The greatest scientist

“Few persons contributed more to the general welfare of mankind and to the advancement of science than the modest, self-effacing woman whom the world knew as Mme. Curie,” wrote the New York Times in its obituary following Marie Curie’s death. “There is one thing rarer than genius. That is radium. Mme. Curie illustrates the combination of both,” said a senior scientist at Yale University when he heard of her death.

The sisterhood

Maria Skłodowska was born on November 7, 1867, in Warsaw, the youngest of five children to her parents, who were both teachers. She lost her mother, who had died of tuberculosis, when she was only ten, just two years after her eldest sister, Zosia, died of typhus. The family faced a difficult financial situation after the father, Władysław, who was a math and physics instructor, was fired from the school where he worked due to his pro-Polish views and lack of loyalty to Russia (which ruled over eastern Poland at the time). The situation got even worse when the family’s savings were wiped out due to unsuccessful financial investments. Nonetheless, her father never gave up on his commitment to educating his children and taught them Polish history and science at home.

At the age of 15, Marie graduated high school with honors, but then suffered an emotional breakdown, possibly depression, and was sent to live with relatives in a village. When she returned to Warsaw, she wanted to continue on to academic studies but found that none of the institutions run by Tsarist Russia would accept women. Marie and her sister Bronisława became involved in the “flying (or floating) university,” a clandestine institution which got its name from the fact that it held classes in different locations every time to avoid the authorities.

Both sisters thrived in the secret evening classes, but knew that the level of education was far inferior to that of other European institutions, which were out of their reach. And so they made a pact: Marie would give private lessons to children and thus help Bronisława finance her medical studies in Paris. And once Bronisława’s financial situation would stabilize, she would help her sister finance her studies.

Marie taught the children of wealthy families, but when she saw that she was not earning enough, she became a governess, working in the homes of rich families, also spending a few years working for a family north of Warsaw. Their father’s financial situation improved too when he found a new teaching job, and he paid Marie back some of the money she sent to her sister.

Morning, noon and night

In the fall of 1891, more than eight years after she graduated from high school, Marie arrived in Paris to study mathematics and physics at the Sorbonne. She first lived with her sister, who now was married, and then moved into a small attic apartment closer to the university, to save the cost of the daily commute. She led a meagre life, almost freezing in winter and frequently hungry, all while trying desperately to bridge the gaps in her knowledge, learn a new language, and keep up with her challenging studies.

But it paid off. She completed her studies with honors and was even awarded a fellowship to study how the chemical composition of materials influences their magnetic properties.

To perform the study, she needed to find a research laboratory, and that’s how she ended up in the lab of Pierre Curie, an instructor at the City of Paris Industrial Physics and Chemistry Higher Educational Institution (ESPCI), which specialized in magnetism. The two fell in love and married in 1895. Their first child, Irène, born in 1897, would become a successful scientist herself. Not long after Irène was born, Marie began her doctoral studies at ESPCI, where Pierre was now a senior professor. Nonetheless, a woman enrolled in doctoral studies was not well received, and she was forced to work out of a converted shed rather than the main laboratory so as not to “distract” the men.

Pierre and Marie Curie in the lab, illustration by a French magazine covering the discovery of radium. Source: Science Photo Library.

New elements

Curie began studying a phenomenon known as uranium rays. In 1896, French physicist Henri Becquerel discovered that uranium salts emitted an unknown type of radiation. Its nature was unknown, and Curie decided to investigate it using a device developed by Pierre years earlier, which enabled measuring extremely low electric currents.

She measured how uranium compounds affected the conductivity of the air around them, and was surprised to discover that the radiation level remained constant whether using pure uranium or compounds, solid or pounded into a powder, wet or dry, and so on. She hypothesized that the radiation is a property of the uranium atoms themselves. When she examined other materials, she discovered that thorium compounds emitted the same radiation, and coined the term radioactive materials – materials that actively radiate.

In early 1898, Curie discovered a strange phenomenon: Certain types of uranium ore were more radioactive than the uranium itself. She hypothesized that these ores must contain an additional, highly radioactive element. Pierre was so intrigued by her work that he decided to abandon his own work on crystals and join his wife in her studies of radiation. The work on isolating this mysterious element was highly intense and required the use of complicated chemistry methods. Eventually, it was discovered that it was not just one element – but two radioactive elements, neither of which were known previously. They named the first polonium (atomic number 84), after Poland, Marie Curie’s native land, which she still dreamed would, one day, gain independence. They named the second radium (atomic number 88), from the Latin word for ray.

In order to produce the amounts required to study the chemical properties of these elements, tons of uranium ore were needed. The Curies received the ores as a donation from Austria, which hoped that an economic use would be found for the new materials. It took more than three years of work to isolate one tenth of a gram of uranium from the ores and to discover that it produced enough energy to bring freezing water to a boil.

Marie Curie received her PhD in physics in June 1903. A short time later, the Nobel Committee decided to award the prize in physics to Henri Becquerel and Pierre Curie for the discovery of radiation. A committee member and advocate for women scientists wrote to Pierre to inform him of the decision, and he responded that he would refuse to accept the award if it failed to acknowledge his wife’s pivotal work. The pressure worked and in December 1903, the Nobel Prize in Physics was awarded jointly to Becquerel for discovering spontaneous radioactivity, and to the Curies for their “joint research on the radiation phenomena discovered by Professor Henri Becquerel.” Marie Curie was the first woman to ever receive the prestigious prize.

Both Marie and Pierre felt ill and illness and weakness, probably due to extended exposure to radiation, and were unable to travel to Stockholm for the ceremony. Their health gradually improved, and Pierre was offered a position as a professor at the Sorbonne, while Marie was appointed as head of the laboratory at the ESPCI. The prize money enabled them to finally have some financial stability and in 1904, their second daughter, Ève, was born.

Tragedy and scandal

But the Curies’ happy days were numbered. In April 1906, Pierre slipped on the road on a particularly rainy day – possibly because of the dizziness he suffered from – and was run over by a horse-drawn carriage He was killed instantly. Marie Curie continued working, harder than ever, with the hopes of commemorating him through their research. She also succeeded him as a lecturer at the Sorbonne, and her lecturers drew in huge crowds. In follow-up research, Curie disproved researchers who claimed that radium was not a separate element, but rather a compound of lead and helium, and proved that it is indeed a true element.

Curie raised the funds to establish Radium Institute in Paris in memory of her husband. Radium was gradually becoming a highly popular material and was being used in a variety of areas – from colors that glowed in the dark to dubious medications to enhance virility. It would be years until it became clear that radium was dangerous and carcinogenic.

In 1910, Curie stood for nomination to the French Academy of Sciences, and was met with a wave of prejudicial rumors spread by her competitors, including that she was Jewish and disloyal to France. She lost the close election, and faced more negative publicity shortly later, when it was revealed that she had an affair with fellow physicist Paul Langevin, before he had divorced his wife. In 1911, amidst all the scandal, Curie was informed that she had won another Nobel Prize, this time in Chemistry. The Prize was awarded to her as the sole recipient for her discovery of the elements of radium and polonium. Curie was the first person to ever win two Nobel Prizes in different scientific fields – and retains that title to this day.

A contribution to humanity and the war effort. One of Curie’s X-ray machines during the First World War. Source: Science Photo Library

X-ray on the front lines

During World War I began in 1914, Curie decided to put her scientific expertise to the aid of French soldiers wounded in the battlefield. She convinced the government to fund military radiology centers, and used x-ray radiation, which was discovered at the end of the previous century, to diagnose fractures and wounds. Curie was appointed director of the Red Cross Radiology Service and used her connections to raise funds to install x-ray machines on trucks and deploy the first mobile x-ray machines to the front lines for the first time in history. Irène, who was 17 when the war started, assisted her mother at the radiology centers, and after a few months was enough of an expert to be able to operate an X-ray machine by herself, including in battlefields. Irène received a military medal for her efforts after the war.

After the war, Marie focused on her work at the Radium Institute in Paris, and on raising funds and recruiting researchers for the institute, which became a world leader in the study and use of radioactivity. She made a point of hiring women and Polish immigrants, but the two most prominent researchers were her daughter Irène and her son-in-law, Frédéric Joliot. Like Irène’s parents, the couple worked together, and were among the pioneers of research into the structure of the atom. In 1934, they made their greatest discovery – artificial radioactivity. They proved that it was possible to make atoms radioactive by bombarding them with alpha particles; today we know this is because theyare composed of protons and neutrons. They were awarded the Nobel Prize for Chemistry for this discovery in 1935 – but Marie Curie was not there to see it.

The Nobel Prize dynasty: Irène and Frederic Joliot-Curie at work in the lab. Source: Science Photo Library.

Global glory

Curie’s health deteriorated in the 1920s, and she continued to suffer from dizziness and headaches. Her eyesight failed because of cataracts in both eyes, and only a series of operations saved her from completely losing her eyesight. When the dangers of radiation were gradually exposed, Curie was among the first to implement strict rules and guidelines in the Radium Institute, but it was too late for her. She died on July 4, 1934, from aplastic anemia, a precancerous condition of the bone marrow – probably brought on by her long-term exposure to radiation.

Curie was buried alongside Pierre, but 60 years later, their remains were moved to the Pantheon in Paris, where France’s great leaders are buried. She was the first woman to be interned there on her own merits.

Curie won many important accolades during her lifetime, and continued to be honored even in her death – including with the element Curium (atomic number 96) named after her and Pierre, and the curie (symbol Ci) unit of radioactivity. Numerous research institutes, streets, scholarships, scientific prizes, and even an asteroid have all been named in her honor as well.

Marie Curie remains an exemplary and inspirational figure to many scholars, and especially women and girls, for showing that women can not only succeed in science, but also push boundaries and ascend far above male colleagues.