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In More or Less, there is great excitement over rumours that one of the predictions Einstein made in his theory of General Relativity has finally been observed. But it’s not the first time it’s been reported that ‘gravitational waves’ have been discovered, and the last time proved to be an equipment test.

What is the total number of possible tweets that could be created from 140 characters? In a recent programme Professor John Allen-Paulos told us that when you take into account all of the symbols available, the total number of possible tweets is Googol^2.8 (which is a 1 followed by 280 zeros.) But has he missed some options?

In ³ÉÈË¿ìÊÖ Trending, two stories about rape in South Africa; one about a woman who posted about her experience on Instagram to find people didn’t believe her and another which gripped the nation butwas totally made up. And why are people so upset about a statue of the British colonialist Cecil Rhodes at Oxford University? We hear from the students who want it taken down.

In the Why Factor, Angie Hobbs asks why do we want or need heroes? What constitutes a heroic act? Is it something you set out to do, or something you don’t choose, but live up to when it’s thrust upon you? And why do societies celebrate heroism? Professor Hobbs talks to people who’ve been hailed as heroes: Colonel Tim Collins who gave a much praised eve-of-battle speech to his troops as they were about to enter Iraq in 2003, Justin Oliphant who tackles gang violence in South Africa and Dame Ellen MacArthur who broke the record for solo round the world sailing.

(Image: A photographer looks at the sky at night to see the annual Geminid meteor shower on the Elva Hill, in Maira Valley, near Cuneo, northern Italy on December 12, 2015. Credit: AFP / Getty Images)