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cataract

(Encyclopedia)cataract, in medicine, opacity of the lens of the eye, which impairs vision. In the young, cataracts are generally congenital or hereditary; later they are usually the result of degenerative changes b...

Bevan, Aneurin

(Encyclopedia)Bevan, Aneurin ənīˈrĭn bĕˈvən [key], 1897–1960, British political leader. A coal miner and trade unionist, he served (1929–60) in Parliament as a member of the Labour party. As minister of ...

Meagher, Thomas Francis

(Encyclopedia)Meagher, Thomas Francis mär [key], 1823–67, Irish revolutionary and Union general in the American Civil War, b. Waterford, Ireland. A leader of the Young Ireland movement, he was arrested and conde...

tempering

(Encyclopedia)tempering, process involving slow and moderate heating to increase the hardness and toughness of metals that have undergone previous heat treatment. Metals are usually hardened (see hardening) by bein...

neutrino astronomy

(Encyclopedia)neutrino astronomy, study of stars by means of their emission of neutrinos, fundamental particles that result from nuclear reactions and are emitted by stars along with light. Approximately 100 billio...

torpedo , in naval warfare

(Encyclopedia)torpedo, in naval warfare, a self-propelled submarine projectile loaded with explosives, used for the destruction of enemy ships. Although there were attempts at subsurface warfare in the 16th and 17t...

totem

(Encyclopedia)totem tōˈtəm [key], an object, usually an animal or plant (or all animals or plants of that species), that is revered by members of a particular social group because of a mystical or ritual relatio...

trench warfare

(Encyclopedia)trench warfare. Although trenches were used in ancient and medieval warfare, in the American Civil War, and in the Russo-Japanese War (1904–5), they did not become important until World War I. The i...

anteater

(Encyclopedia)anteater, name applied to various animals that feed on ants, termites, and other insects, but more properly restricted to a completely toothless group of the order Edentata. There are four species cla...

McDonald, Arthur Bruce

(Encyclopedia)McDonald, Arthur Bruce, 1943–, Canadian astrophysicist, Ph.D. California Institute of Technology, 1969. McDonald was a researcher at the Chalk River Nuclear Laboratories in Ottawa, Canada, from 1970...