Xi

This article covers the Greek letter Xi, further meanings under XI

Xi
pronunciation
antique	[ ks ] ​​
modern	[ ks ] ​​
Equivalents
Latin	Xx
Cyrillic	Ѯѯ
Phoenician	?
transcription
From the ancient world	x
From the modern	x
Coding Capitals Unicode number U + 039E Unicode name GREEK CAPITAL LETTER XI HTML & # 926; HTML entity ?? Minuscule Unicode number U + 03BE Unicode name GREEK SMALL LETTER XI HTML & # 958; HTML entity ?

The Xi ( ancient Greek ξεῖ, modern Greek ξι , capitals Ξ, minuscule ξ) is the 14th letter of the Greek alphabet and has the numerical value 60 according to the Milesian system . The name of the letter is pronounced [ ksi ], the double consonance (k + s) , which the letter represents, has the sound value [ ks ].

origin

The Greek Ξ only replaced the pre-Greek letter combination ΚΤΣ ([ kts ]) linguistically and graphematically at a later time.

Today grapheme Xi has its origins in Phoenician characters samech that [⁠ s ⁠] was spoken. The Greek letter Chi (X) also comes from Samech . The name, however, was transferred to the Sigma (Σ) derived from the Schin . The Xi was adopted later than other Phoenician letters in Greece and did not find its way into all dialects.

use

• In physics, ξ is used as
  • dimensionless position variable , mostly as a substitute for x
  • mean logarithmic energy decrement in reactor physics and as
  • Coherence length of a Cooper pair in a superconductor .

• In physics, Ξ is used as
  • Identifier of a Ξ-baryon and as
  • Symbol for the sound deflection (also called sound deflection )

• In chemistry
  • ξ denotes the conversion variable (reaction run number) of a reaction.
  • Ξ denotes an ambiguous stereochemical arrangement in a chiral molecule as a descriptor .

• In mechanics
  • ξ denotes the screw coordinates of a rigid body movement (vector with 6 components)

• In aerospace engineering
  • ξ denotes the amount of aileron deflection

• In math
  • ξ often denotes a random variable .
  • stand and for the Riemann Xi functions ${\displaystyle \xi (s)}$ ${\displaystyle \Xi (t)}$
• In thermodynamics
  • ξ denotes the mass ratio of a component of an ideal gas mixture.

• In the medicine
  • ξ denotes a dimer made up of two polypeptide chains that belong to the T cell receptor of a T cell .

• In geodesy
  • ξ denotes the north-south component of the vertical deviation.

• As a currency symbol
  • Ξ denotes an ether of the Ethereum currency

• In construction and production technology
  • ξ denotes the related adhesive dimension, e.g. for (press) connections

Mix-up

The letter is very similar to the Chinese number three: Sān (三) and is often confused with it.

swell

1. ↑ R. Brockhaus, W. Alles, R. Luckner: flight control . 3. Edition. Springer-Verlag, 2011.

Web links

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