Looking at this mountain from a distance, why is it blue?

The results of scattering and absorption are the same. First of all, let's start with the effect of air on light. The atmosphere above the earth is composed of air molecules, which contain some tiny particles (such as dust particles). When sunlight passes through the atmosphere, it will scatter, that is, the light shines on small particles and then scatters around, so that we can see light from all directions. It is the scattering of light by the atmosphere that makes our living space full of colors. There is no atmosphere around the moon, and the sky above the moon seen by astronauts on the moon is dark. If a beam of light enters the window and there is smoke or dust in the room, we can see it from all directions. Sunlight consists of seven colors of light: red, orange, yellow, green, blue, indigo and purple. However, the light scattering intensity of different colors in the atmosphere is different, with blue-violet light scattering the most and red light scattering the least, and the scattered blue-violet light can reach more than 10 times of red light. In this view; The air mainly scatters the blue light of the sun in all directions, so that you can look up at the sky in clear weather. It is blue. This is the blue scattered light in the air that enters your eyes and makes you have blue vision. Then, is the blue color of the distant mountains also caused by the blue scattered light in the air? The answer is yes. So where is the color of the mountain itself? It turns out that air not only scatters light, but also attracts light. Because there is thick air between the distant mountains and us, the reflected light of the distant mountains will be constantly attracted and scattered by the air, making its own color very weak and completely covered by the color of blue scattered light in the air. In this way, when the reflected light from the distant mountains and the blue scattered light in the air enter your eyes, you will feel that the distant mountains are all blue.