Is it hard to fly a helicopter in the Antarctic cold? What do penguins sound like? How about the instruments designed to test ...

Boom Supersonic's XB-1 jet went out in style on Monday (Feb. 10). The XB-1 broke the sound barrier three times during its 13th and final test flight, which lifted off Monday from the Mojave Air & ...

When Erik Christopher heard it coming from a distance, he thought it was a train. Then it got louder, a booming noise overhead. “Then my lights and windows shook a bit and the sound faded,” ...

The noise is barely audible at first, just a low rumble somewhere in the distance. Within seconds it rises to a growl, then swells to a roar, a predator lurking just overhead. The sound makes windows ...