Gravity seems to be able to do work, and it can never be used up. In stars, it causes hydrogen to be crammed together, creating massive amounts of energy. On earth, we can utilize it through riding a bike or creating hydroelectric power. It seems intuitively incorrect for things to have an infinite supply of energy simply because of having mass. Yet, gravity effects everything with mass, and there has yet to be evidence that you can run out of it.

Some say the Theory of Relativity gets around this issue by asserting that gravity isn’t actually a force, it is simply a result of space curvature. I don’t think space curvature adequately answers this question. Space curvature seems to be a viable explanation behind why objects are drawn to other objects with greater mass. The analogy of a bowling ball on a mattress is often used. But, just like in this analogy, curvature still requires the existence of a force that continuously pulls space towards dense deposits of matter. Seemingly, this force is never extinguished.

However, there is a major practical hurdle in utilizing this energy. Something has to be moved for work to be done; after gravity has moved an object, energy must be expended against gravity for the object to be moved again. Tesla claimed to have figured out a way to access limitless energy. Supposedly this discovery was based on his Dynamic Theory of Gravity, which unified the theories of gravity and electromagnetism. But, he came up with this theory at the end of his life, and died before publishing the papers. Upon his death, the U.S. government confiscated much of his work, so who knows whether his claims were justified.

I do not have PhD in theoretical physics. So, if anyone understands where my misunderstanding is please correct me.