One hundred years ago, and a year before Schrödinger’s more famous wave mechanics theory, Heisenberg discovered the key rules of quantum physics. Although their formulations are ultimately the same, Vlatko Vedral argues that Heisenberg’s way of thinking gives us a clearer understanding of reality. He argues for purging physics of classical notions to pave the way for a new physical theory, explaining a lab-based experiment that can test the quantum features of gravity.