All articles starting with H
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Horseball
Horseball (horse-ball) is a team equestrian sport from Argentine pato, codified in France in 1979: four riders a side pass a six-handled ball and score through a 3.50 m ring; FEI-recognised since 2004, FIHB-governed, France dominant.
HorsegiirL
HorsegiirL, aka Stella Stallion, is a Berlin-based German DJ, producer, and singer who performs masked as a half-human, half-horse pop star; known for the viral 2023 hit "My Barn My Rules," the 2025 EP v.i.p. - very important pony, and the 2026 RCA debut album Nature Is Healing.
Horsehead Nebula
The Horsehead Nebula (Barnard 33) is a dark nebula in Orion, about 1,300 light-years away, silhouetted against the bright nebula IC 434 and first recorded in 1888.
Horsemen of Apocalypse
Horsemen of Apocalypse: Marvel Comics supervillain team serving En Sabah Nur as Death, War, Famine, and Pestilence; debuted in X-Factor #15 (1987); members include Archangel, Wolverine, Gambit, and Polaris.
Horsens
Horsens is a city on Horsens Fjord in eastern Jutland, Denmark, seat of Horsens Kommune (98,999 inhabitants, 2026). Settled since the 900s, a mint town in the 1100s, and Denmark's fifth-largest city in 1901, it grew as an industrial town and is known for Industrimuseet and FÆNGSLET.
Horsens Fjord and Endelave
Horsens Fjord and Endelave (Horsens Fjord, havet øst for og Endelave) is a shallow East Jutland fjord, adjacent Kattegat sea and island in Denmark, protected as Ramsar site 152 (1977) and Natura 2000 site 56 (DK00DY156), 46,154 ha, threatened by nutrient enrichment and fish farms.
Horsepower
Horsepower (hp) is a unit of power, originally defined by James Watt in the 1780s to compare steam engines with draft horses; one mechanical horsepower equals about 745.7 watts.
Horserace (drinking game)
Horserace, also Horse Race or Racing Aces (German Pferderennen, Ass-Rennen), is a drinking card game where four Aces race along a track of face-down cards, players bet drinks on a suit, and the dealer flips cards to move horses.
Horseracing Integrity and Safety Authority
Horseracing Integrity and Safety Authority (HISA): private nonprofit self-regulatory body created by the 2020 Horseracing Integrity and Safety Act, overseen by the FTC, enforcing uniform Thoroughbred racetrack safety and anti-doping rules; distinct from state racing commissions and from HIWU, its ADMC enforcement agency.
Horseradish
Horseradish (Armoracia rusticana), a Brassicaceae perennial from southeastern Europe and western Asia, grown over 3,000 years for its pungent taproot; allyl isothiocyanate from sinigrin gives the heat, and it substitutes for wasabi.
Horseradish peroxidase
Horseradish peroxidase (HRP, EC 1.11.1.7) is a heme glycoprotein enzyme from horseradish roots (Armoracia rusticana), the standard reporter enzyme in ELISA, Western blot, and immunohistochemistry, with isoenzyme C1A (34 kDa) best studied.
Horses (album)
Horses is Patti Smith's 1975 debut album on Arista, produced by John Cale at Electric Lady Studios with a Mapplethorpe cover; a poetry-punk landmark in the National Recording Registry and Grammy Hall of Fame.
Horses (video game)
Horses, a first-person psychological horror adventure game by Santa Ragione, was released in 2025 and became a controversy after being banned by Steam and Epic Games Store.
Horses in the United States
Horses in the United States, about 6.65 million strong, descend from animals Spanish colonists reintroduced in the 1490s, and the equine industry adds $177 billion a year to the economy.
Horses in warfare
Horses in warfare: the military use of the horse as cavalry mount, artillery draft, and pack animal from roughly 5,000 years ago to mechanization; over 368,000 horses served on the WWI Western Front, and today only ceremonial units remain.
Horses in World War I
Horses in World War I: British Army draught, pack and cavalry horses, 1914-1918. Over 368,000 on the Western Front by 1917; 75 percent of deaths from disease or exhaustion; Remount Department spent £67.5 million procuring them.
Horses in World War II
Horses in World War II: belligerents used millions of horses, chiefly for hauling artillery and supplies. Germany employed about 2.8 million horses and lost over 1.55 million; the US and Britain mechanized, with the mule leading US animal transport.
Horses of Saint Mark
The Horses of Saint Mark (Cavalli di San Marco) are four gilded copper horses looted from Constantinople in 1204 and displayed at St Mark's Basilica in Venice.
Horseshoe
A horseshoe is a crescent-shaped metal or composite plate fitted to a horse's hoof to protect it from wear, a practice possibly first done by the Celts.
Horseshoe bat
Horseshoe bats (Rhinolophidae, genus Rhinolophus) are Old World insectivorous bats with a horseshoe-shaped noseleaf, high-duty-cycle constant-frequency echolocation, Doppler shift compensation, about 106–112 species, and roles as SARS-like coronavirus reservoirs.
Horseshoe Bend (Arizona)
Horseshoe Bend (Arizona) is a 270-degree entrenched meander of the Colorado River near Page, in Glen Canyon National Recreation Area, about 1,000 feet deep, formed by plateau uplift, with a City of Page parking lot and Navajo Nation overlook trail.
Horseshoe Canyon Formation
Horseshoe Canyon Formation, Upper Cretaceous (late Campanian–early Maastrichtian) coal-bearing sandstone, siltstone, and mudstone unit in Alberta, Canada; dinosaur-fossil-rich Drumheller Badlands, Edmonton Group, up to 750 m thick.
Horseshoe crab
Horseshoe crab (Limulus polyphemus and three Asian Tachypleus/Carcinoscorpius species): ancient chelicerate arthropods, not true crabs, with 450-million-year fossil record; blue blood supplies the LAL endotoxin test; American species Vulnerable, tri-spine Endangered.
Horseshoe Curve (Pennsylvania)
Horseshoe Curve is a three-track railroad curve west of Altoona, Pennsylvania, built by the Pennsylvania Railroad and opened in 1854 to carry its main line over the Allegheny Mountains.
Horseshoe Falls
Horseshoe Falls, also called the Canadian Falls, is the largest of Niagara Falls' three waterfalls, carrying about 90 percent of the river's flow on the Canadian side of the border.
Horseshoe Island
Horseshoe Island (Isla Herradura) is a small rocky Antarctic island in Marguerite Bay, Fallières Coast, named by Rymill's BGLE in 1936-37 for its crescent shape; it hosted FIDS Base Y (1955-1960), now Historic Site and Monument No. 63, and Farrier Col became ASPA 181 in 2024.
Horseshoe kidney
Horseshoe kidney, a congenital renal fusion anomaly (fused kidney, renal fusion), joins both kidneys at the lower poles via an isthmus; affects about 1 in 500 people, causing stones, PUJ obstruction, reflux, and elevated malignancy risk.
Horseshoe prior
The horseshoe prior is a Bayesian shrinkage prior for sparse regression, introduced by Carvalho, Polson, and Scott in 2009, that shrinks noise hard while leaving strong signals unshrunk.
Horseshoe theory
Horseshoe theory, attributed to Jean-Pierre Faye, claims the far left and far right resemble each other in authoritarian methods and rhetoric while the center stands apart; peer-reviewed evidence is mixed and many scholars treat it as metaphor, not established political science.
Horseshoe vortex
The horseshoe vortex is a closed loop of vortex filaments that models the lift and wake of a finite wing, introduced by Ludwig Prandtl in lifting-line theory.