Radiation as Self-Action via a Cosmological Mirror

Abstract Expressed in conformal coordinates, the cosmological scale factor is anti-symmetric about the conformal singularity. Does this imply the existence of a post-singularity ‘image’ universe?. If so, what degree of reality should be conferred on the image? Is it a mathematically redundant copy of our (real) presingularity universe, or something more substantial? This paper initially considers these questions in the light of the behavior of matter and radiation at and just beyond the singularity. We draw attention to the fact that the conformal singularity presents no barrier to radiation, so that a post-singularity universe, if it exists, must be electromagnetically coupled to our own. Further, the time-reversed scale factor, taken literally, predicts this radiation is destined to be progressively blue-shifted after passing through the singularity event. Consistency appears to demand the existence of a substantial mirror universe, fully populated with matter and radiation so as to be compatible with the time-reversed scale factor. Either that, or there is deadwood in the mathematics. Motivated by these considerations, we argue a role for a mirror universe which depends on electromagnetic coupling through the singularity, in which it appears as essential rather than optional. We point out that the post-singularity universe provides the missing absorbers required by the Wheeler-Feynman absorber theory in the framework of direct particle interaction. This theory explains radiation in terms of particle-particle interactions, without appeal to independent degrees of freedom of an electromagnetic field. The proposed mechanism involving two universes ties the electromagnetic arrow of time to the cosmological arrow associated with expansion. We conclude with suggestions about why this is perhaps just the first step toward a fuller integration, wherein both universes are recognized necessary parts of theories and phenomena in other areas of physics.