Youth in Mannheim; studies in Heidelberg; conflict with Philip P. Lenard; doctoral work in Gottingen under James Franck; the Hanle effect; brief stay in Tubingen; position in Halle with Gustav L. Hertz, and then in Jens, Gottingen and Giessen during scientifically and politically eventful years in Germany; work in Jena on the excitation function and response to Otto Hahn's discovery of fission and the giessen; reconstruction of the university; range of scientific work since the war, especially level crossing techniques and dosimetry; the development of nuclear power; comments on the DDR; current political outlook.