Marie Curie

Marie Curie the Polish and French physicist and chemist (1867-1934) who pioneered the study of radioactivity and remains the only person to have won Nobel Prizes in two different sciences. Her discovery of the elements polonium and radium, and her development of methods for isolating radioactive substances, transformed both physics and chemistry and opened the field of nuclear science.

Early Life and Education in Poland

Maria Sklodowska was born in Warsaw, then part of the Russian Empire, the fifth child of two teachers. Her family valued learning, but the repression of Polish culture under Russian rule limited educational opportunity, and the death of her mother when she was young added hardship to the household. From an early age she showed exceptional ability and an intense determination to study.

Because women were barred from higher education in Russian-controlled Poland, she worked for several years as a governess to earn money and to support her sister Bronislawa's medical studies in Paris. The sisters agreed that Bronislawa would help Maria in turn once she had qualified, and in 1891 Maria travelled to Paris to enrol at the Sorbonne.

As a student she lived in poverty, studying by day and tutoring by night, and she completed degrees in physics and in mathematics with distinction. Her frugality and her capacity for concentrated work became legendary among her classmates, and she emerged from her studies with a thorough training in experimental physics.

Radioactivity and the Discovery of Radium

Curie began her research by investigating the radiation emitted by uranium compounds, a phenomenon first observed by Henri Becquerel. Using a sensitive electrometer designed by her husband Pierre Curie, she showed that the radiation was a property of the atom itself rather than a result of chemical reaction, and that certain minerals emitted far more radiation than their uranium content could explain.

This observation led her to postulate the existence of an unknown element, and after painstaking chemical separation of pitchblende ore she and Pierre announced the discovery of polonium in 1898 and of radium later the same year. To prove the existence of radium she processed tonnes of ore in a leaking shed, isolating a tiny quantity of the element and establishing its properties.

She coined the term radioactivity to describe the phenomenon, and she showed that the radiation was accompanied by the transformation of one element into another, a finding that overturned the assumption that atoms were immutable. Her work founded a new branch of physical science and laid the groundwork for later advances in nuclear physics and medicine.

Nobel Prizes and Scientific Recognition

In 1903 the Nobel Prize in Physics was awarded jointly to Henri Becquerel and to Marie and Pierre Curie for their work on radioactivity. Marie Curie was the first woman to receive a Nobel Prize, and the award brought the couple international fame and a measure of financial security, though it also brought unwelcome publicity.

After Pierre's death in a street accident in 1906, she took up his professorship at the Sorbonne, becoming the first woman to teach there, and she continued her research with great determination. In 1911 she was awarded the Nobel Prize in Chemistry for the discovery of radium and polonium and for the isolation of radium, making her the first person to win a second Nobel Prize.

She established a laboratory at the Radium Institute in Paris and trained a generation of researchers, including her daughter Irene, who later won a Nobel Prize with her husband Frederic Joliot. Curie insisted on publishing her methods openly so that others could build on her work, and she declined to patent the radium-isolation process, holding that scientific knowledge belonged to everyone.

The First World War and Later Work

During the First World War Curie organised the provision of mobile radiology units, popularly called little Curies, to bring X-ray equipment to field hospitals near the front. She trained women to operate the machines and herself travelled to the battlefront to instruct surgeons, and she helped to equip and staff permanent radiology facilities.

After the war she worked to secure funding for her institute and campaigned for the supply of radium for medical research and for the treatment of cancer. She travelled to the United States, where she was received with great acclaim and where donations of radium were made to her laboratory. Her health declined in her later years, largely as a result of prolonged exposure to radiation.

She died in 1934 of aplastic anaemia, a condition caused by years of unprotected contact with radioactive materials. Her notebooks remain radioactive to this day and are stored in lead-lined boxes, a physical reminder of the hazards she accepted in the course of her research.

Influence and Legacy

Curie's discoveries transformed the understanding of matter and energy and made possible much of twentieth-century nuclear science and radiotherapy. Her insistence on measuring and isolating radioactive elements with rigorous chemical method provided a model of quantitative experimental work that shaped the training of physicists and chemists for decades.

Her legacy is also cultural. She demonstrated that a woman could reach the summit of scientific achievement in a male-dominated world, and she became an emblem of scientific dedication and of the pursuit of knowledge for its own sake. Her daughter Irene continued the family tradition of Nobel-winning research.

Institutions, awards and scholarships around the world are named in her honour, and her life has been the subject of numerous biographies and films. She is remembered as a founder of radioactivity research, a pioneer of radiochemistry and one of the most influential scientists in history.

See also

• Radioactivity
• Radium
• Polonium
• Pierre Curie