`Time's definition is elusive but Dan Falk is keen to track it down. In this thoroughly readable, broad-sweeping and thought-provoking book, Falk surveys humanity's attempts to record and understand time, and poses some fascinating questions.' - New Scientist `Falk seamlessly combines science with literary and philosophical observations... and digresses to fascinating topics like root notions of past and future, the vagaries of memory and the behavior of birds at breakfast time.' - Publishers Weekly (starred review) `What is time?'Falk considers cultural attitudes towards time from prehistory to the present, recounts different philosophers' explanations of the phenomenon of time, outlines the history of time-keeping, and examines centuries of scientific thought on the topic, from Newton through Einstein to the Big Bang and beyond. He speaks with anthropologists and historians about our deep desire to track time's cycles, asks psychologists and neuroscientists about the mysteries of memory, and quizzes physicists about the beginning and end of time - not to mention the latest theories about time travel and the paradoxes it seems to entail. What can ancient sites such as the`passage tomb' in Newgrange, Ireland, tell us about our ancestors' understanding of time? Why is the medieval clock at the Salisbury Cathedral so special? How do human differ from other species in our perception of the past and future? What implications do Einstein's theories have for the possibility of time travel? Is time an illusion? From ancient observatories to nanoseconds, from the layers of geological`deep time' to atomic clocks, Falk offers an engaging, thought-provoking account of how humans have come to understand time over the centuries and how that understanding continues to evolve today, not only in the fields of physics, astronomy, philosophy and psychology but also in everyday life.