Today, lotus petals and high-tech. The University
of Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
created them.
An article by Hans Christian
von Baeyer seems to be talking about lotus
blossoms, but he's really after different game
entirely. The lotus is only a contemplation object
that leads him to talk about non-technology,
halfway technology, and high
technology.
But, like von Baeyer, let us begin with the lotus.
The revered lotus grows in turgid stagnant waters,
in swamps. Yet its blossoms are dazzling white.
Buddhist monks were moved to write,
The white lotus, born in the water and grown in
the water,
rises beyond the water and remains unsoiled by the
water.
The lotus' pristine cleanliness is what makes it
such a powerful icon. So how does it stay so clean?
Scientists have turned scanning electron
microscopes on lotus petals and made an astounding
discovery. Their surface is covered with tiny
knobs, maybe a few ten thousandths of an inch wide
- too small to see and too small to keep the
surface from feeling slick to the touch.
To see what the knobs do, we look at the action of
surface tension. Surface tension allows a liquid
surface to bend, but not sharply enough to get in
and around those knobs. So droplets roll across the
tips of the knobs, without wetting the surface.
They simply skitter off, picking up dirt particles
as they go.
The lotus surface hints at means for creating
kitchenware and automobiles that don't get dirty.
Companies are already gearing up to sell new paints
and surface finishes. And that brings us back to
the no-tech, halfway-tech, hi-tech issue.
Consider polio: America's first polio epidemic
struck New York in 1916, killing nine thousand
people and debilitating twenty-seven thousand more.
For the next forty years polio was a constant
presence - the hovering threat in my childhood
years. At first, doctors could do no more than sit
with a victim and offer sympathy. The technology of
curing polio didn't get beyond some attempted
massage therapies.
By the 1930s, we'd created the iron lung for polio
victims with paralyzed diaphragms. Iron lungs were
huge cylinders that drew air into patients who were
placed inside them. They looked like the iron
maidens once used to torture heretics. That's what
we might call half-way-technology. Big,
complicated, and ugly - but only a stopgap, waiting
for the high-tech solution. That, of course, was
the Salk vaccine, which has practically eliminated
polio since 1955.
That drama plays out in car washing. A pail and a
rag come close to being a no-tech solution. We now
use the halfway-tech service-station car-wash
machine - big and complex, with whirling brushes
and water cycles. But the elegant lotus offers
high-tech: Car finishes, with arrays of microscopic
knobs, may well let mud and rain slide off without
dirtying the car in the first place.
So an ancient contemplation object offers us a new
way to think about mechanical design. For it is a
tortuous path that leads, at last, to delightful
simplicity.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
