Pendulum Experiment number 3

When Galileo was in church in Pisa he started watching the light hanging from the ceiling. It was swinging.

He was interested in how it was moving. Sometimes the wind would blow and it would swing more, then gradually it would slow down.

So he began experimenting with pendulums. He tried changing the size of the swing, the weight at the end of the string and the length of the string, and each time measured how long the swing took.

We did the same three experiments. Here's the third one:

So we found out that the pendulum with a short string completed its swing more quickly than the one with a long string.

With the first two experiments, we found that the size of the swing and the weight on the end of the string made hardly any difference to the time the swing took. Galileo found the same thing and used the sameness of the pendulum swing to design a clock that would keep steady time: a pendulum clock. This was the beginning of pendulum clocks:

How the pendulum gives the tick tock of the clock

Galileo's design

The design built

Here it is, made out of cardboard by J. E. Johnson: