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Sociology of Physics: comment and indices

by marcus
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marcus
#37
Jul18-09, 03:37 PM
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A couple of days ago I thought the spike was over and it was back to normal (like 0.5 - 0.7) but that hasn't happened yet actually. Trouble is still doing somewhat better than par.

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9

2 July 3.78
3 July 5.88
4 July 5.11
5 July 16.10
6 July 15.81
7 July 7.09
8 July 5.98
9 July 5.58
10 July 3.87
11 July 2.92
12 July 2.67
13 July 6.42
14 July 4.88
15 July 2.37
16 July 0.81
17 July 1.67
18 July 2.76
19 July 1.50


At noon pacific on 19 July, Trouble was 4081 and the most popular stringies (elegant, parallel, blackhole, fabric, hyperspace) were 3403, 5943, 6152, 7098, 8108 for an average of 6140.8 making the ratio 1.50.
Fra
#38
Jul21-09, 01:49 AM
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Thanks. I was just curious if the explanation could have been a random fluctuation. A random fluctuation as an explanation would be more plausiable the lower the total # of books is.

The larger # of individual books it is, the more remarkable is it.

So maybe one explanation could have been: A drop in totals sales# of all books (due to bad times?) + fluctuations which are bound to come in the small n limit :)

/Fredrik
marcus
#39
Jul21-09, 03:54 PM
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The main cause of turbulence just this past week, that I have seen, is the appearance of "Kindle" e-book versions of all these titles. Amazon is listing e-book ranks (from the "Kindle store") mixed into the physics bestseller list, which is quite confusing. e-book ranks are calculated on a different basis. I suspect that Kindle store sales (of the e-books) is small compared with total sales of ordinary books, so for the time being I am ignoring the Kindle versions of the titles. TwP now has a kindle version and it is doing quite well in the ranks, which surprises me. I thought that it would be mostly children and young people who buy the e-books, and I don't think of them as the main market for TwP. The appeal is that you get the book instantly, by wire, and also it is cheaper.
In any case, in doing these numbers I am focusing only on real books, and ignoring e-books.

Also there was a jump in sales of the Susskind black hole book (not really about string but I include it in calculating the stringy topfive because of some string-inspired stuff in chapters near the end.) This jump in sales came immediately after an article by Susskind appeared in Physics World. This makes it more believable that Smolin's spike in sales was at least partly caused by his having an article in Physics World (with some follow-on comment) a couple of weeks earlier. It was the magnitude of the spike that strikes me as unusual, not the timing.

Trouble is still doing somewhat better than par.

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9

2 July 3.78
3 July 5.88
4 July 5.11
5 July 16.10
6 July 15.81
7 July 7.09
8 July 5.98
9 July 5.58
10 July 3.87
11 July 2.92
12 July 2.67
13 July 6.42
14 July 4.88
15 July 2.37
16 July 0.81
17 July 1.67
18 July 2.76
19 July 1.50
20 July 1.19
21 July 1.30
22 July 1.39


At noon pacific on 21 July, Trouble was 3750 and the most popular stringies (blackhole, elegant, fabric, parallel, hyperspace) were 2071, 2121, 5145, 6722, 8284 for an average of 4868.6 making the ratio 1.30.

At noon pacific on 22 July, Trouble was 3055 and the most popular stringies (fabric, blackhole, elegant, parallel, hyperspace) were 2778, 3161, 3491, 3637, 8223, for an average of 4258.0 making the ratio 1.39.
marcus
#40
Jul24-09, 03:14 PM
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Something made the Smolin book sales pick up in late June/early July. There was an unexplained two-week spike in sales during the first half of July, which is now over. But the salesrank is still better than par, and better than in the first half of this year. I'm wondering if this indicates anything for the long term.

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
19 July 1.50
20 July 1.19
21 July 1.30
22 July 1.39
23 July 1.79
24 July 1.09
25 July 0.53


At noon pacific on 23 July, Trouble was 2190 and the most popular stringies (elegant, blackhole, fabric, parallel, hyperspace) were 1701, 2234, 2379, 4976, 8333 for an average of 3924.6 making the ratio 1.79.

At noon pacific on 24 July, Trouble was 3848 and the most popular stringies (elegant, hyperspace, fabric, blackhole, parallel) were 2257, 3600, 4369, 4648, 6013 for an average of 4176.8 making the ratio 1.09.

On the 25th Trouble ranked 6714 compared with a stringy topfive average of 3564.2 making the ratio 0.53, more like what was typical during the first half of the year.

=====================
EDIT TO REPLY TO NEXT POST
Hi Views,
Since I can still edit this, I will save a post and reply to yours here. You asked what are my thoughts. I think the Kachru et al paper you refer to would not have had anything to do with the increase in sales of Smolin's book, The Trouble with Physics, during July.
ViewsofMars
#41
Jul25-09, 09:40 AM
P: 463
Quote Quote by marcus View Post
Something made the Smolin book sales pick up in late June/early July.
Marcus, it might have peeked due to this publication:

Work supported in part by US Department of Energy contract DE-AC02-76SF00515
Published in Annu. Rev. Nuc. Part. Sci
June 2009

MPP-2009-15
UPR-1205-T
SLAC-PUB-13531

D-brane Instantons in Type II String Theory

Ralph Blumenhagen1, Mirjam Cvetiˇc2, Shamit Kachru3,4 and Timo Weigand4
1 Max-Planck-Institut f¨ur Physik, F¨ohringer Ring 6,
D-80805 M¨unchen, Germany
2 Department of Physics and Astronomy, University of Pennsylvania,
Philadelphia, PA 19104-6396, USA
3 Department of Physics, Stanford University,
Stanford, CA 94305, USA
4 SLAC National Accelerator Laboratory, Stanford University,
Menlo Park, CA 94309, USA

Abstract
We review recent progress in determining the effects of D-brane instantons
in N = 1 supersymmetric compactifications of Type II string theory to four
dimensions. We describe the abstract D-brane instanton calculus for holomorphic couplings such as the superpotential, the gauge kinetic function
and higher fermionic F-terms. This includes a discussion of multi-instanton
effects and the implications of background fluxes for the instanton sector.
Our presentation also highlights, but is not restricted to the computation
of D-brane instanton effects in quiver gauge theories on D-branes at singularities. We then summarize the concrete consequences of stringy D-brane instantons for the construction of semi-realistic models of particle physics or SUSY-breaking in compact and non-compact geometries.

[68 pages – Please read.]
http://www.slac.stanford.edu/cgi-wra...-pub-13531.pdf
I was especially interested in CONCLUSIONS AND OUTLOOK (p. 56 - 58). What are your thoughts about it?
ViewsofMars
#42
Jul25-09, 04:12 PM
P: 463
Quote Quote by marcus View Post
=====================
EDIT TO REPLY TO NEXT POST
Hi Views,
Since I can still edit this, I will save a post and reply to yours here. You asked what are my thoughts. I think the Kachru et al paper you refer to would not have had anything to do with the increase in sales of Smolin's book, The Trouble with Physics, during July.
Hi Marcus. That's fine.

Getting back to what you stated, "Something made the Smolin book sales pick up in late June/early July." I hope you won't mind me mentioning that I’m still new here so I hope it is ok for me to share with you what I just earlier observed elsewhere on physicsforums. You might consider in the future that because of you the 'increase in sales of Smolin's book' may have resulted when you presented on June 2, 2009 in Physics, Sub-Forums : Beyond the Standard Model, Topic: re: Introduction To Loop Quantum Gravity (page 11):

“This wide audience article by Smolin in PhysicsWorld (June 2, 2009) could turn out to be influential. It is part of the development of Unimodular Relativity (UR) in conjuctions with evolutionary cosmology (the conjectured evolutionary basis for the laws of physics).
It's a very readable article, called The Unique Universe."

and this quote of yours too may have had an effect on sales:
Quote Quote by marcus View Post
That true! And it's a fairly deep insight. I think in the United States it has been difficult to do social criticism because of a widespread fatuous complacency---an unquestioned conviction that our society is so good it should be the model for democracy all over the world. Bush-heads and Palin-drones think this. Maybe now that belief is not so widespread but in the 40s and 50s there was a pious creed that America was special, a land of freedom and fairness etc etc etc., example to the world.

Don't get me wrong, I'm very patriotic and always read the Declaration of Independence out loud on the 4th of July. Or encourage the young people to do it. I'm proud of some things about my country. But there has been excessive self-satisfaction.

And so because of this deafness to explicit social crit, I think that some of the energy of social criticism was channeled into SCIENCE FICTION. Which often, in the 1950s anyway, would really be exploring alternate forms of social and political organization. The imaginative exploration of technology was actually masking what was really going on in the genre. It was not science fantasy, it was social fantasy. The invention of social alternatives was so to say enabled by the technological alternatives.

But we are not talking about American Exceptionalism, we are talking about String Exceptionalism: "The Only Game In Town".
Marcus, I'd appreciate a response as I earlier asked of you on the the Kachru et al paper, D-brane Instantons in Type II String Theory that was supported in part by US Department of Energy. I'd like your input on it. Comments please. Thank you in advance for your consideration. I do think it is important for the public to realize that research is important. And, I'm most definately a big fan of the BIG BANG! (A round of applause for George Smoot!)
marcus
#43
Jul26-09, 02:23 PM
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Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
19 July 1.50
20 July 1.19
21 July 1.30
22 July 1.39
23 July 1.79
24 July 1.09
25 July 0.53
26 July 0.76
27 July 1.11


At noon pacific on 26 July, Trouble was 4686 and the most popular stringies (blackhole, elegant, fabric, idiotguide, parallel) were 1245, 2383, 4435, 5016, 5090 for an average of 3633.8 making the ratio 0.76.

At noon pacific on 27 July, Trouble was 3631 and the most popular stringies (blackhole, elegant, fabric, hyperspace, parallel) were 2617, 3653, 3915, 4027, 5976, for an average of 4037.6 making the ratio 1.11.

Quote Quote by ViewsofMars View Post
...
and this quote of yours too may have had an effect on sales:
That's a curious thought. I rather doubt that anything we say here in SocialSci forum significantly influences the mass science book market or any other sector of the world at large.

... I do think it is important for the public to realize that research is important. And, I'm most definately a big fan of the BIG BANG! (A round of applause for George Smoot!)
You sound like you see your role as getting a message across to the general public. What I'm interested in is accurately tracking what is going on. I'm interested in how some indices behave---and in trying to follow and understand certain trends.

I guess there is a secondary idea here also that public support for scientific research will be more solid and effective in the long run if the public is well-informed. If the public knows the truth about what is happening in physics research (not just the hype as per discovery channel and gee whiz science specials.) But that is a secondary consideration. First of all I want some objective comprehension for myself, of what is going on.
==================
BTW View, you keep referring to a technical paper by Kachru et al:
http://arxiv.org/abs/0902.3251
That is not sociology of physics by a long shot! If you want comment on that, you should start a thread about it in Beyond forum. Some of the folks there might be interested in discussing it with you.
marcus
#44
Jul28-09, 02:21 PM
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Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
19 July 1.50
20 July 1.19
21 July 1.30
22 July 1.39
23 July 1.79
24 July 1.09
25 July 0.53
26 July 0.76
27 July 1.11
28 July 1.04
29 July 0.78

At noon pacific on 28 July, Trouble was 4317 and the five most popular stringies (elegant, blackhole, hyperspace, fabric, parallel) were 2917, 3538, 4463, 4632, 6966 for an average of 4503.2 making the ratio 1.04.
===================

Here's a source for another index or two that we could be keeping track of:
http://www.slac.stanford.edu/spires/...tecount%28d%29
This is Loop/Spinfoam research published since 2006 (i.e. 2007-present) ranked by cites.
As of 28 July there are 251 papers listed, and the citecounts for the top ten run from 65 down to 25.

Maybe I should take a two-year chunk, like 2007-2008, and watch that because the number of papers will not increase. Then compare that with 2008-2009, or eventually with 2009-2010. We can track the rate of research publication that way, as well as the citations picture.

Here is the same search but restricted to [2007, 2008]. The search finds 196 papers in the Spires data base.
http://www.slac.stanford.edu/spires/...tecount%28d%29
As you might expect, the ten topcited papers are the same ones, and range from 65 down to 25.

Loop/Spinfoam publication rate (entries in the Spires database for two-year intervals)

[2003 2004] 126
[2005 2006] 136
[2007 2008] 196

For some reason there has been a dramatic increase in the rate that Loop/Spinfoam reserch papers have been entered into the Spires database. Probably at least part due to the increased activity in the field. Considerably more papers were written in the period [2007 2008] than were written in the period [2005 2006].
ViewsofMars
#45
Jul29-09, 07:16 PM
P: 463
Quote Quote by marcus View Post
Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
19 July 1.50
20 July 1.19
21 July 1.30
22 July 1.39
23 July 1.79
24 July 1.09
25 July 0.53
26 July 0.76
27 July 1.11


At noon pacific on 26 July, Trouble was 4686 and the most popular stringies (blackhole, elegant, fabric, idiotguide, parallel) were 1245, 2383, 4435, 5016, 5090 for an average of 3633.8 making the ratio 0.76.

At noon pacific on 27 July, Trouble was 3631 and the most popular stringies (blackhole, elegant, fabric, hyperspace, parallel) were 2617, 3653, 3915, 4027, 5976, for an average of 4037.6 making the ratio 1.11.
I'd like a link (url) that I can review from Amazon where you are obtaining those figures.

Quote Quote by marcus View Post
That's a curious thought. I rather doubt that anything we say here in SocialSci forum significantly influences the mass science book market or any other sector of the world at large.
I'm sure of the readership on physicsforums, and what you write on physicsforums is noted on peoples' blogs.



Quote Quote by marcus View Post
You sound like you see your role as getting a message across to the general public. What I'm interested in is accurately tracking what is going on. I'm interested in how some indices behave---and in trying to follow and understand certain trends.
You mean about George Smoot. Yup! He is a nobel prize winner. Top notch physicist.

Quote Quote by marcus View Post
I guess there is a secondary idea here also that public support for scientific research will be more solid and effective in the long run if the public is well-informed. If the public knows the truth about what is happening in physics research (not just the hype as per discovery channel and gee whiz science specials.) But that is a secondary consideration. First of all I want some objective comprehension for myself, of what is going on.
Yes, I agree with you 'that public support for scientific research will be more solid and effective in the long run if the public is well-informed'. And, maybe I can be of help to you in a sociological sense. Here is an excerpt of an article, Cosmology's Golden Age, from CERN ( International Journal of High-Energy Physics) Courier dated Jun 8, 2009 that was written by George F Smoot, Lawrence Berkeley National Laboratory:

The situation in cosmology is rife with opportunities. There are well defined but fundamental questions to be answered and new observations arriving to guide us in this quest. We should learn much more about inflation from the observations that we can anticipate over the next few years. Likewise we can hope to learn about the true nature of dark matter from laboratory and new accelerator experiments that are underway or soon to be operating, as at the LHC. We hope to learn more about possible extra dimensions through observations.

We continue to seek and encourage new ideas and concepts for understanding the universe. These concepts and ideas must pass muster – like a camel going through the eye of a needle – in agreeing with the multitude of precise observations and thereby yield an effective version of our now-working cosmological model. This is the key point of modern cosmology, which is fully flowering and truly exciting. It is the natural consequence and culmination of the path that Galileo started us on four centuries ago.
http://cerncourier.com/cws/article/cern/39163
I don't think a book should be the only indicator for future research as my example previously noted above. Funding is important.

Regarding strings, under Smoot Astrophysics Group Personnel (1) is Scientist Jodi Lamoureux-Christiansen. On her homepage (2) under RESEARCH INTERESTS, please note Cosmic Strings (3):
“CMB results rule out topological defects as the primary source of structure in the universe. They may only be a low-level source of structure. Their importance, however, has recently been recognized in theoretical work on hybrid inflation, D-Brane inflation and SUSY GUTS which all favor cosmic string formation. The discovery of Cosmic Strings would solve another dark theoretical mystery by putting a physical face to the yet another component of the universe.”
And please do review in Astrophysics (4):
Title: Search for Cosmic Strings in the GOODS Survey
Authors: J.L. Christiansen, E. Albin, K.A. James, J. Goldman, D. Maruyama, G.F. Smoot
(Submitted on 29 Feb 2008 (v1), last revised 24 May 2008 (this version, v2))
1. http://aether.lbl.gov/people.html
2. http://atom.physics.calpoly.edu/~jodi/
3. http://atom.physics.calpoly.edu/~jodi/strings.html
http://arxiv.org/abs/0803.0027v2
4. http://arxiv.org/PS_cache/arxiv/pdf/...803.0027v2.pdf
###

Marcus, ever heard of Blue Ocean Strategy? Look, I'm creating a new market space by using a teaching module within your space along with providing you and our audience what I consider to be important feedback. Your topic "Sociology of Physics:comment and indices" isn't meant to reflect only *your* feedback without critique. It wouldn't be a democracy if I weren't allowed to comment. Also, at times, less certainty yields better decisions.

I should mention that I'm enjoying our exchanges. Sorry I didn't get back to you sooner.
marcus
#46
Jul30-09, 02:29 PM
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Getting close to the first of August. For compactness, I only save smoothed first-of-month readings.

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
30 July 0.90
31 July 0.44

At noon pacific on 30 July, Trouble was 4736 and the five most popular stringies (fabric, elegant, hyperspace, parallel, blackhole) were 3418, 3651, 3804, 4623, 5714 for an average of 4242.0 making the ratio 0.90. I intend to smooth with a 5 day average around the first of the month. Take readings on the 30, 31, 1, 2, and 3 of August, which will average out some of the random fluctuation.
===================

In my previous post I introduced another index which we can track. First of all there's this:
http://www.slac.stanford.edu/spires/...tecount%28d%29
This is Loop/Spinfoam research published since 2006 (i.e. 2007-present) ranked by cites.
As of 28 July there are 251 papers listed, and the citecounts for the top ten run from 65 down to 25. Both publication rate and citations matter.

And here it is restricted to [2007, 2008]. The search finds 196 papers in the Spires data base.
http://www.slac.stanford.edu/spires/...tecount%28d%29

Loop/Spinfoam publication rate (entries in the Spires database for two-year intervals)

[2003 2004] 126
[2005 2006] 136
[2007 2008] 196

A similar check shows string research publication declining over the past three years, and that citations to string papers have declined from highs in the late 1990s and early 2000s.
The research mix may be finding a new balance.
Various things suggest this and maybe I should also mention some anecdotal evidence tending to confirm it.
marcus
#47
Aug1-09, 02:09 PM
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Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
...
30 July 0.90
31 July 0.44
1 August 0.51
2 August 0.81
3 August ?

One more noon reading to take, for an average around 1 August.
At noon pacific on 2 August Trouble ranked 5824 and the stringy top five (blackhole, elegant, fabric, hyperspace, parallel) ranked 2715, 3797, 4024, 6387, 6555, for an average of 4695.6 making the ratio 0.81.
marcus
#48
Aug3-09, 02:18 PM
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The noon readings around 1 August turned out to be:
30 July 0.90
31 July 0.44
1 August 0.51
2 August 0.81
3 August 0.53

So the final average, giving the smoothed figure for 1 August is 0.64

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
1 August 0.6
...

As far as I can see the most remarkable thing about Trouble sales long term is how steady the book's rank is holding. It came out in September of 2006 and so far shows no sign of going away. In case anyone is curious at noon pacific on 3 August Trouble ranked 9242 and the stringy top five (hyperspace, elegant, fabric, blackhole, parallel) ranked 2879, 3554, 3557, 5474, 8961, for an average of 4885.0 making the ratio 0.64.
===============================
Another index to keep track of is the:

Loop/Spinfoam publication rate

[2003 2004] 126
[2005 2006] 136
[2007 2008] 196

To check these figures use this Spires keyword search and adjust the dates accordingly---here the dates are set to give research output from [2007 2008]:

http://www.slac.stanford.edu/spires/...tecount%28d%29

==============
Another is a string publication index using keywords "superstring, M-theory, AdS/CFT, brane, compactification, heterotic" to search the Harvard archive.
Here are the results as of 3 August, for the first 6 months of three consecutive years:

2007: 2669
2008: 2597
2009: 2418

The links used are:
2007
http://adsabs.harvard.edu/cgi-bin/np...=YES&version=1

2008
http://adsabs.harvard.edu/cgi-bin/np...=YES&version=1

2009
http://adsabs.harvard.edu/cgi-bin/np...=YES&version=1
marcus
#49
Aug9-09, 04:12 PM
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Checking in on Smolin's book.

Trouble with Physics salesrank compared with string benchmark:

1 January 0.6 (2009)
1 February 0.7
1 March 0.5
1 April 0.6
1 May 0.6
1 June 0.7
1 July 1.9
1 August 0.6
...
8 August 0.89
9 August 1.49
10 August 0.39
...

At noon pacific 9 August, Trouble ranked 4129 and the five most popular string books (elegant, fabric, parallel, hyperspace, blackhole) ranked 2446, 3289, 3902, 5033, 16039 for an average of 6141.8, making the ratio 1.49.

I would say that although public interest and perception is a factor, there are some more important sociological indicators of changes in the fundamental physics research picture. Loop and allied research publication rate going up (see earlier post) and string publication lapsing. More researchers getting into nonstring QG and QC (the application of quantum gravity to cosmology). Exodus of smart people from string.

One can see a major shift in focus in the work of leaders like Hermann Nicolai, Petr Horava, Edward Witten, Steve Gidding, Juan Maldacena, Arkani-Hamed. Physicists show recognizable herd behavior, so what the leaders do is imporrtant.

Besides this exodus or shift in focus there has this summer been a remarkable run of conferences which combine Loop-and-allied speakers with String and ex-String folks. There is apparently more interest and openness on the part of the String and ex-String community---more desire to listen and discuss.
To mention a few:

Planck Scale (Wroclaw, June)
Marcel Twelve (Paris, July)
FQXi IV (Azores, July)
Emergent Gravity (Vancouver, August)
Ellisfest (Cape Town, August)
AsymSafe (Perimeter, November)

Another indicator of a change in the mental climate was Steven Weinberg's 7 July talk at CERN. (Basic message: string not the only game in town, SW currently chooses to work on an alternative, undercutting string motivation.) Five years ago Weinberg was an influential and staunch supporter: string as "our one best hope" of unification. No longer.
atyy
#50
Aug11-09, 11:08 PM
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Quote Quote by marcus View Post
Emergent Gravity (Vancouver, August)
Vidal: Entanglement, symmetries, and the simulation of strongly interacting systems on a lattice, AND its (VERY CLOSE) relation to spin networks: A Tensor Network (TN) exploits the structure of entanglement in strongly interacting systems on a lattice to provide an efficient representation of its ground state. TN algorithms are becoming increasingly popular, thanks to its ability to simulate systems that cannot be addressed with quantum Monte Carlo techniques, such as frustrated antiferromagnets and interacting spins on a 2D lattice. In my talk I will explain how, in the presence of a symmetry, a TN reduces to a linear superposition of exponentially many Spin Networks (of the type you like in loop quantum gravity). It follows that TN algorithms can be used to evaluate such linear superpositions efficiently.

Hmmm, are LQG spin networks still alive or have they been replaced by spin foams (sorry, am completely confused on by the whole state of LQG/spinfoams)?
marcus
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Aug12-09, 10:40 AM
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Quote Quote by atyy View Post
Hmmm, are LQG spin networks still alive or have they been replaced by spin foams (sorry, am completely confused on by the whole state of LQG/spinfoams)?
They are essentially the same theory. As the theory appears to be coming together, a spinfoam is how a spin network evolves.
So it would be impossible for one to replace the other. Or maybe I should say unnecessary.

Thanks for mentioning the Vidal presentation. Do you have a link?
What you quote here is what it says in the conference program http://www.emergentgravity.org/index..._programme.php
(in case anyone wants to see source and context---there are a lot of other interesting looking talks)
But what about a link to the corresponding work by Vidal?
marcus
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Aug12-09, 11:41 AM
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Actually Atyy one of the talks that I think interesting from a sociological point of view, at that Vancouver EG4 conference, is Matt Visser's. He's very influential and not allied to any one approach.

I know it doesn't bear directly on your condensed-matter-related QG perspective but I'll copy the abstract as a kind of sociological straw in the wind. It might catch other people's attention as well:

Visser
Who's afraid of Lorentz symmetry breaking?
"Is Lorentz symmetry truly fundamental? Or is it just an "accidental" low-momentum emergent symmetry? Opinions on this issue have undergone a radical mutation over the last few years. Historically, Lorentz symmetry was considered absolutely fundamental --- not to be trifled with --- but for a number of independent reasons the modern viewpoint is more nuanced. What are the benefits of Lorentz symmetry breaking? What can we do with it? Why should we care?"

Here are some citation numbers to gauge Visser's prominence:
http://www.slac.stanford.edu/spires/...tecount%28d%29

Here is a recent paper on "Phenomenologically viable Lorentz-violating quantum gravity"
submitted arxiv April 2009 and already published Physical Review Letters and cited 34 times (!)
http://arXiv.org/abs/0904.4464

Again here is "Quantum gravity without Lorentz invariance"
arxived May 2009 and already has 31 cites
http://arXiv.org/abs/0905.2798

He is talking about the situation where the bending of Lorentz invariance is only perceptible at ultra-high energies. Like TeV gamma photons, I guess.
So in a normal lower-energy regime, ordinary Lorentz invariance emerges. OK he seems to like this. And he is influential. It is sometimes these "loose cannon" senior people that by behaving unpredictably and carrying some weight can get things to happen. I'm not a fan of Visser but I am glad to see the cannon rolling around on the deck.

His co-author here Silke Weinfurtner is an attractive woman who played a prominent role at the Planck Scale conference in Wroclaw in June 2008. I'll have to check out her video lecture from that conference, may have something to do with Matt Visser's presentation at EG4.
atyy
#53
Aug12-09, 12:17 PM
Sci Advisor
P: 8,784
Quote Quote by marcus View Post
I'm not a fan of Visser but I am glad to see the cannon rolling around on the deck.

His co-author here Silke Weinfurtner is an attractive woman who played a prominent role at the Planck Scale conference in Wroclaw in June 2008. I'll have to check out her video lecture from that conference, may have something to do with Matt Visser's presentation at EG4.
He, he - You are not a fan of Visser, while I'm a fan of Visser and not a fan of LQG (actually, just not a fan of "Trouble with Physics", and I like the tenor of Baez's and Freidel's work). Even more he, he - I suppose since this is sociology of physics you are allowed to mention that Silke Weinfurtner is an attractive woman. I shall have to watch her lecture now. Another recent surprise for me was that Zheng-Cheng Gu, Wen's collaborator, is a guy - I had assumed he was a lady until I saw his picture on Wen's Azores slides.

Here's a Vidal reference that seems relevant: http://arxiv.org/abs/0809.2393
marcus
#54
Aug12-09, 12:59 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,270
These conferences are sociological machines that help define what constitutes a particular field of science and who the authorities are and what directions of research are considered interesting. We can study conferences to get sociological clues. Maybe I will get links to the main QG ones that happened recently. You already have the links, Atyy, but I mean post them here for convenience. How else can you find a video of Silke Weinfurtner in a hurry when you want? Certain isolated key talks are also important landmarks (Rovelli at Strings 2008, Weinberg at CERN 7 July 2009) in part because the video shows audience reaction and response. But I'll leave that for later. Here are some main QG conference links:

Black Holes and Loop Quantum Gravity (Valencia, March)
http://www.uv.es/bhlqg/
Planck Scale (Wroclaw, June)
http://www.ift.uni.wroc.pl/~planckscale/
http://www.ift.uni.wroc.pl/~rdurka/p...ndex-video.php
Marcel Twelve (Paris, July)
http://www.icra.it/MG/mg12/en/
http://www.icra.it/MG/mg12/en/invite...rs_details.htm
FQXi IV (Azores, July)
http://www.fqxi.org/conference/talks
Loops 2009 (Beijing, August)
http://www.mighty-security.com/loop/timetable1.htm
Emergent Gravity (Vancouver, August)
http://www.emergentgravity.org/
http://www.emergentgravity.org/index..._programme.php
Ellisfest (Cape Town, August)
http://www.mth.uct.ac.za/~jeff/Quant...ity/About.html
Corfu QG School (Corfu, September)
http://www.physics.ntua.gr/corfu2009/qg.html
AsymSafe (Perimeter, November)
http://www.perimeterinstitute.ca/Eve...0_Years_Later/
http://www.perimeterinstitute.ca/Eve...ited_Speakers/
http://www.perimeterinstitute.ca/en/...ety/Abstracts/

Silke's Wroclaw video has a bad audio track for the first 3 minutes and 30 seconds. So you have to wait until 3:30 before turning on the sound. Otherwise an annoying echo.
It's just a nice easy intro to Horava Lifschitz (and also the Visser-Weinfurtner modification or extension of it.)


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