Pierre-Simon Laplace and Siméon Denis Poisson are among the most technically accomplished mathematical physicists in history — and they worked together for much of their careers, with Poisson essentially extending and applying Laplace's methods. Their names appear ubiquitously in physics and mathematics: Laplace transform, Laplace equation, Laplace distribution, Poisson distribution, Poisson's equation, Poisson brackets. This is a comparison of two men who shaped the mathematical language of physics.
| Category | Pierre-Simon Laplace | Siméon Denis Poisson |
|---|---|---|
| Born | 1749, Beaumont-en-Auge, France | 1781, Pithiviers, France |
| Died | 1827, Arcueil, France | 1840, Paris, France |
| Celestial mechanics | Mécanique Céleste — proved solar system's stability; perturbation theory; tidal theory | Extended Laplace's perturbation methods; contributed to orbital mechanics |
| Probability | Bayesian probability; Laplace distribution; normal approximation to binomial | Poisson distribution — probability of rare events in fixed intervals |
| Mathematical physics | Laplace equation (∇²φ = 0) — electrostatics, gravity, fluid flow | Poisson's equation (∇²φ = -ρ/ε₀) — generalization with sources; electrostatics, gravity |
| Political career | Minister of the Interior under Napoleon (briefly); survived Revolution, Empire, Restoration | Less politically involved; professor at École Polytechnique |
| Famous claim | 'Give me the initial conditions of the universe and I can predict everything' — Laplace's demon | Extended Laplace's determinism; less philosophically flamboyant |
Laplace was the greater visionary — the Laplace transform, Laplace's demon (determinism), and celestial mechanics are foundational. Poisson extended and applied Laplace's tools with precision. Laplace without Poisson is still Laplace; Poisson without Laplace is much diminished.
See the full interactive comparison of Pierre-Simon Laplace vs Siméon Denis Poisson on Geniuses.Club