An illustrated guide to the biggest of the 'big ideas' by one of the UK's best loved scientists and historians. Adam Hart-Davis is the author of 27 informative and entertaining books on science and history which have collectively sold more than 110,000 copies. Time is explained in an accessible way that makes it the perfect illustrated guide for fans of popular science.

Adam Hart-Davis is a scientist, author, photographer, historian and broadcaster, well-known for presenting the BBC television series "Local Heroes" and "What the Romans Did for Us" (and spinoff series on the Victorians, the Tudors, the Stuarts, and the Ancients). He was also a co-presenter of "Tomorrow's World", and presented "Science Shack". His most recent book is Science: The Definitive Visual History (Dorling Kindersley).

Foreword 6; Introduction 8; What is time? 14 Everyone agrees that time exists, but people don't agree about what it is. What does time means for physics, philosophy, psychology and religion? Also, why can time be perceived in different ways - why can a minute seem to last for hours while an hour can pass in seconds? Countdown:?All time ... Epochs ... Millennia ...; Nature's clock 64 The key role of the natural world in our experience of time - the sun, the moon, the tides, the seasons. The way these changes and cycles are mirrored in our bodies, and in Mother Nature - from the salmon that swim up river to spawn at the full moon to the agaves that flower after decades. Countdown: Centuries ... Years ... Months ...; Setting the time 92 How humans have tried to organize time for social, religious, commercial or administrative purposes - from the first calendars to the creation of timezones and daylight savings. Countdown: Days ... Hours ... Minutes ...; Time machines 140 How humans have created machines to measure time, from the most primitive water clocks and sundials to atomic clocks that are accurate to within a second every 300 million years. Countdown: Seconds ... Milliseconds ... Microseconds ...; The science of time 192 Time is central to science. From Aristotle to Einstein, from acceleration to relativity, this chapter explores how time has been essential for scientists in their quest to understand the universe and everything in it. And then there's the tricky issue of time travel... Countdown: Nanoseconds ... Femtoseconds ... Attoseconds;; Index 268; Acknowledgements.