They may point to the middle, but that's not a reference to half an object. ;) The assumption is that the thing is its entirety, as you said. Hypothetically,

They may point to the middle, but that's not a reference to half an object. ;) The assumption is that the thing is its entirety, as you said. Hypothetically, I imagine an array index reference, in human terms, would be communicated as "this thing starts here" or "this is the beginning of this thing." Which isn't a concept or phrasing we have much occasion to use, other than for routes or long length-measured objects?