美国数学家麦克·哈特尔(Michael Hartl)创建了网站 Tau Day,呼吁人们用希腊字母 τ(发音:tau)来表示“正确的”圆周率 C/r。并建议大家以后在写论文时,用一句“为方便起见,定义 τ = 2π ”开头。
英语百科
Tau Τ
Tau (uppercase Τ, lowercase τ; Greek:ταυ[taf]) is the 19th letter of the Greek alphabet. In the system of Greek numerals it has a value of 300.
The name in English is pronounced /taʊ/ or /tɔː/, but in modern Greek it is [taf]. This is because the pronunciation of the combination of Greek letters αυ has changed from ancient to modern times from one of [au] to either [av] or [af], depending on what follows (see Greek orthography).
近义、反义、联想词
近义词
n.
letter, letter of the alphabet, alphabetic character