We are working on a post about our lab on radio waves that will be ready soon. In the meantime, I wanted to make a note of a website I found when looking for an explanation of Maxwell's Equations (mentioned in the "Joy of Science" lecture on electromagnetic radiation) that we could understand without the math. This explanation comes from a site called Irregular Webcomic, the creation of David Morgan-Mar, an astrophysicist and former science teacher in Australia.
Maxwell's equations are a set of four equations that describe the relations between electricity and magnetism. Written more neatly, they look like this:Morgan-Mar even spells out the connection between Maxwell's equations and radio waves:
To understand the mathematical notation here, you need to know vector calculus. I believe, however, that anyone can understand Maxwell's equations, and why they are so important and amazing, if they're explained clearly enough.
From this breakthrough have come countless other discoveries about the nature of light, as well as its sibling electromagnetic waves: radio, microwaves, infrared and ultraviolet, x-rays, and gamma rays. All these forms of radiation are made of electric and magnetic fields, moving through space at the speed of light, exactly as described by Maxwell's equations. We now know that radio waves, for example, can be generated by switching an electric current on and off at high speed. The electrons in the wires wiggle back and forth, creating wiggling electric fields, which create magnetic fields, and so on - the overall effect being radio waves. And radio waves in turn wiggle the electrons in your radio or TV antenna, creating electric currents that various electric circuits turn back into sound and pictures.I enjoyed browsing around Morgan-Mar's site, including his pages celebrating LEGO and Star Trek. I suggest you take a look.
Update: My kids tell me that everyone on the Internet has already heard of Irregular Webcomic except me. Ah well.