Columbia Encyclopedia
Search results
500 results found
Rømer, Olaus
(Encyclopedia)Rømer, Olaus or Ole ōläˈo͝os, ōˈlə römˈər [key], 1644–1710, Danish astronomer. He is noted for his discovery that light travels at a definite speed and does not move through space instant...light-year
(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...hour circle
(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...Maclaurin, Colin
(Encyclopedia)Maclaurin, Colin məklôrˈĭn, –lärˈĭn [key], 1698–1746, Scottish mathematician and natural philosopher, one of the greatest mathematicians of his time. He was professor at Aberdeen and from 1...Pallas, in astronomy
(Encyclopedia)Pallas pălˈəs [key], in astronomy, 2d asteroid to be discovered. It was found in 1802 by H. Olbers. The second largest asteroid, it has a diameter of c.300 mi (480 km). Its orbit has a semimajor ax...Al-Farghani
(Encyclopedia)Al-Farghani ălfrəgāˈnəs [key], d. after 861, Arab astronomer. Al-Farghani was born in Farghana, Transoxania (present-day Fergana, Uzbekistan), and died in Egypt. His most important work, written ...Brahmagupta
(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...Canopus, in astronomy
(Encyclopedia)Canopus, in astronomy, 2d brightest star in the sky, located in the constellation Carina, which is part of the ancient constellation Argo Navis; Bayer designation α Carinae; 1992 position R.A. 6h23.8...Blaeu, Willem Janszoon
(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...Mauna Kea Observatories
(Encyclopedia)Mauna Kea Observatories mouˈnə kāˈə [key], astronomical observatory complex located on Mauna Kea peak, the “white mountain” on the island of Hawaii, at an altitude of more than 13,600 ft (4,1...Browse by Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
-
Places
+-
- Africa
- Asia
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-
