Why is the sky blue?


Why is the sky blue?

We all know that the sky is usually blue but have you ever wondered why the sky is Blue?

The sunlight reaching earth looks white but it consists of seven colors. We can clearly observe this when the light is sent through a prism.

Light divided in to seven colors

Light travels as waves. Some colors in the light travel as long waves (wavelength) while some colors travel as short waves (wavelength). Out of all these colors , Blue color has the shortest wavelength.


Whenever there’s an obstruction in the path of light, three things can happen. Reflect as in a mirror, Bend as in a prism or Scatter in molecules of the atmosphere. Out of these, Scattering is the reason for the sky to become blue in color.

When it comes to blue color it has the shortest wavelength. So it scatters more in the atmosphere than the other colors. So the sky looks blue. But why does the sky become lesser blue or white when it closes to the horizon or at lower levels? sunlight through lower skies pass through more air than sunlight which falls directly from above and the blue color is more scattered. This reduces the visible blue color.

When the sun gets lower in the sky, the light has to travel through more atmosphere to reach your eyes. So the blue color scatters more and the red and yellow colors get highlighted. This makes the sky look redder rather than the usual blue color.


Leave a Reply

Your email address will not be published. Required fields are marked *