Today, technology on hold. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
The history of technology is
filled with inventions that looked good, then got
put on hold until we caught up with them. Take
feedback control: Hellenistic
engineers invented all kinds of liquid-level
controllers during the last few centuries BC. They
created devices to control the level of oil in a
lamp or the flow of liquid into a water clock. They
invented a bowl that refilled itself automatically
as guests ladled wine from it.
Then the Romans took over Egypt (where all this
invention was going on), and feedback control
vanished from the human scene for two millennia. It
could've served all kinds of needs, but it
disappeared. Imperial Rome didn't want the control
of anything out of imperial hands. Not until
the extraordinary epoch of 18th-century revolution
could this radical idea resurface to regulate
liquid levels in steam boilers and to keep
windmills facing into the wind.
Another example: The eighth-century Frankish kings
began breeding horses for use in war. A century
later, people figured out how to harness a horse to
a plow, how a nailed horseshoe could protect the
horse's hooves, and how to change the planting of
fields so horses could share the extra food they
helped to produce. Once people put all that together, everyone
would live better.
Yet it took until the 11th century to put all that
in place, because it meant rearranging real estate.
People resisted changes that would vastly improve
their lives to avoid short-term disruption. If it'd
been your life or mine that stood to be disrupted,
I don't doubt that we too would join the opponents
So what technologies are on hold today? I expect
that, if we put a fraction of the cost of
individual automobiles into city transit systems,
we could make such systems so efficient that
automobiles would become a bother. As a child I got
around my city on electric trolleys. The automobile
blew systems like that away. Yet simple economics
tells us they will come back in mutated forms.
Herbal medicines are coming back after centuries on
hold. Today, dubious and credible advocates alike
are recommending them. Some are junk, and some are
effective pharmacology. Another decade and the
smoke will clear.
Nowhere is the on-hold phenomenon as clear as it is
in power production. Until we began using coal in
the 13th century, all energy sources were
renewable. Since then fossil and nuclear power have
been dominant. Economics has necessarily dictated
our choices, but we haven't been paying up front.
Our payments have been strung out over decades as
environmental costs build up, and as we send
expensive armies to fight over cheap
unrenewable energy sources.
So look around you. Ask yourself what really good
technologies are on hold from other ages, just
waiting for us to reawaken to their value? Those
technologies are waiting for us to figure out what
they are, and how to take them into our lives.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds