Light and Dark

Episode one
Wouldn’t it be great to be able to stand in front of a blackboard and churn out an equation which explains the speed of light? Professor Jim Al-Khalili can. Moreover, for the most part, he brings an audience along for the ride too. This two-parter acts as a nice companion piece to Brian Cox’s ‘Doctor Who’-themed lecture on Thursday.

Tonight’s ‘light’ segment is essentially a potted history of how we know what we know – with appropriate props to the likes of Euclid, Galileo and Robert Hook. By the end, however, Jim’s moved into truly head-spinning territory – it’s around the time that he starts explaining cosmic microwave background (it’s essentially light from the beginning of time that is only just appearing in view, despite travelling at 300,000km a second) that you’ll feel your mind being well and truly boggled. But in the best way; this is more epic popular science in something of a golden era for the form.