I think this one gets more complicated when you include beliefs about things like theorems of logic, e.g., "Any consistent formal system powerful enough to describe Peano arithmetic is incomplete." It seems to me that this belief is meaningful, yet independent of any sensory experience or physical law. That is, it's not really a belief about "the universe" of atoms or quantum fields or whatnot. Perhaps it would be better to talk about these "beliefs" as a separate category.