B is the second letter of the Latin alphabet. B may also refer to:

Science, technology, and mathematics

Astronomy

* Astronomical objects in the Barnard list of dark nebulae (abbreviation B) * Latitude (''b'') in the

galactic coordinate system The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an a ...

Biology and medicine

Haplogroup B (mtDNA) In human mitochondrial genetics, haplogroup B is a human mitochondrial DNA (mtDNA) haplogroup. Origin Haplogroup B is believed to have arisen in Asia some 50,000 years before present. Its ancestral haplogroup was haplogroup R. The greatest var ...

, a human mitochondrial DNA (mtDNA) haplogroup *

Haplogroup B (Y-DNA) Haplogroup B (M60) is a human Y-chromosome DNA haplogroup common to paternal lineages in Africa. It is a primary branch of the haplogroup BT. B (M60) is common in parts of Africa, especially the tropical forests of West-Central Africa. It was ...

, a Y-chromosomal DNA (Y-DNA) haplogroup * Blood type B * ATC code B ''Blood and blood forming organs'', a section of the Anatomical Therapeutic Chemical Classification System *

Vitamin B B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. Though these vitamins share similar names (B1, B2, B3, etc.), they are chemically distinct compounds that often coex ...

Hepatitis B Hepatitis B is an infectious disease caused by the '' Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. ...

Berlin Botanical Garden and Botanical Museum The Berlin Botanic Garden and Botanical Museum (german: Botanischer Garten und Botanisches Museum Berlin) is a botanical garden in the locality of the borough of , Berlin, Germany. Constructed between 1897 and 1910 under the guidance of archi ...

, assigned the abbreviation B as a repository of herbarium specimens

Computing

B (programming language) B is a programming language developed at Bell Labs circa 1969 by Ken Thompson and Dennis Ritchie. B was derived from BCPL, and its name may possibly be a contraction of BCPL. Thompson's coworker Dennis Ritchie speculated that the name might be ...

B-Method The B method is a method of software development based on B, a tool-supported formal method based on an abstract machine notation, used in the development of computer software. Overview B was originally developed in the 1980s by Jean-Raymond Abr ...

, for computer software development *

B-tree In computer science, a B-tree is a self-balancing tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time. The B-tree generalizes the binary search tree, allowing for ...

, a data structure *

Bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

(b) *

Byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...

(B) * , an HTML element denoting bold text

Physical and chemical quantities and units

* One of the

reciprocal lattice In physics, the reciprocal lattice represents the Fourier transform of another lattice (group) (usually a Bravais lattice). In normal usage, the initial lattice (whose transform is represented by the reciprocal lattice) is a periodic spatial fu ...

vectors (''b*'') * Breadth (''b''); see length *

Impact parameter In physics, the impact parameter is defined as the perpendicular distance between the path of a projectile and the center of a potential field created by an object that the projectile is approaching (see diagram). It is often referred to in ...

(''b'') *

Molality Molality is a measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent. This contrasts with the definition of molarity which is based on a specified volume of solution. A commonly used unit for molali ...

(''b'') *

Barn (unit) A barn (symbol: b) is a metric unit of area equal to (100 fm2). Originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions, today it is also used in all fields of high-energy physics to exp ...

(b), a unit of area * Magnetic field (''B'') * Napierian

absorbance Absorbance is defined as "the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)". Alternatively, for samples which scatter light, absorbance may be defined as "the negative lo ...

(''B'') *

Rotational constant In rotordynamics, the rigid rotor is a mechanical model of rotating systems. An arbitrary rigid rotor is a 3-dimensional rigid object, such as a top. To orient such an object in space requires three angles, known as Euler angles. A special rig ...

(''B'') * Second

virial coefficient Virial coefficients B_i appear as coefficients in the virial expansion of the pressure of a many-particle system in powers of the density, providing systematic corrections to the ideal gas law. They are characteristic of the interaction potenti ...

(''B'') * Susceptance (''B'') * Bel (''B''), a logarithmic unit equal to ten decibels

Other uses in science, technology, and mathematics

* ''B'', a modal logic *

Boolean domain In mathematics and abstract algebra, a Boolean domain is a set consisting of exactly two elements whose interpretations include ''false'' and ''true''. In logic, mathematics and theoretical computer science, a Boolean domain is usually written as ...

(

\mathbb

), in mathematics * Boron, symbol B, a chemical element *

Bulb (photography) The Bulb setting (abbreviated B) on camera shutters is a momentary-action mode that holds shutters open for as long as a photographer depresses the shutter-release button. The Bulb setting is distinct from shutter's Time (T) setting, which is ...

, a shutter-speed setting * B battery, a battery used to provide the plate voltage of a

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as ...

B horizon A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. ...

, a layer of soil commonly known as subsoil * B, B+ and B−, expressions of buoyancy in

convective available potential energy In meteorology, convective available potential energy (commonly abbreviated as CAPE), is the integrated amount of work that the upward (positive) buoyancy force would perform on a given mass of air (called an air parcel) if it rose vertically thro ...

Linguistics

* В, a letter of the Cyrillic alphabet *

Voiced bilabial stop The voiced bilabial plosive or stop is a type of consonantal sound used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , and the equivalent X-SAMPA symbol is b. The voiced bilabial stop ...

(b, in the International Phonetic Alphabet)

Arts and media

Music

Musical notation

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 re ...

* B major, a scale *

B minor B minor is a minor scale based on B, consisting of the pitches B, C, D, E, F, G, and A. Its key signature has two sharps. Its relative major is D major and its parallel major is B major. The B natural minor scale is: : Changes need ...

, a scale * B major chord,

Chord names and symbols (popular music) Musicians use various kinds of chord names and symbols in different contexts to represent musical chords. In most genres of popular music, including jazz, pop, and rock, a chord name and its corresponding symbol typically indicate one or more ...

* Flat (music), a note lower in pitch by a semitone

Performers

* Beyoncé * B, member of Superorganism (band)

Recordings

* ''B'' (BamBam EP), an extended play by BamBam * ''B'' (Battles EP), an extended play by Battles * ''B'' (I Am Kloot album), a compilation album by I Am Kloot * ''b'' (Moxy Früvous EP), an extended play by Moxy Früvous * "b", an

Iamamiwhoami iamamiwhoami ( ) is the electronic music and audiovisual project of Swedish singer-songwriter Jonna Lee in collaboration with her longtime record producer Claes Björklund. The project has, since 2009, released audiovisual series on their ch ...

song * "B", a song by Todrick Hall from his 2018 album '' Forbidden''

Other media

* /b/, a board on 4chan * ''b'' (newspaper), a free daily, tabloid sized newspaper, published by ''The Baltimore Sun'' * '' Codex Vaticanus Graecus 1209'', an ancient bible *

Rajawali Televisi Rajawali Televisi (RTV, stylized as rtv) is a commercial television network in Indonesia, owned by Rajawali Corpora. RTV is currently segmented as "family television", licensed via the Ministry of Communication and Information Technology, and ...

, previously named B Channel, a television channel in Indonesia * B, the production code for the 1963–64 ''Doctor Who'' serial ''

The Daleks ''The Daleks'' (also known as ''The Mutants'' and ''The Dead Planet'') is the second Serial (radio and television), serial in the British science fiction on television, science fiction television series ''Doctor Who'', which was first broadca ...

'' * B, a character in '' Total Drama: Revenge of the Island'' * '' "B" Is for Burglar'', the second novel in Sue Grafton's "Alphabet mystery" series, published in 1985

Places

* Belgium, on the

vehicle registration plates of the European Union A vehicle registration plate, also known as a number plate (British English), license plate or licence plate ( American English and Canadian English respectively), is a metal or plastic plate or plates attached to a motor vehicle or trailer for ...

* Bucharest, on the

vehicle registration plates of Romania The most common format for vehicle registration plates in Romania consists of black letters on white background in the format CC 12 ABC, where CC is a two letter county code, 12 is a two digit group, and ABC is a three letter group. F ...

Sport

* Australian rules football positions#Full back, in Australian Rules football * B, often used after the name of football clubs to denote a

reserve team In sports, a reserve team is a team composed of players under contract to a club but who do not normally play in matches for the first team. Reserve teams often include back-up players from the first team, young players who need playing time to i ...

Transportation

B (New York City Subway service) The B Sixth Avenue Express is a rapid transit service in the B Division of the New York City Subway. Its route emblem, or "bullet", is colored , since it uses the IND Sixth Avenue Line in Manhattan. The B operates only on weekdays between Br ...

* B Line (Los Angeles Metro) *

Line B (Buenos Aires Metro) Line B of the Buenos Aires Underground runs from Leandro N. Alem to Juan Manuel de Rosas in Villa Urquiza. Line B opened to the public on 17 October 1930. In recent years, it has held the title of being the most used line of the Buenos Aires ...

* B (S-train), in Copenhagen *

RER B RER B is one of the five lines in the Réseau Express Régional (English: Regional Express Network), a hybrid commuter rail and rapid transit system serving Paris, France and its Île-de-France suburbs. The RER B line crosses the region from no ...

, a line in the RER of Paris *

Bundesstraße ''Bundesstraße'' (German for "federal highway"), abbreviated ''B'', is the denotation for German and Austrian national highways. Germany Germany's ''Bundesstraßen'' network has a total length of about 40,000 km. German ''Bundesstraßen'' ...

(federal highway) in Austria and Germany (abbreviation B) *

Bayshore Route The signed as Route B, is one of the routes of the tolled Shuto Expressway system in the Greater Tokyo Area. The Bayshore Route is a stretch of toll highway that runs from the Kanazawa ward of Yokohama in the west, northeast to the city of ...

of Shuto Expressway in Japan, numbered as route B

Other uses

* B (grade), for evaluation of students' work *

B (bank) B was a banking brand in the United Kingdom which operated between 2016 and 2019 as a trading division of Clydesdale Bank plc. B focused on app-based banking and computer learning of personal finances to help customers manage their money. Histo ...

, a banking brand in the United Kingdom *

Barnabites , image = Barnabites.svg , image_size = 150px , caption = One version of the Barnabite logo. "P.A." refers to Paul the Apostle and the three hills symbolize the vows of poverty, chastity and obedience. , a ...

( la, Clerici Regulares Sancti Pauli), a religious order abbreviated to the postnominal ''B.'' * Bravo, the military time zone code for UTC+02:00 *

Brutus Marcus Junius Brutus (; ; 85 BC – 23 October 42 BC), often referred to simply as Brutus, was a Roman politician, orator, and the most famous of the assassins of Julius Caesar. After being adopted by a relative, he used the name Quintus Serv ...

, a Roman cognomen (abbreviation B) * Farmall B, a tractor produced by International Harvester from 1939 to 1947 * Dominical letter B for a common year starting on Saturday