Depth explanation of solar terms

"Twenty-four solar terms" reflect the influence of the sun on the earth. By observing the movement of the sun in a year, we can understand the knowledge system formed by the changing laws of the four seasons and climate in a year, which also plays a guiding role in agricultural production.

For example:

1, Grain Rain: Rain produces 100 grains, which reflects the agroclimatic significance of "Grain Rain". At this time, the precipitation increased obviously, which promoted the growth and development of cereal crops. At this time, the seedlings in the field are newly planted, and new crops need rain most, so there is a saying that "spring rain is as expensive as oil". During the solar term in Grain Rain, ancient people had the custom of "going to Grain Rain", "tasting Grain Rain tea" and "enjoying peony flowers".

2. Summer solstice: The hot summer is coming. After this day, it is about to "turn back". The direct sunlight point starts to move south from the Tropic of Cancer, and the days in the northern hemisphere become shorter day by day. After the summer solstice, the Tropic of Cancer and its northern region, the midday sun altitude angle also began to decrease.

3. beginning of spring: beginning of spring means the beginning of a new cycle, which means that everything is the beginning and everything is new. Standing means "start"; Spring represents warmth and growth. In the era of main branches, beginning of spring is the beginning of a year, and beginning of spring is the beginning of spring and the beginning of a year.

Twenty-four solar terms refer to the special festivals in the dry calendar that indicate the season, phenology, climate change and the establishment of "December construction". Originally determined by the bucket handle direction of the Big Dipper, bucket handle revolved around the east, south, west and north for a period of time, which was called one of the "years old"; Every rotation cycle starts from beginning of spring and ends with the Great Cold.

"Twenty-four solar terms" is a special festival in the calendar, indicating the season, phenology, climate change and the establishment of "December construction". The repeated rotation of the Big Dipper is closely related to the change of seasons. Taking the direction pointed by bucket handle, namely the Big Dipper, as the standard for judging seasons, it is called sword fighting, also known as Jian Yue. The method of the era of cadres and branches, the first month to build Yin, beginning of spring as the beginning of the year, the beginning of the month to pay the festival.