Archive for July, 2022

The Soundtrack of Summer

Posted in Biographical, Music, Television on July 31, 2022 by telescoper

I just heard of the death on 4th July at the age of 82 of Austrian actor Robert Hoffmann who I remember very well for his role as Robinson Crusoe in the TV series The Adventures of Robinson Crusoe. That series was first broadcast in 1964 and was repeated frequently over the years, especially during the long summer holidays. I loved the theme music when I was a child and it is now redolent with nostalgia, forever associated with memories of childhood summers before life got complicated. I’m sure that is also the case for many others, so perhaps you won’t mind wandering off down memory lane with this:

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?

PhD Stipends in Ireland

Posted in Education, Maynooth with tags , on July 29, 2022 by telescoper

Some time ago I posted an item about the planned introduction of a higher PhD stipend (€28K) for a small number of research students in Ireland. It being obvious that he current level of PhD stipends (e.g. €18.5K per annum for IRC-funded studentships) being far too low, my main comment on that was that if that level is a fair level for a PhD then all PhD students should get it.

Now there’s an open letter going around signed by over 400 PhD students arguing for an uplift in their stipends. I support this wholeheartedly. I’m surprised there aren’t even more signatories than that, actually, but I think they have now opened it up again and let others sign it who didn’t know about it. I encourage all PhD students reading this to sign it

With inflation rampant at over 9%, even the IRC level of stipend is difficult for a student to live on (especially in the Greater Dublin area) yet many receive even less than that. Maynooth University, for example, funds many of its PhD students at the paltry level of €10K per annum. This is completely impossible to live on and it forces recipients to undertake large amounts of tutoring or other work (including bar work and retail) in order to get by financially. In my opinion stipends paid at this level are simply exploitative. I have argued repeatedly, but without success, for these to be scrapped.

The deliberate impoverishment of PhD students exists in order to force them to undertake extensive and poorly paid teaching duties because there aren’t enough teaching faculty to cover what is required. That situation is a direct result of the chronic underfunding of higher education in Ireland. Universities will argue that they don’t have any choice, but that doesn’t make the situation is acceptable.

Third level institutions don’t care. If they did they’d do something about it. Maynooth University ran up a surplus of €13.2M during the first year of the pandemic largely by exploiting unpaid overtime by lecturers and tutors, the latter predominantly PhD students. It could be used to provide emergency relief for PhD students but I bet it won’t be. In fact has anyone working at Maynooth received anything at all in return for generating this surplus?

It is of course good for a research student to get some teaching experience during their PhD but this should be on a voluntary basis. A PhD student who chooses to teach will probably do a better job than one who is forced to do it in order to pay the rent. My basic point, though, is that a full-time research student should be funded to do research full time, and it is grossly unfair to pay them too little for this to be possible.

The Kindness of Faces

Posted in Biographical, Cardiff, Film, Television with tags , on July 28, 2022 by telescoper
Bernard Cribbins

Another bit of sad news arrived today. The much-loved character actor, singer and comedian Bernard Cribbins has passed away at the age of 93. He was a remarkably versatile performer who appeared in scores of films and TV programmes over the years, including numerous stints on Jackanory, on which he revealed himself to be a superb reader of children’s stories, and providing all the voices for the TV series of The Wombles. Rest in peace, Bernard Cribbins (1928-2022).

Reading about his death and looking at pictures of him taken during his long and varied career got me thinking about something I’ve wondered about many times over the years, namely what is it about certain faces that makes them appear kind?

I know it’s a subjective judgment whether or not someone has a kind face but it does seem that many people do agree on it. I certainly think Bernard Cribbins had a kind face and it stayed with him all through his long career. Among actors, Tom Hanks is another prominent example. His face has clearly influenced the roles he has been cast in. No doubt you can think of others.

This is not just about showbusiness of course. I have met many people in the course of my life who have what I’d describe as kind faces, but what exactly is it about their faces that makes them so? It seems to involve a certain shape – softer features perhaps, not too angular – with rounder eyes and an easy smile. Other than those vague considerations I really don’t know. I have looked back through the personal library of kind faces in my memory and they don’t really have much in common at all. Whatever it is, it’s not the same thing that makes a face handsome or beautiful or sexy, though those are also of course subjective. For me there has to be a hint of danger for someone to be very sexy; a kind face is perhaps too bland.

Anyway, I remember many years ago talking with a (female) graduate student in a pub in Cardiff about this subject. In fact we started talking about which men in the Department we thought were the most handsome – I’d better keep quiet about that bit – but got onto a more general discussion. She had – and presumably still has – what I’d call a kind face, and I told her so when the subject came up. She was very aware that people thought that too and wasn’t entirely pleased about it. She said her face made people assume she was extremely emphatic and proceed to burden her with their personal problems even if she didn’t know them very well. I’d never thought of that downside before then.

In Macbeth, Duncan says “There’s no art / to find the mind’s construction in the face”, and there’s no necessary connection between a kindly disposition and a kind face. No doubt there are successful criminals, con-artists and the like, who trade on their apparently kind faces to manipulate their victims. On the other hand, in a world that can be incomprehensibly cruel, it can be nice to see a kind face even if it’s just a superficial relief.

Any theories on what makes a kind face and/or other examples of people who have such please use through the box below.

R.I.P. James Lovelock (1919-2022)

Posted in Literature, The Universe and Stuff with tags , , on July 28, 2022 by telescoper

I heard this week of the death, on his 103rd birthday, of scientist and writer James Lovelock. He started out as a chemist but became what is now called an “independent scientist” and “futurist”. These terms are often applied to people who are simply cranks, but he wasn’t just that. Unorthodox he was, certainly, but there was depth to his thinking that mere cranks never reach.

James Lovelock was best known to me – and I suspect to many others – for his work on the Gaia Hypothesis, which is roughly speaking the idea that the system of life on Earth functions as a single organism that defines and maintains the conditions necessary for its own survival.

I’ve just had a rummage around my bookshelves and found my copy of his famous book on this topic, which I bought and read back in the 80s. The first edition was published in 1979, but the one I bought was the version published in 1987 after the topic had been featured on the BBC TV programme, Horizon:

The Gaia hypothesis has been widely criticized by biologists and ecologists but I remember finding it a very thought-provoking book, though I interpreted more as a metaphor than a mechanism. At any rate it seems to me to be a useful counter to the extreme reductionism of many prominent life scientists. It’s also very well written and definitely worth reading over 40 years after it was written. James Lovelock was as inventive and ingenious a thinker as he was unorthodox.

Rest in peace, James Ephraim Lovelock (1919-2022).

A pretty simple thing…

Posted in History, The Universe and Stuff with tags , , , on July 27, 2022 by telescoper

In a state of not inconsiderable excitement, I showed the above picture (which appears in yesterday’s post) to a friend who shrugged and said “It doesn’t look like much..”. My response was “Well, you wouldn’t look like much at z=16.7…”

That reply was of course inspired by a famous exchange between Fred Hoyle and R.O. Redman recounted here:

Fred once started a talk by saying, ‘Oh, Ooh, basically a star is a pretty simple thing.’ And from the back of the room was heard the voice of R. O. Redman, saying, ‘Well, Fred, you’d look pretty simple too, from ten parsecs!

I’ve heard this story told by many people in different versions involving different characters, including Eddington, but I think it is generally accepted to have been between Hoyle and Redman, though this may well not have been the first comment of its type. If anyone knows any more please let me know!

Now a Galaxy at z>16?

Posted in The Universe and Stuff with tags , , , , , , on July 26, 2022 by telescoper

It’s less than a week since I posted an item about an object which is possibly the highest redshift galaxy ever observed (with z ~13) and now along comes a paper describing an object that may be of even higher redshift (with z~16.7). The abstract of the new paper – lead author of which is Callum Donnan of the University of Edinburgh – is here:

As with the previous object the redshift of this one is not obtained via spectroscopy (which usually involves the identification of spectral lines) but via fitting a spectral profile to photometric imaging data seen in different bands. The process for this galaxy is illustrated by this diagram from the paper:

There are 7 images along the top showing the source through various broad band filters. Suitably calibrated these can be converted to the flux measurements shown on the graph. Notice the first three images are significantly fainter than the others, so the first three points on the left of the graph are lower.

If this is a galaxy its spectrum is expected to possess a Lyman Break resulting from the fact that radiation of shorter wavelength than the Lyman Limit (912 Å) is absorbed by neutral gas surrounding the regions where stars are formed in the galaxy. In the rest frame of a galaxy this break is the ultraviolet region of the spectrum but because of the cosmological redshift it is observed in the infrared part of the spectrum for very distant galaxies. In this case the best fit is obtained if the break is positioned as shown, with the first three fainter points to the left of the break and the rest to the right. The break itself is straddled by two observational bands. Employing a number of different estimates the authors conclude that the redshift of this galaxy is z=16.7 or thereabouts.

There is no direct evidence for the sharp edge associated with the Lyman Break – and no spectral lines are observed either – so this all depends on the object being correctly identified as a high-redshift galaxy and not some other object at lower redshift. You have to assume this to get a redshift, but then all inferences are based on assumed models so there’s nothing unusual about this approach. The authors discuss other possibilities and conclude that there is no plausible alternative source. Take away the green template spectrum and you just see a spectrum that rises to a peak and falls again. The authors claim that there is no plausible low-redshift source with such a spectrum.

Anyway, here is a composite colour image of the source:

So is this now the earliest galaxy ever observed? And what object will I be asking this question about next week? One thing I can predict is that there are going to be many more such objects in the very near future!

GAA Clustering

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

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.

random or non-random?

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.

How to be a better PhD supervisor

Posted in Education with tags , , , on July 24, 2022 by telescoper

The text for this Sunday’s sermon is provided by a piece by a Danish PhD student called Rikke Plougmann in the latest Physics World entitled How to become a better supervisor. The article is quite interesting, though I was a bit alarmed by the first of the two paragraphs here:

While it certainly is “scary” I don’t think the “misconception” described in the first paragraph is “widespread”, or at least I sincerely hope it isn’t. I think any supervisor who behaves in such a way towards their research students shouldn’t be allowed to have any! Does your supervisor use “negative, condescending language”? If so I think you should get a new one!

Whether or not the first paragraph is accurate, the second definitely is. It is important for a supervisor (and the rest of a research group and the rest of a department and indeed the whole institution) to try their best to create a welcoming environment for all.

I have written several times on here about my own experiences as a PhD student, most recently here. I have written much less about my experiences as a supervisor. That’s partly because I don’t feel comfortable writing about what I think should really be confidential matters relating to PhD students and partly because each student-supervisor relationship is different.

I certainly don’t think I’m any sort of role model as a PhD supervisor. Among many other failings, I have let my students down at various times when I’ve been mentally unwell and/or when struggling with workload. But I’ve always tried to be friendly and supportive, and encouraged students to look after their work-life balance.

Other than that, it has always seemed to me that it is important for a supervisor to create a healthy working relationship. It’s not simply about training an early-career researcher. The fact of the matter is that when you take on a research student it’s because there is a project you think should be done but you’re not able to do it on your own. The student should realize that their work is not some sort of prolonged test but is highly valued as an essential contribution to a project. In other words, you need the student. I have known some supervisors to act as if they are doing students a favour by taking them on, when the reality is the other way round.

Another thing that I think a supervisor should do is make it clear that they do not have a monopoly on wisdom. Students should be encouraged to question what the supervisor suggests. I always feel I’m succeeding as a supervisor when a PhD student has the confidence to say something like “I thought about what you suggested and decided it wouldn’t work so I did this instead….”

Certainly, by the end of a PhD, the student should know more about the topic than their supervisor. At the beginning, though, the supervisor will know more and it is more of a teacher/pupil relationship then. Managing the transition from that to the equal partnership it should become is tricky as it depends on individual personalities, and it doesn’t always work out. That’s not always the fault of the supervisor. On the other hand, recognizing that’s where you should be headed is at least a start.

Above all, a supervisor should try the best they can to enable the student to enjoy their PhD. I certainly enjoyed mine and I am immensely grateful to my supervisor, who is alas no longer with us, for being so kind and supportive to me during the difficult times as well as giving me such interesting projects to do.

I’m aware this is all rather vague so I’d welcome any comments either from students about how they feel their supervisor might be better or from supervisors with advice to others. The box below is at your disposal.

Can SpaceX save Euclid?

Posted in The Universe and Stuff with tags , , , , , , , on July 23, 2022 by telescoper

A little over a month ago I posted a piece about the European Space Agency’s Euclid Mission which had been due to be launched in 2023 on a Soyuz ST 2-1b rocket. That no longer being possible because of Russian’s invasion of Ukraine, it seemed there would be a lengthy delay in the launch of Euclid, with late 2024 seeming the earliest feasible date for launch on the obvious alternative, the new Ariane 6.

I ended that piece with this:

It seems to me that the best hope for a resolution of this problem would be for ESA to permit the launch of Euclid using something other than Ariane 6, which means using a vehicle supplied by an independent commercial operator. I sincerely hope ESA is able to come up with an imaginative solution to this very serious problem.

In the Dark, 17th June

I have heard various rumours since then but yesterday I saw a piece by Paris-based astronomer Henry Joy McCracken (a famous name in Ireland) that reveals that a proposal is being actively investigated to launch Euclid on a Falcon 9 rocket operated by Elon Musk’s outfit SpaceX. If all goes well it might be possible to launch Euclid by the end of 2023, and at a fraction of the cost of the alternative Ariane 6-2.

Setting aside any personal opinions about Elon Musk, the Falcon 9 has proved to be very reliable, with the latest version having 110 out of 110 successful launches. Euclid will not be in an Earth orbit, like most of the satellites so far launched by SpaceX, but has to be delivered to the 2nd Lagrange Point, L2. That should not pose to much of a difficulty.

As far as I understand it the decision whether or not this is feasible will be taken later this year after extensive engineering tests, especially to see how Euclid can cope with the spectrum of vibrations generated by Falcon 9. There’s no guarantee this will work out but it might just save a lot of money and a lot of careers.