The role of mathematics in physics: building knowledge and describing the empirical world

This paper considers why mathematics is used in physics. It traces the use of mathematics in physics through primary school, junior high school and senior high school in NSW, Australia, considering its role from the point of view of Systemic Functional Linguistics and Legitimation Code Theory. To understand the development of mathematics, two genres that play differing roles in the discipline of physics are introduced: ‘derivation’ and ‘quantification’. Through an analysis using the concepts of semantic density and semantic gravity from Legitimation Code Theory, these genres are shown to aid physics in developing new knowledge and linking its theory to the empirical world. This paper contributes to the growing body of research considering forms of knowledge in academic disciplines and the role of non-linguistic semiotic resources in organizing this knowledge