The beginning of the 20th century heralded a scientific revolution: what a few brilliant minds uncovered about our reality in the first 20 years has shaped the history of our species. And one of them in particular stands out: Einstein, with his celebrated E=mc2. In this remarkable and insightful book, Christophe Galfard describes how E=mc2 is a direct consequence of the Theory of Special Relativity, the theory of how objects move and behave, at speeds close to the speed of light. He considers Einstein’s legacy in the light of the 21st century, with fresh hindsight, and considers its impact on our vision of reality. The reader will discover that far from being just a formula, it is a brand new understanding of the nature of space and time.