Columbia Encyclopedia
Search results
500 results found
Leiden
(Encyclopedia)Leiden or Leyden both: līˈdən [key], city (1994 pop. 114,892), South Holland prov., W Netherlands, on the Old Rhine (Oude Rijn) River. Manufactures include medical equipment, machinery, graphic art...Comte, Auguste
(Encyclopedia)Comte, Auguste ōgüstˈ kôNt [key], 1798–1857, French philosopher, founder of the school of philosophy known as positivism, educated in Paris. From 1818 to 1824 he contributed to the publications ...ephemeris
(Encyclopedia)ephemeris ĭfĕmˈərĭs [key] (pl., ephemerides), table listing the position of one or more celestial bodies for each day of the year. The French publication Connaissance de Temps is the oldest of th...synodic period
(Encyclopedia)synodic period sĭnŏdˈĭk [key], in astronomy, length of time during which a body in the solar system makes one orbit of the sun relative to the earth, i.e., returns to the same elongation. Because ...antenna
(Encyclopedia)antenna ăntĕnˈə [key], in electronics, system of wires or other conductors used to transmit or receive radio or other electromagnetic waves (see radio); sometimes called an aerial. The idea of usi...planet
(Encyclopedia)planet [Gr.,=wanderer], a large nonluminous body of rock, gas, or ice that orbits the sun or another star, has a rounded shape due to gravity, and has cleared its orbit of smaller objects. The term, o...node
(Encyclopedia)node, in astronomy, point at which the orbit of a body crosses a reference plane. One reference plane that is often used is the plane of the earth's orbit around the sun (ecliptic). Since the moon's o...quasar
(Encyclopedia)quasar kwāˈsär [key], one of a class of blue celestial objects having the appearance of stars when viewed through a telescope and currently believed to be the most distant and most luminous objects...spectral class
(Encyclopedia) CE5 spectral class, in astronomy, a classification of the stars by their spectrum and luminosity. In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically....retrograde motion
(Encyclopedia)retrograde motion, in astronomy, real or apparent movement of a planet, dwarf planet, moon, asteroid, or comet from east to west relative to the fixed stars. The most common direction of motion in the...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 +-
