# Laplace, Pierre Simon, Marquis de[laplas], also known as **Comte de** (Count of) **Laplace**(1749--1827) Mathematician and astronomer, born in Beaumont-en-Auge, NW France. He studied at Caen, and became professor of mathematics at the Ecole Militaire, Paris. He applied his mathematical knowledge to physical astronomy, particularly the stability of orbits in the Solar System. His five-volume *Mécanique céleste* (1799--1825, Celestial Mechanics) is a landmark in applied mathematics. In his study of the gravitational attraction of spheroids, he formulated the fundamental differential equation in physics which now bears his name. He entered the Senate in 1799, and was made a peer in 1815. |