why the sky is blue?
by Ramya[ Edit ] 2010-01-30 09:27:57
why the sky is blue?
A clear cloudless daytime sky is blue because molecules in the air scatter blue light from the Sun more than they scatter red light. This scattering effect is known as Rayleigh scattering. Because the blue light is scattered in random directions, some of it reaches the planet surface, where we see it.
When we look towards the Sun at sunset, we see red and orange colors because the blue light has been scattered out (filtered) and away from our line of sight.
In the evening, the sky sometimes looks orange or red because of air pollution. dust, water vapor, and other floating particles in the air act as a filter on the sunlight. When the Sun is low, the air layer is thicker and the light is more filtered, so it looks yellow, orange and finally red.
Blue Sky