Tonight we did a fun little science experiment. We recorded the sound the largest metal bowl makes when you tap it and it hits a harmonic frequency that creates a feedback loop inside the bowl, which is why the sound seems to go on forever inside the bowl. The vibrations on one side are fueling the other and vice versa. So we recorded the sound and then overlaid it on itself a couple times to produce a long oscillating hum, put that sound on an ipod and played it over the speakers next to the bowl. You could then touch the bowl and feel it vibrating like it had just been struck. I was hoping we could get it to ring but I don’t think my sound recording was pure enough or at the right frequency. So then I got to thinking we need an oscilloscope, which is crazy expensive, then I realized that an oscilloscope would not be a tough application to write. Then I find one on the iPad for $.99. Gotta love technology. Until it tries to rise up against you and destroy you, but until then, you gotta love it.
Here is the sound file we used to vibrate the bowl. bowl.mp3