Gerolamo Cardano

Gerolamo Cardano, or Girolamo Cardano (September 24, 1501 - September 21, 1576), was a physician, biologist, physicist, chemist, astrologer, Italian astronomer, philosopher, writer, player and mathematician of the Renaissance. Cardano was the author of one of the first modern autobiographies, and was one of the key figures in the founding of probability. He is also known for being the first to publish a complete general solution of the quadratic equation and the quadratic equation, and for his contributions to mechanics, such as the gimbal suspension that bears his name.

Biography

Born in Pavia, Italy, Gerolamo Cardano was the illegitimate son of Fazio Cardano, a lawyer with a talent for mathematics who was a friend of Leonardo Da Vinci. In 1520, he entered the University of Pavia and studied medicine at Padua with excellent grades. Eventually, he gained a considerable reputation as a physician at Saccolongo (near Padua) and his services were highly valued at various courts (he attended the Pope and the Scottish Archbishop of St. Andrews).

Overcoming various obstacles, he was accepted in 1539 at the Medical College of Milan, reaching the pinnacle of his profession.

In Bologna, Cardano was accused of heresy in 1570 due to the controversial and sharp tone of his writings and for being the author of the horoscope of Jesus in 1554. He was prosecuted by the Inquisition, spent several months in prison, abjured and obtained the freedom but with the prohibition to publish. He then moved to Rome and got a pension from Pope Gregory XIII, and there he practiced medicine, wrote medical books and finished his celebrated autobiography. He died in Rome (a legend says that on the day that he himself had predicted) and his body was transferred to Milan and buried in the church of San Marco.

Work

Cardan suspension of a compass (about 1570)

Subtilitate, 1559

Today he is known for his multiple interests. His original texts, written in Latin, are the subject of laborious interpretations. Among his books are the two encyclopedias of general knowledge that he published: De subtilitate rerum (1550) and De varietate rerum (1559).

First, Cardano stands out for his work Algebra. In 1539 he published his book of arithmetic Practica arithmetica et mensurandi singulares. He published the solutions to the equations of third and fourth grade in his Magna Ars dated in 1545. The solution to a particular case of cubic equation x3+ax=b{displaystyle x^{3}+ax=b} (in modern notation), it was communicated through Niccolò Fontana (more known as Tartaglia) to whom Cardano had sworn not to reveal the secret of the resolution; however, Cardano considered that the oath had expired after obtaining information from other sources, so he polluted with Tartaglia, whom he also quotes. In fact, the finding of the solution of the cubic equations is not due either to Cardano or Tartaglia (he had found a first formula Scipione dal Ferro about 1515) and today Cardano's honesty recognized it in his book. A fourth grade equation was resolved by a disciple of Cardano named Lodovico Ferrari. In his exhibition, he revealed what is now known as imaginary numbers.

His book on games of chance, Liber de ludo aleae, written in the 1560s but published posthumously in 1663, is the first serious treatise on probability dealing with methods. of some effectiveness. He also introduced the Cardano grid, a cryptographic tool, in 1550.

Cardano made contributions to hydrodynamics, drawing on schemes from the 15th century d. C., and maintained that perpetual motion is impossible except in celestial bodies. Likewise, he developed a device that allows maintaining horizontality through two axes that rotate at an angle, used to stabilize compasses on ships, called gimbal suspension. Gerolamo invented the transmission system between two axes that bears his name, the cardan or universal joint.

In the field of optics, his work De subtilitate rerum advises using a lens in the camera obscura to improve the sharpness of the image, and he is considered the inventor of this device, since it is at least the first testimony in this regard that is known, almost three hundred years before the appearance of photography.

As a physician in Renaissance medicine he has been acutely studied by N. Siraisi, in The Clock and the Mirror. Cardano was the first to describe typhoid fever, noting his interest in various medical subjects and his comments on Galen and Hippocrates. His Contradicentium medicorum, from 1536, addresses issues of discussion in medicine in the XVI century d. C.. His The Book of Dreams is the last oneirocritique of ancient roots (which had begun with Artemidorus in the II AD) and medieval, passed through the critical filter of the Renaissance, which makes it an extremely valuable text; being quoted by Freud in his Interpretation of Dreams (1900).

In philosophy —where it has been thoroughly studied by A. Ingegno, Saggio sulla filosofia di Cardano— he not only wrote on moral issues (as in De consolatione, De sapientia and Pimp). In De immortalitate animorum Cardano reopened a discussion that had taken place years before mainly between Pietro Pomponazzi, Agostino Nifo, Alessandro Achillini and Marcantonio Zimara. Within the philosophical traditions of Aristotle and Averroes, this work discussed what their positions had been, and what natural reason could say about the immortality of man. Cardano was meant in opposition to Pietro Pomponazzi, follower of Alexander of Aphrodisias.

His two biographical books, My life, and My books (his autobibliography) are two masterpieces, which also make an excellent portrait of what could have been a wise man of the XVI century d. C., and the valuation of his books.

His Opera omnia was published in Lyon in the 17th century d. C., and has had a facsimile edition in the XX century d. C. (there is a miniature version of the University of Valencia ISBN 978-84-370-1887-4). Recovery work continues from Milan today.

Posts

De propria vita1821.

• De malo recentiorum medicorum usu libellusVenice, 1536 (medicine)
• Practica arithmetice et mensurandi singularis, Milan, 1539 (mathmatic)
• De consolationeVenice, 1542 (philosophy)
• From sapientia, Nuremberg, 1544 (philosophy)
• Artis magnae, sive de regulis algebraicis —known as Ars Magna—, Nuremberg, 1545 (algebra)
• De immortalitate animorum, Lyon, 1545 (reissued by José Manuel García Valverde, Milan, FrancoAngeli, 2006 ISBN 88-46474-46-5) (philosophy). There is version of José Manuel García Valverde in [1] Archived on March 5, 2016 at Wayback Machine..
• Liber somniorumBasel, 1562. Tr.: The Book of Dreams, Madrid, Spanish Psychiatry Association, 1999 ISBN 978-84-921633-9-7, version of M. Villanueva. Last piece, but renovated, of the old onirocritic
• Contradicentium medicorum, Venice 1536, topics of discussion in medicine
• In Cl. Ptolemaei... Quadripartitae Constructionis Books CommentariaBasel, 1554 (astrology)
• Subtilitate rerumNuremberg, Johann Petreius, 1550 (encyclopedia)
• Liber de libris propriisLeiden, 1557. Tr.: My books, Madrid, Akal, 2002 ISBN 978-84-460-1263-4 version of Francisco Socas. Auto-bibliography
• De varietate rerumBasel, Heinrich Petri, 1557 (encyclopedia)
• Neronis encomium1562 (historic and philosophical)
• Opus novum de proportionibus numerorum, motuum, ponderum, sonorum, aliarumque rerum mesurandarum. Item of alia regulatesBasel, 1570.
• Prosseneta. Tr.: Proxeneta. Civil prudenceMilan, Mondadori, 2001. Book on the Treatment of Humans
• From his own vitaParis, 1643. Tr.: My life, Madrid, Alianza, 1991, version of Francisco Socas. Autobiography
• Freedom of ludo aleae (probability)
• MethodoscopyParis, 1658 on physionomics
• Theonoston1663, philosophy

Acknowledgments

• The lunar crater Cardanus carries this name in his honor.
• The asteroid (11421) Cardano also commemorates its name.
• The blockchain Cardano network bears that name in its honor.