Gerolamo Cardano

Gerolamo Cardano (also known with the Latin name of Hieronymus Cardanus) was born in Pavia on 24 September 1501 and died in Rome on 21 September 1576.

He was an illegitimate son of Fazio Cardano, a notary public skilled in mathematics friend of Leonardo da Vinci, and the much younger widow Chiara Micheria.

In his autobiography Cardano states that his mother had sought an abortion. A little before his birth, to escape an epidemic of black plague that killed her other three children, she moved from Milano to Moirago, near Pavia.

Cardano is portrayed variously by historians because of his contradictory personality and irregular and adventurous life.

As a young man his father urged him to study mathematics. In 1520, he went to the University of Pavia and later that of  Padova to study medicine. His eccentric behaviour got him many enemies, and at the end of the course it was difficult to find work, because as an illegitimate son, he could not be allowed into the Medical Association of Milano. He did his best to get a good reputation as a doctor and ended up being highly appreciated in several courts. He was the first to describe typhoid fever.

Today, he is known for his contributions to algebra. He published the solutions of the cubic equation and of the quartic equation in his work entitled Ars Magna printed in 1545, published for the first time in Nuremberg.

Part of the solution of the cubic equation had been told him by Tartaglia, who later said that Cardano had sworn to not make it public. This initiated a dispute with him lasting a decade. However the solution is called Cardano-Tartaglia.

He was invited to Scotland to treat Cardinal Hamilton for asthma. He managed to put him back on foot, using extremely modern treatments for the time, such as eliminating feathers, dust, and ordering him to have a balanced diet. On his way back, he stopped in London, where he met the king of England and made a very good impression on the Court. His fame was at the peak in those months: he was rich, feared and respected almost in the whole of Europe. According to the historian Angelo Paratico, Shakespeare drew inspiration from him for the character of Prospero in “The Tempest". Moreover, Hamlet’s famous monologue "to be or not to be" would be in part a meditation on a similar phrase contained in "Comforte", Cardano’s translation of the “Liber consolationis”.

Cardano also designed several devices: the combination lock; the gimbals, consisting of three concentric rings that can support a compass or a Gyroscope that may rotate freely; the universal joint, a device that allows you to send a rotating motion from an axle to another of a different angle and is still used in millions of vehicles. He made several contributions to hydrodynamics and stated the impossibility of perpetual motion, with the exception of celestial bodies. He also published two huge works of natural sciences containing a wide variety of inventions, facts and propositions relating to occultism and superstition: “De subtilitate” and later “De varietate”. In 1550 he presented the cardan grid, a cryptography technique.

Giambattista, Cardano’s first son and pet child, married Brandonia de’ Seroni, a woman who Cardano considered immoral. Feeling betrayed and deceived by his wife, Giambattista poisoned her and in 1560 he was executed. These traumatic events destroyed Cardano irrecoverably. Other children displeased him. His daughter became a prostitute and died of syphilis. His other son Aldo devoted himself to gambling and stole from his father to pay off his debts.

Cardano himself was accused of heresy in 1570 because he had computed and published the horoscope of Jesus in 1554. Apparently, his own son contributed to the prosecution. He was arrested, had to spend several months in prison and was forced to abjure his professorship. He moved to Rome, received a lifetime annuity from Pope Gregory XIII (after first having been rejected by Pope Pius V) and finished his autobiography. He died there on the day he had (supposedly) astrologically predicted earlier; some suspect that he may have committed suicide so that the "prophesied" date of his death would come true.