For thousands of years， people of all cultures have made and used clocks。 From the city sundials of ancient Rome to the medieval water-clocks of imperial China， and from sand-clocks fomenting revolution in the Middle Ages to Enlightenment observatories in India， a history of clocks is a history of civilization。 Clocks have helped us navigate the world， build empires， and have even taken us to the brink of destruction。 Elites have used them to wield power， make money， govern citizens， and control lives—and sometimes， the people have used them to fight back。


Through the stories of twelve clocks， from a Roman sundial to a 10，000-year clock being built inside a Texas mountain， About Time brings pivotal moments from the past vividly to life， and explores how time has been imagined， politicized， and weaponized over the centuries。