In mid-1938, Meitner and chemists Otto Hahn and Fritz Strassmann at the Kaiser Wilhelm Institute for Chemistry demonstrated that isotopes of barium could be formed by neutron bombardment of uranium. Meitner was informed of their findings by Hahn, and in late December, with her nephew, fellow physicist Otto Robert Frisch, she worked out the physics of this process by correctly interpreting Hahn and Strassmann's experimental data. On 13 January 1939, Frisch replicated the process Hahn and Strassmann had observed. In Meitner and Frisch's report in the February 1939 issue of Nature, they gave the process the name "fission". The discovery of nuclear fission led to the development of atomic bombs and nuclear reactors during World War II.