Maria Skłodowska (later Marie Curie) is well known as the recipient of two Nobel Prizes and the discoverer of radium. Critically, she demonstrated that radiation was not caused by an interaction between molecules. Radiation, she theorized, was an atomic property, proportional to the amount of the radioactive substance being measured. That insight made Curie one of the most important theoretical physical scientists of the early 20th century.
Curie's success was the product of not only her creativity and perseverance, but also the relationships that she developed with her male colleagues. Some of the relationships were positive, particularly her partnership with her husband, Pierre. Others, including an affair with the physicist Paul Langevin, threatened to disrupt her career. Well after Pierre's death, Curie had to fight the assumption that she had been merely his assistant, since women scientists were not expected to come up with theoretical advances.