Rainbows and lenses: refraction in history

Presented by Robert Goulding
Optics -- the study of light and vision -- is one of the oldest sciences. As well as his more famous Elements of Geometry, Euclid (3rd cent. BC) also wrote two short treatises on optics and mirrors. In this seminar, we will discuss ancient and early-modern texts on optics (beginning with Euclid's works), paying attention in particular to the phenomenon of refraction. The bending of light as it passed from one medium to another proved to be the most difficult optical problem to resolve; the mathematical law which describes its action was discovered only in the early seventeenth century. Nevertheless, in the centuries before the discovery of the law, there was a great deal of speculation about some important effects of refraction: in particular, the rainbow, and the magnifying power of lenses. In our seminar, we will reproduce some of the historical experiments that were used to probe the nature of these phenomena, and, by examining the notes and writings of contemporary scientists, we will explore the difficulty of distilling a simple pattern out of complex appearances.

About Robert Goulding
Robert Goulding is an Associate Professor in the Program of Liberal Studies, with a concurrent appointment in History. His areas of specialization are Renaissance science and mathematics, and the history of magic. He is the Director of the John J. Reilly Center for Science, Technology, and Values, and the Director of the Program in History and Philosophy of Science. Professor Goulding’s current book project is a history of the law of refraction of light. His previous monograph was entitled Defending Hypatia: Ramus, Savile, and the Renaissance Rediscovery of Mathematical History. His recent articles include: “Five Versions of Ramus's Geometry," "Illusion in Medieval Magic," and "Binocular Vision and Image Location before Kepler." Professor Goulding was a Member in residence at the Institute for Advanced Study, Princeton in 2016-17.  Among other awards, he has also received a National Endowment for the Humanities Faculty Fellowship for 2006-2007,  a National Endowment for the Humanities Faculty Fellowship in 2012, and in the spring and fall of 2013, he was on leave as an American Council of Learned Societies Fellow.