From Boing Boing, ACOUSTIC LEVITATION. Sounds that are so loud that when adjusted to form standing waves, their nodes can support light objects in the air.

This is a great example of how sound is actually a physical, material phenomenon. People so often think of sounds as immaterial or transcendent or intellectual objects, but here they are, just picking stuff up. An interesting corollary to the use of sound as weapon.

(via Boing Boing)

If high frequencies are good for keeping away unruly teenagers, then low frequencies are good for keeping away hail storms. (Maybe.)

In the video, you can hear a hail cannon in action. (I kind of wish that link was a game based on hail cannons, not just a flash animation.)

See more pictures from a hail cannon supplier here.

(via nacken)

EU Seeks to Turn Down MP3 Music Player Volumes

5-10 percent of MP3 users risk permanent hearing loss if they listen to a music player at high volume for more than 1 hour per day, each week over at least 5 years. “It can take years for the hearing damage to show, and then it is simply too late,” she added.

(via nytimes)

Wow, the actual use of an LRAD system in a riot situation is totally Big Brothery and and terrifying.

(via Boing Boing)