It is easy to imagine that there are a lot of people who started Stephen Hawking’s "A Brief History of Time" with great enthusiasm only to find it too hard going to complete. The fact that it may be too advanced for many to understand is acknowledged by Hawking in the introduction to his sequel, "The Universe in a Nutshell". This sequel covers similar ground to the first book but has been updated to include all the subsequent developments and breakthroughs in theoretical physics from 1988 to 2001. The main difference, however, is that this time his text is lavishly illustrated by a myriad of full-colour illustrations by Moonrunner Design and The Book Laboratory. Hawking intended that these images and diagrams will make the book much more accessible to the lay reader. A sound approach in concept and the illustrations are well drawn and clever, but those expecting an easy ride will find that they will still need their thinking caps in place to get to grips with the amazing theories presented in this book.

After a gentle start with Einstein's theory of General Relativity, the second chapter, "The Shape of Time" will have the reader wrestling with some Quantum Theory favourites such as Feynman's "Multiple Histories" theory and Heisenberg's "Uncertainty Principle". The fact that in the quantum world, we cannot accurately measure the position & velocity of a particle at the same time seems illogical in comparison to the larger world we experience. It also seems counter-intuitive that the "ground state" or lowest possible energy of quantum systems is not zero. This means that even a vacuum has energy! Quantum Theory is littered with such unbelievable notions and Hawking rattles off an array of amazing statements in his usual authoritative and matter-of-fact fashion.

This brings us to a criticism that some have made about the book. Hawking may do a good job of describing complex theories but some are short of proper explanations. In this case, all the layman can do is take his statements as read. The difficulty with modern advanced physics is that a lot of theories are based on possible solutions to complex equations and cannot be demonstrated by physical experimentation. I would imagine that Robert Hooke, the genius 17th-century curator of experiments for the Royal Society, would be very dismissive of all the theories which could not be proven by any experimental apparatus he could contrive. In this book, it is the job of Hawking's mathematical constructs (such as "Imaginary Time") and the excellent illustrations to explain the theories and convince us of their validity. Notwithstanding, you might still find yourself asking "Why?" quite a lot. If some explanations are lacking you will have to adopt the "Anthropic principle" where things are as they are because they have to be "for the universe to exist in such a way for galaxies to form and the human race to evolve and experience it"!

Kudos must go to Moonrunner Design and The Book Laboratory whose extraordinary images and diagrams really help to put the concepts across. If you tried just reading the text of a chapter and then re-reading but taking time to study the pictures as well you would appreciate how effective they are in aiding your understanding. Listeners to the audiobook version will be missing out without also having a hard copy to refer to! I will no longer be able to think of the "spin" property of an elementary particle without recalling the illustration that compares it to a set of playing cards. Hawking explains that "M-Theory", which seeks to unify all the different versions of superstring theory, needs nine or ten dimensions to work properly. The text tells us that we cannot perceive the extra dimensions because they may be "small and curved". That seems like a bit of an obscure statement until you consider the illustration of a drinking straw in a glass. Close up, the straw is a three-dimensional cylindrical shape with open ends. However, if you were to view it at a distance, say the drink is resting on a bar counter at the far side of the room, then the straw would look like a simple one-dimensional line. It obviously hasn't "lost" any dimensions, it's just that we cannot perceive its full three-dimension shape from a distance.

Subjects such as “relativity”, “the speed of light”, and “black holes” hold great fascination for many people and reading an authoritative, well-presented and richly illustrated book like this is a great way for the layman to learn about them. Science never stands still and this was written over twenty years ago so many theories presented here will have developed in the meantime. Nonetheless, this book remains a compelling read and a good starting point for further studies.