It has infused new scientific theories that, in turn, have led to other technologies, including electronics. And it has helped to push astronomy from an intriguing pursuit, akin to stamp collecting, to an analytical science. Light reveals how far away stars are, how fast they move, what chemical elements they contain, how massive they are, and whether they have planets. One day, maybe soon, the faint light from a planet may bring the news that we are not alone. For teachers, one of best things about light is that it is cheap.
Students can make rainbows.
They can learn why mixing red, green, and blue pigment makes black paint, whereas mixing red, green, and blue light makes white light. They can learn not only about light, but also about the methods of science. In the last 50 years, new instruments, such as radio telescopes and ultraviolet detectors, have become our seeing-eye dogs outside that window. Electromagnetic radiation is one of the many forms that energy can take. Like runners in a three-legged race, the two fields are locked together.