Re: CRYO: Nature's little cryonauts
Thu, 5 Aug 1999 09:56:40 -0700

Jeff Fabijanic, <>, 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".