How water-based clocks revolutionised the way we measure time

For the vast majority of human history, we’ve relied on the Sun to tell time – a reliably unreliable method, given the body’s tendency to disappear behind clouds and the horizon. This animation from the YouTube channel Deconstructed explores how, as ancient civilisations began to need more reliable timekeeping mechanisms, the technology took an extraordinary leap forward with the advent of dependable water clocks, which would remain the best technology available for the next 1,800 years. In particular, the video focuses on the engineering brilliance of a Greek inventor in Alexandria named Ctesibius who, in the 3rd century BCE, solved several mechanical riddles that had previously made water clocks’ measurements woefully imprecise. Through its detailed breakdown, the video makes the case that, more than just a major innovation in timekeeping, Ctesibius’s water clock was one of the world’s first automatically operating machines.