Science history: Lise Meitner, mother of the bomb

Lise Meitner lecturing at Catholic University, Washington, DC, in 1946.

Lise Meitner lecturing at Catholic University, Washington, DC, in 1946.

Lise Meitner has been called “the mother of the atomic bomb”, a description she despised for many reasons, not least of which was that she did not work in any capacity on building the bomb.

She is also credited as the scientist who discovered nuclear fission, for which her longtime colleague Otto Hahn won the 1944 Nobel Prize in Chemistry, while she was not mentioned in the honours.

To be fair, both lapses in recognition can be fairly explained.

In her 1996 New York Times review of Ruth Lewin Sime’s biography, Lise Meitner: A Life in Physics, Marcia Bartusiak says Meitner’s “perceptive realisation that atomic nuclei can be split in half was the first step in a cascading set of discoveries that would relentlessly lead to the atomic bomb”.

But as Bartusiak explains, Meitner had been forced to flee from Nazi Germany in the late-1930s, leaving behind her colleagues and her work. “While this exile saved her life, it cost her the Nobel Prize and a prominent niche in many annals of physics,” she says.

Meitner was born on 7 November 1878 in Vienna, capital of the Austro-Hungarian Empire, into a prosperous family. They were non-religious Jews who later in life converted to Christian denominations.

At a time when young women were not expected to pursue schooling beyond basic education, Meitner was allowed to continue with her studies, majoring in physics at the University of Vienna, and earning a PhD in 1906.

Continuing to break with tradition, in 1907 she was allowed to move to Berlin and attend a semester of lectures by renowned physicist Max Planck at the University of Berlin. She worked as Planck’s physics department assistant for nearly seven years.

In Berlin she joined a group of visionary scientists that included Albert Einstein (he referred to her as “our Marie Curie”) and a talented chemist, Otto Hahn.

Hahn would become her collaborator and friend in a relationship lasting 30 years, and they delved deeply into the young field of radioactivity, where their respective studies of physics and chemistry met.

Working together in the Kaiser Wilhelm Institute for Chemistry, the pair delved into the heart of the atom, its nucleus. As Marcia Bartusiak writes in her review, by bombarding uranium with neutron particles, the researchers “encountered a nightmarish jumble of radioactive species that could not be easily identified”.

“For four long years, Hahn, the expert chemist, carefully separated and processed the radioactive materials; Meitner’s job was to explain the nuclear processes going on.”

Meitner and Hahn produced many highly regarded research papers and were nominated 10 times for the annual Nobel Prize in chemistry or physics, without success.

As Nazi oppression tightened its grip on Germany in the late 1930s, Meitner, who in 1908 had converted to the Christian faith, fled the country, eventually settling in Stockholm, Sweden, where she went to work at the Nobel Institute for Physics.

Remaining in Germany, Hahn and his assistant, Fritz Strassmann, continued to analyse the byproducts of neutron bombardment experiments. They found that the elements weren’t heavier than uranium, but lighter.

In the US Department of Energy’s interactive history of the Manhattan Project and the creation of the atomic bomb, their discovery folIowed from Albert Einstein’s E=mc2 equation that the loss of mass resulting from the splitting process must have been converted into energy, in the form of kinetic energy that could in turn be converted into heat.

Bartusiak continues the story, saying Hahn wrote to Meitner: “Perhaps you can come up with some sort of fantastic explanation. We knew ourselves that [uranium] can’t actually burst apart into [barium]. “

In Sweden, now working with her nephew, Otto Robert Frisch, also a noted physicist, she worked out a theoretical model of nuclear fission. They concluded that so much energy had been released that a previously undiscovered kind of process was at work. Frisch, borrowing the term for cell division in biology – binary fission – named the process “fission”.

Hahn eventually published the chemical evidence for fission without listing Meitner as a co-author. Some sources claim that Hahn hoped to add Meitner’s name to this historic paper, although others dispute this.

Meitner became a dual Swedish-Austrian citizen in 1949 and worked in Stockholm until she retired, age 75, in 1953.

In 1960 she moved to Cambridge, in Britain, to be near her nephew, Otto Frisch, and his family. She died there, at 89, on 27 October 1968. She was buried in the churchyard of St James Church, Bramley.

Leave a Reply