Phi
Phi (uppercase Φ; Ancient Greek: ϕεῖ, pheî, [pʰé͜e]; modern Greek: φι, fi, [fi]; English: /faɪ/) is the 21st letter of the Greek alphabet.
Description
In Ancient Greek, it represented an aspirated voiceless bilabial plosive ([pʰ]), which was the origin of its usual romanization as "ph".
In modern Greek, it represents a voiceless labiodental fricative ([f]) and is correspondingly romanized as "f".
Its origin is uncertain but it may be that phi originated as the letter qoppa and initially represented the sound /kʷʰ/ before shifting to Classical Greek [pʰ].
In traditional Greek numerals, phi has a value of 500 (φʹ) or 500 000 (͵φ).
Cyrillic
The Cyrillic letter Ef (Ф, ф) descends from phi.
Golden ratio
Phi is also used as a symbol for the golden ratio and on other occasions in mathematics and science.
This use is separately encoded as the Unicode glyph ϕ.
The modern Greek pronunciation of the letter is sometimes encountered in English (as /fiː/) when the letter is being used in this sense.
See also
External links
- Phi @ Wikipedia
