"Why is the sky blue?" is one of the most frequently asked questions in every age group. We know that the sky is not a solid surface, so why does it have a colour?

Read on if you want to know why we see the sky as blue on clear and cloudless days.

Light is made up of a colour spectrum. The long-wave colours are reddish, the short-wave colours are blue-violet.

When sunlight enters our atmosphere, it collides with oxygen and nitrogen. The short-wave colours are more affected by this collision than the long-wave colours.

As the blue/violet spectrum is the shortest wavelength, this is the colour of the sky. The human eye is more sensitive to blue rays than to violet rays, which is why we see the sky as blue and not violet.

Our eyes have thousands of cones and rods, the so-called light receptors. If you poke yourself in the eye, you see a large blue dot. This is because the blue receptors have been activated. Blue is one of the primary colours and is therefore more easily perceived by our eyes.

Summary:

The sky is not blue, it appears blue. The sky appears blue because the light rays from the sun collide with the molecules in the air and the short-wave blue light rays are scattered.