Why is the sky blue?

Every child will surely wonder at some point why the sky above us is blue. In this little info, I want to pursue this question and answer it.

Rumors about the blue color

First, I have to go into two rumors that are often told to answer that question. The first rumor states that the sky reflects the blue of the sea. The second rumor is that it is the space we see there.

Both rumors are not true. If the first rumor were correct, the sky over the mainland would not be blue at all. Secondly, water is transparent and not blue. That the second rumor can not be true, you can also observe every night, when you look into the black darkness of the universe.

But where does the blue come from?

It is solely due to the scattering of the incoming light of the sun through the atmosphere of our earth. The sunlight consists of a wide range of different colors.

When a ray of light reaches our earth, it is broken by the small particles in the sky. Since every color of the light is broken differently, each color dissipates to different degrees.

The blue color part of the light has the shortest wavelength, the red color part has the longest. So, the blue light is therefore scattered the strongest, the red the least.

Sky Blue and Sunset Red

The color of our sky depends on which way the light has to go through the atmosphere. During the day, this way is quite short, as the sun is high in the sky. As a result, mainly the blue light is scattered and the sky appears blue. In the evening and in the morning, on the other hand, the way for the light is much longer, because the light must shine through the atmosphere at an angle to reach our point of view. As a result, most of the blue light is already scattered before it reaches us. The sky appears red at sunset.