The planiverse
by A.K. Dewdney
A mind-bending, paradigm shifting visit with Yedred, a denizen of the 2 dimensional Universe. It is written so that the physics comes through very easily for those without science training. A university student discovers that this being Yendred is communicating with him through his computer. There begins a lively dialog as both the 2D Yendred and the 3D author struggle to explain and understand each others worlds. This book opens your mind with delight and challenge.