Friday, December 2, 2005

Toucan Beaks

Most engineering that people are familiar with is accomplished by engineers with an understanding of the science underlying their discipline. They use that understanding to determine how to approach the problem they’re solving. Most of the time there are multiple possibilities — for example, there are many ways to build a 100 foot long bridge — and engineers use other factors (cost, aesthetics, experience, etc.) to choose amongst the possible approaches. This science-driven engineering is what we’re used to, but it is not empirical engineering. It is enabled by our accumulated scientific understanding, and by our human ability to apply that understanding to solve a problem.

However, science-driven engineering is not the only kind of engineering. Empirical engineering is accomplished by trying solutions over and over again, trying to improve the result each time. Empirical engineers don’t understand the whys and wherefores of what they’re doing; they just try things to see if they work — and when they do, they remember it, incorporate it in their design, and move on to the next empirical engineering optimization.

A few years ago, I read of a very good example of empirical engineering by humans: the Roman’s development of catapults, trebuchets, and the like (weapons that hurl large weights). The Romans who designed these machines had zero understanding of the science underlying the mechanics and physics of what they were building — and yet, over time, the machines they designed evolved into designs that a modern engineer (similarly restricted in choice of materials) would be proud of. The really interesting part of this example is that there is quite a good history of the Roman weapons' development over time — so archaeologists have been able to recreate an approximate history of their empirical engineering.

A few lines ago, I used a phrase ("and yet, over time, the machines they designed evolved into designs that a modern engineer would be proud of") that ought to give you a little mental nudge — because that phrase describes the process of biological evolution quite nicely. Biological evolution is the ultimate in empirical engineering. Here’s a great example of that:

From UCSD’s Jacobs School of Engineering:

In a paper to be published Dec. 1 in Acta Materialia, Meyers and graduate students Yasuaki Seki and Matthew S. Schneider reported that the secret to the toucan beak’s lightweight strength is an unusual bio-composite. The interior of the beak is rigid “foam” made of bony fibers and drum-like membranes sandwiched between outer layers of keratin, the protein that makes up fingernails, hair, and horn. Just as the hook-shaped barbs on cockleburs inspired the development of Velcro, Meyers said the avian bio-composite could inspire the design of ultra-light aircraft and vehicle components with synthetic foams made with metals and polymers.

"The big surprise was our finding that the beak’s sandwich structure also behaves as a high energy impact-absorption system,” said Meyers. “Panels that mimic toucan beaks may offer better protection to motorists involved in crashes."

Read the whole thing!

Creationists (using the term very loosely) have trouble imagining that something like the toucan’s beak could develop through evolution. After debating many of these folks, I think there are two things (other than pure blind faith) that drive the trouble they have: one is their incomprehension of the amount of time available for evolution to have occurred, and the other is their incomprehension of empirical engineering. I’m not at all sure how to solve these problems <smile>, but I have had some success in debating creationists by raising the topics. There are abundant examples of empirical engineering all around us, so simple and obvious that absolutely anyone could understand them (I’ve used the example of the Roman’s weapons many times; their bridge-building is equally good). The concept of the passage of millions or even billions of years is more challenging to communicate — especially if the person you’re debating is of the fundamentalist persuasion and is convinced that the Earth is only a few thousand years old…

A tip of the hat to GrrlScientist at “Living the Scientific Life” for the pointer to the article in her most recent Birds in the News post. If you’re at all interested in birds, and you’re not familar with her blog, check it out — she does a wonderful job of presenting all kinds of news about birds…

No comments:

Post a Comment