Phi

Phi
pronunciation
antique	[ p h ] ​​
modern	[ f ] ​​
Equivalents
Latin	Ff
Cyrillic	Фф
Hebrew	פ
Arabic	ﻑ
Phoenician	?
transcription
From the ancient world	ph
From the modern	f
Coding Capitals Unicode number U + 03A6 Unicode name GREEK CAPITAL LETTER PHI HTML & # 934; HTML entity ? Minuscule Unicode number U + 03C6 Unicode name GREEK SMALL LETTER PHI HTML & # 966; HTML entity ? variant Unicode number U + 03D5 Unicode name GREEK PHI SYMBOL HTML & # 981; HTML entity

The Phi ( Greek neuter Φι , Majuskel Φ respectively , minuscule φ ( ) or φ ( ), usual pronunciation of the designation of the letter: [fi:]) is the 21 letter of the Greek alphabet , and has according to the Milesian system the numerical value 500 . ${\displaystyle \Phi \,}$ ${\displaystyle \varphi \,}$ ${\displaystyle \phi \,}$

use

• In the mathematics called
  • the small phi ( ) represents an angle in polar coordinates and the azimuth angle in spherical polar coordinates. ${\displaystyle \varphi }$
  • the small Phi ( ) is Euler's φ-function . ${\displaystyle \varphi }$
  • the big phi (Φ) the irrational numerical value of the golden section .
  • the large Phi (Φ) the probability function (also called Gaussian error integral ).
• In physics :
  • the small phi ( ) denotes a meson in particle physics . ${\displaystyle \varphi }$
  • the small phi ( ) stands for the flow rate in fluid mechanics . ${\displaystyle \varphi }$
  • The small Phi ( ) stands for the relative humidity in thermodynamics and air conditioning . ${\displaystyle \varphi }$
  • the capital phi (Φ) is the general symbol for physics , e.g. B. in the logo of the German Physical Society .
  • the big phi (Φ) stands for the electrical potential in theoretical physics .
  • The big phi (Φ) stands for the luminous flux in lighting technology .
  • the large Phi (Φ) referred to in the materials and construction technology as well as in the Earth Sciences the porosity .
  • The large Phi (Φ) denotes the equivalence ratio in engine technology
• In electrical engineering and physics referred
  • the small phi ( ) is the phase shift angle . ${\displaystyle \varphi }$
  • the big phi (Φ) the magnetic flux .
  • the large phi (Φ) the number of outer conductors , e.g. B. 1Φ means single phase alternating current , while 3Φ means three phase alternating current . Another frequently used notation uses the tilde instead of the capital phis .
• In chemistry
  • the small Phi ( ) is the symbol for the volume fraction of a component in a mixture of substances. ${\displaystyle \varphi }$
• In biochemistry referred
  • Phi is the torsion angle around the C alpha-N bond in a protein and is thus one of the two rotation angles, along with Psi, with which the framework conformation of a polypeptide chain can be largely described.
• In biology refers
  • Phi a group of bacteriophages with single-stranded DNA ( Microviridae ).
  • Phi Solenidia (mechano- or chemosensory setae ) on the tibia of the Acariformes .
• In geography
  • Phi is the latitude .
• In geology , especially engineering geology , stands
  • the small phi ( ) for the angle that a geological surface forms with an imaginary horizontal surface, the so-called angle of incidence . ${\displaystyle \phi }$
• In geomechanics it says
  • the small phi ( ) for the friction angle of a loose rock . ${\displaystyle \phi }$
• In structural geology
  • to name a Klast type (see Phi-Klast )
• In the statistics referred
  • the Phi coefficient ( ) the relationship between two dichotomous features (features that can only take two forms, e.g. gender, yes-no or have-not). ${\displaystyle \phi }$
• In phonology
  • the little Phi denotes a phonological phrase .
• In the construction of fiber-plastic composites (FRP)
  • Phi denotes the fiber volume fraction .
• In forming technology
  • Phi denotes the degree of deformation .
• In cybernetics
  • the Phi value (after Giulio Tononi ) describes the consciousness or the consciousness of a system.
• In neuroinformatics
  • Phi describes the activation function of a neuron.

Φ - ph / f

See also : Ancient Greek Phonology # loanwords

In ancient Greek, the phi was not pronounced as [f], but as aspirated p [p ^h ]. When Greek words were adopted into Latin, loanwords , especially technical names and proper names, which contained the letter Φ, were transcribed with “p” or “ph”, which the scribes tried to reproduce this sound, which Latin did not know. Later, in the first centuries after Christ, spellings with "f" appeared for the first time in such loanwords, which indicates that the Phi in Greek had become a fricative ( fricative ). In the second century, "P (h) ilippus" was replaced by "Filippus". In modern Greek and in school pronunciation of ancient Greek , the pronunciation is [f]. In German words of Greek origin that contain the sequence of letters “ph” (e.g. philology, philosophy ), “ph” can be replaced by “f” under certain conditions.

Web links

Wiktionary: Phi  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ^ GW Krantz, DE Walter (Ed.): A manual of acarology . Lubbock (Texas) 2009, ISBN 978-0-89672-620-8 .