economic planning: The work of Gosplan: …drawing up a series of material balances, which expressed anticipated supply of, and demand for, all key commodities. The successive versions of the plan were revised until a general balance was attained, since it was no use planning an increase in production of any item if the necessary additional machinery,…

treaty: In the case of a material breach—i.e., an impermissible repudiation of the treaty or a violation of a provision essential to the treaty’s object or purpose—the innocent party of a bilateral treaty may invoke that breach as a ground for terminating the treaty or suspending its operation. Multilateral treaties may…

Aristotle: Causation: This is called the material cause. Second, there is the form or pattern of a thing, which may be expressed in its definition; Aristotle’s example is the proportion of the length of two strings in a lyre, which is the formal cause of one note’s being the octave of…

material culture, tools, weapons, utensils, machines, ornaments, art, buildings, monuments, written records, religious images, clothing, and any other ponderable objects produced or used by humans. If all the human beings in the world ceased to exist, nonmaterial aspects of culture would cease to

telecommunications media: Optical fibres: …distortion in optical fibres are material dispersion and waveguide dispersion. Material dispersion is a phenomenon in which different optical wavelengths propagate at different velocities, depending on the refractive index of the material used in the fibre core. Waveguide dispersion depends not on the material of the fibre core but on…

envy: Material envy is resentment toward others who have more material fortune, such as money, talent, strength, beauty, or friends. Spiritual envy is resentment toward others’ spiritual goodness or those who have progressed in holiness. Spiritual envy is more evil than material envy and is considered…

equivalence, in logic and mathematics, the formation of a proposition from two others which are linked by the phrase “if, and only if.” The equivalence formed from two propositions p and q also may be defined by the statement “p is a necessary and sufficient condition for

fallacy: Material fallacies: The material fallacies are also known as fallacies of presumption, because the premises “presume” too much—they either covertly assume the conclusion or avoid the issue in view.

formal logic: Basic features of PC: … [then] q” or “p [materially] implies q”) is to count as false when p is true and q is false and as true in all other cases; hence it has the same meaning as “either not-p or q” or as “not both p and not-q.” The symbol “⊃” is…

predication: …excludes) the predicate; it is material if the entailment is contingent.

sin: Material sin consists of an act that is wrong in itself (because contrary to God’s law and human moral nature) but which the sinner does not know to be wrong and for which he is therefore not personally culpable.

history of logic: The theory of supposition: …(2) simple supposition, and (3) material supposition. These types are illustrated, respectively, by the occurrences of the term horse in the statements “Every horse is an animal” (in which the term horse refers to individual horses), “Horse is a species” (in which the term refers to a universal), and “Horse…

marketing: Marketing intermediaries: the distribution channel: Manufacturers use raw materials to produce finished products, which in turn may be sent directly to the retailer, or, less often, to the consumer. However, as a general rule, finished goods flow from the manufacturer to one or more wholesalers before they reach the retailer and, finally,…

materialism, in philosophy, the view that all facts (including facts about the human mind and will and the course of human history) are causally dependent upon physical processes, or even reducible to them. The word materialism has been used in modern times to refer to a family of metaphysical

Jorie Graham: Graham’s subsequent collections include Materialism (1993); The Dream of the Unified Field: Selected Poems 1974–1994 (1995), a survey of her work for which she received a Pulitzer Prize; and The Errancy (1997). In Swarm (2000) and Never (2002) she departed from her characteristic imagery-focused style.

Marxism: Lenin: …in Materializm i empiriokrititsizm (1908; Materialism and Empirio-criticism (1908). In 1912 at the Prague Conference the Bolsheviks constituted themselves as an independent party. During World War I Lenin resided in Switzerland, where he studied Hegel’s Science of Logic and the development of capitalism and carried on debates with Marxists like…

spiritualism: History of spiritualism: …of mediumship, especially the occasional materialization of spirit entities. Many who participated in psychic research hoped for positive results and occasionally concluded that they had proved the existence of clairvoyance or established the reality of spirit contact. Among the most prominent supporters of spiritualist claims was the chemist William Crookes…

Nicephorus Bryennius: …he wrote the chronicle (“Materials for a History”) of the Comnenus family in the 11th century, particularly during the years 1070–79. In addition to information derived from older contemporaries such as his father and his father-in-law and from official sources, Bryennius also used the works of Michael Psellus, Joannes…

materials handling, the movement of raw goods from their native site to the point of use in manufacturing, their subsequent manipulation in production processes, and the transfer of finished products from factories and their distribution to users or sales outlets. In early systems of handling

materials processing, series of operations that transform industrial materials from a raw-material state into finished parts or products. Industrial materials are defined as those used in the manufacture of “hard” goods, such as more or less durable machines and equipment produced for industry and

materials recovery facility (MRF), solid-waste management plant that processes recyclable materials to sell to manufacturers as raw materials for new products. MRFs are generally classified as either “clean” or “dirty,” depending on whether the facility handles materials that are mixed with other

materials recovery facility (MRF), solid-waste management plant that processes recyclable materials to sell to manufacturers as raw materials for new products. MRFs are generally classified as either “clean” or “dirty,” depending on whether the facility handles materials that are mixed with other

materials recovery facility (MRF), solid-waste management plant that processes recyclable materials to sell to manufacturers as raw materials for new products. MRFs are generally classified as either “clean” or “dirty,” depending on whether the facility handles materials that are mixed with other

recycling, recovery and reprocessing of waste materials for use in new products. The basic phases in recycling are the collection of waste materials, their processing or manufacture into new products, and the purchase of those products, which may then themselves be recycled. Typical materials that

materials science, the study of the properties of solid materials and how those properties are determined by a material’s composition and structure. It grew out of an amalgam of solid-state physics, metallurgy, and chemistry, since the rich variety of materials properties cannot be understood

Humans have long had an insatiable appetite for materials—natural resources, chemicals, building products, and everything in between. Materials-focused companies, including those listed in the S&P 500, operate to satisfy our demand for these physical products. Materials are made up of commodities,

materials testing, measurement of the characteristics and behaviour of such substances as metals, ceramics, or plastics under various conditions. The data thus obtained can be used in specifying the suitability of materials for various applications—e.g., building or aircraft construction,

Sweden: Manufacturing: …also has an advanced war matériel industry.

maternal imagination, idea that maternal thoughts during pregnancy are transmitted directly to the developing fetus, resulting in a congenital disorder at birth. Belief in maternal imagination was prevalent in Europe during the 16th to 18th centuries. Throughout the late Renaissance and

maternal imagination, idea that maternal thoughts during pregnancy are transmitted directly to the developing fetus, resulting in a congenital disorder at birth. Belief in maternal imagination was prevalent in Europe during the 16th to 18th centuries. Throughout the late Renaissance and

metabolic disease: Inheritance: …of the cell) is termed maternal (mitochondrial) inheritance. Mitochondrial DNA (mtDNA), although much smaller than nuclear DNA, is critical in cellular metabolism. Most of the energy required by a cell to drive its metabolism is produced in mitochondria by proteins in a series of electron donor-acceptor reactions that make up…

Nicolae Ceaușescu: …to curtail their fertility, but maternal mortality rates skyrocketed as women sought unsafe and outlawed means to terminate their pregnancies. In an effort to pay off the large foreign debt that his government had accumulated through its mismanaged industrial ventures in the 1970s, Ceaușescu in 1982 ordered the export of…

maternal school, a French school for children between two and six years old. Private schools for young children were founded in France around 1779, under the influence of Jean-Jacques Rousseau’s Émile. The central government took over most of them in 1833 and named them maternal schools, hoping

three-parent baby: Mitochondrial replacement therapy: In maternal spindle transfer, the nucleus is removed from a donor egg, leaving behind the cytoplasm. The nucleus from the mother’s egg cell is then inserted into the donor egg. The egg is fertilized with the father’s sperm and then transferred to the mother’s uterus for…

human genetic disease: Imprinted gene mutations: So-called maternally imprinted genes are generally expressed only when inherited from the father, and so-called paternally imprinted genes are generally expressed only when inherited from the mother. The disease gene associated with Prader-Willi syndrome is maternally imprinted, so that although every child inherits two copies of…

lactation: Composition and properties of milk: The nutritional status of the mother is important throughout this period. The mother’s daily caloric intake must increase significantly in order to replenish the mother’s nutrient and energy stores. The use of drugs or smoking by the mother can adversely affect the infant; many drugs are secreted in breast milk,…

public health: Variations among developed countries: …of statutes, of which the Maternity and Child Welfare Act (1918) was probably the most important, placed responsibility for most of the work on county governments. National health insurance (1911) gave benefits to 16 million workers and marked the beginning of a process upon which the National Health Service Act…

Sweden: Labour and taxation: …is well known for its maternity and parental leave schemes that allow up to 13 months’ leave at about four-fifths of their pay. Employers pay additional fees of more than two-fifths of gross wages for statutory social benefits, including pensions. As of 1999, a new general pension system was introduced,…

epistemology: Skepticism: The contemporary American philosopher Benson Mates, who claimed to be a modern representative of that tradition, held that all philosophical arguments are equally good.

Greek literature: Heptanesian School: …to cultivate the Demotic, particularly Antónios Mátesis, whose historical social drama, O vasilikós (1859; “The Basil Plant”), was the first prose work of any length to be written in the Demotic. Aristotélis Valaorítis continued the Heptanesian tradition with long patriotic poems inspired by the Greek national struggles.

José Luandino Vieira is an Angolan writer of short fiction and novels. Vieira immigrated with his parents to Angola in 1938, living in and around the musseques (African quarters) of Luanda. His writings reflect the fusion of Kimbundu (the language of the Mbundu people) and a variety of Portuguese

Juliusz Kaden-Bandrowski: …Barcz (1922–23; “General Barcz”), and Mateusz Bigda (1933; “Matthew Bigda”). The latter two satirically describe political life after Poland regained independence. Considered by many critics to offer caricatures of real political personalities (e.g., Józef Piłsudski), these novels evoked wide public reaction, mostly critical of the author’s unrestrained, often brutal depiction…

John Sayles: (1983); Baby, It’s You (1983); Matewan (1987), a drama about coal miners fighting to form a union in the 1920s; The Brother from Another Planet (1984), a science-fiction comedy that lacerates discrimination; City of Hope (1991); Passion Fish (1992), which earned Sayles an Academy Award nomination for a best original…

Math, in the Welsh collection of stories known as the Mabinogion, king of Gwynedd in the North. He is also the brother of Dôn, who is probably the Welsh counterpart of the Irish goddess Danu. Whenever at peace, it was necessary for Math to have his feet upon a virgin’s lap. The virgin who held

mathematics, the science of structure, order, and relation that has evolved from elemental practices of counting, measuring, and describing the shapes of objects. It deals with logical reasoning and quantitative calculation, and its development has involved an increasing degree of idealization and

Danica McKellar: …math among girls, she wrote Math Doesn’t Suck: How to Survive Middle-School Math Without Losing Your Mind or Breaking a Nail (2007), Kiss My Math: Showing Pre-Algebra Who’s Boss (2008), Hot X: Algebra Exposed! (2010), and Girls Get Curves: Geometry Takes Shape (2012). The popular books were written in the…

The Four Branches of the Mabinogi: Math fab Mathonwy (“Math Son of Mathonwy”) is a complex tale focusing on Math, a prince of northern Wales, his nephew Gwydion, and Gwydion’s nephew Lleu Llaw Gyffes (“Lleu Skilled Hand”); among many other events, Gwydion’s magic and duplicity lead to the death of Pryderi.…

number game, any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved. They may involve arithmetic, algebra, geometry, theory of numbers,

number game, any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved. They may involve arithmetic, algebra, geometry, theory of numbers,

matha, in Hinduism, any monastic establishment of world renouncers or sannyasis. The first mathas were founded by the great teacher Shankara in the 8th century ce. Shankara was said to have established four mathas at strategic points in India as bulwarks for Hindu missionary activity and as centres

Egyptian Museum, museum of Egyptian antiquities in Cairo, which was founded in the 19th century by the French Egyptologist Auguste Mariette and which housed the world’s most valuable collection of its kind into the 21st century. The Egyptian Museum was founded in 1858 at Būlāq, moved to Al-Jīzah

Mathaf: Arab Museum of Modern Art, museum in Doha, Qatar, exhibiting works by artists from the Arab world. Mathaf’s name comes from the Arabic word for museum, matḥaf. (Read Sister Wendy’s Britannica essay on art appreciation.) Since Mathaf opened in December 2010, the collection has been displayed

Arabic literature: Compilations and manuals: …compilation, Ḍiyāʾ al-Dīn ibn al-Athīr’s Al-Mathal al-sāʾir fī adab al-kātib wa al-shāʿir (“The Current Model for the Literary Discipline of the Scribe and Poet”), where the sequence of functions found in the title very much reflects the author’s own career as an accomplished writer of belles lettres. Ibn Rashīq’s Al-ʿUmdah…

Rudolph Maté was a Polish-born filmmaker who was best known for his work as a cinematographer, though he later had some success as a director. Maté studied at the University of Budapest. His film career began in 1919, after Alexander Korda hired him as an assistant cameraman. He worked in Berlin

Stephen Wolfram: …year to concentrate on marketing Mathematica, a computer program he had devised that allowed complex mathematical equations to be manipulated and solved algebraically, rather than using numerical analysis to find approximate solutions. Software sales made the physicist a millionaire and allowed him to finance his own research. The release of…

history of logic: Boole and De Morgan: Boole published two major works, The Mathematical Analysis of Logic in 1847 and An Investigation of the Laws of Thought in 1854. It was the first of these two works that had the deeper impact on his contemporaries and on the history of logic. The Mathematical Analysis of Logic arose…

Iannis Xenakis: He established the School of Mathematical and Automatic Music in 1966. Other works by Xenakis include Polla ta dhina for children’s chorus and orchestra (1962), Akrata (1964–65) for 16 wind instruments, and Cendrées (1974) for chorus and orchestra. He also composed works solely for electronic reproduction, such as…

philosophy of mathematics: Mathematical anti-Platonism: Many philosophers cannot bring themselves to believe in abstract objects. However, there are not many tenable alternatives to mathematical Platonism. One option is to maintain that there do exist such things as numbers and sets (and that mathematical theorems provide true descriptions of…

computational biology: Distinctions among related fields: …is more easily distinguished from mathematical biology, though there are overlaps. The older discipline of mathematical biology was concerned primarily with applications of numerical analysis, especially differential equations, to topics such as population dynamics and enzyme kinetics. It later expanded to include the application of advanced mathematical approaches in genetics,…

mathematics: Analytic geometry: …Géométrie was to achieve the construction of solutions to geometric problems by means of instruments that were acceptable generalizations of ruler and compass. Algebra was a tool to be used in this program:

expected value, in general, the value that is most likely the result of the next repeated trial of a statistical experiment. The probability of all possible outcomes is factored into the calculations for expected value in order to determine the expected outcome in a random trial of an experiment.

John von Neumann: European career, 1921–30: …culminated in von Neumann’s book The Mathematical Foundations of Quantum Mechanics (1932), in which quantum states are treated as vectors in a Hilbert space. This mathematical synthesis reconciled the seemingly contradictory quantum mechanical formulations of Erwin Schrödinger and Werner Heisenberg. Von Neumann also claimed to prove that deterministic

number game, any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved. They may involve arithmetic, algebra, geometry, theory of numbers,

mathematical induction, one of various methods of proof of mathematical propositions, based on the principle of mathematical induction. A class of integers is called hereditary if, whenever any integer x belongs to the class, the successor of x (that is, the integer x + 1) also belongs to the

linguistics: Mathematical linguistics: What is commonly referred to as mathematical linguistics comprises two areas of research: the study of the statistical structure of texts and the construction of mathematical models of the phonological and grammatical structure of languages. These two branches of mathematical linguistics, which may…

formal logic, the abstract study of propositions, statements, or assertively used sentences and of deductive arguments. The discipline abstracts from the content of these elements the structures or logical forms that they embody. The logician customarily uses a symbolic notation to express such

mathematical model, either a physical representation of mathematical concepts or a mathematical representation of reality. Physical mathematical models include reproductions of plane and solid geometric figures made of cardboard, wood, plastic, or other substances; models of conic sections, curves

philosophy of mathematics: Nominalism: Nominalism is the view that mathematical objects such as numbers and sets and circles do not really exist. Nominalists do admit that there are such things as piles of three eggs and ideas of the number 3 in people’s heads, but they do not…

mathematical physics, Branch of mathematical analysis that emphasizes tools and techniques of particular use to physicists and engineers. It focuses on vector spaces, matrix algebra, differential equations (especially for boundary value problems), integral equations, integral transforms, infinite

mathematical Platonism, in metaphysics and the philosophy of mathematics, the doctrine that there exist abstract objects—objects that are wholly nonspatiotemporal, nonphysical, and nonmental—and that there are true mathematical sentences that express true descriptions of such objects. The

Principia, book about physics by Isaac Newton, the fundamental work for the whole of modern science. Published in 1687, the Principia lays out Newton’s three laws of motion (the basic principles of modern physics), which resulted in the formulation of the law of universal gravitation. The Principia

mathematical programming, theoretical tool of management science and economics in which management operations are described by mathematical equations that can be manipulated for a variety of purposes. If the basic descriptions involved take the form of linear algebraic equations, the technique is

completeness: In proof theory, a formal system is said to be syntactically complete if and only if every closed sentence in the system is such that either it or its negation is provable in the system. In model theory, a formal system is said to be semantically…

Francis Ysidro Edgeworth: His most famous work, Mathematical Psychics (1881), presented his new ideas on the generalized utility function, the indifference curve, and the contract curve, all of which have become standard devices of economic theory.

number game, any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved. They may involve arithmetic, algebra, geometry, theory of numbers,

number game, any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved. They may involve arithmetic, algebra, geometry, theory of numbers,

number game: 20th century: Rouse Ball’s Mathematical Recreations and Essays appeared in 1892; it soon became a classic, largely because of its scholarly approach. After passing through 10 editions it was revised by the British professor H.S.M. Coxeter in 1938; it is still a standard reference.

information theory: Historical background: …1948 of Claude Shannon’s “A Mathematical Theory of Communication” in the Bell System Technical Journal. A key step in Shannon’s work was his realization that, in order to have a theory, communication signals must be treated in isolation from the meaning of the messages that they transmit. This view…

Edward Thomas Copson: Baker, The Mathematical Theory of Huygens’ Principle (1939), concerning the generation and structure of waves. His other publications include Asymptotic Expansions (1965) and Metric Spaces (1968).

Arthur Eddington: Early life: … (1920) and his great treatise The Mathematical Theory of Relativity (1923)—the latter considered by Einstein the finest presentation of the subject in any language—made Eddington a leader in the field of relativity physics. His own contribution was chiefly a brilliant modification of affine (non-Euclidean) geometry, leading to a geometry of…

Sir Horace Lamb: …was enlarged and transformed into Hydrodynamics (1895); the latter was for many years the standard work on hydrodynamics. His other publications include Infinitesimal Calculus (1897), Dynamical Theory of Sound (1910), Statics (1912), Dynamics (1914), and Higher Mechanics (1920). His many papers, principally on applied mathematics, detailed his researches on wave…

Pythagoreanism: Two Pythagorean sects: , the esoteric teachings) and mathēmatikoi (from mathēmatikos, “scientific”), may have occurred at that time. The acousmatics devoted themselves to the observance of rituals and rules and to the interpretation of the sayings of the master; the “mathematics” were concerned with the scientific aspects of Pythagoreanism. Philolaus, who was rather…

G.H. Hardy: A Mathematician’s Apology (1940), which gives a completely personal account of how mathematicians think, continues to be widely read. He was widely honoured for his work, being elected a fellow of the Royal Society (1910) and president of the London Mathematical Society (1926–28, 1939–41).

mathematicism, the effort to employ the formal structure and rigorous method of mathematics as a model for the conduct of philosophy. Mathematicism is manifested in Western philosophy in at least three ways: (1) General mathematical methods of investigation can be used to establish consistency of

Clark L. Hull: …theories were first presented in Mathematico-Deductive Theory of Rote Learning (1940), a collaboration with several coworkers, in which he expressed his findings through postulates stated in both mathematical and verbal forms. Hull believed that psychology had its own quantitative laws that could be stated in mathematical equations. He further developed…

mathematics, the science of structure, order, and relation that has evolved from elemental practices of counting, measuring, and describing the shapes of objects. It deals with logical reasoning and quantitative calculation, and its development has involved an increasing degree of idealization and

logic puzzle: The brakeman, the fireman, and the engineer: …Oswald Jacoby and William Benson’s Mathematics for Pleasure (1962).

East Asian mathematics, the discipline of mathematics as it developed in China and Japan. When speaking of mathematics in East Asia, it is necessary to take into account China, Japan, Korea, and Vietnam as a whole. At a very early time in their histories, Japan, Korea, and Vietnam all adopted the

foundations of mathematics, the study of the logical and philosophical basis of mathematics, including whether the axioms of a given system ensure its completeness and its consistency. Because mathematics has served as a model for rational inquiry in the West and is used extensively in the

Indian mathematics, the discipline of mathematics as it developed in the Indian subcontinent. The mathematics of classical Indian civilization is an intriguing blend of the familiar and the strange. For the modern individual, Indian decimal place-value numerals may seem familiar—and, in fact, they

philosophy of mathematics, branch of philosophy that is concerned with two major questions: one concerning the meanings of ordinary mathematical sentences and the other concerning the issue of whether abstract objects exist. The first is a straightforward question of interpretation: What is the

Eric Temple Bell: …Men of Mathematics (1937) and Mathematics, Queen and Servant of Science (1951). He also wrote a history of Fermat’s last theorem, The Last Problem (1961). Although rather fanciful and not always historically accurate, these works, particularly Men of Mathematics, continue to attract a wide readership. Under the pen name of…

Pythagoreanism: Two Pythagorean sects: , the esoteric teachings) and mathēmatikoi (from mathēmatikos, “scientific”), may have occurred at that time. The acousmatics devoted themselves to the observance of rituals and rules and to the interpretation of the sayings of the master; the “mathematics” were concerned with the scientific aspects of Pythagoreanism. Philolaus, who was rather…

Cotton Mather was an American Congregational minister and author, supporter of the old order of the ruling clergy, who became the most celebrated of all New England Puritans. He combined a mystical strain (he believed in the existence of witchcraft) with a modern scientific interest (he supported

Increase Mather was a Boston Congregational minister, author, and educator, who was a determining influence in the councils of New England during the crucial period when leadership passed into the hands of the first native-born generation. He was the son of Richard Mather, son-in-law of John

John C. Mather is an American physicist, who was corecipient, with George F. Smoot, of the 2006 Nobel Prize for Physics for discoveries supporting the big-bang model. Mather studied physics at Swarthmore University (B.S., 1968) and the University of California at Berkeley (Ph.D., 1974). He later

Richard Mather was an English-born American Congregational minister, father of Increase Mather and three other Puritan ministers. After joining the Great Migration of Puritans from England to New England (1635), he was elected “teacher” minister at Dorchester, Mass., and became locally celebrated

National Park Service: Establishment of the NPS: In 1914 Stephen Mather, a wealthy businessman, wrote the secretary of the interior about the poor condition of parks he had visited that summer in the Sierra Nevada. The secretary suggested that Mather work to improve the system by joining the department in Washington, D.C. Two years…

Matheran, hill station (resort town) in western Maharashtra state, west-central India. It is located at an elevation of about 2,625 feet (800 metres) on the western side of the Western Ghats range, about 28 miles (45 km) east of Mumbai (formerly Bombay). Matheran was first frequented in the