X-Message-Number: 4826 From: Garret Smyth <> Newsgroups: sci.cryonics Subject: Re: Blue Blood Date: Mon, 21 Aug 95 00:38:29 GMT Message-ID: <> References: <40sc33$> > > The cracking in large tissue samples is usually attributed to > > mechanical strain because of a temperature gradient. One part of the > > patient has contracted more than the rest and stress is built up. > > Is it known for sure that this is the cause, rather than the different > constituents of flesh having different coefficients of expansion? Dr Johnson, best known for writing the first dictionary and for leaving a lot of quotes, was once at a dinner party. A woman at the table pointed out to him a rather simple mistake he had made in his dictionary, which he acknowledged. She added that she was surprised by his being tripped up by such a simple error when she, not known for great intelligence, spotted at once. How could this be? "Sheer ignorance, ma'am, sheer ignorance." Okay, you've guessed it, I don't know whether cracking is due to different coefficients of expansion or the same one at different temperatures. CI's recent work suggests that very slow cooling avoids cracking which would weigh in on the gradient theory. Perhaps others better equipped than me to answer this could come in. > > > ... clean cracks that occur in solids should allow us (or our friends > > in the future) to map both surfaces and work out where they fitted > > together, and then knit up the molecules. > > Maybe. On the other hand, where does the released strain energy go > when a crack happens? If it goes into extremely localized heating, > it could thoroughly scramble the structure for several microns on both > sides of the crack. Yes, I admit to being overly positive. I've heard this suggestion before and can't give an answer off the top of my head. Scary thought, eh? In reply to Y. Bonnozzetti's posting, I still don't think that it is the expansion of ice that causes problems but in saying that don't get the impression I am trivialising the problems. As I mentioned above, the cracking problem is scary, fine physiological damage problems are scary, just getting suspended (and then staying in long enough) is scary. All the reasons why cryonics might not work, at least for those frozen today, add up to an awful lot of scaryness. The upside is that your chances of revival are far better with cryonics than with anything else, such as burial or being put on a disc. It occurs to me that the form of the cracks might give some info about their cause. Differences in the rate of contraction of different tissues might lead to changes in the fracture patterns at junctions between tissues, but fractures solely due to strain from a temperature gradient should go clean across different tissues. Anyone got any pictures? TTFN Garret -- Garret Smyth Phone: 0181 789 1045 or +44 181 789 1045 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4826