Why is the sky blue?

First of all, understand how light works, as light travels from the sun, it moves up and down like ocean waves, and when the wavelengths come together, we look as if they are white.

Everyone knows that the sky is blue, but not everyone knows why it is blue.

In the sky above our planet, there is a thick layer of atmosphere. Air has no color, so what about blue?

There are seven colors in sunlight: red, orange, green, yellow, blue, chow, and purple. Red light is the strongest, orange, yellow, and green are also stronger, and the weakest are blue, yellow, and purple.

When the sunlight penetrates the thick atmosphere, the red light runs the fastest and passes through it at once;The orange, yellow, and green lights also passed;Most of the blue and blue light is detained by the atmosphere, and they are pushed around by the dust and water droplets in the atmosphere, and they are reflected back and forth, resulting in the atmosphere being "dyed" blue.

Let's put it simply...

First of all, light waves may diffract (scatter) when they encounter particles (dust) in the air, and the probability or proportion and degree of diffraction are inversely proportional to the wavelength of light, that is, the shorter the wavelength of light, the larger the particle diameter relative to the wavelength, the more likely it is to diffract (scatter).

Then: red, orange, yellow, green, blue, violet, the wavelengths of the seven colors decrease in order, red light has the longest wavelength, violet light has the shortest wavelength, and the rest are in the center In order, this means that orange-red light is not easily scattered, while blue-violet light is easily scattered.

And finally: the book says that sunlight should be white because the colors red, orange, yellow, green, blue, and purple are mixed to form white. But when we look at the sun, we think it's orange-red, because blue-violet light is easily scattered (diffrified) by particles in the air, so when we look at the sky, there's particles everywhere in the sky, so there's blue-violet light scattered everywhere and we see itAnd the remaining orange-red light in sunlight is not easily scattered, and it will enter our eyes, so when we look directly at the sun, we will see orange-red.

It's because the sunlight is absorbed by the atmosphere, absorbing all the other colors, leaving the blue, and the sky looks blue.

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The angle of refraction of light is different for each color.

There are seven colors in sunlight: red, orange, yellow, green, blue, indigo, and violet. Red light is the strongest, orange, yellow, and green are also stronger, and the weakest are blue, yellow, and violet.

When the sunlight penetrates the thick atmosphere, the red light runs the fastest and passes through it at once;The orange, yellow, and green lights also passed;Most of the blue and indigo light are detained by the atmosphere, and they are pushed around by the dust and water droplets in the atmosphere, and they are reflected back and forth, resulting in the atmosphere being "dyed" blue.

The sky is blue from the ground, but if you look out at the sky from an airplane, the sky is even bluer. If you take a spaceship to a higher place to look at the sky, then the sky is not blue, but purple, because of the weakest violet light, most of them can't even enter the first door of the atmosphere.

The sky is colorless, but due to the refraction of sunlight, it has color. And that's why the sky looks dark at night. At night, the sun does not shine on this half of the earth's sky, and without strong sunlight, the sky has no color, and some, it is only black.

Of course, there is also the light of the moon and the stars, but the moon does not shine, the light of the moon reflects the sun's light, of course, it is not bright, and the stars are too far away from us, so the night sky we see will not be as bright as the day. Resources.

The blue light in sunlight is easily scattered in the atmosphere, which is a physical property of the atmosphere.

The atmosphere is blue, so ...