The myth isnt that the rocks move they really do. However, its not down to alien intervention or humourous teenage pranksters. Without an explanation the rocks at Death Valley were eerie completely still to the human eye, but a trail carved behind them that would suggest otherwise, as if they came alive when nobody was looking. Theories abounded, from magnetic forces to slippery algal films, and psychic energy to transdimensional vortices. The truth of this phenomenon is that the stones are literally blown by the wind, but within the flow of thin, melting sheets of ice - something known as ice shove. In a study released in August, researchers inserted GPS tracking units into bored holes in rocks, and recorded the playa using time lapse photography. They found that a specific sequence of events was required to shift a stone. The playa fills with water, not deeper than the stones themselves, and freezes overnight. Sheets of ice break up - thin enough to move around but thick enough to maintain strength - and are driven by the wind into the rocks, shoving them at up to five metres per minute.
