
This is an installation called “Sonolevitation” by the artists Dmitry Gelfand and Evelina Domnitch. Objects – here, little triangles of gold leaf – are trapped in negative pressure zones created by standing waves of sound. The symmetry of the leaves as they rotate is lovely.
Gelfand and Domnitch are neo-Mr. Wizards, exploiting simple-strange physical phenomena in artwork that is, essentially, about how weird and vast the universe is. (Be sure to check out some of their other stuff as well.)
G+D describe Sonolevitation as a research project about the behavior of objects in microgravity, where motion is frictionless. But what Sonolevitation most effectively exploits (and demonstrates) are our biases about matter here on Earth. If the piece used the airflow from two fans to hold the objects in place, it would be much less striking. We’re used to the idea that streams of ventilated air exert physical pressure. Not so with sound. Sonolevitation “wows” us because we imagine sound as propagating in an autonomous and indescribable channel – a channel that isn’t quite physical. There is, then, a cognitive dissonance in watching it exert a visible force.
Sonolevitation will be at festivals in Great Britain and France this March.

This is great. I posted a "scientific" video of the same effect over at my blog a few days ago, but your example inspired me to ruminate a little on the nature of the "sonorous object" over there: http://noiseforairports.com/post/342977817/over-a...
Hey Nick: Excellent coincidence. By the way, since you linked to Sonic Warfare in your post, have you read it yet? It just arrived here, and I was thinking of reviewing it soon.
I haven't read it yet, although it certainly seems like the right thing to do now! (Maybe once I've got more thesis in the bank—I'm on an "automation and musicality-only" reading diet for a while…)