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Re: starship-design: Cryogenic Suspension

Oops: sent this wrong the other day, didn't get to the list.

Ben says:

Does a bear need a hospital every winter.

You're right, but...
Bears are natural hibernators. We don't know how or why it happens. We just
don't know what this state of being is. I saw a paleontologist suggest on TV
that some polar dinosaurs may have hibernated.

Again from Ben:

  But who says it has to be a 60 or 90 days at a time.A two week sleep
followed be one week on may be good starting point for inter-planetary
trips.I see hibernation as a start for low temperature sleep around +4C.

Might be. I personally get a creepy crawly feeling about hibernation, that
doesn't come when I think about deep freeze.

Ben again:

why all that? use hamsters and steel needles. Liquid nitrogen is cheap.

But we already know we can sucessfully freeze, thaw and revive small
animals, with no special preparations. Like you say, in LN2. The technical
hurdle is in bigger beasts, say fox size and larger. Steel needles and LN2
are fine, and experiments with dogs would test the concept, but with
hamsters the concept would not be tested. But we would have to test an
animal of at least human mass, before it could be concientiously applied to
a human.

Kyle quotes me, and asks:

>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.

How would the subject be thawed out? At what rate of thawing?


so pk sez:

> > How would the subject be thawed out? At what rate of thawing?
> Well, i'd guess as fast as possible 8)
> (though, while taking care not to cause tissue damage bc of the
> difference)
> Injecting hot air/water into the previously used fine needle could work,

Hey, folks, I don't know. I can tell you what I had in mind, though. I had
in mind, that the heat pipe needles would be withdrawn right after inducing
freezing. Then for the thawing, what I had in mind was low intensity
microwave heating, which would be "as fast as possible". I don't know why it
would have to be done quickly, but my gut feeling goes along with pk here,
to get it over with. Nuke that corpsicle.

Deep freeze is a very secure, snuggly state. Nothing happens. I'm sure that
radiation damage can still happen to DNA, but such damage is isolated and
doesn't spread by replication. Chromosome repair on thawing can take care of
this primary damage, before it has a chance to become carcinogenisis. If
freezing can be proved out, using heat pipe needles or not, it can be a
relatively simple way to save lives which are otherwise lost.

Johnny Thunderbird