I have asserted many times here that physicalism as degraded into an undecidable question, and I would like to see how strong my understanding is.
It seems to me that whenever we approach the boundary of what should be considered physical, it retreats, without those insistent on physicalism ever having to admit any new limitation on what the new boundaries are.
We accepted that there is an absolute limitation on how well we can apply any physical law. And we declared that physics... Previous generations would have declare that mysticism (and quite a few since, have, actually, to the resounding dismissive moans of the literati.)
If an angel came up to someone and demonstrated his powers, a modern man is just as likely to assume they are some kind of advanced alien, rather than an angel. Or we will anthropologically and psychologically explain why they are the 'cause' of the mythology of angels, like in Arthur Clarkes "Childhood's End."
So, is there something that we could imagine having no physical explanation? Is physical well-defined enough to even have boundaries? If not, why ask questions about it?
Direct violations of existing paradigms don't count. We all know what happens when you break a physical law -- the law changes. What is really physically impossible (for you)?