The origin of the twenty-four solar terms

"Twenty-four solar terms" is the product of ancient farming civilization. It is a special festival in the trunk calendar to express the change of natural rhythm and establish "December" (month). "Twenty-four solar terms" and "December" are the basic contents of the elephant trunk calendar. The twenty-four solar terms were originally formulated according to the changes of stars. The Big Dipper consists of seven stars, including Shu Tian, Tian Xuan, Celestial Pole, Tianquan, Yuheng, Kaiyang and Yaoguang. It is named after the twists and turns of the Big Dipper.

The Big Dipper is an important astrological sign in the northern hemisphere (China is located in the northern hemisphere), and the natural rhythm of the corresponding area in the northern hemisphere is gradually changing when the stars change, so it has become the basis for the ancients to judge the change of solar terms, that is, the so-called "bucket handle refers 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 the world is winter. ". Because the 24 solar terms are determined by the rotation direction of Beidou bucket handle, this calendar is also called "ephemeris".

According to documents, four solar terms, midsummer, midsummer, midsummer and winter solstice, appeared in the Central Plains of China in Shang Dynasty, and eight solar terms appeared in Zhou Dynasty. During the period of Taosi ruins more than 4,000 years ago, the Central Plains area has measured its position in the world with the soil regulation method (standard table) in Luoyi, Henan Province, and it has been designated as soil. The first of the 24 solar terms determined by Duke Zhou is the "winter solstice" determined by standard chart mapping, and is considered to be the first of the 24 solar terms.

The essence of the method of Surveying Shadows by Soil Gauge is that "the tree is eight feet high, and the scenery is five inches long from summer to the sun (equivalent to no pole on the Tropic of Cancer); On the solstice of winter, the scene is one foot, three feet and five inches long (that is, an eight-foot high benchmark is erected). On the summer solstice, the shadow of noon is 65,438+0.5 feet, and on the winter solstice, the shadow of noon is 65,438+03.5 feet. " Measure the soil depth, correct the shadow, find the ground, and check at four o'clock. "In the Spring and Autumn Period, Shangshu recorded the solar terms.

There were only four solar terms in Shang dynasty, while there were eight solar terms in Zhou dynasty. The names of the twenty-four solar terms first appeared in Liu An's "Instructions of Huainan Tian Zi" in the Western Han Dynasty, and the concepts of Yin and Yang, four seasons, eight places, twelve degrees and twenty-four solar terms were also mentioned in the preface to Historical Records Taishi Gong. In BC 104, taichu calendar written by Deng Ping set 24 solar terms in the calendar.

Related instructions

"Twenty-four solar terms" is a special festival to express the natural rhythm changes in the dry calendar and establish "December" (monthly order), which is a solar month based on "Twenty-four solar terms". One-year-old (taking photos) is divided into twelve days (made in December, made in December), and the monthly order is calculated by the Big Dipper. The day referred to by bucket handle is called "sword fighting" (also called Jian Yue).

In traditional culture, the branch and the eight diagrams are linked in time, and the yin position is the root position of "the day after tomorrow's eight diagrams", which represents the end and the beginning, such as "Yi Shuo Gua Zhuan": "The root, the northeast eight diagrams, is also the beginning of everything."

That is, bucket handle rotates clockwise from due east to north (yin position and acquired gossip position), which is one of the "years old" (from beginning of spring to the next beginning of spring, it is one year old). Silver moon said that "spring is positive", and the beginning of spring is the beginning of a year. Beginning of spring is the beginning of all things and the meaning of all self-renewal. Bucket handle, the Big Dipper, points to the establishment of the 24 solar terms, starting from beginning of spring and ending in severe cold.

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