Hélène Langevin-Joliot (1927) es una física nuclear francesa perteneciente a una saga de físicos que cuenta con cinco premios Nobel. Es nieta de Marie Sklodowska-Curie (Premio Nobel de Física 1903, Premio Nobel de Química 1911) y Pierre Curie (Premio Nobel de Física 1903) e hija de los ganadores del Premio Nobel de Química de 1935 Irène Curie y Frédéric Joliot. Y por si eso no fuese suficiente, su marido era el físico Michel Langevin, hijo del físico André Langevin y nieto del físico Paul Langevin (Medalla Hughes 1915 y Medalla Copley 1940) que fue alumno de Pierre Curie, colaborador de Marie y Pierre y profesor de Irène y Frédéric.
Hélène ha concedido numerosas entrevistas acerca de su familia entre las que destacaría la publicada en el blog Mujeres con Ciencia que edita Marta Macho y la que he querido compartir en este post. En ella, aparte de hablar de los hitos científicos más relevantes de su familia, descubre muchos aspectos de la vida de sus abuelos y de sus padres que no son conocidos por el gran público. Asimismo, habla de su propia experiencia en el campo de la física nuclear, haciendo especial hincapié en la vigente discriminación de las mujeres en este campo. Todo lo que dice me ha resultado tan interesante que he decidido transcribir los subtítulos para poder releerla en cualquier momento.
Mi primera intención era limitarme a compartir la entrevista por Twitter, pero he pensado que quizás a alguna de las personas que visitáis estos mundos también os interese esta transcripción y he decidido añadirla en un post.
La entrevista está realizada por Cindy Kelly y pertenece a la Atomic Heritage Foundation, que es quien ha puesto los subtítulos en inglés. Yo solo me he limitado a transcribirlos, corregir alguna errata y darle formato.
Antes de dejaros con la entrevista, quería comentaros que, si os interesa la saga Curie, en este enlace os podéis descargar un documento con la correspondencia original digitalizada por la Biblioteca Nacional de Francia de la correspondencia de Marie y sus hijas. Esta fuente es un tesoro que descubrí gracias a Pedro F. Ruiz Huete (@pfrhuete).
ENTREVISTA
Cindy Kelly: I’m Cindy Kelly, Atomic Heritage Foundation. It is Monday, May 28, 2018, in Antony, France. I have with me Hélène Langevin-Joliot.
Hélène Langevin-Joliot: My name is Hélène. The name of my husband was Langevin, so I am Hélène Langevin, and Joliot. I was a young girl in a scientific family. I became a scientist. I engage in politics —not in politics every day, but in political ideas, as my father [did], but at a smaller level. I spent all my time studying nuclear physics. After my retraite [retirement], I stopped scientific research ten years ago completely.
Kelly: That’s wonderful. I want to come back to more of your story. But first, let’s go back two generations and talk about your grandparents.
Langevin-Joliot: I never met Pierre Curie, who died in 1906 in an accident, a street accident. I was seven when Marie died. But it’s true that I have a slight feeling of my grandmother when I was a child. But I wish to say not so much, and the reason is simple. In the family, including Marie, as in many families, the important person is not the grandmother—it is the children. You understand what I mean? In a family, the children are the most important persons.
I have read about her. I have heard my parents speaking about Marie and her love of science. I remember my parents saying, «She was a very good director of the Radium Institute after the French war [World War I]. She was really a very good director. But it happened that she didn’t make the good decision at that time, that day. She was not always right every day». It’s a life, it’s not a myth. I see Marie and Pierre, frankly, more difficult —as exceptional persons, but also in life, as other people are. They are nearer to me. They are not mythical persons.
Kelly: Tell us about her background. Was she born in France? Where is Marie from?
Langevin-Joliot: Marie was born in Poland, in Warsaw, in a family with several children. She was a younger one. The family was —I would not say poor, but with a very high level of education, her father and her mother. At that time, Warsaw was in the Russian Empire. The situation when she was a girl was very difficult because there had been protests in Poland, so she could not study in Polish. She was obliged to do that in Russian. After that, she wished to enter a university. She was a very good student. But at that time, women were not accepted in Warsaw University. Her sister wished to become a doctor. She [Marie] didn’t know exactly what she wished —but she wished something about science. But of course, she needed to go abroad. Her father did not enough money to help. The elder sister went to France first to study medicine. Marie decided to become a governess to children in a rich Polish family. It was sometimes not so bad, but sometimes rather difficult. Finally, she succeeded several years after. She was twenty-four when she came to Paris, and entered easily the Sorbonne University. It was more easy for her than for a French student, because French women didn’t get at, that time, the baccalaureate. It was very difficult to enter the university. Marie had a certificate from the Russian Empire and that certificate was at the level of the baccalaureate, so it was accepted. It’s not special—you have in physics and mathematics about the same amount of French and foreign students at that time for women.
Kelly: How many women were there at that time?
Langevin-Joliot: I would say, it depends if you take all the universities or not, and it was changing every year. Because it was what I call a transition period, where you start from zero, then one, two, three, ten, more or less twenty, and the year after there were twenty-five, and so on. It was increasing, but it was a small number. The total number of students was very small, 200, 2,000, something like that, two or three thousand. The women were 20, 30, 50 maybe, depending of the year of your viewpoint.
Kelly: So she was clearly a minority.
Langevin-Joliot: Oh more than a minority. A special situation. Changing rather quickly, if you compare with the situation at the beginning of the nineteenth century.
Kelly: She was a good student?
Langevin-Joliot: Very good, very good. She had success in Paris, first in physics and then in mathematics. Then she decided to come to Poland to try to find a position to teach. But it happened that after a French Professor of Physics, [Gabriel] Lippmann, was impressed by this Polish student. He finds for her a research contract to make some measurements, some rather easy in principle, some easy measurements about the magnetic property of steel. It is when she wished to start that work that she met Pierre Curie, who at that time had a lot of research, research very important. Already he had discovered piezoelectricity with his brother [Jacques Curie] twenty years before. He had produced a theoretical paper about symmetry. He was finishing his thesis about magnetic properties, the first important thing after [Michael] Faraday on the subject. They met, and it happens that Pierre Curie at first decided that he will make everything to become her husband. It was difficult for Marie to decide, because Poland or France? They exchanged letters, very beautiful letters. In fact, letters from Pierre Curie were successful to decide her to remain in France and remain with him. He wrote something like that, «It will be a beautiful thing to spend our life together, a humanitarian life and also your patriotic life and your scientific life». She married. Marie studied, and was able in principle—she could have a teaching position in France, and then she decides it’s better to try research and to try to have a thesis on that.
They discussed about what subject, and they choose the discovery of Henri Becquerel of the uranium radiation. It is a starting point of the two discoveries. In September 1897, she started arranging the apparatus with Pierre because the system was built by him, and she started measurements. She studied uranium. It is radiation, uranium radiation is really anatomic radiation. She had the idea to compare to see if other elements, chemical elements have the same property—not so much. One. Then she had the idea to look again at minerals and was very much surprised that pitchblende and another one were more active, as it is written in the publication, as uranium. They began to work together, Pierre and Marie. By the end of 1898, they have discovered first, polonium in July, and radium in December. There was a note of the French Academy of Science just before the polonium. The first note was signed only by Marie, and you will understand that many physicists would have signed the note with Marie. All the experimental setup was from Pierre, and maybe he decided that it was better. He was already known as a physicist. I am sure that the fact that this first note had been signed by Marie alone was the starting point of all her career, because you cannot say, «It’s Pierre». After that, it’s true that the two discover it, they worked together, and they have their common discovery. For a thesis, she found it very important to not only to use the work they had done together about polonium and radium, but to go farther, to get to have radium as a pure salt. Because at the end of 1898, it was trace, so the things they wanted to produce, you have not one part in 100 of radium, for example, in the barium salt. They were at work for at least three, four years. Very difficult. It was a huge amount of pitchblende. It must be said that they never had four tons of pitchblende in the lab. It was completely impossible. Pierre Curie arranged to ask an external society to treat the beginning of this huge mass of pitchblende. But they have tens of kilos to have to process, and it was already enough. The Nobel Prize in 1903 was given for physics to Becquerel and Pierre and Marie Curie, divided in two. The reason was that the Nobel committee received first a French proposal for Becquerel and Pierre Curie, without Marie. Pierre was aware of that and he wrote to say that on this work, it was necessary to have Marie included, and she was.
Kelly: Tell us about the hazards of working for three or four years with these huge vats of pitchblende. How dangerous was that?
Langevin-Joliot: It was dangerous because of radioactivity increasing and increasing. When she had at the end one decigram or less of radium, there is a lot of radiation in that, and no special means for chemistry in this place. They had their fingers burned. But at that time, people don’t know so much about the risk of cancer, in fact. Marie started to be aware of that maybe fifteen or twenty years after. It was Pierre Curie who at that time began to have some collaboration with medical people who tried to use radium to cure.
Kelly: Cure cancer?
Langevin-Joliot: Not immediately cancer. Radium was destroying things, so it was possible to use first for skin problems. Then they say, «Maybe we can try on cancer, to cure cancer.« But medical people need twenty years to be able to start, I would say, scientific, a really scientific trial with measurement of the radiation, looking at the ways and then so on. At the beginning, it was just, «The people are dying, so we try something».
Kelly: I have read the laboratory where they worked was part of the School of Medicine once. It was a morgue.
Langevin-Joliot: Pierre Curie was a professor at the School for Chemistry and Physics, a school for engineers. The place of the school was organized from a public school, more general. In a part, there was an older place, which had been not a medical school, but a place with some medical tie. It was old and not convenient at all as a laboratory, that was the point. It was the reason that Pierre was trying to get a real laboratory. After he died, Marie takes her work. The Nobel Prize helps, but it takes a long time before the faculty of science in Paris [of the University of Paris] and the Pasteur Institute agree to start the building of the Radium Institute. There was already at that time a Radium Institute in Vienna. The Radium Institute in France was just finished at the beginning of the First [World] War. There was in the Radium Institute a part for chemistry and physics, directed by Marie, and a part for biology and medicine, directed by a very important, very good researcher, Claude Regaud.
So they combined. It happens that during the first war, Marie decided it was not time to start study on the radioactivity at the Radium Institute. She devoted completely her time and her effort for radiology tests for the soldiers. In other countries, the same thing happened. Lise Meitner, for example, does the same thing. But Marie, with her energy, was able to convince the military stage, convince the medical people, with things that take searching—that X-rays were not so useful, and they don’t understand how to use X-rays. She was able to convince them. She searched for people to help. My mother, who was seventeen years old, started to help. Just after the war, Marie was the director of a lab. She increased the lab, she developed the Radium Institute. Between the end of the French war and her death in 1934, she makes the Radium Institute one of the main laboratories in the world. Two or three were maybe comparable to that.
She had to get money, especially during the first year after the end of the war, because France was in a very poor situation. It happened that this journalist, Mrs. [Marie Mattingly] Meloney, was successful in getting an interview from Marie, which was amazing because she never gave interviews, and Mrs. Meloney was successful to get one. It happened that instead of asking Marie that she was very unhappy with that and that and that, she asked the situation about the lab. Immediately, Marie answered. They discussed together in the interview. She didn’t imagine an interview for that. It was the starting point of the petition for money to pay for one gram of radium to Marie, and the trip in America to get such radium in 1921. I would say this travel probably made more, or the same level, than the Nobel Prize. It was a promotion, an exceptional promotion. It’s true that it was built on serious things, but I am not sure that without that travel, Marie would not have been known as much as she was in those times. Because the two trips in the States, in 1921 and 1929, with all the publicity and all the newspapers speaking about it, that gave the idea to an important editor just after Marie’s death to ask Ève Curie to write a biography of Marie. That biography was in English, published in English earlier than in French, in spite of the fact that it was translated from French. It was a very important first printing of the book, because the book was known even more to English-speaking people than in France, the number of people.
There have been other books about Marie after the Second [World] War. Several of them at the beginning were people by historians, because the archive was opened. Many things that my aunt could not know about—for example, this story about the first Nobel Prize, nobody knows until historians open the archive of the Nobel Committee. It was not immediately after the war, it was much later. You have serious works written about Marie, and also some books for children, summaries, and all that. Marie has become really a symbol of the myth about women in science, and a number of books have been written. I read some of them, I discussed with the writers in some cases, and you have a lot of books I never know about. Some are good, some are interesting. Or you arrange the life of Marie so that it becomes a roman, which have in some cases nothing to do with the truth. It’s like that. If you wish to know about Marie, we made publicity for a book I took care of for the publication, I took care of with the director of the Curie Museum. We have gathered parts of the letters exchanged between Marie Curie and her daughters, Irène and Ève. You have a thousand of letters in total. That really is the true Marie Curie, you will find in that.
Kelly: That’s great. Could you go back a little bit on World War I, when she used X-rays—was that the first time they were used in war, in hospitals even, to detect where the bullet might be or broken bones? Was that the first time that X-rays were used for that purpose?
Langevin-Joliot: X-rays had been used before the First [World] War in hospitals. But not so much in France, but also in Germany, in England, all those places. It was the beginning of the use of X-rays. As the war started, the number of soldiers who needed X-ray was huge. Marie appreciated that immediately in the first weeks of the war. She thought that she could do something on that. She searched for a car to be able to change things, or to put the X-ray apparatus and use [them]. She began to teach to medical people and women so that they were able to use the X-ray apparatus, which at that time were laboratory apparatus.
Kelly: Do you remember what people called those ambulances she fixed with the X-ray apparatus? Do you know the term «petite Curie»?
Langevin-Joliot: Yes. To tell the truth, Marie organized this «petite Curie», this car. It must be said that during the war, once the military stage was convinced that it was really needed, there were a huge number of those cars, and so those cars are not «petite Curie».
Kelly: That’s great.
Langevin-Joliot: Yes, not all. You had «petite Curie» in Germany, because it was obvious at some time, even the military understood that it was necessary.
Kelly: That’s great. One other image I have of Marie and Pierre is on their honeymoon. Is it true they went on a bicycle trip in Brittany? Can you tell us about how much they liked to bicycle?
Langevin-Joliot: Yes. They loved trips in the country, with bicycle or by foot. They thought it was very important for children not only to study, but also to be in good health. This is a tradition, which came to the next generation. Few people used to do so, in those times. You have a number of things like that. They were not always at the laboratory. It happens that they may come back at night to continue some operation or to look at a result. But at other times, they take some vacation. You may ask a question: between the discovery of polonium and radium, they knew that there was another element than polonium to discover. And what they do they do? They take a vacation, and they spend on vacation more than one month, or maybe two. If you look at the mention in the notebook—it’s completely incredible for a scientist in all time. You have made a discovery; you know that there is another one to do. And you stop everything to go and take a vacation, and take care of the young children, and so on. Among the many things, many ideas which came from Pierre and Marie to my parents —and I would say to me and my brother— was the love of science, of research. An idea about the fact that everybody needs good condition of life. At each generation, they hoped that more people are happier, with better social conditions. This was something from one generation to the other, in different conditions, because the time of Marie and Pierre is not the same as my time, for example. And also, the fact that children—boy and girl—I would say my parents, because for Marie and Pierre, it was two girls [Irène and Ève]. For my parents, boy and girl [Hélène and her brother Pierre]. They need the same kind of teaching, the same kind of education, and the whole family needs to not always be working at the lab or at the school, but needs to have vacation, to do sports, taking some time for active vacation. All that was transmitted from one generation to the other.
Pierre et Marie Curie devant leur maison de Sceaux en 1895 /photo Boyer-Viollet /sc
My parents, they did not have to come from one country to the other. Frédéric Joliot and Irène Curie were both born in Paris. Irène was born in a scientific family, and she was quickly interested in science. I would say, she dropped in science quite naturally. For Frédéric Joliot, it’s completely different, because his family had no connection at all with science. Maybe some arts. They loved theater very much and all that. They had money before the First War. It was a rather big family, two girls, my father, an older brother. The family was rather rich and the father, retired, had money, was not working for money for a long time. My father, he goes to school. He was not especially good. Chemistry is interesting, but football is very interesting also. It happens that it was the First [World] War. The First War was not simple for their family. The older brother of my father was lost in the two first weeks of the war. It was very important for my father, during all the life of my father, the number of times he spoke about that. During that time, Irène was helping Marie in the “[petite] Curie,” so at the end they have one thing in common: war is awful. My father entered the School for Chemistry and Physics to become an engineer. The school was only three years. You don’t need the complete baccalaureate to enter. You have a competition for entering. It was considered preparing engineers for production, not research. It happened that one of the professors was Paul Langevin, and physics by Paul Langevin was something much more than ordinary physics.
At the end, my father was the first in his promotion in the year of when he entered the school. He could have chosen industry, with a very good salary. And finally, he wished to try research. How? There was no position for that at all, only very few positions—not only for a woman, but very few positions for everybody. Marie asked Paul Langevin, «Do you know a young man who could enter the Radium Institute as my preparateur [assistant], a person helping me for various things, because my preparateur is retiring». Paul Langevin proposed Frédéric Joliot, and he enters the Radium Institute in 1925. At that time, my mother was in the year where she finished her thesis. You see, in that generation, the woman was the teacher of my father. The number of times he spoke about that, saying, «I don’t like so much to be taught by a woman». As my mother was not at all a diplomatic person, things were like that and that. She just said, «This is wrong, this is wrong». But this was not for long. Finally, these two people understood that they were with completely different characteristics. My father was exuberant young man, rather happy with women. My mother didn’t like to speak, only discussing with a few persons she knew about. But they understood they were happy together working. They shared the same kind of values. They were happy doing sports. And they shared the same ideas about science. My mother had her thesis in 1925, and my father had his thesis in 1931. He had to complete the baccalaureate and take some teaching again to be able to present the thesis because the School of Chemistry and Physics, at that time, was not considered an equal level of the Sorbonne.
Starting in 1929, they started to work together. We were living in Paris at that time, and they were very much in what I call the marvelous years of radioactivity and nuclear physics. During those years, until the war, you have a number of steps taken in that field, incredible. Irène Curie and Frédéric Joliot, because they signed their papers like that— they never signed «Joliot-Curie». When they published something together, it was «Irène Curie and Frédéric Joliot», which was not used so much at the time. They were not completely successful in all cases. One says that they have missed the discovery of the neutron. This is more or less true. The way my father presented that case much later, he said, «The discovery of neutrons is a very good example that science is international». Because the starting point of the discovery of the neutron is not only the experiment performed at the Radium Institute and the conclusion of my parents, it started two years before with a discovery by [Walther] Bothe and [Herbert] Becker in Germany of an extraordinary radiation able to travel a piece of lead. All physicists in the conference are thinking about that. Nobody understood what this radiation is, and the radiation being started in the different place. Then my parents, both in one year after, start to work with that. It was a work where a secondary radiation was observed. That gives them the idea of preparing the experiment to be able to search not only for neutrons—which the radiation property—but to be able to look at the radiation, whatever it is. Because other people during that time, in Cambridge in particular, they were interested in the same problem. The radiation is able to cross lead. Why? I need a very thin window of the ionization chamber to look at that radiation. No reason. The experiment of my parents, they just decide to put a thin window. That is not useful for that radiation, but useful for the secondary radiations that they observed when they looked at many foils of one element, and another one and another one. They used a foil with a composition with ionization and the radiation, the very energetic radiation crossing that very small foil, was able to project out ionizing radiation, called «protons» after. The conclusion my parents, when they published that, they say, «This is the same thing that [Niels] Bohr, that the other players —this is due to gamma rays». At that time, people don’t know about what happens to gamma rays when they are energetic gamma rays. The paper arrived in Cambridge. [Ernest] Rutherford says, «I don’t trust that. But you have to check». Chadwick checked, and confirmed that it was true. He performed marvelous experiments to prove, without any doubt, that it was a neutral particle. The neutral particle that Rutherford, ten years before, had a quote about in a lecture—which was not a good one because he looked at that, especially a known force bringing together a proton and an electron to make a neutral particle. And the neutron is not that at all. So, you see the story. It’s really an international story. It’s a neutron, it’s incredible. In that year, 1932, in January, [Harold] Urey discovers deuterium. Next, [James] Chadwick discovers neutrons. In the summer, [Carl] Anderson discovers the positive electron [positron]. [Paul] Dirac had predicted anti-matter may exist, but nobody takes care of that. Anderson discovers the positive electron in cosmic rays, in the rays coming from space. What is that? All physicists tried to look in the lab, and they understood that they have already seen positive electrons, without recognizing them. In the years after, everybody looks at production of positive electrons, and understood that that came from gamma rays. During one year and a half, in all the labs with activity, people were working on neutrons, nuclear reactions producing neutrons, and various ways of producing positive electrons.
My parents were working on that during all the year 1933. In the fall, this very important meeting, discussions, the Solvay Conference, a special meeting organized by Ernest Solvay, a very rich man from—it was an industry of people. He invited the better physicists in the world to discuss only [one] problem. The subject in 1933 was the structure of atoms. It happens that my parents present their research, and their research was a nuclear reaction producing neutrons. But it was very difficult to understand how this was possible. The same reaction seems to produce also positive electrons, and nobody understood this. My parents say, «Okay. It’s simpler. It’s an ordinary nuclear reaction, but sometimes the protons give a neutron and a positive electron together». Everybody did not appreciate the idea. It was theoretically very bad. Lise Meitner says, «I don’t see neutrons». It was a controversy. They came back to the lab, rather unhappy. Finally, they understood in January that the process was in two steps. You have an ordinary reaction first from aluminum, and you have a reaction giving phosphorus, but this phosphorus was radioactive. It was impossible to understand, because you have to say you produced not a stable nucleus, but a radioactive one. They published two papers: one, a new type of radioactivity, emitting a positive electron. Then artificial radioactivity—this produces artificial radioactivity. The Nobel Prize for Chemistry was given because they were able to prove that they have produced phosphorous in that reaction. And in another one, they have produced radioactive nitrogen. When you think of radioactivity and artificial radioactivity, it’s one of the discoveries with—the day after people got the publication, a number of physicists were able to see that radioactivity exists. It was incredible. It may have been discovered much earlier, and my parents were especially happy when [Ernest] Rutherford sent them [a letter], saying, «I have searched a long time for such a phenomenon». This was a turning point in their lives, because a few months later [after] the discovery, Marie Curie died. She had seen their experiment, so probably she knew that they would get the Nobel Prize. But she died in July, and they needed a new director in the Radium Institute.
In spite of the fact that the neutron, the property of gamma rays, artificial radioactivity has been discovered by sending alpha ray projectiles from radioactive polonium and all of that. In the lab, accidental particles start to be built. None of this accidental plays a role in this big discovery. But it was clear that the future of nuclear physics cannot continue using alpha particles for a polonium source. You need more energy, different particles, and all that. It was a reason for my parents to separate. They didn’t work together after. They discussed together a lot, but they didn’t work together. My mother remained at the Radium Institute, and my father got a position in—not the National Center for Research, but something before that. He had a position, not very high, but he started to try to build an accelerator in the new lab, then an industrial one. Especially because he was convinced that radioactive isotopes will become very important in many applications, and especially for biology and medicine. He started to collaborate on that subject, not nuclear physics. At the same time, preparing things for a nuclear physics lab, because he was named as a professor at the Collège de France, which is a very high-level position. But the time he had to make research was about using radioactive isotopes for biology and medicine. It happens at the end of 1938, that [Otto] Hahn and [Fritz] Strassmann discovered the fission process. It takes no more than two days for my father to prepare a very simple experiment giving a physical proof. [Otto] Frisch also gave nearly immediately physical proof. He understood immediately that fission may be the way to induce reaction chains. At the end of their Nobel lecture, my mother presents research on physics, he presents research on chemistry. He gives a conclusion, and the conclusion was, «Now physicists are able to do many things, to use radioactivity for many things. One can think of a time where we will be able to produce some kind of chemical reaction, able to transmit from one to the other, and you can imagine a huge amount of energy, which will be produced». That was at the end of the Nobel Prize presentation. You understand that he immediately understood that uranium is a very heavy nucleus. It breaks into a lighter nucleus. Neutrons must be emitted together, if you calculate the energy from this. If you have several neutrons, you can expect a nuclear reaction. It happened that two people in the lab, from the two people immediately interested in the subject, one was [Lew] Kowarski, who was not at all a specialist. But [Hans] Halban was a specialist of neutrons. He was aware of the discovery of fission by Hahn, before my father. He looked at the experiment done by my father to prove that fission exists, as he had tried himself to find an experiment for that. When my father asked him to collaborate, it was a very good team. Within three months, they have proved that you have neutrons, they have proved that energetic neutrons—that was known before, by Fermi especially—were not the best ones. That it was necessary to decrease in every other neutron, to have a chance to have more fission reactions.
They think that, if you have to slow neutrons, you have to do something—not absorbing, if you absorb the neutron, this will not. To recognize this, they give four–no, three at that time, three patents in France and two or three countries about production of energy. It’s a question of the manner to spread the matter, and the possibility for an explosive produced. To tell the truth, the patent about producing energy, it’s a good patent. The one about the possibility of an explosive power using normal, ordinary uranium, you need a huge system, probably, we don’t know. No possibility of working, certainly. What must be said is that there was a French team working on that, and you have at Columbia in the States, the team by Fermi. The two were within two weeks [of each other], the work of Paris before —the Paris results were slightly before those of team by Fermi. The team in Paris continued to work to increase their study, and on September 2 [1939], France became in war.
The Ministry of Armaments was very interested by the idea of producing energy, because France had not so much. They gave money, and this was continued until the defeat, at which time my parents had a big decision to make. In fact, they were not together at that time. They left Paris, or they left this place together. But my mother was in a very bad condition of health. She suffered from tuberculosis from the time I was born. This was a crisis. Evacuation was something very tiring, so on the trip to Bordeaux, where they were able to leave France, my mother has to stop in a place where one can take care of her. My father reached Bordeaux with Kowarski, Halban, and the papers of the experiment and the heavy water needed for the project of a small atomic reactor, a «pile», as it was said at that time. Finally, he decides not to go with Halban and Kowarski, not to go to England, not to leave France, with the idea that people have also to make something, that the Germans will be defeated at the end. And that you need, during that time, to be able to maintain some science in France, to be able to do it again. My father’s family was from this part of France, near Strasbourg, Alsace, which became German in 1870 [after the Franco-Prussian War]. The French people, some came to France, and others remain in Alsace. Among the people having feeling for France, they think, «We have to maintain the fact that Alsace is French, and others will speak in French again». There is forty years before the First [World] War. Then my father at the second one says, «I remain there». Germany will be defeated anyway. Some people claim he said, «It will take five years». But I heard him so many times speaking about Alsace and the fact, [Alsace] coming France to Germany to France, that I’m not sure that he imagined the [German] defeat so quickly. But the idea was the same.
Kelly: So, he stayed in Paris?
Langevin-Joliot: He stayed. He came back, and my mother was able to come back also. During the time of the war, it was very difficult for my mother because of her health. I see her number of hours obliged to rest, and it began to be very decreasing. She was allowed to go to Switzerland for nearly one year to take care, she was operated to block one of the lungs. I would say it saved her. When she was in Paris, she came to the lab, but not as before. It was not possible. She became very active after the war. After two or three years, I would say the discovery of streptomycin and penicillin used to cure tuberculosis changed her life for the ten last years, clearly. She would have died before.
We arrive at this very complicated period following of the Second [World] War. I would say the idea of physicists was clearly, when it is possible, try to research again, and having exchange between different countries again, free exchange. This was a common idea during 1945, 1946. There is this problem with atomic weapons and so on. My father was first, after Paris was liberated, he became the Director of the National Center for Research. [Charles] de Gaulle was very much convinced that it was necessary to develop atomic energy in France. The report of my father and a few others, knowing that you have Kowarski and others working in Canada to prepare the starting point for what we call in French «atomique énergie». He became the head of the Atomic Energy Commission. But in fact, the turning point for physicists was Hiroshima and Nagasaki. When you look at what happens immediately after—it was announced, nobody knew exactly what happened. They knew that the two towns had been destroyed by one bomb. He was not surprised, because he knows that there was work on this. His comment the same day hearing about that—we were on vacation in Brittany at that time. It was, «Atomic energy maybe used, will be used for the good of society, will have a useful application, and not only the bomb. And also, to tell French people that, yes, this is a very important result obtained in the States. But the starting point of the Manhattan Project is not only an American work. You have also the French work». He was not completely happy of the way the American government behaved for him. He was unable to go to the States. He could go to England, but to go to the States, he could not do so at the end of 1944. There was this official report, the Smyth Report, telling the story of the Manhattan Project, and giving an introduction at the beginning, summarizing the people, the reason from fundamental research. There was nothing in the report about French research. They put some research from Copenhagen but that, strictly nothing. The reaction of my father: «We must explain that we have done something». It’s only later that the fact that if you imagine a new war with the atomic bomb, it was the future of mankind. The newspapers and radio came from the States and from England to Paris. They have connections between the physicists. A number of physicists, nuclear physicists or chemical physicists, having taken part in the Manhattan Project gave statements advertising that fact of, with the atomic bomb, it was completely necessary to have an agreement for peace, not to use them. This was the case of a number of physicists. Some of them, even before the bomb, proposed that one give a demonstration of the bomb, not using the bomb on the civilians, on the population. Those with [James] Franck and a few others, with [Leo] Szilard and a few others, there was a small number. But after the bomb is there, there were a number of physicists saying the same thing, «You have to take care of that». This statement by Einstein, who was not involved in the Manhattan Project—he was the man who had said to [President Franklin] Roosevelt that something has to be done about the chain reaction and the atomic possibility of the Germans having it. But he was not involved at all in the Manhattan Project itself. The statement was with this situation, the future of all mankind. The only possibility that this doesn’t happen is to turn to a world government—which is not so surprising. It’s exactly the things he said after the First [World] War, as a pacifist very much engaged. His reaction was more than the approach. More realistically, it has to be said, we must be able to control more or less that, in order not to have a war with atomic weapons. But Einstein was, «If you have not a world government, this will happen one day». That idea, he pushed it for some time.
The bomb is really a turning point in the life of many nuclear physicists. Among them, my father. I would say the general opinion of nuclear physicists, more or less, thinking about the future was, «You need to avoid a nuclear war, absolutely. But the situation was such that very quickly the combination of the need for peace based off no atomic weapons and developing science as before with liberty». Because this was completely opposite to what was needed to have science again. You find in the statement not only from my father saying that in Paris, but the others were saying that in other countries: «It not only is the end of the civilization if we have an atomic war, but it is the end of science if we are not able to have the condition for fundamental research and freedom of ideas all among the world». The two questions became mixed together. And for the last one, a statement by Einstein about the law—to those people saying that the law was good, «Science is international, gentlemen, whether you like that or not». I like the statement very much. It happened that in July 1946, the United Nations opened a special discussion, diplomatic and scientific discussion about the way of applying nuclear energy for useful purposes and controlling the production of armament, of atomic arms. You have diplomats and you have scientific experts. My father, as High Commissioner of Atomic Energy in France, was one of the experts starting this discussion in the States in July and in September. All that, after that, continued for two years without a real result. In July, it started with a report from America, from the States, a report has been prepared by the scientists knowing the situation, five American scientists. They have prepared the Lilienthal Report, and taking the Lilienthal Report, the diplomats and governmental people taken what they want, and introduced a number of things. The secret about the bomb: «The bomb must remain at one only place, which is the States». In spite of the fact that physicists state to everybody who will hear that there was no secret of the bomb, that a big country will be able to make an atomic bomb. Some say one year, some say two years, but ten years it will XXX. Most say three or four years, which was exactly what happened. The diplomats, they were in between two choices: «The security of the States rely on the fact that we are the first. We have to remain the first, and we build more bombs, or the security of the States will make us rely on other countries, on an agreement. And you cannot prepare an agreement when you take steps to war». When the discussion occurred in this commission, diplomats and scientists, I heard my father commenting to my mother, «If scientists were alone, we will find a solution». If I look at the position of the Soviet Union and other states, of the United States, you can pick some of the proposals and you can find some proposals which are more reasonable than others. The situation after this period, all the politics, strictly political problems, and history and all that, results in the fact that this main problem. You had to be one side or the other. You could not be on the middle side thinking, «Really, the fact that the States could think the Soviet Union has the army in Europe or very near. And Russia» —as many physicists pointed out— «they have more reason to fear the United States, than the United States has to fear Russia».
So, it’s another story after. But the way scientists were able to decide what to do, my father was engaged rather quickly in the World Federation of Scientific Workers. Not only to fight against the possible use of a bomb, but to try to develop not only atomic energy, but all kinds of science, science as a social function. That idea did not come especially from my father. It came in particular from a book written by Bernal, a very well-known English scientist, Desmond Bernal. His book, The Social Function of Science, my father read it, and many others also. So it was that. We cannot speak of all the story of what happened until the death of my parents. My father first focused on what the scientists can do. But after one or two years, he convinced himself that scientists alone were not enough to push on this problem. Really, you must involve the public, other cities. So, that is the reason they tried to find ways to motivate people for that. He was in this Greek World Congress for Peace in 1949. We were a number. The year after, there was this Stockholm Appeal, given in Stockholm to adopt a clear position to forbid any use of the bomb and to say, «We must find a way to control». This was signed by many, many, many people. But the political situation was such that people read what is stated here and here, adding many other considerations. I think this is true —this is really not their position, because of reasons which have nothing to do with it. And it was the same thing, one side, and the same thing, the other one. It takes time. It’s a pity, because in the States or even in England, people don’t understand at all the position of my father as a scientist. And my father didn’t understand the position of others. Unfortunately, it happened that hydrogen atomic bombs began to be produced. This time, there is only one year between the States and the Soviet Union. And the bomb from the Soviet Union was somewhat better, it seems. You produce that, and you have this use in the atmosphere, and you have radioactive products everywhere on the earth and accidents and so on. The discussion among physicists starts again here and here and here. In 1955, what is known as the Einstein-Russell Declaration, which for the first time starts with eleven signatures. One only in France, my father, agreed, especially with Russell, Bertrand Russell saying, «I am anti-communist completely. And you are communist. We have two sides together». It was the last declaration of Einstein, as it is known. This was a special year, because at the time the declaration was made public, there was at the same time the conference in Geneva with a number of physicists invited. Not my parents. There was a story—and the French were the worst in that—because there was an exhibition to remind the progress of science before the war. There was nothing on the work of the Joliot-Curies, nothing, not a photograph, nothing. Many people were upset at that. Otto Hahn visiting that exhibition, told them because there was a photo of him, «If you don’t have something [about the Joliot-Curies], I wish that you take my photograph out».
After, the situation became better for my parents. Because the world hoped to find agreement. My mother was in good condition in 1954, she was in good condition. She decided, «It’s impossible at the Radium Institute to build the accelerators. We need a new place to do that». She started all the necessary things to have a new institute in the south of Paris. She found the place at Orsay, which is now the place of University Paris-South. When she died in 1956, my father took the job there after, and finished. When he died, the institute was finished. We had a cyclotron working. The last thing my father did was to be the President of the International Congress of Nuclear Physics, which was in France that year, 1958.
Kelly: Marvelous. We have some time to talk a little bit about yourself.
Langevin-Joliot: There was a problem with women, the lower level of the position of French women compared to men when I started research. But hopefully, at that time—nobody spoke out, nobody spoke so much about Pierre and Marie Curie. My parents a little more, because it was nearer, because they were alive. I started research after having made the physics and chemistry school and began to be a researcher at the National Center for Research. Hopefully, I say, nobody spoke so much about the Curies. I was a researcher like the others. This was not completely like the other, ten years after. Because, for example, the institute started to have exchange with Harwell [Laboratory]. One physicist from Harwell had spent three months in our lab, and it was decided that I will spend three months in Harwell, the place where they have the same cyclotron as we have, so it was very useful for me. They had all the papers; the physicists of this lab had taken all decisions necessary for me to have this position for three months there.
It happened [we received a] letter that says, «We’re obliged in a letter to explain» that I could not [go to Harwell] because my mother was not allowed to visit Harwell in 1948. As I was the daughter of the Joliot-Curies, I was not allowed to work at Harwell for three months. The discrimination against women, I don’t think about that at all. But I met political discrimination, which is amazing. I remember, it was in the ‘80s—maybe before, I was in the States. Each time I go to the States, I have to explain that I will not kill the President of the States, everything. It makes plain which places I will visit in the States. It was like that way. There was a conference and the physicists had arranged to have a new important lab with a very beautiful, new accelerator at Los Alamos. At the conference, I have not asked to visit Los Alamos, but the director of that new lab, I met him at the conference I was attending in San Francisco. Told me, «I will be very happy that you give a talk at our lab, at Los Alamos». I explained to him, «I have not written that, and I am not sure that I am the best person to go to Los Alamos». He says, «Yes, you are especially the best person, because I wish to give a demonstration that this lab in Los Alamos is as free as anywhere in the university, anywhere, and that it doesn’t have conditions». He really wished that I come there, because people were afraid to go. «I will have to give, explanation and all that». So, I gave my talk there. Everything was very well prepared; it was true this time. We were in normal time, even at Los Alamos.
Kelly: Wonderful. You have such a rich history. You have such a rich story to tell, and you did a great job.
Langevin-Joliot: The number of women, I was saying previously—the students in science were very small at the beginning of the century, but it was increasing. When after the Second [World] War, the number of women in science was not very large, depending on the place. But it happened that in physics, and especially in fundamental nuclear physics, it was not so bad. I never counted exactly, but maybe 20%, 25%, which is not so bad if you think of the situation now in several places. I entered in a field where you find women in France, in the Scandinavian countries, a few in Spain and in Italy, especially in physics, astrophysics. Very few in the States, very few in Great Britain. When I come to an international conference on nuclear physics, we are looking for the women. We don’t meet colleagues from some of the countries, many of them, in those fields. I would say in Great Britain, in the labs, even in nuclear physics, maybe the number of women is not more than in the time of Rutherford, who had women at different levels coming in his lab. Women in the best front of science.
Extraordinaire. Why Spanish women or Italian women are not, German women nearly never, it’s the worst. In France, in comparison, the situation was not so bad. We were thirty, fifty, we have money in the institute. I was not a professor, but I became a director of research, which is the same level. In the team we work, our team, we have two women in this team and maybe three in this other one. When the question came on the table in the ‘80s, because it’s the ‘80s, so we are as other women. We are older women, we start to look around, and looking around, we were forced to say, «There is discrimination against women, yes». I remember when the discussion came from above to down, and [inaudible] said, «It’s better if women—would it be good to put a quota on the number of women in this position and this position?» This is the kind of thing most humans of my age, we don’t like quotas. But at the end, the government started also to give some women very important official positions in research institutions. Things improved, more or less, in intermediate levels. But when you look at scientific researchers is one thing, but when you look at other workers, I understand that the situation was much worse. This was a turning point for me. It was in the 1980s, and there was a Polish delegation of scientists invited in France, a very important Polish delegation. The Minister of Research invited very important scientists of France to meet for an official dinner—not dinner, but lunch at the ministry. I was invited. We were maybe twenty, twenty-five. It was the kind of thing starting to be discussed, but probably, we were not thinking of the situation. Somebody started about the women in size. One spoke, and everybody seemed to agree that more women [should be present]. I say, «I have something to say». When I say something, it was, «Look around the table. I am the only woman. And the delegation, I know very well for what reason I am here. I am here because I am the granddaughter of Marie Curie». It was obvious. But for me, it was an experiment, because I had never seen that at that point. Scientists representing France, Poland, and the others, and not one woman. After that, each time I come to a meeting, I estimate the number of women.
In 1998, the International Conference for Nuclear Physics was in France. I was retired at that time. It was a celebration of 100 years after the discovery of polonium and radium. I was asked—no, it was my idea—I was asked to give the after-dinner talk of the conference. It was to speak about Pierre and Marie Curie, quite normal. But my ending point was the following. I showed there a number of PowerPoints and photographs, and I finished with the Solvay Conference in 1933. In this conference, you have probably about twenty Nobel Prize, or physicists who will have a Nobel Prize after. You have three women: Marie Curie, Irène Joliot-Curie, and Lise Meitner. 1933. I told, «If you take a picture of the president and invited speakers of this conference on nuclear physics in 1998, you will not have more women compared to men than in 1933». It was the end of my talk about Pierre and Marie Curie. I think that even for that, it was worth it, to speak at this after-dinner talk. I say, «There is something to change in the state of nuclear physics». This was my conclusion.
Kelly: Well it just makes it even more remarkable that both your grandmother and your mother were the Nobel Prize winners, two of the three women.
Langevin-Joliot: Yes.
Kelly: It’s remarkable.
Langevin-Joliot: Yes, in 1933, it’s not bad. In 1911, Marie was alone. In 1933, there were three. If you extrapolate, you will have to solve the problem. The levels are not changed. I feel that presently it is what happened. I see things improving since 1890, it’s improved. But for the last five years, my feeling is, it is stopping. In fact, I am convinced, for example, that the way science is developing now is a reason for that. Competing, having it necessary to take three postdoc positions to get a chance to have a stable position. That is worse and worse. This is more difficult for women than for men, even if things are slightly improving in the way you share the work at home, which is true. Things are improving, but really, I think that things are leveling. Doesn’t change. I discuss with others, and they said to me the same thing.
