Cardán

Cardán typically refers to Girolamo Cardano (1501–1576), an Italian Renaissance polymath whose work spanned mathematics, medicine, astrology, and philosophy. He is regarded as a key figure in the emergence of algebra and mathematical notation, and his writings influenced later developments in science.

In mathematics, Cardano is best known for Cardano's formula, the general method for solving cubic equations. This result appeared in Ars Magna (The Great Art), published in 1545, a landmark treatise that presented systematic approaches to solving polynomial equations and helped establish a more formal approach to algebra. Cardano’s work built on earlier discoveries and stimulated further advances in mathematics, including later solutions to higher-degree equations.

Cardano also engaged with probability and the study of games of chance. He discussed dice games and risk, contributing to early thinking about uncertainty and the quantification of outcomes. These ideas prefigure later formal developments in probability theory.

The Cardan grille, a cipher technique, is associated with Cardano. It uses a mask with holes placed over a sheet of text; letters visible through the holes form a secret message when read in a prescribed order. The method is one of the most noted steganographic devices linked to Cardano and his era.

In engineering and common usage, the name Cardan appears in terms such as Cardan shaft or Cardan joint, a universal joint used to transmit rotation between misaligned shafts. The attribution of the name varies by language and tradition, but the association with Cardano has endured in many regions.