Gerolamo Cardano

Gerolamo Cardano was born in Italy in 1501 and trained as a physician, but his restless intellect wouldn't stay in one discipline. He gambled seriously enough to study chance itself, introducing binomial coefficients and laying groundwork for probability theory in the West. In 1545 he published Ars Magna, the first European work to systematically use negative numbers and to acknowledge imaginary numbers; it also included solutions to cubic and quartic equations he credited to other mathematicians. Between medical practice and mathematical breakthroughs he invented mechanical devices—the combin…