The H-index is Redundant…

An interesting paper appeared on the arXiv last week by astrophysicist Henk Spruit on the subject of bibliometric indicators, and specifically the Hirsch index (or H-index) which has been the subject of a number of previous blog posts on here. The author’s surname is pronounced “sprout”, by the way.

The H-index is defined to be the largest number H such that the author has written at least H papers having H citations. It can easily be calculated by looking up all papers by a given author on a database such as NASA/ADS, sorting them by (decreasing) number of citations, and working down the list to the point where the number of citations of a paper falls below the number representing position in the list. Normalized quantities – obtained by dividing the number of citations a paper receives by the number of authors of that paper for each paper – can be used to form an alternative measure.

Here is the abstract of the paper:

Here are a couple of graphs which back up the claim of a near-perfect correlation between H-index and total citations:

The figure shows both total citations (right) and normalized citations (left); the latter, in my view, a much more sensible measure of individual contributions. The basic problem of course is that people don’t get citations, papers do. Apportioning appropriate credit for a multi-author paper is therefore extremely difficult. Does each author of a 100-author paper that gets 100 citations really deserve the same credit as a single author of a paper that also gets 100 citations? Clearly not, yet that’s what happens if you count total citations.

The correlation between H index and the square root of total citation numbers has been remarked upon before, but it is good to see it confirmed for the particular field of astrophysics.

Although I’m a bit unclear as to how the “sample” was selected I think this paper is a valuable contribution to the discussion, and I hope it helps counter the growing, and in my opinion already excessive, reliance on the H-index by grants panels and the like. Trying to condense all the available information about an applicant into a single number is clearly a futile task, and this paper shows that using H-index and total numbers doesn’t add anything as they are both measuring exactly the same thing.

A very interesting question emerges from this, however, which is why the relationship between total citation numbers and h-index has the form it does: the latter is always roughly half of the square-root of the former. This suggests to me that there might be some sort of scaling law describing onto which the distribution of cites-per-paper can be mapped for any individual. It would be interesting to construct a mathematical model of citation behaviour that could reproduce this apparently universal property….

Follow @telescoper

Giant Steps, from Astrophysics to Jazz

I’m indebted to Alan Heavens (currently of Edinburgh University, shortly to move to Imperial College) for drawing my attention to outstanding young jazz pianist and composer Dan Tepfer. I’ve been listening to quite a lot of Dan’s music, over the past few days and I think he’s brilliant. What’s even more interesting about him from the point of view of this blog is his background:  he is a former Astrophysics student (at the University of Edinburgh). He changed direction away from academic studies in order to focus on his music, relocated to New York and has subsequently received rave reviews for his performances both live and on various albums. He tours extensively in the USA and worldwide; next time he’s in the UK I’m definitely going to check out one of his live gigs. Do visit his website; as a taster here’s his  highly original (and pretty long) live version of the John Coltrane classic Giant Steps..

Follow @telescoper

Baby Planet Pictures…

My eye was caught this morning by this dramatic picture on the front page of the Guardian website, linked to a story about the discovery of a very young planet:

I wonder how many people looking at it thought that it was an actual picture of a planet actually forming? In fact the above graphic is just an “artist’s conception” of the view near the planet, which is called LkCa 15b. The real picture is considerably less dramatic:

What you see is (left) a disk of dust and gas surrounding a star cleverly made visible by masking out the light from the star, which is much brighter than the disk.  On the right you can see a blow up of the inner region of the system, which appears to show a Jupiter-like planet associated with an irregular blob of material, out of which it probably condensed and from which it may still be accreting.

The size of the picture on the right is worth noting. The angle indicated is 76 milli-arcseconds. This is the angle subtended by  the  width of a  human hair at distance of about 130 metres…

Follow @telescoper

The Laws of Extremely Improbable Things

After a couple of boozy nights in Copenhagen during the workshop which has just finished, I thought I’d take things easy this evening and make use of the free internet connection in my hotel to post a short item about something I talked about at the workshop here.

Actually I’ve been meaning to mention a nice bit of statistical theory called Extreme Value Theory on here for some time, because not so many people seem to be aware of it, but somehow I never got around to writing about it. People generally assume that statistical analysis of data revolves around “typical” quantities, such as averages or root-mean-square fluctuations (i.e. “standard” deviations). Sometimes, however, it’s not the typical points that are interesting, but those that appear to be drawn from the extreme tails of a probability distribution. This is particularly the case in planning for floods and other natural disasters, but this field also finds a number of interesting applications in astrophysics and cosmology. What should be the mass of the most massive cluster in my galaxy survey? How bright the brightest galaxy? How hot the hottest hotspot in the distribution of temperature fluctuations on the cosmic microwave background sky? And how cold the coldest? Sometimes just one anomalous event can be enormously useful in testing a theory.

I’m not going to go into the theory in any great depth here. Instead I’ll just give you a simple idea of how things work. First imagine you have a set of observations labelled . Assume that these are independent and identically distributed with a distribution function , i.e.

Now suppose you locate the largest value in the sample, . What is the distribution of this value? The answer is not , but it is quite easy to work out because the probability that the largest value is less than or equal to, say, is just the probability that each one is less than or equal to that value, i.e.

Because the variables are independent and identically distributed, this means that

The probability density function associated with this is then just

In a situation in which is known and in which the other assumptions apply, then this simple result offers the best way to proceed in analysing extreme values.

The mathematical interest in extreme values however derives from a paper in 1928 by Fisher \& Tippett which paved the way towards a general theory of extreme value distributions. I don’t want to go too much into details about that, but I will give a flavour by mentioning a historically important, perhaps surprising, and in any case rather illuminating example.

It turns out that for any distribution of exponential type, which means that

then there is a stable asymptotic distribution of extreme values, as which is independent of the underlying distribution, , and which has the form

where and are location and scale parameters; this is called the Gumbel distribution. It’s not often you come across functions of the form !

This result, and others, has established a robust and powerful framework for modelling extreme events. One of course has to be particularly careful if the variables involved are not independent (e.g. part of correlated sequences) or if there are not identically distributed (e.g. if the distribution is changing with time). One also has to be aware of the possibility that an extreme data point may simply be some sort of glitch (e.g. a cosmic ray hit on a pixel, to give an astronomical example). It should also be mentioned that the asymptotic theory is what it says on the tin – asymptotic. Some distributions of exponential type converge extremely slowly to the asymptotic form. A notable example is the Gaussian, which converges at the pathetically slow rate of ! This is why I advocate using the exact distribution resulting from a fully specified model whenever this is possible.

The pitfalls are dangerous and have no doubt led to numerous misapplications of this theory, but, done properly, it’s an approach that has enormous potential.

I’ve been interested in this branch of statistical theory for a long time, since I was introduced to it while I was a graduate student by a classic paper written by my supervisor. In fact I myself contributed to the classic old literature on this topic myself, with a paper on extreme temperature fluctuations in the cosmic microwave background way back in 1988..

Of course there weren’t any CMB maps back in 1988, and if I had thought more about it at the time I should have realised that since this was all done using Gaussian statistics, there was a 50% chance that the most interesting feature would actually be a negative rather than positive fluctuation. It turns out that twenty-odd years on, people are actually discussing an anomalous cold spot in the data from WMAP, proving that Murphy’s law applies to extreme events…

Follow @telescoper

Why’s the Sun not Green?

It’s Friday afternoon and time for a mildly frivolous post.

I’ve been recently been teaching first-year astrophysics students (and others) about the radiation emitted by stars, and how stellar spectra can be used to diagnose their physical properties.

Received wisdom is that the continuous spectrum of light emitted by stars like the Sun is roughly of black-body form, with a peak wavelength inversely proportional to the surface temperature of the star. Here are some examples of black-body curves to illustrate the point.

The Sun has a surface temperature of about 6000 K – actually, more like 5800 K but we won’t quibble. The peak wavelength for the Sun’s spectrum  therefore corresponds to bluey-green light, which is why the Sun appears … er… yellow.

Anyone care to offer an explanation as to why the Sun isn’t green? Answers on a postcard or, preferably, through the comments box.

And while you’re at it, you might want to comment on why,  if the Sun produces so much green light, chlorophyll is actually green?

The Next Decade of Astronomy?

I feel obliged to pass on the news that the results of the Decadal Review of US Astronomy were announced yesterday. There has already been a considerable amount of reaction to what the Review Panel (chaired by the esteemed Roger Blandford) came up with from people much more knowledgeable about observational astronomy and indeed US Science Politics, so I won’t try to do a comprehensive analysis here. I draw your attention instead to the report itself  (which you can download in PDF form for free)  and Julianne Dalcanton’s review of, and comments on, the Panel’s conclusions about the priorities for  space-based and ground-based astronomy for the next decade or so over on Cosmic Variance.  There’s also a piece by Andy Lawrence over on The e-Astronomer’s blog. I’ll just mention that Top of the Pops for space-based astronomy is the Wide-Field Infrared Survey Telescope (WFIRST) which you can read a bit more about here, and King of the Castle for the ground-based programme is the Large Synoptic Survey Telescope (LSST). Both of these hold great promise for the area I work in – cosmology and extragalactic astrophysics – so I’m pleased to see our American cousins placing such a high priority on them. The Laser Interferometer Space Antenna (LISA), which is designed to detect gravitational waves, also did very well, which is great news for Cardiff’s Gravitational Physics group.

It will be interesting to see what effect – if any – these priorities have on the ranking of corresponding projects this side of the Atlantic. Some of the space missions involved in the Decadal Review in fact depend on both NASA and ESA so there clearly will be a big effect on such cases. For example, the proposed International X-ray Observatory (IXO) did less well than many might have anticipated, with clear implications for  Europe (including the UK).  The current landscape  of X-ray astronomy is dominated by Chandra and XMM, both of which were launched in 1999 and which are both nearing the end of their operational lives. Since X-ray astronomy can only be done from space, abandoning IXO would basically mean the end of the subject  as we know it, but the question is how to bridge the  the gap between the end of these two missions and the start of IXO even if it does go ahead but not until long after 2020? Should we keep X-ray astronomers on the payroll twiddling their thumbs for the next decade when other fields are desperately short of manpower for science exploitation?

On a more general level, it’s not obvious how we should react when the US gives a high priority to a given mission anyway. Of course, it gives us confidence that we’re not being silly when very smart people across the Pond endorse missions and facilities similar to ones we are considering over here. However, generally speaking the Americans tend to be able to bring missions from the drawing board to completion much faster than we can in Europe. Just compare WMAP with Planck, for instance. Trying to compete with the US, rather than collaborate, seems likely to ensure only that we remain second best. There’s an argument, therefore, for Europe having a programme that is, in some respects at least, orthogonal to the United States; in matters where we don’t collaborate, we should go for facilities that complement rather than compete with those the Americans are building.

It’s all very well talking of priorities in the UK but we all know that the Grim Reaper is shortly going to be paying a visit to the budget of the  agency that administers funding for our astronomy, STFC. This organization went through a financial crisis all of its very own in 2007 from which it is still reeling. Now it has to face the prospect of further savage cuts. The level of “savings” being discussed  – at least 25%  -means that the STFC management must be pondering some pretty drastic measures, even pulling out of the European Southern Observatory (which we only joined in 2002). The trouble is that most of the other ground-based astronomical facilities used by UK astronomers have been earmarked for closure, or STFC has withdrawn from them. Britain’s long history of excellence in ground-based astronomy now hangs in the balance. It’s scary.

I hope the government can be persuaded that STFC should be spared another big cut and I’m sure that there’s extensive lobbying going on.  Indeed, STFC has already requested input to its plans for the ongoing Comprehensive Spending Review (CSR). With this in mind, the Royal Astronomical Society has produced a new booklet designed to point out the  relevance of astronomy to wider society. However I can’t rid from my mind the memory a certain meeting in London in 2007 at which the STFC Chief Executive revealed the true scale of STFC’s problems. He predicted that things would be much worse at the next CSR, i.e. this one. And that was before the Credit Crunch, and the consequent arrival of a new government swinging a very large axe. I wish I could be optimistic but, frankly, I’m not.

When the CSR is completed then STFC will have yet again to do another hasty re-prioritisation. Their Science Board has clearly been preparing:

… Science Board discussed a number of thought provoking scenarios designed to explore the sort of issues that the Executive may be confronted with if there were to be a significant funding reduction as a result of the 2010 comprehensive spending review settlement. As a result of these deliberations Science Board provided the Executive with guidance on how to take forward this strategic planning.

This illustrates a big difference in the way such prioritisation exercises are carried out in the UK versus the USA. The Decadal Review described above is a high-profile study, carried out by a panel of distinguished experts, which takes detailed input from a large number of scientists, and which delivers a coherent long-term vision for the future of the subject. I’m sure not everyone agrees with their conclusions, but the vast majority respect its impartiality and level-headedness and have confidence in the overall process. Here in the UK we have “consultation exercises” involving “advisory panels” who draw up detailed advice which then gets fed into STFC’s internal panels. That bit is much like the Decadal Review. However, at least in the case of the last prioritisation exercise, the community input doesn’t seem to bear any obvious relationship to what comes out the other end. I appreciate that there are probably more constraints on STFC’s Science Board than it has degrees of freedom, but there’s no getting away from the sense of alienation and cynicism this has generated across large sections of the UK astronomy community.

The problem with our is that we always seem to be reacting to financial pressure rather than taking the truly long-term “blue-skies” view that is clearly needed for big science projects of the type under discussion. The Decadal Review, for example, places great importance on striking a balance between large- and small-scale experiments. Here we tend slash the latter because they’re easier to kill than the former. If this policy goes on much longer, in the long run we’ll end up a with few enormous expensive facilities but none of the truly excellent science that can be done from using smaller kit.  A crucial aspect of this that that science seems to have been steadily relegated in importance in favour of technology ever since the creation of STFC.  This must be reversed. We need a proper strategic advisory panel with strong scientific credentials that stands outside the existing STFC structure but which has real influence on STFC planning, i.e. one which plays the same role in the UK as the Decadal Review does in the States.

Assuming, of course, that there’s any UK astronomy left in the next decade…

The Planck Sky

Hot from the press today is a release of all-sky images from the European Space Agency’s Planck mission, including about a year’s worth of data. You can find a full set of high-resolution images here at the ESA website, along with a lot of explanatory text, and also here and here. Here’s a low-resolution image showing the galactic dust (blue) and radio (pink) emission concentrated in the plane of the Milky Way but extending above and below it. Only well away from the Galactic plane do you start to see an inkling of the pattern of fluctuations in the Cosmic Microwave Background that the survey is primarily intended to study.

It will take a lot of sustained effort and clever analysis to clean out the foreground contamination from the maps, so the cosmological interpretation will have to wait a while. In fact, the colour scale seems to have been chosen in such a way as to deter people from even trying to analyse the CMB component of the data contained in these images. I’m not sure that will work, however, and it’s probably just a matter of days before some ninny posts a half-baked paper on the arXiv claiming that the standard cosmological model is all wrong and that the Universe is actually the shape of a vuvuzela. (This would require only a small modification of an earlier suggestion.)

These images are of course primarily for PR purposes, but there’s nothing wrong with that. Apart from being beautiful in its own right, they demonstrate that Planck is actually working and that results it will eventually produce should be well worth waiting for!

Oh, nearly forgot to mention that the excellent Jonathan Amos has written a nice piece about this on the BBC Website too.

Experiments and Observations

It’s nice to be able to pass on some upbeat news for once.

The first thing is that, after a lot of delays and a bit of haggling, the School of Physics & Astronomy at Cardiff University has finally issued advertisements for a bunch of new Faculty positions in Experimental Physics. The positions, which are tenured,  involve both Chair and Lecturer/Reader levels and there are several positions available. The School and University  have  put together a handsome start-up package for a new group and there’s plenty of spanking new experimental laboratory space to set up shop. Coupled with the fact that Cardiff is a great city to live in, with low costs and great sporting and cultural infrastructure, this should prove a tempting opportunity for someone to set up their own group.

It’s also a welcome vote of confidence from Cardiff University which, despite cuts in its overall budget, has decided to invest heavily in the School’s strategic plan. I hope and believe we’ll attract a strong field for these appointments and look forward to seeing what develops. We need a shot in the arm and this might just deliver it.

What’s particularly interesting about this clutch of new appointments is that they are open to people working in any area of physics, with the exception of astrophysics. Given the massive cuts in STFC’s budget, this is no time to be expanding in areas covered by its remit. I say that as an astrophysicist, with considerable regret but pragmatism in the face of the changing landscape of British science funding. In times of risk you have to broaden your portfolio. However, that’s not to say that astrophysics at Cardiff is downbeat. Far from it, in fact.

ESA held an international press conference to present exciting new results from the Herschel Observatory at the European Space Research and Technology Centre, Noordwijk, The Netherlands, on Thursday 6 May. A webcast of the press conference with Cardiff’s Professors Matt Griffin and Steve Eales taking part, can be seen at from http://www.esa.int/SPECIALS/Herschel. At the conference Steve Eales talked about the latest results from the Herschel ATLAS survey: an ATLAS of the Universe. ATLAS will cover one eightieth of the sky, four times larger than all the other Herschel surveys combined and is led by Professor Eales and Dr Loretta Dunne at Nottingham University.

Herschel ATLAS has measured the infrared light from thousands of galaxies, spread across billions of light-years. Each galaxy appears as just a pinprick but its brightness allows astronomers to determine how quickly it is forming stars. Roughly speaking, the brighter the galaxy the more stars it is forming. The Herschel images show that in the past there were many more galaxies forming stars much faster than our own Galaxy. But what triggered this frantic activity is not completely understood. Steve Eales said

every time astronomers have observed the universe in a new waveband, they have discovered something new. So as well as our regular science programmes, I am hoping for the unexpected.

I am hoping to get involved with the ATLAS data myself at some point as I am formally a member of the consortium, but I’ve been too busy doing other things to get involved in these initial stages so am not on any of the preliminary science papers. I hope I can get properly involved in this project sooner rather than later…

The ATLAS survey, image courtesy of ESA and the ATLAS consortium

The full press release also includes surprises on how stars are formed including work carried out by Cardiff’s Professor Derek Ward-Thompson. Herschel’s star formation surveys are beginning to reveal the mysteries behind how massive stars are created.

Skepsis

This past week was the final week of proper teaching at Cardiff University, so I’ve done my last full lectures, tutorials and exercise classes of the academic year. Yesterday I assessed a bunch of 3rd-year project talks, and soon those students will be handing in their written reports for marking.  Next week will be a revision week, shortly after that the examinations begin. And so the cycle of academic life continues, in a curious parallel to the  football league season – the other routine that provides me with important markers for the passage of the year.

Anyway, this week I gave the last lecture to my first-year class on Astrophysical Concepts. This is a beginning-level course that tries to introduce some of the theory behind astronomy, focussing on the role of gravity. I cover orbits in newtonian gravity, gravity and hydrostatic equilibrium in extended bodies, a bit about stellar structure, gravitational collapse, and so on. In the last part I do a bit of cosmology. I decided to end this time with a lecture about dark energy as, according to the standard model, this accounts for about 75% of the energy budget of the Universe. It’s also something we don’t understand very well at all.

To make a point, I usually show the following picture (credit to the High-z supernova search team).

 What is plotted is the redshift of each supernova (along the x-axis), which relates to the factor by which the universe has expanded since light set out from it. A redshift of 0.5 means the universe was compressed by a factor 1.5 in all dimensions at the time when that particular supernova went bang. The y-axis shows the really hard bit to get right. It’s the estimated distance (in terms of distance modulus) of the supernovae. In effect, this is a measure of how faint the sources are. The theoretical curves show the faintness expected of a standard source observed at a given redshift in various cosmological models. The bottom panel shows these plotted with a reference curve taken out so the trend is easier to see.

The argument from this data is that the high redshift supernovae are fainter than one would expect in models without dark energy (represented by the   in the diagram. If this is true then it means the luminosity distance of these sources is greater than it would be in a decelerating universe. They can be accounted for, however, if the universe’s expansion rate has been accelerating since light set out from the supernovae. In the bog standard cosmological models we all like to work with, acceleration requires that be negative. The “vacuum” equation of state provides a simple way of achieving this but there are many other forms of energy that could do it also, and we don’t know which one is present or why…

This plot contains the principal evidence that has led to most cosmologists accepting that the Universe is accelerating.  However, when I show it to first-year undergraduates (or even to members of the public at popular talks), they tend to stare in disbelief. The errors are huge, they say, and there are so  few data points. It just doesn’t look all that convincing. Moreover, there are other possible explanations. Maybe supernovae were different beasties back when the universe was young. Maybe something has absorbed their light making them look fainter rather than being further away. Maybe we’ve got the cosmological models wrong.

The reason I show this diagram is precisely because it isn’t superficially convincing. When they see it, students probably form the opinion that all cosmologists are gullible idiots. I’m actually pleased by that.  In fact, it’s the responsibility of scientists to be skeptical about new discoveries. However, it’s not good enough just to say “it’s not convincing so I think it’s rubbish”. What you have to do is test it, combine it with other evidence, seek alternative explanations and test those. In short you subject it to rigorous scrutiny and debate. It’s called the scientific method.

Some of my colleagues express doubts about me talking about dark energy in first-year lectures when the students haven’t learned general relativity. But I stick to my guns. Too many people think science has to be taught as great stacks of received wisdom, of theories that are unquestionably “right”. Frontier sciences such as cosmology give us the chance to demonstrate the process by which we find out about the answers to big questions, not by believing everything we’re told but by questioning it.

My attitude to dark energy is that, given our limited understanding of the constituents of the universe and the laws of matter, it’s the best explanation we have of what’s going on. There is corroborating evidence of missing energy, from the cosmic microwave background and measurements of galaxy clustering, so it does have explanatory power. I’d say it was quite reasonable to believe in dark energy on the basis of what we know (or think we know) about the Universe.  In other words, as a good Bayesian, I’d say it was the most probable explanation. However, just because it’s the best explanation we have now doesn’t mean it’s a fact. It’s a credible hypothesis that deserves further work, but I wouldn’t bet much against it turning out to be wrong when we learn more.

I have to say that too many cosmologists seem to accept the reality of dark energy  with the unquestioning fervour of a religious zealot.  Influential gurus have turned the dark energy business into an industrial-sized bandwagon that sometimes makes it difficult, especially for younger scientists, to develop independent theories. On the other hand, it is clearly a question of fundamental importance to physics, so I’m not arguing that such projects should be axed. I just wish the culture of skepticism ran a little deeper.

Another context in which the word “skeptic” crops up frequently nowadays is  in connection with climate change although it has come to mean “denier” rather than “doubter”. I’m not an expert on climate change, so I’m not going to pretend that I understand all the details. However, there is an interesting point to be made in comparing climate change with cosmology. To make the point, here’s another figure.

There’s obviously a lot of noise and it’s only the relatively few points at the far right that show a clear increase (just as in the first Figure, in fact). However, looking at the graph I’d say that, assuming the historical data points are accurate,  it looks very convincing that the global mean temperature is rising with alarming rapidity. Modelling the Earth’s climate is very difficult and we have to leave it to the experts to assess the effects of human activity on this curve. There is a strong consensus from scientific experts, as monitored by the Intergovernmental Panel on Climate Change, that it is “very likely” that the increasing temperatures are due to increased atmospheric concentrations of greenhouse gas emissions.

There is, of course, a bandwagon effect going on in the field of climatology, just as there is in cosmology. This tends to stifle debate, make things difficult for dissenting views to be heard and evaluated rationally,  and generally hinders the proper progress of science. It also leads to accusations of – and no doubt temptations leading to – fiddling of the data to fit the prevailing paradigm. In both fields, though, the general consensus has been established by an honest and rational evaluation of data and theory.

I would say that any scientist worthy of the name should be skeptical about the human-based interpretation of these data and that, as in cosmology (or any scientific discipline), alternative theories should be developed and additional measurements made. However, this situation in climatology is very different to cosmology in one important respect. The Universe will still be here in 100 years time. We might not.

The big issue relating to climate change is not just whether we understand what’s going on in the Earth’s atmosphere, it’s the risk to our civilisation of not doing anything about it. This is a great example where the probability of being right isn’t the sole factor in making a decision. Sure, there’s a chance that humans aren’t responsible for global warming. But if we carry on as we are for decades until we prove conclusively that we are, then it will be too late. The penalty for being wrong will be unbearable. On the other hand, if we tackle climate change by adopting greener technologies, burning less fossil fuels, wasting less energy and so on, these changes may cost us a bit of money in the short term but  frankly we’ll be better off anyway whether we did it for the right reasons or not. Of course those whose personal livelihoods depend on the status quo are the ones who challenge the scientific consensus most vociferously. They would, wouldn’t they? Moreover, as Andy Lawrence pointed out on his blog recently, the oil is going to run out soon anyway…

This is a good example of a decision that can be made on the basis of a  judgement of the probability of being right. In that respect , the issue of how likely it is that the scientists are correct on this one is almost irrelevant. Even if you’re a complete disbeliever in science you should know  how to respond to this issue, following the logic of Blaise Pascal. He argued that there’s no rational argument for the existence or non-existence of God but that the consequences of not believing if God does exist (eternal damnation) were much worse than those of behaving as if you believe in God when he doesn’t. For “God” read “climate change” and let Pascal’s wager be your guide….

Nobel Betting

I’m reminded that the 2009 Nobel Prize for Physics will be announced tomorrow, on Tuesday 6th October. A recent article in the Times Higher suggested that British physicists might be in line for glory (based on a study of citation statistics). However, the Table they produced showed that their predictions haven’t really got a good track record so it might be unwise to bet too much on the outcome! This year’s predictions are at the top, with previous years underneath; the only successful prediction is highlighted in blue:

The problem I think is that it’s difficult to win the Nobel Prize for theoretical work unless confirmed by a definitive experiment, so much as I admire (Lord) Martin Rees – and would love to see a Nobel Prize going to astrophysics generally – I think I’d have to mark him down as an outsider. It would be absurd to give the prize to string theory, of course, as that makes no contact whatsoever with experiment or observation.

I think it would be particularly great if Sir Michael Berry won a share of the physics prize, but we’ll have to wait and see. The other British runner in the paddock is Sir John Pendry. While it would be excellent for British science to have a Nobel prize, what I think is best about the whole show is that it is one of the rare occasions that puts a spotlight on basic science, so it’s good for all of us (even us non-runners).

I think the panel made a bit of a bizarre decision last year and I hope there won’t be another steward’s enquiry this year to distract us from the chance to celebrate the achievements of the winner(s).

I’d be interested to hear any thoughts on other candidates through the comments box. No doubt there’ll be some reactions after the announcement too!