X-Message-Number: 20865 From: Date: Tue, 14 Jan 2003 10:46:46 EST Subject: Re: CryoNet #20847 - #20863 --part1_1c5.377bc4b.2b558ae6_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Someone is quoted as responding to my entropy post, claiming I don't understand it and including the statement: > talking about the entropy of a specific configuration or state is > [wrong]. It tells you nothing. One state is not > inherently more ordered or less ordered than another. I don't want to waste much time on this, but anyone interested can consult any standard reference. In ordinary thermodynamics (heat engines) entropy is symbolized S and is a function of state variables volume and temperature. S = S(V,T). An infinitesimal change in entropy is dS = dQ/T, where dQ is heat transfer. A macroscopic system DOES have a definite entropy, or a difference in entropy from the system with different values of the variables. More generalized entropy definitions include other kinds of systems and even information. Does anyone doubt that a scrambled sentence contains less information than a structured one--assuming a random scrambling? Anyway, as I said, under certain reasonable assumptions, the Law of Return was long ago proven by eminent names--that any closed system must eventually come arbitrarily close to any previous configuration, so that entropy cannot increase to a maximum and stay there. There is one slightly interesting fact related to the writer's point of view. Any particular random hand in Bridge, with no point count, is just as likely (and just as unlikely) as a royal flush. From this point of view, no hand is more "ordered" than another. But once you specify any criterion of order, in any system, random events are likely to reduce the amount of order or to "increase the entropy"--up to the point of Return. Then, in the long run, increases and decreases in entropy must be about equal. Robert Ettinger --part1_1c5.377bc4b.2b558ae6_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=20865