Like all the other stars, the sun emits
radiation. This radiation travels at the speed of light, and
includes radio waves, microwaves, infrared light waves, visible
light waves (the ones that we can see), ultraviolet light waves,
X-rays and Gamma rays.
Some of these waves are long
and of low energy. These waves pass through the atmosphere easily.
They can also pass through our bodies, but they do not harm us.
Some of these waves are short
and have very high energy. The strongest of these, gamma rays
and X-rays, are called hard radiation. Over-exposure to these
waves is harmful to life forms, so we are lucky that they do
not pass through the atmosphere to the surface of the earth.
Gamma rays are given off by radioactive substances.
The visible spectrum is a very
small part of the radiation that the sun generates. However,
the wave lengths that we can see make up the greater part of
the radiation that reaches the earth's surface. Both the chlorophyll
used by plants and the designs of terrestrial eyes make use of
Long Wave Length Low
20 cm to 20 meters
8 inches to 8.5 yards
| Radio Waves
|| These very long waves are
the signals that our radios receive.
|| .01 to 21 cm
|| These long waves cook the
food in our microwave ovens.
|| 700-100,000 nanometers
||These heat rays are invisible to
|| 400 - 700 nanometers
||We see only these wave lengths
|| 4-400 nanometers
Ultraviolet rays are invisible to us, but they cause sunburn.
The ozone layer of the atmosphere protects us from over-exposure
to ultraviolet rays.
||The atmosphere protects us from
dangerous X-rays. These short, high energy rays can travel right
through our bodies, and are used for diagnosis by doctors and
||smaller than .1 nanometer
|| Gamma Rays
||These very short, very high energy
waves would kill life on earth if they were able to penetrate
Short Wave Length
Dangerous to living
© 1998, 2003. Elizabeth Anne Viau. All rights reserved. This material
may be used by individuals for instructional purposes but not
sold. Please inform the author if you use it at email@example.com