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hydroponics

(Encyclopedia)hydroponics, growing of plants without soil in water to which nutrients have been added. Hydroponics has been used for over a century as a research technique, but not until 1929 were experiments condu...

Janus, in astronomy

(Encyclopedia)Janus jāˈnəs [key], in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn X (or S10), Janus is an irregularly shaped (nonspherical) body measuring about 122 m...

Guggenheim Museum

(Encyclopedia)Guggenheim Museum, officially Solomon R. Guggenheim Museum, major museum of modern art in New York City. Founded in 1939 as the Museum of Non-objective Art, the Guggenheim is known for its remarkable ...

smart weapon

(Encyclopedia)smart weapon, missile or steerable bomb equipped with a laser, television, or satellite guidance system. Smart weapons, which use guidance systems that rely on external assistance, are distinguished f...

Bergson, Henri

(Encyclopedia)Bergson, Henri äNrēˈ bĕrgsôNˈ [key], 1859–1941, French philosopher. He became a professor at the Collège de France in 1900, devoted some time to politics, and, after World War I, took an inte...

Bengaluru

(Encyclopedia)Bengaluru băng-gəlôrˈ [key], city (2021 pop. 5,104,047; est. pop. metropolitan area 12,327,000), ...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

matter

(Encyclopedia)matter, anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles. The atomic th...

niobium

(Encyclopedia)niobium nīōˈbēəm [key], metallic chemical element; symbol Nb; at. no. 41; at. wt. 92.90638; m.p. about 2,468℃; b.p. 4,742℃; sp. gr. 8.57 at 20℃; valence +2, +3, +4, or +5. Niobium is a rare...

Oakland

(Encyclopedia)Oakland, city (1990 pop. 372,242), seat of Alameda co., W Calif., on the eastern side of San Francisco Bay; inc. 1852. Together with San Francisco and San Jose, the city comprises the fourth largest m...