Pierre-Simon Laplace, 1749-1827. A Life in Exact Science

Abstract

Laplace is a name known to most physical scientists and mathematicians, if only for the Laplace transform method of solving differential equations, but few will know much about his life and work. He was one of the most influential scientists the world has known, both for his contributions to mathematics and mathematical physics, and for his political role in developing scientific disciplines, before and after the watershed of the French Revolution. One reason why his work is not better known is that, most unusually among scientists of his stature, he worked within existing systems of knowledge, almost as an article of faith, never producing a truly revolutionary idea. He believed in a deterministic universe in which the position and motion of every particle were calculable for all time, and in a stable universe where all motion was periodic and there was no irreversible change. He was an indefatigable calculator but, paradoxically, the mathematical techniques he used, though powerful, were inelegant and far from rigorous, making full use of judicious approximations. Laplace contributed to many aspects of physics, but his major preoccupations, which he pursued throughout his life, were celestial mechanics and probability theory. He was concerned to explain the fine detail of the motions of heavenly bodies caused by the mutual interactions that are ignored in simple calculations, and by their departures from ideal spherical shapes. Handling the unknown observational errors in astronomical data was only one use for the probabilistic methods he developed. He was also deeply involved in the introduction of the metric system. After the revolution he exerted a powerful influence on the early development of the Institut de France and the �cole Polytechnique. He became more isolated towards the end of his life, when his reputation suffered from his willingness to accommodate to every change of political regime, though he was no worse in that respect than most others. The book is an exhaustive account of Laplace's scientific work, with the fullest possible bibliography, both of his own publications and of secondary material. It is not a full biography: Laplace's childhood is over within the first two pages and nothing is said about him as a person except that he led a warm and tranquil family life. The author, Charles Coulston Gillespie, is Emeritus Professor of History at Princeton and well known as the editor of the monumental Dictionary of Scientific Biography. The book is a development of the extensive monograph about Laplace that Gillespie contributed to that work, and it is structured in the same way. Two collaborators on that monograph have also contributed to this book. Robert Fox, now Professor of Modern History at Oxford, has written four chapters on Laplace's physics, and Ivor Grattan-Guinness, Professor of Mathematics and Logic at Middlesex Polytechnic University, is responsible for the chapter on the Laplace transform. The book does not attempt a full critical analysis of Laplace's mathematical achievements: the reader is referred to other writings by Grattan-Guinness for that. It is an excellent book, but not for the faint-hearted. It makes no concessions whatever to mathematical weakness on the part of the reader, and it is so detailed that in places it can be difficult to keep sight of the main objective. It is the only full-scale account of Laplace's science and mathematics, and as such it is a major work in the history of science. It is as near definitive as any single volume about Laplace is likely to be. Where it does not cover some aspect of his work in detail it directs the reader to a fuller discussion elsewhere. For the historian it will be invaluable. It does not fulfil the need for a straightforward book to help the more casual reader, whether a scientist or not, appreciate the importance of Laplace's work, but for anyone with a deeper interest this book is well worth the modest price and will amply repay the time and concentration needed to study it.