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A Unified Theory of Animal Locomotion
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."
Isn't Will Wright doing this in Spore? (generating creature animations procedurally)
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
Roland Piquepaille and Slashdot
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.
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.
and how rapidly and forcefully they step, flap or paddle in relation to their mass.
Can't we do that already, as in... Oh look, the animal weighs 100 lbs and has two legs on the ground at any given point, so each leg has an average of 25 lbs of force on it?
http://www.TheGamerNation.com/Forums
...they've come up with A Unified Theory of Female Behavior. Meanwhile, back to yanking another one off.
Oh sweet Christ. Why, oh why, did they have to imply some sort of design? Is this some sort of attempt to get funding from the Creationist Institute?
Wow, I never would have guessed that you could predict the charactaristics and shape of an animal by the physics. When's the last time you would have guessed a bird was shaped like a cube? Or maybe a fish shaped like a donut? I hardly think it is amazing that you can predict the shape of an animal from it's physics. But hey, maybe these guys don't get out much...
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
"Can't we do that already, as in... Oh look, the animal weighs 100 lbs and has two legs on the ground at any given point, so each leg has an average of 50 lbs of force on it?"
*Fixed*
Sorry.
http://www.TheGamerNation.com/Forums
It is the same thing, swimming through a liquid, just many orders of magnitude different in viscosity.
I'm pretty sure that my own running speed is within an order of magnitude of almost anything with legs, regardless of its mass. That leaves a lot of biological interest within these simple physical parameters.
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. How can such tripe make it to slashdot? I mean, theres always been a lot of drivel, but this thing, doesnt anybody notice...its gawdawful dumb?
Evolutionarily, one of the constraints on what features are successful is the physical ruleset. If the feature is to be successful, to some degree it must work reliably and efficiently within the rules of physics.
That said, we have discovered solutions for locomotion that take better advantage of physics principles than those developed by life. Rotary motion, almost entirely missing from biology, is the basis for some of our simplest and most efficient devices, such as the wheel and the screw. If such methods are better, why has no animal evolved them?
So my two ton exoskeleton will let me fly?
extremely interesting anyway mirror http://www.thebesttrek.net/forum/index.php?topic=3 31.0
http://www.thebesttrek.net/forum/index.php - visit my FORUM
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?
... if "physics" predicted a shape of an animal that doesn't exist, suggesting a style of locomotion we haven't seen before.
In Nature, as in many other things- Form follows function.
Fight psychopharmacological mccarthyism. http://www.norml.org/
the duckbilled platipus. I don't think physics could've put together that frankenstein of an animal, or quite describe it's shape/locomotion relationship.
Bejan finally realized the answer. Although fish are neutrally buoyant, they still have to push water out of the way to move forward, he said. So THAT'S what I've been doing wrong! Push water OUT of the way to move forward...thank you Bejan. Thank you. God this article was dumb.
This Unified Theory also applies to piston engines and sand flows.
To point you to a previous post i've made on this subject3 77094
http://slashdot.org/comments.pl?sid=172700&cid=14
For those to lazy to click, the important part is that Roland Piquepaille has been submitting articles since 2002 and people have probably been bitching about it since.
Y'all need to simmer down. AC's and registered users alike.
[Fuck Beta]
o0t!
...in this article is, "...with a given gravity and density of their tissues, the same basic patterns of their design would evolve again."
This is important because it would suggest that were humans ever to travel to an "Earth-like" planet, we would likely find life-forms that would appear quite familiar to us. We would not likely find "exotic" life-forms that were nothing like what we'd seen before.
Over-the-top Response Guy! Giving "Over-the-Top Responses" since 1970.
I was thinking the exact same thing.
How we know is more important than what we know.
"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.
"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."
Hey look everybody! Intelligent Physics!
I don't think that makes sense. What if the fish sat partly above the water like a ship does? Is it still lifting anything? Isn't it just regular friction that slows a fish?
How come there aren't three/five/seven limbed critters running around? (star fish don't count)
Is symmetry that important?
I wouldn't claim a monkey's tail or an elephant's nose is a fifth limb, even though they're very functional.
[Fuck Beta]
o0t!
For doing software simulations of walking creatures or robots, I've used the Yobotics Simulation Construction Set. It's reasonably easy to get started, given the complexity of physics simulations. Also, they have a free trial download, so it's great if, like me, you just want to play around.
Your design to a real part online: Big Blue Saw
I don't get it. First, these glorious physicists tell us the laws of physics dictate that a Bumble-Bee can't possibly fly, then they tell us there's an equation that shows us how fast he can go, and how far. (flying, at that.) Somebody let me know what I'm missing here.... I'm not Sherlock Holmes, ya know?
Some bacteria have a neat rotary motor. There's way more flagellated bacteria than humans on the earth, so I wouldn't classify it as "almost entirely missing".
Even better, sperm has a rotary joint. Just think, you could be holding a counterexample to the above post in 5-10 minutes (well, male Slashdotters anyway - female ones might have to drive a bit).
Science fiction writers! Yes, SF writers, never again hand me your alien in the form of a flaming flying football, or a man crayola'd green with spikes taped to his ears, or an 80-ton katydid. If you have one of those, it belongs in the *fantasy* section. In science fiction, I should be able to picture the whole chain of evolution for the species, and if it's sentient, I should be able to marvel at it's natural design and be able to appreciate how it must have become the dominant species on it's planet.
I'm curious what his equations would reveal about dinosaur locomotion. I've seen a lot of people claim that dinosaurs could never move under today's Earth gravity, or that pterodactyls could never fly. Wouldn't this guy's equations tell us not only whether or not they could, but how fast they'd likely travel and what they're walking, swimming, and flying capabilities might have been?
E pluribus unum
title says all
..........FULL STOP.
Comment removed based on user account deletion
the wheel and the screw. If such methods are better, why has no animal evolved them?
Because they aren't better: The real world has rocks on it.
You can't take the sky from me...
Bored. Noone calls. No sex.
Just being a geek.
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.
make world, not war
And here we go again: another rule of thumb and back of the envelope calculation that biologists used to perform anyway gets reified and turned into a fundamental theory.
This is, perhaps, is the most universal law of the 21st century: ideas that didn't use to count as sound scientific theories or engineering principles have become acceptable as such.
This is slashdot! you think people are gonna RTFA?
Speaking of animal motion, I just stumbled upon this antique book for sale from 1882. I remember learning about it a while ago from an animation class I had in art school. It's a fabulous book with loads of early photos and research into the motion of a horse. I believe it's a first edition as well.
Horse in Motion
that would be enough to assist a 5 oz. bird carrying a 1 lb. coconut to Mercia? ;-)
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});
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."
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.
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.
Much like humans "are" bananas, if the statistic I heard of 60% shared DNA is correct...
Finally, proof that you can learn kung fu moves by watching animals.
What is the airspeed velocity of an unladen swallow?
On a similar vein are all fish rear wheel drive?
I know on the land animal front most are, with exceptions such as the elephant (4-wheel drive) and the hyena (I believe has a strange and unique front wheel drive motion).
So giant ant overlords could only evolve on a planet with less gravity or intense pressures?
From what I've heard, the primary factor that keeps insects from growing much larger than they do here on earth, is the oxygen level. From what I remember, this is because the insects "breathe" through their skin, and as the insect increases in size, the interior grows too large to be sustained from the limited surface area.
Here I was re-reading my somewhat battered copy of "On Growth and Form" and this turns up ... sweet.
Bitter and proud of it.
The drag of a streamlined body underwater in deep water does not include a significant term that is a function of gravity.
If you really want to look into it start from the wave resistance equations invented by Michell, rediscovered by Havelock and solved by Castle.
So, does that mean the rest of the article is wrong?
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.
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.
...it's almost as if they were designed that way, by, oh, i dunno, the same creator.
How many ducks could a woodchuck fuck if a woodchuck could fuck ducks?
or a point! These are common assumptions for modeling.
Damn ! they are smart
I'm positive, don't belive me look at my karma
The hoop snake is very good at rolling.
Exam 4/C again. Maybe I'll do better this time.
Why not? NatGeo even talks about flying whales and hydrogen-filled floating plants...
As long as nobody grabs their antennae or tries to put one on a plate, we should be safe!
There's another sad tale of modern pollution. I looked it up, and hoop snakes are dying out. It seems that, due to pollution, the hoop snakes are no longer breeding like they once were. Apparently the females now roll counter-clockwise and the males still roll clockwise. This makes breeding difficult, as anyone can see.
I cried real tears when Li Mu Bai died.
the primary factor that keeps insects from growing much larger than they do here on earth, is the oxygen level
There are other factors, and one was actually discovered back in the Renaissance. That is, muscular strength increases with height squared, but body weight increases with height cubed.
Take a 1 cm ant which can lift 25 times its own weight (as is typical). If it magically grew to 10 cm long, it could only carry itself plus 1.5 other ants. (Compare how little ants carry around leaves bigger than they are, while large dung beetles can barely roll a ball of around their own weight) And if it expands to a full meter long, it could only lift 1/4 of it's weight, making it totally immobile.
...'Cause they're fast!