In this paper, we bring together various of our published and unpublished
findings from our recent 2D multi-group, flux-limited radiation hydrodynamic
simulations of the collapse and explosion of the cores of massive stars. Aided
by 2D and 3D graphical renditions, we motivate the acoustic mechanism of
core-collapse supernova explosions and explain, as best we currently can, the
phases and phenomena that attend this mechanism. Two major foci of our
presentation are the outer shock instability and the inner core g-mode
oscillations. The former sets the stage for the latter, which damp by the
generation of sound. This sound propagates outward to energize the explosion
and is relevant only if the core has not exploded earlier by some other means.
Hence, it is a more delayed mechanism than the traditional neutrino mechanism
that has been studied for the last twenty years since it was championed by
Bethe and Wilson. We discuss protoneutron star convection,
accretion-induced-collapse, gravitational wave emissions, pulsar kicks, the
angular anisotropy of the neutrino emissions, a subset of numerical issues, and
a new code we are designing that should supercede our current supernova code
VULCAN/2D. Whatever ideas last from this current generation of numerical
results, and whatever the eventual mechanism(s), we conclude that the breaking
of spherical symmetry will survive as one of the crucial keys to the supernova
puzzle.Comment: To be published in the "Centennial Festschrift for Hans Bethe,"
Physics Reports (Elsevier: Holland), ed. G.E. Brown, E. van den Heuvel, and
V. Kalogera, 200