The field of astronomy is in many ways unique. In most other sciences, experimental investigation has been a major source of knowledge. Astronomy, however, is observational rather than experimental. Astronomers cannot carry out controlled experiments with their objects of interest—they are too big and too far away. We are stuck here on our small, insignificant planet and forced to simply observe. This observational nature of the discipline affects the ways in which astronomical knowledge is created, and this, in turn, affects the ways in which astronomy is taught and learned. 

This project aims to examine how astronomy knowledge is created and mediated through the use of representations (semiotic resources) and the role these representations then play in student learning. Following a social semiotic approach (Airey & Linder, 2017), we carry out a semiotic audit (Airey & Erikson, 2019) in order to determine the disciplinary and pedagogical affordances (Airey, 2015) of the representations used in the observation and visualization of large-scale structures in the Universe The ultimate goal is a better understanding of how these representations can be used and potentially adapted for educational purposes.  Our research questions are as follows:

RQ1       What is the ecosystem of representations presented to students of astronomy?

RQ2       What are the disciplinary and pedagogical affordances of these representations?

RQ3       In what ways do the individual representations work together to mediate astronomy knowledge?

In order to answer RQ1, we carried out an audit of the range of representations in three courses at Stockholm University (Cosmology, Introduction to Astrophysics and Observational Astronomy). We observed lectures, analysed lecture notes and textbooks and interviewed university lecturers. From the data collected, our analysis followed two steps: first, we categorised the representations we found using the framework developed by Salimpour et al. (2021) for the topic of cosmology. Thereafter, for RQ 2 we chose to focus our analysis on three specific representations that are highly relevant for the discipline and therefore have high disciplinary affordance—namely the Cosmic Microwave Background Temperature Fluctuations Map, the Galaxy Density & Redshift Distribution and the Properties of the Universe Graph. We analysed these three central representations with a focus on identifying their disciplinary affordance, comparing this with those aspects of disciplinary knowledge that are present (noticeable) in each representation and those that are appresent: i.e., aspects that are obvious to disciplinary experts, but strictly speaking not directly observable for a novice (Marton & Booth, 2013).

Our audit shows a wide variety of different representational forms are presented to students, from graphs and mathematics to computer coding and 3D animations. However, despite this range, there is no indication that the coordination of these representations in the educational setting is performed in such a way that focuses on making the appresent aspects of disciplinary knowledge more accessible for students. The pedagogical affordance of the individual representations used was generally low and it was usual for the representational products of observations to be used in an unmodified form. The results point out to further conclusions regarding the underdevelopment of teaching methods and explanatory mechanisms when it comes to teaching subjects of modern science using the latest research findings.