For 100 years, 700-pound rocks seemed to move on their own in California's Death Valley. In 2013, scientists finally saw the strange force that was pushing them

For nearly a century, massive rocks weighing up to 700 pounds appeared to move across Californias Death Valley without any visible force behind them. Their long, winding trails on the remote Racetrack Playa puzzled visitors and scientists alike, leading to several theories about what could be moving the stones. Despite years of observation, no one managed to witness the process firsthand. That changed when a team of researchers set up equipment to monitor the area and unexpectedly arrived at the playa during a rare event that finally offered a clear look at what was happening.

Raccontata daeconomictimes.indiatimes.com