Zu Chongzhi (AD 429-500) was born in Laiyuan County, Hebei Province during the Northern and Southern Dynasties. He read many books on astronomy and mathematics since childhood, studied hard and practiced hard, and finally made him an outstanding mathematician and astronomer in ancient China.
Zu Chongzhi's outstanding achievement in mathematics is about the calculation of pi. Before the Qin and Han Dynasties, people used "the diameter of three weeks a week" as pi, which was called "Gubi". Later, it was found that the error of Gubi was too large, and the pi should be "the diameter of a circle is greater than the diameter of three weeks". However, there are different opinions on how much is left. Until the Three Kingdoms period, Liu Hui put forward a scientific method to calculate pi-"secant" which approximated the circumference of a circle with the circumference inscribed by a regular polygon. Liu Hui calculated the circle inscribed with a 96-sided polygon and got π=3. 14, and pointed out that the more sides inscribed with a regular polygon, the more accurate the π value obtained. On the basis of predecessors' achievements, Zu Chongzhi devoted himself to research and repeated calculations. It is found that π is between 3. 14 15926 and 3. 14 15927, and the approximate value in the form of π fraction is obtained as the reduction rate and density rate, where the six decimal places are 3. 14 1929. There's no way to check now. If he tries to find it according to Liu Hui's secant method, he must work out 16384 polygons inscribed in the circle. How much time and labor it takes! It is obvious that his perseverance and wisdom in academic research are admirable. It has been more than 1000 years since foreign mathematicians obtained the same result in the secrecy rate calculated by Zu Chongzhi. In order to commemorate Zu Chongzhi's outstanding contribution, some mathematicians abroad suggested that π = be called "ancestral rate".
Zu Chongzhi exhibited famous works at that time and insisted on seeking truth from facts. He compared and analyzed a large number of materials calculated by himself, found serious mistakes in the past calendars, and dared to improve them. At the age of 33, he successfully compiled the Daming Calendar, which opened a new era in calendar history.
Zu Chongzhi and his son Zuxuan (also a famous mathematician in China) solved the calculation of the volume of a sphere with ingenious methods. They adopted a principle at that time: "If the power supply potential is the same, the products should not be different." That is to say, two solids located between two parallel planes are cut by any plane parallel to these two planes. If the areas of two sections are always equal, then the volumes of two solids are equal. This principle is based on the following points. However, it was discovered by Karl Marx more than 1000 years ago. In order to commemorate the great contribution of grandfather and son in discovering this principle, everyone also called this principle "the ancestor principle".
After Emperor Xiaowu of the Song Dynasty ascended the throne, the Song Dynasty declined rapidly. During this period, an outstanding scientist Zu Chongzhi emerged.
Zu Chongzhi's grandfather, Zuchang, was an official in charge of royal architecture in the Song Dynasty. Zu Chongzhi grew up in such a family and learned a lot from childhood. People all praise him as a knowledgeable young man. He especially likes studying mathematics, and he also likes studying astronomical calendars. He often observes the movements of the sun and planets and makes detailed records.
When Emperor Xiaowu of Song heard of his fame, he sent him to work in a government office specializing in academic research in Hualin Province. He is not interested in being an official, but he can concentrate more on mathematics and astronomy there.
There have been officials who studied astronomy in all previous dynasties in our country. They made calendars according to the results of astronomical research. By the Song Dynasty, the calendar had made great progress, but Zu Chongzhi thought it was not accurate enough. Based on his long-term observation, he created a new calendar called "Daming Calendar" ("Daming" is the title of Emperor Xiaowu of Song Dynasty). The number of days in each tropical year measured by this calendar (that is, the time between winter and sun in two years) is only 50 seconds different from that measured by modern science; It takes less than one second to measure the number of days for the moon to make one revolution, which shows its accuracy.
In 462 AD, Zu Chongzhi requested Emperor Xiaowu of Song Dynasty to issue a new calendar, and Emperor Xiaowu called ministers to discuss it. At that time, Dai Faxing, one of the emperor's minions, stood out against it and thought that it was deviant for Zu Chongzhi to change the ancient calendar without authorization.
Zu Chongzhi refuted Defarge on the spot with his own research data. Relying on the emperor's favor, Dai Faxing said arrogantly: "The calendar was formulated by the ancients and cannot be changed by future generations."
Zu Chongzhi is not afraid at all. He said very seriously, "If you have a solid basis, argue it out. Don't scare people with empty talk. "
Emperor Xiaowu of Song wanted to help Dai Faxing, and found some people who knew the calendar to argue with Zu Chongzhi, but Zu Chongzhi refuted them one by one. However, Emperor Xiaowu of Song still refused to issue a new calendar. It was not until ten years after Zu Chongzhi's death that his Da Ming Li was put into practice.
Although the society was very turbulent at that time, Zu Chongzhi studied science tirelessly. His greater achievement is in mathematics. He once annotated the ancient mathematics book Nine Chapters Arithmetic and wrote a book Composition. His most outstanding contribution is to get quite accurate pi. After a long and arduous study, he calculated pi between 3. 14 15926 and 3. 14 15927, becoming the first scientist in the world to calculate pi to more than seven digits.
Zu Chongzhi is a generalist in scientific inventions. He built a kind of compass, and the copper man in the car always pointed south. He also built a "Thousand-Li Ship" and tried it in Xinting River (now southwest of Nanjing). It can sail 100 Li a day. He also used hydraulic power to rotate the stone mill, pounding rice and grinding millet, which was called "water hammer mill".
After Zu Chongzhi's death, his son Zu Xuan and grandson Zu Hao both inherited Zu Chongzhi's career and studied mathematics and calendar hard. It is said that Zuxuan was so absorbed in his study that he couldn't even hear the thunder. He often thinks while walking. Once, he was walking on the road when a big bureaucrat, Xu Mian, came up to him. Zuxuan didn't notice and bumped into Xu Mian. When Xu Mian greeted him, Zu Xuancai woke up like a dream and hurriedly resaluted him. Xu Mian knows that he has studied God, and he doesn't blame him.
In Zu Chongzhi's later years, Xiao Daocheng, who mastered the Song Guards, wiped out the Song Dynasty.
In 479 AD, Xiao Daocheng proclaimed himself emperor and established Nanqi. He is the Emperor Gaudi of Qi.