Physicists Discover Universal "Wet-Dog Shake" Rule

Dog owners can sleep easy tonight because physicists have discovered how rapidly a wet dog should oscillate its body to dry its fur. Presumably, dogs already know. From the article: "Today we have an answer thanks to the pioneering work of Andrew Dickerson at the Georgia Institute of Technology in Atlanta and a few buddies. But more than that, their work generates an interesting new conundrum about the nature of shaken fur dynamics. Dickerson and co filmed a number of dogs shaking their fur and used the images to measure the period of oscillation of the dogs' skin. For a labrador retriever, this turns out to be 4.3 Hz."

Comments

Tragedy

[Sonny Yatsen]

Let's hope this doesn't catch on in Japan. We don't need Dog shaking machines to complement their dog washing machines.

Re:Tragedy

[severoon]

Awesome! Now there's enough research in this field to get funding for that baby shaking study I've been wanting to do...

Ig Noble...

[Defenestrar]

Here we come!!!

Before sarcasm is toted around here...

[Anonymous Coward]

The formula is significant for us in the ad/entertainment industry who relies on algorithms to animate such motions. It sure beats trying to manually animating each fur (impossible), or coming up with a workaround that only approximates reality through trial and error. This will significantly reduce render times.

The same could be said about fluid dynamics a decade ago - now we can create whole above/underwater environments within the computer - saving time and cost of flooding entire soundstages.

"Wet-Dog Shake"

[clang_jangle]

We have Classic Poop, New Poop, Cherry Poop, Diet Poop, Salty Lemonade, and our new Wet Dog Shake!

Not yet...

[Ecuador]

Ok, FTFA, it seems that the researchers did a very simplistic model and then found some videos so that they can measure what the animals actually do and noticed that they did not fit their model. So, nothing to see here until someone really sits down and models the wet dog oscillations with accuracy and tell us what the optimal frequency is (so that we can teach our dog if it is not that good with drying of course!).

Re:Not yet...

[powerlord]

Ok, FTFA, it seems that the researchers did a very simplistic model and then found some videos so that they can measure what the animals actually do and noticed that they did not fit their model. So, nothing to see here until someone really sits down and models the wet dog oscillations with accuracy and tell us what the optimal frequency is (so that we can teach our dog if it is not that good with drying of course!).

Nah, there are easier ways to get dry. My dog quickly moved from the "shake myself dry method" to the "the rug and furniture are my towel method".

She's found this to be truly superior although some preliminary research showing a combined "shake myself dry" followed by "the rug and furniture are my towel" method may be her best option.

When I told her to get off the couch she just grinned and said "I'm a bitch, deal with it."

Why?

[Quantus347]

What possible application could this research be for? In what way does this benefit mankind, expand out understanding of the universe, or improve the Human Condition. And perhaps the most important question, what moron paid for this? Please tell me it wasn't taxpayer money, because then technically I am one of the morons, and I don't very much appreciate it!

Re:Why?

[bkaul01]

What possible application could this research be for?

If they're scientists rather than engineers, the obvious answer is, "Who cares?" ... Perhaps the most distinguishing aspect of "science" is that it's a search for knowledge for its own sake, not tied to a practical application. Engineering research is generally tied to something practical. Scientific research need not be. That's not to say that scientists never take up research that has practical application, just that the mindset of a scientist is that the practical application isn't the ultimate goal: the knowledge itself is. If you're curious about dog-fur-shaking, research it. That's science.

That said, the dynamics of water droplets on fibrous materials probably aren't well understood, given that there are open questions about the dynamics of liquid films on some solid surfaces [1], and there are numerous applications that could be imagined there - filters, absorptive mats, perhaps new methods of creating sprays using some sort of shaking synthetic fibers, etc. If we only studied the questions for which the technological benefit was directly obvious, we'd still be in the pre-industrial era. I don't know if this particular study was well-designed or will provide useful information, but any knowledge has potential to prove valuable, often in areas not directly related to the question that was being studied initially. These studies may sound silly when explained superficially, but that doesn't mean they're worthless.

[1]The breakup and atomization of the shear-driven fuel film on an intake valve at cold start in a PFI gasoline engine, for example, depends on whether the film will separate from the valve surface when it reaches the corner, or flow around the corner and down the side. This is a relatively simple problem, geometrically, but the interplay of surface tension, viscosity, inertia, and the boundary with the air flow is something that current models really didn't handle at all until a year or two ago - the experimental side of the project is something that a couple of the MS students in my research group were working on while I was in grad school. Something as complicated as how the effect of the frequency of the oscillations of the underlying layer to which fibers are attached affects the behavior of droplets clinging to those fibers is more complex, and thus I would guess it's most likely not understood well at all at the level of being able to explain and model it in detail.

Wet dogs vs. wet t-shirts

[PatPending]

Leave it to a bunch of nerds to focus on wet dogs. I for one would rather focus on wet t-shirts: what is the period of oscillation of those boobs?

Re:Wet dogs vs. wet t-shirts

[tool462]

It's just a mass on a spring, so I assume sqrt(k/m) is a pretty good approximation. We'll need a pretty good sample size to determine k to a reasonable level of precision though. I'll work on collecting data, can you write up the grant proposal?

Maybe, mabe not...

[jpbelang]

I don't know how seriously the scientist took this research.

But I do remember that Richard Feynman wrote a paper on the wobbling movement of a spinning plate. He did this because he was depressed and had scientific writer's block. And nobody would deny the importance of his later work.

Science is science. If what they find is correct in the scientific sense, it really doesn't bother me too much.

I'd be worried if scientists started really competing for the Ig Nobel prizes. But I doubt that they ever will :-).

I take it that the theory assumes...

[John Hasler]

...a spherical dog of uniform density?

Grant application in process.

[blair1q]

Now that they have solved this pressing problem, the researchers have moved on to filling out grant application for their next project: the Large Doberman Collider.

Re:One of mankind's biggest questions...

[JonStewartMill]

My question was never "how does a dog shake so as to dry his fur?" but rather "WHY must my dog walk up next to me immediately before doing so?"