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mathematics

(Encyclopedia)mathematics, deductive study of numbers, geometry, and various abstract constructs, or structures; the latter often “abstract” the features common to several models derived from the empirical, or ...

photography, still

(Encyclopedia)photography, still, science and art of making permanent images on light-sensitive materials. See also photographic processing; motion picture photography; motion pictures. By the end of ...

trade

(Encyclopedia)trade, traffic in goods. Conducted by gift, barter, or sale, trade is one of the most widespread of all social institutions. The theory of commerce as imposed by the national state has varied from...

numeral

(Encyclopedia)numeral, symbol denoting anumber. The symbol is a member of a family of marks, such as letters, figures, or words, which alone or in a group represent the members of a numeration system. The earliest ...

mass extinction

(Encyclopedia)mass extinction, the extinction of a large percentage of the earth's species, opening ecological niches for other species to fill. There have been at least ten such events. The five greatest were thos...

museums of science

(Encyclopedia)museums of science, institutions or buildings where collections relevant to science and technology are preserved and displayed to promote education and research. While the preponderance of these museu...

navigation

(Encyclopedia)navigation, science and technology of finding the position and directing the course of vessels and aircraft. The next great revolution in navigation occurred in the 20th cent., when radio signals ...

Shanghai

(Encyclopedia)Shanghai shăngˈhīˈ, shängˈhīˈ [key], city and municipality (2010 pop. 23,019,148), in, but independent of, Jiangsu prov., E China, on the Huangpu (Whangpoo) River where it flows into the Chang...

television

(Encyclopedia)CE5 Video transmission and reception of color and black-and-white television: The camera lens focuses collected light rays into mirrors, which separate the image into its three primary color compon...

periodical

(Encyclopedia)periodical, a publication that is issued regularly. It is distinguished from the newspaper in format in that its pages are smaller and are usually bound, and it is published at weekly, monthly, quarte...