X-Message-Number: 12839 From: Thomas Donaldson <> Subject: once more, re nanotechnology and the coming Conference Date: Thu, 25 Nov 1999 22:42:44 +1100 (EST) Hi! I was quite interested by the list of speakers for the cryonics conference; and not only that, the organizations that had consented to be sponsors. I have only one thing to say: when we want to repair a badly damaged brain, that damage is likely to include missing parts. Yes, we may well be able to work out just what was missing in detail; but to do so will necessarily involve analyzing (and so examining) the damaged brain on a much larger than molecular scale. Virtually all of current neuroscientists studying memory believe that our memories are somehow encoded in the connections of our neurons. (Yes, there are a few on the fringe who have other ideas, but it's important to understand not only that they are in a crashing minority but that research into how memory works has made their ideas look less and less likely). Connectivity of neurons isn't simply something that can be worked out purely on a nanoscale. Yes, we can work out that one piece is part of a broken connection, but to work out just which OTHER piece it connected to requires that we look at data from many other neurons nearby, and possibly even further afield. This means that any means to look at the damaged brain on a suitable scale must also combine its data with the results from many other areas. Whether we do this in a computer outside the brain, or try to have our devices communicate and combine the data while within the brain, does not fundamentally matter. Clearly trying to make a nanoscale device capable not only of finding damaged pieces of neurons but also of holding the data from many other such devices and working out computationally how they all hook together would be much harder than just making one which finds broken connections, specifies their location and characteristics, and reports that to a computer outside the brain. As we know, nobody's brain is itself nanoscale (though some may claim so for others!). Any means to recover a damaged brain cannot be done on a nanoscale either, even though it will very likely use devices on that scale. And yes, PERIASTRON has paid lots of attention to research on how memory works for years now. I believe it is a critical issue for cryonics, which still lacks a fully complete scientific understanding. Yet that understanding has already come quite far, compared, say, to what most neuroscientists believed only 10 years ago. And yes, I'm happy if asked to give some things we DON'T understand. But the fundamental point I make here is that any ability to work on molecular scales will not alone solve all our problems of revival. It will certainly help, and is probably necessary (even though our ideas about how brains can be induced to repair themselves have turned far more optimistic than 10 years ago). But it isn't sufficient, not by light years. Best wishes and long long life to all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12839