Trends in physics, esp. new fundamental-a calm place to discuss trends

[marcus]

Trends in physics, esp. new fundamental---a calm place to discuss trends

Hans de Vries, I think it was, suggested a subforum where one could discuss trends. I think he meant trends in fundamental physics. Notice however that the way you measure trends, besides subjective judgement, is with data like publication rates, citatation rates, faculty hiring etc. And this gets categorized as sociology. So here we are.

As a parenthetical remark, people may react with hostility to data if they don't like what it seems to them to be saying. Factual data is not harmful itself, but you have to be careful how you interpret it. And there is sometimesa risk that people won't like what it seems to suggest and will attack the messenger instead of responding to the message.

There needs to be a calm place where one can discuss trends. And people should avoid naive over-interpretation. For instance just because string publication rate goes down one year doesn't mean a valid theory won't someday emerge, having something to do with Nature, or that the same publication rate won't turn around and go up the next year. Likewise with book sales and readership---the numbers hardly decide the scientific truth or falsity of propositions!

So here's a place where one might discuss a trend or two in basic physics, if someone wanted. I will wait a little bit and see if anyone shows up and posts something. Likely enough they will not, so eventually I will post about some trend in QG and cosmology which interests me.

 

[marcus]

Well, to give an example of a trend there is the recent tendency for Loop and allied approaches to prevail in Quantum Cosmology. This development was reported earlier here:
https://www.physicsforums.com/showthread.php?p=1610996#post1610996

There the presentation was flawed by using time periods that overlapped. I will redo the data taking more care, so that this time intervals will be disjoint. It doesn't change the conclusions. The intervals are [1997,2000], [2001, 2004], and [2005, 2008] inclusive, each being a period of four years.
This means going to Spires
http://www.slac.stanford.edu/spires/
and asking for all the QG papers published in each period, ordered by citation count.

FIND K QUANTUM COSMOLOGY AND DATE > 1996 AND DATE < 2001
FIND K QUANTUM COSMOLOGY AND DATE > 2000 AND DATE < 2005
FIND K QUANTUM COSMOLOGY AND DATE >2004 AND DATE < 2009

What ever comes up, we restrict attention to the top ten: the ten most highly cited QC papers in that period, according to the Spires base. And we sort these into LQC and other.
Typically the other quantum cosmology papers will be explicitly string or in some sense string inspired---talking about branes, tachyons and such. In the LQC count I have included one CDT cosmology paper (Loll et al) and one Causal Sets cosmology paper (Sorkin), these being closely allied approaches.

time period     number of papers in the top ten
             LQC       other (mostly stringy)
1997-2000     1             9
2001-2004     6             4        
2005-2008     7             3

The upshot is that if you are a researcher in Quantum Cosmology and your work cites some QC paper (one that Spires classifies with that keyword) then it is most likely going to be a Loop cosmology paper that you cite. It is not a big deal but it shows that Loop has gained some predominance in cosmology, which could be found surprising. I have the impression that not many people are aware of this increasing prominence.

Nevertheless, it was reflected in the last major international conference, the GR8 conference in Sydney 2007, dealing with General Relativity and Cosmology. And in some other widely-attended conferences as well. But not everyone follows these things.

One thing about a measure like this is it can always swing the other way! A shift like this could go in the other direction. And there is no assumption that it has any ultimate validity or significance. But in my opinion it is worth keeping an eye on. (Especially as it parallels what one sees in the invited talk lineups at some of the broader conferences---people outside the group of LQC researchers paying increasing attention to this approach to cosmology.)

I don't want to overstress this trend, so I will try to think of another one that might possibly interest people. If you have data on any interesting trends in new fundamental physics, please consider contributing it to this thread!

 

[starkind]

Hi Marcus
A vote of confidence. I am not interested in sociology and don't read much in Physics Forums outside of BTSM. But I do value your work, which is careful and detailed and in the best traditions (IMHO) of academic research. If it weren't here I probably wouldn't see it.

I suggest the whole fracus is a matter of jealous people who have too much time on their hands. Instead of fouling the waters, they should be doing some meaningful work. Fie on them.

R

 

[marcus]

Hello starkind,
probably least said soonest mended. Minimize expressions of hostility.
Incidentally I started this thread in Sociology and was surprised to see it (and two others) moved to Beyond. Which was fine. I think you commented while it was in Beyond. Later I saw it was moved back to Sociology. Which is also fine. Lo que será, será.

I haven't had time to dig up any interesting new trends lately, but I see that the QG2 conference is going to be the biggest QG conference ever.
It is two months off and already has 160 registered participants, and 48 speakers confirmed.

Loops 07, in Mexico, had if I remember correctly just about that number---some 150-160---who registered by the final deadline.

I recall Loops 05, in Germany, had some 120 participants. Wanna bet that the 2008 conference has over 180?

Actually I wouldn't be too surprised if it topped 200.
http://www.maths.nottingham.ac.uk/r...ntum_geometry_and_quantum_gravity_conference/

The big theme of QG2 is putting Noncommutative Geometry/Quantum Geometry together with Quantum Gravity. But a number of other topics are going to surface. Just to mention a couple at random: Rovelli will be talking about the merger of Loop and Foam approaches to QG, and Yidun Wan, who has been working on braid-matter, is one of the participants.

If you look at the list of participants you may see other names that ring a bell.

Derek Wise, who got his PhD under John Baez last year, will be there. I wonder what he will talk about. Some may remember his
"hamster ball" paper from last year.

There will obviously be some Triangulations (CDT) work presented. I see for instance that Dario Benedetti, who got his PhD with Renate Loll last year and went postdoc to Perimeter, will be there.

Quite a few of those who have registered already are Quantum Cosmologists, a lot has been going on in that area. Besides the invited QC talk by Ashtekar there will evidently be a bunch of other presentations. Cosmology is important because it holds the most immediate promise of making testable predictions.

 

[Moonbear]

The papers you're counting above, are they all primary research articles, or do they include review articles? Review articles can skew such counts; it's a good indicator of popularity or interest in a research subject, but not a good indicator of actual productivity or progress in research in the field.

I ask because I noticed something like that happening with a research topic of interest to me; the review articles were far outnumbering the primary research articles. In the first year or two of it being a "hot new topic" there were all of 3 primary research articles and about a DOZEN review articles discussing those three primary research articles. It was certainly amusing to me, perhaps an indicator of people padding their CVs for promotion and tenure decisions, or maybe simply a way to get a topic to seem hotter for those who were seeking funding for it.

 

[marcus]

The papers you're counting above, are they all primary research articles, or do they include review articles? Review articles can skew such counts; it's a good indicator of popularity or interest in a research subject, but not a good indicator of actual productivity or progress in research in the field.

I ask because I noticed something like that happening with a research topic of interest to me; the review articles were far outnumbering the primary research articles. In the first year or two of it being a "hot new topic" there were all of 3 primary research articles and about a DOZEN review articles discussing those three primary research articles. It was certainly amusing to me, perhaps an indicator of people padding their CVs for promotion and tenure decisions, or maybe simply a way to get a topic to seem hotter for those who were seeking funding for it.

Hi Moonbear, thank for asking an interesting question!
In nonstring QG, review papers are few and far between. They represent a negligible percentage of total peer-reviewed publication. My impression is that it is pretty much the same with string. I do a moreorless daily scan of the new literature on arxiv in hep-th (theoretical high energy physics) so I see most new string titles and that is my impression.

However, review articles especially when they are in short supply DO get highly cited! And what I am counting in this thread are the TEN MOST CITED recent papers in a certain field namely Quantum Cosmology. So restricting to the top ten is certainly likely to make review articles pop up. I will see. Maybe I can copy in links so that you can see for yourself!

Here is the link that does the search for the most recent time period ONE REVIEW ARTICLE by Martin Bojowald SHOWS UP
http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+K+QUANTUM+COSMOLOGY+AND+DATE+%3E2004+AND+DATE+%3C+2009&FORMAT=WWW&SEQUENCE=citecount%28d%29
None of the other top ten are reviews.

The same happens when I check the previous time period. One review, the rest not.
Reviews are overrepresented in the top ten because people often refer to review articles as standard references to make clear what they are talking about. The actual percentage of reviews in the whole QG literature is probably more like one percent. It certainly isn't ten!