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sapphire

(Encyclopedia)sapphire, precious stone. A transparent blue corundum, it is classified among the most valuable of gems. Sapphires are found chiefly in Madagascar, Sri Lanka, and Myanmar and also in Thailand, Tanzani...

resistor

(Encyclopedia)resistor, two-terminal electric circuit component that offers opposition to an electric current. Resistors are normally designed and operated so that, with varying levels of current, variations of the...

skywriting

(Encyclopedia)skywriting, advertising medium in which aircraft spell out trade names and sales slogans in the sky by means of the controlled emission of thick smoke. The technique was first developed (1922) by J. C...

cape buffalo

(Encyclopedia)cape buffalo, species of short-haired African ungulate, or hoofed mammal, Syncerus caffer. The cape, or African, buffalo may reach 7 ft (2.1 m) in length, weigh more than 1,500 lb (670 kg), and reach ...

Webb Space Telescope

(Encyclopedia)Webb Space Telescope or James Webb Space Telescope (JWST), is an infrared space telescope, the largest in space at its launc...

Lenz's law

(Encyclopedia)Lenz's law, physical law, discovered by the German scientist H. F. E. Lenz in 1834, that states that the electromotive force (emf) induced in a conductor moving perpendicular to a magnetic field tends...

Lang, Fritz

(Encyclopedia)Lang, Fritz läng [key], 1890–1976, German-American film director, b. Vienna. His silent and early sound films, notably the iconic masterpiece Metropolis (1926) with its dystopian vision of the futu...

kapok

(Encyclopedia)kapok kāˈpŏk, kăpˈək [key], name for a tropical tree of the family Bombacaceae (bombax family) and for the fiber (floss) obtained from the seeds in the ripened pods. The floss has been important...

incinerator

(Encyclopedia)incinerator, furnace for burning refuse. The older and simpler kind of incinerator was a brick-lined cell with a metal grate over a lower ash pit, with one opening in the top or side for loading and a...

inflammation

(Encyclopedia)inflammation, reaction of the body to injury or to infectious, allergic, or chemical irritation. The symptoms are redness, swelling, heat, and pain resulting from dilation of the blood vessels in the ...