Why is the sky blue?
(Najamuddin Ghanghro, Karachi (original from Larkana))
When sunlight travels through
the atmosphere, it collides with gas molecules. These molecules scatter the
light. The shorter the wavelength of light, the more it is scattered by the
atmosphere. Because it has a shorter wavelength than the other colours, blue
light is scattered more, ten times more than red light, for instance. That is
why the sky is blue.
Why does the setting sun look reddish orange? When the sun is on the horizon,
its light takes a longer path through the atmosphere to reach your eyes than
when the sun is directly overhead. By the time the light of the setting sun
reaches your eyes, most of the blue light has been scattered out. The light you
finally see is reddish orange, the colour of white light minus blue