LMI Seminar: Mirages and mirrors
Prof. Sir Michael Berry, H H Wills Physics Laboratory, University of Bristol UK
Zoom: https://zoom.us/j/91104099148
Abstract:
This concerns two different optical illusions. In his paper with S Pancharatnam on mirages, C V Raman misunderstood the relevant geometrical optics, with an error – the paradox of the horizontal ray – that goes back several centuries. I will explain Raman’s subtle mistake, and how the part of the paper that is correct is probably Pancharatnam’s contribution. Oriental magic mirrors cast ghostly reflections revealing the relief pattern on their back, even though this is invisible on the polished front face. The explanation of this 2000 year old puzzle involves an elementary but little-explored aspect of geometrical optics, with the Laplacian function as a central feature.