The mirror is fascinating for its ability to duplicate things, people, ourselves. But what exactly does a mirror do, and why does it reverse left and right but not up and down? Would we be able to explain to an extraterrestrial civilization what we mean by left and right? Associated with the concept of the mirror is an ideal of beauty that fits well with what it represents in geometric terms: symmetry, which conveys a sense of harmony and balance and which we are accustomed to considering a cornerstone of nature. We can also combine the spatial mirror with a temporal mirror. Imagine a physical phenomenon occurring in reverse: does the symmetry of natural laws also apply to this temporal inversion? Finally, in addition to space and time, matter also has its own mirror in which to reflect itself: antimatter. In this book, Giorgio Chinnici describes the profound connection between the three mirrors; An investigation that exposes and addresses questions about the very essence of time, where the theory of relativity opens unexpected horizons and uncovers highly evocative phenomena such as the relativity of simultaneity, time dilation, and the twin paradox.