Archive for February, 2009

Eccentric Sphere

Posted in Jazz with tags , on February 21, 2009 by telescoper

Some weeks ago I posted a clip of Billie Holliday and Lester Young that was part of a 1958 TV programme called Sounds of Jazz. I found another clip from that show and decided to put it on here because it’s absolutely fascinating. The star this time is the great Thelonious Monk, whose middle name was Sphere.

Thelonious Monk was a unique musician. His remarkable self-taught style of piano playing was unlike that of anyone who came before him. Look at his hands in this clip and you’ll see that his fingers are straight as he plays: he uses them a bit like mallets in order to get such a percussive sound from the instrument (although the audio is a bit muffled on this track).

Monk was often called “The High Priest of Bop” and regarded as one of the leaders of the post-war bebop revolution in Jazz alongside Charlie Parker and Dizzy Gillespie. Actually, I don’t think Monk ever really played bebop: the archetypal bop pianist was undoubtedly Bud Powell whose style was quite different to Monk. But the “High Priest” tag owed at least something to his eccentric personality: he hardly ever spoke and, aside from his music, he communicated mainly through his choice of hat.

Monk’s piano style is hard to describe – his wife Nellie once described it as “Melodious Thunk” – but I’ve always loved his music. To me his solos sound like someone talking directly at you in a strange and wonderful language that you don’t quite understand but which sounds beautiful anyway. His use of syncopation is quite different from the usual bebop musicians and it seems, to me anyway, to echo the rhythms of everyday speech. But, above all, when you hear Monk play the piano, you know immediately who it is. He had many admirers, but nobody could play like him. He was a genius.

In later life his behaviour became disturbingly erratic; he would sometimes stand up in the middle of a performance and go wandering around the stage.  His music also deteriorated, I think, from the early sixties onwards. His best records are from the 40s and 50s. I think it was generally assumed that he had a drugs problem, which he may well have had, but it was eventually realised that he was suffering from a serious mental illness. Although attempts were made to treat this, he stopped playing in the 1970s and lived out the rest of his as a recluse.

I remember very well the day he died in February 1982. It was during the Newcastle Jazz Festival and on the day when the great British jazz pianist Stan Tracey was due to give a concert there. As we took our seats in the Newcastle Playhouse for the gig, an announcement was made that Thelonious Monk had died. Stan Tracey, for whom Monk had been a major musical inspiration, responded to the occasion by playing two sets exclusively consisting of tunes by his hero. It was one of the best concerts I’ve ever been to and remains strong in my memory to this day.

That also reminds me to say that as well as being a completely unique and individualistic piano player, Thelonious Monk was also a great Jazz composer who penned some of the great modern standards of the idiom: ‘Round Midnight, Straight No Chaser, Epistrophy, the list is substantial. And then of course there is the tune he plays on this clip which became something of a signature tune.

Off the record, I don’t think it’s completely fair to say that Thelonious actually wrote Blue Monk. The main theme was in fact borrowed from an earlier tune called Pastel Blue written by the trumpeter Charlie Shavers. It’s basically a straightforward 12 bar blues, lacking the twists and turns  and stops and starts of his more typical compositions, but Monk recorded more varied versions of this tune than practically any other. This clip is a short rendition, but it’s fascinating to see the other characters in shot. Sitting at Monk’s piano looking straight at him is none other than Count Basie, and we also get a glimpse of blues singer Joe Turner standing at the side. Later on, there’s a shot of the great saxophonist Coleman Hawkins clearly enjoying the music as I hope you will.

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Throwing a Fit

Posted in Bad Statistics, The Universe and Stuff with tags , on February 18, 2009 by telescoper

I’ve just been to a very interesting and stimulating seminar by Subir Sarkar from Oxford, who spoke about Cosmology Beyond the Standard Model, a talk into which he packed a huge number of provocative comments and interesting arguments. His abstract is here:

Precision observations of the cosmic microwave backround and of the large-scale clustering of galaxies have supposedly confirmed the indication from the Hubble diagram of Type Ia supernovae that the universe is dominated by some form of dark energy which is causing the expansion rate to accelerate. Although hailed as having established a ‘standard model’ for cosmology, this raises a profound problem for fundamental physics. I will discuss whether the observations can be equally well explained in alternative inhomogeneous cosmological models that do not require dark energy and will be tested by forthcoming observations.

He made no attempt to be balanced and objective, but it was a thoroughly enjoyable polemic making the point that it is possible that the dark energy whose presence we infer from cosmological observations might just be an artifact of using an oversimplified model to interpret the data. I actually agreed with quite a lot of what he said, and certainly think the subject needs people willing to question the somewhat shaky foundations on which the standard concordance cosmology is built.

But near the end, Subir almost spoiled the whole thing by making a comment that made me decide to make  another entry in my Room 101 of statistical horrors.  He was talking about the  spectrum of fluctuations in the temperature of the Cosmic Microwave Background as measured by the Wilkinson Microwave Anisotropy Probe (WMAP):

 

 

I’ve mentioned the importance of this plot in previous posts. In his talk, Subir wanted to point out that the measured spectrum isn’t actually fit all that well by the concordance cosmology prediction shown by the solid line.

A simple way of measuring goodness-of-fit is to work out the value of chi-squared which relates to the sum of the squares of the residuals between the data and the fit. If you do this with the WMAP data you will find that the value of chi-squared is actually a bit high, so high indeed that there is only a 7 per cent chance of such a value arising in a concordance Universe.  The reason is probably to do with the behaviour at low harmonics (i.e. large scales) where there are some points that do appear to lie off the model curve. This means that the best fit concordance model  isn’t a really brilliant fit, but it is acceptable at the usual 5% significance level.

I won’t quibble with this number, although strictly speaking the data points aren’t entirely independent so the translation of chi-squared into a probability is not quite as easy as it may seem.  I’d also stress that I think it is valuable to show that the concordance model isn’t by any means perfect.  However, in Subir’s talk the chi-squared result morphed into a statement that the  probability of the concordance model being right is only 7 per cent.

No! The probability of chi-squared given the model is 7%, but that’s quite different to the probability of the model given the value of chi-squared…

This is a thinly disguised example of the prosecutor’s fallacy which came up in my post about Sir Roy Meadow and his testimony in the case against Sally Clark that resulted in a wrongful conviction for the murder of her two children.

Of course the consequences of this polemicist’s fallacy aren’t so drastic. The Universe won’t go to prison. And it didn’t really spoil what was a fascinating talk. But it did confirm in my mind that statistics is like alcohol. It makes clever people say very silly things.

Chinese Puzzles

Posted in Uncategorized with tags , , on February 17, 2009 by telescoper

On Friday 13th February I made one of my sporadic trips to London to go to the Royal Astronomical Society monthly meeting, catch up with friends, and dine at the Athenaeum with the RAS Club. That also gave me the excuse to stay in London over Valentine’s day and go with an old friend to the Opera followed by dinner in Chinatown on Saturday night.

As it happens, the RAS meeting also had a taste of the Orient about it because there were two absolutely fascinating talks about the Dunhuang Star Chart. This is a paper scroll found amongst many thousand similar objects squirrelled away by Buddhist monks in a tomb which was then subsequently bricked up and painted over. It lay undisturbed for a thousand years until rediscovered and basically plundered by treasure hunters, adventurers and archaeologists and its contents dispersed around the globe.

The Dunhuang Star Chart thus found its way to the British Library in London where it has recently been the subject of a special study involving both historians and astronomers. You can see this huge and very ancient sky map in full online here.

I had read about this sky map before in some book about the history of astronomy, but I hadn’t realised that its date had recently been re-evaluated to put it not in the 10th century (as I had previously believed), but in the middle of the 7th centur,  possibly as early as 640 AD. Moreover, recent quite convincing mathematical analysis has shown that the chart is not just made of freehand sketches but was produced with some mathematical precision using a form of cylindrical projection. Once again, we find the Chinese were well in advance of their western counterparts in terms of scientific knowledge.

So why were these scrolls hidden away? There are two theories. One is that the monks were concerned about imminent invasion from the west and they simply wanted to safeguard their knowledge until it could be reclaimed. Unfortunately it never was. The other theory is based on the fact that astronomical knowledge was highly classified in this period of Chinese imperial rule, the Tang Dynasty. The astrological clues contained in star charts could be used to cast doubt on the Emperor if they fell into the wrong hands, so were  forbidden to all but the inner court. Astronomy was Top Secret. The monks at Dunhuang may have hidden their papers because they shouldn’t have had them in the first place, and feared the wrath of the Emperor if they  were discovered by the Imperial heavies.

I find mysterious artefacts like this absolutely fascinating and they also strengthen my conviction that astronomy and archaeology have much in common. Both are observational rather than experimental sciences, and both rely on making inferences based on indirect and sometimes scanty clues. Perhaps its this that makes both disciplines prone to a few flights of fancy every now and again as well as posing puzzles which perhaps will never be solved.

Anyway, topping the bill at the RAS was the President, Andy Fabian, whose Presidential Address was entitled Black Holes at Work. Unfortunately,  the thing that didn’t work was the data projector so we had an embarassing delay while people rushed around trying to fix it. One of the charms of the RAS is that it never seems to be quite at the forefront of  technology. Anyway, once he got going the talk was very interesting. He was short of time at the end, though, so I didn’t have time to ask the  obligatory question about magnetic fields.

Then it was down to the Atheneaum and a nice dinner and rather a lot to drink.

The following evening after the Opera we went for dinner in Chinatown in Soho. The chilly West End streets were crowded, with what I originally assumed to be Valentine dates but which appeared instead to be mainly standard tourists taking advantage of the weak pound. Many restaurants were completely full, but eventually we found a table in a good place and all was well.

Coming back to Cardiff the following day I bought the Observer so I could do the crosswords on the train, and was reminded of the Azed competition crossword a couple of weeks ago which involved a quotation from a poem about St Valentine’s day by Coventry Padmore. It was quite a strange puzzle of a type called “Letters Latent” in which the cryptic part referred to the answer minus one or more letters.  The quote concerned was

Well dost thou, Love, thy solemn Feast to hold
In vestal February;

the poem is trying to make the point that wintry February is  a good time for St Valentine’s day as during spring and summer nobody needs to be reminded about the birds and the bees.

The task for competition entrants was to clue the word “vestal” in such a way that the definition referred to the whole word but the cryptic part omitted the s. My attempt was

Volatile components make this oil extra virgin

(The components of volatile give oil+vetal; virgin is the definition for vestal.)

Since I’ve now meandered far off the original subject, I think I’d better finish there!

The Magic Flute

Posted in Opera with tags , , on February 15, 2009 by telescoper

On Saturday 14th February I went to the Coliseum in St Martin’s Lane to see ENO‘s revival of Nicholas Hytner’s acclaimed production of Mozart’s The Magic Flute.

I’ve lost track of how many different productions I have seen of this strange and wonderful masterpiece, but this one was as good as any I can remember. It is sung in English rather than the original German (all productions by English National Opera are in English, in fact). Translating the libretto isn’t at all necessary for this work because the plot makes no sense whatsoever in whatever language the words happen to be sung or spoken. It’s all so weird it might as well be about particle physics.

Technically it’s not an opera, but a singspiel: the recitative – the bit in between the arias – is spoken rather than sung. It’s really more like a musical comedy in that sense, and was originally intended to be performed in a kind of burlesque style. That blends rather nicely with the Coliseum‘s own history: it only became an opera theatre relatively recently; before the Second World War it was  a Variety Theatre or  Music Hall. The Magic Flute also has many points of contact with the pantomime tradition, including the character of the  villainous Monostatos (Stuart Kale) who, at this performance, was roundly booed at his curtain call in authentic panto fashion. His retaliatory snarl was priceless.

I won’t even attempt to explain the plot, if you can call it that, because it’s completely daft. It’s daft, though, in a way that much of life is daft, and I think that’s the secret of its enduring popularity. Mozart’s music carries you along and constantly seems to be telling you not to take it all too seriously.

This production never gets bogged down  or, worse, stuck up its own backside as some I have seen. Instead it’s played straight to the gallery and none the worse it is for that.

The English text is very clever, including dextrous rhymes and plenty of puns, but I’d still have to say I prefer the original language because it fits so much better with the music. The Queen of the Night’s aria “Die Holle Racht” has so many harsh Germanic sounds in the original which just can’t be done in English with anything like the same effect.

I don’t think there are any really weak points in this production. The sets are simple but stylish and effective, and it all looks and sounds wonderful. Tamino (Robert Murray) is earnest and rather dull, but then I think he’s supposed to be. It might have been a mistake for him to go bare-chested in Act II though, as I don’t think man boobs were really what the audience wanted on St Valentine’s day. The comic momentum was kept on the boil by on the crazy birdcatcher Papageno (Roderick Williams). Pamina (Sarah-Jane Davis) was a little hesitant at first, and can’t act at all well, but sang her show-piece aria in the Second Act with real emotion. Robert Lloyd’s Sarastro added the right amount of gravitas without the pomposity the role sometimes generates; his bass is a lovely voice too, deep and warm with a rich texture to it. And then there’s the Queen of Night (Emily Hindrichs) who also seemed a little hesitant as she found her way through the difficult coloratura of the famous Act I aria that culminates in a nerve-jangling Top F, but was awesome in the second act when calling for the death of Sarastro. Her costume and hairstyle were more than a little reminiscent of Elsa Lanchester in Bride of Frankenstein. The three ladies had similar hairstyles, but without the side streaks and in a shocking blue. I couldn’t help thinking of Marge Simpson.

There were many funny moments, perhaps the best being when Papageno and Papagena fasten their safety belts before being hoisted into the rafters in a giant bird’s nest. Papageno even managed a reference to a Valentine.  I wonder if that was put in specially for Saturday?

Ecliptic Anomalies

Posted in Cosmic Anomalies, The Universe and Stuff with tags , , , , on February 12, 2009 by telescoper

Once a week the small band of cosmologists at Cardiff University have a little discussion group during which we look at an interesting and topical subject. Today my PhD student Rockhee chose an interesting paper by Diego et al entitled “WMAP anomalous signal in the ecliptic plane”. I thought I’d mention it here because it relates to an ongoing theme of mine, and I’ll refrain from commenting on the poor grammatical construction of the title.

The WMAP referred to is of course the Wilkinson Microwave Anisotropy Probe and I’ve blogged before about the tantalising evidence it suggests of some departures from the standard cosmological theory. These authors do something very simple and the result is extremely interesting.

In order to isolate the cosmic microwave background from foreground radiation produced in our own Galaxy, the WMAP satellite is equipped with receivers working at different frequencies. Galactic dust and free-free emission dominate the microwave sky temperature at high frequencies and Galactic synchotron takes over at low frequencies. The cosmic microwave background has the same temperature at all frequencies (i.e. it has a thermal spectrum) so it should be what’s left when the frequency-dependent bits are cleaned out.

What Diego et al. did was to make a map by combining the cleaned sky maps obtained at different frequencies obtained by WMAP in such a way as to try to eliminate the thermal (CMB) component. What is left when this is done should be just residual noise, as it should contain neither known foreground or CMB. The map they get is shown here.ecliptic

What is interesting is that the residual map doesn’t look like noise that is uniformly distributed over the sky: there are two distinct peaks close to the Ecliptic plane delineated by the black tramlines. Why the residuals look like this is a mystery. The peaks are both very far from the Galactic plane so it doesn’t look like they are produced by Galactic foregrounds.

One suggestion is that the anomalous signal is like an infra-red extension of the Zodiacal light (which is produced inside the Solar System and therefore is too local to be confined to the Galactic plane). The authors show, however, that a straightforward extrapolation of the known Zodiacal emission (primarily measured by the IRAS satellite) does not account for the signal seen in WMAP. If this is the explanation, then, there has to be a new source of Zodiacal emission that is not seen by IRAS but kicks in at WMAP frequencies.

Another possibility is that it is extragalactic. This is difficult to exclude, but is disfavoured in my mind because there is no a priori reason why it should be concentrated in the Ecliptic plane. Coincidences like this make me a bit uncomfortable. Some turn out to be real coincidences, but more often than not they are clues to something important. Agatha Christie would have agreed:

“Any coincidence,” said Miss Marple to herself, “is always worth noting. You can throw it away later if it is only a coincidence.”

On the other hand, the dipole asymmetry of the CMB (thought to be caused by our motion through a frame in which it is isotropic) is also lined up in roughly the same direction:

The dipole has a hot region and a cold region in places where the residual map has two hot regions and anyway it’s also a very large scale feature so the chances of it lining up by accident with the ecliptic plane to the accuracy seen is actually not small. Coincidences definitely do happen, and the rougher they are the more commonly they occur.

Obviously, I don’t know what’s going on, but  I will mention another explanation that might fit. As I have already blogged, the WMAP satellite scans the sky in a way that is oriented exactly at right angles to the Ecliptic plane. If there is an as yet unknown systematic error in the WMAP measurements, which is related in some way to the motion of the satellite, it could at least in principle produce an effect with a definite orientation with respect to the Ecliptic.

The only way we can rule out this (admittedly rather dull) explanation is by making a map using a different experiment. It’s good, then, that the Planck satellite is going to be launched in only a few weeks’ time (April 16th 2009). Fingers crossed that we can solve this riddle soon.

Leontyne Price

Posted in Opera with tags , on February 11, 2009 by telescoper

I’m getting a habit of forgetting birthdays. I meant to post this yesterday but it slipped my mind owing to me writing some bullshit for a grant application.

Anyway, I just wanted to post a birthday greeting to the wonderful Leontyne Price who was 82 years old on Tuesday 10th February. In case you’ve never heard of her, before she retired from the stage she was one of the great opera singers of her generation, famous for her enormous vocal range and smoky mezzo tones. She had a relatively light voice, without the thrilling power or dangerous edge of, say, Maria Callas, but she certainly knew how to use it for a big dramatic effect.

Amongst the many notable things about her was that she was the first black soprano to star at the Metropolitan Opera in New York. The great jazz trumpeter Miles Davis, never one to be exaggerated in his praise of other musicians, said of her

I have always been one of her fans because in my opinion she is the greatest female singer ever, the greatest opera singer ever. She could hit anything with her voice. Leontyne’s so good it’s scary. Plus, she can play piano and sing and speak in all those languages… I love the way she sings Tosca. I wore out her recording of that, wore out two sets.

I’m not sure she was the greatest singer ever, and she wasn’t that marvellous as an actress, but she’s definitely up there amongst the very best. I have an old LP of her singing Aida which is truly magnificent (despite all the scratches). In fact, according to a BBC poll in 2007 she was voted the 4th greatest opera singer, behind Maria Callas (who else?), Dame Joan Sutherland, and Victoria de los Angeles. That’s pretty exalted company.

Anyway, the later performances on Youtube aren’t the best, so I’ve picked an older one of her near the peak of her powers, with her voice gorgeously expressive and very fluid in the upper register. Here she is in probably her best role, as the eponymous Aida who, incidentally, is Ethiopian.

Happy Birthday Leontyne Price and very many happy returns!

The Marriage of Figaro

Posted in Opera with tags , , on February 8, 2009 by telescoper

After a week of miserable inclement weather it was a relief to have beautifully crisp sunny Saturday yesterday, capped by the prospect of a Night at the Opera. The “Spring” season of Welsh National Opera is now underway so I went to the Wales Millennium Centre in Cardiff Bay to see their production of Mozart’s The Marriage of Figaro (italian name: Le Nozze di Figaro).

I’ve been going to the opera for quite a while now, and I’m definitely mildly addicted to it. It’s quite an expensive thing to get hooked on, but not compared to some things. For me, there’s a kind of excitement about opera that is almost childish. As we settled down into our seats last night, I had butterflies in my stomach and when the overture started, the hairs stood up on the back of my neck.

Here’s the overture played at a good lick by the English Baroque Soloists.

With that as your starter, who wouldn’t be looking forward to the rest of the meal?

The Marriage of Figaro, a classic Opera Buffa , was the first of three to derive from a collaboration between Mozart and Lorenzo da Ponte that also produced Cosi fan Tutte and Don Giovanni. According to the programme notes, da Ponte wrote the libretto for Le Nozze di Figaro in less than six weeks, which is truly remarkable considering what a wonderfully polished work it is.

And of course there’s the music. Starting from the bustling ebullience of the briliant overture, the score is just beautiful from start to finish, the slapstick comedy punctuated by truly moving expressions of love and heartache such as the arias Porgi amor and Dove sono i bei momenti that make this piece much more than just a bit of fun. It also boasts one of the most beautiful duets in all opera, Sull’aria….Che soave zeffiretto, also known as the Letter Duet. Anyone will who has seen the memorable film Shawshank Redemption will recognize it because that’s what’s on the record Andy plays over the prison public address system after breaking into the warders’ office.

The lovely tunes wash over you one after the other in a way that’s so typical of Mozart; only Puccini had anything like his gift for wonderful melodies. With such sublime music and such a clever text, it’s very difficult to go very wrong. The one thing you have to make sure of in an Opera Buffa is to keep the pace going, much like a classic stage farce: if you dwell on it too much it’s no longer funny, just embarrassing to watch. The hectic pace only abates when the characters sing their wonderful solo arias, the surrounding comic context heightening their dramatic impact, but when these pieces are over we’re off again into the mayhem. The whole thing scurries along with never a dull moment and, by the end, you can hardly believe that it’s been the best part of four hours. The running time for last night’s performance, including one interval, was about 3 hours and 45 minutes but I never once looked at my watch.

This production is slick, beautifully sung, and keeps the momentum going in exactly the right way. The costumes are dated somewhere in the early 20th Century, with Susanna‘s French maid costume reminding me a little bit of the dress Kylie Minogue wore in Doctor Who. The sets are quite spare (although with sufficient props to hide behind, and there’s a lot of hiding behind things in this opera), with large mirrors at the side giving an extra sense of space. I was wondering how they would manage the garden setting for Act IV with this relatively simple set, but this was all done with mirrors too, this time with images of trees superimposed on them. It was quite effective, at least at first, although the mirrors kept moving around in a distracting and sometimes alarming way which spoilt it a little.

The cast was very good, especially Rosemary Joshua’s pert Susanna and Rebecca Evans as the Contessa Almaviva (both of them born in South Wales). The unflappably resourceful and charismatic Figaro was sung by David Soar, who played the part quite “straight” and let the libretto do the work. A good call, in my opinion. The Count Almaviva, Jacques Imbrailo, also sang very well and had considerable presence, but he wasn’t nearly pompous enough for my taste. Part of the joy of this opera is the subversion of roles, Figaro being so much smarter than his boss. I don’t think they quite made the most of this.

I should make a special mention of the stunningly beautiful Fiona Murphy as Cherubino. This character is a sex-starved adolescent boy, sung by a girl soprano, with definite shades of the principal boy in English pantomime. In fact, the English translation of the libretto seen in the surtitles cleverly uses the word pantomime in his/her scenes. In her Cherubino persona in the first Act, wearing a sports jacket and plus-twos, and with her hair cut short, Fiona Murphy had more than a touch of KD Lang about her. Later on Cherubino has to dress as a girl, and I found the result very interesting in all kinds of unexpected ways, not all of them comic…

Oh and I should mention that it is sung in Italian too. Call me old-fashioned but I always prefer things in the original language, especially when it’s Italian.

All in all, an excellent night out, and judging by the prolonged cheering and applause at the end, I don’t think I’m the only one who thought it so!