For the particle in box, if we examine the solution of Schrodinger equation when n → ∞ for the velocity, we found that this velocity is equal to the classical velocity for the same energy level, in this case, Einstein says [1] that the quantum mechanic is satisfactory complete for the momentum, but it is not for the position! because (based on the probability density for finding the particle) we have always some points that the particle can never exist.
If we examine the probability density for finding the particle when n → ∞ we found a sequence of peaks separated by a distance equal λ/2 that λ is de Broglie wavelength: λ= h/mv and v is the classical velocity, so if the correspondence principle of Bohr describes exactly the reality we should deduce that in fact, the motion does not continue!
So can we found a model of motion that supports quantum mechanics and classical mechanics?
God willing, my answer is yes,
for more information please see this paper:
Preprint The Theory of Universal Quantum Jump
Reference:
[1] A. Einstein, In: Scientific Papers presented to Max Born,pp. 33-40. Oliver and Boyd, Edinburgh, 1953.