"Cold knowledge" of the 24 solar terms (3)

Although the 24 solar terms are practical, they can only be understood literally, and sometimes they can't correspond one by one. Take autumn as an example. The season in beginning of autumn usually starts in early August, which is the hot summer. This day in beginning of autumn does not mean the arrival of cool autumn. So "beginning of autumn is not autumn".

Millennium is a season that indicates the change of hot and cold. Folks often say, "Autumn night in the white dew is cool all night." In the Millennium, although the daytime temperature is still high, the nighttime temperature drops obviously, and the temperature difference between day and night is large. Small dewdrops appear on flowers and trees because of the large temperature difference between day and night and the condensation of water vapor in the atmosphere at night when the weather is cold. But crystal dew is not white, and white dew is not "white"?

In fact, the Millennium "white" does not mean the color white. The ancients thought about the world according to Jin Mu's five elements of fire, water and soil, and the five elements were colorless. The "white" in the Millennium refers to the "color matching" given by the ancients to the four seasons and five elements-"metallic white in autumn in Geng Xin". Therefore, the dew in autumn is described by "white", hence the name "Bailu".

There is a folk saying, "A slight cold is worse than a heavy cold, which is common but not rare." Since the slight cold is the coldest, why is there a big cold solar term behind it? In fact, this problem cannot be generalized, but there are differences between the north and the south, and the years are different. For most parts of the north, slight cold is indeed colder than severe cold, but for most parts of the south, it is the coldest of the severe cold. There are also some areas that are different. For example, in western Sichuan and most parts of Yunnan, it is the coldest in the second half of 65438+February in a year, which is probably the winter solstice solar term; The coldest time in Tibet and parts of Xinjiang occurred in early June of 5438+10.