Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Porbability Density?

  1. Apr 2, 2014 #1
    In quantum mechanics, given ψ, we calculate the probability density in a given space by (mod[ψ]^2)*dx*dy*dz (as given in any standard textbook). But my suggetion is that it should be (mod[ψ]^2)*dx*dy*dz*dt where dt is the differential time element. Its seems to me to be more fundamental. Then why dont we do that?
    Curious undergrad!
  2. jcsd
  3. Apr 2, 2014 #2


    User Avatar
    Science Advisor

    The probability density is at a given instant, not per unit time.
  4. Apr 2, 2014 #3


    User Avatar
    Science Advisor

    Also we do NOT use [itex]\Psi[/itex] to calculate the probability density. [itex]\Psi[/itex] is the probability density. The integral, over a space interval, gives the probability that the object is in that space at the given instant.
  5. Apr 3, 2014 #4


    User Avatar
    Science Advisor
    Gold Member

    @HallsofIvy I think you mean the absolute square of the wave function is the probability density.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook