[g82918]

People have at least once though the citation escapes me, it was 2006ish. And it could be found in agreement with observation. Not that I believe in it.

[eesmith]

I missed this the first time - https://en.wikipedia.org/wiki/Variable_speed_of_light (I used Google Scholar to find that first reference).

There are about a dozen references in the 2006ish timeframe.