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It happens every time. Challenge the ancient association of gravitation with force long enough, and you’ll end up talking to yourself, as those few willing to indulge you at all will, if finally cornered by specifics, abandon their indulgence with the self-assurance that you just don’t understand.

In my previous comment I showed that the association of inertial acceleration with rest or uniform motion, and of gravitation with inertial acceleration, can be invalidated with concrete experimental observations. But so powerful is the pull, the adherence to an established paradigm, that the concrete carries no weight against the abstract.

Evidently, the state of rest/uniform motion can’t be considered absolutely distinct from inertial acceleration, never mind the observable, absolute distinction, because an established abstract theory considers them relative. Inertial acceleration can’t be considered absolutely distinct from gravitation, never mind the observable distinction, because they coincide in our most familiar experience on the earth’s surface, and an established abstract theory considers them equivalent. Distinctions can’t be distinctions because they’re irrelevant. Distinctions can’t be distinctions because they’re not.

I’ll abandon my annoying objections with one last illustration which may manifest the distinction between gravitation and inertial acceleration most clearly, for the benefit of anyone genuinely curious - or maybe just for my own sense of closure. (Warning: The following may be disturbing to conservative physicists and young children.)

Let a spacecraft in a region far from significant mass simulate an orbit around an imaginary star with some specified mass and location. Navigation of the simulated orbit is plotted by means of the "fixed stars" and accomplished by the continuous firing of a thruster. Let the inertial effects on the craft due to the simulation be detectable. (A "static gravitational field" of some intensity will be observed at the inside surface of the craft that is farthest away from the imaginary star as it rotates around the imaginary position -- unsecured objects will press against that surface.) Now introduce an actual star of the specified mass at the location posited in the simulation, and let the engine of the craft be simultaneously switched off. The craft will continue on the accelerated path, but now without inertial effects -- the "static field" immediately disappears and the occupants of the craft float weightlessly as the craft follows an actual geodesic around the star. Thus, without altering the craft's trajectory relative to the "fixed stars", their supposed influence has been entirely canceled by the introduction of a local mass. A fundamentally different sort of acceleration has replaced the earlier acceleration, even though its trajectory as it would be described by a distant observer remains consistent. The former “gravitation” that is supposed to be equivalent to inertial acceleration has been replaced by an actual gravitation, with manifestly different characteristics, and without a trace of inertial involvement.

No doubt, gravitation can be found on occasion to be involved with inertial acceleration, as it is when a body presses against the surface of another of sufficient mass, as it is for residents on the earth’s surface, but instead of identifying gravitation and inertial acceleration by their coincidence, and ignoring their distinction, surely their manifest independence must be taken as fundamental. Surely a coincidence implies a distinction. Unless, of course, other - non-physical - considerations are more pressing.