Today, we ask how an invention is born. 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.
Let's ask whether inventions
fight their way into the world from inside
inventors' heads, or are they made in response to
worldly needs? Look at the steamboat. It was
reinvented dozens of times before Fulton. But it
never caught on. When Fitch ran a steamboat line in
Philadelphia 20 years before Fulton, he couldn't
attract enough passengers to pay for it. Of course,
Fulton made a much better boat in 1807; but what's
more important is that by then there was a public
demand for the steamboat.
Compare that with the invention of man-made
superconductors. In 1911, mercury was found to have
no measurable electric resistance below about four
degrees Kelvin. During the next 75 years,
scientists found natural superconductors all the
way up to 23 degrees Kelvin. Of course, this wasn't
invention -- it was just scientific reporting.
But the practical promise of superconductivity is
so great. By getting rid of electric resistance, we
can work technological feats of near magic. In
fact, the US Navy has, for some time, worked on the
design of ships using superconducting generators.
It requires a helium cryostat to cool them; but
these hi-tech generators promise to save far more
weight and cost than the cryostats add.
A few years ago, scientists began to see that it
might be possible to invent superconductors that
would work at higher temperatures -- above the
boiling point of inexpensive liquid nitrogen
coolant -- maybe even at room temperature.
The break came in 1986 when two Swiss scientists,
Mueller and Bednorz, discovered a superconducting
oxide. Then Paul Chu, at the University of Houston,
rapidly created oxides that were superconducting at
twice the temperature of any natural material.
Pretty soon he went well beyond the boiling point
of nitrogen. Suddenly the dream of practical
superconductors could be realized with man-made
materials -- it could be done by invention.
And the race was on. The public didn't have to be
convinced about the value of this invention.
Electrical industries went to war over it. The race
to make practical superconducting systems has
spawned remarkable tales of determination, on the
one hand, and intrigue and espionage on the other.
So what is the stimulus for invention? Well, Fulton
studied water transportation for years before his
sudden success. And Paul Chu actually began his
search for man-made superconductors back in the
1970s, when the task still seemed hopeless. It's
nice when the public welcomes your ideas. But it's
the human mind -- and not mere necessity -- that
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds