Archive for April, 2018

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Welcome Back To Sophia Gardens

Posted in Cardiff, Cricket with tags , , on April 30, 2018 by telescoper

As a member of Glamorgan County Cricket Club I today received some important news by email.

It seems that at the end of this month (ie today), the sponsorship deal with an electricity company that involved the cricket ground in Cardiff being called the SSE SWALEC Stadium lapses.

From tomorrow, the First of May, therefore, the ground will be known by the far more attractive name of Sophia Gardens Cardiff. That also happens to be the name by which it was known from 1967 to 2007…

I have to admit that I always struggled to bring myself to call it the SSE SWALEC Stadium, so I’m glad that I no longer have to try!

And while we’re on about gardens here is a picture of some flowers I saw in Cathays Park on my way to work this morning.

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The Arithmetic of Relegation

Posted in Biographical, Sport with tags , , , on April 30, 2018 by telescoper

When I got back home after yesterday’s concert, I ate some dinner and settled down to have a look through the Sunday papers. Most of the news was as grim as expected, especially the ongoing fiasco of Brexit, and the scandal engulfing Home Secretary former Home Secretary Amber Rudd who obviously lied to Parliament on at least one occasion. Anyway, turning my attention to the Sports pages there was a write-up of Saturday’s disappointing home defeat for Newcastle United against bottom club West Bromwich Albion. I was gloomy enough to wonder whether Newcastle might actually still get relegated, so looked at the Premiership Table:

Neither West Brom (28 points) nor Stoke (30) can catch Newcastle with only two games to play, but Southampton can in principle get 41 points from here if they win all three games. It’s true that they have a worse goal difference but if Newcastle lost all their three remaining games, and Southampton won all theirs that would change. It therefore looks mathematically possible for Newcastle to be relegated.

However, I then glanced at the fixture list and found that Southampton have to play Swansea in one of their remaining matches. If Southampton win that fixture then the maximum number of points Swansea can get by the end of the competition is 39, so Newcastle can’t be relegated. If Southampton lose or it’s a draw then they can’t catch Newcastle.

I conclude, therefore, that Newcastle United are mathematically safe from relegation. Hooray!

But who will go down? I think West Brom and Stoke will probably get relegated, but I’m not sure about the third team. Huddersfield must be very nervous because their recent form has been poor and they have a very bad goal difference. The betting odds are interesting: BetFred are offering 200/1 on West Brom not being relegated and most bookies are about 8/1 on Stoke to stay up. PaddyPower are quoting 4/9 on Huddersfield and even money on Southampton to go down. If you want to bet on Brighton to get relegated your best odds are with BetVictor who are offering 50-1. Few bookies are quoting odds on West Brom to get relegated, so they obviously think that’s the likely outcome.

I expect these odds to change a lot after the next round of matches.

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Prokofiev, Grieg and Beethoven at St David’s Hall

Posted in Music with tags , , , , , , , , on April 29, 2018 by telescoper

This afternoon found me once again at St David’s Hall, Cardiff, waiting for a concert to start.

This time it was the Orchestra of Welsh National Opera under the direction of Tomáš Hanus. And very enjoyable it was.

The first number was a bit of a taster for the forthcoming WNO season, which includes Prokofiev’s War and Peace and Rossini’s Lá Cenerentola. The latter being the story of Cinderella, it made sense to include Prokofiev’s Cinderella Suite from the ballet he wrote in the 1940s.

After that we had the evergreen Grieg’s Piano Concerto, by Grieg, played by the excellent Peter Donohoe, exactly how I like it: with all the right notes in the right order, and the Orchestra not too heavy on the banjoes.

Following the wine break we had Beethoven’s Symphony No. 7, a work which has to be one of his most uplifting pieces. Beethoven was very good at ‘uplifting’ so that means it is very special indeed.

A lovely concert, warmly received by the audience and a very pleasant way to spend a Sunday afternoon.

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Judgement Day

Posted in Cardiff, Rugby with tags , , , on April 28, 2018 by telescoper

I’m up early again on a Saturday, travelling back to Cardiff this weekend for the above event later today. It’s actually a School social event for members of the School of Physics & Astronomy that involves two rugby matches at the Principality Stadium in Cardiff, featuring all four Welsh teams in the Guinness Pro 14 tournament: the Blues (from Cardiff); Ospreys (from Neath/Swansea); Scarlets (from Llanelli); and Dragons (from Newport). Tickets for the whole event cost just £10 each…

Should be a good day out! I may post a few pictures from the Stadium, so watch this space.

The scene about 20 minutes before Scarlets v Dragons..

It did fill up: the overall attendance was over 65,000.

The Scarlets versus Dragons match was rather one-sided, ending 33-8 to the team from Llanelli. The thing that struck me most about the game was the dire state of the scrummaging. I think only one scrum completely properly in the whole match! The Dragons also conceded a penalty try after repeated infringements at scrums under their own posts.

After a break we had the Ospreys versus Cardiff Blues. Here is the scene shortly after kick off with the Blues (right) immediately under pressure from the Ospreys (left, in white).

After the first 10 minutes I thought the Ospreys were going to run away with the game but it turned out to be an excellent close-fought contest, of much higher quality than the first. Cardiff were actually ahead for much of the game, despite their atrocious performance at the line out. The match ended 26-23 to the Ospreys, with the winning points coming from a drop goal 2 minutes from the end…

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The LGBT+ Physical Sciences Climate Survey – Final Reminder!

Posted in LGBT with tags , , , on April 27, 2018 by telescoper

This morning, a tweet from the Institute of Physics containing the above image reminded me to remind you all to participate (if you are so minded) in the LGBT+ Physical Sciences climate survey, which was launched amid the snows of 1st March this year. The deadline is coming up so if you want to complete the survey form and haven’t yet done so, please get on with it!

The survey is open to anyone (whether a member of a professional organisations or not) who identifies as LGBT+ or an ally and who may be working, teaching or studying in a physical sciences field. Respondents will need to be at least 16 years of age and above. The Institute of Physics (IOP), Royal Astronomical Society (RAS) and Royal Society of Chemistry (RSC) are managing this survey on behalf of the LGBT+ Physical Sciences Network. Its aim is to collect evidence for what the working and studying climate is like for LGBT+ physical scientists in the UK and Ireland.

You can complete the survey here.

The survey is open until Monday 30th April, which is very close so why not do it right away?

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Gaia’s Second Data Release!

Posted in The Universe and Stuff with tags , , , on April 26, 2018 by telescoper

It seems like only yesterday that I was blogging excitedly about the first release of data (DR1) from the European Space Agency’s Gaia Mission. In fact it was way back in 2016! Anyway, yesterday came another glut of Gaia goodness in the form of the second release of data, known to its friends as DR2.

In case you weren’t aware, Gaia is an ambitious space mission to chart a three-dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracy needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population.

You can find links to all the DR2 science papers here, a guide to how to use the data here, and of course a link to the full Gaia Archive here.

Here’s a (brief!) list of the contents of DR2:

  • The five-parameter astrometric solution – positions on the sky (α, δ), parallaxes, and proper motions – for more than 1.3 billion (109) sources, with a limiting magnitude of G = 21 and a bright limit of G ≈ 3. Parallax uncertainties are in the range of up to 0.04 milliarcsecond for sources at G < 15, around 0.1 mas for sources with G=17 and at the faint end, the uncertainty is of the order of 0.7 mas at G = 20. The corresponding uncertainties in the respective proper motion components are up to 0.06 mas yr-1 (for G < 15 mag), 0.2 mas yr-1 (for G = 17 mag) and 1.2 mas yr-1 (for G = 20 mag). The Gaia DR2 parallaxes and proper motions are based only on Gaia data; they do no longer depend on the Tycho-2 Catalogue.
  • Median radial velocities (i.e. the median value over the epochs) for more than 7.2 million stars with a mean G magnitude between about 4 and 13 and an effective temperature (Teff) in the range of about 3550 to 6900 K. This leads to a full six-parameter solution: positions and motions on the sky with parallaxes and radial velocities, all combined with mean G magnitudes. The overall precision of the radial velocities at the bright end is in the order of 200-300 m s-1 while at the faint end the overall precision is approximately 1.2 km s-1 for a Teff of 4750 K and about 2.5 km s-1 for a Teff of 6500 K.
  • An additional set of more than 361 million sources for which a two-parameter solution is available: the positions on the sky (α, δ) combined with the mean G magnitude. These sources have a positional uncertainty at G=20 of about 2 mas, at J2015.5.
    G magnitudes for more than 1.69 billion sources, with precisions varying from around 1 milli-mag at the bright (G<13) end to around 20 milli-mag at G=20. Please be aware that the photometric system for the G band in Gaia DR2 is different from the photometric system as used in Gaia DR1.
  • GBP and GRP magnitudes for more than 1.38 billion sources, with precisions varying from a few milli-mag at the bright (G<13) end to around 200 milli-mag at G=20.
  • Full passband definitions for G, BP and RP. These passbands are now available for download.
  • Epoch astrometry for 14,099 known solar system objects based on more than 1.5 million CCD observations. 96% of the along-scan (AL) residuals are in the range -5 to 5 mas, and 52% of the AL residuals are in the range of -1 to 1 mas. The transit observations are part of Gaia DR2 and have also been delivered to the Minor Planet Center (MPC).
  • Subject to limitations (see below) the effective temperatures Teff for more than 161 million sources brighter than 17th magnitude with effective temperatures in the range 3000 to 10,000 K. For a subset of about 87 million sources also the line-of-sight extinction AG and reddening E(BP-RP) are given and for a part of this subset (around 76 million sources) the luminosity and radius are available as well.
  • Classifications for more than 550,000 variable sources consisting of Cepheids, RR Lyrae, Mira and Semi-Regular Candidates as well as High-Amplitude Delta Scuti, BY Draconis candidates, SX Phoenicis Candidates and short time scale phenomena.
  • Planned cross-matches between Gaia DR2 sources on the one hand and Hipparcos-2, Tycho-2, 2MASS PSC, SDSS DR9, Pan-STARRS1, GSC2.3, PPM-XL, AllWISE, and URAT-1 data on the other hand.

There’s much more to Gaia than pictures, but here’s a map of the stars in our galaxy to give you an idea:

I remember first hearing about Gaia about 17 years ago when I was on a PPARC advisory panel and was immediately amazed  by the ambition of its objectives. As I mentioned above, Gaia is a global space astrometry mission, which will make the largest, most precise three-dimensional map of our Galaxy by surveying more than a billion stars. In some sense Gaia is the descendant of the Hipparcos mission launched in 1989, but it’s very much more than that. Gaia monitors each of its target stars about 70 times over a five-year period. It is expected to discover hundreds of thousands of new celestial objects, such as extra-solar planets and brown dwarfs, and observe hundreds of thousands of asteroids within our own Solar System. The mission is also expected to yield a wide variety of other benefits, including new tests of the  General Theory of Relativity.

For the brighter objects, i.e. those brighter than magnitude 15, Gaia  measures their positions to an accuracy of 24 microarcseconds, comparable to measuring the diameter of a human hair at a distance of 1000 km. Distances of relatively nearby stars are measured to an accuracy of 0.001%. Even stars near the Galactic Centre, some 30,000 light-years away, have their distances measured to within an accuracy of 20%.

It’s an astonishing mission that will leave an unbelievably rich legacy not only for the astronomers working on the front-line operations of Gaia but for generations to come.

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Memories of Humph

Posted in Jazz, Politics with tags , , on April 25, 2018 by telescoper

Humphrey Lyttelton, who died on 25th April 2008

Today is a rather sad anniversary: it’s ten years to the day since the death of Humphrey Lyttelton. I posted a tribute to him here and have posted quite a few other items about Humph and his band (under this tag), including one that included this picture of my Dad (who died in 2007 and who was a lifelong fan of Humph) playing the drums with him in a pub in Newcastle:

I was reminded about Humph by the ongoing saga of this the UK Government’s scandalous treatment of the Windrush generation, who came to Britain from the West Indies in the late 1940s and early 1950s. Their arrival coincided with the rise of Humph’s career as a musician and bandleader; he started recording a long series of 78s for the Parlophone labour in late 1949. In the mid-50s Humph formed what he called his Paseo Jazz Band with a group of London-based Caribbean musicians and they made some lovely records, complete with infectious calypso rhythms. In his first volume of autobiography, I Play As I Please Humph wrote very frankly about the racism faced by these black musicians, even from Jazz fans. It is indeed hard to see how anyone can be a jazz fan and have such attitudes, but some people seem to manage it. Humph was one of those who welcomed this generation of immigrants with open arms, and in his book he argued strongly against racial prejudice. If he’d been alive today he would have had no time for the xenophobic attitudes espoused by the current Government that have created such a hostile environment in the UK for anyone deemed to be foreign.

Anyway, some time ago I came across this film from 1950 showing Humph’s band in full swing (playing King Oliver’s Snake Rag, a tune guaranteed to fill the dance floor) at a downstairs club on Oxford Street in London. Jazz was very much for dancing to in those days, and the opportunity to let the hair down and burn some leather on the floor must have been a welcome distraction from post-war austerity. As the voice-over says, the drinks on sale in the club were non-alcoholic, but I’m told a van used to turn up and sell beer surreptitiously outside…

Rest in peace, Humph. We still miss you.

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Winning start to the season for Glamorgan

Posted in Cricket with tags , , , , , , on April 24, 2018 by telescoper

Well, I’m still in the office after a very busy afternoon of pre-examination stuff. It’s raining very heavily outside so I thought I’d dash off a post while I hope for the deluge to abate.

I was busy yesterday afternoon too, but during the meeting I was at I kept a tab on my web browser open to follow the final afternoon of Glamorgan’s first County Championship match of the season against Gloucestershire, over the River Severn in Bristol. When I got back to the office I continued to follow on the Radio. It turned out to be quite an exciting finish.

Having bowled out Gloucestershire for 236 in the first innings and scored 522 for 9 declared in reply, Glamorgan then had Gloucestershire in deep trouble at 133 for 5 going into the final day. An innings victory for Glamorgan looked a racing certainty but Gloucestershire’s lower-order played very well indeed, not only defending capably but scoring runs reasonably quickly (no doubt against very attacking fields); for the first three days the scoring rate was less than three an over, but that’s pretty typical for the county championship. When Gloucestershire were finally all out they had reached 372, requiring Glamorgan to bat again.

The target of 83 to win off 21 overs looks on paper to have been easy, but the weather was drawing in and there was no chance of all 21 overs actually being bowled. In the gathering gloom, Glamorgan’s batsmen decided to come out with all guns blazing to try to rattle the runs off before bad light stopped play. Selman and Murphy put on an opening partnership of 50 off just 7 overs, but then a flurry of wickets fell and suddenly it was 67 for 4. Eventually, though, Glamorgan recovered their composure and Aneurin Donald finished the game by hitting Worrall for six. Glamorgan won by six wickets.

Anyway, that was a nice start to the County Championship season for Glamorgan – they didn’t play last weekend, which was the first round of matches for most other clubs. Their next game is away to Middlesex (at Lord’s). I would like to have gone to at least one day of that, but unfortunately I’m busy this weekend with other things. Shaun Marsh and David Lloyd both scored centuries in his match, and Marchant de Lange took five wickets in the first innings as well as scoring 50 not out. Hopefully they will take strength from that performance and improve their County Championship position compared to last year.

Now, it’s stopped raining so I can go home. Goodnight all!

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Project Work

Posted in Biographical, Education, mathematics with tags , , , , , on April 23, 2018 by telescoper

I’m progressively clearing out stuff from my office prior to the big move to Ireland. This lunchtime I opened one old box file and found my undergraduate project. This was quite an unusual thing at the time as I did Theoretical Physics in Part II (my final year) of Natural Sciences at Cambridge, which normally meant no project but an extra examination paper called Paper 5. As a member of a small minority of Theoretical Physics students who wanted to do theory projects, I was allowed to submit this in place of half of Paper 5…

The problem was to write a computer program that could solve the equations describing the action of a laser, starting with the case of a single-mode laser as shown in the diagram below that I constructed using a sophisticated computer graphics package:

The above system is described by a set of six simultaneous first-order ordinary differential equations, which are of relatively simple form to look at but not so easy to solve numerically because the equations are stiff (i.e. they involve exponential decays or growths with very different time constants). I got around this by using a technique called Gear’s method. There wasn’t an internet in those days so I had to find out about the numerical approach by trawling through books in the library.

The code I wrote – in Fortran 77 – was run on a mainframe, and the terminal had no graphics capability so I had to check the results as a list of numbers before sending the results to a printer and wait for the output to be delivered some time later. Anyway, I got the code to work and ended up with a good mark that helped me get a place to do a PhD.

The sobering thought, though, is that I reckon a decent undergraduate physics student nowadays could probably do all the work I did for my project in a few hours using Python….

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Cardiff Bound

Posted in Biographical, Cardiff, Maynooth with tags , , , on April 21, 2018 by telescoper

Just time for a quick post using the airport WIFI to fill some time before my flight leaves from Dublin Airport. Once again on a Saturday morning I was up at 5am to get the 6am bus here from Maynooth. The journey back to Cardiff is far from arduous, but I won’t be sorry when I won’t have to do it every week. Fortunately, term is coming to an end and after teaching finishes I won’t be dictated to by the timetables of Cardiff and Maynooth Universities. And after July I won’t have to do the trip at all!

This morning a large group – I believe the correct collective noun is a murder – of crows gathered to give the bus a sendoff. I did think of Hitchcock’s The Birds but the birds in this case were more interested in rummaging through the rubbish bin than attacking any of us waiting for the bus. Incidentally, it was the anniversary of Daphne Du Maurier’s death on 19th April; she wrote the short story on which that film was based.

Anyway, it’s a lovely sunny morning. Yesterday was a nice day too, both in terms of weather and other things. In the afternoon there was a staff barbecue and an awards ceremony at Maynooth University. There was a big crowd already there when I arrived, a bit late because I’d been at a seminar. Standing at the back I couldn’t really hear the speeches. I didn’t win any awards, of course, but I did get a glass of wine and a beefburger.

On my way home I bumped into the President, Philip Nolan, who is the equivalent of a Vice-Chancellor. To my surprise he mentioned a point I had raised in a recent Faculty meeting about the possibility of Maynooth signing up to the San Francisco Declaration on Research Assessment (DORA). To my even greater surprise he went on to say that this was going to be in the University’s strategic plan. Good news!

Anyway, I’d better make my way to the gate.  Have a nice day!

 

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