abacus: …with its place value and zero, gradually replaced the abacus, though it was still widely used in Europe as late as the 17th century. The abacus survives today in the Middle East, China, and Japan, but it has been largely replaced by electronic calculators.

aleph-null (ℵ0), in mathematics, the cardinality of the infinite set of natural numbers {1, 2, 3, …}. The cardinality, or cardinal number, of a set is the number of elements of a set. For example, the number 3 is the cardinality of the set {1, 2, 3} as well as of any set that can be put into a

Liu Xiaobo: …2008 Liu helped draft “Charter 08,” a 19-point program that called for greater political freedoms in China and concluded with the signatures of more than 300 academics and intellectuals. Liu was arrested hours before the document’s release onto the Internet, and, at a trial the following year, he was…

Every weekday is expiration day. Is that a bad thing?If you’re a regular follower of financial news, you’ve probably seen media reports about a relatively new phenomenon called zero-days-to-expiration (0DTE) options trading. As the name implies, this refers to options traders getting in and out of

Middle Eastern religion: Association of religion with the arts and sciences: The most perfect number was one, for by advancing from zero to one men believed they proceeded from nonexistence to existence. Moreover, all other whole numbers were regarded as multiples of one, representative of the Creator, the Prime Mover, of the universe. The Egyptians called Re “the one One”; the…

books of the Chronicles, two Old Testament books that were originally part of a larger work that included the books of Ezra and Nehemiah. These three (Ezra and Nehemiah were one book in the Jewish canon) were the final books of the Hebrew Bible. Together they survey Israel’s history from Adam to

Big Star: …Big Star’s 1972 debut album, #1 Record. Although the record was subsequently hailed as a masterpiece, it initially sold so poorly that a discouraged Bell left the group. The follow-up, Radio City (1974), included a few Bell songs but was largely driven by Chilton, who pursued a slightly tougher-sounding but…

One Thousand Guineas, one of the five English Classic horse races, run over a straight mile (1.6 km) on the Rowley Mile course at the Newmarket (Suffolk) spring meeting. The race was first run in 1814. It is for three-year-old fillies and is run on the Friday following the Wednesday running of the

tetrachloroethane: The other isomer, 1,1,1,2-tetrachloroethane, has no commercial application.

DDT, a synthetic insecticide that belongs to the family of organic halogen compounds and is highly toxic toward a wide variety of insects as a contact poison that apparently exerts its effects by disorganizing the nervous system. DDT, prepared by the reaction of chloral with chlorobenzene in the

methoxychlor, a largely banned synthetic insecticide. Methoxychlor, a colourless crystalline organic halogen compound, is very similar to DDT but acts more rapidly, is less persistent, and does not accumulate in the fatty tissues of animals as DDT does. Effective against flies, mosquitoes,

trichloroethane: One isomer, 1,1,1-trichloroethane, was used as a solvent for cleaning and degreasing metal and electronic machinery. It was also used as a coolant and in the manufacture of other chemicals and products, including insecticides and household cleaners. It was produced by the reaction of 1,1-dichloroethylene and hydrogen…

tetrachloroethane: One isomer, 1,1,2,2-tetrachloroethane, also called acetylene tetrachloride, is highly toxic. Almost the entire production of the compound is consumed in manufacturing chlorinated solvents, especially trichloroethylene and tetrachloroethylene; it has minor uses as a solvent and as an insecticide, particularly against the greenhouse white fly. It is made…

trichloroethane: …produced by the reaction of 1,1-dichloroethylene and hydrogen chloride.

organohalogen compound: Reactions: to vinyl chloride to yield 1,1-dichloroethane. The product is a geminal dihalide (both halogens are bonded to the same carbon).

vinylidene chloride, a colourless, dense, toxic, volatile, flammable liquid belonging to the family of organic halogen compounds, used principally in combination with vinyl chloride, acrylonitrile, or methyl methacrylate for the manufacture of a class of plastics called saran. Vinylidene chloride

benzene hexachloride (BHC), any of several stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexane formed by the light-induced addition of chlorine to benzene. One of these isomers is an insecticide called lindane, or Gammexane. Benzene hexachloride was first prepared in 1825; the insecticidal

pyrogallol, an organic compound belonging to the phenol family, used as a photographic film developer and in the preparation of other chemicals. Pyrogallol was first obtained in 1786 from gallic acid, obtainable from galls and barks of various trees. It is converted to pyrogallol by heating with

phthalic acid, colourless, crystalline organic compound ordinarily produced and sold in the form of its anhydride. The annual production of phthalic anhydride exceeded 1,000,000 metric tons in the late 20th century; most of it was used as an ingredient of polyesters, including alkyd resins

ethylene bromide (C2H4Br2), a colourless, sweet-smelling, nonflammable, toxic liquid belonging to the family of organohalogen compounds. Ethylene bromide was once used in conjunction with lead-containing antiknock agents as a component of gasoline; however, this use disappeared with the banning of

ethylene chloride (C2H4Cl2), a colourless, toxic, volatile liquid having an odour resembling that of chloroform. It is denser than water, and it is practically insoluble in water. Ethylene chloride is produced by the reaction of ethylene and chlorine. The annual production of ethylene chloride

isomerism: Conformational isomers: …for deuterium atoms to make 1,2-dideuterioethane—isomeric staggered forms become possible. These staggered forms, called “anti” and “gauche,” of 1,2-dideuterioethane are different but are interconverted through rotations around the central carbon-carbon bond and are called “conformational isomers.”

hydrocarbon: Stereoisomerism: Methyl groups in 1,2-dimethylcyclopropane, for example, may be on the same (cis) or opposite (trans) sides of the plane defined by the ring. The resulting two substances are different compounds, each having its own properties such as boiling point (abbreviated bp here):

organosulfur compound: Preparation: …acetylene with sulfur yields a 1,2-dithiete, a four-membered ring compound with two sulfur atoms that exhibits aromatic stability similar to thiophenes. 1,2-Dithiins, six-membered ring disulfides found in thiarubrines, can be prepared by reaction of titanacyclopentadienes (formed in one step from acetylenes) with sulfur monochloride (S2Cl2) or thiocyanogen (SCN)2 and samarium…

ethylene glycol, the simplest member of the glycol family of organic compounds. A glycol is an alcohol with two hydroxyl groups on adjacent carbon atoms (a 1,2-diol). The common name ethylene glycol literally means “the glycol derived from ethylene.” Ethylene glycol is a clear, sweet, slightly

propylene glycol, synthetic organic compound with the chemical formula C3H8O2. Propylene glycol is a colourless liquid that is relatively viscous, has no odour, and tastes slightly sweet. It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. Annual production of

renal system: Nonexcretory functions: …reaching the body tissues; and 1,25-dihydroxycholecalciferol, which is the metabolically active form of vitamin D. Finally, although the kidneys are subject to both nervous and humoral (hormonal) control, they do possess a considerable degree of autonomy; i.e., function continues in an organ isolated from the nervous system but kept alive…

butadiene, either of two aliphatic organic compounds that have the formula C4H6. The term ordinarily signifies the more important of the two, 1,3-butadiene, which is the major constituent of many synthetic rubbers. It was first manufactured in Germany during World War I from acetylene. During World

metabolism: The formation of ATP: …a high-energy phosphate compound—namely, as 1,3-diphosphoglycerate, an anhydride of a carboxylic acid and phosphoric acid. The hydrogen atoms or electrons removed from the aldehyde group during its oxidation are accepted by a coenzyme (so called because it functions in conjunction with an enzyme) involved in hydrogen or electron transfer. The…

organosulfur compound: Reactions: …derivative of the cyclic bis-sulfide 1,3-dithiane, widely used in the synthesis of ketones and aldehydes (the Corey-Seebach reaction, shown below). 1,3-Dithiane and other thioacetals can also be converted to olefins by the Takeda olefination reaction.

hydroquinone, colourless, crystalline organic compound formed by chemical reduction of benzoquinone. See

Herb Elliott: …was world-record holder in the 1,500-metre (metric-mile) race (1958–67) and the mile race (1958–62). As a senior runner, he never lost a mile or a 1,500-metre race.

PCP, hallucinogenic drug with anesthetic properties, having the chemical name 1-(1-phenylcyclohexyl)piperidine. PCP was first developed in 1956 by Parke Davis Laboratories of Detroit for use as an anesthetic in veterinary medicine, though it is no longer used in this capacity. Used for a brief time

antiprotozoal drug: Metronidazole is usually given orally for the treatment of vaginal infections caused by Trichomonas vaginalis, and it is effective in treating bacterial infections caused by anaerobes (organisms that can survive without oxygen). It affects these organisms by causing nicks in, or breakage of, strands of…

amantadine, drug used to treat infections caused by influenza type A virus, the most common cause of influenza epidemics. Amantadine and its derivative, rimantadine, can be used successfully in the prevention and treatment of influenza A; however, these agents have no effect against influenza B

organohalogen compound: Synthesis: …in the following synthesis of 1-bromobutane.

liquid: Partial miscibility: …the solubility (weight percent) of n-butyl alcohol in water is 6.5 percent, whereas that of water in n-butyl alcohol is 22.4 percent. At 127° C, the upper consolute temperature, complete miscibility is attained: above 127° C the two liquids mix in all proportions, but below 127° C they show a…

butene: The isomeric forms are 1-butene, cis-2-butene, trans-2-butene, and isobutylene. All four butenes are gases at room temperature and pressure.

organohalogen compound: Reactions: … to the halogen, as in 1-chloro-4-nitrobenzene:

cetyl alcohol, [CH3(CH2)15OH], a solid organic compound that was one of the first alcohols to be isolated from fats. Cetyl alcohol was discovered in 1817 by the French chemist Michel Chevreul. When he heated a sample of spermaceti (a solid wax formed by the cooling of sperm whale oil) with caustic

parkinsonism: …neurotoxin known as MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), previously found in contaminated heroin, also causes a form of toxin-induced parkinsonism. The ability of this substance to destroy neurons suggests that an environmental toxin similar to MPTP may be responsible for Parkinson disease. Pugilistic parkinsonism results from head trauma and has affected professional…

stearyl alcohol, waxy solid alcohol formerly obtained from whale or dolphin oil and used as a lubricant and antifoam agent and to retard evaporation of water from reservoirs. It is now manufactured by chemical reduction of stearic

acetophenone (C6H5COCH3), an organic compound used as an ingredient in perfumes and as a chemical intermediate in the manufacture of pharmaceuticals, resins, flavouring agents, and a form of tear gas. It also has been used as a drug to induce sleep. The compound can be synthesized from benzene and

chemical industry: Other alcohols: …is called n-propyl alcohol (or 1-propanol), the other isopropyl alcohol (or 2-propanol).

golden ratio, in mathematics, the irrational number (1 + 5)/2, often denoted by the Greek letter ϕ or τ, which is approximately equal to 1.618. It is the ratio of a line segment cut into two pieces of different lengths such that the ratio of the whole segment to that of the longer segment is equal

decimal system: …mathematics, positional numeral system employing 10 as the base and requiring 10 different numerals, the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. It also requires a dot (decimal point) to represent decimal fractions. In this scheme, the numerals used in denoting a number take different place…

Blake Edwards: Films of the 1970s: …the United States to make 10 (1979), a romantic comedy that became an enormous hit. Dudley Moore was much praised for his deft comic timing in the role of man going through a midlife crisis who becomes smitten with a beautiful younger woman (Bo Derek). Andrews played his patient fiancée.

Bradley Cooper: …cast of the horror film 10 Cloverfield Lane.

10 Downing Street, address in London of the official office and residence of the prime minister of the United Kingdom and, by extension, the name of the building itself. It has been associated with the prime minister since that office came into being in the 18th century, and it has served as the

asteroid: Size and albedo: …km (320 miles), and (10) Hygiea at 410 km (250 miles). Three asteroids are between 300 and 400 km (190 and 250 miles) in diameter, and about 23 are between 200 and 300 km (120 and 190 miles). It has been estimated that 250 asteroids are larger than 100 km…

Dick Francis: … (1995), To the Hilt (1996), 10 Lb. Penalty (1997), Second Wind (1999), Shattered (2000), and Under Orders (2006). Late in life he began coauthoring novels with his son Felix, including Dead Heat (2007), Silks (2008), and Even Money (2009). Hot Money (1987) is considered one of his best works.

Richard Fleischer: Later work: …and found box-office success with 10 Rillington Place (1971), a pseudodocumentary about the John Reginald Christie–Timothy Evans murder case that shocked England in the 1940s; Richard Attenborough starred as the mass murderer, and John Hurt was the simpleminded man framed for one of the killings and hanged. In 1971 Fleischer…

Ray Kurzweil: Kurzweil also wrote The 10% Solution for a Healthy Life (1993), which details a diet that he had used to help cure himself of diabetes. His book The Age of Spiritual Machines (1999) presents a vision of the 21st century as a time when computer technology would have…

Yobes Ondieki: …a world record in the 10,000 metres, an event he had not run on a track in 10 years. At the time, his performance was considered by some as the best distance race ever run.

promethazine, synthetic drug used to counteract the histamine reaction, as in allergies. Promethazine, introduced into medicine in the 1940s, is used in the form of its hydrochloride. It is administered orally in tablets and syrups and intramuscularly in an aqueous solution. Promethazine is

bicycle: The modern bicycle: …the young consumers switched to 10-speeds, so named because two chainwheels and five freewheel sprockets allowed a total of 10 different gear ratios. Young buyers generated a second boom; from 1972 to 1974 annual U.S. sales doubled from 7 million to 14 million. About half of the bicycles sold were…

number symbolism: 100: Because our notational system for numbers is decimal (base 10), the number 100 takes on a significance that it would probably not possess if we employed other systems of notation. It is a round number and holds hints of perfection. The Western calendar is…

Takashi Murakami: …pieces included the multi-paneled painting 100 Arhats (2013)—in Buddhism, an arhat is one who has reached the state of enlightenment—and large-scale sculptures of demons, Embodiment of “A” and Embodiment of “Um” (both 2014).

Henry Koster: Early work: …included Three Smart Girls (1936); One Hundred Men and a Girl (1937), recipient of an Academy Award nomination for best picture; and First Love (1939)—proved highly popular and were credited with saving the studio from bankruptcy. It Started with Eve (1941) was the sixth and last of Koster’s films to…

Sheryl Crow: …songs and personal reminiscences; and 100 Miles from Memphis (2010), a collaborative effort featuring artists such as Justin Timberlake and Keith Richards of the Rolling Stones. After the country album Feels Like Home (2013), Crow returned to her earlier work with Be Myself (2017). On Threads (2019),

Roland Matthes: …and 1973, Matthes took the 100-metre backstroke world record from 58.4 to 56.3 seconds and the 200-metre mark from 2:07.9 to 2:01.87.

Usain Bolt: …to let him try the 100 metres, and he ran 10.03 sec in his first professional race at the distance. On May 3, 2008, he lowered his best time to 9.76 sec, then the world’s second fastest mark. Four weeks later in New York City, Bolt broke the world record,…

flood: …100 years is called a 100-year flood. The magnitudes of 100-, 500-, and 1,000-year floods are calculated by extrapolating existing records of stream flow, and the results are used in the design engineering of many water resources projects, including dams and reservoirs, and other structures that may be affected by…

1000 Genomes Project, an international collaboration in which researchers aimed to sequence the genomes of a large number of people from different ethnic groups worldwide with the intent of creating a catalog of genetic variations occurring with a frequency of at least 1 percent across all human

Anish Kapoor: …bodies of work such as 1000 Names. Created between 1979 and 1980, this series consisted of arrangements of abstract geometric forms coated with loose powdered pigments that spilled beyond the object itself and onto the floor or wall.

Richard Thompson: …it inspired him to record 1000 Years of Popular Music (2003), a compilation that traced the development of pop music from Early Middle English rounds to Britney Spears. Thompson reunited with the remaining members of Fairport Convention in 2007 for a celebration of the band’s 40th anniversary. His subsequent albums…

Rachid Boudjedra: With Les 1001 Années de la nostalgie (1979; “1,001 Years of Nostalgia”), Boudjedra created a satire of an imaginary Saharan village confronted with what he viewed as the newest symbol of contemporary cultural imperialism, an American film company. After writing his first several novels in French,…

Arctic National Wildlife Refuge: Human impact: That region—now known as the 1002 Area (for the section name of the 1980 law)—subsequently was assessed, with estimates of petroleum deposits there put in the billions-of-barrels range. The future of the 1002 Area has since been hotly and repeatedly debated between proponents and opponents of further oil exploration and…

baseball: Baseball and the arts: Rockwell’s paintings 100th Year of Baseball (1939) and Game Called Because of Rain (also known as Bottom of the Sixth; 1949), first printed on covers of The Saturday Evening Post, now hang in the art gallery of the National Baseball Hall of Fame and Museum.

1O1, orchestral work by John Cage that premiered in Boston on April 6, 1989, one of the rare large-scale works he composed in order to explore his fascination with aleatory, or chance, music. For much of his career, Cage investigated in various ways the contradiction between standard compositional

One Hundred and One Dalmatians, American animated film, released in 1961, that became a Walt Disney classic, especially known for the villainous character Cruella De Vil. When dalmatians Pongo and Perdita have 15 puppies, Cruella De Vil attempts to buy them from their owners, a composer and his

Ruby McKim: Her only book, 101 Patchwork Patterns, was published in 1931 and remains a classic. McKim was inducted into the Quilters Hall of Fame in 2002.

logic puzzle: Truths and lies: …was the guilty man? (From 101 Puzzles in Thought and Logic by C.R. Wylie, Jr.; Dover Publications, Inc., New York, 1957. Reprinted through the permission of the publisher.)

Amitabh Bachchan: In 102 Not Out (2018), he played a man trying to break the record for the oldest man alive. The crime drama Badla (2019) was among the biggest hits of Bachchan’s career.

New South Wales Corps, (1789–1818), British military force formed for service in the convict colony of New South Wales. It figured prominently in the early history of Australia. With the arrival of the corps in 1790–92, the colony gained a new dynamic force: officers and soldiers received land

It’s a “like-kind” kind of thing.A 1031 exchange refers to the section of IRS code that spells out the law and specific requirements regarding “like-kind” transactions. In short, when selling real property that’s held “for productive purposes,” the IRS says that, as long as the investment proceeds

Herschel: …forms of water in Comet Hartley 2 also revealed that the cometary water had the same isotopic signature as the water in Earth’s oceans, which was evidence that Earth’s water may have come from comets. Data gathered by Herschel showed that previous observations had underestimated by a third the amount…

East-West Schism, event that precipitated the final separation between the Eastern Christian churches (led by the patriarch of Constantinople, Michael Cerularius) and the Western church (led by Pope Leo IX). The mutual excommunications by the pope and the patriarch in 1054 became a watershed in

vagus nerve, longest and most complex of the cranial nerves. The vagus nerve runs from the brain through the face and thorax to the abdomen. It is a mixed nerve that contains parasympathetic fibres. The vagus nerve has two sensory ganglia (masses of nerve tissue that transmit sensory impulses): the

Aaron Bank: …new Unconventional Warfare unit, the 10th Special Forces Group (Airborne). Bank, now a colonel, was selected as the unit’s first commanding officer, and it was activated in June 1952 at Fort Bragg, North Carolina, a site that would become the centre of U.S. special forces training and tactics. Volunteers were…

number symbolism: 11: Sandwiched between the two auspicious and important numbers 10 and 12, the number 11 generally has negative connotations. Bungus stated that 11 has no connection with the divine, and medieval theology refers to the “11 heads of error.” Because at any time one of…

September 11 attacks, series of airline hijackings and suicide attacks committed in 2001 by 19 militants associated with the Islamic extremist group al-Qaeda against targets in the United States, the deadliest terrorist attacks on American soil in U.S. history. The attacks against New York City and

rod: …chemical derived from vitamin A, 11-cis-retinaldehyde. Photons of light entering the eye cause the 11-cis-retinaldehyde to undergo isomerization (a change in configuration), forming all-trans-retinaldehyde. This isomerization activates the opsin protein, which then interacts with and activates a small protein called transducin. The association of opsin with transducin couples the external…

Stephen King: …Dome (2009; TV series 2013–15); 11/22/63 (2011; TV miniseries 2016); Joyland (2013); Doctor Sleep (2013; film 2019), a sequel to The Shining; Revival (2014); The Outsider (2018; TV miniseries 2020); The Institute (2019); and Later (2021).

September 11 attacks, series of airline hijackings and suicide attacks committed in 2001 by 19 militants associated with the Islamic extremist group al-Qaeda against targets in the United States, the deadliest terrorist attacks on American soil in U.S. history. The attacks against New York City and

Agnes de Mille: …in Pink Tights (1954), and 110 in the Shade (1963). She also arranged dances for the films Romeo and Juliet (1936) and Oklahoma! (1955), directed plays, and choreographed television programs.

Liu Xiang: …2000, finishing fourth in the 110-metre event. He won the same race at the 2001 World University Games and in 2002 set world junior records indoors in the 60-metre hurdles (7.55 sec) and outdoors in the 110-metre hurdles (13.12 sec). In 2003 he earned bronze medals at the indoor and…

Julio Iglesias: …his breakout hit English-language album, 1100 Bel Air Place. The album, which went on to sell some four million copies in the U.S. alone, was an eclectic mix of styles that included duets with popular American artists such as Willie Nelson and Diana Ross. His song with Nelson, “To All…

Charles Ives: His 114 Songs (1919–24) for voice and piano vary from ballads to satire, hymns, protest songs, and romantic songs. In technique they range from highly complex (e.g., with tone clusters, polytonality, and atonality) to straightforward and simple.

American literature: Multicultural writing: …brother’s death from AIDS in 1185 Park Avenue (1999); and Dave Eggers’s A Heartbreaking Work of Staggering Genius (2000), a painful but comic tour de force, half tongue-in-cheek, about a young man raising his brother after the death of their parents.

human nervous system: Accessory nerve (CN XI or 11): The accessory nerve is formed by fibers from the medulla oblongata (known as the cranial root) and by fibers from cervical levels C1–C4 (known as the spinal root). The cranial root originates from the nucleus ambiguus and exits the…

James Patterson: …series, including 7th Heaven (2008), 11th Hour (2012), 14th Deadly Sin (2015), 16th Seduction (2017), and The 20th Victim (2020), were written with coauthors. Patterson’s other thriller series included one involving Michael Bennett, a detective. The first installment, Step on a Crack, was published in 2007, and later books included…

Leonardo DiCaprio: The 11th Hour, an environmental documentary that he wrote and narrated, premiered at the Cannes film festival in 2007. He later produced and narrated Ice on Fire (2019), a documentary that considers the possibility of reversing climate change.

number symbolism: 12: The number 12 is strongly associated with the heavens—the 12 months, the 12 signs of the zodiac, and the 12 stations of the Moon and of the Sun. The ancients recognized 12 main northern stars and 12 main southern stars. There are 24 =…

12 Angry Men, American courtroom film drama, released in 1957, considered a classic of the genre. It marked the feature-film directorial debut of Sidney Lumet. The film was adapted from a 1954 television play that aired on the series Studio One. It centres on the deliberations of 12 jurors serving

Some of the most exciting and prominent authors of the 21st century are also essential contributors to the impressive canon of African American literature. The authors in this list have published award-winning works of fiction, nonfiction, and poetry. Whether you’re a fan of science fiction or

lü pipes: …open ends, they produced the 12 lü, or fundamental pitches, of the octave. These pipes should not be confused with the panpipe, or paixiao.

Robert Duvall: In 2021 he appeared in 12 Mighty Orphans, a football drama based on a true story from the 1930s.

Zhang Huan: …experience, as in the piece 12 Square Metres (1994) for which he covered himself in fish oil and honey and sat motionless for several hours in a public latrine while insects crawled over him. He also initiated several group performances, such as To Add One Metre to an Anonymous Mountain…

Chris Hemsworth: …in the Afghanistan War story 12 Strong (2018), and he played a heroic mercenary in the action movie Extraction (2020).