pg. 30 "Quantum Theory" by David Bohm.
'A similar analysis may be made for other classical processes. For example, a planet in a gravitational field can be regarded as absorbing gravitational quanta that are emitted by the central star. These gravitational quanta carry gravitational momentum and energy, just a electromagnetic quanta carry electromagnetic momentum and energy. We visualize the sun as continually throwing out and reasbsorbing gravitational quanta, producing a steady state of the mean number of quanta present in space. If we imagine that a planet can absorb quanta only when they are returning to the sun, we see that an inward force is produced by an enormous number of tiny impulses. The planet also emits quanta that are absorbed by the sun. Thus, the two bodies attract each other, even in a very short time, the average force will be practically constant.' Published in 1951.
From The Unification Theory, 2006, by Jon Woodward. Sun Earth à 
ß As the Graviton forces from the Galaxy hit these two objects they are pushed, not pulled together. Since the gravitons would have a hard time passing through a
solid object we can use the classical approach and say that mass causes gravity. However an objects density also plays a role in this theory as gravity is only present where gravitons are reflected or absorbed by a body. An object that can interact with gravitons is the basis for being a gravitational body.
The Sun and the Earth happen to follow this proportionally. As
the gravitons are coming down from space they collide with the Sun and some collide with the Earth. This pushes them together. The reason for this is because the Sun blocked gravitons so the Earth experienced less force coming from the Sun than it did from outer-space.
Galaxies can push each other apart because they are
producing the gravitons in this theory. The actions of the particles causes the expansion of galaxies because of the force’s on each other. That is why galaxies drift apart because they are pushing each other apart using gravitons.
Finally when you reach outer-space you become suspended in
mid air. This is because the gravitons are hitting you from all sides, in equal amounts in random directions. This amounts to zero motion either toward or away from you position because the forces of outer-space are in balance. Please reference this Unified theory in either the articles section of the Toequest or my personal website at www.TheUnificationTheory.Com, all donations can be made to Toequest from my site.