Meet the Woman Who Supervised the Computations That Proved an Atomic Bomb Would Work


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Nic Lewis: She was walking past where Oppenheimer was living. And he had walked outta his house just a little before her and he paused and waited for her to catch up. he asked all about how she was doing, what was happening in the punch card operation, what kind of results they were getting. Did she need anything?

She was astounded .

Katie Hafner: During World War II, thousands of scientists took part in the three year race led by J. Robert Oppenheimer to build an atomic bomb that would end the war. Hundreds of those scientists were women. They were  physicists, chemists, biologists, mathematicians … and computation experts, whose calculations helped determine if the theoretical ideas behind the bomb would work. 

This is Lost Women of the Manhattan Project, a special series of Lost Women of Science focusing on a few of those women.

This episode is about a young woman’s dashed efforts at being taken seriously as a mathematician. It’s about the benefit that redounded to the U.S. military because of a pervasive bias against women in the field of mathematics. And it’s about a young historian who acted on a hunch that there might just be something interesting behind one woman’s name.

Over the years, Nic Lewis, a historian of technology at Los Alamos National Laboratory, had heard the names of many of the women who worked on the Manhattan Project, but about 10 years ago while working on his Ph.D. dissertation on the evolution of computing at Los Alamos, Nic came across one name that stood out: Naomi Livesay.

He saw that she worked on computations that were the basis for implosion simulations, which eventually led to the successful detonation of the device that was tested in the New Mexico desert on July 16, 1945.

Nic Lewis: I discovered that she was the supervisor for the punch card computing operation that the theoretical division of the lab ran and that she was a crucial part of this computing story at the lab during the war. But she was rarely mentioned as anything more than a footnote.

Katie Hafner: So Nic decided to chase after that footnote.

Nic Lewis: Naomi Livesay operated the machines. Well, what does that mean? Knowing that these machines were crucial for the implosion work on what would become the fat man weapon. I knew it had to be a lot more involved than just supervising the operation. 

I had a feeling that her importance was far more significant than most of the few people who wrote about lab computing were letting on, and that proved to be correct. 

Katie Hafner: But first, here’s what  you need to know about the Los Alamos computation lab. Without the work of the computation lab, the development of the atomic bomb would have been much slower than it was.

 “Computation” in this case refers to the numerical calculations that were done in the course of testing an implosion method for creating a more efficient nuclear bomb. Computers as we know them today didn’t exist yet. Instead, the computation lab employed “computers,” i.e. people, almost exclusively women, whose job it was to perform calculations mostly using mechanical calculators. Most of those mechanical calculators were eventually replaced by IBM punch card accounting machinery. 

And here’s where Naomi Livesay joins the story. She was an expert in the operation of these IBM punch card machines, but not because she wanted to be. Her first love was mathematics.

Nic Lewis: Naomi Livesay was born in 1916 in Montana. She went for a bachelor’s degree in mathematics from Cornell College in Iowa. Then she tried to pursue a PhD in mathematics at the University of Wisconsin, but the department there wouldn’t let her. 

Katie Hafner: The men of the mathematics faculty at Wisconsin believed that women had no place in mathematics. This was a stance that was par for the course back then. And in this brief episode, we are not even gonna go down that particular dark path of sexism. 

For Naomi, it meant this: she couldn’t go for a Ph.D. in mathematics, but she was permitted to complete a Ph.M., a master of philosophy, that’s something between a master’s and a Ph.D., which Nic says was closer to a teaching credential.

Nic Lewis: So she had to do the same coursework that all the men who were pursuing a PhD had to do while also doing all the coursework for educational training.

There’s a very telling line from Rudolph Langer, who’s one of the mathematics professors in her department, when he told her there’s no place in higher mathematics for any woman, however brilliant. 

Katie Hafner: So Naomi finished that Ph.M. degree in 1939, and then, along came someone who would help set the course of her career.

Nic Lewis: One of the faculty members at Wisconsin, Joe Hirschfelder, believed that the university had done Naomi wrong.

Katie Hafner: So the sympathetic Hirschfelder helped to set Naomi up with a job at the Princeton Surveys.

Nic Lewis: They needed mathematicians to work on statistics.

Katie Hafner: Specifically, statistics about the costs of state and local government surveys.

Pretty dry stuff. And for this, she needed to learn how to use IBM punch card accounting machinery, which, as Nic explains…

Nic Lewis: As the name suggests, normally used for accounting, but it could be repurposed for doing scientific calculations.

Katie Hafner: So Naomi now had a job at Princeton, and she was…bored stiff. That’s according to Naomi’s unpublished memoir which she wrote in 1994. Let’s not forget she was a mathematician, and here she was working at a job that was one step above a switchboard operator. Well, maybe two steps, given that she was also instructing the machine on mathematical operations…still, it was less than intellectually satisfying.

Enter, once again, Joe Hirschfelder, the chemistry professor at Wisconsin who was a fan of Naomi’s. In 1943, he called her up and he offered her a job working for him on a highly classified  project for the war. Of course, she couldn’t just show up for work. She had to wait for her security clearance to come through, which it did in early 1944. 

Nic Lewis: That’s when she hopped on the train, went down to Lamy in New Mexico, where an army car picked her up and carried her into Santa Fe. From there she was instructed to take a bus “up the hill.” 

Katie Hafner: “The hill” was the way people referred to Los Alamos because the very name “Los Alamos” was forbidden. 

When Naomi reported to Hirschfelder, he told her that … she didn’t have a job after all. At least, not the job he’d had in mind for her.

Nic Lewis: The group that Hirschfelder had been leading was in charge of a weapon design that, it was discovered through experiment, was not going to work. 

Katie Hafner: So pretty much all of Los Alamos then retrenched around a different design, an implosion weapon that would become the Trinity device and then the Fat Man bomb that was dropped on Nagasaki. And all this refocusing on implosion was going to require a lot of calculations to make sure the lab was selecting the right design.

The men running the hastily reconfigured computation lab had ordered a collection of IBM punch card accounting machines, which were almost identical to the type of machines Naomi had been using back at Princeton. The machines were miraculous. They could perform a large number of very tedious calculations that were too voluminous for hand calculation.

There was just one problem: the men didn’t know how to operate them. Naomi, on the other hand, knew not just how to operate these machines, but how to program them as well.

Nic Lewis: You can’t see my air quotes, but “program” at that point meant rewiring plug boards that would make some of these machines perform different operations and generally learned how to make them perform mathematical operations.

Katie Hafner: And Naomi was one of the best qualified people in the country to do this. But the men had another problem: Naomi herself.

She didn’t want that job. She’d done it at Princeton and she had been bored. In her  memoir, she described a meeting with Stanley Frankel and Eldred Nelson, the two men running the lab. Just as she was insisting that the job wasn’t for her, this happened.

Nic Lewis: There was a very odd fellow, as Naomi described him, an odd character that kept wandering in and outta the room, he was this brown haired, very thin guy. He was maybe 25. He looked more like a sophomore in college than a scientist. 

Katie Hafner: Then this odd character introduced himself to Naomi. He was the physicist Richard Feynman. And in what Noami later described as a very beautiful, soft voice, he said…

Nic Lewis: That she needed to take this job because no one else could fulfill  this desperately needed role. And she said that the way that he asked, in that moment she decided to take the job.

Katie Hafner: And it may not be too much of an  exaggeration to say that that decision, made  over the course of  this intensely complicated enterprise, was crucial to the success of the Manhattan Project.

Nic Lewis: Because of time and the extreme cost and rarity of the nuclear materials involved, it wasn’t possible to do live experiments on the proposed weapon designs, so computer numerical simulations took the place of real-world physical experiments.

These calculations, even though they would be very large and involved and would take a long time, they would save a huge amount of time in the long run in making sure that the lab selected what was most likely to be a working design choice.

Katie Hafner: Over the following months Naomi organized the computation operation which ran 24 hours a day, 6 days a week with the machines performing calculations and people, mostly Naomi, checking the results by hand. Just how lucky those men got when they recruited Naomi Livesay is best summed up here by Nic.

Nic Lewis: This is a trajectory that no one could possibly have predicted that someone could be plucked out of the sky, in a sense, and given the responsibility to perform a volume of calculations that even the most demanding sciences typically didn’t do at the time. This was a unique role at a unique place under unique pressures.

Katie Hafner: And it seems that Robert Oppenheimer himself recognized the vital importance of the work Naomi Livesay was doing.

Nic Lewis: Naomi only interacted with Oppenheimer one-on-one, just the one time, but it left a lasting impression on her. She was walking past where Oppenheimer was living. He lived at the end of the lane and he had walked out of his house just a little before her. And he paused and he waited for her to catch up.

And he asked all about how she was doing, what was happening in the punch card operation, what kind of results they were getting. Did she need anything? 

She was astounded. He knew who she was. He knew exactly what she was working on, and, he was seeing if there was anything that she needed, and it left quite an impression that this person, whom she’d never talked to one-on-one, knew exactly who she was and what she was working on.

Katie Hafner: Amid the enormous pressure the computation lab was under, Oppenheimer wanted to make sure that Naomi Livesay had everything she needed in order to pull it off.

And, says Nic:

Nic Lewis: She  more than pulled it off. She excelled. Greatly. She was absolutely indispensable.

Katie Hafner: Okay, I’m gonna go out on a bit of a limb here and say…isn’t it just ironic  that the shortchanging of Naomi Livesay, a young woman deprived of a dream, ultimately led her to the position of becoming indispensable to the success of  the Manhattan Project?

Should we then thank the extreme sexism and bias against female mathematicians that prevailed at the time for helping to bring someone of Naomi Livesay’s caliber to do that computation work on machines that confounded the men? If none of that had happened, who knows how much more slowly things would have gone at Los Alamos.

But as it was, she was there, in the thick of it.  Hirschfelder recruited her, Richard Feynman persuaded her to do the job, and Robert Oppenheimer made sure she had everything she needed in order to do it.

She also found her life partner at Los Alamos, as many people did while working there. In 1945, she married Tony French, a  British physicist. They had two kids , and eventually settled in Cambridge, Massachusetts where Tony joined the physics department at MIT. Naomi briefly returned to teaching math having never earned that PhD. 

And it’s thanks to Nic Lewis, and that simple hunch of his, that we can tell Naomi’s story.

She died in 2001 at the age of 84.

This has been Lost Women of the Manhattan Project, a special series from Lost Women of Science. This episode was produced by me, Katie Hafner, with help from Deborah Unger and Mackenzie Tatananni. Lizzy Younan composes our music. Paula Mangin creates our art. Alex Sugiura is our audio engineer and Danya AbdelHameid is our fact-checker. Thanks too to Amy Scharf, Jeff DelViscio, Eowyn Burtner, Lauren Croop, Carla Sephton and Sophia Levin.

We’re funded in part by the Alfred P. Sloan Foundation and Schmidt Futures. We’re distributed by PRX and produced in partnership with YEAR CATFISH. 

You can find a lot more – including the all-important donate button – at

 A special shout-out  to the folks at Los Alamos National Laboratory for helping us tell the stories of the women who worked on the Manhattan Project. We can’t tell you all their stories, but we can tell you many of their names, which we’ve been reading aloud for you on and off through this series. Here are a few more….

Speaker: Juanita Wagner.

Speaker: Ruth Rhodes.

Speaker:  Rozel Curtis.

Speaker: Melba Johnston

Speaker: Kay Manley.

Speaker: Alice Martin.

Speaker: Laura Fermi.

Speaker: Margaret Keck.

Speaker: Donna Robinson.

Speaker: Beverley Lewis.

Speaker: Rose Carney.

Speaker: Dorothy Wallace.

Speaker: Mary Parrish.

Speaker: Eleanor Reace.

Speaker: Elizabeth Boggs.

Speaker: Mary Nell McDaniel.

Speaker: Pearl Leach Gordon.

Speaker: Marjorie Woodard.

Speaker: Marcia Wooster.

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