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 ...

For more than 50 years, scientists theorized that an electromagnetic wave could be reflected temporally—not just spatially.

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." For more than 50 years, scientists theorized that an electromagnetic wave could be reflected ...