My students, Andrew Stephens, Joey Cozza, and Jeric Rocamora are highly accomplished musicians. They were inspired to blend physics, music, waves, and optics by something they saw on the Internet.
Here's the video record of their inspired work.
Physics - Waves Water Experiment
Pretty groovy, right?
Of course, you don't see these structures when watching with the naked eye. You only see them when they are captured in frame-rate-specific video.
The iPhone app they were using is the free FreqGen.
Here is the video that inspired them.
Amazing Water & Sound Experiment #2
I think this one benefits from brighter ambient light. This allows a faster shutter speed. Filming at 24 fps doesn't mean the shutter is set to 1/24th of a second. And a faster shutter (1/500 s) allows for a sharper capture.
When I first saw this, it wasn't clear to me what was going on. And it's not unhealthy to assume anything that looks supernaturally groovy on YouTube is likely a fake. Captain Disillusion debunks video fakery all the time.
But what we're seeing in these videos is artfully captured stroboscopic effect. The classic example is the wagon-wheel effect. Here's a nice video of an "impossible helicopter." The wagon wheel effect is not the same thing as the rolling shutter artifact.
Here's a thorough explanation of the difference between the classic wagon wheel effect and the newer rolling shutter artifact.
I'm pretty sure I promised them a post on The Blog of Phyz. Consider yourselves famous, guys! You even scored the highly-coveted "groovy" tag.