In my Sunday column in the Columbus Dispatch, I refer to the contributions of Ray Hively and Robert Horn to our understanding of the purpose and meaning of the Newark Earthworks. In a 2007 column, I described their rigorous attempts to test the claim that the astronomical alignments they had documented could be more parsimoniously explained by sheer coincidence. In other words, what are the odds that the Hopewell built the Newark Earthworks with no thought given to the Moon and that the Octagon just happens to line up with all those key moonrises and moonsets? Since that column is no longer available on The Dispatch website, I got permission to post it here.

The Octagon Earthworks in Newark is one remnant of the Newark Earthworks, recently listed by The Dispatch as one of the Seven Wonders of Ohio. Earlham College professors Ray Hively and Robert Horn demonstrated in 1982 that the walls of this 2,000-year-old circle and octagon were aligned to the points on the horizon, marking the limits of the rising and setting of the moon during an 18.6-year cycle. The implications of this argument for our understanding of the knowledge and abilities of the ancient American Indian builders of the earthworks are astounding. But how can we know whether they deliberately lined the walls up with the moon or whether the series of alignments is just an odd coincidence?

In the current issue of the Midcontinental Journal of Archaeology, Hively and Horn use statistics to address this question. And while they acknowledge that they cannot provide a definitive answer, their analyses certainly offer compelling evidence to support their idea that the sites are among the worlds earliest astronomical observatories. Hively and Horn focused on five alignments. These are the main axis of the site, which points toward the maximum northerly rise point of the moon, and the orientation of four of the octagons eight walls, which align variously with the moons maximum southern rise point, the minimum northern rise point, the maximum northern set point and the minimum southern set point. They performed a “Monte Carlo” analysis in which a computer randomly generated more than 10 billion equilateral octagons, randomly aligned them to a compass bearing and then checked how many astronomically significant alignments resulted. They determined that, even “making the most generous plausible combination of assumptions favoring chance alignments,” the odds that the alignments at Newark are merely accidental are about one in a thousand. Using more reasonable assumptions, the odds are more like one in 40 million. This does not take into account several other lunar alignments incorporated somewhat more subtly into the earthworks. Neither does it consider the fact that Hively and Horn have shown that High Bank Works in Chillicothe, the only other circle and octagon combination built by the Hopewell culture, also is aligned to the same series of lunar rise and set points. Its a safe bet that these ancient Ohioans understood a lot more about astronomy than most of us have recognized.

Originally published in the Columbus Dispatch, 13 February 2007