On Aug 23, 2011, at 4:47 PM, Paul Zielinski wrote:*Of course the advantages of a local interaction model for inertia include being able to account for instantaneous isotropic inertial reaction in a natural, intuitive and mathematically straightforward manner.*

Right.

On 8/23/2011 4:43 PM, Paul Zielinski wrote:*These kinds of questions are not hard to answer if it is assumed that we start in Minkowski SR with a "flat" inertial guide field, and then interpret the covariant "warping" of spacetime in GR as the objective physical modification of the pre-existing gravity-free inertial trajectories resulting from the influence of gravitating matter. Then the GR geodesics naturally serve as local dynamical references for forced motion in a 4D geometric model for gravity.*

Right.*Exactly what physically maintains the motion of free test objects along the spacetime geodesics in a flat or a curved spacetime is an interesting question, but since we now accept the reality of the "physical vacuum", it seems natural to suppose that a deeper theory of gravity and inertia will explain this in terms of local interactions between moving matter and the gravitationally distorted vacuum.*

No, it's the tensor curvature field that shapes the geodesics. You don't need a deeper theory for that.*I would say that the Higgs mechanism of the Standard Model could provide some clues, if gravity is conceived as a physical modification of the "flat" (gravity free) inertial guide field (modeled geometrically in GR in terms of 4D spacetime curvature).*

Wake up and smell the coffee. The appendix in

http://journalofcosmology.com/SarfattiConsciousness.pdf

shows how to do that.*I think we are way beyond the point where where one could plausibly dismiss such ideas as the "idle metaphysics" of Newtonian absolute space. And I don't see how, as things stand, one could reasonably argue that the various "Machian" models for inertia are any less speculative.*