Horizon: How to Build a Time Machine
9pm, BBC2
Time travel is theoretically possible. This tantalising prospect lends itself to all manner of odd postulations, as explored in this head-spinning documentary. Boffins seem confident that, at some point, we will work it out. And when we do, it will involve quantum entanglement. Or travelling faster than the speed of light. Or wormholes. These fields of study tend to be divided into “legitimately crazy” and “crazy crazy”. Accordingly, the scientists involved are excellent value. Phil Harrison
Ackley Bridge
8pm, Channel 4
The enjoyable, if by-the-numbers, school drama continues. Following Sami’s shock death, Emma looks for answers from the local community. Meanwhile, Missy is far from ecstatic to hear that Riz has been spreading rumours about her sister, Hayley – until she finds out that they just might be true. Hannah J Davies
The Rise and Fall of Nokia
9pm, BBC4
In a time when phones were just phones, yours was probably a Nokia. These days, Nokia remains an electronics company, but it stopped mobile phone production in 2013. As this fine documentary asks: what happened? Great archive footage and an air of innocent endeavour will keep you charmed as the saga unfolds. John Robinson
David Walliams Presents: Revenge of Alright On the Night
9.15pm, ITV
Pratfalls, expletives, corpsing. Succeeding Denis Norden and Griff Rhys Jones, the comedian, children’s novelist and Britain’s Got Talent judge takes up the reins of the bloopers show. Don’t expect too many changes to a tried-and-tested format. Jonathan Wright
Africa’s Great Civilisations
10pm, BBC4
The final episode of Henry Louis Gates Jr’s terrific survey of the history of Africa reaches the 19th century, during which the continent was colonised by European powers. But, as Gates reminds us, some regions, such as the Zulu empire and the unconquerable Ethiopia, were beyond their grasp. Andrew Mueller
Hollywood Homicide
10pm, Really
When there is a definitive exploration of the OJ Simpson case, as there is with the superlative OJ: Made in America, all other coverage seems somehow redundant. Particularly so in the case of this lurid awfulness, with its cheap reconstructions and exploitatively graphic crime-scene photographs. Ben Arnold
Film choice
Westworld (Michael Crichton, 1973), 9pm, TCM
In 1973, Michael Crichton’s sci-fi tale of a wild west theme park where lifelike androids indulge humans’ fantasies was a flight of fantasy; now, in the age of HBO’s precision-engineered reboot, it is all quite familiar. But Richard Benjamin’s fight for survival when the robots go awry still grips, with Yul Brynner terrifying as a prototype Terminator. Paul Howlett
Live sport
Cycling: Tour de France noon, ITV4. Day four, featuring a journey from La Baule to Sarzeau.
Women’s ODI cricket: England v New Zealand 12.30pm, Sky Sports Main Event. Second in a three-match series.
World Cup football 6.30pm, BBC1/ITV. The first semi-final, featuring two teams from what is being called the “tough” side of the draw.
