X-Message-Number: 20852 From: Date: Mon, 13 Jan 2003 10:18:15 EST Subject: entropy --part1_197.13d68b79.2b5432b7_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Simon mentioned entropy as evidence of the malice of the universe. All work and no play makes Jack a dull boy, so while the "heat death" of the universe is not one of our more pressing problems, no harm in a little fooling around. Actually, entropy is a concept poorly understood by most people. If the Second Law is a genuine law at all, it is apparently an "emergent" one, not derivable from "basic" laws governing the behavior of matter at the submicroscopic level. People tend to swallow the Second Law uncritically because it is so obviously correct, in the short run, in so many cases. Hard to unscramble the eggs etc. Nevertheless, under reasonable assumptions, it was proven long ago that a closed system must eventually return arbitrarily close to any previous configuration. This means that, averaged over very long time periods, entropy must decrease as much as it increases. Ergo, no heat death, no inexorable deterioration. You don't even need any math to prove to yourself that it is impossible to reach AND MAINTAIN a state of maximum disorder. If a system could reach a state of maximum disorder--the "most probable" distribution of components--then the next change MUST be toward greater order or lower entropy. (After that, a large decrease in entropy in a short time would still be unlikely under usual assumptions, but that isn't the issue.) R.E. --part1_197.13d68b79.2b5432b7_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=20852