Keats complained that a mathematical explanation of rainbows robs them of their magic, conquering "all mysteries by rule and line". But rainbow geometry is just as elegant as the rainbows themselves.

It's 21st of October and for puzzle lovers this can only mean one thing: the G4G Celebration of mind. This annual party celebrates the legacy of Martin Gardner, magician, writer and father of recreational maths, with mathemagical events in his honour happening all over the world.

This year's Nobel Prize in Physics was awarded for a discovery that proved Einstein wrong and right at the same time.

What makes a perfect football? Anyone who plays or simply watches the game could quickly list the qualities. The ball must be round, retain its shape, be bouncy but not too lively and, most importantly, be capable of impressive speeds. We find out that this last point is all down to the ball's surface, the most prized research goal in ball design.

If you manage a large organisation, then people will come and go. There are always decisions to make about promoting people, promising newcomers versus experienced middle managers, all of whom are aspiring to move up the corporate ladder. But is it better to promote the least competent rather than the most competent? Some new research suggests that it may be.

Why can we remember the past and not the future? Why does time appear to move in only one direction when the laws of physics have no preferred direction in time? According to one physicist, it might be because we live in a bubble multiverse.

According to Einstein, the past, present and future have exactly the same character - so why do we feel that there is a particular moment we call "now"? The physicist George Ellis looks for an answer in the curious laws of quantum mechanics.

Looking out to Canary Wharf, to the arch at Wembley Stadium, and down onto the Gherkin, the 700 people working on the construction site of the Heron Tower in London had one of the best views in London. Plus was lucky enough to speak to two engineers involved in building the tower and asked how maths was involved in the construction of such an impressive addition to the London skyline.

Convex or concave? It's a question we usually answer just by looking at something. It's convex if it bulges outwards, and concave if it bulges inwards. But when it comes to mathematical functions, things aren't that simple. A team of computer scientists from the Massachusetts Institute of Technology have recently shown that deciding whether a mathematical function is convex can be very hard indeed.