Ψ is either the top of Neptune's trident, or one of those funky Hanukkah candle stands without a base. ♆ is the symbol for the decorated top of Neptune's trident. Ψ is called "psi" when translated to English. Ψ is pronounced *sigh*. Ψ is also used in equations for calculating pressure per square inch (or, what do you know, psi). So that is why it is called psi. Since it also looks like the top of Neptune's trident or one of those funky Hanukkah candle stands without a base, it is also used in chat and semi-everyday life. Ψ is used in many equations, such as Ψw = Ψp + Ψs + Ψg, Ψs= -iRTcs, Jv = ∆Ψw/r, Jv = (∆Ψw /∆x) (r2/8n), ∆E= (2.3RT/zF)log[cout/cin], and Ψwair = (RT/Vw) 1n (RH). Ψ comes after Y in the alphabet.