This month marks the hundredth anniversary of the tragic death of Pierre Curie, one of the great pioneers of modern science. On April 16th 1906, a street accident in Paris cut short the career of one of France's most famous physicists, leaving his wife Marie to continue their groundbreaking research alone.
On that day, Prof Curie had intended to visit his publisher. Finding the premises locked because of a strike, he decided to return to his office in the Sorbonne, despite a heavy rainstorm. As he crossed the Rue Dauphine, he was struck by a large horse-drawn wagon coming from the Pont-Neuf and killed instantly. The accident was a great shock to the world of science and left his young wife alone with two small daughters.
Born in Paris in 1859, Pierre Curie was educated at home by his father, a doctor, before entering the faculty of science at the Sorbonne. By the age of 18, he had completed a higher degree in science. Employed as a laboratory assistant at the Sorbonne, he made several important discoveries about the effect of electricity on crystals. In 1895, he submitted a landmark study of magnetism for his doctoral thesis, a work that established his reputation as a scientist of the highest calibre.
That same year, Pierre married Marie Sklodowska, a Polish graduate student at the Sorbonne. The marriage marked the beginning of an extraordinary scientific collaboration. In considering a topic for research, Marie had become interested in Henri Becquerel's discovery of a mysterious radiation emitted by uranium salts. Pierre and Marie decided to undertake a detailed investigation of the new phenomenon, which Marie later named radioactivity.
Marie scored an early success with the discovery that the chemical element thorium also spontaneously emitted radiation. After years of painstaking work, she and Pierre succeeded in isolating two new, unknown elements that were highly radioactive, naming them polonium and radium. Most striking of all, the research led Marie to propose that the phenomenon was related to fundamental properties of atoms.
Meanwhile, Pierre discovered that radioactivity had an extraordinary heating effect (the first observation of nuclear energy). He established that the radiation comprised three distinct types of emission, one of which resembled the famous X-rays discovered just a few years earlier. He also discovered that radioactivity decreased over time, an effect that could be used to calculate the age of materials containing radioactive elements.
Studying the effects of radiation on animals, Pierre discovered that small doses could cure malignant growths and cancers by destroying diseased cells. Aware of the enormous medical potential of this discovery, the Curies declined to patent their expertise, making their preparation methods freely available. Their efforts resulted in the early adoption of radiotherapy as a standard medical treatment around the world.
The scientific discoveries of the Curies attracted international acclaim. In 1903, they shared the Nobel Prize for Physics with Henri Becquerel; however, the extra attention simply increased their administrative workload and they struggled to keep up. In fact, both Pierre and Marie had begun to suffer serious health problems. Unknown to them, the cause of this ill-health was their research material - it was not realised at the time that large doses of radiation could be dangerous. By 1906, Pierre had become very sick indeed and he may well have stumbled in the street on the day of his death.
After the tragic accident, Marie was appointed to Pierre's former position at the Sorbonne, where she set up a prestigious institute for the study of radioactivity. Despite several scandals in the French press, she became one of the world's most respected scientists. In 1911, she was awarded the Nobel Prize for Chemistry and remains the only person to have won the prize for both physics and chemistry. Later, her daughter Irene and son-in-law Frédéric Joliot joined her research institute, making important discoveries themselves and sharing a Nobel Prize in 1935. Sadly, Marie eventually succumbed to radiation poisoning, and died in July 1934.
The influence of the Curies' research can be seen throughout science today, from the carbon-dating of the oldest fossils to the use of radiotherapy in medical care. Their work precipitated the discovery of the atomic nucleus and forms a cornerstone of the modern view of matter. In 1995, the ashes of Pierre and Marie were laid to rest under the famous dome of the Panthéon in Paris, the highest honour bestowed by France on its citizens.
Dr Cormac O'Raifeartaigh lectures in physics at Waterford Institute of Technology.