Brown, Ernest William (1866–1938)

English mathematician and astronomer. He studied the effect of gravity on the motions of the planets and smaller members of the Solar System, and published extremely accurate tables of the Moon's movements.

He suggested that the fluctuations in the Moon's mean longitude arose as a consequence of a variable rate in the rotation of the Earth. He was also interested in the asteroid belt, rejecting the theory that the asteroids had at one time been part of a planet. During the later years of his career he calculated the gravitational effect exerted by the dwarf planet Pluto on the orbits of its nearest neighbours, Uranus and Neptune.

Brown was born in Hull and educated at Cambridge University, where he was a fellow of Christ's College. In 1891 he went to the USA to teach mathematics at Haverford College, Pennsylvania. He was professor of mathematics at Haverford 1893–1907, and then at Yale University from 1907. He was elected Fellow of the Royal Society at the age of 31. His principal work was the mathematical theory of the Moon's motion: his Tables of the Motion of the Moon 1919 was a standard reference work.