Have you travelled through a rainbow and seen the other side? One reader wrote to our expert Robert Matthews about a childhood experience that had always puzzled him.

Saw this on the BBC Wallace & Gromit's World of Invention programme the other day - you've got to check it out...

There have been wackier ideas suggested to save the planet, but this surely should be near the top of the list. Or should it?

Many glaciers in the Andes are slowly vanishing – 22 per cent of Peru’s glaciers already melted away.

We all know how tiresome it can be when a friend or a relative insists that you look through their entire holiday reel. And with the advent of digital cameras, and with it the ability to take thousands of shots, it’s been worse than ever.

Whenever I go into a bike shop looking for a new helmet, the trainee sales monkey always uses the excellent line of “how much is your head worth?” to which I reply “About £100”.

But on reflection I should be willing to pay a lot more to protect what I think is a fairly useful bit of my body.