FAITH... WITH REASON

Again, good reply, and yes, this is what I meant by always. However, I could ask the same about the speed of light, if it's constant velocity as always been constant but this is by-the-by really as I don't particularly want to get metaphysical and go off topic. The point of my original question was that if ArArArchStanton didn't know the evidential for the axiom posited then it's okay to take it on faith; unjustified but still held true.  


Take your explanation for example; I think you're talking about spectroscopy, which I know nothing about, and I've taken your explanation on good faith because, inductively, I feel that most people tend to speak truthfully and, abductively, you seem to know what you're talking about so have no need to lie. Yes, I have reasoned to this but it doesn't mean that my reasoning is justified therefore known. Of course, I could go and read a physics textbook and fully justify my belief but for now, I take it on good faith and feel no need to scramble for another word other than faith for the sake of sensibilities.



I do have one off-topic question though: if this spectroscopy is done within a relativistic method of the universe then isn't the evidential of invariant laws somewhat circular?