Mesa Verde Vma-so-'ver-deV National Park National park, south¬ western Colorado, U.S. It was established in 1906 to preserve prehistoric Indian cliff dwellings. Occupying a high tableland area of 52,085 acres (21,078 hectares), it contains hundreds of pueblo ruins up to 13 centuries old. The most striking are multistoried apartments built under overhang¬ ing cliffs. Cliff Palace, the largest, was excavated in 1909 and contains hundreds of rooms, including kivas, the circular ceremonial chambers of the Pueblo Indians.
mescaline Vmes-ks-linX Hallucinogen, the active principle in the flow¬ ering heads of the peyote cactus. An alkaloid related to epinephrine and nore¬ pinephrine and first isolated in 1896, mescaline is usually extracted from the peyote and purified, but can also be synthesized. When it is taken as a drug, its hallucinogenic effects begin in two to three hours and may last over 12 hours; the hallucinations vary greatly among individuals and from one time to the next, but they are usually visual rather than auditory. Side effects include nausea and vomiting.
Meselson Yme-sol-sonV Matthew Stanley (b. May 24, 1930, Den¬ ver, Colo., U.S.) U.S. molecular biologist. He received his Ph.D. from California Institute of Technology; from 1964 he taught at Harvard Uni¬ versity. He conducted research with Franklin Stahl that showed that, dur¬ ing cell division, DNA splits into its two component strands, each of which acquires a newly synthesized partner strand before passing into one of the daughter cells.
Meshed See Mashhad
Meslamtaea \,mes-lam-'te-3\ In Mesopotamian religion, the god of the city of Cuthah in Akkad. The name of his temple, Emeslam or Meslam (“luxuriant mesu tree”), may indicate that he was originally a tree god. Later he was identified as the ruler of the netherworld and the spouse of its queen, Ereshkigal. He was the son of Enlil, god of the atmosphere, and Ninlil, goddess of grain, and he often appears in hymns as a warrior. He sometimes visited terrible plagues on his people and their herds.
Mesmer Vmez-msrV Franz Anton (b. May 23, 1734, Iznang, Swabia—d. March 5, 1815, Meersburg) German physician. After study¬ ing medicine at the University of Vienna, he developed his theory of “ani¬ mal magnetism,” which held that an invisible fluid in the body acted according to the laws of magnetism and that disease was caused by obstacles to the free circulation of this fluid. In Mesmer’s view, harmony
L_
M
N
© 2006 Encyclopaedia Britannica, Inc.
1242 I Mesoamerican civilization ► Messerschmltt 109
L_
N
could be restored by inducing “crises” (trance states often ending in delirium or convulsions). In the 1770s he carried out dramatic demon¬ strations of his ability to “mesmerize” his patients using magnetized objects. Accused by Viennese physicians of fraud, he left Austria and settled in Paris (1778), where he also came under fire from the medical establishment. Though his theories were eventually discredited, his abil¬ ity to induce trance states in his patients made him the forerunner of the modern use of hypnosis.
Mesoamerican civilization Complex of aboriginal cultures that developed in parts of Mexico and Central America before the Spanish conquest in the 16th century. This civilization and the Andean civilization in South America constituted a New World counterpart to those of ancient Egypt, Mesopotamia, and China. Humans have been present in Mesoamerica from as early as 21,000 bc; a shift from hunting and gath¬ ering to agriculture, which began c. 7000 bc as the climate warmed with the end of the Ice Age, was completed by c. 1500 bc. The earliest great Mesoamerican civilization, the Olmec, dates to c. 1150 bc. The Middle Formative period (900-300 bc) was a time of increased cultural region¬ alism and the rise of the Zapotec people. Civilizations of the Late Forma¬ tive and Classic periods (lasting until c. ad 900) include the Maya and the civilization centred at Teotihuacan; later societies include the Toltec and the Aztec. See also Chichen Itza; Mixtec; Monte Alban; Nahua; Nahuatl language; Tenochtitlan; Tikal.
Mesoamerican religions Religions of the pre-Columbian cultures of Mexico and Central America, notably the Olmec, Maya, Toltec, and Aztec. All religions of Mesoamerica were polytheistic. The gods had to be constantly propitiated with offerings and sacrifices. The religions also shared a belief in a multilevel universe that had gone through five cre¬ ations and four destructions by the time of the Spanish conquest. Mesoamerican religions heavily emphasized the astral bodies, particularly the sun, the moon, and Venus, and the observations of their movements by astronomer-priests were extraordinarily detailed and accurate. The Aztecs approached the supernatural through a complex calendar of cer¬ emonies that included songs, dances, acts of self-mortification, and human sacrifices performed by a professional priesthood, in the belief that the welfare of the universe depended on offerings of blood and hearts as nourishment for the sun. The Mayan religion likewise called for human sacrifices, though on a smaller scale. Information on the astronomical cal¬ culations, divination, and ritual of the Mayan priests has been gathered from the Maya Codices. See also Mesoamerican civilization.
Mesolithic \,me-z3-'li-thik\ Period or Middle Stone Age Ancient technological and cultural stage (c. 8000-2700 bc) between the Paleolithic and Neolithic periods in northwestern Europe. Mesolithic hunters, using a tool kit of chipped and polished stone together with bone, antler, and wooden tools, achieved a greater efficiency than their predecessors and were able to exploit a wider range of animal and vegetable food sources. Immigrant Neolithic farmers probably absorbed many indigenous Mesolithic hunters and fishers. There is no direct counterpart to the Mesolithic outside Europe, and the term is no longer used to reflect a hypothetical worldwide sequence of sociocultural evolution.
meson \'me-,zan\ Any member of a family of subatomic particles com¬ posed of a quark and an antiquark (see antimatter). Mesons are sensitive to the strong force, have integral spin, and vary widely in mass. Though unstable, many mesons last a few billionths of a second, long enough to be observed with particle detectors. They are readily produced in the col¬ lisions of high-energy subatomic particles (e.g., in cosmic rays).
Mesopotamia Region between the Tigris and Euphrates rivers in the Middle East, constituting the greater part of modern Iraq. The region’s location and fertility gave rise to settlements from c. 10,000 bc, and it became the cradle of some of the world’s earliest civilizations and the birthplace of writing. It was first settled by the Sumerians, who were suc¬ ceeded by the Akkadians and later by the Babylonians. Successive peoples came to dominate the region until the rise of the Persian Achaemenian dynasty in the 6th century bc. The Achaemenids were overthrown by Alexander the Great in the early 4th century bc, and Mesopotamia was ruled by the Seleucid dynasty from c. 312 bc until the mid-2nd century bc, when it became part of the Parthian empire. In the 7th century ad the region was conquered by Muslim Arabs. The region’s importance declined after the Mongol invasion in 1258. Rule by the Ottoman Empire over most of the region began in the 16th century. The area became a British mandate in 1920; the following year Iraq was established there.
Mesopotamian religions V.me-so-po-'ta-me-onV Religious beliefs and practices of the Sumerians and Akkadians, and later of their succes¬ sors, the Babylonians and Assyrians, who inhabited ancient Mesopotamia. The deities of Sumer were usually associated with aspects of nature, such as fertility of the fields and livestock. The gods of Assyria and Babylonia, rather than displacing those of Sumer and Akkad, were gradually assimi¬ lated into the older system. Among the most important of the many Meso¬ potamian gods were Anu, the god of heaven; Enki, the god of water; and Enlil, the earth god. Deities were often associated with particular cities. Astral deities such as Shamash and Sin were also worshiped. The Meso¬ potamians were skilled astrologers who studied the movements of the heavenly bodies. Priests also determined the will of the gods through the observation of omens, especially by reading the entrails of sacrificed ani¬ mals. The king functioned as the chief priest, presiding at the new-year festival held in spring, when the kingship was renewed and the triumph of the deity over the powers of chaos was celebrated.