Scrutiny of experimental observations of bending of EM radiation, one of the determinant proofs of General Relativity, suggests a clue of profound significance; gravity appears to deflect EM radiation proportionally to its frequency. Differences in the deflection of light beams and microwave radiation are minimal, but de facto under an accurate statistical exam. The GEM Experiment described in this paper, patent released on December 2022 by the Italian "Ministero delle Imprese e del Made in Italy", aims to definitely validate this theory. The proposed system employs a tunable source of γ-rays, about the Higgs resonance, as the one tendered by the LHC facilities at CERN. The γ-ray source is tunable for being tunable the energy employed to let Hadrons collide. This is essential to check out extra deflections occurring as the energy employed to let Hadrons collide is modulated. The proposal, fully detailed in the text "A critical discussion about Gravitation" ISBN 978-1-7948-5105-4, is based on a critical discussion of the prescriptions suggested by the general theory of relativity. Clues lead to the resurrection of an Ether-like concept, not in the sense of a rigid structure where drifting through, but as a fabric where things of Nature show their existence. This eventually suggests a quantum approach based on a graviton conjecture. In particular GR is not seen as a theory encompassing Newtonian Dynamics, bus as a ND correction which unfortunately misses of the Gravito-ElectroMagnetic (GEM) interaction. The proposed theory wants to eke the general theory of relativity adding a NNLO correction to the NLO one provided by GR. The correctness of this model, definitely substantiated by the outcome of the proposed Experiment, will finally complete the general theory of relativity, bypassing any demonstrative weakness of the most recent PPN formalisms, and eventually tendering a new way of construing Physics.

Scrutiny of experimental observations of bending of EM radiation, one of the determinant proofs of General Relativity, suggests a clue of profound significance; gravity appears to deflect EM radiation proportionally to its frequency. Differences in the deflection of light beams and microwave radiation are minimal, but statistically appreciable. The GEM Experiment described in this paper, patent released on December 2022 by the Italian “Ministero delle Imprese e del Made in Italy’‘, aims to employ a tunable source of gamma-rays, about the Higgs resonance, as the one tendered by the LHC facilities at CERN. The gamma-ray source is tunable for being tunable the energy employed to let Hadrons collide. The proposal is based on a critical discussion of the clues (fully detailed in the text “A critical discussion about Gravitation” ISBN 978-1-7948-5105-4) that the general theory of relativity suggests. Those lead to the resurrection of an Ether concept, not in the sense of a rigid structure where to drift through, but as a medium where to move. This eventually suggests a quantum approach based on a graviton conjecture. This model adds a NNLO correction to the NLO one provided by GR. The correctness of the model would finally explain the statistical bias observed above the value of deflection of the EM radiation, as expected from GR, and its remarkable dependence on frequency. The theory and the Experiment discussed in this paper aim to complete the general theory of relativity, and so propose a new way of construing Physics.