In the 1930s the logician Kurt Gödel showed that if you set out proper rules for mathematics, you lose the ability to decide whether certain statements are true or false. This is rather shocking and you may wonder why Gödel's result hasn't wiped out mathematics once and for all. The answer is that, initially at least, the unprovable statements logicians came up with were quite contrived. But are they about to enter mainstream mathematics?

Many things make a noise when you hit them, but not many are commonly used to play music — why is that? Jim Woodhouse looks at harmonic and not so harmonic frequencies and at how percussion instruments are tuned.

It's been nearly 18 months since the Large Hadron Collider at CERN started up and scientists are eagerly awaiting their first glimpse into the cosmic mysteries it was designed to explore. But when can we realistically expect the first ground-breaking discoveries to come through? Last week, John Ellis, outgoing leader of the theory division at CERN, addressed an audience of physicists at the University of Cambridge to update them on the current state of play. Plus went along and also managed to catch Ellis for a quick interview.

Many people like mathematics because it gives definite answers. Things are either true or false, and true things seem true in a very fundamental way. But it's not quite like that. You can actually build different versions of maths in which statements are true or false depending on your preference. So is maths just a game in which we choose the rules to suit our purpose? Or is there a "correct" set of rules to use? We find out with the mathematician Hugh Woodin.