Laplace, Marquis de, << la PLAS, mar KEE duh >> (1749-1827), a French astronomer and mathematician, became famous for his theory regarding the origin of the solar system. In Laplace’s Exposition of the System of the Universe (1796), he started with a theoretical primitive nebula. He believed that this huge, lens-shaped cloud of gas rotated, cooled, contracted, and threw off planets and satellites. The remaining matter formed the sun. Laplace’s nebular hypothesis was accepted by scientists for a long time. But that hypothesis has now been replaced by other theories. However, scientists still have not solved the problem of the solar system’s origin. See Earth ( Formation) .
Laplace also contributed studies in mathematical astronomy. Sir Isaac Newton had satisfactorily explained movements of the solar system in general. But certain problems were not solved because no one in Newton’s time had devised the necessary mathematical tools. Laplace accounted for the intricacies in the movements of the heavenly bodies. In Celestial Mechanics (1799-1825), he summed up the achievements in theoretical astronomy from the time of Newton.
Laplace was born Pierre Simon Laplace on March 23, 1749, at Beaumont-en-Auge, France, the son of a farmer. He became a professor of mathematics in Paris at the age of 20. Laplace was probably made a marquis in 1817. He died on March 5, 1827.
