Lise Meitner (; German: ['ma?tn?]; 7 November 1878 – 27 October 1968) was an Austrian-Swedish physicist who worked on radioactivity and nuclear physics.
Meitner, Otto Hahn and Otto Robert Frisch led the small group of scientists who first discovered nuclear fission of uranium when it absorbed an extra neutron; the results were published in early 1939.
Meitner, Hahn and Frisch understood that the fission process, which splits the atomic nucleus of uranium into two smaller nuclei, must be accompanied by an enormous release of energy.
Their research into nuclear fission helped to pioneer nuclear reactors to generate electricity as well as the development of nuclear weapons during World War II.
Meitner spent most of her scientific career in Berlin, Germany, where she was a physics professor and a department head at the Kaiser Wilhelm Institute; she was the first woman to become a full professor of physics in Germany.
She lost these positions in the 1930s because of the anti-Jewish Nuremberg Laws of Nazi Germany, and in 1938 she fled to Sweden, where she lived for many years, ultimately becoming a Swedish citizen.
Meitner received many awards and honors late in her life.
But she and Otto Frisch did not share in the 1944 Nobel Prize in Chemistry for nuclear fission, which was awarded exclusively to her long-time collaborator Otto Hahn.
Several scientists and journalists have called her exclusion "unjust." However, Meitner has received many posthumous honors, including the naming of chemical element 109 meitnerium in 1992.
According to the Nobel Prize archive, she was nominated 19 times for Nobel Prize in Chemistry between 1924 and 1947, and 29 times for Nobel Prize in Physics between 1937 and 1965.
Despite not having been awarded the Nobel Prize, Meitner was invited to attend the Lindau Nobel Laureate Meeting in 1962.