I'm well aware not all atheists are physicalist, materialist, naturalist, etc, but I'm specifically talking to this common subcategory of atheists. I want to know if there's any solid support/evidence or reasoning for your position. Literally anything at all. Usually there are only two responses. First is a "lack of evidence," which itself isn't evidence at all. People also tend to confuse "I'm unconvinced" with "that's not evidence," but even "I'm not convinced" is a simply a subjective feeling, an appeal to your own emotion. The other is simply "prove otherwise," but physicalism is not a default position, and it's specifically physicalism being put forth, the asker is not making some claim.
So beside a subjective appeal (unconvinced) and dodging the question (prove otherwise), is there any evidence or reasoning to support a purely "physical" universe without any gods currently posited, knowingly to you, by human beings?