I do not ignore it. I showed you that it doesn't mean a thing.
It is creative research based on highly questionable numbers.
Didn't you see what I posted earlier? According to the numbers tuppence gave c hasn't decreased more then 0.5 kilometers per second between 1951 and 1983?
In this article you will even find reasons why the measured speed of light would have been "higher" in earlier days.
It also claims that the speed of light is constant indeed.