In northwest China, China successfully tested the Feitian 2, a new hypersonic vehicle. This test marks a major step forward in high-speed flight technology. Feitian 2 is not an ordinary aircraft. It ...

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 ...