Daniel Bernoulli, Swiss mathematician, c 1750s.

SWITZERLAND - MAY 23: Bernoulli (1700-1782) was the son of Jean Bernoulli (1667-1748), who founded a dynasty of highly talented mathematicians. Daniel Bernoulli became professor of mathematics at St Petersburg, Russia, in 1725. He went on to become professor of anatomy, botany and physics. Bernoulli made important contributions to hydrodynamics, notably with his 1738 publication 'Hydrodynamica' which, amongst other things, contains a pioneering kinetic theory of gases. He solved a differential equation which had been proposed by Jacopo Riccati, now known as Bernoulli�s equation. He also contributed significantly to calculus and probability. (Photo by SSPL/Getty Images)