But today in a thread in the Spirituality forum someone brought up the subject of string theory and I threw in:
QUOTE
I just want to point out that there's a good many people who don't think string theory's all it's cracked up to be; there're even some popular-level (or close to popular-level at least) books out this year that can counter Brian Greene's enthusiastic books, like Lee Smolin's The Trouble with Physics and Peter Woit's Not Even Wrong. Strings need not be the be-all end-all of physics.
Tonight in my late night web-surfing I happened across Woit's recent review of Smolin's book; in many ways it threatens to invalidate my defenses of (and affection for) science--rather, specifically physics (and a specific area of physics at that--but still).
QUOTE
Smolin begins his book by explaining what he (and I) see as the most important fact about the past thirty years of theoretical particle physics research. We’re in a historically unprecedented situation, with virtually no progress being made on the fundamental problems of particle physics for a very long time, despite huge efforts. In his description, the field has “hit a wall”; I like to describe it as a victim of its own success. The standard model is just too good. It’s too hard to find an experimental result that disagrees with it, and too hard to come up with theoretical advances that will address some of the things it leaves unexplained. Smolin sees the source of the problem in the field’s insistence on sticking with a way of doing science which worked until 30 years ago, but now has become dysfunctional, with string theory only a symptom of the underlying problem. He writes:
I have mentored several talented young people through crises very similar to my own. But I cannot tell them what I told my younger self - that the dominant style was so dramatically successful that it must be respected and accomodated. Now I have to agree with my younger colleagues that the dominant style is not succeeding.
Elsewhere he writes:
My hypothesis is that what’s wrong with string theory is the fact that it was developed using the elementary-particle-physics style of research, which is ill-suited to the discovery of new theoretical frameworks… This competitive, fashion-driven style worked when it was fueled by experimental discoveries but failed when there was nothing driving fashion but the views and tastes of a few prominent individuals.
Smolin was a student of Stanley Deser’s, and during his graduate student years supergravity was a field that was just taking off. He describes getting to know Peter van Nieuwenhuizen and Martin Rocek and being offered a chance to get into the field at the ground floor, one he passed up because he couldn’t believe that the kind of lengthy algebraic calculations they were doing could give real insight:
It was like being offered one of the first jobs at Microsoft or Google. Rocek, van Niewuwenhuizen, and many of those I met through them have made brilliant careers out of supersymmetry and supergravity. I’m sure that from their point of view, I acted like a fool and blew a brilliant opportunity.
Smolin didn’t join the Stony Brook supergravity group, but found that he could make a place for himself in the physics community working on quantum gravity, but using particle physicist’s methods:
… an easy opportunity opened up while I was a graduate student, which was to attack the problem of quantum gravity using recent methods developed to study the standard model. So I dould pretend to be a normal-science kind of physicist and train as a particle physicist. I then took what I learned and applied it to quantum gravity.
Smolin ended up with a post-doc at the new ITP in Santa Barbara, which luckily was running a program on quantum gravity that year. His career tactic almost didn’t pay off:
One day, as we were waiting for the results of our applications, a friend came by to tell me that I was unlikely to get any jobs, because it was impossible to compare me with other people. If I wanted a career, I had to stop working on my own ideas and work on what other people were doing, because only then could they rank me against my peers.
The most powerful part of the book are the chapters entitled How Do You Fight Sociology?, and How Science Really Works. They give a detailed and clear diagnosis of the problematic way string theory research is being conducted, and decisions are being made about who deserves a job. Smolin has an insider’s point of view, particularly because he himself worked on string theory:
… during the years I worked on string theory, I cared very much what the leaders of the community thought of my work. Just like an adolescent, I wanted to be accepted by those who were the most influential in my little circle. If I didn’t actually take their advice and devote my life to the theory, it’s only because I have a stubborn streak that usually wins out in these situations. For me, this is not an issue of “us” versus “them,” or a struggle between two communities for dominance. These are very personal problems which I have been contending with internally for as long as I have been a scientist.
So I sympathize strongly with the plight of string theorists, who want both to be good scientists and to have the approval of the powerful people in their field. I understand the difficulty of thinking clearly and independently when acceptance in your community requires belief in a complicated set of ideas that you don’t know how to prove yourself. This is a trap it took me years to think my way out of.
Smolin gives many examples of the “groupthink” behavior of the string theory community, while characterizing string theorists as “almost all more open-minded and self-critical and less dogmatic than they are en masse.” He describes string theorists as:
… supremely confident both of the truth of string theory and of their superiority over those unable or unwilling to do it. To many string theorists, especially the young ones with no memory of physics before their time, it is incomprehensible that a talented physicist, given the chance, would choose to be anything but a string theorist.
…Anyone who hangs out with string theorists encounters this kind of supreme confidence regularly. No matter what the problem under discussion, the one option that never comes up (unless introduced by an outsider) is that the theory might simply be wrong. If the discussion veers to the fact that string theory predicts a landscape and hence makes no predictions, some string theorists will rhapsodize about changing the definition of science.
Some string theorists prefer to believe that string theory is too arcane to be understood by human beings, rather than consider the possibility that it might just be wrong.
Smolin finds in the string theory community a sense of entitlement and disdain for anyone who works on alternatives to the theory, with major string theory conferences never inviting people who work on alternatives to speak. An editor from Cambridge University Press told him that one string theorist said he would never consider publishing with the press because it had put out a book on LQG (I see why their publishing my book was out of the question…). At string theory conferences Smolin would be asked “what are you doing here?” or told “It’s so nice to see you here! We’ve been worried about you.” Some friends explained to him that if he wanted to be considered part of the string theory community he had to work not just on string theory, but on the particular string theory problems that were fashionable at the moment.
One problem for physicists trying to get tenured positions that Smolin mentions is that most universities now require letters from 10-15 people evaluating their work, with a small number of negative evaluations sufficient to sink their chances. If you’re working on something other than a mainstream topic, finding 10-15 people who can comment knowledgeably on your work can be impossible. He describes string theorists as mostly submitting the same two or three research proposals. This narrow concentration on a small number of problems is defended by some senior theorists as a “disciplined” approach, one that will more surely lead to progress than encouraging people to pursue a variety of different research directions.
Very recently, Smolin sees things changing:
Until last year I had hardly ever encountered an expression of doubt from a string theorist. Now I sometimes hear from young people that there is a “crisis” in string theory. “We have lost our leaders,” some of them will say. “Before this, it was always clear what the hot direction was, what people should be working on. Now there’s no real guidance,” or (to each other, nervously) “Is it true that Witten is no longer doing string theory?”
One can quantify this new situation by noting that there have been virtually no heavily cited new papers during the past few years, except perhaps for the KKLT one that is part of the landscape story.
Smolin notes that many string theorists (including himself) have often been ill-informed about the exact state of knowledge concerning crucial conjectures about string theory. . .
I have mentored several talented young people through crises very similar to my own. But I cannot tell them what I told my younger self - that the dominant style was so dramatically successful that it must be respected and accomodated. Now I have to agree with my younger colleagues that the dominant style is not succeeding.
Elsewhere he writes:
My hypothesis is that what’s wrong with string theory is the fact that it was developed using the elementary-particle-physics style of research, which is ill-suited to the discovery of new theoretical frameworks… This competitive, fashion-driven style worked when it was fueled by experimental discoveries but failed when there was nothing driving fashion but the views and tastes of a few prominent individuals.
Smolin was a student of Stanley Deser’s, and during his graduate student years supergravity was a field that was just taking off. He describes getting to know Peter van Nieuwenhuizen and Martin Rocek and being offered a chance to get into the field at the ground floor, one he passed up because he couldn’t believe that the kind of lengthy algebraic calculations they were doing could give real insight:
It was like being offered one of the first jobs at Microsoft or Google. Rocek, van Niewuwenhuizen, and many of those I met through them have made brilliant careers out of supersymmetry and supergravity. I’m sure that from their point of view, I acted like a fool and blew a brilliant opportunity.
Smolin didn’t join the Stony Brook supergravity group, but found that he could make a place for himself in the physics community working on quantum gravity, but using particle physicist’s methods:
… an easy opportunity opened up while I was a graduate student, which was to attack the problem of quantum gravity using recent methods developed to study the standard model. So I dould pretend to be a normal-science kind of physicist and train as a particle physicist. I then took what I learned and applied it to quantum gravity.
Smolin ended up with a post-doc at the new ITP in Santa Barbara, which luckily was running a program on quantum gravity that year. His career tactic almost didn’t pay off:
One day, as we were waiting for the results of our applications, a friend came by to tell me that I was unlikely to get any jobs, because it was impossible to compare me with other people. If I wanted a career, I had to stop working on my own ideas and work on what other people were doing, because only then could they rank me against my peers.
The most powerful part of the book are the chapters entitled How Do You Fight Sociology?, and How Science Really Works. They give a detailed and clear diagnosis of the problematic way string theory research is being conducted, and decisions are being made about who deserves a job. Smolin has an insider’s point of view, particularly because he himself worked on string theory:
… during the years I worked on string theory, I cared very much what the leaders of the community thought of my work. Just like an adolescent, I wanted to be accepted by those who were the most influential in my little circle. If I didn’t actually take their advice and devote my life to the theory, it’s only because I have a stubborn streak that usually wins out in these situations. For me, this is not an issue of “us” versus “them,” or a struggle between two communities for dominance. These are very personal problems which I have been contending with internally for as long as I have been a scientist.
So I sympathize strongly with the plight of string theorists, who want both to be good scientists and to have the approval of the powerful people in their field. I understand the difficulty of thinking clearly and independently when acceptance in your community requires belief in a complicated set of ideas that you don’t know how to prove yourself. This is a trap it took me years to think my way out of.
Smolin gives many examples of the “groupthink” behavior of the string theory community, while characterizing string theorists as “almost all more open-minded and self-critical and less dogmatic than they are en masse.” He describes string theorists as:
… supremely confident both of the truth of string theory and of their superiority over those unable or unwilling to do it. To many string theorists, especially the young ones with no memory of physics before their time, it is incomprehensible that a talented physicist, given the chance, would choose to be anything but a string theorist.
…Anyone who hangs out with string theorists encounters this kind of supreme confidence regularly. No matter what the problem under discussion, the one option that never comes up (unless introduced by an outsider) is that the theory might simply be wrong. If the discussion veers to the fact that string theory predicts a landscape and hence makes no predictions, some string theorists will rhapsodize about changing the definition of science.
Some string theorists prefer to believe that string theory is too arcane to be understood by human beings, rather than consider the possibility that it might just be wrong.
Smolin finds in the string theory community a sense of entitlement and disdain for anyone who works on alternatives to the theory, with major string theory conferences never inviting people who work on alternatives to speak. An editor from Cambridge University Press told him that one string theorist said he would never consider publishing with the press because it had put out a book on LQG (I see why their publishing my book was out of the question…). At string theory conferences Smolin would be asked “what are you doing here?” or told “It’s so nice to see you here! We’ve been worried about you.” Some friends explained to him that if he wanted to be considered part of the string theory community he had to work not just on string theory, but on the particular string theory problems that were fashionable at the moment.
One problem for physicists trying to get tenured positions that Smolin mentions is that most universities now require letters from 10-15 people evaluating their work, with a small number of negative evaluations sufficient to sink their chances. If you’re working on something other than a mainstream topic, finding 10-15 people who can comment knowledgeably on your work can be impossible. He describes string theorists as mostly submitting the same two or three research proposals. This narrow concentration on a small number of problems is defended by some senior theorists as a “disciplined” approach, one that will more surely lead to progress than encouraging people to pursue a variety of different research directions.
Very recently, Smolin sees things changing:
Until last year I had hardly ever encountered an expression of doubt from a string theorist. Now I sometimes hear from young people that there is a “crisis” in string theory. “We have lost our leaders,” some of them will say. “Before this, it was always clear what the hot direction was, what people should be working on. Now there’s no real guidance,” or (to each other, nervously) “Is it true that Witten is no longer doing string theory?”
One can quantify this new situation by noting that there have been virtually no heavily cited new papers during the past few years, except perhaps for the KKLT one that is part of the landscape story.
Smolin notes that many string theorists (including himself) have often been ill-informed about the exact state of knowledge concerning crucial conjectures about string theory. . .
Some "rhapsodize about changing the definition of science"? Think the alleged final theory is "too arcane to be understood by human beings"? What the f***?
Frankly that scares me. I have no idea how prevalent such thinking is but certainly string theory has experienced quite a bit of popularity in physics departments around the world and it would seem its practitioners are well-rewarded. But one of the hallmarks of science is that it doesn't look to undetectable, unprovable mysterious entities beyond human understanding as a solution to a problem. Honestly, how can I continue defending science from claims that its merely "the new religion" if we're ready to do something like that? Where's the integrity in changing the definition of science so that theories making no testable predictions and coming in 10^500 different flavors make the cut?
Call me crazy but I'm of the Einstein school of thought that the most incomprehensible thing about the whole universe is that it's comprehensible. And that physics should include a little, well, physics here and there. I won't deny that I'm a little disturbed by the way things are going. I take a little comfort in the fact that things always seem to sort themselves out in the long run, slowly but surely. If there's a better alternative it will be explored. It's just going to take some time.
But this whole thing leaves a bad taste in my mouth.
ya it does.
As an amateur physicist, I must agree with StarTraveler in all he says. Instead of being the theory of everything, String Theory has turned out to be the theory of anything, and thus nothing. There are at least 10^500 quite different universes compatible with it.
Physics took a wrong turn at the fifth Solvay conference in 1927, where the wave-particle paradox was simply accepted as an integral part of the emerging Standard Model. After that, de Broglie dropped out of physics, and Einstein went his own way, emerging from his study from time to time to aim barbs at quantum mechanics.
Some years later, the great logician Kurt Goedel proved a number of fundamental theorems about any logical system, including this one: if a logical system incorporates a logical impossibility, anything can be proved with it, such as that 1 = 2. Thus, the origins of quantum weirdness, and the rejection of common sense. Everything in physics after Einstein incorporates logical impossibilities. The wave-particle paradox is not the only one. Heisenberg applied his uncertainty relations to the vacuum and came up with virtual particles. The only problem with this is that it gives infinite energy density to the vacuum. Thiis reductio ad absurdem didn't bother the physicists at all. A mathematician would conclude that therefore virtual particles don't exist. After Feynman all of physics was based on virtual particles. Having swallowed several logical impossibilities, one more wouldn't hurt.
Physics jumped the tracks of scientific method in 1927, and has been moving steadily farther into the realms of mathematical fantasy, as represented by String Theory. Physics is no longer our best example of scientific method. Plate tectonics in geology is a much better model. This has also been a great age for astronomy and biology.
and Richard Feynman's famous quote "shut up and calculate."
