Fun with physics

Paul Falstad is a software engineer who likes to make nifty applets. His Math and Physics Applets site is just loaded with beautiful illustrations of interesting phenomena. I remember fifteen or so years ago when the Mac was young, my physicist friend Dan at Stanford was busy (among other things) writing fun little graphical programs that illustrated various physics experiments. But it really seems like this kind of demo-ware really needed Java and the web to fulfill its promise.
Anybody can go to Falstad’s site and browse quickly for the good stuff. And there’s a lot of good stuff here. Recommended: the Fourier visualization, the 2-D vector fields demo, and the 3-D vector fields demo.