Out of the 881 individuals who won Nobel Prizes between 1901 and 2016, only 48 have been women. In some disciplines, the drought has persisted for decades: The last woman to win a Nobel Prize for physics, Maria Goeppert Mayer, was honored in 1964. The gap reflects longtime institutional biases against women within the sciences, a lag exacerbated by the decades-long backlog of Nobel-worthy discoveries.