In 2014 Maryam Mirzakhani, an Iranian mathematician at Stanford University, became the first woman to win the Fields Medal, one of the highest honours in mathematics. She won it for work on the geometry of curved surfaces and on the space of all the shapes such surfaces can take.
In her field, a Riemann surface can be pictured as a doughnut-like surface with one or more holes, and its moduli space as a map in which every point stands for one possible shape of that surface. Mirzakhani, born in Tehran in 1977, made her name with her 2004 Harvard doctorate. It worked out how the number of simple closed geodesics, loops on the surface that never cross themselves and are as short as possible, grows with their length, and used that to measure the size of moduli spaces. She joined Stanford in 2009 and worked by drawing on large sheets of paper, which her young daughter called “painting”. She was also the first Iranian to win the Fields Medal. She died of breast cancer in 2017, aged 40, and her birthday, 12 May, is now International Women in Mathematics Day.