The Mössbauer rotor experiment and the general theory of relativity

In the recent paper Yarman et al. (2015), the authors claim that our general relativistic analysis in Corda (2015), with the additional effect due to clock synchronization, cannot explain the extra energy shift in the Mössbauer rotor experiment. In their opinion, the extra energy shift due to the clock synchronization is of order 10−13 and cannot be detected by the detectors of γγ-quanta which are completely insensitive to such a very low order of energy shifts. In addition, they claim to have shown that the extra energy shift can be explained in the framework of the so-called YARK gravitational theory. They indeed claim that such a theory should replace the general theory of relativity (GTR) as the correct theory of gravity.In this paper we show that the authors Yarman et al. (2015) had a misunderstanding of our theoretical analysis in Corda (2015). In fact, in that paper we have shown that electromagnetic radiation launched by the central source of the apparatus is redshifted of a quantity 0.6̄v2c2 when arriving to the detector of γγ-quanta. This holds independently by the issue that the original photons are detected by the resonant absorber which, in turns, triggers the γγ-quanta which arrive to the final detector. In other words, the result in Corda (2015) was a purely theoretical result that is completely independent of the way the experiment is concretely realized. Now, we show that, with some clarification, the results of Corda (2015) hold also when one considers the various steps of the concrete detection. In that case, the resonant absorber detects the energy shift and the separated detector of γγ-quanta merely measures the resulting intensity.In addition, we also show that the YARK gravitational theory is in macroscopic contrast with geodesic motion and, in turn, with the weak equivalence principle (WEP). This is in contrast with another claim of the authors of Yarman et al. (2015), i.e. that the YARK gravitational theory arises from the WEP. Therefore, the YARK gravitational theory must be ultimately rejected. We also correct the confusion of the authors of Yarman et al. (2015) concerning their claims about the possibility to localize the gravitational energy and, in turn, to define a stress–energy tensor for the gravitational field. In fact, we show that these claims are still in macroscopic contrast with the WEP.