Upsilon

This is an accepted version of this page Upsilon (US: /ˈʌpsɪˌlɒn, ˈ(j)uːp-, -lən/, UK: /(j)uːpˈsaɪlən, ʊp-, -lɒn/;[1][2][3][4][5][6] uppercase Υ, lowercase υ; Greek: ύψιλον ýpsilon [ˈipsilon]) or ypsilon /ɪp-/[1] is the twentieth letter of the Greek alphabet.

[7] In early Attic Greek (6th century BCE), it was pronounced [u] (a close back rounded vowel like the English "long o͞o").

As an initial letter in Classical Greek, it always carried the rough breathing (equivalent to h) as reflected in the many Greek-derived English words, such as those that begin with hyper- and hypo-.

[13] As the Roman writer Persius wrote in Satire III: and the letter which spreads out into Pythagorean branches has pointed out to you the steep path which rises on the right.

320), refers to this: For they say that the course of human life resembles the letter Y, because every one of men, when he has reached the threshold of early youth, and has arrived at the place "where the way divides itself into two parts," is in doubt, and hesitates, and does not know to which side he should rather turn himself.