Today, we attend the wedding of science and
technology. 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.
The early 17th-century
philosopher Francis Bacon
codified a radical change in our thinking. He wrote
this in 1620:
The empire of man over things is founded on the
sciences ... for nature is only to be commanded
by obeying her.
On one level that statement is troublesome. Nature
is female. We humans are male. Nature may be mother
but she is there for her male heirs to command. The
early Greeks put it differently: "Mastered by
Nature, we o'ercome by Art." Art was, for the
Greeks, any use of technique. It included all of
technology.
By 1620 we'd readopted many of the old Hellenic
ideals. Male dominance was only one of those.
Another was the Aristotelian idea that by observing
Nature we can control it.
Scientists and the people who built things lived in
different worlds in 1620. The modern engineer could
come into existence only after the people who made
things had joined forces with the scientists. That
happened for the first time in the West just after
Bacon told us that "Nature is only to be commanded
by obeying her," and it happened because people
wanted to improve clock accuracies.
A mechanical clock depends on a mechanism called an
escapement that moves back and forth in a steady
rhythm. Most escapements were masses on the ends of
a crossbar that rhythmically rotated back and forth
on a shaft. But another kind of oscillation had a
remarkable steadiness that could serve timekeeping:
In 1583 a young student at Pisa watched a swinging
lamp in the Cathedral there. He was struck by its
steadiness. The student was Galileo, and five years
later he began his studies of pendulums -- studies
which eventually showed that the period of
oscillation of a gently swinging pendulum was
always the same, whatever the amplitude of its
swing. In 1602 he suggested using that steady
motion of a pendulum to check the pulse of a
patient.
By 1641 Galileo, now aging and blind, realized the
pendulum would make an ideal escapement device
because its pace stays steady while it runs down.
He described the idea to his son Vincenzio, who
made a working drawing of a pendulum clock. A
machine was born of pure theory. The Dutch and
English scientists Christian Huygens and Robert
Hooke followed Galileo's idea, both with improved
theories of the pendulum and with working clock
designs.
None of this sounds impressive to our 20th-century
ears. That's how things are supposed to work. Yet
it was the first instance I can point to where a
scientific principle preceded a technology. Ever
since then, we've listened to Bacon's assertion.
We engineers today are trained to the teeth in
science because we expect to have to submit to
Nature before we deal with the physical world.
Indeed, we have trouble seeing how radical this
350-year-old story really is, just because we've
never imagined things working any other way.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
Usher, A. P., A History of Mechanical
Inventions. Cambridge: Harvard University Press,
1970, Chapter XII.
Wolf, A., A History of Science, Technology, and
Philosophy in the 16th and 17th Centuries.
London: George Allen & Unwin, Ltd, 1950.
For more on Galileo and the pendulum, see the
following website:
http://es.rice.edu/ES/humsoc/Galileo/Things/pendulum.html
This is a substantially revised version of Episode 5.
Drawing by John Lienhard
A Pendulum Escapement Mechanism
From the 1832 Edinburgh
Encyclopaedia
Detail of the "Anchor Escapement"
From the 1832 Edinburgh
Encyclopaedia
Huygens's Pendulum Clock
The Engines of Our Ingenuity is
Copyright © 1988-1998 by John H.
Lienhard.
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