The weblog page above clearly demonstrates something of its author's reasons for using the pseudonym Plato.
Nigel's physics page (linked top right) contains a series of quotations from famous people about the spacetime fabric, the ether. While Einstein in his most famous paper of 1905 said that a light aether would prove superfluous, he did say at Leyden University in October 1920 that 'according to the general theory of relativity, space without ether is unthinkable.'
Despite this, nobody took the ether of general relativity seriously. It is amazing when you look into the history of the ether theories, you find that the greatest mathematical physicists of antiquity, like Maxwell and Kelvin, were ether theorists. The major arguments between them were not concerned with the existence of ether, but which model to use.
All of the models were completely absurd. Some claimed ether was a very low density gas, and then tried to make it responsible for gravity. Now a gas - any gas - tends to exert a drag force of (cross-sectional area) x (drag coefficient) x (dynamic pressure, 1/2 density times speed^2 relative to gas). This drag force would slow down objects continuously, causing them to spiral into the sun, as Feynman pointed out in 1965.
Not only that, but gas pressure doesn't act in only the radial direction. The molecules strike one another and the kinetic energy is diffused dispersed in all directions, so the pressure on you sideways is similar to the vertical pressure. This objection can be overcome if the ether is solid, which obviously looks like a ridiculous model for something which permeates atoms and causes gravity and other forces.
The reality appears to be that the ether, as such, is virtual radiation pressure. As Dirac pointed out in Nature in 1951 (quoted on Nigel's home page) quantum electrodynamics is a kind of ether theory. The virtual radiation goes at light speed and carries momentum, causing forces. It does not fill in shadows of shielding like a gas would. If you deny the ether, you deny modern physics as well as a preductive gravity mechanism.
t'Hooft suggested that the underlying solution to the whole ether problem - or the spacetime fabric as he called it (according to Plato) - is that the fifth dimension contains the ether as black holes (matter) which appear as radiation in the 4-D hologram we experience.
This, as I said commented before, seems to get around all of the difficulties. It means that Kaluza's 5-D spacetime with its unification of Maxwell equations and general relativity survives, and this is attractive. If you cannot explain Maxwell's equations in terms of something deeper, you are left in a world of the electromagnetic field, electric field and magnetic field lines related to light velocity by E (volts/metre) = c B. (Whenever you don't see both E and B in that fixed ratio, it is because either the Pauli exclusion principle is pairing electrons with opposite spins so the magnetism cancels and disappears, or because you have similar amounts of positive and negative charge).
It is attractive to have electromagnetism manufactured from general relativity by a fifth dimension which is the spacetime fabric.