Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site rtp47.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!genrad!decvax!mcnc!rti-sel!rtp47!throopw From: throopw@rtp47.UUCP (Wayne Throop) Newsgroups: net.origins Subject: Re: thermodynamics again Message-ID: <39@rtp47.UUCP> Date: Fri, 17-May-85 13:13:59 EDT Article-I.D.: rtp47.39 Posted: Fri May 17 13:13:59 1985 Date-Received: Sun, 19-May-85 06:37:38 EDT References: <1083@uwmacc.UUCP> Reply-To: throopw@rtp47.UUCP (Wayne Throop) Distribution: net Organization: Data General, RTP, NC Lines: 55 In article <1083@uwmacc.UUCP> dubois@uwmacc.UUCP (A Ray Miller) writes: >Imagine the traditional `Maxwell Demon' who opens and closes a little door in >the wall of a closed vessel containing gas under pressure every time a molecule >of gas within a certain velocity range approaches the door, thus sorting out >molecules in terms of velocity and decreasing the entropy of the system. Ob- >viously the `demon' must be preprogrammed to do as he does. Actually, this turns out to misleading. In a Scientific American article from the 70's, an ingenuous gadget is described which separates cool air from warm air by passing mixed air through a valve with a peculiar internal geometry. The valve had two outlets: warm air came from one, and cool air from the other. The valve was not "programmed" to select energetic or nonenergetic air molecules in any traditional sense. It simply created an environment where energetic molecules tended to go "left" while nonenergetic molecules tended to go "right". So what is the difference between this gadget and Maxwell's demon? The thought experiment for the demon specifies a closed system (two chambers connected by a valve that operates very quickly), while the actual gadget is an open system (a stream of air passing through a "valve"). Therefore, I agree completely that an increase in "order" or "total information" or "available energy" in a closed system violates thermodynamic "law" (or isomorphs of thermodynamic law), but this simply does not apply to an open system. And lest the argument of the valve being "programmed to do as it does" be raised, let me point out that fresh water is extracted from salt water in the natural world by evaporation. Another example of "increasing order" in an open system. The other commonly used argument is that "the universe is a closed system". Granted, but it is far from being in equilibrium, and thus subsystems (such as the Earth) can be found which constitute open systems. > [discussion of why thermodynamic arguments do/don't apply in biology > and how this is accounted for by evolutionists] >This usually manifests itself in statements such as "Well, given enough time, >anything will happen". Actually, it is more usually manifested in statements such as "Well, the Earth is not a closed system". And it isn't. >Personal comment here. Why don't you evolutionists all move your homes over a >toxic waste dump? Mutations are how you claim evolution progresses; increasing >the mutation rate should increase the rate of evolution. Should we disband the >EPA? I'd really like an answer to this question from any evolutionist who >doesn't consume heavy metals with his scrambled eggs for breakfast. Personally, I don't really WANT to evolve. I'm not aware of evolutionists who think evolution is desirable or pleasant, just ones who think it occurs. >A. Ray Miller Wayne Throop -- Wayne Throop at Data General, RTP, NC !mcnc!rti-sel!rtp47!throopw