42,772 articles
Green–Tao theorem
The Green–Tao theorem is a result in number theory proved by Ben Green and Terence Tao in 2004, stating that the prime numbers contain arbitrarily long arithmetic progressions.
Green's function
Green's function is the response of a linear differential equation with its boundary conditions to a point source, named for George Green, who introduced it in 1828.
Green's identities
Green's identities, also known as Green's formulas, are two integral formulas relating smooth functions inside a region to their values and normal derivatives on the boundary.
Green's relations
Green's relations are five equivalence relations defined on a semigroup from its principal ideals, introduced by J. A. Green in 1951 and central to semigroup theory.
Green's theorem
Green's theorem relates a line integral around a closed plane curve to a double integral over the region it encloses, generalizing the Fundamental Theorem of Calculus.
Greenberger–Horne–Zeilinger state
The Greenberger–Horne–Zeilinger state (GHZ state) is a maximally entangled quantum state of three or more qubits whose perfect correlations conflict with local realism, shown in 1989.
Greenbushes Mine
The Greenbushes Mine is a mine in south-west Western Australia that has produced tin, tantalum, and lithium since 1888 and is now a major lithium source.
Greenfield tornado
The Greenfield tornado was a violent EF4 tornado that struck Greenfield, Iowa, on May 21, 2024, killing five people, injuring at least 35, and destroying more than 100 homes.
Greenhouse and icehouse Earth
Greenhouse and icehouse Earth are Earth's two recurring climate states, defined by polar ice, alternating for over 2.5 billion years; Earth is now in an icehouse state.
Greenhouse effect
The greenhouse effect, also called greenhouse warming, warms a planet's surface as gases like water vapor and carbon dioxide absorb infrared radiation, adding about 33 °C on Earth.
Greenhouse gas
A greenhouse gas (GHG) is a gas, such as carbon dioxide, methane, or nitrous oxide, that absorbs infrared radiation and warms Earth's lower atmosphere and surface.
Greenhouse gas emissions
Greenhouse gas emissions, also known as carbon or GHG emissions, are releases of gases like carbon dioxide and methane that warm the atmosphere, reaching 59 GtCO2-eq in 2019.
Greenhouse Gas Pollution Pricing Act
The Greenhouse Gas Pollution Pricing Act is a 2018 Canadian federal statute establishing the federal carbon pricing backstop, upheld by the Supreme Court of Canada in 2021.
Greenland Ice Core Project
The Greenland Ice Core Project (GRIP) was a European project that drilled a 3,029-meter ice core to bedrock at Summit, Greenland, between 1989 and 1992, covering 250,000 years of climate.
Greensand
Greensand, also called glauconitic sandstone, is a typically marine sand or sandstone whose green color comes from glauconite; it is used as fertilizer, water softener, and heavy-metal filter.
Greensburg tornado
The Greensburg tornado was a violent EF5 tornado that struck Greensburg, Kansas, on May 4, 2007, destroying about 95 percent of the town and killing 11 people.
Greenschist
Greenschist is a schistose metamorphic rock whose green color comes from chlorite, epidote, or actinolite; it forms by low-grade regional metamorphism of shale or basalt.
Greenstone belt
A greenstone belt is a curving belt of volcanic and sedimentary rocks altered to green minerals, mostly in Archean terranes of the oldest continents, and rich in gold.
Greenstone Gold Mine
Greenstone Gold Mine is an open-pit gold mine near Geraldton, Ontario, wholly owned by Equinox Gold, on the historic Hardrock deposit. First gold poured in May 2024.
Greenwich Mean Time
Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, which became the basis for the world's time zones in 1884.
Greenwich Time Signal
The Greenwich Time Signal, known as the BBC pips or Greenwich pips, is a series of six tones broadcast by the BBC at each hour since 1924.
Greg G. Qiao
Greg G. Qiao, also known as Greg Qiao, is an Australian polymer scientist and professor at the University of Melbourne, leading its Polymer Science Group.
Greg Lawler
Greg Lawler, born 1955 in Alexandria, Virginia, is an American probabilist at the University of Chicago known for loop-erased random walks, the Brownian frontier, and the 2019 Wolf Prize.
Greg Moore
Gregory W. Moore is an American theoretical physicist at Rutgers University working on string theory, M-theory, and gauge theory, elected to the National Academy of Sciences in 2020.
Greg Pitz
Greg Pitz is an American laser physicist at the Air Force Research Laboratory's Directed Energy Directorate at Kirtland Air Force Base, New Mexico, who received a PECASE award in 2012.
Grégoire Nicolis
Grégoire Nicolis (1939–2018) was a Belgian physicist at the Université Libre de Bruxelles who helped build the theory of dissipative structures and co-created the Brusselator model with Ilya Prigogine.
Gregor Wentzel
Gregor Wentzel was a German-born theoretical physicist known for the WKB approximation and the first quantum field theory book, holding the Zurich chair from 1928 to 1948 before moving to Chicago.
Gregorian calendar
The Gregorian calendar, also called the Western calendar, is the solar civil calendar used in most of the world, instituted by Pope Gregory XIII in 1582.
Gregorio Ricci-Curbastro
Gregorio Ricci-Curbastro (1853–1925) was an Italian mathematician who held the chair of mathematical physics at the University of Padua and created the tensor calculus Einstein used in general relativity.
Gregory A. Fiete
Gregory A. Fiete is an American theoretical condensed matter physicist, a professor at Northeastern University known for work on topological quantum matter and chiral phonons.