Background:
On the most recent LessWrong readership survey, I assigned a probability of 0.30 on the cryonics question. I had previously been persuaded to sign up for cryonics by reading the sequences, but this thread and particularly this comment lowered my estimate of the chances of cryonics working considerably. Also relevant from the same thread was ciphergoth's comment:
By and large cryonics critics don't make clear exactly what part of the cryonics argument they mean to target, so it's hard to say exactly whether it covers an area of their expertise, but it's at least plausible to read them as asserting that cryopreserved people are information-theoretically dead, which is not guesswork about future technology and would fall under their area of expertise.
Based on this, I think there's a substantial chance that there's information out there that would convince me that the folks who dismiss cryonics as pseudoscience are essentially correct, that the right answer to the survey question was epsilon. I've seen what seem like convincing objections to cryonics, and it seems possible that an expanded version of those arguments, with full references and replies to pro-cryonics arguments, would convince me. Or someone could just go to the trouble of showing that a large majority of cryobiologists really do think cryopreserved people are information-theoretically dead.
However, it's not clear to me how well worth my time it is to seek out such information. It seems coming up with decisive information would be hard, especially since e.g. ciphergoth has put a lot of energy into trying to figure out what the experts think about cryonics and come away without a clear answer. And part of the reason I signed up for cryonics in the first place is because it doesn't cost me much: the largest component is the life insurance for funding, only $50 / month.
So I've decided to put a bounty on being persuaded to cancel my cryonics subscription. If no one succeeds in convincing me, it costs me nothing, and if someone does succeed in convincing me the cost is less than the cost of being signed up for cryonics for a year. And yes, I'm aware that providing one-sided financial incentives like this requires me to take the fact that I've done this into account when evaluating anti-cryonics arguments, and apply extra scrutiny to them.
Note that there are several issues that ultimately go in to whether you should sign up for cryonics (the neuroscience / evaluation of current technology, estimate of the probability of a "good" future, various philosophical issues), I anticipate the greatest chance of being persuaded from scientific arguments. In particular, I find questions about personal identity and consciousness of uploads made from preserved brains confusing, but think there are very few people in the world, if any, who are likely to have much chance of getting me un-confused about those issues. The offer is blind to the exact nature of the arguments given, but I mostly foresee being persuaded by the neuroscience arguments.
And of course, I'm happy to listen to people tell me why the anti-cryonics arguments are wrong and I should stay signed up for cryonics. There's just no prize for doing so.
Cryonics success is an highly conjunctive event, depending on a number of different, roughly independent, events to happen.
Consider this list:
Cryocompanies actually implement the cryorpreservation process susbstantially as advertised, without botching or faking it, or generally behaving incompetently. I think there is a significant (>= 50%) probability that they don't: there have been anecdotal allegations of mis-behavior, at least one company (the Cryonics Institute) has policies that betray gross incompetence or disregard for the success of the procedure ( such as keeping certain cryopatients on dry ice for two weeks ), and more generally, since cryocompanies operate without public oversight and without any mean to assess the quality of their work, they have every incentive to hide mistakes, take cost-saving shortcuts, use sub-par materials, equipment, unqualified staff, or even outright defraud you.
Assuming that the process has actually preserved the relevant information, technology for recover it and revive you in some way must be developed. Guessing about future technology is difficult. Historically, predicted technological advances that seemed quite obvious at some point (AGI, nuclear fusion power, space colonization, or even flying cars and jetpacks) failed to materialize, while actual technological improvements were often not widely predicted many years in advance (personal computers, cellphones, the Internet, etc.). The probability that technology many years from now goes along a trajectory we can predict is low.
Assuming that the tech is eventually developed, it must be sufficiently cheap, and future people must have an incentive to use it to revive you. It's unclear what such an incentive could be. Revival of a few people for scientific purposes, even at a considerable cost, seems plausible, but mass revival of >thousands frozen primitives?
Your cryocompany must not suffer financial failure, or some other significant local disruption, before the tech becomes available and economically affordable. Very few organizations survive more than one century, and those which do, often radically alter their mission. Even worse, it is plausible that before revival tech becomes available, radical life extension becomes available, and therefore people stop signing up for cryonics. Cryocompanies might be required to go on for many decades or centuries without new customers. It's unclear that they could remain financially viable and motivated in this condition. The further in the future revival tech becomes available, the lower the chances that your cryocompany will still exist.
Regional or planetary disasters, either natural (earthquake, flood, hurricane, volcanic eruption, asteroid strike, etc.) or human-made (war, economic crisis, demographic crisis due to environmental collapse, etc.) must not disrupt your preservation. Some of these disaster are exceptional, other hit with a certain regularity over the course of a few centuries. Again, the further in the future revival tech becomes available, the lower the chances that a disaster will destroy your frozen remains before.
You can play with assigning probabilities to these events and multiplying them. I don't recommend trusting too much any such estimate due to the fact that it is easy to fool yourself into a sense of false precision while picking numbers that suit whatever you already wanted to believe.
But the takeaway point is that in order to cryonics to succeed, many things have to happen or be true in succession, and the failure of only one of them would make cryonics ultimately fail at reviving you. Therefore, I think, cryonics success is so improbable that it is not worth the cost.