The Greek letter θ (theta) was derived from the ancient Phoenician letter 𐤈 (ṭēt) which meant “wheel”. The Cyrillic letter Ѳ (fita), derived from θ, was a part of the Russian alphabet until 1918. Gogol wrote in a footnote to Dead Souls:
«Ѳетюкъ — слово обидное для мужчины, происходитъ отъ Ѳ, буквы, почитаемой нѣкоторыми неприличною буквою.»
(“Thetuk” is an offensive word to a man, it comes from Ѳ, a letter thought by some indecent.)
Speaking of decency: according to Real Academia Española, this letter should be called zeta, perhaps to avoid using the word teta, while the letter ζ is supposed to be called dseta.
The lower-case letter θ has quite a few uses in maths and sciences, for instance:
- in astronomy, geography, mathematics and physics: one of the coordinates in spherical coordinate system (r, θ, φ)
- in neurophysiology: θ-waves, a type of brain waves detected by electroencephalography
- in linguistics: θ-role
- in mathematics: a number of different fuctions called theta functions
- in particle physics: symbol for theta meson
- in phonetics: voiceless dental fricative, as in theta /ˈθiːtə/ or /ˈθeɪtə/
- in thermodynamics: a symbol for potential temperature
More photos related to letters, numbers and sea glass @ Shutterstock.
No comments:
Post a Comment