Encyclopædia Britannica Australia -

Encyclopedias since 1768

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reduccion: in colonial Latin America, an Indian community set up under ecclesiastical or royal authority to facilitate the conversion of Indians to Christianity, to protect them, to teach them better farming methods and simple crafts, and in the case of civil ...
reduced mass: in physics and astronomy, value of a hypothetical mass introduced to simplify the mathematical description of motion in a vibrating or rotating two-body system. The equations of motion of two mutually interacting bodies can be reduced to a single equation ...
reductio ad absurdum: (Latin: "reduction to absurdity"), in logic, a form of refutation showing contradictory or absurd consequences following upon premises as a matter of logical necessity. A form of the reductio ad absurdum argument, known as indirect proof or reductio ad impossibile, ...
reduction: in syllogistic, or traditional, logic, method of rearranging the terms in one or both premises of a syllogism, or argument form, to express it in a different figure; the placement of the middle, or repeated, term is altered, usually to ...
reduction: any of a class of chemical reactions in which the number of electrons associated with an atom or a group of atoms is increased. The electrons taken up by the substance reduced are supplied by another substance, which is thereby ...
reductionism: in philosophy, a view that asserts that entities of a given kind are collections or combinations of entities of a simpler or more basic kind or that expressions denoting such entities are definable in terms of expressions denoting the more ...
redwood: (species Sequoia sempervirens), coniferous evergreen timber tree of the deciduous cypress family (Taxodiaceae), found in the fog belt of the coastal range from southwestern Oregon to central California, U.S., at elevations up to 1,000 m (3,300 feet) above sea level. ...
Redwood City: city, seat (1856) of San Mateo county, California, U.S. It lies on the western shore of San Francisco Bay, at the mouth of Redwood Creek, 25 miles (40 km) south of San Francisco. Originally inhabited by Ohlone Indians, the area ...
Redwood National Park: national park in the northwestern corner of California, U.S. It was established in 1968, with a boundary change in 1978, and was designated a World Heritage site in 1980. Preserving virgin (old-growth) groves of ancient redwood trees, including the world's ...
reed: in botany, any of several species of large aquatic grasses, especially the four species constituting the genus Phragmites of the grass family (Poaceae). The common, or water, reed (Phragmites australis) occurs along the margins of lakes, fens, marshes, and streams ...
reed instrument: in music, any of several wind instruments (aerophones) that sound when the player's breath or air from a wind chamber causes a reed (a thin blade of cane or metal) to vibrate, thereby setting up a sound wave in an ...
reed organ: any keyboard instrument sounded by vibration of metal reeds under wind pressure. "Reed organ" commonly refers to instruments having free reeds (vibrating through a slot with close tolerance) and no pipes.
Reed, Ishmael: African-American author of poetry, essays, and satiric novels.
Reed, Jimmy: American singer, harmonica player, and guitarist who was one of the most popular blues musicians of the post-World War II era.
Reed, John: U.S. poet-adventurer whose short life as a revolutionary writer and activist made him the hero of a generation of radical intellectuals.
Reed, Sir Carol: British film director noted for his technical mastery of the suspense-thriller genre. He was the first British film director to be knighted.
Reed, Stanley F: associate justice of the United States Supreme Court (1938-57).
Reed, Thomas B: vigorous U.S. Republican Party leader who, as speaker of the U.S. House of Representatives (1889-91, 1895-99), introduced significant procedural changes (the Reed Rules) that helped ensure legislative control by the majority party in Congress.
Reed, Walter: U.S. Army pathologist and bacteriologist who led the experiments that proved that yellow fever is transmitted by the bite of a mosquito. The Walter Reed Hospital, Washington, D.C., was named in his honour.
Reed, Willis: American professional basketball player and professional and collegiate basketball coach.
reedbuck: (genus Redunca), any of three graceful antelopes in the family Bovidae (order Artiodactyla), found in open and lightly wooded areas over much of sub-Saharan Africa. Reedbucks live alone or in small groups. When running, they raise their tails to expose ...
reedfish: eellike African fish related to the bichir (q.v.).
reedling: (species Panurus biarmicus), songbird often placed in the family Panuridae (order Passeriformes) but of uncertain relationships (see Muscicapidae). It lives in reedy marshes from England to eastern Asia. About 16 cm (6.5 inches) long, the male wears subtle reddish, yellowish, ...
Reedsport: city, Douglas county, southwestern Oregon, U.S., on the Pacific Coast near the mouth of the Umpqua River at its confluence with the Smith River. Founded in 1912 by Alfred Reed, the city developed as a shipbuilding and timber-shipping centre; shellfish ...
reel: in motion pictures, a light circular frame with radial arms and a central axis, originally designed to hold approximately 1,000 feet (300 m) of 35-millimetre motion-picture film. In the early days of motion pictures, each reel ran about 10 minutes, ...
reel: genre of social folk dance, Celtic in origin. It is a variety of country dance in which the dancers perform traveling figures alternating with "setting" steps danced in one place. Reels may be for sets of two or more couples. ...
Reelfoot Lake: shallow lake on the boundary between Lake and Obion counties in northwestern Tennessee, U.S., near Tiptonville. It was formed by the earthquakes that occurred along the New Madrid Fault in the winter of 1811-12. In the upheaval, land on the ...
Reese, Lizette Woodworth: American poet whose work draws on the images of her rural childhood.
Reeve, Tapping: U.S. legal educator and jurist.
Reeves, Steve: American bodybuilder and actor. He was one of the handsomest and best-built men of his era. By Reeves's own account, at his bodybuilding peak he stood 6 feet 1 inch (1.85 metres) tall, weighed 216 pounds (98 kg), had 18.25-inch ...
Reeves, William Pember: New Zealand statesman who, as minister of labour (1891-96), wrote the influential Industrial Conciliation and Arbitration Act (1894) and introduced the most progressive labour code in the world at that time.
reference frame: in dynamics, system of graduated lines symbolically attached to a body that serve to describe the position of points relative to the body. The position of a point on the surface of the Earth, for example, can be described by ...
referendum and initiative: electoral devices by which voters may express their wishes with regard to government policy or proposed legislation. They exist in a variety of forms.
reflection: abrupt change in the direction of propagation of a wave that strikes the boundary between different mediums. At least part of the oncoming wave disturbance remains in the same medium. Regular reflection, which follows a simple law, occurs at plane ...
reflex: in biology, an action consisting of comparatively simple segments of behaviour that usually occur as direct and immediate responses to particular stimuli uniquely correlated with them.
Reform Bill: any of the British parliamentary bills that became acts in 1832, 1867, and 1884-85 and that expanded the electorate for the House of Commons and rationalized the representation of that body. The first Reform Bill primarily served to transfer voting ...
Reform Judaism: a religious movement that has modified or abandoned many traditional Jewish beliefs, laws, and practices in an effort to adapt Judaism to the changed social, political, and cultural conditions of the modern world. Reform Judaism sets itself at variance with ...
Reform Party: political movement in Upper Canada (now in Ontario) and the Maritime Provinces that came into prominence shortly before 1837. Reformers in Lower Canada (now in Quebec) were known as Patriotes.
Reforma, La: (Spanish: The Reform), liberal political and social revolution in Mexico between 1854 and 1876 under the principal leadership of Benito Juarez.
Reformation: the religious revolution that took place in the Western church in the 16th century; its greatest leaders undoubtedly were Martin Luther and John Calvin. Having far-reaching political, economic, and social effects, the Reformation became the basis for the founding of ...
Reformation Day: anniversary of the day Martin Luther is said to have posted his Ninety-five Theses on the door of the Castle Church in Wittenberg, Ger. (Oct. 31, 1517), later identified by Protestants as the beginning of the Reformation. (See Researcher's Note.) ...
reformatory: a correctional institution for the treatment, training, and social rehabilitation of young offenders.
Reformed and Presbyterian church: name given to various of the churches that share a common origin in the Reformation in 16th-century Switzerland. Reformed is the term identifying churches regarded as Calvinistic in doctrine. The term presbyterian designates a collegial type of church government by ...
Reformed church: any of several major representative groups of classical Protestantism that arose in the 16th-century Reformation. Originally, all of the Reformation churches used this name (or the name Evangelical) to distinguish themselves from the "unreformed," or unchanged, Roman Catholic church. After ...
Reformed Church in America: church that developed from the Dutch settlements in New Netherlands (New York) in the 17th century. The Dutch Reformed Church was the first Reformed church of continental European background in North America. During the period of Dutch sovereignty over New ...
Reformed Church of France: church organized in 1938 by merging several Reformed groups that had developed in France during and after the 16th-century Protestant Reformation. During the early part of the Reformation, Protestant movements made slow progress in France. Yet reforming movements within the ...
Reformed Church of Hungary: Reformed church that developed in Hungary during and after the 16th-century Protestant Reformation. The influence of the Reformation was felt early in Hungary. A synod at Erdod adopted the Lutheran Augsburg Confession in 1545, and by 1567 the Synod of ...
Reformed Churches in The Netherlands: second largest Protestant church in The Netherlands, organized in 1892 by a merger of the Christian Reformed Church and a group of Reformed churches that were followers of Abraham Kuyper, a Dutch theologian and statesman.
Reformed League: voluntary association of German Reformed churches founded at Marburg in 1884 to aid Reformed churches and to conserve the Reformed heritage in Germany. It was organized by Reformed pastors and elders who met to commemorate the 400th anniversary of the ...
reforming: in chemistry, processing technique by which the molecular structure of a hydrocarbon is rearranged to alter its properties. The process is frequently applied to low-quality gasoline stocks to improve their combustion characteristics. Thermal reforming alters the properties of low-grade naphthas ...
refraction: in physics, the change in direction of a wave passing from one medium to another caused by its change in speed. For example, waves in deep water travel faster than in shallow; if an ocean wave approaches a beach obliquely, ...