Beza 1598 at 12:45, 8 March 2016

2016-03-08T12:45:53Z

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	[[Category:Greek letters]]		[[Category:Greek letters]]

			{{Donate}}

Nick at 06:05, 7 March 2015

2015-03-07T06:05:01Z

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	[[Image:Sigma.~~png~~\|thumb\|150px\|Sigma]]'''Sigma''' (upper case '''Σ''', lower case '''σ''', lower case in word-final position '''ς'''; [[Ancient Greek\|Greek]] σίγμα) is the eighteenth letter of the [[Greek alphabet]], and carries the 'S' sound. In the system of [[Greek numerals]] it has a value of 200. When used at the end of a word, and the word is not all [[upper case]], the final form (ς) is used, e.g. Ὀδυσσεύς (Odysseus) - note the two sigmas in the center of the name, and the word-final sigma at the end. It is not to be confused with the [[cedilla]] [[ç]].		[[Image:Sigma.jpg\|thumb\|150px\|Sigma]]'''Sigma''' (upper case '''Σ''', lower case '''σ''', lower case in word-final position '''ς'''; [[Ancient Greek\|Greek]] σίγμα) is the eighteenth letter of the [[Greek alphabet]], and carries the 'S' sound. In the system of [[Greek numerals]] it has a value of 200. When used at the end of a word, and the word is not all [[upper case]], the final form (ς) is used, e.g. Ὀδυσσεύς (Odysseus) - note the two sigmas in the center of the name, and the word-final sigma at the end. It is not to be confused with the [[cedilla]] [[ç]].

	==History==		==History==

Nick at 07:18, 28 March 2011

2011-03-28T07:18:36Z

← Older revision		Revision as of 07:18, 28 March 2011
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	'''Sigma''' (upper case '''Σ''', lower case '''σ''', lower case in word-final position '''ς'''; [[Ancient Greek\|Greek]] σίγμα) is the eighteenth letter of the [[Greek alphabet]], and carries the 'S' sound. In the system of [[Greek numerals]] it has a value of 200. When used at the end of a word, and the word is not all [[upper case]], the final form (ς) is used, e.g. Ὀδυσσεύς (Odysseus) - note the two sigmas in the center of the name, and the word-final sigma at the end. It is not to be confused with the [[cedilla]] [[ç]].		[[Image:Sigma.png\|thumb\|150px\|Sigma]]'''Sigma''' (upper case '''Σ''', lower case '''σ''', lower case in word-final position '''ς'''; [[Ancient Greek\|Greek]] σίγμα) is the eighteenth letter of the [[Greek alphabet]], and carries the 'S' sound. In the system of [[Greek numerals]] it has a value of 200. When used at the end of a word, and the word is not all [[upper case]], the final form (ς) is used, e.g. Ὀδυσσεύς (Odysseus) - note the two sigmas in the center of the name, and the word-final sigma at the end. It is not to be confused with the [[cedilla]] [[ç]].

	==History==		==History==

Nick at 07:16, 28 March 2011

2011-03-28T07:16:16Z

← Older revision		Revision as of 07:16, 28 March 2011
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	[[~~Image:Sigma~~.~~png\|thumb\|150px\|Sigma~~]]		'''Sigma''' (upper case '''Σ''', lower case '''σ''', lower case in word-final position '''ς'''; [[Ancient Greek\|Greek]] σίγμα) is the eighteenth letter of the [[Greek alphabet]], and carries the 'S' sound. In the system of [[Greek numerals]] it has a value of 200. When used at the end of a word, and the word is not all [[upper case]], the final form (ς) is used, e.g. Ὀδυσσεύς (Odysseus) - note the two sigmas in the center of the name, and the word-final sigma at the end. It is not to be confused with the [[cedilla]] [[ç]].

	~~Σσς~~ Sigma		==History==
			[[Image:Madaba Jerusalem Mosaic.jpg\|thumb\|200px\|The [[Madaba Map]], a sixth-century mosaic map of [[Jerusalem]] ("Η ΑΓΙΑ ПОΛΙΣ") uses the lunate sigma.]]

			The shape and alphabetic position of Sigma is derived from [[Phoenician alphabet\|Phoenician]] [[Shin (letter)\|shin]] 𐤔.

			===Etymology===
			The name of sigma, according to one theory,<sup>[1]</sup> may continue that of Phoenician [[Samekh]]. According to a different theory,<sup>[2]</sup> its original name may have been "''[[San (letter)\|San]]''" (the name today associated with another, obsolete letter), while "Sigma" was a Greek innovation that simply meant "hissing", based on a nominalization of a verb σίζω (''sízō'', from earlier *''sig-jō'', meaning 'I hiss').

			===Uppercase of esh===
			The uppercase form of sigma was re-borrowed into the [[Latin alphabet]] to serve as the uppercase of modern [[esh (letter)\|esh]] (lowercase: ʃ).

			=== Lunate sigma ===
			In handwritten Greek during the Hellenistic period (4th and 3rd centuries BC), the epigraphic form of Σ was simplified into a C-like shape.<sup>[3]</sup> It is also found on coins from the fourth century BC onwards.<sup>[4]</sup> This became the universal standard form of Sigma during late antiquity and the Middle Ages. It is today known as ''lunate sigma'' (upper case Ϲ, lower case ϲ), because of its [[crescent]]-like shape.

			It is still widely used in decorative typefaces in Greece, especially in religious and church contexts, as well as in some modern print editions of classical Greek texts. The forms of the [[Cyrillic alphabet\|Cyrillic letter]] [[Es (Cyrillic)\|С]] (representing /s/) and [[Coptic alphabet\|Coptic letter]] Ⲥ ''sima'' are derived from lunate sigma.

			A dotted lunate sigma (''sigma periestigmenon'', encoded at U+03FE Ͼ) was used by [[Aristarchus of Samothrace]] as an editorial sign indicating that the line so marked is at an incorrect position. Similarly, an [[antisigma]] or reversed sigma (Ͻ) may mark a line that is out of place. A dotted [[antisigma]] or dotted reversed sigma (''antisigma periestigmenon'': Ͽ) may indicate a line after which rearrangements should be made, or to variant readings of uncertain priority.

			==Uses==
			===Greek===
			In both [[Ancient Greek\|Ancient]] and [[Modern Greek]], the sigma represents the [[voiceless alveolar fricative]] /s/. In Ancient Greek, this sound was [[voice (phonetics)\|voiced]] to /z/ before /m/ or /n/.

			===Berber===
			Upper case Σ may be used in the [[Berber Latin alphabet]] for [ʕ], though the [[INALCO]] standard uses [[Ɛ]] instead.

			===Science and mathematics===
			====Upper case====
			Upper case Σ is used as a symbol for:
			* the [[summation]] operator
			* a class of [[baryon]]s in [[particle physics]]
			* macroscopic [[Cross section (physics)\|cross section]]s in [[nuclear physics\|nuclear]] and [[particle physics]]
			* [[self-energy]] in [[condensed matter physics]]
			* the [[Balance (accounting)\|balance]] of the invoice classes and the overall amount of the debts and demands in [[economics]]
			* the set of symbols that form an alphabet in [[linguistics]] and [[Computer Science\|computer science]]

			====Lower case====
			Lower case σ is used for:
			* [[sigma bond]]s in [[chemistry]]
			* the [[sigma receptor]] in [[biology]]
			* the [[standard deviation]] of a [[Standard deviation#Estimating_population_standard_deviation\|population]] or [[probability distribution]] in [[statistics]]
			* a quality model for business, [[Six Sigma]], based on the [[standard deviation]], often referred to as "'''6σ'''"
			* [[sigma-algebra]]s, sigma-fields and [[Sigma-finite measure\|sigma-finiteness]] in [[Measure (mathematics)\|measure theory]]; more generally, the symbol ''σ'' serves as a shorthand for "[[countable set\|countably]]", e.g. a ''σ''-compact [[topological space]] is one that can be written as a countable [[union (set theory)\|union]] of [[compact space\|compact subsets]].
			* the [[Sigma-algebra#Generated_.CF.83-algebra\|generated sigma-algebra]] of a set <math>A</math> is denoted <math>\sigma(A)</math>
			* the [[divisor function\|sum-of-divisors function]] in [[number theory]]
			* the [[Stefan–Boltzmann constant]]
			* the "[[sigma factor]]" of [[RNA polymerase]]
			* a measure of [[electrical conductivity]]
			* the [[Surface charge]] density in electrostatics
			* [[Normal stress\|Normal]] [[Stress (physics)\|stress]] in [[continuum mechanics]]
			* volatility of a [[stock]] generally needed for [[options pricing]]
			* a [[syllable]] in [[phonology]]
			* the [[spectrum of a matrix]] <math>A</math>, denoted as <math>\sigma(A)</math>, in [[applied mathematics]]
			* [[surface tension]]
			* the unary operation of [[Selection (relational algebra)\|selection]] on a database relation in [[relational algebra]]
			* the [[Pauli matrices]] in [[quantum mechanics]]
			* a target's [[radar cross-section]] (RCS) in [[radar jamming]] or [[Electronic warfare\|Electronic Warfare]] (EW)
			* the [[Sigma (bone remodeling)\|life span]] of a basic multicellular unit (BMU) in [[bone remodeling]]

			===Politics===
			During the 1930s, an upper case Σ was in use as the symbol of the [[Brazilian Integralism\|Ação Integralista Brasileira]], a radical right-wing party in [[Brazil]].

			===Miscellaneous===
			* [[Mercury-Atlas 8]] was called Sigma 7.
			* Upper-case Σ is sometimes substituted jocularly for upper-case [[E]] to impart a "Greek" air; [[Film poster\|posters]] for the film ''[[My Big Fat Greek Wedding]]'' and promotional materials for the television series ''[[Greek (TV series)\|Greek]]'', for instance, have "GRΣΣK" instead.
			*Sigma 2,3,5,6,7,8,9 computers produced by [[Xerox\|Xerox Data Systems]] in the 1970s following purchase of SDS, Scientific Data Systems, by it. Successful range of scientific computers similar to IBM 370s.
			* [http://sigmakee.sourceforge.net Sigma] is the name of a system for [[ontology]] development and reasoning
			* Project Sigma was the name of a proposal for a "spontaneous university" by the Scottish writer [[Alexander Trocchi]].
			* The French mathematician and poet [[Jacques Roubaud]] used the symbol as a title for his first book of poems, ''Σ'', published in 1967.<sup>[5]</sup>
			* The main antagonist in the [[Mega Man X]] series is named Sigma.
			* In the video game [[Lux-Pain]], Sigma is often mentioned as a power used to destroy "Silent".
			*[[Doctor Who]]'s Ood Sigma was a primary character in [[Planet of the Ood]] he also played a minor role in [[The Waters of Mars]] and [[The End of Time]]. He has the letter Σ on his tunic. Sigma was also part of the name which the Doctor used whilst living on Gallifrey, the name being Theta Sigma.
			* The last part of the colon in the human body is called " sigmoid" as it is "S" shaped, as it descends down into the pelvis.
			* [[Six Sigma]] is a popular business management strategy.

			==See also==
			*[[Antisigma]]
			*[[Greek letters used in mathematics, science, and engineering]]
			*[[Sampi]]

			==References==

			* 1. Jeffery, Lilian H. (1961). The local scripts of archaic Greece. Oxford: Clarendon. pp. 25–27.
			* 2. Woodard, Roger D. (2006). "Alphabet". In Wilson, Nigel Guy. Encyclopedia of ancient Greece. London: Routldedge. p. 38.
			* 3. Edward M. Thompson (1912), Introduction to Greek and Latin paleography, Oxford: Clarendon. p.108, 144
			* 4. Parthia.com: Numismatica Font Projects.
			* 5. Auster, Paul, editor, The Random House Book of Twentieth-Century French Poetry: with Translations by American and British Poets, New York: Random House, 1982 ISBN 0-394-52197-8

			[[Category:Greek letters]]

Nick at 07:11, 28 March 2011

2011-03-28T07:11:18Z

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			[[Image:Sigma.png\|thumb\|150px\|Sigma]]

	Σσς Sigma		Σσς Sigma

Nick: Protected "Sigma" [edit=autoconfirmed:move=autoconfirmed]

2009-03-01T03:37:39Z

Protected "Sigma" [edit=autoconfirmed:move=autoconfirmed]

← Older revision	Revision as of 03:37, 1 March 2009
(No difference)

Nick: New page: Σσς Sigma

2009-03-01T03:37:35Z

New page: Σσς Sigma

New page

Σσς Sigma