(Phys.org)—Although there are many counterintuitive ideas in quantum theory, the idea that influences can travel backwards in time (from the future to the past) is generally not one of them. However, recently some physicists have been looking into this idea, called “retrocausality,” because it can potentially resolve some long-standing puzzles in quantum physics. In particular, if retrocausality is allowed, then the famous Bell tests can be interpreted as evidence for retrocausality and not for action-at-a-distance—a result that Einstein and others skeptical of that “spooky” property may have appreciated.