I haven’t used my Youtube channel very much recently so to avoid disappointing my subscribers, of whom there are several, I have today uploaded a video showcasing the work of colleagues in the Physics Department at Maynooth.
This zoom in from an optical Hubble Space Telescope (HST) image shows how infrared observations by the James Web Space Telescope reveal the surprising details of the structure at the heart of the Butterfly Nebula, NGC 6302
For background to this video, see here.
On September 4th, when I posted a piece about the forthcoming Presidential Election in Ireland, I forgot to mention that just two days earlier was the 50th anniversary of the funeral of Éamon de Valera, founder of Fianna Fáil (one of the two largest political parties in Ireland) and architect of the Irish constitution, who died on 29th August 1975 at the age of 92. Here’s some coverage at the time by (British) Movietone News, the commentary is rather generous to him:
De Valera (nickname `Dev’) is an enigmatic figure, who was a Commandant in the Irish Republican Army during the 1916 Easter Rising, but despite being captured he somehow evaded execution by the British. There’s no evidence, incidentally, that he escaped the firing squad because he was born in America. Dev subsequently became Taoiseach (Prime Minister) and then President (Head of State) of the Irish Republic.
There’s no question in my mind that de Valera is the most significant Irish politician of the 20th Century, which is not to say I fid him an agreeable figure at all and his legacy isn’t particularly positive. Nevertheless, his funeral was perhaps as significant event for the Irish as that of Winston Churchill had been for the British just a decade earlier.
Over the past couple of weeks RTÉ television broadcast a two-part documentary called Dev: Rise and Rule; the second part was on last night. It is quite nicely made, but disappointingly superficial and lacking in any real historical insight. The suggestion that it would “decode” Dev was unfulfilled. This is a pity because RTÉ often does good documentaries.
Anyway, this gives me an excuse to mention again, Dev’s connection with Maynooth. De Valera was a mathematics graduate, and for a short time (1912-13) he was Head of the Department of Mathematics and Mathematical Physics at St Patrick’s College, Maynooth, which was then a recognised college of the National University of Ireland. The Department became incorporated in Maynooth University when it was created in 1997. Mathematical Physics is no longer a part of the Mathematics Department at Maynooth, having first become a Department in its own right, then changing its name to the Department of Theoretical Physics and then, just last year, being subsumed within a new Department of Physics.
De Valera missed out on a Professorship in Mathematical Physics at University College Cork in 1913. He joined the the Irish Volunteers, when it was established the same year. And the rest is history. I wonder how differently things would have turned out had he got the job in Cork?
One of the consequences of living in a (relatively) small Irish town surrounded by farmland is that every now and again you notice authentic countryside smells. This time of year is often accompanied by the whiff created by the slurry being spread on nearby fields. The farmers typically do this in mid to late September, depending on the weather; it is actually not allowed after 30th September). When I first noticed this sort of pong I thought there was something wrong with the drains, but you get used to it.
Anyway, this made me think of this painting
Of course the manure isn’t spread by hand nowadays. It’s done like this:
(I got this picture from a piece in the Irish Times about slurry as a poetic metaphor.)
About a month ago I posted an item about the National Famine Way, at the end of which I signalled my future intention to walk the 165 km 6-day route from Strokestown to Dublin. I was subsequently contacted by a number of people warning me that I might not be up to it. They didn’t put me off, but I have come up with a plan. This week – on Wednesday in fact – I will have the injections I get every six months or so to control the arthritis in my knees. Thus fortified, I intend next week to do a trial run walk consisting of the last stage of the Famine Way, from Maynooth to Dublin, along the Royal Canal. That’s about 27km and will take most of a day. I’ll stop on the way for lunch and when I get to the end I can get the train back to Maynooth. And if I run walk into difficulties I can stop at one of the intermediate stations and return from there; the canal runs right alongside the railway line for most of the way. If all goes to plan I’ll take time off next year to do the whole trip from Strokestown.
Meanwhile here’s a picture of one the poignant bronze sculptures of children’s shoes placed along the way. This one is at Maynooth harbour; there are 8 others on the way to Dublin.
To learn more about these shoes, see here, and here’s a video telling the story
With just two weeks to go before we resume teaching at Maynooth University, I find that next week I have no fewer than three medical appointments next week, on different days and in different locations. All of them are (or should be) routine, and none are particularly serious. Much as I dislike hospitals, etc, it will be good to get these bits of scheduled maintenance out of the way before the start of term.
On the other hand, they mean that I have to miss what looks like a very nice meeting in Italy in honour of Sabino Matarrese. I was invited, and initially accepted, but had to cancel. I hope that it goes well!
For old time’s sake I thought I’d post this picture of a youthful Sabino from years ago; he’s in the middle of the row nearest the camera; I’m at the end in the yellow shirt.
Anyway, last Friday our first cohort of MSc students in Theoretical Physics and Mathematics received their final results. This course lasts a calendar year so the results come out later than for the undergraduate courses. Congratulations to them all, but especially to Enda who completed a project under my supervision that we hope to turn into a paper before long.
Some familiar faces will no longer be around, but soon we will be joined by some new ones. Tomorrow, registration opens up for incoming first-year students at Maynooth and later in the week for returning second-, third-, and fourth-year students. By this time next week we’ll have a much better idea how many students there will be in our classes for the new academic year.
On Friday (12th September) I’ll be off to the National Concert Hall for the 2025/6 Season Opener with the National Symphony Orchestra conducted by Leonard Slatkin, another indication that Autumn Semester is nigh.
A very comprehensive review article has appeared on arXiv with the title Hitchhiker’s Guide to the Swampland: The Cosmologist’s Handbook to the string-theoretical Swampland Programme by Kay Lehnert (who just happens to be my PhD student). The paper is 170 pages long and contains over 1,800 references, which gives some idea of what a large field this is and how much work Kay has put into writing it!
The abstract reads
String theory has strong implications for cosmology: it tells us that we cannot have a cosmological constant, that single-field slow-roll inflation is ruled out, and that black holes decay. We elucidate the origin of these statements within the string-theoretical swampland programme. The swampland programme is generating a growing body of insights that have yet to be incorporated into cosmological models. Taking a cosmologist’s perspective, we highlight the relevance of swampland conjectures to black holes, dark matter, dark energy, and inflation, including their implications for scalar fields such as quintessence and axions. Our goal is to inspire cosmological model builders to examine the compatibility of effective field theories with quantum gravitational UV completions and to address outstanding cosmological tensions such as the Hubble tension. This comprehensive literature review presents clear definitions, cosmological implications, and the current status – including evidence and counterexamples – of the following swampland conjectures: the anti-de Sitter distance conjecture (AdSDC), the completeness conjecture (CC), the cobordism conjecture, the de Sitter conjecture (dSC), the swampland distance conjecture (SDC), the emergence proposal (EP), the Festina Lente Bound (FLB), the finite number of massless fields conjecture (or finite flux vacua conjecture (FFV)), the no global symmetries conjecture, the no non-supersymmetric theories conjecture, the non-negative null energy condition conjecture, the positive Gauss-Bonnet term conjecture, the species scale conjecture, the gravitino swampland conjecture (GSC), the tadpole conjecture, the tameness conjecture, the trans-Planckian censorship conjecture (tPCC/TCC), the unique geodesic conjecture, and the weak gravity conjecture (WGC), including the repulsive force conjecture (RFC).
This is essentially the literature review part of Kay’s thesis; the aim of his research is to study the implications of the string-theoretical swampland programme for cosmology. He’s particularly interested in the predictions string theory makes regarding inflation, dark energy, and dark matter, and the impact this has on the Hubble tension. The point of writing this review was to suggest projects that might be undertaken to bring string theory into the realm of testability, thus suppling material for the rest of Kay’s thesis, but I think it is also a very good guide for cosmologists of all types to what the swampland conjectures are and what they do and do not say about the Universe we actually live in.
While I remember, and before I get caught up in start-of-term things, I thought I would pass on news that two calls administered by Research Ireland will open on September 11th. These are the Government of Ireland Postgraduate Scholarships and the Government of Ireland Postdoctoral Fellowships. These are open to applications from candidates anywhere in the world.
You can find information about the Postgraduate Scholarships here and the Postdoctoral Fellowships here. The postdoctoral positions are for one or two years; postgraduate positions are for 2 years (Research Masters) or 4 years (PhD).
The application deadline is 23rd October 2025 and positions of both types are to start on 1st September 2026. You will need to contact possible supervisors at your planned host institute in advance of application so there isn’t much time.
Anyone interested in applying to hold one of these positions in Maynooth is welcome to contact me privately for advice or assistance. Given my rapidly approaching retirement, however, I am not able to act as nominated supervisor for postgraduate positions. I would happily support an applicant for a postdoctoral fellowship in the area of cosmology. There are of course many other potential supervisors both at Maynooth and elsewhere.
Today is the last day of August, which, according to my calculations, means that tomorrow is the first day of September. Last week the kids started to go back to school and some of course started for the first time. I think the schools vary in the timetable for new arrivals and returning students, but they’re basically all operating fully from tomorrow, Monday 1st September.
Universities start back a little later, though this also varies. In Maynooth, Orientation Week (for new students) begins on September 15th, and lectures commence for all years on September 22nd, which happens to be the day of the Autumnal Equinox. My first lecture of the new academic year is on that day. I don’t know how many students I’ll have in my class yet. It’s a 4th-year class, and those students don’t register for modules until Friday 12th September, at the end of a week that begins with new students starting to enrol on Monday 8th September.
The first week of September will therefore be a bit quieter in the University than in the local schools. Next week sees a number of conferring ceremonies at which students who completed their studies with the examinations in May will receive their degrees. That includes a number of Physics students, who will graduate on Wednesday 3rd September. Unfortunately, when I tried to register to attend the ceremony, a few weeks ago, I was unable to because it was booked up so I’ll have to send my congratulations virtually. In any case, Conferring ceremonies at Maynooth are not what they used to be. Instead of the atmospheric surroundings of the Aula Maxima, they are now held in the soulless environnment of a lecture theatre. Instead of a nice buffet reception afterwards the graduates used to get, they now get a cup of tea in a paper cup and (if they’re lucky) a very small Danish pastry. It’s quite embarrassing actually. I wouldn’t be surprised if, in future, graduands were told to being their own sandwiches and a thermos flask. Anyway, a PhD student of mine will attend a conferring ceremony at the end of October. I’ll have to ensure I register on time for that one as I will be reading out the title of her thesis. Our first cohort of MSc students will graduate then too.
Just time for a quick update about a paper that I posted about at the start of the summer, when it appeared on arXiv. At that time it had already gained a bit of traction in the media, e.g. here. Well, the paper is now published in the Open Journal of Astrophysics. Obviously, as an author I was conflicted so not involved in the editorial process.
Here is the overlay:
For those of you not in the field, there is currently a big mystery about how galaxies we have found at high redshift with JWST managed to acquire massive black holes so early in the Universe’s evolution. Black holes can grow quickly in a dense environment by accreting mass onto an initial seed, but what are the seeds? In this paper we investigate the possibility that they were primordial black holes. These form directly from fluctuations in the early Universe, as opposed to astrophysical black holes which form from stellar collapse. We don’t know exactly what mass primordial black holes would have nor how numerous they would be, but this paper uses high-resolution numerical experiments to investigate their effects if they do exist.
Here’s a pretty picture which is a zoom into 200 pc of the full simulation. I think 10pc counts as high resolution for a cosmological simulation! The blue circle shows the most massive PBH in the simulation, the green circle shows its nearest neighbour. The colour scale represents the number-density of dark matter particles.
For more details, read the paper!
Today (27th August) is the day that students across Ireland receive offers of places at Third-Level Institutions to start next month. The offers for all courses and all institutions are available on the official CAO website here; they are also widely available elsewhere, including this searchable list.
The official numbers for Maynooth are here. Minimum points required for Maynooth’s – and indeed Ireland’s – most important course, MH206 Theoretical Physics and Mathematics, are 520 this year, up a little from 513 last year. MH204 Physics with Astrophysics is 385, up two points on last year’s 383. MH201 General Science (of which Physics is a part) is on 352 points, up two from 350 last year. Just for comparison, the points for these courses from 10 years ago were: MH206 550; MH204 480; and MH201 435, all significantly higher than this year.
Maynooth’s biggest course (by student numbers) – and indeed the biggest course in Ireland reckoned that way – is the Omnibus Arts programme MH101 which has an entry level this year of just 300 CAO points. Ten years ago it was 390.
It seems the first-round entry points for most courses at Maynooth have not changed dramatically despite the reduction in Leaving Certificate grades this year after several years of artificial inflation over the Covid-19 years. Leaving Certificate results are just one factor in determining the CAO points for a particular course at a particular Institution. Overall the picture is rather complex. Across Ireland, points are up for about 50% of courses and down for about 42%. The CAO points needed for a course is largely a matter of demand versus capacity rather than academic performance. For the last few years Maynooth University has been recruiting more and more students, putting pressure on accommodation, teaching loads and campus space. This strategy will prevent any significant rise in CAO points for the foreseeable future. This is probably happening to some extent across the sector, though Maynooth has a more urgent need for more students: to pay for the legions of new managers it has appointed. Two new €100K managerial jobs have been advertised so far this week…
All this just concerns the first round of offers so things may change significantly over the next week or two. Students now have to decide whether to accept their first-round offer or try to change course. They have until next week to do this. Departments won’t know how many new students they have for a while yet.
Update: Thursday 28th August. Here is the traditional Irish Times First Round Offers supplement.
In the Dark 