ESHS/HSS Annual Meeting

Using Dabīrān in Analyzing Medieval Astronomical Tables: The Case of Zīj-i Īlkhānī

• In Event: DH in the History of Premodern Sciences 1

English Abstract

Medieval astronomical tables offer a fascinating and invaluable glimpse into the scientific practices of the past. However, the methodologies for studying these sources remain underdeveloped. While works of pioneering scholars have laid the groundwork, much remains to be done to establish a comprehensive standard for analyzing these intricate works. The limited availability of published editions and analyses of medieval astronomical tables highlights the need for more systematic approaches to understanding these historical sources. As computational methods become increasingly central to the study of medieval astronomy and the history of science more broadly, I am collaborating with colleagues in the Dabīrān Research Group to develop specialized software for analyzing astronomical tables. These tools enable researchers to encode tables into digital platforms, navigate between manuscript copies, and perform complex calculations based on the numerical data within these tables. This presentation focuses on how the Dabīrān tools were employed to analyze the astronomical tables in the Zīj-i Īlkhānī, a comprehensive astronomical handbook compiled by Naṣīr al-Dīn al-Ṭūsī (d. 672/1274) as part of the observational project conducted at the Maragha Observatory under the patronage of the Ilkhanid kings. In my presentation, I will discuss the process of encoding the tables of Zīj-i Īlkhānī into a platform developed by Dabīrān, including the challenges of reconstructing the original layout of the tables and ensuring that the database facilitates accurate calculations. Dabīrān allows users to reconstruct calculations outlined in the Zīj-i Īlkhānī, such as determining planetary positions in longitude and latitude, calculating relative positions of celestial bodies, and converting dates across various calendar systems described in the text. Ultimately, this approach enables systematic comparison of manuscript witnesses while ensuring computational fidelity to the original astronomical methods.

Author

• Sajjad Nikfahm-Khubravan