I don’t understand the distinction being made. The chance of revival and peace of mind aren’t separate things: it is the former that causes the latter.
If you are not a cryonics member, what would make you decide that it is a good idea?
I don’t think it’s a crazy idea, but I’m not signed up. I might reconsider after some leaps and bounds in the technology, like successful short-term freezing and revival of humans. I am not expecting to see that within my expected lifespan.
C. Elegans can be already cryopreserved and revived, mice can’t.
Keep in mind that any success on small organism doesn’t necessarily translate to larger organisms due to the square-cube law: the heat capacity of an organism, or its brain, is proportional to its volume, while the speed at which you can cool it for a given temperature difference is proportional to its surface.
If the temperature difference between the inside and the outside is too high, the outer layers freeze/vitrify and contract before the inner layers, causing cracking. If the cooling speed is too low, you get lots of ischemic damage and large ice crystal formation. Ice crystal formation can be reduced or inhibited using cryoprotectants, but the slower the cooling speed the higher the concentration of cryoprotectants is needed, and cryoprotectants are toxic at certain concentrations (used by cryonics companies), causing protein denaturation an cell membrane distortion. The speed at which you can perfuse cryoprotectants is also limited by a square-cube law. In the protocol used by cryonics companies, cryoprotectants perfusion takes many hours.
A mouse brain is about 3,000 times smaller than a human brain by mass, therefore even if someone managed to cryopreserve and revive a mouse it wouldn’t imply that the method is scalable to humans.
Those would be steps on the way, of course. I thought C. elegans had been done already, and anyway, there are any number of tinier creatures that can go into decades-long stasis naturally. A mouse is where it begins to get interesting, but it is future me who would be reconsidering, and I can’t speak for him.
I don’t understand the distinction being made. The chance of revival and peace of mind aren’t separate things: it is the former that causes the latter.
I don’t think it’s a crazy idea, but I’m not signed up. I might reconsider after some leaps and bounds in the technology, like successful short-term freezing and revival of humans. I am not expecting to see that within my expected lifespan.
Would you reconsider if you saw successful revival of a small organism? C. Elegans? A mouse?
C. Elegans can be already cryopreserved and revived, mice can’t.
Keep in mind that any success on small organism doesn’t necessarily translate to larger organisms due to the square-cube law: the heat capacity of an organism, or its brain, is proportional to its volume, while the speed at which you can cool it for a given temperature difference is proportional to its surface.
If the temperature difference between the inside and the outside is too high, the outer layers freeze/vitrify and contract before the inner layers, causing cracking. If the cooling speed is too low, you get lots of ischemic damage and large ice crystal formation.
Ice crystal formation can be reduced or inhibited using cryoprotectants, but the slower the cooling speed the higher the concentration of cryoprotectants is needed, and cryoprotectants are toxic at certain concentrations (used by cryonics companies), causing protein denaturation an cell membrane distortion.
The speed at which you can perfuse cryoprotectants is also limited by a square-cube law. In the protocol used by cryonics companies, cryoprotectants perfusion takes many hours.
A mouse brain is about 3,000 times smaller than a human brain by mass, therefore even if someone managed to cryopreserve and revive a mouse it wouldn’t imply that the method is scalable to humans.
Those would be steps on the way, of course. I thought C. elegans had been done already, and anyway, there are any number of tinier creatures that can go into decades-long stasis naturally. A mouse is where it begins to get interesting, but it is future me who would be reconsidering, and I can’t speak for him.