[Eliezer]

Cryonics advocates are by and large not very interested in trying to justify estimates that give a reasonable chance of success

Sounds simply wrong to me, and I know a lot of cryonics advocates. The ones I know try to explain why current vitrification technology ought to preserve neural microstructure. Others work on better vitrification technology. I really don't know where you're getting this from.

[arakyd]

Sorry, it would be more accurate to restrict that to "Based on the above FAQs and other discussions on Overcoming Bias and Less Wrong, cryonics advocates don't seem...."

From http://www.benbest.com/cryonics/CryoFAQ.html#_VQ_: What is the chance that cryonics will work ?

The chance that cryonics will work depends greatly upon the conditions under which a person is cryopreserved. [...] Probability estimates of future technology cannot be anything other than guesswork, although molecular repair technology does appear to be inevitable. [...] Rather than passively attempting to calculate probability, a person is better advised to realized that preparation to prevent potential problems will greatly affect the probability of success for that person and his/her loved-ones. The chance that cryonics will work also depends greatly upon how much money and effort is put into the technologies and organizational enhancements that can make cryonics work. [...]

From http://www.alcor.org/sciencefaq.htm: What can scientists disagree on about cryonics?

[...] The likelihood that technologies capable of the required analysis, repair, and tissue regeneration will be developed.

The practicality of maintaining cryopreserved people long enough for such technologies to be developed. [...]

The ethics of not cryopreserving people until cryonics is proven to work.

There certainly is plenty of discussion about vitrification, but that is a relatively small part of the equation. Looking at Robin Hansen's post again, he links another breakdown of the total chance of success at http://www.alcor.org/Library/html/WillCryonicsWork.html. These are the only two attempts I know of, and they do a pretty good job of showing how speculative the whole thing is and how much variation that produces in the estimates.

[sho]

Well, yes, it's still a bit of a leap of faith. But a slim chance is better than none at all, right?

As long as it doesn't influence one's life choices - ie, relying on a successful reanimation to fulfil some goal or what not - I don't see why anyone would not at least give it a shot. Best case scenario, you wake up healthy and hearty in the magnificent future. Worst case scenario, you're dead. But if you don't freeze you're dead anyway, for sure. So why not?

[arakyd]

It sounds pretty good when you focus on the payoff, gloss the probability of success (as if the difference between 77% and 0.002% is negligible, or either estimate is anything other than pure speculation), and ignore the costs entirely.

[sho]

Well, we're obviously unable to estimate the probabilities accurately, but from what I know of the subject 0.002% is exceedingly pessimistic. I am no expert, but do follow this stuff, and IMO the chances are actually pretty good. And the payoff, if successful, is basically infinity.

The Harris essay (on the Amcor site) you linked to, by the way, I have many problems with. It purports to take a scientific approach to estimating the probably of success and yet has many inexplicable red herrings that bring down the final total, for example a fanciful excursion into numerous world disaster scenarios which, while entertaining, are pretty tangential to the question at hand. Other "risks" he factors in, like the company going out of business or the storage becoming illegal in that country, are not related to the technology per se and would be handled by the suspendee's descendents or trustees - they are only reasonable if one assumes a complete lack of preparation for the execution of your wishes, and a complete lack of action by your living representatives if you had. They do not belong in the final estimate either. I would take his "optimistic" estimate and multiply it by three, or more.

The cost is somewhere around $250k. That's not insignificant but certainly not out of reach for many, especially in their old age. What else would you do with the money? Even if it's unsuccessful, at least you're capitalising companies doing research for the good of the species. And what's the alternative? Certain oblivion, rotting in the ground, with the money going to general revenue?

When the payoff is infinity it is rational to take any non-zero bet, and the entry price is not even that high. I'll be taking that bet. Don't know why you're so down on it really.