Though not as warm as it has been over the last few days, today still found Maynooth University Library Cat in need of a siesta. There aren’t many students around these days so he’s not disturbed by so many people wanting to pet him, and was sound asleep in a shady spot when I passed by this afternoon.
So here I am, back from a sweltering London to an almost-as-sweltering Maynooth. It was 33 degrees where I was in London yesterday and 30 degrees here in Maynooth earlier today, though it is now cooling slightly. Such a temperature is very unusual for this part of the world.
I was visiting South Kensington Technical College Imperial College for the last couple of days, working there. The surrounding area is of course looked very posh and looked resplendent in the summer sun. The area around the Museums was very busy with tourists, but it was nice to see people out and about, enjoying themselves in the sunshine.
I had hoped to publish a few OJAp papers on Wednesday morning before leaving for the airport. Unfortunately, as explained here, Crossref was offline all day Wednesday so I couldn’t do that. I caught up on Thursday morning by getting up before 6am and publishing 4 papers before heading down for a very nice hotel breakfast at 7am.
The journey to London on Wednesday didn’t get off to a very good start. My Aer Lingus flight from Dublin was delayed for an hour waiting the arrival of the aircraft from, of all places, Barcelona. Worse was to follow. I had decided to take the tried-and-trusted route from Heathrow Terminal 2 to South Kensington via the Piccadilly line. All went well until we approached Acton Town when the driver explain that there was a signal failure ahead at Covent Garden which meant the line in front was congested. Thereafter we inched along waiting for a succession of red lights to clear. The Piccadilly line has rather old trains without air conditioning, so it was like sitting in a slowly-moving sauna. Then we reached Turnham Green (where the train was not supposed to stop), and the driver opened the doors to give us a bit of fresh air. I spotted a District Line train to Upminster on the other side of the platform. That line does not go through Covent Garden so I dashed across and took it for the rest of the journey. I got to my hotel about 90 minutes later than planned, but not late enough to miss the welcome dinner at Ognisko, a very nice Polish restaurant.
Fortunately the hotel the Imperial staff had booked for me was very nice, and had good airconditioning. The rest of my stay was very pleasant, if intense. I even got back to Dublin on schedule yesterday evening and had time to go to the shops to get something for dinner last night and breakfast this morning.
Now that I’m back I have a report to write, but that can wait until tomorrow. Today I have to attend to a thirsty garden.
It’s Saturday morning again, so it’s time again for an update of papers published at the Open Journal of Astrophysics. Since the last update we have published seven new papers, which brings the number in Volume 8 (2025) up to 92, and the total so far published by OJAp up to 327.
This was a slightly strange week, starting with the fact that there were no new arXiv announcements on Monday 7th July because of the 4th July holiday in the USA on Friday so no papers were published that day. We were not able to publish any papers on Wednesday 9th July either because Crossref was offline for 24 hours that day while its data was migrated into the cloud. Our publishing process requires a live connection with Crossref to deposit metadata upon publication so we can’t publish while that service is down. Fortunately the update seems to have gone well and normal services resumed the following day. That partially accounts for the fact that four of this week’s papers were published on 10th July.
Anyway, The papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The first paper to report is “The Jackknife method as a new approach to validate strong lens mass models” by Shun Nishida & Masamune Oguri (Chiba University, Japan) , Yoshinobu Fudamoto (Steward Observatory, USA) and Ayari Kitamura (Tohoku University, Japan). This article, which is in the folder marked Cosmology and NonGalactic Astrophysics, describes and application of the Jackknife statistical resampling techique to gravitational lensing by removing lensed images and recalcualting the mass modelIt was published on Tuesday 8th July 2025. The overlay is here:
The officially-accepted version can be found on arXiv here.
The second paper is “Low redshift post-starburst galaxies host abundant HI reservoirs” by Sara Ellison (U. Victoria, Canada) and 10 others based in China, UK, Spain, USA and Canada. This one was also published oon Tuesday 8th July but in the folder Astrophysics of Galaxies. This paper uses 21cm observations of a sample of post-starburst galaxies, to show that they contain large reservoirs of neutral hydrogen. Here is the overlay:
You can find the final version of the manuscript on arXiv here.
Next one up, one of four published on Thursday 10th July, is “Predicting the number density of heavy seed massive black holes due to an intense Lyman-Werner field” by Hannah O’Brennan (Maynooth University, Ireland) and 7 others based in Ireland, USA and Italy. This paper presents an exploration of the scenario for black hole formation driven by Lyman-Werner photons (i.e. ultraviolet radiation in the range 11.2 to 13.6 eV). It is in the folder marked Cosmology and NonGalactic Astrophysics, and the overlay is here:
You can read the final accepted version on arXiv here.
The fourth paper this week, and the second published on 10th July, is “Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster” by Sam A. Usman (U. Chicago, USA) and 8 others based in the USA, Canada and Australia. This paper, which is in the folder Astrophysics of Galaxies, presents a detailed spectroscopic study of the chemical abundances in a Milky Way globular cluster ESO 280-SC06. The overlay is here:
The officially accepted version of the paper can be read here.
Next one up, also published on 10th July and also in the folder marked Astrophysics of Galaxies is “Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory” by Kabelo Tsiane (U. Michigan) and 9 others on behalf of the LSST Dark Energy Science Collaboration.
The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
The penultimate paper for this week, and the last of the batch published on 10th July, is “Systematically Measuring Ultra-Diffuse Galaxies. VIII. Misfits, Miscasts, and Miscreants” by Dennis Zaritsky, Richard Donnerstein, and Donghyeon J. Khim (Steward Observatory, U. Arizona, USA). This paper presents a morphological study of weird and wonderful galaxies as part of an effort to Systematically Measure Ultra-Diffuse Galaxies (the SMUDGes survey). It is in the folder marked Astrophysics of Galaxies. The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
The last article published this week is “Differential virial analysis: a new technique to determine the dynamical state of molecular clouds” by Mark R. Krumholz (ANU, Australia), Charles J. Lada (Harvard, USA) & Jan Forbrich (U. Herts, UK). This paper presents simple analytic models of supported and collapsing molecular clouds, tested using full 3D simulations and applied to observed clouds in Andromeda. It is in the folder marked Astrophysics of Galaxies and was published yesterday, i.e on Friday 11th July 2025. Here is the overlay
You can find the officially-accepted version on arXiv here.
And that’s all the papers for this week. I will, however, take this opportunity to mention that a while ago I was interviewed about the Open Journal of Astrophysics by Colin Stuart on behalf of the Foundational Questions Institute; the write-up of the interview can be found here.
I am going to be away until the weekend, and in any case I’ve been a bit overwhelmed with things over the last few days, so I’m going to take a short break from blogging. I’ll (probably) start again on Saturday. Normal service will be resumed as soon as possible.
At the Social Dinner at the EAS in Cork I got talking to a young postgraduate student while we were both in the queue for burgers. We chatted about the trials and tribulations of doing a PhD and about the general perception that it is a very hard slog. What I said was that, although at times it was definitely tough going, I had the best time of my life doing my PhD – well, DPhil actually – and I know many others who feel the same. I think you need work hard, but also enjoy it.
The main point is that a postgraduate research degree is very different from a programme of undergraduate study. For one thing, as a research student you are expected to work on your own a great deal of the time. That’s because nobody else will be doing precisely the same project so, although other students will help you out with some things, you’re not trying to solve the same problems as your peers as is the case with an undergraduate. Your supervisor will help you of course and make suggestions (of varying degrees of helpfulness), but a PhD is still a challenge that you have to meet on your own.
(Incidentally, I don’t think it is good supervisory practice to look over a research student’s shoulder all the time. It’s part of the purpose of a PhD that the student learns to go it alone. There is a balance of course, but my own supervisor was rather “hands off” and I regard that as the right way to supervise. I’ve always encouraged my own students to do things their own way rather than try to direct them too much.)
That loneliness is tough in itself, but there’s also the scary fact that you do not usually know whether your problem even has a solution, let alone whether you yourself can find it. There is no answer at the back of the book; if there were you would not be doing research. A good supervisor will suggest a project that he or she thinks is both interesting and feasible, but the expectation is that you will very quickly be in a position where you know more about that topic than your supervisor.
I think almost every research student goes through a phase in which they feel out of their depth. There are times when you get thoroughly stuck and you begin to think you will never crack it. Self-doubt, crisis of confidence, call it what you will, I think everyone who has done a postgraduate degree has experienced it. I certainly did. A year into my PhD I felt I was getting nowhere with the first problem I had been given to solve. All the other research students seemed much cleverer and more confident than me. Had I made a big mistake thinking I could this? I started to panic and began to think about what kind of job I should go into if I abandoned the idea of pursuing a career in research.
So why didn’t I quit? There were a number of factors, including the support and encouragement of my supervisor, staff and fellow students in the Astronomy Centre at Sussex, and the fact that I loved living in Brighton, but above all it was because I knew that I would feel frustrated for the rest of my life if I didn’t see it through. I’m a bit obsessive about things like that. I can never leave a crossword unfinished either…
What happened was that after some discussion with my supervisor I shelved that first troublesome problem and tried another, much easier one. I cracked that fairly quickly and it became my first proper publication. Moreover, thinking about that other problem revealed that there was a way to finesse the difficulty I had failed to overcome in the first project. I returned to the first project and this time saw it through to completion. With my supervisor’s help that became my second paper, published in 1987.
I know it’s wrong to draw inferences about other people from one’s own particular experiences, but I do feel that there are some general lessons. One is that if you are going to complete a research degree you have to have a sense of determination that borders on obsession. I was talking to a well-known physicist at a meeting not long ago and he told me that when he interviews prospective physics students he asks them “Can you live without physics?”. If the answer is “yes” then he tells them not to do a PhD. It’s not just a take-it-or-leave-it kind of job being a scientist. You have to immerse yourself in it and be prepared to put long hours in. When things are going well you will be so excited that you will find it as hard to stop as it is when you’re struggling. I’d imagine it is the just same for other disciplines.
The other, equally important, lesson to be learned is that it is essential to do other things as well as your research. Being “stuck” on a problem is part-and-parcel of mathematics or physics research, but sometimes battering your head against the same thing for days on end just makes it less and less likely you will crack it., I’m sure that I’m not the only physicist who has been unable to sleep for thinking about their research or who has spent hours sitting at their desk achieving nothing at all. The human brain is a wonderful thing, but it can get stuck in a rut. One way to avoid this happening is to have more than one thing to think about.
I’ve lost count of the number of times I’ve been stuck on the last clue in a crossword. What I always do in that situation is put it down and do something else for a bit. It could even be something as trivial as making a cup of tea, just as long as I don’t think about the clue at all while I’m doing it. Nearly always when I come back to it and look at it afresh I can solve it.
It can be difficult to force yourself to pause in this way, but I think it is essential to learn how to effect your own mental reboot. In the context of my actual research this involved simply turning to a different research problem, but I think the same purpose can be served in many other ways: taking a break, going for a walk, playing sport, listening to or playing music, reading poetry, doing a crossword, or even just taking time out to socialize with your friends. Back in Brighton in the 1980s I spent most evenings in bars and nightclubs. I never felt the slightest bit of guilt for having so much fun. Without the nightlife and all that I’m not sure I would have finished my PhD.
So, for what it’s worth, here is my advice to new or prospective postgraduate students: work hard but enjoy the challenges. Listen to advice from your supervisor, but remember that the PhD is your opportunity to establish your own identity as a researcher. So take ownership of it. And never feel guilty about establishing a proper work-life balance. Having more than one dimension to your life will not only improve your well-being but may also make you a better researcher.
This is a big weekend for fans of hurling, as we have reached the semi-final stage of the All Ireland Senior Hurling Championship. Yesterday Cork trounced Dublin by 7-26 to 2-21. I’ve never seen such a high scoring game at the top level, nor a margin as large as 20 points (a goal is worth 3 points)! Though not expected by many to progress, Dublin had deservedly beaten Limerick in the quarter-finals but they were never in the game yesterday.
The other semi-final takes place this afternoon at 4pm, and is between Kilkenny and Tipperary. Which of these will meet Cork in the Final? We’ll soon find out!
Update: it was another high scoring match, finishing Kilkenny 0-30 to Tipperary’s 4-20, so Tipperary won by 2 points (with a goal in the last minute). The All Ireland Final will therefore be between Cork and Tipperary.
Both semi-finals are held at Croke Park, as is the final. Many supporters come through Maynooth on their way to these matches, as we’re on the train line that goes into Dublin Connolly via Drumcondra (the nearest station to Croke Park). There is an arrangement by which supporters can park their cars at the GAA ground in Maynooth and take the train, as there is no chance of parking near Croke Park.
Yesterday evening I needed to do a quick trip to the shops and ran into a crowd of returning Cork supporters who had just arrived by train. Most fans were in very good humour (unsurprisingly) but a few were very much the worse for drink: one young lad had passed out on the footpath and concerned pedestrians called an ambulance; over the road at the bus terminus Gardaí were dealing with a drunk and aggressive person; and in Supervalu a hopelessly inebriated bloke staggered into the off-licence part to get more booze but ended up falling over and dropping the cans he had picked up, with one bursting and making a mess all over the floor.
Anyway, none of this is to do with the intended subject of this post. Cork’s victory yesterday reminded me of a little bit of hurling information that I found interesting, concerning the way to hold the hurley. Having been brought up on a different bat-and-ball game (cricket), I was surprised to learn that in hurling you are supposed to hold the bat the wrong way round! What I mean by that is that in cricket the batter holds the bat with the dominant hand at the bottom of the handle near the blade and the other hand at the top. For illustration, here’s a forward defensive shot played by a right-hander:
For illustration, on the left, there’s a forward defensive shot played by a right-hander. You can see the left hand at the top of the handle and the right hand near the bottom. Shots like this are played predominatly with the bat moving in a vertical plane, guided by the left hand with the right hand guiding the direction. A hook or pull shot is played with the same grip but swinging the bat across the body from right to left with more bottom hand.
When I was at school I tried batting left-handed in the nets. It was quite interesting. I found I could play defensive shots equally well that way as with my usual right-handed stance, but I couldn’t play attacking shots very well at all.
It’s the same arrangement in baseball (or rounders, as we call it on this side of the Atlantic). The batter will hold the bat with their weaker hand nearer the end of the handle, i.e. towards the thin end.
On the other hand (!), a hurler holds the hurley the other way round. On the right you can see a hurler at the ready position, with his right hand at the top of the handle and the left hand near the blade. When striking the sliotar (ball), the hands are moved closer together. Holding the end of the hurley in the dominant hand means that more strength can be applied when reaching away from the body with one hand, something that isn’t really done in cricket. The typical long-range strike of the sliotar is rather like a hook shot in cricket, except it’s played the opposite way across the body.
Here’s a video:
This seems very unnatural if you have been brought up to use the opposite basic grip, which explains why so many struggled even to hit the sliotar at the practice at the EAS Social Dinner in Cork a couple of weeks ago. In Ireland, however, kids learn to play hurling when they’re still in kindergarten so this is instilled at a very early age.
It’s Saturday so, once again, it’s time for the weekly update of papers published at the Open Journal of Astrophysics. Since the last update we have published three new papers, which brings the number in Volume 8 (2025) up to 85, and the total so far published by OJAp up to 320.
The three papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The first paper to report is “Stellar reddening map from DESI imaging and spectroscopy” by Rongpu Zhou (Lawrence Berkeley National Laboratory, USA) and an international case of 56 others too numerous to mention individually. This paper was published on 1st July 2025 in the folder marked Astrophysics of Galaxies. It describes maps of stellar reddening by Galactic dust inferred from observations obtained using the Dark Energy Spectroscopic Instrument, and a comparison with previous such maps. The overlay is here:
You can find the final, accepted, version on arXiv here.
Next one up is “On inertial forces (indirect terms) in problems with a central body” by Aurélien Crida (Université Côte d’Azur, France) and 17 others – again too numerous to be listed individually – based in France, Italy, Germany, Mexico and the USA. This paper discusses the indirect terms that arise the Newtonian dynamics of multi-body systems dominated by a central massive body, upon which other bodies exert a gravitational pull, when the massive body is treated as the origin of the coordinate system. This one, also published on July 1st 2025, is in the folder marked Earth and Planetary Astrophysics.
The overlay is here:
You can find the officially accepted version on arXiv here.
The last paper of this batch is “Stellar ejection velocities from the binary supernova scenario: A comparison across population synthesis codes” by Tom Wagg (U. Washington, USA), David D. Hendriks (U. Surrey, UK), Mathieu Renzo (U. Arizona, USA) and Katelyn Breivik (Carnegie Mellon U., USA). It was published on July 2nd 2025 in the folder Solar and Stellar Astrophysics and it presents comparison of the ejection velocities of stars ejected from binary systems by supernova explosions predicted in three different population synthesis codes.
The overlay is here:
You can read the final accepted version on arXiv here.
That’s all the papers for this week. I’ll post another update next weekend.
The summer examinations at Maynooth being over and the finalists having received their degree results I was reminded that I’d missed the anniversary of my own graduation. The main reason for that is that I couldn’t remember the date. I thought it was in July, actually, but rummaging through my files reminded me that it was on Saturday 22nd June 1985. Maynooth graduands will have to wait until September at the earliest for their conferring ceremony.
The degree certificate, incidentally, is not at all fancy. The only thing that surprised me about it was that it’s not in Latin!
The one I got when I collected my DPhil from Sussex University is far more elaborate. It’s also worth mentioning that although I did Natural Sciences (specialising in Theoretical Physics), the degree I got was Bachelor of Arts.
I don’t remember much about the Cambridge graduation, perhaps because the previous evening (Friday 21st June) we were plied with alcohol at the MacFarlarne-Grieve Dinner (a special event for graduands), then finished up in The Pickerel, the closest pub to the College. Our ceremony started at 9.15am and I wasn’t the only person graduating with a hangover.
The whole ceremony was dpme in Latin (or was when I graduated) and involved each graduand holding a finger held out by their College’s Praelector and then kneeling down in front of the presiding dignitary, i.e. either the Vice-Chancellor or Deputy Vice-Chancellor. I can’t remember which. The magic formula that turns a graduand into a graduate is:
Auctoritate mihi commissa admitto te ad gradum Baccalaurei in Artibus, in nomine Patris et Filii at Spiritus Sanctii
Other than that, and the fact that the graduands had to walk to the Senate House from their College through the streets of Cambridge, I don’t remember much about the actual ceremony.
After the ceremony we returned to Magdalene College for a garden party. I found this quite stressful, because my parents had divorced some years before and my Mum had re-married. My Dad wouldn’t speak to her or her second husband. At the garden party, the two parts of my family occupied positions at opposite corners of the lawn and I scuttled between them trying to keep everyone happy. It was like that for the rest of the day and I was glad when it was all over.
Anyway, the following October I started as a research student at the University of Sussex doing a Doctorate in Philosophy. I finished my thesis in 1988. Those three years were hard work but, on the whole, very enjoyable. I have a similar length of time in front of me before I retire. By the end I’ll have had 40 years in higher education (29 in the UK and 11 in Ireland). Hopefully, by then I’ll have figured out what to do when I leave University.
In the Dark 