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and —in an astounding leap into modernity— they built a wind tunnel to
test their theories. As a result, the Wright brothers developed better
mathematical and physical models of airplane wings. Lesson 2 from their
experience, then, is that models can help in unde rstanding the behavior of
complex systems, but they need to be both tested and improved.
After the Wright brothers had solved the lift problem, their glider
experienced continued difficulties with stability and control. Thus, lesson 3
regards stability and control, problems with which the Wrights stru ggled
for four years. Stability and control are general problems for moving sys-
tems, and your motor system is no exception. Temporarily stymied, Wil-
bur Wright returned to an examination of bird flight. That is, in a tight
spot he resorted to reverse engineering. Wright noticed that bird wings
warp during flight and, fiddling around with a flexible box, he saw how
wing surfaces could warp in a similar way. Through such observations,
the Wright brothers developed wing-warping controls to promote aircraft
stability. Lesson 4: Combining reverse and forward engineering seems like
a good idea.
After that breakthrough, the Wrights’ glider no longer behaved
erratically. Stability had been achieved, but problems remained with con-
trol. When, as pilots, the Wright brothers made maneuvers that should
have turned the glider to the left, it often slid to the right instead. The
addition of vertical tail fins alleviated that problem but generated new
problems w ith stability. A t that p oint, the Wright brothers must have
begun to wonder whethe r stability and control were mutually exclusive. It
is tempting in such situations to break down a complex system into its
components and, by better understanding how each part works, hope to
comprehend the overall system. This approach, called reductionism, has
its place in understanding complex systems. However, the Wrights’ big-
gest breakthrough came from enlarging the problem, not from reducing it.
They recognized that it made no sense to study turning left or right in
isolation from rolling the plane along its long axis; they saw that airplanes
turn by rolli ng. If you want to turn an airplane to the right, you roll it
so that its right wing rotates downward. This clockwise roll changes the
direction of lift to the right, and the plane moves in that direction. Lesson
5, then, is that complex systems can be understood only at the systems
level; reductionist methods help, but only in a limited way.
And the Rest Is History
In late 1903, Orville Wright took off on the first powered flight. He flew
about 35 m, moving at less than 10 km/hour. The era of aeronautics had
begun. (The era of really small seats and screaming infants followed
shortly thereafter.) It is difficult in hindsight to appreciate the magnitude
of the Wright brothers’ breakthrough, but a few facts might help: Just 5
years later, Wilbu r Wright flew his plane for 2 hours; 8 years later, a pilot
flew across North America; 24 years after the first flight, a pil ot flew
an airplane from New York to Paris; and just 65 years after the Wright
xvi Preface