sorry. What I meant to say was, was that there was no physical property that could define the physical limits of a TV. Unless, of course, that you had a;lready defined a TV and its physical limits.
'Colour is not a thing' I said - I meant a physical thing. You used the term "interaction". But an interaction poses as a thing between two domains, in this case colour and nervous system. The two domains cannot be merged by the tern "interact". It only falls between them, as a reference to a metaphor.
Thank you, but you seem to define color, sound, nervous system, mind in such a way as to produce the result you would like -- either toward some form of property dualism or idealism.
To a physicalist, both sound/color/etc. and nervous system are physical -- so there is no issue in their interaction and interaction is not simply a reference to metaphor.
Physicalists speak of physical 'things' that act in the world and part of that action is interaction between two physical 'things'. The deeper insight is that those physical 'things' are themselves actions or interactions. We do not have a proper definition of 'energy'.
If you want to speak about interaction between the physical and non-physical, perhaps you could provide a mechanism? How do such things happen? Isn't interaction defined in physical terms and so impossible for the non-physical? I've yet to encounter a proper explanation of mind body dualism if that is what you are after, so I would appreciate your explanation if you have one.
As to the physical limits of a TV, properly speaking there is no precise physical limit when examined at an extremely small scale. At the scale in which we carry out our daily lives the physical limit, for vision, is created by edge detectors that begin their processing in the retina and carry on their processing in our brains. That aspect of object/ground distinction does not depend on language or the concept of function. The function of the TV produces another aspect of how we distinguish such an object from others that surround it, though.
But we can still define objects that serve one function in one setting as performing another function in another setting. That, in itself, should tell you that defining the function of an object is not the sine qua non of determining what is and what is not an object. We already saw the rock as different from its background because of those edge detectors (and other processing) before we ever decided to define its function as a table.
And, just to drive the point home, a physicalist views the 'mental' processes involved in all those perceptions as physical and not non-physical.