Wednesday, May 30, 2012

The Tragedy of Everest

Yesterday, the 29th of May, was the 59th anniversary of the first ascent of Mount Everest, by Edmund Hillary and Tenzing Norgay: a success that followed more than three decades of failed attempts and several deaths on the mountain. At the time, the first ascent was not just the superb achievement of two individuals, but a victory of humankind itself, adjusting the boundary of what was known to be possible.

About two weeks before this anniversary came the sad news that four climbers had been killed on Everest this year. The sadder news is that they died as a direct result of being delayed in an extraordinary pedestrian traffic jam on their way to the summit.

The Guardian today carried a photograph, taken by Ralf Dujmovits, showing a small section of the 600-strong queue of people attempting the climb up the Lhotse face to the South Col before heading for the summit.
Long queue of people climbing up to the South Col on Everest
Pedestrian traffic jam on Everest. Photo credit: Ralf Dujmovits.
I don't know that I have ever seen a sadder mountaineering photograph.

In other news, in the Himalaya alone there are several hundred peaks over 6000 m high that have never been climbed by any human being before. 

Tuesday, May 29, 2012

Can peer review be improved?

Last week I was back in Oxford briefly and visited my DPhil supervisor Subir Sarkar, who, in the course of a long conversation about various things, told me about a discussion he had apparently had with Professor Anton Zeilinger after a recent colloquium there. Zeilinger had apparently mentioned the academic peer review process and had some ideas about how the process might be made to serve science better by being more transparent. I found these ideas (as relayed to me) rather thought-provoking, and I'd like to promote a bit of discussion about them on this blog.

To paraphrase the argument: an important problem with the peer review system as it stands is that in many (or even most) cases there is only one referee who decides whether the submitted paper meets the scientific standards of the journal in question, this referee is completely anonymous, and his or her report on the paper remains entirely confidential, seen only by the journal editor and the author(s) of the paper in question.

Guaranteed anonymity is well known to alter people's behaviour on the internet, in general making people more opinionated, far ruder, and less receptive to reasoned discussion about alternative points of view. Unfortunately, scientists being only human, this is almost certainly also true to some extent in the peer review process. So removing the referee's anonymity might well improve civility in some cases, and you can see why senior academics might be in favour of it — though I notice that my feeling that even anonymous reviewers are more polite when the corresponding author on a paper is a senior figure rather than a graduate student or young postdoc seems to be shared by some others, so senior academics should have the least to complain about.

Removing referee anonymity is not a completely crazy idea: I'm told it is the norm in Scandinavian countries for the identity of the panels reviewing grant proposals to be known to applicants — though here there is some aspect of collective responsibility, within the panel there may only be a single expert on a particular field, so in practice this doesn't offer a lot of cover. If all authors and reviewers were perfectly objective, with no tendency to personal animosity or desire for retribution, and all had the same permanent job security, it might work. But they aren't, and they don't, so it can't. In particular, much reviewing is actually done by younger scientists, postdocs at the start of their careers, who may well one day be applying for a job to the author whose paper they are reviewing. The potential conflicts of interest don't bear thinking about. I'm pretty sure referees must remain anonymous.

Similarly, it is impractical to demand several referees for each submitted paper. In physics a few, very high profile, journals do use multiple referees, but usually only for short papers in a Letter format (i.e., less than about 5 pages long). Having more than one referee for each full-length paper at each journal would presumably increase the time taken to accept or reject submitted papers to unacceptable levels.

What about the third option? Why can't journals put a link next to the online version of accepted papers, that allows those interested to read the correspondence between the authors and the (still completely anonymous) referee? Knowing this correspondence was to be made public might cause referees (and, equally importantly, authors replying to the referee's criticisms!) to be far more civil. It would certainly help put an end to the unfortunate but not-entirely-unknown incidents of referees holding up publication on specious grounds until certain citations are added to the manuscript. I think it would also raise the level of debate. Journals of course would only provide such a summary of correspondence for accepted papers, but authors could perhaps, if they felt their paper was unfairly rejected, also put the correspondence online, say on the arXiv.

But as I see it, the most important argument in favour of such a model is that it increases the information available to the readers of the papers. I personally often discover some interesting preprints on the arXiv from fields somewhat beyond my expertise. When looking at the published version of the paper on the journal website, I'd like to know what changes the referee requested, and how the authors responded to the request: this would give me an idea of what the contentious issues are in that field, and help me to decide how much weight to assign to claims made in the paper. This sort of information ultimately surely helps the advance of scientific knowledge.

For instance, in the case of the recent dark matter argument I blogged about here, I'd like to know whether the referee for the first paper just didn't realise there was a problem with the authors' assumptions, knew about the issue but didn't think it was a problem, or knew that it was contentious but decided on balance the paper was interesting enough to be published anyway? If the referee simply missed it, does that tell us something about the standards of refereeing at the journal in question (a well-respected one in this case), or did the authors of the second paper have some unique insight?

At the moment I can see lots of positives but no drawbacks to this idea of providing more information about the process of peer review. Other people might have other ideas, and I'd like to hear from you in the comments — I'm happy to be convinced either way!

Sunday, May 27, 2012

Links for the week: 27th May

Physics links:
  • At partner blog The Trenches of Discovery, my colleague and regular co-author Shaun has put up the 4th part of a series of blog postings on "The ISW Mystery". The earlier ones are here, here and here. This is an ambitious attempt by him to describe some research we have recently done in a manner accessible to the layman. Definitely worth a little investment of time.
  • Sean Carroll draws attention to some nice "back of the envelope" physics problems by Edward Purcell, and points out that quantum mechanics is needed to explain how our eyes work.
  • In the UK, the STFC have decided that the gigantic Square Kilometre Array (SKA) radio telescope will be built in both South Africa and Australia and not in either country exclusively. Andy Lawrence evaluates the decision. (Incidentally, SKA is not known as SKA because the radio dishes will be placed over an area of a square kilometre on the ground -- that would actually be rather small for a radio telescope. Instead it is because the total area of the dishes themselves will add up to a square kilometre, which really is enormous.)
Other links:
  • The New York Review of Books features a journalistic report drawn in comic form, by artist and journalist Joe Sacco, about his visit to Kushinagar district in Uttar Pradesh, India. The novel presentation is worth a look in itself, but the report also deals with a very serious and important issue: the continuing caste-based discrimination faced by the Dalits in rural India, more than 60 years after such practices were officially outlawed in the constitution.
  • Rhys has a very justified rant about the mindless abuse of scientific terms in art; he describes a particularly bad example of this "drivel".
  • Peter Coles has an equally justified rant about a ridiculous article in The Guardian attempting to justify the astronomical profits made by academic publishers. See also here for a similar angry rebuttal by Mike Taylor.

Thursday, May 24, 2012

The World's 50 Highest Peaks

There hasn't been enough about mountains or maps on this blog yet, despite my promises. But today The Guardian has a simply wonderful feature on their data blog: an interactive map that allows you to view the 50 most prominent (note: not "highest", despite my post title!) peaks in the world. It's integrated with Google, so you can view maps, satellite images, and terrain details. In some cases the satellite images are supplemented by aerial photographs. If you download the Google Earth plugin, it will even allow a virtual "flypast" over the mountain in question, letting you view it in 3D. Plus there's lots of data on elevation, prominence, first ascents and so on.

I've included a screenshot from the map. This is a zoom in on the Google Earth view of Kangchenjunga. Click on it for a bigger version.

I dare say I will spend a few hours playing with this!

(The map was originally made by Robert Mundigi, and was taken from here.)

Wednesday, May 23, 2012

Collective Marvelling

Another, very quick, post to say that as some of you might have noticed, this blog is now part of a fledgling blog network called Collective Marvelling. I've put a little tab at the top of this page describing the network and linking to it. The individual blogs in the network are also among those linked in the panel on the right. If you haven't already checked them out, you should!

Grexit or not?

(Update: The Tim Duy post I linked to below has now been superseded by this report from him on the outcome of the meeting of Eurozone officials yesterday. He's still not happy!)

Over the last few months I have been following the continuing chaos in the Eurozone, much like everybody else in Europe who has a TV, radio or internet connection, I suppose. The spectre of a Greek exit from the Euro seems to have been dominating the front pages a lot more just recently, but most (or certainly most American) economists have been predicting this since about late 2010.

Anyway, this is a subject way outside my personal expertise, so I'm not going to make any comment of my own other than to say I find it darkly amusing that irresponsible borrowing is generally regarded as a far greater moral sin than irresponsible lending. What I will do is to provide some snippets of more expert opinions and share some links where you can read stuff to help you make sense of what's likely to happen in the next couple of months.

Monday, May 21, 2012

Links for the week: 20th May

I meant to put this out yesterday, but the supernova post took a bit longer to write than I was hoping. Anyway, here's a list of interesting links.

Physics links:
  • Last week I linked to a paper by Moni Bidin, Carraro, Mendez and Smith that claimed to have detected no evidence for dark matter affecting the kinematics of stars in the solar neighbourhood. I mentioned that this was not without controversy, and indeed this morning there was a new preprint by Bovy and Tremaine on the arXiv, who claim the Moni Bidin et al result is due to a key assumption that is not supported by the data. I haven't had time to read the paper yet, so I'll just quote from the abstract:
"We show that this result is incorrect and that it arises from the invalid assumption that the mean azimuthal velocity of the stellar tracers is independent of Galactocentric radius at all heights; the correct assumption -- that is, the one supported by data -- is that the circular speed is independent of radius in the mid-plane."
  • Suppose you have three upturned cups, and you are 90% certain that there is a ball under one of them. You turn two of them over and find no ball — how confident are you that the ball is under the third cup? Philip Gibbs gives a nice little argument illustrating Bayes' theorem, and uses it to argue that we shouldn't give up on SUSY yet.

Other links:

Sunday, May 20, 2012

What makes a supernova?

At the beginning of the month we had a short cosmology meeting here in Bielefeld, known as Kosmologietag (though in fact it was spread over two days). One of the main talks was given by Fritz Röpke, of the Universität Würzburg. Fritz spoke about a very important sub-class of supernova explosions, known as Type Ia, and our current understanding of what causes them to explode in the first place.

Although I have worked in the past with supernovae data in a cosmological context, much of what he said during his talk was new to me, and also was very interesting. Supernovae are particularly amazing events, after all! The slides of his talk are available here though unfortunately some of the movies he showed will not work (incidentally, all the other talks from the meeting — including my own — can be found here, in case anyone is interested).

This post is somewhat experimental because I'm writing about a subject I don't have much expertise in, and also because I will try to convey some of the new things I learned from Fritz's research-level talk while assuming little or no prior knowledge about the subject among my readers. So please bear with me. I suppose I'd better start by briefly explaining what a supernova is, and what the 'Type Ia' business refers to.

Supernovae are explosions that occur at the end of the life cycle of some types of massive stars, that cause the exploding star to increase rapidly in brightness for a short period of time. The first thing everyone should know about supernovae is that they are truly catastrophic explosions, the most dramatic events that occur in the Universe today, which cause a single star to become as bright as an entire galaxy containing about a hundred billion stars. Indeed when the star whose remnants are now known as the Crab Nebula went supernova in 1054 AD, it was bright enough to be seen in the daytime, and was recorded by Chinese astronomers of the time as a 'guest star'.

Here's a picture from the Hubble Space Telescope of Supernova 1994D (this means it was the fourth supernova observed in 1994) in Galaxy NGC 4526:

Supernova 1994D exploding in galaxy NGC 4526

The second thing you should know is that all the metal in the computer that you are reading this on was formed in such a gigantic supernova several billion years ago. We, and everything around us, are really composed of the debris of one of these stellar explosions. Now that should be enough to capture your interest!

Tuesday, May 15, 2012

Links for the week - dark matter special

A longer blog posting should ready by the weekend, but is proving a little harder to write than I had hoped. In the meantime, here is a collection of interesting things to read elsewhere. I will make this sort of a roundup of worthwhile links a weekly feature on this blog, though it will make more sense to put it out at the weekend next time. Anyway, here you go:

Physics links:
  • Dark matter detection experiments have been in the news a lot recently. A couple of pre-prints have claimed to have seen some tentative evidence for a dark matter annihilation signal in gamma-ray data from the Large Area Telescope on the Fermi satellite, that somehow wasn't seen by the Fermi guys themselves. Matt Strassler discusses the first of these papers here. Rhys provides a nice short summary of both; you may also want to read a more bombastic discussion on Lubos Motl's blog.
  • The Cryogenic Dark Matter Search (CDMS) detection experiment earlier this year found no evidence for an annual modulation of dark matter interaction events in its detector, apparently contradicting earlier experiments DAMA and COGENT. A new pre-print from two members of COGENT claims CDMS mis-analysed their own data and there isn't a contradiction. (I'm not sure what to make of this: the argument seems pretty straightforward but I'm no expert so I might be missing some elementary things. Comments welcome!)
  • To make the story murkier still, this paper accepted by the Astrophysical Journal claims to find no evidence for dark matter in the solar neighbourhood based on the dynamics of stars in our galaxy, which would presumably rule out the possibility of direct detection. There are a number of caveats, so caution is advised: see here and Matt Strassler's post above. But then this paper, accompanied by this press release, makes an even more inflammatory claim about the non-existence of dark matter. Peter Coles provides a sceptical review (and entertaining arguments in the comments section!).
  • In case you are now thoroughly confused by the status of evidence for dark matter, Sean Carroll at Cosmic Variance gives us the transcript of a debate that sums up the main cosmological issues.
Phew, what a lot of dark matter. I realise some of the links above are not very recent — this blog is new and has some catching up to do! Now for other stuff.

Other links:
    • In the Guardian, Barney Ronay has a brilliant piece recalling an inspiring Olympic moment: Michael Johnson breaking the 200 m world record at Atlanta '96. If, like me, you watched the race at the time, you will have it forever seared in your memory. If not, here's a video:

    Sunday, May 13, 2012

    Problems of sight and hearing

    Following the previous rather long post it might be a little while before I post something substantial again. This is just a short note to explain the change in appearance of the blog. I chose the previous light-on-dark colour scheme somewhat warily: I don't personally have a problem with reading light text on a dark background, but I knew some people might. On the other hand, I really wanted the map image at the top, and for some reason I couldn't make that template look at all good with a dark-on-light colour scheme, so I just let it be.

    I was however reprimanded by a friend with good taste, who found that reading from my colour scheme gave her a headache. Apparently light-on-dark is known to be a problem for roughly 50% of the population (apparently everyone who has even mild astigmatism). Anyway, with that additional motivation, I managed to tinker with the HTML to obtain the current look, which probably works better in any case. I hope you agree!

    Sticking with the topic of sensory impairment (if I can cheekily characterise an inability to read light-on-dark as an impairment): yesterday I happened to be in Bonn for the day, and naturally went to visit the Beethoven Haus Museum. Now we all know that Beethoven tragically and slowly went deaf in later life, but that this didn't stop him composing several of his most amazing works. Obviously this is a remarkable achievement, but despite having heard the story of how he could not even hear the tumultuous applause of the audience at the premiere of his Ninth Symphony, I really had no appreciation of just what going deaf might have felt like to him.

    The audioguide available at the museum attempts to aid the understanding a little. As you walk past the display case containing Beethoven's ever-longer ear trumpets (some around two foot long!), you can hear parts of his famous Fifth Symphony as it would have sounded to him at the age of 38 in 1808, and what he would have heard of the Ode to Joy in 1824. The Fifth Symphony sounds as though it were coming from a small radio, tuned in the middle of two stations and muffled by a pillow. The Ode to Joy sounds as though one were listening to an orchestra hundreds of metres away, while lying at the bottom of a swimming pool. When the audioguide switches to a recording of the actual work, the beauty, complexity and sheer volume of the piece hits you with great force.

    I found it a very moving experience, and I would thoroughly recommend a visit to the museum if you are ever in Bonn.

    Saturday, May 12, 2012

    Steven Weinberg: The Crisis of Big Science

    A few weeks ago, via Peter Woit's excellent blog, I was alerted to a recent article in The New York Review of Books by Steven Weinberg, titled The Crisis of Big Science. Woit added his own thoughts on the article, and there are many interesting opinions expressed in the comments section there. However, I felt that a very important question was not satisfactorily answered, as I will try to discuss here.

    Weinberg provides a brief and personal overview of the development of particle physics experiments, starting from Rutherford's pioneering gold foil experiment in 1911 (the "experimental team consisted of one postdoc and one undergraduate [...] supported by a grant of just £70 from the Royal Society of London"), through the invention of cyclotrons, the postwar development of accelerators and the construction of dedicated accelerator facilities at Fermilab and CERN, to the current multi-billion dollar Large Hadron Collider (LHC) which (we hope) will confirm a detection of the Higgs boson later this year, and might yet — if we are lucky — provide exciting clues about the correct particle physics theory at higher energy scales than we have yet probed.

    One of the obvious themes in this short history is the enormous and growing cost of building the experimental facilities required to increase our knowledge about particle physics. Obtaining the money for these facilities is always difficult, and sometimes impossible. Weinberg reflects in particular on the cancellation in the 1990s of the Superconducting Super Collider (SSC):
    Then in 1992 the House of Representatives canceled funding for the SSC. Funding was restored by a House–Senate conference committee, but the next year the same happened again, and this time the House would not go along with the recommendation of the conference committee. After the expenditure of almost two billion dollars and thousands of man-years, the SSC was dead.  
    One thing that killed the SSC was an undeserved reputation for over-spending. There was even nonsense in the press about spending on potted plants for the corridors of the administration building. Projected costs did increase, but the main reason was that, year by year, Congress never supplied sufficient funds to keep to the planned rate of spending. This stretched out the time and hence the cost to complete the project. Even so, the SSC met all technical challenges, and could have been completed for about what has been spent on the LHC, and completed a decade earlier.
    (The claim that projected costs only increased because of insufficient spending every year is interesting, and something I hadn't heard before. I don't know whether it is true, but it sounds plausible.)

    This is not simply a problem for particle physics. The same pattern holds — though at a somewhat lower cost level — for my own field of astrophysics and cosmology. Recently, the US Congress decided to scrap funding for NASA's James Webb Space Telescope and the US has also decided to terminate the IXO (X-ray) and LISA (gravitational waves) projects, which caused the European Space Agency to choose to fund a mission to explore Jupiter's moons (known as JUICE) over projects that would have been more relevant to cosmology.

    In the end, the point is that the political support for a such massive science experiments is hard to obtain. Weinberg says
    During the debate over the SSC, I was on the Larry King radio show with a congressman who opposed  it. He said that he wasn't against spending on science, but that we had to set priorities. I explained that the SSC  was going to help us learn the laws of nature, and I asked if that didn't deserve a high priority. I remember every word of his answer. It was "No."
    Now this is the question I'd like to focus on. Let's leave aside for now the question of whether a convincing science case can in fact be made for an SSC-like accelerator or JWST-like space mission (Peter Woit's post discusses this for a new particle accelerator); I will assume that the proposed experiment, whatever it may be, will indeed help us "learn the laws of Nature." Is this justification enough for vast government funding?

    Wednesday, May 9, 2012

    A Blog Manifesto

    Welcome to Blank On The Map! I have spent a long time reading and commenting on other people's blogs — long enough now, I feel, to have a good idea of what I would like my own blog to look like. In this first post I'd like to set out an overview of what you can expect to find here.

    My main intention is to provide a discussion of interesting issues and topics in physics, and in particular in my own area of expertise, cosmology. Of course there already exist several excellent blogs that cover part of the same subject area: you can find some of my favourite ones listed in the right-hand panel. But in my opinion the broad questions that cosmology is concerned with — what is the Universe made of, how did it start, and how will it end? — are sufficiently interesting that the interwebs can handle another blog on the topic!

    Different science bloggers approach the question of what level to pitch their offerings at differently. Although I will from time to time discuss relatively technical issues, and occasionally open research questions, in general I will address my posts to the educated layman rather than the expert. In most cases I will link in to other discussions on the 'blogosphere'; some of these may occasionally provide more details for those who are interested.

    Of course, many of the best physics blogs do not restrict themselves merely to physics, and this one will not be any different! I enjoy writing in general, and constructing arguments in particular; one of the main motivations behind starting this blog was to provide an outlet for these urges. So on these pages you may also expect to find pieces on mountaineering and mountains, philosophical discussions of the point of universities and science education, arguments on economic and political issues, and general whimsical diversions. On some of these issues I am well aware I have no special expertise, and I will try to avoid the stereotype of the arrogant physicist talking of that which he does not know. But as friends and family will testify, a lack of knowledge of a subject does not usually prevent me from expressing an opinion on it, and it's probably not going to start now.

    I reckon on putting something on here every week, perhaps more often while I have a backlog of things I have been meaning to write about.

    Finally, before I end a somewhat over-long first post, a word of explanation about the title of the blog. In part it is intended as a description of what research is about: venturing where no-one has been before, pushing the boundaries and adding, by whatever tiny fraction, to the sum total of human knowledge. It is also the title of a famous book by Eric Shipton, one of the great mountaineers and explorers of the 20th century, an inspiring author and a teenage hero of mine — about whom I might write a little more in the future.

    In a lighter vein, Blank On The Map also appealed to me as a reference to the Bellman's map in Lewis Carroll's wonderful The Hunting of the Snark -- a map the crew could all understand -- and to my current location here in Germany, which is rumoured not to exist. An obvious choice then!