Maria Sklodowska (her birth name) was born on November 7, 1867, in Warsaw, Poland. Her parents were schoolteachers, so Maria and her elder sister, Bronya, grew up in a family that valued education. However, a politically active student, she soon found it prudent to leave Warsaw, which was then under Russian domination. She went to Cracow (then ruled by Austria), but conditions there did not allow the opportunity for advanced scientific training she desired. Because of the family’s limited financial means, Maria agreed to work as a governess to help Bronya earn her medical degree at the Sorbonne in Paris. Bronya, in turn, promised to help Maria fulfill her own dream of studying mathematics and physics in Paris.
Finally, in 1891, Maria was able to follow her older sister to Paris. Living under impoverished conditions in a tiny attic near the Sorbonne, Maria worked hard to succeed in her studies. After two years, she received her degree in physics, graduating at the head of her class. She completed a second degree, in mathematics, in 1894. Her next academic objective was to earn a teacher’s diploma and return to Poland. However, fate intervened, and the course of nuclear technology was forever changed.
In 1894, she met Pierre Curie (1859–1906), an accomplished physicist who had codiscovered piezoelectricity with his brother Jacques. At the time, the 35-year-old French scientist was the head of a laboratory at the School of Industrial Physics and Chemistry. Maria and Pierre bonded instantly because of their mutual interest in scientific research and were married in July 1895. At the wedding, the gifted Polish graduate student Maria Sklodowska became Marie Curie—adopting France as her new home and the French spelling of her first name.
Later that year, responding to encouragement from both his new wife and his father, Pierre submitted and successfully defended his doctoral thesis. It was a notable effort and included a discussion of the important physical relationship for certain substances between temperature and magnetism now called Curie’s Law. Marie earned her teacher’s diploma in 1896 and decided to pursue her doctoral degree.
Pregnant with her first child, she began searching for an interesting research topic in 1897. Pierre suggested that she consider a detailed investigation of the mysterious “ray” phenomenon exhibited by uranium salts that had recently been reported to the French Academy of Sciences by a fellow physics professor, Henri Becquerel. Intrigued with the phenomenon she would later call radioactivity, Marie started one of the most important research efforts in the history of nuclear technology. This effort was slightly delayed due to the birth of the couple’s first daughter, Irène, in September 1897.
Becquerel’s March 1896 announcement to the French Academy had not caused much of a scientific stir. But Marie began vigorously investigating the new phenomenon in early 1898. After just a few days of focused effort, she discovered that thorium too emitted Becquerel rays, like uranium. What followed was a brilliant research effort under extremely difficult conditions. At this point, Pierre abandoned his own research interand supported his wife in her quest to fully understand the phenomenon of radioactivity.
After confirming Becquerel’s earlier findings, Marie found that two uranium minerals, namely, pitchblende and chalcolite, were actually more “active” than uranium itself. In early 1898, she came to the important conclusion that these uranium ores must contain more intensely radioactive elements. So, assisted by her husband, she began the tedious and arduous search for them. Marie methodically ground up and chemically processed tons of pitchblende in small, 20-kilogram batches. This effort slowly began to extract minute but chemically identifiable quantities of the elements polonium and radium. The Curies discovered polonium in July 1898 and named the new radioactive element (a radioactive decay product of natural uranium) after Marie’s native land, Poland. Then, they announced the discovery of radium in September 1898. The French chemist Eugène Demarçay (1852–1904) had used spectroscopy to help confirm the presence of radium—a naturally radioactive element chemically similar to barium.
The Curies’ primitive processing laboratory was set up in a vacant shed, and its contents soon began to exhibit the glow of a faint blue light—the sign of extensive radioactive contamination due to the scientists’ monumental efforts to extract small quantities of radium and polonium out of tons of uranium ore. By early 1902, Marie had obtained about one-tenth of a gram of radium chloride—a material that she used in her doctoral investigation of radioactivity. At the time, neither she, Pierre, nor any of the scientists (like Becquerel and Ernest Rutherford [1871–1937]) with whom they willingly shared their minute quantities of radium for research were aware of the dangers posed by chronic exposure to nuclear radiation. The transnational collaborative spirit that characterized early radioactivity research enabled Rutherford and Frederick Soddy (1877–1956) to develop the theory of radioactive decay.
Marie Curie successfully presented her doctoral dissertation in 1903 and became the first woman to earn an advanced scientific degree in France. That same year, she became the first woman to win the Nobel Prize, when she shared the physics prize with her husband and Becquerel for their pioneering work on radioactivity. In 1904, Pierre Curie received a teaching position at the Sorbonne and Marie obtained a part-time position as a physics instructor at a school for girls in Sèvres. Later that year, their second daughter, Eve, was born. Around that time, both Marie and Pierre began to exhibit significant signs of radiation sickness. As the tissue-damaging effects of radium exposure became more obvious to researchers, creative individuals also began to consider its possible therapeutic applications. For example, in 1903, the American inventor, Alexander Graham Bell (1847–1922), suggested the idea of implanting radium into a patient’s tumor to treat cancer.
Tragedy struck on April 19, 1906, when Pierre Curie was killed in a street accident in Paris. Possibly because of the effects of radiation sickness, he absentmindedly stepped in front of a horse-drawn wagon. The accident left Marie a widow with two young daughters: Irène was nine and Eve was two. Exhibiting her characteristic perseverance, Marie rejected the offer of a modest pension from the Sorbonne and decided to support her family by filling her husband’s teaching position as a professor of physics at the Sorbonne. In 1908, she became the first woman professor at the Sorbonne.
In 1911, she became the first scientist to win a second Nobel Prize. Marie Curie received the 1911 Nobel Prize in chemistry in recognition of her work involving the discovery and investigation of radium and polonium. Her work clearly showed that one element could transmute into another through the process of radioactivity. This concept revolutionized chemistry.
Max Karl Planck (1858 – 1947)
