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 ...

In 2020, scientists at Purdue University developed a new super-white acrylic paint that reflects 95.5 percent of sunlight. Since then, they’ve made it even whiter, with a new formula that has ...