# Who is Gerolamo Cardano?

June 25, 2021 Off By Felso

Gerolamo Cardano or Girolamo Cardano (English Jerome Cardan, Latin: Hieronymus Cardanus) (24 September 1501, Pavia – 21 September 1576, Rome) was an Italian Renaissance mathematician, physicist, astrologer and physician.

He is the illegitimate son of the mathematically gifted Lawyer Fazio Cardano, who was also a friend of Leonardo da Vinci.

Cardano prepared Practica Arithmetica for publication in Milan (1539). Cardano invited Tartaglia and, after many insistence, learned from him how to solve the result of the third-degree equation. He took Cardano’s word that this information he received from Tartaglia would remain confidential until he published it in his book, but Cardano did not keep his promise. In 1545 he published Ars Magna (great art), the first Latin scholarly work on algebra.

When Cardano applied it to certain cubes, he noticed strange things happening. Solving x³=15x+4, he found an expression containing -121. Cardano knew that the square root of a negative number cannot be taken. He also knew that one of the solutions to his equation was x=4. To remedy this difficulty, he wrote a letter to Tartaglia on 4 August 1539. Tartaglia did not fully understand. In Ars Magna, Cardano gave a calculation of complex numbers to solve a similar question. But he could not fully understand his account, which was as difficult to understand as it was unnecessary. After Tartaglia showed Cardano how to solve third-degree equations, Cardano encouraged his own student, Lodovico Ferrari, to solve fourth-degree equations.

Ferrari succeeded in solving a fourth-degree equation with perhaps the most elegant of the methods available for solving such problems. Cardano has printed 20 types of quadratic equations in Ars Magna.

He invented various mechanical tools. Some of them are: combination lock, cardan grill with a password work, cross swivel bed etc. is The cross-link bearing (cross) is a device that provides the communication of rotational movement at different angles, and in today’s vehicles, the connecting shaft is named “Cardan Shaft” in memory of Cardano.

He has several theories on hydrodynamics. He put forward the theory that “infinite motion is impossible”.

In 1550, he published 2 encyclopedias containing Science subjects.

In 1551, realizing that amber attracts some light materials, he made the first connection between electricity and magnetism.

He has studies on the education of the hearing impaired.

Cardano was also a good gambler and chess player. He wrote a book called “Games of Chance” in 1560. However, this book was published posthumously in 1663.