ABSTRACT
To understand science, students need to learn a large interconnected set of uncommon-sense meanings. But despite decades of research, the precise nature of these meanings has not been made clear. This chapter focuses on the meanings involved in scientific explanations of complex phenomena such as seasons. It synthesizes three decades of research into scientific discourse to renovate the SFL register dimension ‘field’, to better deal with the technical meanings of science. The chapter focuses on explanations of seasons as they are taught in secondary school science and illustrates the ways in which scientific meanings are construed dynamically as series of unfolding activities, and statically as relations between items. It also considers how the gradable properties of science are presented in multimodal discourse and how all of these features of scientific meaning can be reconstrued and connected together to make an integrated whole. The model clarifies the interdependent meanings at play in scientific understandings of the world and the challenges faced by teachers and students when navigating teaching/learning pathways through these networks of meaning. In doing so, it shows how the meanings made through both language and an ensemble of multimodal resources organize scientific knowledge.
