The American Institute of Physics credits the photo [1] to AB Lagrelius & Westphal, which is the Swedish printmaker used by the Nobel Foundation for most prints/engraving of its book series Les Prix Nobel. · Public domain

A German experimental physicist who shared the 1925 Nobel Prize in Physics with James Franck for demonstrating, in what became known as the Franck-Hertz experiment, how electrons transfer energy to atoms in discrete steps. Classified under Nazi race law in 1934 as a "second degree part-Jew" on account of a grandfather who had converted from Judaism generations earlier, he was pushed out of his post at the Technische Hochschule Berlin. In 1945 he struck a deal with Soviet authorities and spent the next decade directing a nuclear research institute near Sukhumi, work for which Moscow awarded him the Stalin Prize.