The Babylonian Theory of the Planets.

• Author: STEELE, J. M.
• Position: Review

The Babylonian Theory of the Planets. By N. M. SWERDLOW. Princeton: PRINCETON UNIVERSITY PRESS, 1998. Pp. xv + 246. $39.50.

It has been almost one hundred years since J. Epping, J. N. Strassmaier, and F. X. Kugler made the discovery that the Babylonians not only watched the skies, but also computed a whole host of celestial events, ranging from the first visibility of the lunar crescent, to the dates of the appearances and disappearances of the five planets. Through the extensive labors of these and later scholars most aspects of the operation of the Babylonian mathematical astronomy are now well understood. However, the question of how the various Babylonian theories were formulated has only recently begun to be addressed.

In The Babylonian Theory of the Planets, Noel Swerdlow has attempted to show how the fundamental parameters of the Babylonian planetary theory could have been derived from the observations that were available to the Babylonian astronomers, as represented by the records in the astronomical diaries. Swerdlow claims that his method, based upon manipulating observations of the length of time between two successive rising or setting phenomena--known as synodic time--"was the way the Babylonians derived the parameters of their mathematical astronomy," or that he "at any rate, can see no plausible alternative" (p. xiii).

Swerdlow begins his book with a discussion of the background to the various cuneiform astronomical texts. He is of the opinion that divination provided the primary motivation for astronomy in Babylon, although he does suggest that eventually the study of astronomy may have come to take on a life of its own through a purely scientific interest on the part of the Babylonian astronomers, writing that "the complexity and diversity of the ephemerides goes far beyond what is necessary to predict ominous phenomena ... and suggests nothing less than a rigorously scientific interest in the mathematical description of periodic phenomena" (p. 174). On the whole, this is a highly interesting and informative discussion, although at times slightly over-simplified in its interpretation of the omen literature and containing a few inaccurate statements in the description of the technical framework of Babylonian astronomy. For example, Swerdlow writes that, "the US of time is principally a unit of computation, although indirectly it can also be measured" (p. 36). However, the US, which corresponds to four of our minutes, is used...