Symmetry and the Beautiful Universe – Leon Lederman & Christopher Hill ****
Although it won’t appeal to everyone, as I will explain in a moment, I think it’s fair to say this is one of most valuable popular science books I have ever read. Symmetry is at the heart of much modern physics, but it is generally concealed under the surface, and when it has to emerge, for example when talking about the standard model of particle physics, every book I have ever read on the subject fails to explain the subject properly. This book doesn’t quite make it, but it is by far the closest I have ever seen to a comprehensible explanation.
Nobel laureate Leon Lederman (the man behind the dreaded ‘God particle’ term) and his usual co-author Christopher Hill pack a huge amount of information into this slim paperback. We begin with an exploration of symmetry itself, bring in the laws of physics, meet Emmy Noether in some detail and specifically her concept that each of the conservation laws corresponds to an underlying symmetry. From there Lederman and Hill bring in classical physics, and particularly inertia, relativity, broken symmetry, quantum physics, local gauge invariance and QED, quarks and QCD, the standard model and the Higgs field. It is a huge achievement just how much of this they get in, and how approachable most of it is with a bit of work.
As that suggests, there is a price to pay for the reader. If you are totally equation averse, you will have problems because there are a lot of them. They are always relatively simple and well explained, but the pages are littered with them (which presents a different problem, as we will discover in a moment). This is a book you will have to work a little bit to read, perhaps occasionally re-reading a section to get the full meaning, but it will be so well worth it.
I just have two issues with the book. Although Lederman and Hill almost make the application of symmetry and gauge theories comprehensible there is one huge gap, where the authors say ‘let’s change something to randomly to have any value as we move through time and space.’ They build the whole explanation of gauge theory on this (this is the first book, by the way, I’ve seen that properly explains where that word ‘gauge’ comes in) – yet as presented it makes no sense. They give no reason why we are asked to choose random values, rather than sticking with a smoothly changing value, or making some other arbitrary decision. Because of this there’s a feeling that your understanding is built on sand. There is also a certain weakness in their historical content – they reproduce the myth that Bruno was burned for his scientific beliefs unquestioningly, for instance.
The other issue is the quality of the physical book itself. I am very careful with books when I read them – paperbacks usually still look brand new with no creases etc. But by the time I had reached the end, half the pages had come away from the spine. I can live with that, but worse still, the book seemed not to have been proof read. Any book has a few typos or small errors that slip through. You can’t spot everything. But page after page there were equations where a character (often the multiply sign, or the Greek letter phi) was replaced with a question mark. It made them much harder to read, the last thing you need with equations in a popular science book. I can’t understand how the publisher or the authors could fail to spot such a glaring error at the proof stage.
Nonetheless an important and hugely informative book on a subject that is at the heart of modern physics but has rarely been comprehensibly explained. Recommended.