Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83 based; site hou2g.UUCP Path: utzoo!watmath!clyde!floyd!harpo!ulysses!mhuxl!houxm!hou2g!stekas From: stekas@hou2g.UUCP (J.STEKAS) Newsgroups: net.physics Subject: Re: Entropy, Gases and fluctuations. Message-ID: <207@hou2g.UUCP> Date: Thu, 22-Mar-84 15:58:15 EST Article-I.D.: hou2g.207 Posted: Thu Mar 22 15:58:15 1984 Date-Received: Fri, 23-Mar-84 21:03:22 EST Organization: AT&T Bell Labs, Holmdel NJ Lines: 23 Sure it's possible for all the gas in a room to find itself in one corner - it's called a "fluctuation". It's easy to calculate the probability of such a fluctuation ... Say the room has a mole of particles (10^23) and we want to find out the probability that all the particles find themselves in a sub-volume which amounts to 10% of the total volume. Now the probability for a given particle to be in that small volume is 0.1, so the probability that ALL of them would be in that small volume is 23 (10 ) p = 0.1 23 Now this number is not of order of magnitude 23, but 10 . That means 10^23 zeros to the right of the decimal point! I think that this is about as "unlikely" as anything one can imagine, considerably less likely than finding a Unicorn in your garage tomorrow. Jim