"Jim Al-Khalili's On Time is a wonderful exploration of one of the most familiar and mysterious aspects of existence: time itself. Clear, concise, and compelling, the book illuminates some of the deepest insights about time discovered by some of our greatest thinkers, which have rewritten the very rules of reality." --Brian Greene, author of Until the End of Time "Time is a crucial aspect of our existence, yet its nature continues to puzzle us. Jim Al-Khalili fearlessly tackles the big questions here: Is time real? Why does it have a direction? How does it fit into the fundamental laws of physics? You will come away from this engaging book with a much deeper understanding of what we know and what we have yet to learn about something so familiar and yet so perplexing." --Sean Carroll, author of The Biggest Ideas in the Universe series "One of the best science writers, on one of the most fascinating topics in contemporary science: a must." --Carlo Rovelli, author of The Order of Time "Jim Al-Khalili has spent a lifetime thinking about time--and in this warm, witty book, he lets us watch him think. Roaming freely among physics, philosophy, and lived experience, he explores competing ideas with fairness and humor. On Time is a rare thing: a deep scientific book with an open heart.

" --Steven Strogatz, author of Infinite Powers "In this fascinating and insightful book, celebrated communicator and distinguished physicist Jim Al-Khalili brilliantly deploys his talents on the nature of time, a challenging topic that has perplexed philosophers for centuries and poses novel mysteries for modern physicists." --Martin Rees, author of On the Future: Prospects for Humanity.