CARDAN Gerolamo (Cardano Girolamo)

(1501-1576)
Was born in Pavia on Sept. 24, 1501. The son of Fazio Cardano, a prominent lawyer, mentioned by Leonardo da Vinci. In 1526 he graduated from the University of Padua Gerolamo. He returned to Milan, he lectured on mathematics. Practiced in the province in 1539 was admitted to the College of Physicians.
In his spare time Cardano horoscopes living and the dead (his services as an astrologer enjoyed himself the Pope), involved the interpretation of dreams. Cardano's Book on thin matter (De subtilitate rerum) served as a popular textbook on statics and hydrostatics for a total of 17 in. Known Cardano's reasoning on the establishment of a perpetual motion machine, the difference between electric and magnetic attraction. A scientist involved in experimental research and design of various mechanisms (in particular, the propeller shaft). Cardano was a passionate lover of gambling. 'Byproduct' of his love for the game of dice has a book on gambling (De Ludo alea, 1563), containing the beginning of probability theory, the wording of the law of large numbers, some of combinatorics. Work Cardano Great Art (Ars magna, 1545) became the cornerstone of modern algebra. In its first attempt to introduce a system of equations in the study, carried out some operations with imaginary numbers. In the same article was first published method for solving equations of the third and fourth degrees (solution of the fourth degree was found student Cardano - Luigi Ferrari). The publication of Ars magna caused a famous lawsuit Cardano on the priority in solving this problem with Niccolo Tartaglia, a lecturer from Venice. Method of solving cubic equations was found Scipione del Ferro of Bologna in 1515 more. In 1535 Tartaglia, regardless of his invented his method and reported it to Cardan, taking an oath to preserve the last opening in the mystery. However, Cardano, published in his book, all he knows about cubic equations, stating that he knew about the content of Ferro and it frees him from all obligations to Tartaglia. In 1546, Tartaglia, Cardano, accused of treachery. The litigation ended after a public dispute in 1548, which represented the interests of Cardano Ferrari.

In 1562, Cardano was appointed professor at Bologna, where in 1570 he was arrested by the Inquisition. The rest of his life in Rome, trying to achieve remission. Cardano died in Rome on September 21, 1576.