First of all, my congratulations to Richard D. Norris, James M. Norris, Ralph D. Lorenz, Jib Ray, and Brian Jackson for their publication in PLOS ONE of Sliding Rocks on Racetrack Playa, Death Valley National Park: First Observation of Rocks in Motion. Although many different mechanisms have been proposed by other publications over the decades, these authors finally got it right. And they beat me to the punch, right under my very nose. They were already collecting data by the time I was just starting to think about taking this on seriously.
As Norris et. al. detail in their article and video, it takes a rare set of conditions to make the rocks move. A thin sheet of ice covering a shallow lake at the south end of the playa gets pushed north by strong winds, then later in the morning as the playa warms under the sun, the winds subside and the ice flows back south as it melts. It is this back and forth movement of broken sheets of ice that has the horsepower to push rocks of nearly any size. Other recent published hypotheses, like “ice forming collars around the rocks and making them buoyant” or “strong winds pushing the rocks across the slick mud” are goofy and wrong. I explained the same process observed by Norris et. al. in one of my very earliest Skeptoid podcast episodes in 2007, having witnessed the same event in 2002.
Here is the winners’ 2014 video:
And here is the video I took in 2002, deficient only in that we did not think (and were not prepared) to take the same time lapses done by Norris et. al.:
My plan had been to use the 2014-2015 winter to capture the rocks on HD video as a project for Skeptoid Media, a plan which is now abandoned since these guys beat me to it. Racetrack Playa is pretty remote. It’s illegal to camp there, and it’s many hours from the nearest accommodations (though it is legal to camp about 15 minutes away). It is illegal to be on the playa when it is wet, since your footprints will be ugly for years. The trick in making this whole thing practical is knowing when to be there. You need:
- Enough water on the playa.
- Enough wind speed in the dawn hours.
- Cold enough temperatures at night.
- Warm enough temperatures in the afternoon.
- The ability to get your butt out there ASAP when these conditions exist.
To determine this, I had arranged the following:
- Permission from the National Park Service to do scientific research within Death Valley.
- A permit to install equipment.
- A planned crowdfunding campaign for a customized weather station with:
- A digital camera to take hourly shots of the playa to detect the presence of the lake
- Temperature sensor
- Anemometer (for wind)
- Solar power
- Integral cell phone transmitter
- Cell signal booster (on an exploratory trip, my son Andrew and I did successfully get a quasi-reliable cell signal, when boosted, at our proposed location).
When conditions were right, I could get to the Playa in about 9 hours from my home in southern California. The equipment would have been installed on the far side of the playa, away from prying eyes. (Despite being camouflage painted, epoxied to the rock, and labeled with a stern National Park Service permit, asshats would still be likely to tamper with it if it was found.) We would love to have put it on the ridge that juts out into the southern end of the playa, which is the source of the moving rocks, but that location is frequently crowded with curious, climbing tourists. So we contrived to put it about 1.25 kilometers further away, up on a hillside that offers an excellent view of the whole southern playa for the automated camera. When we got the bat signal, we needed to go only to the nearer point to get the best HD video.
Norris et. al. put their weather station a bit further north from where we were going to, even farther from any prying eyes.
Allow me to offer some sage advice. There is a much, much easier way to see the “sailing stones”. Go instead to Bonnie Claire playa. You can drive right up to it on a proper paved highway, it’s outside the National Park, and you will see just as many moving stones.
In conclusion, my congratulations again to Richard D. Norris, James M. Norris, Ralph D. Lorenz, Jib Ray, Brian Jackson, and any other members of their team. Nice work gentlemen, and thank you for your contribution for replacing pseudoscience with real science.
(For fun, view this joke video made by Richard Saunders and I in 2011, parodying some of the sillier New Age explanations.)