Well, I was going to try to drop out of this thread, but I will go ahead and try one more time.

Potential energy is the energy you can get out of a system when it transforms from one state to another. It depends on the difference in energy levels between the 2 states. As such it is purely relative to the system in which it is being calculated. Oh, it does have to be calculated, I don't think you can measure potential energy. It is a valuable concept in some areas, such as engineering a hydroelectric station. But in itself it is just another useful concept for making calculations. It does not exist as an independent entity. As I have said before it is just a form of book keeping.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.