Today, we expect to be surprised. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
I love those lines from the
operetta Pinafore, where Gilbert and
Sullivan warn us that
Things are seldom what they seem,
Skim milk masquerades as cream;
Highlows pass as patent leathers;
Jackdaws strut in peacock's feathers.
And demographer Joel Cohen agrees. Our complex
world, Cohen says, is full of surprises. Example:
So much conflict in the world, and common sense
says that adversaries will resolve their
differences if they'll just sit down and talk. But
you've had the experience of entering a
conversation with an adversary, bathed in sweet
reason, and found yourself, half an hour later, in
a shouting match.
When we describe negotiation mathematically, we
have to include the rate at which negotiation
hardens the positions of the negotiators.
Whether opposing parties eventually agree, or
trigger a nuclear holocaust, depends on how fast
that hardening goes. Of course, that's why we have
professional counselors and arbitrators. That's why
we limit contact between leaders during summit
In another example, Cohen talks about engineers who
wonder if they might ease traffic congestion by
including crossroads between crowded highways. We
certainly expect crossroads to speed traffic by
increasing driver options.
But analysis fools us. It shows that such roads
often make matters worse by creating local traffic
jams. Cohen shows how adding redundancy to a design
can make it less safe. He shows that successful
paths of pursuit should often be indirect, and so
First we're intrigued by his arguments; then a
second realization kicks in: We would live in a
deadly-dull world if common sense alone could lead
us through all the thickets that surround us.
Any engineer or scientist is taught to think
abstractly. We study mathematics and complex
science. That's because it's the very nature of the
creative process to take us where we don't expect
to go. Abstract analysis is simply an aid to seeing
things that direct vision won't reveal.
Besides, if what we learn is what we expect to
learn, then we've learned nothing. Sooner or later,
every student of heat flow finds that adding
insulation to a small pipe can often increase the
heat loss from it. You don't get that from common
sense. By the same token, no one had ever put
liquid in tension until a nineteenth-century
scientist first showed that it was
theoretically possible to do such a
Some oddities are right under our noses all the
time, surprising us only when we look closely --
like the fact that no wind, not even a gale, can
ever blow a flag out straight. It'll always flap.
Common sense is that center of gravity to which we
return from our flights of fancy. But thank heaven
for the delicious surprise
-- the idea that precedes expectation. That's what
makes technology, science, and invention such a
delight to work in.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
J. E. Cohen, The Counterintuitive in Conflict and
Cooperation. American Scientist, Vol. 76,
No. 6, 1988, pp. 576-584.
To learn more about the small insulated pipe or the
flapping flag, see J. H. Lienhard IV and J. H.
Lienhard V, A Heat Transfer Textbook, 3rd
ed., at: http://web.mit.edu/lienhard/www/ahtt.html,
Chapters 2 and 9 respectively.
For more on water above its boiling point, see:
Shamsundar, N., and Lienhard, J.H., Equations of
State and Spinodal Lines -- A Review. Nuclear
Engineering and Design, Vol. 141, 1993, pp.
This is a greatly revised version of Episode 194.
From A Heat Transfer Textbook
The Engines of Our Ingenuity is
Copyright © 1988-2003 by John H.