Mahfouz Interdisciplinary Forum 2014

Forming the Body of the Cosmos: Robert Grosseteste’s ‘On Light’


A Bridge between Medieval and Modern Colour Science: Robert Grosseteste’s ‘On Colour’ and ‘On the Rainbow’

Ordered Universe at the Mahfouz Interdisciplinary
Forum: two public lectures delivered on 3rd October, 2014, as part of the project symposium On the Generation of Sounds: The De generatione sonoroum by Robert Grosseteste (c.1170-1253). The symposium was sponsored by the Mahfouz Foundation at Pembroke College, University of Oxford – for an engaging account of what we got up to see Lee de Wit’s post on the subject.

Both lectures are included in one film here, the second begins at 47 minutes 40 seconds.

Following an introduction by Dame Lynne Brindley, Master of Pembroke College, the first lecture, given jointly by Tom McLeish, Giles Gasper and Richard Bower, outlines the context and analysis of Grosseteste’s treatise On Light which deals with the question of how the universe was formed. Grosseteste begins with a spherical shape formed instantaneously from a single point of light – an eerie resonance of the Big Bang? Tom and Richard explore how the mathematical aspects of the treatise led to a complex, but achievable, modelling of the medieval universe as conceived by Grosseteste.

The second lecture takes on the theme of light as the primary force within Grosseteste’s universe. More on Grosseteste’s historical influences and the different sources to which he had access opens the discussion. The notion of light embodied in a diaphanous medium as generative of colour is explored, including Grosseteste’s apparent 3D model for tracing colours from whiteness and blackness. The application of his own colour theory to the rainbow and differences within and between natural rainbows deepens the discussion. The stunning results of a modern modelling of a natural rainbow using Grosseteste’s conceptual parameters are then shown.