Kathleen Lonsdale

Born on 28 January 1903 in Newbridge, Ireland, crystallographer Kathleen Lonsdale was the first woman physicist elected as a fellow to the Royal Society of London. After earning a BSc in physics from the Bedford College for Women in London in 1922, she joined the University College London laboratory of Nobel laureate William H. Bragg. She earned a research grant from Bedford College after she was rejected for another fellowship because the committee “would be breaking the spirit of the regulations in awarding an exhibition to a married woman.” Using the Bedford grant, Lonsdale performed a careful crystallographic analysis of the benzene ring, the structure of which was hotly debated at the time. In 1928 and 1929 reports, she showed conclusively that the benzene ring is planar. She continued her research at home in the early 1930s while caring for her three children. In 1943 the nearly 300-year-old Royal Society launched a campaign to nominate its first female fellows. Two years later, Lonsdale and biologist Marjory Stephenson were elected. Lonsdale won the Society’s Davy Medal in 1957. She died at age 68 in 1971. Physics Today books editor Melinda Baldwin wrote a profile of Lonsdale, whose story “demonstrates how far science has come in making space for women—but it also highlights how many of the obstacles she faced remain with us.” (Photo credit: National Portrait Gallery, London, CC BY-NC-ND 3.0 )

Date in History: 28 January 1903