Technology & Medicine › Electric age › X-rays (Röntgen)
Marie Curie and radioactivity
1867–1934; polonium and radium 1898· Person· Medicine & surgery
Well documentedSolid records, physical evidence or scientific consensus.
Polish-born scientist in Paris who showed radiation comes from inside atoms, discovered polonium and radium, and won two Nobel Prizes.
See it on the Technology & Medicine map →How it works
Born Maria Skłodowska in Warsaw, she studied in Paris. In 1897 she took up Henri Becquerel's 'uranium rays' for her doctorate, measuring them with an electrometer invented by her husband Pierre and his brother. The rays depended only on the amount of uranium, so they came from the atoms themselves; she coined 'radioactivity'. In 1898 the couple found polonium, named for Poland, and radium, then spent years processing tons of ore to isolate a tenth of a gram of radium.
Why it mattered
Curie showed atoms are not unchanging, opening nuclear physics. Radium launched radiation therapy for cancer, and her mobile X-ray units examined an estimated million wounded World War I soldiers.
Legacy and how we know
Her notebooks, still radioactive and kept in lead-lined boxes in Paris; her 1903 physics and 1911 chemistry Nobel Prizes, making her the first person to win two; papers in the French Academy's journal.
Still unknown or debated
Her 1934 death from aplastic anemia is blamed on radiation; how much came from handling radium versus unshielded wartime X-ray work is uncertain.
Connections (2)
▸X-rays (Röntgen) led, via Becquerel, to Marie Curie and radioactivityWell documented
The connection
Röntgen's X-rays seemed to come from the glowing spot on his tube, so Henri Becquerel tested whether glowing uranium salts gave off similar rays. In 1896 he found uranium emitted rays even in the dark. Marie Curie picked these 'Becquerel rays' for her doctorate in late 1897, which led to radioactivity, polonium and radium.
When and how
Paris, 1896–98: Becquerel at the Natural History Museum in February–March 1896; Marie and Pierre Curie at the School of Industrial Physics and Chemistry.
How we know
Becquerel's 1896 reports to the French Academy of Sciences, Curie's lab notebooks and her 1903 thesis trace the sequence directly.
Debates and open questions
Becquerel's discovery was partly luck: cloudy weather made him store plates with uranium in a drawer. Whether he expected to see an image when he developed them is debated.
▸Marie Curie and radioactivity opened the path to Nuclear energy (bombs and reactors)Mostly agreed
The connection
Curie proposed in 1898 that radioactivity comes from inside atoms, and in 1903 Pierre Curie showed radium gives off heat steadily. That revealed vast energy stored in atoms. Her daughter Irène and son-in-law Frédéric Joliot-Curie created artificial radioactivity in 1934, and Irène's work on uranium helped lead to the discovery of fission.
When and how
Paris, 1898 (Marie and Pierre Curie: polonium and radium); Paris, 1934 (the Joliot-Curies); Berlin, 1938 (fission).
How sure are we?
The Curies' papers and the Joliot-Curies' 1934 report are on record; Hahn and Strassmann's fission work began partly as checks on Irène Joliot-Curie's uranium results.
Debates and open questions
Early researchers, Curie included, misjudged radiation's danger; her 1934 death from aplastic anemia is widely blamed on exposure, and her notebooks are still radioactive.