Although described as a Ladybird book for adults, and published by Ladybird (part of the Penguin Random House group), and labelled 'A Ladybird Expert Book', It is so brief that I'm not sure quite what it comes under. The content is far from easy for the layman, but it also very superficial. I suppose it might be the sort of thing to give one a vocabulary before moving on to another, slightly more detailed introduction, such as Oxford's Very Short Introduction series. But they are about 130 pages, this is about 26 pages of text. Having said that, Jim Al-Khalili is a good guide, who writes as clearly as the subject allows.