Astronomy and Urban Planning in the Inkaic Empire (Invited)

Raymond E. White

The University of Arizona

The Inkaic name for their own empire was "tawantinsuyu," or "the land of the four suyus." Each village, town, and city -- as well as the entire empire -- was divided geographically into four sectors, or "suyus." From his seminal treatise over the people of the village of Mismanay in Peru, "Between Earth and Sky: an Andean Cosmology," the author, Gary Urton, tells how the four sectors have been defined on the ground at Mismanay: traditional pathways and streams play the significant role.

At the ruined citadel on a SW-to-NE ridge of the mountain Machu Picchu, there are no "traditional pathways" (the site was abandoned probably around 1570 A.D., after the abortive rebellion by the putative Inka Tupac Amaru) and only a single spring-fed stream, located between the "drinking hut" and the Torreon. So how was this site, built by the Inka Pachacuti ca. 1450 A.D., partitioned into its suyus?

In the presentation, copiously illustrated by color graphics, the clues to solving this "partitioning" problem will be discussed: from the discovery of the clues themselves, to their identification to certain asterisms, and, finally, how they are applied to local ground features. Last, the traditional site of the ceremonial "ushnu" will be indicated on a copy of Hiram Bingham's groundplan of the Citadel.