dinary professor" in 1926 at the age of 48, Germany's first woman professor of physics.
Lise developed a close circle of friends, mostly physicists. Music played an important role in her friendships. The Institut had a choir. Lise and her friends met for regular musical evenings. Einstein played his violin and Meitner taught her friends Brahms songs. In the laboratory, Lise's research focused on clarifying the relationships between the beta spectra and gamma rays emitted by radioactive material. She was at the height of her career. Each year she was among the people discussed for a Nobel Prize.
By the early 1930s nuclear physics had advanced dramatically, and Meitner was fascinated by the emerging information. After twelve years apart, she asked Hahn to team up with her again. She needed an expert radiochemist to identify the new heavy isotopes. To help identify their minute samples, Hahn brought in Fritz Strassmann, an analytical chemist. Two other women completed the group: an American chemist, Dr. Clara Leiber, and their technician, a German, Irmgard Bohne. Meitner was the intellectual leader of the team.
At this time, however, Meitner was forced to interrupt her research and leave Germany. Nazi racial laws were making it increasingly difficult for her to work. At first, Meitner was safe because as an Austrian she was not subject to Germany's anti-Semitic laws and the Kaiser- Wilhelm Institut was controlled by powerful industrialists who were able to protect her. However, Meitner's situation became critical following the invasion of Austria. She was banned from teaching, attending conferences, and publishing her research. When Hahn gave a talk outside the Institut on his work with Meitner, he could not mention her name. Her reputation was being obliterated. In 1938, Dirk Coster at the University of Groningen arranged for Meitner to enter Holland despite her lack of papers. She took a train there on the pretext that she was going on a week's vacation. She left behind all her belongings and her scientific papers.
Meitner remained in Holland for a short time and then went to Denmark, where she was the guest of Niels Bohr. She subsequently accepted an invitation from Manne Siegbahn to work in the new Nobel Institute in Stockholm. Meitner was 60 years old when she went to Sweden. Nevertheless, she acquired a good command of the language and built up a small research group. Her thoughts on her career never changed: "Life need not be easy, provided only that it is not empty." 1
Meitner made her most famous contribution to science shortly after arriving in Stockholm. Mail between Stockholm and Berlin could be delivered overnight, so Hahn and Meitner continued their collaboration. They corresponded several times a week and once met secretly in Copenhagen. Hahn and Strassmann turned to her when they found that