Today, we ask about permanence in a civilization. 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.
Every region has its
defining piece of architecture -- Egypt's Great
Pyramid, Paris's Eiffel Tower, Rome's Coliseum. And
the great pueblos of Mesa Verde conjure up the
American Southwest.
Those huge cliff houses were, in fact, a very brief
flash in the pan. We call their builders the
Anasazi -- or the Ancient Ones. Around 350 BC, they
moved into the four-corners region of Arizona, New
Mexico, Utah, and Colorado. By AD 1300 they'd
finally developed from hunting and gathering into a
settled, house-building, agricultural society. Then
they just disappeared.
By AD 550 the Anasazi were building pit houses, dug
into the ground. They entered and left by ladders
through a smoke hole in the roof. By AD 750 they
were building one and two-story houses above
ground. They became basket weavers, then fine
potters.
They began building the multi-storied pueblos of
Mesa Verde around AD 1200 -- the ones we see on
every postcard from the area. One Mesa Verde house
had 223 rooms. They built on a heroic scale.
By then, the Anasazi were conducting wide-ranging
trade with other tribes. Their remains include
shells from the Pacific coast, clays and wood from
other regions. Their sophisticated technologies
included complex decorative pottery and abstract
petroglyphs.
But that last epic of building lasted less than
three generations. Around AD 1250, the Anasazi were
involved in a war against another tribe. They
survived, but then, in 1276, a drought came. They'd
weathered other droughts, but, by now, Anasazi life
was turning weird. At the last, we find evidence of
nasty human sacrifices. We also find people were
beginning to leave.
By 1300 the exodus was complete. The last people
left suddenly -- leaving beautiful pottery and
other goods behind. The brief age of Anasazi
greatness blew away like summer smoke. Did they run
out of water or wood? Did they just lose their
confidence? Did some mad prophet turn Mesa Verde
into a crazy cult?
We don't know, but the story is not unique. It's
been repeated all over the world, down through the
ages. After Rome fell apart in the 5th century AD,
Central European nomads and African camel trains
moved among its abandoned architectural remains
with no inclination to make use of them. Monuments
have simply been left behind all the way from
Easter Island to the rose-red city of Petra.
And so the great pueblos stood, isolated and
unoccupied, protected by overhanging cliffs, for
700 years -- until the anthropologists finally came
to puzzle over the mystery of impermanence.
It's unsettling that many great spurts of building
actually signal instability rather than permanence.
The Anasazi pueblos warn that civilization is held
together by subtle and complex factors. In the end,
it is much more than mere stone and mortar.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
