Columbia Encyclopedia

(Encyclopedia) Great Falls, city (2020 pop. 60,442), seat of Cascade co., N central Mont., second largest city in the state, at the confluence of the Missouri and Sun ...

(Encyclopedia) chromosphere krōˈməsfērˌ [key] [Gr.,=color sphere], layer of rarefied, transparent gases in the solar atmosphere; it measures 6,000 mi (9,700 km) in thickness and lies between the photosphere (th...

(Encyclopedia) Manco Capac mängˈkō käpäkˈ [key], legendary founder of the Inca dynasty of Peru. According to the most frequently told story, four brothers, Manco Capac, Ayar Anca, Ayar Cachi, and Ayar Uchu, an...

(Encyclopedia) Orbiting Solar Observatory (OSO), series of eight orbiting observatories (see observatory, orbiting) launched between 1962 and 1971 by the National Aeronautics and Space Administration (NASA) to study...

(Encyclopedia) Baalbek bälˈbĕk [key], ancient city, now in Lebanon, 35 mi (56 km) NW of Damascus, in the Al Biqa (Bekaa) valley. Originally it was probably devoted to the worship of Baal or Bel, the Phoenician su...

(Encyclopedia) Shklovsky, Iosif Samuilovich yôsˈĭf səmo͞oēlˈəvĭch shklŏfˈskē [key], 1916–85, Soviet astronomer. He was head of the department of radio-astronomy at the Sternberg Astronomical Institute,...

(Encyclopedia) ecliptic ēklĭpˈtĭk, ĭ– [key], the great circle on the celestial sphere that lies in the plane of the earth's orbit (called the plane of the ecliptic). Because of the earth's yearly revolution a...

(Encyclopedia) Cousteau, Jacques Yves zhäk ēv ko͞ostōˈ [key], 1910–97, French oceanographer and naval officer. In 1943, with Émil Gagnan, he invented the self-contained underwater breathing apparatus (scuba)...

(Encyclopedia) tide, alternate and regular rise and fall of sea level in oceans and other large bodies of water. These changes are caused by the gravitational attraction of the moon and, to a lesser extent, of the s...

(Encyclopedia) sundial, instrument that indicates the time of day by the shadow, cast on a surface marked to show hours or fractions of hours, of an object on which the sun's rays fall. Although any object whose sha...