Lilli Hornig's Los Alamos ID. Photo: Wikimedia / Federal Government of the United States

‘Oppenheimer’ also features a female Czech scientist who worked on the Manhattan Project

Christopher Nolan‘s jaw-dropping new movie Oppenheimer depicts some of the most well-known scientists of the 20th century, including Albert Einstein, Niels Bohr, Werner Heisenberg, Kurt Gödel, and Richard Feynman in addition to the title character. But it also includes (albeit briefly) one whose name is not so well known: Lilli Hornig, the only female scientist seen in the movie, who happens to hail from what is now the Czech Republic.

In Oppenheimer, Hornig is portrayed by by Olivia Thirlby (Goliath, Dredd). She’s initially seen in the role of a typist in Los Alamos, with Cillian Murphy‘s titular character explaining that it’s easier to give the wives of scientists, who have already received security clearance, side jobs on the Manhattan Project rather than recruit from outside the area. Later, however, Thirlby’s Hornig takes a more active role in the development of the nuclear bomb.

Lilli Hornig really was the wife of a scientist recruited to work on the Manhattan Project, chemist and explosives expert Donald Hornig, played in the film by David Rysdahl. As depicted in Oppenheimer, she was offered a typist position before her scientific skills were recognized and she began working with the group researching plutonium chemistry.

Hornig was born Lilli Schwenk in Ústí nad Labem, about 65 kilometers north of Prague, in 1921 to parents of Jewish German heritage. The family moved to Berlin in 1929, but fled the country for America years later to escape Nazi persecution.

“I was born in what is now the Czech Republic; a little town about—probably about fifty miles north and slightly east of Prague, and I lived there until I was eight,” Hornig told the Atomic Heritage Foundation in a 2011 interview. “My father was a scientist. He was a chemist working in the big dyestuffs plant there, Dyestuffs was still big business in the ‘20s.”

“My father took me occasionally, very occasionally, on a Sunday to his lab, and I just loved all the glassware, and he gave me some micro-sized glassware for my doll house. I always assumed I would—well, they assumed—to I think that I would be either a chemist or a physician. And I was kind of squeamish at the time, so I went for chemistry. I was pretty determined on that.”

In the United States, Hornig received a BA from Bryn Mawr College and a Ph.D. from Harvard. In-between, she married Donald Hornig, and the couple would have four children. When her husband was recruited to work in Los Alamos by George Kistiakowsky, portrayed by Trond Fausa in Oppenheimer, she asked what she would be doing there.

“Oh, we’re scouring the country for people—anybody with a Master’s in chemistry, especially from Harvard, is going to be more than welcome,” Kistiakowsky told the couple, as related by Hornig in 2011.

“Don of course went straight to work, and I went to the personnel office,” Hornig said. “And the first question was, ‘How fast can you type?’ And I said, ‘I don’t type.'”

“In three days, I had a job in the chemistry department doing what was called “fundamental wet research,” which involved working with plutonium, determining the solubility of various plutonium salts,” Hornig recalled. “There was essentially nothing known about plutonium chemistry at the time.”

Los Alamos scientists and their families in Oppenheimer (2023)
Los Alamos scientists and their families in Oppenheimer (2023)

After months of plutonium research, it was found that the plutonium-240 the group was studying was more active than plutonium-239, and women were banned from research due to concerns that it could result in reproductive damage.

“I complained a bit about that, and they were worried obviously about reproductive damage,” Hornig noted. “I tried delicately to point out that [the men] might be more susceptible than I was; that didn’t go over well. But I guess I wasn’t very good at handling things like that.”

Hornig ultimately wound up developing high-explosive lenses until the successful Trinity test. While working on the Manhattan Project, she signed a petition along with other scientists, as seen in Oppenheimer, that urged that the first bomb not be used as a weapon, but detonated on an uninhabited island as a demonstration.

Later in life, Hornig would become a chemistry professor at Brown University and chaired the chemistry department at Trinity College. She was also the founding director of HERS (Higher Education Resource Services), which promoted gender equity research and leadership programs for women, and the research chair at the Committee for the Equality of Women at Harvard.

Hornig passed away at the age of 96 on November 17, 2017 at her home in Providence, Rhode Island.

Oppenheimer is now playing in cinemas across Prague. Screenings include the EU’s only 70mm IMAX print at Cinema City Flora.

Pictured at top: Lilli Hornig’s Los Alamos ID via the Federal Government of the United States.


Jason Pirodsky

Jason Pirodsky

Jason Pirodsky has been writing about the Prague film scene and reviewing films in print and online media since 2005. A member of the Online Film Critics Society, you can also catch his musings on life in Prague at and tips on mindfulness sourced from ancient principles at

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