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

This is a great book. Not great in the sense of changing the world as Newton, Darwin, and Freud did, but great in the sense of well done. It is informative and entertaining at the same time. Most of the book is a "compare and contrast" man made things and things in nature. A small part is devoted to debunking the belief that whatever nature does is the best way to do it. Vogel explains why airplanes do not have flapping wings. The laws of physics apply in both worlds. Bones and I beams break under sufficient loads. The chapter titled "The Matter of Magnitude" is important throughout the book. Things do not scale up. An elephant's legs are not as slender as a deer's. Almost all of a small animal's mass is close to the surface, so it is easy to disapate heat from a hard working muscle. A large animal would cook itself without additional means of cooling. There are chapters about shapes, surfaces, angles, rigidity, tension and compression, pulling versus pushing, engines, transmissions, pumps, jets, manufacturing, and copying. You do not have to be a mechanical engineer or have a great interest in biology to enjoy this book. I think most readers with a variety of interests will enjoy it and learn a lot from it. Even language fans will enjoy it. There is a pleasant phrase on almost every page, an expression that will make you think "I wish I had said that."

For anyone who has wondered about the design of nature and compared it to the design of man, where are the similitudes and the sticking differences.. why?. This is a superb book that should make engineers have a deeper insight of the restrictions imposed by the enviroment, but also to see how nature's forms follow funtion

This book proved to be unexpectedly fascinating. It presented a wide-ranging comparison of human technology with the way nature gets things done. Several great questions were asked: e.g. why do humans use metals so much, but not nature? Examples cover a huge range of nature. His coverage is authoritative, well-documented and balanced. It was very refreshing to read a nature book with such a different perspective.

What a pleasurable and stimulating book! Vogel is one of those rare authors who can communicate the essence of a complex technical field without either dumbing it down or making it so complex as to be unapproachable to the lay reader. "Cat's Paws and Catapults" is just full of elegant, clear text and beautiful pen-and-ink illustrations that make the difficult clear. Vogel begins by comparing nature's solutions to problems of structure, propulsion and so forth with the creations of man, illustrating the differences and the similarities in how the two evolve. He differs with those philosophers who have argued that within nature might be found the ideal solutions to the problems of engineering and design, and gives convincing examples to support his case. He works though issues in structure, transport, proplsion and so on showing the differnt ways in which nature and man arrive at solutions, and argues why each may or may not be optimal.One chapter is devoted to the question of scale, and how it influences design. For example, the houses built by humans are, despite all their nails and other fasteners, mainly held together by gravity. Things like nails and mortar serve mainly to keep bits from sliding off each other. That's not possible when building something the size of a bacterium; at that scale, gravity is essentially negligible. Scale is similarly important in building a flying machine. Aircraft and insects fly in very different environments. Airplanes must fly fast to overcome gravity, whereas insects fly slowly, in an environment where drag is the main force to be overcome.And that's just one small section. There are chapters on surfaces and angles, on soft versus hard, on pulling versus pushing, on the problem of making copies and many other topics as well.As I read "Cat's Paws" I found myself making a tremendous number of penciled notes in the margin, arguing with some points and agreeing with others. It's not that there was that much I disagreed with, but rather that the book engaged me to the point that I felt I was in a dialogue with the author. It's that good.If you're the kind of person who can't resist taking something apart to see what makes it work, buy this book. If you're fascinated by the workings of the natural world, buy this book. If you're just looking for a really good example of non-fiction writing in the best traditions of John McPhee, Tracy Kidder or Jeremy Bernstein, buy this book. You will not be disappointed.

"This wonderful, insightful book will excite your curiosity and change the way you view the living world. Professor Steven Vogel, world authority on motion in fluids, takes the reader on a tour of discovery, comparing human inventions with the ingenuity of Nature. Beautifully and clearly written, this important new book brings biology and technology together for a wider readership. I really love this book and could not put it down." .... Christopher McGowan, paleontologist, author of "Dinosaurs, Spitfires, and Sea Dragons." ........ "Who is the better technologist, Mother Nature - source of seashells, spider webs, and birds' wings - or the human engineer - creator of skyscrapers, nylon, and airplanes. This engrossing question lies at the heart of a fine new book by Steven Vogel, an expert in biomechanics with a flair for genial philosophizing." ........ Samuel Florman, engineer, author of "The Existential Pleasures of Engineering."