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

Rating:
Summary: a book you must read
Review: A wonderful book. Steven Vogel has the skill to to grasp attention of the reader and to mantain it over the whole book. And he can explain the way many very complex mechanical items work or many phisical law in a very clear way and with great rigour.Really, a wonderful book everyone must read.

Rating:
Summary: Interesting.
Review: This book contains numerous examples of design, from an engineering perspective. The theme is on comparing the design of evolution with that of technological invention. Although the book is almost precisely 50% natural and 50% artificial, you get the impression that the author is slightly biased in favour of technology. He acknowledges they are different: nature abhors using straight lines, engineers love them; nature has not been able to employ metals, yet they are commonly used in our constructions.

I for one would never be critical (as this guy sometimes is) of nature by saying that it never utilises metals or whatever. It doesn't need to - it isn't required. To favour an I-beam over a tree limb is foolish and misguided. Is a piece of metal or lump of concrete alive? Certainly not. The astonishing feature of nature is that it manages to evolve these things, that are inherently living entities, which can grow and replicate themselves with no awareness or foresight!
So the trouble with this book is that it doesn't address the fact that a tree does way more than just support itself: a tree is not just a vertical structure; it is an extremely complex photosynthesis machine. It is self-powered AND self-generating. It would take a tremendous amount of technology to create a very minuscule and seemingly simple creature such as an amoeba, let alone an extremely complex multicellular organism such as a hummingbird - currently, it is totally impossible. Yet nature does it for free and that is some accomplishment.

There are many obvious observations in the book, and in places it can be a little dull. I really don't think there are many people who will thoroughly enjoy this book. Either you'll be the type of person who prefers natural evolution, or you'll prefer technological invention, and so either way half of the book will not be very appealing.

A similar book is called "Diatoms to Dinosaurs". I think that book is a much more interesting read - it is predominantly concerned with nature, not with technology, and some of the examples are just so much more alluring/enticing/intriguing.

Rating:
Summary: A captivating look at the natural and the synthetic
Review: 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.