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satellite, artificial

(Encyclopedia)CE5 A. Nimbus weather satellite B. Syncom communications satellite satellite, artificial, object constructed by humans and placed in orbit around the earth or other celestial body (see also space ...

space shuttle

(Encyclopedia)space shuttle, reusable U.S. space vehicle (1981–2011). Developed by the National Aeronautics and Space Administration (NASA) and officially known as the Space Transportation System (STS), it was th...

enzyme

(Encyclopedia)enzyme, biological catalyst. The term enzyme comes from zymosis, the Greek word for fermentation, a process accomplished by yeast cells and long known to the brewing industry, which occupied the atten...

forgery, in art

(Encyclopedia)forgery, in art, the false claim to authenticity for a work of art. A forger often unconsciously produces a confusion of styles or subtly accents elements reflecting contemporary bias. A major examp...

art conservation and restoration

(Encyclopedia)art conservation and restoration, the preservation of structurally sound works of art, the halting of processes that lead to the damage of works of art, and the repair of already damaged works of art....

Lewinsky scandal

(Encyclopedia)Lewinsky scandal ləwĭnˈskē [key], sensation that enveloped the presidency of Bill Clinton in 1998–99, leading to his impeachment by the U.S. House of Representatives and acquittal by the Senate....

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...

musicals

(Encyclopedia)musicals, earlier known as musical comedies, plays that incorporate music, song, and dance. These elements move with the plot, heightening and commenting on the action. Mixing the sprightly songs and ...

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...

galaxy

(Encyclopedia)CE5 Hubble classification of galaxies: Elliptical galaxies (E) are classified according to the degree of flattening of the ellipse. Spiral galaxies (S) and barred spiral galaxies (SB) are classifie...