The power of music

In honor of my newly rented bass clarinet, I decided to do a post on the science of sound. I instantly think of that scene in Fantasia with the line and how it changes based on the sounds of each instrument, especially the tuba bit where the line gets all flabby at the bottom.


Childhood silliness aside, Wired had a guest post about the physics of sound waves and how they can be used to levitate things. The author draws on the example of an ad in which a person's hair is blown back by their speakers, or the vibration you can see when you flick a rubber band (rubber band guitars, anyone?). In the latter, the wave travels back and forth between two ends and ultimately disrupts itself, creating the oscillating bit in the middle and stationary points at the ends - this is known as a standing wave.

As one might expect, you can't levitate something on a rubber band. You also need a net upward force (more pressure underneath than above) and an object small enough so that it doesn't press back down too much. The device referenced in the article and this paper, while able to levitate an object with a density of 1000 kg/m2, has a distance between anti-nodes (the oscillating bits, like in the middle of the rubber band) of only 8mm, so levitation on a large scale wouldn't be feasible.

So the next time your neighbor blasts the bass on the stereo, you can always hope that the frequency would be just right to throw your neighbor across the house.