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radiation pressure ... Rahman, Mujibur

radiation pressure: the pressure on a surface resulting from electromagnetic radiation that impinges on it, which results from the momentum carried by that radiation; radiation pressure is doubled if the radiation is ...
radiation therapy: use of radiation sources in the treatment or relief of diseases. Radiation therapy almost always makes use of ionizing radiation, deep tissue-penetrating rays, which can physically and chemically react with ...
radiation-damage dating: method of age determination that makes use of the damage to crystals and the radiation from radioactive substances caused by storage of energy in electron traps. In the mineral zircon, ...
Radic, Stjepan: peasant leader and advocate of autonomy for Croatia (within a federalized Yugoslavia).
radical: in politics, one who desires extreme change of part or all of the social order. The word was first used in a political sense in England, and its introduction is ...
radical: in chemistry, molecule that contains at least one unpaired electron. Most molecules contain even numbers of electrons, and the covalent chemical bonds holding the atoms together within a molecule normally ...
Radical Civic Union: major centre-left political party in Argentina. For much of the 20th century, the Radical Civic Union (UCR) was the primary opposition party to the Peronists, who are represented by the ...
Radical Democratic Party: centrist political party of Switzerland. With the Christian Democratic People's Party, the Social Democratic Party, and the Swiss People's Party, the Radical Democratic Party has governed Switzerland as part of ...
radical empiricism: a theory of knowledge and a metaphysics (theory of Being) advanced by William James, an American pragmatist philosopher and psychologist, based on the pragmatic theory of truth and the principle ...
Radical Republican: during and after the American Civil War, a member of the Republican Party committed to emancipation of the slaves and later to the equal treatment and enfranchisement of the freed ...
Radical-Socialist Party: the oldest of the French political parties, officially founded in 1901 but tracing back to "radical" groups of the 19th century. Traditionally a centrist party without rigid ideology or structure, ...
Radiguet, Raymond: precocious French novelist and poet who wrote at 17 a masterpiece of astonishing insight and stylistic excellence, Le Diable au corps (1923; The Devil in the Flesh), which remains a ...
Radin, Paul: U.S. anthropologist who was influential in advancing a historical model of primitive society based on a synthesis of economic and social structure, religion, philosophy, and psychology. He pioneered in such ...
radio: transmission and detection of communication signals consisting of electromagnetic waves that travel through the air in a straight line or by reflection from the ionosphere or from a communications satellite. ...
radio and radar astronomy: study of celestial bodies by examination of the radio-frequency energy they emit or reflect.
radio direction finder: radio receiver and directional antenna system used to determine the direction of the source of a signal. It most often refers to a device used to check the position of ...
radio interferometer: apparatus that is used to study heavenly bodies by receiving and analyzing electromagnetic radiation that these bodies emit or reflect in the radio wavelengths. A radio interferometer is a radio ...
radio range: in aerial navigation, a system of radio transmitting stations, each of which transmits a signal that not only carries identification but also is of intrinsic value to a navigator in ...
radio source: in astronomy, any of various objects in the universe that emit relatively large amounts of radio waves. Nearly all types of astronomical objects give off some radio radiation, but the ...
radio telescope: astronomical instrument consisting of a radio receiver and an antenna system that is used to detect radio-frequency radiation emitted by extraterrestrial sources. Because radio wavelengths are much longer than those ...
radio-frequency heating: process of heating materials through the application of radio waves of high frequency-i.e., above 70,000 hertz (cycles per second). Two methods of radio-frequency heating have been developed. One of these, ...
radioactive fallout: the deposition of radioactive materials on the Earth from the atmosphere. See fallout.
radioactive isotope: any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, ...
radioactive series: any of four independent sets of unstable heavy atomic nuclei that decay through a sequence of alpha and beta decays until a stable nucleus is achieved. These four chains of ...
radioactivity: property exhibited by certain types of matter of emitting energy and subatomic particles spontaneously. It is, in essence, an attribute of individual atomic nuclei.
radiolarian: any protozoan of the class Polycystinea (superclass Actinopoda), found in the upper layers of all oceans. Radiolarians, which are mostly spherically symmetrical, are known for their complex and beautifully sculptured, ...
radiology: branch of medicine using radiation for the diagnosis and treatment of disease. Radiology originally involved the use of X rays in the diagnosis of disease and the use of X ...
radiometer: instrument for detecting or measuring radiant energy. The term is applied in particular to devices used to measure infrared radiation. Radiometers are of various types that differ in their method ...
radiosonde: balloon-borne instrument for making atmospheric measurements, such as temperature, pressure, and humidity, and radioing the information back to a ground station. Special helium-filled meteorological balloons made of high-quality neoprene rubber ...
radiotelegraphy: radio communication by means of Morse Code or other coded signals. The radio carrier is modulated by changing its amplitude, frequency, or phase in accordance with the Morse dot-dash system ...
radish: (Raphanus sativus), annual or biennial plant in the family Brassicaceae that is grown for its large, succulent root. The edible part of the root, together with some of the seedling ...
Radishchev, Aleksandr Nikolayevich: writer who founded the revolutionary tradition in Russian literature and thought.
Radisson, Pierre Esprit: French explorer and fur trader who served both France and England in Canada.
radium: radioactive chemical element, heaviest of the alkaline-earth metals of main Group IIa of the periodic table. Radium is a silvery white metal that does not occur free in nature.
radius: in anatomy, the outer of two bones of the forearm when viewed with the palm facing forward. All land vertebrates have this bone. In humans it is shorter than the ...
Radke, Lina: German athlete who set several middle-distance running records between 1927 and 1930. Her victory in the 800-metre race at the 1928 Olympic Games-the first Olympics to include women's athletics-set a ...
Radlov, Vasily: German scholar and government adviser who made fundamental contributions to the knowledge of the ethnography, folklore, culture, ancient texts, and linguistics of the Turkic peoples of Southern Siberia and Central ...
Radnorshire: historic county, east-central Wales, on the English border. It covers an area of mountainous terrain and highlands, including Radnor Forest, with a central valley formed by the River Wye. Radnorshire ...
Radom: city, Mazowieckie wojewodztwo (province), east-central Poland. It is a rail junction and an administrative and industrial centre; the economy of the city relies predominantly on textile milling, ...
radon: (Rn), chemical element, a heavy radioactive gas of Group 0 (noble gases) of the periodic table, generated by the radioactive decay of radium. Radon is a colourless, odourless, tasteless gas, ...
Radowitz, Joseph Maria von: conservative Prussian diplomat and general who was the first statesman to attempt the unification of Germany under Prussian hegemony (from 1847), anticipating Otto von Bismarck's more successful efforts by almost ...
radula: horny, ribbonlike structure found in the mouths of all mollusks except the bivalves. The radula, part of the odontophore, may be protruded, and it is used in drilling or in ...
Radziwill Family: an important Polish-Lithuanian princely family that played a significant role in Polish-Lithuanian history.
Rae Bareli: town, administrative headquarters of Rae Bareli district, Uttar Pradesh state, northern India, southeast of Lucknow, on the Sai River. Named for the Bhar people, it is a road and rail ...
Rae, John: Scottish-born American economist, physician, and teacher.
Rae, John: physician and explorer of the Canadian Arctic.
Raeburn, Sir Henry: leading Scottish portrait painter during the late 18th and early 19th centuries.
Raeder, Erich: commander in chief of the German Navy (1928-43) and proponent of an aggressive naval strategy, who was convicted as a war criminal for his role in World War II.
Raedwald: also spelled Redwald king of the East Angles in England from the late 6th or early 7th century, son of Tytili.
Raemaekers, Louis: Dutch cartoonist who gained international fame with his anti-German cartoons during World War I.
Raetia: ancient Roman province comprising Vorarlberg and Tirol states in present-day Austria, the eastern cantons of Switzerland, and parts of Bavaria and Baden-Wurttemberg states in Germany. Its native inhabitants were probably ...
Raetian language: language spoken by the ancient Raetians in southern Germany and in the Alpine regions of Italy, Austria, and Switzerland in pre-Roman times. The language is known from a number of ...
Raff, Joachim: German composer and teacher, greatly celebrated in his lifetime but nearly forgotten in the late 20th century.
Raffi: celebrated Armenian novelist.
Raffles, Sir Stamford: British East Indian administrator and founder of the port city of Singapore (1819), who was largely responsible for the creation of Britain's Far Eastern empire. He was knighted in 1816.
Rafflesiales: order of flowering plants constituting three families (Rafflesiaceae, Mitrastemonaceae, and Hydnoraceae) and up to 60 species, although Mitrastemonaceae is not included in some classifications. The order is notable for being ...
Rafidah: (Arabic: "Rejectors"), broadly, Shi'ite Muslims who reject (rafd) the caliphate of Muhammad's two successors Abu Bakr and 'Umar. Many Muslim scholars, however, have stated that the term Rafidah cannot be ...
Rafinesque, Constantine Samuel: naturalist, traveler, and writer who made major and controversial contributions to botany and ichthyology.
Rafsanjani, Hashemi: Iranian cleric and politician, who was president of Iran from 1989 to 1997.
raft: simplest type of watercraft, made up of logs or planks fastened together to form a floating platform. The earliest were sometimes made of bundles of reeds. Most rafts have been ...
RAG Aktiengesellschaft: German company that was created in order to consolidate all coal-mining activities in the Ruhr region. Company headquarters are in Essen.
rag worm: any of a group of mostly marine or shore worms of the class Polychaeta (phylum Annelida). A few species live in fresh water. Other common names include mussel worm, pileworm, ...
raga: ("colour," or "passion"), in the music of India and Pakistan, a melodic framework for improvisation based on a given set of notes (usually five to seven) and characteristic rhythmic patterns. ...
ragfish: (genus Icosteus aenigmaticus), marine fish, the single species in the family Icosteidae (order Perciformes). The ragfish is found throughout the North Pacific. The name refers to their floppy, limp bodies, ...
ragged school: any of the 19th-century English and Scottish institutions maintained through charity and fostering various educational and other services for poor children, such as elementary schooling, industrial training, religious instruction, clothing ...
Raghunatha Siromani: philosopher and logician who brought the New Nyaya school, representing the final development of Indian formal logic, to its zenith of analytic power.
Raglan, FitzRoy James Henry Somerset, 1st Baron: field marshal, first British commander in chief during the Crimean War. His leadership in the war has usually been criticized.
Ragnar Lothbrok: Viking whose life passed into legend in medieval European literature.
Ragnarok: (Old Norse: "Doom of the Gods"), in Scandinavian mythology, the end of the world of gods and men. The Ragnarok is fully described only in the Icelandic poem Voluspa ("Sibyl's ...
ragtime: propulsively syncopated musical style, one forerunner of jazz and the predominant style of American popular music from about 1899 to 1917. Ragtime evolved in the playing of honky-tonk pianists along ...
Ragunan Zoological Gardens: zoo in Jakarta, Indon., that is one of the world's notable collections of Southeast Asian flora and fauna. More than 3,500 specimens of approximately 450 animal species are exhibited on ...
Ragusa: city, capital of Ragusa provincia, southeastern Sicily, Italy. The city lies in the Hyblaei Hills above the gorge of the Irminio River, west of Syracuse. The old lower town of ...
ragweed: (genus Ambrosia), any of a group of about 15 species of weedy plants of the family Asteraceae. Most species are native to North America. The ragweeds are coarse annuals with ...
rahbaniyah: (Arabic: "monasticism"), the monastic state, whose admissibility in Islam is much disputed by Muslim theologians. The term appears but once in the Qur'an: "And we set in the hearts of ...
Rahimyar Khan: town, southern Punjab province, Pakistan. The town was founded in 1751 as Naushehra and received its present name in 1881. It is linked by road and rail with Bahawalpur, Multan, ...
Rahman, Mujibur: Bengali leader and first prime minister (1972-75) and later president (1975) of Bangladesh.