Maria Skłodowska-Curie, together with her husband Pierre, was the first to conduct systematic research into radioactivity. She discovered two new chemical elements based on the phenomenon. Kennislink did a 'fictional interview' with the diligent but publicity-shy scientist from Poland.
Together with her husband, Marie Curie pioneered the idea that radioactivity was a fundamental property of the atoms in various chemicals. This led to insight into radioactive decay:the natural process in which unstable isotopes spontaneously change into a different type of atom.
Born in Poland, she was regularly the target of the conservative French scandal press in her 'second homeland' France. Despite frequent personal attacks and plagued by ill health, she continued her scientific work.
Madame Curie, first of all I would like to thank you very much for this interview. I understand that you rarely speak to journalists. "That's right. I always think we should be interested in business, not people. I don't really like publicity at all. In addition, I unfortunately had to endure many clashes with the French press during my scientific career.
Okay, so let's talk about your scientific work for starters. You have received both the Nobel Prize in Physics and Chemistry. You have contributed a lot to research into radioactivity, a phenomenon that was previously largely misunderstood. How did your interest in radioactivity begin? “In 1896 Henri Becquerel accidentally discovered that uranium emits radiation that was visible on photographic plates. It was a completely new phenomenon, but no one – not even Becquerel himself – bothered to investigate it extensively. Shortly before that, Wilhelm Röntgen had discovered his fascinating 'X-rays' (today known as X-rays, ed.), which could make the bones in a human hand visible. Most physicists found that much more exciting. Precisely because uranium radiation was so new and hardly anyone had published anything about it yet, we decided to tackle it.”
We? You mean..? “Me and my husband Pierre Curie. In 1906 he died unexpectedly in a fatal traffic accident in Paris. Unfortunately, that didn't do any good for the quality of my life. Since then I have mainly focused on my work so as not to have to think about him too much.”
“Becquerel had already noticed that uranium radiation made air behave as a conductor of electricity. Initially I wanted to measure this accurately for my dissertation. But Pierre and I soon discovered something interesting:the ionizing radiation from uranium turned out to be constant, independent of external factors such as temperature or lighting. Moreover, the purer the uranium, the stronger the steel. Therefore it seemed to me that radioactivity, a term I myself first used for an 'active radiator', is an atomic property of the element uranium had to be.”
“Then I also wanted to know whether there are other materials that emit radiation. Metals such as gold and silver clearly did not emit ionizing radiation, but thorium turned out to be much more radioactive than uranium. When we tried the black, heavy mineral pitchblende, we saw something interesting. Pitchblende – from which uranium was usually extracted – emitted much stronger radiation than uranium itself.”
“Pitchblende's powerful radiation couldn't just come from the uranium it contained. There must be another radioactive element hidden in it that we didn't know about yet. Or perhaps several unknown elements. In 1898, after extensive chemical analysis, we were able to isolate one of those radioactive elements and determine its atomic number. I named it polonium, after my native Poland.
“Shortly afterwards we also discovered radium, which turned out to be much more radioactive. By isolating these two new elements, we showed that new elements could be detected by relying solely on their radioactivity, a fundamental atomic property."
Exciting science! We now know a great deal about the chain of radioactive decay:uranium, for example, decays over time into thorium, emitting radiation in the process. Did you have an idea of what the radiation actually was in the beginning?
“The radiation seemed to come spontaneously from the materials. Since the law of conservation of energy stated that energy could not be created out of thin air, we thought that perhaps uranium would extract energy from the atmosphere and then emit it again. However, our German colleagues Julius Elster and Hans Geitel quickly ruled that out experimentally.”
“It was ultimately the brilliant New Zealand physicist Ernest Rutherford who discovered in 1902 that a non-radiant material could become temporarily radioactive if placed near a radioactive source. Apparently radioactivity could change the properties of materials. In doing so, Rutherford laid the foundations for the modern theory of transmutation, for which he more than rightly received his Nobel Prize in 1908.”
You named one of your discovered elements polonium, so your homeland has always had a special place in your heart. May I ask why you ever chose to leave Poland and move to Paris? Was that because you had better scientific opportunities there? “Come on, I love my homeland dearly so I'll tell you something about it. Our family, the Skłodowskas, came from old Polish nobility, but we were very impoverished. For much of my childhood in Warsaw, Poland was under Russian occupation. At night before going to sleep, my father read Polish poems to me and my sister Bronisława, although the Russians had forbidden it. This is how we learned to love our language and our people.”
“My sister and I thought we had a right to higher education. But in Poland, women were not allowed to go to university, especially not by the Russians. However, there was a progressive mood among Polish scientists. They wanted to teach women. Thus a true clandestine university was born. First in attic rooms at scientists' homes, later in rooms of sympathetic institutions. We called it 'The Flying University'."
“My sister and older brother both left for Paris to study. After much hesitation, I went after them. At the Sorbonne University in Paris I would receive a much better education than in secret in Poland. But my heart broke when I had to say goodbye to my parents and get on the train.”
You have lived in France for the rest of your life. Have you never thought about returning to Poland? Certainly. After graduating from the Sorbonne, I really wanted to go back to my family in Warsaw. But in the end I chose to continue living in Paris with Pierre, whom I met towards the end of my studies. But we regularly traveled to Poland together. I also wanted our two daughters, Irene and Ève Curie, to learn Polish and get to know the country.
It also seems to have been a good choice for your scientific career. You and your husband were awarded the Nobel Prize in 1904 for your pioneering research into radioactivity. “Initially, in 1904, when we were awarded the prize together with Henri Becquerel for the discovery and research of radioactivity, only Pierre was nominated for the prize. There were a lot of conservatives on the Nobel Committee who would rather not see the prize go to a woman. Only when Pierre had made it known that the discovery and isolation of radium and polonium was largely my merit, I was also nominated.”
“With the Nobel Prize, we suddenly became famous in France. Of course I wasn't expecting that at all. Especially because many right-wing conservative French media were not used to a woman being able to conduct independent scientific research. The merits were mainly attributed to Pierre. Some media even wrote that I should do the housework instead of standing in the lab. I had a really hard time with that.”
How did you manage to win another Nobel Prize in 1911, this time for chemistry? It almost never happens that a scientist receives a Nobel Prize twice. “Shortly after we managed to isolate polonium, we discovered that there must be another radioactive material in the pitchblende, which radiated much more strongly than uranium or polonium. We called it radium. Only in 1908, so after the death of Pierre, I managed to isolate it in pure metal form (previously only in the form of radium chloride, ed.). That, the earlier discovery of polonium and my insight that radioactivity is an atomic property of matter worthy of a Nobel Prize in Chemistry in 1911.”
“I know that some fellow scientists – and again the media – felt that I was actually awarded a Nobel Prize twice for the same scientific achievement. But the discovery and isolation of radium was apparently also considered to be of great importance for chemistry.”
Speaking of the media, they weren't afraid to sign you up when it became known that you were having an affair with another scientist, Paul Langevin. “Well, I don't see why people always want to write about my private life, but it was like this:Paul and I fell in love, but he was a married man of wealth. In France you could have a mistress as a public figure, but she had to stay in the background. And of course I was a celebrity.”
“When it leaked out that he was having an extramarital affair with me, the turnips were done. Because of my Polish origin, it was written that I would pollute French morals. Some newspapers even wrote that I was Jewish. Xenophobia and aversion to anything not authentically French were the order of the day. It was terrible, I had no life anymore.”
“My second Nobel Prize in 1911 had saved me. As a result, I got my own state-funded research institute, the Institute du radium (today the Institute Curie, ed.) Despite the sordid attacks in the media, I had come to love France. During the First World War I helped at the front by helping to treat bone fractures of soldiers with self-designed mobile X-ray equipment. It felt very good to be able to do something for my second homeland.”
Did the press actually understand anything about your scientific discoveries at the time? “No, not at all of course. They were just looking for gossip and thrills. They found Radium very exciting. After all, it radiates so strongly that it gives off heat and light and causes red spots on the skin. Stories surfaced in the media that Pierre and I would have said it was a panacea that could cure diseases like cancer. Manufacturers incorporated it into paint and lipstick. Only later (around 1925, ed.), when women in particular developed all kinds of deformities of lips, jaws and fingers, did it become clear that radioactivity is extremely dangerous. Unfortunately, I saw that myself too late in…”
Have you also become ill from your work with radioactivity? Unfortunately, I suffer from bone marrow depression, a very severe form of anemia. Indeed, probably caused by years of radiation exposure. The dangers of radioactivity have not been known for very long. I often just carried my materials in my handbag, unaware of the dangers. But I try to continue with my work for as long as possible, because as soon as I can no longer stand in the lab, my life is not worth much anymore."