💨 A pressure unit 🔤 A Greek letter

psi

14 7.7

The twenty-third letter of the Greek alphabet written as Ψ or ψ

noun
/saɪ/

Specialized

: psi

The wave function PSI is surely fundamentally a real function.
PSI Subscale
PSI program

Examples

Parapsychology, insofar as it confirms the existence of a transcendent psi factor, thus opens up the world of human experience.

Academic text (1995)
The wave function is this PSI and then each of the axis here is for a particle.
Further, it is necessary to conduct instruction and research using the PSI with gifted students at the secondary level.

Academic text (1990)
In my judgment, parapsychology has produced significant evidence for a transcendent psi factor in nature.

Academic text (1995)
The purpose of this study was to determine the efficacy of Keller's PSI with gifted junior high public school students.

Academic text (1990)
There are six dual-range high- and low-pressure models that can measure from fractions up to 3,000 psi.

Academic text (2001)
In mathematics, the letter psi is often used to represent complex functions.
Many publications use the Greek letter psi to denote specific scientific variables.
The symbol psi appears in various equations throughout physics and engineering.

Compounds

psi particle

Specialized

9.9

A heavy neutral meson made of a quark and an antiquark seen in physics experiments

Surface Forms

psi singular

psis plural

Etymology

Psi is the name of the Greek letter Psi Ψ ψ and comes from the Greek alphabet, so it is used as a symbol in science and math; a helpful way to remember it is that the 'psy-' in psychology comes from Greek for 'mind', so psi often stands for ideas about the mind or other scientific things.