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Probability of finding a particle [concept behind it]

  1. Oct 15, 2014 #1
    okay so i'm having a bit hard time understanding this:

    i get that probability of finding a particle in between [a,b] is integral (over a,b) (Ψ(x,t)*)Ψ(x,t) dx.

    however, can it also be integral (over a,b) of (Ψ(x,0)*)Ψ(x,0) dx?

    if not, why?

    i saw an example where Ψ(x,0) was given and problem asked user to find prob between some interval. i noticed that the example found Ψ(x,t) first (using usual unitary operator e^(-ikE/h)). i don't understand why it can't be found right away from Ψ(x,0).

    thanks a bunch!
     
  2. jcsd
  3. Oct 15, 2014 #2

    bhobba

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    They are both correct. The second one is simply the first at time t=0.

    Thanks
    Bill
     
  4. Oct 15, 2014 #3
    oh i see. mathematically, i suppose e^(-i) part always goes away so they have to be equal.

    in terms of physics, could you give a quick reasoning for why this is true? why is the probability of finding a particle in interval [a,b] the same as the probability of finding the particle at time t=0 in same interval [a,b]? kinds having a hard time putting intuition behind it.
    thanks.
     
  5. Oct 15, 2014 #4

    bhobba

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    It isn't.

    Why would you think such a thing?

    Thanks
    Bill
     
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