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8 natural mysteries that can't be explained

By: Melissa Breyer on Sept. 28, 2015, 1:01 p.m.
Singing sand dunes

Photo: Nepenthes/Wikimedia Commons

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Singing sand dunes

Um, so, yeah … the Earth is singing! Well maybe not the planet itself, but a number of sand dunes across the globe — in at least 35 deserts from California and Africa to China and Qatar — are definitely making some intense noise. Sounding like a deep hum of bees or some rumbling Gregorian chant, the moaning mountains have baffled scientists for years. One study discovered that different notes produced by the sands relied on the size of the grains and the speed at which they whistle through the air, but scientists still have no idea how the flowing grains of sand manage to sound like music in the first place. Have a listen below: