Today, let's talk about heat and language. 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.
I think about the words
Dylan Thomas used to begin his collected works as I
write on this hot 1997 Labor Day:
This day winding down now
At God-speeded summer's end
In the torrent salmon sun.
Houston has had an unusual year. We had endless
spring rain, followed by endless summer days in the
90s. The torrent salmon sun has poured energy upon
us while we've tried vainly to sweat that energy
away. Our tended plants have done better than
people.
Understanding heat has been a huge hurdle for
science down through the centuries. As I talk about
the hot Houston summer, three entirely different
scientific ideas tangle in one another: heat,
energy, and our own sensate physiology.
The word heat originally referred only to what we
felt. "Fear no more the heat of the sun," wrote
Shakespeare. Energy flows from the sun by the
processes of thermal, visible, and ultraviolet
radiation. We call that movement of energy heat, or
heating. As the sun's energy absorbs into our
clothing, our skin, and the air around us, our
temperature rises. We feel hot.
In 1800, our language had no means for identifying
the pieces of that process. For one thing, no one
yet understood that lifting a brick, and heating a
brick in the fire, were both means for conveying
energy into the brick. No one yet understood that
mechanical energy and heat energy were two forms of
the same thing.
But a new machine entered everyday life during the
18th century. It was the steam engine -- a device
that burned coal and delivered useful work. It
would be 1850 before scientists and engineers
figured out that the engine was actually converting
chemical energy into thermal energy into mechanical
energy.
The great writers of the age may well have run
ahead of scientists in creating the vocabulary for
straightening things out. As the new steam engines
went up around William Blake, he wrote, "Energy is
pure delight." Wordsworth, more than anyone,
studied science and wove accurate images of energy
flow into his verse. In describing death, he called
on the image of earth reradiating energy to black
night. He wrote,
A power is passing from the earth
To breathless Nature's dark abyss;
In a poem to child, he said,
The daisy, by the shadow that it casts,
Protects the lingering dewdrop from the sun.
Scientists only figured out how energy moves from
form to form 150 years ago. Energy's kinship to
physical sensation and to the intimacy of language
made it very hard to see it on a larger canvass. In
the end, it took people who knew how to stretch the
reach of language to stretch the reach of the
concept itself.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
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