X-Message-Number: 28467 Date: Tue, 19 Sep 2006 21:09:05 -0400 From: Francois <> Subject: Time limit on cryonic preservation? Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7BIT Lets assume we have a functionally perfect vitrification and cryonic preservation procedure. By that I mean that it causes no additional damage to the preserved organs, even down at the molecular level. The bodies prepared with this technique are stored in liquid nitrogen, which effectively stops all chemical interractions within their tissues. In principle, they would be preserved forever, provided that the supply of liquid nitrogen is reliably maintained. But, would they in fact be preserved indefitely? We all exist in a mildly radioactive environment. Our very bodies contain radioactive isotopes, most notably carbon 14 and potassium 40. Radioactive material occurs in small amounts in the soil and many of the rocks that make up the ground we walk on. Cosmic rays are always bombarding us from the depths of space. All of this adds up to a small but not insignificant annual dose of radiation. Life has evolved ways to cope with this, but the preserved bodies in their cryogenic storage have no way to repair the damage caused by this radiation. It will therefore slowly accumulate, eventually making reanimation impossible. Has any estimate been made of how much time it would take to reach that stage? If this time is measured in millions of years, then it could be safely ignored, I don't think it will take that long to invent the technology needed for reanimating a preserved person. If, however, that time is measured in mere centuries, then it does become a matter of great concern. Francois Good health is merely the slowest possible rate at which one can die. Content-type: text/html; charset=iso-8859-1 [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=28467