Humboldt-Universität zu Berlin

James Franck studied in Berlin and was awarded his doctorate there under Emil Warburg; he qualified as a professor in 1911. This was the time when his collaboration began with Gustav Hertz at the Institute of Physics of Friedrich-Wilhelms-Universität. It led to a spectacular result after only two years of research. The physicists conducted impact tests with electrons and atoms in 1913. They made the discovery that (mercury) atoms that are in the ground state cannot absorb energy below a certain threshold, which was important for the development of quantum theory.

The two scientists were awarded the Nobel Prize for Physics in 1925 for the discovery of these laws.