Episode Description

Leona Woods Marshall Libby was the only woman hired onto Enrico Fermi's team at the Metallurgical Laboratory at the University of Chicago. She was just 23 years old, already had a Ph.D. in molecular spectroscopy and a deep understanding  of vacuum technology. She was also the only woman present at the world’s first successful nuclear chain reaction. Amid all this, she managed to conceal her pregnancy until two days before her baby was born.

Episode Transcript

One of Many Lost Women of the Manhattan Project: Leona Woods Marshall Libby

Katie Hafner: On July 16th, 1945, as J. Robert Oppenheimer watched the first successful test of a nuclear bomb in the New Mexico Desert, a piece of Hindu scripture came to him: “Now I am become death, the destroyer of worlds.”

As Oppenheimer remembered it, death is a common translation of this section of that scripture. But a more literal translation would be, “Now I am become time,” signifying the cycle of life and death.

This is a Lost Women of Science series about a certain pivotal time in the history of humankind. During World War II, thousands of scientists and engineers worked on the Manhattan Project, developing the first nuclear weapons. As the staggering power of atomic weaponry became clear, many scientists wrestled with challenging questions: what is the moral obligation we have to the knowledge that we are now, in the words of Oppenheimer himself, intervening – explicitly and heavy-handedly – in the course of human history? Was the creation of an atomic bomb inevitable? Was deploying it absolutely necessary in order to end the war? Were we death, or were we time?

Speaker: Hoylande Young.

Speaker: Augusta Teller.

Speaker: Eleanor Bowman.

Katie Hafner: Hundreds of the scientists who worked on the Manhattan Project were women. They were physicists, chemists, engineers, and mathematicians working from Los Alamos, New Mexico, Oak Ridge, Tennessee, Chicago, Illinois. Through their work on the Manhattan Project and beyond, they left legacies of technical achievement, scientific curiosity, and discovery.

These women, too, wrestled with the question of moral responsibility, and as you'll see, they differed widely in their views. Over the next few weeks, we're bringing you Lost Women of the Manhattan Project. We'll read hundreds of their names aloud, and we'll also get to know a half dozen of them and the work they did particularly well. For this first episode, producer Erica Huang brings you the story of Leona Woods Marshall Libby.

SL Sanger: But I, I was just curious if you had any particular – if anybody took note of the fact you were a woman. Did you have any problems, I mean, or were you treated differently?

Leona Woods Marshall Libby: That's a dumb thing to say!

Erica Huang: This is Leona Woods. Later known by the names Leona Woods Marshall and Leona Marshall Libby.

SL Sanger: I'll turn this off.

Erica Huang: And, as interviewer S. L. Sanger points out in this interview from 1986, a woman. Specifically, the only woman present during the world's first demonstration that a nuclear chain reaction was possible.

Leona Woods was born on a farm in Illinois. She rocketed through school, graduating from high school at 14 and receiving her BS in chemistry from the University of Chicago at 19. By 1942, Leona Woods was 23 and had just completed her PhD in molecular spectroscopy.

As part of her doctoral research, she studied vacuum technology. Her friend, physicist Herbert Anderson, needed someone with that knowledge to build boron fluoride detectors for the world's first nuclear reactor, known as the Chicago Pile 1, which was built in a squash court under the stands of the football field at the University of Chicago. So as soon as Leona's doctorate was approved, he hired her onto Enrico Fermi's team.

Leona Woods Marshall Libby: Enrico was – as long as he was there, I worked with him.

Erica Huang: Leona was the youngest scientist there. There's this picture of her taken in 1946. She's standing among the other Chicago pile scientists – Fermi's there – a Nobel Laureate, and Leo Szilard, Walter Zinn, Harold Agnew – renowned leaders in their fields. She stands tall among the sea of older men, looking steadily at the camera.

Enrico Fermi's team was working to create a self-sustaining chain reaction, the first crucial step in creating an atomic bomb.

Leona writes in her book, The Uranium People, about some of her brushes with radioactivity.

One morning she was soldering a canister full of hazardous materials, and she absorbed so much radiation that her white blood cell count dropped to half its normal level.

SL Sanger: How did it happen that you were mixed up with that?

Leona Woods Marshall Libby: They got me into everything and I take it very kindly.

Erica Huang: When Leona says she “takes it kindly,” she's not kidding. She seemed completely unfazed by this event.

When doctors expressed concern about her fertility and the egg cells she could be jeopardizing by working so closely with radioactive material, Leona shrugged off their concern. She writes in her book, “The job was correctly done, and it had had to be done.”

Leona married fellow physicist John Marshall and when she became pregnant in 1943, she decided to keep it a secret from the head of the Chicago Pile operations with Enrico Fermi as a co-conspirator. She wore baggy overalls into the reactor building, vomited in the morning in the women's bathroom – which by the way, she had all to herself – and got right to work.

She writes that Fermi “asked for instructions from [his wife] on how to deliver a baby if need be on top of [the Chicago Pile].” Leona let Fermi know in no uncertain terms that he was not going to be her midwife.

She gave birth to a healthy boy in the hospital in 1944.

SL Sanger: Well then how did you handle your –  the child?

Leona Woods Marshall Libby: My mother was there.

SL Sanger: For the whole time?

Leona Woods Marshall Libby: Sort of.

Erica Huang: Leona survived the radiation, and having the child and her work on the Chicago Pile paved the way for the atomic bombs to be built and dropped on Hiroshima and Nagasaki.

Leona falls squarely on one side of the debate about the ethics of creating and dropping the atomic bomb. In her view, dropping the bombs was necessary to end the war.

Leona Woods Marshall Libby: My brother-in-law was a captain of the first bombs’ minesweeper scheduled into Sasebo harbor. I'm sure these people wouldn't have lasted. It's pretty clear we would've had half a million of our fighting men dead, and not to say whom we would've killed of the Japanese.

Erica Huang: In other words, Leona had no regrets about using the atomic bomb.

Leona Woods Marshall Libby: It was a desperate time. When you're in a war to the death, I don't think you stand around and say, “Is it right?”

Erica Huang: There's one other story that Leona tells in this interview that I thought was interesting because it put me in the mind of Leona herself. They're talking about a problem that came up with the slugs, which are metal elements on the reactor that hold fuel.

They had to figure out how to build a shell that could withstand enormous pressure.

Leona Woods Marshall Libby: Nothing was gonna work if those slugs didn't work. I mean, the corrosion of all that water rushing through was just too powerful.

Erica Huang: This image of the slugs reminds me of Leona. She laughs off the interviewer and calls him dumb. She scoffs at the doctors that are concerned over her health. She writes at one point that she told Enrico Fermi that his book on thermodynamics was “good as a baby book.” She's got a tough exterior that's built to withstand enormous pressure, and on the inside, there's this fuel that refuses to quit.

After the war, Leona's expertise in nuclear pile design led her to a job overseeing the operation and construction of the plutonium production reactors in Hanford, Washington. Later, she returned to her first love: astronomical spectroscopy. She held fellowships at the University of Chicago's Institute for Nuclear Studies – now named, appropriately enough, the Enrico Fermi Institute–and the Institute for Advanced Study in Princeton. She also taught at a number of universities including New York University and UCLA. 

She had one more son with her first husband John Marshall. They eventually divorced, and in 1966, she married Willard Libby, a fellow scientist who had worked with her on the Manhattan Project.

Leona Marshall Libby died in 1986 at age 67, just two months after the interview you've heard in this show was conducted. At the end of her life, she'd published more than 200 scientific papers. Her last paper explored quasi-stellar objects – giant, bright galaxy centers powered by super massive black holes – the light of which would make a splitting atom seem like a tiny flash in the universe.

Katie Hafner: This has been Lost Women of the Manhattan Project, A Lost Women of Science podcast miniseries. Erica Huang produced this episode. Lizzie Younan composes our music and Paula Mangin creates our art. Thanks to Mackenzie Tatananni, Deborah Unger, Lauren Croop, Jeannie Stivers, Eowyn Burtner, Amy Scharf, and Jeff Delviscio. Lost Women of Science is funded in part by the Alfred P. Sloan Foundation and Schmidt Futures. We're distributed by PRX and published in partnership with Scientific American. I'm Katie Hafner.

Speaker: Ruth Hillard.

Speaker: Aime Zakoian.

Speaker: Elaine Palevsky.

Speaker: Grace Priest.

Speaker: Eleanor Gish.

Speaker: Edith Wright.

Speaker: Yvette Berry.

Speaker: Elizabeth Graves.

Speaker: Mary Rose Ford.

Katie Hafner

Host & Executive Producer

Katie Hafner was a longtime reporter for The New York Times, where she continues to be a frequent contributor. Katie is uniquely positioned to tell the stories of lost women of science. Not only does she bring a skilled hand to complex narratives, but she has been writing about women in STEM for nearly 30 years. She is the author of six books of non-fiction, and her first novel, The Boys, was published in July 2022 by Spiegel & Grau. Katie is also the host and executive producer of Our Mothers Ourselves, an interview podcast that celebrates extraordinary mothers.

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