Kathleen Lonsdale
Dame Kathleen Lonsdale DBE FRS (née Yardley; 28 January 1903 – 1 April 1971) was a British pacifist, prison reformer and crystallographer. She got her degree from University College London in 1924, and was awarded a doctorate in 1934. She used X-ray diffraction to work out the structure of lots of chemicals, and used X-rays to study crystals.