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!