From: Dani Eder (danielravennest@yahoo.com)
Date: Tue Dec 07 2004 - 08:29:14 MST
[Re: Cryonics storage in Antarctica]
>
> It just isn't cold enough. The numbers are here:
http://www.alcor.org/Library/html/HowColdIsColdEnough.html
>
> >Right now, if your LN2 supply is
> >disrupted, you will lose the patients when it
> >evaporates. Down there, at least the frozen will
> >remain frozen, so you will have longer to recover.
> >
Let me try to be clearer - I'm not suggesting the
patients are stored at Antarctic temps. I'm
suggesting
the LN2 will last longer in Antarctica than Riverside,
CA (where Alcor is now).
Vostok station has a wintertime air temperature of
-65C. Since the sun never gets very high, you can
erect a reflective fence to keep the sun off a
patch of ground, then place heat pipes in the ground
connected to radiators pointed at the sky to provide
passive cooling. This should get the ice down to
-80 to -100C. Into this chilled patch of ice you
install your insulated LN2 storage chamber. In
designing cryogenic tanks for spacecraft, the best
results are obtained using multi-layer insulation
consisting of many layers of reflective foil
separated by plastic netting, all in a vacuum.
Aerogel might do better, but I haven't seen
performance numbers for it. So you build essentially
a large insulated dewar flask underground.
This type of storage should keep the LN2 for
years, possibly longer. The bigger you make it,
the longer the storage time will be without
replenishment - It's a surface to volume ratio
relationship. Yes, doing anything in Antarctica
is horribly expensive right now, so it probably
makes more sense to stay in California for now,
but if technology improves to the point of having
replicating robot factories, such projects could
be relatively affordable.
Dani Eder
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