Bruce Hevly Department of History University of Washington, Seattle, U.S.A. Arctic Empires: Terrestrial Physics and the Frontiers of Science 'Arctic imperialism' has become the term associated with Norwegian claims on northern territories in the period leading up to, and immediately following, the separation from the Swedish crown in 1905. Historians have focused on the years from 1890 to the 1920s, discussing the ways in which nationalism shaped scientific practices in this period and, in turn, how science contributed to the nationalist agenda. Here I argue that Norway's experience in using science to buttress territorial claims in the polar regions -- Spitzbergen/Svalbard and Queen Maud's Land, Antarctica -- may serve as a point of departure for an understanding of the development of terrestrial physics in the twentieth century. The science of frontiers -- of establishing, exercising, and maintaining boundaries -- provided the context for terrestrial physics during the Cold War. The American case, in which science and sovereignty provided a matrix in which results in atmospheric physics and physical oceanography were crafted to enlist the world in a series of technological systems, is illuminated by parallels with the Norwegian experience and especially at the points where the NATO partners cooperated in Cold War scientific research.