This java applet is a simulation that demonstrates electrodynamics in two dimensions, including setups which demonstrate electromagnetic waves, reflection at conductors, radiation from antennas, standing waves, waveguides, and diffraction.

To get started with the applet, just go through the items in the Setup menu in the upper right. The arrows indicate electric field (and current, in the gray conductors); the green and red indicate magnetic field.

This is the TE version of the applet. There is also a TM version.

Full Directions.

Full screen version.

Java Version.

More applets.

Huge thanks to Bob Hanson and his team for converting this applet to javascript.