why is the sky blue?

Question

Why is the sky blue?

Answer 1

The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. 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. The absorbed blue light is 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.

As you look closer to the horizon, the sky appears much paler in color. To reach you, the scattered blue light must pass through more air. Some of it gets scattered away again in other directions. Less blue light reaches your eyes. The color of the sky near the horizon appears paler or white.

Answer 2

Adding to "Taken's" correct answer, if you watch the sunset over a flat horizon, or a sunrise, for a short time it is red. Instead of passing straight through the atmosphere, the longer wavelength red light hits your eyes. Blue light is bent away.

Remember Roy G. Biv - longest to shortest.

Answer 3

It's blue because all the things in the atmosphere make the sky look blue.

Answer 4

Some people say its the Nitrogen in the air and some say its a refection of the ocean

Answer 5

It's not!