"I'm not sure how compatible is it with the proposal in the article discussed here."
Right. It seems to me that both approaches make sense. Perhaps with some cleaver yet-to-be-determined math both ideas can finally be mated.
I've never been convinced that the æther doesn't exist. Sure, it's been long debunked in the luminiferous æther sense but as the article points out "...the aether hypothesis was abandoned, and to this day, the classical theory of electromagnetism does not provide us with a clear answer to the question in which medium electric and magnetic fields propagate in vacuum." It is this aspect of the abolition of the æther that has always worried me.
For starters, any new model of the æther would have to exhibit Lorentz-invariant properties. Then there's the matter of vacuum permittivity ε0 and vacuum permeability μ0 to consider as the speed of light/aka 'electromagnetism' is directly linked to these physical constants via the expression c = 1/(μ0 ε0)^0.5. If one constant were to change then so too would the others including α Sommerfeld's fine structure constant, RK the von Klitzing constant, and Z0 the vacuum (free space) impedance, etc., etc. (Anyway, one would expect them to change—not that we'd ever know as we'd likely not exist if they did). ;-)
But I digress a little. We know that ε0 and μ0 have actual non-zero values and cannot be equated out (as we sort of tried to do in the days when we expressed electromagnetism in cgs units). In essence, physical constants ε0 and μ0 are absolutely intrinsic to electromagnetism, and whilst I cannot prove the fact, it seems to me they would be just as intrinsic to any new definition of the æther. Moreover, similar reasoning makes me think that QFT, ZPE/Zero-point energy/quantum vacuum state, ε0 and μ0 are all inextricably linked to GR.
It seems to me that whilst matters such as whether the spacetime manifold is Ricci-flat, etc. are extremely important principally from the perspective that when properly dovetailed into any new theory they'll provide proof thereof—are secondary to the proposition (note, I'm not saying they're secondary aspects of physics, only that they're secondary to the initial proposition).
Moreover, an equally important question to ask is why the constants ε0 and μ0 have the values they do given the quantum vacuum state, etc. Of course, the same logic applies to both α and c. Finally, we base just about everything on c it being the fundamental immutable constant (despite the the perennial emphasis/importance of α ≈ 1/137). The question is, is it in fact so, or is it that underlying physics first determines ε0 and μ0 and thus these constants could be considered more fundamental to any new formulation of the æther than that of c, it being the consequential resultant of the properties of those constants. (Heresy I know, but it would seem to make sense to view c in this context if or when we end up with new definition for the æther.)
My personal take on the question of space is that because of Lorentz contraction there is always an observer that sees the universe as a flat pancake. There is no true "distance" between any particles, and therefore no space. Every interaction between particles is because these particles actually collided for some specific hypothetical observer.
Right. It seems to me that both approaches make sense. Perhaps with some cleaver yet-to-be-determined math both ideas can finally be mated.
I've never been convinced that the æther doesn't exist. Sure, it's been long debunked in the luminiferous æther sense but as the article points out "...the aether hypothesis was abandoned, and to this day, the classical theory of electromagnetism does not provide us with a clear answer to the question in which medium electric and magnetic fields propagate in vacuum." It is this aspect of the abolition of the æther that has always worried me.
For starters, any new model of the æther would have to exhibit Lorentz-invariant properties. Then there's the matter of vacuum permittivity ε0 and vacuum permeability μ0 to consider as the speed of light/aka 'electromagnetism' is directly linked to these physical constants via the expression c = 1/(μ0 ε0)^0.5. If one constant were to change then so too would the others including α Sommerfeld's fine structure constant, RK the von Klitzing constant, and Z0 the vacuum (free space) impedance, etc., etc. (Anyway, one would expect them to change—not that we'd ever know as we'd likely not exist if they did). ;-)
But I digress a little. We know that ε0 and μ0 have actual non-zero values and cannot be equated out (as we sort of tried to do in the days when we expressed electromagnetism in cgs units). In essence, physical constants ε0 and μ0 are absolutely intrinsic to electromagnetism, and whilst I cannot prove the fact, it seems to me they would be just as intrinsic to any new definition of the æther. Moreover, similar reasoning makes me think that QFT, ZPE/Zero-point energy/quantum vacuum state, ε0 and μ0 are all inextricably linked to GR.
It seems to me that whilst matters such as whether the spacetime manifold is Ricci-flat, etc. are extremely important principally from the perspective that when properly dovetailed into any new theory they'll provide proof thereof—are secondary to the proposition (note, I'm not saying they're secondary aspects of physics, only that they're secondary to the initial proposition).
Moreover, an equally important question to ask is why the constants ε0 and μ0 have the values they do given the quantum vacuum state, etc. Of course, the same logic applies to both α and c. Finally, we base just about everything on c it being the fundamental immutable constant (despite the the perennial emphasis/importance of α ≈ 1/137). The question is, is it in fact so, or is it that underlying physics first determines ε0 and μ0 and thus these constants could be considered more fundamental to any new formulation of the æther than that of c, it being the consequential resultant of the properties of those constants. (Heresy I know, but it would seem to make sense to view c in this context if or when we end up with new definition for the æther.)