Freedhoff had summer jobs in Harold Johns ' biophysics lab. Johns was a pioneer of medical biophysics, developing cobalt radiation therapy for cancer in the 1940s. Although she enjoyed her time there, and was interested in the work Harry Welsh was doing on lasers, laboratory work was not her forte. Freedhoff was inspired by Jan Van Kranendonk, a theoretical physicist, who encouraged her to undertake postgraduate studies under his supervision. From then on, she dedicated her career to what she has described as "the exhilaration of scientific research" and teaching. "Basic science," she wrote, "is indeed a high form of culture, no less so than music or literature because it is also useful".