* That was why wood got lighter as it was consumed by flames. But, inconveniently, metals got heavier when they were heated (calcined) in air, even though they were supposed to be losing phlogiston. No problem, said the advocates of phlogiston theory: apparently this volatile ‘principle of combustion’ can sometimes have negative weight.
CHAPTER 3
New Light
The Curies’ Radium and the Beauty of Patience
Paris, 1898–1902—In a cold and damp wooden shed at the School of Chemistry and Physics, the Polish scientist Marie Curie, occasionally assisted by her French husband Pierre, crushes and grinds and cooks literally tons of processed pitchblende, the dirty brown material left over from the mining of uranium. The Curies are convinced that this unpromising substance contains two new elements, which they name polonium and radium. After endless chemical extractions, Marie obtains solutions that glow with pale blue-green light: a sign that they contain the intensely radioactive element radium. The significance of the work is recognized straight away, as Marie and Pierre, still struggling to forge scientific careers in France, are awarded the Nobel prize in physics in 1903.
Marie Curie may well have felt ambivalent about becoming an icon for women’s place in science. Like several trail-blazing women scientists, she seemed eager that her sex be seen as irrelevant. Sadly, it was not. Those scientists, such as Albert Einstein and Ernest Rutherford, who accepted Marie without question as an equal, stand out for their lack of prejudice; most of the scientific community at the end of the nineteenth century was reluctant to believe that a woman could contribute new, bold and original ideas to science. When Marie was grudgingly awarded prizes for her groundbreaking studies of radioactivity, as likely as not the news would be communicated via her husband. It was only by a hair’s breadth that she was included in the decision of the 1903 Nobel committee. And when the Paris newspapers discovered that, several years after Pierre’s death, Marie had had an affair with one of his former colleagues, they bit on the scandal with relish, when similar behaviour from an eminent male scientist would probably have been deemed too trivial to mention.
It is hardly surprising, then, that Marie took great pride in her work, carefully emphasizing her own contributions and hastening to publish them in the face of Pierre’s habitual indifference to public acclaim. Marie knew that, to make her mark, she would have to achieve twice as much as her male colleagues. And she did – which is why she became the only scientist to win two Nobel prizes in science.
Her life has been so often romanticised – that process began as soon as the news came from Stockholm in 1903 – that Marie Curie herself has tended to disappear behind the stereotype of the tragic heroine. Yet it is true that her life was marred by several tragedies and by considerable adversity, and it is not surprising that in the end this left her hardened, appearing aloof and cold to those around her. Her determination and dedication to her work could translate as a certain prickliness and unfriendliness towards her colleagues. If she expected others to ignore the fact that she was a woman, likewise she herself had no concern about protecting brittle male egos.
In as much as she discovered new elements, Marie Curie did nothing that others had not done previously. But the elements that she unearthed in her long and arduous experiment were like nothing anyone had seen before.
New physics
The elements that debuted in the periodic table in the late nineteenth and early twentieth century hint at the unattractive nationalism of that age: they bear names like gallium, germanium, scandium, francium. We can hardly begrudge Marie Curie her polonium, however, since her own sense of national pride was born out of Russian oppression. Poland was then part of the Russian empire, and after a rebellion in 1863 (four years before Marie’s birth) the country suffered from an intensive programme of ‘Russification’, during which the tsar forbade the use of the Polish language in official circles. The struggle of the Polish intelligentsia against the Russian authorities was a dangerous business in which some lost their lives.
Figure 3 Marie Curie (1867–1934), the discoverer of radium and polonium
(© CORBIS)
When Maria Sklodowska (Figure 3) came to Paris to study science and mathematics at the Sorbonne, it must have seemed a land of opportunity – this was the Paris of Debussy, Mallarmé, Zola, Vuillard and Toulouse-Lautrec. Yet women risked their reputation simply by venturing out into the city alone, and Maria was more or less confined to her garret lodgings in the Quartier Latin. She graduated in 1894 and began working for her doctorate under the physicist Gabriel Lippmann, who later won the Nobel prize for his innovations in colour photography.
That year she met the 35-year-old Pierre Curie, who taught at the School of Chemistry and Physics and studied the symmetry properties of crystals. Pierre did not possess the right credentials to become part of the French scientific élite – he had studied at neither of the prestigious schools, the École Normale or the École Polytechnique – but nonetheless he had made a significant discovery in his early career. With his brother Jacques at the Sorbonne in 1880, he had found the phenomenon of piezoelectricity. When the mineral quartz is squeezed, the Curie brothers discovered, an electric field is generated within it. They used this effect to make the quartz balance, which was capable of measuring extremely small quantities of electrical charge. Pierre’s colleague Paul Langevin used piezoelectricity to develop sonar technology during the First World War.
Shy and rather awkward in public, Pierre had never married. His work was almost an obsession and he did not seem interested in acquiring a token wife. ‘Women of genius are rare’, he lamented in his diary in 1881. But he quickly recognized that Maria Sklodowska was just that kind of rarity, and in the summer of 1894, when she had returned temporarily to Poland, he wrote to her: ‘It would be a beautiful thing, a thing I dare not hope, if we could spend our life near each other hypnotized by our dreams: your patriotic dream, our humanitarian dream and our scientific dream’.
His courtship was a little unorthodox – he dedicated to Maria his paper ‘Symmetry in physical phenomena’. But it seemed to work: they were married in 1895, the same year in which Pierre (never one to rush his research) completed his doctoral thesis on magnetism.* The marriage delayed Marie (as she now called herself) from starting on her own doctorate, for she soon had a daughter, Irène, who was later to become a Nobel laureate too. This hiatus turned out to be doubly fertile, for Marie’s eventual research topic was a phenomenon discovered only in March 1896.
The fin-du-siècle produced something of a public fad for the latest science and technology. Gustave Eiffel’s steel tower rose above the Paris skyline in 1889 as a monument to technological modernism, and was quickly embraced as such by Parisian artists like Raoul Dufy and Robert Delaunay. Emile Zola claimed to be writing novels with a scientific spirit, and his book Lourdes (1894), which Pierre gave to Marie, was a staunch defence of science against religious mysticism. When Wilhelm Conrad Roentgen discovered X-rays in 1895 and found that they could ‘look inside’ matter by imprinting a person’s