Kappa 4341954 225516709 2008-07-14T02:46:05Z Jumbuck 116385 robot Modifying: [[es:Κ]] [[Image:Greek lc kappa2.png|thumb|left|75px|Variant kappa]] {{wiktionarypar2|Κ|κ}} {{Table_Greekletters|letter=kappa}} {{otheruses}} '''Kappa''' (uppercase '''Κ''', lowercase '''κ''' or '''{{Unicode|ϰ}}'''; {{lang-el|Κάππα}}) is the 10th letter of the [[Greek alphabet]], used to represent the [[voiceless velar stop]], or "k", sound in [[Ancient Greek|Ancient]] and [[Modern Greek]]. In the system of [[Greek numerals]] it has a value of 20. It was derived from the Phoenician letter [[Kaph]]. Letters that arose from kappa include the Roman [[K]] and Cyrillic [[Ka (Cyrillic)|Ka]]. Greek proper names and placenames containing kappa are often written in English with "c" due to contemporary rendering into the [[Latin alphabet]] by ancient Romans. However, modern transliteration of the Greek language invariably use the letter "k". Compare ''Κυνοσκεφαλαι'', ''Cynoscephalae'' (ancient placename); ''κυνος κεφαλαι'', ''kunos kephalai'' (phrase), meaning "[[dog]]'s [[head]]s". [[Image:kappa-variant.PNG|frame|left|Greek word ''καί'' written with a handwritten variant of kappa, from the Byzantine period]] In [[mathematics]], the [[kappa curve]] is named after this letter; the [[tangent]]s of this [[curve]] were first calculated by [[Isaac Barrow|Barrow]] ([[17th Century]]). ==Symbol== In [[graph theory]], the [[Connectivity (graph theory)|connectivity]] of a [[graph (mathematics)|graph]] is given by κ. In [[differential geometry]], the [[curvature]] of a curve is given by κ. In [[physics]], the [[torsional constant]] of an [[oscillator]] is given by κ. In [[chemistry]], the [[compressibility]] of a compound is given by κ. In [[physics]], the [[dielectric constant]] of a [[capacitor]] is also given by κ. In [[psychology]] and [[psychiatry]], kappa represents a measure of diagnostic reliability. In [[biology]], kappa and kappa prime are important [[nucleotide]] motifs for a tertiary interaction of group II introns. In [[biology]], kappa designates a subtype of an [[antibody]] component. In [[pharmacology]], kappa represents a type of [[opioid receptors]]. [[Kappa statistics]] such as [[Cohen's kappa]] and [[Fleiss' kappa]] are methods for calculating interannotator agreement. Upper-case letter Κ is used as a symbol for: *In [[textual criticism]], the [[Byzantine text-type]] (from Κοινη, ''Koine'', the common text). [[Category:Greek letters]] [[als:Κ]] [[ar:كبا (حرف إغريقي)]] [[arc:Κ]] [[br:Kappa (lizherenn)]] [[bg:Капа (буква)]] [[ca:Kappa]] [[cy:Kappa]] [[da:Kappa]] [[de:Kappa]] [[el:Κάππα]] [[es:Κ]] [[eo:Kapo (litero)]] [[ext:Capa]] [[eu:Kappa]] [[fr:Kappa]] [[ga:Capa]] [[gd:Kappa]] [[gl:Kappa]] [[ko:Κ]] [[hr:Kapa]] [[is:Kappa]] [[it:Kappa (lettera)]] [[he:קפא]] [[ka:კაპა (ასო)]] [[ht:Κ]] [[ku:Kappa]] [[la:Cappa]] [[lt:Kapa (raidė)]] [[hu:Kappa]] [[ms:Kapa]] [[nah:Κ]] [[nl:Kappa (letter)]] [[ja:Κ]] [[no:Kappa (bokstav)]] [[nn:Kappa]] [[nds:Kappa]] [[pl:Kappa (litera)]] [[pt:Κ]] [[ru:Каппа (буква)]] [[simple:Kappa (letter)]] [[sk:Kapa]] [[sl:Kapa (črka)]] [[sh:Kapa]] [[fi:Kappa (kirjain)]] [[sv:Kappa (bokstav)]] [[th:แคปปา]] [[vi:Kappa]] [[tr:Κ]] [[uk:Каппа (літера)]] [[vo:Kappa]] [[zh:Κ]]