Light consists of electromagnetic waves that oscillate in time and propagate in space. Scalar waves are described by their intensity and phase distributions. These are the spatial (orbital) degrees of ...

Introduction Can you imagine a bouncy ball that could bounce back and forth between two walls, infinitely—that is, forever? Wouldn't that be amazing? What if, instead of a ball, light was bouncing ...

Can we turn back time? Ask a savvy physicist, and the answer will be “it depends.” Schemes for retrograde time travel abound but usually involve irreconcilable paradoxes and rely on outlandish ...