  The electromagnetic interaction is characterised by discrete states for bound
systems in contrast to continuous states for unbound systems. The difference
merely arises because the characteristic equations do not exhibit the same
behaviour for negative and positive energy parameter values, thus the apparent
distinction between bound and unbound states can be considered purely
descriptive and completely superficial - there is no indication that bounded
and unbounded systems are subject to differing physical laws. However, the
remarkable suggestion has been made that there exists a behavioural distinction
between bound and unbound states of systems under gravitational influence. This
notion is critically evaluated here. At the very basic level, a severe problem
is found in defining a local concept of boundedness consistent with the current
understanding of the gravitational interaction. Nevertheless it is difficult to
exclude the possibility that bound and unbound systems are dynamically
distinct, a distinction that may be relevant to existing cosmological and
astronomical anomalies.
