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Jim:

You quote me with

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

After which you respond with

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'll get to the reference to "quantum theory" and "string theory" a little later.

First, the only "mine" field I see has been lain by you.  Most specifically with your use of absolute statements like "ubiquitous", "routinely, implicitly, and illegitimately treated as givens", "absolute distinction between gravitation and force".  So what I was commenting on, above, was your use of "ubiquitous", not your reference to "true" forces.  (I'm sorry you appear to have misunderstood this.)

Then you go on to rail about so much else you have misunderstood (or intentionally misconstrued).  I'll skip all that, at least for now.

Now, let's return to the "quantum theory" and "string theory" references.

First and foremost, "quantum theory" is far from a singular.  In fact it's something more like a theory of theories, at least in its present form.  Or, perhaps, it would be more reasonable to characterize it as an approach or methodology toward the creation of theories that are "quantum" in nature.  So it's rather difficult, if not impossible, to characterize "quantum theory" as treating gravity as or not as a "force", of some kind.

Early, non-relativistic "quantum theories", if they even looked at gravity, did treat it as a force in the same manner as Newtonian mechanics (after all, early "quantum theory" stemmed from a reassignment of differential operators for classical quantities like energy and momentum).  Then, after the advent of relativistic "quantum theory" it was quite natural to try and incorporate gravity via General Relativity's curved spacetime (an approach you appear to endorse in some of your posts where you declare there to be an "absolute" distinction between gravity and "forces" of any kind or nature—suggesting that if we were to cease and desist in any attempt that even smells of treating gravity as "force" or related to "energy", then all would be far better).

Unfortunately, as I tried to point out in my first post, all such attempts that have tried to incorporate General Relativity's curved spacetime in any dynamic form (so the "quantum particles/fields", and their associated mass-energy-momentum-etc., "properly" give rise to the source term for the spacetime curvature) have ended in predictions that are violently inconsistent with observed reality.  (Talk about "non-empirical".)

So, at this point, there are multiple "quantum theories" that try to incorporate gravity, in various ways.  "String theory" is only one of many such.

Now, I certainly cannot claim to be an expert in "string theory", but I'm not sure it would be proper to characterize the way in tries to incorporate gravity as "force"-like, except that it is a fair example of a theory/model that tries to use the success of General Relativity as a guide by trying to treat all "forces" (interactions, really) as curvature (in a higher dimensional spacetime).  (Admittedly, it also does a great many other things, like treat particles as "strings" or higher dimensional "brains", and incorporating "super symmetry".)

So, Jim, at this point it appears that your greatest enemy is your own predilection for "absolute" statements.  Have you not learned that, especially in matters of science, such are seldom, if ever, fully valid?

I hope you understand now.

David

P.S.  My first attempt at a response was primarily focused on what statements you could make that would be at least defensible.  With the final emphasis on what you have been asserting that can in no wise be construed as defensible, unless you wish to challenge the field equations of General Relativity, as opposed to your assertion that you only challenge certain interpretations thereof.

I'll attempt this process again, later.