Columbia Encyclopedia

Search results

437 results found

soapstone

(Encyclopedia)soapstone or steatite stēˈətīt [key], metamorphic rock of which the characteristic and usually chief mineral is talc, but which also contains varying parts of chlorite, mica, tremolite, quartz, ma...

silicon carbide

(Encyclopedia)silicon carbide, chemical compound, SiC, that forms extremely hard, dark, iridescent crystals that are insoluble in water and other common solvents. Widely used as an abrasive, it is marketed under su...

turquoise

(Encyclopedia)turquoise, hydrous phosphate of aluminum and copper, Al2(OH)3PO4·H2O+Cu, used as a gem. It occurs rarely in crystal form, but is usually cryptocrystalline. Turquoise is opaque and has a waxy luster; ...

Tyndall, John

(Encyclopedia)Tyndall, John tĭnˈdəl [key], 1820–93, British physicist, b. Ireland. He became (1853) professor of natural philosophy at the Royal Institution and in 1867 succeeded Michael Faraday, his friend an...

thunder

(Encyclopedia)thunder, sound produced along a path of a lightning flash, caused by the rapid heating and expansion of the adjacent air; lightning can heat air to temperatures as much as five times hotter than those...

Vatnajökull

(Encyclopedia)Vatnajökull vätˈnäyöˈko͝ol [key], glacier, c.3,150 sq mi (8,160 sq km), SE Iceland; largest glacier in Europe. At an elevation of from 4,200 to 6,100 ft (1,280–1,860 m), it covers a huge volc...

Cagney, James

(Encyclopedia)Cagney, James, 1899–1986, American movie actor, b. New York City. He worked on Broadway as an actor and dancer before appearing in films. He is best remembered as a brash, sadistic, tough guy in suc...

energy, sources of

(Encyclopedia)energy, sources of, origins of the power used for transportation, for heat and light in dwelling and working areas, and for the manufacture of goods of all kinds, among other applications. The develop...

arthritis

(Encyclopedia)arthritis, painful inflammation of a joint or joints of the body, usually producing heat and redness. There are many kinds of arthritis. In its various forms, arthritis disables more people than any o...

humidity

(Encyclopedia)humidity, moisture content of the atmosphere, a primary element of climate. Humidity measurements include absolute humidity, the mass of water vapor per unit volume of natural air; relative humidity (...