Silently Shirley Slides over Scorching Sandy Stretches
Meet Shirley, “Rock #53″ — a sliding rock, no less — as recorded by Paula Messina and Phil Stoffer. In 1996 Messina and Stoffer took a then-new GPS receiver into Death Valley’s Racetrack Playa to plot the positions and tracks of over 100 of these sliding rocks, rocks large and small that move around the dry lake-bed for reasons that nobody is entirely sure of. They move uphill, downhill, and even sideways, but to my knowledge they do not roll over. They just slide and leave a tilled trail behind them.
Via Chap, who sent me a photo by Fred Miranda. This rock’s name and number are unknown.
September 28th, 2005 at 9:08 am
“They move uphill, downhill, and even sideways, but to my knowledge they do not roll over.”
From the Wiki article:
“Stones sometimes turn over, exposing another edge to the ground and leaving a different-sized track in the stone’s wake.”
Peh! Some researcher your are! Gah, Adam!
September 28th, 2005 at 9:18 am
Thank you for pointing that out, Vince. I should have been more expansive in my wording.
I believe the “turn over” maneuver described in the Wikipedia article is actually caused by a high degree of heat tension building up beneath the rock. When the heat tension reaches its critical point (HTC), the stone will be propelled up, off of the surface of Racetrack Playa, potentially rotate in the air, and land with a new edge or side downward. This “turn over” maneuver may also be attributed to overly curious human visitors checking for wheels, grease, or other propulsion mechanisms.
This is quite different from rolling over.
Thank you.
September 28th, 2005 at 9:50 am
“Racetrack Playa” brings to mind the greasy gangster I always see at the Tampa Bay Downs that slides his entire rubber-banded bankroll under the betting window and hits on all of the chance taking women the moment he seems them drop their cigarette. That’s his territory, all right, and I’ve never seen a challenger even attempt to set foot in “The Silk’s Cardroom” when RTP is on the scene.