In Adam Bobbette tells the story of how modern theories of the earth emerged from the slopes of Indonesia’s volcanoes. Beginning in the late nineteenth century, scientists became concerned with protecting the colonial plantation economy from the unpredictable bursts and shudders of volcanoes. Bobbette follows Javanese knowledge traditions, colonial geologists, volcanologists, mystics, Theosophists, orientalists, and revolutionaries to show how the earth sciences originate from a fusion of Western and non-Western cosmology, theology, anthropology, and geology. Drawing on archival research, interviews, and fieldwork at Javanese volcanoes and in scientific observatories, he explores how Indonesian Islam shaped the theory of plate tectonics, how Dutch colonial volcanologists learned to see the earth in new ways from Javanese spiritual traditions, and how new scientific technologies radically recast notions of the human body, distance, and the earth. In this way, Bobbette decenters the significance of Western scientists to expand our understanding of the evolution of planetary thought and rethinks the politics of geological knowledge.