Theory and Observation in the Pseudo-Annular Eclipse reported near Vienna on 17 June 1433
This talk analyzes a solar eclipse that is described as annular, but that other reports and modern calculations show to have been very total. I explore the reasons for this odd state of affairs, since most eclipse observers are impressed by the darkness, not what’s happening immediately around the Sun. I argue that the report comes from a theoretically sophisticated observer with access to a 14th c. annular eclipse report that shaped his observation, which was then used to refute the concentric-sphere astronomy of al-Bitruji, an influential 12-13th century Arab astronomer.
Michael H. Shank is Professor emeritus in the now-defunct Department of the History of Science at the UW-Madison, specializing in 14-15th-c. natural philosophy and astronomy. Most recently, he was Visiting Professor in the Department of History of Science at Tsinghua University (Beijing; fall 2017, fall 2019) and Visiting Fellow at the Institute for Advanced Study in the Humanities and Social Sciences, Zhejiang University (Hangzhou; fall 2018).
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