X-Message-Number: 4690
From:  (Brian Wowk)
Newsgroups: sci.cryonics
Subject: Re: Rebooting a suspendee
Date: 29 Jul 1995 23:02:06 GMT
Message-ID: <3veele$>
References: <>


In <>  (Anders
Sandberg) writes:

>Have anybody found a solution to how to "reboot" a
>suspendee after having the body repaired? In the most
>detailed schemes I have seen, we let nanomachines
>survey the body and the  rearrange and repair it while 
>frozen. But how to thaw it without any additional
>damage? Rebuilding it at room temperature is probably
>not a good idea, since different parts will begin
>to move around in a most complex way, from the
>cellular level and up. 

	I'm wondering what "detailed schemes" you have seen,
since most of the ones I'm aware of (even Drexler's
1981 PNAS paper) do deal with this problem explicity.
Solutions include:

a) Selective blocking and unblocking of enzyme active
   sites to inhibit unwanted reactions during the
   rewarming phase.

b) Crosslinking everything in place until rewarming
   is complete.  (Leaving the crosslinks in place
   after rewarming also gives the option of true room
   temperature biostasis.) 

c) Continuous repair and reversal of unwanted reactions
   on the way back up.  This is conceptually equivalent
   to progressive "redesign" of your metabolism so that
   it is optimized for operation at whatever temperature
   you are at-- essentially what Drexer meant in his
   PNAS paper when he spoke of "modifying metabolism
   to resemble that of freeze-tolerant species."

Look, in the worst possible case, once you are repaired
we can use rf heating to take you from -130'C to body
temp in a matter of minutes (the approach now being
used by organ preservationists to avoid devitrification
and cryoprotectant toxicity in cryopreserved organs during 
rewarming).  That leaves at worst a few minutes of 
ischemic injury to fix.

	To summarize: Taken in the context of the
difficultly of the overall repair problem, the rewarming
problem is TRIVIAL.  This should be obvious after the
most modest amount of thought.  


>This is of course yet another argument in my opinion
>for uploading - 

	Aye, and there's the rub.  I don't think you
gave this problem much thought because you simply saw
it as an opportunity to post some uploading propaganda.

	Forgive me, but after years of being told
that cryonics is obsolete and uninteresting because
we are going to have uploading *real soon now*, I'm
starting to develop a real disdain for uploaders.

	I do agree with you, though, that uploading (when
it becomes available) will mostly likely be done with
the brain in some kind of biostasis.  This is of course
yet another argument in my opinion for cryonics. :)

---Brian Wowk    


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