An astronomical feat

Think of a computer and your mind might conjure the brushed steel contours of the latest must-have laptop or, for those of a certain age, a room full of whirring cabinets and reel-to-reel tape decks. The era of electronic computing has its roots in the code-breaking exploits of Bletchley Park; but the need for repetitive and reliable number-crunching did not suddenly begin with the wartime threat of Nazi submarines. For centuries, such
everyday activities as banking, commerce, engineering and navigation have all relied on computing to manipulate large amounts of numerical information. But before there were machines to do the mathematical
donkey-work, there were human brains, and in the 19th and early 20th centuries a computer was not a device but a person.

The physical sciences have a particular appetite for big numbers, and perhaps none more so than astronomy, in which vast distances and dizzying spans of time are coupled with the sheer quantity of objects that populate the night sky. In the late 19th century, astronomers were faced with an explosion of data driven by advances in photographic technology, and at Harvard Observatory the problem of cataloguing and analysing it all was solved in what was, for the time, a rather unusual way. The director, Edward Pickering, was actively recruiting ladies to join his team of human computers, and over the next few decades his policy opened the way for a cohort of remarkable women to make their mark.

Their story is the subject of Dava Sobel’s The Glass Universe. Sobel is hugely successful as a populariser of scientific history and her instinct for unearthing compelling but largely untold stories has led to a string of bestsellers. Part of her popularity is down to a knack for channelling the dry facts of biography and scientific research into a dramatic narrative, an approach that has occasionally set her at odds with academic historians of science, but in The Glass Universe it serves her well; and, while her affection for her subjects is obvious, she wisely lets their stories speak for themselves.