It is well known that Einstein at different times and occasions, for understandably different reasons, gave different answers to questions about the occurrences that had prompted him to his views on motion, rest, and space-time. “By his own account the experimental results that had influenced him were the observations on stellar aberration and Fizeau’s measurements on the speed of light in moving water. ‘They were enough,’ he is reported to have said in 1950.”(40) Yes, and I think I understand the sentiment motivating him. If we cannot prove what we a priori “know” to be true, then we have to find a reason why such a proof eludes us.
Yet I will be the first one to admit that his clarification of the enigma baffling Michelson and his followers is a masterful movement of thought in a great and subtle mind on a high level of abstraction. Given the post-Christian Weltanschauung of our time, it is for those enmeshed in it pretty much mandatory to believe the relativity postulates. Surveying the struggle to keep Galileo enshrined, notwithstanding the accumulating evidence to the contrary, and recognizing the inefficacious logical shortcomings of every argument employed, they cannot but side with Einstein. With him they have to hail all those Copernican crusaders aspiring to a rational solution with an “A plague on both your houses!” For indeed, if the logical inference, time after time looming behind thought and test, is by all and sundry being declared impossible since unacceptable, then the only way out of the impasse is a move to supersede logic. That is to say: nothing less than a premise capable of turning all evidence favouring a geocentric Universe into evidence for an a-centric homogeneous one will suffice. But two wrongs don’t make a right!
Permit me, before I pursue the matter any further, to quote a wise warning by Sir Arthur Stanley Eddington (1882-1944). He himself certainly did not heed it when he presented the results of his 1919 SobralPrincipe eclipse expedition as hard facts, for today the scientific establishment looks at those askance.(41) Yet Sir Arthur’s warning is thereby not disqualified. One man’s failing is another man’s lesson – we should, and I shall, take Eddington’s caveat to heart.
“For the reader resolved to eschew theory and admit only definite observational facts, all astronomical books are banned. There are no purely observational facts about the heavenly bodies. Astronomical measurements are, without exception, measurements of phenomena occurring in a terrestrial observatory or station; it is only by theory that they are translated into knowledge of a universe outside.”(42) So it is, and setting theory against theory in the quest for knowledge I hold that truly objective and unprejudiced appraisers will acknowledge a glaring datum. To wit: logically evaluated the contra-Copernican testimony willy-nilly obtained by levelheaded classical experimental science is not overwhelming only for those who with open eyes decide to be blind. Airy and Hoek were compelled to accept as already proven what was – and is! – not yet proven: an omnipresent Fresnel drag caused by an at least 30 km/sec aether wind in all transparent materials, whether water, glass, perspex, champagne, or castor oil. However, no observer at rest on the Earth’s surface can measure this drag as such. Only a supposed “change” in that drag becomes visible by setting these substances in motion relative to such an observer. Michelson and Morley, on the other hand, found the luminiferous aether nearly unaffected by the motion of the matter that it permeates. Hence it can be argued that Fresnel’s theory holds for transparent substances moving through an aether at rest and therefore can only be measured by an observer at rest in that aether. Which is tantamount to saying that Hoek and Airy, (observer and substance both at rest), Fizeau, (observer at rest, substance in motion), and Michelson and Morley, all five of them have with one accord been vainly striving to show that the Earth is not at rest.
Unhappily: since 1905 this appraisal no longer presents a definite plus for the geocentric theory. Albert Einstein (1879-1955) came, saw, and conquered with his special theory of relativity. Declared that the physical laws are the same in all inertial frames of reference and that the speed of light in a vacuum is hence constant for all observers regardless of the motion of the source or observer. Then the controversial aspects that late nineteenth-century scientists had to wrestle with dissolve into thin air. As J. H. Poincaré (1854-1912) in 1904 already formulated it: the laws of physical phenomena are such that we do not have and cannot have any means of discovering whether or not we are carried along in a uniform motion of translation.(43) Or to phrase Einstein’s theoretical substructure for this principle of relativity popularly: to us it looks as if the Universe is geocentric, but of course it is not. The Lorentz transformations, quantifying “equal” contractions that are never directly observable but necessarily true, explain why this is the case. For one result of these transformations is “that the two velocities in coordinate systems that are in relative motion do not add according to the methods used in classical mechanics. For example, the resultant of two velocities in the same line is not their arithmetic sum”.(44) Hushing up a few experimental results that do not fit too well in the Einsteinian-Lorentzian scheme,(45) this non-measurable but not to be doubted “fact” again allows us (and that now non-classically!) to give short shrift to any effort aiming at a geocentric explanation of Airy’s failure. The velocity of the light traversing the water-filled telescope “as seen by the observer is changed by the fraction 1-1/n2… No assumption of any ‘dragging’ is involved in the relativity arguments, nor is the existence of an aether even postulated.”(46) Glory be, but this only if Lorentz’ ipse dixit, which ipso facto cannot be shown to be true, really is true!
Gladly and without any mental reservations I admit that the theory of special relativity wonderfully “saves the phenomena”. A summary of its prowess by Panofski and Phillips(47) almost convinces any doubting Thomas who peruses the evidence. Yet such a Thomas shall do well to bethink himself twice before becoming a true believer. No question about it: if the STR is true then the logically understandable hierarchical and Earth-centered Universe of Antiquity and the Middle Ages was a pipe dream. The problem remains the “if” in the last sentence. Time and theoretical thought do not stand still; the Special Theory, after eleven years of gestation, gave birth to the General Theory, a totally different kettle of fish. “Historians of future generations, therefore, will likely view the Special Theory more as a mark of stunning intellectual brilliance, which presaged the General Theory, rather than as a thing of value or permanence in itself. Hindsight now discloses it to be but one of four imposing and permanent steps into the new era. First was the problem with which such as Lorentz, Larmor, and Poincaré wrestled regarding covariant transformation between systems in relative motion when the instrumentation of experimental physics failed to record the expected factor of Earth velocity relative to interplanetary space… Fourth was Einstein’s fascination in turn for Minkowski’s geometric approach, followed by his determination to tackle the gravitational problems in similar manner’ involving acceleration and non-Euclidian geometry in place of the flat space and constant velocity of the Special Theory, with the resulting General Theory. Among these four, only the climactic fourth is essential to Einstein’s historical position in relativistic physics, the Special Theory being but one of the preliminary steps… No more value need therefore attach to the permanence of the Special Theory than to the discarded models of Lorentz and others, which preceded it.”(48)
- The Verdict of Logic
- Non-observables Prove Nothing