X-Message-Number: 4632 Date: Sun, 16 Jul 1995 19:47:51 -0700 From: (Ted Skrecky) Subject: Re: message #4574 Date: Thu Jul 13 02:15:58 1995 From: (Doug Skrecky) Subject: cryonet reply To: Ted, could upload the following message to the cryonet? thx ________________________________________________ From: Doug Skrecky Newsgroups: sci.cryonics Subject: Re: why is deep freezing necessary? Date: In message 4574 Brian Wowk writes: "Foods do not stay fresh indefinitely in refrigerators or even deep freezers. Traces of liquid water within which diffusion can occur remain inside cells all the way down to -120'C. Below this temperature the last traces of liquid water will vitrify (become as viscous as glass), and only then will all molecules be locked in place and unable to react. Long-term storage of biological materials therefore requires temperatures of -130'C or lower. Liquid nitrogen (cheap and convenient) is -196'C." I would like to add my own 2 cents to this. Brian illustrates one way to obtain stable storage of biological materials. He shows that the deleterious effects of liquid water can be eliminated by lowering the temperature sufficiently to solidify the water. An alternative more straight forward method would be to eliminate the problems associated with liquid water by eliminating the water itself. There exist a number of creatures which can survive complete desiccation and enter a state called anhydrobiosis (or life without water). Provided these are shielded from moisture and oxygen they can apparently survive indefinitely at room temperature. The current record for longevity of anhydrobiotic organisms is some bacterial spores sealed inside amber. These have been revived after over 25 million years of storage. *1 In a way it is unfortunate that temperature reduction instead of desiccation has been chosen for preserving bodies. Cryonics by its very nature is only a short-term solution which is completely dependant on the replenishing of liquid nitrogen which boils away. Although I am speaking as a cryonics skeptic here, I believe there is a great deal of agreement among cryonicists as well with my claim that maintaining cryonic storage for more than 200 years will likely prove to be very difficult. Anhydrobiosis suffers from no such limitations. Whether if takes 50, 200 or even 2000 years or more to develop and perfect reanimation technology is a matter of complete indifference to a body appropriately prepared, freeze-dried, then stored in a titanium armoured time capsule and then (what the heck) buried in the permafrost. Anhydrobiosis is the ONLY method capable of truly long-term storage of biological materials. *1 "Revival and Identification of Bacterial Spores in 25 to 40 Million Year Old Dominican Amber" 1060-1064 Vol.268 May 19,1995 Science Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4632