The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next

Smolin's book "The Trouble With Physics" is a very candid account of what the author percieves to be "wrong" with physics as it is being practiced in today's large research universities. Smolin's writing is clear and matter-of-fact. Although he makes his opinions known he is not demeaning to those with whom he disagrees, which makes the polemic all the more effective. Smolin takes aim at the current diadem of theoretical physics research, String Theory, and attempts to shed light on the true nature and promise of the theory. Smolin's main thesis is that String Theory, and the culture that has grown up around it, is essentially stifling theoretical physics. He shows that string theory has produced no unique, testable predictions and that recent developments in the field suggest that there may be as many as 10^500 different string theories thus making it unlikely that the theory could ever be falsified (for perspective, it is estimated that there are 10^80 atoms in the entire universe). Essentially what this means is that string theory can be taylored to fit any experimental data and, thus, can never be proven wrong. Smolin argues convincingly that String Theory is not even really a theory in the scientific sense. It is more of "hunch" or a "conjecture". That is, while some of the consequences of the theory have been ascertained, the mathematical structure of the theory remains largely unknown. Furthermore, no one really has any idea of what the overall structure might look like, or how it might be rigorously developed. As a result, hundreds of millions of research dollars are being poured into the elucidation of a project which has made no unique testable predictions, offers no practical applications, and in which only one person (Ed Witten) has made any truly significant advances over the past 15 years. In spite of all this, what I found most interesting was the pure dysfunctionality of the physics community. The ideological bickering, and the petty struggles for power and prestigue are pretty ironic considering that that hot-shots of the physics community often consider themsleves to have reached the very pinnacle of rationality. It's kind of sad really, and perhaps unavoidable in a situation where certain people are given so much power and authority. But, Smolin believes it can be better than it currently is. I believe that he is right and hope that people in positions of power at our major research universities will take his criticisms to heart.

I have a PhD in theoretical physics so this can be regarded as an insider's review. But before that I need to digress a bit... The other day I was watching a re-run of the BBC "science" program "Parallel Universe" on TV and I found myself so furious about what's being shown that I shook my head repeatedly and even cursed at the TV more than a few times. The reasons I was furious are: 1. The utterly shameless (to the point of immoral) promotion by string theorists (Kaku, Rendall and the usual suspects) of string theory as the Theory of Everything that explains everything (including the Big Bang!), despite the fact that string theory explains precisely NOTHING in REALITY (the "explanations" only work inside the fantasy worlds of string theorists). 2. The presentation of the outrageous fantasies and speculations of string theorists as scientific facts. This is especially unforgivable, because a respectable media company like BBC has the responsibility to clearly distinguish between fact and speculation in their science programs. It's like showing a science program on modern medicine and then interviewing witch doctors as though they're the authorities! 3. The air of superiority, arrogance and blindness displayed by string theorists, who seem to think that their utterly unproven (and unprovable) theory is absolutely correct and nothing can contradict it, not even reality itself. And if reality doesn't seem to fit their mathematics (e.g. there is ZERO PHYSICAL EVIDENCE of 11 dimensions, branes, parallel universes and ANYTHING that string theory proposes), then reality must be wrong! It is really amazing to me that these seemingly brilliant people (string theorists) have absolutely no intuition in physics, and only blindly followed their mathematics (and string guru's like Ed Witten), even though their mathematics is clearly leading them into dead-end after dead-end after dead-end. Mathematics alone should never be allowed to dictate the directions in theoretical physics. We've seen time and again in the history of physics that when mathematics is allowed to dictate a theory without the checks and balances allowed by physical evidence and intuition, the result is always a dead end. This is a lesson that must be learned. That's why I'm very glad that this book by Smolin and Not Even Wrong by Woit finally came out. I hope that these books can serve as wake-up calls that would finally lift the wool of mathematical fantasies and speculations that has been pulled over our eyes by string theory for the last 30 years. We have already lost a whole generation of brilliant young physicists to string theory, something must be done now if theoretical physics is to save itself from self destruction in the hands of string theory. I fully agree with Smolin that if we're to save theoretical physics, we need to nurture more "seers" (thinkers) in physics, who do not follow blindly the fads and fashions in physics, but instead try to examine the very foun

The part of the book I found most interesting was the part which tells how the string theorists were scammed by Nature (or Mathematics). Of course, Smolin doesn't put it exactly like this, but imagine the following conversation. String theorists: We've got the Standard Model, and it works great, but it doesn't include gravity, and it doesn't explain lots of other stuff, like why all the elementary particles have the masses they do. We need a new, broader theory. Nature: Here's a great new theory I can sell you. It combines quantum field theory and gravity, and there's only one adjustable parameter in it, so all you have to do is find the right value of that parameter, and the Standard Model will pop right out. String theorists: We'll take it. String theorists (some time later): Wait a minute, Nature, our new theory won't fit into our driveway. String theory has ten dimensions, and our driveway only has four. Nature: I can sell you a Calabi-Yau manifold. These are really neat gadgets, and they'll fold up string theory into four dimensions, no problem. String theorists: We'll take one of those as well, please. Nature: Happy to help. String theorists (some time later): Wait a minute, Nature, there's too many different ways to fold our Calabi-Yao manifold up. And it keeps trying to come unfolded. And string theory is only compatible with a negative cosmological constant, and we own a positive one. Nature: No problem. Just let me tie this Calabi-Yao manifold up with some strings and branes, and maybe a little duct tape, and you'll be all set. String theorists: But our beautiful new theory is so ugly now! Nature: Ah! But the Anthropic Principle says that all the best theories are ugly. String theorists: It does? Nature: It does. And once you make it the fashion to be ugly, you'll ensure that other theories will never beat you in beauty contests. String theorists: Hooray! Hooray! Look at our beautiful new theory. Okay, I've taken a few liberties here. But according to Smolin's book, string theory did start out looking like a very promising theory. And, like a scam, as it looks less and less promising, it's hard to resist the temptation to throw good money (or research) after bad in the hope of getting something back for your effort. One of the questions Smolin addresses in the rest of the book is why the theoretical physics community has kept with string theory and largely abandoned all the other approaches to quantum gravity. The short answer is that it's hard to admit that you've been scammed. The long answer is much more complicated. Another thing Smolin addresses in the book is other approaches to quantum gravity. And as could be predicted, he gives lots of space to his own approach and too little space to others, especially Alain Connes' non-commutative geometry. But overall, I found it very worthwhile and entertaining, and a good explanation as to how theoretical physics came to be in the state it is today.

Fundamental physics has been exceedingly successful for over two centuries. The rapid advances in our understanding of natural laws in the first three quarters of the 20th century were just as breathtaking as those in microchips or hard drives in the last. But this progress came to a screeching halt 30 years ago. There has been no real progress since the establishment of the standard model. To observers outside of the physics community, this fact is far from obvious. Theorists in fundamental physics continue to make announcements on new ideas and results. Books are written and TV shows are made to trumpet the progress in string theory. Many models based on string theory are taken and marketed as facts. As years and decades go by and waves of string theory "predictions" are repeatedly superceded by new, incompatible ones, doubts begin to grow in the minds of knowledgeable outsiders. How can a "theory of everything" that completely describes an "elegant universe" keep contradicting itself on issues as basic as the dimensionality of spacetime? How can the string theorists be so sure of what happens at 10^19 GeV while being totally silent on the physics just beyond the standard model at 10^3 GeV? How can 30 years go by and nothing in particle physics theory is remotely Nobel-worthy? How can the two most important experimental results (non-zero neutrino masses and a positive cosmological constant) catch string theory by such surprise? Inquiries regarding these and many other suspicious signs are stonewalled by string theorists. The person who raises the issue is inevitably called ignorant, stupid, malicious, anti-science or all of the above. There are just too many beautiful results in string theory to be explained by coincidence, we are told. String theory is just too vast and too deep for human to comprehend easily, they assure us. Trust us, they say, this is not a case of "it is difficult to get a man to understand something when his job depends on not understanding it". But they did not address any of the questions. Worse, the list of questions grows longer by the year. Is the universe a 4-dimensional brane floating in the extra dimensions or a glorious 10-(should it be 11 now?)dimensional spacetime with 6 of the dimensions curling up? Why 6 and not, say, 7? If there are countless numbers of ways to curl up the extra dimensions, does each way correspond to a string universe? All these universes cannot be real at the same time, can they? As the string story gets stretched thinner and thinner, so is its credibility. After it became increasingly clear that string theory would never be capable of making any meaningful predictions, the final straw, for many objective observers, finally fell when a large faction of string community pushed for the wholesale adoption of the Cosmic Anthropic Principle, an erstwhile anathema of modern science. String theory is too important, they claimed, to be bounded by conventional scientific principles, very much t