X-Message-Number: 8503
From:  (Thomas Donaldson)
Subject: Re: CryoNet #8489
Date: Fri, 29 Aug 1997 11:01:27 -0700 (PDT)

To Yvan:

I don't understand your claim that LN2 is toxic. Cells have been preserved in
LN2 for decades and revived afterwards.

If you keep something at CO2 temperature it does still deteriorate. If you 
vitrify it (using some cryoprotectant as yet unknown) CO2 temperature might
work.      

Finally, about "uploading". If the "uploading" means basically the storage of
information, I have no metaphysical problems about uploading. However I'd add
that if you want a difficult problem in 1997 practice the problem of uploading
looks far harder than vitrification. In the first place, to upload we must
first understand how our brain works, which we don't yet do. Secondly, we want
some way to upload a 3 D scan of brain structure AND chemistry on a microscopic

scale. Not only that, but ideally this scan must NOT be immediately destructive,
so that we may check it for correctness before we destroy the original tissue.
That's a hard physics and electronics problem.

Not only this, but even for those now suspended and those suspended under poor
conditions (which you quite correctly point out will go on for some time even
with full suspended animation possible under GOOD conditions) we are left with

freezing as the most likely form of storage. Any improvements here will 
decreasethe destruction caused by suspension and thus make revival easier... and
upload-
ing easier too, if ultimately we go that route.

Basically I think "uploading" is too often just a copout, and would challenge
anyone who proposes it to explain just how to do it. NOW. We do have ideas on
how to improve our freezing methods. Those who favor uploading as a strategy
for 1997 should provide their own ideas as to how to do it.

			Best and long long life,

				Thomas Donaldson

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