What you don't know is that Zu Chongzhi didn't just calculate pi. According to what we say now, Zu Chongzhi is a great god. ?
Zu Chongzhi's most famous identity, mathematician.
His book Composition was included in the famous Ten Books of Calculating Classics, which was used as a teaching material for imperial academy in the Tang Dynasty, but it was later lost. Sui Shu Li Zhi left a brief record about pi: "At the end of the Song Dynasty, South Xuzhou engaged in the history of Zu Chongzhi and opened a more dense method. The diameter of a circle is 100 million, and the circumference of an abundance is three feet, four inches, one minute, five millimeters, nine seconds, seven seconds, three feet, one inch, five millimeters, nine seconds, six seconds, six seconds. Positive numbers are between surplus and two limits. Density, circle diameter 1 13, circumference 355. Agreed rate, circle diameter 7, Tuesday 12. "
Zu Chongzhi calculated that the true value of π is between 3. 14 15926 and 3. 14 15927, which is equivalent to being accurate to the seventh place after the decimal point and simplified to 3. 14 15926.
Zu Chongzhi also gave two fractional forms of π: 22/7 (approximate rate) and 355/ 1 13 (secret rate), in which the secret rate was accurate to the seventh place after the decimal point, and it was not rediscovered by the Dutch mathematician Otto until the west16th century. Zu Chongzhi, together with his son Zuxuan, successfully solved the problem of calculating the volume of the ball by using "Mu He Fang Gai" and got the correct formula of the volume of the ball.
Astronomical calendar jurist: Zu Chongzhi
Zu Chongzhi successfully produced the most scientific and progressive calendar at that time-Daming Calendar. This is the genius of Zu Chongzhi's scientific research and his most outstanding contribution to the astronomical calendar.
Liu Song Daming six years (AD 462), Zu Chongzhi years, Li Cheng 33 years old. The tropic year is 365.2428, which is the most ideal data before the Zhao-Song calendar (A.D. 1 199) in China. Precession is considered first in the duration of the system. The so-called "precession" means that the direction of the earth's rotation axis changes slowly and slightly due to the attraction of other celestial bodies during the operation of the earth. Therefore, from the winter solstice this year to the winter solstice the following year, from the earth's point of view, the sun did not return to its original position, but moved backwards year after year, which also caused the change of the position of the 24 solar terms. Zu Chongzhi has determined that the monthly difference 1 1 every 45 years is 1. Although this "year difference" is very inaccurate, it is a calendar that introduces "precession".
The leap method has also been improved, and the leap in the old calendar has been changed from every 19 to every 39 1 to 144, which is more in line with the astronomical reality. For the first time in China, the so-called "moon-crossing" day is set at 27.2 1223, which is very close to the modern measured data (27.438+0222).
This is the second major reform in the history of China.
Mechanical Engineer: Zu Chongzhi
In 4 17 AD, Emperor Wu of the Eastern Jin Dynasty (later the founding emperor of the Song Dynasty) marched straight into Chang 'an, and he was given an old compass by Yao Xing, the ruler of the late Qin Dynasty. The machinery in the car has been lost, so when the car is walking, it can only be turned by people to point to the south. Later, Xiao Daocheng, the Emperor of Qi Gao, asked Zu Chongzhi to copy it. The inner parts of the south guide car made in Zu Chongzhi are all made of copper. After it was made, Xiao Daocheng sent two ministers, Wang Sengqian and Liu Xiu, to test it. Practice has proved that the system is exquisite in structure and flexible in operation. No matter how you turn, Woodenhead's hand always points to the south.
Zu Chongzhi also made very useful labor tools. He saw that the working people threshed and milled rice very hard, so he created a food processing tool called water hammer mill. Ancient working people invented water reefs and water mills for milling rice very early. In the early years of the Western Jin Dynasty, Du Yu improved it and invented "continuous mill" and "water-to-water continuous mill". A connecting machine can drive several stone pestles to land together; A water mill can drive eight mills to grind at the same time. On this basis, Zu Chongzhi has further improved it, combining water hammer with water mill to further improve the production efficiency. This processing tool is still used in some rural areas in southern China.
Zu Chongzhi also designed and built a thousand-mile ship. It may be caused by the principle of using wheels to push water forward, and it can travel 100 miles a day.
Zu Chongzhi also made a "ritual vessel" and gave it to Xiao Liang Zi, the second son of Emperor Wu of Qi. Fences were used by the ancients to warn against complacency. When there is no water in the container, it is horizontal. After it is filled with water, it will stand up if the amount of water is moderate; If the water is full, it will fall to one side and throw the water out. Tu Yu, a scholar in Jin Dynasty, tried this instrument three times, but failed. Zu Chongzhi copied successfully. Thus, Zu Chongzhi has a profound research on all kinds of machinery.
Philosopher: Zu Chongzhi.
Zu Chongzhi also wrote the Book of Changes, Lao, Zhuang, Interpretation of the Analects of Confucius and Interpretation of Filial Piety, all of which have been lost.
Judging from the title of the book, it is basically an annotation and interpretation of pre-Qin classics. Moreover, this kind of annotation and explanation speculation should not only be an exegetical explanation, but also an exposition of views. This is a great move to explain a book, and more importantly, he expounded his views on several most influential pre-Qin ancient books at the same time. In addition, Zu Chongzhi himself is a very high-level astronomer, and astronomy itself cannot be separated from the basic understanding of the world in China's cultural system. Therefore, it is no exaggeration to call Zu Chongzhi a philosopher.
In fact, he also wrote a literary work "Stories about Different Stories", but he didn't stay. We can see fragments of this work in books such as Taiping Yu Lan, and dare not call him a writer.