rt of the world (space, time, energy,
    and matter) that we choose to model.  The separation of semantics (measurement of particular events)
    from syntax (the formal model of universal laws) is essential for physical theory.

HP: I often quote von Neumann, although there is general consensus in physics:

    | That is, we must always divide the world into two parts, the one being the observed system,
    | the other the observer.  In the former, we can follow up all physical processes (in principle
   