A childhood in Warsaw
Marie Curie was born Maria Salomea Skłodowska on November 7, 1867, in Warsaw. At that time most of Poland was divided among neighboring empires, and Warsaw was under Russian control. Her parents were both teachers, and her father taught mathematics and physics. She was the youngest of five children, and she did very well at school. Her family lost income and faced hardship during her youth, and her mother and one of her sisters died while she was young.
Women could not attend the university in Warsaw. Maria took part in an informal, secret network of classes sometimes called the “Flying University,” where Polish students could study subjects that were restricted under Russian rule. She also began some practical laboratory work at a museum in Warsaw. Details of these years are mostly drawn from family accounts and her later writings.
Working to fund an education
She and her older sister Bronisława made a pact: Maria would work to help pay for Bronisława’s medical studies in Paris, and Bronisława would then help Maria. Maria worked for several years as a governess and tutor, and she kept studying on her own in her spare time. In 1891 she moved to Paris to join her sister and enrolled at the Sorbonne, using the French form of her name, Marie.
Her early years in Paris were financially tight, and she lived modestly in small rooms. She studied physics and then mathematics and completed degrees, earning a physics degree in 1893 and a mathematics degree in 1894. Accounts generally describe her as placing at or near the top of her classes.
Meeting Pierre Curie
In 1894 she met Pierre Curie, a French physicist known for his work on magnetism and crystals. They shared an interest in physics and soon became close. They married in 1895. She continued with her studies and her scientific work, and the two began working side by side. Their relationship, both personal and professional, shaped the next decade of her life.
Starting on radioactivity
In 1896 Henri Becquerel reported that uranium salts give off rays that can darken photographic plates, even without being exposed to light. The phenomenon was little understood. For her doctoral research, Marie decided to study these rays in detail. This is where her early career as a researcher truly begins.
She used a sensitive electrical instrument, developed in part by Pierre and his brother Jacques, to measure the faint electrical effect the rays had on the air. This allowed her to compare materials quantitatively rather than by eye. Several observations followed:
- The strength of the radiation depended on the amount of uranium present, not on its chemical form.
- This suggested the radiation came from the atoms themselves, rather than from a chemical reaction. The idea that atoms could give off radiation was an important step in understanding what atoms are and what they are made of.
- Thorium compounds also gave off similar rays. She introduced the word “radioactivity” for this property.
- Some natural ores, such as pitchblende, were more radioactive than the uranium they contained could explain. She reasoned that they must contain some other, more strongly radioactive substance.
Polonium and radium
Pierre set aside his own work to join her. In 1898 they announced the likely existence of a new element, which they named polonium after Marie’s homeland, and later that year announced another, radium. To confirm radium, they needed to separate it from tons of ore residue, a long, physically demanding chemical process carried out in a poorly equipped shed that was used as a laboratory. By 1902 Marie had obtained a small amount of a radium compound pure enough to estimate its atomic weight, which strengthened the case that it was a genuinely new element.
Chemists at the time were used to demands for hard proof before accepting a new element. Her careful measurements helped make the case, and it also showed how the periodic table could keep growing as new elements were discovered.
Recognition
In 1903 Marie received her doctorate, and the Nobel Prize in Physics was awarded for that year to Henri Becquerel and to Pierre and Marie Curie for their work on radiation. Reports suggest that Marie’s name was initially left off the proposed list, and that Pierre and others urged that she be included. Historians discuss the exact sequence of events, so it is best to say simply that she was eventually named a co-recipient.
The prize brought money, attention and better laboratory space. It also brought pressure and ill health to both Curies, now widely thought to be linked in part to long exposure to radioactive materials, though the exact causes are difficult to trace in individual cases. At the time the hazards of radiation were not well understood.
Where the story goes next
Pierre died in a street accident in 1906. Marie took over his teaching position at the Sorbonne, becoming the first woman to teach there. She later won a second Nobel Prize, in Chemistry, in 1911, and she led efforts to use radiation in medicine. Those later chapters go beyond her early career, but they grew from the careful measurements and persistence she showed in the 1890s.