Well, I would say the question of whether ball had the "same" bounciness when you filled it back up with air would either mean just that it bounces the same way (i.e., has the same amount of air in it) or is meaningless. The same goes for your faculties. I don't think the question of whether you're the same person when you wake up as when you went to sleep - absent your being abducted and replaced with a doppelgänger - is meaningful. What would "sameness" or "difference" here mean? That seems to me to be another case of conceiving of your faculties as something object-like, but in this case one set disappears and is replaced by another indistinguishable set. How does that happen? Or have they undergone change? Do they change without there being any physical change? With the ball we let the air out, but what could happen to me in the night that changes my identity? If I merely lost and regained by faculties in the night, they wouldn't be different and it wouldn't make sense to say they were indistinguishable either (except to mean that I have suffered no loss of faculties).
It's correct that two balls can bounce in the same way, but quite wrong to think that if I replace one ball with the other (that bounces in the same way) I have the same ball. That's true regardless of how many attributes they share in common: colour, size, material composition, etc. I can make them as similar as I like and they will never become the same! And so it goes with people. So while your doppelgänger might have the same faculties as you, it doesn't make him the same human being as you, and, unlike you, he wasn't the person who did X on your nth birthday, etc, and no amount of tinkering will ever make it so. Compare: I painstakingly review footage of a tennis ball bouncing at Wimbledon and carefully alter another tennis ball to make it bounce in just the same way. No amount of effort on my part will ever make it the ball I saw bounce at Wimbledon! Not even the finest molecular scan would do the trick. Perhaps that is the scenario you prefer, but, you're quite right, I find it very odd.
I don't think the question of whether you're the same person when you wake up as when you went to sleep [..] is meaningful.
I'm content to say that, though I'd also be content to say that sufficient loss of faculties (e.g., due to a stroke while I slept) can destroy my identity, making me no longer the same person. Ultimately I consider this a question about words, not about things.
Do [your faculties] change without there being any physical change?
Well, physical change is constant in living systems, so the whole notion of "without physical cha...
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:
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:
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:
is one way. But:
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.