42,772 articles
Goal programming
Goal programming is a branch of multi-objective optimization that finds a single compromise solution minimizing deviations from conflicting targets, introduced by Charnes, Cooper, and Ferguson in 1955.
Gödel metric
The Gödel metric, also called the Gödel universe, is an exact solution of Einstein's field equations found by Kurt Gödel in 1949, describing a rotating, non-expanding universe.
Gödel numbering
Gödel numbering is a method assigning a unique natural number to each symbol, formula, and proof of a formal language, introduced by Kurt Gödel in his 1931 incompleteness paper.
Gödel, Escher, Bach
Gödel, Escher, Bach is a 1979 book by Douglas Hofstadter exploring self-reference and consciousness through mathematics, art, and music, and it won the Pulitzer Prize.
Gödel's completeness theorem
Gödel's completeness theorem, proved in Kurt Gödel's 1929 doctoral thesis, states that every valid formula of first-order predicate logic is provable, answering a 1928 question of Hilbert and Ackermann.
Gödel's incompleteness theorems
Gödel's incompleteness theorems are two results of mathematical logic published by Kurt Gödel in 1931, showing that any consistent formal system with elementary arithmetic contains undecidable statements.
Gödel's ontological proof
Gödel's ontological proof, also known as Gödel's ontological argument, is a formal modal argument for the existence of God written by Kurt Gödel around 1970.
GOES-16
GOES-16 is a NOAA weather satellite, launched November 19, 2016 as GOES-R, that served as GOES East watching the eastern United States and western Atlantic until 2025.
GOES-17
GOES-17, known as GOES-S before launch, is a NOAA geostationary weather satellite serving as GOES-West from 2019 to 2023; a cooling anomaly degraded its imager but recovered over 97 percent of capability.
GOES-18
GOES-18, known as GOES-T before reaching orbit, is an American geostationary weather satellite operated by NOAA, launched in 2022 and serving as GOES-West from 137.0 degrees west since January 2023.
Goethite
Goethite is an iron oxyhydroxide mineral named for Johann Wolfgang von Goethe, forming as a weathering product of iron-bearing minerals and serving as ore and yellow ochre pigment.
Goetz Oertel
Goetz Oertel, born 1934, is a German-born American solar physicist who served as president of AURA from the mid-1980s to 1999, overseeing Hubble and Gemini.
Goki Eda
Goki Eda (枝 五紀) is a Japan-born physicist at the National University of Singapore known for research on atomically thin two-dimensional materials and exciton physics.
Golay code
The Golay codes are two perfect error-correcting block codes, one binary and one ternary, introduced by Marcel Golay in 1949 and used for error control in the Voyager mission.
Gold
Gold, a chemical element with symbol Au and atomic number 79, is a dense, soft yellow metal prized since prehistoric times as jewelry, coinage, and a store of value.
Gold (color)
Gold is the characteristic yellow color of the metallic element gold, produced by relativistic effects on its electrons, which make it absorb blue light instead of reflecting a silvery white.
Gold bar
A gold bar, also known as a gold ingot, is refined gold cast or minted into a standardized shape, from 1-gram retail bars to 400-ounce wholesale bars.
Gold catalysis
Gold catalysis is the use of gold, as nanoparticles, clusters, cations, or soluble complexes, to accelerate chemical reactions, long thought impossible because bulk gold is chemically inert.
Gold extraction
Gold extraction, also called gold processing, is the set of mining, concentration, and chemical processes used to recover gold from ore, dominated by cyanide leaching in industry and mercury amalgamation in artisanal mining.
Gold mining
Gold mining is the extraction of gold from ore bodies, placer gravels, and recycled material, an industry that produced 3,661.2 tonnes of mine gold in 2024.
Gold nanocages
Gold nanocages (AuNCs) are hollow, porous gold nanostructures with cubic outlines, made from silver nanocubes and studied for cancer imaging, photothermal therapy, and drug delivery.
Gold nanocluster catalysis
Gold nanocluster catalysis uses atomically precise, ligand-protected gold clusters as catalysts and electrocatalysts, notably for CO2 reduction to CO, hydrogen evolution, and tunable syngas production, with Au25(SR)18 as the best-studied example.
Gold nanorods
Gold nanorods (AuNRs) are rod-shaped gold nanoparticles whose optical absorption is tuned from the visible into the near-infrared by aspect ratio, used in biosensing, bioimaging, and photothermal cancer therapy.
Gold nanoshell
A gold nanoshell is a silica-cored nanoparticle with a thin gold shell, invented at Rice University and used to ablate prostate cancer with near-infrared light.
Gold nanostars
Gold nanostars (GNS) are star-shaped gold nanoparticles with about 8 to 10 sharp branches on a 20 to 25 nm core, concentrating near-infrared light for photothermal tumor ablation, SERS, and imaging.
Gold nanowire
A gold nanowire is a wire-like gold nanostructure ranging from a few nanometers wide down to a single chain of atoms, used in transparent electrodes, sensors, and wearable devices.
Gold nugget
A gold nugget is a naturally occurring mass of native gold, ranging from a few grams to tens of kilograms, found in veins or concentrated in placer deposits.
Gold Quarry Mine
The Gold Quarry Mine is a large open-pit gold mine about seven miles north of Carlin in Eureka County, Nevada, operated by Nevada Gold Mines as part of the Carlin Complex.
Gold rush
A gold rush is a sudden migration of people to a region where gold has been newly discovered, recurring through the nineteenth century, most famously in California in 1848.
Gold Sodium Thiomalate
Gold sodium thiomalate, also called sodium aurothiomalate (Myocrisin, Myochrysine), is an injectable organogold drug used from the 1930s to treat rheumatoid arthritis, largely displaced by methotrexate.