In the Dark

Nicola Cabibbo (1935-2010)

Posted in The Universe and Stuff with tags CKM matrix, Nicola Cabibbo, Particle Physics, quarks, weak interactions on August 16, 2010 by telescoper

Just a short post to convey the very sad news that the great Italian physicist Nicola Cabibbo passed away today at the age of 75. I know I’m not alone in thinking that he should have received a share of the Nobel prize in 2008, which was awarded to Yoichiro Nambu (half the prize) and the other half was split between Makoto Kobayashi and Toshihide Maskawa.

As I wrote in 2008:

All three are extremely distinguished physicists and their contributions certainly deserve to be rewarded. But, in the case of Kobayashi and Maskawa, the Nobel Foundation has made a startling omission that I really can’t understand at all and which even threatens to undermine the prestige of the prize itself.The work for which these two were given half the Nobel Prize this year relates to the broken symmetry displayed by weak interactions between quarks. We now know that there are three generations of quarks, each containing quarks of two different flavours. The first generation contains the up (u) and the down (d), the second the strange (s) and the charmed (c), and the third has the bottom (b) and the top (t). OK, so the names are daft, but physicists have never been good at names.

The world of quarks is different to penetrate becauses quarks interact via the strong force which binds them close together into hadrons which are either baryons (three quarks) or mesons (a quark and an anti-quark).

But there are other kinds of particles too, the leptons. These are also arranged in three generations but each of these families contains a charged particle and a neutrino. The first generation is an electron and a neutrino, the second a muon and its neutrino, and the third has the tau and another neutrino. One might think that the three quark generations and the three lepton generations might have some deep equivalence between them, but leptons aren’t quarks so can’t interact at all by the strong interaction. Quarks and leptons can both interact via the weak interaction (the force responsible for radioactive beta-decay).

Weak interactions between leptons conserve generation, so the total number of particles of electron type is never changed (ignoring neutrino oscillations, which have only relatively recently been discovered). It seemed natural to assume that weak interactions between quarks should do the same thing, forbidding processes that hop between generations. Unfortunately, however, this is not the case. There are weak interactions that appear to convert u and/or d quarks into c and/or s quarks, but these seem to be relatively feeble compared to interactions within a generation, which seem to happen with about the same strength for quarks as they do for leptons. This all suggests that there is some sort of symmetry lurking somewhere in there, but it’s not quite what one might have anticipated.

The explanation of this was proposed by Nicola Cabibbo who, using a model in which there are only two quark generations, developed the idea that states of pure quark flavour (“u” or “d”, say) are not really what the weak interaction “sees”. In other words, the quark flavour states are not proper eigenstates of the weak interaction. All that is needed is to imagine that the required eigenstates are a linear combination of the flavour states and, Bob’s your uncle, quark generation needn’t be conserved. This phenomenon is called Quark Mixing. What makes it simple for only two generations is that it can be described entirely by one number: the Cabibbo angle, which measures how much the quark flavour basis is misaligned with the weak interaction basis. The angle is small so the symmetry is only slightly broken.

Kobayashi and Maskawa generalized the work of Cabibbo to the case of three quark generations. That’s actually quite a substantial task as the description of mixing in this case requires not just a single number but a 3×3 matrix each of whose entries is complex. This matrix is universally called the Cabibbo-Kobayashi-Maskawa (CKM) matrix and it now crops up all over the standard model of particle physics.

And there’s the rub. Why on Earth was Cabibbo not awarded a share of this year’s prize? I was shocked and saddened to find out that he’d been passed over despite the fact that his work so obviously led the way. I can think of no reason why he was omitted. It’s outrageous. I even feel sorry for Kobayashi and Maskawa, because there is certain to be such an outcry about this gaffe that it may detract from their success.

But really…

I hope, however, that controversy doesn’t intrude too much on what I hope will be the forthcoming celebration of Cabibbo’s immense contributions to particle physics. I’ll leave it to the experts to write more detailed appreciations that do better justice to his achievements. I’ll just say that I only met him once in real life, but found him charmingly modest and altogether quite delightful company. He will be greatly missed.

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Cat Nap

Posted in Columbo with tags cats, Columbo on August 15, 2010 by telescoper

It’s been a month since I last posted an update about Columbo so I thought I’d put up a quick item.There’s been no repeat of his recent nosebleed, and he’s showing no after-effects at all. As you all know, he’s not exactly in the first flush of youth – so there’s no more of the racing-around-like-a-mad-thing he did when he was kitten. He still likes to go for the odd wander about, but it’s strictly in his own time. In fact he’s still spending quite a lot of time out of doors, as the weather, though not as good as June and July because it has rained a bit, is at least reasonably warm.

However, he did recently discover a new comfy spot, in the cupboard under the stairs which he has now added to his collection of places to sleep. Other well-established locations are: under the coffee table in the sitting room, on the mat next to the bath, behind the trees at the end of the garden, and in the corner of the spare bedroom, as well as his basket of course. It must occupy his mind to a considerable degree deciding which of these spots to sleep in. Still, sleeping is mainly what he does so it’s obviously important to do it right. It’s a hard life, being a cat…

The other day I did a bit of work in the garden. When I’d finished I swept up various bits and pieces into a pile but realised I’d forgotten to bring a shovel. When I came back with said implement, Columbo had appeared from nowhere and was rolling around in the pile of muck. It seems far from unusual for cats to enjoy rolling around in leaves, twigs and general dirt. Probably it’s a good way for a moggy to scratch their back. Anyway, after a few minutes’ escstatic rolling around, Columbo nodded off on the path right next to the rubbish so I decided to take a picture.

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The Next Decade of Astronomy?

Posted in Science Politics, The Universe and Stuff with tags astronomy, Astrophysics, Cosmology, Decadal Review, ESA, European Space Agency, NASA, STFC on August 14, 2010 by telescoper

I feel obliged to pass on the news that the results of the Decadal Review of US Astronomy were announced yesterday. There has already been a considerable amount of reaction to what the Review Panel (chaired by the esteemed Roger Blandford) came up with from people much more knowledgeable about observational astronomy and indeed US Science Politics, so I won’t try to do a comprehensive analysis here. I draw your attention instead to the report itself (which you can download in PDF form for free) and Julianne Dalcanton’s review of, and comments on, the Panel’s conclusions about the priorities for space-based and ground-based astronomy for the next decade or so over on Cosmic Variance. There’s also a piece by Andy Lawrence over on The e-Astronomer’s blog. I’ll just mention that Top of the Pops for space-based astronomy is the Wide-Field Infrared Survey Telescope (WFIRST) which you can read a bit more about here, and King of the Castle for the ground-based programme is the Large Synoptic Survey Telescope (LSST). Both of these hold great promise for the area I work in – cosmology and extragalactic astrophysics – so I’m pleased to see our American cousins placing such a high priority on them. The Laser Interferometer Space Antenna (LISA), which is designed to detect gravitational waves, also did very well, which is great news for Cardiff’s Gravitational Physics group.

It will be interesting to see what effect – if any – these priorities have on the ranking of corresponding projects this side of the Atlantic. Some of the space missions involved in the Decadal Review in fact depend on both NASA and ESA so there clearly will be a big effect on such cases. For example, the proposed International X-ray Observatory (IXO) did less well than many might have anticipated, with clear implications for Europe (including the UK). The current landscape of X-ray astronomy is dominated by Chandra and XMM, both of which were launched in 1999 and which are both nearing the end of their operational lives. Since X-ray astronomy can only be done from space, abandoning IXO would basically mean the end of the subject as we know it, but the question is how to bridge the the gap between the end of these two missions and the start of IXO even if it does go ahead but not until long after 2020? Should we keep X-ray astronomers on the payroll twiddling their thumbs for the next decade when other fields are desperately short of manpower for science exploitation?

On a more general level, it’s not obvious how we should react when the US gives a high priority to a given mission anyway. Of course, it gives us confidence that we’re not being silly when very smart people across the Pond endorse missions and facilities similar to ones we are considering over here. However, generally speaking the Americans tend to be able to bring missions from the drawing board to completion much faster than we can in Europe. Just compare WMAP with Planck, for instance. Trying to compete with the US, rather than collaborate, seems likely to ensure only that we remain second best. There’s an argument, therefore, for Europe having a programme that is, in some respects at least, orthogonal to the United States; in matters where we don’t collaborate, we should go for facilities that complement rather than compete with those the Americans are building.

It’s all very well talking of priorities in the UK but we all know that the Grim Reaper is shortly going to be paying a visit to the budget of the agency that administers funding for our astronomy, STFC. This organization went through a financial crisis all of its very own in 2007 from which it is still reeling. Now it has to face the prospect of further savage cuts. The level of “savings” being discussed – at least 25% -means that the STFC management must be pondering some pretty drastic measures, even pulling out of the European Southern Observatory (which we only joined in 2002). The trouble is that most of the other ground-based astronomical facilities used by UK astronomers have been earmarked for closure, or STFC has withdrawn from them. Britain’s long history of excellence in ground-based astronomy now hangs in the balance. It’s scary.

I hope the government can be persuaded that STFC should be spared another big cut and I’m sure that there’s extensive lobbying going on. Indeed, STFC has already requested input to its plans for the ongoing Comprehensive Spending Review (CSR). With this in mind, the Royal Astronomical Society has produced a new booklet designed to point out the relevance of astronomy to wider society. However I can’t rid from my mind the memory a certain meeting in London in 2007 at which the STFC Chief Executive revealed the true scale of STFC’s problems. He predicted that things would be much worse at the next CSR, i.e. this one. And that was before the Credit Crunch, and the consequent arrival of a new government swinging a very large axe. I wish I could be optimistic but, frankly, I’m not.

When the CSR is completed then STFC will have yet again to do another hasty re-prioritisation. Their Science Board has clearly been preparing:

… Science Board discussed a number of thought provoking scenarios designed to explore the sort of issues that the Executive may be confronted with if there were to be a significant funding reduction as a result of the 2010 comprehensive spending review settlement. As a result of these deliberations Science Board provided the Executive with guidance on how to take forward this strategic planning.

This illustrates a big difference in the way such prioritisation exercises are carried out in the UK versus the USA. The Decadal Review described above is a high-profile study, carried out by a panel of distinguished experts, which takes detailed input from a large number of scientists, and which delivers a coherent long-term vision for the future of the subject. I’m sure not everyone agrees with their conclusions, but the vast majority respect its impartiality and level-headedness and have confidence in the overall process. Here in the UK we have “consultation exercises” involving “advisory panels” who draw up detailed advice which then gets fed into STFC’s internal panels. That bit is much like the Decadal Review. However, at least in the case of the last prioritisation exercise, the community input doesn’t seem to bear any obvious relationship to what comes out the other end. I appreciate that there are probably more constraints on STFC’s Science Board than it has degrees of freedom, but there’s no getting away from the sense of alienation and cynicism this has generated across large sections of the UK astronomy community.

The problem with our is that we always seem to be reacting to financial pressure rather than taking the truly long-term “blue-skies” view that is clearly needed for big science projects of the type under discussion. The Decadal Review, for example, places great importance on striking a balance between large- and small-scale experiments. Here we tend slash the latter because they’re easier to kill than the former. If this policy goes on much longer, in the long run we’ll end up a with few enormous expensive facilities but none of the truly excellent science that can be done from using smaller kit. A crucial aspect of this that that science seems to have been steadily relegated in importance in favour of technology ever since the creation of STFC. This must be reversed. We need a proper strategic advisory panel with strong scientific credentials that stands outside the existing STFC structure but which has real influence on STFC planning, i.e. one which plays the same role in the UK as the Decadal Review does in the States.

Assuming, of course, that there’s any UK astronomy left in the next decade…

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In the Dark

Posted in Poetry with tags Felix Dennis on August 13, 2010 by telescoper

Here’s a verse by a poet who’s quite new to me – Felix Dennis – who I learned about because he’s doing a nationwide tour this autumn to celebrate the publication of a new book and a flyer for it came in the post this morning. I only read it because it wasn’t a bill, but it seems he’s quite a colourful character, and I might go along when he visits Cardiff (on 29th September, at the Glee Club in Cardiff Bay). Anyway, I had a shufti at his website and found a poem on it called In the Dark, so obviously I just had to post it here! Enjoy!

I knuckle an eye with my fist—
Fragments of non-existent light
Erupt where they cannot exist,
Blinding my non-existent sight.

We huddle by day in our joys,
Swaddled in rags of silk and hope
Like toddlers at play with toys:
By night, we twist all silk to rope

To tether the tiger, Desire,
And cradle demons, lest they wake
And set the lakes of Guilt afire,
As the walls of our dreaming shake.

The candle has guttered and died.
Here in the dark— within my mind
My terrors and tigers collide:
And all have eyes, but I am blind.

Grade Inflation

Posted in Education, Politics with tags A-levels, education, mathematics, Physics on August 12, 2010 by telescoper

Still too busy to post anything too substantial, but since this year’s A-level results are out next week – with the consequent scramble for University places – I thought I’d take a few minutes to share this graph (taken from an article on the BBC website) which shows the steady ~~dumbing-down~~ improvement of educational standards student performance over the last few decades.

Nowadays, on average, about 27 per cent of students taking an A-level get a grade A. When I took mine (in 1981, if you must ask) the fraction getting an A was about 9%. It’s scary to think that I belong to a generation that must be so much less intelligent than the current one. Or could it be – dare I say it? – that A-level examinations might be getting easier?

Looking at the graph makes it clear that something happened around the mid-1980s that initiated an almost linear growth in the percentage of A-grades. I don’t know what will happen when the results come out next week, but it’s a reasonably safe bet that the trend will continue.

I can’t speak for other subjects, but there’s no question whatsoever that the level of achievement needed to get an A-grade in mathematics is much lower now than it was in the past. This has been proven over and over again. A few years ago, an article in the Times Higher discussed the evidence, including an analysis of the performance of new students on a diagnostic mathematics test they had to take on entering University. The same test, covering basic algebra, trigonometry and calculus, had been administered every year so provided a good diagnostic of real mathematical ability that could be compared with the A-level grades achieved by the students. They found, among other things, that students entering university with a grade B in mathematics in 1999 performed at about the same level as students in 1991 who had failed mathematics A-level.

The steadily decreasing level of mathematical training students receive in schools poses great problems not only for mathematics courses, but also for subjects like physics. We have to devote so much more time on the physics equivalent of “basic training” that we struggle to cover all the physics we should be covering in a degree program. Thus the dumbing down of A-levels leads to pressure to dumb down degrees too.

That brings me to the prospect of huge cuts – up to 35% if the stories are true – in government funding for universities, leading to pressure to shorten the traditional three-year Bachelors degree to one that takes only two years to complete. If this goes ahead it won’t be long before a student can get a degree by achieving the same level of knowledge as would have been displayed by an A-level student 30 years ago. Are we supposed to call this progress?

Or perhaps this business about two year degrees all really does make sense. Maybe we should just accept that universities have to offer such courses because the school system has become broken beyond repair over the last 30 years, and it will be up to certain Higher Education institutions from now on to do the job that school sixth-forms used to do, i.e. teach A-levels.

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Hothouse Flowers

Posted in Literature, Poetry with tags An Alien Heat, Dancers at the End of Time, Hothouse Flowers, Michael Moorcock, Theodore Wratislaw on August 11, 2010 by telescoper

At the weekend I shifted quite a lot of stuff around the house, in preparation for a major redecoration project in my main bedroom, which, when it gets started, means I’ll be sleeping in the spare room for quite a while. I moved a whole case of old paperback novels I’ve kept since I was a teenager and couldn’t help opening one that happened to be at the top. It was An Alien Heat, the first novel in the classic Dancers at the End of Time trilogy by Michael Moorcock whose books I devoured voraciously when I was at school. At the front of this one is a quotation from a poem by Theodore Wratislaw which contains the title phrase. I had a quick google about and found the whole poem, which turned out to be a very sensual and well-constructed sonnet, as opposed to the cack-handed parody I put up recently. The title of this poem also of course furnished the name of a well-known band.

I hate the flower of wood or common field.
I cannot love the primrose nor regret
The death of any shrinking violet,
Nor even the cultured garden’s banal yield.
The silver lips of lilies virginal,
The full deep bosom of the enchanted rose
Please less than flowers glass-hid from frost and snows
For whom an alien heat makes festival.
I love those flowers reared by man’s careful art,
Of heady scents and colors: strong of heart
Or weak that die beneath the touch of knife,
Some rich as sin and some as virtue pale,
And some as subtly infamous and frail
As she whose love still eats my soul and life.

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Dizzy on the BBC

Posted in Jazz with tags BBC, Dizzy Gillespie, Humphrey Lyttelton, James Moody, Jazz 625 on August 10, 2010 by telescoper

It’s a grey gloomy and rainy August lunchtime here in Wales and so I thought I’d just try to brighten things up a little by posting this video of a lovely set by the quintet led in the early 60s by the great Dizzy Gillespie, clearly enjoying himself on the BBC TV program Jazz 625. This was the band that also featured the brilliant James Moody on saxophones and flute. As you can hear, they played music that was strongly flavoured by Dizzy’s lifelong interest in Cuban jazz. The programme was introduced by the late great Humphrey Lyttelton and it’s in several bits which you will have to click through if you want to see them all. I hope you at least go as far as Part 3, where there’s a big laugh waiting for you…

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Notes for the Reader

Posted in Uncategorized on August 9, 2010 by telescoper

I’m going to be too busy to post much this week so I thought I’d take the opportunity to point out a couple of things for the benefit of regular readers, newcomers and occasional visitors to this blog.

First, about RSS Feeds. If you wish to subscribe to the whole blog via an RSS feed you will find it at

https://telescoper.wordpress.com/feed/

If you wish only to see posts in a particular category, you can do so via

https://telescoper.wordpress.com/category/categoryname/feed/

So if, for example, you only want to read the “Science Politics” items via RSS the feed is at

https://telescoper.wordpress.com/category/science-politics/feed/

A full list of categories, together with the number of posts so far published in each one, can be found on the home page. You can use this to browse my back catalogue, so to speak, although I should point out that I didn’t file that many of my earlier posts in categories and haven’t had time to go back through them and sort them out…

I also wanted to make some comments about comments. Please note what it says on my home page:

Feel free to comment on any of the posts on this blog but comments may be moderated; anonymous comments and any considered by me to be abusive will not be accepted.

You may use a nickname or anonymous handle on a comment, but I insist on a valid email address that identifies you (although the email address will not be visible to anyone but me). The system that operates on comments is that, if you haven’t posted before, your comment will be held until I have approved it. Comments are posted immediately from “approved” users but I reserve the right to moderate them if they turn out to be abusive. Serial offenders are put on a blacklist and their comments will be treated as spam.

Even if you are a regular commenter you may find that some comments don’t appear straight away. That is because I operate a spam filter – spam comments outnumber genuine ones by more than two-to-one – and it sometimes makes mistakes. If this happens it is probably because your comment contains several embedded URLs, which makes the spam filter suspicious. I usually manage to rescue comments blocked in this way, but it may take a while before your comment appears.

Let me point out that there is a separate RSS feed for comments at

https://telescoper.wordpress.com/comments/feed/

if you wish to follow discussion that way.

I realise that there isn’t really a convenient way to communicate suggestions for improvements or to ask general questions about the blog, so when I have a bit of time I’ll set up a permanent page to serve that purpose.

Astronomy (and Particle Physics) Lookalikes, No. 39

Posted in Astronomy Lookalikes with tags Ian Halliday, Jim Broadbent on August 8, 2010 by telescoper

Well, having got the positive discrimination out of my system (at least for today), I’ll add just one more. I’ve always been struck by the similarity between distinguished former Chief Executive of PPARC, current Chief Executive of the Scottish Universities Physics Alliance and President of the European Research Council, Professor Ian Halliday and actor Jim Broadbent.