I have my own ATM theory, but, as a newcomer to the forums, I feel it to be preferable to “test the water” with an apparent conceptual flaw in Einstein’s theory. If this is well received, I would like to expand on it. I would apologise in advance if this conundrum has been aired before…

Firstly, I propose to include a brief resume of the history leading up to Einstein’s theory. I am aware that this is well recorded and well known; but it is fundamental to the discussion, and I feel it necessary to reiterate it briefly…

Prior to Einstein’s theories, it was thought that space existed as a material medium. In Einstein’s words “It is characteristic of Newtonian physics that it has to ascribe independent and real existence to space and time as well as to matter, for in Newton’s law of motion the idea of acceleration appears. But in this theory, acceleration can only denote ‘acceleration with respect to space’. Newton’s space must thus be thought of as ‘at rest’, or at least as ‘un-accelerated’, in order that one can consider the acceleration … as being a magnitude with any meaning”1.

It was realised that the velocity of the Earth as it orbited the Sun was sufficient that the motion with respect to the “light medium” of an observer on the Earth should cause measurements of the velocity of light to vary. However, Michelson and Morley’s results (published in 1887) found no such variation. In 1895 H A Lorentz proposed that the effect of the motion was there, but could not be detected because there was another factor that counteracted, and hid, it. This was the effect of the motion on the physical dimensions of the measuring apparatus. In 1904 he formalised this idea and quantified it as an effect on the shape of the orbits of the electrons of the atoms making up the apparatus. The motion of the Earth with respect to space was minutely foreshortening them. This was originally referred to as the Lorentz contraction, but is now know as the Fitzgerald-Lorentz effect.

However, to conform to Michelson’s results it must be noted that:
· If either effect existed in isolation, it would be detected by Michelson’s apparatus.
· Hence, both effects must exist, or neither.

What is the relevance of this to Einstein’s theory?


Einstein’s Special Theory of Relativity

In 1905 Einstein published his original Theory of Relativity. In this he not only rejected the existence of the ether as a medium occupying space, but also the existence of space itself as a real entity with physical properties. In his words “The introduction of a ‘luminiferous ether’ will prove to be superfluous inasmuch as the view here to be developed will not require an ‘absolutely stationary space’ provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place”2.

Einstein also suggested that it was not just the material objects that were being foreshortened by the Lorentz effect; it was also acting on the distances between objects. However, there is a problem with this view. If there is no “preferred frame of reference” or “light medium” then the effects of motion with respect to it cannot arise. This suggests that Einstein’s use of the Lorentz contraction in this conceptual framework is inappropriate.


Einstein’s General Theory of Relativity

Einstein changed the conceptual context for his General Theory. In this he introduced the idea that field effects in general, and the gravitational field in particular, exists as a material entity. Einstein described electro-magnetic fields as an “irreducible element of physical description, irreducible in the same sense as the concept of matter in the theory of Newton… There is no such thing as an empty space… Space-time does not claim existence on its own, but only as a structural quality of the field”.3

I wish to avoid a discussion of whether Einstein's treatment of the gravitational field is, for practical purposes, tantamount to a material space. It is sufficient to note that:
. If we assume that the theory implies that space exists as a material entity, Einstein’s use of the Lorentz contraction does not conform to Michelson’s results, because he has omitted the contrary effect.
. If we assume that the theory does not imply that space exists as a material entity, then (as above) the Lorentz effect cannot arise.

References:
1,3 Appendix V “Relativity The Special And The General Theory” A. Einstein. June 9th 1952.
2 “On the Electrodynamics of Moving Bodies” A. Einstein, Annalen der Physik, 17, 1905.