Re: starship-design: Cryogenic Suspension

["N. Lindberg" <nlindber@u.washington.edu>]

This is a really novel (afaik) and intruiging idea.  How are you going to
get at body parts protected by bone, especially the brain and spinal cord?
Also, how are you going to keep the needles from bending as they go in
real fast? If they bend they either cut through flesh or break off.
Anyway, i think this is an idea worthy of discussion.  I think it beats
the heck out of lopping someones head off and dunking it in LN2.

Nels



On Thu, 22 Mar 2001, bugzapper wrote:

> Cryogenic Suspended Animation
>
> I've been familiar with this science fiction theme since my childhood.
> Always, I've been a bit dubious about it, as a personal reaction as well as
> technically. Having since learned the fundamental drawback to reviving a
> frozen human is almost intractable, I shelved the concept. But it has been
> recently mentioned here, in a casual throwaway line, and I did once come up
> with a potential approach to this problem. Taken from the shelf and lightly
> dusted off, here it is.
>
> Ice crystals slowly forming in blood and tissue have a characteristic size
> which is larger than the dimensions of cells. That's the problem. Freezing
> tissue ruptures cell membranes, and that spells dead. OK, but some small
> creatures, mouse size, can be frozen and revived. Protoplasm is water-based,
> but has solutes and suspensions which disorder the ice crystals so that most
> individual cells come out viable, and normal body processes can then replace
> the minority of destroyed cells in a small organism which has been
> successfully thawed.
>
> Large creatures, however, will not freeze as fast as small ones, for their
> body bulk is thermally insulating. Fast freezing occurs near the outer
> surface, so skin and outer regions sustain little damage, but internal
> organs retain heat, and suffer a slow freezing process which allows growth
> of larger ice crystals, which spells dead. Obviously body passages, the
> lungs and digestive tract, are amenable to coolant access to speed freezing,
> but large organs are still left vulnerable. Among our favorite parts, the
> central nervous system is protected within bone chambers, still left out of
> the cold. To use our circulatory system to spread coolant as a temporary
> replacement for our blood seems far too iffy.
>
> My proposal would involve transfixing the entire body rapidly with fine
> platinum needles, which are heat pipes containing liquid helium as their
> working fluid. The object of this macabre "iron maiden" treatment is to
> chill all parts of the body below freezing in less than a second. This
> should allow large creatures, such as ourselves, to recover on thawing as
> well as small animals can. Supplementary measures, such as antifreeze
> proteins added to the blood to reduce ice crystal size, are also called for.
>
> This sounds freaky for sure, to allow oneself to be rapidly pierced by
> jillions of needles, but it could be a key to survival. The subject would of
> course be unconscious for this ordeal. Later, when thawed and revived to
> consciousness, it would hurt. Big deal, death hurts worse. Fine needles
> actually cause little tissue damage, and in this case the body has no time
> for a histamine response or other trauma. The tiny leaks of fluids would be
> largely repaired in the thawing process, and nearly healed before the
> subject regains consciousness.
>
> It's just a thought. People here know I don't go for slow starship journeys,
> but a technique like this would be good to have around anyway. There might
> be all sorts of reasons for somebody to decide they didn't want to die.
>
> Johnny Thunderbird
>
>