Today, we go from ice to diamonds to ideas. 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.
Diamonds are called ice, but
we're also told that you can tell diamonds from
glass because diamonds are warm. Actually, diamonds
aren't like ice at all. Ice is a good thermal
insulator. But diamond is the best natural
conductor of heat we know -- three or four times
better than copper or silver. Diamonds feel warm
because they come up to body temperature so
quickly. Diamonds warm up, while glass keeps on
feeling cold.
Good heat transfer is highly prized these days. So
much energy has to be moved in modern systems.
Nuclear reactors put out as much energy as we can
carry away. They'd be a lot more effective if we
were better at moving energy. The same is true of
solar receivers. A field of mirrors focuses the
sun's energy on a central tower. We could easily
focus enough energy to melt the tower. We're
limited only by our ability to carry all that heat
away. Super-computers are limited by the need to
remove more and more energy from smaller and
smaller spaces; and so on.
Modern equipment fairly groans with problems like
that, and diamonds -- even commercial diamonds --
are too expensive use on a commercial scale. But
during the last few decades a new technology has
come into use. It's the heat pipe -- a man-made
conductor that carries heat a hundred times better
than even diamond.
A heat pipe is a tube whose inner walls are lined
by copper-wool or some other gauze-like material.
It contains a little liquid -- maybe water,
mercury, or alcohol. The liquid evaporates on the
warm end. The vapor flows down the middle and
condenses on the cold end. The condensed liquid is
returned to the hot end by a sort of blotter action
in the gauze.
It's amazing how anything so simple works so well.
In this case, the inventor is a friend of mine -- a
man whose mind I've been privileged to watch in
flight many times. In this case I've seen the
inventive process that created this new technology.
His name is Lloyd Trefethen. He teaches engineering
at Tufts University. Conversation with Lloyd is
always a kind of roller-coaster ride. He'll take
nothing for granted. He deflects the most
straightforward notion so it turns into something
else. We were given the heat pipe, where nature
left off, because one man simply refuses to see the
world the same way each time he looks at it.
Pure invention is ice turned into diamond --
diamond into a heat pipe -- one thing transmuted by
a leap in the dark into something wholly other. And
it's so exciting to watch happening in another
person, or -- better yet -- in yourself.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
