Columbia Encyclopedia

(Encyclopedia) twilight, period between sunset and total darkness or between total darkness and sunrise. Total darkness does not occur immediately when the sun sinks below the horizon because light from the sun that...

(Encyclopedia) Tàpies, Antoni (Antoni Tàpies Puig) äntōˈnē täˈpēĕs pwēg [key], 1923–2012, Catalan artist. Largely self-taught, he became a painter after first studying law. His earliest works were inven...

(Encyclopedia) reconnaissance satellite, artificial satellite launched by a country to provide intelligence information on the military activities of foreign countries. There are four major types. Early-warning sate...

(Encyclopedia) Burton, Richard, 1925–84, British actor, b. Pontrhydfen, Wales; his original name was Richard Jenkins. A dark, introspective actor with a splendid speaking voice, Burton specialized in portraying co...

(Encyclopedia) aardwolf ärdˈwo͝olf [key], carnivore of the hyena family. The aardwolf, Proteles cristatus, resembles the true hyena but is smaller and more delicate. It has less powerful teeth and jaws and five i...

(Encyclopedia) graphite grăfˈīt [key], an allotropic form of carbon, known also as plumbago and black lead. It is dark gray or black, crystalline (often in the form of slippery scales), greasy, and soft, with a m...

(Encyclopedia) guinea fowl gĭnˈē [key], common name for any of the seven species of gallinaceous birds of the family Numididae, native to Africa and Madagascar. The helmeted guinea fowl, Numida meleagris, from wh...

(Encyclopedia) abominable snowman or yeti yĕtˈē [key], humanlike creature so named because it is associated with the perpetual snow region of the Himalayas. A figure unknown except through tracks ascribed to it a...

(Encyclopedia) power, in physics, time rate of doing work or of producing or expending energy. The unit of power based on the English units of measurement is the horsepower, devised for describing mechanical power b...

(Encyclopedia) Christie, Dame Agatha, 1890–1976, English detective story writer, b. Torquay, Devon, as Agatha Mary Clarissa Miller. Christie's second husband was the archaeologist Sir Max Mallowan, and she gained ...