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 that the circle inscribed by a 96-sided polygon is π=3. 14, and pointed out that the more sides inscribed by a regular polygon, the more accurate the π value is. On the basis of predecessors' achievements, Zu Chongzhi worked hard and repeatedly calculated that π was between 3. 14 15926 and.
Xu Ruiyun, 19 15 was born in Shanghai, and 1927 was admitted to Shanghai famous public girls' middle school in February. Xu Ruiyun liked mathematics since he was a child, but he was more interested in mathematics when he was in middle school. So, 1932 entered the mathematics department of Zhejiang University after graduating from high school in September. At that time, the professors in the Department of Mathematics of Zhejiang University were Zhu, Qian Baoyu, Chen and Su. Besides, there are several lecturers and teaching assistants. The courses in the Department of Mathematics are mainly taught by Chen and Su. There were few students in the department of mathematics at that time. There were five students in two classes in the last session, and this time she was only a dozen.
Thales (an ancient Greek mathematician and astronomer) came to Egypt. People wanted to test his ability, so they asked him if he could measure the height of the pyramids. Thales agreed, but on one condition-Pharaoh must be present. The next day, Pharaoh arrived as scheduled and many onlookers gathered around the pyramid. Before Cyrus came to the pyramids, the sun cast his shadow on the ground. Every once in a while, he asked someone to measure the length of his shadow. When the measured value is completely consistent with his height, he immediately made a mark on the projection of the Great Pyramid on the ground, and then measured the distance from the bottom of the Pyramid to the projection spire. In this way, he reported the exact height of the pyramid. At the request of Pharaoh, he explained how to push the principle from "shadow length equals body length" to "tower shadow equals tower height", which is today's similar triangles theorem.
Archimedes
King Shiloh of Syracuse asked the goldsmith to make a crown out of pure gold. Because it is suspected that there is silver mixed in it, Archimedes is invited to identify it. When he entered the bathtub to take a bath, the water overflowed outside the bathtub, so he realized that although the weight of objects made of different materials was the same, the discharged water would be different because of their different volumes. According to this truth, it can be judged whether the crown is adulterated.
Galois was born in a town not far from Paris. His father is the headmaster of the school and has served as mayor for many years. The influence of family makes Galois always brave and fearless. 1823, 12-year-old galois left his parents to study in Paris. Not content with boring classroom indoctrination, he went to find the most difficult mathematics original research by himself. Some teachers also helped him a lot. Teachers' evaluation of him is "only suitable for working in the frontier field of mathematics".
Von Neumann, one of the most outstanding mathematicians in the 20th century. As we all know, the electronic computer invented by 1946 has greatly promoted the progress of science and technology and social life. In view of von Neumann's key role in the invention of electronic computers, he is called "the father of computers" by westerners. From 19 1 1 to 192 1, von Neumann got ahead when he was studying in Lu Se Lun Middle School in Budapest, and was highly valued by teachers. Under the individual guidance of Mr. Fichte, von Neumann published his first mathematical paper in cooperation.
On the Discovery of Irrational Numbers
The Pythagorean school of ancient Greece believed that any number in the world could be expressed by integer or fraction, which was their creed. One day, hippasus, a member of this school, suddenly found that the diagonal of a square with a side length of 1 was a strange number, so he studied hard and finally proved that it could not be expressed by integers or fractions. But it broke the Pythagorean creed. So Pythagoras ordered him not to reveal it. But Siberus revealed the secret. Pythagoras was furious and wanted to put him to death Siberus ran away at once, but he was caught and thrown into the sea, giving his precious life for the development of science. The numbers discovered by Siberus are called irrational numbers. The discovery of irrational numbers led to the first mathematical crisis and made great contributions to the development of mathematics.
history of chinese mathematics
Mathematics is an important subject in ancient science in China. According to the characteristics of the development of ancient mathematics in China, it can be divided into five periods: the germination period; The formation of the system; Development; Prosperity and the integration of Chinese and western mathematics.
The Germination of Ancient Mathematics in China
At the end of primitive commune, after the emergence of private ownership and commodity exchange, the concepts of number and shape developed further. The pottery unearthed during Yangshao culture period has been engraved with the symbol representing 1234. By the end of the primitive commune, written symbols had begun to replace knotted notes.
Pottery unearthed in Xi 'an Banpo has an equilateral triangle with 1 ~ 8 dots and a square pattern with 100 small squares. The houses in Banpo site are all round and square. In order to draw circles and determine straightness, people have also created drawing and measuring tools such as rulers, moments, rulers and ropes. According to Records of Historical Records Xia Benji, Yu Xia used these tools in water conservancy.
In the middle of Shang Dynasty, a set of decimal numbers and notation had been produced in Oracle Bone Inscriptions, the largest of which was 30 thousand; At the same time, the Yin people recorded the date of 60 days with 60 names, including Jiazi, Yechou, Bingyin and Dingmao, which were composed of ten heavenly stems and twelve earthly branches. In the Zhou Dynasty, eight kinds of things were previously represented by eight diagrams composed of yin and yang symbols, which developed into sixty-four hexagrams, representing sixty-four kinds of things.
The book Parallel Computation in 1 century BC mentioned the methods of using moments of high, deep, wide and distance in the early Western Zhou Dynasty, and listed some examples, such as hook three, strand four, chord five and ring moments can be circles. It is mentioned in the Book of Rites that the aristocratic children of the Western Zhou Dynasty have to learn numbers and counting methods since they were nine years old, and they have to be trained in rites and music, shooting, controlling, writing and counting. As one of the "six arts", number has begun to become a special course.
During the Spring and Autumn Period and the Warring States Period, calculation has been widely used and decimal notation has been used, which is of epoch-making significance to the development of mathematics in the world. During this period, econometrics was widely used in production, and mathematics was improved accordingly.
The contention of a hundred schools of thought in the Warring States period also promoted the development of mathematics, especially the dispute of rectifying the name and some propositions were directly related to mathematics. Famous scholars believe that the abstract concept of a noun is different from its original entity. They put forward that "if the moment is not square, the rules cannot be round", and defined "freshman" (infinity) as "nothing outside the big" and "junior" (infinitesimal) as "nothing inside the small". He also put forward such propositions as "a foot away, within half a day, inexhaustible".
Mohism believes that names come from things, and names can reflect things from different sides and depths. Mohist school gave some mathematical definitions. Such as circle, square, flat, straight, sub (tangent), end (point) and so on.
Mohism disagreed with the proposition of "one foot" and put forward the proposition of "non-half" to refute: if a line segment is divided into two halves indefinitely, there will be a non-half, which is a point.
The famous scholar's proposition discusses that a finite length can be divided into an infinite sequence, while the Mohist proposition points out the changes and results of this infinite division. The discussion on the definition and proposition of mathematics by famous scholars and Mohists is of great significance to the development of China's ancient mathematical theory.