Why is the sky blue? And why is the sunset glow red? And why does the sky look yellow in sandstorm weather?

First of all, the earth has an atmosphere, and the composition of the earth's atmosphere determines its different reflectivity to light, with the lowest reflectivity to red light and the highest reflectivity to blue light. The white light of the sun is composed of seven colors of light. Because of the high reflectivity of the earth to blue light, the earth is a blue star in space.

Secondly, due to the reflection of blue light in the atmosphere, blue light diffuses in the atmosphere, so the clear sky is blue, which is why the sea water is blue.

Thirdly, the sunset glow is caused by the oblique projection of the sun to the atmosphere, which scatters light. Just like the prism experiment in middle school physics, the conclusion is that white light is divided into red, orange, yellow, green, indigo and purple, so if you observe the light source in the prism in the red light region, the light source will appear red.

Fourthly, when a sandstorm occurs, because there are a lot of sand grains in the atmosphere, the reflectivity increases, so the transmittance decreases and the intensity of sunlight weakens. It looks like a lampshade has been added to the lamp, which looks very dim.

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