An aether model based upon a degenerate Fermion fluid, composed primarily o
f electrons and positrons in a negative energy state relative to the null s
tate or true vacuum, is proposed and its consequences are explored for phys
ics and cosmology. The model provides both insight and quantitative results
for a large number of phenomena for which conventional theory provides no
answers or unsatisfactory answers. Among the concepts treated are wave-part
icle duality; the nature of spin (a vortex in the aether); the derivation o
f Hubble's law; electric fields (polarization of the aether); Zitterbewegun
g (a bare particle orbiting within a vortex core); inflation in cosmology;
the arrow of time; the Pauli exclusion principle (repulsion between paralle
l spin vortices); the nature of the photon (a region of rotating polarized
aether propagating with a screw-like motion); neutrinos (a spin vortex with
no particle in its core); redshifts; gamma-ray bursters; and a number of o
ther topics. A key assumption is that the speed of light is the Fermi veloc
ity of the degenerate electron-positron plasma that dominates the aether. A
s a consequence the speed of light decreases with time on the scale of the
age of the universe.