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) * H,

B major B major (or the key of B) 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 ...

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 * H (born 1976), British singer Ian Watkins (Steps) * h (born 1959), British vocalist Steve Hogarth * H (born 1981/82), one of the attackers in the

Sydney gang rapes The Sydney gang rapes were a series of gang rape attacks committed by a group of up to 14 youths led by Bilal Skaf against Australian women and teenage girls (2 with Italian parents, 1 with Greek parents and one part Aboriginal girl), as young as ...

* H. (born 1925), girl who gave birth to a child when she was six years old *

H Waldman H Waldman ('ולדמן אייץ; nickname: H; born January 21, 1972) is an American-Israeli former basketball player. He played the point guard and shooting guard positions. Waldman played in the Israel Basketball Premier League from 1996 to 2001. ...

(born 1972), American-Israeli basketball player

Science and mathematics

* h,

hour An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as of a day and scientifically reckoned between 3,599 and 3,601 seconds, depending on the speed of Earth's rotation. There are 60 minutes in an hour, and 24 ho ...

* h, hecto-, the SI prefix for hundred or 10²

Biology

* Haplogroup H **

Haplogroup H (mtDNA) Haplogroup H is a human mitochondrial DNA (mtDNA) haplogroup. The clade is believed to have originated in Southwest Asia, near present day Syria, around 20,000 to 25,000 years ago. Mitochondrial haplogroup H is today predominantly found in Europ ...

, human mitochondrial DNA ** Haplogroup H (Y-DNA), human Y-chromosome DNA *

ATC code H See also *Sex hormones are in the ATC group G03. * Insulins are in the ATC group A10A. References {{Calcium homeostasis H ...

''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 researchers Justin Fay and Chung-I Wu. The purpose of the test is to distinguish between a DNA sequence evolving randomly ("neutrally") and one evolving under positive selection. T ...

, a statistical test used in DNA analysis

Chemistry

Hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

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

sulfur mustard Mustard gas or sulfur mustard is a chemical compound belonging to a family of cytotoxic and blister agents known as mustard agents. The name ''mustard gas'' is technically incorrect: the substance, when dispersed, is often not actually a gas, b ...

Computer science

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

hexadecimal In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexa ...

in Intel-derived assembly languages * .h, the filename extension for the C include directive called header

Linguistics

* , the

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

symbol for a

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

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

diglossia In linguistics, diglossia () is a situation in which 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 " ...

Mathematics

* H, the

upper half-plane In mathematics, the upper half-plane, \,\mathcal\,, is the set of points in the Cartesian plane with > 0. Complex plane Mathematicians sometimes identify the Cartesian plane with the complex plane, and then the upper half-plane corresponds to t ...

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 (1850–1925), the value of which is zero for negative arguments and one for positive argume ...

* h, impulse response in

LTI system theory LTI can refer to: * ''LTI – Lingua Tertii Imperii'', a book by Victor Klemperer * Language Technologies Institute, a division of Carnegie Mellon University * Linear time-invariant system, an engineering theory that investigates the response of ...

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

Physics and cosmology

Constants

* h,

Planck constant The Planck constant, or Planck's constant, is a fundamental physical constant of foundational importance in quantum mechanics. The constant gives the relationship between the energy of a photon and its frequency, and by the mass-energy equivale ...

* 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 they are, the faster they are moving ...

* 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 they are, the faster they are moving ...

Measures

* H,

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

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

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

* h,

convective heat transfer Convection (or convective heat transfer) is the heat transfer, 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 combin ...

coefficient * H,

magnetic field A magnetic field is a vector 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 to its own velocity and to ...

intensity

Other uses in physics

* H, symbol for the Henry (unit), 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 quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Stand ...

Planets

* H, distortion of symbol for

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...

* 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 nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

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 obvious success indicators such as winn ...

, 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 television series created by Jed Mercurio and produced by World Productions. On 26 June 2012, BBC Two began to broadcast the first series; it was its best-performing drama series in ten years wit ...

'' * "H", the fifth episode of the sixth series of '' Taskmaster'' that aired in 2018

Music

*''h'', a 1990 compilation album by Hitomi (singer) *''H'', a 1980 album by Bob James (musician) * ''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

Other uses

Heroin Heroin, also known as diacetylmorphine and diamorphine among other names, is a potent opioid mainly used as a recreational drug for its euphoric effects. Medical grade diamorphine is used as a pure hydrochloride salt. Various white and brow ...

* Н, a letter of the Cyrillic alphabet analogous to N * Һ, letter

Shha Shha or He (Һ һ; italics: ) is a letter of the Cyrillic script. Its form is derived from the Latin letter H (H h ), but the capital forms are more similar to a rotated Cyrillic letter Che (Ч ч) or a stroke-less Tshe (Ћ ћ) be ...

of the Cyrillic alphabet * 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 and Flintholm. It is one of the six base lines of the S-train network, running ...

, 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 connects with the train at Broad Channel station and is the latest iteration of the Rockaway Shuttle services that have been running on the Rockaway ...

subway service in New York **

Line H Line H is a line of the Buenos Aires Underground. The first phase, between Plaza Once and Caseros, which opened on 18 October 2007, currently stretches over 8.8 km between Hospitales and Facultad de Derecho stations. It is the first entirely ...

of the Buenos Aires Subte * H, a

Hitachi, Ltd. () is a Japanese multinational conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan ''zaibatsu'' and later DKB Group and Fuyo G ...

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

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 (physics), tension. It is the opposite of a strut or column, which is designed to resist compressio ...

, used in construction * Conservative Party of Norway (''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 attributes ...

, such as the UH-60 Blackhawk and AH-64 Apache * H, a symbol for a heliport * H, the international license plate code of Hungary *

Hit (baseball) In baseball statistics, a hit (denoted by H), also called a base hit, is credited to a batter when the batter safely reaches or passes first base after hitting the ball into fair territory with neither the benefit of an error nor a fielder's ...

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 pro ...

, a tractor produced by International Harvester from 1939 to 1953 * Hotel, the military time zone code for UTC+08:00