May 1, 2024• Physics 17, 65A proposed experiment could bring scientists closer to answering the long-standing question of whether gravity is a classical or a quantum phenomenon. L. Lami et al. [1]; adapted by APS/R. Wilkinson Lami and his colleagues suggest that the “quantumness” of gravity could be tested by carefully examining the gravity-induced dynamics of a quantum system of two oscillating pendulums (green) [1]. The pendulums are separated by an electromagnetic and optical shield (purple...