Is String/M becoming obsolete?

[Martin]

My sense is that, at least temporarily, it is becoming less fashionable---particularly outside the US. There are younger rivals with better near term prospects for testing. I've noticed a tendency for people to get out of Stringy research and move into other fields. String papers have lost standing in the Spires citation index of what's currently hot in physics (astrophysics and condensed matter physics have pulled ahead.)

 

The String/M theories-under-construction remain unfinished in the sense that they are incapable of making unequivocal predictions which would allow them to be tested---any theory which does not risk refutation by making testable predictions is vacuous.

 

Non-string theories of quantum gravity seem comparatively better-funded outside the United States than in, and much of the progress developing them is currently made outside the US. Meanwhile the physics departments at most major US universities are ill-prepared to shift direction. I see that some people are speculating about a reduction in funding for String research and the defensive reation that seems most prevalent is for US String rearchers to make derogatory statements about a visible rival---fostering the impression that, no matter how badly things are going with String, funding should not be cut because it is "our best hope". The "our best hope" argument should be taken with a grain of salt

 

These issues are worth exploring and clarifying, and I hope we can do that some in this thread, even though they should not influence our guesses about what theory or theories will ultimately take a testable shape and what sort(s) of theory may ultimately predict the parameters of the standard models of particle physics and cosmology.

[Martin]

Just to get some objective idea of the financial and intellectual resources being poured into String research, have a look at the number of papers posted on the ArXiv, by year for 10 years. The Cornell Preprint Archive was set up in the early 1990s partly to facilitate String/M research and for many years the large "hep-th" category was almost synonymous for String.

 

The following links use the arXiv search enging to count papers whose abstract summary has the following keywords:

string OR brane OR braneworld OR D-brane OR M-theory OR p-brane.

 

Year 1994:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1994/0/1

 

Year 1995:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1995/0/1

 

Year 1996:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1996/0/1

 

Year 1997:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1997/0/1

 

Year 1998:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1998/0/1

 

Year 1999:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/1999/0/1

 

Year 2000:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2000/0/1

 

Year 2001:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2001/0/1

 

Year 2002:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2002/0/1

 

Year 2003:

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/2003/0/1

 

Last twelve months (e.g. 1 October 2003 to 1 October 2004):

http://lanl.arXiv.org/find/nucl-ex,astro-ph,nucl-th,math-ph,hep-ex,physics,cond-mat,hep-lat,quant-ph,gr-qc,hep-ph,hep-th/1/OR+OR+abs:+OR+string+brane+abs:+OR+braneworld+D-brane+abs:+OR+M-theory+p-brane/0/1/0/past/0/1

 

The preprint archive and search tools are not totally stable and show some unexplained variation, which however does not affect the qualitative impression one gets. To show this variation (which is mostly in the counts for 2003 and "Last Twelve Months", the first column was gotten using these links on Monday 9 August, the second column was using the same links on 5 October.

 

1994    610    610
1995    801    801
1996   1002   1002
1997   1248   1248
1998   1299   1299
1999   1403   1403
2000   1492   1492
2001   1546   1546
2002   1570   1523
2003   1408   1287
LTM    1117    872

[Martin]

One way to get the issues in sharp focus is to look at the comment around a recent paper by Michael Douglas

Basic Results in Vacuum Statistics

http://www.arxiv.org/abs/hep-th/0409207

 

Peter Woit's blog made the most pointed comment:

 

---quote Woit blog of September 20, 2004---

 

This Week's Predictions

 

A new preprint (http://www.arxiv.org/abs/hep-th/0409207 ) by Michael Douglas indicates that, at least this week, the latest "predictions" from string theory are for:

 

1. No large extra dimensions.

 

2. No low scale supersymmetry.

 

So it looks like the "prediction" of the string theory "Landscape" will be that no physics related to string theory beyond that of the standard model will ever be observable. Thus the only "prediction" of string theory will be that you can never see any physics related to it. This kind of "prediction" is great since it proves string theory must be true. Either you don't ever see any effects of string theory in which case you have confirmed its predictions so it must be true, or you do see effects of string theory, in which case string theory is even more true....

---end quote---

http://www.math.columbia.edu/~woit/blog/archives/000082.html

 

Michael Douglas is a prominent string theorist. A crisis in String developed around January 2003 with the posting of a paper by Kachru et al which indicated that there were a large number (like 10¹⁰⁰) of possible models of string, or "string vacuums", each with different properties. No predictive way has been found to designate one model as the right one. Douglas was the string theorist who took the lead in exploring this misty realm of possibilities.

 

Douglas commented on his own paper, at sci.physics.string:

 

He said the goal of his work is to estimate N_SM, the number of vacua consistent with observed Standard Model behavior, then

 

---quote from Douglas---

 

"Based on this information, we can decide whether we should continue the search for the right vacuum directly (appropriate if N_SM <= a few), look for additional principles to cut down the number (if N_SM is large), or give up and start making anthropic arguments or whatever (if N_SM is ridiculously large)."

 

----end quote----

For Douglas entire post, see:

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=edd7c2f0.0409301316.27a441f9-100000%40posting.google.com&prev=/groups%3Fhl%3Den%26lr%3D%26ie%3DUTF-8%26group%3Dsci.physics.strings