Archive for May, 2011


Posted in Opera with tags , , on May 31, 2011 by telescoper

On the way to the Wales Millennium Centre in Cardiff Bay this evening it struck me that it was quite fitting to be going to see Welsh National Opera‘s production of Turandot so soon after Friday’s concert. After all this was Giacomo Puccini‘s last Opera and it was incomplete at the time of the composer’s death in 1924. It’s a work most famous for the rousing tenor aria Nessun Dorma from Act III , which was made even more famous when, sung by the great Pavarotti, it became the theme tune for the Italia 90 World Cup. But there’s also the gorgeous Signore Ascolta in Act I and, even better, the dramatic fulcrum of the Opera, and one of the greatest Puccini’s arias of all, the climactic In Questia Reggia. Puccini undoubtedly had a great gift for writing memorable songs but there’s much more to him than that, as this opera proves. Turandot is a particularly dark and troubling story, with music to match the drama at every stage, and it contains some extremely interesting “modern” ideas alongside the classic showpiece numbers.

The story is set in China (“in legendary times”). Princess Turandot (definitely pronounced “-dot” rather than “-doh”) is a tyrannical ruler who challenges potential suitors to solve three riddles. The penalty for failure is death; no resits allowed. The Opera begins with the Prince of Persia being led to his doom. You know the sort of thing – girl meets boy, boy falls in love with girl, girl beheads boy, etc. Calaf, Prince of the Tartars, arrives with his elderly father Timur and faithful servant Liu. Crazy fool that he is, he decides to have a go at the riddles. Three sinister ministers, Ping Pang and Pong, prepare the trial, letting on as they do so just how many others have died in the attempt to woo Turandot. Calaf, of course, succeeds, but Turandot doesn’t want to go along with her side of the bargain. Calaf sets his own riddle – Turandot simply has to guess his name by dawn and he’ll give up his suit and let Turandot execute him too. She tries everything she can think of to identify the mystery contestant, including keeping the entire population of Peking up all night and torturing Liu to the point where she kills herself rather than risk giving away her master’s name. Liu loves Calaf herself, you see, so naturally she dies for her beloved’s sake. That’s what women do, in Opera. Moved by Liu’s sacrifice, Turandot feels the power of love and agrees to marry Calaf. And they all live happily ever after. Apart from Liu, of course, who’s dead.

That’s one of the thing’s that’s so problematic about this Opera for me. If Calaf is meant to be so noble and courageous, so why does he fall for Turandot who, at least at the beginning, is cruel beyond belief? And if he’s such a good egg why does he let the innocent Liu die just so he can get his leg over? This isn’t the only Puccini opera in which the romance has a dark undertone and in which the hero isn’t all that heroic when you look hard enough at him. Calaf isn’t quite as bad as the ghastly Pinkerton in Madame Butterfly, but I still think he’s basically a prat.

This production is a revival of one first performed in 1994. The setting spans a number of epochs, ancient Chinese costumes mingling with 20th century dress, and the minimal set periodically hung with mugshots of slain suitors evoking the “disappeared” in a South American dictatorship. Turandot’s dress and hairstyle in Act II made her look a lot like a cross between Ymelda Marcos and Eva Peron. In the crowd scenes, the chorus writhe with stylised anguish of an almost masochistic nature, as if their oppression by the brutal regime has become a sort of fetish for them.

Star of the show was dramatic soprano Anna Shafajinskaia as Turandot. With a name like an Icelandic volcano and a voice of exceptional power to match, she sent shivers down my spine on several occasions, especially in Act II. Gwyn Hughes Jones was a fine Calaf. Rebecca Evans being unfortunately indisposed, Liu was played by Michelle Walton. She started very hesitantly, and I wasn’t at all impressed with her rendition of Signore Ascolta; what she sang was quite nice, but it was only a vague approximation to what Puccini wrote. She did settle down as the performance went on, however, and was much more impressive in Act III. The rest of the cast were good and, as always, the Chorus of Welsh National Opera were superb throughout.

It’s difficult to explain to people who don’t “get” Opera how it can possibly work. People don’t actually sing to each other in real life, after all. All I can say is that, when it’s good, you somehow just fall into it and it takes on its own dramatic logic. That doesn’t always happen, of course, but for me it certainly happens sufficiently frequently to make it worthwhile. This one took a while to get going, and I didn’t really start to get involved until Act II, but thereafter I was gripped.

I should also say that it was very nearly a full house. Not bad for a Tuesday night!

Never Say Never …

Posted in Cricket with tags , , , , on May 30, 2011 by telescoper

It was tipping down with rain this morning so I wrote off the prospect of there being any result in the First Test between England and Sri Lanka at Cardiff which I’ve blogged about once already. However, the weather steadily improved and play eventually got started at about 3pm. England, resuming on 491 for 5, batted on for a couple of overs to allow Ian Bell to get his century then – perhaps surprisingly – declared on 496-5, with a lead of 96 on the first innings. An unusually adventurous decision by Strauss to declare so early, in fact. Nevertheless, a draw looked a virtual certainty to me (and most sports writers) so I wasn’t paying much attention to the cricket at first, deciding instead to get on with some other stuff at home.

When I checked the score around 4 o’clock I discovered Sri Lanka had lost a couple of early wickets and had gone in for tea at 33-2. It being free to get in for the last session and the weather now being very sunny, I finally decided to go and watch the final stages. A draw still seemed the likeliest outcome – Sri Lanka only had to bat out time for 35 overs or so. However, we don’t get much Test cricket in Cardiff and the last match here had an exciting finish, so I walked to the ground just after tea. There couldn’t have been more than a few hundred spectators in the ground, but what we saw turned out to be a demonstration of what Test cricket is all about.

I had hardly got to my seat when Tremlett produced a beauty that found the edge of M. Jayawardene’s bat and was caught at slip. Sri Lanka 33-3. A few minutes later Samaraweera played an inexplicable slash at spinner Graham Swann and dragged the ball onto his stumps; 36-4. Swann then disposed of Sangakkara and Maharoof, and Tremlett took the wicket of P. Jayawardene, all with the score on 43. Sri Lanka’s batting, so solid in the first innings was now in pieces on the floor. In came Herath with the air of a man wishing to commit suicide. Eventually he succeeded, playing an agricultural swipe at a delivery from Swann; he missed and the ball hit him on the back leg, plumb in front of the wicket. At 52-8 Sri Lanka looked doomed. Perera decided to take the attack to England. He played some good shots, as well as some lucky ones, and was fortunate to be dropped when two fielders ran into each other. Nevertheless, he and Mendis steadied the Sri Lankan ship for a while. I on the other hand was literally shaking with excitement and anticipation, hoping that I was about to witness a spectacular finale.

The score quickly moved onto 82 and it looked like Sri Lanka might at least have a chance of making England bat again. Then Broad replaced Tremlett, Perera tried to flick him away and Ian Bell took a superb reaction catch at short leg. 82-9. Last man Lakmal departed without troubling the scorers just three balls later, caught at 3rd slip by Alastair Cook. England had won by an innings and 14 runs. Amazing.

It had all been so exciting I hadn’t even had time to think about going for a beer. I think I’ll have one while I watch the highlights on TV.

There really is nothing like Test cricket, you know…

Missing Mass Hysteria

Posted in Astrohype, The Universe and Stuff with tags , , , on May 30, 2011 by telescoper

It’s usually very satisfying to see science get covered in the popular media. Even if the story gets a little simplified or, more likely, garbled, press coverage often succeeds in getting at least a bit of the truth across. My own field of astrophysics has more popular appeal than many other branches of physics, but can nevertheless involve complex theoretical ideas and difficult observations that can be difficult to disseminate in a form suitable for public consumption. For the most part, the press do a good job for astronomy but occasionally news stories emerge that are simply ridiculous.

Take this one, for example, which begins:

A Monash student has made a breakthrough in the field of astrophysics, discovering what has until now been described as the Universe’s ‘missing mass’. Amelia Fraser-McKelvie, working within a team at the Monash School of Physics, conducted a targeted X-ray search for the matter and within just three months found it – or at least some of it.

What makes the discovery all the more noteworthy is the fact that Ms Fraser-McKelvie is not a career researcher, or even studying at a postgraduate level. She is a 22-year-old undergraduate Aerospace Engineering/Science student who pinpointed the missing mass during a summer scholarship, working with two astrophysicists at the School of Physics, Dr Kevin Pimbblet and Dr Jasmina Lazendic-Galloway.

On the face of it, this sounds an extremely interesting story not only because it apparently involves a major scientific breakthrough, but also because the result was achieved by an undergraduate student working on a summer programme. Unfortunately, however, a little digging reveals that there is much less to it than meets the eye. I know of many astronomers around the world who think the Press Office at Monash University is guilty of shameless exaggeration in the press release that initiated this bubble. This sort of deliberately misleading distortion is very bad for science, as it almost inevitably ends up splattered in unrecognisable form all over the media, especially the downmarket end.

Here is the abstract of the actual paper which this story is supposed to be about:

Most of the baryons in the Universe are thought to be contained within filaments of galaxies, but as yet, no single study has published the observed properties of a large sample of known filaments to determine typical physical characteristics such as temperature and electron density. This paper presents a comprehensive large-scale search conducted for X-ray emission from a population of 41 bona fide filaments of galaxies to determine their X-ray flux and electron density. The sample is generated from Pimbblet et al.’s (2004) filament catalogue, which is in turn sourced from the 2 degree Field Galaxy Redshift Survey (2dFGRS). Since the filaments are expected to be very faint and of very low density, we used stacked ROSAT All-Sky Survey data. We detect a net surface brightness from our sample of filaments of (1.6 +/- 0.1) x 10^{-14} erg cm^{-2} s^{-1} arcmin^{-2} in the 0.9-1.3 keV energy band for 1 keV plasma, which implies an electron density of n_{e} = (4.7 +/- 0.2) x 10^{-4} h_{100}^{1/2} cm^{-3}. Finally, we examine if a filament’s membership to a supercluster leads to an enhanced electron density as reported by Kull & Bohringer (1999). We suggest it remains unclear if supercluster membership causes such an enhancement.

You won’t find anything in there about finding the “missing mass” of the Universe, nor will you find it anywhere else in the paper, because they haven’t. The “targeted X-ray search” involved stacking old ROSAT observations of filaments that were discovered and catalogued in previous papers; this study merely matched them to existing X-ray data. ROSAT ceased operations in 1999. The results do give some evidence for a higher electron density than previously thought in some of the filaments, so it’s a fairly interesting “incremental” paper, not by any stretch of the imagination revolutionary.

I’ve got nothing against Amelia Fraser-McKelvie, who seems to have done some solid scientific work during her summer internship, and who may not have played any role in spinnng the shameless press release that led to this story getting into the world’s media. However, the more senior scientists involved in this work should not have let the story come out in this form.

Guest Post – Bayesian Book Review

Posted in Bad Statistics, Books, Talks and Reviews with tags , , , on May 30, 2011 by telescoper

My regular commenter Anton circulated this book review by email yesterday and it stimulated quite a lot of reaction. I haven’t read the book myself, but I thought it would be fun to post his review on here to see whether it provokes similar responses. You can find the book on Amazon here (UK) or here ( USA). If you’re not completely au fait with Bayesian probability and the controversy around it, you might try reading one of my earlier posts about it, e.g. this one. I hope I can persuade some of the email commenters to upload their contributions through the box below!


The Theory That Would Not Die: How Bayes’ Rule Cracked the Enigma Code, Hunted Down Russian Submarines, and Emerged Triumphant from Two Centuries of Controversy

by Sharon Bertsch Mcgrayne

I found reading this book, which is a history of Bayes’ theorem written for the layman, to be deeply frustrating. The author does not really understand what probability IS – which is the key to all cogent writing on the subject. She never mentions the sum and product rules, or that Bayes’ theorem is an easy consequence of them. She notes, correctly, that Bayesian methods or something equivalent to them have been rediscovered advantageously again and again in an amazing variety of practical applications, and says that this is because they are pragmatically better than frequentist sampling theory – ie, she never asks the question: Why do they work better and what deeper rationale explains this? RT Cox is not mentioned. Ed Jaynes is mentioned only in passing as someone whose Bayesian fervour supposedly put people off.

The author is correct that computer applications have catalysed the Bayesian revolution, but in the pages on image processing and other general inverse problems (p218-21) she manages to miss the key work through the 1980s of Steve Gull and John Skilling, and you will not find “Maximum entropy” in the index. She does get the key role of Markov Chain Monte Carlo methods in computer implementation of Bayesian methods, however. But I can’t find Dave Mackay either, who deserves to be in the relevant section about modern applications.

On the other hand, as a historian of Bayesianism from Bayes himself to about 1960, she is full of superb anecdotes and information about
people who are to us merely names on the top of papers, or whose personalities are mentioned tantalisingly briefly in Jaynes’ writing.
For this material alone I recommend the book to Bayesians of our sort and am glad that I bought it.

Testing Times

Posted in Cricket with tags , , , , on May 29, 2011 by telescoper

It’s raining this morning (again), delaying the start of the fourth day’s play in the First Test between England and Sri Lanka which is taking place at the SWALEC Stadium here in Cardiff, just a few hundred yards from my house.

One of the advantages of living so close to the ground is that I can stay home and dry when there is a delayed start and simply toddle down there when start of play is announced on the radio. That’s my plan for today, in fact. It was a similar state of affairs yesterday. There was heavy rain first thing, which had been forecast, but it was exacerbated by persistent heavy drizzle for hours afterwards, which hadn’t. The covers therefore stayed on all morning with the result that (a) play didn’t start until 2pm but (b) I had time to write a lengthy blog post about Friday’s concert and (c) have lunch at home before walking to the ground.

The match was interestingly poised, with Sri Lanka all out for exactly 400 and England on 47-1 having lost Andrew Strauss late on Friday evening. Jimmy Anderson, who had come in as nightwatchman, departed almost immediately on Saturday, bringing in Jonathan Trott to join Alastair Cook. The pair batted steadily on. And on. Seventy overs passed, in fact, and the two accumulated runs in remorseless fashion without offering any significant chances, adding 240 runs to bring England to 287-2 at stumps, both reaching fine centuries. It wasn’t thrilling strokeplay of the crash-bang-wallop style you get in Twenty20, but good old-fashioned Test cricket. I thought it was magnificent, although it’s probably precisely the kind of cricket that puts some people off Test matches.

Unfortunately, the state of the game and the weather both mean that anything other than a draw is extremely unlikely. There’s already been quite a lot of time lost to the rain and only Sri Lanka’s first innings is complete. The forecast for today is showery – it’s raining right now, in fact – so it’s unlikely we’ll get a full day’s play. The forecast for Day 5 is even worse – with heavy rain in store most of the day. It’s hard to see how two more innings can possibly be completed. Moreover, England’s best bowler, James Anderson, is injured and will not be bowling in the Sri Lanka second innings (if there is one). The Cardiff wicket is basically a good batting pitch, although it is a bit on the slow side,  and I don’t see how England can bowl out Sri Lanka with only two seamers and a spinner. If England could have got to 600 plus then with a full bowling attack they might have had a chance at an inning’s victory – especially if the pitch starts to turn, which it shows signs of doing – but that seems very unlikely now.

At the risk of being too critical, I think this all illustrates the folly of England’s selection policy. They went into this game knowing that Sri Lanka was a good batting side, and Sri Lanka’s fine first innings display should not have come as a surprise. I wasn’t at the first two days’ but it seems that the England bowling attack looked quite ordinary even at full strength. I think a Test team really needs five bowlers. In the absence of a genuine all-rounder, England should not have picked a specialist batsman (Morgan) at number 6, but another bowler and the top-order batsmen told to stand up and be counted (which is precisely what they are doing). Wicket-keeper Prior should be at 6, with Broad and Swann counting as half an all-rounder each. The injury to Anderson reinforces this argument, as does Broad’s obvious lack of match fitness. They might get away with it for this game, but think they need to rethink this before taking on India who are a much stronger side than Sri Lanka.

I had been hoping to take a few snaps in the ground, but like the idiot I am I forgot to charge my phone up beforehand and when I got there the battery was almost flat. I decided to preserve what juice there was for emergency calls – though that was an unlikely contingency – by refraining even from Tweeting for the duration, regular intakes of beer staving off any sense of boredom. It was well after 7pm when the final over was bowled, and I only just got home to watch Barcelona’s comprehensive dismantling of Manchester United in the Champion’s League final.

UPDATE: Just for the record, England ended day 4 on 491-5 with Trott out for 203 and Bell unbeaten on 98. Great batting from everyone, except Pietersen. Not much chance of a result, though, especially if the weather forecast for tomorrow is accurate…

Final Thoughts

Posted in Music with tags , , , , , , on May 28, 2011 by telescoper

I decided to round off the working week last night with a trip to St David’s Hall in Cardiff to hear the BBC National Orchestra of Wales under the baton of guest conductor Jac van Steen in a programme of music by Richard Strauss and Anton Bruckner. Both pieces featured in the concert are longstanding favourites of mine and I’d been looking forward to the event for some time. The concert was billed Final Thoughts as each piece was in fact the respective composer’s last.

First up were the Vier Letzte Lieder (“Four Last Songs“). Richard Strauss had a particularly wonderful gift for writing music for the female voice and these pieces are perfect demonstrations of his art. Only published posthumously, they were never performed in Strauss’ lifetime but they quickly established themselves as concert favourites. In fact there’s no evidence that they were ever intended to form a set; the last – which happens to be my favourite, Im Abendrot, a setting of a poem by von Eichendorff, was completed before Strauss decided to set the other three, which are poems by Herman Hesse. There is more unity in compositional approach in the first three of the four, but nothing for me matches the sheer gorgeousness of the last. I freely admit that I quite often burst into tears listening to it, it’s so beautiful. I posted a favourite version elsewhere on this blog, and I have six different versions on CD.

Last night’s performance featured Swedish mezzo soprano Katarina Karnéus who has a very fine voice. They were performed at a slightly brisker tempo than is often the case (which is no bad thing) and the orchestra was in good form. The only problem was that the singer was standing so far back into the orchestra that she had difficulty projecting her voice, particularly since she was almost behind the conductor from where I was sitting. Some of her singing was barely audible, but when she did break through she brought out the beauty of Strauss music in fine style. Overall, a very nice performance. But no, I didn’t burst into tears this time.

After the interval we had Anton Bruckner‘s monumental Symphony No. 9, which was unfinished at Bruckner’s death in 1896. Insufficient material was recovered after the composer’s death to enable a reconstruction of the missing 4th movement, so this work is generally performed in its incomplete state with only three movements. Even so, it’s an immense work in both length and ambition. The majestic first movement (marked Feierlich, Misterioso; solemn & mysterious) with its soaring themes and thunderous climaxes always puts me in mind of a mountaineering expedition, with wonderful vistas to experience but with danger lurking at every step. At times it’s rapturously beautiful, at times terrifying. It’s not actually about mountaineering, of course – Bruckner meant this symphony to be an expression of his religious faith, which, in the latter years of his life must have been pretty shaky if the music is anything to go by.

The second movement (Scherzo) is all juddering rhythms, jagged themes and harsh dissonances reminiscent (to me) of Shostakovich. It alternates between menacing, playful and cryptic; the frenzied animation of central Trio section is especially disconcerting.

The last movement  (Adagio)  begins restlessly, with an unaccompanied violin theme and then becomes more obviously religious in character in various passages of hymn-like quality, still punctuated by stark crescendi. In this movement Bruckner doffs his cap in the direction of Richard Wagner,  especially when the four Wagner tubas appear, and the movement reaches yet another climax with the brass bellowing out the initial violin theme. This dies away and the movement comes to an unresolved, poignant conclusion. With a long pause in silence as if to say “that’s all he wrote”, the concert came to an end.

Although I’ve loved this work for many years I’ve only ever heard it on CD before last night.  The live performance definitely adds another dimension and I enjoyed it enormously. The BBC National Orchestra of Wales may not be the Berlin Philharmonic but I was generally very impressed, especially with the strings, who brought warmth and colour to a piece some people find a bit cold. On the other hand, on the way out people were raving about the four Wagner tubas, which I thought sounded ill-at-ease and unconvincing.

The concert was broadcast live last night on BBC Radio 3 (you can here it here for the next week or so), which is why it had to start at 7pm. A crazy decision by the controller of BBC Radio3, in my opinion, to insist that live concerts all start so early. There being no time to go home first, I just went straight there from work. I was deeply disappointed to see such a low turnout – the Hall was less than half full. Curiously, though, when I had tried to book a ticket just a week or so ago the vast majority of seats were sold and I had to settle for a place upstairs. I’m told that large numbers of seats are kept back for corporate guests and for BBC employees, of whom there are many in Cardiff as Auntie Beeb is a big employer here. Since these folk haven’t paid anything they often don’t turn up. The effect of this is that no matter how interesting the programme is, how fine the venue is, and how cheap the tickets are (top price is less than £30), the place is often pretty empty. It’s a shame.

Anyway, the one advantage of a 7pm start is that the concerts finish quite early, just after nine in this case. It was still twilight when I emerged from St David’s Hall, so I decided to take a crepuscular perambulation along the Taff embankment past the cricket ground at Sophia Gardens (where England are currently playing a Test Match against Sri Lanka). When I got near the SWALEC Stadium I was beset on all sides by a number of bats, no doubt feasting on insects flying over the river. They didn’t bother me at all. I find them fascinating creatures, in fact. At one point however, one of the critters flew into my leg at about knee level and fell back onto the path, apparently stunned. I stopped to find out whether it was badly hurt but after a bit of a struggle getting airborne it flapped off into the murk. It was a tiny little thing and, judging by the poor standard of its navigation, I suspect it was merely a trainee.

Echo of Creation – the Trailer

Posted in Education, The Universe and Stuff with tags , , , on May 27, 2011 by telescoper

Each day I find myself pressed for time and unable to think of anything to post, something seems to come along to rescue me. I found this on Twitter this morning and couldn’t resist sharing it, partly because it’s a cute video in its own right, and partly because it gives me the chance to advertise the event that it trails. Here’s the film …

..and it advertises a forthcoming event at the Cheltenham Science Festival, featuring the excellent Andrew Pontzen who is based at the Institute of Astronomy in Cambridge. Andrew is not only a whizzkid cosmology theorist but also an excellent public speaker, so do go and see his lecture if you can. Here’s the blurb:

Billions of years after the birth of the Universe, scientists realised they could tune into an echo of creation itself using nothing more sophisticated than a de-tuned television set. Andrew Pontzen explains the cosmos’ ‘background noise’ with hula hoops, beach balls and amazing telescopic pictures. But hold onto your hats: all is not as it seems with space and time…

Sounds fascinating! The talk is on Saturday 11th June 2011, 10am at the Town Hall in Cheltenham. You can book tickets here.

An easy physics problem…

Posted in Cute Problems with tags , , , on May 26, 2011 by telescoper

Based on the popularity of something I posted last week, I thought some of you might find this little problem amusing. It’s from a Physics A-level paper I took in 1981. The examination comprised two papers in those days (and a practical exam); one paper had long questions, similar to the questions we set in university examinations these days, and the other was short questions in a multiple-choice format. This is one of the latter type, from the mechanics section.

And here is a poll in which you may select your answer:

Pump up the Volume

Posted in Music with tags , on May 26, 2011 by telescoper

In the course of an archaeological investigation into one of the cupboards in my study last night I unearthed a box full of old vinyl 12″ singles, including this, Pump up the Volume by MARRS. Clearly inspired by the theory of cosmic inflation, it was very popular in dance clubs way back when I was a graduate student living in Brighton, then it got into the charts and climbed to Number 1 thus endowing MARRS with the status of One Hit Wonder. I was shocked when I realised that all this happened in 1987, before most of my students were born. Sigh. Anyway, it was nice to see the cute video again so I thought I’d share it for the benefit of other oldies out there, with the excuse that it’s slightly space-related. Try playing “spot-the-sample” as the record plays – it’s entirely cobbled together from bits of other tracks..

The Cosmos according to Disney

Posted in The Universe and Stuff with tags , , on May 25, 2011 by telescoper

Not really time for a proper post today but I’m grateful to one of my PhD students for coming to the rescue by pointing out this clip in which our own Professor Mike Disney tell us everything he knows about cosmology. The video lasts 2 minutes and 48 seconds.