This post is off-topic, as it is not concerned with the art of refining human rationality.
Edit: Rather more helpful response downthread.
Nonsense. It concerns the instrumental (and epistemic) rationality of personal survival.
Aside from that though, weren't you the one complaining about lack of practical research in cryonics as opposed to speculation? I'd think this was right up your alley in that respect.
You mean, "rationality is about getting the things I want, this post is about something I want, therefore this post is about rationality"?
Your post appears to be asking for suggestions as to methods of gathering engineering effort to improve a particular medical technology. You haven't made it clear how this is any more relevant to refining the art of human rationality than any other possible thing that any given person might want to happen.
Also, you appear to be using the term "epistemic rationality" for what I believe is termed "instrumental rationality".
I have an interest in the subject, but discussion of it is, I would think, on-topic here insofar as it relates to the art of refining human rationality. This post really doesn't seem to relate to that very much at all.
The primary focus of the article is instrumental, but there are epistemic elements as well because if you can run actual experiments, you can get closer to the truth than by thought experiments alone. Perhaps I should edit the article to say more about that directly.
If you can make it more on-topic - for instance, a worked example of a detailed abstract point about thinking, where you lead with the abstract point and then give the worked example - that'd make quite a good post IMO.
(I find writing here I tend to use the conventional "good writing" rule of "show, don't tell", when really I suspect I should be using "tell, then also show". If this post is really about thinking, then it's all "show" and no "tell".)
Vitrification already eliminates all ice formation -- we know enough to know that without toxicity, it should work for trivially reversible forms of long-term suspended animation.
There is still fracturing during cool-down, which is damage independent of toxicity, and there are likely other problems to take care of before freezing is reversible.
Fracturing only happens (in properly vitrified tissues) when you cool to LN2 temperatures. If you cool only to just below the glass transition temperature, there is no cracking. 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.
Vitrification, toxic or not, clearly preserves information in the same sense and for the same reasons fracturing doesn't additionally lose it. 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.
Fracturing only happens (in properly vitrified tissues) when you cool to LN2 temperatures.
I agree, to this extent your statement holds (barring the unknowns).
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.
If you can make it more on-topic - for instance, a worked example of a detailed abstract point about thinking, where you lead with the abstract point and then give the worked example - that'd make quite a good post IMO.
(I find writing here I tend to use the conventional "good writing" rule of "show, don't tell", when really I suspect I should be using "tell, then also show". If this post is really about thinking, then it's all "show" and no "tell".)
From the article The red blood cell as a model for cryoprotectant toxicity by Aschwin de Wolf
One simple model that allows for “high throughput” investigations of cryoprotectant toxicity are red blood cells (erythrocytes). Although the toxic effects of various cryoprotective agents may differ between red blood cells, other cells, and organized tissues, positive results in a red blood cell model can be considered the first experimental hurdle that needs to be cleared before the agent is considered for testing in other models. Because red blood cells are widely available for research, this model eliminates the need for animal experiments for initial studies. It also allows researchers to investigate human cells. Other advantages include the reduced complexity of the model (packed red blood cells can be obtained as an off-the-shelf product) and lower costs.
It sounds to me like this is a very cheap assay for viability. You don't need much equipment. High toxicity compounds can be screened on visual appearance. More detailed analysis can be done by a light microscope or a spectrophotometer.
The biggest issue facing cryonics (and the holy grail of suspended animation with true biostasis) is the existence of cryoprotectant toxicity. Less toxic solutions can be perfused for a longer period of time, and thus penetrate the entire organism without triggering additional loss of viability. Vitrification already eliminates all ice formation -- we know enough to know that without toxicity, it should work for trivially reversible forms of long-term suspended animation.
Thus if we want to ask what can be done cheaply by a lot of people to help cryonics move forward, one possibility is that they could perform empirical tests on the compounds most likely to prove effective for cryoprotection.
We can speculate about the brain being reparable at all kinds of levels of damage -- but that is speculation. Sure we do have to make a decision to sign up or not based on that speculation. But the more hard evidence we can obtain, the more of a chance that we aren't being distracted from the reality of the situation by wishful thinking -- and the more likely we are to persuade our fellow self-identifying rational skeptics to take our side. Furthermore (and I know this sounds obvious, but it still needs to be said) in taking a more empirical approach to actually resolving the issues as quickly as possible, we are more likely to survive than otherwise.
There are still a lot of questions that are raised in my mind by this crowdsourcing idea. What kinds of mechanisms would be best for collaboration and publication of results? Are there many other dirt-cheap empirical testing methods that small unfunded groups of nonspecialists could employ for useful research? How many people and groups could/should get involved in such a project? Aschwin mentions "theoretical work in organic chemistry" as the first step -- how much of that has already been done, or needs to be done? What kind of a learning curve is there on learning enough organic chemistry to propose a useful test?