A photon was apparently detected in two places at once in a twist on the classic double-slit experiment, but many physicists ...

“This retroactive idea. It has to be that,” says Nobel Prize-winning mathematical physicist Sir Roger Penrose, reflecting on a problem about the building blocks of reality that has dogged physics for ...

In recent years, physicists have been trying to better understand the behavior of individual quantum particles as they move in space. Yet directly imaging these particles with high precision has so ...