Pierre-Simon Laplace

In March 1788, he married Marie-Charlotte de Courty de Romanges, a girl from Besançon who was twenty years younger to him. The couple had a son, Charles-Émile, and a daughter, Sophie-Suzanne.

Pierre-Simon Laplace died on March 5, 1827, in Paris, France, at the age of 77. After he died, his physician, François Magendie, removed Laplace’s brain which was later displayed in a roving anatomical museum in Britain.

Pierre-Simon Laplace was born on March 23, 1749, in Beaumont-en-Auge, a village in Normandy, France, to Pierre de Laplace, owner of small farms of Maarquis, and his wife, Marie-Anne Sochon.

Despite his family’s poor financial condition, Laplace was able to receive a good education courtesy his wealthy neighbors. His father wanted him to be ordained in the Roman Catholic Church and thus sent him to Caen University to study theology at the age of 16. But, Laplace developed a keen interest in mathematics.

At the age of 19, he dropped out of college and moved to Paris where he worked as a professor of mathematics at the École Militaire from 1769 to 1776. During this time, he published several papers regarding integral calculus, mechanics and physical astronomy, which gained him much acclaim all over France.

In 1771, his early published work focused on differential equations and finite differences. Subsequently, he started to think about the mathematical and philosophical concepts of probability and statistics.

In 1774, his paper titled ‘Mémoire sur la probabilité des causes par les événements’ was published. Two years later, he published another paper which further elaborated his statistical thinking and also began his systematic work on celestial mechanics and the stability of the solar system.

During 1784–87, he worked on the subject of attraction between spheroids which laid the mathematical foundation for the scientific study of heat, magnetism, and electricity.

In 1796, he published ‘Exposition du système du monde (The System of the World)’, which included his ‘nebular hypothesis’.

Between 1799 and 1825, he published five volumes of ‘Traité de mécanique céleste (Celestial Mechanics)’, which summarized the results obtained by his mathematical development and application of the law of gravitation.

Pierre-Simon Laplace is highly regarded for his influential five-volume treatise ‘Traité de mécanique céleste’ (Celestial mechanics; 1799-1825), which developed a strong mathematical understanding of the motion of the heavenly bodies. He established that the small perturbations observed in the orbital motion of the planets will always remain small, constant and self-correcting.

He formulated Laplace's equation, and pioneered the Laplace transform which appears in many branches of mathematical physics. The Laplacian differential operator, widely used in mathematics, is also named after him.