Today, we look at heat transfer and product
innovation. 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.
George Wise talks about
three ways innovation takes place in industry. The
most obvious way is a response to a need. We've
seen again and again in this series that things are
seldom that straightforward. The second way is more
common. That's when innovation is driven by some
revolutionary discovery. The transistor, for
example, triggered all sorts of new technology. But
Wise is most interested in a third pattern. He
calls it the product-driven innovation cycle.
An engineer works to improve an existing product.
It needn't be anything fancy. Then he suddenly sees
it in a new light. A radically different concept
suddenly pops out of it. A butterfly is born of a
caterpillar. Wise tells us that that sort of thing
is far more common than we might think; and he
gives several illustrations which all involve heat
transfer. Here's one:
In 1908, General Electric hired a young man -- an
American with a German Ph.D. in applied chemistry.
His name was Irving Langmuir. His thesis had dealt
with the way air carried heat away from small
wires. He seemed to be just the person to work on
heating elements.
Langmuir went to work on the G.E. line of stoves,
flatirons, and other heaters. He used what he knew
to improve their heating elements. Now G.E. had
another product that also used heated wires -- that
was the light bulb. G.E.'s bulbs were all evacuated
to keep the filament from burning. Low-wattage
bulbs did well enough at the time. But the tungsten
wires in brighter bulbs began to evaporate.
Tungsten vapor was gradually deposited on the
inside of the bulbs. It eventually turned them
black.
Then Langmuir realized that evaporation would be
suppressed if the light bulb were be filled with a
gas -- an inert gas, that wouldn't burn the
filament. The trouble was that gas circulating in a
light bulb removed too much heat -- the bulb
wouldn't stay bright. But he knew from his research
that a lot less heat would be shed if the filament
were wound in a tight coil. By knowing about heat
removal, Langmuir gave us the bright argon-filled
bulbs we use today. And all because he was put to
work on stoves and irons.
Wise traces other connections -- how refrigerators
led to turbo-superchargers and how steam-turbines
led to air conditioners. Of course he's pointing
out a process common to invention. A good engineer
makes one thing turn into another. He lets
innovation be driven by whatever's in front of him.
And Langmuir had the vision to do this. In 1932, by
the way, he won the Nobel Prize for his work on the
surface chemistry of metals.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
