[visionlist] geometrically ambiguous images

[Lewis Griffin]

There is a sculpture by Anish Kapoor, exhibited at the Hayward Gallery in
London last decade, which provokes a tri-stable perception.

>From memory, the sculpture is of a large (1m+) smooth greyish boulder, with
a roughly hemispherical hole (30cm diameter) excavated into it. The interior
of the hole has been meticulously painted with light-grey pigments of
varying lightness. Three percepts are possible:

	As a light-grey painted patch on the boulder's surface
	As a translucent window into the boulder's interior, which is lit.
	As a hole.


Lewis Griffin

Computer Science
University College London
UK


>I wonder if you may be able to help me with a brief query. I am a PhD 
>student in the History and Philosophy of Science Department at 
>Cambridge University. I have recently become interested in the Necker 
>Cube as it provides an interesting analogy for certain cases in 
>philosophy. I am trying to find out two things with respect to the Necker
Cube:
>
>(1) are there any geometrical images which are TRIPLY ambiguous in the 
>way that the Necker Cube is doubly ambiguous, where the transitions 
>between ambiguities are obvious, regular, and spontaneous (i.e. not 
>dependent upon "effort")?
>
>(2) is there a name (or names) for the CLASS of geometrically ambiguous 
>images which includes Necker Cubes as well as some other nameless 
>geometrically ambiguous forms I have encountered in the past? If there 
>is such a term for this class, I would be interested in finding it out 
>as I may be able to mutate it into a philosophical "-ism" which would 
>express the sort of position I am developing in my thesis.
>
>Thanks for taking the time to read this. I hope you might be able to help!
>_________