This introductory text is exploratory in nature, and is intended as a bridge between Euclid’s geometry and the modern geometry of curved spaces. It is organized around a collection of simple experiments which the reader can perform at home or in a classroom setting. Methods for physically exploring the intrinsic geometry of commonplace curved objects (such as bowls, balls and watermelons) are described. The concepts of Gaussian curvature, parallel transport and geodesics are treated. The book also contains biographical chapters on Gauss, Riemann and Levi-Civita.
