It travels at 186,287.490 miles per second (299,792,458 meters per sec.). Its visible spectrum ranges from 400 to 700 nanometers. Its smallest unit is a packet of energy, a photon. While its chief use is illumination, it has many other commercial, industrial, and military applications. It is light, and its use is growing in tube and pipe production and fabrication facilities throughout the world. Inmost of its natural and artificial forms, light has little power. However, a groundbreaking invention in the latter half of the 1950s increased its power and concentrated it in a small area. Thus was born a modern and revolutionary concept: light amplification by stimulated emission of radiation, or laser.
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