After googling around a bit, it seems Noitartst is referring to this:
The concept of c-decay was first proposed by Barry Setterfield in 1981 in an article for the Australian creationist magazine, Ex Nihilo. He selected a number of historical measurements of c starting with the original measurement by Ole Rmer in 1667, and proceeding through a series of more recent experiments, culminating in "modern" measures in the 1960s. These showed a decreasing speed over time, which Setterfield claimed was in fact an exponential decay series that implied an infinite speed in the not distant past. The claim was later expanded to cover an apparent similar decay of several other physical constants.