There’s something many people find embarrassing about the history of science – very few women feature in it. Things have changed hugely in the last 50 years, but inevitably, looking back in time, there are few women characters. (It’s odd – no one worries about the lack of women generals, prime ministers or presidents 100 years ago, but the missing female scientists seem to cause more concern.) Perhaps because of that, there are quite a few books around picking out women’s roles in the history of science, including this book that uses as a peg the short life of Henrietta Swan Leavitt, the woman who identified the measure that was used to estimate the size of the universe.
It’s significant that the book is called “Miss Leavitt’s Stars” not “Miss Leavitt” because, to be honest, there’s not that much about Leavitt in it. This isn’t because George Johnson hasn’t tried, but because there is very little known about her outside her work. He comments “I had intended to use her as nothing more than a device, a way to get into the story…” but says she refused to exit on cue and kept turning up. This seems a trifle exaggerated. She really is just a device. Much of the action in the book takes place after her death. This isn’t to say her contribution wasn’t significant – it was. But anyone picking this up and expecting to find a scientific biography of one of the first important women in the field would be disappointed.
On the positive side, it is a short and very readable excursion into the discovery of the size of the universe and how this was made possible. We see how Leavitt was more than just a measurer of photographic plates and someone who added up numbers, but someone who contributed ideas and theories. There are also good brief sketches of Shapley and Hubble, the two contenders in the academic battle, and a careful explanation of how distance measurements can be made at interstellar distances, from simple triangulation to the less certain, but more penetrating assumption of “standard candles” – stars whose brightness can be predicted from other properties like the speed of pulsation, which could then be compared in brightness to estimate distances. It’s not a bad book at all. But I couldn’t help wanting, like Johnson, to know more about Leavitt having been given a brief glimpse of her in the early pages.
Review by Martin O'Brien