It acts like an acceleration, rather than a force. Imagine a bowling ball and a marble at rest from your perspective, and an apparatus with a pair of pneumatic

It acts like an acceleration, rather than a force. Imagine a bowling ball and a marble at rest from your perspective, and an apparatus with a pair of pneumatic guns that eject pistons with the same precisely-calibrated amount of force. You arrange the guns so that they will hit the marble and the bowling ball at the same moment, and you trigger them together. The marble and the bowling ball are hit at the same time by the same amount of force. The marble, being much lighter takes off much faster than the bowling ball. Now take the same marble and bowling ball to a place a mile above the moon (so that there is no confounding atmosphere to complicate things) and release them next to one another at the same moment. If gravity is a force, then we should expect that the marble will fall much faster than the bowling ball, because the same force is acting on two different masses; the lighter mass should be accelerated more, just as it was when the source of the force was the pneumatic gun. F = ma, after all. If the force is the same and the mass is less, then the acceleration must be more. That's not what happens, though. The marble and the bowling ball fall together at the same accelerating rate. Gravity acts like an acceleration, not a force. Lo these many years ago when I was an undergraduate physics student, my advisor told me that we should say "the force due to gravity", not "the force of gravity". In every day colloquial speech it doesn't matter, of course.