**(September 24, 1501 – September 21, 1576)**

One of the most versatile scientists of the Renaissance period, Girolamo Cardano was a jack-of-all-trade (and master-of-all) who made pioneering contributions to mathematics, physics, chemistry and biology. In the process, he inspired generations of researchers. Apart from refurbishing the foundations of Algebra, Arithmetic and Geometry, he placed both Probability and Binomial theorems on the firm footings from where Pierre de Fermat, Blaise Pascal, Isaac Newton, Gottfried Leibniz, the Bernoulli brothers, Leonhard Euler, Joseph-Louis Lagrange and Pierre-Simon Laplace took them farther. Cardano was also one of the first Europeans to appreciate the usefulness of negative numbers. These he employed in his works on cubic and quartic equations. And as a polymath, he drew from his scientific findings to develop some of the earliest known Combination Locks (which were hi-tech feats in those days). His good understanding of biology motivated him into practicing medicine: where he became the first person to research on typhoid fever, albeit without an official license. However, the brilliant inroads he made secured him admission into the Royal College of Physicians. Similarly, he delved into alchemy, as well as the precursors of modern chemistry. His works in physics pertained mainly to astronomy; although as a hands-on equipment maker, he engineered gadgets such as gimbals and propeller shafts (which are also known as *Cardan shafts* in his honor). Among his 200-plus treatises is *De Proportionibus*, which was published around 1570, and dealt mostly with hypocycloids. In a bizarre twist, Cardano reportedly predicted his own death-date: by committing suicide.

Constructive and accurate!

I remember reading somewhere that although he worked as a doctor, he was among the first Europeans to publish solutions of general cubic and quartic equations.