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Gegenbauer polynomials
Gegenbauer polynomials, also called ultraspherical polynomials, are classical orthogonal polynomials on (-1,1), introduced by Leopold Gegenbauer in 1875, generalizing the Legendre polynomials and arising as zonal spherical harmonics.
Geiger–Marsden experiment
The Geiger–Marsden experiment was a series of alpha-particle scattering measurements made at the University of Manchester by Hans Geiger and Ernest Marsden, leading Rutherford to propose the atomic nucleus.
Geiger–Müller tube
The Geiger–Müller tube, also known as the GM tube or Geiger tube, is a gas-filled radiation detector invented in 1928 by Hans Geiger and Walter Müller in Kiel, Germany.
Geissler tube
A Geissler tube is a sealed glass tube with gas at low pressure that glows in a color set by its gas when high voltage is applied, invented by Heinrich Geissler in 1858.
Gel
A gel is a non-fluid colloidal or polymer network expanded throughout its whole volume by a fluid, as defined by IUPAC in 2007, solid enough to hold its shape yet soft and largely liquid by volume.
Gel permeation chromatography
Gel permeation chromatography (GPC), also called size-exclusion chromatography, is a liquid chromatography technique that separates polymers by size in solution to determine molar mass distributions.
Gelasian
The Gelasian is a geological stage from about 2.58 to 1.80 million years ago, now the lowest stage of the Pleistocene and defining the base of the Quaternary.
Gelatin
Gelatin, also called collagen hydrolysate or collagen peptide, is a protein obtained by partial hydrolysis of collagen from animal skins, bones, and tendons, used in food, pharmaceuticals, and photography.
Geldanamycin
Geldanamycin is a benzoquinone ansamycin antibiotic isolated in 1970 from Streptomyces hygroscopicus, best known as the prototype Hsp90 inhibitor and starting point for experimental anticancer drugs.
Gelfand representation
The Gelfand representation, also called the Gelfand transform or Gelfand duality, sends each element of a commutative Banach algebra to a function on its character space, introduced by Gelfand in 1941.
Gelfand–Naimark theorem
The Gelfand–Naimark theorem, also called the Gelfand–Naimark representation theorem, is a 1943 result stating that every commutative C-algebra is a function algebra C₀(X) and every C-algebra is a -algebra of bounded operators on a Hilbert space.
Gelfand–Naimark–Segal construction
The Gelfand–Naimark–Segal construction, also called the GNS construction or GNS theorem, converts a state on a C-algebra into a Hilbert-space representation with a cyclic vector, a correspondence Segal completed in 1947.
Gelfond's constant
Gelfond's constant is the transcendental number e^π, approximately 23.1407, proven transcendental in 1934 by Aleksandr Gelfond and independently by Theodor Schneider in 1935, settling Hilbert's seventh problem.
Gelisol
Gelisol is one of the twelve soil orders in USDA Soil Taxonomy, defined by permafrost within 100 cm of the surface; in the United States, Gelisols occur only in Alaska.
Gellan gum
Gellan gum, sold as Phytagel and Gelrite, is a polysaccharide made by fermenting the bacterium Sphingomonas elodea and used as a gelling and thickening agent in food.
Geminate recombination
Geminate recombination is the reaction of two transient species from a common precursor, typically radicals trapped together in the solvent cage first described by Franck and Rabinowitsch in 1934.
Geminga TeV halo
The Geminga TeV halo is an extended gamma-ray glow around the nearby pulsar Geminga, spatially resolved by HAWC in 2017 and the canonical TeV pulsar halo.
Gemini (constellation)
Gemini is one of the 88 constellations recognized by the International Astronomical Union and one of twelve crossed by the ecliptic, best known for the bright star pair Castor and Pollux.
Gemini Observatory
The Gemini Observatory is a pair of identical 8.1-meter optical and infrared telescopes, Gemini North on Maunakea in Hawai'i and Gemini South on Cerro Pachón in Chile.
Geminids
The Geminids are an annual meteor shower, active each December with a peak around December 13–14 and up to about 150 meteors per hour, supplied by asteroid 3200 Phaethon.
Gemstone
A gemstone, also called a precious or semiprecious stone, is a mineral or organic material cut and polished for jewelry and valued for beauty, durability, and rarity.
Gen (probabilistic programming system)
Gen is an open-source probabilistic programming system embedded in the Julia language, introduced by MIT researchers at PLDI in 2019 and known for programmable inference, which lets users write custom inference algorithms as ordinary Julia programs.
Gen Shirane
Gen Shirane (1924–2005) was a Japanese-born American condensed matter physicist at Brookhaven National Laboratory who used triple-axis neutron spectroscopy to study ferroelectricity, magnetism, and high-Tc superconductivity.
Gender equity programs in physics
Gender equity programs in physics are organized interventions, including mentoring networks, targeted funding and fellowships, targeted hiring, and accreditation schemes, that aim to improve women's participation and advancement in physics.
Gene Dresselhaus
Gene Frederick Dresselhaus (1929–2021) was an American solid-state physicist at MIT whose 1955 analysis of spin-orbit coupling in semiconductors gave his name to the Dresselhaus effect, earning him the 2022 Buckley Prize.
General Catalogue of Variable Stars (Общий каталог переменных звёзд)
The General Catalogue of Variable Stars (GCVS) lists about 60,000 named variable stars, mostly in the Milky Way, and has been compiled in Moscow since 1946.
General circulation model
A general circulation model (GCM), or global climate model, is a numerical computer model simulating a planet's atmosphere and, in coupled form, oceans, land, and sea ice.
General Conference on Weights and Measures
The General Conference on Weights and Measures (CGPM) is the supreme authority of the Metre Convention, meeting every four to six years; it established the SI in 1960.
General Dirichlet series
A general Dirichlet series is a series of the form sum a_n e^{-lambda_n s} that generalizes ordinary Dirichlet series and power series through a chosen frequency sequence.
General knowledge
General knowledge is the breadth of facts a person holds about the world, spanning history, science, and the arts; psychometrics treats it as crystallized intelligence.