Re: Weird illusion...

["Margaret Mazzolini" <mmazzolini@swin.edu.au>]

Dwight,
These illusions (with construction and operation details)  are in the Exploratorium
Cookbooks (from the San Francisco Exploratorium) and also, from 
memory, in a wonderful text book 
called "Seeing the Light"
Margaret Mazzolini
Swinburne University of Technology
Melbourne, Australia



> Date:          Sun, 25 Aug 1996 21:48:49 -0400 (EDT)
> Reply-to:      phys-l@atlantis.cc.uwf.edu
> From:          Delissa Souder <dsouder@ASHLAND.EDU>
> To:            phys-l@atlantis.cc.uwf.edu
> Subject:       Weird illusion...

> 	I have another question.  Many, many years ago I saw a demo on 
> tv.  The person had a large rotating disk with black and white spirals on 
> it.  If you stared in the center of the spiral and looked at a picture, 
> the picture appeared to become 3-D.  I've heard of people using the same 
> demo and had the people stare at each others' faces.  The people's face 
> appeared to expand or shrink.
> 	Does anyone know the name of this device?  Is there a web page 
> that shows the design of the disk and the rate at which it should spin?
>
> Thanks,
> Dwight
> dsouder@ashland.edu