Episode two of The Secret Scientists aired last week on the BBC World Service.
Just as in the first episode, the documentary used the resources of the Wellcome Library to illuminate figures from the History of Science.
In this second episode, Prof Jim al-Khalili and Dr Nader el-Bizri, visit the Library to investigate the work and legacy of Ibn al-Haytham.
In particular they discuss his groundbreaking research into light and optics and also the claims that al-Haytham was the instigator of what we now call the scientific method.
More details on how to listen again to the series are available on the World Service website.