Sunlight at dawn on the Winter Solstice at Newgrange
Just a quick note to point out that the Winter Solstice in the Northern hemisphere happens tomorrow, Saturday 21st December 2024, at 9.21 UT (GMT). I am posting this in advance as I am planning to have a line-in tomorrow morning.
In Dublin, sunrise today (20th December) was at 8.37 am and sunset at 4.07 pm, while tomorrow the sunrise is at 8.38 am and sunset at 4.08 pm. Notice that both sunrise and sunset happen later tomorrow than today, so the Solstice marks neither the latest sunrise nor the earliest sunset: the interval between the two events will, however, be about 2 seconds shorter tomorrow than today. For a full explanation of this, see this older Winter Solstice post.
Anyway, today is has been the last day of teaching at Maynooth University. I did my final lecture of 2024 this morning and attended project presentations this afternoon. Campus has been very quiet all day, most people having already departed for the break. That makes me feel less guilty about going home earlier than usual at 4.15pm. Now it’s time power down everything in my office for the break and head home via the shops!
Today I completed the lectures for one of my modules, the one on Differential Equations and Transform Methods for Engineering students, and gave the penultimate lecture for Differential Equations and Complex Analysis for final-year Mathematical Physics students. Both were revision lectures. As campus has been very quiet for the last few days I didn’t expect many (if any) students to show up for either of these classes, but some did, although numbers were a long way down on the start of the year.
Campus is always quiet this close to the holiday, but this time there has been a bug going around which has led to a few more absences than usual among students. Some staff have been affected too. I had a mild dose of whatever it was earlier in the week but got over it relatively quickly.
Tomorrow, the last day of Semester 1, I have my last lecture of this term, followed by a couple of final-year project presentations. Then that’s it until 2025. I am already thinking about what to do tomorrow evening to mark the end of term. I haven’t reached any definite conclusions yet, but it will almost certainly involve wine. Then I suppose I’ll have to start my Christmas shopping which will include buying more wine.
I am a bit flush this week because I’ve finally received rebates of overpayment from OVO Energy and Dŵr Cymru Welsh Water relating to my former house in Cardiff. I sold this property months ago, after much tedious to-ing and fro-ing, but getting money back from utility companies is like getting blood out of a stone. OVO Energy were particularly bad, violating their statutory obligations. The offer3d me £60 additional payment in recognition of this but, although they eventually settled the bill, they never paid the compensation. It seems they just lied.
In contrast, and giving credit where it’s due, I am grateful to Cardiff City Council for paying back my overpaid Council Tax very promptly.
The forthcoming week is the second-to-last week of teaching term at Maynooth and, as usual at this stage of the Semester, we’re getting busier and busier.
The examinations for January have been sent off for printing and are (presumably) ready to go, so that’s one item crossed off the to-do list. I’m still behind on the coursework grading for one of my two modules, but should be able to catch up in the next few days. Other than that, I am miraculously on schedule as far as teaching is concerned. I should finish covering the respective syllabuses by Friday 13th, which means the following week will be devoted to revision. I expect attendance on campus will be fairly sparse in the last week of term, especially later on. I’ll be there until the bitter end, however, as I have a lecture scheduled on Friday 20th and have to attend final-year student presentations that afternoon. After that I will probably collapse in a state of exhaustion into the welcoming arms of the Christmas break.
While the week ahead will be fairly normal from the point of view of teaching itself, there are quite a few extra things in my calendar, as people try to get various things done before the break. Extra items for next week including a meeting about a staff recruitment (of which, hopefully, more anon) and another about the possible reorganization of teaching in the light of the merger of the Departments of Theoretical and Experimental Physics. Rationalization of teaching could lead to an improvement in the courses offered and also, by removing duplication, reduce our very heavy teaching workloads. Whether it will actually be possible to achieve either or both of these aims remains to be seen. In any case I’m not sure if any significant changes to teaching will be implemented before I retire, but I’ll probably go along to the meeting anyway in case there’s anything I can contribute.
I’ve also agreed to give a talk on Wednesday to the student Pride Society which I am looking forward to, although such events invariably make me feel very old!
As it happens, Friday 13th December is the date for the first Christmas dinner of the newly formed Department of Physics; previously, the Departments of Theoretical Physics and Experimental Physics held separate celebrations. It will be a much bigger group this time and, it being on a Friday evening we’ll have the weekend to recover before the last week of term.
Anyway, although it’s a Sunday I’ll be working all afternoon as I have a task to finish that is due tomorrow so I had better sign off. When I was younger I used to look forward to Christmas as a time for feasts and parties and socialising. Now that I’m older I look forward to it more than anything as a time for the sense of relaxation that comes from the lack of deadlines.
Maynooth University Library, home of the famous cat
As the count continues in the General Election in Ireland, the result of which seems likely to be the same old government, I am reminded that today is 1st December 2024, which means that it’s seven years to the day since I started work at Maynooth University. Despite the frustrations I’m still happy I made the move all that time ago.
One big change that has happened over the last year is that the Department of Theoretical Physics that I joined in 2017 no longer exists. It has now been subsumed into a new Department of Physics alongside the old Department of Experimental Physics. This is something that should have happened years ago, and should also have been handled in a better way. As it is, The Merger really just involved merging the two budgets with little thought given to how the new Department would function. As a result it still operates largely as two separate sub-Departments. Any benefits of the reorganization have therefore yet to accrue. The good side of this is that Senior Management seems to have lost interest in pushing us around, and it’s now up to the new Department to self-organize. I suppose in due course there will be changes, but in due course I will have retired.
When I wrote last year on the occasion of the sixth year of my appointment at Maynooth, I complained that the University had still not fulfilled the terms of my employment contract. With The Merger, members of the former Department of Theoretical Physics now have access to the technical support previously enjoyed by the Department of Experimental Physics so I suppose that particular ticket is closed. This blatant disregard for written contractual terms demonstrates, however, why I have so little trust in the University management. In that vein, it still concerns me that my contract says that I am employed by the Department of Theoretical Physics. Legally, does it matter that I am employed to work in an entity that doesn’t exist?
The thing I’m probably most proud of over the past seven years is, with the huge help of staff at Maynooth University Library, getting the Open Journal of Astrophysics off the ground and attracting some excellent papers. This year has seen yet more significant growth, with submissions and publications more than doubling this year, after an increase of a factor of three the year before. We’re still smaller than many of the mainstream astrophysics journals, but we’re still growing.
Anyway, I continue to enjoy the teaching, though doing two new modules in a term, plus an undergraduate project, plus supervising three PhD students, is quite a lot of work for an old man. That reminds me I have some correcting to do…
It’s Saturday morning once again so it’s time for the usual weekly update of publications at the Open Journal of Astrophysics. This week’s report will be short because, like last week, there is only one paper to report this week, being the 106th paper in Volume 7 (2024) and the 221st altogether. It was published on Thursday 28th November 2024. We have some more papers in the publishing pipeline, which I thought might appear, but they didn’t come out this week possibily because of the Thanksgiving holiday in the USA.
Anyway, The title of the latest paper is “Growth of Light-Seed Black Holes in Gas-Rich Galaxies at High Redshift” by Daxal Mehta, John Regan and Lewis Prole (all of the National University of Ireland, Maynooth*. This paper presents a discussion of the rate of growth of black holes in the early Universe on the basis of simulations run using the Arepo code.
Here is the overlay of the paper containing the abstract:
You can click on the image of the overlay to make it larger should you wish to do so. You can also find the officially accepted version of the paper on the arXiv here.
That’s all for this week – tune in next Saturday for next week’s update!
*The authors being from Maynooth, I of course recused myself from the editorial process for this article.
Today friend of mine send me a message pointing out that in order to save money the University of Sussex is planning to make about 300 staff redundant; you can see an article about it in the Times Higher here. For the time being it seems the plan to make these savings via a voluntary severance scheme. I don’t know whether academic and administrative staff will be treated equally, either.
This is grim news. I worked at Sussex from 2013 until 2016 when I resigned my post as Head of School of Mathematical and Physical Sciences. I took that decision largely for personal reasons but there were professional reasons too. From 2013 the University had embarked on an ambitious growth plan based on buoyant student numbers and the fee income generated thereby. Staff numbers grew too, to cope with the increased demand for teaching. Unfortunately the management was unable to match this with real improvements in infrastructure, largely due to the disastrous outsourcing of campus estates and services. Many promises made to me as Head of School by Senior Management were broken. I wasn’t the only Head of School to compain of this, either. Although things were still going relatively well when I left in 2016, and I was optimistic for the future of the School then, there were severe risks to its financial stability if student recruitment dived. Sadly, that’s exactly what happened. Falling student numbers – especially from overseas – left the institution very vulnerable, especially since the fee per student did not change. That problem was exacerbated by a burst of inflation. AlthoughIt has clearly been a very difficult time for the University of Sussex, largely due to national and international forces beyond its control, but exacerbated by ineffective, and at times incompetent, institutional management. It should be said also that many University leaders enthusiastically embraced the fees-based system that has led their institutions where they are now, though most of them have now departed and left others to carry the can.
It worries me that Maynooth University is also trying to grow very quickly, without adequate investment in infrastructure especially teaching. It isn’t increasing the number of academic staff much either, preferring to hire more and more managers; yet another such position was advertised this week. I don’t know whether Maynooth’s financial trajectory will follow that of Sussex. The funding environment is very different in Ireland compared to the UK, so it may not. It is clear that the enviroment for education and research here is being steadily degraded by the current leadership.
Anyway, when I saw the announcement about Sussex, I checked other Universities I’ve worked in over the years. There’s a list here. It seems that while there are particular factors at play at Sussex, there are similar difficulties across the Board. Cardiff University has a deficit of £35 million and the VC has refused to rule out compulsory redundancies there. I’m not sure how this is all affecting the School of Physics & Astronomy. Nottingham University, where I worked from 1999 to 2007, has deficit of £30 million, in response to which it has opened a voluntary severance scheme, introduced hiring freezes, cut non-pay budgets, and refused to renew 500 fixed-term contracts.
There certainly are cold winds blowing across the University landscape in the United Kingdom, and there is no sign of any respite. This is just the start.
We’re in Week 9 of teaching in the Autumn Semester at Maynooth University, which means we’ve got one eye on the forthcoming Examination Period, which starts on 10th January 2025. Examination papers have already been prepared in draft form, and are now being checked ahead of printing. A draft examination timetable has also been released to staff, but not yet to students in case it has to be revised because of clashes.
I’m still on schedule with both my modules to finish the actual content in time to do use the last week for revision classes, going through past examination papers and generally helping the students prepare for the ordeals of January. There is a continuously-assessed component of both my modules, which counts 20% of the overall grade. One purpose of these assignments is to give the students some practice at the sort of problems they might encounter in the examinations: if they can do the assignments, they shouldn’t be too fazed by the examination questions. The purpose of the coursework is not just about passing examinations, however. I think the only way really to learn about mathematical physics is by doing it; the coursework is at least as important as the lectures and tutorials in terms of actually learning the subject. I think that modern higher education involves drastic over-assessment. Too much emphasis on grades and scores can be detrimental to real learning, but assessment that is formative can be extremely beneficial. Continuous assessment provides a way to give feedback to students on how they are doing, and to lecturers on how well the message is getting across; giving grades to such coursework is really just an incentive to the students to do it. It’s not primarily intended to be summative.
Anyway, back to examinations. One big difference between our examinations in Theoretical Physics in Maynooth and those at other institutions at which I’ve taught (in the UK) is that most of the papers here offer no choice of questions to be answered. Elsewhere it is quite common to find a choice of two or three questions from four or five on the paper. In my module on Differential Equations and Complex Analysis, for example, there are four questions on the examination paper and students have to do all of them for full marks.
One advantage of our system is that it makes it much harder for students to question-spot in the hope that they can get a good grade by only revising a fraction of the syllabus. If they’re well designed, a few longish questions can cover most of the syllabus for a module, which they have to in order to test all the learning outcomes. To accomplish this, questions can be split into parts that may be linked to each other to a greater or lesser extent in order to explore the connections between different ideas, but also sufficiently separate that a student who can’t do one part can still have a go at others. With such a paper, however, it is a dangerous strategy for a student to focus only on selected parts of the material in order to pass.
As an examiner, the Maynooth style of examination also has the advantage that you don’t have to worry too much if one question turns out to be harder than the others. That can matter if different students attempt different questions, as students might be penalized if they chose a particularly hard one, but not if everyone has to do everything.
But it’s not just the number of questions that’s important, it’s the duration. I’ve never felt that it was even remotely sensible for undergraduate physics examinations to be speed tests, which was often the case when I was a student. Why the need for time pressure? It’s better to be correct than to be fast, I think. I always try to set examination questions that could be done inside two hours by a student who knew the material, including plenty of time for checking so that even a student who made a mistake would have time to correct it and get the right answer. If a student does poorly in this style of examination it will be because they haven’t prepared well enough rather than because they weren’t fast enough.
We’re about two-thirds of the way into the Autumn Semester here at Maynooth and, by a miracle, I’m just about on schedule with both the modules I’m teaching. It’s always difficult to work out how long things are going to need for explanation when you’re teaching them for the first time.
One of the modules I’m doing is Differential Equations and Transform Methods for Engineering Students. I’ve been on the bit following the “and” for a couple of weeks already. The first transform method covered was the Laplace transform, which I remember doing as a physics undergraduate but have used only rarely. Now I’m doing Fourier Series, as a prelude to Fourier transforms.
As I have observed periodically, the differential equations and transform methods are not at all disconnected, but are linked via the heat equation, the solution of which led Joseph Fourier to devise his series in Mémoire sur la propagation de la chaleur dans les corps solides (1807), a truly remarkable work for its time that inspired so many subsequent developments.
In the module I’m teaching, the applications are rather different from when I taught Fourier series to Physics students. Engineering students at Maynooth primarily study electronic engineering and robotics, so there’s a much greater emphasis on using integral transforms for signal processing. The mathematics is the same, of course, but some of the terminology is different from that used by physicists.
Anyway I was looking for nice demonstrations of Fourier series to help my class get to grips with them when I remembered this little video recommended to me some time ago by esteemed Professor George Ellis. It’s a nice illustration of the principles of Fourier series, by which any periodic function can be decomposed into a series of sine and cosine functions.
This reminds me of a point I’ve made a few times in popular talks about astronomy. It’s a common view that Kepler’s laws of planetary motion according to which which the planets move in elliptical motion around the Sun, is a completely different formulation from the previous Ptolemaic system which involved epicycles and deferents and which is generally held to have been much more complicated.
The video demonstrates however that epicycles and deferents can be viewed as the elements used in the construction of a Fourier series. Since elliptical orbits are periodic, it is perfectly valid to present them in the form of a Fourier series. Therefore, in a sense, there’s nothing so very wrong with epicycles. I admit, however, that a closed-form expression for such an orbit is considerably more compact and elegant than a Fourier representation, and also encapsulates a deeper level of physical understanding. What makes for a good physical theory is, in my view, largely a matter of economy: if two theories have equal predictive power, the one that takes less chalk to write it on a blackboard is the better one!
Anyway, soon I’ll be moving onto the complex Fourier series and thence to Fourier transforms which is familiar territory, but I have to end the module with the Z-transform, which I have never studied and never used. That should be fun!
It has been an unusually mild November until today, when it has suddenly turned colder and wetter. This alteration does not seem to have pleased Maynooth University Library Cat.
Just a quick post to point out that today is LGBTQIA+ STEM Day, which aims to celebrate to celebrate the work of LGBTQIA+ people in science, technology, engineering, and maths (STEM), but also to highlight the barriers still facing us.
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In the Dark 