The mysterious moving stones of the packed-mud desert of Death Valley have been a center of scientific controversy for decades. Rocks weighing up to hundreds of pounds have been known to move up to hundreds of yards at a time. Some scientists have proposed that a combination of strong winds and surface ice account for these movements. However, this theory does not explain evidence of different rocks starting side by side and moving at different rates and in disparate directions. Moreover, the physics calculations do not fully support this theory as wind speeds of hundreds of miles per hour would be needed to move some of the stones.
Racetrack stones only move once every two or three years and most tracks last for just three or four years. Stones with rough bottoms leave straight striated tracks while those with smooth bottoms wander. Stones sometimes turn over, exposing another edge to the ground and leaving a different-sized track in the stone's wake.
Sliding rock trails fluctuate in direction and length. Some rocks which start next to each other start out travelling parallel, but one may abruptly change direction to the left, right, or even back the direction it came from. Length also varies because two similarly size and shaped rocks could travel uniform, then one could burst ahead or stop dead in its track.
Speed is also an unknown variable. Since these stones are transported very rarely and nobody has ever witnessed movement, the speed the rocks travel at are not known.
