Madame Curie's Passion
The pioneering physicist's dedication to science made it difficult for outsiders to understand her, but a century after her second Nobel prize, she gets a second look
By Julie Des Jardins
Smithsonian magazine, October 2011View More Photos »
Marie Curie, in Paris in 1925, was awarded a then-unprecedented second Nobel Prize 100 years ago this month.
AFP / Getty Images
When Marie Curie came to the United States for the first time, in May 1921, she had already discovered the elements radium and polonium, coined the term “radio-active” and won the Nobel Prize—twice. But the Polish-born scientist, almost pathologically shy and accustomed to spending most of her time in her Paris laboratory, was stunned by the fanfare that greeted her.
She attended a luncheon on her first day at the house of Mrs. Andrew Carnegie before receptions at the Waldorf Astoria and Carnegie Hall. She would later appear at the American Museum of Natural History, where an exhibit commemorated her discovery of radium. The American Chemical Society, the New York Mineralogical Club, cancer research facilities and the Bureau of Mines held events in her honor. Later that week, 2,000 Smith College students sang Curie’s praises in a choral concert before bestowing her with an honorary degree. Dozens more colleges and universities, including Yale, Wellesley and the University of Chicago, conferred honors on her.
The marquee event of her six-week U.S. tour was held in the East Room of the White House. President Warren Harding spoke at length, praising her “great attainments in the realms of science and intellect” and saying she represented the best in womanhood. “We lay at your feet the testimony of that love which all the generations of men have been wont to bestow upon the noble woman, the unselfish wife, the devoted mother.”
It was a rather odd thing to say to the most decorated scientist of that era, but then again Marie Curie was never easy to understand or categorize. That was because she was a pioneer, an outlier, unique for the newness and immensity of her achievements. But it was also because of her sex. Curie worked during a great age of innovation, but proper women of her time were thought to be too sentimental to perform objective science. She would forever be considered a bit strange, not just a great scientist but a great woman scientist. You would not expect the president of the United States to praise one of Curie’s male contemporaries by calling attention to his manhood and his devotion as a father. Professional science until fairly recently was a man’s world, and in Curie’s time it was rare for a woman even to participate in academic physics, never mind triumph over it.
This year marks the 100th anniversary of her second Nobel Prize, the first time anyone had achieved such a feat. In her honor, the United Nations named 2011 the International Year of Chemistry. Curie has always been a fascinating character, the subject of books and plays and movies, and this anniversary has prompted several new works about her. October is Nobel Prize season, so it’s a good time to examine the story of her story—how she lived, but also how she has been mythologized and misunderstood.
Curie was born ManyaSklodowska in November 1867 in Warsaw, Poland, and raised there during a Russian occupation. Her mother died of tuberculosis when Marie was 10 years old. A prodigy in both literature and math, as a teenager Marie attended a secret school called the “Floating University”—its locale changed regularly to avoid detection by the Russians—which taught physics and natural history as well as the forbidden subjects of Polish history and culture. Her father, a science teacher, encouraged his daughter’s curiosity but could not afford to send her to college. Marie worked as a governess until, at 24, she had saved enough money and purchased a train ticket to Paris, where she gravitated to the Latin Quarter and enrolled at the Sorbonne.
She immersed herself in French and math and made ends meet cleaning glassware in university labs. She rationed her intake of food until, on more than one occasion, she collapsed of weakness. Science thrilled her, and she earned a degree in physics in 1893 and another in mathematics the following year.
In 1894, she met Pierre Curie, a 35-year-old physicist at a French technical college who had been studying crystals and magnetism. More than a decade before, he and his brother Jacques had discovered piezoelectricity, the electric charge produced in solid materials under pressure. Pierre was taken by Marie’s uncommon intellect and drive, and he proposed to her. “It would...be a beautiful thing,” he wrote, “to pass through life together hypnotized in our dreams: your dream for your country; our dream for humanity; our dream for science.”
They were married in 1895 in a civil service attended by family and a few friends. For the occasion, Marie donned a blue cotton dress, one practical enough to wear in the laboratory after the ceremony. From then on, she and Pierre followed what they called an “anti-natural” path that included a “renunciation of the pleasures of life.” They lived plainly in their apartment on the rue de la Glacière within walking distance of their experiments. Pierre earned a modest 6,000 francs per year, about $30,000 today, while Marie worked gratis in his laboratory and prepared for an exam that would certify her to teach girls.
The Curies’ first daughter, Irène, was born in 1897. A difficult pregnancy had forced Marie to spend less time in the lab just as she was gathering data for a doctoral thesis. When her mother-in-law died weeks after Irène’s birth, her father-in-law, Eugene, a retired physician, stepped in, becoming the hands-on parent that others expected Marie to be.
By the time her second daughter, Eve, was born in 1904, Marie had grown accustomed to the disdain of colleagues who thought she spent too much time in the lab and not enough in the nursery. Georges Sagnac, a friend and collaborator, eventually confronted her. “Don’t you love Irène?” he asked. “It seems to me that I wouldn’t prefer the idea of reading a paper by [Ernest] Rutherford, to getting what my body needs and looking after such an agreeable little girl.”
But read scientific publications she did. In labs across Europe, scientists were studying new and surprising phenomena. In 1895 Wilhelm Röntgen had discovered X-rays, and the mathematician Henri Poincaré sought to understand the luminescent rays that could pass through a hand and impress a ghostly image on photographic paper. Henri Becquerel was noting the emission of a different kind of mysterious rays, those from uranium salts. J. J. Thomson discovered negatively charged particles, which we now know as electrons (and which we now know are the source of X-rays).
Curie built on Becquerel’s observations of the element uranium. At first, she and other scientists were baffled about the source of the high-energy emissions. “The uranium shows no appreciable change of state, no visible chemical transformation, it remains, in appearance at least, the same as ever, the source of the energy it discharges remains undetectable,” she wrote in 1900. She wondered whether the emitted rays were violating a basic law of thermodynamics: the conservation of energy.
Finally, she posited a daring hypothesis: The rays emitted might be a basic property of uranium atoms, which we now know to be subatomic particles released as the atoms decay. Her theory had radical implications. Trish Baisden, a senior chemist at the Lawrence Livermore National Laboratory, describes it as a shocking proposal: “It was truly amazing and a bold statement at the time because the atom was thought to be the most elementary particle, one that could not be divided. It further meant that atoms are not necessarily stable.” Curie’s hypothesis would revise the scientific understanding of matter at its most elemental level.
Curie set out to measure the intensity of uranium’s rays by adapting the electrometer Pierre had invented with his brother. The device allowed her to measure extremely low electrical currents in air near mineral samples that contained uranium. She soon repeated the experiment with thorium, which behaved in similar ways.
But she was puzzled by data that showed that the intensity of the radiation emitted by uranium and thorium was greater than expected based on the amounts of the elements she knew to be in her samples. “There must be, I thought, some unknown substance, very active, in these minerals,” she concluded. “My husband agreed with me and I urged that we search at once for this hypothetical substance, thinking that, with joined efforts, a result would be quickly obtained.”
In 1898 she indeed identified one of the substances and named it polonium, after her homeland. Five months later, she identified a second element, which the world came to know as radium. Curie described the elements she studied as “radio-active.”
Pierre put his crystals aside to help his wife isolate these radioactive elements and study their properties. Marie extracted pure radium salts from pitchblende, a highly radioactive ore obtained from mines in Bohemia. The extraction required tons of the substance, which she dissolved in cauldrons of acid before obtaining barium sulphate and other alkalines, which she then purified and converted into chlorides. The separation of radium from the alkalines required thousands of tedious crystallizations. But as she wrote to her brother in 1894, “one never notices what has been done; one can only see what remains to be done.” After four years, Curie had accumulated barely enough pure radium to fill a thimble.
Working in a dilapidated shed with broken windows and poor ventilation, she nonetheless was able to make sensitive measurements. It is remarkable, says Baisden, that Curie calculated the atomic weight of radium so accurately given such deplorable conditions. “Large swings in temperature and humidity undoubtedly affected the electrometer...but Marie’s patience and tenacity prevailed.”
Both Curies were plagued by ailments—burns and fatigue—that, in retrospect, were clearly caused by repeated exposures to high doses of radiation. Both, too, were resistant to the suggestion that their research materials caused their ailments.
In 1903, Curie became the first woman in France to earn a PhD in physics. Professors who reviewed her doctoral thesis, which was about radiation, declared that it was the greatest single contribution to science ever written.
Rumors of a Nobel Prize began to circulate, but some members of the French Academy of Sciences attributed the brilliance of the work not to Marie, but to her co-workers. These skeptics began to lobby quietly for the prize to be split between Becquerel and Pierre. But Pierre insisted to influential people on the Nobel committee that Marie had originated their research, conceived experiments and generated theories about the nature of radioactivity.
Both Curies shared the Nobel Prize in physics with Becquerel in 1903. It was the first Nobel to be awarded to a woman.
At the awards ceremony, the president of the Swedish Academy, which administered the prize, quoted the Bible in his remarks about the Curies’ research: “It is not good that man should be alone, I will make a helpmeet for him.”
Whether Marie Curie took the remark as an insult is not known—it surely rankles today—but it must be among the most grudging comments ever said to a laureate. Moreover, the notion that Marie was a mere helpmeet to Pierre—one of the more persistent myths about her—was an opinion widely held, judging from published and unpublished comments by other scientists and observers.
“Errors are notoriously hard to kill,” observed her friend, the British physicist HerthaAyrton, “but an error that ascribes to a man what was actually the work of a woman has more lives than a cat.”
At the Sorbonne, it was Pierre who got the plum job, a full professorship. Marie was not promoted. Pierre hired more assistants and made Marie the official head of the laboratory, freeing her to conduct experiments and for the first time, be paid for it.
The most successful collaboration between a husband and wife in the history of science ended suddenly on April 19, 1906, when Pierre, apparently lost in thought, walked into traffic on the rue Dauphine and was killed instantly by an onrushing carriage.
Instead of accepting a widow’s pension, Marie took over Pierre’s position at the Sorbonne, becoming the first woman to teach there. Hundreds of people—students, artists, photographers, celebrities—lined up outside the university on November 5, 1906, hoping to attend her first lecture. She gave no outward sign of mourning. She began by summarizing the recent breakthroughs in physics research. “When one considers the progress of physics in the last decade,” she said, “one is surprised by the changes it has produced in our ideas about electricity and about matter.”
She wrote a diary during this time, addressed to her late husband, about continuing their research. “I am working in the laboratory all day long, it is all I can do: I am better off there than anywhere else,” she wrote. In 1910, she published a 971-page treatise on radioactivity. Some men in the scientific establishment still didn’t consider her an equal, however; she applied for membership in the French Academy of Sciences in 1910, and although Pierre had been a member, she was denied by two votes. One Academy member, the physicist Emile Amagat, claimed that “women cannot be part of the Institute of France.”
In 1911, rumors spread that Curie was having an affair with the prominent physicist Paul Langevin, a man five years her junior who had been Pierre’s student and had worked closely with Albert Einstein. Langevin’s estranged wife discovered apparent love letters from Curie to her husband and gave them to a tabloid newspaper. It and other publications ran stories with headlines such as “A Romance in a Laboratory.” Although a widower under similar circumstances would likely not have suffered any consequences, Curie found her reputation tarnished. Neither Curie nor Langevin discussed their relationship with outsiders. “I believe there is no connection between my scientific work and the facts of private life,” she wrote to a critic.
The front-page coverage of the scandal threatened to overshadow another news story later that year: her second Nobel Prize.
This one, in chemistry, was for the discovery of polonium and radium. In her acceptance speech in Stockholm, she paid tribute to her husband but also made clear that her work was independent from his, spelling out their separate contributions and describing the discoveries she had made after his death.
At the end of 1911, Curie became very ill. She had an operation to remove lesions from her uterus and kidney, followed by a long recovery. In 1913, she began to travel again and return to science. In March of that year, Einstein paid her an extended visit, and later she opened and headed a new research facility in Warsaw. As she was setting up a second institute, in Paris, World War I broke out. She outfitted 18 portable X-ray stations that could treat wounded soldiers on the front lines. She sometimes operated and repaired the machines herself, and established 200 more permanent X-ray posts during the war.
Eve became a journalist and wrote the definitive biography, Madame Curie, published in 1937. Irène studied at her mother’s institute in Paris and married her mother’s assistant, the charismatic physicist Frédéric Joliot, with whom she bore two children. Irène maintained a strong presence in the lab, and in 1935, Irène and Frédéric Joliot-Curie were awarded a Nobel Prize for synthesizing new radioactive elements. It was another record: the first time both a parent and child had separately won the Nobel Prize.
After Marie Curie’s second Nobel Prize and her subsequent research, she was rarely dismissed as a helpmeet. And once the tabloids moved on from the Langevin scandal, her image as a homewrecker faded. But there were deliberate efforts to shape her story. A case in point was Curie’s first trip to America, in 1921.
The tour was largely the work of a New York City journalist named Missy Meloney, who had interviewed Curie in 1920 in Paris for the women’s magazine the Delineator, which Meloney edited. Meloney learned that the Curies had never patented the process for purifying radium. As a result, other scientists and U.S. chemical companies were processing radium, then selling it for cancer treatments and military research for $100,000 per gram. Curie was now unable to afford the element she had discovered. Sensing a human-interest story, Meloney created the Marie Curie Radium Fund to raise money to purchase radium for Curie’s continuing research.