|Biography:||Arns is engaged in research on the history of 20th century physics and on the history of technologies. The results of this work also have significance for physics education, public policy relative to the support of research and development, and the management of scientific and technological change in industry. He has numerous publications in experimental nuclear physics. Work in progress includes continuing research on the persistence of ether concepts in the 20th century; the influence of naive beliefs on the development of scientific understanding; the history of the field-effect transistor; the early history of neutrino detection; and the discovery of electron spin. In 1998, he was awarded the IEEE Life Members' Prize for the best research on any aspect of the history of electrical, electronic or computing technologies published in any journal during 1997.