The Lightness of Being, By Frank Wilczek

So, Mr Physicist, you say your theories are truly, deeply fundamental. Tell me: why is there something rather than nothing? Frank Wilczek has his answer. Funny you should ask. Just lately, we have been glimpsing a new way of tackling that question. It turns out that nothing is really a kind of something.

That notion lies at the heart of this book about what lies at the heart of things. Wilczek, a Nobel winner who roams the frontier where physics shades into metaphysics, takes his reader on a search for the origin of mass, hence of matter. Most of us have got the news that atoms are not the building blocks of matter. Show them enough violence and they are divisible, contingent, prone to decay and recomposition. Inside are more tiny things - electrons, protons, neutrons and, revealed more recently, quarks.

But these particles, though called elementary, are not the fundamentals of stuff either. They arise from the properties of space. What lay people think of as empty space is actually, at the ultrananomicroscopic level, a continual churning of fields and forces, of energies in tension, which manifest themselves as matter.

Wilczek unfolds this theoretical tale from relativity and quantum mechanics, and the long effort to unite them. In his story, the dream of a single framework for all physics is almost realised. It ends with a distant descendant of the ether, the ineffable stuff which 19th-century physicists believed pervaded empty space. Wilczek's ether is a highly structured affair, imbued with complex symmetries. He calls it the Grid, to convey the rule-governed regularity of this "multilayered, multicoloured superconductor". The Grid may also harbour something called supersymmetry, a so far imaginary property which implies the existence of a complete new set of elementary particles.

Wilczek has high hopes that the great new particle accelerator in Geneva, the Large Hadron Collider, will find evidence they actually exist. If so, he sees physics entering a new golden age.

The results from Geneva, when they come, will test the soundness of the top storey built on this beautiful castle of theory. Meanwhile, a popular science book has some other hard tests to pass. The abstruse mathematics of physical theory stretch the limits of English. One of the cover endorsements - all from fellow-physicists - describes the book as "mind-stretching". True, but is one's mind stretched far enough to really grasp the point?

That is a test of explanatory skill. Well, two tests. One is that you feel you vaguely understand what is going on while you are reading. Wilczek passes that, most of the time. There are moments of astounding lucidity, and some moderately good jokes. There is an appealing sense that striving to develop these theories is more than high-level fun for the gifted, but really matters, and a heady whiff that part of what matters is aesthetic. There is certainly an intellectual adventure, and you get an idea where it might be headed.

The second, harder, test is when you put the book aside and explain the theory to someone else. That can mean just parrotting what the author says. Better still, you make it your own to some extent. For that, you have to believe it. Some of the many books on the famous superstrings can do this - though they are much longer than this one. Wilczek's briefer effort sometimes compresses too much explanation into too few pages, takes too much for granted. The result is probably a book for people who already believe, not those who need more careful persuasion.

Jon Turney is writing 'The Rough Guide to the Future'