Editing Variable speed of light (section)

=== General critique of varying ''c'' cosmologies ===
From a very general point of view, [[George Francis Rayner Ellis|G. F. R. Ellis]] and [[Jean-Philippe Uzan]] expressed concerns that a varying ''c'' would require a rewrite of much of modern physics to replace the current system which depends on a constant ''c''.<ref name="Ellis">{{cite journal |author=Ellis |first=George F. R. |date=April 2007 |title=Note on Varying Speed of Light Cosmologies |journal=General Relativity and Gravitation |volume=39 |issue=4 |pages=511–520 |arxiv=astro-ph/0703751 |bibcode=2007GReGr..39..511E |doi=10.1007/s10714-007-0396-4 |s2cid=119393303}}</ref><ref>{{Cite journal |last1=Ellis |first1=George F. R. |last2=Uzan |first2=Jean-Philippe |date=March 2005 |title=c is the speed of light, isn't it? |url=http://aapt.scitation.org/doi/10.1119/1.1819929 |journal=American Journal of Physics |language=en |volume=73 |issue=3 |pages=240–247 |arxiv=gr-qc/0305099 |bibcode=2005AmJPh..73..240E |doi=10.1119/1.1819929 |s2cid=119530637 |issn=0002-9505}}</ref> Ellis claimed that any varying ''c'' theory (1) must redefine distance measurements; (2) must provide an alternative expression for the metric tensor in general relativity; (3) might contradict Lorentz invariance; (4) must modify [[Maxwell's equations]]; and (5) must be done consistently with respect to all other physical theories. VSL cosmologies remain out of mainstream physics.