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Durham University

Institute of Medieval and Early Modern Studies (IMEMS)

Staff and Governance

Core Staff

The day-to-day running of IMEMS is the responsibility of the Core Executive Committee, comprising the Director and Associate Directors and the Administrator. 

Publication details for Prof Brian Tanner

Harvey, Joshua, Smithson, Hannah, Siviour, Clive, Gasper, Giles E. M., Sonnesyn, Sigbjorn O., Tanner, Brian K. & McLeish, Tom (2017). Bow-shaped Caustics from Conical Prisms: a 13th Century Account of Rainbow Formation from Robert Grosseteste’s De iride. Applied Optics 56(19): G197-G204.

Author(s) from Durham

Abstract

The rainbow has been the subject of discussion across a variety of historical periods and cultures, and numerous optical explanations have been suggested. Here, we further explore the scientific treatise De iride [On the Rainbow] written by Robert Grosseteste in the 13th century. Attempting to account for the shape of the rainbow, Grosseteste bases his explanation on the optical properties of transparent cones, which he claims can give rise to arc-shaped projections through refraction. By stating that atmospheric phenomena are reducible to the geometric optics of a conical prism, the De iride lays out a coherent and testable hypothesis. Through both physical experiment and physics-based simulation, we present a novel characterization of cone–light interactions, demonstrating that transparent cones do indeed give rise to bow-shaped caustics—a nonintuitive phenomenon that suggests Grosseteste’s theory of the rainbow is likely to have been grounded in observation.

Full Executive Committee

Our Full Executive Committee is made up of the Core Executive Committee, listed above, plus a number of executive members including:

International Advisory Board

We are extremely fortunate to have be able to call on the help and guidance of colleagues from around the world who help to shape and guide our direction, strategy and international reach. Our current Advisory Board members are: