The Universe Before the Big Ban

The idea of preparing this book grew out of a series of lectures and seminars held over several years in various Italian universities. The interest aroused in the students – and in colleagues not specialized in the field, who were also present at the talks – led me to the idea of writing a non-technical introduction to the newly-born field of string cosmology, aimed at a wider range of readers than just the professional community who usually attend the international conferences and read the specialized journals. The challenge with this book is to present new possible scenarios for the primordial Universe emerging from recent developments in theoretical physics, but without resorting to too many numbers and equations, and using instead a series of illustrative cartoons. The book is addressed, in particular, to all those readers with at least a basic (high-school) knowledge of physics, but not necessarily equipped with an academic scientific background. As a consequence, the discussion of many issues will be qualitative, often incomplete, and sometimes even grossly approximate. Nevertheless, I hope that the introductory picture provided by this book will be detailed enough to enable the reader to understand the most recent cosmological models, the key underlying ideas and, above all, how they can be tested using the experimental tools provided by current technology.