laser

What can be used to perform surgery, cut metal, and even listen to your favorite CD? A laser! The term "laser" is actually an acronym for "Light Amplification by Stimulated Emission of Radiation." You can also think of a laser as a special kind of light that's released in a very tight, bright beam. Lasers work by exciting a lot of atoms at one time, emitting the same kind of energy in the same direction.

Image credits: main image: courtesy of AMNH.