Images depicting the Laplaces Nebula Hypothesis. Left: The formation of a solar system Stage 1 - a nebula condensing into a star. Centre: Maturity. Right: Star with surrounding nebulosity in constellation Pegasus. It was believed that this summed Laplaces hypothesis in action. From Amedee Guillemin L Astronomie Populaire; Paris; 1870. Pierre-Simon; marquis de Laplace (1749 - 1827) was an influential French scholar whose work was important to the development of mathematics; statistics; physics and astronomy. Dated 19th Century.