gambling Betting or staking of something of value on the outcome of a game or event. Commonly associated with gambling are horse racing, boxing, numerous playing-card and dice games, cockfighting, jai alai, rec¬ reational billiards and darts, bingo, and lottery. In most gambling games it is customary to express the idea of probability in terms of “odds against winning.” In the U.S. casino gambling, once highly restricted, is now legal in many states, and lotteries are employed by many states to raise rev¬ enues. The Internet has also become a venue for placing bets. See also bookmaking; casino.
game show or quiz show Radio or television show designed to test the knowledge, luck, or skill of contestants or experts. Among the shows popular on U.S. radio were Dr. I.Q. (1939-49), Information, Please (1938-48), and The Quiz Kids (1940-53). The genre was adopted by tele¬ vision and cash awards were increased, so that radio’s $64 Question became television’s $64,000 Question. In the mid-1950s, to increase their shows’ popularity, some producers began feeding answers to contestants who had been chosen to win. An accusation of unfair practices on Twenty- one (1958) led to a government investigation and the quick demise of the big-money shows. The game show later regained popularity when it was revived in formats with lower stakes and easier questions, as on Jeop¬ ardy! and Wheel of Fortune. At the turn of the 21st century, game shows such as Who Wants to Be a Millionaire boasted large cash prizes and gained popularity in prime time, and reality shows like Survivor adopted aspects of the game show genre.
game theory Branch of applied mathematics devised to analyze cer¬ tain situations in which there is an interplay between parties that may have similar, opposed, or mixed interests. Game theory was originally devel¬ oped by John von Neumann and Oscar Morgenstem in their book The Theory of Games and Economic Behavior (1944). In a typical game, or competition with fixed rules, “players” try to outsmart one another by anticipating the others’ decisions, or moves. A solution to a game pre¬ scribes the optimal strategy or strategies for each player and predicts the average, or expected, outcome. Until a highly contrived counterexample was devised in 1967, it was thought that every contest had at least one solution. See also decision theory; prisoner's dilemma.
gamelan Vga-ms-.lanV Indigenous orchestra of Java and Bali and, more generally, of Indonesia and Malaysia. A gamelan usually consists largely of gongs, xylophones, and metallophones (rows of tuned metal bars struck with a mallet). Gamelan polyphony is complex and many-voiced. The melody is taken by the voice, flute, or rebab (a bowed stringed instru¬ ment); under it, most of the other instruments provide rhythmic para¬ phrases of the melody, producing a shimmering, variegated texture. The gamelan has influenced many Western composers, including Claude Debussy, Olivier Messiaen, John Cage, Steve Reich, and Philip Glass.
Gamelin \,gam-Ta n ,\ English \,ga-m9-Tan\, Maurice (-Gustave) (b. Sept. 20, 1872, Paris, France—d. April 18, 1958, Paris) French army commander. He entered the army in 1893 and rose to division command in World War I and army chief of staff in 1931. He supported the defen¬ sive strategy based on the Maginot Line and, as commander of Allied forces when World War II broke out, took no offensive action during the Phony War. Surprised by the German assault in the Ardennes (May 1940), he was dismissed and replaced by Maxime Weygand, but France collapsed the next month. He was tried by the Vichy government and interned in Germany in 1943-45.
gametophyte Vgo-'me-ta-.fhA In certain plants, the sexual phase (or an individual representing the phase) in the alternation of generations. The alternate, nonsexual phase is the sporophyte. In the gametophyte phase, male and female organs (gametangia) develop and produce eggs and sperm (gametes), which unite in fertilization (syngamy). The fertilized egg (zygote) develops into the sporophyte, which produces numerous single-celled spores, which in turn develop directly into new gametes.
gamma decay Type of radioactivity in the most common form of which an unstable atomic nucleus dissipates energy by gamma emission, producing gamma rays. Gamma decay also includes two other processes,
internal conversion and internal pair production. In internal conversion, excess energy in a nucleus is transferred to one of its own orbiting elec¬ trons and the electron is ejected from the atom. In internal pair produc¬ tion, excess energy is converted into an electron and a positron, which are emitted together. Typical half-lives (see half-life) for gamma emission range from about 10 -9 to 10 -14 second.
gamma globulin Vglab-yo-bnX Subgroup of the globulins. In humans and many other mammals, most antibodies are in the gamma globulin fraction of blood. A human gamma globulin preparation may be admin¬ istered (by injection) to persons lacking immunity, either generally or to a particular disease, after exposure or before expected exposure.
gamma ray Penetrating very short-wavelength electromagnetic radia¬ tion, similar to an X-ray but of higher energy, that is emitted spontaneously by some radioactive substances (see gamma decay; radioactivity). Gamma radiation also originates in the decay of certain subatomic particles and in particle-antiparticle annihilation (see also antimatter). Gamma rays can ini¬ tiate nuclear fission, can be absorbed by ejection of an electron (see pho¬ toelectric effect), and can be scattered by free electrons (see Compton effect).
gamma-ray astronomy Study of astronomical objects and phe¬ nomena that emit gamma rays. Gamma-ray telescopes are designed to observe high-energy astrophysical systems, including stellar coronas, WHITE DWARF STARS, NEUTRON STARS, BLACK HOLES, SUPERNOVA remnants, CLUSTERS OF galaxies, and diffuse gamma-ray background radiation found along the plane of the Milky Way Galaxy. Because Earth’s atmosphere blocks most gamma rays, observations are generally conducted by high-altitude bal¬ loons or spacecraft. In the 1960s defense satellites designed to detect X rays and gamma rays from clandestine nuclear testing serendipitously discovered enigmatic gamma-ray bursts coming from deep space. In the 1970s Earth-orbiting observatories found a number of gamma-ray point sources, including an exceptionally strong one, dubbed Geminga, that was later identified as a pulsar, the nearest yet detected. The Compton Gamma Ray Observatory, launched in 1991, mapped thousands of celestial gamma-ray sources; it also showed that the mysterious bursts are distrib¬ uted across the sky, implying that their sources are at the distant reaches of the universe rather than in the Milky Way.
Gamow Vga-.moft, George orig. Georgy Antonovich Gamov
(b. March 4, 1904, Odessa, Russian Empire—d. Aug. 19, 1968, Boulder, Colo., U.S.) Russian-born U.S. nuclear physicist and cosmologist. After studying at Leningrad University with Aleksandr Friedmann (1888— 1925), he subsequently developed his quantum theory of radioactivity, the first successful explanation of the behaviour of radioactive elements. His “liquid drop” model of atomic nuclei served as the basis for modern theo¬ ries of nuclear fission and fusion. After immigrating to the U.S. in 1934, he collaborated with Edward Teller in researching beta decay (1936) and developing a theory of the internal structures of red giant stars (1942). In the 1950s he became interested in biochemistry, proposing theories of genetic code structure that were later found to be true. Throughout his career he also wrote popular works on such difficult subjects as relativity and cosmology.
Gan \'gan\ River or Kan River River, southeastern China. Located in Jiangxi province, it flows north through Lake Poyang to enter the Yangtze River (Chang Jiang) after a course of 506 mi (815 km). A major southern tributary of the Yangtze, the Gan valley provided an important route in historical times from Guangzhou to the Yangtze valley and the north.