The Trouble With Physics

Review by Andrew Crumey

Published in Scotland on Sunday

The Trouble With Physics
Lee Smolin
Allen Lane, £20

The trouble with physics, Lee Smolin claims, is that it has made remarkably little real progress in the last thirty years. Given that we constantly hear of major new breakthroughs on the road to an ultimate theory of everything, this may sound like the carpings of a crank. But Smolin is a leading player in theoretical physics, known to the wider reading public through two previous, outstanding books. He has to be taken seriously, and his assessment is a grim one.

In the nineteen seventies, Smolin explains, physicists perfected the so-called “standard model” which explains how particles called quarks and leptons combine to form the familiar atoms of matter. The theory was triumphantly vindicated in particle accelerator experiments, but the one force still left unexplained was gravity. What has been going on since then has been a worldwide attempt to explain how quantum particles make things fall down.

The search led to conjectures that our universe has more dimensions than three, and that matter might really be made of tiny “superstrings”. But as Smolin emphasises, these remain conjectures. Despite acres of overheated coverage that have appeared in popular science magazines and documentaries, there remains not one shred of hard physical evidence for superstrings, supersymmetry, extra dimensions, parallel realities, and all the other wonders that feed science fiction with an endless supply of useful jargon.

Nevertheless, despite lacking evidence, superstring theory has taken over as the number one research topic for physicists around the world. Smolin says that if you want to get a job in a university theoretical physics department, you have to work on superstrings or its even more hypothetical successor, “M theory”.

The picture he paints will be of interest to academics in other fields who have seen similar take-overs by modish theories. Physicists themselves seem aware of a fundamental change in their subject: in Harvard it became fashionable to speak of “postmodern physics”, with “mathematical beauty” considered the essential mark of validity in the absence of anything more concrete.

The downside of Smolin’s book is the amount of time he takes explaining details of a theory in which from the outset he expresses doubts, lessening the reader’s willingness to unpick the technical minutiae. Anyone who has struggled with more optimistic accounts of string theory written by true believers will have a hard time here.

More interesting to a general audience is Smolin’s account of possible alternatives to string theory, which a few brave souls (Smolin included) are pursuing in the academic wilderness, while all the big research grants go to the string people. He offers sensible advice on how the system might be improved so that young researchers are less dependent on the patronage and approval of older scientists eager to see their own ideas vindicated. Einstein had trouble finding a job one hundred years ago – Smolin says he would have an equally hard time now, since the dominance of string theory favours virtuoso problem solvers rather than deep thinkers.

Recently, though, it seems that even the string theorists have begun to have doubts, having managed to find more potential “theories of everything” than there are atoms in the universe, with no way of choosing which one might be right. History may look back on string theory as an intellectual triumph or a thirty-year mistake. Only time will tell.