Today, we ask why more of the ancients didn't study
astronomy. 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.
The science historian Jacob
Bronowski raises an odd question and offers an even
odder answer. The question is, "Why did astronomy
develop in the old world, but not in the new one?"
In the Southern hemisphere no civilization at all
developed astronomy. In the Americas, only the
Aztecs did serious astronomy before Columbus. The
Aztecs were fine mathematicians, but their
astronomy dealt only with time-keeping -- with
calendars. They didn't invent planetary models, and
they didn't use the stars to navigate. The
Mediterranean civilizations knew the world was
round centuries before the birth of Christ. But
that idea never occurred to people in the New World
or in the Southern Hemisphere.
Bronowski suggests that two elements drove the
development of astronomy. One was the Northern Star
-- that great celestial flagpole that was a point
of reference to people in the North. Without it,
the starry host was relatively random and
uninteresting in the Southern hemisphere.
The Aztecs had the polestar to guide them, and they
took an interest in the heavens. So it seems odd
that, even knowing mathematics, they didn't develop
theories and models for the movements of the stars.
But the second missing element outside of Europe,
Asia, and North Africa was the wheel -- that
strange device, so simple to those who know it and
so unimaginable to those who don't. The wheel led
us to see the rotary motion of planets and of a
round earth. The steady rotary repetition of
planetary and astral positions gave ancient sailors
courage to step away from shore, and modern
astronauts courage to step away from air and
gravity.
Bronowski finally takes us to Easter Island -- to
that primitive, landlocked, land-imprisoned people
who came there some 1200 years ago. Those people
gazing at a featureless sky were reduced to making
huge statues of identical faces -- 40-ton monoliths
called Ahu, with their backs to the sea, gazing
inward on a world complete in itself -- a world
which, unlike ours, cannot open up to infinity.
Easter Island, with its sad stone faces, becomes
Bronowski's metaphor for a world without the wheel
and without the polestar. Without these two
triggers to the imagination, more than just
astronomy is missing. The whole dream-driven
technology that shapes our world is absent. Without
the polestar and the wheel, Easter Island life
becomes featureless -- without hope or fear or
adventure or change.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
