This week, Dr Sophie Ritson is in conversation with Professor Peter Galison, Joseph Pellegrino University Professor in History of Science and Physics at Harvard University, a founding member of the Black Hole Initiative, and coordinator of the History, Philosophy and Culture (HPC) Working Group of the next-generation Event Horizon Telescope (ngEHT). Galison is a historian and philosopher of science whose work has explored how experiments end, how scientific images are made and interpreted, and how practices of objectivity have developed. His books include How Experiments End, Image and Logic, Einstein’s Clocks, Poincaré’s Maps, and Objectivity (with Lorraine Daston). He also co-directed Secrecy and directed Black Holes: The Edge of All We Know, which follows the effort to produce the first image of a black hole. Sophie Ritson is a historian and philosopher of science at the University of Melbourne, and one of the leaders of the Collaborations focus group within the ngEHT’s HPC Working Group. The group brings historians, philosophers, ethnographers and sociologists into a physics collaboration while it is still being built, rather than studying it retrospectively. Its work examines questions of governance and social epistemology, including authorship, consensus and disagreement. Ritson’s own research has explored the string theory controversy, “non-discovery” in high-energy physics, and research governance, drawing closely on her engagement with physicists at CERN and the Large Hadron Collider. In this episode, Galison traces his path into the history and philosophy of science through family, teaching, and laboratory experience, emphasising how experimentalists taught him to distinguish effects from artefacts—a question that shaped his first book. He explains his interest in scientific images as a way of recovering the craft and tacit knowledge obscured by the protocol-driven view inherited from logical empiricism. The conversation then turns to the 2019 M87* image, which he presents as the culmination of his interest in secrecy and invisibility. The discussion concludes with broader questions about distributed knowledge, the state of HPS, and how to design billion-dollar instruments that remain open to the unexpected. This episode: Describes Galison's path into physics and the history of scienceExplains how distinguishing a real effect from an artefact shaped How Experiments EndIntroduces visualisation as a topic in HPS, against protocol-driven accounts of knowledgeDiscusses the materiality of science, and why the laboratory has looked like a church, a factory, and a startupFrames secrecy as "anti-epistemology," and how blocked knowledge illuminates how knowledge is securedArgues the black hole image is a computational image, and that photography is an expansive categoryReflects on the reconvergence of history and philosophy of science with contemporary practiceCloses on why images can surprise us, and how to design experiments open enough to find the unexpectedThis interview was recorded in July 2025. Relevant Links Peter Galison, HarvardSophie RitsonngEHT History, Philosophy and Culture Working Group"Big STEM collaborations should include humanities and social science", Nature Human Behaviour (2023)A unique collaboration using a virtual Earth-sized telescope shows how science is changing in the 21st century, The ConversationThe HPC White Paper, Galaxies (2023)Black Holes | The Edge of All We Know (2020)Black Hole Initiative, Harvard UniversityEvent Horizon Telescope, first image, 10 April 2019Objectivity (Zone Books, 2007)How Experiments End (University of Chicago Press, 1987)S3 Ep 7, Sophie Ritson on 'Collaboration in Science' Episode production assistant: Paul Carter Thanks for listening to The HPS Podcast. You can find more about us on our website, Bluesky, Instagram and Facebook feeds. This podcast would not be possible without the support of School of Historical and Philosophical Studies at the University of Melbourne and the Hansen Little Public Humanities Grant scheme. Music by ComaStudio. Website HPS Podcast | hpsunimelb.org
