X-Message-Number: 13307
From: "john grigg" <>
Subject: Eugene Leitl of the extropian's has experts look at the damage.....
Date: Fri, 25 Feb 2000 18:26:47 PST

In these posts from the extropian digest, Eugene Leitl explains how his work 
on studying freezing damage to cells is progressing.  He even gives URL's so 
people can look at it for themselves.  He explains that in the next few 
weeks Mike Darwin and Greg Fahy will hopefully have given in their papers 
regarding the story to be told by the slides.


sincerely,

John Grigg

Date: Tue, 22 Feb 2000 12:58:25 -0800 (PST)
From: Eugene Leitl <>Subject: RE: Why 
Cryonics
Robin Hanson writes:
 > It is a bad sign for cryonics, the worst that I know, that such pictures
 > are not available on the web for us all to browse.  It makes one suspect
 > they are hiding something.
Hang on for 1-2 weeks, by then the interpretations should be
ready. Hopefully, the thing will be published on cryobiology.org.
I also intend to OCR the compleat Biodynamica, provided (as to be
expected) the copyright is lapsed.

With these picture it will be of course still possible to remain in
the state of denial, but at least it will prevent proliferation of
pure (i.e. uninformed) fabrication.




Date: Tue, 22 Feb 2000 12:32:46 -0800 (PST)
From: Eugene Leitl <>Subject: RE: Why 
Cryonics
 writes:
 > The unanswered question is whether this information loss is sufficient
 > to obliterate personality, memory, and other important brain state.
 > I don't think we know enough at this time to give any sort of definitive
 > answer to this question. >
 > This was my objection to the Ralph Merkle essay mentioned a couple of
 > weeks ago; I thought he was excessively optimistic in claiming that the
 > answer was largely known.  But other people who have actually looked at
 > frozen brains, including Eugene and cryonics "godfather" Mike Darwin,
 > seem to have a more pessimistic view.
I have scanned a few selected slides (they are on a website right now,
but without comments they are less than helpful). Hopefully, Darwin &
F*hy will soon find time to write interpretations of them.

The difference between freezing and vitrification is quite striking,btw.


Date: Tue, 22 Feb 2000 13:38:19 -0800 (PST)
From: Eugene Leitl <>
Subject: Cryonics and TurbulenceJohn Clark writes:
 > If you plug these numbers into the formula you get a Reynolds number of 
about
1. > 1 is a lot less than 2000 so it looks like any mixing caused by 
freezing
 > would probably be laminar not turbulent.

I don't think that the formula is applicable to the actual process
occuring. I am not at all sure that I understand at what is happening
(and the molecular part of the picture as what happens in the 3d
volume is still missing), but the damage appears to be fractal in
nature (i.e. occurs at all scales), and the compression
ratio/displacement of the tissue seem to be very large, which is not good 
news.

Macro:       http://4.3.78.106/cryo/ccr4.jpg
       http://4.3.78.106/cryo/ccr8.jpg
(the scale below is in mm)Micro:
  http://4.3.78.106/cryo/ccr1.jpg       http://4.3.78.106/cryo/ccr3.jpg
       (this is still light micro, probably 300-400x)
The white areas are ice, removed by freeze-substitution.
I'm omitting the cellular scale here, because interpretation is harder
there. As I said, hang on for the comments done by the gurus.


Date: Tue, 22 Feb 2000 14:19:50 -0800 (PST)
From: Eugene Leitl <>Subject: RE: Why 
Cryonics
Robert J. Bradbury writes:
 > Denial that there is extensive damage or denial that there is a chance
 > of repairing the damage?
I think vitrification might really change the outcome. As of today, I
am inclined to think that vanilla (i.e. freezing) cryonics is not going to 
work.

Whether vitrification will be enough, is still an open question. After
5-10 years of research we should know a lot more, perhaps enough to answer 
it.



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