Time

What is time? Does it exist? Can it be stopped? Can time's arrow be reversed? Can we ever free ourselves from the seemingly inexorable flow of time? Chronos is a mystery, and not only for us: it was a mystery for our distant ancestors too. In this book, Guido Tonelli guides us along the path to understanding a reality that is very different from what we believe it to be. Modern science allows us to explore the deepest recesses of the universe, and when we observe the giant objects which inhabit the cosmos over great distances – galaxies and clusters of galaxies – time acquires characteristics which are quite different from those that we are used to. The same happens when we analyse the phenomena which occur on a sub-nuclear scale. In these two worlds which are so far apart from one other, the harmonious and constant flow of time which has enchanted us for millennia twists, melts and shatters. Space and time appear as an indissoluble couple – not some abstract concept but a material substance which occupies the entire universe, which vibrates, oscillates and is in a constant process of change. With Tonelli's erudite assistance, we discover the long history of time, its violent birth and strange evolution. In our imaginations, we travel to terrifying places where time stops and explore the close link which binds time to energy. This is a bewildering journey that forces us to discard our preconceptions and abandon all certainty, a journey in which myth, art and philosophy will come to our aid when our minds begin to falter.

Introduction Part 1: The fascination of spinning tops 1. The desire to master time When the spell is broken Life's time Urns and sepulchres: the birth of past, present and future 2. Our time The sense of time When Chronos ran wild and free Caging time The Triumph of Chronos Part 2: Where time stops 1. The odd couple Time which melts and shatters: Soft clocks: Fantastic accuracy: making money from relativity: Great philosophers and Little Red Riding-Hood 2. The long history of time The beginning of time The end of time Time in the world of great cosmic distances Magnificent illusions and fantastic chimeras When the energy of three suns travels lightly over the waves of Space-time 3. When time stops The clocks of the Paris Commune The Hellish places where time vanishes The spectacular end of Betelgeuse The terror champions Physics at the points of empty time Part 3: Between ephemeral existence and eternal life 1. The life of particles A world full of weirdness Masses which explode and times which dilate disproportionately Cosmic super-accelerators The little red and white brick house 2. The time of the infinitely small A handful of chosen ones In the ivanescent realm of the ephemeral The reckless life of muons Beauty, charm and the timidity of quarks 3. A very special relationship A Castor and Pollux like-existence Grabbing Kairos by the hair Measuring time with energy The raids of the messengers, Hermes' protégés The perfect couple 4. Can time's arrow be reversed? An equation reveals a world whose existence nobody had suspected The Holy Grail of symmetry The secret of a poem, or a fine wine Entropy and the irreversibility of time 5. The dream of killing Chronos The ancient poetry of the idea of stopping time Time's assassins Nosferatu Epilogue: The brief time Acknowledgements Index