Today, an ancient beast outlives its species. 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.
Analog computers were the
great promise of the early '50s. We found a small
army of natural processes that were analogs of each
other. The flow of electricity in a man-made
circuit models the flow of heat. Waves in shallow
water model shock waves in air. Soap bubbles model
The digital computer blew all that away like summer
smoke. By the 1960s digital machines let us solve
equations in place of making physical analogs. A
whole generation of high-tech analog modeling
vanished in a few years.
In 1955 the gas industry went looking for a better
way to design systems for moving natural gas. 1955
was the heyday of the analog. So they went to an
electric analog for gas flow. They went to the
Southwest Research Institute, SwRI, in San Antonio.
SwRI put in a huge wall of capacitors, coils and
We look at the system. It stretches from room to
room. A task that would fit on a minicomputer today
takes up almost 2000 square feet. It's a dinosaur.
But there's a catch. This dinosaur is going to
enter the 21st century. This dinosaur can look back
and smile at the mammoth and the saber-toothed
tiger. She's outlived the whole history of the
This dinosaur was the best of a breed. It's been
used on 6000 industrial compressor systems. On
fifty billion dollars' worth of equipment! Over the
years, its vacuum tubes gave way to transistors.
But the old coils and capacitors are still there.
This machine walks around mathematics. It simply
dodges the equations that are still so hard to
For a generation this grand old machine has
interacted with experts. It has become a mirror of
engineering experience. It's so like the systems it
describes that it speaks to engineers' hearts as
well as their heads. Of course we're now writing
codes to do the analog's work on digital machines.
But as we do, the analog takes on a new role. Now
it's an elder statesman. We still use it to design
systems, but it also helps test the new digital
High quality gives indefinite life to some of the
things we make. The wooden pencil survives hundreds
of fancier writing systems. You can still fly on a
DC-3. A really good technology has features that
make it too good to forget. So it is with the
violin, silverware, and the bicycle. And so it is
too with this fine old remnant from the computer
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds