There are two themes this year: one is communication, but that is not so important, because the really big thing is DNA. The molecule of life is one of the most significant discoveries of the past century and as the decades roll by it can only increase in significance . We now know the ‘junk’ DNA that was discovered by the Genome Project was not junk at all, but an integral part of the workings of the body, controlling the switching of genes on and off.

We are becoming aware that the hinterland of our DNA – our close environment, our diet, our emotional state – affect the way genes are expressed. We are coming close to knowing exactly how, when and why that is the case. DNA is a strand throughout the Festival. Meanwhile, communication – our other theme – is what we do to put the message across. But the hinterland of our communication – our close environment, our diet, our emotional state – affects what we hear and whether we believe it. That is a good thing; we can’t just accept what we hear, but must (in the words of the Royal Society’s motto) take nobody’s word for it.