Essay, Research Paper: Light

Light
By David Carlson

Light is emitted from many different sources. It comes from the
sun, the moon, flashlights, light bulbs, and other things. It is essential to our
everyday life. Without it we would stumble around and have no clue what is
going on around it.

The main source of light on Earth is the Sun. Without it their would be
no life on Earth. Light travels at 186,282 miles per SECOND. Nothing can
travel faster than this. According to Einstein this is the cosmic "Speed limit".
Lights speed is invariant. This means that light get emitted at the same speed
from a moving object that it does from a stationary object. Scientists do not
know why. This is one of the main principles of Einstein's Theory of
Relativity.

Light is emitted in to forms, particles and waves. The particles are
called photons. Light comes in both forms. This is called the dual nature of
light. Photons can be observed by atoms, while waves radiant energy. The
frequency of visible light is very small it comes in 7 main wavelengths. Red
,orange, yellow, green, blue, indigo, violet. To the extremes of these are ultra-
violet and inferred with we cannot see.

Light Has many uses. We need it to live. Plants use it to make food
and keep themselves alive. We and other animals use it to see. We use it for
energy in solar cells for electricity or to heat water. It is an inexpensive
source of energy witch we can use to to replace gasoline.

Light is a small part of the energy spectrum. It is the middle range and
beside it is ultra-violet and infa-red. The extremes of this range are gamma
radiation and microwaves. Both of these are lethal to us, even though they
have very useful for cooking and energy.

If you where to put light to pass threw a prism it would divide into 7
colors. This is called a spectrum. These seven colors make up all the colors
we can see. Color is just a particular wavelength of light. Color is just a
wavelength of light that is not reflected by an atom of a substance. For
example a red item will reflect red light and absorb all the other and a blue
object will reflect blue light and absorb all other light.

When you mix all the different light colors together you get white
light. Other stars emit white light while the sun mostly emits yellow and red
with some blue in it.

Light will boucle off an object at the opposite angle in witch it hit the
object. If it hits at 90 degrees it will bounce off at 90 degrees. Light does not
loose speed or energy when it hits an object.