"Twenty-four solar terms" is the product of ancient farming civilization. It is a knowledge system formed by ancient ancestors who followed the farming season and recognized the changing laws of seasons, climate and phenology in one year by observing the movement of celestial bodies.
The 24 solar terms were originally formulated according to the change of stars. The Big Dipper rotates in a cycle, and bucket handle rotates clockwise for one cycle, which is called one of the "years" (photo); The current "twenty-four solar terms" are formulated according to the position of the sun on the ecliptic, that is, the annual movement track of the sun is divided into 24 equal parts, each 1 5 is 1 equal part, and each1equal part is a solar term. At the age of four, there are three months in spring, summer, autumn and winter, and two solar terms in each month, each of which has its own unique meaning.
Twenty-four solar terms are specific festivals in the calendar that express the change of natural rhythm and establish "December construction". Twenty-four solar terms accurately reflect the changes of natural rhythm and play an extremely important role in people's daily life. It is not only a time system that guides agricultural production, but also a folk system that contains rich folk customs. The twenty-four solar terms contain a long cultural connotation and historical accumulation, and are an important part of the long history and culture of the Chinese nation.
Astronomical latitude of 24 solar terms
The conversion of natural solar terms is closely related to the astronomical "intersection angle of yellow and red" The intersection of the ecliptic and the equator is about 23 degrees and 26 minutes north latitude, which is the northernmost boundary of direct sunlight on the earth. The Tropic of Cancer is a special latitude line with typical astronomical significance on the earth, which is of great significance to astronomy, geography, climate and biology. China is located in the northern hemisphere, and the Tropic of Cancer (Cape Huang Chi Jiao) runs through China.
The latitude of the Tropic of Cancer is the angle of Huang Chi Jiao, which determines the range of the regression motion of the direct point of the sun, that is, the latitude of the Tropic of Cancer. It also profoundly affects other natural geographical phenomena closely related to it, such as the changes of four seasons on the earth and natural phenomena such as the changes of five zones, pressure zones, wind zones, climate zones and natural zones. The arrangement of "Twenty-four solar terms" is closely related to this special astronomical latitude and the climate type of China.
Baidu Encyclopedia-Twenty-four solar terms