Capt.Albatross (1301561) writes "The flat surface of the Racetrack Playa in Death Valley is littered with rocks, some weighing hundreds of kilograms, each at the end of a track indicating that it has somehow slid across the surface. The mechanism behind this has been the subject of much speculation but little evidence, until a trio of scientists caught them in action with cameras and GPS."
It isn't easy being the parent of a six-year-old. However, it's a pretty small
price to pay for having somebody around the house who understands computers.