How does talk work, and can we engage the public in a dialogue about the scientific study of talk? This article presents a history, critical evaluation and empirical illustration of the public science of talk. We chart the public ethos of conversation analysis that treats talk as an inherently public phenomenon and its transcribed recordings as public data. We examine the inherent contradictions that conversation analysis is simultaneously obscure yet highly cited; it studies an object that people understand intuitively, yet routinely produces counter-intuitive findings about talk. We describe a novel methodology for engaging the public in a science exhibition event and show how our ‘conversational rollercoaster’ used live recording, transcription and public-led analysis to address the challenge of demonstrating how talk can become an informative object of scientific research. We conclude by encouraging researchers not only to engage in a public dialogue but also to find ways to actively engage people in taking a scientific approach to talk as a pervasive, structural feature of their everyday lives.