Imagine I have a setup like this:
(The objects are not attached to each other. The red objects are much heaver than the black one, and the setup is balanced.)
This setup has a non-zero gravitiational potential energy. The red objects, if the black object was removed, would crash into each other. However, the black object is stopping this.
However, since the expansion of the universe is accelerating, there will come a point when the expansion of the universe starts to move these objects away from each other.
These objects are now moving away from each other. There are two scenarios that I think might happen:
- They don't have gravitational potential energy anymore; they can't attract each other because of the expansion of the universe forcing them apart. As such, gravitational potential energy is now 0. However, at the time of the initial setup of these objects, the gravitational potential energy was more than zero. As such, we have destroyed energy.
- Their gravitational potential energy increases, because they have further to fall due to the expansion of the universe. However, at the time of the initial setup of these objects, the gravitational potential energy was below what it is at the current time. As such, we have created energy.
Where is the flaw in my logic?