1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Physical meaning of a commutator?

  1. Mar 25, 2012 #1
    I know how to use a commutator as a mathematical formula but I really don't understand what it means. Can anyone explain it to me.

    Is a commutator nothing more than a check to see if it commutes or not since I know that if you use a commutator with a wave function and the result equals zero then you can have a definite value for the observables (operators) simultaneously?

  2. jcsd
  3. Mar 25, 2012 #2

    If two operators do not commute, then they cannot be measured simultaneously with infinite precision - the pair of observables has to obey Heisenberg's uncertainty principle.

    If an operator commutes with the Hamiltonian, then its expectation value is constant.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook