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nitrous oxide

(Encyclopedia)nitrous oxide or nitrogen (I) oxide, chemical compound, N2O, a colorless gas with a sweetish taste and odor. Its density is 1.977 grams per liter at STP. It is soluble in water, alcohol, ether, and ot...

Penrose, Sir Roger

(Encyclopedia)Penrose, Sir Roger, 1931–, British mathematical physicist, Ph.D. Cambridge, 1958. He taught and conducted research at a number of British and American colleges and universities before becoming a pro...

statin

(Encyclopedia)statin, any of a class of drugs that reduces the amount of cholesterol in the blood by interfering with the production of cholesterol in the liver; commonly prescribed statins include atorvastatin, lo...

Reynolds number

(Encyclopedia)Reynolds number [for Osborne Reynolds], dimensionless quantity associated with the smoothness of flow of a fluid. It is an important quantity used in aerodynamics and hydraulics. At low velocities flu...

earth, in geology and astronomy

(Encyclopedia)CE5 A. Cross section of the earth, showing its shells B. Detailed cross section of the crust and upper mantle: The lithosphere consists of the hard rock in the crust and upper mantle, lying above t...

Neptune, in astronomy

(Encyclopedia)Neptune, in astronomy, 8th planet from the sun at a mean distance of about 2.8 billion mi (4.5 billion km) with an orbit lying between those of Uranus and the dwarf planet Pluto; its period of revolut...

corona, in astronomy

(Encyclopedia)corona, luminous envelope surrounding the sun, outside the chromosphere. Its density is less than one billionth that of the earth's atmosphere. The corona is visible only at the time of totality durin...

center of mass

(Encyclopedia)center of mass, the point at which all the mass of a body may be considered to be concentrated in analyzing its motion. The center of mass of a sphere of uniform density coincides with the center of t...

Cavendish, Henry

(Encyclopedia)Cavendish, Henry, 1731–1810, English physicist and chemist, b. Nice. He was the son of Lord Charles Cavendish and grandson of the 2d duke of Devonshire. He was a recluse, and most of his writings we...

transition elements

(Encyclopedia)transition elements or transition metals, in chemistry, group of elements characterized by the filling of an inner d electron orbital as atomic number increases. This includes the elements from titani...