George William Hill

George William Hill (March 3, 1838 – April 16, 1914) was an American astronomer and mathematician. Working independently and largely in isolation from the wider scientific community, he made major contributions to celestial mechanics and to the theory of ordinary differential equations. The importance of his work was explicitly acknowledged by Henri Poincaré in 1905. In 1909 Hill was awarded the Royal Society's Copley Medal, "on the ground of his researches in mathematical astronomy". Today, he is chiefly remembered for the Hill differential equation. Early life and education Hill was born in New York City to painter and engraver John William Hill and his wife, Catherine Smith. He moved to West Nyack with his family when he was eight years old. After high school, Hill attended Rutgers College, where he became interested in mathematics. At Rutgers, Hill came under the influence of professor Theodore Strong, who was a friend of pioneering US mathematician and astronomer Nathaniel Bowditch. Strong encouraged Hill to read the great works on analysis by Sylvestre Lacroix and Adrien-Marie Legendre, as well as the treatises on mechanics and mathematical astronomy by Joseph-Louis Lagrange, Pierre-Simon Laplace, Siméon Denis Poisson, and Gustave de Pontécoulant. Hill graduated from Rutgers College in 1859, with a Bachelor of Arts degree. In that same year he published his first scientific paper, on the geometrical curve of a drawbridge. Two years later he earned a prize from the Runkle Mathematical Monthly for his work on the mathematical theory of the figure of the Earth.