What is a laser?
A new discovery must be given a name and the laser, pronounced lay zer, is a fairly recent discovery. Its name is built from the first letters of a string of grand sounding science words. The world of science is still agog at what this young invention can do, yet we have only just started to explore its possibilities.
A flashlight beam fans out and its target is far away it spreads over a wide area with a dim glow. If a flashlight beam could reach the moon, 240,000 miles away, it would cover a circle 25,000 miles wide. But the newly invented laser prevents a light beam from fanning out in a wide circle. Its beam of intensified light is certainly strong enough to reach the moon and far, far beyond it. The beam from a laser no bigger than a quarter inch can light with brilliance a small area of the moon and then return.
Its full scientific name is Light Amplification by Stimulated Emission of Radiation. Gather up the first letters of these impressive words and you get laser and if you are in the know you pronounce it to rhyme with amazer. The laser is certainly an amazer.
The first little laser used the light beam from a red ruby crystal. Atoms in the crystal were excited by radiation energy. The teeming energy of the excited atoms was controlled and timed to hit a target with a spurting cascade of radiation. For the first time in history, a beam of light was tamed and driven in one direction instead of fanning out in all directions.
The light from a laser is millions of times brighter than the sun and scientists expect that one of these narrow beams could be seen
20 million miles out into space.
For the first time, a light beam can be disciplined to carry messages like the electromagnetic waves of radio. One band of color on the laser beam, however, can carry ten million TV channels. The beam could communicate with other worlds, bring down missiles in outer space and link orbiting satellites to the earth with power and communications. It could map the moon in detail or serve as a surgeon's knife by cutting through flesh without danger of infection. No one can guess what other magic tricks the amazing laser has in store for us.
The ruby laser was followed with other varieties. The helium ¬neon laser operates with a tube of gases and does fine work tracking satellites. A laser using a 200 inch telescope and a mere ten kilowatts of electric power can send a beam ten light years out into space. A laser beam can carry a. million times more information that radio and there are plans to power this small marvel with the energy of sunlight.