All articles starting with G
18,970 articles
Gibberellic acid
Gibberellic acid (GA₃) is a plant hormone in the gibberellin family, isolated from the rice fungus Gibberella fujikuroi and used to promote germination and stem growth.
Gibberellin
Gibberellins (GAs), tetracyclic diterpenoid plant hormones named after Gibberella fujikuroi, promote stem elongation, germination, and flowering; perceived by GID1 receptors, they trigger DELLA degradation and oppose ABA in seed dormancy.
Gibberish
Gibberish, also jibber-jabber or gobbledygook, is unintelligible or meaningless speech or writing. First attested about 1450 (long dated 1550s), it is likely onomatopoeic from gibber/jabber, with a rejected folk etymology from the alchemist Geber.
Gibberlink
Gibberlink is an open-source protocol in which two AI voice agents, after recognizing each other as AI, switch from speech to data-over-sound transmission, saving compute on calls.
Gibbethon
Gibbethon (Hebrew גִּבְּתוֹן) was a Levitical city of Dan, a Philistine-held frontier town whose sieges in the 10th and 9th centuries BCE brought down two Israelite dynasties.
Gibbeting
Gibbeting, or hanging in chains, was a British post-execution punishment placing an executed criminal's body in an iron cage on a tall pole. Regulated by the 1752 Murder Act, it gibbeted 144 people, ended with James Cook in 1832, and was abolished in 1834; live gibbeting in Britain is legend.
Gibbon
Gibbons (family Hylobatidae), the lesser apes of South and Southeast Asia: 20 species in four genera, pair-living, brachiating, duet-singing apes, all threatened, with a 70 percent population decline since 1980.
Gibbon (site)
A gibbon site is a purpose-built zoo or sanctuary enclosure for gibbons, small arboreal apes of Southeast Asian rainforests that need tall, connected climbing structures for arm-swinging movement.
Gibbons v. Ogden
Gibbons v. Ogden (22 U.S. 1, 1824), the Steamboat Case: Supreme Court decision by Chief Justice Marshall holding that Congress's Commerce Clause power covers navigation and that federal law supersedes New York's Livingston-Fulton steamboat monopoly.
Gibbons–Hawking temperature
The Gibbons–Hawking temperature is the thermal radiation temperature produced by the cosmological event horizon of an expanding de Sitter universe, equal to H/(2π), shown by Gibbons and Hawking in 1977.
Gibbons–Hawking–York boundary term
The Gibbons–Hawking–York (GHY) boundary term is a surface integral added to the Einstein–Hilbert action, identified by York in 1972, that makes the variational principle of general relativity well posed.
Gibbs (lunar crater)
Gibbs is a 78.76-km-wide impact crater on the Moon's eastern limb at 18.37°S, 84.27°E, named by the IAU in 1964 for American mathematical physicist Josiah Willard Gibbs (1839–1903); satellite feature Gibbs D.
Gibbs energy minimization
Gibbs energy minimization is a computational method for finding the equilibrium composition of a chemical or multiphase system by minimizing total Gibbs free energy under element conservation constraints.
Gibbs energy of activation
The Gibbs energy of activation, ΔG‡, is the standard Gibbs energy difference between the transition state and the reactants; a larger barrier means a slower reaction.
Gibbs energy of mixing
The Gibbs energy of mixing is the change in Gibbs energy when pure substances combine to form a mixture at constant temperature and pressure, deciding whether mixing is spontaneous.
Gibbs free energy
Gibbs free energy, or Gibbs energy, is a thermodynamic state function, G = H − TS, whose change at constant temperature and pressure determines whether a process is spontaneous.
Gibbs Island
Gibbs Island (Ostrov Rozhnova) is a ~22 km² island in the South Shetland Islands, Antarctica, 25 km southwest of Elephant Island, known for its dunite-serpentinite mantle complex and large chinstrap penguin, macaroni penguin, and southern fulmar colonies.
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.
Gibbs–Duhem equation
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.
Gibbula
Gibbula Risso, 1826 is a Mediterranean genus of small marine top-shell snails (Trochidae, Cantharidinae), type species G. magus; since a 2017 revision many former species belong to Steromphala or Phorcus.
Gibby Haynes
Gibby Haynes (Gibson Jerome Haynes, born 1957) is the American lead vocalist and co-founder of the psychedelic punk band Butthole Surfers, known for his Gibbytronix vocal effects rig, the 1996 hit Pepper, the 2004 solo album Gibby Haynes and His Problem, and current touring with student musicians.
Gibco
Gibco, short for Grand Island Biological Company, is a cell culture brand owned by Thermo Fisher Scientific. Founded in 1962 in New York, it supplies media, sera, and reagents.
Gibeah
Gibeah, known in Arabic as Tell el-Ful and in the Bible as Gibeah of Saul, is a hilltop site 3.5 miles north of Jerusalem, traditionally identified as King Saul's capital.
Gibeon
Gibeon, also known as el-Jib, is an ancient biblical town at Al Jib in the West Bank, north of Jerusalem, excavated by James Pritchard in the 1950s.
Gibil Patera
Gibil Patera is a 107.63-km-wide volcanic depression (patera) on Jupiter's moon Io, IAU-approved in 1979 and named for the Sumerian fire god, located at −14.91°, 294.59° near Ra Patera.
Gibraltar
Gibraltar, a self-governing British Overseas Territory on Spain's southern tip, ceded by the 1713 Treaty of Utrecht, claimed by Spain, governed by the 2006 Constitution, and tied to the EU by the 2026 UK-EU treaty.