20. Brownian Motion

Smoke is drawn into a small chamber and examined under a microscope to observe Brownian motion.

Another demonstration for Brownian motion is an apparatus which gets placed on the overhead projector. Balls of different size can be used to show the random motion of molecules. As the speed on the agitator is turned up, the balls move faster.

Lastly, an ephysics applet for Brownian motion is available on the web.