For centuries, children were taught that the grass is green and the sky is blue. While the former might be true, the latter has been recently proven by scientists to be incorrect! As it so happens, the color of the sky is violet!
How did we come to the conclusion that the sky was blue in the first place? Was it because, on a clear, cloudless day, the vivid blue meets our eyes when we stare at the heavens?
Reason Why The Sky Is Blue
Apart from how our eyes perceive the sky, there is also the matter of scientific reasoning, which says that blue is more readily scattered when it interacts with the earth’s atmosphere than any other color. Since we are enveloped by the atmosphere, the sky seems to be painted blue.
If we go into the details of the phenomenon, the dispersal of the blue color is known as Rayleigh scattering. It takes place when the sunlight reflects the air molecules in the atmosphere. The phenomena takes place at a larger angle but shorter wavelength, which is ideal for Rayleigh scattering.
According to Hyper Physics, “…the sun’s light is predominantly in the blue end of the spectrum.” This is why the blue looks less saturated when one looks further away from the sun.
This also explains why sunsets take on more of a red hue than a blue one. The wavelengths become longer, and the blue light is no longer rapidly scattered.
The Sky Is Really Violet?
However, since violet seemed to have a shorter wavelength than blue, scientists were always puzzled as to why the sky looks blue, not violet. But now, they have finally uncovered the secret. The sky is indeed violet, but humans perceive it as blue!
It is because our eyes are created in a way that cannot differentiate between different wavelengths of colors. Instead it carries three kinds of color-sensitive cells, one each for red, blue and green.
Hence, when the time comes for our brain to pick up signals from light striking our retina, we rely on the three cones to determine which color is before us. While the wavelengths of the perceived colors are more or less the same as the actual colors, there are subtle differences.
But the sky is a mixture of violet and blue. However, since the greenish tint of blue and the reddish tint of violet cancel each other out, our eyes are left with perceiving only a pale blue color.