Oil painting by Hugh Chevins, 1955, showing Huygens and Coster with their first pendulum clock. Christiaan Huygens (1629–1693), a Dutch physicist, designed the first clock controlled by the motion of a pendulum. Huygens based his clock on the observations made by the scientist Galileo (1564–1642), but improved the design and brought the pendulum clock to the world. (SSPL/Getty Images)

The Physics Of Why Timekeeping First Failed In The Americas

The world’s greatest clockmaker sent a clock to the new world, and everything went haywire. The reason why will shock you.

For millennia, humanity’s one-and-only reliable way to keep time was based on the Sun. Over the course of a year, the Sun, at any location on Earth, would follow a predictable pattern and path through the sky. Sundials, no more sophisticated than a vertical stick hammered into the ground, were the best timekeeping devices available to our ancestors.

For countless millennia, sundials were the most accurate way of keeping time. Despite the repetitious nature of orbits, there is an inherent uncertainty, at any given moment, of approximately 15 minutes in what a sundial records. (Public domain)

All of that began to change in the 17th century. Galileo, among others, noted that a pendulum would swing with the same exact period regardless of the amplitude of the swing or the magnitude of the weight at the bottom. Only the length of the pendulum mattered. Within mere decades, pendulums with a period of exactly one second were introduced. For the first time, time could be accurately kept here on Earth, with no reliance on the Sun, the stars, or any other sign from the Universe.