  This article aims to answer the question, "What is the simplest system that
embodies the essence of Foucault's pendulum?" We study a very elementary
idealized system that exhibits a precession behavior analogous to the classic
pendulum. The system consists of a particle without inertial mass, constrained
to an inclined plane that rotates about a vertical axis. Insights gained from
this analysis are used to understand the rate of precession in a
straightforward way.
