  We highlight the fact that the lack of scale invariance in the gravitational
field equations of General Relativity results from the underlying assumption
that the appropriate scale for the gravitational force should be linked to the
atomic scale. We show that many of the problems associated with cosmology and
quantum gravity follow directly from this assumption. An alternative scale
invariant paradigm is proposed, in which the appropriate scale for General
Relativity takes the Universe as its baseline, and the gravitational force does
not have any fixed relationship to forces that apply on the atomic scale. It is
shown that this gives rise to a quasi-static universe, and that the predicted
behaviour of this model can resolve most of the problems associated with the
standard Big Bang model. The replacement of Newton's gravitational constant in
the quasi-static model by a scale-dependent re-normalisation factor is also
able to account for a number of astronomical observations that would otherwise
require ad-hoc explanations. Some of the implications of scale invariant
gravity for Planck scale physics, quantum cosmology, and the nature of time are
discussed.

General Relativity and Quantum Cosmology