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gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...

relativity

(Encyclopedia)relativity, physical theory, introduced by Albert Einstein, that discards the concept of absolute motion and instead treats only relative motion between two systems or frames of reference. One consequ...

Nagasaki

(Encyclopedia)Nagasaki nägˌäsäˈkē [key], city (1990 pop. 444,599), capital of Nagasaki prefecture, W Kyushu, Japan, on Nagasaki Bay. It is one of Japan's leading ports. Shipbuilding is the chief industry; mac...

Groton

(Encyclopedia)Groton grŏtˈən [key]. <1> Town (2020 pop. 38,411), New London co., SE Conn., includi...

Schawlow, Arthur Leonard

(Encyclopedia)Schawlow, Arthur Leonard shôˈlō [key], 1921–99, American physicist, b. Mount Vernon, N.Y., grad. Univ. of Toronto (Ph.D. 1949). Although his research focused on optics, in particular, lasers and ...

Wilmut, Sir Ian

(Encyclopedia)Wilmut, Sir Ian, 1944– British embryologist, b. Warwickshire, England, Ph.D. Cambridge, 1971. While doing postdoctoral research at Cambridge, he was part of the team that produced Frostie, the first...

Tarim

(Encyclopedia)Tarim dārēmˈ [key], Mandarin Dayan, chief river of Xinjiang Uygur Autonomous Region, NW China, c.1,300 mi (2,090 km) long, formed by the union of the Aksu and the Yarkant rivers at the western end ...

apatite

(Encyclopedia)apatite ăpˈətīt [key], mineral, a phosphate of calcium containing chlorine or fluorine, or both, that is transparent to opaque in shades of green, brown, yellow, white, red, and purple. Apatite is...

Laird, Melvin Robert

(Encyclopedia)Laird, Melvin Robert, 1922–2016, American politician, U.S. secretary of defense (1969–73), b. Omaha, Nebr. After serving (1942–46) in the navy during World War II, he entered politics as a Repub...

Morgenthau, Hans Joachim

(Encyclopedia)Morgenthau, Hans Joachim, 1904–80, American political scientist and foreign policy analyst, b. Coburg, Germany. After studying at the universities of Frankfort and Munich, he attended the Graduate I...