Of Clocks and Time takes readers on a five-stop journey through the physics and technology (and occasional bits of applications and history) of timekeeping. On the way, conceptual vistas and qualitative images abound, but since mathematics is spoken everywhere the book visits equations, quantitative relations, and rigorous definitions are offered as well. The expedition begins with a discussion of the rhythms produced by the daily and annual motion of sun, moon, planets, and stars. Centuries worth of observation and thinking culminate in Newton's penetrating theoretical insights since his notion of space and time are still influential today. During the following two legs of the trip, tools are being examined that allow us to measure hours and minutes and then, with ever growing precision, the tiniest fractions of a second. When the pace of travel approaches the ultimate speed limit, the speed of light, time and space exhibit strange and counter-intuitive traits. On this fourth stage of the journey, Einstein is the local tour guide whose special and general theories of relativity explain the behavior of clocks under these circumstances. Finally, the last part of the voyage reverses direction, moving ever deeper into the past to explore how we can tell the age of "things" - including that of the universe itself.

Until the nineteenth century all time was local time. On foot or on horseback, it was impossible to travel fast enough to care that noon was a few minutes earlier or later from one town to the next. The invention of railways and telegraphs, however, created a newly interconnected world where suddenly the time differences between cities mattered. The Clocks Are Telling Lies is an exploration of why we tell time the way we do, demonstrating that organizing a new global time system was no simple task. Standard time, envisioned by railway engineers such as Sandford Fleming, clashed with universal time, promoted by astronomers. When both sides met in 1884 at the International Meridian Conference in Washington, DC, to debate the best way to organize time, disagreement abounded. If scientific and engineering experts could not agree, how would the public? Following some of the key players in the debate, Scott Johnston reveals how people dealt with the contradictions in global timekeeping in surprising ways - from zealots like Charles Piazzi Smyth, who campaigned for the Great Pyramid to serve as the prime meridian, to Maria Belville, who sold the time door to door in Victorian London, to Moraviantown and other Indigenous communities that used timekeeping to fight for autonomy. Drawing from a wide range of primary sources, The Clocks Are Telling Lies offers a thought-provoking narrative that centres people and politics, rather than technology, in the vibrant story of global time telling.