Tuesday, March 9, 2010

Just How Important Is WMAP?

We had some prospective grad students visiting Irvine the other day.  I said something about WMAP and one of the prospectives said "What's WMAP?"  Coming from a lay man I can understand, but a physics major!  I was in shock.  Here's why:

First off, "Since 2000, the three most highly cited papers in all of physics and astronomy are WMAP scientific papers." (Emphasis added.)

Second, today WMAP is just a relevant as ever.  I draw your attention to the most cited papers in 2009.  (The first one, Review of Particle Physics, isn't a research article but an "encyclopedia" people quote for values of things like constants. We've discussed this book before.)

In 2009, the #1, #3, #9 and #10 most cited research articles were the WMAP papers.  To be in physics and to not know about WMAP, to me, means you are living under a rock.  There is no experiment in this last decade producing more follow up scientific research!

I point you to two other interesting observations from that list:

First, the #4, #5 and #6 most cited papers from 2009 are other cosmology papers.  That means 7 of the top 10 most cited papers, tracked by Spires, are cosmology papers.  Cosmology is hot baby!

Second, the #2 most cited paper last year is the famous paper by Juan Maldacena introducing the ADS/CFT correspondance.  As pointed out by Peter Woit, at this rate this paper will surpass "Weinberg’s 1967 paper as the most heavily cited particle physics paper of all time."


  1. Joe,

    I don't question the importance of WMAP, but using the SPIRES rankings is a little misleading since that database is clearly focused on particle physics and topics directly relating to particle physics. I have a hard time believing that in all of physics last year the top 25 most-cited list doesn't include a single paper from condensed matter, AMO, nuclear, plasmas, or astrophysics outside of cosmology.

    Again, I'm not disputing point #1 (to steal a phrase from Zoolander "Cosmology is so hot right now"), but I think it might be better to say that WMAP and cosmology dominate particle physics right now.

  2. Nick,

    The statement "Since 2000, the three most highly cited papers in all of physics and astronomy are WMAP scientific papers." is Spires independent.

    #2, I'd be interested in knowing if there are " condensed matter, AMO, nuclear, plasmas, or astrophysics outside of cosmology." that have been cited thousands of times in the last decade.

    I will confess, Spires is biased toward high energy physics. However, the WMAP papers being cited more than any other papers in the last decade still holds.

  3. And just to clear things up:

    The point was not to say WMAP is better science than other things, only that it has been such a big deal in science that I have a hard time understanding how a graduating physics major could not know about it.

  4. I'd agree that WMAP and cosmology are HUGE right now, but I think we ought to forgive the ignorance in this regard even from a physics major, and here's why. Most physics programs teach 2 main branches (1) core physics (mechanics, E&M, quantum, thermo, etc) and (2) research. As hot as cosmology is right now, it hasn't yet made it into core physics. (You can imagine your surprise and shock if he had responded similarly to a statement about Maxwell or Schrodinger.) Also, if it's not related to the student's area of research (assuming that he doesn't come from one of the undergraduate programs that doesn't require research), there is a possibility he's never run into it. (As often as the WMAP papers have been cited, they still don't have much direct relevance to things like AMO or condensed matter.)

    As much as we'd love to think that every graduating physics major should have been enlightened to the point of being imbued with innate curiosity about every subject relating to science, in large part this doesn't happen. Each specialty has their major field-changing papers that are a must-read for anyone in that field, but no matter how big they are in that field, they can all too easily be overlooked by someone not involved.

    That all being said, I agree that it really is important to keep up on the major breakthroughs in science, even if it's not your specialty. Speaking of which, I might have to get some info on ferrous superconductors or Josephson junctions from some of my condensed matter friends. They'd probably be equally distraught that a bunch of so-called physicists have a blog with never a mention of the stuff. ;) All-in-all, great post as always.

  5. Thanks Bill.

    Your right, cosmology is not part of the core curriculum so they're forgiven. :)

    "They'd probably be equally distraught that a bunch of so-called physicists have a blog with never a mention of the stuff. ;) "

    Hey, nobody's preventing the condensed matter people from making blog posts about their research. I just don't because I don't do it.

    But yes, major advances (like "Science Breakthrough of the Year" as WMAP was in 2003) in all sub-fields should be understood by recognized by physicists on a basic level.

  6. Speaking of blog posts, I encourage all the authors to blog about the major advances in their field.

    And I promise I am not going to attack you. :)

    The rest of science isn't somehow threatened or less important because your field happens to have cool stuff going on.

  7. Why do these people feel threatended by cosmology experiments? Do they feel theirs is not as good?

  8. Anonymous,

    personally I don't think anyone was threatened. Only that we argued over some tangential issue of making statements using Spires data.

  9. Anonymous,

    First of all, I have to admit that I wouldn't mind if solar physics were as big right now as cosmology. A quick glance through the AAS Job Register shows 6 post-doc openings for cosmologists and only 1 in solar physics.

    Second, I do think that in physics we tend to focus in our our sub-field - sometimes to the exclusion of other areas. One evidence of this is that there are different databases for different areas in physics. For example the particle physicists use SPIRES and the astrophysicists use NASA ADS. Both databases often include the major journals (Physical Review and the Astrophysical Journal to name two) but not some more specialized journals. SPIRES for example does not include the journal Solar Physics and Space Science, which is included in NASA ADS. This leads to different citations counts between databases, which means that a paper may look more influential in one database than another.

  10. Joe, I agree that people really ought to know about the major breakthroughs. Who knows, the way cosmology is going, it may be in the core for a lot of programs in the next 10-20 years. As far as posting (which I've been horribly lazy on), I'm hoping to post some things once research calms down a bit (more on that later -- hopefully).

    Anonymous, thanks for the comment. I at least never felt threatened. I was really just commenting on how it is understandable that someone might not know about the big breakthroughs because we tend to specialize so much. It's not really how it probably ought to be, but it is how it is.


To add a link to text:
<a href="URL">Text</a>