Radiobiologist Tikvah Alper, who spent a lifetime questioning accepted theories and the established order, discovered that diseases like scrapie and mad cow replicated without DNA. Alper earned her master’s from Cape Town University in 1929 and studied at the Kaiser Wilhelm Institute for Chemistry in Berlin until 1933, when she was forced to return to South Africa. After her son Jonathan was born deaf in 1935, she researched and created new methods of speech therapy for the deaf while continuing her work in physics and chemistry in her home lab and raising her children. From 1948–1951 she ran the Biophysics Section of the National Physics Laboratory, until her protest of apartheid forced the family to immigrate to Britain. There she began working at the MRC Experimental Radiopathology Research Unit at London’s Hammersmith Hospital, working her way up from unpaid researcher in 1951 to director from 1962–1973. During this time she discovered that encephalitic diseases like mad cow and scrapie don’t replicate like viruses and can’t be killed like viruses, challenging our modern understanding of disease. From 1974–1977 she worked as senior advisor at the Gray Laboratory, then retired to write her 1979 book, Cellular Radiobiology.