Gravity Is Not Like the Other Forces
I know this is tangential, but as lay person regarding physics I am stuck on the following thought experiment regarding gravity:We know about gravitational potential energy. We harness it all the time with dams and whatnot. Generally speaking, when we lift matter high above, we get some of the used energy back when it falls back down.But when we talk about sending say, a spaceship into space, it may fall on a different planet, with a different gravity (a function of the planet's mass), changing the amount of energy yielded by the fall.The question is: Where is the energy stored in the meantime? Where does the extra energy, if the ship falls into a heavier planet, come from?It seems that the energy is being stored somewhere, and that matter itself allows us to tap into that, but is not the place where it is stored. Is there anything I can read to better understand what we know about this?