Three thought experiments involving “demons” have haunted physics for centuries. What should we make of them today?

Time travel has long lived in the realm of science fiction, but a growing body of physics research now argues that journeys into the past might fit inside known laws of nature without tearing ...

Pen spinning looks impressive, but it’s built on a few simple movements. This video breaks it down step by step, starting from zero. Once the motion clicks, it becomes natural fast. Dropping the pen ...