Heavenly stems and earthly branches 1, used in the calendar era. Branches are mainly used in the calendar era. The original branch is "social body", also known as "Tai Sui". Tai sui meets in A, is blessed in B, is gentle in C, and is strong. Take a picture of a mandarin fish in the shade, a mandarin fish in the hair, Chen Zhong holding Xu, ... If you are trapped in the child, you will be excited about the ugliness. (The language is "Erya Shi Tian"). This set of chronological records has a far-reaching influence, and later generations have used it in calendar, arithmetic, calculation, naming, etc. (Zi Tongzhi Jian, an official history book compiled in the Northern Song Dynasty, is based on this set of official terms). Later generations simplified this set of terms into a word name in the process of inheritance and development. The original names of the main branches in Erya and Historical Records are compared with those of the simplified main branches. In the early days of observing images and timing, bucket handle made a clockwise rotation according to the movement of stars, which was called one year old. Beidou turns round, bucket handle returns to Yin, and Ganyuan stays for the Spring Festival. Tian Yuan began in Yin, such as "Xun in Huainan", which says: "Emperor, transport troops to fight, move to his place once a month, the first month refers to Yin, December is ugly, turn around at the age of one, and start all over again". The bucket handle of the Big Dipper starts from the "Yin Jian" moon pointing to the northeast, then rotates clockwise and repeats; /kloc-refers to the ugly face at the end of 0/2, and returns to the shade in the first month, and beginning of spring begins a new cycle, "bucket handle returns to the shade". In ancient China, heavenly stems and earthly branches was mainly used to determine the year, month, day and time.
2. Used for ordinal number, rating and classification. After the main ordinal function of heavenly stems and earthly branches was replaced by numbers such as one, two, three and four, people still used it as a general ordinal number. In particular, A, B, C and D can be used not only to list classified articles, but also to rate and classify things in daily life. In the nomenclature of organic chemistry, compounds with the number of carbon atoms 1- 10 are named after Rhizoma Dryopteris, such as methane (1 carbon atom), ethane (2 carbon atoms), propane (3 carbon atoms), etc ... Another example is ethylene (2 carbon atoms) and butene (4 carbon atoms).
3, used in science, medicine, feng shui, Shu Shu and numerology. In the theory of Yin-Yang and Five Elements, branches are divided into Yin-Yang, odd numbers belong to Yang and even numbers belong to Yin. A, C, E, G and N in the heavenly stems, and Zi, Yin, Chen, Wu, Shen and Xu in the earthly branches are yang numbers; The heavenly stems of B, D, Ji, Xin and Gui, and the earthly branches of Ugly, Mao, Si, Wei, You and Hai are all negative. On this basis, according to the theory of mutual restriction, the harmony, rise and fall, conflict and its birth and death of personnel are calculated. Symbols such as heavenly stems and earthly branches are endowed with rich and mysterious cultural connotations, which are important materials for understanding the thinking habits and lifestyles of ancient China people. Ganzhi calendar is still popular in books such as perpetual calendar, which is used for astrology, geomantic omen and numerology.
This is the application field of heavenly stems and earthly branches.