On this day, 198 years ago, March 5, 1827 (February 8, 1827, the French astronomer, mathematician, and physicist Laplace passed away. Laplace (1749-1827.3.5) was a famous French mathematician and astronomer. Laplace was the main founder of celestial mechanics, one of the founders of celestial evolution, the founder of analytical probability theory, and the precursor of applied mathematics. Laplace used mathematical methods to prove that the size of a planet's orbit only changes periodically. This is the famous Laplace's theorem. He has published more than 270 papers on astronomy, mathematics and physics, and his monographs total more than 4006 pages. Among them, the most representative monographs are "Celestial Mechanics","Theory of Cosmic Systems" and "Theory of Probability Analysis". In 1796, he published The Theory of the Cosmic System. He is known as France's Newton and the father of celestial mechanics for studying the dynamics of the stability of the solar system. He also made important contributions to mathematics and physics. The Laplace transform and Laplace equation named after him have wide applications in various fields of science and technology. In 1799, he served as director of the French Bureau of Longitude and served as Minister of the Interior in the Napoleon government for six weeks. Supplementary notes: 1. Laplace was Napoleon's teacher, so he had an indissoluble bond with Napoleon. 2. Laplace was a master in mathematics and a small figure in politics. He was always loyal to the powerful side and was looked down upon by others. Napoleon once laughed at him for bringing infinitesimal spirit into the cabinet.