“At noon, Straßmann’s colleague, the well-known chemist Otto Hahn, returned from the tax office,” says Fürste with a smile. He points to a three-dimensional reconstruction of the experimental rooms on the computer monitor in his office. “When he came back on Saturday morning – back then you still worked on Saturdays, and Straßmann liked to start early – he got the sample and separated the elements,” Fürste says.

Their hope: the neutrons would be absorbed by the uranium and form a transuranium, an atom even heavier than uranium, the heaviest atom known at the time. It was an experiment similar to those being done by other scientists around the world at the time. “On Friday, December 16, 1938, Fritz Straßmann went into the irradiation room to bombard uranium atoms with slow neutrons,” Fürste begins. If you hear him talk about the discovery of nuclear fission, it sounds as if Fürste had been there back then. After studying biochemistry at Freie Universität and doing research at the University of Colorado, Fürste returned to Berlin as a research assistant and began to be interested in the history of the Dahlem science district. Jens Peter Fürste, who holds a doctorate in biochemistry, is something like a living memory of the building. On December 17, 1938, it was the scene of a great moment in science: Here chemists Otto Hahn and Fritz Straßmann discovered nuclear fission, the basis for the peaceful use of nuclear energy, but also the atomic bomb.

The building has been used by the Institute of Biochemistry at Freie Universität Berlin since 1980. With its column-framed portal and fortress-like tower, the Hahn-Meitner Building stands out among the numerous impressive Wilhelminian-style buildings in Dahlem’s science district.

Fission uranium 1938