The atmosphere of Earth contains gases and particles that scatter sunlight in all directions. Since blue light travels in shorter, smaller waves than other colors, it scatters more than other colors. This explains why the sky is typically blue.
You’ve undoubtedly wondered why the sky is blue at some point, just like most inquisitive people. Or perhaps you questioned, “Why is the sky red?” if you witnessed a stunning sunset or sunrise.
You could assume that the explanations would be equally evident, given how obvious it is that the sky is blue. They’re not! Why blue, out of all the colors in the rainbow?
The sky could have been green just as easily or orange. Green, yellow, blue, violet, orange, yellow, red, and all the colors in between can be seen in the sky when we view a rainbow.
All the hues of the rainbow are actually present in the white light that the Sun emits. When we observe rainbows, we see all those hues. When illuminated by the Sun, raindrops behave like tiny prisms, bending and dispersing light into various colors.
But Why Are There Many Shades of Color?
The light you see is merely a tiny fraction of all the different types of light energy that surround you and the entire universe! Light energy moves in waves, just like energy moving through the ocean.
The wavelength, or range of wavelengths, of a given type of light is what distinguishes it from other types of light.
The wavelengths of light that are visible to human vision are included. The longest visible wavelengths appear red to us. The shortest visible wavelengths have a blue or violet appearance.
Wavelengths of red and blue or violet light are 400 and 750 nanometers, respectively. One billionth of a meter is known as a nanometer.
A human hair is 50,000 nanometers thick on average. Therefore, the wavelengths of visible light are incredibly small.
Another crucial fact about light is that, barring obstructions like mirrors, prisms, or other optical devices, it always moves forward in a straight line (like molecules of the gases in the atmosphere)
Much of the red, yellow, and green light (combined and still virtually white) passes directly through the atmosphere to our eyes as the white light from the Sun enters Earth’s atmosphere.
However, the blue and violet waves are precisely the proper size to strike and reflect off the gas molecules in the atmosphere.
As a result, the blue and violet light waves are cut off from the other light waves and are dispersed for everyone to view. The remaining wavelengths remain white because they coalesce into a single group.
What Then Happens To All the Wavelengths That Are “Non-Blue”?
They still appear white because they are still mixed together and have not been affected by the atmosphere. The sky seems blue because of the violet and blue light that is dispersed throughout it.
How does the violet fare? The upper atmosphere filters out some of the violet light. Additionally, violet is not as sensitive to our eyes as blue is.
The sky changes to a paler blue or white as it approaches the horizon. Even more, the air has been filtered out of the sunshine that reaches us from the horizon than it has from above.
We receive less blue light now because the gas molecules reflect the light in many different directions.
As we have read why the sky is blue in this article, we have many more answers to such innovative questions.
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