New tools became necessary. In this book, Hawking and Ellis attempt to establish the axiomatic foundation for the geometry of four-dimensional spacetime as described by Albert Einstein's general theory of relativity and to derive its physical consequences for singularities, horizons, and causality. Whereas the tools for studying Euclidean geometry were a straightedge and a compass, those needed to investigate curved spacetime are test particles and light rays.[1] According to the mathematical physicist John Baez from the University of California, Riverside, The Large Scale Structure of Space-Time was "the first book to provide a detailed description of the revolutionary topological methods introduced by Penrose and Hawking in the early seventies."[3]