LIGHT IN THE AIR
Perfectly reflected light appears white because it still contains all of the same colors.
However, gas molecules are smaller than the wavelength of visible light. When light hits a
gas molecule, some of it may get absorbed. After awhile, the molecule radiates (releases,
or gives off) the light in a different direction. All of the colors can be absorbed, but
the higher frequencies (blues) are absorbed more often than the lower frequencies (reds).
This process is called Rayleigh scattering.
WHY IS THE SKY BLUE?
T
he blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere,
little of the red, orange and yellow light is affected by the air. However, much of the
shorter wavelength light is absorbed by the gas molecules then radiated in different directions.
It gets scattered all around the sky. Whichever direction you look, some of this scattered
blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.
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