|
|
|
 |
History : Hall of Fame : Lise Meitner
|
Lise Meitner (1878 - 1968)
Meitner was an Austrian-Swedish physicist, who first identified nuclear fission. She was born in Vienna and educated at the universities of Vienna and Berlin. In association with the German physical chemist Otto Hahn, providing the theoretical basis for fission, she helped discover the element protactinium in 1918, and was a professor of physics at the University of Berlin from 1926 to 1933. When Nazi Germany annexed Austria in 1938, Meitner, a Jew, fled to Sweden. In her absence, Hahn and Fritz Strassmann continued experiments they had begun earlier with Meitner and demonstrated that barium was produced when a uranium nucleus was struck by neutrons. This was absolutely startling because barium is so much smaller than uranium! Hahn wrote to Meitner, "it [uranium] can't really break up into barium . . . try to think of some other possible explanation." While visiting her nephew Otto Frisch for the Christmas holidays in Denmark, she and Frisch proved that a splitting of the uranium atom was energetically feasible. They employed Niels Bohr's model of the nucleus to envision the neutron inducing oscillations in the uranium nucleus. Occasionally the oscillating nucleus would stretch out into the shape of a dumbbell. Sometimes, the repulsive forces between the protons in the two bulbous ends would cause the narrow waist joining them to pinch off and leave two nuclei where before there had been one. Meitner and Frisch described the process in a landmark letter to the journal Nature with a term borrowed from biology: fission. In 1939 Meitner published the first paper concerning nuclear fission. She is also known for her research on atomic theory and radioactivity. In her work she predicted the existence of chain reaction, which contributed to the development of the atomic bomb.
|
|
