From Textus Receptus
Epsilon (uppercase Ε, lowercase ε; Έψιλον) is the fifth letter of the Greek alphabet, corresponding phonetically to a close-mid front unrounded vowel /e/. In the system of Greek numerals it has a value of 5. It was derived from the Phoenician letter He . Letters that arose from Epsilon include the Roman E and Cyrillic Ye.
The uppercase form of epsilon looks essentially identical to Latin E. The lowercase version has two typographical variants, both inherited from medieval Greek handwriting. One, the most common in modern typography and inherited from medieval minuscule, looks like an inverted "3". The other, also known as lunate or uncial epsilon and inherited from earlier uncial writing, looks like a semicircle crossed by a horizontal bar. While in normal typography these are just alternate font variants, both may have different meanings as mathematical symbols. Computer systems therefore offer distinct encodings for both. In Unicode, the character U+03F5 "Greek lunate epsilon symbol" (ϵ) is provided specifically for the lunate form. In TeX, () denotes the lunate form, while () denotes the inverted-3 form.
There is also a Latin epsilon or "open e", which looks similar to the Greek lowercase epsilon. It is encoded in Unicode as U+025B ("Latin small letter open e", ɛ) and U+0190 ("Latin capital letter open e", Ɛ) and is used as an IPA phonetic symbol. The lunate or uncial epsilon has also provided inspiration for the euro sign (€).
The letter Ε was taken over from the Phonician letter He () when Greeks first adopted alphabetic writing. In archaic Greek writing, its shape is often still identical to the Phoenician letter. Like other Greek letters, it could face either leftwards or rightwards (), depending on the current writing direction, but just like in Phoenician, the horizontal bars always faced in the direction of writing. Archaic writing often preserves the Phoenician form with a vertical stem extending slightly below the lowest horizontal bar. In the classical era, through the influence of more cursive writing styles, the shape was simplified to the current E glyph.
The initial sound value of Ε was determined by the vowel occurring in the Phoenician letter name He, which made it a natural choice for being reinterpreted from a consonant symbol to a vowel symbol denoting an [e] sound. Besides its classical Greek sound value, the short /e/ phoneme, it could initially also be used for other [e]-like sounds. For instance, in early Attic before c.500 B.C., it was used also both for the long, open /ɛː/, and for the long close /eː/. In the former role, it was later replaced in the classic Greek alphabet by Eta (Η), which was taken over from eastern Ionic alphabets, while in the latter role it was replaced by the digraph spelling ΕΙ.
Some dialects used yet other ways of distinguishing between various e-like sounds.
In Corinth, the normal function of Ε to denote /e/ and /ɛː/ was taken by a glyph resembling a pointed B (), while Ε was used only for long close /eː/. The letter Beta, in turn, took the deviant shape .
In Sicyon, a variant glyph resembling an X () was used in the same function as Corinthian .
In Thespiai (Boeotia), a special letter form consisting of a vertical stem with a single rightward-pointing horizontal bar () was used for what was probably a raised variant of /e/ in pre-vocalic environments. This tack glyph was used elsewhere also as a form of "Heta", i.e. for the sound /h/.
After the establishment of the canonical classic Greek alphabet, new glyph variants for Ε were introduced through handwriting. In the uncial script (used for literary papyrus manuscripts in late antiquity and then in early medieval vellum codices), the "lunate" shape () became predominant. In cursive handwriting, a large number of shorthand glyphs came to be used, where the cross-bar and the curved stroke were linked in various ways. Some of them resembled a modern lowercase Latin "e", some a "6" with a connecting stroke to the next letter starting from the middle, and some a combination of two small "c"-like curves. Several of these shapes were later taken over into minuscule book hand. Of the various minuscule letter shapes, the inverted-3 form became the basis for lower-case Epsilon in Greek typography during the modern era.
|Uncial||Uncial variants||Cursive variants||Minuscule||Minuscule with ligatures|
International Phonetic Alphabet
Math and science
- In mathematics (particularly calculus), an arbitrarily small positive quantity is commonly denoted ε; see (ε, δ)-definition of limit.
- In mathematics, Hilbert introduced epsilon terms εx.φ as an extension to first order logic; see epsilon calculus.
- In mathematics, the Levi-Civita symbol.
- In mathematics, to represent the dual numbers: a + bε, with ε2 = 0 and ε ≠ 0.
- In mathematics, sometimes used to denote the Heaviside step function.
- In set theory, the limit ordinal of the sequence .
- In computing, the precision of a numeric data type and floating-point machine epsilon.
- In computer science, the empty string, though different writers use a variety of other symbols for the empty string as well, including the lower case Greek letter lambda.
- In physics, the permittivity of a medium.
- In physics and electronics, the emf of a circuit
- In physics, the strain of a material (a ratio of extensions).
- In automata theory, a transition that involves no shifting of an input symbol.
- In astronomy, the fifth-brightest star in a constellation (see Bayer designation).
- In astronomy, Epsilon is the name for Uranus' most distant and most visible ring.
- In chemistry, the molar extinction coefficient of a chromophore.
- In economics, ε refers to elasticity.
- In statistics, to refer to error terms.
- In agriculture, to represent the "photosynthetic efficiency" of a particular plant or crop.
- In the popular web series "Red vs. Blue", Epsilon is the name of Agent Washington's AI, possessing memories from the breaking of the Alpha AI by Project Freelancer.
- Epsilon in Malaysian Pale is the name of the second solo album released by Tangerine Dream leader Edgar Froese in 1975.
- Epsilon is also an Australian light-powered female-looking robot that fought Pluto in an episode of Astro Boy.
- Epsilon Eridani III is the planet that the spacestation Babylon 5 orbited in the eponymous sci-fi television series.
- E-104 Epsilon is also the name of a robot in Sonic Adventure.
- Epsilon is an otherworldy being in the book The Riddles of Epsilon by Christine Morton-Shaw.
- "Epsilon 9" is the name of the Federation space station consumed by the V'ger cloud in Star Trek: The Motion Picture.
- Epsilon is the name of an unlockable creature in the game Monster Rancher 2.
- In Greek it is used for Epsilon Team.
- "Epsilon Mirror" is the name of one of Aika's moves in the video game Skies of Arcadia.
- Epsilon is the leader of the Rebellion in Mega Man X: Command Mission.
- "The Epsilon Program" is a mysterious cult in the video game Grand Theft Auto: San Andreas by Game Developer Rockstar North. This cult is thought to be based on Scientology.
- The Epsilon Project is a fictional experiment mentioned in the Dreamcast and Xbox versions of Dead or Alive 2 and is based on cloning.
- Epsilon is the lowest of five social castes in the Aldous Huxley novel Brave New World.
- "Plan Epsilon" was one of many plans to restore Doctor Doom to life in the event of his death, as shown in Fantastic Four issue no. 246, written by Stan Lee.
- Epsilon-Eagle is the name of the protagonist in the Sega Mega Drive game Alien Soldier.
- Epsilon was the name given to one of the ground support teams in the Sony Playstation game G-Police.
- Epsilon is the name of the newly resurrected Yuri Faction in the Yuri's Revenge mod Mental Omega.
- Epsilon was one of the warriors of Asgard in the Anime series Saint Seiya, Fenrir Epsilon, The Northern Wolf, when Dragon Shiryu had to fight for his life against him on his way to rescue Hilda.
- Epsilon was the name of the chef dog in the Pixar movie Up when Carl and Russell are in Muntz's lair.
- "Epsilon Knight" is the name of a racer in the Extreme-G racing game series who, if controlled by the computer, always happened to finish 5th.
- Epsilon was a man-made God in the game AdventureQuest.
- "Epsilon" is the name used by General Motors for the post-2003 Epsilon platform.
- Epsilon Euskadi, a carmaker and EpsilonEuskadi LMP1 car.
- Barazi-Epsilon, a manufacturer in the 2009 Superleague Formula season for the Olympique Lyonnais car.
- Hurricane Epsilon, a storm of the 2005 Atlantic hurricane season.
- Epsilon TB-30 is a training aircraft made by Socata and used by the French, Portuguese, Senegalese and Togo airforces. Introduced in 1984 it provides basic and intermediate training, and has a 300 hp lycoming engine.
- Stars Epsilon Eridani and 40 Epsilon.
- Epsilon is a multi-platform Emacs-like programmer's text editor by Lugaru Software Ltd
- Epsilon is used in the "reverse cat-face" emoticon.
- 1. Nick Nicholas: Letters, 2003–2008. (Greek Unicode Issues)
- 2. Colwell, Ernest C. (1969). "A chronology for the letters Ε, Η, Λ, Π in the Byzantine minuscule book hand". Studies in methodology in textual criticism of the New Testament. Leiden: Brill. pp. 127.
- 3. Jeffery, Lilian H. (1961). The local scripts of archaic Greece. Oxford: Clarendon. pp. 63–64.
- 4. Jeffery, Local scripts, p.24.
- 5. Jeffery, Local scripts, p.114.
- 6. Jeffery, Local scripts, p.138.
- 7. Jeffery, Local scripts, p.89.
- 8. Thompson, Edward M. (1911). An introduction to Greek and Latin palaeography. Oxford: Clarendon. pp. 191–194.