The hard sphere gas is
a mathematical model in which
several spherical particles collide elastically
with each other in a compact Euclidean domain.
Using the fact that this system can be modeled as point billiard,
its dynamical properties
have been investigated extensively, with a great
deal of progress towards establishing a central
hypothesis, viz., that the system is ergodic.
Here we consider the implications of extending
the model to include non-spherical particles which
have rotational as well as translational components
of motion. We show that the point billiard model which
forms the basis of the hard sphere gas investigations
can be extended to the non-spherical case.