Phi (uppercase Φ, lowercase φ, or math symbol ϕ), pronounced /faɪ/ FY or sometimes /fiː/ FEE in English, and in modern Greek, is the 21st letter of the Greek alphabet. In modern Greek, it represents, a voiceless labiodental fricative. In Ancient Greek it represented, an aspirated voiceless bilabial plosive (from which English ultimately inherits the spelling "ph" in words derived from Greek). In the system of Greek numerals it has a value of 500 (φʹ) or 500,000 (͵φ). The Cyrillic letter Ef (Ф, ф) arose from Φ.

Read more about Phi:  Use As A Symbol, Computing

Famous quotes containing the word phi:

    Adolescents have the right to be themselves. The fact that you were the belle of the ball, the captain of the lacrosse team, the president of your senior class, Phi Beta Kappa, or a political activist doesn’t mean that your teenager will be or should be the same....Likewise, the fact that you were a wallflower, uncoordinated, and a C student shouldn’t mean that you push your child to be everything you were not.
    Laurence Steinberg (20th century)