How far would you have to travel so that the light of the full sun would provide "daylight" no brighter than twilight on Earth? This project describes a method to verify the inverse square law: how light, sound, electrical signals, and...

Here is an introduction to the concept of waves and wavelike motion people experience anywhere and everywhere.

All waves will reflect and refract in the right circumstances. The reflection and refraction of light explain how people see images, color and even optical illusions. This tutorial discusses each concept and presents an experiment to try...