As part of the interdisciplinary Ordered Universe project we’ve just submitted a paper on the “Medieval Multiverse”. I hope you’re as fascinated as I am. Far from being a dark and ill-informed era, the 13th century was full of new scientific discoveries and dominated by logical thinking. In his paper “De Luce” the medieval scientist (and later Archbishop) Robert Grosseteste uses his theory of the interactions of light and matter to explain the origin of the (Aristotelian) Universe. His mode of working is very much like that of a modern cosmologist.
“In his treatise on light, written in about 1225, Robert Grosseteste describes a cosmological model in which the Universe is created in a big-bang like explosion and subsequent condensation. He postulates that the fundamental coupling of light and matter gives rises to the material body of the entire cosmos. Expansion is arrested when matter reaches a minimum density and subsequent emission of light from the outer region leads to compression and rarefaction of the inner bodily mass so as to create nine celestial spheres, with an imperfect residual core. In this paper we reformulate the Latin description in terms of a modern mathematical model. The equations which describe the coupling of light and matter are solved numerically, subject to initial conditions and critical criteria consistent with the text. Formation of a universe with a non-infinite number of perfected spheres is extremely sensitive to the initial conditions, the intensity of the light and the transparency of these spheres. In this “medieval multiverse”, only a small range of opacity and initial density profiles lead to a stable universe with nine perfected spheres. As in current cosmological thinking, the existence of Grosseteste’s universe relies on a very special combination of fundamental parameters.”