If you've never heard of the Chladni plate experiment, the principle is very simple. Sound frequencies create patterns. If you can make a metal at certain frequencies, acoustic resonance will cause those plates to vibrate with those patterns.
Normally, you can't actually see this -- unless you sprinkle something granular over the top. Which is exactly what YouTube user Brusspup has done in his latest video. Using a metal plate attached to a speaker, he drove frequencies through it using a tone generator to create intricate configurations of sand. … Read more