Ellen Gleditsch (1879-1968) began her long career in chemistry as Marie Curie's assistant but quickly grew to prominence in her own right. She pioneered the field of chemical radioactivity, becoming one of the first specialists. Gleditsch established the half-life of radium and aided in proving the existence of isotopes. In addition, Gleditsch was in contact with many prominent scientists of the time, and her friendship and work connected them all.

Ellen Gleditsch was born on December 29, 1879, in Mandal, Norway, the first of ten children born to Karl Kristian Gleditsch, a teacher, and Petra Birgitte (Hansen) Gleditsch. Although poor, the Gleditsch family was an exceptionally happy and close one. Both Karl and Petra were intellectual and politically liberal. The children were exposed to cultural, musical, and natural activities in addition to their regular studies. Gleditsch's mother was an advocate of women's rights.

Gleditsch graduated from high school in 1895 as...