Marie Curie

Maria Salomea Sklodowska was born on November 7, 1867, in Warsaw, then a city under the control of the Russian Empire, the youngest of five children of two Polish teachers ^[1]. Her father, Wladyslaw Sklodowski, taught mathematics and physics, and her mother, Bronislawa, ran a respected boarding school for girls before illness forced her to give it up. The family's finances collapsed after Wladyslaw lost savings in a bad investment and was demoted by Russian school authorities for his Polish patriotism, so the children grew up taking in boarders and learning thrift early ^[2].

Loss marked Maria's childhood. Her eldest sister Zofia died of typhus in 1876, and her mother died of tuberculosis in 1878, when Maria was ten. Despite these blows she excelled at school, graduating from her gymnasium at fifteen with a gold medal ^[1]. Because the Russian-run University of Warsaw did not admit women, she and her sister Bronislawa attended the clandestine Flying University, an underground Polish institution that taught banned subjects and admitted female students ^[2].

The sisters struck a practical bargain: Maria would work to fund Bronislawa's medical studies in Paris, and Bronislawa would later return the favor. For several years Maria worked as a governess, most notably for the Zorawski family in the countryside north of Warsaw, teaching by day and studying mathematics, physics, and chemistry from books at night ^[3].

In late 1891 Maria left Warsaw for Paris, enrolled at the Sorbonne, and registered under the French form of her name, Marie. She lived in cheap garret rooms in the Latin Quarter, sometimes going hungry, and immersed herself in study. The effort paid off: she finished first in her class for the licence in physics in 1893 and took a second degree in mathematics the following year ^[1].

A commission to study the magnetic properties of steels led her, in 1894, to Pierre Curie, an instructor at the School of Industrial Physics and Chemistry who had already done notable work on crystals and magnetism. They married in July 1895 in a simple civil ceremony, and Marie famously used a wedding gift of money to buy a bicycle for their honeymoon tour ^[3].

Searching for a doctoral topic in 1897, Marie chose the mysterious rays that Henri Becquerel had recently observed coming from uranium salts. Using an electrometer that Pierre and his brother Jacques had developed, she measured the faint electrical currents the rays produced in air. Her decisive insight was that the intensity of the radiation depended only on the quantity of uranium present, which suggested the rays came from the atom itself rather than from any chemical reaction ^[4]. She coined the word radioactivity to describe the phenomenon, and her systematic survey showed that thorium was radioactive too ^[1].

When Marie tested the uranium ore pitchblende, she found it far more radioactive than its uranium content could explain, evidence of an unknown element hidden inside. Pierre abandoned his own research to join the hunt. In July 1898 the couple announced the discovery of a new element they named polonium, after Marie's partitioned homeland, and in December of the same year they reported a second, far more radioactive element, radium ^[4].

Proving radium's existence to skeptical chemists required isolating a weighable amount. Working in a leaky shed at the School of Industrial Physics and Chemistry, Marie processed tonnes of pitchblende residue over nearly four years, stirring boiling vats with an iron rod, until in 1902 she obtained about a decigram of pure radium chloride and determined radium's atomic weight ^[3]. Anyone assembling a list of Marie Curie achievements starts here: it was chemistry on an industrial scale carried out with almost no funding.

Recognition followed. In 1903 the Royal Swedish Academy of Sciences awarded the Nobel Prize in Physics jointly to Becquerel and the Curies for their work on radiation, making Marie the first woman ever to receive a Nobel Prize ^[5]. That same year she became the first woman in France to earn a doctorate in physics. In 1911 she won an unshared Nobel Prize in Chemistry for the discovery of radium and polonium and for isolating radium, which made her the first person to win Nobel Prizes in two different sciences, a distinction she still holds among individual laureates in two separate scientific fields ^[5].

The Curies had two daughters: Irene, born in 1897, and Eve, born in 1904. The household ran on science and frugality. Pierre's father, a physician, lived with the family and helped raise the girls, and Marie later organized a teaching cooperative in which scientist friends instructed one another's children ^[3].

Disaster struck on April 19, 1906, when Pierre was killed instantly after slipping under a horse-drawn wagon on a rain-slicked Paris street. Widowed at thirty-eight with two young children, Marie refused a state pension and instead accepted Pierre's professorship at the Sorbonne, becoming the first woman to teach there. Her opening lecture began at the exact point in the syllabus where Pierre's final lecture had ended ^[1].

Her later personal life drew hostile public attention. In 1911 French newspapers exposed her relationship with the physicist Paul Langevin, a former student of Pierre who was estranged from his wife. The scandal, laced with xenophobic attacks on her Polish origins, broke just as her second Nobel Prize was announced, and one Swedish academician suggested she stay away from the ceremony. She went to Stockholm anyway and accepted the prize in person ^[2]. Anyone asking who was Marie Curie beyond the laboratory finds a reserved, stubborn woman who answered public attacks with work rather than words.

When the First World War began in 1914, Curie put radioactivity aside and turned to medical service. She championed the use of X-ray equipment near the front lines, helped equip a fleet of mobile radiology cars that soldiers nicknamed petites Curies, trained about 150 women as radiological operators, and drove one of the vehicles herself, often with her teenage daughter Irene at her side ^[6]. Historians estimate that more than a million wounded men were examined with the radiology services she organized ^[6].

After the war she led the Radium Institute in Paris, founded jointly by the University of Paris and the Pasteur Institute, and built it into a leading center for research on radioactivity. Fundraising took her abroad: in 1921 the American journalist Marie Mattingly Meloney organized a campaign among women in the United States that raised the money for a gram of radium, which President Warren Harding presented to Curie at the White House ^[1]. A second American tour in 1929 funded radium for the institute her sister Bronislawa directed in Warsaw.

Decades of handling radioactive material without protection eventually broke her health. Suffering from aplastic anemia, a condition of the bone marrow attributed to her long exposure to radiation, she died on July 4, 1934, at the Sancellemoz sanatorium in Passy in the French Alps ^[1]. Her laboratory notebooks remain so radioactive that they are stored in lead-lined boxes at the Bibliotheque nationale de France, and researchers who consult them must sign a liability waiver ^[7].

Curie's research opened the door to twentieth-century atomic physics. Her demonstration that radioactivity is an atomic property helped overturn the ancient assumption that atoms are indivisible and unchangeable, and radium quickly became a tool for probing the structure of matter and, in medicine, an early weapon against cancer through what was long called Curietherapy ^[4]. The scientific dynasty she founded continued the work: her daughter Irene Joliot-Curie and son-in-law Frederic Joliot-Curie won the 1935 Nobel Prize in Chemistry for discovering artificial radioactivity ^[5].

Honors accumulated long after her death. In 1944 the artificially produced element 96 was named curium for Marie and Pierre, and the curie remains a unit of radioactivity. In 1995 her remains and Pierre's were transferred to the Pantheon in Paris, making her the first woman honored there for her own accomplishments ^[2]. The Curie Institutes in Paris and Warsaw still treat cancer patients and conduct research, and Poland and France jointly declared 2011 the Year of Marie Curie on the centenary of her second Nobel Prize.

Any Marie Curie biography must reckon with her symbolic weight as well as her science. She worked through poverty, grief, scandal, and institutional exclusion, was refused membership in the French Academy of Sciences in 1911 by a narrow vote, and never patented the radium isolation process, believing scientific knowledge belonged to everyone ^[3]. Among the most repeated Marie Curie facts is that she remains the only person to win Nobel Prizes in both physics and chemistry, but her deeper legacy lies in the generations of scientists, and especially women in science, who cite her example.