Classical Illustrations of CP Violation in Kaon Decays

It is easy to construct classical 2-state systems illustrating the behavior of the short-lived and long-lived neutral $K$ mesons in the limit of CP conservation. The emulation of CP violation is more tricky, but is provided by the two-dimensional motion of a Foucault pendulum. Analogies are drawn between the pendulum and observables in neutral kaon decays. An emulation of CP- and CPT-violation using electric circuits is also discussed.