How do we "see" using Visible Light?
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Cones in our
eyes are receivers for these
tiny visible light waves. The
Sun is a natural source for
visible light waves and our eyes
see the reflection of this
sunlight off the objects around
us.
The color of an object that
we see is the color of light
reflected. All other colors are
absorbed.
Light bulbs are another
source of visible light waves.
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| This is an
photograph taken from the space
shuttle of Phoenix, Arizona. |
  |
This is a true-color satellite
image of Phoenix, Arizona. Can
you see a difference between
this image and the photo above
it? |
|
There are two types of color images
that can be made from satellite data -
true-color and false-color. To take
true-color images, like this one, the
satellite that took it used sensors to
record data about the red, green, and
blue visible light waves that were
reflecting off the earth's surface. The
data were combined later on a computer.
The result is similar to what our eyes
see.
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