Is there proof gravity can not be a energy source?

[Low-Q]

Correct, it is a violation of CoE. At the top, because it can't be gotten there without moving it, that is, because of imparting velocity to it, the car will have both potential and kinetic energy. Now, once at rest at the top and then let go down the hill it will give back only the potential energy when reaches the foot of the hill. The kinetic energy will be lost. The energy balance along the closed loop ground-top-ground will be non-zero which is a violation of CoE.

This clearifies everything. Now I finally understand what your definition of violation of CoE is.
It's simply this: Your definition of CoE are different than my definition. Not strange I have been arguing against your theories all the time.
Good luck with your definition, and let's hope you one day are able to find the key to perpetual motion - based on your own definitions about violating CoE.

On the other hand, the car will remain on the bottom if no one pushes it up the hill... CoE are obeyed.

All the best.

Vidar

[Omnibus]

I don't know what your definition of violation of CoE is. Mine is what science requires.

[utilitarian]

This clearifies everything. Now I finally understand what your definition of violation of CoE is.
It's simply this: Your definition of CoE are different than my definition. Not strange I have been arguing against your theories all the time.
Good luck with your definition, and let's hope you one day are able to find the key to perpetual motion - based on your own definitions about violating CoE.

On the other hand, the car will remain on the bottom if no one pushes it up the hill... CoE are obeyed.

All the best.

Vidar

Unfortunately, Omnibus's definition is not one that can ever result in a self running machine.

As far as Brian, the guy is an obvious troll.  He just asks questions in the dumbest way possible, and repeatedly attempts to invert the burden of proof (e.g.  "Prove to me that gravity cannot be used as energy!").

Brian, if you want energy from gravity so bad, prove to us that it is possible.  Show us the design for a gravity motor, and we can poke holes in your proof.

[Omnibus]

Why are you referring to this definition as 'Omnibus' definition'? The definition in question is what science requires, not I. Of course, the example with the car up and down the hill (placing of a book on a bookshelf is not violating CoE; to violate CoE there must be a closed loop), although violating CoE, doesn't allow to make a self-sustaining device. Violation of CoE can be in the negative sense as well. There are other, already well known examples, whereby a similar violation of CoE can be the basis of a self-sustaining machine.

[utilitarian]

Why are you referring to this definition as 'Omnibus' definition'? The definition in question is what science requires, not I. Of course, the example with the car up and down the hill (placing of a book on a bookshelf is not violating CoE; to violate CoE there must be a closed loop), although violating CoE, doesn't allow to make a self-sustaining device. Violation of CoE can be in the negative sense as well. There are other, already well known examples, whereby a similar violation of CoE can be the basis of a self-sustaining machine.

Assuming zero friction, a car going up and down between two hills will still not make a self sustaining overunity machine.  At best, you will have perpetual motion - unity.  But not overunity.

So what is the point of this alleged CoE violation if it can never produce excess energy?  And to be clear, I do not see how there can be any CoE violation here whatsoever.  Potential energy is converted to kinetic, then back to exactly the same amount of potential.  Energy is perfectly conserved.