In June 2012, Robin Hanson wrote a post promoting plastination as a superior to cryopreservation as an approach to preserving people for later uploading. His post included a paragraph which said:
We don’t actually know that frozen brains preserve enough brain info. Until recently, ice formation in the freezing process ripped out huge brain chunks everywhere and shoved them to distant locations. Recent use of a special anti-freeze has reduced that, but we don’t actually know if the anti-freeze gets to enough places. Or even if enough info is saved where it does go.
This left me with the impression that the chances of the average cryopreserved person today of being later revived aren't great, even when you conditionalize on no existential catastrophe. More recently, I did a systematic read-through of the sequences for the first time (about a month 1/2 ago), and Eliezer's post You Only Live Twice convinced me to finally sign up for cryonics for three reasons:
- It's cheaper than I realized
- Eliezer recommended Rudi Hoffman to help with the paperwork
- Eliezer's hard drive analogy convinced me the chances of revival (at least conditionalizing on no existential catastrophe) are good
Note: Signing of this letter does not imply endorsement of any particular cryonics organization or its practices. Opinions on how much cerebral ischemic injury (delay after clinical death) and preservation injury may be reversible in the future vary widely among signatories.
I don't find that terribly encouraging. So now I'm back to being pessimistic about current cryopreservation techniques (though I'm still signing up for cryonics because the cost is low enough even given my current estimate of my chances). But I'd very much be curious to know if anyone knows what, say, Nick Bostrom or Anders Sandberg think about the issue. Anyone?
Edit: I'm aware of estimates given by LessWrong folks in the census of the chances of revival, but I don't know how much of that is people taking things like existential risk into account. There are lots of different ways you could arrive at a ~10% chance of revival overall:
- (50% chance of no existential catastrophe) * (30% chance current cryopreservation techniques are adequate) * (70% chance my fellow humans will come through for me beyond avoiding existential catastrophe) = 10.5%
is one way. But:
- (15% chance no existential catastrophe) * (99% chance current cryopreservation techniques are adequate) * (70% chance my fellow humans will come through for me beyond avoiding existential catastrophe) = ~10.4%
is a very similar conclusion from very different premises. Gwern has more on this sort of reasoning in Plastination versus cryonics, but I don't know who most of the people he links to are so I'm not sure whether to trust them. He does link to a breakdown of probabilities by Robin, but I don't fully understand the way Robin is breaking the issue down.
I was referring cryonics scenarios where the brain is being scanned because you cannot be revived and a new entity is being created based on the scan, so I was assuming that your brain is no longer viable rather than that the scan is destructive.
The resulting being, if possible, would be a being that is confused about its identity. It would be a cruel joke played on those who know me and, possibly, on the being itself (depending on the type of being it is). I am not my likeness.
Consider that, if you had this technology, you could presumably create a being that thinks it is a fictional person. You could fool it into thinking all kinds of nonsensical things. Convincing it that it has the same identity as a dead person is just one among many strange tricks you could play on it.
Fair enough.
I'm positing that the ... (read more)