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Lights and Devices: lasers - What is Light?
by Jeanette Cain
Scientists have discovered an unusual device known as the "laser", which sounds like razor, but pronounced "lay' zer". The laser produces a beam of
light, which can be so powerful that it can cut through metal. A laser beam is the light of only one color. If you remember from the previous articles, regular, ordinary "white" light is
really many colors mixed together. Ordinary light spreads in all directions, but a laser beam stays almost parallel.
Rather than spreading out like the beam of light from a flashlight, the light from a laser is concentrated in a tight beam. This prevents any of the light energy from being wasted. All the
light waves work together to make the beam concentrated and bright.
The theory of laser light was presented in 1957 by two Americans, Charles Townes and Arthur Schawlow. In 1960, an American named Theodore Maiman, created the first laser. He made it from a rod of
synthetic ruby, which made a beam when an intense flash of ordinary light was shown on it. Many materials can be used, but each will make slightly different beams, which will be useful for
many different jobs.
Doctors can use lasers to perform surgery without causing a patient to bleed. Engineers think lasers can be used for instant welding or for making a hole in a diamond. One laser sent it's beam of
light to the moon and back in less than three seconds. Surgeons have re-attached torn parts of the eye by welding them with a laser. Dentists think it may be possible to harden teeth with a laser
beam so that they will never decay. Astronauts may be able to use the laser to talk to Earth when they travel into the deepest parts of space. Lasers may also be used as a weapon against enemy
missiles and asteroids.
Lasers may prove to be great problem solvers for us. It is a better locator than radar, and better with carrying TV signals, telephone and radio waves. A single laser could carry over 100 million
telephone conversations.
Lasers can be used to cut, engrave, weld and make things from newspapers to micro chips. They can be used to build skyscrapers, align underground pipes, measure distances from a vast area to a
microscopic view. They can be used to play videos and cd's, make 3-D photos called "holograms", used in concerts or light shows, and they can be used to scan bar codes on supermarket products.
Can you imagine other great benefits that the laser will give to the world?
Definitions:
1. parallel: This means being the same distance apart everywhere. It also means having the same direction or course, like the two rails of the railroad track.
2. concentrated: This can mean to pay close attention like focusing your mind and it can mean bringing or coming together in one place.
3. synthetic: This means to make up by combining parts or elements, or combining elements into a whole.
Sources:
Barnhart, Clarence L. Thorndike-Barnhart Comprehensive Desk Dictionary Doubleday and Company, Inc: NY. 1965
Editors. The World Book Encyclopedia. World Book-Childcraft International, Inc: Chicago. 1980
Related Resource:
Beyond Discovery, Preserving the Miracle of Sight
Explores the use of lasers and eye surgery from diabetic complications.
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