Causes of loss of interest in String program

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."
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

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 in to 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

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

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

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:
http://physicsforums.com/showthread....11#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

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/...1/annual.shtml (twelve)
http://www.slac.stanford.edu/spires/...3/annual.shtml (six)
http://www.slac.stanford.edu/spires/...5/annual.shtml (two)
http://www.slac.stanford.edu/spires/...7/annual.shtml (one)
http://www.slac.stanford.edu/spires/...9/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

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


.

yoda jedi

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/...1/annual.shtml (twelve)
http://www.slac.stanford.edu/spires/...3/annual.shtml (six)
http://www.slac.stanford.edu/spires/...5/annual.shtml (two)
http://www.slac.stanford.edu/spires/...7/annual.shtml (one)
http://www.slac.stanford.edu/spires/...9/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/s...tecount%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/s...tecount%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/s...tecount%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/s...tecount%28d%29
4 out of 10. The stringy ones are numbers 1, 3, 6, 8.

2008:
http://www-library.desy.de/cgi-bin/s...tecount%28d%29
3 out of 10. Numbers 1, 6, 10.

2010:
http://www-library.desy.de/cgi-bin/s...tecount%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

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.

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 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.