Causes of loss of interest in String program

[yoda jedi]

just throw away string theory (and the froot loop theory too)...



.

 

[marcus]

just throw away string theory (and the froot loop theory too)...

Come on, Yoda, these things are quite fascinating and you know it.

 

[Sardano]

I'm tired of arguing about that one, Atyy. "Subtle" or not, I'm very interested in the points that Suprised has made here. I'd like to understand better how the program is going to evolve---what direction it will take going forward.

Maybe you should understand String Theory first, and then you could speak about the ST research program with some knowdlege at least... What would you say if you were a ST physicist and if someone who has never studied ST, who has never made any research in ST, who quote ST papers that does not understand enters in your office and starts making claims about the "ST research program" and the "evolution of ST".

I mean, were you a part of the ST research and the ST program? Do you know the ST program from the inside, or just from the ST abstracts you hardly read in the arxiv?

No ofense but all this together with your obscure intentions of showing fake satistics make everything you write non reliable.

 

[marcus]

Thanks for sharing your views.

 

[marcus]

Atyy has been prodding me to define what I mean by "interest" in this thread. What I have been concerned with all along is the quality which many of us remember characterized the string program in the early part of the last decade. Vitality, excitement, clear sense of direction, large volume of highly-cited papers,...etc.

I'm not talking about the interest that an individual person might have for this or that topic, but rather a bulk collective quality that infuses the program itself.

In academic circles it's fairly usual to gauge that by (1) citations to current work, and (2) attendance at the main annual conference. Neither measure is perfect, of course, but that's often how you get a rough idea of how active a field is----outside of physics as well.

So that's basically how we define "interest" in this thread---by how it is measured. Operational definition

=============

It is not necessarily bad for a program to lose steam in this sense. There may be good reasons for it. And it may be temporary.

Nobody needs to get defensive, go into denial, think they are being attacked and so forth. The program may or may not have lost steam since say 2004. It may even have lost momentum/direction and then regained some. We don't know. In any case whatever has happened the reasons might be interesting.

================

I recently went back to the Strings 2004 conference website and it was like being in a different world (from say Rome 2009 or College Station 2010). You might try that.
Or contrast David Gross closing talk (overview of the program) at Madrid 2007 with his opening talk (also overview, where we are) at Rome 2009. He is talking concrete physics in both cases.
================

Anyway I claim that this kind of change can occur in a research program and is a legitimate thing to try to understand especially when it rests on physics reasons.
And it can go either way, a program can lose energy and gain energy and may even do so in different sectors, I imagine, at the same time. We'll see what are brought up as reasons.
================

btw several people (PAllen? Suprised?) have mentioned difficulty. Citations may have gone down because it's harder to write a paper nowadays that will have significant impact on the field. Harder to write and longer. Short papers no longer have as much impact---I think it was one or the other of them who said that. Doesn't matter who, could have been someone else.
================

I was also thinking that some things Suprised and Fzero said could represent reasons for a loss in program direction/energy/interest (as gauged by current citations and conference participation). The dispersion of the paradigm into an abstract flock of alternatives no one of which is to be considered real. It may make the field intellectually intriguing but at the same time interfere with a coherent sense of direction.

Just a tentative thought. Maybe someone else will come up with better reasons.
=====================

Then there is Bohr's Truth: it's not about what nature IS. Physics is about how Nature responds to measurement. Where are the measurements in the various string theories or proto-theories? How are measurements represented mathematically? It might be interesting if someone would discuss that a bit.

 

[atyy]

In academic circles it's fairly usual to gauge that by (1) citations to current work, and (2) attendance at the main annual conference. Neither measure is perfect, of course, but that's often how you get a rough idea of how active a field is----outside of physics as well.

I'm a biologist. Whenever anyone does that for my field, I conclude they are not willing to think for themselves.

 

[marcus]

I'm a biologist. Whenever anyone does that for my field, I conclude they are not willing to think for themselves.

Then since judging by citations is so common there must be a great many people whom you deem unwilling to think for themselves. Academics have a love-hate relation with cite-counts.

I sympathize since I also tend to evaluate stuff independently on my own. But hiring committees and deans are aware of citations and such. Funding agencies would pay attention to this kind of measure. You may have applied for grants or been up for tenure--and have first hand experience of this.

We devoutly believe that nothing beats an intelligent person's subjective assessment. But even so we are always getting rated on the basis of objectifiable external circumstances. Especially if it is by a committee, because the various subjective judgments may not coincide.

 

[suprised]

marcus, you state always as actual fact what you believe and/or want to make others believe. It is simply not true that there is lack of steam, motivation, and progress, etc. The new things and the people behind this may perhaps not be visible to you, but this doesn't mean they they don't exist.

Many of the interesting an important things that happen right now or recently have to do with the interplay of string theory and gauge theory; not only in the sense of AdS/CFT, but also in the sense of amplitudes, and in the sense of TFT. Why don't you check names like (random order) Gaiotto, Nekrasov, Neitzke, Alday, Drummond, etc? These are people that may be too young for you to appear on your radar screen. But they are among the driving forces of what ppl are excited about these days.

With regards to string conference attendance: there was only one dip, and this was last year. Ppl have attributed this to the grossly unattractive conference site in the middle of nowhere, in contrast to previous ones. As far as I can tell, the collegues around me incl myself didn't go largely for this reason.

In order to make claims as you do, you should make out a longer term trend. What you do is to stir in a coffe pot and try to make general conclusions about the pattern you choose to see. You are warmly invited to do this for yourself, but you also attempt to influence other people with this. As I said, you don't do any favor to science by that, on the contrary.

 

[marcus]

...
With regards to string conference attendance: there was only one dip, and this was last year. Ppl have attributed this to the grossly unattractive conference site in the middle of nowhere, in contrast to previous ones. As far as I can tell, the collegues around me incl myself didn't go largely for this reason.

In order to make claims as you do, you should make out a longer term trend. What you do is to stir in a coffe pot and try to make general conclusions about the pattern you choose to see...

Suprised, I very much appreciate this comment. First of all you are quite right! The conference attendance measure of interest/activity in the field appears FLAT! It shows no decline of interest at all.

What you say about the dip in 2010 has a completely adequate explanation, I would say, that obviously has nothing to do with physics. It has to do with TEXAS.

I really appreciate your taking my effort here seriously enough to point this out in a calm polite manner.
======================
People quibble so frantically about the word "interest" that I have to be careful to stick to the measures that I have set out and committed to.
I have chosen two conventional academic measures of the level of interest/activity in a field:
(1) citations to current work
(2) main conference attendance.
At least in this thread, I have to stick to those two and see what they show, if anything.
============================

On the other hand, I also hear what you say about tracking output of younger people. One difficulty with just looking at top people is their output may be declining anyway due to age. You made that point several posts ago and I noted it but did not get around to replying.

Why don't you check names like (random order) Gaiotto, Nekrasov, Neitzke, Alday, Drummond, etc? These are people that may be too young for you to appear on your radar screen. But they are among the driving forces of what ppl are excited about these days.

Since I decided to concentrate on those two measures (1) and (2), I would not ordinarily be tracking research output of anybody young or old. But since you mention some excellent young people (I have a high opinion e.g. of Andy Neitzke and have seen a lot of references to papers where Allday has at least been co-author) I think I may try giving them the same treatment. Gaiotto and Nekrasov are also familiar names.

We can have an explicit clear understanding that tracking research output is NOT to be considered a measure of interest as I have defined it, but is just a sideline auxiliary measure, which might or might not correlate.

You understimate my openmindedness I shall be interested to see what shows up.

 

[oldman]

I’m provoked into posting in this thread by your remarks in post 145, Marcus. You quote
Bohr's Truth as:

...it's not about what nature IS. Physics is about how Nature responds to measurement.

And then
add:

Where are the measurements in the various string theories or proto-theories? How are measurements represented mathematically? It might be interesting if someone would discuss that a bit.

I agree.

A quibble: did Bohr talk of measurement in this quote? Or did he just say:

It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature?

Which is not quite the same thing. Talk is cheap. Measurement is probably impossible in the
realm of string theory and loop quantum gravity, etc. Both are (mathematical) talk that so far has failed to meet the long-established gold standard that distinguishes physics from say, literary criticism; namely of being able to make verifiable predictions.

Secondly, it seems to me that this thread exemplifies a Truth expressed by John Horgan in
June 1996: that some folk ...

...pursue science in a speculative, non-empirical mode that (Horgan calls) ironic science. Ironic science resembles literature or philosophy or theology in that it offers points of view, opinions, which are, at best, "interesting," which provoke further comment.

.

 

[suprised]

So who is Horgan...a second Niels Bohr?

 

[unusualname]

@oldman

this is a fundamental physics forum, anyone slightly lightweight usually perishes pretty soon (me soon unless...)

It's all deep mathematical understanding here, do you get the topological arguments of string theory mathematically or are you a noob thinking of extra space dimensions as really existing?

Basically, reality is a work in progress by mankind, if the popular press want to portray the state-or-the-art expert thinking in simple terms like "extra space dimensions" then that's the way it is. The fact the some of the people involved contribute to this portrayal doesn't help. But it's a mathematical model, sorry suckers but reality really isn't the way your mind conceives it,

 

[atyy]

Then since judging by citations is so common there must be a great many people whom you deem unwilling to think for themselves. Academics have a love-hate relation with cite-counts.

I sympathize since I also tend to evaluate stuff independently on my own. But hiring committees and deans are aware of citations and such. Funding agencies would pay attention to this kind of measure. You may have applied for grants or been up for tenure--and have first hand experience of this.

We devoutly believe that nothing beats an intelligent person's subjective assessment. But even so we are always getting rated on the basis of objectifiable external circumstances. Especially if it is by a committee, because the various subjective judgments may not coincide.

I didn't say that any particular subjective judgement was better than random statistics. But I did say that random statistics are not better than subjective judgement. (They are all bad, except for my personal objective view )

More seriously, people on committees know they will make mistakes, but they do their best given limited time and funding and responsibility to the source of funding. But I'm sure the best people on committees do not rely on statistics, preferring to make their own mistakes.

But silly games are fun! Please give us the p value for your statistics, and make sure they are corrected for multiple comparisons. The use of any test that assumes Gaussianity must also be justified.

 

[marcus]

Bohr's Truth (actual quote as found by Oldman):

"It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature."

Which is not quite the same thing. Talk is cheap. Measurement is probably impossible in the
realm of string theory and loop quantum gravity, etc. Both are (mathematical) talk that so far has failed to meet the long-established gold standard that distinguishes physics from say, literary criticism; namely of being able to make verifiable predictions.
.. .

But he said it roughly 100 years ago, so I interpret the Bohr quote in the light of a stern Lutheran north-Europe culture where you could go to hell for saying what you didn't know---for making up stories about nature without firm justification. "What we can say..." I (personally) interpret to mean what we can say with sober righteous empirical justification.

And empiricism is not about what it IS but about how it responds to measurement. One is in a continuous interrogatory dialog.

So I disagree with your interpretation but nevertheless find your post a cheerful ray of light. It is good to have the exact (English translation?) Bohr quote.

 

[marcus]

...
Basically, reality is a work in progress by mankind, if the popular press want to portray the state-or-the-art expert thinking in simple terms like "extra space dimensions" then that's the way it is. The fact the some of the people involved contribute to this portrayal doesn't help. But it's a mathematical model, sorry suckers but reality really isn't the way your mind conceives it,

YESSS!
This has the ring of truth. And where is the act of measurement represented in this mathematical model? Or collection of models?

There is probably a simple obvious answer, so just to make it explicit: Where in various related models are we told about the limitations of measurement?

I would like to have built into my model the idea of what information is accessible about the world's geometry---a concrete representation of the geometrical measurements we are allowed to make.

 

[unusualname]

YESSS!
This has the ring of truth. And where is the act of measurement represented in this mathematical model? Or collection of models?

There is probably a simple obvious answer, so just to make it explicit: Where in various related models are we told about the limitations of measurement?

I would like to have built into my model the idea of what information is accessible about the world's geometry---a concrete representation of the geometrical measurements we are allowed to make.

I think we've got pretty close to the "geometry" of reality, just that we've gone off on all sorts of really weird and convoluted paths trying to complete it. Mainly because we're trying to make nature conform to a deterministic model at some level, when it doesn't, but that's just my (maybe wrong) idea.

 

[marcus]

...
More seriously, people on committees know they will make mistakes, but they do their best given limited time and funding and responsibility to the source of funding. But I'm sure the best people on committees do not rely on statistics, preferring to make their own mistakes.
...

Your moral certainty about this does you credit, Atyy! And I would like to think that we ALL make up our own minds, reasoning subjectively and independently, "preferring to make our own mistakes."

Committee's are set up to force people to come to agreement. Statistics together with other external evidence can help settle difference and arrive at collective decision. They play a useful role even if none of the brilliant subjective minds on the committee believes in the infallibility of statistics.

Your post expressed tolerance, and I appreciate that.

BTW I don't know how the citations and participation measures will turn out this year or the next or the next and they could well turn out quite favorably!
This would not necessarily make me change my mind!

There may NOT currently be a lull in the enthusiasm of string theorists, or if there is it could be merely temporary---and whether there is or not should not influence how one evaluates the field. One's opinion should be based on principles.

But I would still like to know the reasons for whatever it is that is going on.

 

[marcus]

I think we've got pretty close to the "geometry" of reality, just that we've gone off on all sorts of really weird and convoluted paths trying to complete it. Mainly because we're trying to make nature conform to a deterministic model at some level, when it doesn't, but that's just my (maybe wrong) idea.

Great! It's good news that you are close to the "geometry" of reality.

I want to understand better this going off on various different paths.

I'm interested in your idea that the divergence or dispersal into different models has to do with nature not conforming to a single deterministic model.

There was an exchange between Tom and Suprised which might interest you, if you didn't happen to see it. One of Suprised's points relates to what you said.

I quoted the exchange in post #129 of this thread, to have it handy:
https://www.physicsforums.com/showthread.php?p=3266311#post3266311
(I note with amusement that this post also contained a tabulation of attendance at past Strings conferences, one of our objective measures of the state of health, ridiculous or not.)

 

[unusualname]

Great! It's good news that you are close to the "geometry" of reality.

I want to understand better this going off on various different paths.

I'm interested in your idea that the divergence or dispersal into different models has to do with nature not conforming to a single deterministic model.

There was an exchange between Tom and Suprised which might interest you, if you didn't happen to see it. One of Suprised's points relates to what you said.

I quoted the exchange in post #129 of this thread, to have it handy:
https://www.physicsforums.com/showthread.php?p=3266311#post3266311
(I note with amusement that this post also contained a tabulation of attendance at past Strings conferences, one of our objective measures of the state of health, ridiculous or not.)

marcus, you should check my home web page, I think we're just a tiny weeny perturbation away from the correct model of reality, unfortunately it's a new landscape with ~(#states in the universe)^2 solutions!

or maybe something more obvious, if you have any ideas pm me!

 

[marcus]

Unusual, for some reason I can't find the URL to your homepage. Also I'm reluctant, here in this thread, to get off into anything that is not in the common vocabulary of string theorist and would not e.g. be discussed in their main annual conference at least once and a while.
I don't know if your new Landscape would form part of that central ground that I'm trying to understand better. It might, but I'm not in a position to judge.

I need to refresh us on the objective measures (humble as they are) which are always there to compare with our subjective views and either explain away or find reasons for.

 

[marcus]

This thread started with a modest bit of objective reality in the form of some cite count observations. It may be time to find some alternative citation count measures. These can always be explained away but useful observations can come up while we do that. Both PAllen and Suprised pointed out some interesting reasons for the last batch.

We also have these figures on the main annual conference attendance

Number of physicists at Strings conferences:
Strings 2003 396
Strings 2004 477
Strings 2005 415
Strings 2006 ~600
Strings 2007 (site broken)
Strings 2008 400
Strings 2009 450
Strings 2010 193

These are essentially FLAT obviously. Suprised has explained the anomalous 2010 figure. The conference was in TEXAS, which is also rather flat. The 2006 figure is from the Chinese news agency. There is some confusion about how many physicists took part, Strings 2006 was a big event in China.

I will go find the earlier citation count figures. For the purposes of this thread, "interest" is what is measured by (1) citations to current research and (2) attendance at the main annual conference---common ways of gauging the health and activity of an academic field.

Here we are, from post #16:
==quote==
Spires top cited articles during odd years 2001-2009
(with number of recent string papers making the top fifty shown in parenthesis)

http://www.slac.stanford.edu/spires/topcites/2001/annual.shtml (twelve)
http://www.slac.stanford.edu/spires/topcites/2003/annual.shtml (six)
http://www.slac.stanford.edu/spires/topcites/2005/annual.shtml (two)
http://www.slac.stanford.edu/spires/topcites/2007/annual.shtml (one)
http://www.slac.stanford.edu/spires/topcites/2009/annual.shtml (one)

A paper is counted as recent here if it appeared in the past five years.
==endquote==
In making the counts I tried to use a broad idea of what research to include as string and examined whatever was in doubt by hand. I did not merely rely on the papers' abstracts. Of course AdS stuff and Randall-Sundrum stuff etc etc are included. Make the count yourself if you want.

What you get is not flat, but the decline has been, in part, explained away by some thoughtful observations that PAllen made. Also as I recall Suprised pointed out that it is more difficult now than it was earlier to write a significant paper that the other string theorists will want to cite a lot.

Objective measures are not the most intriguing part of the discussion (recent posts by Oldman, Suprised, Unusualname, and others deserve serious attention please look back to the previous page!) but I do want to try to find a fresh measure of citations-to-current-research.

Also Suprised suggested looking at the publication record of some younger string theorists, which I think is a very good idea. He mentioned Alday, Gaiotto, Drummond, Neitzke, and Nekrasov.

There's a fair amount to be attended to, I see.

 

[yoda jedi]

Come on, Yoda, these things are quite fascinating and you know it.

was fascinating, I think the string theory will not survive.


.

 

[yoda jedi]

Bohr's Truth (actual quote as found by Oldman):

"IIt is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature."


But he said it roughly 100 years ago, so I interpret the Bohr quote in the light of a stern Lutheran north-Europe culture where you could go to hell for saying what you didn't know---for making up stories about nature without firm justification. "What we can say..." I (personally) interpret to mean what we can say with sober righteous empirical justification.

And empiricism is not about what it IS but about how it responds to measurement. One is in a continuous interrogatory dialog.

So I disagree with your interpretation but nevertheless find your post a cheerful ray of light. It is good to have the exact (English translation?) Bohr quote.

yes bohr, can be changed:

"IIt is wrong to think that the task of physics is to find out what nature is. Physics concerns what we can say about nature."

and that is called the epistemic view.

...and maybe can be right.

.

 

[marcus]

I don't know if String models incorporate what you call the epistemic view.

I would like if someone could show me how the Program does this. If it does not then this could be one of the root reasons for what has happened to the program. Something clearly has happened. People get emotional and squabble about what words to use to describe it but the bickering is not so important.

What I hear in this thread is that the Program does not offer a single handle on the world, but rather has broken into a tribe of different models.

The sophisticated view is that none of these models represents reality. However they are all interesting to examine and find relations between.

I would not say that this dispersion and this sophisticated view is inherently wrong! However these two things may help to understand the decline in citations (and possible other measures of direction and vitality.)

In any case I would be glad to be contradicted by anyone who thinks they know that this sophisticated proliferation is NOT a factor, or even that it does not exist. I might learn something from a counterargument.
=======================

Yoda, about the epistemic view. It's one of the things I look for. An "information-oriented" theory of geometry. I want our geometric measurements of the world to be incorporated in the theory---present mathematically. Perhaps as tangible operators on a tangible Hilbertspace, or in some other concrete mathematical form.
Because "not about what the world IS, but about how it responds when we measure" and that includes the measurements corresponding to preparation of experiment and subsequent predictions.
For me it is pragmatic/operational. I don't myself say "epistemic" but I think you understand very well what I am trying to say.

Since there is one world (that all observers share) why is there not one "string theory" that describes how that world responds to each observer's measurements of it? And in particular to geometrical measurements, since everything else rests in and on the geometry.

And what has one done, if one gives up the goal of such a theory and adopts a more sophisticated view? Do you understand my viewpoint?

 

[marcus]

Looking back to post #161, this is a quick way of showing declining string representation in the Spires ALL-HEP Top Fifty. The 50 most cited papers in all that Spires HEP database covers.
==quote==
Spires top cited articles during odd years 2001-2009
(with number of recent string papers making the top fifty shown in parenthesis)

http://www.slac.stanford.edu/spires/topcites/2001/annual.shtml (twelve)
http://www.slac.stanford.edu/spires/topcites/2003/annual.shtml (six)
http://www.slac.stanford.edu/spires/topcites/2005/annual.shtml (two)
http://www.slac.stanford.edu/spires/topcites/2007/annual.shtml (one)
http://www.slac.stanford.edu/spires/topcites/2009/annual.shtml (one)

A paper is counted as recent here if it appeared in the past five years.
==endquote==

Several people pointed out that this includes a lot of EXPERIMENTAL AND OBSERVATIONAL competition. So it doesn't bring out how highly cited current string research could be if you restrict to some THEORY branch. I'll pick a theory branch and do the even years this time, to see how it goes. To save trouble I will just count string appearances in the Spires Top Ten "quantum gravity" listing.

String papers appearing in the indicated year making the Spires "quantum gravity" top ten:
2000:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2000&FORMAT=WWW&SEQUENCE=citecount%28d%29
4 out of 10 here (that I can see). The string papers I identify are numbers 1,3,5, and 9. I'm happy if anyone wants to check that.

2002:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2002&FORMAT=WWW&SEQUENCE=citecount%28d%29
3 out of 10, this time. I would say 1, 6, and 7 are the stringy ones.

2004:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2004&FORMAT=WWW&SEQUENCE=citecount%28d%29
1 out of 10. The one string paper making the top ten is number 8.

2006:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2006&FORMAT=WWW&SEQUENCE=citecount%28d%29
4 out of 10. The stringy ones are numbers 1, 3, 6, 8.

2008:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2008&FORMAT=WWW&SEQUENCE=citecount%28d%29
3 out of 10. Numbers 1, 6, 10.

2010:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=dk+quantum+gravity+and+date+%3D+2010&FORMAT=WWW&SEQUENCE=citecount%28d%29
2 out of 10. Numbers 5 and 8.

So nothing remarkable. I would call it roughly FLAT.

 

[atyy]

I think it's generally agreed there hasn't been another string revolution yet (although there have been a few "minirevolutions" as Lubos likes to say)

That is very different from any loss of interest (in plain English, not your technical definition) in string theory.

If you are asking for people to put their ideas here how to make another string revolution, I'm pretty certain no one is going to say. If they knew, they'd write the paper!

But progress can be made in many different ways, including an accumulation of "small" steps. After all, AdS/CFT has roots going back to QCD, to 't Hooft's holography, and to Brown and Henneaux's paper relating AdS3 to a CFT. Enough small steps can be revolutionary too, the computer industry is a clear example.

 

[negru]

String theory is usually classified under high energy, not quantum gravity, so I'm not sure how useful that is.

 

[Sardano]

String theory is usually classified under high energy, not quantum gravity, so I'm not sure how useful that is.

The thing is, we already know that string theory is a perturbative consistent theory of gravity. We already know that we can include non perturbative effects and that gravity has a consistent unitary realization in String Theory. So the problem of Quantum Gravity in String Theory has been solved long ago. The String Theory program has another problems and challeneges, like applying this quantum theory of everything to solve physical problems and make cuantitave unique predictions.

 

[marcus]

@Atyy, negru, Sardano
All reasonable observations! Thanks--especially for what Atyy says about making progress in small steps. I'd be glad if anyone wants to check my counts of string papers in the Spires quantum gravity top ten of these years. For the links look back a few to post #165.

Papers making the QG top ten
Year               2000      2002      2004      2006      2008      2010
String-related       4         3         1         4         3         2

For String-related I included some Sugra4 and Sugra8 that did not explicitly mention string, and also some Randall-Sundrum and several AdS/CFT. Also Bousso's holography result that Ashtekar has extended to a stronger result in LQC (it is not solely a string result but works in other contexts.)
I tried to be generously inclusive. You can see how it went, if you want.

The most obvious thing I guess is that the string presence in QG is FLAT. There is no decline shown here. Interestingly there is a decline if you look at the Spires HEP database as a whole. Look back to post #161. You might want to try to figure out why that is. From 12 out of the TopFifty down to 1 out of the TopFifty. Maybe you can decide on some simple explanation.

Atyy has already given an explanation for the decline from 12/50 to 1/50. But you might want to think of your own preferred reasons.

BTW traditionally a theory of quantum gravity is expected to resolve the singularity at the start of expansion, and therefore to make testable predictions about early universe (CMB observations). I think this expectation goes back to John Archibald Wheeler, possibly earlier.

 

[marcus]

...
The most obvious thing I guess is that the string presence in QG is FLAT. There is no decline shown here. Interestingly there is a decline if you look at the Spires HEP database as a whole. Look back to post #161. You might want to try to figure out why that is. From 12 out of the TopFifty down to 1 out of the TopFifty. Maybe you can decide on some simple explanation.
Atyy has already given an explanation for the decline from 12/50 to 1/50. But you might want to think of your own preferred reasons.

BTW traditionally a theory of quantum gravity is expected to resolve the singularity at the start of expansion, and therefore to make testable predictions about early universe (CMB observations). I think this expectation goes back to John Archibald Wheeler, possibly earlier.

The measure of interest (vitality) we are using here is based on annual citations to recent literature---plus annual attendance (which doesn't show a drop.)
So looking at individual researchers' outputs cannot directly show a decline of interest. However it can indicate causes to us.

Changes in the researcher's output can suggest reasons for a decline in the field as a whole.

One hypothesis (which some of the best posts by others in this thread tend to confirm) is that stringers have become sophisticated and are no longer apt to view their vibrating geometrical objects in their extra-dimensional backgrounds as real. The conception of reality (and how we may measure it) has dispersed into a flock of sophisticated abstract alternatives. So far this is just a hypothesis to be considered. A certain degree of this kind of dispersion is natural in any kind of exploration, but if it gets extreme it might have something to do with a decline in annual citations to recent work.

Suprised has suggested looking at the research output of Gaiotto, Alday and others to see if there is a contrast with what we were seeing earlier. What we found earlier was a drop in research specifically about strings and branes. That is what DESY classifies with the terms "string model" and "membrane model". They also have some minor categories called "M-brane" and "string, spin", but those are the two main ones.

What we found earlier by looking at the work of a sampling of top people was admittedly pretty crude and undecisive but suggested a change in the character of research.
Since the people Suprised suggested are younger, I will just look at recent years 2006-2010.

 

[marcus]

Here's for Gaiotto:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Gaiotto%2C+d+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2006&FORMAT=WWW&SEQUENCE= (5)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Gaiotto%2C+d+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2007&FORMAT=WWW&SEQUENCE= (3)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Gaiotto%2C+d+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2008&FORMAT=WWW&SEQUENCE= (2)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Gaiotto%2C+d+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2009&FORMAT=WWW&SEQUENCE= (4)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Gaiotto%2C+d+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2010&FORMAT=WWW&SEQUENCE= (0)

Here's for Alday:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Alday%2C+L+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2006&FORMAT=WWW&SEQUENCE= (1)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Alday%2C+L+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2007&FORMAT=WWW&SEQUENCE= (1)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Alday%2C+L+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2008&FORMAT=WWW&SEQUENCE= (3)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Alday%2C+L+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2009&FORMAT=WWW&SEQUENCE= (1)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Alday%2C+L+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2010&FORMAT=WWW&SEQUENCE= (1)

I have to say nothing remarkable is happening. So my hypothesis of a change in character of research is not showing up, not clearly and unambiguously in any case. Of course it is just a spot check with a very small sample---names suggested by Suprised.


Here's for Nekrasov:
http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Nekrasov+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2006&FORMAT=WWW&SEQUENCE= (2)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Nekrasov+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2007&FORMAT=WWW&SEQUENCE= (0)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Nekrasov+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2008&FORMAT=WWW&SEQUENCE= (1)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Nekrasov+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2009&FORMAT=WWW&SEQUENCE= (1)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Nekrasov+and+%28DK+string+model+or+membrane+model+or+M-brane%29+and+date%3D2010&FORMAT=WWW&SEQUENCE= (1)

Well that tends to shoot down the hypothesis of a change in character (away from concrete geometric paradigms). On a quick spot check basis, there is no marked decline in specifically string and brane research by these young people unless it happened EARLiER with Alday and Nekrasov.

 

[marcus]

As a reminder of what the main topic is here:
https://www.physicsforums.com/showthread.php?p=3268516#post3268516
What I mean by interest is field vitality measured by annual cites to current research (and annual conference attendance, but that shows no decline).

So what I'd like to explain away or understand the reasons for is this:

Spires top cited articles during odd years 2001-2009
(with number of recent string papers making the top fifty shown in parenthesis)
2001:
http://www.slac.stanford.edu/spires/topcites/2001/annual.shtml (twelve)
2003:
http://www.slac.stanford.edu/spires/topcites/2003/annual.shtml (six)
2005:
http://www.slac.stanford.edu/spires/topcites/2005/annual.shtml (two)
2007:
http://www.slac.stanford.edu/spires/topcites/2007/annual.shtml (one)
2009:
http://www.slac.stanford.edu/spires/topcites/2009/annual.shtml (one)

A paper is counted as recent here if it appeared in the past five years.

What I'm interested here is not absolute numbers but the change. Is it flat? Or if not, which way does the change go? And can we explain it?

At least on the surface this looks remarkable. And we don't have, as yet, a satisfactory explanation although several have been suggested.

It could have to do with "Bohr's Truth" (discussed by Oldman and Yoda and myself). Namely the models do not contain a mathematical representation of measurement, but instead refer to concrete physical objects which are imagined to exist---something that reality is supposed to be made of. Bohr and others have said that is not the way to go.

It could have to do with "increased sophistication" (presented in a favorable light by some of us) where the researchers no longer believe in the real existence of strings and branes that reality was earlier supposed to be made of, or in the extra dimensions wherein they were thought to vibrate. Instead, there are a lot of different mathematical models to study and compare.

It could have to do with the explanation Atyy offered, that "there hasn't been another string revolution yet". The last one was, as I recall, around 1998. There was an interesting panel discussion of this at the Toronto Strings 2005 conference, called "The Next String Theory Revolution". If Atyy's explanation is right, then annual citations to current literature just naturally decline if there is no revolution.

It could be that something is wrong with the annual Spires Top 50 HEP listing.

There is a remote possibility, I guess, that the obvious decline has to do with the increased interest in the early universe, over the past 10 years. This would tend to favor physical theories that say something definite about the start of expansion. Maybe there is something to that, and we may be able to check on it. Perhaps I should look at LQG occurrene in some annual series analogous to the annual Spires Top 50. Since Loop is a much smaller program, it wouldn't show up at all in the overall Spires HEP Topcites. But we can look at it in the narrower gr-qc context (general relativity-quantum cosmology).

Number of recent Loop papers making the annual Spires gr-qc Top 50
2003:
http://www.slac.stanford.edu/spires/topcites/2003/eprints/to_gr-qc_annual.shtml (5)
2005:
http://www.slac.stanford.edu/spires/topcites/2005/eprints/to_gr-qc_annual.shtml (7)
2007:
http://www.slac.stanford.edu/spires/topcites/2007/eprints/to_gr-qc_annual.shtml (5)
2009:
http://www.slac.stanford.edu/spires/topcites/2009/eprints/to_gr-qc_annual.shtml (5)
A paper is counted as recent here if it appeared in the past five years.

At least in this case there are some clear physics grounds that could help explain the sustained performance. We have been getting a lot of data on the early universe and there is a lot of interest in understanding it. The start of expansion is something we can expect to get improved models of. Physically speaking it is a fertile field, so that conceivably could have something to do with what we are looking at.

EDIT: I guess "Bohr's Truth" also would apply to explain this, since LQG is not about what the buildingblocks of reality might be (if there are such things), but about the interrelationship of measurements. The quantum state of geometry is defined by a hypothetical network of measurement.

 

[marcus]

Suprised suggested I look at the publication of some younger theorists (Alday, Gaiotto, Neitzke, Nekrasov,...) in the same light as we earlier looked at some famous people that came to mind as a kind of informal spot check.

I finally got around to doing this in a systematic way. Note that we are not gauging interest as defined here, but looking for a shift in focus, a change in the character of these people's research.
(In some cases part of any observed decline could be due to the decline in output that often comes with age, but most here are young or in middle years.)

Because the younger people were not producing papers so far back as the earlier tabulation went, I shortened the time range down to 2003-2010. This counts the papers that DESY classified "string model" or "membrane model", as was done before in the earlier tabulation.

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=a+Silverstein+and+%28dk+string+model+OR+dk+membrane+model%29+and+date+%3E+2002+and+date+%3C+2005&FORMAT=WWW&SEQUENCE= (9)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=find+a+Silverstein+and+%28dk+string+model+or+dk+membrane+model%29+and+date+%3E+2004+and+date+%3C+2007&FORMAT=WWW&SEQUENCE= (7)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=find+a+Silverstein+and+%28dk+string+model+or+dk+membrane+model%29+and+date+%3E+2006+and+date+%3C+2009&FORMAT=WWW&SEQUENCE= (5)

http://www-library.desy.de/cgi-bin/spiface/find/hep/www?rawcmd=find+a+Silverstein+and+%28dk+string+model+or+dk+membrane+model%29+and+date+%3E+2008+and+date+%3C+2011&FORMAT=WWW&SEQUENCE= (5)

          2003-2004      2005-2006      2007-2008      2009-2010
Gaiotto         5              9              5              4
Alday           1              5              4              0
Neitzke         3              2              1              0
Nekrasov        4              3              1              2  
Strominger     15              7              4              0
Dijkgraaf       4              5              3              4
Polchinski      8              3              2              2
Maldacena      17              7              5              4 
Gibbons,G       6              5              1              1
Harvey,J        4              5              2              0
Ooguri          7              6              3              4
Silverstein,E   9              7              5              5

 

[fzero]

Alday had at least 9 papers in 2009-2010 that directly use string theory to compute results in gauge theory. An example is http://www-library.desy.de/cgi-bin/spiface/find/hep/www?irn=8558248 The DESY keywords for the paper are

supersymmetry, 4
surface, minimal
space, anti-de Sitter
scattering amplitude
strong coupling
Bethe ansatz, thermodynamical
free energy
gluon

The minimal surfaces being referred to are classical string configurations whose boundary is the gauge theory Wilson loop. Once again, DESY keywords are completely insufficient for distinguishing between papers which either use or do not use string theory techniques. None of the above keywords, either alone or in combination, could be used to conclude that string techniques were being used without making additional assumptions.

 

[MTd2]

I guess it should be done something like this, a Boolean search like "N=1" OR "N=2" OR "N=4" OR "N=8". It would give a better picture.