# Galileo and the Pendulum Clock

20105

Ever wondered how we got to the point of being able to measure time accurately using clocks?

One of the huge discoveries for the development of accurate clocks was the invention of Pendulum Clocks by Galileo in the second half of the 17th century1.

Until the invention of Pendulum Clocks, minutes couldn’t be measured accurately using the primitive clocks that were in existence.

Doing research on the subjects of time and the history of clocks, I unearthed a fascinating story about how Galileo came upon the idea of using pendulums in clocks to more accurately measure time.

He got the idea while sitting in church.

It was the Pisa Cathedral, to be exact.

Galileo was sitting in the cathedral and was fascinated by the swinging movements of the chandeliers hanging high overhead from the cathedral’s ceiling.

While observing the back and forth motions of these swinging chandeliers, Galileo noticed that, although the angle of the swinging movements changed over time, the amount of time required for the pendulum to swing in one direction and then return to its original starting point (known as the period of a pendulum) appeared to remain constant.

Et Voilà!

A light bulb went off in Galileo’s head and he began working on all kinds of possible applications of pendulums, including the idea of using pendulum clocks to accurately measure time.

Long Before the Invention of the Online Clock, People Stared at This

Some of the first useful applications of the idea of pendulum clocks included the invention of the metronome and the use of a device to measure the human pulse in medicine (a pulsometer).

Although Galileo worked extensively on pendulums during his life time and did indeed design the world’s first pendulum clock, it was not until 1656, many years after Galileo’s death, that Christiaan Huygens, a Dutch mathematician, actually created the first working pendulum clocks.

Today we know that pendulums are not as accurate at measuring time as Galileo had originally thought.

But the invention of pendulum clocks was a huge step forward in the development of accurate clocks.

This is a process which continues to this day, as we continue to fine-tune atomic clocks into devices capable of measuring time with an accuracy of up to 10-9 seconds per day.

Now that’s accurate!

But don’t forget how we got here:

It’s all because Galileo got bored one day in church.