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					LIGHT AND COLOR
Almost everything in
nature depends on light
for life:
    -Plants use light to
    make food as a
    byproduct oxygen
    is produced.
    -Humans use light
    to see, make X-
    Rays, as electricity
    (solar energy), and
    many other things.


                           http://home.howstuffworks.com/irriga
                           tion1.htm
Light – Wave or particle?

 For many years scientists argued over the nature of
  light, "Is light a wave or a stream of particles?"
 The fact is that light exhibits behaviors which are
  characteristic of both waves and particles.
How is it a wave?

 Electromagnetic waves (light) originate from vibrating or
  accelerating electric charges
 Electromagnetic waves are made up of an electric field
  and a magnetic field oscillating at right angles relative to
  one another
How is it a particle?

 Particle of light are called photons

 Photons have zero rest mass and travel at the speed of
  light through a vacuum.
            Colors in a Rainbow

How can I remember the seven colors of the rainbow?



    ROY G BIV
Complementary Colors

Complementary Colors - any two
 colors that add together to produce white
White Light

 White light contains all colors of the rainbow.
                 Why do we see color?

When our eyes see different wavelengths of light in the visible
spectrum, we see colors.
How do humans see color?
     What we actually see is the light an object reflects or in some
     cases the light an object produces.
     Our eyes absorb the wavelengths of light in the visible spectrum.
     Then, turn these wavelengths into signals our brains can
     understand. The brain interrupts these signals as color images.
      Why are objects a specific color?

-The grass appears green, because the leaves reflect
green light. The leaves do not absorb (soak up) this
wavelength of light and reflect it back (like a mirror),
so we see the grass as green.

-On the other hand a green stoplight appears green
because it produces green light
b
Color Blindness
Colorblindness - about 10% of population
     Red-green is predominant
     Yellow-blue - a few
     Total - some

				
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posted:11/30/2011
language:English
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