Pierre-Simon Laplace

Pierre-Simon, Marquis de Laplace (March 23 1749 – March 5 1827) was a French mathematician and astronomer who put the final capstone on mathematical astronomy by summarizing and extending the work of his predecessors in his five volume Mécanique Céleste (Celestial Mechanics) (1799-1825). This masterpiece translated the geometrical study of mechanics used by Newton to one based on calculus, known as physical mechanics http://scienceworld.wolfram.com/biography/Laplace.html. He is also the discoverer of Laplace's equation and the Laplace transform, which appear in all branches of mathematical physics - a field he took a leading role in forming. He became count of the Empire in 1806 and was named a marquis in 1817 after the restoration of the Bourbons. Pierre-Simon Laplace was among the most influential scientists in history.

Quotes

• What we know is not much. What we do not know is immense.
• I have no need of that hypothesis. ("Je n'ai pas besoin de cette hypothèse", as a reply to Napoleon, who had asked why he hadn't mentioned God in his book on astronomy)
• "It is therefore obvious that..." (frequently used in the Celestial Mechanics when he had proved something and mislaid the proof, or found it clumsy. Notorious as a signal for something true, but hard to prove.)