1581

Events in 1581 1

• 1581 Galileo discovers the pendulum's regular motion Isochronism — the basis of mechanical timekeeping Around 1581, a young Galileo Galilei observed that a swinging chandelier in the cathedral of Pisa kept time at a constant rate regardless of the width of its swing — the property known as isochronism. He realised the pendulum could be used to measure time. This led eventually to the pendulum clock (built by Huygens in 1656) and transformed timekeeping, navigation, and scientific measurement.