QR5.6.1 Is Energy Always Conserved?

Thermodynamics began as the study of energy in the form of heat. It was observed that in a closed system, heat always flows from hot to cold but the total heat is constant. The second law of thermodynamics is the generalization that the universe is closed system with a constant energy that always disperses.

However, physics also has potential energy based on position in a gravitational field. Raising an object stores potential energy that is returned later when it falls. This balances the ledger, so energy isn’t lost or made, but what stores and releases potential energy?

For example, if a rocket is shot into earth orbit, where the liftoff energy goes isn’t seen. If it leaves the earth and travels in space forever, presumably its potential energy is stored forever. If it crashes on a bigger planet like Jupiter to release more energy than leaving earth took, where does the extra energy come from? Energy is conserved if objects stay in the same place but they never do, so is potential energy just a way to cover up any discrepancies?

Those who explain physics say that energy is conserved because if the Jupiter rocket was re-assembled and returned to earth, the energy would be restored. But how can future options explain the present? Applying that logic to entropy, does an egg broken on the floor have potential entropy because it can be reassembled again? One would ask, where is this potential entropy stored? So is potential energy stored in space, matter or gravity itself? Current physics can’t say.

Most energy transfer has a means, so when a car loses kinetic energy to friction its tires become hot and radiate heat energy, so we can observe kinetic energy turning into heat energy. In contrast, a ball thrown up loses kinetic energy to where? With no means of exchange, potential energy is just a way to say that energy is conserved when it isn’t. What then is always conserved?