X-Message-Number: 4760 Date: Thu, 10 Aug 1995 21:23:31 -0400 From: "Keith F. Lynch" <> Subject: Re: multiple comments on last cryonet digest Eugen Leitl <> writes: > I wonder how one keeps stainless steel from corrosion for 5 kyrs... I don't know. I'm skeptical of any claim that something that was built last week will last for 5000 years. > Gold would have been better, ... I doubt it. Gold atoms tend to wander around within the metal. > Even so, there is no better replica than the original itself: > the brain. True. But it's always good to have backups, since the original can be lost or destroyed. > they have lost a lot of data this way even now: forgetting the data > format. I don't consider that to really be lost. Merely made more difficult to recover. >> Alternatively, why not simply use RF heating? > The problem is power: you'd need several kW RF to heat even a modest > organ as Fahy says. So? Then you use several kW. Or several MW if necessary. If you can't get enough power out of the wall in real time, you store it in capacitor banks or batteries. Where I used to work, we used an array of diesel batteries to heat a block of graphite by several thousand degrees per *second*. Another possibility is a gas turbine generator. > Concerning shockwaves: you might be getting some if you'd use MW or > GW RF power. Sure. But no more than you'd get from any other form of equally rapid heating. However, Ralph Merkle's idea of mixing two different forms of ice to get a flat coefficient of expansion sounds promising. > The highest cooling rates for tissue known is based on bringing a > tiny slice into direct contact with a copper block at liquid He > temperature _very_ rapidly, ... I wonder if there's any way to construct a superconductor of heat, or a heat pipe which acts like one. It could be threaded into all the capillaries, and externally cooled (or heated) very rapidly, to change the brain's temperature equally rapidly. (It's a myth that superconducters of electicity are superconductors of heat.) -- Keith Lynch, http://www.access.digex.net/~kfl/ Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4760