Hi Mark, thank you for your gracious contributions to the discussion.

On the “assumption” of uniformitarianism, I wrote the following comment some time ago in another thread:

I hope that helps to shed some light on “uniformitarianism”.

Now, concerning the speed of light, we have verified that this value has remained constant with many different measurements / lines of reasoning. For example, if it would not have been constant, many physical systems would have collapsed. Think about the famous equation: E = mc^2 (or in words, energy equals mass times the square of the speed of light). Now imagine tweaking the speed of light, c. Suddenly, all nuclear processes that convert mass (m) into energy (E) will produce totally different amounts of energy! Stars in the universe would not remain stable if we would allow the speed of light to vary even a very small amount. Yet we see normal, stable stars even very, very far away from us.

Casper