The Notebooks Too Dangerous to Touch

Maria Skłodowska was born in Warsaw in 1867, in a Poland that did not officially exist — partitioned between empires, its language suppressed, its universities closed to women. She got her forbidden education anyway, through the "Flying University", an illegal network of classes that met in private apartments and changed address constantly to stay ahead of the police. For years she worked as a governess to pay for her sister's medical studies in Paris — the sisters had made a deal: first Bronia would study while Maria earned, then they would swap. In 1891, aged twenty-four, she finally boarded the train to Paris, enrolled at the Sorbonne as one of a handful of women among thousands of men, and lived in an unheated attic where, one famous winter, she fainted from hunger during her studies. She finished first in her class in physics.

She intended to return to Poland. A Polish university turned her down — a woman — and Paris held other attractions by then: Pierre Curie, a brilliant, unworldly physicist who courted her with a copy of his research papers and the argument that they could share a life "in a scientific dream". They married in 1895; she wore a dark dress she could use afterwards in the laboratory. When she needed a doctoral subject, she chose the strangest result in recent physics: Henri Becquerel had found that uranium salts fogged photographic plates through black paper — invisible rays, coming from nowhere, powered by nothing anyone could name.

Her first great insight was quiet and enormous: measuring precisely, she showed the radiation depended only on the amount of uranium — not its chemistry, not its temperature, not anything done to it. The energy was coming from inside the atoms themselves. She gave the phenomenon its name, radioactivity, and then noticed something stranger: pitchblende, the ore uranium came from, was far more radioactive than its uranium content allowed. Hidden in the ore was something new — and she was going to find it.

Finding the hidden elements meant separating them from tonnes of ore, and no proper laboratory was offered. The Curies were given a leaking wooden shed — a former dissection room that a visiting chemist described as a cross between a stable and a potato cellar. Into its courtyard came sacks of pitchblende waste from Austrian mines, and for four years Marie did the work of a factory: dissolving, boiling, filtering, crystallising, stirring vats with an iron rod nearly as tall as herself. In 1898 the couple announced two new elements — polonium, named defiantly after her occupied homeland, and radium, "the shining one". But announcing is not proving: chemistry demanded a visible, weighable sample. In 1902, from roughly a tonne of ore, she finally held one tenth of a gram of radium chloride — enough to enter the element in the periodic table beyond argument. The shed, meanwhile, had become quietly magical: the residues on the benches glowed in the dark, and Pierre and Marie would return at night to look at their faintly shining jars — carrying, though they could not know it, the poison in their pockets.

Recognition arrived almost without her. When the 1903 Nobel Prize in Physics was being arranged for Becquerel and Pierre, Marie was simply left off — until Pierre, warned by a sympathetic Swedish mathematician, insisted her name be added. She became the first woman to win a Nobel Prize; the committee's president still quoted scripture about man's helpmate in his speech. Fame brought a professorship for Pierre and, for the family, a strange new life in which radium was a sensation — luminous watches, radium tonics, radium beauty creams — while its discoverers, who had refused on principle to patent the extraction process, remained comparatively poor and increasingly, mysteriously, unwell.

Then, on a rainy April afternoon in 1906, Pierre — weakened, and absent-minded as ever — slipped crossing the rue Dauphine and fell under a horse-drawn cart. He died instantly. Marie's diary entries from the weeks after are almost unbearable to read; her response in public was granite. Offered a widow's pension, she refused it. Offered, instead, Pierre's chair at the Sorbonne, she accepted — the first woman ever to teach there — and began her first lecture, before a packed and weeping hall, at the exact sentence of the physics course where Pierre had stopped.

1911 delivered the cruellest month of her public life and its greatest honour almost simultaneously. The French press discovered her relationship with the married physicist Paul Langevin and detonated: she was attacked as a foreigner, a home-wrecker, and — in the venomous press of the day — worse; a mob gathered outside her house; Langevin fought a duel over the affair (both men, being physicists, fired into the air, or not at all — accounts differ). In the middle of the storm, Stockholm announced her second Nobel Prize, this time in Chemistry, for radium and polonium — and a committee member wrote suggesting she stay away from the ceremony given the scandal. Her reply is one of the great sentences of scientific dignity: the prize, she wrote, was for the discovery of radium and polonium, and there was no connection between her scientific work and the facts of her private life. She went, and collected it. No one else, before or since, has won Nobel Prizes in two different sciences.

When war came in 1914, she converted fame into logistics. Reasoning that a wounded soldier X-rayed at the front need not be X-rayed on an operating table hours later, she created mobile radiography cars — "petites Curies" — learned to drive, drove one herself at the front, trained around 150 women as operators, and equipped hundreds of radiological stations. By war's end, over a million wounded men had been X-rayed by her service. She attempted to donate her Nobel medals to the war effort; the Bank of France declined to melt them.

The bill arrived slowly. Decades of unshielded exposure — she had carried test tubes of radium in her pockets and kept a glowing sample by her bed — destroyed her blood, and in 1934 she died of aplastic anaemia, almost certainly caused by her own element. She was buried with Pierre; in 1995 France transferred them both to the Panthéon, making her the first woman honoured there for her own achievements — her coffin lined with lead. And in the Bibliothèque nationale, her laboratory notebooks survive: still radioactive, stored in lead boxes, consultable only by readers who sign a waiver and wear protection. Radium-226 has a half-life of 1,600 years. Her handwriting will outlive every institution that once refused her a place.