I just finished my Quantum Mechanics module and i have somethings that i already discussed with my professor but i didn't get what he was saying. Does the quantum model of the simple pendulum "exist" as in real or verified experimentally? because in the quantum model, there are some places where the probability of finding the pendulum at some places is zero..it simply doesn't make any sense to me. one more thing , the quantum model of the SP suggested that the pendulum crosses the classical border/boundary....has this been verified experimentaly ? if yes then under what conditions does this happen? Last but not least, what solution to the time-independent Schrodinger Equation leads to the above? I have been in the search function but after 20 mins i couldn't find what i was asking about. BTW, i'm in first year electrical engineering.