Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site entropy.UUCP
Path: utzoo!watmath!clyde!floyd!vax135!cornell!uw-beaver!uw-june!entropy!alan
From: alan@entropy.UUCP (Alan King)
Newsgroups: net.physics
Subject: Re: Thermodynamics and probability
Message-ID: <9@entropy.UUCP>
Date: Tue, 27-Mar-84 12:59:28 EST
Article-I.D.: entropy.9
Posted: Tue Mar 27 12:59:28 1984
Date-Received: Thu, 29-Mar-84 05:04:13 EST
References: <936@ihuxm.UUCP>, <2833@brl-vgr.ARPA>
Organization: UW MathStat, Seattle
Lines: 22

concerning a close look at a room full of air:

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!  Thus it
is hard to see the justification for the comment that
dynamical laws explain motion in the microscale.  To put it
another way: there is no interval of time of positive length
during which an individual molecule of air travels along
a "classical" trajectory.  The path is known only in a 
statistical sense even for individual particles.  Of course
the dynamical laws must be obeyed -- but they cannot be used
to explain the motion of individual particles in a swarm of air.
It was the attempt to explain this motion that led Einstein
to develop his explanation of Brownian motion.

alan king 
dept of mathematcs
university of washington