  The theoretical vacuum energy density estimated on the basis of the Standard
Model of particle physics and very general quantum assumptions is 59 to 123
orders of magnitude larger than the measured vacuum energy density for the
observable universe which is determined on the basis of the Standard Model of
cosmology and empirical data. This enormous disparity between the expectations
of two of our most widely accepted theoretical frameworks demands a credible
and self-consistent explanation, and yet even after decades of sporadic effort
a generally accepted resolution of this crisis has not surfaced. Very recently,
however, a discrete self-similar cosmological paradigm based on the fundamental
principle of discrete scale invariance has been found to offer a rationale for
reducing the vacuum energy density disparity by at least 115 orders of
magnitude, and possibly this new paradigm offers a means of eliminating the
vacuum energy density crisis entirely.
