Phil
Thanks for the Fermi link. It did what you said in the packet, but only on the basis of as assumption which is not the only one possible. Conceptually, if an inertial frame is represented by a London bus, we could find that both postulates are complied with inside it, and similarly for all buses, but also for the backgrounds they're moving in. The real difference then is, if we have a bus within a bus, the same is true within the smaller bus. The background itself is then local, overcoming the problem of a single 'absolute' field. The windows of the bus do the same transformation (n=1.5) whether glass or plasma. (Thus my earlier reference to Eddington and Ducks). This avoids inequalities by the same token to allow Local Reality.
I agree when you say; "It is a widely held view that spacetime is not fundamental, but instead emerges from a description of interactions between particles that remains somehow free from the constraints of placement in a background spacetime."
Also; "It is possible to imagine a model of reality in which the vacuum emerges from a sea of interacting spacetime atoms, just as a continuous fluid or solid is made of molecules, but in such a picture the discrete atoms would affect the passage of light waves in a way we could detect. Just as we can probe the structure of a crystal using diffraction, we should be able to probe the structure of spacetime using the passage of light or other waves."
The Fermi results wouldn't falsify the London bus approach. No-one has (yet!) falsified the logic, but I'm struggling to get many to take it seriously enough to try. It seems only to resolve empirical issues (identified in the previous papers you know). It only needs Doppler equations, but it still also needs some kind of maths basis developed, which is not my personal bag so needs help.
I do hope you'll be able to perceive the quite testing initial dynamic relationships conceptually, and let me know if there are any problems you can find. I'm kind of getting desperate for someone to find something not based purely on prior beliefs.
In terms of the essay subject, it says the continuum )(or dis-continuum!) is continuous up to the point where change is needed and matter condenses to implement the change, i.e. initially a plasmasphere or fine structure cloud/halo.
Very many thanks. Well done with your own essay, not as obscure as I'd feared.
Peter