Does light behave more like a particle, or like a wave? Today we know the surprising answer. Here's why it took so long to get there. When you purchase through links on our site, we may earn an ...

The speed of light is a fundamental constant, approximately 299,792,458 meters per second. It's the same for all observers and hasn't changed measurably over billions of years. Nothing can travel ...

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 ...

The reliable manipulation of the speed at which light travels through objects could have valuable implications for the development of various advanced technologies, including high-speed communication ...

From the most distant stars in the sky to the screen in front of your face, light is everywhere. But the exact nature of ...