What are time and space made of? Where does matter come from? And what exactly is reality? Theoretical physicist Carlo Rovelli has spent his whole life exploring these questions and pushing the boundaries of what we know. Here he explains how our image of the world has changed over the last few dozen centuries. In elegant and accessible prose, Rovelli takes us on a wondrous journey from Aristotle to Albert Einstein, from Michael Faraday to the Higgs boson, and from classical physics to his own work in quantum gravity. As he shows us how the idea of reality has evolved over time, Rovelli offers readers a deeper understanding of the theories he introduced so concisely in Seven Brief Lessons on Physics. His evocative explanations invite us to imagine, beyond our ever-changing idea of reality, a whole new world that has yet to be discovered.