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bin Laden, Osama

(Encyclopedia)bin Laden, Osama or Usama ōsäˈmə bĭn lädˈən, ŭsäˈmə [key], 1957?–2011, Saudi-born leader of Al Qaeda, a terrorist organization devoted to uniting all Muslims and establishing a transnati...

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, ...

caliphate

(Encyclopedia)caliphate kălˈĭfˌ [key], the spiritual head and temporal ruler of the Islamic state. In principle, Islam is theocratic: when Muhammad died, a caliph [Arab.,=successor] was chosen to rule in his pl...

transistor

(Encyclopedia)CE5 Simple transistor circuit transistor, three-terminal, solid-state electronic device used for amplification and switching. It is the solid-state analog to the triode electron tube; the transist...

explosive

(Encyclopedia)explosive, substance that undergoes decomposition or combustion with great rapidity, evolving much heat and producing a large volume of gas. The reaction products fill a much greater volume than that ...

Cleveland, cities, United States

(Encyclopedia)Cleveland. 1 City (2020 pop. 372,674), seat of Cuyahoga co., NE Ohio, on Lake Erie at the mouth of the Cuyahoga River; laid out (1796) by Moses ...

Defense, United States Department of

(Encyclopedia)Defense, United States Department of, executive department of the federal government charged with coordinating and supervising all agencies and functions of the government relating directly to nationa...

nuclear strategy

(Encyclopedia)nuclear strategy, a policy for the use of nuclear weapons. The first atomic bombs were used in the context of the Allies' World War II policy of strategic bombing. Early in the cold war, U.S. policy w...

Marshall Islands

(Encyclopedia)Marshall Islands, officially Republic of the Marshall Islands, independent nation (2015 est. pop. 53,000), in the central Pacific. The Marshalls extend over a 700-mi (1,130-km) area and comprise two m...

Johnson, Samuel, English author

(Encyclopedia)Johnson, Samuel, 1709–84, English author, b. Lichfield. The leading literary scholar and critic of his time, Johnson helped to shape and define the Augustan Age. He was equally celebrated for his br...