A few days ago we noticed an interesting article at the PhyOrg website, but we decided that it wasn’t relevant to the usual subject matter of this blog: Uncovering Da Vinci’s rule of the trees. But as you’ll soon see, it’s relevant now. Here are a few brief excerpts, with bold added by us:
Da Vinci wrote in his notebook that “all the branches of a tree at every stage of its height when put together are equal in thickness to the trunk.” In other words, if a tree’s branches were folded upward and squeezed together, the tree would look like one big trunk with the same thickness from top to bottom.
To investigate why this rule may exist, physicist Christophe Eloy, from the University of Provence in France, designed trees with intricate branching patterns on a computer.
Eloy found that the proportions in his model trees stayed the same regardless of wind speed or the height of the branches, as the rule would predict. His work has been accepted for publication by the journal Physical Review Letters.
Explanations for the rule generally fall into two categories — hydrological and structural. Hydrological theories suggest trees have their characteristic shape because it’s conducive to efficiently transporting sap, while structural explanations focus on trees’ ability to withstand stresses. With his new research, Eloy has bolstered the structural theory.
Here’s Christophe Eloy’s paper, but all you can see without paying is the abstract: Leonardo’s Rule, Self-Similarity, and Wind-Induced Stresses in Trees.
Now the tale gets complicated. Probably because da Vinci’s name was involved, the research found its way into the media. NPR wrote a piece about it: The Wisdom Of Trees (Leonardo Da Vinci Knew It). “Wisdom”? Well, it’s journalism. Here are a few excerpts:
[A] French scientist has come up with an explanation for the resilience of trees. And astonishingly, the answer was first described by Leonardo da Vinci 500 years ago. Leonardo noticed that when trees branch, smaller branches have a precise, mathematical relationship to the branch from which they sprang. Many people have verified Leonardo’s rule, as it’s known, but no one had a good explanation for it.
Leonardo’s rule is fairly simple, but stating it mathematically is a bit, well, complicated. Eloy did his best:
“When a mother branch branches in two daughter branches, the diameters are such that the surface areas of the two daughter branches, when they sum up, is equal to the area of the mother branch.”
Translation: The surface areas of the two daughter branches add up to the surface area of the mother branch.
But then the NPR article starts to get fanciful:
From an engineering point of view, if you wanted to design a tree that was best able to withstand high winds, it would branch according to Leonardo’s rule. Apparently, trees have figured out the sophisticated engineering principles all on their own.
Ooops! Prose like that might come to the attention of a creationist. NPR continues:
Of course, engineers have known for a long time that they have to think about wind when they’re building things. “The most famous example for a man-made structure that was built with wind load considerations in mind is the Eiffel Tower,” says Pedro Reis, a professor of engineering at the Massachusetts Institute of Technology. Reis says the Eiffel Tower’s shape was based not just on aesthetics but on those design principles trees know all about.
Right, the trees “know” design principles. Okay. So far we’ve gone from Physical Review Letters to PhysOrg to NPR’s romantic treatment of the topic. From there the story sinks to the very bottom — it has become the subject of an article by David Klinghoffer in the blog of the neo-theocrats at the Discovery Institute‘s creationist public relations and lobbying operation, the Center for Science and Culture (a/k/a the Discoveroids, a/k/a the cdesign proponentsists).
Klinghoffer’s article is Eiffel’s Tower and the Lesson from the Trees. Here are some excerpts, with bold font added by us:
The Eiffel Tower was in the news last week, if tangentially, when NPR noted a curious fact about the inspiration the lies behind its design. Eiffel himself drew on a biomimetic theory going back now 500 years to Leonardo da Vinci. Biomimetics, as Casey has pointed out here on more than one occasion, is the approach to human technology and engineering that looks to models in nature for superior structures even as, by a rigid convention and in defiance of all intuition, nature’s brilliance is always attributed to unplanned and unenvisioned causation — evolution — rather than to intelligent design.
Aaaargh!! He quotes Casey as an authority and suggests that “nature’s brilliance” couldn’t possibly be the result of evolution — it must be due to intelligent design. Let’s read on:
No one sensible would say that the striking fruitfulness of this approach “proves” ID but it is, well, striking. Why pretend that that’s not so?
Aaaargh!! Klinghoffer continues:
Don’t miss this wonderful irony: In engineering his now iconic monument, built to celebrate a revolution that sought to displace any idea of a designing being behind nature or anything else, Eiffel looked to Leonardo who looked to the trees.
We can’t go on; we just can’t. The only reason we’re writing about this mess is to show the progression — or rather, the degeneration — of information as it moves from science journals to the popular media, until it finally descends into the cesspool of creationism.
Copyright © 2012. The Sensuous Curmudgeon. All rights reserved.