Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law [Hardcover]

This came out the same year that Lee Smolin's The Trouble with Physics (2006) and it carries the same message, namely that particle physicists need to move away from string theory because it is beginning to look like it isn't valid science. The main point in both books is that after two or three decades of work on string theory--or superstring theory, M-theory, brane theory, etc.--string theorists are unable to make any predictions that can be scientifically tested.

The deep problem for the reader of either book is that only particle physicists themselves can know whether progress is being made. For the rest of us we have to accept what they say on--dare I use the word?--faith. Without empirical support string theory is, as Woit has it, "Not Even Wrong" (the phrase is from Wolfgang Pauli).

The Preface and the first two chapters up to page 29 are eminently readable and interesting. Starting with Chapter 3 "Quantum Theory" the book becomes difficult and continues to be more than challenging until Chapter 13 "On Beauty and Difficulty" beginning on page 193 where it becomes readable again. The problem? With or without mathematics it really is impossible to make particle physics understandable to a general readership. Woit tries to make QM and string theory clear without equations and I give him credit for trying. But it is the nature of modern science but especially of something like particle physics that it is impossible to really grasp the subject without years of study.

Perhaps the beginnings of trouble for particle physics began in May, 1963 when P.A.M. Dirac famously said "It is more important to have beauty in one's equations than to have them fit experiment." (p. 195) This view, shared in some respects by Einstein, is the source of the problem today. While it turned out to be true that some mathematical equations that came before experimental support back in the grand old days of physics proved to be valid many did not. And of course it was understood that experimental support would have to follow otherwise the beautiful math would have to be put aside as wrong, arbitrary or perhaps not even wrong. The interesting thing about the equations in string theory, according to Woit, is that they are not beautiful. (p. 196) I would hasten to point out that beauty is indeed in the eye of the beholder and such claims really get to the heart of the matter: without experimental proof or predictive power, it really doesn't matter from a scientific point of view whether the math is all that beautiful or not.

Woit goes into the politics and economics of present day particle physics with his main point being string theorists control access to all the good jobs and that furthermore once you're on the string theory path it is hard to get off because of the enormous commitment in terms of time and energy required. So those people in string theory tend to support the theory despite its lack of empirical support because it is their livelihood and they have almost nowhere else to go because as Woit says, "It's the only game in town" (see Chapter 16). Woit compares string theory to postmodern theory in its arrogance saying that "In both cases, there are practitioners that revel in the difficulty and obscurity of their research, often being overly impressed with themselves because of this. The barriers to understanding what this kind of work entails make it very hard for any outsiders to evaluate what, if anything, has been achieved." (p. 202)

The title of the next chapter is "Is Superstring Theory Science?" and Woit's answer is no. He writes, "...superstring theory is at the moment unarguably an example of a theory that can't be falsified, since it makes no predictions." (p. 207) I would add that this is similar to so-called Intelligent Design, another "theory" that fails because it can't be falsified. This in a nutshell is why string theory is not science. Here is the situation: you have a "theory," an edifice of equations and ideas about reality. You have an insulated and esoteric cadre of high priests who are the only ones that have access to this "knowledge," and you have to take their word for it being true since they can't prove it. Maybe it is true, maybe it isn't. Maybe God did part the waters and maybe the Pope really is infallible in certain matters. But without experimental support none of this is science.

Woit goes on to remind us of "the Bogdanov affair" in which some string theory mumble jumble got past some peer review journal editors. This sort of thing, reminiscent of the Sokal Hoax from a few years back, suggests that things are indeed getting lax in the same way that postmodern literary journals can be lax since so much of what is expressed is either arbitrary or simply a matter of opinion without any sort of scientific rigor.

Woit even cites an anonymous scientist as saying that there is a string theory "mafia" in charge of the physic departments in our prestigious universities (p. 223). On the next page he has an "excitable" "Harvard faculty member" say that "those who criticized the funding of superstring theory were terrorists who deserved to be eliminated by the U.S. military." Woit adds, "I'm afraid he seemed to be serious about this." (p. 224)

I have read books by renowned physicists Leonard Susskind and Brian Greene in which they come out strongly in support of string theory and hopeful that it will someday gain some experimental proof or be formulated in such a way that predictions can be made. But to be candid I feel they are in the unfortunate position of people who have to justify a lifetime of work otherwise admit that they might have better spent their time in other pursuits. The cognitive dissonance they face is difficult to resolve even for august scientists. Richard Feynman is quoted on page 246 as saying, "String theorists make excuses, not predictions."

Okay why does this really matter? It matters because this unscientific approach from string theory gives aid and comfort to not only postmodernists who believe that all of science is merely a social construction but also to creationists who can now claim that string theory and their intelligent design theory are similar in that neither one is falsifiable. If this is the case, by what authority do we choose one and not the other? In other words, a non-falsifiable string theory is a retreat from science into something akin to religion.

From a marketing standpoint, it's probably a pity that Dr Woit has targeted this fairly technical book at a non-technical audience, and that he has included discussion about the failure of string theory. The first section is focussed on explaining mainstream solid particle physics, and this gets fairly abstract in places, but it contains some deep physical insights about the handedness of the weak force, the problems of the Standard Model, and so on that you won't easily understand from any other book. The second half is focussed on the failure of string theory, which is very upsetting because those guys keep hyping abject speculation based on wishful thinking and "groupthink must be right" arrogance.

However, no real harm is done. You can easily skip over the quotations from Richard Feynman, Sheldon Glashow, Gerard 't Hooft and many others attacking string theory for being non-falsifiable religion, and learn about the basic concepts behind the maths of quantum field theory.

Then you can easily find more technical material as you need it. The author has some more mathematical stuff on his university home page, and the book has extensive references for further reading.

The book makes you familiar with the basic way in which gauge symmetry works and how it connects to particle interactions. A Lagrangian equation is written to describe a field, a path integral is then used to evaluate the action of that Lagrangrian. In practice the path integral, which sums over all possible ways an interaction can occur in spacetime, is expanded into a series of terms each being a power of the strength or coupling constant of the force determining the interaction. Each term in the expansion then represents one member of a set of increasingly complicated types of interaction, which can be pictorially illustrated by a Feynman diagram. Evaluating the sum of the series of terms enables you to work out reaction cross-sections, corrections to the magnetic moments of leptons, or whatever you have set up the Lagrangrian to achieve.

After reading this book, if you have also had some exposure to the kind of maths used in quantum mechanics and general relativity, you are ready to begin studying books like Ryder's "Quantum Field Theory".

This is clearly an important book - it is a critique of String theory, which has apparently failed to produce verifiable predictions in the quarter centuary since the establishment of the standard model. But it is very difficult to evaluate the truth of the author's arguments.

The author argues that particle physics has gone down a blind alley. There are an infinite number of possible string theories, with the very few predictions the theory actually makes, disagreeing with experimental results. Additionally, because String Theorists hold the tenured positions at the heights of academic physics, they are able to ensure that this is the only game in town.

From the negative review on this page, it is clearly a controversial argument.

Following his descriptions of the maths of string theory requires a lot more than my (Engineering degree level) maths, and it does not read as well as Fermat's Last Theorem for the interested lay reader. Given the difficulty of the subject (and string theory requires post doctoral research for physicists to achieve an acquaintance with the subject) the author does write a readable book. (At least, I finished it, and managed to follow the main arguments, even if I didn't understand the maths being referred to.)