  We show that the Hamiltonian mean field (HMF) model describes the equilibrium
behavior of a system of long pendula with flat bobs that are coupled through
long-range interactions (charged or self gravitating). We solve for the
canonical partition function in the coordinate frame of the pendula angles. The
Hamiltonian in the angles coordinate frame looks similar to the form of the HMF
model but with the inclusion of an index dependent phase in the interaction
term. We also show interesting non-equilibrium behavior of the pendula angles,
namely that a quasistationary clustered state can exist when pendula angles are
initially ordered by their index.
