Χ

Ji in a capital letter Etymologicum Magnum (1499).

Ji (uppercase Χ, lowercase χ; Ancient Greek call χ(ε) ῖ kh(e)î /kʰêː, kʰîː/, in modern Greek χι ji /çi/) is the twentieth second letter of the Greek alphabet. It was romanized in Latin as chi.

The Romans transliterated it with the digraph ch in words such as: chorus, chaos, Christus, Charon (chorus, chaos, Christ, Charon, respectively) to represent the sound [kʰ], voiceless aspirated velar plosive, which it had in ancient Greek. In Modern Greek it is pronounced as [ç] (voiceless palatal fricative) before [e̞] or [i]; or as [x] (voiceless velar fricative) in any other position.

In the Greek numeral system it has a value of 600 (Χʹ).

History

Ji is apparently not based on a letter of the Phoenician alphabet, like most other Greek letters, but is an invention of the Greeks themselves. For this reason, it is placed at the end of the Greek alphabet, after the letters of phoenician genesis.

Ji was used in most archaic local alphabets. There were two common ways to represent its sound: one in the shape of a cross, like the current X of the Latin alphabet, and another in turn more similar to the letter psi. However, some local alphabets, such as Thera and Milo, had no ji, so their sound was represented by kapa plus heta.

However, in some Western Greek alphabets, such as the Euboean alphabet, Χ represented the sound of the consonant cluster /ks/. That is why in the Latin alphabet the letter X has this sound. In the Cyrillic alphabet, which was created much later, Х has the Modern Greek sound and its name is pronounced "ja".

Epigraphic variants

In archaic epigraphic sources the following variants appear:

Use

In Greek

Its value in ancient Greek was a voiceless aspirated velar plosive /kʰ/ (in the Western Greek alphabet: /ks/).

In Koine Greek and later dialects it became a fricative ([x]/[ç]), as did Θ and Φ.

In Modern Greek, it has two distinct pronunciations: in front of high or front vowels (/e/ or /i/) it is pronounced as a voiceless palatal fricative [ç], as in German ich or as the h in some pronunciations of the English words hew and human. Before low or back vowels (/a/, /o/ or /u/) and consonants, it is pronounced as a voiceless velar fricative ([x]), as in German ach.

In Greek numerals it has a value of 600.

Transliteration

The old Latin way of transcribing this letter is as ⟨ch⟩, since C in Old Latin was pronounced /k/ and in Ancient Greek Χ was pronounced an aspirated k (/kʰ/). For this reason, ancient Hellenisms such as Κρόνος or Χάος, passed into Latin as Chronos and Chaos. In Spanish, the orthography removed the H from these words (which originally denoted aspiration) turning them into Cronos and Caos, since in Spanish consonant aspiration is not significant and would also be confused with the che sound in words like "noche". or "chocolate."

However, in other languages, such as French and English, the etymological transcription ⟨ch⟩ is maintained, but ⟨kh⟩ is sometimes used.

In English, it is appropriate for modern Greek words to transcribe it as J, since it is the sound of this letter in modern Greek. Also, in Modern Greek, it is often romanized as ⟨h⟩ or ⟨x⟩ in informal writing as well.

As a symbol

The lowercase chi (χ) is used to symbolize:

• In probability and statistics, Pearson or ji-square distributions (χ2).
• The molar fraction in mixtures (solute/total models of dissolution).
• In the Greek numeration system it has a value of 600 (χ+). An example of known use of this numbering is the Number of the BeastIn the Revelation of San Juan, where it appears as χφςji, xi, stigma), which represents the value 666.
• In electrostatic, electrical susceptibility, a constant that relates the strength of the electrostatic field to the dipolar moment by volume unit (also called induced electrical polarization) and the permitivity of the vacuum.

Unicode

• Greek

• Copt

• Latino (AFI)

• Maths