Psi

From Wikipedia, the free encyclopedia

Psi has multiple meanings:

• Psi (letter) (Ψ, ψ) of the Greek alphabet
• Psi (Cyrillic) (Ѱ, ѱ), letter of the early Cyrillic alphabet, adopted from Greek
• Psi (parapsychology)
• Psi (instant messaging client), a popular Jabber client program
• J/ψ particle, a subatomic particle
• Wavefunction in Quantum Mechanics, ψ
• In mathematics, Ψ is used to denote the angle between the tangent and the x-axis in the intrinsic coordinates system
• Again in mathematics, Ψ is also used to denote the Digamma and Polygamma functions.
• PSI (prion), an infectious protein in yeast
• Psi, is a common shortening of the word psychic
• Psi (comics), a DC Comics character
• An abbreviation of the Psion (Dungeons & Dragons) or Psionicist character class
• PSI Records, a record label

A homophone of Psi is Sai, which is an Asian weapon shaped (probably coincidentally) like the Greek letter Psi.

PSI stands for:

• Pandemic Severity Index
• pound-force per square inch (psi), a non-SI unit of pressure
• PSI (computational chemistry) software
• Pandemic Severity Index by Centers for Disease Control and Prevention
• Italian Socialist Party (Partito Socialista Italiano)
• Paul Scherrer Institute in Villigen, Switzerland
• Permanent Staff Instructor in the British Army
• Permanent Subcommittee on Investigations (PSI) of the U.S. Senate
• Planetary Science Institute, a nonprofit science research institute [1]
• Pollutant Standards Index, an air pollution index developed by the United States Environmental Protection Agency (USEPA)
• Population Services International, an international healthcare NGO based in Washington D.C.
• Professional Secretaries International
• Presentence Investigation
• Professors for a Strong Israel
• Program Specific Information, metadata for digital transmission
• Proliferation Security Initiative
• Project Server Interface, programming interface for MS-Project servers
• Public Services International, a global union federation of public sector trade unions
• Socialist Party of the Islands (Partit Socialista de les Illes)
• People with Speech Impairment
• Pechersk School International, a school in Kiev
• Protein Synthesis Inhibition
• Printing Souvenirs Inclusive, a Chicago souvenirs distributor
• Postpartum Support International, 501(c)3 organization devoted to women's mental health issues
• Statisticians In The Pharmaceutical Industry, the PSI acronym (rather than SPI) is chosen for its relation to the Greek letter Ψ, commonly used in statistical formulae.
• Personal Soldier Inc., an Arizona based bodyguard firm (www.personalsoldier.com)

pSi stands for:

• Porous silicon
• protective security international, a british security company