One of the simplest machines in engineering has to be the pendulum, a device known to anyone who has ever tied anything to a bit of string. But it has a strange and misunderstood history.

You might imagine that the history of the pendulum is as old as history itself, but it is only really during the Renaissance that people started to wonder about them as timekeepers. The first clock with a pendulum appears, perhaps not surprisingly, in a drawing by Leonardo da Vinci from 1494 but, as with so many of his devices, he never built one, so we can’t be sure it would have worked any better than his helicopter.

The list of illustrious scientists and pendulum myths grows from there. A story tells how Galileo Galilei was standing in Pisa Cathedral in 1581 when a breeze set the lamps of the building swaying. Observing this, he sagely noticed that the period of each lamp’s swing depended only on the length of the pendulum, not the amplitude of the swing or the weight of the bob. This gave him the idea...