That's right. Apparently you can create sound with sand dunes. Title link takes you to some video samples so you can see and hear it for yourself. Below is the abstract from this white paper. I guess if you can "play" water, why not sand. Another one of Earth's synthesizers."Since Marco Polo [1] it has been known that some sand dunes have the peculiar ability of emitting a loud sound with a well-defined frequency, sometimes for several minutes. The origin of this sustained sound has remained mysterious, partly because of its rarity in nature. It has been recognized that the sound is not due to the air flow around the dunes but to the motion of an avalanche, and not to an acoustic excitation of the grains but to their relative motion. By comparing several singing dunes and two controlled experiments, one in the laboratory and one in the field, we finally demonstrate here that the frequency of the sound is the frequency of the relative motion of the sand grains. The sound is produced because some moving grains synchronize their motions. The existence of a velocity threshold in both experiments further shows that this synchronization comes from an acoustic resonance within the flowing layer: if the layer is large enough it creates a resonance cavity in which grains self-synchronize. Sound files are provided as supplementary materials."
I have heard the "singing" sand. It was on a Nova program I believe. They played the sand by starting a slide. It sounded like a self oscillating filter sweep with a bit of white noise thrown in. "I'm just a singer in sand playing band!"
ReplyDeleteNeeds a beat. Perhaps Frank Herbert style thumpers.
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