Cats鈥� Paws and Catapults by Steven Vogel, W.W. Norton, $27.50, ISBN
0393046419 (March 1999 in Britain)
WE have all, even the scientists among us, been artists at some time. We all
drew and painted as children, and probably had to do Art at school. One of the
earliest lessons we learnt was that things made by people are much easier to
draw than the people who make them. A chair and a teacher have the same
superficial complexity, but somehow in our drawings the chair looked like a
chair while the teacher resembled a sadly mutated gorilla. It may have been
psychologically accurate, but we knew it wasn鈥檛 up to the standards we set
ourselves.
Part of the problem, besides our sensitivity to the human form, is that there
are two completely independent technologies at work. The human way of making
things produces hard-edged shapes that are easy to draw; nature鈥檚 way creates a
subtle squidginess that leaves you wondering where to put your pencil. This
problem does not afflict the 100 or so line drawings in Steven Vogel鈥檚
fact-packed, wittily written book.
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A biologist who specialises in biomechanics, Vogel offers a mind-expanding
compendium of comparisons between two very different ways of turning the
materials of our planet into the gadgetry of survival.
Neither way is superior, he believes: they鈥檙e just different, and largely
incompatible, based on irrevocable decisions made a long way back. So although
we can often learn from nature, it鈥檚 not an infallible method of improving our
technology.
Vogel uses technology freely as a convenient metaphor for nature鈥檚 way of
doing things. He sometimes even refers to 鈥渘atural designs鈥�. But don鈥檛 be
fooled: his whole thrust is towards a critical, not reverential, assessment of
nature as a designer, and towards debunking the myth that countless good designs
have resulted from engineers imitating nature. It鈥檚 simply easier, at first, to
see the differences and similarities between human activities and natural
processes if you use the same words for both.
The comparison is certainly worth making. Although all the world鈥檚 creatures,
including us, have to put up with the same gravity, temperatures and materials,
humans tend to solve the problems of living in fundamentally different ways.
Nature is curvy; we prefer to go straight. Nature is wet; we like to be dry.
Nature moves things around by diffusion and smooth flows; we go for gravity and
turbulence. We like stiff materials; nature favours flexible strength and
toughness. We are addicted to structural metals; nature never uses them. Nature
pulls when we push, speeds up when we slow down. You get the picture: nature鈥檚
way, the way of the blindly self-taught, more often turns our technology on its
head than anticipates or inspires it.
Vogel doesn鈥檛 stoop to the sixth-form debating point that everything is
natural really, that humans are just nature鈥檚 way of producing a Mercedes. The
fact is that we鈥檙e looking at two distinct technologies that have little in
common. Each is self-sufficient, even at times magnificent, but it鈥檚 harder than
you鈥檇 think for us to pinch good ideas from natural systems.
It鈥檚 sometimes difficult to believe that human and natural technologies
belong on the same planet. There are natural designs so odd that biomechanics
can鈥檛 explain them, like the long, skinny but serviceable appendages of the
crane fly (known to British kids as 鈥渄addy-longlegs鈥�). There are natural
mechanisms that you might not want to imitate, such as the strutless but
unpredictable stiffening of the penis. And, although the flight of birds
undoubtedly inspired the Wright brothers, modern humans鈥� flying machines knock
spots off anything feathery when it comes to speed and efficiency.
Nature has got a few tricks we鈥檇 love to get a handle on, though. Insects
reinforce their wings with amounts of material a human engineer would consider
dangerously frugal. Muscle is wonderfully versatile, capable of finely graded
movement and available in sizes from gnat鈥檚 wing to elephant鈥檚 thigh; although
it only knows how to pull, it would be just the thing for robots if we could
find a way of making it. Fish move through the oceans with almost no resistance;
we now know how they do it, but haven鈥檛 yet produced a submarine which people
will travel in without being paid to. I could go on鈥攂ut I鈥檇 be risking the
selective adulation of nature that makes Vogel cringe. Loving nature, he says,
is not the same thing as finding her perfect. That鈥檚 what his head says, but I
couldn鈥檛 help noticing an uncontrollable admiration of nature鈥檚 weird ways
sneaking in from time to time.
And why not? A biologist who wasn鈥檛 deeply impressed by what he studied would
probably not be as good as Vogel. He鈥檚 great at using the contrast provided
by human technology to clarify the detail of natural mechanisms. But he鈥檚
careful to point out the dangers of trying to make a single terminology describe
processes that are fundamentally different.
Natural structures like bone or tendon are built up by tiny machines that are
dwarfed by what they produce, in processes that depend on exquisite feedback to
keep everything lined up under constantly changing conditions. Human products
such as cars or toasters tend to emerge from factories much bigger than these
objects, and are assembled from rigid components guaranteed to fit together come
what may.
So using an engineering term like 鈥渂lueprint鈥� to describe DNA, for instance,
is deeply misleading. A blueprint is a fixed, explicit set of instructions,
while DNA is more like a recipe, leaving a lot for the cook to interpret as
circumstances dictate. Likewise, using a biological word, 鈥渟election鈥�, in the
context of human technology can mislead you into thinking that engineering
products evolve by some blind process driven by market forces or whatever.
Given this awareness, Vogel鈥檚 constant reference to nature鈥檚 way of making
things as 鈥渢echnology鈥�, which implies a conscious purpose and knowledge that
nature doesn鈥檛 have, is perhaps a little strange. But his apparent misuse of
language is a bold and successful rhetorical device. As an engineer, I felt that
Vogel鈥檚 incisive comparisons gave me a real understanding of nature, buffeted
and constrained as it is by the same forces that trouble and determine our own
efforts. A more literal-minded approach would not have worked so well. I fancy
that those who know more about biology than engineering may well experience the
same effect in reverse.
And for those who know little of either, Vogel has provided a wonderful
opportunity to learn about the universal realities of adhesion and aerodynamics,
blimps and bones, stresses and strains, trees and transmissions, that make our
world and nature鈥檚 so different and yet so much the same. He doesn鈥檛 explain how
to draw lifelike people, but lays out a rich treasury of clues as to why it is
so difficult.