The idea of using pulses of focused, high-intensity light to carry coded information goes back to the heliograph of ancient times. But it wasn't until 1958 that two AT&T researchers outlined the basic principles of the laser (Light Amplification through Stimulated Emission of Radiation). By the mid-1960s lasers were in commercial use and today, they're everywhere. Laser checkout price scanners keep our store clerks from having to do math. Laser-scanning CD players -- using signal sampling -- have spared an entire generation from warped and scratched records, and deliver music clearer and more purely than ever before.

  And, admit it, arena rock concerts just wouldn't be the same without lasers sweeping through smoke machine fog.

[More information about the laser.]