The Glass Universe highlights the under-appreciated role of a group extraordinary women in the history of science. This is the little-known true story of a group of women whose contributions to the burgeoning field of astronomy in the mid-nineteenth century, forever changed our understanding of the stars and our place in the universe. Harvard College Observatory began employing women as calculators, or “human computers,” to interpret the observations made via telescope by their male counterparts each night. Initially, the female corps grew from a group of sisters and wives of the astronomers to include graduates of Vassar, Wellesley, and Smith. As photography transformed the practice of astronomy, the women turned to studying the stars captured nightly on glass photographic plates. The “glass universe” of half a million plates that Harvard amassed from their work enabled the women to make extraordinary discoveries that attracted worldwide acclaim. They helped discern what stars were made of, divided the stars into meaningful categories and found a way to measure distances across space by starlight. We will be reading The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars, by Dava Sobel (Penguin Books, 2017). No class on 11/21/18.