CRYO: Nature's little cryonauts

Eugene Leitl (
Tue, 10 Aug 1999 13:12:42 -0700 (PDT)

Jeff Fabijanic writes:

> Maybe you wish to have a highly technical discussion about cryobiology -
> that would be most welcome. But please take pains to define all your terms

I'm pretty new to cryobiology so I'm not actually capable of holding a "highly technical" discussion.

> precisely beforehand and take care not to patronize those of us who are
> sharing legitimate and truthful experiences. So far, you haven't said much

Look, if we have difficulties at very basic concepts this will lead exactly nowhere. Let's assume "frozen" means that the entire organism has undergone a phase transition to ice. No residual fluid, little if any water glass present.

> in this thread other than to attempt to discredit the first-hand
> observations of fellow list members.

I cannot hardly try to discredit "observation", because as used in this particular context it can mean basically anything. Let's go for "measurement", ok?

So, how do you know how much of the tissue was frozen (in above sense)?

> 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. Instead of
> chastising us for our venacular use of language, why don't you educate us
> as to what is happening in the body of that fish and those flies, and what
> it suggests for the future of human cryonics. After all, most people here

I thought it was pretty obvious that a nontrivial organism that is frozen cannot spontaneously resume functioning (and its repair is well beyond our capabilities). Also, long-term stability of cryogenically stored biological systems is only viable below -80..-100 deg C (best vitrified and stored at ~-130 deg C, somewhat higher if vitrification agents with higher glass transition temperatures are used). At this temperatures the phase transition is complete, which incidentially damages the organism sufficiently (with the exception of a few primitive, hardy critters).

Temperatures used by Suda give preservation on week and month scale. At this temperatures both deterioration is not arrested, and devitrification is a very rapid process (i.e. you can watch the ice crystals growing in the glass).

> don't care if it's an ice sitzbath, a dip in liquid N, a shot in the arm,
> or a combination of those and other technologies that allow us to extend
> our 'natural' life spans - perhaps to a world with technologies capable of
> vastly lengthening that span, perhaps to new worlds all together.

All this is very laudable, but one should try to keep the science/BS ratio in the constructive regime.