We continue the story of Jewish physicist Lise Meitner, the first person to understand that the atom had been split. This is the second in a two-part series featuring new letters from and to Lise Meitner translated by author Marissa Moss, author of The Woman who Split the Atom: The Life of Lise Meitner (2022). The letters show the fraught and complex relationship between Otto Hahn and Meitner, and the role that antisemitism played in the decision to give the Nobel Prize in 1944 to Hahn and not to Meitner.

After the discovery of nuclear fission, Meitner grappled with its implication: the advent of nuclear weapons and who would get credit for the discovery of nuclear fission. This would lead to a breakdown of Meitner and Hahn’s decades-long scientific collaboration. Meitner, who had fled Germany because of the Nazis, was horrified at the thought of an atomic bomb. She also faulted Hahn for not speaking out about Nazi atrocities, and questioned his character, though she remained loyal to him to the end. It was their working relationship that defined her life.

Listen to part one of this profile of physicist Lise Meitner here.

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EPISODE TRANSCRIPT

Katie Hafner: About a half hour into the movie Oppenheimer, there’s an exciting scene that starts at a barbershop in Berkeley, California. A young physicist named Luis Alvarez is in the middle of a haircut, reading the morning paper. By Alvarez’s account, this actually happened, and it plays beautifully on film: he sees a story that causes him to leap up and run out the door. He dashes down the street, then into the UC Berkeley Radiation Laboratory and calls out…

[Clip from the movie Oppenheimer]

Luis Alvarez: Oppy! Oppy!  

Oppenheimer: What, what is it? 

Luis Alvarez: They've done it. They've done it. Hahn and Strassman in Germany. They split the uranium nucleus. They split the atom. 

Oppenheimer: It’s not possible.

Katie Hafner: And the rest is atom bomb history. I'm Katie Hafner and this is Lost Women of Science. 

That scene in Oppenheimer is definitely dramatic. But it’s also problematic. It’s missing an important name: Lise Meitner. She was the physicist who made sense of the experimental findings. She realized that the nucleus had split. And if you look up the first few articles about the discovery published in the States, her name’s in there. But in the movie, she’s missing. 

Today we bring you part two of a two-part episode on physicist Lise Meitner. If you haven't listened to the first episode, please do go back and listen. Carefully.

Both of these episodes are aimed at revisiting the historical record, which is what we like to do at Lost Women of Science. We do it one female scientist at a time. And we’re doing this particular repair of historical potholes with the help of author Marissa Moss, who in the course of writing her biography of Lise Meitner read thousands of letters Meitner wrote and received – to and from her longtime colleague Otto Hahn –  and others. Marissa estimates that hundreds of those letters had never been translated into English.

So here's part two of our story about the woman who split the atom and her complicated relationship with Otto Hahn. He received the Nobel Prize. She didn't.

Speaker: These are today's main events, Germany has invaded Poland. General mobilization has been ordered in Britain and France.

Katie Hafner: In September of 1939, as World War II began, Lise Meitner was living and working in Stockholm. Only a year earlier, she'd been in Berlin.

Marissa Moss: She is the last Jewish scientist to leave Berlin. She just hangs on there. She doesn't leave till the end of 1938, and she just is hanging on by her claws because she is terrified that she will not be able to do science as a woman anywhere else. 

Katie Hafner: That's author Marissa Moss, whose latest book is The Woman Who Split The Atom: The Life of Lise Meitner. Although Meitner did finally escape Berlin, she left behind the work that had defined her life for nearly three decades: her work with chemist Otto Hahn.

But they managed to continue their collaboration by exchanging letters - he from Berlin and she from Stockholm. The past year had been an eventful one for both of them. In his laboratory at the Kaiser-Wilhelm Institut, Hahn had found that when uranium was bombarded with slow-moving neutrons, the result was smaller, lighter elements. At the time, he wasn't at all sure what those results meant. He thought it was all a big mistake; that he was missing something that he, as a chemist, couldn't understand. 

Still, in January of 1939, Otto Hahn and Fritz Strassman published their findings.

Marissa Moss: And he says in the article he writes: we as chemists cannot interpret this, what's happening here. We will leave it to physicists to understand it and explain it to us.

Katie Hafner: Physicists like Meitner. She soon tackled the problem, and together with her nephew Otto Robert Frisch, published an interpretation of the experimental results: the uranium nucleus had split, resulting in the lighter elements. 

They called the process nuclear fission, a word Frisch borrowed from a biologist friend who used it to describe cell division. The discovery took the world by storm. Meitner's colleague Niels Bohr, presented her work at the 1939 Fifth Washington Conference on Theoretical Physics in D.C.

Marissa Moss: And he makes this big announcement at this conference that nuclear fission has occurred, and everybody leaps up and the reporters are going, what happened? What happened? What happened? They don't understand the import of what happens. And Bohr is very conscious. He's very conscious of the fact that Meitner would, is very likely to have this stolen from her. So he makes it crystal clear that Lise Meitner, with the help of Otto Robert Frisch, since he wrote the article with her, have discovered this, based on chemical work done by Otto Hahn back in Berlin.

Katie Hafner: That’s right. Niels Bohr was worried even then, and made a point of stressing Meitner’s incredible interpretation of results that had so confused Otto Hahn. 

And Bohr was right to worry. The news quickly made its way to California and the newspaper Alvarez is reading just before he sprints down the street to report to Oppenheimer that two men had split the atom. And here’s what all that dashing out the door of the barbershop should have been about: The actual interpretation of what Otto Hahn had seen. Meitner, a physicist, was the first to realize what the results meant: the nucleus had split. 

Putting together Hahn and Strassman’s lab work with Meitner and Frisch’s explanation presented extraordinary possibilities. One atom dividing doesn't release a huge amount of energy. Physicists had to see if they could generate a self-sustaining chain reaction. Then they could explore the possibility of harnessing that energy.

But for Meitner and Hahn, the discovery that should have been the culmination of decades of collaboration, instead tested their relationship and threatened their trust in each other. Hahn, working in Nazi Germany, wasn't supposed to be exchanging ideas with a Jew.

Marissa Moss: He was basically, he was unofficially working with her, but he was doing it very surreptitiously. And it's why the physicists at the Kaiser Wilhelm Institute were furious when they found out he was still sending his experiments to Meitner.

Katie Hafner: Both Meitner and Hahn worried that they wouldn't get sufficient individual credit for the discovery. In their letters, they struggle to communicate, constantly apologizing or clarifying. 

Speaker: 12 Juli 1939. July 12th, 1939. Lieber Otto, I obviously don't know what you intended, but it can’t be misunderstood. I also don't understand why you didn't mention Bohr and our work in your theoretical explanation of the fission process.

Speaker: 13 Juli, 1939. July 13, 1939. Liebe Lise. Unfortunately, it sounds like you're a bit upset in your letter. So I'm writing back right away, even though I'm exhausted.

(Leider glaube ich aber eine leichte Verstimmung aus Deinem Brief herauslesen zu müssen und deshalb will ich gleich schreiben, obgleich ich recht abgespannt bin.) 

Speaker: 15 Juli 1939. Lieber Otto. What I meant by my comment was that you related the theoretical interpretation of the fission process to Bohr's already three-years-old droplet model and not to our work. I only mentioned it because it seems to me that you could be misunderstood.

( Was nun meine Bemerkung darüber betrifft, dass ihr bei der theoretischen Deutung des Fission Prozesses Euch auf das Bohr’s schon drei Jahre alte Tröpfchen Modell bezogen habt und nicht auf unsere Arbeit, so habe ich sie nur angeführt, weil mir scheint, dass Ihr missverstanden werden könnt.) 

Katie Hafner: The tone of the letters grows increasingly fraught. We’ll get back to how that had an impact on who won the Nobel Prize. But apart from identifying who actually understood the science, it was the implications of splitting the atom in 1939 that was about to truly test their relationship. They had radically different perspectives on the war, Nazi atrocities, nuclear weapons. 

During the war, both Allied and Axis powers invested heavily in wartime technology. Rocketry, cryptography and computing all boomed. Meitner and Hahn's discovery of nuclear fission also opened up the possibility of an atomic bomb.

Marissa Moss: At the time, people didn't think a chain reaction was possible.

Katie Hafner: But the threat was real enough that in August of 1939, before the United States had even entered the war...

Marissa Moss: Einstein was convinced to write a letter to the President, to Roosevelt, encouraging him to work on the nuclear bomb, the atomic bomb, because the thought was, if such a weapon could be developed, the Germans are already working on it and we can't let them get it first.

Katie Hafner: In later years, Einstein would regret signing and sending that letter to Roosevelt, saying, “had I known that the Germans would not succeed in developing an atomic bomb, I would have done nothing for the bomb.”

As for Meitner, initially she wasn't worried about the prospect of a bomb. The instances of fission she'd analyzed couldn't occur at the scale necessary. You'd need a massive amount of uranium to create a bomb. Her nephew, Otto Robert Frisch, however, worked with a colleague and… 

Marissa Moss: They discovered that if you use a different isotope of uranium, you needed much less of it. And you could create a chain reaction where one fission sets off another, sets off another, sets off another, sets off another, sets off another, sets off another until you have this huge bomb.

Katie Hafner: Frisch and his colleague were quickly recruited to work on the Manhattan Project. So was Niels Bohr.

Marissa Moss: Almost all, every single major physicist, German physicist, goes to America to work on this project with two very notable exceptions, Einstein and Meitner.

Katie Hafner: Meitner would get letters from Bohr and Frisch, but throughout the war, the two men had to keep quiet about what they were working on. The world would find out on August 6th, 1945, when the US dropped the first atomic bomb on Hiroshima, Japan. Three days later, the US dropped a second atomic bomb on Nagasaki. Reporters called Meitner, asking for her comment. 

Marissa Moss: She was, she was appalled. And when the reporter came to her door to tell her this, I mean, she didn't know. She was just horrified that anything she had done could have led to this.

Katie Hafner: The newspapers, though, ran with the story. Meitner was dubbed “the mother of the atomic bomb.” 

Marissa Moss: And they were writing all these ridiculous stories about her, how she ran away from Germany with the secret of the bomb in her pocketbook as if it was a recipe, and how Hitler had tried to get her to make the bomb for him but she refused. They just totally made up garbage.

Katie Hafner: By that point, Germany had already surrendered. Since the spring of 1945, Hahn, along with a number of other German scientists, were being held at Farm Hall, a country estate near Cambridge, England. The scientists there were secretly recorded, and Marissa has read those transcripts. When they heard the first announcement of the Hiroshima bombing on the BBC. 

Marissa Moss: They are astonished and they don't believe it. They feel like it's a fake. They say it’s just a very powerful bomb and they're pretending it's an atomic bomb ‘cause no one could have done it.

Katie Hafner: Later that evening, they listened to a second broadcast. Now, they accepted the reality and immediately began to debate the science of how it could have worked.

The Germans themselves had decided to direct their nuclear research efforts to a nuclear reactor, believing that a bomb would be too impractical.

Marissa Moss: They never even tried to develop an atomic weapon because they did not know about a nuclear chain reaction. 

Katie Hafner: They were stunned that the Allies had succeeded in so little time. 

Marissa Moss: And then they had this big long conversation saying, I don't understand how if we Germans couldn't do it, how could those Americans do it? It doesn't seem possible. And then they say, well, of course we didn't really wanna do it because we're so noble and good. We would never have done something so sinister. 

Katie Hafner: But they were still keen to get Germany credit for the discovery that made nuclear weapons possible: the discovery of nuclear fission. The previous year, both Hahn and Meitner had been nominated for a Nobel Prize. It would be Hahn alone who got the award. That’s after the break.

(AD BREAK)

Marissa Moss: Her friends joke to her. In fact, this became a joke in the physics community that the crowning achievement of Lise Meitner was to win a Nobel Prize for Otto Hahn.

Katie Hafner: In December of 1946, Otto Hahn, Nobel Prize winner, went to Stockholm to receive the honor at a delayed ceremony. He had been awarded the prize in 1944, but for two years because of the war and its aftermath, he hadn't been able to attend. When he arrived by train, Lise Meitner met him at the station. The ceremony was held a few days later. 

Marissa Moss: So she assumes that he'll finally make good by recognizing her in his speech, and he doesn't. And it's a very, very frosty dinner afterwards, and she is incredibly depressed. She doesn't confront him then and there she writes letters to him afterwards. 

Katie Hafner: There's been much written about the decision to give the award to Hahn alone. Meitner's biographer, Ruth Lewin Sime, read many of the letters between the scientists of the day and concluded anti-semitism was at least part of the reason. In 1997, after new documents were released in Sweden, Sime co-authored an article in Physics Today, concluding that the decision was also complicated by the politics of the Nobel Committee itself.

For Meitner, even worse than not being given credit for the work, was her increasing sense that Hahn was in denial about the extent of Nazi atrocities during the war.  

Marissa Moss: She has written him repeatedly to take responsibility for what Germany did during World War II. She says that the new generation needs to hear from people like you that complicity is also a form of guilt because you were basically complicit by your passivity that you said not a word as Jews were carted away, thrown out of the country and murdered.

Katie Hafner: She wrote to her friend, the Swedish physicist Eva Von Bahr, about an exchange she had with Hahn.

Speaker: He wrote to me in a letter that the Americans were doing the same things in Germany that the Germans had done in the occupied lands. I answered him that he couldn't be serious.

Katie Hafner: In another letter, this one to the Dutch physicist Dirk Coster, she was brutally frank about her attempts to get through to Hahn. She was writing the letter in German, she told Coster, because, quote:  "One can only speak the deepest truths in one’s mother tongue."

 Speaker: 15 Oktober 1945. October 15th, 1945. When Otto came here in the fall of 1943, I had daily long conversations about this where he thought I was being unfair. He refused to admit that everyone, even those not officially in the Nazi party bore responsibility for the horrible things that Germany brought to the whole world. But when he parted and we did it as better friends than we had been in the years since 1938, he did admit all sorts of things to me.

Katie Hafner: Hahn did give her a large share of the Nobel Prize money, which she donated to the Emergency Committee of Atomic Scientists to help settle Jewish refugee scientists. In 1947, Hahn also invited Meitner to return to Berlin, offering her a position as the head of physics at the old KWI, now called the Max Planck Institute. 

Marissa Moss: She declines because she said she wouldn't feel comfortable there. That she felt like the, the students and her colleagues would never trust her as an Austrian and as a Jew. And in fact, she finds, she does go back to Germany several times to accept awards and she finds the anti-semitism just as bad and ugly as ever.

Katie Hafner: She was disappointed not only in Hahn, but also in many of her former colleagues. She wrote this in a letter to her friend, the physicist James Franck.

Speaker:  22 Februar 1946. Lieber Frank, I had so hoped that the decent scientists would give an official explanation of Nazi Germany and move away from it, and express the desire to do well, what can be done well. 

Katie Hafner: In another letter to  Franck, she gives him her unbridled assessment of Hahn as a person.  

Speaker: Hahn is without doubt a decent man with many good traits. He only lacks thoughtfulness and perhaps also a certain strength of character, things that in normal times are minor flaws, but in the complicated times of today have deeper implications.

Katie Hafner: Meitner also knew that anti-semitism played a role in her not being recognized by the Nobel Prize Committee. 

Marissa Moss: Years later in ‘47 after Hahn gets the Nobel Prize for this, Otto Robert writes a letter to Meitner saying that he's been approached by these Austrian journalists who are curious. They've heard these rumors that Otto Robert and Meitner are trying to take credit for this good German science because they're evil Jews trying to profit off of it because of course that's what Jews do. And he's asking Meitner how to answer this because he said we have to stand up for ourselves. 

Katie Hafner: Meitner's reply to her nephew shows her struggling to reconcile her friendship with Hahn and her disappointment in his actions. She starts by laying out the chronology.

Speaker: 15 Juli 1947. In reality, Hahn first shared his results with me when he had actually submitted his manuscript to Naturwissenschaften, and he had at the same time as the letter sent me a copy of the manuscript.

Katie Hafner: Then she explains that although Hahn had gathered the experimental results for fission, he didn't comprehend what was happening.

Speaker: As can be seen from a letter to me, Hahn did not at first understand what we were thinking.

Katie Hafner: She also writes that he allowed some of the other scientists at the Kaiser Wilhelm Institute to persuade him that she was trying to wrest credit away from him.

Speaker: I also know that his attitude contributed to the Nobel Committee deciding against us.

Katie Hafner: While Meitner doesn't explain how she knows, to Marissa, this correspondence shows that Meitner was pretty certain that Hahn and the other scientists at the Kaiser Wilhelm Institute had persuaded the committee not to award the prize to Frisch and Meitner. Still, Meitner closes the letter by telling her nephew.

Speaker: But that's purely private stuff that we don't want to make public.

Katie Hafner: It's clear that Meitner was hurt by Hahn's betrayal. Yet she wanted to preserve their relationship. And Hahn too made efforts at a rapprochement. In 1948, he nominated Meitner and Otto Robert Frisch for the Nobel Prize in physics. But once again, they didn't win.

I asked Marissa what she thought Meitner would make of her having read through all this correspondence.

Marissa Moss: You know, I think she would still be protective of Otto Hahn. She was so careful of his feelings. For some, it was really kind of a, it was a work marriage. He was the closest person to her in some very strange way, and she was protective of him throughout her life, even as she grieved and was very sorrowful about how he saw her experience and the experience of the rest of the world in the face of German fascism.

And she says about Hahn he wasn't a Nazi or fascist, he wasn't a zealot, he wasn't a true believer. But, he never spoke up. 

Katie Hafner: Meitner in stark contrast insisted on speaking up. 

Marissa Moss: She started working really right after the fall of the bombs – she started working on basically nuclear peace. She was very, very worried about how America was demonizing Russia. She saw that clearly happening at the close of the war and she thought that it was gonna start an arms race. And of course she was right. 

Katie Hafner: She became an outspoken advocate for nuclear peace and directed some of her own scientific research to developing a nuclear reactor.

Marissa Moss: She wanted nuclear power to be used for peaceful reasons, not for military reasons, and that was something she was actively working on the entire last decades of her life.

Katie Hafner: After she retired, she joined her nephew in England. It's where she spent the last years of her life. By the 1960s, her health was deteriorating. In 1968, her family placed her in a nursing home. That same year, in July, Otto Hahn died. Meitner's family decided not to tell her. They worried the news of Hahn’s death would worsen her condition.

Lise Meitner died on October 27th, 1968. She was 89 years old.

So you think the church might be coming up? Okay. So do you see a church? 

Speaker: I think it's just a little ways down here. 

Katie Hafner: Oh one minute. Oh, look, we're going just the right way.

I was in the UK earlier this year and with a friend and we drove out to find Meitner's grave, in Bramley, which is west of London. This blue line. We’re almost there. Oh my goodness. Ok. Great we’ll have to get Marissa. 

We parked and managed to get Marissa on Skype. I had a hard time finding the grave. 

Marissa Moss: Did I send you to the wrong place? I can't believe I did. 

Katie Hafner: It's gotta be here somewhere. I mean, there, it's gotta be here somewhere. 

Katie Hafner: It was a small churchyard but we still found ourselves going around in circles. But then, we found it.

Oh I think we just found it. 

Marissa Moss: Did you find it? 

Katie Hafner: Okay. Does this look right?

Katie Hafner: It was hard to make out the words on the gravestone. But while we were standing there, Marissa on Skype, Marissa noticed…

Marissa Moss: There's a stone. 

Katie Hafner: Oh my gosh. There's a stone on top. 

Marissa Moss: Well, someone Jewish has been to see her grave. That's a Jewish ritual. 

Katie Hafner: Yes, it is. Indeed it is. 

Katie Hafner: Placing a stone on a headstone is a way to show respect or love, or just an act of remembrance. I decided to gather some stones myself. I put one on from me, one from my friend, one from Marissa. One for her nephew Otto Robert Frisch. One for Niels Bohr. One for Einstein. And yes, I put one on for Otto Hahn.

I found myself thinking back to the gift Hahn gave to Meitner when they said goodbye before she escaped Berlin: his mother’s ring. That night, he told her she might need the money, but the ring seemed to have more meaning than that for both of them. It was a symbol of friendship, a gesture of caring. According to Marissa, Meitner kept the ring all her life.

To Marissa, Meitner's greatest legacy is her ethics.

Marissa Moss: Because she just never lost her moral compass. And that's one reason why she was upset at Hahn because he lost his moral compass over and over again. He lost it in World War I when he worked on chemical weapons. He lost it in World War II when he allowed the Nazis to take over his lab. And he lost it when he got the Nobel Prize, when he refused to share credit with a Jew.

And that was something she never lost. And that's, that's something that really is, I think it's why she has that on her grave that it’s written, “A physicist who never lost her humanity.” She never lost her deep sense of what matters and what's right. 

Ashraya Gupta: This has been Lost Women of Science. This episode was produced by me, Ashraya Gupta. Lizzy Younan composes our music. Paula Mangin creates our art. Alex Sugiura is our audio engineer and Danya AbdelHameid is our fact-checker. Thanks to Amy Scharf, Jeff DelViscio, Jeannie Stivers, Eowyn Burtner, Nora Mathison, Deborah Unger, Hilda Gitchell, and Lauren Croop. 

Katie Hafner: Thanks also to Barbara von Bechtolsheim, Peter Wehmeier and Arno Puder for reading the Meitner-Hahn letters. Special thanks to Marissa Moss for all her input. And a shout out to Everett Hafner's old Olympia typewriter for its cameo appearance in both of these episodes.

Ashraya Gupta: Lost Women of Science is funded in part by the Alfred P. Sloan Foundation and Schmidt Futures. We’re distributed by PRX and produced in partnership with Scientific American

Katie Hafner: You can find a lot more – including the all-important donate button – at lostwomenofscience.org. Thanks so much for listening. I’m Katie Hafner.

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Further Reading:

The Woman Who Split the Atom: The Life of Lise Meitner, Marissa Moss, Abrams Books for Young Readers, 2022

Lise Meitner: A Life in Physics, Ruth Lewin Sime, University of California Press, 1997

Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction, L. Meitner & O.R. Frisch, Nature, 11 February, 1939 

Lise Meitner Looks Back, Bulletin of the Atomic Scientists 20, no. 9 (November 1964), p.2-7

Operation Epsilon: The Farm Hall Transcripts, Sir Charles Frank, Berkeley, University of California Press, 1993

Lise Meitner, Atomic Pioneer, Deborah Crawford, New York, Crown, 1969