Why is the sky blue?
The sky is blue because of a phenomenon known as Rayleigh scattering—named after Lord Rayleigh, the British scientist who explained the process first in the 19th century.
Sunlight, as it reaches Earth’s atmosphere, is made up of various color wavelengths, like in a rainbow. As it passes through the atmosphere, it interacts with nitrogen, oxygen, and other air molecules scattering the wavelengths in all directions. Each wavelength is different. Blue and violet, because of their shorter, choppy wavelength, scatters more effectively, but also, our eyes are more sensitive to blue light, which is why we see a blue sky during the day. However, the time of day and atmospheric conditions can also have an active influence on the color of the sky.
At sunrise, the sun’s light passes through a thick layer of atmosphere. The blue wavelengths are scattered and this allows the longer red, yellow, and orange wavelengths to dominate the sky. This enables us to see the beautiful hues of these colors as they blend together until the sun is fully up.
There is so much more to know regarding how the different colors in the sky are made. I hope you’ll look at these two sources, and others, to learn more.
Did You Know?
All light travels in a straight line. Unless something gets in the way.
Did You Know?
The wavelengths of color that compose the sun’s light are the same as those that make up the rainbow.
It is also interesting to note that the colors in the light that God made to sustain our planet, and His rainbow, the symbol of His covenant promise with man to never destroy the entire Earth again with a flood, are composed of the same colors.
Sources: https://spaceplace.nasa.gov/blue-sky/en/; https://www.space.com/why-is-the-sky-blue