Archive for November, 2011

I can’t be satisfied

Posted in Music with tags , on November 23, 2011 by telescoper

I’m up early, if not so bright, on this dark November morning in order to take an overpriced train to London for yet another  meeting of the STFC Astronomy Grants Panel, this one being the final “plenary” meeting of the current grant round at the Institute of Physics in London . Anyway, I won’t have time for a proper post as I travel hither and thither (or vice versa) so here’s one of them there blues to you to listen towhile I’m having fun (?). This is by the late and very great Big Bill Broonzy. And, yes, it is just him playing the guitar, although at times it sounds like at least two people playing…

 

Yet another cute physics problem

Posted in Cute Problems, The Universe and Stuff with tags , , on November 22, 2011 by telescoper

I’ve spent all day either teaching or writing draft grant applications and am consequently a bit knackered, so in lieu of one of my usual rambling dissertations here is another example from the file marked Cute Physics Problems, this time from thermodynamics. It’s quite straightforward. Or is it? Most people I’ve asked this question in private have got it wrong, so let’s see if the blogosphere is smarter:

Three identical bodies of constant  heat capacity are at temperatures of 300, 300 and 100 K. If no work is done on the system and no heat transferred to it from outside, what is the highest temperature to which any one of the bodies can be raised by the operation of heat engine(s)?

Thinking of Applying for a PhD in Physics or Astronomy?

Posted in Education with tags , , , , , , on November 21, 2011 by telescoper

This afternoon I gave a short talk to our final-year students about postgraduate research in which I passed on some, hopefully useful,  information about how to go about applying for PhDs  in Physics  and Astronomy. I am, for my sins, the Director of Postgraduate Studies within the School of Physics & Astronomy here at Cardiff University.

Although quite a lot of what I talked about was about our own arrangements in Cardiff, I thought I’d jot down here a few general remarks that might be useful to people elsewhere who are thinking of taking the plunge when they graduate. I’m aiming this primarily at UK students applying for places in the UK; special considerations apply for students wanting to do graduate research abroad.

What is a PhD? The answer to that is relatively easy; it’s a postgraduate research degree. In order to obtain a PhD you have to present a thesis like that shown on the left (which happens to be mine, vintage 1988), typically in the range 100-250  pages long. A thesis has to satisfy two conditions for the award of the degree: it should contain original research, which is publishable in an academic journal; and it should present a coherent discussion of that original work within the context of ongoing work in the area of study. In Physics & Astronomy, the PhD is pretty much a prerequisite for any career in academic research, and it usually takes between 3 and 4 years to complete. After submission of the thesis you will have to undergo a viva voce examination conducted by two examiners, one internal and one external. This is quite a tough test, which  can last anywhere between about 2 and about 6 hours, during which you can be asked  detailed questions about your research and wide-ranging questions about the general area.

The Money Side. In the UK most PhDs are supported financially by the research councils, either EPSRC (most physics) or STFC (nuclear & particle physics, astronomy). These generally award quotas of studentships to departments who distribute them to students they admit. A studentship will cover your fees and pay a stipend, currently £13590 pa. That doesn’t sound like a lot, but you should at least remember that it is a stipend rather than a wage; it is therefore not taxed and there is no national insurance payable.

How do I choose a PhD? During the course of a postgraduate degree you are expected to become an expert in the area in which you specialize. In particular you should reach the point where you know more about that specific topic than your supervisor does. You will therefore have to work quite a lot on your own, which means you need determination, stamina and enthusiasm. In my view the most important criterion in your choice of PhD is not the institution where you might study but the project. You need to be genuinely excited by the topic in order to drive yourself to keep through the frustrations (of which there will be many). So, find an area that interests you and find the departments that do active research in that area by looking on the web. Check out the recent publications by staff in each department, to ensure that they are active and to have something to talk about at interview!

Qualifications. Most universities have a formal requirement that candidates for admission to the PhD should have a “good honours degree”, which basically means at least an Upper Second Class Honours degree. Some areas are more competitive than others, however, and in many disciplines you will find you are competing with a great many applicants with First Class degrees.

How to apply successfully. The application procedure at most universities is quite simple and can be done online. You will need to say something about the area in which you wish to do research (e.g. experiment/theory, and particular field, e.g. cosmology or star formation). You’ll also need a CV and a couple of references. Given the competition, it’s essential that you prepare. Give your curriculum vitae some attention, and get other people (e.g. your personal tutor) to help you improve it. It’s worth emphasizing particular skills (e.g. computing). If you get the chance, make use of your summer vacations by taking on an internship or other opportunity to get a taste of research; things like that will undoubtedly give your CV an edge.

The Interview. Good applicants will be invited for an interview, which is primarily to assess whether you have the necessary skills and determination, but also to match applicants to projects and supervisors. Prepare for your interview! You will almost certainly be asked to talk about your final-year project, so it will come across very badly if you’re not ready when they ask you. Most importantly, mug up about your chosen field. You will look really silly if you haven’t the vaguest idea of what’s going on in the area you claimed to be interested in when you wrote your  application!

Don’t be shy! There’s nothing at all wrong with being pro-active about this process. Contact academic staff at other universities by email and ask them about research, PhD opportunities. That will make a good impression. Also, don’t be afraid to ask for advice. Although we’re all keen to recruit good PhD students for our own departments, we academics are  conscious that it is also our job to give impartial advice. Ask your tutor’s opinion.

How many places should I apply for? Some research areas are more fashionable than others so the level of competition varies with field. As a general rule I would advise applying for about half-a-dozen places, chosen because they offer research in the right area. Apply to fewer than that and you might lose out to the competition. Apply to many more and you might not have time to attend the interviews.

What’s the timetable?  Most applications come in early in the new year for entry to the PhD in the following October. The Christmas break is therefore a pretty good time to get your applications sorted out. Interviews are normally held in February or March, and decisions made by late March. STFC runs a deadline system whereby departments can not force students to accept or decline offers before the end of March, so there should be ample time to visit all your prospective departments before having to make any decisions.

That’s all I can think of for now. I hope at least some of these comments are useful to undergraduates anywhere in the UK thinking of applying for a PhD. If there are any further questions, please feel free to ask through the comments box. Likewise if I’ve missed anything important, please feel free to suggest additions in the same manner…

Are Quantum States “Real”?

Posted in The Universe and Stuff with tags , , on November 20, 2011 by telescoper

Busy day today, despite it being a Sunday, so I’ve only got time for a quick post, by way of a diversion while I take a break for a cup of tea.

There’s been an attack of the hyperbolics this week arising from a paper entitled “The quantum state cannot be interpreted statistically”.  The abstract of the paper reads:

Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state represents. There are at least two opposing schools of thought, each almost as old as quantum theory itself. One is that a pure state is a physical property of system, much like position and momentum in classical mechanics. Another is that even a pure state has only a statistical significance, akin to a probability distribution in statistical mechanics. Here we show that, given only very mild assumptions, the statistical interpretation of the quantum state is inconsistent with the predictions of quantum theory. This result holds even in the presence of small amounts of experimental noise, and is therefore amenable to experimental test using present or near-future technology. If the predictions of quantum theory are confirmed, such a test would show that distinct quantum states must correspond to physically distinct states of reality.

According to a commentary published in the journal Nature, this paper could “rock quantum theory to the core” and a number of quantum physicists have reacted, e.g.:

“I don’t like to sound hyperbolic, but I think the word ‘seismic’ is likely to apply to this paper,” says Antony Valentini, a theoretical physicist specializing in quantum foundations at Clemson University in South Carolina.

I have to admit I haven’t had time to read the paper in detail yet, so I’m just passing this on as something fresh that may be of wider interest, rather than something I’ve got particularly strong views about. I have to admit, though, that I find the way quantum theorists use words, especially what is meant by “physically real” and what “states of reality” could be. Can a mathematical theorem ever prove itself to be applicable to the physical world anyway? You’ll see that ontology was never my strong suit.

However, if anyone out there in blogland has read this paper and would like to pass on their thoughts for the edification of me and my readers I’d be delighted. I might return to it in a longer post if and when I’ve been able to digest it fully.

Now, back to reality…

 

Goodbye Dolly

Posted in Cricket, Politics with tags , , on November 19, 2011 by telescoper

This is turning out to be a sad month for cricket fans, for today saw the death of legendary all-rounder Basil D’Oliveira. “Dolly”, as he was affectionately known, was born in South Africa but was unable to play first-class cricket there because of the apartheid regime’s policy of racial segregation; as a “Cape Coloured” he wasn’t allowed to play what was basically a whites-only game. He emigrated to England in 1960 and was subsequently picked to play for England and quickly established himself as an excellent player at Test level. Selected basically as a batting all-rounder, and usually coming in between 5 and 7 in the order,  his  average was over 40, and he scored 5 centuries in 44 Test matches in a career that lasted from 1966 to 1972. These are impressive figures, especially considering that his Test career didn’t even start until he was in his mid-thirties.

His selection (as a late replacement) for the England side that was to tour South Africa in 1968 precipitated the D’Oliveira Affair, which led to South Africa being ostracised from international cricket until the end of apartheid in the 1990s. Although this episode must have been personally distressing for him, D’Oliveira behaved with great courage and dignity throughout and won many admirers on and off the field, and the warmth of the tributes being paid in today’s media demonstrate the high regard in which he was held by cricketers, fans of the sport, and  by campaigners against racism.

Rest in peace, Basil D’Oliveira (1931-2011), one of the true gentlemen of cricket.

 

Not Waving but Drowning

Posted in Poetry with tags , on November 19, 2011 by telescoper

Nobody heard him, the dead man,
But still he lay moaning:
I was much further out than you thought
And not waving but drowning.

Poor chap, he always loved larking
And now he’s dead
It must have been too cold for him his heart gave way,
They said.

Oh, no no no, it was too cold always
(Still the dead one lay moaning)
I was much too far out all my life
And not waving but drowning.

by Stevie Smith (1902-1971)

P.S. This is by far the most famous poem by Stevie Smith; it even has its own wikipedia page.

 

Google Citations

Posted in Uncategorized with tags , , on November 18, 2011 by telescoper

Just time for a quick post this morning to pass on the news that Google Citations is now openly available. I just had a quick look at my own bibliometric data and, as far as I can tell, it’s pretty accurate. As well as total citations, Google Scholar also produces an h-index and something called the i10-index (which is just the number of papers with more than 10 citations). It also gives the corresponding figures for the past 5 years as well as for the entire career of a given researcher.

I’ve bragged blogged already about my most popular paper citation-wise, which has 287 citations on Google Scholar, which doesn’t exactly make it a world-beater but I’m still quite please with its impact. What I find particularly interesting about that paper is its longevity. This paper was published in 1991, i.e. 20 years ago, but I  recently looked on the ADS system at its citation history and found the following:

Curiously, it’s getting more citations now than it did when it was first published. I’ve got quite a few “slow burners” like this, in fact, and many of the citations listed for me in the last 5 years actually stem from papers written much earlier. Unfortunately, although I think this steady rate of citation is some sort of indicator of something or other, this is exactly the wrong sort of paper for the Research Excellence Framework, as it is only papers that are published within the roughly 5-year REF window that are taken into account. It would be more useful for the REF panels if the “5-year” window listed citations only to those papers actually published within the last five years. I wonder how the panel will try to use this limited information in assessing the true quality of  a paper?

I should also say that although this paper is, by a large margin, the nearest I’ve got to the citation hit parade, I don’t think it’s by any means the best paper I’ve ever written.

Another weakness is that Google Scholar doesn’t give a normalized h-index (i.e. one based on citations shared out amongst the authors of multi-author papers).

Still, you can’t have everything. Now that this extremely useful tool is available (for free) to all scientists and other denizens of the interwebs, I re-iterate my point that the panels involved in the assessing research for the Research Excellence Framework should use it rather than the inferior commercial versions, which are much less accurate.

 

Polished Cox

Posted in Uncategorized with tags , on November 17, 2011 by telescoper

It looks like impressionist Jon Culshaw has been working hard on Cox in his spare time judging by the following, rather polished, article recently unveiled on TV:

 

 

Kennst du das Land

Posted in Music, Poetry with tags , , on November 16, 2011 by telescoper

I listened to this recording on CD last night and couldn’t resist sharing it on here because it’s so lovely. It’s Hugo Wolf‘s  setting of a poem by Goethe,  called Mignon’s Song, which is actually a reminiscence about Italy (hence the distinctly Italianate flavour of the images in the video).  I’ve actually posted the verse before;  I learned it at school, where I studied German for one year before giving it up to concentrate on science subjects.

I had a rather eccentric teacher who thought the best way to learn a language was to read poetry rather than learning how to say banal things like “Please can you direct me to the railway station?”. It wasn’t a very good idea from an educational point of view, but at least it left me with bits of German poetry still in my head over 30 years later. I can still remember every word of this wonderful poem…

Kennst du das Land wo die Zitronen Blühn,
Im dunklen Laub die Gold-Orangen glühn,
Ein sanfter Wind vom blauen Himmel weht,
Die Myrte still und hoch der Lorbeer steht,
Kennst du es wohl?
Dahin! Dahin,
Möcht ich mit dir, o mein Geliebter, ziehn.

Kennst du das Haus? Auf Säulen ruht sein Dach,
Es glänzt der Saal, es schimmert das Gemach,
Und Marmorbilder stehn und sehn mich an:
Was hat man dir, du armes Kind getan?
Kennst du es wohl?
Dahin! Dahin
Möcht ich mit dir, o mein Beschützer, ziehn!

Kennst du den Berg und seinen Wolkensteg?
Das Maultier sucht im Nebel seinen weg:
In Höhlen wohnt der Drachen alte Brut;
Es stürzt der Fels und über ihn die Flut,
Kennst du ihn wohl?
Dahin! Dahin
Geht unser weg! o Vater, laß uns ziehn!

For an English translation you can look here. But  here it is in its beautiful musical setting by Hugo Wolf,  as performed by the inimitable Elisabeth Schwarzkopf. Gorgeous.

 

Depressed Superman

Posted in Art with tags , on November 15, 2011 by telescoper

It’s been a while since I posted anything in the box marked “Art”, but I’m inspired to do so now by a short piece in Sunday’s Observer about an artist who is quite new to me called Lora Zombie. It also kind of fits with a theme established by a recent post. The Observer piece about her series of Depressed Superheroes was in the print edition, but doesn’t seem to be available on the website – or if it is I couldn’t find it – but I found another blog article about it here. The pieces are made using acrylics on paper and there are four altogether. I think they’re really excellent. I particularly liked the rather effete and slightly Byronesque Depressed Superman:

You can order a limited edition print of this work here.