Optics For Kids - What is Light?

by **Algerien1970** Sun 7 Jun - 13:30

What is Light? - The Science and Engineering Behind Optics

By Bruce Irving, Optical Solutions Group, Synopsys

What is Light?
It's a kind of energy called "electromagnetic (EM) radiation" (but this kind of radiation is not harmful, except for an occasional sunburn). There are other kinds of EM radiation too (radio waves, microwaves, x-rays, etc.), but light is the part WE can see, the part that makes the rainbow.

How does light travel?
FAST and STRAIGHT.

How FAST?
About 186,000 miles per second [300,000 kilometers per second], so light from the sun takes about 8 minutes to go 93 million miles [149 million kilometers] to earth. Does this seem SLOW? Well, if you could DRIVE to the sun at 60 mph [100 kph], it would take you 177 years to get there! In one second, light can go around the earth 7 times!

Optics For Kids - What is Light? Optics-kids-light-fig1

How STRAIGHT?
Perfectly straight, until something bends it. The straight paths of light are called LIGHT RAYS.

Block it ... with something (this makes a shadow)

Reflect it (change its path with a mirror)

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Bend it

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The fine print: There are actually other ways to bend or deflect light, including diffraction gratings and holographic lenses. These depend on the wave nature of light, and are a little more difficult to explain. Scientists have also found that gravity can bend light, but it takes a very large object with strong gravity such as a star to bend light very much, so it's not an effect you see every day!

Light is produced, controlled, and detected in so many ways around you!

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