Radioactivity is a great thing. Terrible, as they say, but great. The medical applications of radioactively tagged molecules, as Rosalyn Yalow proved, are legion, and have saved millions of lives since their introduction. Tricky thing, though – the big atoms that tend to be radioactive also tend to be achingly rare and not particularly present in biological compounds. Radium, to take just one example, is around 100,000,000,000 times less concentrated than sodium in the earth’s crust. To change the face of medicine, a way had to be found to make normal atoms exhibit radioactive properties, a task of inter-war alchemy that fell to the daughter of the twentieth century’s greatest chemist.

If you were one of Marie Curie’s students, chances are you’d eventually find yourself invited to her home to partake of tea and science talk. If your eyes were quick, you could catch, scowling at you from just behind the doorway, the jealous eyes of a little girl who did not at all appreciate your casual invasion of her home. Her mother would tell you her name, Irène, and try, unsuccessfully, to coax her out to greet the guests. If you kept visiting regularly, though, and let the child get used to you, you’d learn the secret behind the suspicion.

For Irene Curie had much to be wary of. While most children had a doting mother who stayed pathologically at home, Irene was left alone with her grandfather during the day and often through the evening as her world famous parents worked away at their world famous lab. And when her mother was home, she spent her time talking about science with other adults or continuing her analysis of the day’s results with father. After the parents Curie won the Nobel Prize, all of that only got worse. Science, publicity, duty… these were the things that conspired to keep the serious child so stoically alone.

Irene Curie

Science, which took Marie so regularly from her child, was therefore the path the young girl followed to reunite with her mother. Irène devoted herself to math and physics at a young age, and proved supremely gifted at the work, so much so that Marie and several of her scientific colleagues decided to form an impromptu school for the teaching of their gifted children – “The Collective.” Every day the children, just past ten years of age, would march to a different genius to learn at their feet – on one day, Marie Curie, on the next, Paul Langevin, on the next, Jean Perrin. They visited unusual museums, played sports, and saw laboratories at first hand, a freely guided and inspiration-driven educational experience, unique but not unheard of in the age, and all but extinct since.

Irène entered the university early and took her first baccalaureate at 17 years of age, just in time for World War I to cast its shadow over Europe. War, and the threat of war, would weave its way through the fabric of the rest of Irène’s career. Her mother, moved to use her knowledge of radiation for the good of her country, created from nothing a fleet of traveling x-ray stations to serve France’s wounded at the front. Marie and the teenage Irène worked side by side, driving these car-mounted machines from field hospital to field hospital, imaging thousands of bones and saving as many lives. Unfazed by the gore of the front, Irène trained new x-ray technicians, advised field surgeons, and exposed herself to more radiation in a day than most of us will see in our lives. In saving so many French lives, she took her first step to prematurely ending her own.

The war over, Marie returned to her research, and Irène became her right hand. In the lab, she was severe, almost comically undiplomatic, and precise. She gave everything to her research, and feared beyond all things the wasting of precious time, her only luxury activities being the strenuous sports that Marie had inculcated in all her children – swimming, skiing, and mountain climbing. Strong of body and keen of mind, she was as intimidating to strangers as she was kind to friends.

In 1926, she married Frederic Joliot, and they both made the modern decision to adopt the joint name Joliot-Curie. As he endured being called the Prince Consort of chemistry, the two of them worked united on radioactivity research as Pierre and Marie had done three decades earlier. Their brilliance was equaled only by their appallingly bad luck. In 1931, they carried out an experiment bombarding Beryllium with alpha particles but failed to correctly interpret the surprising results they obtained. James Chadwick, reading of their work, repeated the experiment and correctly saw that it pointed to the existence of a neutral nuclear particle, the neutron.

It was such a clear conclusion that Irène and Frederic couldn’t believe that they hadn’t thought of it. Having missed out on the discovery of the neutron, seven years later they missed out equally on the discovery of nuclear fission. Lise Meitner and Otto Hahn had been working on radioactive elements, but their results didn’t convince Joliot-Curie. She repeated the experiment with a different source, and found a product that Hahn and Meitner had missed. Hahn was violently skeptical of these results, but the scientist in him couldn’t help but repeat them. Confirming Joliot-Curie’s results, he sent them to Meitner, then in exile in Sweden, who correctly worked out the process of nuclear fission from them. Once again, failure to draw the right conclusions from their own critically important experiments had kept Frederic and Irène from claiming a page in scientific history.

Fortune cast them one break, however. In 1934, they noticed that an aluminum source bombarded with alpha particles continued to exhibit signs of radiation even after the original radioactive source was removed from the room. The perfectly ordinary aluminum had become, itself, radioactive. The implications were so striking that even the Joliot-Curie luck couldn’t obscure them – stable atoms could be transformed into radioactive ones. The skies of radioactivity research opened in that moment, and the whole world of elements suddenly became the sandbox of radioisotope scientists. It was a discovery of such broad importance that it earned for the pair a Nobel prize. Marie and Pierre had earned one in 1904, Marie by herself again in 1911, and now their daughter and stepson made the familiar trek to Stockholm to take their turn.

She had won a Nobel Prize, been a nation’s first female minister, and spoken out for a woman’s right to work and against the weaponization of nuclear power, and yet there was always the worry that she hadn’t done enough.

Two years later, Irène was appointed the first female minister of France, working in the Ministry of Scientific Research, and almost immediately left that position, unable to tolerate the inefficiency of politics. Positively allergic to the wasting of time, she was known for getting up and leaving in the middle of meetings that were taking too long to get things done. Politics, however, would never leave the Joliot-Curie household. Frederic was devoted to political action, and on the invasion of France in the Second World War, he joined the Communist party while fighting for the French Resistance, a decision that would dog the remaining decade of Irène’s life.

She never joined the party, but in the post World War II environment, being married to a Communist was, in many countries, to be suspicious one’s self. On a trip to America to speak with anti-fascist Spanish refugees, she was detained at Ellis Island overnight for suspected Communist sympathies. While she and Frederic were appointed two of the five chiefs of the new French atomic energy commission, charged with creating the first sustained nuclear reactor in France, the connection with the Communists worked against them, and eventually forced them from their positions.

Which was just as well. Irène had, for some time, been compelled to spend longer and longer parts of each year in a mountain sanatorium to regain her ever declining health. Leukemia, certainly the result of her World War I x-ray heroism, and not at all helped by a lifetime of working daily with poorly understood radioactive elements, was eating her alive, as it had her mother. She hoped to put together a new lab to study the nature of cosmic rays, but between her health, her children, her husband’s unfortunate political choices, and her devotion to speaking out against nuclear arms proliferation anywhere in the world that would listen, time was at a premium. She had won a Nobel Prize, been a nation’s first female minister, and spoken out for a woman’s right to work and against the weaponization of nuclear power, and yet there was always the worry that she hadn’t done enough. The image of her mother, stoically rejecting involvement in anything that didn’t further her research, was potent and difficult to live up to in the age of Big Research and among the creeping petty resentments of Cold War politicking.

She died in a hospital bed, a few rooms down from her husband, who was suffering from viral hepatitis and would only live two years more himself. She recognized in herself the same agonized fatigue that had attended her mother’s last days, and knew that there would be no triumphant return to research this time. She died on March 17, 1956, just 58 years old. She was given a national funeral in spite of her husband’s blacklisting, the religious ceremony being omitted out of respect to her strictly avowed atheism. On the front lines, in the depths of darkest invasion, under political persecution, and during failing health, she continued to devote herself to a science without boundaries, an open-spirited human ingenuity that she feared was being ground to extinction in the age of scientific privatization.

Her mother could not have been anything but proud.

FURTHER READING: The book to read is definitely Noelle Loriot’s Irene Joliot-Curie. The first half of it is as charming and understanding a portrait of a scientist’s life as has ever been written. Unfortunately, it’s only available in French, and no full-scale non-juvenile biography of Joliot-Curie yet exists in English, though there are of course substantial sections about Irène’s life up to 1934 in biographies of her mother, including that written by her sister and antipole, Eve Curie.

Photo courtesy Smithsonian Institution Archives. Acc. 90-105 – Science Service, Records, 1920s-1970s, Smithsonian Institution Archive. Stokley, James 1900-1990. University of Pennsylvania. WikiCommons/Public domain.