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Gravity casting
Gravity casting is a metal casting process in which molten metal fills a mold under gravity alone, producing castings in sand molds or reusable metal dies.
Gravity compensation
Gravity compensation is a robotics technique that cancels the torques and forces gravity exerts on a mechanism, so actuators or users need not work against its weight.
Gravity dam
A gravity dam is a dam that resists water pressure by its own weight, typically built as a straight wall of mass concrete on a rock foundation.
Gravity knife
A gravity knife is a knife whose blade is released by gravity or centrifugal force and locks in place, a category long entangled in American criminal law.
Gravity loss
Gravity loss is the reduction in a rocket's velocity gain caused by gravity during powered flight, typically the largest loss in an ascent to orbit.
Gravity Recovery and Interior Laboratory (GRAIL)
The Gravity Recovery and Interior Laboratory (GRAIL) was a NASA mission that used twin spacecraft, Ebb and Flow, to map the Moon's gravity field from 2011 to 2012.
Gravity separation
Gravity separation is a physical beneficiation method that separates particles of different densities by their settling behavior in water, used mainly for coal washing and gold recovery.
Gravity turn
A gravity turn, also called a zero-lift turn, is a rocket ascent maneuver where gravity bends the trajectory from vertical flight toward the horizontal velocity needed for orbit.
Gravity well
A gravity well is the region around a mass within which objects are bound by its gravity, visualized as a depression in gravitational potential energy.
Gravity-1
Gravity-1 (Yinli-1) is a Chinese solid-propellant orbital launch vehicle developed by Orienspace, the world's largest solid rocket, capable of 6.5 tonnes to low Earth orbit.
Gravity-2
Gravity-2 (引力二号, also romanized Yinli-2) is a two-stage, partially reusable Chinese launch vehicle under development by Orienspace, designed to place 21.5 tonnes into low Earth orbit with a recoverable first stage.
Gravity-aided navigation
Gravity-aided navigation is a passive positioning technique matching a vehicle's onboard gravity measurements to a geo-referenced gravity map, correcting inertial drift where satellite signals cannot reach.
Gravity-gradient stabilization
Gravity-gradient stabilization is a passive spacecraft attitude control method using the torque from gravity's variation across a spacecraft to keep one axis pointed toward Earth, requiring no propellant.
Gray goo
Gray goo, also spelled grey goo, is a hypothetical doomsday scenario in which self-replicating nanorobots multiply out of control and consume all material on Earth. Eric Drexler proposed it in 1986.
Gray Oak Oil Pipeline
The Gray Oak Pipeline is an 850-mile Enbridge-operated crude oil pipeline carrying Permian Basin and Eagle Ford crude to Corpus Christi, Freeport, and Houston, started up in 2019.
Gray wolf optimizer
The gray wolf optimizer is a swarm intelligence metaheuristic introduced by Mirjalili, Mirjalili, and Lewis in 2014, mimicking wolf pack hierarchy and hunting to minimize continuous optimization problems.
Gray-box model
A gray-box model (also spelled grey-box) is a mathematical model of a dynamical system combining physical structure with data-driven components, offering interpretability and accuracy on limited data.
Graybar
Graybar Electric Company is an American employee-owned distributor of electrical, industrial, automation, and connectivity products, headquartered in St. Louis, Missouri, and one of North America's largest electrical distributors.
Grayscale
Grayscale, also spelled greyscale, is a digital image type in which each pixel carries one intensity value rather than separate red, green, and blue components; 8-bit images have 256 levels.
Grbl
Grbl is a free, open-source CNC firmware, released under GPLv3, that turns an Arduino Uno into a motion controller: it interprets G-code, plans acceleration, and drives stepper motors.
Grease trap
A grease trap, also called a grease interceptor, is a plumbing device that removes fats, oils, and grease from kitchen wastewater before it reaches the sewer.
Great Ballcourt of Chichén Itzá
The Great Ballcourt of Chichén Itzá (Gran Juego de Pelota) is the largest known Mesoamerican ballcourt, built at Chichén Itzá in Yucatán, Mexico, and famous for its whispering acoustics.
Great Belt East Bridge
The Great Belt East Bridge is a Danish suspension bridge carrying the motorway between Zealand and Funen, opened in 1998 with the Great Belt Link.
Great Britain road numbering scheme
The Great Britain road numbering scheme is the system of identifiers like A1 and M25 used to label classified roads, created by the Ministry of Transport in the early 1920s.
Great British Energy – Nuclear
Great British Energy – Nuclear, formerly Great British Nuclear, is the UK government body delivering new nuclear projects, including the country's first small modular reactors at Wylfa, Wales.
Great Central Railway
The Great Central Railway (GCR) was a British railway company, formed in 1897 by renaming the Manchester, Sheffield & Lincolnshire Railway, whose 1899 London Extension reached Marylebone.
Great County Adit
The Great County Adit, also called County Adit, is a branching mine drainage tunnel network in Cornwall, begun in 1748, draining mines around Gwennap, Redruth, and St Day.
Great Eastern Highway
Great Eastern Highway is the main road link between Perth and Kalgoorlie in Western Australia, running about 592 km and forming part of National Highway 94.
Great Eastern Railway
The Great Eastern Railway was a British railway company, incorporated in 1862, that operated a near-monopoly network across East Anglia and eastern London until absorbed into the London and North Eastern Railway in 1923.
Great Hall of the People (人民大会堂)
The Great Hall of the People, also known as Renmin Dahuitang, is a government building on Tiananmen Square in Beijing, built in 1959 as one of the Ten Great Buildings.