If there were no dust, would the sky be blue at night?

The sky is blue because of the scattering of the sun, and the sky is the color of the universe, which is black.

Kindness? No, because there's no sunlight.

No, it's black without dust.

First, the earth is surrounded by the atmosphere, and the sunlight must penetrate the atmosphere in order to reach the ground where we live.

Second, sunlight is composed of a variety of wavelengths of light (lasers are mostly single-wavelength rays), and each wavelength basically represents a visual color, and mixed light is visible to humans as white.

Third, the composition of the atmosphere is not single, and it is divided into many layers from the outside to the inside, each layer and each component will correspond to reflecting, refracting, and scattering a specific wavelength of light, and the blue, violet, indigo, and other colors of light that are shorter than Sun Nazhi's are scattered in all directions, making the sky appear blue.

Fifth, the grass in the wild grassland is very high, and the cattle and sheep are flooded into the sea of grass when they graze, and the Min's wind drafts low cattle and sheep. Now overgrazing, I'm afraid I won't see it.

This is because blue light is the strongest scattering of sunlight from the atmosphere.

Sunlight is composed of red, clear, yellow, green, blue, indigo, and violet light, blue is the largest energy in the short wavelength band, scattered by particles in the atmosphere, so it presents the blue color of the sky, and its blue depth is directly related to the nature of the air mass. Blue light is the most energetic in the short wavelength range, so it scatters the most light waves, so the sky we see appears blue.

Sky

Sky, a Chinese word, pinyin tiānkōng, means that the sky is empty; A vast space where the sun, moon and stars are listed. It is an important part of the earth, and in ancient China there was a saying that the sky is round and the place is round. People can observe meteorological or astronomical phenomena in the sky to know how the weather changes, the passage of time, or their own direction.

The sun rises and sets to know the time of day, and the waxing and waning of the moon at night can know the time of the month. The Big Dipper can indicate the north. The thickness and shape of the clouds can tell if it will rain or not.

Many beautiful phenomena can be enjoyed in the sky, such as rainbows, aurora aurora and meteor showers. Birds will fly in the sky.

The above content reference:Encyclopedia – Sky

The reason is simple, the scattering of sunlight by the atmosphere makes the sky appear blue as we see.

The Earth's surface is surrounded by an atmosphere, and when sunlight enters the atmosphere, air molecules and particles (dust, water droplets, ice crystals, etc.) scatter sunlight around. Sunlight is composed of seven kinds of light: red, clear, yellow, green, blue, indigo, and violet, with red light having the longest wavelength and violet light having the shortest wavelength. Color light such as red light, which has a longer wavelength, has the greatest transmittance and can directly penetrate particles in the atmosphere to the ground.

Blue, indigo, violet and other colors with shorter wavelengths are easily scattered by particles in the atmosphere. In the shortwave band, blue light has the most energy and scatters the most light waves, so the sky we see appears blue.

Speaking of which, the reason is actually quite simple, it is the scattering effect of the atmosphere on the sun's rays.

As we all know, the Earth's surface is surrounded by an atmosphere, and when sunlight enters the atmosphere, air molecules and particles (dust, water droplets, ice crystals, etc.) scatter sunlight in all directions. Sunlight is composed of red, orange, yellow, green, blue, indigo, and violet light, among which red, orange, and yellow light with longer wavelengths have the greatest transmittance, which can penetrate the atmosphere and directly hit the ground; Blue, violet, indigo and other colored light with shorter wavelengths are easily blocked by particles suspended in the air, thus scattering in all directions. In the shortwave range, blue light has the most energy and scatters the most light waves, so the sky we see is blue.

However, when there is fog or thin clouds in the sky, because the diameter of the droplet is larger than the wavelength of the visible light, all wavelengths of light will be scattered "equally", so the sky appears white in color. Yesterday, after the heavy rain, the cold air swept away the turbid warm and humid air mass, and the weather was clear, and the number of dust particles, water droplets, and ice crystals in the air was very large, so in such weather, it is no wonder that the sky looks particularly blue.