Dr. Lise Meitner, the Austrian-born physicist whose calculations helped reveal the immense energy released by splitting the uranium atom, died at 89 in Cambridge, England. A pioneering figure in nuclear physics, she laid much of the theoretical groundwork for the atomic bomb, though she did not participate in its development and later distanced herself from its destructive use.

For three decades, Meitner worked closely with German chemist Otto Hahn at the Kaiser Wilhelm Institute, producing influential research in radioactivity. In 1938, as antisemitism intensified under Nazi rule, she fled Germany to Sweden. Months later, Hahn reported experimental results showing that the uranium atom could be split. From exile, Meitner correctly interpreted the findings, calculated the vast energy release, and, with her nephew Otto Frisch, published the first explanation of what she named nuclear fission.

Although her insights helped usher in the nuclear age, Meitner expressed regret that the discovery was weaponized during wartime. She consistently emphasized that she had not worked on building a bomb and later advocated for international cooperation to prevent the destructive use of atomic energy. Over her long career, she received numerous honors, including a major award from the United States Atomic Energy Commission, shared with Hahn and Fritz Strassman.