Scattering and Colors
q Short wavelengths (blue and violet)
of visible light are scattered more
effectively than are longer
wavelengths (red, orange). Therefore,
when the Sun is overhead, an
observer can look in any direction
and see predominantly blue light that
was selectively scattered by the gases
in the atmosphere.
q At sunset, the path of light must take
through the atmosphere is much
longer. Most of the blue light is
scattered before it reaches an
observer. Thus the Sun appears
reddish in color.