Kathleen Lonsdale, Irish crystallographer and 1st female FRS (died 1971)

Dame Kathleen Lonsdale was an Irish crystallographer, pacifist, and prison reform activist. She proved, in 1929, that the benzene ring is flat by using X-ray diffraction methods to elucidate the structure of hexamethylbenzene. She was the first to use Fourier spectral methods while solving the structure of hexachlorobenzene in 1931. During her career she attained several firsts for female scientists, including being one of the first two women elected a Fellow of the Royal Society (FRS) in 1945, first female professor at University College London, first woman president of the International Union of Crystallography, and first woman president of the British Association for the Advancement of Science.

The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, education and public engagement and fostering international and global co-operation. Founded on 28 November 1660, it was granted a royal charter by King Charles II and is the oldest continuously existing scientific academy in the world.

January 28 is the 28th day of the year in the Gregorian calendar; 337 days remain until the end of the year.