Why is the sky blue?

In our last science experiment we saw that sunlight is actually made up of a number of different wave lengths of light each of which can have a different color. So why is it that the sky, on a clear day, appears to us in the color blue? Why is the sky not plain white like sunlight or a kaleidoscope of different colors as found in the rainbow?

The sky above earth is not a vacuum. It is full of gases of all kinds. One of which is oxygen and it is thanks to this oxygen in the air that all of us are alive. This mixed bag of gases in the atmosphere also is responsible for the color of the sky. As the sunlight comes through this set of gases some wavelengths of light pass clear through while others get bounced around by the molecules in the gases.

Colors like red, yellow, and orange pass straight through the mix of gases in the atmosphere while the blue color manages to get reflected all over. The bits of reflected blue hits your eyes as you look up. This is why it becomes the most predominantly present light wave length in the sky making the sky appear blue in color. There are a number of interesting science projects based on the sky that you can try out.