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Should the passive voice be avoided?

Posted in Education with tags , , , , , on May 1, 2013 by telescoper

It’s another very busy day (as well as another lovely one) so I thought instead of sitting indoors this lunchtime writing a typically verbose blog item I’d just pick something out of my back catalogue and give it another airing because it deals with something that’s come up a couple of times recently.

This is the time of year when final-year students are drafting their project reports. Yesterday I was back in Cardiff giving feedback on two such articles.  I usually quite enjoy reading these things, in fact. They’re not too long and I’m usually pretty impressed with how the students have set about the (sometimes quite tricky) things I’ve asked them to do for their project work. I think the project report is quite a challenge for UK physics students because they generally haven’t had much practice in putting together a lengthy piece of writing before or during their university course, so haven’t developed a style that they feel comfortable with and are often unfamiliar with various conventions (such as reference style, punctuation of equations, etc). Some of these are explained in quite a lot of detail in the instructions the students are given, of course, but we all know that only girls read instructions….

The thing that strikes me most forcibly about the strange way students write project reports is that they are nearly always phrased entirely in the passive voice, e.g.

The experiment was calibrated using a phlogiston normalisation widget….

I accept that people disagree about whether the passive voice is good style or not. Some journals actively encourage the passive voice while others go the opposite way entirely . I’m not completely opposed to it, in fact, but I think it’s only useful either when the recipient of the action described in the sentence is more important than the agent, or when the agent is unknown or irrelevant. There’s nothing wrong with “My car has been stolen” (passive voice) since you would not be expected to know who stole it. On the other hand “My Hamster has been eaten by Freddy Starr” would not make a very good headline.

The point is that the construction of a statement in the passive voice in English is essentially periphrastic, in that it almost inevitably involves some form of circumlocution – either using more words than necessary to express the meaning or being deliberately evasive by introducing ambiguity. Both of these failings should be avoided in scientific writing.

Apparently, laboratory instructors generally tell students to write their reports in the passive voice as a matter of course. I think this is just wrong. In a laboratory report the student should describe what he or she did. Saying what “was done” often leaves the statement open to the interpretation that somebody else did it. The whole point of a laboratory report is surely for the students to describe their own actions. “We calibrated the experiment..”  or “I calibrated the experiment…” are definitely to be preferred to the form I gave above.

That brings me to the choice of pronoun in the active voice. One danger is that it can appear very bombastic, but that’s not necessarily the case. I don’t find anything particularly wrong in saying, e.g.

We improve upon the technique of Jones et al. (1848) by introducing a variable doofer in the MacGuffin control, thereby removing gremlins from the thingummy process.

But the main issue is whether to use the singular or plural form. It can be irritating to keep encountering “I did this..” and “I did that..” all the way through a journal paper, and I certainly  would feel uncomfortable writing a piece like that in the first person singular. I think it feels less egotistical to use “we”, even if there is only one author (which is increasingly rare in any case). If it’s good enough for the Queen it’s good enough for me! However, I just looked “we” up in Chambers dictionary and found

..used when speaking patronizingly, esp to children, to mean `you’.

which wasn’t at all what I had in mind!

However in the case of a student project that I’m assessing I actually want to know what the particular student  writing the report did, not what was done by person or persons unspecified or by a group of uncertain composition. So I encourage my students to put, e.g.,

I wrote a computer program in 6502 Assembly Language to solve the Humdinger equation using the Dingbat-Schnitzelgruber algorithm.

I also (sometimes) like “we” when there’s, e.g., a complicated mathematical derivation.  Going  line by line through a lengthy piece or difficult technical argument seems friendlier if you imagine that the reader is trying to do the calculation along with you as you write it:

if we differentiate the right hand side of equation (8), use the expression for x obtained in equation (97), expand y in a power-series and take away the number we first thought of we find…

The “we” isn’t necessarily an  author with delusions of grandeur (or schizophrenia), but instead denotes a joint operation between author and reader.

Anyway, to resume the thread, it seems to me that sometimes it is appropriate to use the passive voice because it is the correct grammatical construction in the circumstances. Sometimes also the text just seems to work better that way too. But having to read an entire document written in the passive voice drives me to distraction. It’s clumsy and dull.

In scientific papers, things are a little bit different but I still think using the active voice makes them easier to read and less likely to be ambiguous. In the introduction to a journal paper it’s quite acceptable to discuss the background to your work in the passive voice, e.g. “it is now generally accepted that…” but when describing what you and your co-authors have done it’s much better to use the active voice. “We observed ABC1234 using the Unfeasibly Large Telescope..” is, to my mind, much better than “Observations of ABC1234 were made using..”.

Reading back over this post I notice that I have jumped fairly freely between active and passive voice, thus demonstrating that I don’t have a dogmatic objection to its use. What I’m arguing is that it shouldn’t be the default, that’s all.

My guess is that a majority of experimental scientists won’t agree with this opinion, but a majority of astronomers and theoreticians will.

This guess will now be tested by reactivating an old poll..

9 Comments »

Breaking down a breakdown

Posted in Biographical, The Universe and Stuff with tags , , , , , on April 25, 2013 by telescoper

A blog piece by Dean Burnett  I read on on the Grauniad website yesterday set me thinking about whether I should post a personal comment in reaction to it. I never know what is the appropriate way to draw the line between the private and the public on In the Dark but since having a blog is clearly an exercise in self-indulgence anyway I thought I’d go ahead and write a piece.

Dean’s piece is about nervous breakdowns, but it’s really about why “nervous breakdown” is not a very good name for what it purports to describe. Regular readers of this blog  (both of them) will know that I went through one last year, and one thing I do remember is the disapproval that the term “nervous breakdown” provoked when I used it during my subsequent course of therapy. Apparently it’s a bit frowned-upon among professionals in the field.

Here is Dean (who is a neuroscientist in his day job) on the subject:

The term nervous breakdown is actually surprisingly old, and stems from a time when both “nervous” and “breakdown” arguably had different meanings to their modern ones. It seems the “breakdown” element refers to a breakdown in the same way that cars or other machines can break down. And nervous just refers to the nervous tissue. So originally it meant a fault or error in the nervous tissue that controls the body. And suddenly my interpretation doesn’t seem so literal.

But this doesn’t mean it’s an invalid term, it’s just more of a rule-of-thumb or generalisation used to refer to what happens when someone becomes psychologically unable to function as normal. In the simplest sense it could be said that, mentally speaking, a nervous breakdown occurs when an individual finds that the number of things that they are able to cope with is lower than the number of things that they have to cope with.

That seems to me to sum up very sensibly why the term is not very useful for an expert: it’s too vague, in that there are so many quite different things that might cause a person to become “psychologically unable to function as normal”. But it also explains quite well why its usage persists in popular language, in that the state of being “”psychologically unable to function as normal” is not as uncommon you might think. Anyway, if someone says they’ve had a nervous breakdown it gives at least a general idea of what they’ve experienced, although the specifics vary widely from individual to individual.

I hope you’ll bear with me if I illustrate this with some personal observations in the light of my own experiences.

I’ve suffered from a form of panic disorder for many years. Actually even that term has a very broad definition, so that different individuals experience different forms of panic attacks and they can also take very different forms for the same individual. For me, a “typical” panic episode begins with a fairly generalized feeling of apprehension or dread. Sometimes that’s as far as it goes. However, more often, there follows a period of increasingly heightened awareness of things moving  in my peripheral vision that I can’t keep track of. This leads to a sense of being surrounded by threats of various kinds and panic ensues. Usually, at that point, I run.

A typical panic episode lasts only a few minutes, but that’s not the end of it. For a considerable period (hours) afterwards I find myself in a state of hypervigilance during which I’m such a bundle of nerves that the slightest sound or movement can trigger a repeat.

I tend to think of these episodes as being a bit like earthquakes. The milder ones happen fairly frequently, but they’re quite easy to cope with. I have altered my behaviour to avoid places likely to trigger them (see below) and to be aware of appropriate exit strategies. The more severe episodes are much harder to deal with, though, and when one starts there’s nothing I can do apart from try to find somewhere that feels safe, wait for it to pass and then just get through the aftermath, hoping for no aftershocks.

In Dean’s piece he writes about the different stressors that can trigger a breakdown. In my case it was a bit more complicated than that.  Thinking about the milder attacks I find it very difficult to identify specific triggers – they seem to occur more-or-less randomly. However,  I can cope with this low-level “noise” pretty well. I’ve had plenty of time to get used to it, at least.  The more severe attacks seem more likely to be triggered by specific places, especially if they’re crowded with people moving around – although I don’t always have a problem in places like that. To give an example, crossing the main concourse at Victoria Station is, for me, like descending into the abyss; I simply can’t do it, and have to go outside the station to get between the trains and the underground station. Paddington Station, on the other hand, is fine. Weird.

I think the probability of one of these episodes is also influenced by background levels of stress arising from other independent things. Anyway, last year I got into a state in which I was experiencing multiple episodes per day. I couldn’t sleep or eat for over a week, and couldn’t leave the house for fear of experiencing another major problem. I think “nervous breakdown” is a pretty apt description for that period, but my breakdown was caused not by a new problem, but the amplification of an old problem to completely intolerable levels.

The reason for writing about the anatomy of my breakdown in this context is twofold. One part is just to reinforce Dean’s point that a “nervous breakdown” can be triggered by many different circumstances and conditions. Mine is probably an unusual example, but I think everybody else’s  is too.

The other reason is to confess how frustrating it is to be a physicist who has experienced a thing like that. It seems natural that having experienced such an episode I should want or need to try to make sense of it, but I’ve struggled to do that. The way we’re used to thinking about things in physics is to make simple models that capture the relatively simple cause-and-effect relationships between relatively few variables, usually based on the objective analysis of data controlled experiments and/or systematic observations.   This all involves trying to break down a phenomenon into its component parts so as to look at their separate action and thus establish the simple rules (if there are any) that govern the overall behaviour.

The trouble with this analytic approach is that the human brain and its interactions with the external world are far too complicated and non-linear to be approached in the simple-minded way we physicists usually do things. Even if you accept that the brain is basically a collection of atoms communicating with each other using electrical impulses, that doesn’t mean that it’s useful to try to describe its action using atomic physics and electromagnetic theory.

On top of all that, there’s the issue that neuroscience is a subject I know very little about at a technical level. There’s only room in my feeble little brain for my own specialism, so I lack the knowledge needed even to understand the literature.

So although I got over my breakdown, it has left me with a huge number of questions I don’t even know how to begin to answer. What is happening in my brain when a panic episode begins? What is going on with my peripheral vision when it goes awry like it does? Why do some particular places  or circumstances trigger an attack but other, apparently similar, ones don’t?

I don’t suppose anyone out to answer these questions, but if any neuroscientists out there happen to read this piece I would be grateful if they could recommend appropriate literature, as long as it’s simple enough for an astrophysicist to read…

21 Comments »

Counting for the REF

Posted in Open Access, Science Politics with tags , , , , , , on April 20, 2013 by telescoper

It’s a lovely day in Brighton and I’m once again on campus for an Admissions Event at Sussex University, this time for the Mathematics Department in the School of Mathematical and Physical Sciences.  After all the terrible weather we’ve had since I arrived in February, it’s a delight and a relief to see the campus at its best for today’s crowds. Anyway, now that I’ve finished my talk and the subsequent chats with prospective students and their guests I thought I’d do a quick blogette before heading back home and preparing for this evenings Physics & Astronomy Ball. It’s all go around here.

What I want to do first of all is to draw attention to a very nice blog post by a certain Professor Moriarty who, in case you did not realise it, dragged himself away from his hiding place beneath the Reichenbach Falls and started a new life as Professor of Physics at Nottingham University.  Phil Moriarty’s piece basically argues that the only way to really judge the quality of a scientific publication is not by looking at where it is published, but by peer review (i.e. by getting knowledgeable people to read it). This isn’t a controversial point of view, but it does run counter to the current mania for dubious bibliometric indicators, such as journal impact factors and citation counts.

The forthcoming Research Excellence Framework involves an assessment of the research that has been carried out in UK universities over the past five years or so, and a major part of the REF will be the assessment of up to four “outputs” submitted by research-active members of staff over the relevant period (from 2008 to 2013). reading Phil’s piece might persuade you to be happy that the assessment of the research outputs involved in the REF will be primarily based on peer review. If you are then I suggest you read on because, as I have blogged about before, although peer review is fine in principle, the way that it will be implemented as part of the REF has me deeply worried.

The first problem arises from the scale of the task facing members of the panel undertaking this assessment. Each research active member of staff is requested to submit four research publications (“outputs”) to the panel, and we are told that each of these will be read by at least two panel members. The panel comprises 20 members.

As a rough guess let’s assume that the UK has about 40 Physics departments, and the average number of research-active staff in each is probably about 40. That gives about 1600 individuals for the REF. Actually the number of category A staff submitted to the 2008 RAE was 1,685.57 FTE (Full-Time Equivalent), pretty  close to this figure. At 4 outputs per person that gives 6400 papers to be read. We’re told that each will be read by at least two members of the panel, so that gives an overall job size of 12800 paper-readings. There is some uncertainty in these figures because (a) there is plenty of evidence that departments are going to be more selective in who is entered than was the case in 2008 and (b) some departments have increased their staff numbers significantly since 2008. These two factors work in opposite directions so not knowing the size of either it seems sensible to go with the numbers from the previous round for the purposes of my argument.

There are 20 members of the panel so 6400 papers submitted means that, between 29th November 2013 (the deadline for submissions) and the announcement of the results in December 2014 each member of the panel will have to have read 640 research papers. That’s an average of about two a day…

It is therefore blindingly obvious that whatever the panel does do will not be a thorough peer review of each paper, equivalent to refereeing it for publication in a journal. The panel members simply won’t have the time to do what the REF administrators claim they will do. We will be lucky if they manage a quick skim of each paper before moving on. In other words, it’s a sham.

Now we are also told the panel will use their expert judgment to decide which outputs belong to the following categories:

  • 4*  World Leading
  • 3* Internationally Excellent
  • 2* Internationally Recognized
  • 1* Nationally Recognized
  • U   Unclassified

There is an expectation that the so-called QR  funding allocated as a result of the 2013 REF will be heavily weighted towards 4*, with perhaps a small allocation to 3* and probably nothing at all for lower grades. The word on the street is that the weighting for 4* will be 9 and that for 3* only 1. “Internationally recognized”  will be regarded as worthless in the view of HEFCE. Will the papers belonging to the category “Not really understood by the panel member” suffer the same fate?

The panel members will apparently know enough about every single one of the papers they are going to read in order to place them  into one of the above categories, especially the crucial ones “world-leading” or “internationally excellent”, both of which are obviously defined in a completely transparent and objective manner. Not. The steep increase in weighting between 3* and 4* means that this judgment could mean a drop of funding that could spell closure for a department.

We are told that after forming this judgement based on their expertise the panel members will “check” the citation information for the papers. This will be done using the SCOPUS service provided (no doubt at considerable cost) by   Elsevier, which by sheer coincidence also happens to be a purveyor of ridiculously overpriced academic journals.  No doubt Elsevier are  on a nice little earner peddling meaningless data for the HECFE bean-counters, but I have no confidence that they will add any value to the assessment process.

There have been high-profile statements to the effect that the REF will take no account of where the relevant “outputs”  are published, including a pronouncement by David Willetts. On the face of it, that would suggest that a paper published in the spirit of Open Access in a free archive would not be disadvantaged. However, I very much doubt that will be the case.

I think if you look at the volume of work facing the REF panel members it’s pretty clear that citation statistics will be much more important for the Physics panel than we’ve been led to believe. The panel simply won’t have the time or the breadth of understanding to do an in-depth assessment of every paper, so will inevitably in many cases be led by bibliometric information. The fact that SCOPUS doesn’t cover the arXiv means that citation information will be entirely missing from papers just published there.

The involvement of  a company like Elsevier in this system just demonstrates the extent to which the machinery of research assessment is driven by the academic publishing industry. The REF is now pretty much the only reason why we have to use traditional journals. It would be better for research, better for public accountability and better economically if we all published our research free of charge in open archives. It wouldn’t be good for academic publishing houses, however, so they’re naturally very keen to keep things just the way they are. The saddest thing is that we’re all so cowed by the system that we see no alternative but to participate in this scam.

Incidentally we were told before the 2008 Research Assessment Exercise that citation data would emphatically not be used;  we were also told afterwards that citation data had been used by the Physics panel. That’s just one of the reasons why I’m very sceptical about the veracity of some of the pronouncements coming out from the REF establishment. Who knows what they actually do behind closed doors?  All the documentation is shredded after the results are published. Who can trust such a system?

To put it bluntly, the apparatus of research assessment has done what most bureaucracies eventually do; it has become  entirely self-serving. It is imposing increasingly  ridiculous administrative burdens on researchers, inventing increasingly  arbitrary assessment criteria and wasting increasing amounts of money on red tape which should actually be going to fund research.

And that’s all just about “outputs”. I haven’t even started on “impact”….

53 Comments »

Your PhD Questions Answered (?)

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

As I mentioned last week, one of the main items on the agenda at the moment is recruitment of new PhD students. As usual, this finds me having to operate on both sides of the fence,  playing a role in selecting students whilst also trying to advise students on how to target their applications, prepare for interview, and choose between offers (for those who manage to get a place).

In my field (astrophysics), the primary route for funding a PhD comes through the Science and Technology Facilities Council (STFC) which operates a national deadline (31st March) before which candidates can not be required to make a decision. This deadline sets the timescale for departments to decide too, as we clearly want to make sure all our first choice applicants get their offers before the cutoff date.

The national deadline prevents students from being pressured into making decisions before they have heard back from all the institutions to which they have applied, so in that sense it’s a good idea. On the other hand, it does mean that there’s often frantic activity on deadline day as offers are accepted or declined. Reserves have to be contacted quickly when a favoured candidate withdraws to go somewhere else and not all of them may still be available. A student who has been waiting anxiously without a first-choice offer may suddenly receive a lifeline on deadline day.

Getting offers is one thing, but deciding between them is quite another. There are many things to take into account, and the criteria are by no means clear. I’m not the only person to have been thinking about this. There are personal matters, of course. Is it a nice place? Are the people friendly? Do you think you can get on with your potential supervisor? That sort of thing. But there’s also the actual research. Is the project really what you want to do? Is is likely to open up a future career in research, or just be a dead end? Is the mixture of theory and experiment (or observation) what you would like?

One of the issues that often arises when I discuss research with potential PhD students is how structured the project  is. Some projects are  mapped out by the supervisor in great detail, with specific things to be done in a specific order with well-defined milestones against which progress can be measured. Others, especially but not exclusively theoretical ones, are much more of the nature of “here’s an interesting idea – let’s study it and see where it leads”. Most PhDs are somewhere between these two extremes, but it’s probably true that experimental PhDs are more like the former, whereas theoretical ones are more like the latter. Mine, in theoretical astrophysics, ended up evolving quite considerably from its starting point.

I’ve always been grateful to my supervisor for allowing me the freedom to follow my own curiosity. But I think it was essential to be given an initial focus, in the form of a specific project to cut my teeth on. Getting a calculation finished, written up and published gave me the confidence to start out on my own, but I did need a lot of guidance during that initial phase. We a;ll need to learn how to walk before we can run.

Another aspect of this is what the final thesis should look like. Should it be a monolithic work, focussed on one very specific topic, or can it be an anthology of contributions across a wider area?  Again, it’s a question of balance. I think that a PhD thesis should be seen as a kind of brochure advertising the skills and knowledge of the student that produced it. Versatility is a good quality, so if you can do lots of different things then your thesis should represent that. On the other hand, you also need to demonstrate the ability to carry out a sustained and coherent piece of research. Someone who flits around knocking out lots of cutesy “ideas papers” may get a reputation for being a bit of a dabbler who is unable or unwilling to tackle problems in depth. The opposite extreme would be a person who is incapable of generating new ideas, but excellent once pointed in a specific direction. The best scientists, in my opinion, have creative imagination as well as technical skill and stamina.  It’s a matter of balance, and some scientists are more balanced than others. There are some (scary) individuals who are brilliant at everything, of course., but us mere mortals have to make the most of our limited potential.

The postdoc market that lies beyond your PhD is extremely tough. To survive you need to maximize the chances of getting a job, and that means being able to demonstrate a suitability for as many opportunities as possible that come up. So if you want to do theory, make sure that you know at least something about observations and data analysis. Even if you prefer analytic work, don’t be too proud to use a computer occasionally. Research problems often require  you to learn new things before you can tackle them. Get into the habit of doing that while you’re a student, and you’re set to continue for the rest of your career. But you have to do all this without spreading yourself too thin, so don’t shy away from the chunky calculations that keep you at your desk for days on end. It’s the hard yards that win you the match.

When it comes to choosing supervisors, my advice would be to look for one who has a reputation for supporting their students, but avoid those who want to exert excessive control. I think it’s a supervisor’s duty to ensure that PhD student becomes as independent as possible as quickly as possible, but to be there with help and advice if things go wrong. Sadly there are some who treat PhD students simply as assistants, and give little thought to their career development.

But if all this sounds a bit scary, I’ll add just one thing. A PhD offers a unique challenge. It’s hard work, but stimulating and highly rewarding. If you find a project that appeals to you, go for it. You won’t regret it.

7 Comments »

What to do with Open Access funding in Physics and Astronomy

Posted in Open Access with tags , , , on March 5, 2013 by telescoper

I’ve been too busy to keep up with the ongoing activity relating to Open Access recently, and I don’t really have time today to do anything other than a brief post on the topic because I’m in the middle of yet another recruitment process and am exhausted by the day’s interviewing.

I do have time to say just a couple of things. One is that it appears that RCUK may be about to back-pedal on its poorly thought out guidelines on Open Access. I hope the new guidance is a significant improvement on the old policy.

Open Access reared its head during a meeting I attended yesterday. RCUK, which is the umbrella organisation for the United Kingdom’s seven research councils, last year announced that it will set aside £17 million next year, and £20 million the year after that, to pay for Gold Open Access publication of the research it sponsors. These funds will be made available to universities in the form of block grants to enable researchers to pay the infamous APCs  (“Article Processing Charges”). The average cost of an APC has been taken from the Finch report (estimated as £1727 plus VAT). Yesterday I was informed of the allocation of funds for Open Access to the School of Mathematical and Physical Sciences at the University of Sussex arising from these block grants. The cash sum involved is too small to pay for Gold Open Access for more than a handful of papers produced within the School, so difficult decisions would have to be made about who is allowed to pay the Author Processing Charges if this pot of money is used in the way RCUK envisages.

Of course, what RCUK should have done was given universities and other research institutions funds to set up and maintain their own Green Open Access databases or international repositories like the arXiv. Throwing money at  Gold Open Access is disastrous way of proceeding. It’s not only ruinously expensive but also unsustainable. In a few years’ time it is inevitable that the traditional academic publishing industry will be bypassed by researchers doing it for themselves. All the money spent propping up the fat cats in the meantime will have been wasted.

Instead of  splashing money around for Gold Open Access,  I think RCUK should mandate that all its research be published in Green Open Access mode. As I’ve mentioned before this would cause considerable fallout not only for the academic publishing industry but also for the learned societies, which largely survive on the income generated subscriptions to their range of overpriced journals.

Nevertheless, we have the RCUK funds and, as Head of School, I’m supposed to decide how to spend them. Even if I could force myself to grit my teeth and agree to fork out out the money in APCs to the Academic Publishing Racketeers, I can’t think of any sensible basis for deciding which papers should be published this way and which shouldn’t. In any case, at least in particle physics and astronomy, most papers are compliant with the RCUK policy anyway because they are placed on the arXiv. I therefore propose not to pay out a single penny of the RCUK OA funds for Gold Open Access, but simply to donate the entire sum as a contribution to the running costs of the arXiv.

I urge Heads of Physics and Astronomy departments elsewhere to do the same with their allocations.

19 Comments »

Planck (but only in name?)

Posted in Science Politics, The Universe and Stuff with tags , , , , , , on March 3, 2013 by telescoper

First, a serious announcement. It appears that the announcement of results from the Planck Mission will be streamed live from ESA HQ on 21st March from 10.00 to 12.00 CET (whatever that is). The UK will remain on GMT until 31st March so the  ESA web server will probably crash at 9am British time on 21st March.

There’s a short press release making this announcement here. It says:

On Thursday 21 March 2013, the main scientific findings from the European Space Agency’s Planck spacecraft will be announced at a press briefing to be held at ESA’s Headquarter in Paris. Simultaneously with this event, data products and scientific papers based on the “nominal” operations period will be made public through the Planck Legacy Archive.

I was interested in the appearance of the word “nominal” in quotes in there so I searched for its meaning in the One True Chambers Dictionary, where I found:

nominal, adj relating to or of the nature of a name or noun; of names; by name; only in name; so-called, but not in reality; inconsiderable, small, minor, in comparison with the real value, hardly more than a matter of form…

Interesting. It seems that the “nominal” could mean, on the one hand, that ESA are being unusually modest about the importance of the forthcoming Planck results or, on the other, that there will now be a host of conspiracy theorists suggesting that the Planck results aren’t real….

That reminds me that years and years ago I had an idea for a crime novel with a plot that revolves around the murder of a prominent cosmologist just as some important scientific discovery is about to be announced. Suspicion gathers that the whole thing is an enormous hoax and the discovery bogus. But the experiment is shrouded in secrecy, and so expensive that it can’t easily be repeated, so  who can tell, and how?

It’s very difficult to know for sure whether any scientific discoveries are genuine or not, even if the data and analysis procedures are made public. There’s always the possibility that everything might have been fabricated simulated, but in most cases the experiment can be repeated at a later date and the fraud eventually exposed, such as in the Schön Scandal.  In Big Science, this may not be practicable. However, Big Science requires big teams of people and the chances are someone would blow the whistle, or try to…

Anyway, I know that there are people out there who take everything I write on this blog absurdly literally so I’ll spell it out that I am in no way suggesting that the Planck mission is a fraud. Or predicting that there’ll be a murder just before the announcements on March 21st. Any similarity purely coincidental and all that. And I’ve never had time to write the book anyway – perhaps a publisher might read this and offer me an advance as an incentive?

Moreover, going back to the Chambers Dictionary, I note the final definition omitted above

…according to plan (space flight)

So that’s that. Nothing sinister. I’m not sure how “nominal” acquired that meaning, mind you, but that’s another story…

8 Comments »

Advice for Prospective Physics Students

Posted in Education with tags , , , , , , , on February 25, 2013 by telescoper

Just got time for a quickie this morning before I head up to the Big Smoke for the first meeting of the Astronomy Grants Panel of the Science and Technology Facilities Council (STFC). I had thought that the last round would be my last, but I must have misbehaved somehow and my sentence has been extended accordingly.

Anyway, I thought I’d follow up Saturday’s post with a response to a question that a few prospective Physics students asked me during our Admissions Day. Those attending these days have already applied to this University but, at this stage of the annual undergraduate admissions cycle, the applicants are still deciding which University to put as their first or firm choice. I see our job in the Admissions Days simply to make available as much information as possible to the applicants to help them make a choice. Quite a few people I spoke to on Saturday, however, said that they had already made up their minds and just wanted some advice about what to do during the summer after they have finished their A-levels to help them prepare for their undergraduate studies in Physics (and/or Astronomy).

The answer I gave was pretty simple: practice your mathematics, especially your calculus! 

The justification for exhortation is that the big difference between Physics at A-level and Physics at undergraduate University level is that the latter is taught in a much more mathematical way than the former. This is because the physical laws that underpin our understanding of the natural world are expressed in a mathematical language; the more fluent you are in this language the easier you will find it to assimilate the physical concepts. To put it another way, you will find it difficult to understand the physical meaning of what is being taught if you are struggling with the mathematical meaning of the symbols being used or the manipulations needed to obtain useful solutions to the relevant equations.

Newton’s Second Law, for example,  relates the rate of change of momentum of a body to the force exerted upon it. If you’re comfortable with calculus you don’t think twice about writing d(mv)/dt for the rate of change of momentum and then constructing a differential equation which you can (hopefully) solve. You won’t absorb the importance of laws like this unless you become so familiar with the mathematics that it ceases to occupy the part of your mind that’s needed to really think.

I think that learning to do Physics is a bit like learning to play a musical instrument. Practicing such basic mathematical procedures as integration and differentiation is analogous to the five-finger exercises you have to do when learning to play the piano. The more you practice them, the greater the extent to which they become hard-wired. Your brain can therefore concentrate on the more interesting conceptual stuff – that’s really the hard part of learning Physics. We do of course do as much as we can to help with this once you’ve got to University, but doing some preparation on your own beforehand would greatly smooth the transition.

So I’d tell any prospective physics student wondering what to do this summer to get hold of as many basic calculus exercises as they can and do them whenever they get the chance. It may not be the most exciting way to spend your post A-level holiday, but it is the single thing you can do that will best prepare you for life as a Physics student.

On the other hand, the advice I’d give to physicists rather later in their careers is to think very carefully before agreeing to be on committees or panels…

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The Problem of the Dangling Magnet

Posted in Cute Problems with tags , , , , on February 20, 2013 by telescoper

Here’s a variation on a physics problem we discussed in my first-ever Skills in Physics Tutorial at the University of Sussex. I hadn’t realized that solutions were provided for Tutors so had to exercise my enfeebled brain in finding a solution. You’ll probably find it a lot easier…

A rectangular bar magnet hangs vertically from a pivot at one of its ends. When gently displaced the magnet undergoes small oscillations either side of the vertical with a period of one second.  A horizontal magnetic field is then applied so that the equilibrium orientation of the magnet is  45° to the vertical. If the magnet is gently displaced from this new position, what is the new period of oscillation?

Comment: you do not need any further information about the size, shape or mass of the magnet in order to solve this problem.

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The Quantum of Teaching

Posted in Education with tags , , , , on February 19, 2013 by telescoper

I’m gradually finding out enough about the way things are organized here at the University of Sussex to make some comparisons between teaching in the School of Mathematical and Physical Sciences here and in the School of Physics and Astronomy at my former employer, Cardiff University.

One difference I’ve noticed is probably something you find rather trivial, but I think it’s quite important. In the usual scheme of undergraduate teaching, which applies across most of the United Kingdom, students gain “credit” for taking and passing modules. A normal year would correspond to 120 credits, so that a three-year BSc degree involves a total of 360 credits and a four-year MPhys (or equivalent) is 480. In universities that run a two-semester teaching year the load per semester is thus 60 credits.

The question then is what is the best way to divide up that 60 credits into smaller pieces? Until recently at Cardiff the basic unit of teaching was a 10-credit module, which meant that students were typically doing six different things alongside each other. An ordinary ten-credit module would involve two lectures per week. Not all of these are lecture courses, however; there’s usually laboratory or computational work as one of the 10 credit chunks. During a recent course review it was decided to increase the size of some of the modules to 20 credits. That’s how it came to pass that I taught a new module of that size last semester (for the first and last time).

The motivation for increasing the size of modules was twofold. One is that having lots of small modules makes the overall study programme disjointed and “bitty”, with students having lots of things on the go at the same time and little opportunity to study any topics in real depth. The other is that having four hours per week instead of two allows the lecturer to use the time more flexibly, in particular with  sessions intended to develop problem-solving skills.

Although the “core” modules at Cardiff increased to 20 credits, the others remained at 10. There was a lot of discussion about increasing all modules, but in the end the new programme was left as a mixture.

Interestingly, here at Sussex the normal module size is 15 credits (and “modules” are also called “courses”), meaning that students actually only do four things at the same time in a typical semester.  In fact this was what I originally suggested when we started the teaching review at Cardiff, but it was thrown out immediately on the grounds that the University had decreed that modules must be multiples of 10 credits only. I’m not sure whether there was an educational reason for this, or just that it made the arithmetic simpler.

Anyway, I like 15 credits as a basic unit but am not sure how many other Schools and Departments run that system. I’d be interested to learn about module sizes favoured elsewhere through the comments box, and here’s a poll so you can vote:

Another difference is that although Sussex has two teaching semesters, the School of Mathematical and Physical Sciences (MPS) does not have mid-year examinations, so First Semester courses are examined in the Summer along with the Second Semester ones.  In Cardiff, modules are examined at the end of the semester in which they are taught. There are pros and cons with this. I think students who are used to mid-year examinations like the fact that the examinations are not all concentrated in one period during the summer and also that they get some feedback on their progress during the year. On the other hand, students may see an end-of-semester examination as an encouragement to close the lid on a particular module and forget about it as soon as it is over, making it harder to understand how different aspects of physics interconnect.

Students at Sussex seem keen not to have mid-year examinations, while those at Cardiff seem equally keen to retain them. I don’t know what that means, so here’s another  poll to see if there’s any clear opinion one way or another among my readers…

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Critical Masses

Posted in Education, Science Politics with tags , , , , , , , on January 26, 2013 by telescoper

One of the interesting bits of news floating around academia at the moment is the announcement that my current employer (until the end of next week), Cardiff University is to join forces with the Universities of Bath, Exeter and Bristol in an alliance intended to create a ‘critical mass of knowledge’ and help Cardiff  ‘better compete for more research income’ (apparently by pretending to be in England rather than in Wales).  How successful this will be – or even what form this alliance will take – remains to be seen.

There’s been a lot of gossip about what inspired this move, but it’s not the first attempt to create a collaborative bloc of this kind. Last year five universities from the Midlands announced plans to do something similar. The “M5” group of   Birmingham, Leicester, Loughborough, Nottingham and Warwick got together primarily to share infrastructure in order to help them win grants, which is probably what also lies behind the Cardiff-Bath-Exeter-Bristol deal.

Of course there are also a myriad  alliances at the level of individual Schools and Departments. I’ll shortly be joining the University of Sussex, which is a major player in SEPNET – the South-East Physics Physics Network which was set up with help from HEFCE There are other such networks in England, as well as SUPA in Scotland, funded by the devolved Scottish Funding Council. Attempts to form a similar arrangement for Physics in Wales were given short shrift by the Welsh Funding Agency, HEFCW. The inability or unwillingness of HEFCW to properly engage with research in Wales is no doubt behind Cardiff’s decision to seek alliances with English universities but I wonder how it will translate into funding. Surely HEFCE wouldn’t be allowed to fund a Welsh University, so presumably this is more aimed at funding from the research councils or further afield, perhaps in Europe. Or perhaps the idea is that if GW4 can persuade HEFCE to fund Bath, Bristol and Exeter, HEFCW will be shamed into stumping up something for Cardiff? Sneaky.

Anyway, good luck to the new “GW4” alliance. Although I’m moving to pastures new I’ll certainly keep an eye on any developments, and hope that they’re positive. The only thing that really disturbs me is that the name “Great Western Four” is apparently inspired by the Great Western Railway, now run by an outfit called First Great Western. My recent experiences of travelling on that have left a lot to be desired and I’m sure the name will have negative connotations in the minds of many who are fed up of their unreliable, overcrowded, overpriced and poorly managed services. They say a rose by any other name would smell as sweet, but so far this is only a name – and one with a distinctly questionable odour.

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