Colóquio
Michelson Morley Experiments: Crossroads of Relativity, Cosmology and Quantum Theory
Maurizio Consoli
In 1887 Michelson and Morley tried to observe in laboratory the "ether wind" by measuring a small difference in the velocity of two perpendicular light beams. Their measurements being much smaller than the classical expectations, the experiment was interpreted as a null result. This was crucial for the first pioneering formulations of the relativistic effects and represents a fundamental step in the history of science. Since then, more and more precise repetitions of that original experiment have been performed and the standard conclusion has been always the same: no genuine ether wind has ever been detected.
However, if the velocity of light in the various interferometers is not exactly the same parameter "c" of Lorentz transformations nothing would prevent in principle a non-zero effect. For instance, in a gaseous medium the small fraction of refracted light could keep track of the motion of matter with respect to some preferred reference frame. Starting from this observation, there is now a new interpretation where the small irregular residuals observed in laboratory show surprising correlations with the direct observations of the Cosmic Microwave Background (CMB) with satellites in space. This opens the possibility of finally linking the CMB with a fundamental reference system for relativity with substantial implications for the interpretation of non-locality in the quantum theory. The Colloquium will focus on the essential aspects of this research with brief historical notes on some leading scientists involved in these measurements.