BROUWER, DIRK

born Sept. 1, 1902, Rotterdam died Jan. 31, 1966, New Haven, Conn., U.S. Dutch-born U.S. astronomer and geophysicist known for his achievements in celestial mechanics, especially for his pioneering application of high-speed digital computers. After leaving the University of Leiden, Brouwer served as a faculty member at Yale University from 1928 until his death, becoming both professor of astronomy and director of the Yale Observatory in 1941. At Yale he first studied changes in the Earth's rotation, later tackling orbital problems. Along with W.J. Eckert, he developed a method of calculating orbit corrections (1937) that has been widely accepted, and, with Eckert and G.M. Clemence (1951), Brouwer was the first to use a computer to calculate planetary positions accurately. Among his other notable contributions, Brouwer formulated the term ephemeris time to describe time measurement unaffected by variation in the rate of the Earth's rotation. Brouwer was elected to the U.S. National Academy of Sciences in 1951, and for his contributions to celestial mechanics he was awarded the Gold Medal of the Royal Astronomical Society in 1955.