  It is first argued that radiation by a uniformly accelerated charge in flat
space-time indicates the need for a unified geometric theory of gravity and
electromagnetism. Such a theory, based on a metric-affine $U_4$ manifold, is
constructed with the torsion pseudo-vector $\Gamma_\mu$ linking gravity and
electromagnetism. This conceptually simple extension results in (i) Einstein's
equations being modified by a vacuum energy $\Gamma_\mu\Gamma_\nu$ and a scalar
field $\Gamma = \Gamma^\mu\Gamma_\mu$ whose zero-mode is a cosmological
constant $\Lambda$ representing `dark energy', (ii) most of the salient
features of `dark matter'-like phenomena, (iii) a modified electrodynamics
satisfying Heaviside duality, (iv) a finite and small Casimir Effect, and at
the same time, (v) the empirical Schuster-Blackett-Wilson relation for the
amazingly universal gyromagnetic ratio of slowly rotating, neutral
astrophysical bodies.
