Why do we see the sky blue?
The white color consists of seven colors of the rainbow. That is, white is a mixture of red, orange, yellow, green, blue, blue, violet. The Earth's atmosphere consists of a mixture of gases. The sun's rays, reaching the Earth, meet with molecules of gas. Here, the rays are reflected and decomposed into seven colors of the spectrum. The beams of the red spectrum (red, orange, yellow here) are longer, they mostly go directly to the ground, without lingering in the atmosphere. Rays of the blue spectrum (green, blue, blue, violet) are shortwave. They are bouncing off molecules of air in different directions (scatter) and filling the upper atmosphere. Therefore, the entire sky is permeated with a blue light, spreading in different directions.
It is worth to clarify why we do not see the sky green, but we see it is blue. This happens because the colors of the blue spectrum are intermingled and the result is a blue sky. In addition, the human eye perceives a blue color better than, for example, purple. Then another interesting point is why the sky is blue and the sunset is red. The fact is that during the day the sun's rays are directed perpendicular to the surface of the Earth, and during sunset and sunrise - at an angle. With this position of the rays relative to the Earth, they have to move in the atmosphere over long distances, so the waves of the short spectrum go to the sides and become invisible, and the waves of the long spectrum are partially scattered across the sky. Therefore, we see the sunset and sunrise in red-orange tones.
How to explain to the child, why the sky is blue?
Knowing your children and the level of their knowledge of our planet, you will be able to understand how it's easier to explain to your child why the sky is blue.