Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site topaz.RUTGERS.EDU Path: utzoo!linus!philabs!cmcl2!seismo!columbia!topaz!Susser.pasa From: Susser.pasa@Xerox.ARPA Newsgroups: net.sf-lovers Subject: Re: Matter transmission and duplication (#366) Message-ID: <3699@topaz.RUTGERS.EDU> Date: Thu, 19-Sep-85 16:41:26 EDT Article-I.D.: topaz.3699 Posted: Thu Sep 19 16:41:26 1985 Date-Received: Sun, 22-Sep-85 13:38:05 EDT Sender: daemon@topaz.RUTGERS.EDU Organization: Rutgers Univ., New Brunswick, N.J. Lines: 29 From: Josh Susser >From: Keith F. Lynch > A duplicate isn't satisfactory? Don't you know that the average >atom in the body only stays there a few weeks? Only a small >percentage of the you of a year ago still exists. I remember when my 9th grade biology teacher told me this. It seems to be a common belief among high-school science teachers. But look at it this way: if "the average atom in the body only stays there a few weeks" (let "a few weeks" = a fortnight), then one would have to replace half his body mass twice a month, with most of the replacement mass coming from food. For a person of average mass, say 80 kg, this would require eating and ABSORBING 20 kg of food a week! While eating 20 kg a week (about 5 lbs a day) isn't unreasonable, absorbing that many molecules is ridiculous. Most of what we absorb from food is glucose, vitamins, some amino acids, a few nucleotides, and water. The rest of what we eat is roughage. So I really can't believe that a human could eat enough to replace an appreciable proportion of its body mass even in a few months. I'm sure there is some amount of turnover in some of the more active structures (muscles, bone marrow, skin, blood), but I can't believe that the atoms in my brain cells or in my DNA molecules are that volatile. Any molecular biologists out there care to tell me what I'm made of? -- Josh Susser "Even the Devil needs an advocate now and then." Brought to you by Super Global Mega Corp .com