"Not directly- I'm a man of science, Magic shit is-" He shakes his head, grimacing. "It's physics with a set of rules I don't have the background to understand yet, that's all, and every person I meet that's got some kind of magic is very hush hush about them. But I don't think I've met anyone with magic from Bull's- your world. I figure different worlds, different systems?"

There are too many variables in things that are concrete and known to him already- it'd be impossible for systems or whatever to stay the same from universe to universe.