It is probably not an overstatement to assert that anyone who does not adequately understand the phenomena of redshifted light in space, emanating from luminous celestial objects and received by observers in Earth, cannot really understand cosmology. Why? Because, depending upon how such redshifts observed from galaxies are interpreted, the universe is either 1) an expanding finite sphere which possibly originated from a microscopic Big Bang; or 2) it is infinite in space and time and has no geometrical shape or systematic motion on a cosmic scale.
To paraphrase Professor Herbert Dingle (President of the Royal Astronomical Society from 1951-53), without the galactic redshift phenomena “Cosmology would scarcely exist as a scientific subject.” In other words, the entire subject of current cosmology is primarily premised on the perception and interpretation of galactic redshifts…and the deductions and extrapolations based thereon.
The remaining discussion is largely devoted to what causes a galactic redshift phenomenon, the fascinating and fantastic deductions that have followed from various interpretations of galactic redshifts, and the validity or invalidity of these speculations. The little-known issues, discussions, and commentary along the way should prove to be thought provoking and insightful, as well as controversial.