Columbia Encyclopedia

(Encyclopedia) hour circle, in astronomy, a secondary axis in the equatorial coordinate system. The hour circle of a celestial body is the great circle on the celestial sphere that passes through both the body and t...

(Encyclopedia) marines, troops that serve on board ships of war or in conjunction with naval operation. A British marine corps was established in 1664, and the need for skilled riflemen aboard military vessels broug...

(Encyclopedia) Picard, Jean, 1620–82, French astronomer, noted for having made the first accurate measurement of a degree of the earth's meridian. The figures he established were of great value to Newton in his ca...

(Encyclopedia) light-year, in astronomy, unit of length equal to the distance light travels in one sidereal year. It is 9.461 × 1012 km (about 6 million million mi). Alpha Centauri and Proxima Centauri, the stars n...

(Encyclopedia) Blaeu, Willem Janszoon vĭˈləm yänˈsōn blou [key], 1571–1638, Dutch cartographer and printer. He studied astronomy and instrument making under the Danish astronomer Tycho Brahe. The printing es...

(Encyclopedia) Brahmagupta bräˌməgo͝opˈtə [key], c.598–c.660, Indian mathematician and astronomer. He was among the first to meaningfully discuss the concepts of zero and of negative numbers. He wrote in ver...

(Encyclopedia) Peralta Barnuevo, Pedro de pāˈᵺrō ᵺā pārälˈtä bärnwāˈvō [key], 1664–1743, Peruvian writer. Although his major literary interests were drama and poetry, he also wrote on astronomy, ma...

(Encyclopedia) Briggs, Henry, 1561–1630, English mathematician. He was the first professor of geometry at Gresham College, London (1596–1619), and Savilian professor of astronomy at Oxford (from 1619). After pub...

(Encyclopedia) K'ang-hsi käng shē [key], 1654–1722, 2d emperor of the Ch'ing dynasty of China (1661–1722). He extended Manchu control and promoted learning in the arts and sciences. K'ang-hsi conquered the feu...

(Encyclopedia) Thoth thŏth, tōt [key], in Egyptian religion, god of wisdom and magic. A patron of learning and of the arts, he was credited with many inventions, including writing, geometry, and astronomy. Perhaps...