The famous sayings about the sunset are as follows:

The falling clouds and solitary swans fly together, the autumn water and the long sky are the same color. The new moon has given birth to birds, and the setting sun is setting in the west. The desert is solitary and the smoke is straight, the sun is setting over the long river. A stream of green water is filled with spring rain, half of the bank is clear of mountains and half of it is sunset. Changlu City is paved with green autumn grass, and the magpie bridge is red with the setting sun.

1. Sunset

Sunset, pinyin wǎn xiá, is a Chinese vocabulary that refers to the colorful clouds that appear on the horizon before and after sunset in the evening.

2. Formation principle

1. In the morning and evening, before and after sunrise and sunset, colorful clouds often appear on the horizon. The formation of morning glow and sunset glow is due to the scattering of light by air.

2. When sunlight enters the atmosphere, it will be scattered when it encounters atmospheric molecules and particles suspended in the atmosphere. These atmospheric molecules and particles themselves do not emit light, but because they scatter sunlight, each atmospheric molecule forms a scattered light source.

3. According to Rayleigh’s law of scattering, the green, blue, purple and other colors of light with higher frequencies in the solar spectrum are the easiest to scatter, while the colors of red, orange, yellow and other colors with lower frequencies are the most easily scattered. The diffraction and transmission capabilities of light are very strong.

4. Therefore, we see that the clear sky is always blue, and the light above the horizon is only red, orange, and yellow light with lower frequencies. After these rays are scattered by impurities such as air molecules and water vapor, the sky there takes on brilliant colors and beautiful red clouds appear.

5. Clouds are caused by sunlight passing through the thick atmosphere and being scattered by a large number of air molecules around sunrise and sunset. When there are more impurities such as dust and water vapor in the air, the color becomes more pronounced. If there are clouds, the clouds will also be dyed in bright orange-red colors.

6. As the saying goes, "If you don't go out in the morning glow, the sunset will travel a thousand miles." That is to say, the bright red alpenglow appears in the morning, indicating that there are already a lot of water droplets in the atmosphere, indicating that the weather will turn rainy.

7. If there is a fiery red or golden sunset, it means that there are no clouds in the west, and the sunlight can penetrate through to form the sunset, so it indicates that the weather will clear up.

8. Colorful clouds sometimes appear on the horizon before and after sunrise and sunset. The clouds seen in the eastern sky before and after sunrise are called morning glow, and the clouds before and after sunset are called sunset glow.

9. Although it is said that the morning glow does not go out, but the sunset glow travels thousands of miles, there is also an ancient saying in the Chaoshan area of ??Guangdong: "The sky is red in the evening, and there will be a typhoon in three days." In other words, when the sunset appears, there will be a typhoon in the next three days.