Why is the Sky Blue?

We’ve been living in this place that we call “Earth” since the beginning of life. When we look up, at the sky, we used to see it as blue, but we don't even question this situation most of the time. Let's think with a child's naivety and wonder why the sky looks blue.

"Why does the sky appear blue?" and "Why does it turn red-orange at sunset?" The answer to the question is the same; Sun. We look up and see the Sun in yellow-orange, the sky in blue, the clouds in white, the sea and oceans in blue, and as the Sun sets we see red-orange everywhere. Actually, none of these colors exist, there is only white.

However, the white possessed by the sunlight hides all the colors we see in the rainbow. In other words, the orange, red, yellow, green, blue, dark blue, and purple colors of the rainbow that we see in rainy weather are hidden in the white color of the Sun.

If sunlight has such a wide color palette, why don't we always see them? Because we need a reflective prism like a raindrop to see. That's why rainbows appear after rain. So, why is the sky blue but not multi-colored?

While the sunlight is coming into our world, it encounters the air molecules in the atmosphere, and the light is scattered everywhere. Colors, on the other hand, have a certain scattering rate, and the fastest of these is blue.

The blue component of the light spectrum has a shorter wavelength and higher frequency than the others. The acceleration of the charged frequency is proportional to the square of the frequency, and the intensity of the scattered light is also proportional to the square of the acceleration obtained. If you are not a physicist, it can be a bit tiring to do this operation, but as a result of the process, we can say that blue is the fastest.

Simply, this is the reason behind the blue color of our beautiful sky. Despite there is a lot to know about this topic, I might mention it in another article.


Alpartun Günhan