L’attimo fuggente: ovvero come verificare la rotazione della Terra in meno di venti minuti

The rotation of the Earth produces an effect on the behaviour of a sufficiently long pendulum, as in Foucault’s experiment in 1851. This article illustrates an easy method to measure the Earth’s angular velocity with acceptable accuracy and in less than 20 minutes. Full details of the experimental apparatus, simple and easy to build, are given.