thermonuclear bomb, weapon whose enormous explosive power results from an uncontrolled self-sustaining chain reaction in which isotopes of hydrogen combine under extremely high temperatures to form helium in a process known as nuclear fusion. The high temperatures that are required for the reaction

fusion reactor: Principles of inertial confinement: For efficient thermonuclear burn, the time allotted for the pellet to burn must be less than the disassembly time. This means that, in the compressed state, the product of the pellet mass density and the pellet radius must exceed about 3 grams per square centimetre. A high…

nuclear energy, energy that is released in significant amounts in processes that affect atomic nuclei, the dense cores of atoms. It is distinct from the energy of other atomic phenomena such as ordinary chemical reactions, which involve only the orbital electrons of atoms. One method of releasing

nuclear fusion, process by which nuclear reactions between light elements form heavier elements (up to iron). In cases where the interacting nuclei belong to elements with low atomic numbers (e.g., hydrogen [atomic number 1] or its isotopes deuterium and tritium), substantial amounts of energy are

thermonuclear reaction, fusion of two light atomic nuclei into a single heavier nucleus by a collision of the two interacting particles at extremely high temperatures, with the consequent release of a relatively large amount of energy. Chains of thermonuclear reactions, such as the proton-proton

fusion reactor, a device to produce electrical power from the energy released in a nuclear fusion reaction. The use of nuclear fusion reactions for electricity generation remains theoretical. Since the 1930s, scientists have known that the Sun and other stars generate their energy by nuclear

thermonuclear warhead, thermonuclear (fusion) bomb designed to fit inside a missile. By the early 1950s both the United States and the Soviet Union had developed nuclear warheads that were small and light enough for missile deployment, and by the late 1950s both countries had developed

nuclear weapon, device designed to release energy in an explosive manner as a result of nuclear fission, nuclear fusion, or a combination of the two processes. Fission weapons are commonly referred to as atomic bombs. Fusion weapons are also referred to as thermonuclear bombs or, more commonly,

thermoperiodicity, the growth or flowering responses of plants to alternation of warm and cool periods. Daily temperature fluctuations produce dramatic effects on the growth or flowering of most plants. The lack of lower night temperatures frequently results in poor growth, as can be observed in

bacteria: Evolution of bacteria: …eubacterial branch consists solely of thermophiles. Both Bacteria and Archaea contain members that are able to grow at very high temperatures, as well as other species that are able to grow at low temperatures. Another prominent difference is that bacteria have widely adapted to aerobic conditions, whereas many archaea are…

bacteria: Evolution of bacteria: …eubacterial branch consists solely of thermophiles. Both Bacteria and Archaea contain members that are able to grow at very high temperatures, as well as other species that are able to grow at low temperatures. Another prominent difference is that bacteria have widely adapted to aerobic conditions, whereas many archaea are…

Thermopylae, narrow pass on the east coast of central Greece between the Kallídhromon massif and the Gulf of Maliakós, about 85 miles (136 km) northwest of Athens (Athína). In antiquity its cliffs were by the sea, but silting has widened the distance to more than a mile. Its name, meaning “hot

thermocouple: A thermopile is a number of thermocouples connected in series. Its results are comparable to the average of several temperature readings. A series circuit also gives greater sensitivity, as well as greater power output, which can be used to operate a device such as a safety…

Thermoplasma, (genus Thermoplasma), any of a group of prokaryotic organisms (organisms whose cells lack a defined nucleus) in the domain Archaea that are noted for their ability to thrive in hot, acidic environments. The genus name is derived from the Greek thermē and plasma, meaning “warmth” (or

adhesive: Adhesive materials: …as an adhesive, as with thermoplastic elastomers such as styrene-isoprene-styrene block copolymers. Polymers impart strength, flexibility, and the ability to spread and interact on an adherend surface—properties that are required for the formation of acceptable adhesion levels.

adhesive: Adhesive materials: …as an adhesive, as with thermoplastic elastomers such as styrene-isoprene-styrene block copolymers. Polymers impart strength, flexibility, and the ability to spread and interact on an adherend surface—properties that are required for the formation of acceptable adhesion levels.

Thermopolis, resort town, seat (1913) of Hot Springs county, north-central Wyoming, U.S., on the Bighorn River, opposite East Thermopolis. The site was originally within the Wind River Indian Reservation (Shoshone and Arapaho). Founded in 1897, its name was derived from the Greek thermos, “hot,”

Thermopylae, narrow pass on the east coast of central Greece between the Kallídhromon massif and the Gulf of Maliakós, about 85 miles (136 km) northwest of Athens (Athína). In antiquity its cliffs were by the sea, but silting has widened the distance to more than a mile. Its name, meaning “hot

Anatolia: Anatolia in the Hellenistic Age (334–c. 30 bce): After two defeats, first at Thermopylae and afterward in Magnesia (not far from Sardis), Antiochus was forced to accept the peace of Apamea (188), which made Rome the predominant power in the Hellenistic East. Rome reorganized the Anatolian states: Lycia and Caria were allotted to Rhodes, though when this period…

Battle of Thermopylae, (480 bce), battle in central Greece at the mountain pass of Thermopylae during the Persian Wars. The Greek forces, mostly Spartan, were led by Leonidas. After three days of holding their own against the Persian king Xerxes I and his vast southward-advancing army, the Greeks

Thermopylae, narrow pass on the east coast of central Greece between the Kallídhromon massif and the Gulf of Maliakós, about 85 miles (136 km) northwest of Athens (Athína). In antiquity its cliffs were by the sea, but silting has widened the distance to more than a mile. Its name, meaning “hot

thermoreception, sensory process by which different levels of heat energy (temperatures) in the environment and in the body are detected by animals. Temperature has a profound influence upon living organisms. Animal life is normally feasible only within a narrow range of body temperatures, with the

thermoreception: Environment and thermoreception: …of specific sensory structures called thermoreceptors (or thermosensors) that enable an animal to detect thermal changes and to adjust accordingly.

thermoregulation, the maintenance of an optimum temperature range by an organism. Cold-blooded animals (poikilotherms) pick up or lose heat by way of the environment, moving from one place to another as necessary. Warm-blooded animals (homoiotherms) have additional means by which they can heat and

oceanic crust: Marine magnetic anomalies: …of permanent magnetization is the thermoremanent magnetization (or TRM) of iron-titanium oxide minerals. These minerals lock in a TRM as they cool below 200–300 °C (392–572 °F) in the presence of Earth’s magnetic field. Although several processes are capable of altering the TRM, including reheating and oxidation at the seafloor,…

oceanic crust: Marine magnetic anomalies: …of permanent magnetization is the thermoremanent magnetization (or TRM) of iron-titanium oxide minerals. These minerals lock in a TRM as they cool below 200–300 °C (392–572 °F) in the presence of Earth’s magnetic field. Although several processes are capable of altering the TRM, including reheating and oxidation at the seafloor,…

vacuum flask, vessel with double walls, the space between which is evacuated. It was invented by the British chemist and physicist Sir James Dewar in the 1890s. Thermos is a proprietary name applied to a form protected by a metal casing. The vacuum flask was devised to preserve liquefied gases by

crustacean: Annotated classification: Pancarida Order Thermosbaenacea Holocene; eyes reduced or absent; brood pouch formed from dorsal extension of carapace; length about 4 mm; fresh and brackish water, some in warm springs; about 9 species. There is no universal agreement on the classification of the Crustacea and even less…

adhesive: Synthetic adhesives: …into two general categories—thermoplastics and thermosets. Thermoplastics provide strong, durable adhesion at normal temperatures, and they can be softened for application by heating without undergoing degradation. Thermoplastic resins employed in adhesives include nitrocellulose, polyvinyl acetate, vinyl acetate-ethylene copolymer, polyethylene, polypropylene, polyamides, polyesters, acrylics, and cyanoacrylics.

adhesive: Synthetic adhesives: …into two general categories—thermoplastics and thermosets. Thermoplastics provide strong, durable adhesion at normal temperatures, and they can be softened for application by heating without undergoing degradation. Thermoplastic resins employed in adhesives include nitrocellulose, polyvinyl acetate, vinyl acetate-ethylene copolymer, polyethylene, polypropylene, polyamides, polyesters, acrylics, and cyanoacrylics.

dye: Disperse dyeing: With the Thermosol process, a pad-dry heat technique developed by the DuPont Company, temperatures of 180–220 °C (356–428 °F) are employed with contact times on the order of a minute.

thermosphere, region of increasing temperature in Earth’s atmosphere that is located above the mesosphere. The base of the thermosphere (the mesopause) is at an altitude of about 80 km (50 miles), whereas its top (the thermopause) is at about 450

thermostat, device to detect temperature changes for the purpose of maintaining the temperature of an enclosed area essentially constant. In a system including relays, valves, switches, etc., the thermostat generates signals, usually electrical, when the temperature exceeds or falls below the

biodiversity: Measuring biodiversity: …such species is the bacterium Thermus aquaticus, found in the hot springs of Yellowstone. From this organism was isolated Taq polymerase, a heat-resistant enzyme crucial for a DNA-amplification technique widely used in research and medical diagnostics (see polymerase chain reaction).

Renenutet, in Egyptian religion, goddess of fertility and of the harvest, sometimes depicted in the form of a snake. In addition to her other functions, she was also counted as the protector of the

Paul Hervieu: …drama of the French Revolution, Théroigne de Méricourt (1902), which he wrote especially for the Comédie’s leading actress, Sarah Bernhardt. His best works had a legal background, notably Les Tenailles (1895; In Chains), La Loi de l’homme (1897; “The Law of Man”), and Le Dédale (1903; The Labyrinth). All of…

Theron was the tyrant of Acragas (modern Agrigento in southwestern Sicily) from 488 to 472, allied with Gelon, the powerful despot of Syracuse. Together they defeated an invading Carthaginian army at Himera in 480. Theron was also known as a patron of the

Charlize Theron is a South African-born actress who was noted for her versatility and earned an Academy Award for best actress for her performance as a real-life serial killer in Monster (2003). Theron grew up on a farm near Benoni, South Africa. At age 13, wanting to continue her ballet studies,

gelada, (Theropithecus gelada), large baboonlike monkey that differs from true baboons in having the nostrils some distance from the tip of the muzzle. The gelada inhabits the mountains of Ethiopia and lives in groups among steep cliffs and high plateaus. Terrestrial and active during the day, it

theropod, any member of the dinosaur subgroup Theropoda, which includes all the flesh-eating dinosaurs. Theropods were the most diverse group of saurischian (“lizard-hipped”) dinosaurs, ranging from the crow-sized Microraptor to the huge Tyrannosaurus rex, which weighed six tons or more. Unlike the

theropod, any member of the dinosaur subgroup Theropoda, which includes all the flesh-eating dinosaurs. Theropods were the most diverse group of saurischian (“lizard-hipped”) dinosaurs, ranging from the crow-sized Microraptor to the huge Tyrannosaurus rex, which weighed six tons or more. Unlike the

history of the Low Countries: The Roman period: …seats of bishoprics, among them Thérouanne, Tournai, Tongeren (Tongres), and Trier (Trèves).

Justin Theroux is an American actor and screenwriter adept at both comedy and drama who is perhaps best known for his role on the TV series The Leftovers (2014–17). Theroux also cowrote the films Tropic Thunder (2008) and Iron Man 2 (2010), both of which were major box-office hits. Theroux is the

Justin Theroux is an American actor and screenwriter adept at both comedy and drama who is perhaps best known for his role on the TV series The Leftovers (2014–17). Theroux also cowrote the films Tropic Thunder (2008) and Iron Man 2 (2010), both of which were major box-office hits. Theroux is the

Paul Theroux is an American novelist and travel writer known for his highly personal observations on many locales. With bestsellers that include the nonfiction travelogue The Great Railway Bazaar (1975) and the adventure novel The Mosquito Coast (1982), he is credited with creating a new brand of

Paul Theroux is an American novelist and travel writer known for his highly personal observations on many locales. With bestsellers that include the nonfiction travelogue The Great Railway Bazaar (1975) and the adventure novel The Mosquito Coast (1982), he is credited with creating a new brand of

Paul Theroux is an American novelist and travel writer known for his highly personal observations on many locales. With bestsellers that include the nonfiction travelogue The Great Railway Bazaar (1975) and the adventure novel The Mosquito Coast (1982), he is credited with creating a new brand of

Roman law: The law of property and possession: According to thesauri inventio, or treasure trove, the final rule was that if something was found by a man on his own land, it went to him; if it was found on the land of another, half went to the finder, half to the landowner.

library: Thesauri: …of the earliest, is the Thesaurofacet (1969), a list of engineering terms in great detail designed by Jean Aitchison for the English Electric Company. The thesaurus has proved very useful both for indexing and for searching in machine systems. It is especially helpful in such areas as medicine, aerospace, and…

Peter Mark Roget: …and philologist remembered for his Thesaurus of English Words and Phrases (1852), a comprehensive classification of synonyms or verbal equivalents that is still popular in modern editions.

library: Thesauri: A new use of the term thesaurus, now widespread, dates from the early 1950s in the work of H.P. Luhn, at International Business Machines Corporation (IBM), who was searching for a computer process that could create a list of authorized terms for the indexing…

Henri II Estienne: …work was his Greek dictionary, Thesaurus graecae linguae, 5 vol. (1572), a masterpiece and a monument of lexicography that appeared in new editions as late as the 19th century.

Roman law: The law of property and possession: According to thesauri inventio, or treasure trove, the final rule was that if something was found by a man on his own land, it went to him; if it was found on the land of another, half went to the finder, half to the landowner.

Thesaurus Linguae Latinae, dictionary of the Latin language, published at Leipzig, Ger., the most important and definitive such undertaking of modern times. It is being prepared by the Universities of Berlin, Göttingen, Leipzig, and Munich in Germany and by Vienna University in Austria. The work,

Thomas Cooper: …Thesaurus, which became known as Cooper’s Dictionary. Cooper, who had been ordained about 1559, was made dean of Christ Church, Oxford, in 1567. Two years later he became dean of Gloucester, in 1571 bishop of Lincoln, and in 1584 bishop of Winchester. Cooper defended the practice and precept of the…

Santes Pagninus: …Pagninus issued a Hebrew lexicon, Thesaurus linguae sanctae (“Thesaurus of the Sacred Language”), which was frequently republished.

trigonometry table: …the word trigonometry, and his Thesaurus Mathematicus (1615) contained tables of sines and cosines calculated at 10′ intervals that were accurate to 15 decimal places. Later, still more accurate tables were constructed with the help of logarithms, invented by John Napier in 1614.

Abraham Zevi Idelsohn: The result was Thesaurus of Hebrew Oriental Melodies, 10 vol. (1914–32). This work and the more than 1,000 recordings made by Idelsohn provided a basis for the first comparative study of Jewish biblical cantillation (intoned recitation) and demonstrated an underlying unity in the religious chants, even among groups…

Nicetas Choniates: …theological sphere Nicetas composed the Panoplia Dogmatike (“Thesaurus of Orthodoxy”), a collection of tracts to use as source material for responding to contemporary heresies and to document the 12th-century Byzantine philosophical movement.

classical scholarship: The Renaissance outside Italy: …De emendatione temporum (1583) and Thesaurus temporum (1606).

Thesavalamai, traditional law of the Tamil country of northern Sri Lanka, codified under Dutch colonial rule in 1707. The Dutch, to facilitate the administration of their colonial territories in Ceylon, established there an elaborate system of justice based on Roman-Dutch law and the customary law

Lawrence Ferlinghetti: …as Endless Life (1981) and These Are My Rivers (1995). In 1988 Ferlinghetti published a short novel, Love in the Days of Rage, about a romance during the student revolution in France in 1968.

Virgil Abloh: Off-White: …Nancy Sinatra’s 1966 hit “These Boots Are Made for Walkin’.” Abloh opened Off-White’s first flagship store in Hong Kong in 2015 and introduced the label’s first furniture collection, Grey Area, the following year. He also frequently collaborated with brands such as Levi’s, IKEA, RIMOWA luggage, Timberland, and Jimmy Choo.…

Heart: Career: …band’s first number-one hit, “These Dreams,” which featured Nancy Wilson on lead vocals. The album also yielded the hits “Never,” “What About Love?” and “Nothin’ at All.” The band followed the success of Heart with Bad Animals (1987), which sold more than three million copies and features the standout…

Burton Cummings: The Guess Who years: …classic songs such as “These Eyes,” “Laughing,” “No Time,” “No Sugar Tonight,” and “American Woman” (the first song by a Canadian band to hit number one on the Billboard Hot 100 chart) before Bachman’s departure in May 1970. While Bachman initially took Cummings under his wing, the relationship between…

Ellen DeGeneres: …Mine; its name changed to Ellen the following season. The show was a success, earning nominations for Golden Globe, American Comedy, and Emmy awards. In 1997 DeGeneres revealed that she was gay, and Ellen became the first prime-time show to feature an openly gay lead character. After the show ended…

Ann Patchett: Later novels and other works: The essay collection These Precious Days appeared in 2021. In 2023 she released Tom Lake, a novel centering on a mother and her three adult daughters as they reflect on family dynamics, love and relationships, and growing up.

William Wyler: Films of the 1930s: …first film for Goldwyn was These Three (1936), Lillian Hellman’s translation of her controversial play The Children’s Hour, with its accusations of lesbianism replaced by those of an immoral heterosexual relationship in response to the strictures of the Production Code, established in 1930 to enforce moral

The Clayhanger Family: …by Hilda Lessways (1911) and These Twain (1915). They were published together in 1925.

Canadian literature: Poetry and poetics: Sharon Thesen (The Beginning of the Long Dash, 1987; Aurora, 1995; A Pair of Scissors, 2001) and Don McKay (Field Marks, 2006) spin evocative poems out of historical events, key personages, the natural world, and the quotidian. The desire of women to express their distinctive…

Robert Barclay: …Aberdeen in 1675, he published Theses Theologicae, a set of 15 propositions of the Quaker faith. To amplify them further, he published the Apology three years later. This early and enduring exposition of Quaker beliefs defined Quakerism as a religion of the “inner light.” Arguing against both Roman Catholicism and…

Theseum, temple in Athens dedicated to Hephaestus and Athena as patrons of the arts and crafts. Its style indicates that this, the best-preserved ancient Greek temple in the world, is slightly older than the Parthenon (i.e., c. 450–440 bc), and its unknown architect may even have changed his plan

The Two Noble Kinsmen: Theseus, duke of Athens, is preparing to marry Hippolyta, queen of the Amazons, accompanied by her sister, Emilia, and his friend, Pirithous, when he is called upon to wage war on the corrupt Theban king, Creon. Palamon and Arcite, two noble nephews of Creon, are…

A Midsummer Night’s Dream: Theseus, duke of Athens, has conquered Hippolyta, the Amazon queen, and is about to wed her. Meanwhile, two lovers, Hermia and Lysander, seek refuge in the forest near Athens when Hermia’s father demands that she marry Demetrius. Hoping to win Demetrius’s favour, Helena tells him…

Theseus, great hero of Attic legend, son of Aegeus, king of Athens, and Aethra, daughter of Pittheus, king of Troezen (in Argolis), or of the sea god, Poseidon, and Aethra. Legend relates that Aegeus, being childless, was allowed by Pittheus to have a child (Theseus) by Aethra. When Theseus reached

André Gide: Late works of André Gide: There he wrote “Theseus,” whose story symbolizes Gide’s realization of the value of the past: Theseus returns to Ariadne only because he has clung to the thread of tradition.

ship of Theseus, in the history of Western philosophy, an ancient paradox regarding identity and change across time. Mentioned by Plutarch and later modified by Thomas Hobbes, the ship of Theseus has spawned a variety of theories of identity within modern and contemporary metaphysics. Discussions

Giovanni Boccaccio: Early works: The Teseida (probably begun in Naples and finished in Florence, 1340–41) is an ambitious epic of 12 cantos in ottava rima in which the wars of Theseus serve as a background for the love of two friends, Arcita and Palemone, for the same woman, Emilia; Arcita…

Frederic John Napier Thesiger, 1st Viscount Chelmsford was an English colonial administrator and statesman who served for several years as governor of Queensland and New South Wales in Australia before becoming viceroy of India. As viceroy, he helped to institute reforms that increased Indian

Wilfred Thesiger was a British soldier and travel writer who was a colonial explorer in the tradition of Sir Richard Burton and T.E. Lawrence. His most important writings, based on his travels to remote areas of Africa and Asia, include descriptions of the societies of the Bedouins of the Arabian

Wilfred Thesiger was a British soldier and travel writer who was a colonial explorer in the tradition of Sir Richard Burton and T.E. Lawrence. His most important writings, based on his travels to remote areas of Africa and Asia, include descriptions of the societies of the Bedouins of the Arabian

arsis and thesis: thesis, in prosody, respectively, the accented and unaccented parts of a poetic foot. Arsis, a term of Greek origin meaning “the act of raising or lifting” or “raising the foot in beating time,” refers in Greek, or quantitative, verse to the lighter or shorter part…

problem play, type of drama that developed in the 19th century to deal with controversial social issues in a realistic manner, to expose social ills, and to stimulate thought and discussion on the part of the audience. The genre had its beginnings in the work of the French dramatists Alexandre

bastard toadflax: …for plants of the genus Thesium, particularly Thesium humifusum, which is also parasitic. The bisexual yellow or yellowish green flowers are grouped in terminal clusters, and the one-seeded fruit is dry and green.

bastard toadflax: …of the genus Thesium, particularly Thesium humifusum, which is also parasitic. The bisexual yellow or yellowish green flowers are grouped in terminal clusters, and the one-seeded fruit is dry and green.

Thesmophoria, in Greek religion, ancient festival held in honour of Demeter Thesmophoros and celebrated by women in many parts of the Greek world. The meaning of the name Demeter Thesmophoros still remains a matter of disagreement, although a possible translation is “bringer of treasure or wealth,”

Women at the Thesmophoria, play by Aristophanes, performed in 411 bce. The play develops from Euripides’ discovery that the women of Athens, angered by his constant attacks upon them in his tragedies, mean to discuss during their coming festival (the Thesmophoria) the question of contriving his

Women at the Thesmophoria, play by Aristophanes, performed in 411 bce. The play develops from Euripides’ discovery that the women of Athens, angered by his constant attacks upon them in his tragedies, mean to discuss during their coming festival (the Thesmophoria) the question of contriving his

archon: Lastly there were six thesmotetai (“determiners of custom”), who dealt with miscellaneous judicial problems.

Thespiae, ancient Greek city of Boeotia by the Thespius (modern Kanavári) River and at the eastern foot of Mt. Helicon; site of the “Eros” of Praxiteles, one of the most famous statues in the ancient world, and home of the sanctuaries and festivals of the Muses. Thespiae is important in Greek

Thespiae, ancient Greek city of Boeotia by the Thespius (modern Kanavári) River and at the eastern foot of Mt. Helicon; site of the “Eros” of Praxiteles, one of the most famous statues in the ancient world, and home of the sanctuaries and festivals of the Muses. Thespiae is important in Greek

Thespis was a Greek poet, said to have been born in the deme (district) of Icaria. According to ancient tradition, Thespis was the first actor in Greek drama. He was often called the inventor of tragedy, and his name was recorded as the first to stage a tragedy at the Great (or City) Dionysia (c.

Thessaly, region of northern Greece south of Macedonia (Modern Greek: Makedonía), lying between upland Epirus (Ípeiros) and the Aegean Sea and comprising chiefly the fertile Tríkala and Lárissa lowlands. It is well delineated by topographical boundaries: the Khásia and Cambunian mountains to the

Antigonus II Gonatas: …also the chief of the Thessalian League and on good terms with neighbouring Illyria and Thrace. He secured his position in Greece by keeping Macedonian occupation forces in the cities of Corinth, Chalcis on Euboea, and Demetrias in Thessaly, the three “shackles” of Hellas.

Letters of Paul to the Thessalonians, two New Testament letters written by St. Paul the Apostle from Corinth, Achaea (now in southern Greece), about 50 ce and addressed to the Christian community he had founded in Thessalonica (now in northern Greece). The First Letter of Paul to the Thessalonians

Thessaloníki, city and dímos (municipality), Central Macedonia (Modern Greek: Kendrikí Makedonía), on the western Chalcidice (Chalkidikí) peninsula at the head of a bay on the Gulf of Thérmai (Thermaïkós). An important industrial and commercial centre, second to Athens (Athína) in population and to

Thessaloníki, city and dímos (municipality), Central Macedonia (Modern Greek: Kendrikí Makedonía), on the western Chalcidice (Chalkidikí) peninsula at the head of a bay on the Gulf of Thérmai (Thermaïkós). An important industrial and commercial centre, second to Athens (Athína) in population and to

Thessaly, region of northern Greece south of Macedonia (Modern Greek: Makedonía), lying between upland Epirus (Ípeiros) and the Aegean Sea and comprising chiefly the fertile Tríkala and Lárissa lowlands. It is well delineated by topographical boundaries: the Khásia and Cambunian mountains to the

star cluster: OB and T associations: …type of multiple star, the Trapezium (named for its prototype in Orion), as well as supergiants, binaries, gaseous nebulas, and globules. Associations are relatively homogeneous in age. The best distance determinations are from spectroscopic parallaxes of individual stars—i.e., estimates of their absolute magnitudes made from studies of their spectra. Most…

neural oscillation: Types of brain rhythms: Large-amplitude theta oscillations (4–10 Hz) dominate the hippocampal-entorhinal system during spatial navigation and memory processing. Delta waves (0.5–1.5 Hz), the largest-amplitude waves in the neocortex (the cerebral cortex region associated with sight and hearing), are present during non-REM sleep. Beta rhythms