THE PROTECTIVE BELT OF SPECIAL RELATIVITY

http://books.google.com/books?id=JokgnS1JtmMC
"Relativity and Its Roots" By Banesh Hoffmann, p.92: "There are various remarks to be made about this second principle. For instance, if it is so obvious, how could it turn out to be part of a revolution - especially when the first principle is also a natural one? Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether. If it was so obvious, though, why did he need to state it as a principle? Because, having taken from the idea of light waves in the ether the one aspect that he needed, he declared early in his paper, to quote his own words, that "the introduction of a 'luminiferous ether' will prove to be superfluous."

This is a remarkable text written by one of the most famous Einsteinians. It turns out that, "without recourse to contracting lengths, local time, or Lorentz transformations", only Newton's emission theory of light with its tenet that the speed of light does depend on the speed of the emitter can explain the null result of the Michelson-Morley experiment. That is, in 1887 the experiment unequivocally confirms the variable speed of light predicted by the emission theory but then "contracting lengths, local time, or Lorentz transformations" are introduced ad hoc and the experiment becomes compatible with the constant (independent of the speed of the emitter) speed of light predicted by the ether theory and adopted in special relativity.

How then can "contracting lengths, local time, or Lorentz transformations" be characterized? Imre Lakatos calls such ad hoc hypotheses "protective belt":

http://bertie.ccsu.edu/naturesci/PhilSci/Lakatos.html
"Lakatos distinguished between two parts of a scientific theory: its "hard core" which contains its basic assumptions (or axioms, when set out formally and explicitly), and its "protective belt", a surrounding defensive set of "ad hoc" (produced for the occasion) hypotheses. (...) In Lakatos' model, we have to explicitly take into account the "ad hoc hypotheses" which serve as the protective belt. The protective belt serves to deflect "refuting" propositions from the core assumptions..."

That is, one very much wants the speed of light to be constant (independent of the speed of the emitter), assumes so and introduces an efficient protective belt ("contracting lengths, local time, or Lorentz transformations") able to deflect refuting propositions such as the null result of the Michelson-Morley experiment from the cherished assumption.

Yet, if protective belts are a legitimate tool in theorizing, how can one claim that the experiment is the ultimate judge of the theory? Any core assumption, if false, can be equipped with a suitable protective belt deflecting experimental challenges...

Pentcho Valev