The terahertz quantum cascade laser on its mounting. Credit: University of Leeds Lasers that switch on and off billions of times per second are the backbone of optical communications networks, but ...

A quiet revolution is taking shape in the world of physics, and it doesn’t rely on exotic particles or massive particle colliders. Instead, it begins with something much more familiar—sound.

Sound has a speed limit. Under normal circumstances, its waves can travel no faster than about 36 kilometers per second, physicists propose October 9 in Science Advances. Sound zips along at different ...