All articles starting with F
15,892 articles
Fidenae
Fidenae (Fidēnae), ancient Latin town at modern Castel Giubileo about 5 miles north of Rome on the Via Salaria; allied with Veii, conquered and destroyed by Rome in the fifth century BC, site of the AD 27 amphitheater collapse killing 20,000-50,000.
Fidesz
Fidesz (Fiatal Demokraták Szövetsége, later Fidesz–Magyar Polgári Szövetség) is Viktor Orbán's Hungarian national-conservative party, founded as a liberal youth movement in 1988, governing 1998–2002 and 2010–2026, defeated by Tisza in April 2026.
Fidget spinner
Fidget spinner: a finger-spun toy of two or three weighted prongs around a central bearing, patented by Catherine Hettinger (patent expired 2005), a 2017 craze marketed for ADHD without scientific support.
FIDIC
FIDIC, the International Federation of Consulting Engineers, is the global body for national consulting engineering associations, known for its standard construction contracts like the Red Book.
Fidji Simo
Fidji Simo is a French-born technology executive who was CEO of Instacart and head of the Facebook app before joining OpenAI as CEO of Applications in 2025.
FIDO (rover)
FIDO, or Field Integrated Design and Operations, was a prototype Mars rover built at NASA's Jet Propulsion Laboratory as a testbed for technologies later flown on Mars rovers.
Fido Dido
Fido Dido, the spiky-haired cartoon mascot created by Joanna Ferrone and Sue Rose in 1985, licensed to PepsiCo for 7 Up advertising worldwide and Slice in the US, revived repeatedly since the 2000s.
FidoNet
FidoNet is a worldwide store-and-forward network of bulletin board systems exchanging email and discussion messages over dial-up phone lines, created by Tom Jennings in 1984.
Fiducia supplicans
Fiducia supplicans is a December 2023 declaration of the Dicastery for the Doctrine of the Faith permitting spontaneous pastoral blessings of couples in irregular situations, including same-sex couples, without validating their unions.
Fiducial inference
Fiducial inference is a statistical inference framework that produces a probability distribution for an unknown parameter without a prior, proposed by R. A. Fisher in 1930.
Fiducial marker navigation
Fiducial marker navigation is a localization method for mobile robots that uses printed visual landmarks, such as AprilTags and QR codes, detected by an onboard camera to fix the robot's position.
Fiducial Markers
Fiducial markers are small objects, often gold and about the size of a grain of rice, implanted in or near a tumor to guide precise radiation therapy.
Fiduciary
A fiduciary is a person legally bound to act in another's best interests. Core duties of loyalty and care, no-profit and no-conflict rules, status- and fact-based identification, common law origins, and global variation.
Fiedler vector
A Fiedler vector is an eigenvector of a graph's Laplacian matrix corresponding to the second smallest eigenvalue, known as the algebraic connectivity, and is central to spectral graph partitioning.
Fief
Fief (Medieval Latin feudum, from Germanic fehu, cattle): a tenure of land, rights, or revenue held from a lord by a vassal after homage, in exchange for chiefly military service, central to European feudalism.
Fief and tax policy of al-Adil and al-Kamil
The fief and tax policy of al-Adil and al-Kamil (السياسة المالية للعادل والكامل) governed fiefs and taxes in Ayyubid Egypt and Syria from 1200, built on Saladin's iqta' system.
Fief of Xue
The Fief of Xue (薛邑) was a Warring States fief centered on ancient Xue in southwestern Shandong, held by Tian Ying and later his celebrated son Lord Mengchang.
Fieke Boekhorst
Fieke Boekhorst (Josephine Francisca Maria Boekhorst, born 1957, Helmond) is a Dutch field hockey defender, 1984 Olympic gold medalist, World Cup winner 1978 and 1983, and Netherlands record scorer with 128 goals in 116 caps until 2013.
Field (mathematics)
In mathematics, a field is a set equipped with addition and multiplication satisfying the usual laws of arithmetic; the rational, real, and complex numbers are the familiar examples.
Field (physics)
In physics, a field, also called a physical field, is a quantity with a value at every point in space, mediating forces like gravity and electromagnetism.
Field army
Field army: a land-force echelon of two or more corps, above corps and below army group; also called numbered army. US doctrine treats it as a provisional multi-corps headquarters; Eighth Army in Korea is the sole standing US example.
Field artillery in the American Civil War
Field artillery in the American Civil War (1861–1865) consisted of horse-drawn, muzzle-loading cannon in batteries of four to six guns, led by the 12-pounder Napoleon and the 3-inch Ordnance Rifle.
Field C. Leonard
Field C. Leonard (Field Case Leonard) was an American vascular surgeon in Springfield, Massachusetts, who published New England Journal of Medicine papers on arterial embolectomy between 1950 and 1954.
Field capacity
Field capacity is the water content retained in soil after saturation, once excess water has drained under gravity; introduced in 1931, it remains standard in irrigation and hydrologic modeling.
Field courts-martial
Field courts-martial (Военно-полевые суды) were summary tribunals of the Russian Empire, instituted by Pyotr Stolypin in August 1906 to speed trials and executions of civilians during the 1905–1907 revolution.
Field D*
Field D is an interpolation-based path planning and replanning algorithm for mobile robots, developed by Dave Ferguson and Anthony Stentz at Carnegie Mellon University and published in 2006.
Field Day Theatre Company
Field Day Theatre Company, also known as Field Day, is a Northern Irish theater company founded in Derry in 1980 by Brian Friel and Stephen Rea.
Field electron emission
Field electron emission, also called cold emission or field emission, is the release of electrons from a solid into vacuum by quantum tunneling under a strong electric field.
Field evaporation
Field evaporation is the removal of atoms from a solid surface as positive ions under an intense electric field of a few volts per nanometer.
Field experiment
A field experiment is a study that randomly assigns an intervention to people, schools, or firms in real-world settings, so outcome differences reveal causal effects.