From: spike66 (spike66@attbi.com)
Date: Sat Jul 13 2002 - 23:48:19 MDT
Mike Lorrey wrote:
>spike66 wrote:
>
>>
>>OK. Does anyone have the actual data for temperatures at the
>>top of the dewar vs the bottom? I am surprised there is more
>>than about a 5C delta.
>>
>
>Well, the N2 molecule is heavier than the H20 molecule (by nearly 2
>times) so its pressure gradient should be similarly more steep. At those
>temps, I'd not be surprised at a 5C delta top to bottom (note that the
>N2 will be infused at the bottom, and rising as it absorbs heat from the
>body, so that during the cooling process, you should easily attain a 5c
>delta over a nearly 2 meter gradient. Since cooling the brain well and
>fast is the primary objective, you want it to receive the coldest N2,
>which it normally wouldn't if the body is upright, since the rising N2
>currents would pass the torso, the largest heat mass of the body, before
>reaching the brain in an upright corpsicle.
>
Clearly I have misunderstood this process. Perhaps Harvey or one
of the others can clear it up. I assumed the patient would be cooled
to LN2 temps before she goes into the dewar. Then there should be
nothing in that dewar except nitrogen and the very hard frozen carbon/
H20 blocks. So there is no heat from the patient.
My contention is that there would be almost no temperature gradient
anywhere in that dewar while there is any LN2 anywhere. In
fact it would stay really cold in there, with patients solidly frozen for
some time after the last drop of LN2 boiled away. So by that reasoning
there is little clear advantage to having the patients head-down. But
that practice does introduce extra squick-factor (for whatever reason)
which actually introduces a danger to the patients.
I would assume Williams' daughter has a problem with cryonics for
four reasons: 1. He wanted to be cremated, 2. He is head down,
3. Junior wanted to sell DNA and 4. She wanted all the money.
I would respond with the following. 1. I doubt Alcor would suspend
a patient without the consent. So I dismiss the first point. 2. Put
this particular patient in the dewar head up. 3. Clearly absurd. If
he wanted DNA for sale, a toenail would do, no freezing necessary,
and 4. Do as Harvey has done, and make Alcor (or equivalent) the
beneficiary of the fee, regardless of whether the family succeeds in
suing to have the patient thawed and incinerated, thus removing the
financial incentive to bury or burn the loved one.
So, does anyone know what the largest temperature delta is in
the dewar? I am amazed if it is greater than 5C. spike
This archive was generated by hypermail 2.1.5 : Sat Nov 02 2002 - 09:15:25 MST