What is time? The 5th century philosopher St Augustine famously said that he knew what time was, as long as no one asked him.

Introducing Time traces our understanding of time, from Augustine's suggestion that there is no time, to the flowing time of Newton, the conventional time of Poincare, the static time of Einstein, and then back, full circle, to the idea that there is no time in quantum gravity.

The study of time raises a myriad of fascinating questions: Is time a fourth dimension similar to space or does it 'flow' in some sense? And if it flows, does it make sense to ask how fast? Does the future exist? Is time travel possible? Why does time seem to pass in only one direction? These are among the deepest and most subtle concepts that one can explore, but Introducing Time presents these ideas in an easily accessible, lucid and engaging manner, wittily illustrated by Ralph Edney.