News Release

'Cats' Paws And Catapults' Offers Enlightening Tour Of Natural, Human Technology

Book Announcement

Duke University

DURHAM, N.C. -- Duke biologist Steven Vogel has just returned from an odyssey into two very different realms -- the rigid, right-angled, dry world of human technology constructed in big factories; and the pliable, curvy, often wet world of natural technology built from tiny cells.

Like any good explorer, Vogel has brought back insights into the two realms that he hopes will inspire layman and engineer alike to think about the physical world in a different and creative way.

In his new book Cats' Paws and Catapults: Mechanical Worlds of Nature and People (Norton, 1998), Vogel reports his intriguing analytical excursions into devices as varied as barbed wire, snail shells, road signs, water lilies and Velcro. The book has already been praised by reviewers, with Nature calling it "written to be enjoyed, with the same clarity as his previous books.

"It is full of ideas and well-explained principles that will bring new understanding of everyday things both to non-scientists and scientists alike."

While Vogel dissects in his book a multitude of fascinating gadgets invented by nature and humans, his major aim is to use each technology to better understand the other.

"It occurred to me that I was studying the only other technology that we have any practical chance of studying," he said in an interview. "We don't have extraterrestrial civilizations around the corner, and what humans build is pretty uniform. A new building in Beijing looks like a new building in New York. We have only one other technology on Earth, and that's nature's."

Doing such a comparative analysis is revelatory, Vogel said. "It gives you the chance to get a little distance on what we humans do, to get another frame of reference. By seeing that there are other ways of doing things, it forces us to ask why we build things the way we do.

"For example, why are we so addicted to right angles -- the edge of every page of a book, the corner of darn near every room, the corners of every brick, every block? By contrast, nature uses very few right angles."

From his vantage point, Vogel developed a new attitude toward both technologies.

"The analysis got more and more interesting after I got out of the mode of thinking one technology was ?good' and another ?bad', or one superior and other inferior. I recognized that each was an integrated harmonious whole, with each arising with an internal coherence from its environment." Such an approach is liberating, said Vogel, for example, allowing a clearer-eyed appreciation of human's technological achievements.

"I think we've been subjected to too much nature worship, in the sense of nature defining the good, the pure, the true. It's worthwhile to go beyond those connotations and recognize that we do things our way for reasons that make enormous sense for us.

"Nature isn't the gold standard, and there are much more interesting reasons to explore natural technology than simply using it as a hammer with which to hit the engineers and to contend that all that's wrong with human society arises from our technology."

Abandoning such a judgmental mode enhances creativity, Vogel said, "because once you see there's a second way of building something, you wonder if there might even be a third way."

He said exploring the two technologies yields a host of surprises. For example, he cites the widespread myth that many human technologies were copied from nature. True, barbed wire was modeled after thorn bushes, and chain-saw teeth after the mandibles of wood-boring beetles, but such instances are far scarcer than most people believe.

"There's a second possibility, the chance that similarities reflect the fact that the same basic physical rules are operative, and the same kind of solutions works -- as in snake's fangs and hypodermic needles.

"I don't think hypodermic needles were copied from rattlesnake fangs, or as another example, suction cups from octopus suckers. It's more likely that since both technologies are in the same physical world, the same kind of devices work for either." Yet a third, and even more surprising possibility, Vogel said, is that humans may use the same device as nature, but do so for a different reason.

"The cone-shape is the best case I know," he said. "We like cones because they nest, so you can ship them efficiently. You can put one into the other, the way you stack paper cones or ice cream cones. And plumbing parts are conical because they make a tight nesting fit.

"But nature makes cones such as limpet shells because they are one of the few shapes that can grow by edge addition, incrementally, without changing shape. We don't grow things, and so that doesn't matter to us."

Vogel believes such comparative insights will become more and more useful as human technology moves into the micro-engineering realm, and takes advantage of the potential of flexible bending, as do natural structures from trees to human joints.

"Human technology has traditionally been built around stiff, rigid objects of metal, of dry wood, of stone," he said. "Now we're building more out of flexible plastic, like file boxes that instead of having sliding hinges have bending hinges of plastic. I wouldn't be surprised to see more objects evolve toward more natural-looking forms, not because we're directly copying, but because if you're working with flexible materials, these may turn out to be rather better designs."

Perhaps, Vogel said, such new ways of thinking may end up changing not only our technology, but ourselves. Someday, he muses, we so-called modern humans may become as flexible in our own thinking as traditional Zulu already are:

"In chasing up material for the book, I discovered that people who don't grow up in rectangular houses are resistant to certain visual illusions that fool us. For example, if we build something that looks like a window, but make it trapezoidal instead of rectangular, we interpret it as a window viewed on an angle. But the Zulu who grows up in a native village where all the huts are round is not fooled the way we are, and usually sees the trapezoid for what it really is."

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