Topology: A Very Short Introduction

How is a subway map different from other maps? What makes a knot knotted? What makes the Möbius strip one-sided? These are questions of topology, the mathematical study of properties preserved by twisting or stretching objects. In the 20th century topology became as broad and fundamental as algebra and geometry, with important implications for science, especially physics.

In this Very Short Introduction Richard Earl gives a sense of the more visual elements of topology (looking at surfaces) ...