The rationality question of cryonics stands even if we learn to revive frozen severed heads, because there still will be cases of damage that is not reversible with contemporary technology.
Suppose an emergency medical procedure such as CPR fails to save the patient 9 times out of 10. We would probably consider it worth attempting in an emergency context where the patient is otherwise dead. Nonetheless it is still desirable to refine the procedure until it saves closer to 10 out of 10. Furthermore if it saved something like 9 out of 10, a rational society would tend to invest more resources in universalizing the procedure than if it only saved 1 out of 10.
Vitrification, toxic or not, clearly preserves information in the same sense and for the same reasons fracturing doesn’t additionally lose it.
These are independent reasons for failure. If cracking causes failure it is for one reason (inability to reconnect things while at cryogenic temperatures), toxicity would be for different reasons (e.g. degradation of enzymes, cell wall rupturing). If both forms of damage are present, the total probability of failure is higher than if only one form of damage is present. They aren’t fully independent in that certain events (friendly superintelligence, extremely high grade nanotech, etc.) seemingly would/should solve both issues simultaneously—but that does not change the fact that scenarios in which only one of them is problematic are also plausible.
The question of whether to do it or not quite clearly does not exist if we’re getting demonstrably nonzero survival rate.
Yes it does stand. There are always tradeoffs and human irrationality to answer it either way. One of the benefits of reversible suspension is, as you pointed out, convincing people who currently don’t respond to non-empirical arguments.
This is not 100% clear to me. It sounds highly likely (I certainly do think it is the case that vitrification does not cause information theoretic damage), but not to quite the same degree that repairing cracks seems likely.
Yes, but don’t allow yourself sliding towards the fallacy of gray. It’s not an uncertainty significant enough to become relevant for any decisions in question, and so I don’t see how your comment points out more than a technical detail. It seems to fail to answer my objection to the grandparent comment, where you said
Furthermore, with cracking there is a lot less guesswork as far as its repairability goes—we know cracks don’t impact information-theoretic criteria. With other kinds of damage the information could go roughly the way of a curiously shaped salt crystal that has been dropped into a glass of water.
which clearly implies rather more uncertainty about whether toxic vitrification preserves information than “I certainly do think it is the case that vitrification does not cause information theoretic damage” in the comment above, even if you can find an interpretation consistent with all this text that doesn’t say so. Which is your present position?
Also worth noting is that these are independent forms of damage—cracking plus toxicity is less likely to be repairable than cracking or toxicity by themselves.
How (much) so? Difficulty of repair is independent of risk of losing information. It’s more difficult to repair it all, but I’d say all information is still there (as sure as the Sun will rise tomorrow, though I won’t argue this level of certainty, and there is also the not so settled question about the Sun) even if you drop a frozen non-vitrified brain (without autophagy-like damage) and shatter it to a thousand pieces; it might merely be impossible to repair using human-level technology afterwards.
Suppose an emergency medical procedure such as CPR fails to save the patient 9 times out of 10. We would probably consider it worth attempting in an emergency context where the patient is otherwise dead. Nonetheless it is still desirable to refine the procedure until it saves closer to 10 out of 10. Furthermore if it saved something like 9 out of 10, a rational society would tend to invest more resources in universalizing the procedure than if it only saved 1 out of 10.
These are independent reasons for failure. If cracking causes failure it is for one reason (inability to reconnect things while at cryogenic temperatures), toxicity would be for different reasons (e.g. degradation of enzymes, cell wall rupturing). If both forms of damage are present, the total probability of failure is higher than if only one form of damage is present. They aren’t fully independent in that certain events (friendly superintelligence, extremely high grade nanotech, etc.) seemingly would/should solve both issues simultaneously—but that does not change the fact that scenarios in which only one of them is problematic are also plausible.
Yes it does stand. There are always tradeoffs and human irrationality to answer it either way. One of the benefits of reversible suspension is, as you pointed out, convincing people who currently don’t respond to non-empirical arguments.
Yes, but don’t allow yourself sliding towards the fallacy of gray. It’s not an uncertainty significant enough to become relevant for any decisions in question, and so I don’t see how your comment points out more than a technical detail. It seems to fail to answer my objection to the grandparent comment, where you said
which clearly implies rather more uncertainty about whether toxic vitrification preserves information than “I certainly do think it is the case that vitrification does not cause information theoretic damage” in the comment above, even if you can find an interpretation consistent with all this text that doesn’t say so. Which is your present position?
How (much) so? Difficulty of repair is independent of risk of losing information. It’s more difficult to repair it all, but I’d say all information is still there (as sure as the Sun will rise tomorrow, though I won’t argue this level of certainty, and there is also the not so settled question about the Sun) even if you drop a frozen non-vitrified brain (without autophagy-like damage) and shatter it to a thousand pieces; it might merely be impossible to repair using human-level technology afterwards.