition, would also not be able to see in which direction any of the other nanobot are. So how would such a nanobot know which direction to point such a nano-sized lazar?
My conclusion here is that, no mater how advanced technology becomes, it is not physically possible to give a nanobot any ’useful’ intelligence -not even useful ‘swarm intelligence’ and it is certainly not possible for nano...