Cats' Paws and Catapults: Mechanical Worlds of Nature and People

by Steven Vogel, Kathryn K. Davis (Illustrator)

Overview

"Full of ideas and well-explained principles that will bring new understanding of everyday things to both scientists and non-scientists alike."—R. McNeill Alexander, Nature

Nature and humans build their devices with the same earthly materials and use them in the same air and water, pulled by the same gravity. Why, then, do their designs diverge so sharply? Humans, for instance, love right angles, while nature's angles are rarely right and usually rounded. Our technology goes around on wheels—and on rotating pulleys, gears, shafts, and cams—yet in nature only the tiny propellers of bacteria spin as true wheels. Our hinges turn because hard parts slide around each other, whereas nature's hinges (a rabbit's ear, for example) more often swing by bending flexible materials. In this marvelously surprising, witty book, Steven Vogel compares these two mechanical worlds, introduces the reader to his field of biomechanics, and explains how the nexus of physical law, size, and convenience of construction determine the designs of both people and nature. "This elegant comparison of human and biological technology will forever change the way you look at each."—Michael LaBarbera, American Scientist

Product Details

ISBN-13:	9780393352955
Publisher:	Norton, W. W. & Company, Inc.
Publication date:	11/09/2015
Sold by:	Barnes & Noble
Format:	eBook
Pages:	384
Lexile:	1210L (what's this?)
File size:	8 MB

About the Author

Steven Vogel (1940—2015) was James B. Duke Professor of Biology at Duke University. He was a prolific author of popular works on the intersection of physics and biology such as Cats' Paws and Catapults and Prime Mover: A Natural History of Muscle.

Table of Contents

	Preface	9
1.	Noncoincident Worlds	15
2.	Two Schools of Design	20
3.	The Matter of Magnitude	39
4.	Surfaces, Angles, and Corners	57
5.	The Stiff and the Soft	82
6.	Two Routes to Rigidity	106
7.	Pulling versus Pushing	128
8.	Engines for the Mechanical Worlds	153
9.	Putting Engines to Work	177
10.	About Pumps, Jets, and Ships	205
11.	Making Widgets	229
12.	Copying, in Retrospect	249
13.	Copying, Present and Prospective	276
14.	Contrasts, Convergences, and Consequences	289
	Notes	313
	References	343
	Index	363

Editorial Reviews

Nature often comes up with simpler solutions to engineering problems than do human engineers. Does that mean that nature's technology is superior? Arguing that nature can be improved upon, Vogel's comparison of biological and human-made technologies shows how and why.

Library Journal

...Perfect for the lay reader, the undergraduate and any scientist with a sense of humor. -- M. R. Montgomery, New York Times Book Review

M.R. R. Montgomery

Has human engineering improved on nature? A biologist answers the question. Biomechanics is the discipline that explores natureþs answers to what are essentially engineering problems. Vogel (Biology/Duke Univ.; Vital Circuits, 1992) doesnþt share the widespread assumption that human engineering is doomed to crank out clumsy imitations of what nature perfected eons before our race first chipped a stone into a cutting edge. For nature, sometimes to its disadvantage, must play by the rules of evolution, via natural selection; it is also restrained by geometrical and physical constants relating to growth and change, and it enjoys far less flexibility than do most human designersþnature cannot easily "go back to the drawing board" when an existing structure won't serve its purposes. Humanity is better at making things big, while nature excels in compactness: No bird can match a jetliner for size, but 10,000 viruses could fit along the length of our tiniest machine. Vogel explains basic principles of engineering science, giving examples both from the familiar human world and from biological entities. The problems discussed include the ways a structure (a skeleton, a bridge, a tower, a wing) can be designed to resist various stresses; ways of generating power (steam engines, wind, and water mills); and ways of building up large structures from small (bricks, cells). Certain overarching verities emerge from this investigation: our preference for the right angle, where nature uses curves; our heavy dependence on the wheel, which is almost completely unknown in nature; and our favoring of sliding surfaces (metal hinges) over bending ones (sinew, muscle). Vogel isgenerally convinced that our technology surpasses nature's evolutionary trial and error, but the reader is likely to emerge with greater respect for both. His well-written overview eyes the larger questions implicit in the subject.

Kirkus Reviews

"A book that should be enjoyed and understood by intelligent non-scientists as much as by scientists ... entertaining and illuminating."

"Fascinating.... [Vogel's] interests seemingly know no bounds, and he takes the readers along with him on a complex, absorbing journey of exploration notable for its unexpected twists and turns."

"Vogel's latest success informs and delights."

From the Publisher