The good of the force of gravity (whatever it’s source is) is that it gives order and determination of place to bodies. The radical and essential goodness we derive from this force is shown very strikingly in the first secret of Fatima:
Our Lady showed us a great sea of fire which seemed to be under the earth. Plunged in this fire were demons and souls in human form, like transparent burning embers, all blackened or burnished bronze, floating about in the conflagration, now raised into the air by the flames that issued from within themselves together with great clouds of smoke, now falling back on every side like sparks in a huge fire, without weight or equilibrium, and amid shrieks and groans of pain and despair, which horrified us and made us tremble with fear.
In speaking of the perdition of the damned, Sr. Lucia speaks of how their bodies are deprived of the good of gravity or of any other principle ordering them to a place (equilibrium). Gravity is a certain rudder that keeps us from drifting away. Gravity is essentially a principle of right order, and therefore can be considered according to properly natural science, as not only determined to a certain term (end) but to a good of bodies as such.