David,

You wrote: “I wouldn't say that any ‘identification of gravitation with 'true' force’ is ‘ubiquitous’ (except possibly in your mind).”

You are of course familiar with quantum theory, and with string theory, just the most prominent examples. I’m trying to imagine what you’re thinking here. I specified “true” force because you’ve frequently invoked the “pseudo” forces, and I hoped to avoid that digression. It seems I’ve stepped on a mine while trying to avoid a trip-wire. Maybe we could be a little less crafty and interpret each other in the interest of productive communication. Gravitation is treated as a force in quantum theory. Let’s just go with that.

“I have never seen… ‘non-empirical, non-four dimensional models’ ‘routinely, implicitly, and illegitimately treated as givens.’ They are only given/proposed/used/etc. as theories and/or models.”

You’ve done it yourself, and repeatedly. I’ve described empirical tests that demonstrate the absolute distinction between gravitation and force (substitute any term you prefer to describe non-gravitational phenomena I’ve described) in our empirical, four-dimensional universe, and you’ve invoked non-empirical, non-four dimensional or super-galactic models to suggest that they undermine the distinction. If they aren’t “givens” then their relevant effects need to be confirmed before they in any way diminish empirical “givens” like the behavior of test particles in a box.

“I would not say that any such [model] is any less legitimate than any four dimensional model.”

The four-dimensional spacetime continuum has been (I don’t think it’s too strong a word) legitimized by various experimental confirmations. Models in excess of four dimensions have less scientific legitimacy, to say the least. You’ve accused me elsewhere of “crankdom.” I don’t know how I would categorize your statement, except to say it’s astounding.

“what is the nature of the motion of a free neutral test particle undergoing any of your listed inertial (pseudo, "false") "forces" (free of any "true" forces)? Are not such motions geodesics? If so, then how are these geodesics to be distinguished from any other geodesics?”

No. I’ve already described the behavior of test particles in a box under centrifugal acceleration - not "free of any 'true' force", I don't know what empirical "pseudo' force that would be. it would be astounding if you would want to describe the effects of centrifugal acceleration (due to the application of force) as geodesic. Are you referring to some hypothetical "pseudo" force no one has ever seen?

“Often times you have suggested that the geodesics of such inertial (pseudo, ‘false’) ‘forces’ will be divergent while gravitational geodesics will be convergent (apparently relying upon an unspoken ansatz [one that appears to rely upon an assumption of a central concentration of mass]). This is why I brought up the observed ring/torus of ‘dark’ matter.”

First, gravitational geodesics can be divergent if, for example, motion of a box is perpendicular to a gravitational field. Second, as you know, the nature and the effects of “dark” matter are still in question, and in any case, the effects are galactic. If there is any reason to think “dark” matter might indicate an equivalence of gravitation with force when controlled empirical tests in our vicinity show no equivalence, when controlled empirical tests leave nothing paradoxical such that recourse to an influence by a ring/torus might promise some plausible avenue of resolution, I can’t imagine what it would be. Can you? Frankly, you seem to be throwing the idea out like nails in the road during a car chase.

“If your ‘box’ was placed within a similar ring/torus, especially if the ring/torus was spinning/rotating (and practically everything we observe in this universe spins/rotates, besides, in order not to have such collapse under its own gravity one would almost certainly need it to spin/rotate) you would observe motions of free neutral test particles, within the box, that would be quite indistinguishable from having the box spin/rotate in a region of space devoid of such a massive ring/torus.”

First, such an effect would be no different from tidal effects, except centrifugal instead of centripetal. And inasmuch as the influence of such a ring/torus has not been observed to have noticeable effects in our vicinity, or in any sub-galactic vicinity, inasmuch as it would presumably be of such dimensions that its complete rotation would take millions if not billions of years, its effects would be flat in the extreme… so why don’t we just pretend it’s not an issue here.

“This is only one of an innumerable set of such possible examples.”

No doubt, and each one evidently credible enough to make “lyin’ eyes” of the effects you observe in a box.

“Basically, given any example of motions of free neutral test particles within a ‘box’ under the influence of whatever inertial (pseudo, ‘false’) ‘forces’ one wishes to conjure up, one may find a distribution of mass-energy-momentum-stress such that those same motions may be attributed to gravity. (Geodesics are geodesics, after all.)”

I’d still like to hear a specific description of the effects one could actually observe in a box. Please conjure one that would render the distinction between gravitation and force invalid.

“This is also why I brought up the ‘box’ in orbit around the Earth…. did you notice that the few test particles you used undergo divergent geodesics, similar to your assertions for non-gravitational inertial ‘forces’?)”

Similar, but not identical. Therefore, “different.”

Yes, I’m frustrated. Let’s not throw nails in the road anymore.