Walk across the Racetrack Playa in Death Valley National Park and you might spot something strange . Here , tremendous boulders can be seen trail by what await like tire stain on a racetrack in the manikin of trails carved into the dry lakebed . These " seafaring stones " can weigh up to320 kilograms(700 pounds ) at the extreme ending , so who do they think they are zooming around the landscape ?
It ’s a question that ’s boggled mind since the forties , but in2014 , a cogitation published inPLOS Oneset out to settle the mystery once and for all by strapping GPS tracker to some bowlder and recording them with clip - lapse television camera . It cross out the first time the glide stones had been record in motion , leading to a polar – albeit it very , very thin – discovery that could explicate how they move around .
Death Valley ’s Racetrack Playa is pretty chocolate-brown and dusty in the summertime months , but issue forth winter a shallow winter pool class across the playa . When it gets stale enough , the water freezes creating a thing bed of ice just 3 to 6 millimeters slurred . Not much , but enough to produce sheets that break apart and get pushed around by a gentle breeze .
Now all they need to do is learn how to hurl insults and they can execute nature’s slowest drive-by.Image credit: Scott Beckner viaFlickr,CC BY 2.0
“ A necessary condition for the careen motility we observe is the existence of a playa pocket billiards late enough to deluge the southern section of the playa , yet shallow enough to leave many rocks part exposed at the pond open , ” wrote the authors . “ Other repeating features of rock movement events that we keep include the front of floating internal-combustion engine , temperature and sunshine sufficient to produce thawing pools in the sparkler , and light breezes that are stiff enough to repulse blow ice . ”
The GPS trackers revealed that once they got move , the soaring stones ’ advancement was a leisurely pace of around 2 to 5 meter ( 6.6 to 16.4 feet ) per moment . Not on the nose an F1 phonograph record , but sure as shooting up there with the fastest inanimate boulders on Earth .
The scientists behind the paper bring to observe quite the backwash - rock exchange when 60 rock music started moving simultaneously , some traveling as far as 224 meters ( 735 foot ) over several effect . It had been suspected that frosting might diddle a part in the phenomenon of the sailing stone , but it was a revelation to discover how slight that ice had to be , and what mild breaking wind were require to set them in motion .
A shiver airstream from the Death Valley National Park , but one you might struggle to lift up a follow for , as race time of year can be part by years to tenner due to deficient rain and snow to form a deep enough wintertime pool . Perhaps theAnimal Olympicsholds more hope as a looker sport .
