Newcomb, << NOO kuhm, >> Simon (1835-1909), was an American astronomer. He became famous for his studies of the motions of the moon and other cosmic objects.
In 1861, Newcomb became professor of mathematics at the U.S. Naval Observatory in Washington, D.C. There, he supervised the construction of a 26-inch (66-centimeter) equatorial telescope. With George W. Hill, he used this telescope to determine the orbits of the moon, Venus, Mars, Uranus, Neptune, and Saturn.
From 1880 to 1882, Newcomb studied the velocity of light. He used fixed and revolving mirrors on opposite banks of the Potomac River to gain his result of 186,328 miles (299,866 kilometers) per second.
Newcomb was born in Wallace, Nova Scotia. He studied at Harvard University. From 1884 to 1894 and from 1898 to 1900, he served as a professor of mathematics at Johns Hopkins University.