Society: Arts and Science – September 12


The Nobel Prize is bestowed annually in categories as selected by Swedish and Norwegian committees in recognition of cultural or scientific advances. The 1895 will of Swedish inventor Alfred Nobel established the prizes.
Irène Joliot-Curie was born on this dare in 1897. She was a French scientist, the daughter of Marie Curie and Pierre Curie and the wife of Frédéric Joliot-Curie. Jointly with her husband, Joliot-Curie was awarded the Nobel Prize for chemistry in 1935 for their discovery of artificial radioactivity. This made the Curies the family with the most Nobel laureates to date. Both children of the Joliot-Curies, Hélène and Pierre, are also esteemed scientists. As she neared the end of her doctorate in 1924 she was asked to teach the precise laboratory techniques required for radiochemical research to the young chemical engineer Frédéric Joliot whom she would later come to wed. From 1928 Joliot-Curie and her husband Frédéric combined their research interests on the study of atomic nuclei. Though their experiments identified both the positron and the neutron, they failed to interpret the significance of the results and the discoveries were later claimed by Carl David Anderson and James Chadwick respectively. These discoveries would have secured greatness indeed, as together with J. J. Thomson’s discovery of the electron in 1897, they finally replaced John Dalton’s theory of atoms being solid spherical particles. Finally, in 1934 they made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre, who had isolated naturally occurring radioactive elements, Joliot-Curies realized the alchemist’s dream of turning one element into another, creating radioactive nitrogen from boron and then radioactive isotopes of phosphorus from aluminum and silicon from magnesium. For example, irradiating the main natural and stable isotope of aluminum with alpha particles (i.e. helium nuclei) results in an unstable isotope of phosphorus : 27Al + 4He → 30P + 1n. By now the application of radioactive materials for use in medicine was growing and this discovery led to an ability to create radioactive materials quickly, cheaply and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Joliot-Curie was awarded a professorship at the Faculty of Science. Irène’s group pioneered research into radium nuclei that led a separate group of German physicists, led by Otto Hahn, Lise Meitner, and Fritz Strassman, to discover nuclear fission; the splitting of the nucleus itself and the vast amounts of energy emitted as a result. The years of working so closely with such deadly materials finally caught up with Joliot-Curie and she was diagnosed with leukemia. She had been accidentally exposed to polonium when a sealed capsule of the element exploded on her laboratory bench in 1946. Treatment with antibiotics and a series of operations did relieve her suffering temporarily but her condition continued to deteriorate. Despite this Joliot-Curie continued to work and in 1955 drew up plans for new physics laboratories at the Universitie d’Orsay, south of Paris.