## The Grand Slam

Posted in Rugby with tags , , , , on March 18, 2023 by telescoper

Just time for a quick post to mark the occasion of the end of the 2023 Six Nations competition, Ireland’s victory over England in Dublin this evening making it a triumphant Grand Slam for the men in green. It wasn’t a great game, to be honest. I think the weight of expectation on the Irish players got to them a bit in the first half, and they made too many handling errors. Ireland also missed a couple of key players after the bruising game against Scotland last week. I half-wondered whether they might fall at the last fence. England couldn’t possibly have played as badly as they did against France last weekend, when they lost 53-10. I dread to think what the mood would have been like around town if Ireland hadn’t won.

In the end, though it was a relatively comfortable victory, with England’s only try, coming very late, was little more than a consolation and was quickly followed by a reply at the other end. In the closing stages The Fields of Athenry was ringing out around the stadium at Lansdowne Road, a celebration only marred by Johnny Sexton having to go off injured in his last-ever Six Nations match. What a career he has had!

Congratulations to Ireland on a magnificent achievement, thoroughly well deserved. This is an excellent team. Bring on the World Cup! (Though with home advantage, the excellent French side who came second in this year’s Six Nations, will be hard to beat.)

I remember Ireland doing the Grand Slam in 2009 by winning their last game against Wales in Cardiff. Judging by the celebrations after that, Dublin will be buzzing tonight, with relief as well as joy!

## Ireland v France in Dublin

Posted in Rugby with tags , , , on February 11, 2023 by telescoper

I forgot to mention in this morning’s post that I walked past the above bus on the way to last night’s concert. It is evidently the official transport of the French rugby team who played Ireland today in the Six Nations this afternoon. I didn’t spot any of the French players at the concert, although I did help a couple of friendly France supporters with directions en route.

As expected, it was a cracking match between two excellent teams, a real heavyweight contest, with no quarter asked and non given. But, in the end, Ireland ran out convincing winners by 32-19 despite the absence of a number of first choice players. It was a very impressive performance from Ireland and the best game of rugby I’ve seen for a very long time.

## R.I.P. David Duckham (1946-2023)

Posted in Rugby with tags , , , on January 11, 2023 by telescoper

I seem to be devoting a lot of this blog to R.I.P. posts these days but sadly I have to do it again because former England rugby union international David Duckham has passed away at the age of 76. With great poise and balance as well as a blistering turn of pace, Duckham was an oustanding player on the wing and his international career would have been even more memorable had he had better players around; the England team of the early 70s was rather weak, actually finishing bottom of the Five Nations in four of the seven years he played.

David Duckham was one of only three England players who made it into the Barbarians side that played New Zealand in Cardiff on 27th January 1973, a match many regard as the greatest game of rugby ever played. Can that really have been 50 years ago?

The Barbarians’ side on that day was packed with Welsh legends and the Welsh supporters after the game changed Duckham’s name from “David” to “Dai” because he was “good enough to be Welsh”. I regarded that great Welsh rugby team of the 70s in exactly the same light as the great Brazilian football team of the same period.

I remember commentator Cliff Morgan during that game describing Duckham as “a man who can really motor” and indeed he could. Here’s a short clip* of him in action:

I’m not sure why New Zealand scrum-half Sid Going decided to kick after controlling the scrum so well with all the Barbarians pack committed and knowing that the ball would probably end up in the hands of JPR Williams, a man who could very quickly turn defence into attack. On this occasion, however, Duckham was already coming in off his wing, so JPR just slipped him the ball and off he went in thrilling fashion. That amazing dummy even fooled the cameraman who nearly let Duckham go out of shot as he scythed through the All Blacks until stopped by Sid Going. Brilliant stuff.

R.I.P. David Duckham (1946-2023)

*Not sure why it won’t embed properly but you’ll just have to click on the link!

## R.I.P. Pelé

Posted in Football with tags , on December 29, 2022 by telescoper

The sad news broke tonight that Edson Arantes do Nascimento, best known to the world as Pelé, has passed away at the age of 82. It’s never easy to come to terms with the loss of a sporting legend, especially one who was a boyhood hero, and news of his death brought back a flood of childhood memories. I am old enough to remember watching the great Brazilian team of the 1970 World Cup finals that included the likes of Jairzinho, Rivellino, and Carlos Alberto, to name but three, which I think was the finest collection of players ever to grace a football field. It says something for the stature of Pelé that he stood out even among that remarkable side. As well as being outrageously skilful, Pelé had a great footballing brain, which manifested itself as a wonderful positional sense and great tactical awareness. Although by no means a tall man – he was 5ft 8 – he was also superb in the air.

After Argentina’s win in the recent World Cup in Qatar many people were quick to dub Lionel Messi the greatest footballer of all time. With no disrespect to Messi, I think the greatest player of all time is unquestionably Pelé, not least because he had far less protection from referees at the time than modern players do. Pelé may have played his football in a very different era, but his influence on the game was, and remains, incalculable. He was a legend.

R.I.P. Pelé (1940-2022)

## The Physics of the Pole Vault Revisited

Posted in Sport, The Universe and Stuff with tags , , , on November 29, 2022 by telescoper

In yesterday’s Mechanics lecture I decided to illustrate the use of energy conservation arguments with an application to the pole vault. I have done this a few times and indeed wrote a blog post about it some years ago. At the time I wrote that post however the world record for the pole vault was held by the legendary Ukrainian athlete Sergey Bubka at a height of 6.14m which he achieved in 1994. That record stood for almost 20 years but has since been broken several times, and is now held by Armand Duplantis at a height of 6.21m.

Here he is breaking the record on July 24th 2022 in Eugene, Oregon:

He seemed to clear that height quite comfortably, actually, and he’s only 23 years old, so I dare say he’ll break quite a few more records in his time but the fact that world record has only increased by 7cm in almost 30 years tells you that the elite pole vaulters are working at the limits of what the human body can achieve. A little bit of first-year physics will convince you why.

Basically, the pole is a device that converts the horizontal kinetic energy of the vaulter $\frac{1}{2} m v^2$,  as he/she runs in, to the gravitational potential energy $m g h$ acquired at the apex of his/her  vertical motion, i.e. at the top of the vault.

Now assume that the approach is at the speed of a sprinter, i.e. about $10 ms^{-1}$, and work out the height $h = v^2/2g$ that the vaulter can gain if the kinetic energy is converted with 100% efficiency. Since $g = 9.8 \, ms^{-2}$ the answer to that little sum turns out to be about 5 metres.

This suggests that  6.21 metres should not just be at, but beyond, the limit of a human vaulter,  unless the pole were super-elastic. However, there are two things that help. The first is that the centre of mass of the combined vaulter-plus-pole does not start at ground level; it is at a height of a bit less than 1m for an an average-sized person.  Nor does the centre of mass of the vaulter-pole combination reach 6.21 metres.

The pole does not go over the bar, but it’s pretty light so that probably doesn’t make much difference. However, the centre of mass of the vaulter actually does not actually pass over the bar.  That  doesn’t happen in the high jump, either. Owing to the flexibility of the jumper’s back the arc is such that the centre of mass remains under the bar while the different parts of the jumper’s body go over it.

Moreover, it’s not just the kinetic energy related to the horizontal motion of the vaulter that’s involved. A human can in fact jump vertically from a standing position using elastic energy stored in muscles. In fact the world record for the standing high jump is an astonishing 1.9m. In the context of the pole vault it seems likely to me that this accounts for at least a few tens of centimetres.

Despite these complications, it is clear that pole vaulters are remarkably efficient athletes. And not a little brave either – as someone who is scared of heights I can tell you that I’d be absolutely terrified being shot up to 6.21 metres on the end of  a bendy stick, even with something soft to land on!

## Rainy Season

Posted in Biographical, Cricket, Irish Language with tags , , , , on September 30, 2022 by telescoper

Yesterday saw the end of this year’s County Championship cricket season*, which many people regard as the official end of summer. As if to prove the point today, strong westerly winds have brought a deluge of rain all morning.

While I was waiting for my coffee to brew before venturing out into the rain this morning I was thinking about some idiomatic expressions for heavy rain. The most familiar one in English is Raining Cats and Dogs which, it appears, originated in a poem by Jonathan Swift that ends with the lines:

Drowned puppies, stinking sprats, all drenched in mud,
Dead cats and turnip tops come tumbling down the flood.

My French teacher at school taught me the memorable if slightly indelicate Il pleut comme vache qui pisse, although there are other French expressions involving, among other things nails, frogs and halberds.

One of my favourites is the Welsh Mae hi’n bwrw hen wragedd a ffyn which means, bizarrely, “It’s raining old ladies and sticks”. There is also Mae hi’n bwrw cyllyll a ffyrc – “It’s raining knives and forks”.

Related idiomatic expressions in Irish are constructed differently. There isn’t a transitive verb meaning “to rain” so there is no grammatical way to say “it rains something”. The way around this is to use a different verb to represent, e.g., throwing. For example Tá sé ag caitheamh sceana gréasaí which means “It’s throwing cobblers’ knives”.

Talking (of) cobblers, I note that in Danish there is Det regner skomagerdrenge – “It’s raining shoemakers’ apprentices” and in Germany Es regnet Schusterjungs – “It’s raining cobblers’ boys”.

Among the other strange expressions in other languages are Está chovendo a barba de sapo (Portuguese for “It’s raining toads’ beards”), Пада киша уби миша (Serbian for “It’s raining and killing mice”),  Det regner trollkjerringer (Norwegian for “It’s raining female trolls”) and Estan lloviendo hasta maridos (Spanish for “It is even raining husbands”).

No sign of any husbands outside right now so I’ll get back to work. My PhD student is giving a seminar this afternoon so I have to think of some difficult questions to ask her! (Joking).

*For the record I should mention that Glamorgan drew their last game of the County Championship against Sussex (at Hove) and thus finished in 3rd place in Division 2. They might have beaten Middlesex to second place had they won and Middlesex lost their final matches but in the end both games were high scoring draws. Glamorgan lost to Middlesex in feeble style a couple of weeks ago so I think it was fair outcome.

## The ABC of A-levels

Posted in Biographical, Education, Rugby with tags , , , on August 25, 2022 by telescoper

Yesterday I was having a bit of a clear-out of my office at home ahead of the new teaching term when I came across the above clipping at the back of a box of old papers. It’s from the Newcastle Evening Chronicle in 1981 and it shows the number of A-levels passed that summer by pupils at the Royal Grammar School in Newcastle, which I went to.

I don’t know why I’ve kept this for so long, neither do I know why the local paper felt important to list this information. It probably isn’t allowed to publish such things these days owing to Data Protection regulations but it did so routinely back then. I think it’s OK to publish it now because it has been in the public domain, technically speaking, for over 40 years. The Chronicle also published O-level passes with names, and I have the list with me in it from 1979.

A few things struck me about this list. One is that, while I can put faces to many of the names, there are many to which I can not. Indeed some of the names don’t ring any bells at all. I’m sure I’ve been forgotten by most people in the list too! When I arrived at the school in 1974 I was assigned to a “House” called Eldon along with about 30 other boys. In the first year we were placed at desks in our classroom in alphabetical order. Obviously the first people I got to know were those sitting in adjacent desks. It’s interesting that seven years on, the two names preceding mine in the list above were also in Eldon and had been sitting next to me on the very first day I arrived and they are among the few people from RGS that I am still in regular contact with.

The Sixth Form (two years, “Lower 6th” and “Upper Sixth” to coincide with the length of the A-level course) was divided into Arts and Sciences. The Arts are listed first in alphabetical order, then the Sciences. I was in the latter group. My 4 A-levels were Mathematics, Further Mathematics, Physics & Chemistry. I also did two special papers, in Physics and Chemistry. After A-levels, along with about 20 of the people on the above list, I stayed on for a “7th term” to do the Cambridge Entrance Examination, and the rest is history.

I also note that very few of us had only a single first initial like me. That’s a Coles family trait. My Dad always said that you only use one name so why have extras?

One final comment. Near the bottom of the list you will see the name “J M Webb”. That name is not to do with the James Webb of Space Telescope fame, but Jonathan Webb did go on to play Rugby for England. I didn’t know him well at school because, as well as being separated by alphabetical considerations, he was in a different House (Horsley if I remember correctly).

## New Away Kit for Newcastle United!

Posted in Football on July 30, 2022 by telescoper

With the start of the new English Premiership football season less than a week away, I notice that Newcastle United’s new away strip accurately reflects the values and traditions of the club’s owners, the Saudi Royal Family:

Perhaps it’s a warning to the players not to lose their heads under pressure?

## GAA Clustering

Posted in Bad Statistics, GAA, The Universe and Stuff with tags , , , , , , on July 25, 2022 by telescoper

The above picture was doing the rounds on Twitter yesterday ahead of this year’s All-Ireland Football Final at Croke Park (won by favourites Kerry despite a valiant effort from Galway, who led for much of the game and didn’t play at all like underdogs).

The picture above shows the distribution of Gaelic Athletics Association (GAA) grounds around Ireland. In case you didn’t know, Hurling and Gaelic Football are played on the same pitch with the same goals and markings on the field. First thing you notice is that the grounds are plentiful! Obviously the distribution is clustered around major population centres – Dublin, Cork, Limerick and Galway are particularly clear – but other than that the distribution is quite uniform, though in less populated areas the grounds tend to be less densely packed.

The eye is also drawn to filamentary features, probably related to major arterial roads. People need to be able to get to the grounds, after all. Or am I reading too much into these apparent structures? The eye is notoriously keen to see patterns where none really exist, a point I’ve made repeatedly on this blog in the context of galaxy clustering.

The statistical description of clustered point patterns is a fascinating subject, because it makes contact with the way in which our eyes and brain perceive pattern. I’ve spent a large part of my research career trying to figure out efficient ways of quantifying pattern in an objective way and I can tell you it’s not easy, especially when the data are prone to systematic errors and glitches. I can only touch on the subject here, but to see what I am talking about look at the two patterns below:

You will have to take my word for it that one of these is a realization of a two-dimensional Poisson point process and the other contains correlations between the points. One therefore has a real pattern to it, and one is a realization of a completely unstructured random process.

I show this example in popular talks and get the audience to vote on which one is the random one. The vast majority usually think that the one on the right that  is random and the one on the left is the one with structure to it. It is not hard to see why. The right-hand pattern is very smooth (what one would naively expect for a constant probability of finding a point at any position in the two-dimensional space) , whereas the left-hand one seems to offer a profusion of linear, filamentary features and densely concentrated clusters.

In fact, it’s the picture on the left that was generated by a Poisson process using a  Monte Carlo random number generator. All the structure that is visually apparent is imposed by our own sensory apparatus, which has evolved to be so good at discerning patterns that it finds them when they’re not even there!

The right-hand process is also generated by a Monte Carlo technique, but the algorithm is more complicated. In this case the presence of a point at some location suppresses the probability of having other points in the vicinity. Each event has a zone of avoidance around it; the points are therefore anticorrelated. The result of this is that the pattern is much smoother than a truly random process should be. In fact, this simulation has nothing to do with galaxy clustering really. The algorithm used to generate it was meant to mimic the behaviour of glow-worms which tend to eat each other if they get  too close. That’s why they spread themselves out in space more uniformly than in the random pattern.

Incidentally, I got both pictures from Stephen Jay Gould’s collection of essays Bully for Brontosaurus and used them, with appropriate credit and copyright permission, in my own book From Cosmos to Chaos.

The tendency to find things that are not there is quite well known to astronomers. The constellations which we all recognize so easily are not physical associations of stars, but are just chance alignments on the sky of things at vastly different distances in space. That is not to say that they are random, but the pattern they form is not caused by direct correlations between the stars. Galaxies form real three-dimensional physical associations through their direct gravitational effect on one another.

People are actually pretty hopeless at understanding what “really” random processes look like, probably because the word random is used so often in very imprecise ways and they don’t know what it means in a specific context like this.  The point about random processes, even simpler ones like repeated tossing of a coin, is that coincidences happen much more frequently than one might suppose.

I suppose there is an evolutionary reason why our brains like to impose order on things in a general way. More specifically scientists often use perceived patterns in order to construct hypotheses. However these hypotheses must be tested objectively and often the initial impressions turn out to be figments of the imagination, like the canals on Mars.

## The All-Ireland Senior Hurling Championship Final

Posted in GAA with tags , , , , on July 17, 2022 by telescoper

Today’s the day! Kilkenny v Limerick from Croke Park for the All-Ireland Senior Hurling Championship Final. Over 80,000 spectators will watch this in Croke Park as well as millions around the world. Let’s hope it’s a good one.

Half Time: Kilkenny 0-16 Limerick 1-17

Reasonably comfortable for Limerick who have been ahead since the 2nd minute. Can Kilkenny fight back in the 2nd half? I’m glad for the sake of the players that it’s “only” 27 °C at Croke Park this afternoon and not even hotter!

Full Time: Kilkenny 2-26 Limerick 1-31

So Limerick have won their 3rd All-Ireland Championship in a row by just two points.

Kilkenny scored two goals in the second half to level the scores at which point Limerick seemed a bit ragged, but Limerick pulled themselves together held on for the victory in what was a thrilling second half. Hurling is not a game for faint hearts but alongside the physicality of the game there is an astonishing level skill: the accuracy of the long-range shooting is quite phenomenal.

Congratulations to Limerick, deserved winners, and commiserations to Kilkenny who made a fantastic game of it. What a magnificent final.