Message #147
From: AzTeC SW Archaeology SIG
To:   "'Matthias Giessler'" 

Date: Mon, 20 Apr 1998
Subject: Archaeo-Astronomy
[ AzTeC / SWA SASIG ] :

Two Disciplines Align to Shed Light on Astronomy
of the Ancients
By Louis Jacobson Special to The Washington Post
Monday, April 20, 1998; Page A03 

PHOENIX—At first glance, the jumble of rocks
resting on an undeveloped mountain 300 feet
above the sprawling and congested city of
Phoenix hardly seems extraordinary. But the
rocks, long assumed to have been an ancient
Hohokam Indian fortress, recently caught the
attention of scientists who suspect they may
have served a less warlike purpose: allowing
the Hohokam to track the sun and the seasons.

"The Hohokam seem to have had a more
sophisticated knowledge of astronomy than we'd
recognized," says Phoenix city archaeologist
Todd Bostwick, who along with amateur astronomer
Stan Plum came up with the new theory. "As
modern-day humans, we ignore half of our world
-- the sky. But for people in the past, that was
their world."

Bostwick is just one of a small band of
self-styled "archaeoastronomers" who are creating
excitement and controversy in the often-insular
worlds of archaeology astronomy.

Archaeoastronomy, which counts about 200 serious
practitioners today, attempts to divine what ancient
societies knew about the moon, the sun and seasonal
cycles by studying archaeological relics for
important "interactions" with celestial bodies, such
as a shaft of sunlight that pierces a hole in a wall
only on the day of the summer solstice. Some
archaeoastronomers use these findings to speculate on
how such societies organized their religious
ceremonies or their social structures.

Archaeoastronomy was long shunned by academic
archaeologists and astronomers, in part because
university professors were often outnumbered by a
variety of inspired -- but sometimes fringy --
amateurs. And even the credentialed academics who
ventured into archaeoastronomy often faced sniping.

One early theory -- that an Arizona site called
Casa Grande could have been used for celestial
observations -- was so widely derided in 1969 that
the scholar who proposed it was all but drummed out
of astronomy. Then, in the 1980s, University of
Arizona astronomer Raymond E. White argued that
portions of the Inca ruin Machu Picchu had served
as an observatory. White recalls that when he
delivered an address on the topic, critics came up
to him and said he was "crazier than a tick."

"It's been difficult," acknowledges W. Bruce Masse,
whose studies linking Hawaiian oral mythologies and
celestial events such as comets and supernovas have
attracted both praise and criticism. Masse, by day an
archaeologist who preserves Indian historic and
sacred sites for the Air Force, explains that "part
of the problem is that archaeoastronomy brings
together people from different disciplines who share
no common language.

Archaeoastronomers have to learn both disciplines,
which requires a lot of effort. That's one reason why
we'll never be truly mainstream until archaeoastronomy
becomes part of the core curriculum."

Recently, though, archaeoastronomy has prompted a
flurry of popular books, and the scholarly attacks
have begun softening. Recent findings, such as
Bostwick's, have been presented -- often with
scholarly approval -- at a growing number of
academic conferences devoted to the specialty.

"Archaeologists have a number of resources to work
with, including structures and artifacts," says Bob
Preston, an astronomer at NASA's Jet Propulsion
Laboratory in California. "Archaeoastronomy gives
them another tool. What archaeoastronomy has that the
other tools don't is a unique insight into a
society's ceremonial life. Because all cultures have
cosmologies of some sort, archaeoastronomy is alive
in a way that much of archaeology is not."

E.C. Krupp, the director of Los Angeles' Griffith
Observatory and the author of several books about
archaeoastronomy, says he doesn't hear much direct
criticism these days except from archaeologists
and astronomers. "That criticism is often correct,
such as when people are accused of not doing their
cultural homework or of not putting their findings
in the proper context," he says. "People are asked,
fairly, how they can talk about Mesoamerican pyramids
without knowing about the social structures of the
societies that produced them."

Bostwick's discovery is one receiving cautious
praise from other archaeoastronomers. His personal
interest in Indian rock art first led him to notice
the interplay of light and shadow on the rocks at
Shaw Butte. Feeling he needed enough sightings
throughout the year to be sure that the patterns
were more than coincidence, took three years of
study before announcing his conclusions about the
800-year-old site.

Preston, an astrophysicist who's used to working
with mathematical data, prods his fellow
archaeoastronomers to be statistically rigorous --
one of the field's past shortcomings. For instance,
Preston initially was skeptical of a contention that
a spiral-shaped Indian rock carving in northern New
Mexico was made to track the path of the sun on
solstice days. So he studied other spirals in the
vicinity -- and even posted his own hand-drawn
spirals at random locations -- and discovered that
there were enough significant interactions between
the sun's rays and the Indian-carved spirals on
solstice days that coincidence could be comfortably
ruled out.

Krupp and Preston agree that the other main
challenge facing archaeoastronomers is the
temptation to over-promise. For instance, Bostwick
suggests that once scientists agree that Shaw Butte
was actually an observatory, they must entertain
the possibility that the Hohokam had an elite,
astronomically aware caste -- something that would
contradict current extrapolations of their society.
While Bostwick makes a point of calling this idea
speculative, Krupp and Preston say that not all
archaeoastronomers are so careful.

While many recent archaeoastronomical findings
suggest that ancient cultures had a surprisingly
broad knowledge of celestial events, Krupp says
these findings mainly highlight our own modern-day
condescension. "The fact that there is astronomy
built into Stonehenge should not be that surprising
to us, because the site's engineering and
construction is at least as complex as its
astronomical orientation is."

Archaeoastronomers also have more immediate worries.
Not long after Bostwick's theory was publicized,
vandals toppled a crucial rock at the Shaw Butte
site, changing forever the observatory's alignment.
"Taxpayers pay for the use of parks, and they feel
they have a right to visit the site," Bostwick
says. "But it's a delicate balance between
allowing controlled visiting while still protecting
the site and ensuring its safety. What's pressing a
lot of us is saving the sites first. We need to
document, document, document."