Uniformitarianism - demonstrated or assumed?

Hey Subbie.IIRC, RAZD's correlations (which to me are bulletproof) extend "only" as far back as ~100ky, taking into account Antarctic ice cores. When I say "only", I'm taking a devil's advocate stance in assuming a YEC may harp, "Well, even if I did believe these floating chronologies, and time extends at least this far back, who's to say constants and laws hadn't varied wildly prior to 100ky? Uniformitarian rubbish! Aarrgh!!" Seems like you'd need some Oklo reactor data (although this assumes you accept radiometric dating) or evidence of normal isotope decay in distant supernovae (although this assumes you accept stellar distances).I'm all ears for any (new) arguments to present to YECers regarding uniformitarianism. Unfortunately, if they remain true to form then per usual we'll be beating our collective head against a brick wall.BTW, are you in MN?Have a good one.