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A Unified Theory of Animal Locomotion

Posted by ScuttleMonkey on from the how-much-wood-can-a-woodchuck-chuck dept.

Roland Piquepaille writes "You probably already know that there is a master equation for all life processes based on metabolism. Now, physicists from Duke University have applied the so-called 'constructal theory' to explain how running, flying and swimming modes of locomotion are similar even if they're apparently unrelated. This single unifying physics theory explains how fast animals get from one place to another and how rapidly and forcefully they step, flap or paddle in relation to their mass. In other words, these scientists argue that the characteristics of animal shape and locomotion are predictable from physics."

43 of 229 comments (clear)

  1. Real animals only by MarkusQ · · Score: 3, Funny

    the characteristics of animal shape and locomotion are predictable from physics

    They must be using real animals only. I know for a fact that the Pegasus's shape (to cite just one famous example) isn't predictable from physics.

    --MarkusQ

  2. Roland Piquepaille by Anonymous Coward · · Score: 5, Interesting

    Roland Piquepaille and Slashdot

    1. Re:Roland Piquepaille by Anonymous Coward · · Score: 2, Informative

      Apprently you didn't look very well. Two links go straight to his blog.

    2. Re:Roland Piquepaille by Anonymous Coward · · Score: 2, Funny

      In related news, scientists also discovered the unified theory behind the ratio of Roland Piquepaille accepted articles to submissions. Applying the so-called 'covetousness theory,' these scientists developed the formula describing the miraculous amount of articles from a single submitter, regardless of merit or ripped-off content. The answer, contrary to popular belief is not 42 but rather one. This ratio therefore implies that every article submitted has been and will be accepted. The reasons for this still remain unclear.

      However, these same scientists are hoping to answer the latter question by applying the same theory to the variables of slashdot editor kickbacks and Roland Piquepaille advertising money. More information on this research can be found In related news, scientists also discovered the unified theory behind the ratio of Roland Piquepaille accepted articles to submissions. Applying the so-called 'covetousness theory,' these scientists developed the formula describing the miraculous amount of articles from a single submitter, regardless of merit or ripped-off content. The answer, contrary to popular belief is not 42 but rather one. This ratio therefore implies that every article submitted has been and will be accepted. The reasons for this still remain unclear.

      However, these same scientists are hoping to answer the latter question by applying the same theory to the variables of slashdot editor kickbacks and Roland Piquepaille advertising money. More information on this research can be found here

    3. Re:Roland Piquepaille by ajs · · Score: 3, Insightful

      I'll point out that the primary concern that you cite in your journal is that this guy is driving traffic to his site instead of to the sites of the source information, and yet this article's primary link goes directly from Slashdot to Duke University.

      It's sad when a canned reply that consists of a single link to an off-topic journal is modded up to a 5. Makes me think of the days when anti-Katz postings would be modded through the roof for no particular reason other than spite.

  3. Swimming Fish = Flying Bird? by jackb_guppy · · Score: 2, Interesting

    This is question I have asked my daughter from time to thing about... Are Bird and Fish the same or different?

    This article starts to show that yes they are.

    For me thought the answer is yes they are. They both can move 3 dimentally in they fuild mediums... Air and Water. Just one is just more dense then the other.

    Best example of this is Penguin. They "fly" in water.

    1. Re:Swimming Fish = Flying Bird? by Anonymous Coward · · Score: 5, Funny

      Yes, they are the same or different. I could have told you that without a research paper.

    2. Re:Swimming Fish = Flying Bird? by Murphy+Murph · · Score: 4, Insightful

      Forget the penguin for a moment.

      Are birds buoyant in their fluid?
      That right there is a big difference.

      --
      I dub thee... Sir Phobos, Knight of Mars, Beater of Ass.
    3. Re:Swimming Fish = Flying Bird? by Ruff_ilb · · Score: 3, Informative

      As far as I'm aware, fish have gills and lay squishy (scientific term) eggs, while birds lay solid eggs and have lungs. Birds also have feathers, and I'm not aware of any feathered fish.

      And heck, if you're going to define our atmosphere and our ocean as a fluid medium, then you're saying that ALL animals are the same - name a single animal that travels through a completely SOLID medium.

      --
      http://www.TheGamerNation.com/Forums
    4. Re:Swimming Fish = Flying Bird? by Anonymous Coward · · Score: 2, Insightful

      Of course they are, just not nearly enough to stop them from plummeting downwards.

    5. Re:Swimming Fish = Flying Bird? by dsanfte · · Score: 4, Funny

      You have obviously never hooked a bird up to a tank of hydrogen. I assure you, they're quite buoyant before they explode.

      --
      occultae nullus est respectus musicae - originally a Greek proverb
    6. Re:Swimming Fish = Flying Bird? by BorgCopyeditor · · Score: 4, Funny
      name a single animal that travels through a completely SOLID medium

      The Horta?

      --
      Shop as usual. And avoid panic buying.
    7. Re:Swimming Fish = Flying Bird? by Akaihiryuu · · Score: 2, Interesting

      Stingrays "fly" in water too (I mean the larger kind that have "wings", not the smaller ones that look like fish frisbees). They are very interesting to watch. They're also very curious...they don't act like fish at all. They act more like puppies than fish actually.

    8. Re:Swimming Fish = Flying Bird? by EvanED · · Score: 2, Insightful

      And heck, if you're going to define our atmosphere and our ocean as a fluid medium, then you're saying that ALL animals are the same - name a single animal that travels through a completely SOLID medium.

      You're missing the point. He's not saying they're related because they move through fluids, he's saying they're related because they have three dimensional control of where they are.

      And to some extent, that is something exclusive to them. Land animals have to do a lot more work than them in order to move in anything but the "plane" of the Earth.

    9. Re:Swimming Fish = Flying Bird? by Deadstick · · Score: 2, Interesting
      No. Fish receive most of their vertical support from hydrostatic buoyancy; if a fish doesn't move a muscle, it will neither rise nor sink very quickly. All the muscular energy it expends goes into overcoming the drag that resists its forward movement.

      Birds have to expend some energy just to stay aloft, plus more to travel. If a bird doesn't move a muscle, assuming it's holding its wings in the gliding position, it will continuously lose altitude. Its drag has two components: parasite drag which resists its forward motion and induced drag which results from the lift-producing process.

      When a penguin (or other diving bird) swims underwater, it has to expend energy just to avoid floating up, because it's positively buoyant in water -- in effect, it's flying upside down.

      rj

    10. Re:Swimming Fish = Flying Bird? by aussie_a · · Score: 2, Interesting

      Land animals have to do a lot more work than them in order to move in anything but the "plane" of the Earth.

      But they can still do it (for instance moving down through the ground can be easier then moving up, but in some cases it can be easier to move up then down, and near cliffs or other walls it is just as easy to move up or down, then it is to move forward or side to side).

    11. Re:Swimming Fish = Flying Bird? by Vellmont · · Score: 2, Informative

      As another poster pointed out, fish are boyant in water. They take advantage of this through an organ designed to control positive and negative boyancy (gas bladder). They use it to ascend and descend in depth without swiming. That's quite a major part of how fish move in water that's vastly different from how birds fly.

      That's not to say that fish and birds aren't similar in how they move through fluids, but to say they're the same is a vast misunderstanding of fish and birds.

      --
      AccountKiller
    12. Re:Swimming Fish = Flying Bird? by 1u3hr · · Score: 3, Informative
      Penguins don't have feathers

      Penguin FAQ
      "Penguin feathers are short, overlapping and densely packed. The outer part of the feather is waterproof while the inner down section traps an insulating layer of air, keeping the penguin warm in the sometimes freezing water."

    13. Re:Swimming Fish = Flying Bird? by RossumsChild · · Score: 3, Informative

      [Ahem]

      I have to type in some non cap letters here, otherwise the server won't let my quote pass. It is not my fault it's all in caps. That's the way it was written the first time!

      So, without further ado, the quote, courtesy of that haven of IRC gems, bash.org:
      YES IS NOT AN ANSWER TO "A OR B?"

    14. Re:Swimming Fish = Flying Bird? by EvanED · · Score: 2, Interesting

      It does seem like there's a qualitative difference in how they move. You yourself argued in other threads that the motions of a bird and fish are different than a mole, because the latter digs. I would add to your distinction the observation that the holes left behind by a mole are permanent in the short term, while the "holes" behind the bird and the fish refill pretty much instantly.

      You can take this point further and say that once a mole digs out a nice house, almost all his motion is constrained to the tunnels that are already dug. So while he has the capability to exercise full 3D motion, the natural state is that he does not. And more than that, even if he does keep digging just so that he can prove that he can go in any direction, he'll eventually make a cavern. At that point his 3D control has been lost, as he can't go up without refilling his home.

      None of these apply to the bird or the fish. Their motion is, to a large extent, not constrained. Look at the paths of either; they don't go in the same motion. There's no loss of control once they have flown a particular route, nor is there any factor to make them fly that exact route again. And the constraints that the DO face, for instance trees in the case of a bird, have parallels in the mole universe: they can't dig through rocks for instance.

    15. Re:Swimming Fish = Flying Bird? by aXis100 · · Score: 2, Informative

      Have you seen images of submarines where they still cause a bit of a bow wave when slightly submerged? Pushing against the water in front creates a bit of a ripple, and even though the total volume of the water is the same, part of it is at a raised height. Due to gravity, this ripple requires some energy that has to be exerted - just like the bounce in running.

  4. Science gibberish by Piroca · · Score: 5, Funny


    these scientists argue that the characteristics of animal shape and locomotion are predictable from physics

    I wonder who could expected the outcome to be the other way around.

    1. Re:Science gibberish by jackb_guppy · · Score: 4, Funny

      I wonder who could expected the outcome to be the other way around.

      Intelligent Design?

    2. Re:Science gibberish by ajs · · Score: 2, Insightful

      "Their argument is that everything fits together so perfectly and logically that there must have been a creator."

      And that's a fine thing to think, but you cannot rely on ID's central theme -- unexpected complexity -- when you have no frame of reference. By expanding the complexity of locomotion to physics in general, we render any assertions about complexity moot. Is physics complex? Maybe, but perhaps we are just poor judges of complexity. That argument is pure philosophy.

  5. Some robot guys already discovered that by Anonymous Coward · · Score: 4, Insightful

    Robotics researchers already knew that something like 'animal' locomotion could be implemented based on the principles of physics. ie. given the right mechanical setup, locomotion is almost automatic and takes no supervision by a computer.

    Actually, it's what you'd expect. Animals would naturally evolve to move in an efficient manner. It would give them an evolutionary advantage. What the bleep did these guys expect?

    www.sciencenews.org/articles/20050806/bob8.asp

    1. Re:Some robot guys already discovered that by qray · · Score: 2, Interesting

      Actually, it's what you'd expect. Animals would naturally evolve to move in an efficient manner.

      I be they were pretty funny to watch before they started moving in an efficient manner.

      Watching my dog chase its tail gives me a glimpse of what it must have been like.
      --
      Q

  6. Re:Wow...never would have guessed. by rbarreira · · Score: 2, Insightful

    Maybe, but maybe you didn't understand the article too... (judging from your post)

    --

    The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
  7. DURR by ClamIAm · · Score: 4, Funny
    This single unifying physics theory explains how fast animals get from one place to another

    Well if they're fast animals, and they're going from one place to another, perhaps they do it by moving quickly? Ever considered that?

  8. Re:Some solutions missing. by Jeremi · · Score: 4, Interesting
    If such methods are better, why has no animal evolved them?


    It could be just "bad luck" -- evolution isn't guaranteed to find the best solution to anything, only a solution that is "good enough" to guarantee survival of the species (otherwise the species would have gone extinct). But putting that aside, there are probably structural reasons why animals never evolved wheels -- for example, how would do you connect nerves or blood vessels to an appendage that needs to be able to rotate freely?


    Finally, it could be that in nature wheels aren't actually "better" after all. There wouldn't be much use in being able to roll down a freeway at 50MPH if there are no freeways, and your snazzy evolved bio-wheels keep getting stuck in the mud...

    --


    I don't care if it's 90,000 hectares. That lake was not my doing.
  9. All fish are donuts but not all donuts are fish by TapeCutter · · Score: 3, Informative

    "Or maybe a fish shaped like a donut?"

    I hate to break this to you but most animals (including fish and humans) are shaped like donuts (tube surrounded by the organisim). This is not the only "body plan", there are ~30 others still around today, (eg: Jellyfish have only one orifice). All body plans that have ever existed hail back to (or before) the Cambrian explosion

    --
    And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    1. Re:All fish are donuts but not all donuts are fish by EvanED · · Score: 4, Funny

      You need to spend less time reading topology books

  10. Re:Dinosaurs by Stevyn · · Score: 2, Insightful

    Gravity? I could understand if the atmosphere was thicker back then it may help the pterodactyls fly, but how was the gravity different? I'm not saying you're wrong, I've just never heard of this idea.

  11. Re:Hold on a minute... by User+956 · · Score: 2, Funny

    No, Will Wright's working on a method to procedurally generate Roland Piquepaille Slashdot submissions.

    --
    The theory of relativity doesn't work right in Arkansas.
  12. Re:Bumbling Theories ??? by TubeSteak · · Score: 2, Informative

    "the laws of physics dictate that a Bumble-Bee can't possibly fly,"

    really should have been explained with the qualifier that (at the time) scientists' understanding of the Bumble-Bee's flight mechanics were not complete.

    Time passed and someone sat down with a highspeed camera + some smoke and figured things out. I can't find a link to the explanation, but it has to do with vortices.

    --
    [Fuck Beta]
    o0t!
  13. Did you read the actual article? by wass · · Score: 2, Interesting
    Good God this article, posted at Duke university, is at the intellectual level of a 5 year old. In print and in person, seems like people are getting really dumb.

    However, it's not as 'dumb' as someone mistaking a press release for the actual scholarly scientific article.

    I didn't find a link to the article in the press release, and I'm too lazy to bother searching through the journal's Table of Contents to find the authors to get the appropriate link to the article itself, so instead I'll cut and paste the relevent part from the press release.

    "The findings, published in the January 2006 issue of The Journal of Experimental Biology, challenge the notion that fundamental differences between apparently unrelated forms of locomotion exist."
    --

    make world, not war

  14. Re:Allow Me by Lord_Dweomer · · Score: 2, Insightful
    How is this informative? So what if he's been abusing the system for that long. It just means he has a long history of not linking directly to the site and instead linking to his blog, thus stealing revenue from the original site.

    This guy is scum and the fact that Slashdot editors continue to post his stuff says a lot about how they view their readers.

    So like hell we'll simmer down, cuz I'm sure that's just what the editors and Roland would want.

    --
    Buy Steampunk Clothing Online!
  15. Yeah, but do you think... by MacDork · · Score: 2, Interesting

    that would be enough to assist a 5 oz. bird carrying a 1 lb. coconut to Mercia? ;-)

  16. So did some computer graphics guys by Pseudonym · · Score: 2, Interesting

    Famously, Pixar's first film Luxo Jr is based on the same principle. They set up the armature, and then did a global optimisation process to minimise the energy expended for the lamps to hop around.

    (BTW, for the would-be pedants present: André & Wally B was not technically a Pixar film, since it was made while everyone was still at Lucasfilm.)

    --
    sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
  17. Re: Max weight on a exoskeleton by ozmanjusri · · Score: 2, Funny

    So my two ton exoskeleton will let me fly?

    Mine does. http://stationair.cessna.com/spec_gen.chtml

    --
    "I've got more toys than Teruhisa Kitahara."
  18. Giant ant overlords are scientificly impossible? by craXORjack · · Score: 2, Insightful
    "Our finding that animal locomotion adheres to constructal theory tells us that -- even though you couldn't predict exactly what animals would look like if you started evolution over on earth, or it happened on another planet -- with a given gravity and density of their tissues, the same basic patterns of their design would evolve again," Marden said.

    So giant ant overlords could only evolve on a planet with less gravity or intense pressures? Or maybe have bouyancy like at the bottom of our oceans. Maybe we should worry about giant lobstermen.

    I would like to know how this applies to humans in space. Will I somday be able to fly under my own power in a lunar gymnasium like in an old Heinlein story I once read?

    --
    Liberals call everyone Nazis yet they are the closest thing to it.
  19. Re:Giant ant overlords are scientificly impossible by corbettw · · Score: 2, Funny

    Maybe we should worry about giant lobstermen.

    Only the ones trying to practice medicine. They're all quacks.

    --
    God invented whiskey so the Irish would not rule the world.
  20. Mythbusters 1855 by EmagGeek · · Score: 2, Funny

    I can just see the MythBusters trying to bust or prove the myth that Bumblebees can fly - or likewise come up with a way to make a bumblebee fly.

  21. Take that, arrogant scientists by 0xdeadbeef · · Score: 2, Funny

    You have finally proven what God knew all along. Could a random process be self-optimizing? This is yet more proof of His infinite wisdom.