In March 2019 I posted on this web site a paper of four and a half pages describing how the expansion of the verse was directly linked to the passage of time. This depended on the assumption that the universe was bounded and finite, with a singular spherical edge expanding outwards as a sphere. If a further assumption was made that this singular this outer edge was travelling at light velocity so that every electromagnetic wave action created within the universe were to be caused to duplicate its motion, then here would be a simple explanation for the transmission of all EM action within.
Furthermore this would also present a very simple diagrammatic explanation for the special theory of relativity. Whereas a spherical bounded and finite universe is not currently fashionable, it is easy to visualise and also one of the alternative models included within the FLRW metric first proposed by Friedman, and then later endorsed by Lemaitre., Robertson and Walker to describe the universe.
Has anybody proposed a similar basis for the mediation of light speed hitherto connected with the shape of the universe, or indeed any basis at all ?