FORT WAYNE, Ind. (WANE) — Remember learning your colors for the first time in kindergarten? One of the first things you learn is that the sky is blue. Everyone knows that, right? But, did they ever explain to you why the sky is blue?
And, what if I told you the sky is actually violet?
There’s a lot of science packed into this explanation, some of which may be very hard to believe. So, let’s break it down.
Creating a colorful VIOLET sky
It all starts with incoming sunlight.
If we think about the sunlight coming in, it contains all colors of the rainbow (think ROY-G-BIV). Each color has a different wavelength, and that wavelength determines the color we see!
If we were to start at the beginning of the rainbow with the color red, we would find that it has the longest wavelength out of all of the colors. As we continue through all of the colors of the rainbow, the wavelengths become shorter. This means that violet has the shortest wavelength.
Keep this in mind as we travel to the top of the Earth’s atmosphere. As the incoming sunlight penetrates the top of the atmosphere, it’s at its highest intensity. With this high intensity comes extremely short wavelengths.
But, there’s another piece of the puzzle.
The atmosphere is LOADED with millions upon millions of molecules like air, water vapor, smoke, and so on. When the incoming sunlight enters the atmosphere and collides with all of these molecules, it causes the light and color to “scatter” out. Colors with extremely short wavelengths, like violet and blue, scatter out much easier due to their short wavelengths. This “scattering” effect is what creates our color in the sky!
Connecting these two puzzle pieces together, it would seem that the color violet would reign supreme in this situation. Why is that? Well, the color violet has the shortest wavelength. Therefore, we should be living under a violet sky.
So, why do we see blue?
Why we SEE blue instead
Leave it to the unique biology of the human eye to change everything!
The human eye is unbelievably sensitive to light. The retina of the eye has three special types of color-sensitive cells called “cones” that allow us to see color. The cones that we have are red, green, and blue. These cones all work together to provide us all of the colors we can see.
While these cones provide us the ability to see hundreds of different shades of color… the human eye doesn’t have the proper cone to see the true shade of violet.
Yes, that’s right. We can’t properly see violet!
Therefore, our brain displays for us the second most-scattered color in the atmosphere: blue!
Science and the human body work together to give us the beautiful blue sky we all know and love so well. Who would’ve thought that we’re the reason why the sky is blue.
So, the next time you find yourself outside on a sunny day, stop and take a look. Now, you’ll be able to see the sky under a new light.