Marie Curie

Maria Sklodowska left Russian-occupied Poland with a dream of education, working as a governess to fund her sister's studies before finally reaching Paris. There she met Pierre Curie, and together they began the grueling work of isolating radioactive elements from tons of pitchblende ore, stirring vats in a leaky shed, performing thousands of crystallizations. They discovered polonium (named for her homeland) and radium. Marie became the first woman to win a Nobel Prize, then won a second in chemistry, still the only person to win Nobels in two different sciences. During World War I, she equipped ambulances with X-ray machines and drove them to the front lines herself. She died of aplastic anemia, caused by decades of radiation exposure. Her notebooks are still too radioactive to handle without protection. She said: 'Nothing in life is to be feared, it is only to be understood.'