Most Active Stories
Under the Microscope
Thu August 9, 2012
Tracking an astronomical mystery
For centuries people have lived and worked in a part of coastal Peru spotted with oddly shaped hills. Most knew that the mounds were man made, but were they significant?
Most didn’t think so. The hills didn’t look like much with their irregular outlines and primitive, rock and dirt construction. That all changed with Dr. Robert Benfer, professor emeritus in the MU anthropology department. With not much more than a sharp eye and a copy of Google Earth, Benfer discovered that these weren’t just hills, they were animals: 4000 year old sculptures designed to be seen from the sky. And they weren’t just decorative either. They were carefully aligned with the movements of the sun and stars.
A very early culture
The people who built these structures were from the “pre ceramic” age in Peru--a time period beginning in 2500 BC. “They lived in the stone age,” said Benfer. “Metal was not developed for a long time and that was several thousand years later.”
Unlike the Egyptians who would build temples with astronomical alignment later on, this culture was in very early stage of development. They had no beasts of burden, no system of written language. But they had domesticated cotton: “That was the first industrial crop, it was very important.” said Benfer. “And one might imagine that since string became very easy to make, it might have helped them to lay out their structures. All of their structures are characterized by extreme symmetry. Except for these mounds which don’t have even one straight line in them.”
Right under your feet
It was the irregularity of these hills that kept archaeologists from seeing them for what they were. “They were just so odd.” said Benfer. “They didn’t fit into what we expected.”
Benfer himself unknowingly walked over some of these mounds while working on nearby, related sites. Things changed when he took a different perspective altogether: “I was looking at google earth” said Benfer, “when I said--by gosh--this structure has teeth!” From satellite photos, you can faintly see jagged lines carved deep into the top of the mounds. Guides told him they were irrigation ditches, but he measured the furrows and found that that was impossible. “The water would have to run uphill” he said.
A “Discovery” Science
The free satellite imaging software, Google Earth, had a major part to play in this discovery. Commercial satellite photos cost $425 for a single photograph. “It would have been hard to get the money,” he said, “because no one wants to give you money for things that are well known not to be there.” Google Earth gave Benfer the ability to freely search for the effigy mounds and measure their alignment in space.
Benfer says that archeology is, by necessity, a “discovery science”--that is, it can’t do experiments. “The order that we find things suggests--well if there are these kinds of effigies in this valley, then there should be some in the next valley.” One discovery leads to another. “It’s not as powerful as an experimental approach,” he said. What Dr. Benfer did was highly unusual in archaeology -- he discovered something without precedent, out of the blue.
Benfer believes that these structures were built by “astronomer-priests,” people of influence who had a fine understanding of the movements of the sun and stars.
Some of these mounds are built such that the sun rises over the exact tip of the structure on the morning of the spring equinox. Because the sun rises and sets at different places throughout the year, this event would only happen at that exact time.
The equinox and solstice defined marked seasons, the passage of time and oriented the community in space. The ancient Peruvians, Benfer said, “do not conceive of time and space as unrelated, but as the same thing. Like modern physicists perceive it. If you’re going to look for the solstice sunrise over the marker on a hill. That’s a particular place and a particular time. It’s all one thing. We just imagine it to be different. Einstein says that their imaginations are right. Our imaginations are wrong.”
Astronomical Orientations in the Modern World
It’s easy to forget, but the movements of celestial bodies still has an effect on our daily lives. Take, for instance, the modern conception of North, South, East and West. It’s how we orient ourselves in space, and it’s how we lay our streets and cities out. But true east is really an astronomical orientation, not an arbitrary one. True East is the not just the general location of the rising sun, it’s where the sun rises on the exact day of the Spring Equinox.
“People aren’t self-consciously saying, ‘let’s lay that street out so that we have a record of where the sun and the moon is,’” says Larry Brown, professor of geography at MU. “No, but it’s a leftover.”
Brown points to Mircea Eliade, historian of religion. “He called this ‘cosmic religion,’ things that are leftover in modern society that reveal for us an older cosmic view. But we still do them.”
Note: This show originally aired on April 12, 2012.
Science, Health and Technology