The Grand Design

Stephen Hawking is not only, without question, one of our greatest surviving physicists, but also, remarkably given his disability, one of the field’s great communicators and educators. Having enjoyed his previous writing I was very much looking forward to his insights on the cosmological advances since A Brief History of Time. However, although this latest book is both entertaining and thought provoking, it ultimately left me frustrated with its failure to properly explain these new scientific concepts.

This is a small and unthreatening book, especially in the Bantam edition, and nicely put together with some apposite cartoons and a series of chapter endplates which develop a recurring graphical theme in multiple contexts. However, in contrast to previous books, especially The Universe in a Nutshell, it’s very light on genuinely explanatory diagrams and equations, forcing the user to try and comprehend complex physical and mathematical concepts from purely textual explanations.

The first third of the book deals mainly with the evolution and nature of scientific “laws”, and the meaning of reality relative to our various mental models. This is very interesting, but perhaps a little ironic given the authors’ statement on the first page that “philosophy is dead”. What other label should be attributed to this discussion?

The next section explains key aspects of quantum theory, in particular wave/particle duality, probabilistic rather than deterministic behaviour, and the effects of observation on the system. That we can now demonstrate this behaviour for relatively large objects, and affect the observed outcome from behaviour originating some considerable time before the observation, is fascinating.

Since Newton science has developed a series of theories describing the workings of our universe, and has then attempted to combine or extend them to provide an ever more comprehensive description. The next section of the book describes this progression. The descriptions of classical physics, relativity and quantum theory are fine, and don’t suffer too much from relative brevity as the older theories will be broadly familiar to most readers. However the pages on M-theory are really too brief, and don’t adequately explain it. Finishing that section with the fact that M-theory admits 10^500 solutions makes it sound very far from the elegant theories espoused earlier in the book.

The final section of the book attempts to describe and explain some of the most problematical aspects of current cosmology, but in my view doesn’t make a very convincing job of it. Cosmological problems include both the fact that universal expansion is still accelerating, and that our current model requires the young universe to have spontaneously “inflated” from coin-sized to many times galaxy sized in less than a second. Neither of these are well explained by current theories as I understand them, and this book doesn’t bridge the gap. Earlier in the book the authors pooh-pooh theories relying on “then a miracle occurs”, but don’t seem to be proposing something much better.

Instead of proposing a theory which explains the observations, the authors seem to be saying that under M-theory all things are possible, and we choose the set of outcomes which matches our measurements. To my mind this is perilously close to saying “God created the Universe as it is”, even though the authors are at pains to refute precisely that interpretation.

It feels to me that Physics is on a threshold similar to its position in the late 19th Century, where we are creating progressively more arcane versions of existing theories in an attempt to prop them up, but what is really required is fresh new ideas – the 21st Century equivalents of Relativity and Quantum Theory. This book confirms that need, but its suggested resolution does not convince me.