ψ
|
|
Translingual
Symbol
ψ
- Psychology.
- Psychiatry.
- Parapsychology, psychics.
- (quantum mechanics) A wavefunction.
- (electrical engineering) Electric flux.
- (physics, biochemistry) Water potential in cells.
- (astrology, dated) Neptune.
- (astrology, italic) asteroid (16) Psyche (a stylized 𝜓)
- (Christianity) The Psalms (a book in the Bible).
- (phonetics, dated) a voiceless retroflex click, IPA ⟨𝼊⟩.
Usage notes
(quantum physics): Some texts use Ψ (uppercase) for the actual wavefunction that appears in the time-dependent Schrödinger equation, and ψ (=ΨeiEt/ħ) (lowercase) for the time-independent spatial wave function that may exist for stationary states (and which then appears in the time-independent Schrödinger equation), but this distinction is not always observed. Otherwise, the distinction may be made by providing the arguments.
Ancient Greek
Etymology
Derived from its majuscule counterpart Ψ.
Letter
ψ • (ps) (lowercase, uppercase Ψ)
- Lower-case psi (ψεῖ), the 23rd letter of the ancient Greek alphabet. It represented the consonant cluster /ps/ in the Eastern Greek alphabet and the voiceless aspirated velar plosive /kʰ/ in the Western Greek alphabet (compare Etruscan 𐌙 khe). It is preceded by χ and followed by ω.
Derived terms
See also psi
See also
Greek
Letter
ψ • (ps) (lowercase, uppercase Ψ)
- The lower case letter psi (ψι), the 23rd letter of the modern Greek alphabet.