Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!we13!ihnp4!zehntel!hplabs!sri-unix!steve@Brl-Bmd.ARPA From: steve@Brl-Bmd.ARPA Newsgroups: net.physics Subject: Re: Thermodynamics and probability Message-ID: <12289@sri-arpa.UUCP> Date: Sun, 15-Apr-84 08:41:15 EST Article-I.D.: sri-arpa.12289 Posted: Sun Apr 15 08:41:15 1984 Date-Received: Fri, 20-Apr-84 01:19:12 EST Lines: 17 From: Stephen Wolff >> From: hplabs!tektronix!uw-beaver!uw-june!entropy!alan@Ucb-Vax.ARPA >> >> Isn't the result of a close look at air or liquids the >> starting point for the development of Brownian motion? >> Once you begin examining things that small with that much >> energy, the paths are not even differentiable! Oh, baloney! These aren't small particles you're talking about - they're m o l e c u l e s ! The paths are for ALL intents and purposes classical. The ABSTRACTION called `Brownian motion' or the `Wiener process' is just that - a very pretty passage to a `conceptual limit' of molecular motion. It's the ABSTRACTION that has all the lovely properties - almost everywhere non-differentiabilty, linearly growing variance, independent increments, the lot - but the REAL process ain't so accommodating.