I saw the stars last night. What can I say next?

Last night, I saw the night sky, purple gas scattered in the west, bulls fighting wolves, purple star red and giant stars entering the palace. I counted it with my fingers, and I knew it was blablabla…… ... ...

The ancients attached great importance to the study of astronomical phenomena. Gu, a beginner in the late Ming and Qing Dynasties, said: "Anyone who knows astronomy has more than three generations. July filariasis', the farmer's words also. Samsung is at home', the language of women is also. The end of the month is also a pawn. "

Ancient astronomical constellation map

When our ancestors were still living in the era of eating and drinking blood, they already knew how to "work at sunrise and rest at sunset" according to the "schedule of work and rest" arranged by nature. The repeated movement of the sun rising in the east and setting in the west has made mankind form the most basic concept of time "day" and also produced the most basic unit of time "day". Around the Shang Dynasty, the ancients had the concept of dividing a day into dawn, early morning, noon, afternoon, afternoon, dusk and night.

The Big Dipper

So, how did the ancients understand these laws by observing the sky at night?

In fact, since human beings entered the farming civilization, they have been particularly sensitive to the change of weather, which has a very important impact on crops. Fishermen also need to master the laws of tides, which requires quite accurate calendar guidance, and the accuracy of calendar is closely related to the accuracy of astronomical observation. Astronomy has become the most closely related subject to human beings.

After a long period of night observation, the ancients finally found that the direction of constellation movement is regular, which can be consistent with the climate change on the earth. Therefore, there is such a record in the ancient book Guanzi 4,000 years ago in China: "The barrel handle refers to the east, the world is spring, the world is summer, the barrel handle refers to the west, the next is autumn, and the barrel handle refers to the north, and the world is winter." This is to judge the season by observing the position of the Big Dipper at dusk.

With the passage of four seasons, the Big Dipper rotates clockwise in the starry sky. Every time the bucket points to the east, everyone knows that spring is coming and farmers can start preparing for sowing. And this method of observing the regular changes of the sky to determine the four seasons is called "observation time", which was used by the ancients for a long time in the era without calendar.