Robert (Bo) Jacobs is a Professor at the Hiroshima Peace Institute and Graduate School of Peace Studies at Hiroshima City University in Japan. He is a historian of science and technology focused on the history of nuclear technologies and radiation technopolitics. He has published multiple books and articles, and is the co-founder and lead researcher of the Global Hibakusha Project. In this interview with JJ Walsh (Seeking Sustainability in Japan with JJWalsh), Prof Jacobs speaks of what Hiroshima has meant to him personally, and what the world still needs to learn and remember of the unspeakable horrors unleashed by the atomic bombing of Hiroshima.