  We review quantum causal histories starting with their interpretations as a
quantum field theory on a causal set and a quantum geometry. We discuss the
difficulties that background independent theories based on quantum geometry
encounter in deriving general relativity as the low energy limit. We then
suggest that general relativity should be viewed as a strictly effective theory
coming from a fundamental theory with no geometric degrees of freedom. The
basic idea is that an effective theory is characterized by effective coherent
degrees of freedom and their interactions. Having formulated the pre-geometric
background independent theory as a quantum information theoretic processor, we
are able to use the method of noiseless subsystems to extract such coherent
(protected) excitations. We follow the consequences, in particular, the
implications of effective locality and time.
