(1867-1934) Polish/French Experimentalist (Radioactivity), Physical Chemist
Marie Curie was a brilliant and dedicated experimentalist, who, with her husband, Pierre, investigated the atomic process first observed by antoine-henri becquerel, which she named radioactivity, and discovered two new chemical elements, polonium and radium. She was not only the first woman to win a Nobel Prize—she won two, in physics and in chemistry.
She was born Marya Sklodowska on November 7, 1867, in Warsaw, Poland, the fifth and youngest child of Vladislav, a professor of mathematics and physics, and Bronislava, a pianist, singer, and schoolteacher. Poland was then under Russian dominance and the Sklodowskis were obliged to hide their strong feelings of Polish patriotism. Marya’s childhood was marked by the death of her mother of tuberculosis, when Marya was 10. She graduated at the top of her high school class at the age of 15 and then worked for eight years as governess for the children of wealthy families. During this period, she never lost sight of her goals, studying mathematics and physics in her spare time and attending a clandestine university run by Polish professors in defiance of the Russian occupiers. With her salary, she helped her older sister, Bronya, pay her tuition at the Sorbonne (the University of Paris), where she was studying to be a physician. When Bronya in turn, after obtaining her medical degree in 1891, sent for her, the 24-year-old Marya promptly changed her name to its French form, Marie, and launched her studies of science and math at the Sorbonne. Although Bronya helped out, Marie led a Spartan existence in an unheated attic, where her diet consisted primarily of bread, butter, and tea. She managed to graduate at the top of her class in the spring of 1893, with the equivalent of a master’s degree in physics. When granted a generous fellowship, she was able to continue her studies, earning a master’s degree in mathematics the following year.
In 1894, she went to work for a French industrial society and, while looking for adequate laboratory conditions, met Pierre Curie, the laboratory director of the Municipal School of Industrial Physics and Chemistry in Paris. Eight years her senior and already established as a physicist, Pierre persuaded her to remain with him in Paris instead of returning to Poland. They married in 1895, just after Pierre had earned his doctorate and become a full professor. Their union would be fruitful on the personal level—their first daughter, Irene (later the scientist Irene Joliot-Curie), was born in 1897 and a second, Eve, in 1904—and spectacular on the scientific.
Marie was determined to pursue a Ph.D. and, for her doctoral research, decided to follow up on Becquerel’s 1896 observation that the element uranium spontaneously emitted radiation. She discovered that the intensity of the radiation was in direct proportion to the amount of the uranium in her sample, and nothing she did to alter the uranium (such as combining it with other elements or subjecting it to light, heat, or cold) affected the rays. This led her to hypothe size that the rays were the result of something happening within the atom itself, which was due to a process she called radioactivity.
Next she tested minerals that contained uranium or thorium and found that pitchblende (a mineral that contains uranium) gave off four times as much radiation as would be expected from the amount of uranium it contained. This led her to believe that the mineral must contain other elements that also give off radiation. In April 1898, she published a paper announcing the radioactivity of thorium and speculating that an even more strongly radioactive element existed.
At this point Pierre abandoned his own physics research to collaborate with Marie on hers. The Curies embarked on what Marie would later describe as the happiest time in their life together, doing rigorous work, at their own expense, in a makeshift lab, lacking heat or ventilation. They focused their investigations on pitchblende because it emitted the strongest rays. Using a painstaking refining method in which tons of the material had to be refined to obtain a tiny sample of radioactive material, they quickly succeeded in isolating a substance from pitchblende that was 400 times more active than uranium. Marie called it polonium, in honor of her native Poland. They soon found a second, even more radioactive element, and called it radium.
Although the Curies announced their discovery on December 26, 1898, it was not until September 1902 that they finally produced 0.0035 ounce (0.1 g) of pure radium chloride— enough to confirm the existence of radium. When, in June 1903, Marie described this research to her doctoral committee, she had the pleasure of hearing that hers was the greatest contribution ever to be made by a dissertation. That fall she won the 1903 Nobel Prize in physics, which she shared with her husband and Becquerel. With the public imagination captured by their discovery, the Curies now enjoyed international renown and enough money to ease some of their financial burdens. The Sorbonne created a new professorship for Pierre in 1904 and promised to build an excellent laboratory for him and Marie.
This spiral of good fortune ended tragically when Pierre was killed on April 19, 1906, as he absentmindedly stepped in front of a horse-drawn wagon. With two small daughters to support, Marie found the strength to master her grief and persuaded the Sorbonne to hire her as its first woman professor. Two years later she was promoted to full professor. She independently continued the research she and Pierre had done together, setting out to refute the critics’ claim that radium was not really an element, by producing pure radium and pure polonium. In 1911, after four years of exacting work, she succeeded in producing radium as a pure metal. That year she won a second Nobel Prize, this time in chemistry, for her discovery and isolation of radium and polonium.
By 1914, she was the head of two laboratories, one in her native Warsaw and one at the Sorbonne called the Radium Institute. Unable to continue her research during World War I, she supported the French war effort by organizing a fleet of wagons, which were called “little Curies,” to carry portable X-ray equipment to battle sites. With her characteristic energy and dedication, she opened 200 X-ray stations that examined over a million soldiers. When the war ended, she campaigned during a 1920 tour of the United States and again in 1929, to raise money for a hospital and laboratory devoted to radiology, the branch of medicine that uses X rays and radium to diagnose and treat disease. She used her celebrity status to campaign for the Radium Institute and other causes she believed in, serving on the council of the League of Nations and on its international committee on intellectual cooperation.
As the 1920s drew to a close, a number of debilitating symptoms, including fatigue, dizziness, low-grade fever, humming in her ears, and a progressive loss of eyesight, became Curie’s constant companions. Although she was aware that many colleagues had suffered similarly and died, for a long time, she refused to attribute their deaths to the element she and Pierre had discovered—radium. When she did finally admit radium’s role, she continued to work with it. When doctors discovered she had leukemia, they concealed the news from the public and from her. She succumbed to the disease on July 4, 1934, at the mountain sanatorium where she had gone to recuperate. Ironically, one of the enduring applications of her work has been in the treatment of cancer with radiation.
Marie Curie discovered the phenomenon of radioactivity and two new chemical elements, polonium and radium.
A devoted scientist, whom fame could not distract from the profound pleasures of her laboratory, she once said:
A scientist in his laboratory is not a mere technician: he is also a child confronting natural phenomena that impress him as though they were fairy tales.
Marie Curie lived to see her work give rise to the field of atomic physics. In 1995, her remains, together with her husband’s, were enshrined in the Pantheon, the memorial to the nation’s “great men,” in Paris. She was the first woman to be so honored.
