Sliding Rocks Bemuse Scientists

An anonymous reader writes "Scientists can't figure out why these rocks — weighing up to several hundred pounds each — slide across a dry lake bed. The leading theory proposes that wind moves the rocks after a rain when the lake bed consists of soft and very slippery mud.

Comments

Mark Newman Poster

[stoolpigeon]

Mark Newman has a very nice sliding rock poster with a good shot of rock and trail in a variety of sizes.

Re:Mark Newman Poster

[An ominous Cow art]

I was there in August this year, and it was quite windy. It's very easy to imagine that if the ground had been muddy, the wind could slide the rocks around.

Re:Mark Newman Poster

[stoolpigeon]

In the desert the ground is really, really hard. It is completely plausible that a thin layer on the top could be slimy mud, while hard clay lies beneath.
 
I don't think you appreciate how remote this site is and what an effort it would be to pull off something like that. I really don't think it is someone messing around or that the wind theory is as unlikely as you think.

Re:Mark Newman Poster

[Basehart]

It's not just beer. I was bathing the other day and my pint sized glass of heavily iced water all of a sudden moved across the smooth plastic surface of the toilet seat lid and fell to the floor.

The toilet seat lid was covered in a fine layer of condensation from the bath water at the time.

I'm betting if the stones are cooled way down to almost freezing by the wind, or maybe frozen overnight and still cold when the rains hit, and the top surface of the mud turns into a slurry of fine particles, the stone will move around all on its own just like my cold glass of water on a fine layer of condensation.

Either that or space aliens.

Re:Mark Newman Poster

[vought]

Just seems to me that instead of crazy rocks sliding round on their own, some damn kids were up there fucking round with rocks. Considering how difficult it is to get out to the Racetrack, I doubt this. Otherwise, I would think someone might camp out there during a storm and find out if they really skate around on their own.

Problem is that storms come up rarely but suddenly there (usually) and it takes almost two hours to get to the Racetrack from the nearest paved road - three hours from the Death Valley visitor's center - and if you get out there before a storm, there's no guarantee that even a very capable 4x4 will get you back afterwards.

Re:Mark Newman Poster

[vought]

It sounds like fun, and it would only take a few years to get results. Compared to raising children the cost is low and the results are fast. I agree. You do it.

It's a Horta!

[loftwyr]

I saw this on TV once! It was this documentary about these very things! They're called Hortas and their intelligent. Apparently they can be taught to mine.

Re:It's a Horta!

[sokoban]

Yes, and though the flow of water surrounding these things can be directed, these Horta do not readily absorb moisture.

Thus, you can lead a Horta water, but you can't make it drink.

Re:It's a Horta!

[jfdawes]

.... the goggles ... they do nothing ....

So this is...

[Anonymous Coward]

...nature's version of desert curling?

Answer on page 42 ...

[foobsr]

... literally:
Quote: "Research of the Racetrack has continued. In the April 1997 GPS World, Paula Messina, Phil Stoffer and Keith C. Clarke reported a GPS study they conducted of the Racetrack. In ten days of intense field work they mapped every featured of the playa using differential GPS to produce, "the first-ever, complete, georeferenced, submeter-resolution map of the wandering rocks." (Messina, 1997, p. 42)"
http://sophia.smith.edu/~lfletche/deathvalley.html

But it seems they have no real conclusion too.

What about 'The Force"?

CC.

Re:Answer on page 42 ...

[orclevegam]

GAH! MY EYES!!! Put a warning on that link, geez.

Isn't it obvious yet?

[CitznFish]

These stones don't want to gather any moss.

no buildup in front

[egburr]

In all those pictures, I don't see any buildup of dust in front of the rocks, though there is plenty on the sides of the paths. Usually, when I push something through the dirt/mud/snow/whatever, I end up with a good buildup in front, too. I wonder where that has gone.

Re:no buildup in front

[Reality Master 101]

In all those pictures, I don't see any buildup of dust in front of the rocks, though there is plenty on the sides of the paths. Usually, when I push something through the dirt/mud/snow/whatever, I end up with a good buildup in front, too. I wonder where that has gone.

I had to think about this for a second... I think the answer is that if a rock was digging into the mud, you wouldn't have this effect, because of having to shove the mass of the mud. If you look at the pictures, the fronts of a lot of them tend to be sticking up, implying they're "surfing" over the mud.

I am pretty sure ...

[Culture]

... that the rocks slide because the lateral forces exerted on the rocks exceed the static and dynamic frictional force cause by the gravity induced weight of the rock acting across the mud-rock interface. I guess I could be wrong and there are worm-holes involved.

god doesn't play dice

[circletimessquare]

but he does hold magnets under the surface of the table, moving objects on top as if by magic, just to bemuse and entertain us

One thing I know for sure

[mcg1969]

is that posting this article in Slashdot is sure to produce a definitive solution to the mystery...
or rather, 100 of them.

Silly scientists...

[VE3MTM]

Clearly the Flying Spaghetti Monster is moving them with his Noodly Appendage.

Re:Any word on magnetic influence?

[TempeNerd]

Obviously, the rocks were casually lurking on Slashdot, when they read "Move along, nothing to see here..."

{rimshot}

Re:Global Warming

[AlamedaStone]

because teutonic plate theory was just too crazy to accept...
 
... although it replaced the even more silly Gaulish plate theory, quickly discarded by history.

Re:Magnetism?

[spun]

Ironic rock is worse than rai-e-ain on your wedding day, or a free-ee ride, when you already paid.

One possibilty

[edwardpickman]

I'd be curious if the under sides of the sliding sliding stones were concave? Why I mention it is I still remember a certain chinese restaurant's tea cups had a habit of sliding across the table. The table tops were resin coated and the concave cups tended to capture moisture under them so when the tea heated the moisture under the cup the expansion provided enough lift to break the friction and allow them to slide. They would move randomly in different directions then stop for a few minutes then slide again. Since the area is hot a unique combination of heated rocks with slippery mud and wind could in combination cause the effect. I remember that some rocks slid and others didn't as well as the direction changes.

Re:Begs the question

[fbjon]

It still seems strange. The place is really dry, meaning there's lots of sun. Just make a small package with a GPS receiver, some simple weather instruments, a radio uplink to a nearby relay, a small camera and a solar panel with battery. If the GPS detects any movement, or the weather instruments detect any drastic changes, turn on all other stuff and start piping data to the relay, which passes it on by whatever means.

If anybody steals the package, it'll sound an alert and record who took it, and where they're taking it.

Re:Amazing how no-one bothers to actually CHECK.

[DigitalCrackPipe]

In true /. form, you either failed to RTFA or to WTFV, as the video clearly does not show the rocks moving. It shows water and miscelaneous floating scum moving, and posits the same theories as in the article (just claiming them to have been proven).

And as to the foolishly simple explanation, H.L. Mekcken is quoted to have said, "Every complex problem has a solution that is simple, direct, plausible, and wrong".

That was Strangely Topical.

[Smordnys s'regrepsA]

Rick Rolled while Reading about Rolling Rock Research, by a link Represented as Relevant.

I Require you Rectify this Rankling Repugnance.


Regards,
Ryan