Irene Curie

Irene Curie Harcourt / CC BY 4.0 via Wikimedia

Irene Curie’s legacy is often overshadowed by that of her more famous mother, Marie. Like her mother, Irene married a fellow scientist, won the Nobel Prize, and bore a daughter, Helene, who would also reach scientific greatness. While her talent was nurtured by Marie, Irene Curie’s accomplishments and scientific genius allow her to stand alone among the greatest scientists of her time.

Irene was born in Paris on September 12, 1897, the older of two daughters born to Pierre and Marie Curie. She was educated at home by her mother, who won two Nobel prizes- the first for Physics in 1903 for the discovery of radium, which forever changed the fields of chemistry, physics, and medicine, and the second for Chemistry in 1911. A strong and brilliant woman, Marie Curie placed a great deal of importance on her children’s education, and she even formed a special “school” for Irene and the similarly-gifted children of other academics when the local schools proved too easy for Irene’s early and obvious talent in mathematics. Irene completed high school at the College Sevigne and began her undergraduate education in mathematics and physics at the Sorbonne. World War I broke out soon after Irene began her studies, casting its dark shadow over Europe, and Irene interrupted her education to bravely assist her mother setting up portable x ray machines and examining wounded soldiers in the field and military hospitals, efforts which earned her France’s Military Medal.

In 1947, after the war was over, Irene was appointed the Director of the Institute of Radium at the University of Paris and Commissioner for Atomic Energy; in this capacity, she helped create the first French nuclear experiments. Like her mother Marie, Irene strongly encouraged the education of women, and served on the National Committee of the Union of French Women. She was a member of the Legion of Honor and the World Peace Council, and numerous scientific societies and foreign universities. Unfortunately, Irene confronted the same discrimination her mother Marie faced, by scientific and cultural institutions that would not accept female members or often even acknowledge women’s accomplishments. Marie was denied a seat in the French Academy of Science after a 1911 vote to maintain its all male status, and forty years later, Irene too would be denied membership after applying three different times.

Aside from the difficulties being a female scientist and academic posed, Irene’s health had always been fragile. She battled tuberculosis, and she and her family visited their country home in Brittany frequently in the hope of easing her ailments. After several operations beginning in 1950, Irene’s health declined precipitously, until she died at the age of 59 of leukemia, a disease brought on by her work with radioactivity which also killed her mother. After his wife’s death, Fred Joliot succeeded her as the Chair of Nuclear Physics at the University of Paris, vowing to continue her unfinished work. Daughter Helene would become a famous scientist in her own right; she is a respected nuclear physicist at the Institute for Nuclear Physics in Orsay, keeping alive the brave and impressive Curie legacy. Because of her brilliant mind, impressive work ethic, political and societal involvement, and monumental scientific discoveries, Irene Curie deserves recognition as a true heroine.

Irene and Marie Curie Unknown author / CC BY 4.0 via Wikimedia

In 1918, Irene once again joined her mother – this time as her assistant at the Institut du Radium at the University of Paris. Seven years later, in 1925, she finished her doctoral thesis on the alpha rays of polonium, a radioactive metallic element discovered by her parents and named after their homeland of Poland. That same year, a young man named Frederic Joliot visited the Institut and soon joined the staff of assistants. Irene was in charge of teaching Frederic the techniques used when working with radium, and they soon discovered a mutual passion for scientific research, shared political opinions, and a love for art and sports. The couple was married a year later, in 1926, and, just like Irene’s parents Pierre and Marie, soon became a powerful scientific team, working together and signing their publications under the name Joliot-Curie.

The path to greatness was bumpy at first, however: Irene had more experience working in the laboratory, and therefore had to teach her husband proper techniques and processes. The young couple did not have much money, and during these early years at the Institut, Frederic also studied for his doctorate (focusing on the properties of the compounds of polonium, which he would not earn until 1930) and taught on the side. In fact, he almost abandoned scientific research for a more lucrative career! As if they were not busy enough, Irene also gave birth to daughter Helene, in 1927, and son Pierre, in 1932.

Irene and her husband spent long hours in the laboratory but focused equally on their young children. Vacationing with her family and other simple pleasures were important to Irene; unlike her fashionable sister Eve, she wore very simple clothing, and preferred outdoor activities to fancy social gatherings. By all accounts, Irene Curie was not interested in the frivolities in life; according to James Chadwick, who wrote her obituary in the journal Nature:

Her parents were both persons of strong and independent mind, and Mme. Joliot-Curie inherited much of their character as well as their scientific genius. She had a powerful personality, simple, direct, and self-reliant. She knew her mind and spoke it, sometimes perhaps with devastating frankness; but her remarks were informed with such regard for scientific truth and with such conspicuous sincerity that they commanded the greatest respect in all circum- stances. In all her work, whether in the laboratory, in discussion, or in committee, she set herself the highest standards and she was most conscientious in the fulfillment of any duties she undertook.

Irene Curie with her mother and sister Unknown author / Public domain via Wikimedia

Irene and Fred both specialized in nuclear physics, the science of studying the nucleus of the atom, the smallest unit of a chemical element, and the interaction of its parts. Their laboratory work examined the composition of the atom, and chemical elements, which combine, like letters in the alphabet together make words, to form chemicals and gases. In 1932, the pair confirmed the discovery of the positron, a positive electron emitted from the nucleus during a nuclear reaction. More significantly, they used alpha particles, charged particles emitted from a radioactive atom, to change elements that are not normally radioactive into radioactive isotopes, or slightly different forms of the same elements. They first proved this with nitrogen, and then with aluminum and magnesium. Irene and Fred’s discovery was so major that they were awarded the Nobel Prize in Chemistry just one year later, in 1935, “for their synthesis of new radioactive elements.” Not only did the discovery add hundreds of new “radioisotopes” to the periodic table of the time, but it also made these isotopes available for further scientific discoveries (helping solve the problem of how to release energy from the atom), and industry and medicine, where it is used to diagnose and treat a number of illnesses including cancer. Because these artificial isotopes were relatively inexpensive, they were widely used. Irene Curie became the second female scientist to win the Nobel Prize – the first was her mother, Marie.

Irene’s new fame helped her become a Professor in the Faculty of Science in Paris in 1937, where she continued her research, focusing on nuclear fission, the splitting of an atomic nucleus which results in a great deal of energy. She also became deeply involved with political causes – around the same time she and Fred made their Nobel Prize-winning discovery, a political movement called fascism was becoming more powerful in Europe. Fascism is a political ideology wherein the state or country is emphasized over the individual; typically, a dictator rules over a centralized government that strongly controls and contains individual freedoms. Irene energetically opposed fascism and aided the political opposition and peace movements, belonging to the Vigilance Committee of Anti-Fascist Intellectuals, aiding the Republicans in the Spanish Civil war, and acting as one of only three women in the Popular Front movement, a coalition of many antifascist groups. In 1936, she was also named Undersecretary of State for Scientific Research. During WWII, Irene and Fred worried that fascists would discover their work in nuclear physics and use it for wrong purposes, and together decided to focus their research on the biological and medical uses of chemical discoveries. When Hitler’s German forces invaded and occupied France, they actively aided the Resistance movement. In 1944, the war forced Irene and her two children to seek safety in Switzerland.