Pierre-Simon Laplace (1749-1827MB). Historical portrait of the French mathematician, astronomer and physicist, Pierre-Simon, Marquis de Laplace. Laplace is best known as a talented mathematician and he used these skills in astronomy. Between 179MB9 and 1825MB Laplace published his most important work, Celestial Mechanics. The book aimed to improve the understanding of the motions in the solar system by studying the gravitational perturbations between the sun and the planets. Laplace also proposed that the solar system was formed from a rotating disk of gas. Engraving from Weltall und Menscheit (Universe and Humanity), by Hans Kraemer (ca. 1880).