X-Message-Number: 1965 From: (Thomas Donaldson) Subject: Re: cryonics: #1943-#1949 Date: Sun, 14 Mar 93 12:44:42 PST To Charles Platt: Cracking is one of the major forms of damage, both on a microscale and a macroscale. We KNOW it happens because at one time Alcor autopsied the body of a patient who had been converted to a neuropreservation case (after remaining frozen for several years) due to financial problems. This cracking does NOT occur when the frozen body is stored about -136 C. That is the reason why this matter gets the attention it does: it is a WAY to reduce the damage. I'm sure that others making postings on the Net about this message will agree with me. To Gregory Bloom: Unless Ralph Merkle's message is different from what I think it is (I don't have access to the Cryonet DBase) I would suggest that you look in one of the older books about cryonics, Ettinger's PROSPECT OF IMMORTALITY. In it he analyzes in great detail the probably damage due to radiation. He calculates that radiation won't become a problem for 50,000 years. Ettinger is still alive & unfrozen, and his group (the Immortality Society) is selling their privately published version of his book. It went through several editions years ago, when it came out as a book by normal publishers. It even came out in paperback. So, rather than just send away to Ettinger, you might visit your public library and check it out--- much quicker. Ettinger is/was a physicist. Best and long life Thomas Donaldson PS: To Marvin Minsky: Technically of course you are quite correct. However, knowing Mike, and the many times he's dealt with LN2, sticking his arm in it, lifting out frozen neuropreservation patients, etc etc, he MAY well have made some observations along the way. Certainly at the LN2 surface the liquid nitrogen and the gaseous nitrogen exist simultaneously, but I don't really know the gradient with which the temperature decreases as you move away from that surface. I intend this not as an argument that you are wrong but to point out that Mike may have been referring to his personal observations --- and even if he didn't say it as well as he might, he might also have seen something, rather than calculated it. -- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1965