Racetrack Playa (national park of Death Valley, California) is famous for its moving stones. The floor of the playa (an ancient lake) is dried, scorched mud which has broken into perfect little octagons and pentagons. It's as flat as flat can be. And there are roaming rocks which seem to move on their own. The stones vary from pebble size to half ton boulders and vary in size and shape due to them breaking off the hills you see behind in the photo. Their tracks vary in length and go every which way from zig-zags to loops and double back on themselves. Some travel only a few feet; others go for hundreds of yards. How wind loops and doubles back on itself and zig zags? Why two rocks right next to each other take totally different paths, why some are left untouched?
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