Original: The Foucault pendulum, or Foucault's pendulum, named after the French physicist LÃ on Foucault, is a simple device conceived as an experiment to demonstrate the rotation of the Earth.
Simplified: The Foucault pendulum, or Foucault's pendulum (named after the French physicist LÃ on Foucault) was created as an experiment to show the rotation of the Earth.