three thoughts that arrived in my mind.
A) Does an objects gravitational pull ever dimish to zero. Does my body exert a non-zero gravitational effect on Abell 1835?
B) Most energies diminish as the effects are used, a highly infrared object gets cooler as the heat energy is tranferred to another object, reducing the overall effect. Does the same happen with Gravity? I know the effects would be neigh unmeasurable, perhaps reducing from 9.81mps to 9.80mps over the next billion years, but does it happen? given enough time, will an object with a permenant mass, end up with zero gravitational pull
C) What is the smallest particle we know exerts gravity, Atoms do. but do Protons, Electrons and Neutrons? and if so, what about quarks and gluons? is there a point at which mass no longer exerts gravity?