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  Astronomy

ASTRONOMY also see Is it a Coincidence

 

“The Moon has been a source of fascination for every civilization since the dawn of man.  Every culture has its myths about our nearest neighbor in the universe.”

 

Alexei Leonov, Russian cosmonaut and the first human to walk in space.

From Two Sides of the Moon, by David Scott and Alexei Leonov (2004).

 

            The cyclical movement of the sun across the sky (or, as we now know, the cyclic rotation of the Earth around its tilted axis) creates a rhythm as regular as a heartbeat.  Each day is framed by sunrise and sunset;  the days lengthen throughout the spring and grow shorter throughout the autumn.  It is a pattern with which we are all familiar.

            The moon, however, seems to defy such regimentation.  Sometimes it appears in the daytime, sometimes at night.  And, whereas the sun shines down upon us with the same radiant face day after day, the moon changes its aspect throughout the month, waxing and waning through a relatively straightforward cycle.  In fact, the moon’s movement through the heavens is as regular as the sun’s;  the cycle is just more subtle.

            By watching the moon from night to night, month to month, and year to year, an observer can discover rhythms in its comings and goings.  The point on the eastern horizon where the moon appears to rise goes back and forth between a northern extreme and a southern extreme every twenty-seven and one-third days.  In some months, those extreme points are farther apart than in others.  At their maximum, the northern and southern rise points are about seventy-seven degrees apart.  At their minimum, they are only about forty-nine degrees apart.  In other words, there are absolute northern and southern limits to where the moon rises on the eastern horizon (and where it sets on the western horizon) – these are the northern and southern maximum extreme rise (and set) points.  At the latitude of central Ohio, these points are about thirty-eight and on-half degrees north and thirty-eight and one-half degrees south of due east respectively.  In some months, however, the point of the moon’s rise swings only between twenty-four and one-half degrees north and twenty-four and one-half degrees south of due east.  These rise points define the northern and southern minimum extremes.  This more complicated cycle, from a month with maximum extremes to a month with minimum extremes and back, takes 18.6 years to complete.

            Some observers in ancient Ohio during the Middle Woodland era (circa 100 B.C. to 400 A.D.), while they certainly did not understand the complexities of the moon’s orbit around the earth and probably didn’t even realize that the earth revolves around the sun, had worked out the rhythms of the moons march up and down the eastern and western horizons.  We know this because the astronomer Ray Hively and the philosopher Robert Horn together determined that the design of Newark’s Octagon Earthworks encodes the eight major rise and set points in its architecture.

            The parallel walls that connect Newark’s Observatory Circle with the octagonal enclosure frame an avenue that, if extended, would neatly bisect (or cut in half) the circle and octagon.  An observer standing upon the Observatory Mound and sighting down the avenue of parallel walls is looking where the moon rises at its northernmost point along the eastern horizon.  An observer standing within the avenue of parallel walls at the entrance to the octagon and sighting along the octagon’s southeastern wall is looking at a point on the horizon where the moon rises at its southernmost extreme.

 


also see Is it a Coincidence

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