In the 1880s, Edward Charles Pickering, the director of the Harvard College Observatory, started amassing what would eventually become the world’s largest collection of photographic plates of stars—500,000 slices of the sky captured on glass.
Many of the images were carefully ferried from observatories not just in North America, but also Peru, South Africa, New Zealand, and Chile. In the Peruvian Andes, a single Harvard astronomer would pack the delicate plates into two wooden crates and carry them down from a mountain, nicknamed Mount Harvard, “on muleback and across a suspension bridge,” according to The New York Times. From there, they traveled on a train to Lima before making it on board a Boston-bound boat to the university.
To analyze this abundant stream of data, Pickering relied on a team of women. Some came to him with college educations, and others received on-the-job training. Gathered in a small library, adjacent to the observatory, they would work for about 25 cents an hour, six days a week, calculating the temperature and motion of the stars via these astronomical plates.
By discovering new stars, nebulae, and novae—and going on in their careers to shape the then-emerging field of astrophysics with their spectral analyses of stars—these “Harvard Computers” gained recognition around the world over the decades for their contributions to astronomy. Their efforts paved the way for women who would work in computing, engineering, and aerospace industries as human computers.
The stories of the women who followed in the Harvard ladies’ footsteps have recently been documented in books such as The Rise of the Rocket Girls and Hidden Figures. But the Harvard Computers’ story remains largely unexplored. In The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars, out on December 6, Dava Sobel, the author of Longitude and Galileo’s Daughter, has painstakingly recreated their efforts to explore the heavens.