The classical Michelson-Morley experiments: A new solution to an old problem

The classical ``ether-drift'' experiments in gaseous media (Michelson-Morley, Miller, Illingworth, Joos, ...) have always shown small, irregular residuals, usually interpreted as typical instrumental artifacts. A recent re-analysis indicates, instead, that these small effects could represent the first experimental indication for the Earth's motion within the Cosmic Background Radiation (CBR). This intriguing possibility, and the overall consistency with the modern experiments with vacuum optical resonators, require to perform a different check with a new generation of dedicated experiments. Without such definite clarification, the classical ether-drift experiments will remain as an enigma for physics and history of science