Scientists have discovered what they believe is the loudest possible underwater sound — a sound so powerful that it can vaporize water on contact.
It’s not the sound of a massive underwater earthquake, nor is it the sound of a pistol shrimp snapping its claws louder than a Pink Floyd concert. It is, in fact, the sound of a tiny water jet — about half the width of a human hair — being hit by an even thinner X-ray laser.
You can’t actually hear this sound, because it was created in a vacuum chamber. That’s probably for the best, considering that, at around 270 decibels, these rumbling pressure waves are even louder than NASA’s loudest-ever rocket launch (which measured about 205 decibels). However, you can see the sound’s microscopically devastating effects in action, thanks to a series of ultra-slow-motion videos recorded at the SLAC National Accelerator Laboratory in Menlo Park, California, as part of a new study.
In the video above, which was filmed in about 40 nanoseconds (40 billionths of a second), the pulsing laser immediately splits the water jet in two, vaporizing the fluid that it touches while sending powerful pressure waves wobbling down either side of the jet. These waves create more waves and, by about 10 nanoseconds in, fizzing black clouds of collapsing bubbles form on each side of the cavity.
According to Claudiu Stan, a physicist at Rutgers University in Newark, New Jersey, and one of the study co-authors, these pressure waves likely represent the loudest possible underwater sound. If it were any louder, the sound “would actually boil the liquid,” Stan told Live Science…