From: hal@finney.org
Date: Thu Aug 05 1999 - 10:56:40 MDT
Jeff Fabijanic, <jeff@primordialsoft.com>, writes:
> Personally, I don't give a chilly rat's ass if a fish frozen to -10F is not
> "technically" frozen. What I care about is that it seems that an animal in
> this state has none of the typical traits we associate with living
> creatures, yet can survive the ordeal and thrive upon thawing.
I think the problem is that at these relatively high temperatures, there
is still considerable chemical activity. It's like meat in your freezer.
Gradually, over time, it is still changing. Ice crystals are continuing
to grow, chemical reactions are occuring, even decay is occuring -
it's just slowed down. But it's not really safe to eat after a period
of years, nor would the goldfish and flies survive many years of being
frozen (presumably).
What we want with cryonics is complete preservation, especially of the
very fine structures in the neural tissue. For that, you want things
to be completely solid, with no liquids where molecules can diffuse
around and engage in chemical reactions. This requires considerably
colder temperatures than what you'd find in your freezer or in nature
(although they don't actually have to be as cold as liquid nitrogen).
So these observations of fish and flies surviving "freezing" aren't that
relevant to cryonics, and the reason does lie in the technical meaning
of the word "frozen".
Hal
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