A conversation with the mathematical physicist at Columbia University.

**Question: **What is string theory?

**Peter Woit: **Well the first thing I can say is, when people sit and talk about String Theory, they're actually talking about a very complex set of ideas that lots of people, a very large amount of people have worked on and have done a lot of different things with. Probably what it's best known for and what got people all excited about it in the physicist community is the conjecture that, at the most fundamental level, you can understand matter and the universe in terms not of point particles, which is the way our best theory is, currently, you can understand things, but in terms of, if you like, vibrating in loops of some elementary objects here, your elementary object instead of being a point-like thing is something you should think of more as a one dimensional loop, or a string which is kind of moving around.

So, it has a lot more - it can do a lot more complicated things than a point, this kind of loop of elementary matter, whatever it is. And so, it gives you a very different class of theories than the ones that have been so successful before. So, during the '60's, this idea was initially developed and initially people tried to do one thing with these passive theories something which didn't work out that well. And then starting in the late '70's and '80's, people then came up with a conjecture that maybe you really could unify all of physics and solve some of the open problems in physics by replacing our standard theories, what we call the standard model with some kind of string theory. So, since this idea because very popular in 1984, and so it's been now 25 years people have been working very hard on that. And I just think the initial thing that got people excited was I would claim it really hasn't worked out and it really can't work out. And that's kind of been, I think, a lot of the reason the controversy has been an argument over this issue of whether this very speculative idea about whether you could use these strings, and you don't have to get a unified theory, about whether that has - is that an idea that's failed or is there still some hope for it, is what I think is really what's the controversial part of it.

rn**Question: **What is the “grand unifying theory” that physicists are trying to formulate?

**Peter Woit:** Well, the main thing to understand about the current state of physics is that we have - are in some sense, a kind of victim of our own success. We have an incredibly successful theory called the Standard Model. And it really explains everything that we can observe about and in terms of a very small number of elementary particles and some basic forces between them. And it's a quite beautiful theory and it really is just absurdly successful. Every experiment anybody knows how to do that in principle can be - that this theory has something to say about, it works out perfectly to whatever experimental and in whatever detail you can do an experiment to whatever precision, it come out to exactly as predicted by the model.

So, we have a semi-unified theory. This quite nice, beautiful structure which explains everything we can see, but it still leaves open several questions. Some of the questions are just kind of why we have all these different particles and they all have different masses. Why do they all have different masses? We don't understand why the electron has a certain mass, quarks have other masses. So, there's just kind of things which the theory doesn't address. It just doesn't answer these questions and then questions which as physicists we think there should be answers to.

rnBut then there is also one remaining force which isn't part of the standard model, which is the gravitational force. The gravitational force is much, much weaker than these other forces and it has a somewhat different nature, so the problem with it is we don't - these other forces we have something which is a quantum theory. It's quantum mechanics. It really works down to the microscopic level and in terms of this very fundamental idea about reality called quantum mechanics.

rnThe theory of gravity that we still use is Einstein’s Theory of General Relativity and it's what we call a classical theory. It's not a quantum mechanical theory. The problem is, you can make an estimate within this theory of how big quantum mechanical effects would be and then that estimate tells you that they are just so absurdly small you can never hope to see them. So, there's kind of this problem of principle. We have this theory which is not a proper quantum mechanical theory and we know that there's things which it can't quite properly explain, but they're far too small for us to study them and to try to see them.

rnSo anyway, we are not completely happy with this setup. We have a force which doesn't quite fit with the others and which for logical reasons we would like to unify it with these others and understand it as a quantum mechanical theory, and we've never been quite successful in being able to do that. And this is what String Theory was, kind of a promise of a way of how to do that. And that's why people got so excited.

rn**Question:** What do you mean when you say that string theory is “not even wrong”?

**Peter Woit:** Well, so that's a famous phrase among physicists, it goes back to a well-known theorist called Wolfgang Pauli in the '50's and the story is that toward the end of his life someone - I guess he was well-known for being very hyper-critical of things that were going on and would get up in the middle of a seminar and start saying it's wrong, it's completely wrong. And then late in his life someone asked him about some work of some speculative idea that someone - and shook his head and said, "Well that one's not even wrong." And so, it's a well-known phrase among physicists. It kind of carries I think two meanings. One of them is more somewhat of a term of abuse, "well that's so bad it's not even wrong." But there's a more interesting it is, it's a more technical meaning that very often you have a speculative idea and if it's not a very good idea, or it turns out that you end up not being able to do very much with it, you end up not being able to predict with it, or to - it's just not useful, so there's also a notion of not being "not even wrong," in the sense that it's not an idea which can be fully developed or can be turned into something which is powerful enough to actually predict something and actually be wrong.

So, one problem of the String Theory is that it's kind of a theory which can explain what the problems are, but the problems are such that you can't even pin it down and say this is exactly what it predicts, so lets go out and test it. So, it's not even capable of being wrong, or being falsified, or being showed to be wrong. So, that's the more relevant meaning here really.

rn**Question:** Will string theory ever be verifiable or unverifiable?

**Peter Woit:** Yeah, well as I said, String Theory is actually a very complicated story. If you start out with this hypothesis that maybe your ephemeral objects are not points, but are these strings, there's a lot of different things you can try and do that you have a whole different class of theories you can play with. So, I think a lot of - if you look at what most people, who are still going String Theory are doing, they're actually not directly trying to develop this unified theory anymore. They're off doing other things with String Theory. People these days are trying to apply it to problems in nuclear physics; they're applying it to problems in Solid State Physics, understanding super conductors. So, the people who are still interested in it are often kind of - even if they may or may not explicitly admit that they've given up on the unified theory idea, but they're often doing other things. So, there's a very active pursuit of String theory with other applications that don't have anything to do with unification.

It's also turned out to be very interesting in mathematics. There's a very, one of the things that I'm most interested in is the intersection between mathematics and physics and the way the two fields affect each other and ideas from physics lead to very interesting things about mathematics, ideas in mathematics get used in **** in physics. And String Theory has been very, very fruitful in terms of raising questions which have led to very interesting mathematics. So, there's a very active field of research kind of in between math and physics in String Theory. But it just doesn't seem to be relevant to this question of unification.

rn**Question: **What model would you propose as an alternative to string theory?

**Peter Woit:** Well, I certainly shouldn't - my criticism of String Theory is not that, well, if you guys have just realized that you should be doing such and such, that would solve a lot of problems. I don't actually - I don't think that I - I have some of my own ideas which I am very excited by it which I'm pursuing which are also new ideas about how to use mathematics to do things in physics which don't have anything to do with String Theory and which kind of, at least lead me to see there's a lot of areas, a lot of things we don't understand which are closer to the standard model which we do know works. There's a lot of mathematical structure behind the standard model which is still kind of mysterious and which is not well understood and I think pursuing that is more likely to get us somewhere than the String Theory Unification idea. Just because you're starting from something which you know - a theory which you know is right and trying to further develop your understand of that theory is maybe a more fruitful thing to do than trying to just throw all that out and start afresh with something more speculative.

I guess one thing to talk about is this - what's happening in Geneva this month, so a lot of the problem with the field, as I said, is this business of being a victim of our own success, not having any experimental results that disagree with the theory, which makes it very, very hard to figure out how to improve a theory if you've got no clues as to what might possibly be wrong about it and needs to be changed. And so, there's this accelerator called the LHC, it's **** in Geneva and it's been in development for quite a few years now and it's been a long process getting it working, but just over the past month, they are finally going to subject beams into the accelerator and start colliding these beams and start doing some new physics. Over the next year they'll start raising the energy of this accelerator to the point where it will be in a new energy regime which allows us to get experimental data about what's happening at a high energy, which corresponds to what's happening at shorter and shorter distances.

rnTo see what's happening in shorter and shorter distances, in some sense you need to use shorter and shorter wave length, or higher and higher energy probes, and this new accelerator, it finally promises some data in this new energy range beyond what we've been able to see so far. And there are reasons to believe that this new energy range is one where we can start getting some answers to some of these questions especially about mass. About why do different particles have different masses?

rn**Question:** What is the Higgs particle, and why does its existence or nonexistence matter?

**Peter Woit: **So, this **** of the standard model, it's quite a beautiful theory, but to make the whole thing work, you need to make sure that a certain kind of physical phenomenon has to happen. And one way of saying it is that the theory has certain symmetries and the lowest energy state, the vacuum of the theory has to have non-trivial properties under one of these symmetries. Normally you say a vacuum state is kind of complete and interesting and if you rotate it around and move it around, the vacuum state - nothing can happen, it's just a vacuum state.

But the vacuum actually has to have interesting properties under these kind of mathematical symmetry transformations and so we know that has to be true in order to make the theory work. And there are many ways you can imagine making that happen, and one way is called the Higgs Mechanism. And so the Higgs Mechanism involves a postulating existence of some new fields, some new kind of matter, which is this Higgs part. This Higgs field. And then giving this dynamics, or making the properties of the Higgs field such that in the vacuum state the Higgs field will have this duntrial property. So, you can do that and in some sense the Higgs field is kind of the simplest way of getting what you want, but when you do it, you also end up losing the ability to predict all sorts of things because then the question of why does a particle have a certain mass, just becomes well because that's how strongly it interacts with the Higgs field. So, it's the simplest way of making something happen you know has to happen, but it's a way which has a lot of things you don't really like. It's not a very satisfactory way of doing it because it kind of, of necessity leaves open a whole range of questions which you would have hoped to have answers to, but you just can't answer it that way.

rnSo, one thing which we hope to learn from the LHC is, is this Higgs Mechanism, or this Higgs field really there? In which case that will actually be somewhat of a disappointment because it'll mean that this theory continues to work and we still don't know how to answer some of these questions. Or I think the much more exciting possibility is going to be that there is something else causing this phenomenon of the vacuum behaving this way. And that something else will give us something else that would be more interesting and would allow answers to these questions.

rnSo, this whole, this name of the Higgs field and finding the Higgs particle, that's kind of an oversimplified way of saying, what we're really hoping is to understand what is causing the vacuum to behave this way and we have good reason, there's kind of a number in the theory which says how big this phenomenon is going into the vacuum is and what the size of it is. And the size is exactly the size that this accelerator should finally be able to probe. So, there's very good reason to believe that this is the right machine to start answering some of these questions.

rn**Question:** If not the Higgs field, what do you suspect is causing the vacuum to behave this way?

**Peter Woit:** I guess the real problem is that there are various ways. People have studied a lot of other alternatives to the Higgs field. The problem is that they are all fairly complicated and they all have as bad or even worse problems even than the Higgs field. None of them are convincing, we don't have a convincing alternative to it. And I don't have either. I guess about all I can say about that is that I've very interested in the mathematical parts of the theory that we don't understand and some of the kind of deep mathematical structure that we don't understand in these theories. Part of what we don't understand in these theories actually is related to the problem of the vacuum, of this behavior of the vacuum. In my ideal world, it would turn out that there is something somebody learned about the mathematical structure of these theories which would in the end explain this Higgs phenomenon and this problem of the vacuum. But I mean, I wish I knew how to do that I certainly don't have some very vague reasons to believe that that's an interesting thing to look at, but I certainly don't have an answer to it.

If I had to assign probabilities to it, what I would guess is there's about a 50% chance the LHC will actually see an actual Higgs particle and there is some kind of Higgs field and this is going to be kind of depressing for us because it means - well whatever, there is this field there, it's working like this and these questions that we would like answers to are, you have to go to even higher energies or smaller distances to understand them, or I think there’s a 50% probability that we won't see a Higgs particle, or at least not a Higgs particle, the kind that you see in the simplest model and that will actually give us clues as to what is going on and that will be much more exciting. But I don't know which is going to happen.

rn**Question: **Will discoveries made using the LHC have any practical applications?

**Peter Woit: **Well, you never know. There's no reason - the general problem with particle physics is that these questions we are asking are happening at such high energy scales in such short distances that it's very hard to see how to do anything very practical with this. I mean, anything - like the particle we are talking about often have lifetimes which are 10 to the minus 20 seconds. I mean, there just - If you produce a Higgs particle it's going to be so short lived it's incredibly difficult to see any evidence of the thing. It's not something that you're going to be able to go out and use these Higgs particles to carry around and do something with.

On the other hand, you don't really know what you're going to find, if you do find. Especially if you find something - I guess I could say it this way. If you do just find this Higgs particle and this Higgs field, it's very hard to make or to do anything really practical with that. If you find some completely new understanding of this theory then who knows. You can **** come up with all sorts of models. You can come up with models in which there's kind of new, heavy, long-lived particles which you can then imagine doing something with. I think it's a pretty good bet that within the near future, this is not really **** practical. This is really not a - just trying to understand the world better, but not in a way that's particularly going to be useful for doing anything too practical that's going to affect people anytime soon.

rn**Question:** Could the LHC create dangerous black holes?

**Peter Woit:** No. That's not going to happen. I mean, some of that is because people - one of the alternatives to this is, this Higgs mechanism is it - and people started studying some models in which - to go back a little bit. One thing about String Theory is, to make String Theory work; you have to have extra dimensions. You have to have more than the three space and one time dimensions, and that's kind of in some sense the main problem with String Theory, you have to have at least five extra dimensions, I'm sorry six extra dimensions and the predictions of the theory in being able to use it for anything is dependent on what is happening with these six other dimensions. And no one has ever - initially the hope was that there was a fairly small number of consistent ways of dealing with these extra dimensions and that would make this a predictive theory, but it's turned out that there's just too much you can do and you can get anything you want by just having these extra dimensions to do different things.

And so, as part of this one thing that people studied was models in which these extra dimensions are actually of exactly the right size that the LHC should start seeing evidence of these extra dimensions and producing black holes because of these extra dimensions. And that's - there's just never been a reason to believe that these extra dimensions would - we'd see no evidence of them at our best accelerator now. We need to go up by a factor of seven in energy and all of a sudden all these extra dimensions would appear. There's absolutely no reason for that to happen. You can make speculative models, which it happens, but first of all - anyways, there no good motivation for these models and for them to happen, and no evidence for them. And even if they were to exist or they were to happen, any such black holes would kind of immediately, they'd become completely unstable and it would just immediately decay into something else and you're not going to produce a dangerous black hole that way.

rnBut the first - I think what caused all this trouble was people kind of wanted to promote these extra dimensional models even though there was no good motivation for them. They promoted them by saying, well in principle, since we don't know what happens with higher energies in the LHC, evidence of extra dimensions will show up. But there's no good reason for that. But once people started promoting the idea of these extra dimensions might show, people were like, well, if they show up maybe they'll be black holes. And it was speculation on top of speculation on top of speculation, but it's all - there is no reason to believe that any such thing could possibly be true.

rn**Question: **In what new ways could math be applied to solve the problems of physics?

**Peter Woit:** The thing that most fascinates me about this whole subject is that something that probably quickly get very technical, but there's an area of mathematics which is known as representation theory. One way of thinking about it is in terms of what physicists often call symmetries. So, for instance, one of the basic facts about the laws of nature is that there are symmetric laws of nature are the same at - if you move in any direction, or you move in time back and forth, the laws of physics don't change. If you rotate things around in three dimensions, the laws of physics don't change. And so, these so-called symmetries have very important physical implications. The fact that the laws of physics don't change as if you move in time has physical implications that there's this thing called energy and energy is conserved, and the same thing - and the fact that the laws of physics don't change of you move back and forth in different directions in space implies that there is something called momentum and momentum is conserve and doesn't change as you evolve in time.

So, the very, very fundamental facts about physics are kind of deeply grounded in the symmetries of nature. And so to a mathematician this question is a question about what we call groups and representation of groups. So, if you go into any math department and look at what they're doing, you'll see that a lot of people in different kinds of mathematics are studying different structures which are also called groups and they're often studying what is called representations of the groups. So, even people studying number theory, abstract things about prime numbers or something, they're also studying groups and certain representations of these groups. So, there's kind of a, to the extent that mathematics has a kind of unifying theme and a unifying principle which shows up in different areas of mathematics, it's about these representations, or representation theory. And the thing that most strikes me about physics, and what fascinates me about it is, if you look at quantum mechanics, quantum mechanics initially looks like a very odd structure. It's not something were we have any kind of intuitive understanding of it. It doesn't look like the way we're used to thinking about physics, based on every day experience. But if you look at the mathematical structure and the basic structure of quantum mechanics, they're exactly the structures that show up in this theory of representations. So, there's a kind of a deep relation between math and physics which is surrounding this whole notion of symmetries and representation of symmetries.

rnSo, that's one thing that's always fascinated me, and my own research and my own interests is in developing - taking a lot that has been learned in mathematics. There's a lot that's been learned in mathematics over the years about how to think about representations and how to construct them and how to work with them. Some of it has made its way into physics and have been used in physics and was used in physics since the early days of quantum mechanics. So, for instance, one of the great ****, there's a kind of hero of this book I wrote about this, it's The Mathematician called Herman Vial, who was one of the first people to understand how quantum mechanics worked and to understand the relation to representations.

rnBut anyway, I think there's still a lot to be learned in that way and very specifically the so-called standard model has this group of symmetries which is called the gage symmetry and it's an infinitial group and the standard kind of physics understanding of the representations of this group is that that should not be an interesting question. There should only be a trivial representation of this group. But anyway, my conjecture is that there is actually a more interesting question there and in pursuing this question of how do you deal with the gauged symmetry of this theory in terms of using ideas from representation theory that are more well-known in mathematics that hadn't been used in physics before that you can actually get somewhere. Well that's maybe too technical, but that's as good as I can do with this.

rn**Question: **What’s the most elegant proof you’ve ever encountered?

**Peter Woit:** Elegant proof. That's a good question. It's hard to say. There's a lot of - the problem with - elegance is actually an interesting question maybe to say what is elegance and what is beauty, I guess. So, one thing that's come up within this String Theory issue is this question of is this a beautiful idea, or beautiful theory. As my colleague, Brian Green has written a very good book about this called The Elegant Universe. And so, within in physics, this is our - we're often very struck by some of these basic ideas are very striking in the way in which we like to describe as being elegant, or beautiful. But the problem with that terminology, especially with the terminology of beauty is that beauty means a lot of different things to a lot of different people. A lot of different ways in which things can be beautiful. But this really has a very specific meaning and which is more along the lines of elegance which is that we say an idea is beautiful or elegant in mathematics or physics if a very simple principle or a very simple idea, or simple set of ideas, turns out to be very powerful and leads to all sort of unexpected structure and unexpected predictions.

I think maybe what I find is the most beautiful and most elegant thing about this whole subject is a little bit about what I was trying to explain earlier. If for instance this idea that the fact that the laws of physics are the same as you move in time means that is has very unexpected significance. It means that there is this thing called energy and you can associate a number called energy to physical systems and it's not going to change it as time evolves. So, in classical physics, there's actually a theorem called Noether's Theorem after a mathematician called Emmy Noether. So, there is a little slightly **** trivial theorem and that's certainly a beautiful theorem. What fascinates me more is that in quantum mechanics, Noether's Theorem isn't even a theorem, it's just implicit in the definition. Just the way you set things up is automatically true, so it's - anyway, there's a theorem and a proven **** and you start to think about quantum mechanics and you think about it, and it's just kind of automatically true. There's not even the Theorem any more. And that's just beautiful.

rn**Question:** How do the politics of math and science affect the objectivity of their inquiry?

**Peter Woit:** Well, I think any kind of thing that human beings do there is a certain politics to it and certain academic politics, and **** of the field. But mathematics is actually a relatively healthy field these days. I mean, people are making good progress in a lot of different ways and it's also - so anyway, I kind of lived part of my professional life in mathematics and part in physics. And one thing to say about mathematics is that it can have its problems, but it's actually hasn't seen a lot of the problems as some of the other sciences and probably also the wonderful thing about mathematics is so much of it in what people are doing is completely useless. Nobody kind of in ***** really cares very much. You don't really have kind of right and left and people in ideology coming in because there isn't any. It just doesn't actually connect up to the kinds of things that people ideologically worry about. So most of mathematics just doesn't tell you anything one way or another about global warming or about healthcare or about any number of things that you might care about.

So, mathematics is immune to a lot of exterior, real-world politics because of that. And the academic politics, it's there, but I think it's actually less than a lot of fields. One of my colleagues likes to say that, mathematics is the - he thinks about the only subject that he knows in academia or in the real world where if two people disagree about something - if people are studying some mathematical object and there's supposed to be a proof and they disagree about whether this proof **** or not, the will go into a room, sit down and talk about it and fairly quickly or at the end of the day one of them will admit they’re wrong. But the problem with a lot of **** is this doesn't happen where in mathematics, this happens all the time. And so there is the notion of logic and proof and rigor in which we can all - it allows us to all stand on one track.

rnPhysics is, well first of all, physics is a very complicated subject in many, many different things. The String Theory and particle physics is only a small part of physics. So when I talk about physics I talk about them and the problems of those subjects. It's really the problems of a very small - one discipline and one sub-field of physics. A lot of physicists, people are happily going along and doing their science and quite successfully and it has nothing to do with - and they get very, very annoyed when they hear people going on about the problems of String Theory as if that's some big problem for physics, because it's not their problem.

rnString Theory and particle theory suffers a lot from this business of being from its own success. From not having any - nobody has been able to come up any really good ideas to make positive progress just because there's been no experimental evidence to give you a clue as to which direction to go. And the subject has traditionally been very connected often, at least from a mathematician's point of view, in a very faddish way, that all the smart people in the subject would all kind of jump on the same problem and would all kind of work on the same problem - very often because the subject was kind of driven by experiment and somebody would go out and turn on an accelerator like the LHC Hadron energy and is this really going to happen next year if the LHC seems something unexpected, everyone in the whole field is going to be trying to explain that one thing, and so you have a very kind of a faddish sociology that everybody is trying to do the same thing at the same time, whereas in other fields like mathematics, people kind of spread out and develop their expertise and work on different things.

rnSo, part of the problem of the politics of particle theory has been that you have people used to the idea that well, you should look around and see what these smart people are working on and I should work on the same thing as them. And so, you've got all these people trying to do this. So, String Theory got identified back in '84 as being the hot topic and for a lot of reasons, partly - probably because it was an intriguing idea, but partly also because one of the great geniuses of our subject, this guy named Edward Whitman who is a fantastic genius and has done these amazing things. He got very interested in it and he started promoting the idea that this is a very promising idea and so everyone kind of jumped on it and my initial reaction at that time, I was just getting out of graduate school at that time and partly the way I work and the way I think, I wasn't so interested in the idea of trying to do the same thing as everybody else I would prefer to work on something a little bit different, and partly also - it didn't seem to me - it wasn't that this was obviously a good idea, it might be a good idea, it might not, but there were obvious problems from the beginning.

rnAnd so, anyway, **** everybody started working on this and I think my reaction to it was, well that's great that they're doing this and what's going to happen is what normally happens in a subject that after six months or a year or two years, people will see whether it's a good idea or not and if it's not a good idea they'll move on and the really peculiar thing that happened here is 25 years later, this is still - there are still a lot of people doing this and it really kind of caught fire and even without succeeding, it still kind of developed into this whole huge subject and it kind of, achieved some kind of critical mass and more and more people are working on it and they've been working on it so long that people ended up devoting their careers to it and it's a very, very difficult and complicated subject. And it requires quite a lot of time just to get to the point of understanding what is going on. So, you had more and more people working on this and investing more and more of their time and their careers and their lives into it and I think it really go tot he unfortunate point where people were unwilling to kind of admit that this wasn't working. And it's a natural human reaction of an idea that you are fond of and you put a lot into it, it's kind of hard to get you to admit that, well maybe this doesn't work and that this is happening very much in spades in this story because it been hard to get people to admit that this maybe hasn't worked out.

rn**Question: **How does blogging affect your relationship with other people in your field?

**Peter Woit:** So, there's actually kind of two things. One is the blog and I also wrote the book. Anyway, for many years I wasn't very happy with what was going on there and I was kind of observing it. Okay, this is becoming more and more problematic. There is this - not only are people not admitting that this isn't working out, but there's this whole - there's a lot of public promotion of the subject and it's very difficult and complicated and a lot of people don't understand it, and so this is not really a healthy situation. Someone should kind of clearly explain to the larger community of physicists and also to non-physicists exactly what the situation is here. And so I wrote an article about this and then I finally wrote this book and it took a while to get the book published. It's a long and interesting story, but then while - I guess it was after the book was written, I also started to see there were a couple of other physicists who had started blogs and I thought, well this is interesting thing to do and I can both talk about the issues related to String Theory and things which I was trying to get through the book but also kind of follow it on a day-to-day basis. And also write about whatever I'm interested in. So, the blog, I guess, I don't worry about the audience for it, it's kind of written just very much whatever I would like to read. So, I'm kind of writing whatever I would like to read. So, if there is somebody out there exactly me, they must find this really fascinating, and if there's someone quite different, then they're probably not at all interesting.

And so because of that, the kinds of things on the blog are often - if I learned something or something new or interesting is going on even in pure mathematics, I'll be writing about that, or pretty much anything going on in between mathematics and physics I'll be writing about that. I'll be writing a lot about the LHC and also just about whatever is going on in the controversy over this String Theory, and it's interesting that more keeps happening with that. My book came out and there's a book by another physicist with a similar point of view as mine and it all came out, so that caused a lot of controversy so a lot of reviews and a lot of argument going on, on the blogs and a lot of people refer to this as the String Wars and so there's this very - for a year or two there, there was a kind of very interesting, if you're interested in this kind of thing, there was a kind of warfare in terms of blog postings and comments going on, on my site and various others and that sort leads to all sorts of strange things.

rn**Question:** Do your readers ever provide useful insights into physics problems?

**Peter Woit:** Well, there's some - it depends. I often learn interesting things from comments. So, now that the blog is fairly well-known, people will write in comments to my blog and often telling me something about something that I hadn't heard about. And that's interesting, or they'll often send to me privately by email saying, hey you might be interested in this, so I get a lot of that and learn a lot that way.

One interesting thing that I found amusing about the whole String Theory discussion was that it's an incredibly complex and difficult subject and so, it's really hard to over emphasize how it's a subject that nobody really understands very well, and even the people who are the experts at it are - I had this amazing experience of having a conversation with a Nobel Prize Winner who people are thought of the brightest people in his field and asking him what they think of String Theory and they'll say, "I don't know. I don't really understand what's going on. I don't want to comment on it. I'm baffled by it." So, one interesting thing about some of these discussions in the blog is I found one way to figure out exactly what's going on in String Theory and whether something is really a problem or not is to just put out my understanding of it in a blog posting or a comment, or whatever, and then fairly quickly you would find that either I was wrong and there was some reason that this actually made sense even though I thought it didn't, and this way I was quickly and often abusively be explained what an idiot I was and why this was - and here's the answer and you really should have known, or and then I found out they **** learn something, or often found out that if I was right and there really was a problem here, the answer I would get was often this abuse of oh, you're a complete jerk and you're a moron, but no scientific answer to the scientific question. So, that was actually an interesting way to see exactly the state of research on the subject was by kind of probing it and getting that sort of response from some of the more hostile people in the subject.

rn**Question: **Are you optimistic or pessimistic about the Internet’s impact on science?

**Peter Woit:** Well, I think it has definitely - I mean, it's mostly a positive thing. I mean one of the main problems with the blogs, one of the most annoying things about the blogs is - especially if a lot of people are reading it, you're really in a situation where there's a small number of people who really understand it and know what's going on and have something really sensible to say about it because a very large number of people who have some kind of interest in it and have the time and energy to sit there and write uninformed things on your blog and kind of just - so actually unlike some blogs, I actually delete a lot of the comment submitted to my blog and try to keep the noise level down and so that's probably the most discouraging thing about the whole experience. It's just this number of people out there who kind of want to go on about this and argue about this but don' know what they are talking about and want to fill the internet with all information sources they can get their hands on with uninformed nonsense.

So, there's a lot of that, but just the kind of discussion of the subject and of it's problems which I think went on in these blogs and of which if you're interested, you can now **** go to **** and real. I don't know if there's any other format, it's an amazing format for that. There's really no other way that discussion could be held in that way. And also the internet just provides us this kind of amazing access to information of a sort which is totally unlike anything we've ever had before. You can just Google some term and immediately have access to all sorts of often high level discussions of the subject.

rnI think the one - it's actually made some of the faddishness of particle theory a bit worse in the sense that, one thing that used to kind of slow down fads was just how long it took to communicate them to people. I mean, there's certain prominent people might have started working on some idea at Princeton or Harvard, but it would take a while for the news of that and an understanding of what these people were doing to filter out to the rest of the community and if people wanted to kind of jump on it and pursue it in a faddish way, it would take them a while to even find out about it. Whereas now, everybody is kind of, every night there's some new set of preprints come out and the preprints are there, and people logging in and looking at these, and the minute that somebody has some new thing which is becoming a kind of faddish thing to work on, everybody throughout the world has it at exactly the same time on their desktop and can start thinking about it and working on it. So, it kind of makes that even more so than it used to be.

**Recorded on December 16, 2009Interviewed by Austin Allen**