Warning! Laymen reasoning ahead :) I've long heard that in science nothing is proven. That proof is a mathematical term. So what exactly do you call a certifiably known fact? An example is that the earth is round or at least that the earth is not flat. What do you call that? Can we not say it's proven or that we have proof that the earth is round? If not technically, what then do we call that fact? Is it really a fact if we can't prove it? Also at what amount of evidence do we call something a fact even if we can't technically prove it?