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.
Actually, let's start by supposing a non-destructive scan.
The resulting being is someone who is identical to you, but diverges at the point where the scan was performed.
Let's say your problem is that you have a fatal illness. You've been non-destructively scanned, and the scan was used to construct a brand new healthy you who does everything you would do, loves the people you love, etc. Well, that's great for him, but you are still suffering from a fatal illness. One of the brainscan technicians helpfully suggests they could euthanize you, but if that's a solution to your problem then why bother getting scanned and copied in the first place? Your could achieve the same subjective outcome by going straight to the euthanasia step.
Now, getting back to the destructive scan. The only thing that's different is you skip the conversation with the technician and go straight to the euthanasia step. Again, an outcome you could have achieved more cheaply with a bottle of sleeping pills and a bottle of Jack Daniels.
After the destructive scan, a being exists that remembers being me up to the point of that scan, values all the things I value, loves the people I love and will be there for them. Regardless of anyone's opinion about whether that being is me, that's an outcome I desire, and I can't actually achieve it with a bottle of sleeping pills and a bottle of Jack Daniels. Absolutely the same goes for the non-destructive scan scenario.
...maybe you don't have kids?