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Stones That Move
In California’s Death Valley is a Racetrack. But no humans, horses, or living creatures for that matter, compete here. Instead, this barren dry lake bed (or playas) is where flat-bottomed stones, some weighing a hundred pounds, move across the ground and leave behind grooves that can stretch as far as thousands of feet.

For years, no one had witness the stones move in person, or explained their cause. In 1967, however, Robert Sharp, a professor of geology at the California Institute of Geology, concluded that the rocks are moved by wind and water. Light rainfall can coat the lake bed with a moist layer of film so slippery that a strong gale of wind will send the stones racing.


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