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exobiology

(Encyclopedia)exobiology or astrobiology, search for extraterrestrial life within the solar system and throughout the universe. Philosophical speculation that there might be other worlds similar to ours dates back ...

Niagara Falls, waterfall, United States and Canada

(Encyclopedia)Niagara Falls, in the Niagara River, W N.Y. and S Ont., Canada; one of the most famous spectacles in North America. The falls are on the international line between the cities of Niagara Falls, N.Y., a...

bell, musical instrument

(Encyclopedia)CE5 Bell bell, in music, a percussion instrument consisting of a hollow metal vessel, often cup-shaped with an outward-flaring rim, damped at one end and set into vibration by a blow from a clappe...

zirconium

(Encyclopedia)zirconium zərkōˈnēəm [key], metallic chemical element; symbol Zr; at. no. 40; at. wt. 91.224; m.p. about 1,852℃; b.p. 4,377℃; sp. gr. 6.5 at 20℃; valence +2, +3, or +4. Zirconium is a very ...

piano

(Encyclopedia)piano or pianoforte, musical instrument whose sound is produced by vibrating strings struck by felt hammers that are controlled from a keyboard. The piano's earliest predecessor was the dulcimer. The ...

Charleston, cities, United States

(Encyclopedia)Charleston. 1 City (2020 pop. 17,286), seat of Coles co., E Ill.; inc. 1835. Charleston is an industrial, rail, and trade center located in an ...

tunnel

(Encyclopedia)tunnel, underground passage usually made without removing the overlying rock or soil. Although tunnels are approximately horizontal, they must be built with sufficient gradient for proper drainage. Tu...

Dylan, Bob

(Encyclopedia)Dylan, Bob dĭlˈən [key], 1941–, American singer and composer, b. Duluth, Minn., as Robert Zimmerman. Dylan learned guitar at the age of 10 and autoharp and harmonica at 15. After a rebellious you...

competition, in economics

(Encyclopedia)competition, in economics, rivalry in supplying or acquiring an economic service or good. Sellers compete with other sellers, and buyers with other buyers. In its perfect form, there is competition am...

Azerbaijan, region, Iran

(Encyclopedia)Azerbaijan äˌzĕrbījänˈ, ăˌzər– [key], Iran. Azarbayejan, region, c.34,280 sq mi (88,785 sq km), NW Iran, divided into the provinces of East Azerbaijan, ...