I agree with you on both points. And also about the error bars—I don’t think I can “prove” cryonics to be pointless.
But one has to make decisions based on something. I would rather build a school in Africa than have my body frozen (even though, to reiterate, I’m all for living longer, and I do not believe that death has inherent value).
Biggest obstacles are membrane distortions, solvent replacement and signalling event interruptions. Mind is not so much written into the structure of the brain as into the structure+dynamic activity. In a sense, in order to reconstruct the mind within a frozen brain, you would have to already know what that mind looks like when it’s active. Then you need molecular tools which appear impossible from the fundamental principles of physics (uncertainty principle, molecular noise, molecular drift...).
My view of cryonics is that it is akin to mercuric antibiotics of the late 19th century. Didn’t really work, but they were the only game in town. So perhaps with further research, new generation of mercuric substances will be developed which will solve all the problems, right? In reality, a much better solution was discovered. I believe this is also the case with life extension—cryonics will fade away, and we’ll move in with a combination of stem cell treatments, technologies to eliminate certain accumulated toxins (primarily insoluble protein aggregates and lipid peroxidation byproducts), and methods to eliminate or constrain cellular senescence (I’m actually willing to bet ~$5 that these are going to be the first treatments to hit the market).
I agree with you that the enormous cost is probably not worth it, when you start thinking what else could be accomplished with the money in the context of it’s low probability of success.
However, those technologies that increase human lifespan are really something entirely different than cryonics, not a replacement for it.
Even if we increase lifespan significantly, as long as we still have a lifespan cryonics would allow us to remain frozen until even more life extension technologies come about. It’s also a potentially viable method for keeping people alive for long distance space travel at sub-relativistic speeds.
I’d look forward to seeing a more detailed post (or even a journal article) from you going into the biochemistry specifics of the problems with cryonics you mention in this post, and your other posts in this thread. I am particularly curious why rehydration would denature proteins which are naturally stable in water? And what sort of membrane distortions would occur that aren’t reversible?
The questions you ask are very complex. The short answers (and then I’m really leaving the question at that point until a longer article is ready):
Rehydration involves pulling off the stabilizer molecules (glycerol, trehalose) and replacing them dynamically with water. This can induce folding changes, some of which are irreversible. This is not theoretical: many biochemists have to deal with this in their daily work.
Membrane distortions also distort relative position of proteins within that membrane (and the structure of synaptic scaffold, a complex protein structure that underlies the synaptic membrane). Regenerating the membrane and returning it to the original shape and position doesn’t necessarily return membrane-bound molecules to their original position.
I agree with you on both points. And also about the error bars—I don’t think I can “prove” cryonics to be pointless.
But one has to make decisions based on something. I would rather build a school in Africa than have my body frozen (even though, to reiterate, I’m all for living longer, and I do not believe that death has inherent value).
Biggest obstacles are membrane distortions, solvent replacement and signalling event interruptions. Mind is not so much written into the structure of the brain as into the structure+dynamic activity. In a sense, in order to reconstruct the mind within a frozen brain, you would have to already know what that mind looks like when it’s active. Then you need molecular tools which appear impossible from the fundamental principles of physics (uncertainty principle, molecular noise, molecular drift...).
My view of cryonics is that it is akin to mercuric antibiotics of the late 19th century. Didn’t really work, but they were the only game in town. So perhaps with further research, new generation of mercuric substances will be developed which will solve all the problems, right? In reality, a much better solution was discovered. I believe this is also the case with life extension—cryonics will fade away, and we’ll move in with a combination of stem cell treatments, technologies to eliminate certain accumulated toxins (primarily insoluble protein aggregates and lipid peroxidation byproducts), and methods to eliminate or constrain cellular senescence (I’m actually willing to bet ~$5 that these are going to be the first treatments to hit the market).
I agree with you that the enormous cost is probably not worth it, when you start thinking what else could be accomplished with the money in the context of it’s low probability of success.
However, those technologies that increase human lifespan are really something entirely different than cryonics, not a replacement for it.
Even if we increase lifespan significantly, as long as we still have a lifespan cryonics would allow us to remain frozen until even more life extension technologies come about. It’s also a potentially viable method for keeping people alive for long distance space travel at sub-relativistic speeds.
I’d look forward to seeing a more detailed post (or even a journal article) from you going into the biochemistry specifics of the problems with cryonics you mention in this post, and your other posts in this thread. I am particularly curious why rehydration would denature proteins which are naturally stable in water? And what sort of membrane distortions would occur that aren’t reversible?
All good reason to keep working on it.
The questions you ask are very complex. The short answers (and then I’m really leaving the question at that point until a longer article is ready):
Rehydration involves pulling off the stabilizer molecules (glycerol, trehalose) and replacing them dynamically with water. This can induce folding changes, some of which are irreversible. This is not theoretical: many biochemists have to deal with this in their daily work.
Membrane distortions also distort relative position of proteins within that membrane (and the structure of synaptic scaffold, a complex protein structure that underlies the synaptic membrane). Regenerating the membrane and returning it to the original shape and position doesn’t necessarily return membrane-bound molecules to their original position.