The Trouble with Physics: The Rise of String Theory, the Fall of a Science and What Comes Next
by Lee Smolin
Penguin Books₤25, 416 pages
FT bookshop price: ₤11.99

The small but intellectually superheated world of theoretical physics is in danger of being torn apart by a schism equal to anything seen in religion or politics. On one side is the establishment: senior academics and their acolytes who espouse a 30-year-old view of the universe - string theory - which has been promising without much success to provide the much-anticipated “theory of everything”. Nobel prizes all round for the individual or individuals who manage to solve that conundrum.

On the other side are the radicals - an increasingly vocal minority who argue that the pursuit of string theory is wrongheaded. Their reasoning is twofold: first, the theory has failed to throw up a single prediction that can be tested by experiment; second, it is damaging the fabric of publicly funded science by excluding those who refuse to subscribe to its beliefs and by stifling more promising lines of investigation.

String theory is in no way intuitive. It holds that the fundamental particles in nature are minute entities or strings whose various modes of vibration give rise to all the myriad particles we have come to recognise from experiments with high-powered atom smashers. The theory is a mathematical construct and requires many more dimensions than the three of space and one of time we know. Nevertheless, it holds out hope of solving many of the problems that bedevil particle science today.

The Trouble with Physics is one of a pair of books (the other, Not Even Wrong, by Peter Woit, was published last year) that set out to explain why the authors believe string theorists have been on the wrong track. Both are concerned that a new barbarism is entering the field, so individuals who fail to agree with or question the wisdom of string theory are ignored or treated with contempt.

Academics can be bitchy and protective of their own ideas. But Woit and Lee Smolin complain that a new nastiness is pervading theoretical physics, so that anybody who challenges string theory risks derision. It has become a world where only the disciples of string theory can hope for research grants or university tenure.

Smolin, a highly regarded theoretical physicist who, earlier in his career, made valuable contributions to string theory, has written essentially two extended essays that are somewhat awkwardly joined at the hip. In the first, he outlines the recent history of particle physics, the emergence of string theory and his reasons for believing that it is more blind alley than true path. The second section is a reflection on the state of physics today and a lament for a more reflective era grounded in physical phenomena: “What I believe is failing is not so much a particular theory, but a style of doing science that was well suited to the problems that we faced in the middle of the 20th century but is ill suited to the kinds of problems we face now.”

Neither section is entirely satisfactory. Smolin gives a clear, concise account of both the development of the “standard model” of fundamental particles and how they interact, and the failure of Einstein’s general theory of relativity to be reconciled with quantum mechanics. But it is an account for those well versed in particle physics rather than the general reader. This is perhaps inevitable. These ideas are complex, heavily technical and depend on some of the most esoteric mathematics scientists have ever devised. Smolin avoids the maths but relies on considerable understanding among readers.

The second section, dealing with the “sociology” of physics, is easier. Smolin adopts an anecdotal approach to illustrate many of the problems that infest science higher education in the US and elsewhere. He fails, for example, to persuade Harvard University to allow him to teach a course in undergraduate quantum mechanics, with the dean of arts and science commenting: “If we let every professor teach what they wanted to, we would have educational chaos.”

Smolin makes telling points, but at too much length: his 16-page introductory section (excerpted in these pages last week) is probably enough for the lay reader. Separate monographs dealing with the failure of string theory and the state of science today would have been more accessible and digestible.

It could be easy, but wrong, to see this book as the outpourings of a scientist sidelined and bitter that his favourite idea - in Smolin’s case, quantum gravity - had been rejected by his peers. Smolin is unfailingly courteous and respectful to other scientists, whether on his side or not, and his message is hard to reject: “There needs to be an honest evaluation of the wisdom of sticking to a research programme that has failed after decades to find grounding in either experimental results or precise mathematical formulation. String theorists need to face the possibility that they will turn out to have been wrong and others right.” Which is precisely what the best scientists have always done.

Alan Cane is the FT’s senior technology correspondent.