What do professional philosophers mean by "physicalism" ?
The definition I use is that physicalism is the worldview that the entities that actually exist in the world are those used for physics (entities like, electrons, quarks, mass, charge etc.) Physics has a set of objects/entities like this and it has equations relating them.
we have a distinction between metaphysical physicalism and linguistic physicalism:
Metaphysical physicalism simply asserts that what there is, and all there is, is physical stuff and its relations. Linguistic physicalism is the thesis that everything physical can be expressed or captured in the languages of the basic sciences…Linguistic physicalism is stronger than metaphysical physicalism and less plausible.
Linguistic physicalism has a well defined meaning as far as I see. But what does metaphysical physicalism even mean?
Another quote from the link:
Similarly to Flanagan, Torin Alter contends that Jackson conflates physical facts with "discursively learnable" facts, without justification: ...some facts about conscious experiences of various kinds cannot be learned through purely discursive means. This, however, does not yet license any further conclusions about the nature of the experiences that these discursively unlearnable facts are about. In particular, it does not entitle us to infer that these experiences are not physical events.
So physical doesn't mean "describable via physics" then what does it mean? What makes a physical fact a "physical" fact if it doesn't mean describable by physics?
In the context of the knowledge argument... we're talking about color... the above quotes are stating, Mary does indeed learn something new about color, but this fact is still "physical" even though it's not describable by physics. What does this even mean?