As if levitating objects with sound alone wasn’t cool enough, science YouTuber Destin of Smarter Everyday is back to prove that it gets even better when those objects explode (in slow-motion of course).
Below, Destin, using some very creative visuals, shows us first how acoustic levitation works and then how to destroy levitated water droplets with a bit of math:
Working with Ford and American Idol (it kind of blows my mind that a science YouTube show has come this far), Destin was able to put an acoustic levitator in front of some powerful Phantom high-speed cameras to see the physics involved.
Acoustic levitation works like a ping pong ball and paddle, Destin explains. When two sound waves are aimed at each other and line up perfectly, a series of “standing waves” are formed that have spots in between them where there are no pressure changes. In these “nodes,” water droplets and other small objects can bounce around on top of pressure waves like a ping pong ball on a paddle.
However, water droplets of a certain size only stay together because of the surrounding air pressure and the surface tension of the water. Change the surrounding pressure, like Destin does with the American Idol contestants by turning up the amplitude of the sound waves, and you get some mesmerizing “explosions.”
Did you get smarter today? I did.