Every quantum mechanical operator has an observable in classical mechanics <x> - position ... <x^2> - ? <p^2> - ? What is the meaning on these expectation values? v^2 = <x^2> - <x>^2 What is the meaning of this? edit: It looks to me like uncertainty in position. Is it the average uncertainty in position? Admin Please move me to the right forum, if i'm not in eet.