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Physicists Discover Universal "Wet-Dog Shake" Rule

Posted by samzenpus on from the thank-you-science dept.

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."

29 of 97 comments (clear)

  1. Tragedy by Sonny+Yatsen · · Score: 3, Funny

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

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    1. Re:Tragedy by severoon · · Score: 5, Funny

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

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      but have you considered the following argument: shut up.
    2. Re:Tragedy by bluie- · · Score: 2, Funny

      sigh. you beat me to it.

      --
      life is a tragedy to those who feel, and a comedy to those who think
  2. One of mankind's biggest questions... by SilasMortimer · · Score: 2, Insightful

    ...finally solved. The world is saved!

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    Omnes tuae crepidines sunt nobis sunt. Ascendo tuum!
    1. Re:One of mankind's biggest questions... by JonStewartMill · · Score: 4, Funny

      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?"

    2. Re:One of mankind's biggest questions... by Anonymous Coward · · Score: 2, Interesting

      My question was, "Can you stop a dog from shaking once it started?"

      I had to give my dog baths all the time when I was a kid. Of course the first thing he would do is shake him self off once he was out of the bath. One time, out of curiosity, I stopped him mid-shake by holding the back part of his body (since the shake from head to tail). I held him for about a minute and then let him go. He finished his shake starting from the point he was at before I stopped him in the middle. Over the course of the next few months, it tried increasing lengths of time but no matter how long I held him, he would finish the shake starting at the point where I stopped him. The last time I did it, I held him for 30 minutes. That still did not stop him. Got bored after that.

  3. Ig Noble... by Defenestrar · · Score: 4, Insightful

    Here we come!!!

  4. Before sarcasm is toted around here... by Anonymous Coward · · Score: 5, Informative

    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.

    1. Re:Before sarcasm is toted around here... by tacktick · · Score: 2, Informative

      Or you could just film a real dog or two that is similar to what you are animating. The "researchers" didnt even come up with a good formula for predicting it based on dog size. Probably because it varies for different breeds and what doggie chow he eats.

    2. Re:Before sarcasm is toted around here... by spammeister · · Score: 2, Funny

      I read that at first as "...us in the adult entertainment industry...".

      Must be a particularily (weird) subset of that industry for shaking wet dogs...

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  5. "Wet-Dog Shake" by clang_jangle · · Score: 3, Funny

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

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    Caveat Utilitor
  6. Not yet... by Ecuador · · Score: 3, Informative

    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!).

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    1. Re:Not yet... by powerlord · · Score: 4, Funny

      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."

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    2. Re:Not yet... by ffreeloader · · Score: 2, Funny

      My dog, at three months old, has adopted that same method, only he looks at me and says, deal with it, I'm a 3 pound bastard so you just try and stop me. He then runs all around the house like a maniac another couple of times rubbing against everything made of fabric.... I think it's probably his favorite thing to do. He looks and acts like he's having more fun than a barrel of monkeys. I don't think I could stop him with anything less than a .45.

      --
      "while democracy seeks equality in liberty, socialism seeks equality in restraint and servitude." de Tocqueville
  7. Why? by Quantus347 · · Score: 3, Interesting

    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!

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    Common Sense isn't as Common as people think...
    1. Re:Why? by bamwham · · Score: 2, Insightful

      While I'm not an expert, I speculate that potential applications would include: using a similar model to study cilial action in human lungs or gut; developing of advanced fabrics which shed water more efficiently; developing algorithms for robotics (I'm thinking in particular military applications) to dry themselves in the wild. The beauty of science to me is that someone answers what appears to be a relatively innocuous and useless question and often can't tell where it might lead. We (often) can't just dive in and answer the most difficult question first, we start with a simple model of a related phenomena and then build up to the real (and useful) examples. I like this problem here, because in practice it does seem that biological systems have spent the eons developing the best solutions to complicated problems (basically through trial and error) so they have a model whose solution agrees with the one found by the biological system. I see it as a win, science has advanced, even if it was only a micro-step.

    2. Re:Why? by John+Hasler · · Score: 2, Funny

      > Please tell me it wasn't taxpayer money

      They borrowed against their igNobel winnings.

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    3. Re:Why? by ChrisMaple · · Score: 2, Insightful

      It's obvious why a thief posts as anonymous coward.

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    4. Re:Why? by bkaul01 · · Score: 3, Insightful

      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.

  8. Wet dogs vs. wet t-shirts by PatPending · · Score: 5, Funny

    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?

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    What one fool can do, another can. (Ancient Simian Proverb)
    1. Re:Wet dogs vs. wet t-shirts by tool462 · · Score: 4, Funny

      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?

    2. Re:Wet dogs vs. wet t-shirts by tool462 · · Score: 2, Funny

      Sorry for the confusion. I was assuming they were spherical breasts in a vacuum.

  9. A shit... by AdamsGuitar · · Score: 2, Insightful

    Who gives one?

  10. Re:Conundrum about the nature of shaken fur dynami by bughunter · · Score: 2, Funny

    This would be the complement to the Super Monkey Collider, no?

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  11. Maybe, mabe not... by jpbelang · · Score: 3, Insightful

    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 :-).

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    1. Re:Maybe, mabe not... by natehoy · · Score: 2, Interesting

      This is a graduate student doing some "tabletop science" in the lab. His specialty in the lab is "Animal Cleaning" http://www.me.gatech.edu/hu/Research/lab.html . I doubt he's trying for anything except his thesis.

      I'd say he did a pretty good job building a preliminary predictive model and testing against that model and refining it. And it stands to reason that animals shaking water out of their fur might be of interest to him, since he probably bathes animals on a pretty regular basis and observes the behavior a lot. Building lab time researching something that interests you sounds pretty good to me.

      It'll probably never cure cancer or give us faster-than-light drives, but most graduate student lab work is done with little expectation of changing the boundaries of science as we know it.

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  12. In addition to smelling wet dog fur... by Cornwallis · · Score: 2, Insightful

    I smell pork.

  13. I take it that the theory assumes... by John+Hasler · · Score: 3, Insightful

    ...a spherical dog of uniform density?

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  14. Grant application in process. by blair1q · · Score: 3, Funny

    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.