Witten remains a strong string theory believer

[ensabah6]

http://www.forbes.com/forbes/2009/0921/opinions-peter-woit-physics-ideas-opinions.html

Princeton's Witten declines to discuss Woit, saying in an e-mail that he prefers to debate these issues only with "critics who are distinguished scientists rather than with people who have become known by writing books."

 

[RUTA]

http://www.forbes.com/forbes/2009/0921/opinions-peter-woit-physics-ideas-opinions.html

Princeton's Witten declines to discuss Woit, saying in an e-mail that he prefers to debate these issues only with "critics who are distinguished scientists rather than with people who have become known by writing books."

Witten won a Fields Medal (Nobel Prize of math) and I understand his IQ is estimated at over 200. Clearly, he's a genius. But, Witten's accomplishments and brilliance don't convince me that string theory is physics. Here's what P.W. Anderson (Physics Nobel) had to say about it:

“Is string theory a futile exercise as physics, as I believe it to be? It is an interesting mathematical specialty and has produced and will produce mathematics useful in other contexts, but it seems no more vital as mathematics than other areas of very abstract or specialized math, and doesn’t on that basis justify the incredible amount of effort expended on it. My belief is based on the fact that string theory is the first science in hundreds of years to be pursued in pre-Baconian fashion, without any adequate experimental guidance. It proposes that Nature is the way we would like it to be rather than the way we see it to be; and it is improbable that Nature thinks the same way we do. The sad thing is that, as several young would-be theorists have explained to me, it is so highly developed that it is a full-time job just to keep up with it. That means that other avenues are not being explored by the bright, imaginative young people, and that alternative career paths are blocked.”

Philip W. Anderson in “God (or Not), Physics and, of Course, Love: Scientists Take a Leap,” The New York Times, Tues, 4 Jan 05, p D3.

 

[Bob_for_short]

How fair!

Vladimir Kalitvianski.

 

[Naty1]

The FORBES article is excellent.

RUTA posts:

it (string theory) is so highly developed that it is a full-time job just to keep up with it. That means that other avenues are not being explored by the bright, imaginative young people, and that alternative career paths are blocked.”

Others have labored in obscurity until their theories were recognized...like early string theorists...It still is worthwhile to pick work that interests YOU...not what necessarily interests others...

 

[RUTA]

Others have labored in obscurity until their theories were recognized...like early string theorists...It still is worthwhile to pick work that interests YOU...not what necessarily interests others...

That's nice if you have the funding! Most young researchers must follow the money.

 

[Bob_for_short]

That's nice if you have the funding! Most young researchers must follow the money.

How true! I have become an old researcher without a decent possibility to extensively develop my nice solutions.

 

[atyy]

“Is string theory a futile exercise as physics, as I believe it to be? It is an interesting mathematical specialty and has produced and will produce mathematics useful in other contexts, but it seems no more vital as mathematics than other areas of very abstract or specialized math, and doesn’t on that basis justify the incredible amount of effort expended on it. My belief is based on the fact that string theory is the first science in hundreds of years to be pursued in pre-Baconian fashion, without any adequate experimental guidance. It proposes that Nature is the way we would like it to be rather than the way we see it to be; and it is improbable that Nature thinks the same way we do. The sad thing is that, as several young would-be theorists have explained to me, it is so highly developed that it is a full-time job just to keep up with it. That means that other avenues are not being explored by the bright, imaginative young people, and that alternative career paths are blocked.”

Doesn't this sound like an argument against not just string theory, but all quantum gravity and much beyond the standard model research? If supersymmetry is somehow excused, then string theory will escape too, since supersymmetry is a prediction of string theory.

I also find Anderson's argument surprising from his emergence or "more is different" viewpoint, since gravity is emergent in string theory. I suppose the reason he wouldn't like string theory is that string theory claims to be non-emergent, although within it, gravity is emergent. I think Wheeler liked "no tower of turtles", perhaps Anderson likes "tower of turtles" - a view I personally find aestheticaly appealing. If string theory turns out to be right, we can take comfort in the fact that strings themselves are emergent within eg. AdS/CFT and presumably M-theory.

 

[Katastrofa]

That's nice if you have the funding! Most young researchers must follow the money.

If that's how things are in theoretical physics now, then what the advantage of staying in the academia? I know quite a few people who continue science after their PhD and they're not that cynical.

 

[Naty1]

That's nice if you have the funding! Most young researchers must follow the money.

Very true, and also true in almost any endeavor.

Even business owners and exhaulted "captain's of industry" must follow their customers money. The trick is to make the compromises that suit you.

 

[ensabah6]

Doesn't this sound like an argument against not just string theory, but all quantum gravity and much beyond the standard model research? If supersymmetry is somehow excused, then string theory will escape too, since supersymmetry is a prediction of string theory.

I also find Anderson's argument surprising from his emergence or "more is different" viewpoint, since gravity is emergent in string theory. I suppose the reason he wouldn't like string theory is that string theory claims to be non-emergent, although within it, gravity is emergent. I think Wheeler liked "no tower of turtles", perhaps Anderson likes "tower of turtles" - a view I personally find aestheticaly appealing. If string theory turns out to be right, we can take comfort in the fact that strings themselves are emergent within eg. AdS/CFT and presumably M-theory.

How does its emergent gravity avoid the Weinberg-Witten theorem?

 

[atyy]

How does its emergent gravity avoid the Weinberg-Witten theorem?

Emergent gravity must have something else emerge with gravity. In string theory, space also emerges. In many condensed matter models, Lorentz invariance emerges.

 

[marcus]

Atyy, keep in mind the context of Philip Anderson's remark. It was at the end of 2004 when the string community seemed dominated by Susskind's anthropic point of view. The idea was to give up on the quest for a predictive testable theory of nature---assume things are loosely constrained by the fact that we are here, physics is accidental like the fact that there happen to be 9 planets, or "environmental", just pick a beautiful theory that compats with past experimental results.

Strings 2005 at Toronto was organized by people who accepted the Susskind line. But at one point discussion moderator Steve Shanker called for a show of hands vote of the whole meeting and about 3/4 of the rank and file rejected the accidental or "environmental" or anthropic approach. They wanted to continue trying to explain why things have to be this way. The leaders had gone anthropic but the rank and file refused to follow. Shanker was on mike and said "holy sh*t!" when he saw the show of hands.

By 2008 the leadership had swung the other way. The organizers of Strings 2008 did not invite any "String Landscape" speakers. Nobody talked about the 10^500 vacua. Susskind was not even there.

Anderson's remark was made at the height of a serious struggle to preserve the foundations of traditional science. When he implied that people (like Weinberg momentarily, like Wilczek briefly) who had compromised with the Landscape talk were "abandoning a 400 year old Baconian tradition" he was nailing the coonskin to the wall. It was time to take a stand and he was doing that.

What happened was Edge magazine (not a scholarly source!) encouraged a bunch of creative scientists from many fields to answer the question What do you believe but can't prove? In other words the editor John Brockman challenged them to risk baring their hunches, dared them to make statements which they could NOT support as scientists, that they would not otherwise make in public. On newyears Jan 2005 several score answers were published by Edge. They were very interesting. Two princeton guys, Philip Anderson and Paul Steinhardt, came our fiercely against String Landscape, against giving up the fundamental science quest and saying it's just an accident which vacuum state. They came out against the prevailing views of the string leadership, which characterized string at that time. But did not characterize it later, like in 2008.

So I think that Philip Anderson's statement---his answer to the Edge Newyears 2005 Question, must be understood in that context. It has nothing to do with other approaches to quantum gravity. Because the leadership of the nonstring QG community had not for a moment suggested that it would be OK to have a theory that was not falsifiable. In that community they had not gone anthropic. They still held to the doctrine that a scientific theory must be empirically testable and not stand by beauty alone. They were not threatening to redefine the science enterprise. So Anderson was not talking to them. He was laying dire Anathema on whatever of the top string people were straying down Susskind's path. I think it helped save the situation.

Steinhardt used more words and made this plainer. There was less chance of misunderstanding the message (as you seem to have done with Anderson.)

I think now the Landscape biz is doornails that these guys would feel no urge to fulminate in exactly this way.

The key sentence is: "It proposes that Nature is the way we would like it to be rather than the way we see it to be." Well it was the leadership in 2004 who were proposing to go party with nontestable theories, if they looked attractive. It was the leadership, not an intrinsic property of the string formalism to be "proposing" this. Anthropery was not intrinsic to the formalism, it was a philosophical "out". Anthropery was merely Susskind's bright idea to save the program---something he thought up when he heard about the KKLT paper's 10^500 vacua. It was a philosophical dodge he took in 2003, and which gained ground for a year or two.

 

[marcus]

Steinhardt's response to the 2005 Edge question is much clearer, he uses more words and avoids the risk of being misunderstood. He has the same things on his mind as Philip Anderson:

http://www.edge.org/q2005/q05_print.html#steinhardt

==quote==
I believe that our universe is not accidental, but I cannot prove it.

Historically, most physicists have shared this point-of-view. For centuries, most of us have believed that the universe is governed by a simple set of physical laws that are the same everywhere and that these laws derive from a simple unified theory.

However, in the last few years, an increasing number of my most respected colleagues have become enamored with the anthropic principle—the idea that there is an enormous multiplicity of universes with widely different physical properties and the properties of our particular observable universe arise from pure accident. The only special feature of our universe is that its properties are compatible with the evolution of intelligent life. The change in attitude is motivated, in part, by the failure to date to find a unified theory that predicts our universe as the unique possibility. According to some recent calculations, the current best hope for a unified theory—superstring theory—allows an exponentially large number of different universes, most of which look nothing like our own. String theorists have turned to the anthropic principle for salvation.

Frankly, I view this as an act of desperation. I don't have much patience for the anthropic principle. I think the concept is, at heart, non-scientific. A proper scientific theory is based on testable assumptions and is judged by its predictive power. The anthropic principle makes an enormous number of assumptions—regarding the existence of multiple universes, a random creation process, probability distributions that determine the likelihood of different features, etc.—none of which are testable because they entail hypothetical regions of spacetime that are forever beyond the reach of observation. As for predictions, there are very few, if any. In the case of string theory, the principle is invoked only to explain known observations, not to predict new ones. (In other versions of the anthropic principle where predictions are made, the predictions have proven to be wrong. Some physicists cite the recent evidence for a cosmological constant as having anticipated by anthropic argument; however, the observed value does not agree with the anthropically predicted value.)

I find the desperation especially unwarranted since I see no evidence that our universe arose by a random process. Quite the contrary, recent observations and experiments suggest that our universe is extremely simple. The distribution of matter and energy is remarkably uniform. The hierarchy of complex structures ranging from galaxy clusters to subnuclear particles can all be described in terms of a few dozen elementary constituents and less than a handful of forces, all related by simple symmetries. A simple universe demands a simple explanation. Why do we need to postulate an infinite number of universes with all sorts of different properties just to explain our one?

Of course, my colleagues and I are anxious for further reductionism. But I view the current failure of string theory to find a unique universe simply as a sign that our understanding of string theory is still immature (or perhaps that string theory is wrong). Decades from now, I hope that physicists will be pursuing once again their dreams of a truly scientific "final theory" and will look back at the current anthropic craze as millennial madness.
==endquote==

In other words, it's not bad to be immature or wrong. Lots of great people have worked on theories that remained unfinished or turned out wrong. What's bad, in his view, is to go Anthropic in desperation and try to relax the standards of scientific endeavor, just to save a pet project.

 

[atyy]

Ah that's too bad, I thought I was going to have a sharp disagreement with Anderson - at the same time I will leave open that we do have a sharp disagreement, since I'm not sure he would like me to understand that his opposition is to the anthropic principle, and not to string theory - I believe Witten also dislikes anthropic stuff. I have to admit that my first gut feeling is horror at the anthropic principle, but some aspects of it are intriguing to me as a neurobiologist - because if the anthropic principle became scientific, that would mean we would have a theory of the physics of intelligence and maybe even of consciousness

The other thing I like about it is it is a discussion of a quote of Einstein's that I like "The most incomprehensible thing about the world is that it is at all comprehensible."

 

[marcus]

The other thing I like about it is it is a discussion of a quote of Einstein's that I like "The most incomprehensible thing about the world is that it is at all comprehensible."

You have to grant that Einstein expected rational explanation. His curiosity would have been unsatisfied if someone had merely declared it was a lucky accident that we happen to live in one of the universes which our intelligence can grasp.

There are possible evolutionary selection mechanisms that one can explore. If, as Alan Guth suggested, "the universe was created by some guy in his garage"----or, as Andrei Linde imagined, it was created by a couple of graduate students, then selection for reproductive success favors comprehensibility. If conscious agents sometimes accelerate or enhance reproduction, there might be a straightforward Darwinian reason that universes typically follow simple mathematical laws. That is just one possible Darwinian explanation for Einstein's mystery---a form of the "efficacy of mathematics" mystery.

And mathematics itself clearly evolves, as long as mathematicians are critical of each other's inventions and discoveries, and as long as they keep trying to mutate the structure by adding new concepts and methods it will evolve. As long as people keep trying to apply math to understand nature, math will be shaped by this process so as to be better at making nature comprehensible. We don't know what "mathematics" ultimately is. It is just a bunch of rules and symbols that continue to evolve for doing physics etc. The useful linguistic inventions survive and reproduce.

(As long as we require predictive understanding and discard what is merely myth, this kind of conceptua/linguistic evolution will continue. It is community and tradition driven. Which is why Anderson is right to cherish the Baconian ethic.)

 

[atyy]

The Darwinism I'm liking best at the moment is Zurek's. It seems to address some problems with his older decoherence approach.

 

[marcus]

The Darwinism I'm liking best at the moment is Zurek's. It seems to address some problems with his older decoherence approach.

You read more widely than I do. What does Zurek say?

 

[atyy]

You read more widely than I do. What does Zurek say?

I'm still trying to understand it, so just my quick impression. Anyway, it's actually just about the emergence of the classical from the quantum, not any of these strange Susskind/Guth/Linde fantasies. The old decoherence approach had the problem that it used the Born rule implicitly in tracing over environmental degrees of freedom, so it still kind of had wave function collapse. Now he says that by adding (i) the universe has subsystems and (ii) measurements can only be made on states that leave multiple fragments in the environment, we can "justify our condence in quantum mechanics as ultimate theory that needs no modications to account for the emergence of the classical."

I'm sure I'm garbling it, so here are the references.

http://arxiv.org/abs/0707.2832
http://arxiv.org/abs/0903.5082

 

[Fra]

I have to admit that my first gut feeling is horror at the anthropic principle, but some aspects of it are intriguing to me as a neurobiologist - because if the anthropic principle became scientific, that would mean we would have a theory of the physics of intelligence and maybe even of consciousness

There has in some papers when people comments on other papers about evolution and antrophics been a confusing between more proper evolution, darwin style, and the anthropic rescue of a situation where something has gone beserk and inflated a gigantic landspace in where we are apparently lost.

I suspect from a brain/biology point of view this would be an important distinction. A proper evolutionary model would IMO rationally inflate the hypothesis space on demand, as not to flood/drown the testing in a gigantic space (landscape). This would be fatal behaviour for say a brain!

If we try to find similarities between the antrophics on string theory and other (IMO) more clever ideas, this is as I see it a key distinction.

One that Smolin tried to make as well in the reasoning motivating this CNS.

/Fredrik

 

[RUTA]

Atyy, keep in mind the context of Philip Anderson's remark. It was at the end of 2004 when the string community seemed dominated by Susskind's anthropic point of view. The idea was to give up on the quest for a predictive testable theory of nature---assume things are loosely constrained by the fact that we are here, physics is accidental like the fact that there happen to be 9 planets, or "environmental", just pick a beautiful theory that compats with past experimental results.

Strings 2005 at Toronto was organized by people who accepted the Susskind line. But at one point discussion moderator Steve Shanker called for a show of hands vote of the whole meeting and about 3/4 of the rank and file rejected the accidental or "environmental" or anthropic approach. They wanted to continue trying to explain why things have to be this way. The leaders had gone anthropic but the rank and file refused to follow. Shanker was on mike and said "holy sh*t!" when he saw the show of hands.

By 2008 the leadership had swung the other way. The organizers of Strings 2008 did not invite any "String Landscape" speakers. Nobody talked about the 10^500 vacua. Susskind was not even there.

Anderson's remark was made at the height of a serious struggle to preserve the foundations of traditional science. When he implied that people (like Weinberg momentarily, like Wilczek briefly) who had compromised with the Landscape talk were "abandoning a 400 year old Baconian tradition" he was nailing the coonskin to the wall. It was time to take a stand and he was doing that.

What happened was Edge magazine (not a scholarly source!) encouraged a bunch of creative scientists from many fields to answer the question What do you believe but can't prove? In other words the editor John Brockman challenged them to risk baring their hunches, dared them to make statements which they could NOT support as scientists, that they would not otherwise make in public. On newyears Jan 2005 several score answers were published by Edge. They were very interesting. Two princeton guys, Philip Anderson and Paul Steinhardt, came our fiercely against String Landscape, against giving up the fundamental science quest and saying it's just an accident which vacuum state. They came out against the prevailing views of the string leadership, which characterized string at that time. But did not characterize it later, like in 2008.

So I think that Philip Anderson's statement---his answer to the Edge Newyears 2005 Question, must be understood in that context. It has nothing to do with other approaches to quantum gravity. Because the leadership of the nonstring QG community had not for a moment suggested that it would be OK to have a theory that was not falsifiable. In that community they had not gone anthropic. They still held to the doctrine that a scientific theory must be empirically testable and not stand by beauty alone. They were not threatening to redefine the science enterprise. So Anderson was not talking to them. He was laying dire Anathema on whatever of the top string people were straying down Susskind's path. I think it helped save the situation.

Steinhardt used more words and made this plainer. There was less chance of misunderstanding the message (as you seem to have done with Anderson.)

I think now the Landscape biz is doornails that these guys would feel no urge to fulminate in exactly this way.

The key sentence is: "It proposes that Nature is the way we would like it to be rather than the way we see it to be." Well it was the leadership in 2004 who were proposing to go party with nontestable theories, if they looked attractive. It was the leadership, not an intrinsic property of the string formalism to be "proposing" this. Anthropery was not intrinsic to the formalism, it was a philosophical "out". Anthropery was merely Susskind's bright idea to save the program---something he thought up when he heard about the KKLT paper's 10^500 vacua. It was a philosophical dodge he took in 2003, and which gained ground for a year or two.

Do you have a more recent quote from Anderson to support this?

 

[marcus]

Do you have a more recent quote from Anderson to support this?

What would you like supported?
My main point here is a self-evident one. You can't take stuff out of context, especially in this case.
Edge is a web-magazine, not a scientific journal. In this case they dared people to say things they could not prove. That means whatever: express attitude, hunch, take a speculative flyer.
So the responses they got were extraordinary---and often not couched in cautious, qualified terms.

That's obvious, I think, and doesn't need to be supported.

Then there was a terrific fight going on. Read Paul Steinhardt's statement, which is more careful, and less off-the-cuff. But part of the same battle. You have to understand Anderson's Edge words in that context. I think the importance of historical context is obvious here, and doesn't need any more support.

I don't see what you imagine a more recent quote from Anderson would be supportive of?
Now that the Anthropic String Landscape drive has been effectively halted and there is general agreement that we don't change the rules (theories still have to be testable, physics is still trying to explain why nature is the particular way it is)----now that this is fairly well settled, I would not expect Anderson to be making statements at all like his Edge words. Why would he be bothering to say anything about superstring at all? It is increasingly less of an issue. So what kind of quote do you imagine? And what proposition would it support?

 

[RUTA]

What would you like supported?
My main point here is a self-evident one. You can't take stuff out of context, especially in this case.

You identified a context and hypothosized a motivating connection to the concerns in his quote.

I don't see what you imagine a more recent quote from Anderson would be supportive of?

Your hypothesis. I can see this supported in at least two ways. Directly, by another Anderson quote like that of Steinhardt's. Or, indirectly, by a newer Anderson quote consistent with a revised context.

Your hypothesis is reasonable, but that doesn't make it true.

 

[marcus]

Your hypothesis is reasonable, but that doesn't make it true.

Thanks for the careful response! No, it certainly doesn't make it true. You could falsify it if you could find a furious rant against string by Anderson say from 2008.
And you possibly could. That would signify a deepseated skepticism, going beyond what was called for by the battle going on at that time.

I'm trying to give the most reasonable interpretation I can, and to put that short remark of his which was taken out of context back into context---which you always have to do.

BTW personally I think those two statements by Anderson and Steinhardt were important---almost Churchillean. They were so timely, and helped to turn the tide. It was enormously important that the organizers of Strings 2008 excluded all multiverse talk, all anthropic landscape accidental probability talk. Even though there were still major people like Michael Douglas doing that kind of research and they could have come and reported on it. It was a significant turnaround. I give Anderson and Steinhardt a lot of credit. They could not be suspected of saying what they did because of an interest in Loop, or some such. They weren't members of a rival "camp". They were Princeton, high establishment. Nor were either in the slightest bit "maverick". And they spoke in a highly visible forum. I think it made a difference.

 

[marcus]

Witten won a Fields Medal (Nobel Prize of math) and I understand his IQ is estimated at over 200. Clearly, he's a genius. But, Witten's accomplishments and brilliance don't convince me that string theory is physics. Here's what P.W. Anderson (Physics Nobel) had to say about it:

“Is string theory a futile exercise as physics, as I believe it to be? It is an interesting mathematical specialty and has produced and will produce mathematics useful in other contexts, but it seems no more vital as mathematics than other areas of very abstract or specialized math, and doesn’t on that basis justify the incredible amount of effort expended on it. My belief is based on the fact that string theory is the first science in hundreds of years to be pursued in pre-Baconian fashion, without any adequate experimental guidance. It proposes that Nature is the way we would like it to be rather than the way we see it to be; and it is improbable that Nature thinks the same way we do. The sad thing is that, as several young would-be theorists have explained to me, it is so highly developed that it is a full-time job just to keep up with it. That means that other avenues are not being explored by the bright, imaginative young people, and that alternative career paths are blocked.”

Philip W. Anderson in “God (or Not), Physics and, of Course, Love: Scientists Take a Leap,” The New York Times, Tues, 4 Jan 05, p D3.

RUTA, on reflection I am beginning to take your point of view. Anderson's remark could be intended to apply beyond that particular late-2004 situation. He might subscribe to it today. That's not how I originally heard it, but could be.

BTW I guess you noticed that the title of the thread is laughable. The Forbes account gave no evidence to support it. Nor did the journalist even state an opinion about the man's state of belief. Nobody but the thread author is pretending to be able to look into a scientist's head and gauge the strength of his belief. I suppose he could have intended the thread title to be tongue-in-cheek, or simply provocative.

What one can truthfully report (as some try to) is based on the talks people give at major conferences, what their current research emphasis is---the objective signals. With top people (whose casual comments may in part be merely politic) watch what they do.

 

[RUTA]

Thanks for the careful response! No, it certainly doesn't make it true. You could falsify it if you could find a furious rant against string by Anderson say from 2008.
And you possibly could. That would signify a deepseated skepticism, going beyond what was called for by the battle going on at that time.

I'm trying to give the most reasonable interpretation I can, and to put that short remark of his which was taken out of context back into context---which you always have to do.

BTW personally I think those two statements by Anderson and Steinhardt were important---almost Churchillean. They were so timely, and helped to turn the tide. It was enormously important that the organizers of Strings 2008 excluded all multiverse talk, all anthropic landscape accidental probability talk. Even though there were still major people like Michael Douglas doing that kind of research and they could have come and reported on it. It was a great turnaround. I give Anderson and Steinhardt a lot of credit. They could not be suspected of saying what they did because of an interest in Loop, or some rival "camp". They were Princeton, the high establishment. Nor were they in the slightest bit "maverick". And they spoke out in a highly visible way.

The reason I'm skeptical is based on what I know from a friend who is going to speak at Pitt on the adversarial relationship between the solid state and high energy physics camps. This friend earned his reputation as a philosopher of science in the emergence community, so I hear about Anderson's ideas all the time. Apparently, Anderson doesn't think too highly of the entire high energy physics program for different reasons. Anyway, this guy thinks Anderson's 2005 quote still reflects his attitude twds string theory and promised me some quotes in support

 

[RUTA]

BTW I guess you noticed that the title of the thread is laughable. The Forbes account gave no evidence to support it. Nor did the journalist even state an opinion about the man's state of belief. Nobody but the thread author is pretending to be able to look into a scientist's head and gauge the strength of his belief.

What one can truthfully report (as some try to) is based on the talks people give at major conferences, what their current research emphasis is---the objective signals. With top people (whose casual comments may in part be merely politic) watch what they do.

I could ask his dad, who was my thesis advisor, but I'm sure he's bothered enough by questions about Ed

 

[marcus]

The reason I'm skeptical is based on what I know from a friend who is going to speak at Pitt on the adversarial relationship between the solid state and high energy physics camps. ... promised me some quotes in support

Wow! This is great. I will be really interested to hear what he comes up with.

I could ask his dad, who was my thesis advisor, but I'm sure he's bothered enough by questions about Ed

Louis Witten! RUTA you are gold. I mean as a source of insight and information. Let me take a moment to regain composure.

 

[Xezlec]

Witten won a Fields Medal (Nobel Prize of math) and I understand his IQ is estimated at over 200. Clearly, he's a genius. But, Witten's accomplishments and brilliance don't convince me that string theory is physics.

Saying something is wrong or a waste of time is one thing, but don't you think it's a little over the line to claim an opposing idea is "not physics"? I mean, is it physics to keep pursuing grand unification when there's not necessarily any reason to expect it to happen, other than the whole aesthetics/symmetry line of thought? Is it physics to keep pursuing physics at all, beyond the standard model? Shouldn't we just quit, until some insurmountable contradiction presents itself? It would seem that the meaning of "physics" is a bit broad. Has to be. Or people wouldn't still be doing it at this point.

Also, arguments like this severely damage the public image of science. The argument over whether this major branch of physics is physics has led a lot of laymen to believe that physics is all silliness and no one knows anything anyway. They equate "string theory is not physics" with things like "healing touch is not physics", and assume that therefore, pseudoscience theories are on about the same footing as cutting-edge physics. This completely false popular idea has led a lot of people down a dark path. I wish physicists could tone down the rhetoric and be a little more accommodating of each other, if only for appearance's sake.

That's nice if you have the funding! Most young researchers must follow the money.

WOW, you are a cynic! If that's true, I wonder what's wrong with their brains? Why would someone whose only interest is "following the money" major in physics, of all things? Why not law or business or medicine? By the same token, petroleum engineering must be the most popular branch of engineering! Heh.

Sure, money is probably a draw. I think the bigger draw is the popularity and attractiveness of the idea. Blame Brian Greene for that. So, write a popular book on LQG or something. And don't make it all just a big, unattractive rant about your enemies, like Smolin did, but an actual book that explores the concept of LQG alone. That might get you the kind of positive attention you want.

If String Theory is BS, I doubt seriously that it will survive another 30 years. People do get bored eventually.

 

[marcus]

... a little over the line to claim an opposing idea is "not physics"? ... equate "string theory is not physics" with ...

Xezlec, you are rambling incoherently. RUTA did not claim that "string theory is not physics".
He indicated that he might not be convinced it was physics. To be in doubt is a legitimate position.

And what he actually said was that so-and-so's accomplishments & brilliance did not convince him---who could reasonably object? The brilliance of a practitioner does not by itself validate a practice.

 

[RUTA]

Wow! This is great. I will be really interested to hear what he comes up with.

I'm curious, but of course Anderson's is just one opinion and, from what I understand, a very biased opinion at that.

Louis Witten! RUTA you are gold. I mean as a source of insight and information. Let me take a moment to regain composure.

Louis was a great advisor and I'm in his debt for taking me as a grad student, especially since I refused to do string theory. I consider him a friend, so I'm trying to be respectful. Capiche?

 

[MTd2]

Louis was a great advisor and I'm in his debt for taking me as a grad student, especially since I refused to do string theory. I consider him a friend, so I'm trying to be respectful. Capiche?

Why is it surprising of him taking you as a advisor? He is Witten, but not Ed. Btw, could you try to reach Edward and convince him to post here?

 

[RUTA]

Saying something is wrong or a waste of time is one thing, but don't you think it's a little over the line to claim an opposing idea is "not physics"? I mean, is it physics to keep pursuing grand unification when there's not necessarily any reason to expect it to happen, other than the whole aesthetics/symmetry line of thought? Is it physics to keep pursuing physics at all, beyond the standard model? Shouldn't we just quit, until some insurmountable contradiction presents itself? It would seem that the meaning of "physics" is a bit broad. Has to be. Or people wouldn't still be doing it at this point.

Some people have said string theory is worth doing because it's "pretty mathematics" even if it turns out to be wrong. Pretty mathematics is worth doing as a society, but I'm not sure to what extent it should be funded by the physics community.

WOW, you are a cynic! If that's true, I wonder what's wrong with their brains? Why would someone whose only interest is "following the money" major in physics, of all things? Why not law or business or medicine? By the same token, petroleum engineering must be the most popular branch of engineering! Heh.

Sure, money is probably a draw. I think the bigger draw is the popularity and attractiveness of the idea. Blame Brian Greene for that. So, write a popular book on LQG or something. And don't make it all just a big, unattractive rant about your enemies, like Smolin did, but an actual book that explores the concept of LQG alone. That might get you the kind of positive attention you want.

Many people major in physics because it's of interest to them, only after they graduate do they concern themselves with finding work. At that point, they must follow the money unless they have other sources of food, medicine, housing, etc. I saw an interview with Duff last night in which he said he lost prospective grad students who told him they were going to do string theory instead because of post-grad job prospects. I can't tell you how many times I've heard students say they were looking into X because of funding prospects. It's a factor.

A major concern from those not doing string theory is whether or not string theory is being funded properly. Is it being funded in the right context (physics instead of math)? Is it being funded to a degree commensurate with its success (as opposed to promise)? Should the physics community continue investing research positions so heavily in string theory (given its history of unfulfilled promises)? In all cases where resources are distributed disproportionately, society eventually demands accountability. Rightfully so, in my opinion.

 

[RUTA]

Why is it surprising of him taking you as a advisor? He is Witten, but not Ed. Btw, could you try to reach Edward and convince him to post here?

He was working and publishing with Ed. Why would he agree to mentor someone infinitely dumber? In GR instead of strings at that? I must've caught him on a good day

Ed wouldn't respond to Woit, why would he respond here?

 

[marcus]

RUTA, capisco!

MTd2, be reasonable! We are small fry here, there is no room for the big fishes.

BTW MTd2 don't underestimate the importance of having a relativist guide your development. The rumpus and loggerheads of recent years has a lot to do with particle physicists, blinded by their own brilliance and success, being unable to see things from a GR perspective. Being unable to ask what space is, or in what sense it exists at all, but building fields on it as if they knew. Would you have, back in 1987, done a thesis in GR/cosmology? Yes, now twenty years later, I know you are speculating that Matt Visser (a relativist) would be a good advisor. We have grasped that understanding the new physics of 1915 remains, in a way, the biggest item on the agenda.

 

[marcus]

RUTA, here's a question that has been on my mind, in case you feel comfortable responding on this topic. You mentioned emergence---and the word has so many different meanings. For me Emergent Gravity basically means whatever approaches to QG were gathered and reviewed at the EG4 conference in Vancouver last month. (Some of which I only dimly grasp.) Broad diversity, a lot of newcomers.

On the other hand, Wikipedia has a (possibly misleading) article on the Weinberg-Witten theorem of 1980 which portrays the W-W as defense against "emergent physics" and we are given to understand this includes "emergent gravity".

Because the same word, "emergent", was used, an uncritical reader might conclude that the 1980 W-W, which dealt with particle physics in the QFT setting, applies to 2009 emergent QG approaches. Do you see any connection?

My understanding is that the W-W was a no-go for certain particles to be composite. It may have ruled out preons under some circumstances. The geometric venue was SR's static Minkowski space. So it seems to me naive to imagine that today's emergent QGs, which don't use conventional QFT particles defined on conventional Minkowski space, are subject to W-W and therefore must get an excuse in order to "avoid" it. But maybe it's not! Any comment? Can you clarify this at all?