Certainly gravity is a force that exists between the Earth and the objects that are near it. As you stand upon the Earth, you experience this force.
“We have very good evidence that there<span> was a </span>Big Bang, so the universe as ... found that before<span> our universe </span>there<span> was nothing, nothing at all, </span>not<span> even time itself. ... behind the more familiar forms of </span>matter<span> and energy that fill the universe today. ... </span>If<span> we assume inflation is eternal into the past </span>
reaction, opposite directions, and more
I would say that this is the first law of thermodynamics.
By putting an apple up on high ground. (That is 1 example)
This creates a higher gravitational force, and when it falls down it would have a lot of kinetic energy. But, if put on low ground, it wouldn't have enough potential energy to increase the kinetic energy.
