Omega 22616 225965656 2008-07-16T06:25:44Z Stub12718696 7369800 /* The symbol ω (lower-case letter) */ {{wiktionarypar2|Ω|ω}} {{Table Greekletters|letter=omega}} {{SpecialCharsNote}} {{otheruses}} '''Omega''' ([[majuscule]]: '''&Omega;''', [[Lower case|minuscule]]: '''&omega;''') is the 24th and last letter of the [[Greek alphabet]]. In the [[Greek numerals|Greek numeric system,]] it has a value of 800. The word literally means "great&nbsp;O" (''ō [[mega]]'', mega meaning 'great'), as opposed to [[Omicron]], which means "little&nbsp;O" (''o [[micro|mikron]]'', micron meaning "little").<ref>[http://www.quinapalus.com/gr0.1.html The Greek Alphabet]</ref> This name is [[Medieval Greek|Byzantine]]; in [[Ancient Greek|Classical Greek]], the letter was called ''ō'' ({{Polytonic|ὦ}}), whereas the [[Omicron]] was called ''ou'' ({{Polytonic|οὖ}}).<ref>Herbert Weir Smyth. ''A Greek Grammar for Colleges''. §1</ref> The form of the lowercase letter derives from a double omicron, which came to be written open at the top. Phonetically, the [[Ancient Greek]] Ω is a [[vowel length|long]] [[open-mid back unrounded vowel|open-mid ''o'']] [{{IPA|ɔː}}], similar to the vowel of English ''raw'' in certain dialects such as RP where this word is pronounced [{{IPA|ɹɔː}}]. It should not be confused with the sound of English so-called "long o" as in ''ocean'', which is either diphthongal [{{IPA|oʊ}}] or [{{IPA|əʊ}}] or a close-mid kind of "o" [o], in either case distinctly different from the "long o" sound of Greek omega and closer to the Classical Greek sound represented by ''ου'' before this came to be pronounced [u]. In [[Modern Greek]] Ω represents the same sound as omicron. The letter omega is [[transcription (linguistics)|transcribed]] ''ō'' or simply ''o''. Omega (the last letter of the Greek alphabet) is often used to denote the last, the end, or the ultimate limit of a [[set theory|set]], in contrast to [[Alpha (letter)|Alpha]], the first letter of the Greek alphabet. In the New Testament book of Revelation, God is declared to be the "alpha and omega, the beginning and the end, the first and the last".<ref>[[Book of Revelation|Revelation]] 22:13, KJV, and see also 1:8, Greek ἐγὼ τὸ ἄλφα καὶ τὸ ὦ, ὁ πρῶτος καὶ ὁ ἔσχατος, ἡ ἀρχὴ καὶ τὸ τέλος. Or in [[Book of Revelation|Revelation]] 1:8 as seen in the [[Latin]] [[Vulgate]] [[Bible]], the Greek is shown, surrounded by Latin: "ego sum α et ω principium et finis dicit Dominus Deus qui est et qui erat et qui venturus est Omnipotens" </ref> Omega was also adopted into the [[early Cyrillic alphabet]]. See [[omega (Cyrillic)|Cyrillic omega]] ({{Unicode|Ѡ}}, {{Unicode|ѡ}}). A [[Raetic alphabet|Raetic]] variant is at the origin of [[Elder Futhark]] [[ᛟ]]. <math>\Omega \omega</math> == The symbol Ω ([[majuscule]] letter) == The upper-case letter Ω is used as a symbol. It is also used often outside its Greek alphabetical context in literature, advertising and other forms of human expression. * in [[physics]]: ** For [[ohm]] — [[SI]] unit of electrical resistance; formerly also used upside down ({{Unicode|℧}}) to represent [[mho]], the old name for the inverse of an ohm (now [[siemens (unit)|siemens]] with symbol S) used for electrical conductance. [[Unicode]] has a separate code point for the [[Ohm (unit)|ohm]] sign (U+2126, &#x2126;), but it is only included for backwards compatibility and the Greek uppercase omega character (U+03A9, Ω) is preferred. <ref>Excerpts from the ''[http://www.unicode.org/versions/Unicode4.0.0/ch07.pdf#search=%22character%20U%2B2126%20maps%20OR%20map%20OR%20mapping%22 The Unicode Standard, Version 4.0]'', accessed [[11 October]] [[2006]]</ref> ** The [[solid angle]] or the rate of precession in a gyroscope. ** In [[particle physics]] to represent the [[Omega baryon]]s. *In [[mathematics]]/[[computer science]]: ** in notation related to [[Big O notation]] to describe the [[asymptotic behavior]] of [[function (mathematics)|function]]s. ** [[Chaitin's constant]]. * In [[mathematics]] ** In [[complex analysis]], the [[Omega constant]], a solution of [[Lambert's W function]] ** A variable for a 2-dimensional region in calculus, usually corresponding to the domain of a double integral. ** In [[set theory]], the first [[uncountable set|uncountable]] [[ordinal number]] (also known as [[Aleph_number#Aleph-one|&omega;<sub>1</sub>]]) ** In [[combinatory logic]], the looping combinator, ''(λ x. x x) (λ x. x x)'' * In [[statistics]], it is used as the symbol for the [[sample space]], or total set of possible outcomes. * In [[astronomy]] ([[physical cosmology|cosmology]]) Ω refers to the density of the universe, also called the [[density parameter]]. * The symbol of the [[Resistance Movement]] against the Vietnam-era draft * Year or date of death * In [[God of War (video game)]], Incorporated into the logo design. * The logo of [[Omega Watches]] SA. * In [[Warhammer 40,000]], the Space Marine chapter "[[Ultramarines]]" uses an upside-down variation of it. == The symbol ω ([[lower case|miniscule]] letter) == The lower-case letter ω is used as a symbol: * In [[textual criticism]], the [[archetype]] of a manuscript tradition * In [[physics]], [[angular velocity]] and [[angular frequency]] * In [[mathematics]], the first [[transfinite number|transfinite]] [[ordinal number]], often identified with the set of natural numbers including 0 * In [[mathematics]], the complex [[roots of unity|cube roots of 1]] * In [[mathematics]], the [[Wright Omega Function|Wright Omega function]] * In [[number theory]], an [[arithmetic function]] * In [[combinatory logic]], the self-application combinator, ''(λ x. x x)'' * In [[computer science]], in notation related to [[Big O notation]], the [[asymptotical dominance|asymptotically dominant]] nature of [[function (mathematics)|function]]s * In [[astronomy]], as a ranking of a star's brightness * In [[particle physics]] to represent the [[Meson|omega meson]] * In [[linguistics]], the [[phonological word]] * In [[circuit analysis]] and [[signal processing]] to represent natural frequency, related to [[frequency]] ''f'' by ω = 2π''f''. * In [[biochemistry]] to denote the carbon atom furthest from the [[carboxyl group]] of a [[fatty acid]]. * Used in place of [[ん]] in Japanese typing shorthand. * In [[Relational database|relational database]] theory to represent [[Null (SQL)|NULL]], a missing or inapplicable value. * In [[phonology]], for a [[phonological word|prosodic (or phonological) word]]. * In [[biochemistry]], for one of the [[RNA]] [[Polymerase]] subunits. * In [[genomics]], as a measure of [[evolution]] at the protein level. == Notes == <references/> [[Category:Greek letters]] [[Category:Vowel letters]] [[als:Ω]] [[ar:أوميغا (حرف إغريقي)]] [[arc:Ω]] [[ast:Omega]] [[br:Omega (lizherenn)]] [[bg:Омега]] [[ca:Omega]] [[cy:Omega]] [[da:Omega (bogstav)]] [[de:Omega]] [[el:Ωμέγα]] [[es:Ω]] [[eo:Omego]] [[eu:Omega]] [[fr:Oméga]] [[gd:Omega]] [[gl:Omega]] [[ko:Ω]] [[hr:Omega]] [[id:Omega]] [[is:Ómega]] [[it:Omega (lettera)]] [[he:אומגה]] [[ka:ომეგა (ასო)]] [[sw:Omega]] [[ht:Ω]] [[ku:Omega]] [[la:Omega]] [[lt:Omega (raidė)]] [[hu:Ómega]] [[ms:Omega]] [[nl:Omega (letter)]] [[ja:Ω]] [[no:Omega]] [[nn:Omega]] [[nds:Omega]] [[pl:Omega]] [[pt:Ω]] [[ru:Омега (буква)]] [[simple:Omega]] [[sk:Ómega]] [[sl:Omega]] [[sh:Omega]] [[fi:Oomega]] [[sv:Omega]] [[th:โอเมกา]] [[tr:Omega (alfabe)]] [[uk:Омега (літера)]] [[zh:Ω]]