Message #47943

[Bianca]

FIG. 2. The rear side of the globe. We see the equator, the ecliptic, the equinoctial colure, and the two tropics. The edge of the horn of Aries is exactly on the colure, and this immediately tells us that the constellations were placed for around the time of Hipparchus.

Photograph by Dr Gerry Picus, Griffith Observatory.





Suggesting a date of c. 128 A.D. Third, art historians all point to the original Greek sculptor as using the constellations based in Aratus’s poem Phaenomena, which has a date of c. 275 B.C. An origin with Aratus was the dominant opinion amongst scholarly publications in the last century. Fourth, we know that Aratus’s work was substantially a copy of an earlier book of the same name by Eudoxus with a date of c. 366 B.C. Fifth, a precessional dating of 172 lore items derived from Eudoxus’s book proves that all of the lore actually dates from 1130 ± 80 B.C.4 So we are left with many candidates, all reasonable, for the date of the observations used to place the constellations: from 1130 B.C. to A.D. 150.

The possibility of deriving a date and latitude from the Farnese Atlas has not been lost on earlier researchers. E. L. Stevenson claims (purely on the basis of the positions of the solstices) that the constellations date “at least three hundred years before the Christian era”, while C. Gialanella and V. Valerio as well as M. Fiorini agree that the constellation positions suggest a date in the fourth century B.C., although Valerio later changed the date to A.D. 150. Thiele points to an origin by Hipparchus and Eudoxus based on stylistic considerations, and he also points to a latitude of 23° which he specifies as being greatly different from that of Rhodes. For the latitude of the observer, Fiorini gives 40° and points to Macedonia, Gialanella and Valerio give 32° and point to Alexandria, while Valerio later gives 33.5° and points to Middle Phoenicia. For the obliquity of the ecliptic, we hear values of 23° from Fiorini, 25.5° from Gialanella and Valerio, 25° from Valerio, and 24° from G. Aujac.

Throughout all the few sentences of discussions by the various authors, no evidence is ever presented, nor are methods of measurement ever discussed, nor is any indication of the accuracy of the claims ever made. With the total lack of these crucial details, we cannot take these off-hand claims seriously. In her appraisal of this situation, Aujac concludes: “A critical review of existing studies of the globe, together with detailed reproduction and careful analysis, is urgently needed to resolve these questions.”