X-Message-Number: 1086
From:  (Perry E. Metzger)
Newsgroups: sci.cryonics
Subject: Re: Possible thawing process?
Message-ID: <>
Date: 31 Jul 92 15:28:53 GMT

References: <> 

In article <>  (Keith 
Lofstrom) writes:
>>>if the thawing process could be accomplished using some sort of
>>>complex microwave system (please, let's not start with the jokes :) ).
>>The real problem isn't in warming the body up. The problem is that
>>cells are critically damaged and need to be repaired -- this will
>>likely require nanotechnology.
>I would be very surprised if the biggest problem in reanimation wasn't 
>heating, but COOLING.  We are talking about trillions of little nanomachines
>rooting around in there, and trillions of MIPS of computing - I would guess
>that most of it is going on external to the body itself, simply for heat
>removal.  Every time you probe a molecule with a little grab and shake, or
>put two things together in an exothermic reaction, a little bit of heat
>is released.

Not a real problem, since you can take 20 years if you like to do the
repair provided you can do it at a low enough temperature. At worst,
you can use the patient's own circulatory system as a cooling duct
system, once you've made some minor temporary adjustments to it.

>It will be easier to work without a lot of thermal motion - the
>actual repair process probably would occur at liquid helium
>temperatures or colder.

Its almost impossible to find anything that operates effectively at
liquid helium temperatures; designing functioning nanomachines that
operate near the glass transition temperature at -130C is going to be
hard enough. As for "colder" than LHe, its very hard to get anything
colder than liquid helium. There are no gasses at that temperature to
use as working fluids for conventional cooling techniques. Maybe you
could use some sort of strange Peltier effect device, but if you could
I haven't heard of it -- hell, I'm not even sure that things like the
Peltier effect still operate as advertised down that cool, (everything
starts acting strange that close to absolute zero -- liquid helium is
a superfluid, many if not most metals start superconducting, anyone
know if the Peltier effect or other similar effects still function?)
and certainly building equipment at those temperatures is a bitch.
Thermal motion is not really a problem -- your body works fine,
doesn't it, and its full of nanomachines. Drexler's arguments about
this in EoC are pretty solid. Another problem is that getting that
cold causes even more thermal stresses on large inhomogeneous objects
like humans -- thermal stress cracking is bad enough just at LN2

Since you don't gain anything at all by getting that cold (indeed,
have no reason whatsoever to get things that cold for cryonics
purposes or biological repair of any sort), and since its bloody
inconvenient to get that cold, with large numbers of really really
really nasty problems cropping up, why would anyone want to do it?

Perry Metzger		
		  Just say "NO!" to death and taxes.
			 Extropian and Proud.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1086