History of Black Hole Visualizations

Existing work on Penrose diagrams has shown how they were used to promote intuition of objects such as black holes by representing General Relativity in the form of ‘paper tools’ (Wright 2012, 2013). Drawing on an extensive collection of visually realistic black hole images (a collection made as part of this project), as well as interviews with black hole researchers, I take the question of intuition to the history of visually realistic representations of black hole shadows. Text framing early representations of this kind would often distinguish between the apparent position of light near a black hole and its actual position when describing the deflection of light. Through interchange between text and image, researchers focused on the unusual behaviour of light in this region in order to explain the nature of what cannot be seen. First, I trace the history of visual and textual representations used to make spaces around black holes intuitive to readers, from early representations drawing on calculations and simulations to the present-day observations. I then focus on accounts from researchers tied to the Event Horizon Telescope Collaboration, the collaboration which released the first observation of the shadow of a black hole in 2019. When discussing the use of images to provide intuition of black holes, we find a wide range of views within the collaboration which first produced images on the basis of observation: some argue that images of light near black holes are in fact counterintuitive, and others describe various ways in which images can help further intuition about black holes in research and communication to audiences of varying degrees of specialization.