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space-time
(Encyclopedia)space-time, central concept in the theory of relativity that replaces the earlier concepts of space and time as separate absolute entities. In relativity one cannot uniquely distinguish space and time...prime minister
(Encyclopedia)prime minister or premier, chief member of the cabinet in a parliamentary system of government. The prime minister is head of the government, in contrast with the head of state, who may be a constitut...cerebellum
(Encyclopedia)cerebellum sĕrˌəbĕlˈəm [key], portion of the brain that coordinates movements of voluntary (skeletal) muscles. It contains about half of the brain's neurons, but these particular nerve cells are...Organization of Petroleum Exporting Countries
(Encyclopedia)Organization of Petroleum Exporting Countries (OPEC), multinational organization (est. 1960, formally constituted 1961) that coordinates petroleum policies and economic aid among oil-producing nations...parity
(Encyclopedia)parity or space parity, in physics, quantity that refers to the relationship between an object or process and the image that it can produce in a mirror. For example, any right-handed object will produ...Economic and Social Council
(Encyclopedia)Economic and Social Council, constituent organ of the United Nations. It was established by the UN Charter and has 54 (18 before 1965) member nations elected for three-year terms (one third every year...Lorentz contraction
(Encyclopedia)Lorentz contraction lôrˈĕnts [key], in physics, contraction or foreshortening of a moving body in the direction of its motion, proposed by H. A. Lorentz on theoretical grounds and based on an earli...computer graphics
(Encyclopedia)computer graphics, the transfer of pictorial data into and out of a computer. Using analog-to-digital conversion techniques, a variety of devices—such as curve tracers, digitizers, and light pens—...Santayana, George
(Encyclopedia)Santayana, George säntäyäˈnä [key], 1863–1952, American philosopher and poet, b. Madrid, Spain. Santayana's philosophic stance has been given the apparently opposite descriptions of materiali...Homeland Security, United States Department of
(Encyclopedia)Homeland Security, United States Department of (DHS), executive department of the federal government charged with protecting the security of the American homeland as its main responsibility. Its prima...Browse by Subject
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