X-Message-Number: 19888 Date: Thu, 22 Aug 2002 09:52:42 -0400 From: Thomas Donaldson <> Subject: CryoNet #19857 - #19867 Back to Steven Harris: I never said that we must have absolute knowledge to estimate probabilities. I merely pointed out that with very little knowledge our estimates were bound to be so off-base that they're very likely to be meaningless or false. The space travel issue to which you allude would be very hard to attach dates to until it actually started to happen, though an understanding of the physics involved in rockets would have told someone that it was indeed possible for it TO happen. Someday, sometime. I will note that early predictions of how far along we would be NOW with space travel were quite wrong. Where are our moon colonies or our Mars colonies? To estimate probabilities in such a situation, say in 1950, would have been meaningless. As time passed, and we learned more (and more was actually done) it became more and more reasonable to estimate probabilities, though the exact events which we were estimating remained cloudy. For cryonics, as work goes on we do learn more, and some events become sharp enough that we can estimate their probability. Successful vitrification of brains would be one case. Just what effect such an event would have on cryonics as a movement, and growth of cryonics, still remains cloudy. (Yes, I'd prefer to be vitrified, given particular conditions). When will cryonics be adopted widely? I have no idea, and still discount any ideas of working out the probability of such an event. As I discussed in a later message on the same subject, probability of either space travel or widespread cryonics (with widespread revivals) suffers from a second problem too: we are not standing apart from these events and estimating their probability like we estimate the probability with a pair of unweighted dice. We are all busily trying to change that probability. That makes it very hard to estimate probabilities when we're constantly changing the assumptions we must use to do so. Perhaps I did not explain these ideas as well as I should have, but there they are. I do not think that science should or does have anything to say about this general problem: we want to reach a greater understanding of how the world works, and then use that understanding. Sometimes that involves an understanding of probabilities, other times not. For Scott Badger: We've had private correspondence on this question. Glucose levels are certainly involved in calorie restriction, but it does not follow that changing them will cause the same effect. Best wishes and long long life for all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=19888