Discussion with Plato on 5-D spacetime as 4-D hologram (general relativity) and the other dimension as the gravity source (spacetime fabric):
The Bekenstein bound conjecture suggests that black holes in 5-D spacetime are seen as electromagnetic radiation in the 4-D hologram which is described by general relativity.
This suggests why gravitational effects propagate at light speed: gravity is observed as the push from this radiation.
There are two equivalent mathematical descriptions of gravity: for example, the concept of a physical push mechanism is consistent with the concept of the curvature of space.
This can be proved by considering the contraction of spacetime around mass, which causes the Earth's radius to diminish by (1/3)GM/c^2 = 1.5 mm.
You can either say that this is a consequence of general relativity, or you can say that it is a squeezing effect by the spacetime fabric.
In the same way, the length contraction in the direction of motion in special relativity can be viewed either as a mathematical consequence of certain experimentally based principles, or as the physical effect of an object pushing into the spacetime fabric, and being compressed.
The curvature of spacetime itself can be considered either as an abstract result of Einstein's field equation, or as the consequence of the physical compression.
The gravitational field compresses the Earth's radius by 1.5 mm, without affecting the circumference at all, because the contraction only occurs along radial field lines, with no affect at right angles to them.
Therefore the value of Pi must vary in the equation: circumference = 2Pi x radius.
The only way to deal with this physical effect is non-Euclidean geometry, curved spacetime.
So I think you can say that dealing with 'spacetime curvature' is mathematically equivalent to dealing with a physical pressure source for gravity.
There are grave problems with the Higgs field and graviton, both of which should be equivalent by Einstein's equivalence principle of inertial and gravitational mass. These problems appear to occur because of the abstract nature of the mathematical models involved, particularly of gravitons in quantum gravity. I think the Higgs boson is spin 1 while the graviton is spin 2 ...
Notice that I have revised my page: http://nigelcook0.tripod.com/