1781-1840

French mathematician important for advances in the Fourier series and for his work on definite integral theory. Poisson began by studying medicine, changing to mathematics in 1798. A year later, he wrote his first paper, which was on finite integrals. Studying under two of the day's premier mathematicians, Pierre Laplace and Joseph Lagrange, Poisson quickly became recognized for his work in both mathematics and physics. Poisson published significant research papers in the areas of mathematics, electricity and magnetism, and astronomy during his career.