Date Published: November 19, 2009
Publisher: Public Library of Science
Author(s): Alun M. Salt, Enrico Scalas. http://doi.org/10.1371/journal.pone.0007903
Abstract: Despite its appearing to be a simple question to answer, there has been no consensus as to whether or not the alignments of ancient Greek temples reflect astronomical intentions. Here I present the results of a survey of archaic and classical Greek temples in Sicily and compare them with temples in Greece. Using a binomial test I show strong evidence that there is a preference for solar orientations. I then speculate that differences in alignment patterns between Sicily and Greece reflect differing pressures in the expression of ethnic identity.
Partial Text: It has long been proposed that classical temples may have been aligned with respect to sunrise on certain dates. The idea was first proposed by Nissen  in 1869. This idea was developed further by other authors such as Penrose , ,  and Dinsmoor,  who argued that a temple could be dated from its astronomical alignment. This explanation was rebutted in the 1980s by Herbert  on the grounds that plenty of Greek temples did not face east. Following a survey of Sicilian and southern Italian temples Aveni and Romano  reasserted that there is an astronomical pattern to the alignment of Greek temples, but the two most recently published statements on the subject ,  both state that there was no evidence of astronomical intent. At best, there is no consensus about the answer, though a more accurate summary would be that opinion is shifting away from the notion of astronomical alignments being embedded within Greek temples.
The survey of the Greek Sicilian temples presented here was conducted with a magnetic compass and a clinometer. Where possible temples were measured in both directions along all four sides with a compass to provide eight measurements in order to derive an axis of alignment. A clinometer used along each wall and the centre of the temple, viewing from the back to the front, provided horizon measurements to enable the calculation of the declination (astronomical latitude) that a temple faced. Frequently this was impossible, due to lack of access or enthusiastic reconstruction involving steel handrails. Therefore all measurements were also examined using the published archaeological plans, with the north arrow calibrated using local observations.
To determine how many temples face east, we must first define what we mean by ‘east’. If we talk about the eastern 180° of the horizon. Then 40 out of 41 temples in the Sicilian sample face east (see data in table 1). This initially looks interesting, but then this would also be true if 40 temples had faced west. The obvious tool to analyse the result is a binomial test, which is trivial to anyone with a basic grasp of statistics, but exotic to those who work in the humanities and so is briefly described below.