X-Message-Number: 5085
From: 
Date: Wed, 1 Nov 1995 11:16:11 -0500
Subject: more pressure

A few additional comments on hyperbaric freezing--with the preface that of
course I am not, at this stage, seriously proposing any substantive effort in
this direction, only kicking the notion around a little,  again. (I
originally mentioned "wild idea.") To switch from procedures that have had
revival success with many living specimens to procedures that have not would
require the most careful and multi-sided consideration, obviously. However,
it is not yet clear to me that the notion should be totally discarded.

Keith Lynch (#5083) says that adequate heat sink (to remove heat of fusion
upon freezing when the pressure is released) could not be obtained except by
very damaging methods. However, I pointed out that, if the freezing were done
at around a sub-zero temperature equal in Centigrade degrees to the heat of
fusion in calories/gram--roughly 80 at standard conditions--then the heat of
fusion, if it remains local, would not raise the temperature above the
normobaric freezing point, so no heat sink would be needed. 

Ben Best (# 5084) says the idea is intended to reduce freezing damage. It is
not. It is intended to reduce degradation of information. Maybe I need to
emphasize or clarify this point.

Compare two situations. (1) Intracellular ice crystals do severe damage, but
no material is moved very far and there is very little mixing or churning. We
then have severe damage, but little loss of information or inferrability.
Revival now is hopeless, but revival by full-fledged future nanotech might be
almost trivial.

(2) The brain is perfectly preserved, except for a few small formations which
are destroyed, and these formations are crucial to individuality and memory.
Very little damage, but severe degradation or loss of essential information.
We could revive most of the brain now, but the person not now and perhaps
never.

If it were established that (1) or (2) are really the clear-cut choices, then
(2) would be preferable.

As to Greg Fahy's work, we all continue to wish him (and the few others
pursuing his line) well, as we have done for many years. If he gets to the
end of the rainbow, wonderful (at least for those who can afford his
procedures).  Ben Best implies that Greg has switched from high pressure to
methods that don't require it; I am not informed as to this. 

Mike Darwin's group, and Paul Segall's/Hal Sternberg's/Harry Waitz's group,
seem to claim very good recent results, so maybe they are near the pot of
gold also. Again, wonderful if it pans out. But until it does we are not
likely to dismiss other possibilities out of hand. I realize there has been
considerable previous discussion of hyperbaric methods, some of which I
missed, but as far as I know not quite along the lines I mentioned.

Robert Ettinger 


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