THE SECRET GENIUS OF MODERN LIFE

BBC2, 8pm

Professor Hannah Fry, right, delves into the inner workings of virtual assistants such as Alexa, which are now in almost half of all UK homes.

At London’s Amazon HQ, she is shown the original sketch of an Alexa that founder Jeff Bezos scribbled on a white board. Then she takes a screwdriver to the device to work out what’s going on inside.

She reveals how noisy Second World War German U-boats inspired the high tech microphones that allow them to hear our commands and there’s a tale of how the defeat of chess legend Gary Kasparov by supercomputer Deep Blue shaped Alexa’s brain. Hannah also asks if Alexa is always listening – and learns that she is certainly trying to...