Columbia Encyclopedia

(Encyclopedia) radar astronomy, application of radar to the determination of distances and planetary features within the solar system, such as rotation rates. A short burst of radio waves is transmitted in the direc...

(Encyclopedia) nebula nĕbˈyo͝olə [key] [Lat.,=mist], in astronomy, observed manifestation of a collection of highly rarefied gas and dust in interstellar space. Prior to the 1960s this term was also applied to b...

(Encyclopedia) solar energy, any form of energy radiated by the sun, including light, radio waves, and X rays, although the term usually refers to the visible light of the sun. Solar energy is needed by green plants...

(Encyclopedia) quantum electrodynamics (QED), quantum field theory that describes the properties of electromagnetic radiation and its interaction with electrically charged matter in the framework of quantum theory. ...

(Encyclopedia)  CE5 Lenses lens, device for forming an image of an object by the refraction of light. In its simplest form it is a disk of transparent substance, commonly glass, with its two surfaces curved or wi...

(Encyclopedia) Leshan lōˈshänˈ [key], city (1994 est. pop. 384,300), central Sichuan prov., China, just S of Chengdu, on the Min River. Heavy industry is the city's largest source of income; agriculture and ligh...

(Encyclopedia) Lompoc lŏmˈpōk [key], city (1990 pop. 37,649), Santa Barbara co., S Calif., in an oil and agricultural area; inc. 1888. It has a huge flower-seed industry and two large diatomaceous earth mines. Pe...

(Encyclopedia) Luray lo͝orāˈ [key], town (1990 pop. 4,587), seat of Page co., N Va., in the Shenandoah valley, in a farm area; inc. 1812. There is light manufacturing and the town is the headquarters of Shenandoa...

(Encyclopedia) Nuevitas nwāvēˈtäs [key], city (1995 est. pop. 52,000), Camagüey prov., E Cuba, on the Guincho peninsula on the north coast. Nuevitas is sheltered by a huge harbor, has two auxiliary ports, and i...

(Encyclopedia) Manamah, Al äl mänämˈä [key], town (1991 pop. 127,578), capital, commercial center, and largest city of Bahrain, on the Persian Gulf. It has oil refineries and light industries and is a free port...