I is the ninth letter of the Latin alphabet. I or i may also refer to:

Language

* I (pronoun), the first-person singular subject pronoun in English *

I (Cyrillic) И и (И и; italics: ) is a letter used in almost all Cyrillic alphabets with the exception of Belarusian. It commonly represents the close front unrounded vowel , like the pronunciation of in "machine", or the near-close near-front u ...

, a letter used in almost all ancient and modern Cyrillic alphabets * ı,

dotless I I, or ı, called dotless I, is a letter used in the Latin-script alphabets of Azerbaijani, Crimean Tatar, Gagauz, Kazakh, Tatar, Kyrgyz, and Turkish. It commonly represents the close back unrounded vowel , except in Kazakh where it represen ...

, letter used in Turkish and Azerbaijani * i,

close front unrounded vowel The close front unrounded vowel, or high front unrounded vowel, is a type of vowel sound that occurs in most spoken languages, represented in the International Phonetic Alphabet by the symbol i. It is similar to the vowel sound in the English wo ...

, in the International Phonetic Alphabet * ɨ,

close central unrounded vowel The close central unrounded vowel, or high central unrounded vowel, is a type of vowel sound used in some languages. The symbol in the International Phonetic Alphabet that represents this sound is , namely the lower-case letter ''i'' with a hori ...

, in the International Phonetic Alphabet * ɪ,

near-close near-front unrounded vowel The near-close front unrounded vowel, or near-high front unrounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , i.e. a small capital letter ''i ...

, in the International Phonetic Alphabet * I (kana), one of the Japanese kana that each represent one mora * I, male prefix to some Balinese names

Science, technology, and mathematics

Biology

Troponin I Troponin I is a cardiac and skeletal muscle protein family. It is a part of the troponin protein complex, where it binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Troponin I prevents myosin from binding to ac ...

, one of the three

troponin image:Troponin Ribbon Diagram.png, 400px, Ribbon representation of the human cardiac troponin core complex (52 kDa core) in the calcium-saturated form. Blue = troponin C; green = troponin I; magenta = troponin T.; ; rendered with PyMOL Troponin, ...

s *

Haplogroup I (mtDNA) Haplogroup I is a human mitochondrial DNA (mtDNA) haplogroup. It is believed to have originated about 21,000 years ago, during the Last Glacial Maximum (LGM) period in West Asia (; ; ). The haplogroup is unusual in that it is now widely distrib ...

, a human mitochondrial DNA (mtDNA) haplogroup *

Haplogroup I (Y-DNA) Haplogroup I (M170) is a Y-chromosome DNA haplogroup. It is a subgroup of haplogroup IJ, which itself is a derivative of the haplogroup IJK. Subclades I1 and I2 can be found in most present-day European populations, with peaks in some Nort ...

, a Y-chromosomal DNA (Y-DNA) haplogroup * Olfactory nerve, the 1st cranial nerve in human anatomy * the Lợn Ỉ or

Vietnamese Pot-bellied Vietnamese Pot-bellied is the exonym for the Lon I ( vi, Lợn Ỉ, italic=no) or I pig, an endangered traditional Vietnamese breed of small domestic pig. The I is uniformly black and has short legs and a low-hanging belly, from which the name ...

pig

Chemistry

* Iodine, symbol I, a chemical element * I, isoleucine, an amino acid * I, ionic strength in a chemical solution * ,

Van 't Hoff factor The van 't Hoff factor (named after Dutch chemist Jacobus Henricus van 't Hoff) is a measure of the effect of a solute on colligative properties such as osmotic pressure, relative lowering in vapor pressure, boiling-point elevation and free ...

Computing

* i, a common generic index variable often used in program loops * <i>, an HTML element for marking italic type * .i, the common filename extension for a file that contains the output from a

preprocessor In computer science, a preprocessor (or precompiler) is a program that processes its input data to produce output that is used as input in another program. The output is said to be a preprocessed form of the input data, which is often used by so ...

* i-, a prefix for

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...

products e.g. iMac, iPod, iPhone * i-, an

Internet-related prefix Internet-related prefixes such as '' e-'', '' i-'', ''cyber-'', ''info-'', ''techno-'' and ''net-'' are added to a wide range of existing words to describe new, Internet- or computer-related flavors of existing concepts, often electronic products ...

used by Internet and electronic companies

Mathematics

* I, the

Roman numeral Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, ea ...

for 1 * ,

imaginary unit The imaginary unit or unit imaginary number () is a solution to the quadratic equation x^2+1=0. Although there is no real number with this property, can be used to extend the real numbers to what are called complex numbers, using addition an ...

, for which * or , identity matrix of indeterminate size (or of size ) * ,

unit interval In mathematics, the unit interval is the closed interval , that is, the set of all real numbers that are greater than or equal to 0 and less than or equal to 1. It is often denoted ' (capital letter ). In addition to its role in real analysis ...

, which contains all real numbers from 0 to 1 inclusive * , an index variable, e. g. in a

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

or for summation * , the regularized incomplete beta function (of a variable and parameters ) * , the

unit vector In mathematics, a unit vector in a normed vector space is a vector (often a spatial vector) of length 1. A unit vector is often denoted by a lowercase letter with a circumflex, or "hat", as in \hat (pronounced "v-hat"). The term ''direction v ...

along the ''x''-axis in Cartesian coordinates

Physics and astronomy

* , , electric current * ,

isospin In nuclear physics and particle physics, isospin (''I'') is a quantum number related to the up- and down quark content of the particle. More specifically, isospin symmetry is a subset of the flavour symmetry seen more broadly in the interactions ...

* ,

luminous intensity In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human e ...

* , moment of inertia * ,

orbital inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth ...

* I (Roman number one), in the Yerkes spectral classification scheme, the symbol for supergiants

Telecommunication

I band (NATO) The NATO I band is the obsolete designation given to the radio frequencies from 8 000 to 10 000 MHz (equivalent to wavelengths between 3.75 and 3 cm) during the Cold War period. Since 1992 frequency allocations, allotment and assignments are ...

, the range of radio frequencies from 8 GHz to 10 GHz in the electromagnetic spectrum * I, the ITU prefix allocated to Italy in radio communication * I, in

QAM Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signa ...

modulation schemes, the in-phase communications channel

Other uses in technology

* i, a suffix unit for

video resolution The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is ...

(vertical Interlaced lines), as in 480i or 1080i * ''I'', in the

YIQ YIQ is the color space used by the analog NTSC color TV system, employed mainly in North and Central America, and Japan. ''I'' stands for ''in-phase'', while ''Q'' stands for ''quadrature'', referring to the components used in quadrature amplitud ...

colorspace commonly used with the NTSC television encoding scheme, the color-difference channel which is in-phase with the subcarrier

Arts and media

Music

I (band) I were a Norwegian black metal supergroup formed in 2006. The band features Immortal members Abbath and Armagedda, Gorgoroth bassist TC King, and Enslaved's Ice Dale. The band cites Bathory as one of their major influences. History The ba ...

, a Norwegian heavy metal band * I, a diatonic function in tonal music theory

Albums

* ''i'' (A.R. Kane album), 1989 * ''I'' (Ben Lester album), 2019 * ''I'' (Cilvaringz album), 2007 * ''I'' (Cursed album), 2003 * ''I'' (Die Krupps album), 1992 * ''I'' (Felix Jaehn album), 2018 * ''I'' (Ikimono-gakari album), 2013 * ''I'' (Jaejoong EP), 2013 * ''I'' (JonnyX and the Groadies album), 2005 * ''I'' (Juju album), 2018 * ''I'' (Kingston Wall album), 1992 * ''I'' (Kurt Nilsen album), 2003 * ''i'' (The Magnetic Fields album), 2004 * ''I'' (Meshuggah EP), 2004 * ''i'' (Misako Odani album), 1997 * ''I'' (Nightingale album), 2000 * ''I'' (Petbrick album), 2019 * ''I'' (Sahg album), 2006 * ''I'' (Taeyeon EP), 2015 * ''I'' (Xerath album), 2009 * ''I'' (soundtrack), by A. R. Rahman from the eponymous 2015 film

Songs

* "i" (Kendrick Lamar song), a 2014 song by Kendrick Lamar from his album ''To Pimp a Butterfly'' * "i" (Lil Skies song), a song 2019 by Lil Skies from his debut album ''Shelby'' * "I" (Taproot song), a 2001 song by band Taproot from their album ''Gift'' * "

I (Who Have Nothing) "I (Who Have Nothing)" (sometimes billed as "I Who Have Nothing") is an English language cover of the Italian song "''Uno dei Tanti''" (English: "One of Many"), with music by Carlo Donida and lyrics by Giulio "Mogol" Rapetti. The initial version ...

", a 1966 Ben. E. King song also recorded by Tom Jones, who used the title for one of his albums * "I", a 2003 song on ''

Weather Systems Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the tr ...

'', an album by Andrew Bird * "I", a 1992 song on ''

Selected Ambient Works 85–92 ''Selected Ambient Works 85–92'' is the debut studio album by Aphex Twin, the pseudonym of British electronic musician Richard D. James. It was released on 9 November 1992 through Apollo Records, a subsidiary of Belgian label R&S Records. Th ...

'', an album by Aphex Twin * "I", a 1992 song on ''

Dehumanizer ''Dehumanizer'' is the sixteenth studio album by English rock band Black Sabbath, released on June 22, 1992. It was Sabbath's first studio album in over a decade to feature vocalist Ronnie James Dio and drummer Vinny Appice, and their first ...

'', an album by Black Sabbath * "I", a 1997 song on ''

Coal Chamber Coal Chamber is an American nu metal band formed by Dez Fafara and Meegs Rascón in Los Angeles, California in 1993. Prior to Coal Chamber, the two had also created the band She's in Pain, in 1992. The original lineup also consisted of bassist ...

'', an album by Coal Chamber * "I", a 1967 song on ''

Underground Underground most commonly refers to: * Subterranea (geography), the regions beneath the surface of the Earth Underground may also refer to: Places * The Underground (Boston), a music club in the Allston neighborhood of Boston * The Underground ...

'', an album by The Electric Prunes * "I", a 2012 song on ''

Muse In ancient Greek religion and mythology, the Muses ( grc, Μοῦσαι, Moûsai, el, Μούσες, Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the ...

'', an album by Jolin Tsai * "I", a 1981 song on ''

Music from "The Elder" ''Music from "The Elder"'' is the ninth studio album released by American rock band Kiss on the Casablanca Records label in 1981. The album marked a substantial departure from their previous output with the concept and orchestral elements. ''Mus ...

'', an album by Kiss * "I", a 1994 song on ''

Made in USA A Made in USA mark is a country of origin label affixed to homegrown, American-made products that indicates the product is "all or virtually all" domestically produced, manufactured and assembled in the United States of America. The label is regu ...

'', an album by Pizzicato Five * "I", a 1999 song on ''

Eternal Eternal(s) or The Eternal may refer to: * Eternity, an infinite amount of time, or a timeless state * Immortality or eternal life * God, the supreme being, creator deity, and principal object of faith in monotheism Comics, film and television * ...

'', an album by Samael * "I", a 2003 song on '' Winter Story'', an album by Shinhwa * "I", a 2015 song on '' I'', an EP by Taeyeon * "I", a 2016 song by Rezz * "I", a 2019 song by

Hey! Say! JUMP Hey! Say! JUMP (HSJ or JUMP) is an eight-member Japanese boy band under the Japanese talent agency Johnny & Associates. The group is split into two sub-groups: Hey! Say! BEST and Hey! Say! 7. In Japan they sold more than 10 million physical co ...

Other media

* ''I'' (2015 film), an Indian Tamil-language film * ''I'' (2016 film), an Iranian film * i (TV network), the former name of ION Television * ''i'' (newspaper), a British newspaper based in London * ''i'' (Portuguese newspaper), a Portuguese newspaper based in Lisbon * I, a character in the comic book series ''

Adventure into Fear ''Adventure into Fear'' is an American horror comic book series published by Marvel Comics from cover dates November 1970 through December 1975, for 31 issues. This is its trademarked cover title for all but its first nine issues, though the ser ...

'' * '' "I" Is for Innocent'', the ninth novel in Sue Grafton's "Alphabet mystery" series, published in 1992 * ''

I, a Man ''I, a Man'' is a 1967 American erotic drama film written, directed and filmed by Andy Warhol. It debuted at the Hudson Theatre in New York City on August 25, 1967. The film depicts the main character, played by Tom Baker, in a series of sexual en ...

'', a 1967 Andy Warhol film

Mythology

* Goddess I, a Mayan deity * Hou-i, or I, a heroic archer and hunter in Chinese mythology

Vehicles

* Italy (I), in the

list of international vehicle registration codes The country in which a motor vehicle's vehicle registration plate was issued may be indicated by an international licence plate country code, formerly known as an International Registration Letter or International Circulation Mark. It is ref ...

* Italy (

aircraft registration An aircraft registration is a code unique to a single aircraft, required by international convention to be marked on the exterior of every civil aircraft. The registration indicates the aircraft's country of registration, and functions much lik ...

prefix) *

Mitsubishi i The is a kei car from automaker Mitsubishi Motors, first released in January 2006, twenty eight months after its debut at the Frankfurt Motor Show#2003, 2003 Frankfurt Motor Show. It is the first four-door automobile since the 1960s to employ ...

, a Japanese kei car

Other uses

* i, an international symbol for visitor or tourist information; see ISO 7001 *

Nintendo DSi The is a dual-screen handheld game console released by Nintendo. The console launched in Japan on November 1, 2008, and worldwide beginning in April 2009. It is the third iteration of the Nintendo DS, and its primary market rival is Sony's ...

, the third model in the Nintendo DS line, released in 2008 *

Nintendo DSi XL The is a dual-screen handheld game console released by Nintendo. The console launched in Japan on November 1, 2008, and worldwide beginning in April 2009. It is the third iteration of the Nintendo DS, and its primary market rival is Sony's ...

, the larger version of the DSi, released in 2009 * I, an alternative romanization of Lee (Korean surname) * I-Foundation, a charity in charge of state-funded Hindu faith schools in the United Kingdom *

Interest rate An interest rate is the amount of interest due per period, as a proportion of the amount lent, deposited, or borrowed (called the principal sum). The total interest on an amount lent or borrowed depends on the principal sum, the interest rate, ...

(i), in economics * Investment (I), in economics *

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, the military time zone code for UTC+09:00