George William Hill

George William Hill was an American astronomer and mathematician, born in New York City in 1838, who worked independently and largely in isolation from the wider scientific community and made major contributions to celestial mechanics and to the theory of ordinary differential equations. Henri Poincaré explicitly acknowledged the importance of his work in 1905, and in 1909 the Royal Society awarded him its Copley Medal for his researches in mathematical astronomy. He graduated from Rutgers College in 1859, worked in the Nautical Almanac Office of the United States Naval Observatory from 1861, and after 1892 retired to the family farm at West Nyack to continue his mathematical work. He is remembered for the Hill differential equation and the Hill sphere.