Physical Systems and Physical Thought

Abstract

The notion of physical system is so ubiquitous it is mentioned in almost every work in physics. Scientists use the term, without much reflection, to refer to an aggregate of physical objects. Attention is sometimes directed to a system when one is interested in the system’s components and their distinct states and properties. But more often, physicists are concerned with the arrangement of the parts and interactions between the parts. They use various theoretical constructs to single out states and properties of the composite system; states and properties that either supervene on the particular configuration of the parts or constitute non-supervening, emergent features.