Laozi or Lao-tzu Vlau-’dzM (fl. 6th century bc, China) First philoso¬ pher of Chinese Daoism. He is traditionally named as the author of the Daodejing, though modern scholars hold that the work had more than one author. Legends about his life abound, but little or no certain information survives. The historical Laozi, if he existed, may have been a scholar and caretaker of sacred books at the royal court of the Zhou dynasty. Accord¬ ing to legend, he was carried 72 years in his mother’s womb, and he met Confucius as a young man. He is venerated as a philosopher by the Con- fucianists, as a saint or god by the common people of China, and as a divinity and the representative of the dao by Daoists.
laparoscopy \,la-p3-'ras-k9-pe\ or peritoneoscopy \,per-3t- 3 n-,e- 'as-k9-pe\ Procedure for inspecting the abdominal cavity using a laparo¬ scope; also surgery requiring use of a laparoscope. Laparoscopes use fibre-optic lights and small video cameras to show tissues and organs on a monitor. Laparoscopic surgical procedures include gallbladder, appen¬ dix, and tumour removal; tubal ligation; and hysterectomy. After carbon dioxide is pumped in to expand the space for the instruments, small inci¬ sions are made and the laparoscope and instruments inserted. Less inva¬ sive than traditional (open) surgery, laparoscopy reduces postoperative pain, recovery time, and length of hospital stay.
Lapidus Ma-'pi-dosN, Morris (b. Nov. 25, 1902, Odessa, Russia—d. Jan. 18, 2001, Miami Beach, Fla., U.S.) Ukrainian-born U.S. architect. He came to the U.S. as a child and grew up in New York City. After earn¬ ing an architectural degree, he worked in New York architectural firms from 1928 to 1942. In 1942 Lapidus moved to Miami Beach, where he ran his own firm until 1986. He designed numerous buildings there in the Art Deco style, including the Fontainebleau and Eden Roc hotels. He designed over 200 hotels worldwide as well as numerous office buildings, shopping centres, and hospitals.
lapis lazuli N.la-pss-'la-zo-leN Semiprecious stone valued for its deep- blue colour caused by the presence of the mineral lazurite, which is the source of the pigment ultramarine. Lapis lazuli is not a single mineral but an intergrowth lazurite with calcite, pyroxene, and commonly small grains of pyrite. The most important mines are in Afghanistan and Chile. Much of what is sold as lapis is an artificially dyed jasper from Germany that shows colourless specks of clear, crystallized quartz and never the gold¬ like flecks of pyrite that are characteristic of lapis lazuli.
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© 2006 Encyclopaedia Britannica, Inc.
1076 I Lapita culture ► Largo Caballero
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Lapita culture Ua-'pe-toX Cultural complex of what were presumably the original human settlers of Melanesia, much of Polynesia, and parts of Micronesia. The Lapita people were originally from New Guinea or some other region of Austronesia. Seaborne explorers, they spread to the Solomon Islands (c. 1600 bc), then to Fiji, Tonga and the rest of western Polynesia (c. 1000 bc), and finally to Micronesia (c. 500 bc). They are known principally on the basis of the remains of their fired pottery, which was first extensively investigated at the site of Lapita in New Caledonia. They appear to have subsisted largely by fishing but may also have prac¬ ticed some domestic agriculture and animal husbandry.
Laplace Uo-'plasX, Pierre-Simon, marquis de (b. March 23,1749, Beaumount-en-Auge, France—d. March 5, 1827, Paris) French mathema¬ tician, astronomer, and physicist. He is best known for his investigations into the stability of the solar system and the theory of magnetic, electri¬ cal, and heat wave propagation. In his major lifework he applied New¬ tonian gravitational theory to the solar system to explain deviations of the planets from the orbits predicted by the theory (1773). Newton believed that only divine intervention could explain the solar system’s equilibrium, but Laplace established a mathematical basis for it, the most important advance in physical astronomy since Newton. He continued to work on elucidating planetary perturbations through the 1780s. A work published in 1796 included his nebular hypothesis, which attributed the origin of the solar system to the cooling and contracting of a gaseous nebula, a theory that strongly influenced future thought on planetary origins. See also Laplace transform; Laplace's equation.
Laplace transform In mathematics, an integral transform useful in solving differential equations. The Laplace transform of a function is found by integrating the product of that function and the exponential function e~ pt over the interval from zero to infinity. The Laplace transform’s appli¬ cations include solving linear differential equations with constant coeffi¬ cients and solving boundary value problems, which arise in calculations relating to physical systems.
Laplace's equation In mathematics, a partial differential equation whose solutions (harmonic functions) are useful in investigating physical problems in three dimensions involving gravitational, electrical, and mag¬ netic fields, and certain types of fluid motion. Named for Pierre-Simon Laplace, the equation states that the sum of the second partial derivatives (the Laplace operator, or Laplacian) of an unknown function is zero. It can apply to functions of two or three variables, and can be written in terms of a differential operator as A F = 0, where A is the Laplace operator.
Lapland Region, northern Europe.
Located within the Arctic Circle, it stretches across northern Norway,
Sweden, and Finland and into Rus¬ sia’s Kola Peninsula. Occupying an area of 150,000 sq mi (389,000 sq km), it is bounded by the Norwegian Sea, the Barents Sea, and the White Sea. Since it straddles several national borders, it does not exist as any unified administrative entity. It is named for the Sami (Lapp) people, who have inhabited the region for several thousand years. Those still practicing reindeer herding have lib¬ erty of movement across national boundaries. Industries include min¬ ing and fishing.
lapwing Any of numerous bird species of the plover family (Charadriidae), especially the Eur¬ asian lapwing (Vanellus vanellus) of farmlands and grassy plains. Lap¬ wings are about 12 in. (30 cm) long and have broad, rounded wings. Sev¬ eral species have crests, and some have wing spurs (sharp projections at the bend of the wing). The Eurasian lapwing is green-glossed black above with white cheeks, black throat and breast, white belly, and
white tail with a black band. About 24 other species are found in South America, Africa, southern Asia, Malaya, and Australia.
L'Aquila Vla-kwe-la\ City (pop., 2001 prelim.: 63,121), capital of the Abruzzi region, central Italy. The area was settled by the Sabini, an ancient Italic tribe, and the city was founded c. 1240. After being ruled by the Kingdom of Naples, it became part of the Kingdom of Italy in 1861. Located near the mountains of Gran Sasso d’ltalia, it is a skiing centre and summer resort. Historic sites include a 14th-century cathedral and a 16th-century castle.
Laramide orogeny Vlar-o-.mld-o-'ra-jo-neX Series of mountain¬ building events that affected much of western North America in Late Cre¬ taceous and Early Tertiary time (c. 65 million years ago). The Laramide orogeny originally was believed to mark the Cretaceous-Tertiary bound¬ ary. It is now considered to have consisted of many separate pulses of deformation that varied in intensity and age from place to place. Lara¬ mide rocks, however, were generally created around the Cretaceous- Tertiary time boundary.
larceny See theft
larch Any of about 10-12 species of coniferous trees that make up the genus Larix of the pine family, native to cool temperate and sub-Arctic regions of the Northern Hemisphere. Though the larch has the pyramid shape typical of conifers, it sheds its short, light-green, needlelike leaves in autumn. The most widespread North American larch, the tamarack, or eastern larch (L. laricina ), matures in 100-200 years, may grow 40-100 ft (12-30 m) tall, and has gray to reddish-brown bark. Coarse-grained, strong, hard, and heavy, larch wood is useful in ship construction and for telephone poles, mine timbers, and railroad ties.