Pierre-Simon Laplace (1749-1827) was a French mathematician of the late Enlightenment period, as well as a political figure in post-revolutionary France (where he earned the title marquis during the short-lived Bourbon Restoration). He was responsible for a number of important innovations in physics and astronomy.
– Youth and Education –
Pierre-Simon’s influential family once possessed a considerable knowledge of its own heritage, which was lost when their estate (or chateau, in French) was destroyed in the early 20th century. As a result, relatively little of Laplace’s youth is known today, although it is known that he was born in Normandy, possibly to a farmer or to a town merchant. He was schooled by Benedictines in preparation for a career in the church, including studies in theology at the University of Caen. However, it was during these university years that Laplace took an interest in mathematics and decided to abandon his future position in the clergy.
Instead of completing his father’s vision for his life, Laplace set out for Paris, where he impressed with his considerable skill another mathematician, Jean le Rond d’Alembert. D’Alembert arranged a teaching position for him at a military institute, and Laplace then embarked on the beginnings of his research career. Along the way, he met and married Marie Charlotte de Courty de Romanges, had two children, and was admitted to the French Academy of Sciences through the assistance of d’Alembert and another ally, Nicolas de Condorcet.
– Career Achievements –
Laplace published rapidly and voluminously on a wide range of subjects, beginning with his first studies on statistics and probability during the 1770s. His analytical skills were stunning and he seldom displayed patience in helping others keep up. These skills were first displayed later in the decade when he turned to a more pressing and controversial subject, the solar system, which Isaac Newton’s work on gravity had already done much to illuminate (along with previous expositions of a heliocentric universe by Galileo, Brahe, and Kepler).
Much of the next twenty years of his life was devoted to studies of gravity in the solar system, with a particular focus on moons, Jupiter, and Saturn. Along the way Laplace was responsible for a reformulation of a relatively new theory on the creation of the solar system, known as the nebular hypothesis – the idea that the sun formed through the collapse of a giant interstellar cloud, and that planets subsequently formed around it through accretion. The nebular hypothesis had first been put forward by a Swedish scholar, and is now (in modified form) the most generally accepted scientific theory on the origins of the solar system. Although he never returned to his theological roots, during this work he did suggest (as was typical of many Enlightenment thinkers) that a god-like being would be defined not by a supernatural control over the natural workings of the universe, but by the capacity to at any point see and understand, on a mathematical level, all of the interactions occurring between all of the particles in the universe. This hypothetical being is known in philosophy as Laplace’s Demon, although Laplace never implied that such a being had to be demonic in nature.
– Later Years –
Laplace continued his scientific and mathematical research throughout his life. However, during Napoleon’s rise to power after the French Revolution stalled, he also displayed political ambitions. Laplace served very briefly as a minister in Napoleon’s government, and then given essentially a sinecure position as senator. He subsequently was given the title Marquis, the French equivalent of a marquess and a senior position of nobility. He died in 1827, after which his brain was removed at autopsy and, in a somewhat gruesome recognition of the fame he had earned during his lifetime, preserved as a museum exhibit.
Today, Pierre-Simon Laplace is regarded as one of the most influential figures in Enlightenment mathematics and physics, second to Sir Isaac Newton of England. His name is engraved on the side of the Eiffel Tower, and his name has been given to an Asteroid Belt asteroid discovered in the 1980s.