epsilon
epsilon 


pronunciation  
antique  [ e ]  
modern  [ ɛ ]  
Equivalents  
Latin  E.  
Cyrillic  Е  
Hebrew  ה  
Arabic  ه  
Phoenician  ?  
Armenian  Ե  
transcription  
From the ancient world  e  
From the modern  e  

The Epsilon ( Greek neuter Έψιλον , Majuskel Ε, minuscule ε or ε) is the fifth letter of the Greek alphabet and has after the Milesian system the numerical value. 5
origin
The character E originally comes from the Phoenician letter "he" and was used by the Greeks for the vowel "E". The name “ e psilón ” ( Gr. Ἔ ψιλόν ) means “simple” or “bare e” (compared to the letter combination “αι”, which has the same sound value as the ἔ ψιλόν since the Hellenistic period ).
use
 In phonetic transcription , epsilon stands for an unrounded, halfopen front tongue vowel ( open e ).
 In mathematics , ε is used to denote an arbitrarily small number greater than zero. Such a number is needed in analysis when defining limit values such as supremum and infimum . This area is therefore also referred to as " epsilontics ".
 In some areas of mathematics, ε (x) describes a Heaviside function ,
 and in tensor calculus ε means the LeviCivita symbol .
 Mathematicians and astronomers use ε (next to e ) for the numerical eccentricity of an ellipse or elliptical orbit .
 In astronomy , ε is
 usually the fourth to sixth brightest star in the respective constellation , such as Alioth = ε Ursae Majoris (the "drawbar of the big dipper")
 and the more detailed description of two meteor streams ( EpsilonGeminids and EpsilonPerseids )
 In space travel, there is the epsilon (rocket) as part of the Japanese solid rocket series
 In geometry and geodesy , ε is often used for a small angle or a special angle difference , and
 in the compensation calculation for the error of a measured variable to be minimized .
 In computer science , the small epsilon (ε) stands for an empty word .
 In physics , ε denotes the permittivity , the coefficient of performance and the emissivity .
 In technical mechanics , it stands for the elongation ,
 and for internal combustion engines for the compression ratio .
 In chemistry , the small epsilon denotes the extinction coefficient .
 In economics , ε is often used for income elasticity (analogous to η for general elasticity) and for the real exchange rate , defined by: ε = nominal exchange rate * domestic price level / international price level.
 The symbol “3” (inverted epsilon) is the conformity symbol for compliance with the EC “Council Directive 75/324 / EEC”  approximation of the laws of the member states on aerosol dispensers from 1975, amended in 1980 and 1994. See also technical rule Pressurized gas TRG300 of the FRG on pressurized gas packs and declaration of conformity from the manufacturer of pressure equipment with more than low pressure hazard potential (CE mark).
 As a European conformity notice on highpressure gas cylinders (stamped on the steel shoulder), it makes it easier for e.g. For example, compressed air or oxygen cylinders that have been tested in one EU country can also be filled in another EU country  in accordance with standards that became mandatory in 2006
 as “Ex” (E in the form of a large, small epsilon) in the circumscribed hexagon it stands for devices that are suitable for explosive environments.
Web links
Wiktionary: Epsilon  explanations of meanings, word origins, synonyms, translations