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How a CD Player Works
When you pop a CD into your player, lasers are behind the music. A CD is simply a piece of plastic with tiny bumps arranged along the grooves. As a drive motor spins the disc, a laser "reads" the bumps. An important component of the player is the tracking system, which must be very accurate to keep the laser beam centered on the grooves, gradually moving outward from the center of the disc. The CD player translates the bumps into sound.
What it stands for: Light Amplification by Stimulated Emission of Radiation, or L.A.S.E.R.
Special properties: monochromatic (one color), coherent (photons move in unison), directional (concentrated beam)
Scientists who helped create lasers: Gordon Gould, Charles Townes, and others
Uses: supermarket scanners, surgical devices, CD players, industrial machines
The light released by a laser contains one specific wavelength, which means the light is:
very cold
very heavy
one particular color
Correct!
A laser releases light that is one particular color, or monochromatic.
Light—such as that released by a laser—is produced when atoms are stimulated, causing the movement of:
electrons
protons
death rays
Correct!
When an atom absorbs energy—such as heat or electricity—electrons jump into a higher-energy orbit. When the electrons return to their normal state, the atom releases energy in the form of a photon, or a tiny particle of light.
All lasers are extremely powerful and dangerous.
Fact
OR
Fiction
?
Fiction
Some lasers can be very powerful and dangerous, but most of the time, when used properly, lasers are safe and helpful.
Lasers were invented by Albert Einstein.
Fact
OR
Fiction
?
Fiction
Einstein did not invent lasers, but his experiments and theories about light led to their development in the 1950s.