Jörg Kärger got his PhD in Physics in 1970 at Leipzig University, followed by habilitation in 1978. In 1994 he became Professor of Experimental Physics and head of the Department of Interface Physics in Leipzig. He served as Dean of the Faculty of Physics and Earth Sciences at Leipzig University (1996 – 1999), President of the German Zeolite Association (1996 – 1999) and Ombudsman of Leipzig University (2002 – 2006). His research activities, unabatedly continued after retirement in 2009, are dedicated to diffusion phenomena and novel techniques of their measurement. They gave rise to the establishment of the Diffusion Fundamentals online journal and conference series. His book on Diffusion in Nanoporous Materials (Wiley-VCH, 2012), co-authored by Douglas Ruthven and Doros Theodorou, became standard in the field. His activities were recognized, among others, by the Donald W. Breck Award for zeolite research, the Max Planck Research Prize and election to the Saxon Academy of Sciences.