Gravity wheel theory-how to make it work

Gravity wheel, yes. Almost people from science know, that an rotated wheel with many weights/balls, can not rotate it self. But, why ? Because the law of physics by Newton explanation. But the gravity force, have no live person ever see it. Only the sides effects, like a falling apple. Have we good reason to do make it work ? If we have an self-rotated wheel with balls, we can choose for green energy.