Have you ever sat on the bottom of a swimming pool and pondered your watery ceiling? Most of the surface is a sheet of light blue, and you can't see through it, even though the water is clear. But ...

Ever wonder how a mirror works? If you want to find the path that light takes when reflecting off a surface, you could use Fermat's Principle. This states something like this: The path that light ...

We are surrounded by waves. tiny vibrational waves transport sound to our ears. Light waves stimulate the retinas of our eyes. Electromagnetic waves bring radio, television and endless streaming ...