Caledonian, that's mere sophistry to say "mathematics is physics because it is performed by a brain or analogous physical device".

According to that definition, no matter what you study at university, you are really doing physics. Every single human being that has ever earned a university degree earned a physics degree (since English is Physics, Art History is Physics, etc.), and every individual whose work involves use of her brain (even if only for respiration and basic metabolic processes) is a physicist.

I think I'll stick with the understanding of physics that the rest of the world uses.