Description:
<jats:p>The general form of the Boltzmann collision operator is discussed. It is argued that this should be the natural transition (super-) operator for a binary collision that is defined analogous to the ordinary transition operator in collision theory. Properties of the collision term are discussed, in particular pointing out its general nonhermiticity and nondefiniteness as well as its behavior under parity, rotations, and time reversal. In general, there is no H theorem.</jats:p>