Hipparchs Himmelsglobus

Susanne M. Hoffmann reconstructed the not preserved celestial globe of ancient Hipparchus of Nicaea digitally. She investigated the data (celestial coordinates) on this globe and traced their sources. By means of error analysis, visualizing, mapping, and correlation plots she examined the potential origin of the Hipparchian star coordinates (or some of them) in observations of earlier Greek or Babylonian data. As preserved by Ptolemy (Almagest) and Pliny the Elder, Hipparchus is famous for his exact observations but he does, of course, also rely on older data - e.g. especially elaborated by Ptolemy's discussion of precession.

Thus, the first three chapters of this book are dedicated to a detailed analysis of Hipparchus's original data. The 4th chapter presents contemporary and earlier works in mathematical astronomy by Babylonian and Greek authors. Concluding, the 5th chapter, re-writes the history of astrometrical data collection, mathematical concepts to describe and predict them, and the variants of uranographies (constellation and star naming cultures) in the millennium before Hipparchus that led to his celestial globe.

Starting from MUL.APIN and giving a new interpretation of its first tablet, the book solves a puzzle on the function of the Akkadian shitqulu text, and discusses the works of Euclid, Eratosthenes, Aratos, and Hypsikles as strong influences on Hipparchus's work. The fact that Hipparchus's hour stars have much higher accuracy than the coordinates of his rising and setting stars is suspicious with regard to potential Babylonian predecessors. A missing link is not ultimately presented but Hypsikles' mathematics and some Babylonian lists of normal stars appear to shape the pillars of the bridge.