An international team that includes Nobel Prize-winning physicist Professor Sir Roger Penrose has directly observed a long-predicted gravitational effect in a falling quantum object for the first time. The finding shows that a central principle of Einstein's theory of gravity continues to agree with quantum behavior under the conditions tested. The research, led by Ben-Gurion University of the Negev, the University of Ulm and the University of Oxford, was published September 2 in Science Advances.
Modern physics rests on two remarkably successful frameworks. Quantum mechanics describes the unusual behavior of atoms and other extremely small objects, while Einstein's theory of gravity explains falling bodies and the large-scale structure of the Universe. Despite their individual success, physicists still do not have a complete theory that brings the two together.
The new experiment explores a region where these two descriptions overlap. Researchers measured a specific change in the quantum properties of atoms as they moved under the influence of gravity. The effect matched the prediction that follows when Einstein's equivalence principle, one of the foundations of his theory of gravity, is extended to a quantum object.
