(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…
(Encyclopedia) Simon, Herbert Alexander, 1916–2001, American social scientist and economist, b. Milwaukee, grad. Univ. of Chicago (B.A., 1936, Ph.D., 1943). A professor of computer science and…
(Encyclopedia) biennial, plant requiring two years to complete its life cycle, as distinguished from an annual or a perennial. In the first year a biennial usually produces a rosette of leaves (e.g…
(Encyclopedia) blood substitute, substance that mimics the function of blood. Blood substitutes typically concentrate only on reproducing the function of hemoglobin, the molecule that carries oxygen…
(Encyclopedia) bluebird, common name for a North American migratory bird of the family Turdidae (thrush family). The eastern bluebird, Sialia sialis, is among the first spring arrivals in the North.…
(Encyclopedia) waveguide, device that controls the propagation of an electromagnetic wave so that the wave is forced to follow a path defined by the physical structure of the guide. Waveguides, which…
(Encyclopedia) nationality, in political theory, the quality of belonging to a nation, in the sense of a group united by various strong ties. Among the usual ties are membership in the same general…
(Encyclopedia) free energy or Gibbs free energy, quantity derived from the relationships between heat and work studied in thermodynamics and used as a measure of the relative stability of a physical…
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CE5
Equilibrium
equilibrium, state of balance. When a body or a system is in equilibrium, there is no net tendency to change. In mechanics, equilibrium has to do with the forces…
(Encyclopedia) poster, placard designed to be posted in some public place for purposes of commercial announcement or propaganda. Advertising makes wide use of posters, as do charitable and political…
