Quantum mechanics deals in something more abstract: possibilities. It predicts the chances that we’ll observe an atom doing this or that, or being here or there. It gives the impression that particles can engage in multiple possible behaviors at once, that they have no fixed reality. So physicists have spent the last century grappling with questions like: What is real? And where does our reality come from?
“We’re privileged to live at a time when the great prize of making sense of quantum theory is still there for the taking,” Spekkens said, “and any one of us could take it.”