Visual Geometry and Topology

Geometry and topology are strongly motivated by thevisualization of ideal objects that have certain specialcharacteristics. A clear formulation of a specific propertyor a logically consistent proof of a theorem often comesonly after the mathematician has correctly "seen" what isgoing on. These pictures which are meant to serve assignposts leading to mathematical understanding, frequentlyalso contain a beauty of their own.The principal aim of this book is to narrate, in anaccessible and fairly vi