Marie Curie and her two Nobel Prizes

The story

A Polish student in Paris

Maria Skłodowska was born in Warsaw in 1867, in a Poland that did not then exist as an independent state: the city was part of the Russian Empire, and Polish schools were controlled by the foreign government. Her father taught physics and mathematics; her mother died when Maria was still a child. Maria was the best in her class, but university was closed to women. Hidden away in private flats, students followed secret courses in Polish, in what was called “the Flying University”.

Maria and her sister Bronisława made a pact: Maria would work as a governess to pay for her sister's medical studies in Paris, and then her sister would help her. For some years Maria worked as a governess for a family in the countryside, and in the meantime she carried on studying on her own. In 1891, aged twenty-four, she left for Paris and enrolled at the Sorbonne, using the French name Marie. She lived in a small attic with no heating, often eating only bread and tea. She graduated in physics, first in her class, and then in mathematics, second.

Pierre and the mysterious rays

In Paris she met Pierre Curie, a good-natured physicist with a passion for crystals and magnetism. They married in 1895 and began to work together. In 1896 the French scientist Henri Becquerel discovered that uranium salts gave off invisible rays that could darken a photographic plate even in the dark. Nobody could explain it. Marie chose that puzzle as the subject of her doctoral thesis.

With an instrument Pierre had built to measure very weak electric currents, she measured the rays from many materials. She noticed that their strength depended only on the amount of uranium, and not on how it was combined with other substances: it had to be a property of the atom itself. For this phenomenon she coined a new word: “radioactivity”. Then she made a surprising discovery: a mineral, pitchblende, gave off many more rays than the uranium it contained. It had to be hiding another element, still unknown and much more powerful.

Four years in a shed

In 1898 Marie and Pierre announced two new elements: polonium, named in honour of occupied Poland, and radium, from the Latin for “ray”. But their colleagues wanted proof: they had to obtain an amount large enough to weigh. To extract a few crumbs of radium, tonnes of pitchblende were needed. The Curies worked in an old shed belonging to the university, cold in winter and boiling in summer, with broken windows. For hours Marie stirred the mineral in big cauldrons with a long iron rod. After four years, in 1902, she managed to isolate a decigram of pure radium chloride.

That powder glowed with a faint blue light when it was dark. The Curies went to look at it in the evening, in their shed, as if it were a treasure. Nobody then knew that radiation could be harmful.

The Nobel Prizes

In 1903 the Nobel Prize in Physics was awarded to Becquerel and to the Curies. At first the committee was thinking of honouring only the men, but Pierre pointed out that the credit belonged to Marie as well, and her name was added. In 1906, though, Pierre died in an accident in Paris, run over by a horse-drawn cart. Marie was devastated, but she carried on with the work and took his place as a professor at the Sorbonne: she was the first woman to teach at that university.

In 1911 she was awarded a second Nobel Prize, this time in Chemistry, for discovering polonium and radium and for isolating radium. She was the first person to win the Nobel Prize twice, and she remains the only one to have won it in two different sciences, physics and chemistry.

The “little Curies”

During the First World War Marie realised that X-rays could save the lives of the wounded, because they showed where bullets and broken bones were. She had about twenty cars fitted with X-ray equipment and took them to the front, driving one herself. They were called “little Curies”. With her daughter Irène, then seventeen, and other women she had trained, she helped to examine more than a million wounded soldiers.