Four geometrical-optics illusions
Abstract:
Centuries after the laws of geometrical optics were established, they still have nontrivial and varied applications. Illustrating this are some illusions: Mirages, and Raman’s error. Understanding why he denied the applicability of geometrical optics requires careful exploration of the continuum limit of a discretely-stratified medium, to reveal its nonuniform convergence. Oriental magic mirrors and the Laplacian image. The optics of these several-millennia-old objects involves the unfamiliar regime of pre-focal brightening. The transmission analogue (‘Magic windows’) raises a challenge for freeform optics. The squint moon and the witch ball. The moon sometimes appears to point the wrong way because we perceive the sphere of directions as a distorted ‘skyview’, on which geodesics appear curved. This can be conveniently viewed and analysed by viewing the sky in a reflecting sphere. Distorted and topologically disrupted reflections in curved mirrors. Mirror-reflected rays from each point of a continuous object form caustic surfaces in the air. Images are organised by those points whose caustics intersect our eyes, and can be systematically understood in terms of the elementary catastrophes of singularity theory.
About the speaker:
Sir Michael Victor Berry is a British theoretical physicist. He is the Melville Wills Professor of Physics (Emeritus) at the University of Bristol. He is known for the Berry phase, a phenomenon observed in both quantum mechanics and classical optics, as well as Berry connection and curvature. He specializes in semiclassical physics (asymptotic physics, quantum chaos), applied to wave phenomena in quantum mechanics and other areas such as optics. He has spent his whole career at the University of Bristol. He was a research fellow, 1965–67; lecturer, 1967–74; reader, 1974–78; Professor of Physics, 1978–88; and Royal Society Research Professor 1988–2006. Since 2006, he has been Melville Wills Professor of Physics (Emeritus) at Bristol University. More about prof. Berry’s research, publications and rewards may be found directly on his website:
This year we will continue with the new format:
- Onsite on Campus Limpertsberg, where you will have the opportunity to meet the speaker over the lunch. Catering is offered from 12:00 PM to all registered participants (BSC Hall). Please register below for the lunch latest on 22 November 2024. Talk at 1:00 PM in BSC 0.03.
- Online – through Webex – to give you the opportunity to listen to the talk in case you are travelling or cannot make it onsite at Campus Limpertsberg. Here are the details to join the talk online: Meeting number: 2793 881 9309. Password: bxCcUiHi399