Cecilia Payne-Gaposchkin, who died in 1979, is one of the many female scientists whose name is less well known than it should be. Astronomy, the field she worked in, was so male-dominated she had to leave her native Britain and move to the US simply to be able to practise it. She swapped one Cambridge for another, and became the first woman to head a department at Harvard.
As a graduate student, she made the paradigm-shifting discovery that stars were made of hydrogen and helium, rather than iron, as was commonly held. Early on in The Lightest Element we see a 25-year-old Cecilia defending her ideas to the leading expert of the time, Henry Norris Russell. Julian Wadham plays him with an indulgent air: he seems supportive, yet still expects Cecilia to pour his tea. But the more she explains, the more riled he becomes, until he explodes: “Don’t you know when to be quiet?”
