Who Invented Pendulum Clocks?

Christiaan Huygens, a Dutch astronomer who made contributions to many fields of science, invented the pendulum clock in 1656. Inspired by the work of Galileo, who had discovered that all pendulums of the same length took the same amount of time to complete one full swing, Huygens developed the first clock that could accurately measure time. Before Huygens, clocks used dripping water or complicated systems of weights and pulleys, but these clocks were very unreliable.

Life

Christiaan Huygens was a Dutch astronomer. He was born on April 14, 1629, in The Hague, Netherlands. Although his grandfather, father and brother were are all high-level government employees, after spending some time studying law and mathematics, Huygens decided to focus his life on the study of the sciences. He spent many years living in Paris, where he was a noted intellectual celebrity. It was in Paris where he did much of his work on the pendulum clock. He left France in 1681 for health reasons and died in The Hague in 1695.

Contributions

Christiaan Huygens was involved in many intellectual pursuits. He made several major contributions in the field of astronomy, including his discovery of the rings around Saturn and Titan, its moon. He was able to do this because of his improvements to optical lenses used in telescopes. He also made contributions to mathematics, physics and the study of internal combustion engines. But perhaps his most wide-reaching contribution was the invention of the pendulum clock.

Galileo's Pendulum

Huygens' work with the pendulum clock was inspired by Galileo, who discovered the pendulum effect. Galileo was sitting in a church when he noticed that a chandelier was swinging. He timed the chandelier's swing using his pulse as a measuring device. Galileo realized that the chandelier took the same amount of time to complete one full swing, no matter how wide the swing was. Today, this is called isochronism.

How a Pendulum Works

Galileo's observations revealed that the period of a pendulum (the amount of time it takes a pendulum to complete a full cycle) doesn't depend on anything but the length of the pendulum. This means that pendulums of different weights will have the same period. Also, two pendulums with different arcs (or lengths of swing) will have the same period. As long as gravity is constant, the only thing that affects the period of a pendulum is its length.

The Pendulum Clock

Huygens realized that this could be used to create a very accurate clock. Up to this point, clocks had been notoriously inaccurate, even the best of them losing at least half an hour each day. Further, they were useless for measuring minutes or seconds. In 1656, by using a pendulum in his clock design, Huygens was able to create a clock that could be hung on a wall and would measure time fairly accurately. The pendulum clock was born. As the years passed, the short-length pendulums of Huygens' design were replaced by longer ones, becoming what we commonly refer to today as "grandfather clocks.

Resources

• More Information About Huygens
• Huygens and Saturn