In the late 1970s, legendary physicist John Wheeler proposed a radical question: Exactly when does the universe notice that we're paying attention to a quantum experiment? And does it really matter?

Scientists have pulled off a mind-bending quantum experiment that sounds almost impossible: they showed that tiny metal particles made of thousands of atoms can exist in multiple places at once. Using ...

(via PBS Space Time) Does quantum mechanics allow the future to retroactively influence the past, as in the infamous delayed choice quantum eraser experiment? How about we get an actual quantum ...