X-Message-Number: 3202 Date: 03 Oct 94 03:33:11 EDT From: Bob Smart <> Subject: CRYONICS: Brain Jelly > Why aren't we all crushed? Because the pressure is exerted in all > directions and is therefore "self-equalizing."...Application of 20,000 > atmospheres to a cubic foot of water would do no harm...If the cubic > foot of water contained a brain, the equalization of pressure in all > directions could mean that the brain is simply turned into a solid state, > without being "crushed." First off, I didn't use the word "crushed," I said "turn to jelly." You're right about pressure being applied in all directions, of course, and a brain may well be watery enough to exhibit relative indifference to pressure just as you propose. My concern isn't over the absolute pressure, so much as it is the RATE of application of that pressure. 20,000 atmospheres in less than a second is a pretty rapid compression; I envision a shock wave traveling inward through the tissue, creating whatever havoc a seismic disturbance in brain tissue can create. > I think potential damages due to rapid application of pressure cannot be > as great as those due to freezing damage. Seems to me, there ought to be an answer (or at least a hint toward the answer) available in the hyperbaric literature somewhere. I can't believe there hasn't been some research somewhere about the effects and propagation of shock waves through various kinds of gelatinous masses undergoing rapid compression; that ought to give us at least some ballpark estimate of the relative havoc of freezing vs. compression. We can certainly agree that freezing is pretty violent--but why do you say sudden compression ought to be less so? Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3202