Physical world and mathematics

Gibbs phenomenon

The Gibbs phenomenon, also called the Gibbs effect, is the fixed overshoot and undershoot of Fourier series partial sums near a jump discontinuity, persisting at about 8.95 percent of the jump.

Gibbs random field

A Gibbs random field is a random field whose probability is proportional to the exponential of a negative energy built from clique potentials, originating in statistical mechanics.

Gibbs sampling

Gibbs sampling, also known as the heat bath algorithm, is a Markov chain Monte Carlo method that samples each variable from its conditional distribution given all the others.

The Gibbs–Duhem equation, or Gibbs–Duhem relation, is a thermodynamic identity relating a phase's intensive variables, temperature, pressure, and chemical potentials, so they cannot change independently; it underlies the Gibbs phase rule.

Gibbs–Helmholtz equation

The Gibbs–Helmholtz equation is a thermodynamic relation giving the temperature dependence of the Gibbs energy at constant pressure, most useful for phase changes and chemical reactions.

Gibbsite

Gibbsite, also known as hydrargillite, is an aluminum hydroxide mineral, Al(OH)₃, and one of the three principal minerals of bauxite, the ore from which nearly all aluminum is produced.

Gibrat's law

Gibrat's law, also called the law of proportionate effect, holds that a firm's or city's growth rate is independent of its size; Robert Gibrat stated it in 1931.

Gideon Henderson

Gideon Henderson is a British isotope geochemist and Professor of Earth Sciences at Oxford who uses radioactive isotopes to date past climate events, and served as Defra Chief Scientific Adviser from 2019 to 2025.

Gideon J. Davies

Gideon J. Davies is a British structural biologist and Professor of Chemistry at the University of York, elected a Fellow of the Royal Society in 2010.

Oct 22, 2026

Giese reaction

The Giese reaction is a carbon–carbon bond-forming reaction in which a nucleophilic carbon-centered radical adds to an electron-deficient alkene by 1,4-addition, named after Bernd Giese of Freiburg.

Gifford H. Miller

Gifford H. Miller is a paleoclimatologist and Quaternary geologist, Distinguished Professor at the University of Colorado Boulder, known for amino acid dating and research on Australian megafauna extinctions.

Gifford-McMahon cryocooler

A Gifford-McMahon cryocooler is a closed-cycle helium refrigerator reaching 4 K to 80 K without liquid cryogens, invented by William Gifford and Howard McMahon in the late 1950s.

Gigabyte

A gigabyte (GB) is a unit of digital information equal to one billion bytes, also widely used for 2^30 bytes, called a gibibyte since 1998.

Gigliola Staffilani

Gigliola Staffilani is an Italian-born mathematician who studies dispersive partial differential equations such as the Schrödinger equation; she is the Abby Rockefeller Mauzé Professor of Mathematics at MIT.

Gijs de Boer

Gijs de Boer is an atmospheric scientist known for studying Arctic clouds and surface radiation and for developing uncrewed aircraft systems as weather-observing platforms; he received a PECASE award in 2016.

Gil Kalai

Gil Kalai is an Israeli mathematician at the Hebrew University of Jerusalem known for work in combinatorics and for arguing that scalable quantum computers cannot be built.

Gilbert Agnew Hunt

Gilbert Agnew Hunt (1916–2008) was an American mathematician at Princeton known for the Hunt process in probability theory, who as a young man beat tennis champion Bobby Riggs in 1938.

Gilbert Ames Bliss

Gilbert Ames Bliss (1876–1951) was an American mathematician at the University of Chicago known for the calculus of variations, including wartime ballistics work at Aberdeen Proving Ground.

Gilbert Baumslag

Gilbert Baumslag (1933–2014) was an American group theorist who introduced the Baumslag–Solitar groups in 1962 and later worked on computation and cryptography at the City College of New York.

Gilbert Chu

Gilbert Chu is an American scientist and Stanford professor of medicine and biochemistry known for creating Significance Analysis of Microarrays and for research on how cells repair damaged DNA.

Gilbert George Lonzarich

Gilbert George Lonzarich is a physicist at the Cavendish Laboratory in Cambridge whose 1994 observation of pressure-induced superconductivity in CeIn3 gave the first strong evidence that magnetic fluctuations can mediate superconducting pairing.

Gilbert N. Lewis

Gilbert N. Lewis, also known as Gilbert Newton Lewis, was an American physical chemist at Berkeley who created Lewis structures, the electron-pair bond, and Lewis acids and bases.

Gilbert Stengle

Gilbert Stengle (1933–2010) was an American mathematician at Lehigh University known for the 1974 Krivine–Stengle Positivstellensatz, a certificate for polynomial positivity that underlies sum-of-squares optimization.

Gilbert Stork

Gilbert Stork was a Belgian-born American organic chemist at Columbia University whose methods for stereochemical control reshaped synthesis, including the Stork enamine alkylation and the first stereoselective quinine synthesis.

Gilbert Strang

Gilbert Strang is an American mathematician at MIT known for work in numerical analysis, linear algebra, and partial differential equations, and for his widely watched linear algebra lectures.

Gilbert U-238 Atomic Energy Laboratory

The Gilbert U-238 Atomic Energy Laboratory was a children's science kit sold by A. C. Gilbert from 1950 to 1951, containing real uranium ore for home nuclear physics experiments.

Gilbert Walker (meteorologist)

Sir Gilbert Thomas Walker (1868–1958) was a British mathematician and meteorologist who led the India Meteorological Department and discovered the Southern Oscillation, key to El Niño research.

Gilbert–Varshamov bound

The Gilbert–Varshamov bound is a lower bound in coding theory: proved by Gilbert in 1952 and Varshamov in 1957, it guarantees codes of a certain size exist.

Gilles Holst

Gilles Holst (1886–1968) was a Dutch physicist who took part in the 1911 Leiden discovery of superconductivity and founded Philips' NatLab, pioneering industrial research in the Netherlands.