X-Message-Number: 1963 From: (Thomas Donaldson) Subject: Re: cryonics: #1950-#1956 Date: Sun, 14 Mar 93 9:38:57 PST To Charles Platt (I think): Ralph Merkle has been arguing that nanotechnology can repair any damage for some time now. At least, long enough that I have come to ignore him. The first problem I have with his argument (which conceivably he may have mended) is that he assumes that the tissue is uninjured: that no other computing process must be carried out to reassemble injured tissue. This begs a BIG question, and of course it requires some knowledge of the KIND AND TYPE of damage differ- ent freezing regimens produce. The second problem I have with his argument is that it assumes that freezing does not completely destroy those structures which preserve memory. To evaluate truth or falsity of such a case, you must again look closely at what freezing does to brain cells of all kinds (neurons, glial cells, connective tissue, blood vessels, etc). I don't want to be too much on the negative here. From what I know about these questions I believe the prospects look good. But I do not know of any argument SOLELY from physics and the possibility of nanotechnology that will deal with these two objections. At one time or another, anyone who wants to evaluate the prospects of recovery must look at the biological, cryobiological evidence ... and also what we know about memory as a PHYSIOLOGICAL process. (That, incident- ally, is why I have hit memory so hard in my own recent writings: I think that 10 years from now we'll have a much better understanding of it. Depending on what we find, this may or may not greatly improve our ability to predict revival from suspension). There are some who say that cryonics is just another shot in the dark: like those who believe in a religion, who may grant that their choice of God may or may not work, but think that they may as well choose God because the alternative is annihilation. If we do not scrutinize empirical biological facts about our brain, that is just what cryonics becomes. I became a cryo- nicist because I decided that these facts, so far as they were know, pointed toward the proposition that revival would someday become possible --- by whatever means. Best, and a long long life, Thomas -- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1963