system
Given the following post, respond as if you're commenting on Reddit:
human
Because of gravity's constant effects, is there infinite energy in the universe?

So it's been a while since i've taken a physics course, but the last one I did take was grade 11 physics. One of the major units we learned about there was energy, and a big part of that was the kinetic vs potential energy balance. Now we also learned that energy is always conserved so it cannot be created or destroyed, but this never sat quite well with me. 

Say we have two apple trees. One at the top of a hill, and one at the bottom of the hill. The trees grow their apples, and when they are ripe enough they fall to the ground. Now the apples at the bottom of the hill just fall straight down to the ground and stop, but the apples at the top of the hill fall straight down, and then roll down the hill. This means that for the apples on the top of the hill, they have a greater potential energy before they fall, and greater kinetic energy during the fall and subsequent roll. 

Now normally you have to lift something up against the force of gravity, for it to gain potential energy, but in this case, there is no extra energy expended to put the apples in a higher location gaining that extra potential and kinetic energy. In other words, both apple trees are expending the same amounts of energy to grow the apples, but the ones of the top of the hill will generate more energy when falling, purely because of their location. 

So it seems like in this scenario, we have a situation where two of the same objects have differing levels of energy based off location in space, but no energy input was required to create that difference in location. And because energy cannot be created, my only explanation for this is because of gravity's constant force on everything with mass, there is infinite energy. 

Sorry for the long post, but I hope this can be answered as it's really bugging me. Thanks.
gpt
No, see the potential is not to the ground, but to the center of mass of the system of the apple and the earth (with the difference of mass this is simply the center of mass of the earth.) The ground is just stable enough to oppose the force of gravity on the apple, so really the same force is being applied to both objects. Now you are correct about there being more energy required to get apple B versus apple A in the first place but what you are failing to recognize is that that energy was applied outside the confines of the system defined in the problem (i.e. the energy was applied by the trees being planted in their separate locations and growing the apples in the first place.)