How did the winter solstice come about?

A map of the heavenly palace from China during the winter solstice. China's astrological culture has a long history and is profound. The twenty-four solar terms were originally formulated on the basis of changing stars. In different seasons and at different times, the Big Dipper will point in different directions, that is, "bucket handle points to the East, and the world is spring; Guide to barrel handle, it's summer in the world; Bucket handle refers to the west, and the world is autumn; Bucket handle refers to the north, and it is winter in the world. " .

"Twenty-four solar terms" is the product of ancient farming civilization, which is related to the time of gossip and has a long history. During the period of Emperor Wu of the Western Han Dynasty, the "twenty-four solar terms" were absorbed into the taichu calendar law as a supplement to the calendar to guide the agriculture in the northern Central Plains, and the "twenty-four solar terms" were measured in the Yellow River basin by the method of Tuguiriying.

The current "twenty-four solar terms" are determined according to the position of the sun on the ecliptic, that is, on a "ecliptic" with a circumference of 360 degrees (the apparent path of the sun on the celestial sphere for one year), the spring is divided into 0 degrees, and every time the sun runs on the ecliptic, 15 degrees is a "solar term". In the process of inheritance and development, the 24 solar terms have been incorporated into the lunar calendar and become an important part of the lunar calendar.

The significance of winter solstice

The winter solstice, known as the "southern solstice", is a solar term reflecting the direct sunlight movement. On the winter solstice, the sun goes south to the extreme, and the sun shines directly on the tropic of Capricorn. Since the winter solstice, the direct point of the sun has returned to the north. The solstice in winter is the turning point of "going south to north". Since then, the sun has risen in height and the days in the northern hemisphere have increased day by day.

The solstice in winter marks the rebirth of the sun and the round-trip movement of the sun into a new cycle. The solstice in winter is an auspicious day. For example, "Hanshu" said: "The sun shines on the winter solstice, and the monarch is long, so congratulations." After the winter solstice, the days are getting longer and longer and the sun rises. This is the beginning of a round-trip cycle of direct sunlight, which should be celebrated.

Refer to the above? Baidu encyclopedia-winter solstice