BOOK REVIEW / All that glitters is not weightless gold: Fear of Physics - Lawrence M Krauss: Jonathan Cape, pounds 16.99

PHYSICISTS are a funny lot. They explain to us what holds the world together, why rubber ducks don't sink in the bath and why apples drop from trees. They tell us how an electron travelling faster than light might just as well be travelling backwards in time or be three elementary particles, two of which have appeared from nowhere. They talk of things that, once observed, cease to exist. And they not only say all this with a straight face - they appear to believe it.

Professor Lawrence Krauss has a talent for explaining complex ideas in simple language, and for conveying his enthusiasm for his subject. Starting with a salutary tale in which a cow is reduced to a sphere for the purpose of simplification, he quickly moves on to quantum mechanics and relativity, explaining on the way why dinosaurs had small heads and how to estimate the number of piano tuners in Chicago.

His primary thesis is twofold: that great ideas come through ignoring the non-essential features of a problem; and that a great breakthrough is not, as is commonly believed, achieved by discarding old ideas, but more often by persisting with them in the face of apparently contradictory data.

Einstein discovered relativity not because he thought Newton was wrong, but because he had the courage to believe he was right: 'I want to leave this as a reminder for anyone who has wanted to use the claim that 'they said Einstein was crazy too]' to validate his or her own ideas.

'What Einstein precisely did not do was to claim that the proven laws of physics that preceded him were wrong. Rather, he showed that they implied something that hadn't before been at all appreciated.'

Despite the book's populist approach, this reader's eyes did glaze over when encountering passages such as: 'What has become the accepted theory of the strong interaction, quantum chromodynamics, in fact should violate both parity and particle-antiparticle symmetry.' Though Krauss lucidly explains all the terms in that sentence, their combined effect is still mind-numbing when joined with an unfortunate tendency to write over-long sentences.

There is a splendid analogy, first suggested by Richard Feynman, that compares nature with a great chess game played by the gods. The goal of physics is to work out the rules just by watching. Krauss returns to that analogy, pointing out the symmetries in the game, the layout of pieces at the start, the colours of the squares, and the invariants underlying the rules for rook and bishop moves. He concludes: 'While I do not claim here that this is any rigorous proof that the game of chess is completely fixed by the symmetries of the board and the pieces, it is worth noting that there is only one version of the game that has survived today. I expect that had there been other viable possibilities, they too would still be in fashion.'

But there are, and they are: Chinese chess is a quite distinct version of the game and in Japan they play by the rules of Shogi, which have been around as long as the western form. Perhaps there are some alternative rules for physics that are just as viable as the ones we use today.

After reading this book, I now feel that with a little more work I would be capable of understanding a wide range of ideas I have long wanted to know about. The odd thing is, I no longer want to know about them. The current rules of physics make me most uncomfortable. I would find it hard to believe an alchemist who told me he could transmute base metal into gold, which was weightless and would disappear if I looked at it, yet I am now informed that: 'Relativity and quantum mechanics imply that particles can spontaneously 'pop' out of empty space only to disappear quickly, as long as they do so for too short a time to be directly measured.' There is something disconcerting about all this. I hope they change the rules soon.