Remembering the Aberfan Disaster

Posted in History with tags , on October 20, 2016 by telescoper

Tomorrow marks the 50th anniversary of a truly appalling tragedy:the disaster at Aberfan which took place on 21st October 1966. A colliery spoil heap in the Welsh village of Aberfan, near Merthyr Tydfil, underwent a catastrophic collapse caused by a build-up of water, and more than 40,000 cubic metres of debris slid downhill into the village. The classrooms at Pantglas Junior School were immediately inundated; young children and teachers died from impact or suffocation. In all, 144 people lost their lives that day, including 116 children at the school. The collapse occurred at 9.15am. Had the disaster struck a few minutes earlier, the children would not have been in their classrooms, and if it had struck a few hours later, they would have left for the half-term holiday. As it happened, it was a tragedy of unbearable dimensions, that shattered many lives and devastated the community. It was caused largely by negligence on behalf of the National Coal Board

The First Minister of Wales, Carwyn Jones, has called upon the people of Wales to pause and remember the Aberfan disaster with a minute’s silence at 9.15am tomorrow (i.e. on Friday 21 October). Cardiff University will be observing this silence, and so will I. I hope readers of this blog will pause to reflect at that time too.

Here is a short video featuring the voice of Jeff Edwards, a survivor of the Aberfan disaster, recalling his harrowing experiences of that day in a conversation with Dr Robert Parker of the School of Earth and Ocean Sciences at Cardiff University. Rob’s research looks at landslide processes, landscape evolution, catastrophe modelling and post-disaster assessment.

KiDS-450: Testing extensions to the standard cosmological model [CEA]

Posted in The Universe and Stuff with tags , , , on October 19, 2016 by telescoper

Since I’ve just attended a seminar in Cardiff by Catherine Heymans on exactly this work, I couldn’t resist reblogging the arXiver entry for this paper which appeared on arXiv a couple of days ago.

The key finding is that the weak lensing analysis of KIDS data (which is mainly to the distribution of matter at low redshift) does seem to be discrepant with the predictions of the standard cosmological model established by Planck (which is sensitive mainly to high-redshift fluctuations).

Could this discrepancy be interpreted as evidence of something going on beyond the standard cosmology? Read the paper to explore some possibilities!


We test extensions to the standard cosmological model with weak gravitational lensing tomography using 450 deg$^2$ of imaging data from the Kilo Degree Survey (KiDS). In these extended cosmologies, which include massive neutrinos, nonzero curvature, evolving dark energy, modified gravity, and running of the scalar spectral index, we also examine the discordance between KiDS and cosmic microwave background measurements from Planck. The discordance between the two datasets is largely unaffected by a more conservative treatment of the lensing systematics and the removal of angular scales most sensitive to nonlinear physics. The only extended cosmology that simultaneously alleviates the discordance with Planck and is at least moderately favored by the data includes evolving dark energy with a time-dependent equation of state (in the form of the $w_0-w_a$ parameterization). In this model, the respective $S_8 = sigma_8 sqrt{Omega_{rm m}/0.3}$ constraints agree at the $1sigma$ level, and there is `substantial concordance’ between…

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Chuck Berry on a Summer’s Day

Posted in Music with tags , , , , , , , on October 19, 2016 by telescoper

I was meaning to post this yesterday about Chuck Berry to mark his 90th Birthday. I’m putting it here as a bit of an oddity but I hope you find it interesting.

Chuck Berry appeared in Bert Stern’s classic film Jazz on Summer’s Day which was filmed at the 1958 Newport Jazz Festival. He performed on that occasion with a pick-up band called the Newport All-Stars, and the number that made it into the film was Sweet Little Sixteen, a tune that he actually wrote. I find two things fascinating about this performance. One is that the “backing band” is a stellar group of Jazz legends: the drummer is the great Jo Jones (who led the lightly swinging rhythm section of the great Count Basie band of the 1930s); the trumpeter is Buck Clayton, another Basie alumnus; and the trombonist is none other than Jack Teagarden. To a Jazz fan like myself, the talents of these musicians are totally wasted: they seem somewhat bemused by Chuck Berry’s gyrations on stage as well as bored by the material. When the time comes for the improvised solos that a jazz audience demands, only the relatively unknown clarinettist Rudy Rutherford – usually a tenor saxophonist who played with a number of bands, including Count Basie’s – was prepared to stand up and be counted, his strange effort is evidently a source of great amusement to the rest of the band, but at least he got into the spirit!

The other fascinating thing is what a historical document this is. During the 1950s Jazz was beginning to lose out to Rock and Roll in the popularity stakes, hence the plan of booking Chuck Berry to boost the audience figures at the Newport Jazz Festival. The tension on stage is almost palpable and even Chuck Berry occasionally looks a bit embarrassed by the whole thing. But it’s also a wonderfully observed portrayal of the styles of the time, especially through the audience shots. I wonder what happened to the cute couple dancing to this performance?

Anyway, belated best wishes on his 90th Birthday, here’s Chuck Berry recorded live 58 years ago at the Newport Jazz Festival in 1958, singing and playing Sweet Little Sixteen.


P.S. I forgot to mention the superb photography.







50 Years of the Astronomy Centre at the University of Sussex

Posted in Biographical, Education, The Universe and Stuff with tags , , , , , on October 18, 2016 by telescoper

On Saturday (15th October) I was back in Brighton for the first time since I left my job there at the end of July. The occasion was a very nice lunch party to celebrate 50 years of the Astronomy Centre at the University of Sussex, which started properly in 1966. It was a pleasant occasion, and great to have the chance to catch up with some people I haven’t seen for far too long. I had two stints in the Astronomy Centre: once as a student then postdoc from 1985 to 1990, and the other from 2013 to 2016 when I was Head of the School of which the Astronomy Centre is part. I had a lot more time to do research in the first incarnation than in the second!

Quite a few people present hadn’t realised I was no longer working at Sussex, which led to one or two slightly awkward conversations, but I was thankfully very far from being the centre of attention.

After the lunch itself we had short speeches from various alumni of the Astronomy Centre: esteemed science writer John Gribbbin (who was one of its first MSc students in 1966); Lord Martin Rees (who was briefly a Professor at Sussex, before he returned to Cambridge to take up the Plumian Professorship); John Barrow (who was my supervisor while I was there); Carlos Frenk (who was a postdoctoral researcher when I arrived in September 1985, but who left to take up a lectureship in Durham at the end of that year so we overlapped only for a short time); Andrew Liddle (who arrived near the end of my stay and was there for 22 years altogether, leaving at the end of 2012 to take up a post in Edinburgh); and Peter Thomas (current Director of the Astronomy Centre).

When I arrived in 1985 there were only four permanent faculty in the Astronomy Centre itself – Roger Tayler, Leon Mestel, John Barrow and Robert Smith – but research there was thriving and it was a great environment to work in. I count myself very lucky at having made such a good choice of a place to do my PhD DPhil. Leon and Robert both worked on stellar astrophysics, but after Leon’s retirement the centre increasingly focussed on cosmology and extragalactic astrophysics, which remains the case today. Roger Tayler sadly passed away in 1997, but Leon is still around: he is 89 years old and now lives in Cambridge.

Those present at the lunch were given a booklet featuring around 50 academic papers or other research “highlights”(e.g. the launch of Planck), approximately one for each year of the Astronomy Centre, chosen to be the “best” of that year. Each page was also shown as a slide during the lunch. I was thrilled to see that two of my papers (from 1987 and 1991 respectively) made it into the collection. The second one was published after I’d left Sussex, but I definitely did the work on it and submitted it while an employee of the Astronomy Centre. Andrew Liddle and John Barrow have the largest number of “greatest hits”, but the most famous paper is probably the classic “DEFW” which won Carlos Frenk and his collaborators the Gruber Prize about five years ago.

The book also contains various bits of interesting bibliometric information, such as this, which shows that the variation in the productivity of the Astronomy Centre over time.


Anyway, for those who are interested, the whole collection of slides can be viewed here:

Thanks to Seb Oliver and the rest of the Astronomy Centre for organizing this very enjoyable event – and for sending me the slides! Here’s to the next 50 years of Astronomy at the University of Sussex!


The Firebird (and more) at St David’s Hall

Posted in Music with tags , , , , , , on October 18, 2016 by telescoper

Just a quick note to catch up on concert-going activities from last week, as for various reasons I had to skip a few days of blogging…

Last Thursday night (13th October) I was lucky enough to attend a tremendous concert at St David’s Hall in Cardiff featuring the BBC National Orchestra of Wales conducted by Thomas Søndergård at the start of their 2016/7 season. The main item on the bill was the complete score for Igor Stravinsky’s ballet The Firebird. This is a thrillingly piece, involving a huge orchestra, numbering about a hundred musicians, including some positioned away from the rest of the orchestra. In a performance of the ballet the main orchestra would be in the pit, not on the stage, and the musicians offstage in the concert would be onstage with the dancers. If you see what I mean.

The orchestration of The Firebird is a tour de force: intricate but vividly coloured, full of excitement and colour and the BBC National Orchestra of Wales played it with great passion and aplomb. A really brilliant performance.

The Firebird filled the second half of the programme. In the first half we heard three pieces by French composers: Prélude à l’après-midi d’un faune by Claude Debussy; the three songs from Shéhérazade by Maurice Ravel, sung by the inestimable Sarah Connolly; and  the Flute Concerto by Jacques Ibert played by Emily Beynon. The first two pieces are fairly standard in the concert repertoire, but the last one was completely new to me. The last piece is very fine indeed, consisting of two dazzlingly virtuosic faster movements (Allegro and Allegro Scherzando) either side of a lyrical Andante. The orchestra was somewhat pared down for this part of the concert, but it’s nevertheless a piece of substantial weight and harmonic complexity. Hats off to Emily Beynon and the BBC NOW for a wonderful introduction to this work.

What a rich and varied programme for a single concert, all wonderfully played. I’m certainly looking forward to the rest of the season!



Passport to Pimlico

Posted in Uncategorized on October 14, 2016 by telescoper

So, here I am one Friday night in Pimlico. This afternoon there has been the first Ordinary Meeting of the Royal Astronomical Society of the new season, followed, this evening,  by  dinner with the RAS Club.

On the bill for the RAS meeting were talks about galaxy formation and extrasolar planets, followed by the headline attraction of this year’s Gerald Whitrow Lecture, by Neil Turok of the Perimeter Institute in Canada. The abstract of his talk reads

A spate of new observations are providing powerful clues about the laws of fundamental physics and the cosmos. The implications are revolutionary: the universe is astonishingly simple on the largest and the smallest observable scales, with great complexity in between. These findings contrast sharply with expectations from popular twentieth century paradigms including inflation, supersymmetry and string theory, which led many to take seriously the idea of a wild and unpredictable “multiverse” on large scales. Key “predictions” derived from that picture have been recently falsified, posing observational challenges to the paradigm which compound its many logical problems. In this talk I will discuss a new, and in my view more promising, approach to understanding the quantum nature and integrity of the universe.

There was a great deal of interesting and stimulating material in his talk, and I found myself in agreement with at least some  of the criticisms he made about the multiverse (of which idea I am myself no fan). I remain however unconvinced (as yet) that his “new approach” is more promising as he claims, probably because the last bit was a bit rushed. I look forward to being proved wrong!

Anyway, after that it was dinner at the Athenaeum with the club, but instead of making the long journey of returning to Cardiff (the Severn Tunnel remains closed) I decided to stay in London.

In fact tomorrow I shall be attending a lunch at Sussex University in honour of the 50th anniversary of the founding of Astronomy Centre, my first trip back there since I left at the end of July, so it makes sense to stay overnight in London, close enough to Victoria that I don’t have far to go to get the train to Brighton tomorrow…

A Universe of Two Trillion Galaxies

Posted in The Universe and Stuff with tags , , , , , on October 13, 2016 by telescoper

I just saw a press-release that describes a paper, just out, authored by Chris Conselice et al from the University of Nottingham (in the Midlands), with this here abstract:


The key conclusion of this paper is that when the universe was only a few billion years old there were about ten times as many galaxies in a given volume of space as there are within a similar volume today, but most of these galaxies were much lower mass systems than, e.g., the Milky Way. In fact their masses are similar to those of the satellite galaxies surrounding the Milky Way. These objects are numerous but so faint that even in very deep surveys with very big telescopes they are very easy to miss.

Here’s an image from a deep survey: this is from the Hubble Space Telescoper Great Observatories Deep Survey (HST-GOODS).


You can click on this to make it larger if you wish. This is typical of a “pencil beam” survey. It opens a very small window on the heavens – about a millionth of its total area of the sky – in a direction chosen to avoid having too many bright stars from our own Galaxy getting in the way. When you look at such a patch with a big telescope for a long time, what you see is basically all galaxies. The few stars in the above image can be identified by the diffraction patterns they produce, but almost every fuzzy blob in the picture is a galaxy. It looks like there are a lot of galaxies in this image, but the real number seems to be substantially higher than we thought.

When I’ve given popular talks about this kind of thing I’ve always said something like “There are at least as many galaxies in the observable Universe as there are stars in our own Galaxy”. It turns out that I was wise to include the “at least as”. There are about 100 billion (1011) stars in the Milky Way, but the latest estimate is now that there are two trillion (2 ×1012) galaxies in the observable Universe. I quote Douglas Adams:

“The Universe, as has been observed before, is an unsettlingly big place, a fact which for the sake of a quiet life most people tend to ignore. Many would happily move to somewhere rather smaller of their own devising, and this is what most beings in fact do.

I believe this explains a lot about modern politics.