H is the eighth letter of the Latin alphabet. H may also refer to:

Musical symbols

* H number,

Harry Halbreich Harry Halbreich (Berlin, 9 February 1931 – Brussels, 27 June 2016) was a Belgian musicologist.Dust jacket biography of Harry Halbreich from #Halbreich2007, Halbreich (2007).Patrick Szersnovicz. Harry Halbreich (obituary). ''Diapason (magazine), ...

reference mechanism for music by Honegger and Martinů * H,

B (musical note) B, also known as Si, Ti, or, in some European countries, H, is the seventh note and the twelfth semitone of the fixed-Do solfège. Its enharmonic equivalents are C (C-flat) and A (A-double sharp). When calculated in equal temperament with a ...

* H,

B major B major is a major scale based on B. The pitches B, C, D, E, F, G, and A are all part of the B major scale. Its key signature has five sharps. Its relative minor is G-sharp minor, its parallel minor is B minor, and its enharmonic equi ...

People

* H. (noble) (died after 1279), an unidentified nobleman in the Kingdom of Hungary who served as master of the horse * H. (1900–1995), British activist and economist Edgar Hardcastle * H (born 1957), British guitarist

Adrian Smith Adrian Smith may refer to: * Adrian Smith (basketball) (born 1936), American basketball player *Adrian Smith (architect) (born 1944), American architect *Sir Adrian Smith (statistician) (born 1946), English statistician and academic *Adrian Smith (m ...

* H (born 1976), British singer

Ian Watkins (Steps) Ian Watkins may refer to: * Ian Watkins (Lostprophets singer) Ian David Karslake Watkins (born 30 July 1977) is a Welsh former singer who was best known as the lead singer and frontman of the rock band Lostprophets. His career ended after he ...

* h (born 1959), British vocalist

Steve Hogarth Steve Hogarth (born Ronald Stephen Hoggarth, 14 May 1956), also known as "h", is an English musician. Since 1989, he has been the lead singer of the rock band Marillion, for which he also performs additional keyboards and guitar. Hogarth was f ...

* H (born 1981/82), one of the attackers in the Sydney gang rapes * H Waldman (born 1972), American-Israeli basketball player

Science and mathematics

* h,

hour An hour (symbol: h; also abbreviated hr) is a unit of time historically reckoned as of a day and defined contemporarily as exactly 3,600 seconds ( SI). There are 60 minutes in an hour, and 24 hours in a day. The hour was initially establis ...

* h,

hecto- ''Hecto'' (symbol: h) is a decimal unit prefix in the metric system denoting a factor of one hundred. It was adopted as a multiplier in 1795, and comes from the Greek , meaning "hundred". In 19th century English it was sometimes spelled "hecato" ...

, the SI prefix for hundred or 10²

Biology

* Haplogroup H **

Haplogroup H (mtDNA) Haplogroup H is a Human mitochondrial DNA haplogroup, human mitochondrial DNA (mtDNA) haplogroup. The clade is believed to have originated in West Asia, near present-day Syria, around 20,000 to 25,000 years ago. A specimen found in South Italy f ...

, human mitochondrial DNA **

Haplogroup H (Y-DNA) Haplogroup H (Y-DNA), also known as H-L901/M2939, is a Y-chromosome haplogroup. The primary branch H1 (H-M69) and its subclades is one of the most predominant haplogroups amongst populations in South Asia, particularly its descendant H1a1 ...

, human Y-chromosome DNA *

ATC code H See also *Sex hormones are in the ATC group G03. *Insulin Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (''INS)'' gene. It is the main Anab ...

''Systemic hormonal preparations, excluding sex hormones and insulins'', a section of the Anatomical Therapeutic Chemical Classification System *

Fay and Wu's H Fay and Wu's H is a statistical test created by and named after two researcherJustin Fayand Chung-I Wu. The purpose of the test is to distinguish between a DNA sequence evolving randomly ("neutrally") and one evolving under positive selection. Th ...

, a statistical test used in DNA analysis

Chemistry

Hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

, symbol H, a chemical element * H, code for a formulation of

sulfur mustard Mustard gas or sulfur mustard are names commonly used for the organosulfur chemical compound bis(2-chloroethyl) sulfide, which has the chemical structure S(CH2CH2Cl)2, as well as other species. In the wider sense, compounds with the substituen ...

* H (or His), an abbreviation for the amino acid

histidine Histidine (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an Amine, α-amino group (which is in the protonated –NH3+ form under Physiological condition, biological conditions), a carboxylic ...

Computer science

* Language H, procedural programming language * or , suffixed to denote

hexadecimal Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbo ...

in Intel-derived assembly languages * .h, the filename extension for the C

include directive An include directive instructs a text file processor to replace the directive text with the content of a specified file. The act of including may be logical in nature. The processor may simply process the include file content at the location of ...

called header

Linguistics

* , the

International Phonetic Alphabet The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standard written representation ...

symbol for a

voiceless glottal fricative The voiceless glottal fricative, sometimes called voiceless glottal transition or the aspirate, is a type of sound used in some spoken languages that patterns like a fricative or approximant consonant '' phonologically'', but often lacks the ...

sound * H or high, the high-prestige register in a

diglossia In linguistics, diglossia ( , ) is where two dialects or languages are used (in fairly strict compartmentalization) by a single language community. In addition to the community's everyday or vernacular language variety (labeled "L" or "low" v ...

Mathematics

* H, the

upper half-plane In mathematics, the upper half-plane, is the set of points in the Cartesian plane with The lower half-plane is the set of points with instead. Arbitrary oriented half-planes can be obtained via a planar rotation. Half-planes are an example ...

of the complex numbers * , the

Heaviside step function The Heaviside step function, or the unit step function, usually denoted by or (but sometimes , or ), is a step function named after Oliver Heaviside, the value of which is zero for negative arguments and one for positive arguments. Differen ...

* h, impulse response in

LTI system theory In system analysis, among other fields of study, a linear time-invariant (LTI) system is a system that produces an output signal from any input signal subject to the constraints of linearity and time-invariance; these terms are briefly define ...

* H, system function, system response, or transfer function in

Physics and cosmology

Constants

* h,

Planck constant The Planck constant, or Planck's constant, denoted by h, is a fundamental physical constant of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and the wavelength of a ...

* H,

Hubble constant Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther a galaxy is from the Earth, the faste ...

* h,

dimensionless Hubble constant Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther a galaxy is from the Earth, the faste ...

Measures

* H, absolute magnitude in the context of the Solar system * H (as in ), magnitude of

enthalpy Enthalpy () is the sum of a thermodynamic system's internal energy and the product of its pressure and volume. It is a state function in thermodynamics used in many measurements in chemical, biological, and physical systems at a constant extern ...

* h,

convective heat transfer Convection (or convective heat transfer) is the transfer of heat from one place to another due to the movement of fluid. Although often discussed as a distinct method of heat transfer, convective heat transfer involves the combined processes of ...

coefficient * H,

magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

intensity

Other uses in physics

* H, symbol for the

Henry (unit) The henry (symbol: H) is the unit of electrical inductance in the International System of Units (SI), defined as 1 kg⋅ m2⋅ s−2⋅ A−2. If a current of 1 ampere flowing through a coil produces flux linkage of 1 weber turn, that coil h ...

, the SI derived unit of inductance * H⁰, the symbol of the

Higgs boson The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the excited state, quantum excitation of the Higgs field, one of the field (physics), fields in particl ...

Planets

* H, distortion of symbol for

Uranus Uranus is the seventh planet from the Sun. It is a gaseous cyan-coloured ice giant. Most of the planet is made of water, ammonia, and methane in a Supercritical fluid, supercritical phase of matter, which astronomy calls "ice" or Volatile ( ...

* h, distortion of symbol for

Saturn Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...

Other uses in science

h-index The ''h''-index is an author-level metric that measures both the productivity and citation impact of the publications, initially used for an individual scientist or scholar. The ''h''-index correlates with success indicators such as winning t ...

, an author-level metric of the productivity and citation impact of the publications of a scientist or scholar

Arts and media

Film and TV

* ''H'' (1990 film), a 1990 Canadian film * ''H'' (2002 film), a 2002 Korean film * ''H.'' (2014 film), a 2014 American film by Rania Attieh and Daniel Garcia * ''H'' (TV series), a 1998-2002 French TV series * H, the production code for the 1964 ''Doctor Who'' serial '' The Reign of Terror'' * H, a codename used to refer to an anonymous individual in the police procedural drama ''

Line of Duty ''Line of Duty'' is a British police procedural and serial drama television programme created by Jed Mercurio and produced by World Productions for the British Broadcasting Corporation (BBC). It began broadcasting on BBC Two on 26 June 2012. ...

'' * "H", the fifth episode of the sixth series of '' Taskmaster'' that aired in 2018 * The H logo used for Globo’s midday news program ''

Jornal Hoje ''Jornal Hoje'' is a news program aired by the Brazilian television broadcaster TV Globo. The program is broadcast in the early afternoon from Monday to Saturday as part of a news block that also includes '' Praça TV'' and ''Globo Esporte''. It i ...

Music

*''h'', a 1990 compilation album by

Hitomi (singer) , known professionally as , is a Japanese singer-songwriter. She began her career as teen model before making her singing debuting under the helm of Tetsuya Komuro in 1994, who produced Hitomi's earliest work in pop music. Hitomi has striven for ...

*''H'', a 1980 album by

Bob James (musician) Robert McElhiney James (born December 25, 1939) is an American jazz keyboardist, arranger, and record producer. He founded the band Fourplay and wrote "Angela", the theme song for the TV show ''Taxi (TV series), Taxi.'' According to ''VICE (m ...

* ''H'' (Ayumi Hamasaki EP), 2002 * ''H'' (Lee Hae-ri EP), 2017 * "H." (song), a song by Tool on their 1996 ''Ænima'' album

Other media

* ''H'' (magazine) * Revista H, a monthly Mexican men's magazine * '' "H" Is for Homicide'', the eighth novel in Sue Grafton's "Alphabet mystery" series, published in 1991

Transportation

* Saviem H, a range of medium/heavy cab-over trucks *

Farmall H The Farmall H is a medium-sized two-plow row crop tractor produced by International Harvester under the Farmall brand from 1939 to 1954. It was the most widely produced of International Harvester's " letter series", with approximately 390,000 pr ...

, a medium-sized crop tractor produced by International Harvester

Trains

H (S-train) H is an S-train service in Metropolitan Copenhagen, Denmark that serves mainly the outer part of Frederikssundbanen, running partially non-stop between Ballerup station, Ballerup and Flintholm station, Flintholm. It is one of the six base lines ...

, a train service in Metropolitan Copenhagen * H,

Rockaway Park Shuttle The Rockaway Park Shuttle is a New York City Subway shuttle train that operates in Queens. It is the latest iteration of the Rockaway Shuttle services that have been running on the Rockaway peninsula since 1956. This shuttle train provides ser ...

subway service in New York * Line H of the Buenos Aires Subte *

Tokyo Metro Hibiya Line The is a subway line in Tokyo, Japan, owned and operated by Tokyo Metro. The line was named after the Hibiya area in Chiyoda, Tokyo, Chiyoda's Yurakucho district, under which it passes. On maps, diagrams and signboards, the line is shown using t ...

, a subway service operated by the Tokyo Metro, labeled Logo of Tokyo Metro Hibiya Line

, the official West Japan Railway Company service symbol for the

JR Tōzai Line is one of several commuter rail lines and services in the Osaka-Kobe-Kyoto Metropolitan Area, operated by West Japan Railway Company (JR West). The line, whose name literally means "east-west", runs underground through central Osaka and conne ...

and

Katamachi Line The , officially nicknamed the , is a commuter rail line and service in the Osaka-Kobe-Kyoto Metropolitan Area of Japan, owned and operated by West Japan Railway Company (JR West). The line connects Kizu Station (Kyoto), Kizu Station in Kyoto Pr ...

Other uses

Heroin Heroin, also known as diacetylmorphine and diamorphine among other names, is a morphinan opioid substance synthesized from the Opium, dried latex of the Papaver somniferum, opium poppy; it is mainly used as a recreational drug for its eupho ...

* H, sexual content or activity, associated with Japanese "Hentai" * H, a

Hitachi () is a Japanese Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1910 and headquartered in Chiyoda, Tokyo. The company is active in various industries, including digital systems, power and renewable ener ...

mobile phone *

Hurricane tie A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. It is the opposite of a strut or column, which is designed to resist compression. Ties may be ...

, used in construction *

Conservative Party of Norway The Conservative Party or The Right (, , , H; ) is a liberal-conservative List of political parties in Norway, political party in Norway. It is the major party of the Norwegian centre-right, and was the leading party in government as part of the ...

(''Høyre'') * The military designation for

helicopters A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribu ...

, such as the UH-60 Blackhawk and AH-64 Apache * H, a symbol for a

heliport A heliport is a small airport which has a helipad, suitable for use by helicopters, powered lift, and various types of vertical lift aircraft. Designated heliports typically contain one or more touchdown and liftoff areas and may also hav ...

* H, the

international license plate code The country in which a motor vehicle's vehicle registration plate was issued may be indicated by an international vehicle registration code, also called Vehicle Registration Identification code or VRI code, formerly known as an Internationa ...

of Hungary *

Hit (baseball) In baseball statistics, a hit (denoted by H), also called a base hit, is credited to a batting (baseball), batter when the batter safely reaches or passes first base after hitting the ball into fair ball, fair territory with neither the benefit ...

* Hotel, the military time zone code for UTC+08:00 * H, a harder grade of

pencil lead A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage and keeps it from marking the user's hand. Pencils create marks by physical abrasion (mechanical), abrasi ...