Optics, Vision, and Evolution, after Mitchell Feigenbaum 1944-2019

27.09.2019 14:15 – 15:15

Many people are aware of Feigenbaum's astonishing
discovery of the universality of period doubling, and the constant
delta=4.66920 which carries his name.
In the last 13 years of his
life Feigenbaum worked on other subjects, and he wrote the manuscript (in TeX) of a book whose title is
"Reflections on a Tube".
This is closely related to his life-long interest in optics and
aspects of vision. It deals with the optics of images
reflected in a cylindrical mirror (usually called anamorphic
He shows that the eye does not interpret ray-tracing, but
caustics. But there are two caustics, and therefore,
the viewer can actually see two different images.
The visual system will often prefer one over the other.
The question is the "which" and "why"? Starting from this
discovery, Feigenbaum derived other aspects of this observation,
dealing with the vision of fish, the "broken" pencil in water, or
aspects of the floor of swimming pools. All these examples show two
possible images.
His study tells me how a simple study in classical optics can lead to
interesting questions in perception and the visual system.
I will give an overview of this project.
As I discussed with him, over those 13 years, many aspects of his work, I
have edited his manuscript so it can be published as a book which
should appear in a forseeable future.


Bâtiment: Ecole de Physique

Salle Stueckelberg

Organisé par

Département de physique théorique


Jean-Pierre Eckmann, Geneva

entrée libre


Catégorie: Colloque

Mots clés: theory, dpt