Thu, 12 Sep 2013 12:41 CDT
Thu, 12 Sep 2013 12:41 CDT
But Göbekli Tepe may also be the world's oldest science building.
Giulio Magli of the Polytechnic University of Milan hypothesizes it may have been built due to the "birth" of a "new" star; the brightest star and fourth brightest object of the sky, what we call Sirius (Greek for "glowing").
Sirius, which we also call the 'dog star' due to its location in the constellation Canis Major, was obviously not born 12,000 years ago, but Hipparchus would not discover the phenomenon of "precession" until 200 BC, when he compared the equinoxes in his time with older charts and made the connection. Precession at the latitude of Göbekli Tepe would have sent Sirius under the viewing horizon of those in ancient Turkey around 15,000 BC, where it remained unseen again until around 9,300 B.C. To those residents it was a new star appearing for the first time.
Anil Ananthaswamy writing in New Scientist has an interesting take as well. The Neolithic revolution hypothesis says that the invention of agriculture led to fixed human settlements and then art and religion other hallmarks of civilization - but there is no evidence of agriculture near the temple, which suggest that religion came first.
There's no doubt that religion and understanding motions of the stars have been mixed throughout history (and still are, as the enduring popularity of astrology can attest) but if it were strictly religious, why would it not have been duplicated more often? The structures that bear the most resemblance to Göbekli Tepe, on the Spanish island of Menorca, were built 8,000 years later.
Magli says this new star may have prompted a new religion that was not evident anywhere else. Or, as is the case of Stonehenge, it could have been a multi-purpose astronomical observatory that also became a religious site. The evidence for astronomy? Excavated rings.
"The extrapolated mean azimuths of the structures (taken as the mid-lines between the two central monoliths) are estimated as follows":
Structure D 172°
Structure C 165°
Structure B 159°
Those azimuths match the rising azimuths of Sirius:
Structure D 172° 9,100 BC
Structure C 165° 8,750 BC
Structure B 159° 8,300 BC
If you want to visit Turkey and give your own hypothesis a try, duplicate this work while you can. We think the stars will be in the same place forever, just like people in the 10th millennium B.C. did, but that really isn't so. The previously mentioned astronomically-oriented sanctuaries of Menorca were built to highlight the then-bright Crux-Centaurus group in the southern sky, but those are disappearing from the sight of those 93,000 Mediterranean island inhabitants - also due to precession.
Precession will also lead to lots of fun science for astronomers to come. Polaris, the 'north star', is only such by coincidence of evolution as I write this. Vega will be our north star of the future - in about 13,000 years.
Preprint: Giulio Magli, 'Sirius and the project of the megalithic enclosures at Gobekli Tepe', arXiv:1307.8397
NOTE: Why the title? In high school, me and my friends competed in a science and math challenge against a few dozen other schools (I only placed second in physics - why is a story for another time) and for the 'College Bowl' challenge, where teams compete against each other to answer questions and solve problems, the first 'question' in our competition went "Astronomers will tell you this is no laughing matter."
I rang the buzzer immediately and answered "Sirius."