A Rubens tube is a long pipe with a bunch of holes on one side, through which gas is pumped. It’s like having 20 Bunsen burners in a row with a shared fuel source. Combined with sound waves, a Rubens tube can visualize wave frequencies, as the sound waves bounce around the tube, disrupting airflow at regular intervals, resulting in the flames plotting out a long wave, the intensity of which varies by the frequency of the tone.
These Danish students have created a flat, two-dimensional version of the Rubens tube and done the only natural thing — made a big flame-based visualizer out of it. By pumping gas into a flat box with 2500 holes on top and angling the speakers appropriately, the flames dance and shoot as the Danes adjust the frequency.
Check out this wicked video below: