The Dire Consequences
“In any case we are driven to extraordinary consequences, and the choice lies between these three:
1. The Earth passes through the ether (or rather allows the ether to pass through its entire mass) without appreciable influence.
2. The length of all bodies is altered (equally?) by their motion through ether.
3. The Earth in its motion drags with it the ether even at distances of many thousands of kilometers from its surface.”(35) Now, first of all, it is strange that this lifelong agnostic Albert Abraham Michelson (1852-1931),(36) appears on one issue not in the least agnostic, but as firmly a fundamentalist Copernican believer as the staunchest Bible-reader who holds on to his Authorized Version. There is no place in Michelson’s only partially agnostic tunnel-vision for possibility Number Four. Yet, aside from any appreciation of its value, a geocentric explanation of the enigmas encountered in the search for the true model of the cosmos… it stares, I repeat and maintain, any open-minded down-to-earth scientist in the face when he surveys all those abortive efforts to disqualify it.
Apart from that, and too easily forgotten: none of these three theoretical attempts to save the appearances, nor sagacious variations on their themes, are without drawbacks or contradictory experimental evidence even when one observes them from the accepted, if unattainable, heliocentric super-cosmical viewpoint.
Michelson’s first extraordinary conclusion may explain his 1887 failure, but it resolutely disqualifies Fresnel. Even worse, for this being the case, Boscovich’s logically and classically impeccable test for pinning down the true cause of aberration then shows the Earth to be at rest, independently from Michelson’s own result witnessing to the trustworthiness of this conclusion. Otherwise Airy would have observed an increased angle of aberration for his water-filled telescope, in this case not affected by such an evasive Fresnel-type aether wind.
The second option, the Fitzgerald-Lorentzian one, does not fare much better, and Michelson’s “equally?” in brackets reveals already its invidious shortcoming. If all bodies moving relative to a stationary aether would expand or shrink at specific and hence presumably unequal rates, we theoretically should, by using measuring devices with different contraction coefficients, be able to pinpoint absolute motion. However, (e.g. in the many variations of the Michelson-Morley experiment subsequently performed), not the faintest indication of such an inequality has ever been found. Until a deviation from its general applicability will be observed the “equally” hence stands. But that means bolstering the case by means of introducing unobservables. And to quote D.W. Sciama, there is a “fundamental reason for objecting” to such a theory. If the length of all bodies is altered equally by their motion through the ether, then these alterations “cannot be observed except through the very phenomenon they were invented to explain”.(37) As Louis Essen, with a typical British understatement, comments on Lorentz’ clever ad hoc: “This theory was put forward very tentatively and was not generally regarded as being entirely satisfactory.” And let me add, to prevent an indignant “Yes, but…”, Essen’s next sentence. “The Lorentz transformations are the basis of the special theory of relativity, but Einstein derived them from two assumptions of a general nature, which he raised to the status of principles “(38)
Michelson’s third intimation looks, Copernically considered, the most promising. Subsequently it has been and is being put forward in many variations on the original theme by a G.G. Stokes (1819-1903) proposed “aetherosphere”, which Michelson, until Einstein’s appearance on the scene, “was to revere above all others”.(39)
It cannot be denied that such semi-geocentric hypotheses take Hoek, Airy, and Michelson & Morley in stride. However, as long as the diameters of the envisaged Earth-bound aether “bubbles” are not experimentally established and their structure – whether homogeneous, stratified, or vorticose – elucidated, these explanations of the unexplained suffer from the same shortcoming as the Lorentzian one. Not yet in the least verified ad hocs fail to qualify as arguments, let alone as “proofs”. They are by themselves only woolly excuses. Worse: until logically incontrovertible test results in their favour will have come to the fore the skeletons of Ptolemy, Aristotle, and Tycho Brahe still rattle happily in their cupboards. Just postulate not an “aetherosphere” embracing Mother Earth, but a “galactosphere” encompassing the stars. Then you will have come close to enthroning Tycho Brahe!