North Atlantic Treaty Organization (NATO), military alliance established in 1949 that sought to create a counterweight to Soviet armies stationed in central and eastern Europe after World War II. Following the end of the Cold War, NATO was reconceived as a “cooperative-security” organization. It

warning system: Air defense systems: …BUIC in the United States, NATO air defense ground environment (NADGE) in Europe, a similar system in Japan, and various land-mobile, airborne, and ship command and control systems. Little information concerning the Soviet systems is available, but they are known to be extensive, automated, and capable.

Paul Natorp was a German Neo-Kantian philosopher, who represented the Marburg school in the philosophy of science and inquired particularly into its necessary presuppositions after the fashion of Kantian “transcendental logic.” He wrote Die logischen Grundlagen der exakten Wissenschaft (1910; “The

water snake, (subfamily Natricinae), any of about 200 species of semiaquatic snakes belonging to 38 genera (family Colubridae). Water snakes feed in or near water, and some leave aquatic environments only to bask in the sun or breed. Water snakes are characterized by stout bodies with strongly

sodium (Na), chemical element of the alkali metal group (Group 1 [Ia]) of the periodic table. Sodium is a very soft silvery-white metal. Sodium is the most common alkali metal and the sixth most abundant element on Earth, comprising 2.8 percent of Earth’s crust. It occurs abundantly in nature in

renal system: The role of hormones in renal function: This hormone, called atrial natriuretic peptide (ANP), exerts a vasodilator effect on the kidney and also reduces tubular reabsorption of sodium. Both actions result in increased urinary elimination of salt and water and tend to restore atrial pressure toward the normal. It is probably an important hormone controlling…

water snake: Natrix, the genus of Eurasian water snakes, is made up of four species. The common grass snake (N. natrix), which is the most terrestrial of the water snakes, inhabits all of Europe and western Asia. It is olive-coloured, green, or gray, with a yellow or…

water snake: The common grass snake (N. natrix), which is the most terrestrial of the water snakes, inhabits all of Europe and western Asia. It is olive-coloured, green, or gray, with a yellow or white collar on the neck. Adults range in length from 0.6 to 1 metre…

natrolite, hydrated sodium aluminosilicate mineral, Na2Al2Si3O10·2H2O, in the zeolite family. It has been found in the form of colourless or white, glassy, slender crystals or fibrous masses filling cavities or fissures in basaltic rocks, as in Trentino, Italy; Brevik, Nor.; Belfast, N.Ire.; the

thermonatrite: It is usually associated with natron (Na2CO3·10H2O) and trona, which alter to it upon partial dehydration; many reported deposits of natron are probably thermonatrite, because normal temperatures and dry air will cause the alteration. Natron, commonly found in solution, was used by ancient Egyptians as a preservative in mummification. For…

Peninj mandible, an almost perfectly preserved fossil jaw of the hominin (of human lineage) species Paranthropus boisei containing a complete set of adult teeth. It was found in 1964 at Peninj, a locale in Tanzania to the west of Lake Natron and about 80 km (50 miles) from Olduvai Gorge, a major

Lake Natron, lake in northern Tanzania on the border with Kenya, lying in the East African Rift System, 70 miles (113 km) northwest of Arusha. The lake is 35 miles (56 km) long and 15 miles (24 km) wide and contains salt, soda, and magnesite deposits. The lake’s warm water is an ideal breeding

mobile telephone: Airborne cellular systems: In the United States the North American terrestrial system (NATS) was introduced by GTE Corporation in 1984. Within a decade the system was installed in more than 1,700 aircraft, with ground stations in the United States providing coverage over most of the United States and southern Canada. A second-generation system,…

Mongolian literature: The 20th century and beyond: Dashdorjiin Natsagdorj (Nachugdorji), one of the founders of modern literature in Mongolia, introduced new genres and subjects through, for instance, his patriotic poems Minii nutag (“My Motherland”) and Tüükhiin shüleg (“Verses on History”), both on revolution and tradition, as well as through Erkh chölöö khüsekhüi…

Natsume Sōseki was an outstanding Japanese novelist of the Meiji period and the first to ably depict the plight of the alienated modern Japanese intellectual. Natsume took a degree in English from the University of Tokyo (1893) and taught in the provinces until 1900, when he went to England on a

Natsume Sōseki was an outstanding Japanese novelist of the Meiji period and the first to ably depict the plight of the alienated modern Japanese intellectual. Natsume took a degree in English from the University of Tokyo (1893) and taught in the provinces until 1900, when he went to England on a

Giulio Natta was an Italian chemist who contributed to the development of high polymers useful in the manufacture of films, plastics, fibres, and synthetic rubber. Along with Karl Ziegler of Germany, he was honoured in 1963 with the Nobel Prize for Chemistry for the development of Ziegler-Natta

Johan Petter Falkberget: …to become his second trilogy, Nattens brød (1940–59; “Bread of the Night”). The title is a reference to the ore for which local farmers give up their independence when they begin to transport it for the Danish rulers of Norway. This clash between local tradition and foreign capital informs the…

Jean-Marc Nattier was a French Rococo painter noted for his portraits of the ladies of King Louis XV’s court in classical mythological attire. Nattier received his first instruction from his father, the portraitist Marc Nattier (c. 1642–1705), and from his uncle, the history painter Jean Jouvenet.

natto, Japanese dish consisting of fermented soybeans. Natto begins as cooked soybeans. These are fermented with bacteria (Bacillus subtilis natto) into a pungent, sticky, and highly nutritious mass, in which the beans retain their shape amid a viscous goo that forms fine threads when stirred.

Ingmar Bergman: Life: …films, Through a Glass Darkly, Winter Light, and The Silence, dealing with the borderline between sanity and madness and that between human contact and total withdrawal, was regarded by many as his crowning achievement. Through a Glass Darkly won an Academy Award for best foreign film.

Bob Marley: Formation of the Wailers, role of Rastafari, and international fame: …Song,” Marley’s landmark albums included Natty Dread (1974), Live! (1975), Rastaman Vibration (1976), Exodus (1977), Kaya (1978), Uprising (1980), and the posthumous Confrontation (1983). Exploding in Marley’s reedy tenor, his songs were public expressions of personal truths—eloquent in their

Natufian culture, Mesolithic culture of Palestine and southern Syria dating from about 9000 bc. Mainly hunters, the Natufians supplemented their diet by gathering wild grain; they likely did not cultivate it. They had sickles of flint blades set in straight bone handles for harvesting grain and

Riau Islands: …Riau (east-central Sumatra); and the Natuna, Anambas, and Tambelan island clusters, widely scattered in the waters between western Borneo, Sumatra, and the Malay Peninsula. The most important islands are Batam, Bintan, and Great Karimun (Indonesian: Karimun Besar), all in the Riau archipelago. Tanjungpinang, on Bintan, is the provincial capital. Area…

Moritz Hauptmann: …der Harmonik und Metrik (1853; The Nature of Harmony and Metric).

Ludwig Büchner: …between mind and matter (Natur und Geist, 1857; “Nature and Spirit”) appealed strongly to freethinkers, but dialectical materialists condemned his acceptance of competitive capitalism, which Büchner viewed as an example of Charles Darwin’s “struggle for survival.” An English translation of his Die Stellung des Menschen in der Natur (1869)…

Emil Brunner: …Barth”; published in 1946 as Natural Theology), Brunner broke with Karl Barth’s theology by asserting that humanity has borne the “image of God” since Creation and has never wholly lost it, a view that provoked Barth’s vigorous disagreement.

Natural History, encyclopaedic scientific work of dubious accuracy by Pliny the Elder, completed in 77 ce as Naturae historiae and conventionally known as Naturalis historia. Although Pliny did not distinguish between fact, opinion, and speculation in his 37-volume treatise, he can be credited with

accidental: …it by a semitone; a natural (♮) restores it to the original pitch. Double sharps (×) and double flats (♭♭) indicate that the note is raised or lowered by two semitones. Sharps or flats that are placed at the beginning of a musical staff, called a key signature, indicate the…

bullfighting: Act three: Especially noteworthy is the left-handed natural, a simple but dangerous pass performed with the muleta held to the matador’s right: the sword is not used to spread the cloth, making for a much smaller target. The matador’s entire body is thereby exposed before the bull passes on the right and…

the Mekons: …(Out of Our Heads) (2002), Natural (2007), Ancient & Modern (2011), and Existentialism (2017), the last of which captures a live experimental performance in Brooklyn featuring just-written politically charged songs.

abrasive: Abrasive materials: their composition and properties: Natural abrasives include diamond, corundum, and emery; they occur in natural deposits and can be mined and processed for use with little alteration. Synthetic abrasives, on the other hand, are the product of considerable processing of raw materials or chemical precursors; they include silicon carbide,…

José de Acosta: …moral de las Indias (1590; Natural and Moral History of the Indies), the earliest survey of the New World and its relation to the Old. His works, missionary and literary, mark the zenith of the period of religious and scientific incorporation of the newly discovered lands into Western culture.

John Graunt: …he was inspired to write Natural and Political Observations . . . Made upon the Bills of Mortality (1662). He produced four editions of this work; the third (1665) was published by the Royal Society, of which Graunt was a charter member.

John Wood Oman: In his main work, The Natural and the Supernatural (1931), Oman developed this view in a wide-ranging treatment of knowledge and perception, of necessity and freedom, and of the history and classification of religions. His other works include Grace and Personality (1917), Vision and Authority (1902), and The Church…

natural bridge, naturally created arch formation resembling a bridge. Most natural bridges are erosion features that occur in massive, horizontally bedded sandstone or limestone. Some bridges, such as the Natural Bridge near Lexington, Va., are formed by the collapse of a cavern’s roof that may

asphalt: Natural asphalt (also called brea), which is believed to be formed during an early stage in the breakdown of organic marine deposits into petroleum, characteristically contains minerals, while residual petroleum asphalt does not.

Oliver Stone: Stone again courted controversy with Natural Born Killers (1994), a film, written by Quentin Tarantino, about the savagely violent exploits of a married couple, played by Woody Harrelson and Juliette Lewis. While Stone claimed that the film was meant to be critical of sensationalized violence, some critics found it guilty…

natural bridge, naturally created arch formation resembling a bridge. Most natural bridges are erosion features that occur in massive, horizontally bedded sandstone or limestone. Some bridges, such as the Natural Bridge near Lexington, Va., are formed by the collapse of a cavern’s roof that may

Natural Bridge, natural limestone arch, Rockbridge county, western Virginia, U.S., 20 miles (32 km) south of Lexington near the village of Natural Bridge and the northern portion of Jefferson National Forest. The arch, spanning a gorge cut by Cedar Creek, is 215 feet (66 metres) high, 90 feet (27

Natural Bridges National Monument, scenic area in southeastern Utah, U.S., containing three natural sandstone bridges. The bridges were carved by two winding streams that formed on the western slopes of Elk Ridge, a formation of the northwestern Colorado Plateau. Established in 1908, the monument

Carolus Linnaeus: Classification by natural characters of Carolus Linnaeus: Linnaeus did not consider the sexual system to be his main contribution toward the “reformation of botany” to which he aspired. His main contribution came in the form of a booklet, Fundamenta Botanica (1736; “The Foundations of Botany”), that framed the…

natural childbirth: …early 20th century, the term natural childbirth was thought of as synonymous with normal childbirth. In 1933 the British obstetrician Grantly Dick-Read wrote a book entitled Natural Childbirth, in which he postulated that excessive pain in labour results from muscular tension arising from fear of the birth process; he proposed…

natural childbirth, any of the systems of managing parturition in which the need for anesthesia, sedation, or surgery is largely eliminated by physical and psychological conditioning. Until the early 20th century, the term natural childbirth was thought of as synonymous with normal childbirth. In

universal: Resemblance nominalism: …matter of belonging to a natural class, and that the naturalness of a class is to be understood in terms of the ways in which the members resemble one another. These “resemblance nominalists” typically adopt a strategy used by the German-born philosopher Rudolf Carnap in Der Logische Aufbau der Welt…

dye: Natural dyes: Until the 1850s virtually all dyes were obtained from natural sources, most commonly from vegetables, such as plants, trees, and lichens, with a few from insects. Solid evidence that dyeing methods are more than 4,000 years old has been provided by dyed fabrics…

atmosphere: Convection: This process, referred to as free convection, occurs when the environmental lapse rate (the rate of change of an atmospheric variable, such as temperature or density, with increasing altitude) of temperature decreases at a rate greater than 1 °C per 100 metres (approximately 1 °F per 150 feet). This rate…

formal logic: Natural deduction method in PC: PC is often presented by what is known as the method of natural deduction. Essentially this consists of a set of rules for drawing conclusions from hypotheses (assumptions, premises) represented by wffs of PC and thus for constructing valid inference…

natural disaster, any calamitous occurrence generated by the effects of natural, rather than human-driven, phenomena that produces great loss of human life or destruction of the natural environment, private property, or public infrastructure. A natural disaster may be caused by weather and climate

dye: Natural dyes: Until the 1850s virtually all dyes were obtained from natural sources, most commonly from vegetables, such as plants, trees, and lichens, with a few from insects. Solid evidence that dyeing methods are more than 4,000 years old has been provided by dyed fabrics…

ocean thermal energy conversion: By 1999 the Natural Energy Laboratory of Hawaii Authority (NELHA) had created and tested a 250-kilowatt plant.

problem of evil: Theistic responses: …it fails to reckon with natural evil, except insofar as the latter is increased by human factors such as greed or thoughtlessness. Another argument, developed by the English philosopher Richard Swinburne, is that natural evils can be the means of learning and maturing. Natural evils, in other words, can help…

natural experiment, observational study in which an event or a situation that allows for the random or seemingly random assignment of study subjects to different groups is exploited to answer a particular question. Natural experiments are often used to study situations in which controlled

contraception: Fertility awareness techniques: Three procedures can be followed to predict ovulation so that, during the approximately six days of a woman’s most fertile monthly phase, sexual intercourse can be avoided. Their effectiveness is typically about 80 percent but may reach as high as 99 percent,…

natural fibre, any hairlike raw material directly obtainable from an animal, vegetable, or mineral source and convertible into nonwoven fabrics such as felt or paper or, after spinning into yarns, into woven cloth. A natural fibre may be further defined as an agglomeration of cells in which the

mechanics: Coupled oscillators: …frequencies, are known as the normal modes of the system.

natural gas, colourless highly flammable gaseous hydrocarbon consisting primarily of methane and ethane. It is a type of petroleum that commonly occurs in association with crude oil. A natural resource and fossil fuel, natural gas is used for electricity generation, heating, and cooking and as a

liquefied petroleum gas (LPG), any of several liquid mixtures of the volatile hydrocarbons propene, propane, butene, and butane. It was used as early as 1860 for a portable fuel source, and its production and consumption for both domestic and industrial use have expanded ever since. A typical

natural gas: Discovery and early application: …bce that the first known well was drilled for natural gas, to reported depths of 150 metres (500 feet). The Chinese drilled their wells with bamboo poles and primitive percussion bits for the express purpose of searching for gas in limestones dating to the Late Triassic Epoch (about 237 million…

liquefied petroleum gas (LPG), any of several liquid mixtures of the volatile hydrocarbons propene, propane, butene, and butane. It was used as early as 1860 for a portable fuel source, and its production and consumption for both domestic and industrial use have expanded ever since. A typical

industrial glass: Natural glasses: Several inorganic glasses are found in nature. These include obsidians (volcanic glasses), fulgarites (formed by lightning strikes), tektites found on land in Australasia and associated microtektites from the bottom of the Indian Ocean, moldavites from central Europe, and Libyan Desert glass from western…

history of the organization of work: Communal organization: Throughout human history, work has often required organization. Capture of game and fish required varying degrees of cooperation among members of the group. Communal activity of this type had important social implications. Food had to be equitably distributed, and a leader was needed…

World Heritage site: Designating World Heritage sites: Natural heritage sites are restricted to those natural areas that (1) furnish outstanding examples of Earth’s record of life or its geologic processes, (2) provide excellent examples of ongoing ecological and biological evolutionary processes, (3) contain natural phenomena that are rare, unique, superlative, or of…

Natural History, encyclopaedic scientific work of dubious accuracy by Pliny the Elder, completed in 77 ce as Naturae historiae and conventionally known as Naturalis historia. Although Pliny did not distinguish between fact, opinion, and speculation in his 37-volume treatise, he can be credited with

Gilbert White: …naturalist and clergyman, author of The Natural History and Antiquities of Selborne (1789), the first work on natural history to attain the status of an English classic.

museum: Natural history and natural science museums: Museums of natural history and natural science are concerned with the natural world; their collections may contain specimens of birds, mammals, insects, plants, rocks, minerals, and fossils. These museums have their origins in the cabinets of curiosities built up…

Natural History Museum, British natural science museum that has national and international responsibilities for taxonomic and associated research based on its outstanding collection of specimens and its extensive libraries. It is located near the Victoria and Albert Museum and the Science Museum in

Sèvres porcelain: …naturalistic birds from the famous Natural History of Birds (1771) of Georges-Louis-Leclerc Buffon. Sèvres porcelain went through the gamut of 18th-century styles, including those associated with the reign of Louis XVI (1774–92).

study of religion: The late 17th and 18th centuries: …gave another account in his Natural History of Religion, which reflected the growing rationalism of the epoch. For Hume, original polytheism was the result of a naïve anthropomorphism (conceiving the divine in human form) in the assignment of causes to natural events. The intensification of propitiatory and other forms of…

Eduardo Kac: …centre of a new installation, Natural History of the Enigma (2009).

Museum of Science, major American museum of science and technology, founded in 1830 in Boston, Massachusetts, as the Boston Society of Natural History. The society moved to permanent quarters in 1864, when it became known as the New England Museum of Natural History. Having outgrown its original

wind instrument: Horns: …as the trumpet is the natural horn, which was derived from an animal horn or a tusk. With their multifarious species of horned animals, the African countries achieved a rich variety of shapes, sizes, and pitches in their musical horns. Although the world’s earliest and most enduring horns were end-blown,…

administrative law: Administrative procedure: …common-law systems, the doctrine of natural justice influences administrative procedure in two ways: (1) that a person may not be judge of his own cause, and (2) that a person shall not be dealt with to his material disadvantage, whether of person or property, or removed from or disqualified for…

immune system: Activation of killer cells: …either cytotoxic T cells or natural killer cells, have receptors that bind to the tail portion of the IgG antibody molecule (the part that does not bind to antigen). Once bound, killer cells insert a protein called perforin into the target cell, causing it to swell and burst. Killer cells…

artificial intelligence: Language: …different from what is called natural meaning, exemplified in statements such as “Those clouds mean rain” and “The fall in pressure means the valve is malfunctioning.”

natural language processing (NLP), in computer science, the use of operations, systems, and technologies that allow computers to process and respond to written and spoken language in a way that mirrors human ability. To do this, natural language processing (NLP) models must use computational

natural law, in philosophy, system of right or justice held to be common to all humans and derived from nature rather than from the rules of society, or positive law. There have been several disagreements over the meaning of natural law and its relation to positive law. Aristotle (384–322 bce) held

ethics: Moral realism: One attempt, Natural Law and Natural Rights (1980), by the legal philosopher John Finnis, was a modern explication of the concept of natural law in terms of a theory of supposedly natural human goods. Although the book was acclaimed by Roman Catholic moral theologians and philosophers, natural…

natural logarithm (ln), logarithm with base e = 2.718281828…. That is, ln (ex) = x, where ex is the exponential function. The natural logarithm function is defined by ln x = 1 x dt t for x > 0; therefore the derivative of the natural logarithm is d dx ln x = 1 x . The natural logarithm is one of

natural gas, colourless highly flammable gaseous hydrocarbon consisting primarily of methane and ethane. It is a type of petroleum that commonly occurs in association with crude oil. A natural resource and fossil fuel, natural gas is used for electricity generation, heating, and cooking and as a

Andrew Weil: …drugs on the mind in The Natural Mind: A New Way of Looking at Drugs and the Higher Consciousness (1972). In this book Weil suggested that altered states of consciousness were innate to the human nervous system and that drugs or other stimuli merely catalyzed them. In a subsequent work,…

natural number, any number in the set of positive integers {1, 2, 3…} and sometimes zero. The term natural likely refers to humanity’s innate understanding and use of positive discrete values. Sometimes called “counting numbers,” natural numbers predate recorded history, as it is believed that

human composting, type of burial rite in which human remains are treated so as to turn into soil or compost. This process usually involves covering the body with plant matter in a special chamber to create an environment in which the corpse is decomposed to base organic soil over a period of 60 to

Jonathan Edwards: Early life and ministry: …of materialism and atheism (“Natural Philosophy”). Throughout his life he habitually studied with pen in hand, recording his thoughts in numerous hand-sewn notebooks; one of these, his “Catalogue” of books, demonstrates the wide variety of his interests.

philosophy of science: From natural philosophy to theories of method: The history of philosophy is intertwined with the history of the natural sciences. Long before the 19th century, when the term science began to be used with its modern meaning, those who are now counted…

Seneca: Philosophical works and tragedies: …natural science, Naturales quaestiones (Natural Questions), where lofty generalities on the investigation of nature are offset by a jejune exposition of the facts. Of the Consolationes, Ad Marciam (To Marcia) consoles a lady on the loss of a son; Ad Helviam matrem (To Mother Helvia), Seneca’s mother on his…

geographic range, in ecology, the collective area in which all members of a particular species are found during their lifetime. The term geographic range has often referred to the natural extent of a species’ distribution; however, it also includes areas where a species was introduced by human

music recording: The role of the producer: …criterion in separating the “natural” or “re-creative” from the “creative” technique of large-scale classical recordings. In a natural setup, microphones are placed in the optimum positions in the hall—often directly over the conductor—in order to re-create the concert-hall or opera-house effect. In the natural arrangement, the conductor is responsible…

rock: Types of remanent magnetization: NRM (natural remanent magnetization) is the magnetization detected in a geologic in situ condition. The NRM of a substance may, of course, be a combination of any of the other remanent magnetizations described here.

resin: …of the physical properties of natural resins but are different chemically. Synthetic resins are not clearly differentiated from plastics.

natural resource, any biological, mineral, or aesthetic asset afforded by nature without human intervention that can be used for some form of benefit, whether material (economic) or immaterial. What is considered a “resource” (or, for that matter, “natural”) has varied over time and from one

natural resource management, ways in which societies manage the supply of or access to the natural resources upon which they rely for their survival and development. Insofar as humans are fundamentally dependent on natural resources, ensuring the ongoing access to or a steady provision of natural

natural resources law, complex body of national and local laws, having both statutory and common-law components, that regulate the use and protection of natural resources. Even when resources extend across national boundaries, or when resource exploitation (e.g., depleting a freshwater lake for

conservation, study of the loss of Earth’s biological diversity and the ways this loss can be prevented. Biological diversity, or biodiversity, is the variety of life either in a particular place or on the entire planet Earth, including its ecosystems, species, populations, and genes. Conservation

civil rights: …such as human rights or natural rights, in which people acquire rights inherently, perhaps from God or nature, civil rights must be given and guaranteed by the power of the state. Therefore, they vary greatly over time, culture, and form of government and tend to follow societal trends that condone…

elastomer: Polymers and elasticity: …common elastomers are cis-polyisoprene (natural rubber, NR), cis-polybutadiene (butadiene rubber, BR), styrene-butadiene rubber (SBR), and ethylene-propylene monomer (EPM). SBR is a mixed polymer, or copolymer, consisting of two different monomer units, styrene and butadiene, arranged randomly along the molecular chain. (The structure of SBR is illustrated in the figure.)…

museum: Natural history and natural science museums: Museums of natural history and natural science are concerned with the natural world; their collections may contain specimens of birds, mammals, insects, plants, rocks, minerals, and fossils. These museums have their origins in the cabinets of curiosities built up by prominent individuals…

Ruth Patrick: …1945, she volunteered at the Academy of Natural Sciences in Philadelphia. She began her tenure as a researcher but became the associate curator of microscopy in 1939. In 1937 she began to consolidate the academy’s diatom collection, augmenting it by collecting species in the field and by acquiring species from…

natural selection, process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype, or genetic constitution. A brief treatment of natural selection follows. For full treatment, see evolution: The concept of natural selection. In

Arkansas, constituent state of the United States of America. Arkansas ranks 29th among the 50 states in total area, but, except for Louisiana and Hawaii, it is the smallest state west of the Mississippi River. Its neighbours are Missouri to the north, Tennessee and Mississippi to the east,