X-Message-Number: 4631 From: (Thomas Donaldson) Subject: Re: CryoNet #4629 - #4630 Date: Sun, 16 Jul 1995 10:49:42 -0700 (PDT) Re: My own posting on Cryonet $4629 I have now looked at the WWW posting which I discussed in the previous Cryonet. It looks to me even worse than his article in CRYONICS, basically because in his recent CRYONICS article on the same subject, he did make a nod (referring to work of Tad Hogg, at Xerox) toward some kind of verification of the second clause of his syllogism. To those who haven't read my first posting, I pointed out that Ralph Merkle consistently produces some quite inarguable truth from cryptography or mathematics and then, without any serious attempt to show that it really applies to our possibilities for revival when frozen with current methods, concludes that it DOES apply and therefore we need not worry about our suspension technology. In his CRYONICS article he quotes Tad Hogg as saying that the method discussed worked on a large majority of problems, that usually there would be a very sharp boundary between an area in which the problem was "easily" solvable and one in which many solutions were possible (ie. the information needed to limit the computed brain structure to our own has been lost). Again, I do not dispute Hogg's statement so much as ask just what field of problems for which he is making this statement. Without such a discussion SPECIFIC TO OUR BRAINS we have again no more than the statement that "probably our suspension will work". Has Dr. Hogg specifically considered the issues involved in suspension? Do we fall in the area where the information does not specify our brain well enough or in the area where it does? Is Dr. Hogg's choice of problems biased? -- after all, very few people try to solve problems which they can easily see are unsolvable. And finally, I personally consider the work done by Mike Darwin and others in preserving brains at high concentrations of glycerol to be not only a significant advance but also an answer to one of the major problems about preservation of information. Although the point has not yet been proven, a high consensus of neurobiologists has come to suspect that our memories are encoded in the actual presence or absence of connections between our neurons, at a very small and nongeneric scale. Darwin's methods look as if they will actually preserve that connectivity. As for the fact that such high concentrations of glycerol poison the cells, we do need to look closely at just why that happens; given that it happens at very low temperatures, it may not even be caused by a chemical reaction. This work isn't the end of our task. Yet it may well establish BY DIRECT EXPERIMENTAL MEANS something which no amount of theory alone could show: preservation of information. If so, it puts an end to any relevance of the purely theoretical arguments made by Ralph Merkle --- and myself. And there is nothing which I could welcome more. Long long life, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4631