gamma

{{further|History of the Greek alphabet}}

The Greek letter Gamma Γ is a grapheme derived from the Phoenician letter {{Script|Phnx|𐤂}} (gīml) which was rotated from the right-to-left script of Canaanite to accommodate the Greek language's writing system of left-to-right. The Canaanite grapheme represented the /g/ phoneme in the Canaanite language, and as such is cognate with gimel ג of the Hebrew alphabet.

Based on its name, the letter has been interpreted as an abstract representation of a camel's neck,{{cite book|last=Russell|first=Bertrand|title=A history of western philosophy|year=1972|publisher=Touchstone book|location=New York|isbn=9780671314002|edition=60th print.|url-access=registration|url=https://archive.org/details/historyofwestern00russ}} but this has been criticized as contrived,{{cite book|last=Powell|first=Barry B.|author-link=Barry B. Powell|title=Writing: Theory and History of the Technology of Civilization|url=https://books.google.com/books?id=PZ2Gr3d9X2UC&pg=PA182|year=2012|publisher=John Wiley & Sons|isbn=978-1-118-29349-2|page=182}} and it is more likely that the letter is derived from an Egyptian hieroglyph representing a club or throwing stick.{{cite book|last=Hamilton|first=Gordon James|title=The Origins of the West Semitic Alphabet in Egyptian Scripts|url=https://books.google.com/books?id=LdANAAAAYAAJ|year=2006|publisher=Catholic Biblical Association of America|isbn=978-0-915170-40-1|pages=53–6}}

File:NAMA Alphabet grec.jpg with a lambda-shaped gamma]]

In Archaic Greece, the shape of gamma was closer to a classical lambda (Λ), while lambda retained the Phoenician L-shape ({{Script|Phnx|𐌋}}).

Letters that arose from the Greek gamma include Etruscan (Old Italic) 𐌂, Roman C and G, Runic kaunan {{Script|Runr|ᚲ}}, Gothic geuua {{Script|Goth|𐌲}}, the Coptic Ⲅ, and the Cyrillic letters Г and Ґ.{{cite web | url=http://www.rapidtables.com/math/symbols/greek_alphabet.htm | title=Greek Alphabet Symbols | publisher=Rapid Tables | access-date=25 August 2014}}

{{further|Ancient Greek phonology|Modern Greek phonology}}

The Ancient Greek /g/ phoneme was the voiced velar stop, continuing the reconstructed proto-Indo-European *g, *ǵ.

The modern Greek phoneme represented by gamma is realized either as a voiced palatal fricative ({{IPA|/ʝ/}}) before a front vowel (/e/, /i/), or as a voiced velar fricative {{IPA|/ɣ/}} in all other environments. Both in Ancient and in Modern Greek, before other velar consonants (κ, χ, ξ – that is, k, kh, ks), gamma represents a velar nasal {{IPA|/ŋ/}}. A double gamma γγ (e.g., άγγελος, "angel") represents the sequence {{IPA|/ŋɡ/}} (phonetically varying {{IPA|[ŋɡ~ɡ]}}) or {{IPA|/ŋɣ/}}.

Lowercase Greek gamma is used in the Americanist phonetic notation and Uralic Phonetic Alphabet to indicate voiced consonants.

The gamma was also added to the Latin alphabet, as Latin gamma, in the following forms: majuscule Ɣ, minuscule ɣ, and superscript modifier letter ˠ.

In the International Phonetic Alphabet the minuscule letter is used to represent a voiced velar fricative and the superscript modifier letter is used to represent velarization. It is not to be confused with the character {{IPA|ɤ}}, which looks like a lowercase Latin gamma that lies above the baseline rather than crossing, and which represents the close-mid back unrounded vowel. In certain nonstandard variations of the IPA, the uppercase form is used.{{Citation needed|date=May 2017}}

It is as a full-fledged majuscule and minuscule letter in the alphabets of some of languages of Africa such as Dagbani, Dinka, Kabye, and Ewe,[http://www.bisharat.net/Documents/poal30.htm Practical Orthography of African Languages] and Berber languages using the Berber Latin alphabet.

It is sometimes also used in the romanization of Pashto.

The lowercase letter $\backslash gamma$ is used as a symbol for:

• Chromatic number of in graph theory
• Gamma radiation in nuclear physics
• Shear strain in physics{{Citation |last=Elert |first=Glenn |title=Special Symbols |date=2023 |work=The Physics Hypertextbook |quote= γ shear strain|url=https://physics.info/symbols/ |access-date=2025-02-01 |publisher=hypertextbook |language=en}}
• Surface tension in physics{{Citation |last=Elert |first=Glenn |title=Special Symbols |date=2023 |work=The Physics Hypertextbook |quote= γ surface tension|url=https://physics.info/symbols/ |access-date=2025-02-01 |publisher=hypertextbook |language=en}}
• The photon, the elementary particle of light and other electromagnetic radiation
• The 434 nm spectral line in the Balmer series{{Cite web |date=2014-06-17 |title=1.4: The Hydrogen Atomic Spectrum |url=https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Physical_Chemistry_(LibreTexts)/01:_The_Dawn_of_the_Quantum_Theory/1.04:_The_Hydrogen_Atomic_Spectrum |access-date=2025-01-23 |website=Chemistry LibreTexts |language=en}}
• Surface energy in materials science
• The Lorentz factor in the theory of relativity{{Cite book |last=Fayngold |first=Moses |title=Special relativity and how it works |date=2008 |publisher=Wiley-VCH |isbn=978-3-527-40607-4 |series=Physics textbook |location=Weinheim |page=32 |quote=Because we will come across this coefficient quite often, we will give it a special name, the Lorentz factor, and stick to our symbol γ(V),...}}
• In mathematics, the lower incomplete gamma function{{Cite web |last=Weisstein |first=Eric W. |title=Incomplete Gamma Function |url=https://mathworld.wolfram.com/IncompleteGammaFunction.html |access-date=2025-01-23 |website=mathworld.wolfram.com |language=en}}
• The heat capacity ratio {{math|C_p{{hairsp}}/C_v}} in thermodynamics
• The activity coefficient in thermodynamics
• The gyromagnetic ratio in electromagnetism
• Gamma waves in neuroscience
• Gamma motor neurons in neuroscience
• A non-SI metric unit of measure of mass equal to one microgram (1 μg).{{cite book |author=François Cardarelli |date=2003 |title=Encyclopaedia of Scientific Units, Weights and Measures |publisher=Springer-Verlag |location=London |isbn=978-1-4471-1122-1}}{{cite book |date=August 7, 2002 |title=Remembrances of LSD therapy past |author=Betty Grover Eisner, Ph.D. |url=https://maps.org/images/pdf/books/remembrances.pdf |archive-url=https://web.archive.org/web/20141205124722/http://maps.org/images/pdf/books/remembrances.pdf |archive-date=2014-12-05 |url-status=live |page=14 |quote=that fateful 100 gamma, the same dosage I had had at my first LSD session}} This always-rare use is deprecated.
• A non-SI unit of measure of magnetic flux density, sometimes used in geophysics, equal to 10⁻⁵ gauss (G), or 1 nanotesla (nT).{{Cite web |last=Weisstein |first=Eric W. |date=30 April 2023 |title=Gamma -- from Eric Weisstein's World of Physics |url=https://scienceworld.wolfram.com/physics/Gamma.html |website=scienceworld.wolfram.com}}
• The power by which the luminance of an image is increased in gamma correction
• In civil and mechanical engineering:
• Specific weight
• The shear rate of a fluid is represented by a lowercase gamma with a dot above it: $\backslash dot\; \backslash gamma$
• Austenite (also known as γ-iron), a metallic non-magnetic allotrope or solid solution of iron.
• The gamma carbon, the third carbon attached to a functional group in organic chemistry and biochemistry; see Alpha and beta carbon
• Hermite constant{{Cite web |last=Weisstein |first=Eric W. |title=Hermite Constants |url=https://mathworld.wolfram.com/HermiteConstants.html |access-date=2025-01-31 |website=mathworld.wolfram.com |language=en}}
• The Euler’s Constant also known as Euler–Mascheroni constant ≈ 0.57721566490153286{{Cite web |last=Weisstein |first=Eric W. |title=Euler-Mascheroni Constant |url=https://mathworld.wolfram.com/Euler-MascheroniConstant.html |access-date=2025-01-23 |website=mathworld.wolfram.com |language=en}}{{Cite web |title=DLMF: §5.2 Definitions ‣ Properties ‣ Chapter 5 Gamma Function |url=https://dlmf.nist.gov/5.2#E3 |access-date=2025-01-31 |website=dlmf.nist.gov}}
• Stieltjes constants{{Cite web |last=Weisstein |first=Eric W. |title=Stieltjes Constants |url=https://mathworld.wolfram.com/StieltjesConstants.html |access-date=2025-01-31 |website=mathworld.wolfram.com |language=en}}
• Chvátal–Sankoff constants

The lowercase Latin gamma ɣ can also be used in contexts (such as chemical or molecule nomenclature) where gamma must not be confused with the letter y, which can occur in some computer typefaces.

The uppercase letter $\backslash Gamma$ is used as a symbol for:

• In mathematics, the gamma function (usually written as $\backslash Gamma$-function) is an extension of the factorial to complex numbers{{Cite web |last=Weisstein |first=Eric W. |title=Gamma Function |url=https://mathworld.wolfram.com/GammaFunction.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en |quote=The (complete) gamma function Γ(n) is defined to be an extension of the factorial to complex and real number arguments.}}{{Cite web |title=DLMF: §5.1 Special Notation ‣ Notation ‣ Chapter 5 Gamma Function |url=https://dlmf.nist.gov/5.1 |access-date=2025-01-31 |website=dlmf.nist.gov}}
• In mathematics, the upper incomplete gamma function{{Cite web |last=Weisstein |first=Eric W. |title=Incomplete Gamma Function |url=https://mathworld.wolfram.com/IncompleteGammaFunction.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en}}
• The Christoffel symbols in differential geometry{{Cite book |last=Baumann |first=Gerd |title=Mathematica for theoretical physics |date=2005 |publisher=Springer |isbn=978-0-387-01674-0 |edition=2nd |location=New York |page=731}}{{Cite web |last=Weisstein |first=Eric W. |title=Christoffel Symbol of the First Kind |url=https://mathworld.wolfram.com/ChristoffelSymboloftheFirstKind.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en}}
• In probability theory and statistics, the gamma distribution is a two-parameter family of continuous probability distributions.{{Cite web |last=Weisstein |first=Eric W. |title=Gamma Distribution |url=https://mathworld.wolfram.com/GammaDistribution.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en}}
• In solid-state physics, the center of the Brillouin zone
• Circulation in fluid mechanics
• As reflection coefficient in physics and electrical engineering{{Cite book |title=Electromagnetic Theory for Microwaves and Optoelectronics |date=2008 |publisher=Springer-Verlag Berlin Heidelberg |isbn=978-3-540-74295-1 |editor-last=Zhang |editor-first=Keqian |edition=2nd |series=SpringerLink Bücher |location=Berlin, Heidelberg |page=82 |quote=The reflection coefficient Γis real when medium 1 and medium 2 are both lossless media,… |editor-last2=Li |editor-first2=Dejie}}
• The tape alphabet of a Turing machine{{Cite book |last=Arora |first=Sanjeev |title=Computational complexity: A Modern Approach |last2=Barak |first2=Boaz |date=2016 |publisher=Cambridge University Press |isbn=978-0-521-42426-4 |edition=4th printing 2016 |location=New York |pages=12 |quote=A tape is an infinite one-directional line of cells, each of which can hold a symbol from a finite set Γcalled the alphabet of the machine.}}
• The Feferman–Schütte ordinal $\backslash Gamma\_0${{Cite book |last=Kahle |first=Reinhard |title=The legacy of Kurt Schütte |last2=Rathjen |first2=Michael |date=2020 |publisher=Springer |isbn=978-3-030-49423-0 |location=Cham |pages=41 |quote=The Veblen approach was quite sufficient even for the ordinal, now known as the Feferman–Schütte ordinal, Γ{{sub|0}} for predictive analysis}}
• Congruence subgroups of the modular group of other arithmetic groups
• One of the Greeks in mathematical finance

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{{notelist}}

{{Wiktionary|Γ|γ}}

{{Wiktionary|Ɣ|ɣ}}

• Г, г - Ge (Cyrillic)
• G, g - Latin
• Gamma correction
• List of storms named Gamma

{{reflist}}

Category:Greek letters

Gz