Metaxas \,met-ak-'sas\ / loannis (b. April 12, 1871, Ithaca, Greece—d. Jan. 29, 1941, Athens) Greek general and premier (1936-41). He rose in the Greek army to become chief of staff (1913-17). An ardent monarchist, he left Greece when King Constantine I was deposed in 1917, but he returned in 1920. After the monarchy’s fall in 1923, he led an opposition ultraroyalist party until the monarchy was restored in 1935. He was appointed premier in 1936 and, with royal authority, established a dictatorship. He suppressed political opposition, carried out some ben¬ eficial economic and social reforms, and brought a united country into the Western alliance in World War II.
Metchnikoff \ , mech-ni- 1 kof\, Elie orig. Ilya llich Mechnikov (b.
May 16, 1845, near Kharkov,
Ukraine, Russian Empire—d. July 16, 1916, Paiis, France) Russian zoologist and microbiologist. In 1888 Louis Pasteur offered him a post at the Pasteur Institute, and he suc¬ ceeded Pasteur as director in 1895.
Working with starfish, he discovered amoebalike cells in their systems that engulf foreign bodies such as bacteria. He established that phago¬ cytes (as he named these cells, using the Greek for “devouring cells”) are the first line of defense against acute infection in most animals. This phe¬ nomenon, now known as phagocyto¬ sis, is fundamental to immunology.
He shared a 1908 Nobel Prize with Paul Ehrlich.
metempsychosis See reincarna¬ tion
meteor or shooting star or falling star Streak of light in the sky
that results when a particle or small chunk of stony or metallic matter from space enters Earth’s atmosphere and is vapourized by friction. The term is sometimes applied to the falling object itself, properly called a meteoroid. Most meteoroids, traveling at five times the speed of sound or more, burn up in the upper atmosphere, but a large one may survive its fiery plunge and reach the surface as a solid body (meteorite). See also METEOR SHOWER.
meteor shower Entry into Earth’s atmosphere of multiple meteoroids (see meteor), traveling in parallel paths, usually spread over several hours or days. Most meteor showers come from matter released during passage of a comet close to the Sun, and they recur annually as Earth crosses the comet’s orbital path. Meteor showers are usually named for a constella¬ tion (e.g., Leonid for Leo) or star in their direction of origin. Most show¬ ers are visible as a few dozen meteors per hour, but occasionally Earth crosses an especially dense concentration of meteoroids, as in the great Leonid meteor shower of 1833, in which hundreds of thousands of mete¬ ors were seen in one night all over North America.
meteorite Any interplanetary particle or chunk of stony or metallic matter (meteoroid) that survives passage through Earth’s atmosphere and strikes the ground or that reaches the surface of another planet or moon. On Earth the speed of entry—at least 7 mi/second (11 km/second)— generates enough friction with the air to vaporize part or all of the mete¬ oroid and produce a streak of light (meteor). Though vast numbers of meteoroids enter Earth’s atmosphere each year, only a few hundred reach the ground.
meteorite crater Depression that results from the impact of a meteor¬ ite with a solid object in space.
Impact craters have been discovered on Earth, the Moon, Mars, other planets and satellites, and asteroids; they probably occur on unprotected surfaces of similar bodies throughout the universe. Impact craters are much less common on Earth than on the Moon, partly because friction burns up most of the smaller bodies that enter Earth’s atmosphere. Thus, any craters formed on Earth’s sur¬ face tend to be larger than the aver¬ age size of all entering meteorites.
meteoritics X.me-te-o-'ri-tiksX Study of the chemistry and mineral¬ ogy of meteorite samples that have been collected on Earth and of mete¬ ors as they pass through Earth’s atmosphere. These studies provide information about the age of meteorites, the conditions under which they formed, where they come from, and the geological history of their bod¬ ies of origin, including comets, asteroids. Mars, and the Moon. The field of study is especially important for understanding the early history and evolution of the solar system.
meteorology Scientific study of atmospheric phenomena, particularly of the troposphere and lower stratosphere. Meteorology entails the system¬ atic study of weather and its causes, and provides the basis for weather FORECASTING. See also CLIMATOLOGY.
methadone Vme-tho-.donV Organic compound, a potent synthetic nar¬ cotic drug, the most effective form of treatment for addiction to heroin and other narcotics (see drug addiction). It has been widely used in heroin- addiction programs in the U.S. since the 1960s. Though addictive itself, it is easier to stop using than heroin. It also causes no euphoric effects and does not lead to development of tolerance, so increasing doses are not required. A person taking a daily maintenance dose does not experience either heroin withdrawal symptoms or a heroin rush from any attempt to resume heroin, so heroin’s psychological hold on the user can be broken.
methanal See formaldehyde
methane or marsh gas Organic compound, chemical formula CH 4 , colourless, odourless gas that occurs in natural gas (called firedamp in coal mines) and from bacterial decomposition of vegetation in the absence of oxygen (including in the rumens of cattle and other ruminants and in the gut of termites). The simplest member of the paraffin hydrocarbons, methane burns readily, forming carbon dioxide and water if supplied with enough oxygen for complete combustion or carbon monoxide if the oxy¬ gen is insufficient. Mixtures of 5-14% methane in air are explosive and have caused many mine disasters. The chief source of methane is natural gas, but it can also be produced from coal. Abundant, cheap, and clean, methane is used widely as a fuel in homes, commercial establishments, and factories; as a safety measure, it is mixed with trace amounts of an odorant to allow its detection. It is also a raw material for many indus¬ trial materials, including fertilizers, explosives, chloroform, carbon tetra¬ chloride, and carbon black, and is the principal source of methanol.
methanol or methyl alcohol or wood alcohol Simplest of the alcohols, chemical formula CH 3 OH. Once produced by destructive dis¬ tillation of wood, it is now usually made from the methane in natural gas. Methanol is an important industrial material; its derivatives are used in great quantities for making a vast number of compounds, among them many important synthetic dyes, resins, drugs, and perfumes. It is also used in automotive antifreezes, in rocket fuels, and as a solvent. It is flammable
Elie Metchnikoff.
H. ROGER-VIOLLET
Meteorite craters on the surface of the Moon, photographed by Lunar Orbiter IV
COURTESY OF NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
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and explosive. A clean-burning fuel, it may substitute (at least in part) for gasoline. It is also used for denaturation of ethanol. A violent poison, it causes blindness and eventually death when drunk.
methionine Vmo-'thl-o-.nenN SuLFUR-containing essential amino acid, present in many common proteins, particularly egg albumin. It is used in pharmaceuticals, in enriched foods, and as a nutritional supplement and feed additive.
Method acting See Stanislavsky method
Methodism Protestant religious movement originated by John Wesley in 18th-century England. Wesley, an Anglican clergyman, underwent an epiphany in 1738 in which he felt an assurance of personal salvation, and he soon began open-air preaching. Methodism began as a movement to revitalize the Church of England and did not formally break with the church until 1795. The Methodists’ well-organized system of church gov¬ ernment combined a strong central authority with effective local organi¬ zation and the employment of lay preachers. Especially successful among the working class in industrial areas, the movement expanded rapidly in the 19th century. The Methodist Episcopal Church was founded in the U.S. in 1784, and Methodist circuit riders won many followers on the frontier. British and U.S. missionaries have since spread Methodism throughout the world. Methodist doctrine emphasizes the power of the Holy Spirit, the need for a personal relationship with God, simplicity of worship, and concern for the underprivileged.