Author Archive

Physics and Statistics

Posted in Bad Statistics, Education with tags , , , on August 16, 2013 by telescoper

Predictably, yesterday’s newspapers and other media  were full of feeble articles about the A-level results, and I don’t just mean the gratuitous pictures of pretty girls opening envelopes and/or jumping in the air.  I’ve never met a journalist who understood the concept of statistical significance, which seems to account for the way they feel able to write whatever they like about any numbers that happen to be newsworthy without feeling constrained by mathematical common-sense.  Sometimes it’s the ridiculous over-interpretation of opinion polls (which usually have a sampling uncertainty of ±3 %), sometimes its league tables. This time it’s the number of students getting the top grades at A-level.

The BBC, for example, made a lot of fuss about the fall in the % of A and A* A-level grades, to  26.3% this year from 26.6% last year. Anyone with a modicum of statistical knowledge would know, however, that whether this drop means anything at all depends on how many results were involved: the sampling uncertainty depends on size N approximately as √N. For a cohort of 300000 this turns into a percentage uncertainty of about 0.57%, which is about twice as large as the reported fall.  The result is therefore “in the noise” – in the sense that there’s no evidence that it was actually harder to get a high grade this year compared with last year – but that didn’t prove a barrier to those editors intent on filling their newspapers and websites with meaningless guff.

Almost hidden among the bilge was an interesting snippet about Physics. It seems that the number of students taking Physics A-level this year has exceeded 35,000 in 2013.  That was set as a government target for 2014, so it has been reached a year early.  The difference between the number that took Physics this year (35,569) and those who took it in 2006 (27,368) is certainly significant. Whether this is the so-called Brian Cox effect or something else, it’s very good news for the future health of the subject.

On the other hand, the proportion of female Physics students remains around 20%. Over the last three years the proportion has been 20.8%, 21.3% and 20.6% so numerically this year is down on last year, but the real message in these figures is that despite strenuous efforts to increase this fraction, there is no significant change.

As I write I’m formally still on Clearing business, sitting beside the telephone in case anyone needs to talk to me. However, at close of play yesterday the School of Mathematical and Physical Sciences had exceeded its recruitment target by quite a healthy margin.  We’re still open for Clearing, though, as our recent expansion means we can take a few more suitably qualified students. Physics and Astronomy did particularly well, and we’re set to welcome our biggest-ever intake into the first year in September 2013. I’m really looking forward to meeting them all.

While I’m on about statistics, here’s another thing. When I was poring over this year’s NSS results, I noticed that only 39 Physics departments appeared in the survey. When I last counted them there were 115 universities in the UK. This number doesn’t include about 50 colleges and other forms of higher education institutions which are also sometimes included in lists of universities. Anyway, my point is that at most about a third of British universities have a physics department.

Now that is a shocking statistic…

Advice for Students on Clearing

Posted in Education, The Universe and Stuff with tags , , , , on August 15, 2013 by telescoper

1-dont-panic

We still have places in the School of Mathematical & Physical Sciences at the University of Sussex. No other Physics & Astronomy department in the UK scored more highly in the latest NSS survey than ours, so whether you’re interested in Physics, Astrophysics, Astronomy or Mathematics (or even a combination of those subjects), why not just take a look at the University’s Clearing Page and give us a ring.?

As a matter of fact, I’ll be there myself from 8am this morning to talk to interested students.

11.30 UPDATE. I finished my first shift at 11am. I’ll be going back at 5pm for the last session, until the lines close at 7pm. During the last hour a minimum of 20 overs must be bowled. Or something.  The main call centre (which has fifty phone lines) is next door to where we were sitting and is operated by admissions experts and student helpers who are processing the queries and, if necessary, routing them through to academics (i.e. people like me) to provide further information or to answer specific questions. You can take a peep behind the scenes here. Some of the calls were from very anxious prospective students, and it’s a very nice feeling being able to help them sort out their course! Now back to other things until I start again this evening.

 

19.30 UPDATE. Phew. Finally been stood down, but I’ll be back on duty tomorrow afternoon. It’s been a very interesting day which has gone very well for us. Lines stay open until 8pm tonight and re-open at 8 in the morning and we’re still in business to see if we can give just a few more students the opportunity to study in the School next academic year. Now I’m off home to chill, probably over a glass or two of wine!

A Three-dimensional Map of the Early Universe

Posted in The Universe and Stuff with tags , , , , on August 14, 2013 by telescoper

I found this video via a web page describing the FastSound project, which is surveying galaxies in the Universe which are at such a huge distance that we are seeing them as they were over nine billion years ago. Using the Subaru Telescope‘s impressive new Fiber Multi-Object Spectrograph (FMOS). This project is “work in progress”. The survey so far contains only 1,100 galaxies, but while that is small by the standards of a modern redshift survey, and will in fact still only comprise about 5000 galaxies when complete, what is amazing about it is that the galaxies are at such enormous distances. Even using a telescope with an 8.2 metre primary mirror, this survey will take another year or so to be completed.

A survey of a representative region of the Universe at such high redshift allows astrophysicists to test theories of the growth of the large-scale structure of the Universe. In the standard cosmology, these form by a process of gravitational instability: small irregularities in the distribution of matter get amplified by the action of gravity to become large structures such as galaxies and galaxy clusters. Comparing the level of clustering at early times with that observed around us today allows us to check whether this growth matches theoretical predictions. There should be much less clumpiness earlier on if the theoretical picture is right.

I began my PhD DPhil at the University of Sussex in 1985, working on the large-scale structure of the Universe. Coincidentally, the largest redshift survey available at that time, the CfA1 Survey, also contained 1,100 galaxies – as displayed in the famous “stick man map”:

cfa2.n30

The galaxies mapped out in that survey, however, are all (relatively speaking) in our back yard: none is further than a few hundred million light years away…

First Among Equals

Posted in Brighton, Education with tags , , , , on August 13, 2013 by telescoper

Well, it’s been a pretty good day so far. I had a very interesting meeting in London this morning about something that will be out in open (geddit?) very soon but which I won’t blog about until the appropriate time. Instead I’ll just mention the news just out that the Department of Physics & Astronomy in the School of Mathematical and Physical Sciences at the University of Sussex finished in (joint ) 1st place in the 2013 National Student Survey (NSS). The full subject-level tables are not yet published – or at least I’ve been unable to find them – so I don’t know who we’re equal with, but I will update this post when I receive this information.

Looking through the detailed breakdown of the results, one figure leapt out at me. The fraction of Physics & Astronomy students at the University of Sussex who expressed overall satisfaction (in response to Question 22) was an amazing

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Obviously it will be difficult to improve on this figure in future (!), but in fact we have already been planning to introduce a number of changes to our courses to boost our scores on other questions. That’s not to say that the result is due to one result: we also scored 100% on Q3 (“the staff are enthusiastic about what they are teaching”), Q4 (“the course is intellectually stimulating”), Q15 (“the course is well-organized and is running smoothly”) and Q18 (“I have been able to access specialised equipment, facilities or rooms when I needed to”).

You can say what you like about the NSS, but it certainly keeps us on our toes. The tables generally show continued improvement in NSS scores across the sector, which I think demonstrates that all Higher Education Institutions do make the effort to respond to student feedback.  That’s where the NSS has real value, as opposed to just being part of yet another league table. The survey also shows that in fact most UK Physics and Astronomy departments are extremely good and the differences between them are actually rather small. Maintaining our high ranking therefore won’t be easy, but we’re certainly going to give it a go for next year, and our influx of new staff will certainly help. Hopefully next year we’ll be out in front on our own again!

On behalf of everyone in the Department of  Physics & Astronomy, I’d like to thank the students who participated in the NSS for this enthusiastic endorsement!

Fracking Confusion

Posted in Politics, Science Politics, The Universe and Stuff with tags , , , , , , on August 12, 2013 by telescoper

The news on the radio this morning featured a story about the Prime Minister wanting the UK to “get behind” hydraulic fracturing (or “fracking” as it is known for short) , a means of  liberating shale gas that offers the prospect of boosting the UK’s energy supply.

There’s not much sign any “getting behind” happening up the road from here in Balcombe, where a sizable anti-fracking protest has been going on for some time. There’s actually no fracking going on in Balcombe at the moment; the company involved, Cuadrilla Resources, is doing exploratory drilling to look for oil but may apply for a licence to pursue hydraulic fracturing if that is unsuccessful.

There’s a simple graphic on the BBC website that illustrates how fracking works:

_65309507_shale_gas_extraction464

In simple terms it involves pumping a mixture of water, sand and chemicals into a deposit of shale ato fracture the solid material contained therein and thus liberate the gas. Environmentalists argue that this technique might cause earth tremors and/or contamination of the water supply; advocates of fracking dispute these claims. I’m not sufficiently expert to be able to comment usefully on the arguments about the possible environmental dangers associated with it, so I’d be glad to receive comments via the box below.

One thing I will comment on, though, is the very poor quality of the media reporting on this issue. I’ve yet to see any meaningful attempt to comment on the science involved when surely that’s the key to whether we should “get behind” fracking or not? It struck me that quite a few readers might also be interested but ill-informed about this issue to, so for them I’d recommend reading the Beddington Report, the key findings of which were:

  • The health, safety and environmental risks can be managed effectively in the UK. Operational best practices must be implemented and enforced through strong regulation. Fracture propagation is an unlikely cause of contamination.
  • The risk of fractures propagating to reach overlying aquifers is very low provided that shale gas extraction takes place at depths of many hundreds of metres or several kilometres. Even if fractures reached overlying aquifers, the necessary pressure conditions for contaminants to flow are very unlikely to be met given the UK’s shale gas hydrogeological environments.
  • Well integrity is the highest priority. More likely causes of possible contamination include faulty wells. The UK’s unique well examination scheme was set up so that independent, specialist experts could review the design of every offshore well. This scheme must be made fit for purpose for onshore activities.
  • Robust monitoring is vital. Monitoring should be carried out before, during and after shale gas operations to detect methane and other contaminants in groundwater and potential leakages of methane and other gases into the atmosphere.
  • An Environmental Risk Assessment (ERA) should be mandatory. Every shale gas operation should assess risks across the entire lifecycle of operations, from water use through to the disposal of wastes and the abandonment of wells.
  • Seismic risks are low. Seismicity should be included in the ERA.Seismicity induced by hydraulic fracturing is likely to be of smaller magnitude than the UK’s largest natural seismic events and those induced by coal mining.
  • Water requirements can be managed sustainably. Water use is already regulated by the Environment Agency. Integrated operational practices, such as recycling and reusing wastewaters where possible, would help to minimise water requirements further. Options for disposing of wastes should be planned from the outset. Should any onshore disposal wells be necessary in the UK, their construction, regulation and siting would need further consideration.
  • Regulation must be fit for purpose. Attention must be paid to the way in which risks scale up should a future shale gas industry develop nationwide. Regulatory co-ordination and capacity must be maintained.
  • Policymaking would benefit from further research. The carbon footprint of shale gas extraction needs further research. Further benefit would also be derived from research into the public acceptability of shale gas extraction and use in the context of the UK’s energy, climate and economic policies.

I’m not sure how many anti-fracking activists, or others involved in the Balcombe protest, have read this report.

Anyway, in an attempt to gauge the mood of my totally unrepresentative readership, I thought I’d try a little poll:

And if you have strong opinions, please feel free to use the comments box.

Surplus Value, Exploitation and Scientific Publishing

Posted in Open Access, Politics with tags , , , , on August 11, 2013 by telescoper

The August edition of Physics World – house organ of the Institute of Physics – contains an article about Open Access Publishing which is available online here.  In fact, I get a mention in it:

Another vocal critic of the science-publishing industry has been astronomer Peter Coles from the University of Sussex. “Publishers want a much higher fee than [the real cost of publishing a paper on the Internet] because they want to maintain their eye-watering profit margins, despite the fact that the ‘service’ they provide has been rendered entirely obsolete by digital technologies,” Coles claimed on his blog In the Dark earlier this year. Yet publishers have been fighting back, pointing out that scientists often do not understand how the publishing industry operates and highlighting the many valuable – and expensive – functions they provide to the scientific community. In addition to the often complex process of managing peer review, these include everything from developing and maintaining IT systems to checking papers through plagiarism detection software – none of which comes cheap (see “The value publishers bring”).

Publishers have indeed been fighting back, but you’d expect that of vested interests.  You can read the rest of the article yourself to see if you’re convinced. I’m not. I think it’s a desperate piece of propaganda.

The last comment in the quoted paragraph (in parenthesis) points to a box purporting to explain why scientific journals should be so expensive. The explanations presented in that box  are so obviously  disingenuous that they don’t merit a detailed debunking because the argument can be refuted without any need to refer to the box: note the deliberate confusion between cost (“none of which comes cheap”) and “value” in the last paragraph quoted above.

IOP Publishing (along with  other profiteering organizations of its type) insist that it brings value to scientific papers. It doesn’t. The authors and referees do all the things that add value. What the IOP does is take that value and turn it into its own profits. The fact that enormous profits are made out of this process in itself demonstrates that what the scientific community is being charged is nothing whatever to do with cost.

This reminds me of many discussions I had in my commie student days about surplus value, a concept that I believe was first discussed by Friedrich Engels, but which was explored in great detail by Karl Marx, in Das Kapital. According to the wikipedia page, the term “refers roughly to the new value created by workers that is in excess of their own labour-cost and which is therefore available to be appropriated by the capitalist, according to Marx; it allows then for profit and in so doing is the basis of capital accumulation.”

Engels is quoted there as follows:

Whence comes this surplus-value? It cannot come either from the buyer buying the commodities under their value, or from the seller selling them above their value. For in both cases the gains and the losses of each individual cancel each other, as each individual is in turn buyer and seller. Nor can it come from cheating, for though cheating can enrich one person at the expense of another, it cannot increase the total sum possessed by both, and therefore cannot augment the sum of the values in circulation. (…) This problem must be solved, and it must be solved in a purely economic way, excluding all cheating and the intervention of any force — the problem being: how is it possible constantly to sell dearer than one has bought, even on the hypothesis that equal values are always exchanged for equal values?

Marx’s solution of this economical conundrum was central to his theory of exploitation:

…living labour at an adequate level of productivity is able to create and conserve more value than it costs the employer to buy; which is exactly the economic reason why the employer buys it, i.e. to preserve and augment the value of the capital at his command. Thus, the surplus-labour is unpaid labour appropriated by employers in the form of work-time and outputs.

In this context of academic publishing, the workers are scientific researchers and the employers are the publishers. The workers  not only produce the science in the first place, but also carry out virtually all of the actions that the employers claim add value. The latter are simply appropriating the labour of the former, which is exploitation. It has to stop.

The Expanding University

Posted in Biographical, Education, The Universe and Stuff with tags , , , on August 10, 2013 by telescoper

Well, I’m a bit busy today – despite the fact that it’s a weekend – so I’m just going to take the opportunity post here  a news item from my employer which has already been posted on the University of Sussex website. 

–o–

The School of Mathematical and Physical Sciences (MPS) will have 63 academics at the start of the 2013-14 academic year – an increase of 58 per cent from February, when only 40 were in post.

The expansion follows a very successful few years for the School, during which the number of students starting degrees in Physics and Astronomy at Sussex has grown almost threefold.

The department has also climbed to 5th in The Times Good University Guide 2013 and Mathematics was ranked in the top 10 for academic support in the 2012 National Student Survey (NSS).

From September, Physics and Astronomy will have 40 academics, up from 25 in February. There are 12 new posts as well as three replacements, including the arrival in February of Professor Peter Coles, who replaced the late Professor David Axon as Head of School.

Mathematics is increasing from 15 academics to 23, with five of these arrivals being new positions. In particular, three new professors will join the Department this year.

Professor Coles says that overseeing this expansion has been his main focus since returning to Sussex. He says: “When I arrived, plans were already under way to get new people in and I knew this had to be my priority in my first few months as Head of MPS.

“We had an incredibly high calibre of applicants for all the posts and, in many cases, have been able to appoint more than one person. For one of the posts in Astronomy, the shortlist was so strong that we have actually appointed four excellent academics in that area. We couldn’t miss that opportunity.

“Our three  new chairs in Mathematics are joining us from Denmark, Greece and Italy, bolstering the School’s international outlook.

“We have been strategic in our appointments to encourage growth into new areas for us, such as probability and stochastic modelling on the Mathematics side, and materials-based experimental research on the Physics side. We anticipate further strategic expansion in these areas in the near future.

“These appointments also represent a step towards more interdisciplinarity and better crossover between the two departments within the School, and indeed with other schools such as Life Sciences, developing still further the University’s traditional strength in interdisciplinary research.

“And, most importantly of all, students in MPS will benefit from more study choices and smaller class sizes.”

A Sussex Alumna

Posted in Biographical, Television, The Universe and Stuff with tags , , , , on August 9, 2013 by telescoper

I had a very nice meeting this morning with Sir Harry Kroto, who is back in the UK for the summer. We chatted about a number of exciting things going on at Sussex University and beyond, in the middle of which I remembered a film featuring my former  PhD Student from Nottingham days, Emma King. The film was part of a series about young scientists made by the Vega Science Trust (which Harry set up) and it was originally broadcast on BBC 2 as part of The Learning Zone.

Emma is a graduate of the Department of Physics & Astronomy at Sussex University. As an undergraduate at the University of Sussex she made history when she became the first woman to win the top prize at the Science, Engineering and Technology Student of the Year award despite tests at school which showed that Emma was not only slightly dyslexic, but that also had very poor arithmetic skills and she says “a nearly non-existent visual memory.” None of that stopped her completing her PhD thesis (on magnetic fields in cosmology) in 2006.

p.s. After completing her PhD, Emma changed career and now runs this outdoor event venue.

The Dark Side of the REF

Posted in Finance, Science Politics with tags , , , , , , , , on August 8, 2013 by telescoper

There’s a disturbing story in the latest Times Higher which argues that the University of Leicester has apparently reneged on a promise that non-submission to the forthcoming (2014)  Research Excellence Framework (REF) would not have negative career consequences. They have now said that except in exceptional circumstances, non-submitted academics will either be moved to a teaching-only contract (where there is a vacancy and they can demonstrate teaching excellence), or have their performance “managed”, with the threat of sacking if they don’t meet the specified targets.  I’d heard rumours of this on the grapevine (i.e. Twitter) before the Times Higher story was published. It’s very worrying to have it confirmed, as it raises all kinds of questions about what might happen in departments that turn out to have disappointing REF results .

There are (at least) two possible reasons for non-inclusion of the outputs of a researcher and it is important to distinguish between them. One is that the researcher hasn’t enough high-quality outputs to submit. In the absence of individual extenuating circumstances, researchers are expected to submit four “outputs” (in my discipline that means “research papers”) for assessment. That’s a pretty minimal level of productivity, actually;  such a number per year is a reasonable average for an active researcher in my field.  A person employed on a contract that specifies their duties as Teaching and Research may therefore be under-performing  if they can’t produce four papers over the period 2008-2013. I think some form of performance management  may be justifiable in this case, but the primary aim should be to help the individual rather than show them the door. We all have fallow periods in research, and it’s not appropriate to rush to sack anyone who experiences a lean time.   Andrew Wiles would have been considered `inactive’ had there been a REF in 1992 as he hadn’t published anything for years. Then he produced a proof of Fermat’s Last Theorem. Some things just take time.

A second reason for excluding researcher from the REF is that the institution concerned may be making a tactical submission. As the Times Higher article explains:

The memo suggests that academics would be spared repercussions if, among other reasons, the number of individuals submitted is “constrained” by the volume of case studies their department intends to enter to demonstrate research impact.

Institutions must submit one case study for every 10 scholars entered.

Maria Nedeva, professor of science and innovation dynamics and policy at Manchester Business School, said the tactic of deciding how many academics to submit based on impact case study numbers was “rife”.

(Incidentally, the second paragraph is not quite right. The number of case studies required depends on the number of staff submitted as follows: for fewer than 15 staff , TWO case studies;  for 15-24.99 staff it is THREE case studies – and then for each additional ten members of staff entered a further case study is required.)

e case study for every scholars included plus one, i.e. forThe statement at the end of the quote there is in line with my experience too.  The point is that the REF is not just a means of allocating relatively small amounts of so-called `QR’ research funding . Indeed, it remains entirely possible that no funding at all will be allocated following the 2014 exercise. The thinking then is that the number of staff submitted is largely irrelevant; all that will count is league table position.

This by no means the only example of the dangers that lurk when you take league tables too seriously.

If a department is required to submit, say, four impact cases if all staff are included in the REF submission, but only has three viable ones, it would not be unreasonable to submit fewer staff because their overall would be dragged down by a poor impact case even if the output quality of all staff is high.  There will certainly be highly active researchers in UK institutions, including many who hold sizable external research grants, whose outputs are not submitted to the REF. As the article points out, it would be very wrong for managers to penalize scholars who have been excluded because of this sort of game-playing. That’s certainly not going to happen in the School of Mathematical and Physical Sciences at Sussex University.  Not while I’m Head of School, anyway.

Moreover, even researchers whose “outputs” are not selected may still contribute to the “Environment” and/or “Impact” sections so they still, in a very real sense, do participate in their department’s REF submission.

My opinion? All this silliness could easily have been avoided by requiring all staff in all units of assessment to be submitted by all departments. You know, like would have happened if the system were actually designed to identify and reward research excellence. Instead, it’s yet another example of a bureaucratic machine that’s become entirely self-serving. It exists simply because it exists.  Research would be much better off without it.

Duet for Violin and Subatomic Particles

Posted in Music, The Universe and Stuff with tags , , , on August 8, 2013 by telescoper

I received an email this morning about this video and thought I’d post the clip here. This short documentary is about the performance of the composition Cloud Chamber (“Duet for violin and subatomic particles”) in San Francisco at the California Academy of Sciences in Golden Gate Park. The video was produced by Patrick Haynes, Adam Behrmann and Chris Whitmore, and features commentaries from , e.g., Hitoshi Murayama, Professor of Physics at Berkeley and Director of the Institute of Physics and Mathematics of the Universe at the University of Tokyo (the commentaries start at 16:10). It is introduced by Professor JoAnne L. Hewitt, Head of Theoretical Physics at SLAC National Accelerator Laboratory, Stanford University. There’s a longer description on the Youtube page if you’re interested in learning more about this interesting project.