[kosciusko51]

This assumes that these natural "constants" are really constant.

[zeugma]

This assumes that these natural "constants" are really constant.

I thought of that too. I think Murphy's rules of such things is as follows:
Constants aren't.
Variables dont.

[Logophile]

From the linked article:

It was only about fifty years later, and twenty years after Rømer’s death, that the British astronomer James Bradley’s measurements could definitively prove that the speed of light was indeed finite; it was 1727.

The speed of light was 1727?