In the previous article, we had a preliminary understanding of the evolution of the dating method in ancient astronomy and the universality and conversion methods of the stem and branch dating method method. So what is the moon dating method in ancient astronomy?
As the name suggests, the lunar method is indeed based on the changes of moon phases . The ancients first observed the moon phases and discovered five changes of the moon phases: new moon , first quarter, full moon, last quarter , waning moon, and then the cycle starts again.
On this basis, people found that in each phase, there are always one or two days during the new moon and full moon phases when the moon can be seen all night long. Then the ancients called the day represented by the new moon "Suo", which means "chu", representing the beginning of the month, and called the day represented by the full moon "Wang". The sun and the moon look at each other, which happens to be a perfect full moon. Then the ancients used "Suo" and "Wang" to mark the month. From "Suo" to "Suo" or from "Wang" to "Wang", it takes about twenty-nine days. This is the return month of , , which is the time interval between the positions of the sun, moon, and earth on a straight line twice in a row.
However, the number of days between a tropical year and the twelve tropical months is not equal. They observed that after running this system for several years, there were more than twelve months in a tropical year, and there was no match. What should we do? Our ancients were very wise, and they came up with the idea of " setting leap month " to solve this problem. If the difference in the number of days is almost a month, then one month will be added to the year. The month of the leap will be determined according to whether there is Zhongqi or not. This is the source of today's " leap month " in our lunar calendar (if you are interested in the explanation of Zhongqi, you can communicate through private messages, and I will not go into details in this article).
So the above is the foundation and basis of the moon counting method. The earliest moon counting actually counted the months in the numerical sequence from one to twelve. In the Spring and Autumn Period and the Warring States Period, because the chronology of the various vassal states was chaotic, astronomers used the stars as the basis, and based on the Big Dipper The direction pointed by the handle of the Big Dipper corresponds to the twelve earthly branches . We reported in the previous issue Rong Zhong knew that the ancients divided the horizon into twelve equal parts and named them according to the twelve earthly branches. Therefore, the specific operation of the twelve earthly branches is that if the handle of the Big Dipper points to the "Yin" position of the horizon, this month is the "Yin" month.
This seems to be able to unify everyone's method of marking the moon. However, the problem arises again. The problem of the coordination of the four seasons and the months is the so-called "Jianzheng". Although the direction pointed by the handle of the bucket is determined, the bucket jian starts from "Zi" and ends with "Hai". This is a celestial phenomenon. It is well-founded and no one will doubt it. But what about the seasons? That is to say, each family has its own opinion on which month the first month of spring is each year. Your family says that spring should start in November, but my family says that spring should start in January. After constant disputes, it may also depend on who has the fist to listen to whom. Finally, the lunar calendar that is still in use today adopts the Jian Yin as the righteous one. The beginning of the year, that is, the first month of spring is the first month, and the first month is the "Yin" month.
The application of the twelve earthly branches and moon method. Ancient astrologers also added ten heavenly stems on the basis of the twelve earthly branches and moon method, which is called the stem and branch system. This system is generally used in numerology. Here we briefly introduce the problem of calculating the first month of the first month using the stem and branch method, that is, using the five tigers. The escape formula is simple and quick to solve the problem of Jiazi calculation. This formula has appeared in the "Sikuquanshu" and other classical books. It is a summary of the experience of numerologists of the past generations in practice. It is the most basic knowledge of numerology . The formula is as follows:
The year of Jiaji has C as the head,
The year of Yigeng has Wu as the head.
The year of Bingxin is Gengyin,
Ding Renrenyin goes with the flow.
If you say where Wu Gui will come from,
Jia Yin will be the one to pursue it.
Here I will explain this formula to everyone, so that everyone can understand it and understand why it is so. That is to say: in the year when the heavenly stems are A and Ji, the Jiazi of the first month starts from Bingyin, then in February, the order of sixty years of Jiazi starts from Dingmao to Dingchou in December.
In the year when the heavenly stems are Yi and Geng, the Jiazi of the first month starts from Wuyin, then the second month of February starts from Jimao in the order of sixty years and counts down to Jichou in December.
In the year when the heavenly stems are Bing and Xin, the Jiazi of the first month starts from Geng Yin, then the second month will be counted from Xinmao to Xin Chou in December according to the order of sixty years of Jiazi.
In the year when the heavenly stems are Ding and Ren, the Jiazi of the first month starts from Renyin, then the second month of February starts from Guimao to Guichou in December according to the order of sixty years of Jiazi.
In the year when the heavenly stems are Wu and Gui, the Jiazi of the first month starts from Jiayin, then the second month of February starts from Yimao to Yichou in December according to the order of sixty years of Jiazi.
So we have introduced some commonly used knowledge about the stems and branches of the lunar system here. In the next issue, we will focus on the calculation and explanation of the Five Rats Escape Element method in the ancient astronomical time system. It is not easy to write. Teachers and enthusiasts are collecting it. While hiding, you can pay attention, like, forward and share, so that the author will be more motivated to continue to interpret, spread classics, and inherit ancient astronomy for everyone. We are so lucky to be able to walk hand in hand. Our bonus of breaking 1,000 followers is continuing. Fans who follow + like, please send a private message to the author, and we will randomly give away an ancient astronomy classic.
