As Mach visualized inertia, the cumulative gravitational effects of this matter distribution on other material bodies was to cause all bodies to resist acceleration. Einstein was very influenced by Mach's ideas and tried to incorporate his ideas into the general theory of relativity. Indeed, the relationship between Einsteinian gravity and inertia is only a weak union at best. A more successful integration of gravity and inertia via Mach's Principle is the purpose of this discussion here. The model proposed here is based upon the idea of reference frame and its relationship with gravity and inertia.
Frame of reference is defined here as one's present-state of uniform motion in a straight line.
As we will see, when there is an acceleration of a body, the object's frame of reference is constantly changing. It is proposed in the author's other work that inertia is caused by a forward-shift of the gravitational radiation void of a body in its direction of motion. This previous model and the model proposed by this text can peacefully coexist without major difficulties. They are, therefore, not incompatible with each other. The uniform motion of a body can only be considered linear and uniform if both the moving body and an observer watching the moving body are in exactly an identical frame of reference.