Nature is filled with remarkable visual phenomena created by microscopic surface structures that interact with light in ...

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 ...

Have you ever sat on the bottom of a swimming pool and pondered your watery ceiling? Most of the surface is a sheet of light blue, and you can't see through it, even though the water is clear. But ...