What is time? The Janus Point offers a ground-breaking solution to one of the greatest mysteries in physics.

For over a century, the greatest minds have sought to understand why time seems to flow in one direction, ever forward. In The Janus Point, Julian Barbour offers a radically new answer: it doesn't.

At the heart of this book, Barbour provides a new vision of the Big Bang - the Janus Point - from which time flows in two directions, its currents driven by the expansion of the universe and the growth of order in the galaxies, planets and life itself. What emerges is not just a revolutionary new theory of time, but a hopeful argument about the destiny of our universe.

'Both a work of literature and a masterpiece of scientific thought' Lee Smolin, author of The Trouble with Physics

'Profound...original...accessible to anyone who has pondered the mysteries of space and time' Martin Rees, Astronomer Royal

'Takes on fundamental questions, offering a new perspective on how the Universe started and where it may be headed' Science Magazine

"Barbour takes on fundamental questions, offering a new perspective - illustrated with lucid examples and poetically constructed prose - on how the Universe started (or more precisely, how it did not start) and where it may be headed. This book is an engaging read, which both taught me something new about meat-and-potatoes physics and reminded me why asking fundamental questions can be so fun" - Science

"A closely argued, substantive take on one of the biggest unsolved mysteries of physics, written by someone who has wrestled with not only the physics, but also the history and philosophy relevant to his subject. What's more, Barbour's approach, unlike many in the popular science game, is to publish only when he thinks he has something worth saying. That alone is enough to make him worth listening to" - Nautilus

"Julian Barbour is one that rare breed, an optimistic scientist, and his engrossing The Janus Point not only turns accepted thinking about the universe on its head...but also suggests our very understanding of the nature of time needs to be reappraised" - Choice

"Any reader willing to engage with Barbour's ideas will come away enlightened" - Physics World