Shadows are the wonders of the visible world. They are ubiquitous in our environment and animal vision can subtly exploit them when reconstructing objects' shapes and locations. Scientists, most notably astronomers, have been using shadows for important measurements. Still, shadows are mysterious and puzzle the mind. Children and painters, among others, have been fascinated and terrified by shadows.

In this seminar we shall explore some of the complexities of shadows. The seminar is organized around some readings or position papers or posters or web pages. Discussants will be invited. Everybody is welcome on board for exploring the contents of the site and send feedback to the authors. If you want to actively participate by proposing a poster, a paper, a topic for discussion, please drop me a note.

Cast shadows and dark zones. Text by RC.	How the impression of a shadow is destroyed by some operations performed on the zone where the shadow is cast. Discussion, some new phenomena, and a hypothesis about the visual system.
A shadowless world. Text by RC.	The visual system uses shadows to reconstruct spatial features of the environment, but does so but in a very approximate way, as is seen from pictures with strange, contradictory or absent shadows.
Shadows on Flatland. Text by RC and Stefano Borgo.	How the shape of shadows depends upon the shape of space.
The language of shadows. (in progress)	Why we say that an object casts a shadow upon a surface, and not viceversa.
Strange shadow pictures. Text by RC.	A number of paintings from art history displaying very puzzling shadows.
Shadow Flatlands and crosscut Flatlands. Text by RC.	A Flatland made of shadows.
The Structure of Shadows. Text by RC.	The metaphysics of shadows as a metaphorical model for geograpic entities.