Song of the Dunes as a Self-Synchronized Instrument

摘要: Since Marco Polo it has been known that some sand dunes have the peculiar ability to emit a loud sound with well-defined frequency, sometimes for several minutes. The origin of this sustained remained mysterious, partly because its rarity in nature. It recognized is not due air flow around but motion an avalanche, and acoustic excitation grains their relative motion. By comparing singing world two controlled experiments, laboratory field, we prove frequency grains. Sound produced moving synchronize motions. experiment shows dune needed emission. A velocity threshold emission found both interpretation proposed.