Physicists have finally confirmed a phenomenon that sounds like pure science fiction: waves that appear to bounce off a sudden change in time rather than a surface in space. The effect, known as a ...

From suffocating heat in India to rampaging wildfires in New Mexico, the planet is sending us a message: the long-dreaded climate emergency is now. The world is poised to blow past the Paris Agreement ...

For more than half a century, the idea that light or radio waves could suddenly reverse in time sounded like a thought experiment, not a laboratory result. Now, a series of meticulous experiments has ...