This is a set of pages devoted to the kinetic theory of gases, and in particular to the work of James Clerk Maxwell, one of my all-time favorite scientists.
The site consists of a number of pages organized around a couple of applets, developed to demonstrate some basic physical principles and, hopefully, to allow the student to explore on his or her own such concepts as irreversibility and the approach to thermal equilibrium. Below is a list of the pages currently (August 2003) available:
Brief historical introduction to the kinetic theory of gases
Demonstration of the Maxwell velocity distribution (with embedded applet)
Further comments on the problem of irreversibility
Demonstration of equilibrium for different gases and Avogadro's principle (with embedded applet)
To view the applets, use a browser that is "Java2" capable (if you have a Macintosh running OS X, most browsers, including Safari, will give acceptable results. On Windows, you may need to run a "Windows Update" to get the latest Java virtual machine).
The original kinetic theory applet was developed by me (Julio Gea-Banacloche) in 1997. The most current version has been updated by Melinda Freeze, who also did most of the work on the second applet (equilibrium for two different gases). You can take a peek at her latest (still unfinished) work here (it's an applet intended to demonstrate a gas's viscosity).Most of this is work in progress. There are still occasional bugs with the applets that may or may not ever get fixed. The "Pause" button may stop working after it's been pressed a few times. The "Set" button may or may not work, depending on the browser or platform. Clicking in a text field and hitting "Enter" or "Return" will usually get things going. Restarting the applet is a temporary fix for most problems.
If you have a really fast computer, you may want to slow down the animation. You may also experience some trouble with the "Number of collisions" and "Time elapsed" fields getting overwritten and not being erased properly. Clicking on "Pause" should clean them up.
The algorithm for the hard-sphere dynamics was taken from the book An Introduction to Computer Simulation Methods, by Harvey Gould and Jan Tobochnik (Addison-Wesley, 2nd edition, 1996). Follow that link for further online resources!