What Is Time?

In 1826, time took a strange turn in New Haven, Connecticut. According to historian Michael O’Malley, over several months, a new clock installed atop Town Hall ran slow and then fast in comparison with the clock that had set the local standard time for decades, at nearby Yale College. After cursing the clockmaker, the citizens discovered that both clocks were accurate, but each kept time according to a different principle: The old clock at Yale had complicated gearwork that varied in speed with the seasons to emulate the time indicated on a sundial, which shifts with Earth’s annual orbital wobble. The more modern timepiece turned at a steady rate, like my wall clock does today.