Gamma
Encyclopedia
Gamma is the third letter of the Greek alphabet
Greek alphabet
The Greek alphabet is the script that has been used to write the Greek language since at least 730 BC . The alphabet in its classical and modern form consists of 24 letters ordered in sequence from alpha to omega...

. In the system of Greek numerals
Greek numerals
Greek numerals are a system of representing numbers using letters of the Greek alphabet. They are also known by the names Ionian numerals, Milesian numerals , Alexandrian numerals, or alphabetic numerals...

it has a value of 3. It was derived from the Phoenician letter
Phoenician alphabet
The Phoenician alphabet, called by convention the Proto-Canaanite alphabet for inscriptions older than around 1050 BC, was a non-pictographic consonantal alphabet, or abjad. It was used for the writing of Phoenician, a Northern Semitic language, used by the civilization of Phoenicia...

Gimel
. Letters that arose from Gamma include the Roman C
C
Ĉ or ĉ is a consonant in Esperanto orthography, representing the sound .Esperanto orthography uses a diacritic for all four of its postalveolar consonants, as do the Latin-based Slavic alphabets...

and G
G
G is the seventh letter in the basic modern Latin alphabet.-History:The letter 'G' was introduced in the Old Latin period as a variant of ⟨c⟩ to distinguish voiced, from voiceless, . The recorded originator of ⟨g⟩ is freedman Spurius Carvilius Ruga, the first Roman to open a fee-paying school,...

and the Cyrillic letters Ge
Ge (Cyrillic)
Ge is a letter of the Cyrillic alphabet. It is also known in some languages as He. In Unicode this letter is called "Ghe".It commonly represents the voiced velar plosive , like the pronunciation of ⟨g⟩ in "go"....

Г and Ghe
Ge with upturn
Ge with upturn is a letter of the Cyrillic alphabet. In Ukrainian, Urum and Rusyn, this letter is called "Ge", and the letter ⟨Г⟩ is called "He"...

Ґ.

### Greek

In Ancient Greek, gamma represented a voiced velar stop /ɡ/. In Modern Greek
Modern Greek
Modern Greek refers to the varieties of the Greek language spoken in the modern era. The beginning of the "modern" period of the language is often symbolically assigned to the fall of the Byzantine Empire in 1453, even though that date marks no clear linguistic boundary and many characteristic...

, it represents a voiced fricative. It is realized either as a palatal /ʝ/ (before a front vowel
Front vowel
A front vowel is a type of vowel sound used in some spoken languages. The defining characteristic of a front vowel is that the tongue is positioned as far in front as possible in the mouth without creating a constriction that would be classified as a consonant. Front vowels are sometimes also...

, /e, i/), or as a velar
Voiced velar fricative
The voiced velar fricative is a type of consonantal sound, used in various spoken languages. It is not found in English today, but did exist in Old English...

/ɣ/ (in all other environments).

Both in Ancient and in Modern Greek, before other velars (κ, χ, ξ k, kh, ks), gamma represents a velar nasal
Velar nasal
The velar nasal is the sound of ng in English sing. It is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , and the equivalent X-SAMPA symbol is N....

/ŋ/. A double gamma γγ represents the sequence /ŋɡ/ (phonetically varying [ŋɡ~ɡ]) or /ŋɣ/.

### International Phonetic Alphabet

In the International Phonetic Alphabet
International Phonetic Alphabet
The International Phonetic Alphabet "The acronym 'IPA' strictly refers [...] to the 'International Phonetic Association'. But it is now such a common practice to use the acronym also to refer to the alphabet itself that resistance seems pedantic...

, lowercase gamma (ɣ) represents the voiced velar fricative
Voiced velar fricative
The voiced velar fricative is a type of consonantal sound, used in various spoken languages. It is not found in English today, but did exist in Old English...

. A lowercase gamma that lies above the baseline
Baseline (typography)
In European and West Asian typography and penmanship, the baseline is the line upon which most letters "sit" and below which descenders extend.In the example to the right, the letter 'p' has a descender; the other letters sit on the baseline....

rather than crossing it (ɤ) represents the close-mid back unrounded vowel
Close-mid back unrounded vowel
The close-mid back unrounded vowel, or high-mid back unrounded vowel, is a type of vowel sound, used in some spoken languages. Its symbol in the International Phonetic Alphabet is , called "ram's horns"...

.

#### Lower case

The lower-case letter is used as a symbol for:
• gamma radiation in nuclear physics
Nuclear physics
Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those...

• surface energy
Surface energy
Surface energy quantifies the disruption of intermolecular bonds that occur when a surface is created. In the physics of solids, surfaces must be intrinsically less energetically favorable than the bulk of a material, otherwise there would be a driving force for surfaces to be created, removing...

in materials science
Materials science
Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates...

• the Lorentz factor
Lorentz factor
The Lorentz factor or Lorentz term appears in several equations in special relativity, including time dilation, length contraction, and the relativistic mass formula. Because of its ubiquity, physicists generally represent it with the shorthand symbol γ . It gets its name from its earlier...

in theory of relativity
Theory of relativity
The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....

• The heat capacity ratio
Heat capacity ratio
The heat capacity ratio or adiabatic index or ratio of specific heats, is the ratio of the heat capacity at constant pressure to heat capacity at constant volume . It is sometimes also known as the isentropic expansion factor and is denoted by \gamma or \kappa . The latter symbol kappa is...

Cp/Cv in thermodynamics
Thermodynamics
Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...

• The activity coefficient
Activity coefficient
An activity coefficient is a factor used in thermodynamics to account for deviations from ideal behaviour in a mixture of chemical substances. In an ideal mixture, the interactions between each pair of chemical species are the same and, as a result, properties of the mixtures can be expressed...

in thermodynamics
Thermodynamics
Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...

• The gyromagnetic ratio in electromagnetism
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

• gamma oscillation in neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...

• Gamma Motor Neurons
Gamma motoneurons
Gamma motoneurons , also called gamma motor neurons, are the efferent component of the fusimotor system, the system by which the central nervous system controls and modifies muscle spindle sensitivity. The fusimotor system refers to the combination of muscle spindles and γ-motoneurons...

in neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...

• Gamma is a non-SI
International System of Units
The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...

metric
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...

unit of measure
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...

of mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...

equal to onemicrogram
Gram
The gram is a metric system unit of mass....

(1 μg). This always rare use is currently deprecated.
• the power by which the luminance of an image is increased in gamma correction
Gamma correction
Gamma correction, gamma nonlinearity, gamma encoding, or often simply gamma, is the name of a nonlinear operation used to code and decode luminance or tristimulus values in video or still image systems...

• The Euler–Mascheroni constant
Euler–Mascheroni constant
The Euler–Mascheroni constant is a mathematical constant recurring in analysis and number theory, usually denoted by the lowercase Greek letter ....

• In mechanical engineering,
• specific weight
Specific weight
The specific weight is the weight per unit volume of a material. The symbol of specific weight is γ ....

• The shear rate of a fluid is represented by a lower case gamma with a dot above it:
• Austenite
Austenite
Austenite, also known as gamma phase iron, is a metallic non-magnetic allotrope of iron or a solid solution of iron, with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of ; other alloys of steel have different eutectoid temperatures...

(also known as γ-iron), a metallic non-magnetic allotrope or solid solution of iron.

#### Upper case

The upper-case letter is used as a symbol for:
• In mathematics, the gamma function
Gamma function
In mathematics, the gamma function is an extension of the factorial function, with its argument shifted down by 1, to real and complex numbers...

(usually written as -function) is an extension of the factorial
Factorial
In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n...

to complex number
Complex number
A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part...

s
• In probability theory and statistics, the gamma distribution is a two-parameter family of continuous probability distributions.
• circulation in fluid mechanics
Fluid mechanics
Fluid mechanics is the study of fluids and the forces on them. Fluid mechanics can be divided into fluid statics, the study of fluids at rest; fluid kinematics, the study of fluids in motion; and fluid dynamics, the study of the effect of forces on fluid motion...

• As reflection coefficient
Reflection coefficient
The reflection coefficient is used in physics and electrical engineering when wave propagation in a medium containing discontinuities is considered. A reflection coefficient describes either the amplitude or the intensity of a reflected wave relative to an incident wave...

in physics and electrical engineering
• The tape alphabet of a Turing machine
Turing machine
A Turing machine is a theoretical device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a...

#### Meteorology

• Gamma was one of the names used in the 2005 Atlantic hurricane season
2005 Atlantic hurricane season
The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering numerous records. The impact of the season was widespread and ruinous with an estimated 3,913 deaths and record damage of about \$159.2 billion...

as Tropical Storm Gamma.

### HTML

The HTML entities for uppercase and lowercase gamma are &Gamma; and &gamma;.

### Unicode

 description LatinLatin alphabetThe Latin alphabet, also called the Roman alphabet, is the most recognized alphabet used in the world today. It evolved from a western variety of the Greek alphabet called the Cumaean alphabet, which was adopted and modified by the Etruscans who ruled early Rome... International Phonetic AlphabetInternational Phonetic AlphabetThe International Phonetic Alphabet "The acronym 'IPA' strictly refers [...] to the 'International Phonetic Association'. But it is now such a common practice to use the acronym also to refer to the alphabet itself that resistance seems pedantic... spacing modifier letters character Unicode HTML LETTER GAMMA Ɣɣ U+0194U+0263 Ɣɣ SMALL LETTERRAMS HORN ɤ U+0264 ɤ MODIFIER LETTERSMALL GAMMA ◌ˠ U+02E0 ˠ LETTER GAMMA Γγ U+0393U+03B3 Γγ LETTERSMALL CAPITALGAMMA ᴦ U+1D26 ᴦ MODIFIER LETTERSMALL GAMMA ◌ᵞ U+1D5E ᵞ SUBSCRIPTSMALL LETTERGAMMA ◌ᵧ U+1D67 ᵧ DOUBLE-STRUCKGAMMA ℾℽ U+213EU+213D ℾℽ LETTER GAMMA Ⲅⲅ U+2C84U+2C85 Ⲅⲅ