Zu Chongzhi has made great achievements in many fields. How did he discover the mistakes in the past legislation and compile the Ming calendar?

Zu Chongzhi lived in the 5th century. At that time, there was already a fairly advanced calendar. The ancients defined the time from the first time to the second time as one month according to the law of the moon's changing and running. This month is about a little over twenty-nine days. Twelve months a year, this is the lunar calendar we use in China.

At the same time, people have mastered the relationship between the changes of the four seasons and the sun through observation, and set a period of this change as one year, which is the solar calendar commonly used by people. Compared with the lunar calendar, there are more days in a year in the solar calendar than in the lunar calendar 1 1 day.

In order to solve this problem, two calendars for calculating days are unified. The ancients used the method of "65438+7 leap years in 2009", which means that there are 7 leap years in 65438+2009. A year with 12 months is called a "flat year" and a year with 13 months is called a "leap year". This is the "leap moon method".

After careful calculation, Zu Chongzhi found that this leap method has a difference of one day every 200 years. Therefore, he broke the traditional concept and calculated repeatedly, and accurately obtained the new leap method of adding1year to every 39 1 44 leap month. In 462 AD, after years of consulting, comparing and studying ancient astronomical calendars, Zu Chongzhi conducted many scientific experiments, and finally made Da Ming Calendar, which broke the old leap method of "65438+7 leap in 2009" which has been used for a long time in China. He is only 33 years old this year.

Zu Chongzhi also applied the precession principle discovered by astronomers in the Eastern Jin Dynasty to calendar calculation for the first time. The so-called precession refers to the phenomenon that the earth orbits the sun once and cannot completely return to its original position. He studied the "intersection point of the moon", which provided conditions for accurately calculating the occurrence time of the solar eclipse. This is another pioneering work in astronomy and calendar.

Using this principle, Zu Chongzhi accurately calculated the tropical year as 365.438+0, which is only 50 seconds worse than the modern scientific calculation, which is a great progress in astronomical history.

The Daming Calendar compiled by him was the most precise calendar at that time, and it was determined by the rulers at that time as the universal calendar in the year of 5 10. It was not until the Southern Song Dynasty that more accurate data were available.