449 years ago today, on September 21, 1576 (August 29, 1576 in the lunar calendar), Italian court astrologist Cardano passed away. Cardano, named Girolamo Cardano in Italy, was born on September 24, 1501 and died on September 21, 1576. He was an encyclopedic scholar of the Italian Renaissance. His main achievements were in mathematics, physics, and medicine. Because its name is spelled Jerome Cardan in English, it is also called Kadang. Cardano, Italian mathematician, medical scientist, and physicist. His surname is spelled "Cardan" in English. Translated as "kadang". This is often used commonly. Born in Pavia and died in Rome. In his early years, he studied classics, mathematics and astrology. In 1520, he studied medicine at the University of Pavia, and later transferred to the University of Padua. In 1526, he received a doctorate in medicine. After graduation, he practiced medicine in Saccolongo, a small town near Padua, for nearly 6 years. In 1532, he moved to Milan and opened his own business. In 1534, he became a part-time mathematics teacher at the Milan Junior College. This led to the beginning of mathematical research. In 1539, he joined the Milan Medical Association. In 1543, he was promoted to Professor of Medicine at the University of Pavia. In 1562, he was hired Professor of Medicine at the University of Bologna. In 1571, he settled in Rome and became a court astrologist for Pope Pius V until his death. Cardano is known as an encyclopedic scholar. He has written more than 200 articles and books of various types in his life, and there are about 7000 pages of existing materials. His mathematical contributions are reflected in several books: Arithmetic Practice and Individual Measurement (1539) showed high skills in calculation methods and algebraic transformations; "On the Game of Dice"(1663) gives some basic concepts and theorems in probability theory. Obtained results such as the so-called "power theorem"; His most important book,"Da Shu"(1545). For the first time, general solutions to algebraic equations of order three and four are published, and it is confirmed that algebraic equations of order higher than one have more than one root. Knowing one root of the equation can reduce the order of the equation. Some relationships between the roots and coefficients of the equation are pointed out. An approximate solution to the equation is obtained by repeatedly implementing substitution methods. Imaginary numbers, etc. are used in solving equations. Among them, the formula for finding roots for general quadratic algebraic equations is now called "Cardan Formula" or "Cardano Formula". His other two books,"The Exquisite of Things"(1550) and "Everything in the World"(1553), contained a large amount of knowledge of natural sciences and technologies such as mechanics, mechanics, astronomy, chemistry, and biology, as well as cryptography, alchemy, and astrology. Known as the best encyclopedia of the time, it was printed many times and widely circulated in continental Europe. He also proposed the "inclined plane principle" for the supporting force of objects, and designed mechanical devices such as "Cardano suspension" and "Cardano joint". In addition, he was one of the first scholars to understand the water cycle theory in nature, and proposed the "three-element" and "two-base" theories to explain natural phenomena. As a doctor. He specializes in both diagnostic prescriptions and surgery. He was also the first to theoretically explain the diagnosis of typhus. Put forward your own opinions on physiological and psychological issues. Regarding his death-he died for a false name and was born in Pavia, the illegitimate child of a lawyer friend of Leonardo da Vinci, and was ill in his early years. In 1526, he received a doctorate in medicine from the University of Pavia and later became a famous European doctor. He served as the royal doctor of King Edward VI of England and taught at the University of Pavia and the University of Bologna. His family life was very unfortunate. His favorite eldest son, Giambatista, was sentenced to death in 1560 for killing his unfaithful wife. His daughter became a prostitute and died of syphilis. His other son was a gambler and often stole his belongings. He himself was accused of treason and heresy for calculating the birth position of Jesus. He was imprisoned in 1570 and lost his teaching position. Even more sadly, his son participated in the accusations. After being released from prison, he moved to Rome, received an annuity from Pope Gregory XIII, and completed his autobiography. It is said that when he was seventy-one, he used astrology to predict that he would die on September 21, 1576, but by that day, he lived like a strong ox; In order to preserve his reputation as a great astrologer, he committed suicide.