• Łukasiński, Walerian (Polish rebel)

    Poland: Early Russian rule: Nevertheless, its leader, Major Walerian Łukasiński, became a national martyr when he was thrown into prison, where he languished half-forgotten for more than 40 years until his death. Other conspiracies of more radical character began to spread. The economy of the kingdom, however, developed, and its finances were put…

  • Lukasz, Paul (Hungarian actor)
  • Luke Skywalker (fictional character)

    Darth Vader: …of the young rebel hero Luke Skywalker, and at the climax of the next film, Star Wars: Episode VI—Return of the Jedi (1983), Vader turns against the Empire to save his son’s life, sacrificing his own in the process.

  • Luke the Evangelist, Saint (biblical author)

    St. Luke ; feast day October 18) was, in Christian tradition, the author of the Gospel According to Luke and the Acts of the Apostles, a companion of St. Paul the Apostle, and the most literary of the New Testament writers. Information about his life is scanty. Tradition based on references in the

  • Luke, Gospel According to (biblical literature)

    Gospel According to Luke, third of the four New Testament Gospels (narratives recounting the life and death of Jesus Christ) and, with The Gospels According to Mark and Matthew, one of the three Synoptic Gospels (i.e., those presenting a common view). It is traditionally credited to St. Luke, “the

  • Luke, Sir Samuel (English military officer)

    Samuel Butler: …passed into the service of Sir Samuel Luke, a rigid Presbyterian, a colonel in the Parliamentary army, and scoutmaster general for Bedfordshire. In his service Butler undoubtedly had firsthand opportunity to study some of the fanatics who attached themselves to the Puritan army and whose antics were to form the…

  • Luke, St. (biblical author)

    St. Luke ; feast day October 18) was, in Christian tradition, the author of the Gospel According to Luke and the Acts of the Apostles, a companion of St. Paul the Apostle, and the most literary of the New Testament writers. Information about his life is scanty. Tradition based on references in the

  • Lukens, Mount (mountain, Los Angeles, California, United States)

    Los Angeles: City site: …beach community of Venice to Mount Lukens, which rises above 5,100 feet (1,550 metres). The city started in 1781 as a tiny village of 28 square miles (73 square km) but expanded greatly through a series of annexations when it first established an ironclad legal monopoly over the Los Angeles…

  • Lukin, Lionel (British engineer)

    Lionel Lukin was a pioneer in the construction of the modern “unsinkable” lifeboat. While he was working as a London coachbuilder, Lukin began experimenting with a Norwegian yawl in 1784, testing his alterations in the River Thames. In 1785 he patented his method of constructing small boats that

  • Luks, George (American artist)

    George Luks was one of a group of American painters popularly known as the Ashcan school because of their realistic treatment of urban scenes. Born in a coal-mining region of north-central Pennsylvania, Luks studied first at the Pennsylvania Academy of the Fine Arts, Philadelphia, and later in

  • Luks, George Benjamin (American artist)

    George Luks was one of a group of American painters popularly known as the Ashcan school because of their realistic treatment of urban scenes. Born in a coal-mining region of north-central Pennsylvania, Luks studied first at the Pennsylvania Academy of the Fine Arts, Philadelphia, and later in

  • Luksic, Igor (prime minister of Montenegro)

    Montenegro: Independence of Montenegro: Ðjukanović’s finance minister, Igor Luksic, succeeded him as prime minister, and Luksic continued his predecessor’s efforts to achieve greater integration with the rest of Europe and with the West.

  • Lukuas-Andreas (Cyrenian king-messiah)

    Judaism: Judaism under Roman rule: …revolt under a Cyrenian king-messiah, Lukuas-Andreas, aimed at freeing Palestine from Roman rule. In 132–135 the same spirit of freedom inspired another uprising, the Second Jewish Revolt, led by Bar Kokhba, who may have had the support of the greatest rabbi of the time, Akiba ben Joseph (40–c. 135). The…

  • Lukuga (Democratic Republic of the Congo)

    Kalemi, town, southeastern Democratic Republic of the Congo, central Africa. It is a port on the west bank of Lake Tanganyika where the Lukuga River exits, and it has an airport and rail links to Lubumbashi and Kananga. In 1915 Kalemi, then the site of a British-Belgian military base, was chosen as

  • Lukuga River (river, Democratic Republic of the Congo)

    Lukuga River, tributary of the Lualaba River in eastern Congo (Kinshasa). It issues from the western shore of Lake Tanganyika at Kalemie, Congo, and flows 200 miles (320 km) west to the Lualaba River 25 miles (40 km) north of Kabalo. There are low-grade coal deposits along its tributaries, north of

  • Lukyanenko, Levko (Ukrainian statesman)

    Ukraine: Ukraine on the path to independence: Headed by Levko Lukyanenko, with Vyacheslav Chornovil as an important leader, the Ukrainian Helsinki Union had branches in all regions of Ukraine by 1989.

  • Lukyanenko, Sergey (Russian author)

    Sergey Lukyanenko is a Russian author of science fiction and fantasy, best known for his six-volume Night Watch series, a seminal body of work in the genre of urban fantasy. Lukyanenko was the son of a Russian Ukrainian father and a Tatar mother. He completed his secondary education in the town of

  • Lukyanenko, Sergey Vasilyevich (Russian author)

    Sergey Lukyanenko is a Russian author of science fiction and fantasy, best known for his six-volume Night Watch series, a seminal body of work in the genre of urban fantasy. Lukyanenko was the son of a Russian Ukrainian father and a Tatar mother. He completed his secondary education in the town of

  • Lukyanov, Anatoly (Soviet political leader)

    Soviet Union: Political restructuring: …group under the chairmanship of Anatoly Lukyanov. The latter proposed a two-stage approach to the election of a Supreme Soviet. Legal authority was to be vested in local soviets, but the relationship between the party and the soviets was left vague. Burlatsky proposed direct elections of the Supreme Soviet, president,…

  • Lula (president of Brazil)

    Luiz Inácio Lula da Silva is a Brazilian politician who served as president of Brazil (2003–11; 2023– ). Born in Pernambuco state to sharecropping parents, Luiz Inácio da Silva (“Lula” was a nickname that he later added to his legal name) worked as a shoe-shine boy, street vendor, and factory

  • Lula da Silva, Luiz Inácio (president of Brazil)

    Luiz Inácio Lula da Silva is a Brazilian politician who served as president of Brazil (2003–11; 2023– ). Born in Pernambuco state to sharecropping parents, Luiz Inácio da Silva (“Lula” was a nickname that he later added to his legal name) worked as a shoe-shine boy, street vendor, and factory

  • LULAC (American organization)

    League of United Latin American Citizens (LULAC), one of the oldest and largest Latino organizations in the United States. Since its founding in 1929, it has focused on education, employment, and civil rights for Hispanics. The League of United Latin American Citizens (LULAC) was formally

  • Lulach (king of Scotland)

    Macbeth: His followers installed his stepson, Lulach, as king; when Lulach was killed on March 17, 1058, Malcolm III was left supreme in Scotland.

  • Lule River (river, Sweden)

    Lule River, river in the län (county) of Norrbotten, northern Sweden. It flows southeast from the Norwegian border for 280 miles (450 km) to the Gulf of Bothnia at Luleå. Between the river’s two main headstreams, the Stora (Big) Lule and the Lilla (Little) Lule, is Mount Sarek National Park, rising

  • Lule, Yusufu (president of Uganda)

    Idi Amin: …was succeeded as president by Yusufu Lule two days later. After escaping first to Libya, Amin finally settled in Saudi Arabia.

  • Luleå (Sweden)

    Luleå, city and seaport, seat of Norrbotten län (county), northern Sweden. The city lies at the mouth of the Lule River, where it enters the Gulf of Bothnia. Gustavus II Adolphus founded the town in 1621, 7 miles (11 km) farther up the river; it was moved to its present site in 1649. In 1887 it was

  • Luleälv (river, Sweden)

    Lule River, river in the län (county) of Norrbotten, northern Sweden. It flows southeast from the Norwegian border for 280 miles (450 km) to the Gulf of Bothnia at Luleå. Between the river’s two main headstreams, the Stora (Big) Lule and the Lilla (Little) Lule, is Mount Sarek National Park, rising

  • Luli (king of Phoenicia)

    Luli was a Phoenician king of the cities of Tyre and Sidon who rebelled against Assyrian rule following the death of the Assyrian king Sargon II. Concurrent with the insurrection of Babylon under Merodach-Baladan, Luli joined with Shabaka of Egypt and Hezekiah of Judah in a revolt against

  • Lüli yuanyuan (Chinese compendium)

    Mei Juecheng: …of the chief editors of Lüli yuanyuan (c. 1723; “Source of Mathematical Harmonics and Astronomy”), a compendium on music, mathematics, and astronomy. Unlike earlier such endeavours, this was purely a work of Chinese authorship; Jesuits were not involved in the compilation. The Lüli yuanyuan reapportioned credit to Chinese scholars for…

  • Lüliang Mountains (mountains, China)

    Lüliang Mountains, range in Shanxi province, China. The name Lüliang Mountains generally refers to the whole system of ranges in the west and southwest of Shanxi, separating the north-south section of the Huang He (Yellow River) to the west from the valley of its tributary, the Fen River to the

  • Lüliang Shan (mountains, China)

    Lüliang Mountains, range in Shanxi province, China. The name Lüliang Mountains generally refers to the whole system of ranges in the west and southwest of Shanxi, separating the north-south section of the Huang He (Yellow River) to the west from the valley of its tributary, the Fen River to the

  • Luling (China)

    Ji’an, city, west-central Jiangxi sheng (province), southeastern China. Ji’an is situated on the west bank of the Gan River, at the head of navigation for small steamboats from Nanchang. The city is a highway centre located on the north-south route up the Gan valley at the point where it is joined

  • Lull, Ramón (Catalan mystic)

    Ramon Llull was a Catalan mystic and poet whose writings helped to develop the Romance Catalan language and widely influenced Neoplatonic mysticism throughout medieval and 17th-century Europe. He is best known in the history of ideas as the inventor of an “art of finding truth” (ars inveniendi

  • Lullaby (novel by Palahniuk)

    Chuck Palahniuk: Other novels: His next three books—Lullaby (2002), Diary (2003), and Haunted (2005)—were horror novels. In an interview with El País in 2022, Palahniuk described this shift as a response to the

  • Lullaby (work by Gershwin)

    George Gershwin: Early career and influences: …his first “serious” work, the Lullaby for string quartet. A study in harmony that Gershwin composed as an exercise for Kilenyi, Lullaby’s delicate beauty transcends its academic origins. Ira Gershwin published the work several years after George’s death, and it has gone on to become a favourite with string quartets…

  • Lulli, Folco (Italian actor)

    The Wages of Fear: Cast:

  • Lulli, Giovanni Battista (French composer)

    Jean-Baptiste Lully was an Italian-born French court and operatic composer who from 1662 completely controlled French court music and whose style of composition was imitated throughout Europe. Born of Italian parents, Lully gallicized his name when he became a naturalized Frenchman. His early

  • Lullubi (people)

    Lullubi, ancient group of tribes that inhabited the Sherizor plain in the Zagros Mountains of western Iran. A warlike people, they were especially active during the reign of the Akkadian king Naram-Sin (reigned c. 2254–c. 2218 bc) and at the end of the dynasty of Akkad (2334–2154 bc). The Lullubi

  • Lully, Jean-Baptiste (French composer)

    Jean-Baptiste Lully was an Italian-born French court and operatic composer who from 1662 completely controlled French court music and whose style of composition was imitated throughout Europe. Born of Italian parents, Lully gallicized his name when he became a naturalized Frenchman. His early

  • Lully, Raymond (Catalan mystic)

    Ramon Llull was a Catalan mystic and poet whose writings helped to develop the Romance Catalan language and widely influenced Neoplatonic mysticism throughout medieval and 17th-century Europe. He is best known in the history of ideas as the inventor of an “art of finding truth” (ars inveniendi

  • Lulonga River (river, Democratic Republic of the Congo)

    Lulonga River, stream formed by the union of the Lopori and the Maringa rivers near Basankusu in north-central Congo (Kinshasa), central Africa. It flows 125 miles (200 km) west and southwest to its confluence with the Congo River north of Lulonga. It is navigable for steamboats along its entire

  • Lulu (fictional character)

    Lulu, fictional character, an amoral femme fatale who is the protagonist of German dramatist Frank Wedekind’s plays Der Erdgeist (1895; Earth Spirit) and Die Büchse der Pandora (1904; Pandora’s Box). German director G.W. Pabst’s silent film of Die Büchse der Pandora (1929), starring the American

  • Lulu (album by Reed and Metallica)

    Metallica: …the audacious but critically reviled Lulu (2011), a two-disc collection inspired by the plays of German dramatist Frank Wedekind. Hardwired…to Self-Destruct (2016), another two-disc release, was a return to form that won over many critics. Metallica reunited with the San Francisco Symphony in 2019 for two concerts, recorded as S&M2…

  • Lulu (Scottish singer and actress)

    To Sir, with Love: …song, which was performed by Lulu, was an international hit. In 1996 Poitier reprised the role of Thackeray in the television movie To Sir, with Love II.

  • Lulu (opera by Berg)

    Lulu: …Wedekind’s plays in his opera Lulu (1937).

  • Lulu in Hollywood (essays by Brooks)

    Louise Brooks: …intelligent collection of autobiographical essays, Lulu in Hollywood, was published in 1982.

  • Lulu in Marrakech (novel by Johnson)

    Diane Johnson: …the clash of cultures with Lulu in Marrakech (2008), which is set in Morocco. In Lorna Mott Comes Home (2021), a woman returns to the United States after living in France for a number of years.

  • Lulu on the Bridge (film by Auster [1998])

    Paul Auster: …wrote and directed the films Lulu on the Bridge (1998) and The Inner Life of Martin Frost (2007). Having witnessed a friend’s death by lightning as a teenager, he appeared in Act of God (2009), a documentary about lightning-strike survivors. Here and Now: Letters 2008–2011 (2013) is a compilation of…

  • Luluabourg (Democratic Republic of the Congo)

    Kananga, city, south-central Democratic Republic of the Congo, situated just east of the Lulua River, a tributary of the Kasai. It is on road and rail routes to Lubumbashi (southeast) and the Kasai River port of Ilebo (northwest) and has air links to those and other Congolese cities. It was named

  • Lulworthiales (order of fungi)

    fungus: Annotated classification: Order Lulworthiales (incertae sedis; not placed in any subclass) Saprotrophic; ascomata subglobose to pear-shaped, paraphyses absent; asci unitunicate, thin-walled; example genera include Lulworthia and Lindra. Order Meliolales (incertae sedis; not placed in any subclass) Lives on other organisms (biotrophic) in tropical

  • Lum, Nora (American comedian, actress, and rapper)

    Awkwafina is an American comedian, actress, and rapper known for her low raspy voice, explicit comedy raps, and quick delivery of comedic one-liners. After she posted her rap song “My Vag” on YouTube in 2012, her fame steadily rose, and she soon landed parts in such movies as Ocean’s Eight (2018),

  • lumbago (pathology)

    lumbago, pain in the lower (lumbar) portion of the back. Lumbago is considered by health professionals to be an antiquated term that designates nothing more than lower back pain caused by any of a number of underlying conditions. The pain may be mild or severe, acute or chronic, confined to the

  • lumbang tree (plant)

    tung tree: cordata), and lumbang tree (A. trisperma), are decorative and are planted as shade trees or as sources of tung oil in the subtropical and tropical areas of many countries, including the American Deep South, where they grow rapidly under favourable soil conditions.

  • lumbar artery (anatomy)

    human cardiovascular system: The aorta and its principal branches: The lumbar arteries are arranged in four pairs and supply the muscles of the abdominal wall, the skin, the lumbar vertebrae, the spinal cord, and the meninges (spinal-cord coverings).

  • lumbar curve (anatomy)

    vertebral column: …is raised, and (3) a lumbar curve, also anterior, which develops as the child sits and walks. The lumbar curve is a permanent characteristic only of humans and their bipedal forebears, though a temporary lumbar curve appears in other primates in the sitting position. The cervical curve disappears in humans…

  • lumbar nerve (anatomy)

    human nervous system: The spinal cord: … (C), 12 thoracic (T), 5 lumbar (L), 5 sacral (S), and 1 coccygeal (Coc). Spinal nerve roots emerge via intervertebral foramina; lumbar and sacral spinal roots, descending for some distance within the subarachnoid space before reaching the appropriate foramina, produce a group of nerve roots at the conus medullaris known…

  • lumbar plexus (anatomy)

    human nervous system: Lumbar plexus: Spinal nerves from lumbar levels L1–L4 contribute to the formation of the lumbar plexus, which, along with the sacral plexus, provides motor, sensory, and autonomic fibers to gluteal and inguinal regions and to the lower extremities. Lumbar roots are organized into dorsal and…

  • lumbar puncture (medical procedure)

    lumbar puncture, direct aspiration (fluid withdrawal) of cerebrospinal fluid (CSF) through a hollow needle. The needle is inserted in the lower back, usually between the third and fourth lumbar vertebrae, into the subarachnoid space of the spinal cord, where the CSF is located. Lumbar puncture is

  • lumbar vein (anatomy)

    human cardiovascular system: Superior vena cava and its tributaries: …the diaphragm, the right ascending lumbar vein continues upward as the azygous vein, principal tributaries of which are the right intercostal veins, which drain the muscles of the intercostal spaces. It also receives tributaries from the esophagus, lymph nodes, pericardium, and right lung, and it enters into the superior vena…

  • lumbar vertebra (bone anatomy)

    herniated disk: …between the fourth and fifth lumbar vertebrae or between the fifth lumbar and first sacral vertebrae). Treatment, depending on the severity of the condition, may include bed rest, analgesic medication (e.g., aspirin), traction, orthopedic support, and physical therapy or surgical removal of the protruded portion of the disk and fusion…

  • lumber (harvested wood)

    lumber, collective term for harvested wood, whether cut into logs, heavy timbers, or members used in light-frame construction. Lumber is classified as hardwood or softwood. The term often refers specifically to the products derived from logs in a sawmill. Conversion of logs to sawed lumber involves

  • Lumberton (North Carolina, United States)

    Lumberton, city, seat (1788) of Robeson county, southern North Carolina, U.S., on the Lumber (Lumbee) River about 30 miles (50 km) south of Fayetteville. Founded about 1787 by John Willis, an officer of the American Revolution, it began as a shipping point for lumber and naval supplies floated

  • Lumbineris (polychaete genus)

    annelid: Annotated classification: Stauronereis, Lumbineris, Onuphis. Order Orbiniida Sedentary; head pointed or rounded without appendages; proboscis eversible and unarmed; body divided into distinct thorax and abdomen; gills arise dorsally from thoracic region; size, minute to 40 cm; examples of genera: Scoloplos,

  • Lumbini (grove, Nepal)

    Lumbini, grove near the southern border of modern-day Nepal where, according to Buddhist legend, Queen Maha Maya stood and gave birth to the future Buddha while holding onto a branch of a sal tree. There are two references to Lumbini as the birthplace of the Buddha in the Pali scripture, the first

  • Lumbrales de Sá Carneiro, Francisco Manuel (prime minister of Portugal)

    Francisco Sá Carneiro was a Portuguese politician who served as prime minister of Portugal (1979–80). A lawyer by profession, Sá Carneiro was elected to the National Assembly in 1969 but resigned in 1973. After a military coup in April 1974, he founded the Partido Popular Democrático (PPD) and

  • Lumbreras, Luis G. (Peruvian archaeologist)

    pre-Columbian civilizations: The Initial Period: …Formative by the Peruvian archaeologist Luis G. Lumbreras, began with the introduction of pottery. The earliest ceramics have yielded radiocarbon dates of about 1800 bce, although Rowe has suggested that even a date of 2100 bce is plausible. Ceramics from this period have been found on the central coast between…

  • Lumbriculida (oligochaete order)

    annelid: Annotated classification: Order Lumbriculida (earthworms) Male gonopores several segments behind segments containing the testes or, when 2 pairs of testes are present, in more posterior segment; size, minute to 30–40 cm; examples of genera: Haplotaxis, Eisenia, Lumbricus (earthworm),

  • Lumbricus (oligochaete genus)

    annelid: Annotated classification: Eisenia, Lumbricus (earthworm), Megascolides. Order Moniligastrida Male gonopores, 1 or 2 pairs on segment posterior to testes; clitellum 1 cell thick; 4 pairs of setae per segment; size, minute to 3 m; examples of genera: Moniligaster, Drawida.

  • Lumbricus terrestris (earthworm)

    oligochaete: ), Lumbricus terrestris. Oligochaetes are common all over the world. They live in the sea, in fresh water, and in moist soil.

  • Lumbwa (people)

    Kipsikis, largest ethnic group of the Southern Nilotic (Kalenjin) language group. They occupy the highlands around the town of Kericho in southwestern Kenya. Like other Nandi speakers, they originated in the highlands north of Lake Rudolf (Lake Turkana) and moved southward at least 1,000 years ago.

  • Lumbye, H. C. (Danish composer)

    Tivoli: The composer H.C. Lumbye (1810–74) conducted the orchestra at Tivoli for its first 30 years, playing popular Viennese dance music as well as his own compositions. Bombing in 1944 destroyed many park buildings, including the old concert hall; a new concert hall, seating 2,000, was opened in…

  • lumen (anatomy)

    human respiratory system: The larynx: …vocal cords span the laryngeal lumen. They correspond to elastic ligaments attached anteriorly in the angle of the thyroid shield and posteriorly to a pair of small pyramidal pieces of cartilage, the arytenoid cartilages. The vocal ligaments are part of a tube, resembling an organ pipe, made of elastic tissue.…

  • lumen (unit of energy measurement)

    lumen, unit of luminous flux, or amount of light, defined as the amount streaming outward through one steradian (a unit of solid angle, part of the volume of space illuminated by a light source) from a uniform point source having an intensity of one candela. The lumen is used in calculations

  • Lumen Gentium (Roman Catholicism)

    Christianity: Fourth transition, from 1950: …Constitution on the Church” (Lumen Gentium; “Light of the Nations”), which insisted upon evangelization but presented a larger understanding of God’s grace for those outside the church, and urged missionaries to pursue dialogue.

  • Lumet, Sidney (American director)

    Sidney Lumet was an American film director who was noted for his psychological dramas, which typically featured characters wrestling with moral or emotional conflicts involving betrayal, corruption, or disillusionment. He was also known for eliciting strong performances from his cast members. (Read

  • Lumi Labs (American company)

    Marissa Mayer: In 2018 Mayer cofounded Lumi Labs, which was involved in “building consumer applications enabled by artificial intelligence.” The company was renamed Sunshine in 2020, and that year it released its first product, Sunshine Contacts, an app for managing contact information.

  • Lumière brothers (French inventors)

    Lumière brothers, were French inventors and pioneer manufacturers of photographic equipment who devised an early motion-picture camera and projector called the Cinématographe (“cinema” is derived from this name). Auguste Lumière (b. October 19, 1862, Besançon, France—d. April 10, 1954, Lyon) and

  • Lumière, Auguste (French inventor)

    Lumière brothers: …to Lyon set Louis and Auguste to work on the problem of combining animation with projection. Louis found the solution, which was patented in 1895. At that time they attached less importance to this invention than to improvements they had made simultaneously in colour photography. But on December 28, 1895,…

  • Lumière, Louis (French inventor)

    Lumière brothers: Louis worked on the problem of commercially satisfactory development of film; at 18 he had succeeded so well that with his father’s financial aid he opened a factory for producing photographic plates, which gained immediate success. By 1894 the Lumières were producing some 15 million…

  • Lumières de Pointe-Noire (memoir by Mabanckou)

    Alain Mabanckou: Nonfiction and translations: …and Lumières de Pointe-Noire (2013; The Lights of Pointe-Noire), described by one critic as “a dazzling meditation on homecoming and belonging.” Le Sanglot de l’homme noir (2012; The Tears of the Black Man) is a collection of literary criticism.

  • Lumières, siècle de (European history)

    Enlightenment, a European intellectual movement of the 17th and 18th centuries in which ideas concerning God, reason, nature, and humanity were synthesized into a worldview that gained wide assent in the West and that instigated revolutionary developments in art, philosophy, and politics. Central

  • luminaire (lighting)

    luminaire, Complete lighting unit, consisting of one or more lamps (bulbs or tubes that emit light), along with the socket and other parts that hold the lamp in place and protect it, wiring that connects the lamp to a power source, and a reflector that helps direct and distribute the light.

  • luminance (physics)

    colour: Tristimulus measurement and chromaticity diagrams: …their different Y values (luminance, or visually perceived brightness).

  • luminance signal (electronics)

    television: Basic principles of compatible colour: The NTSC system: …amplitude modulated by (1) the luminance signal, to represent changes in the intended luminance, and (2) the chrominance subcarrier, which in turn is amplitude modulated to represent changes in the intended saturation and phase modulated to represent changes in the intended hue. When a colour receiver is tuned to the…

  • luminance transmission (electronics)

    television: Basic principles of compatible colour: The NTSC system: …when viewing white light, the luminance transmission carries the impression of fine detail. Because it employs methods essentially identical to those of a monochrome television system, it can be picked up by black-and-white receivers. The chrominance transmission has no appreciable effect on black-and-white receivers, yet, when used with the luminance…

  • luminescence (physics)

    luminescence, emission of light by certain materials when they are relatively cool. It is in contrast to light emitted from incandescent bodies, such as burning wood or coal, molten iron, and wire heated by an electric current. Luminescence may be seen in neon and fluorescent lamps; television,

  • luminescence, biological (chemical reaction)

    bioluminescence, emission of light by an organism or by a laboratory biochemical system derived from an organism. It could be the ghostly glow of bacteria on decaying meat or fish, the shimmering radiance of protozoans in tropical seas, or the flickering signals of fireflies. The phenomenon occurs

  • luminescent lamp

    lamp: Modern electrical light sources: Luminescent lamps, which produce less heat than incandescent lamps, include electric discharge lamps, semiconductor lamps, and chemical lamps. Of the electric discharge lamps, the fluorescent lamp gives off a neutral white light, the sodium vapour lamp emits a yellow-orange light, and the mercury vapour lamp…

  • luminiferous ether (theoretical substance)

    ether, in physics, a theoretical universal substance believed during the 19th century to act as the medium for transmission of electromagnetic waves (e.g., light and X-rays), much as sound waves are transmitted by elastic media such as air. The ether was assumed to be weightless, transparent,

  • luminism (painting)

    luminism, late 19th-century painting style emphasizing a unique clarity of light. It was characteristic of the works of a group of independent American painters who were directly influenced by the Hudson River school of painting. The term, however, was not coined until 1954 by John Baur, director

  • Luminodesmus sequoiae (millipede)

    bioluminescence: The range and variety of bioluminescent organisms: The entire body of Luminodesmus sequoiae, a millipede found in the Sierra Nevada mountains of California, glows with a diffuse light. Luminous insects include some true flies (order Diptera), notably Arachnocampa luminosa, the larva of which luminesces a greenish blue from a knob at the end of its body.…

  • luminol (chemical compound)

    luminol, chemical compound that emits a blue fluorescent light when it reacts with certain oxidizing agents. Luminol is most widely known for its application in forensic science, in which it is used to detect the presence of blood at crime scenes. The chemical formula of luminol is C8H7N3O2. It is

  • luminosity (astronomy)

    luminosity, in astronomy, the amount of light emitted by an object in a unit of time. The luminosity of the Sun is 3.846 × 1026 watts (or 3.846 × 1033 ergs per second). Luminosity is an absolute measure of radiant power; that is, its value is independent of an observer’s distance from an object.

  • luminosity function (astronomy)

    Milky Way Galaxy: The stellar luminosity function: The stellar luminosity function is a description of the relative number of stars of different absolute luminosities. It is often used to describe the stellar content of various parts of the Galaxy or other groups of stars, but it most commonly refers…

  • luminous intensity (physics)

    luminous intensity, the quantity of visible light that is emitted in unit time per unit solid angle. The unit for the quantity of light flowing from a source in any one second (the luminous power, or luminous flux) is called the lumen. The lumen is evaluated with reference to visual sensation. The

  • luminous moss (plant species)

    luminous moss, (Schistostega pennata; formerly S. osmundacea), light-reflecting plant of the subclass Bryidae, native to the Northern Hemisphere. It forms green mats in caves, holes in wood or earth, or cavities between rocks or under tree roots. A luminous moss is about one centimetre (12 inch) or

  • luminous mysteries (religion)

    rosary: In Christianity: …set of mysteries, the “luminous mysteries,” or mysteries of light. The five new mysteries celebrate events in Jesus’ ministry, including his baptism; his miracle at Cana, where he turned water into wine; his proclamation of the kingdom of God; the Transfiguration, in which he revealed his divinity to three…

  • luminous paint

    luminous paint, paint that glows in the dark because it contains a phosphor, a substance that emits light for a certain length of time after exposure to an energy source, such as ultraviolet radiation. Zinc sulfide and calcium sulfide are such phosphors. Some luminous paints contain a source of

  • luminous range (light)

    lighthouse: Geographic range and luminous range: The range at which a light can be seen depends upon atmospheric conditions and elevation. Since the geographic horizon is limited by the curvature of Earth, it can be readily calculated for any elevation by standard geometric methods. In lighthouse work the observer is always assumed…

  • Luminy (France)

    Marseille: Health: …center in the suburb of Luminy links the region’s hospitals.