Researchers have created what they believe is the loudest underwater sound possible by hitting a thin jet of water with a powerful x-ray laser beam. In this video, which takes place over about 40 nanoseconds, the laser splits the water jet in half, sending powerful shockwaves wobbling down the jet in either direction. Black clouds of bubbles form as the water comes to a near boil. Credit: Courtesy of Claudiu Stan/ SLAC National Accelerator Laboratory