Jean-Baptiste le Rond d'Alembert (November 16, 1717 - October 29, 1783) was a French mathematician, mechanician, physicist, philosopher, music theorist and co-editor (for mathematics and science) with Denis Diderot of the Encyclop矇die. D'Alembert's formula for obtaining solutions to the wave equation is named after him. In 1739 he made his first contribution to the field of mathematics, pointing out the errors he had detected in L'analyse d矇montr矇e. In 1740, in regards to the field of fluid mechanics, he theoretically explained refraction. In 1743 he published his most famous work, Trait矇 de dynamique, in which he developed his own laws of motion. In 1752, he wrote about what is now called D'Alembert's paradox: that the drag on a body immersed in an inviscid, incompressible fluid is zero. He suffered bad health for many years and his death was as the result of a urinary bladder illness.