Fat Tuesday – Bourbon Street Parade

Posted in Biographical, Jazz with tags , , , on February 17, 2026 by telescoper

Today’s  the day folk in England  Shrove Tuesday, when one is supposed to get “shriven” by doing a penance before Lent. Another name for the occasion – favoured in Ireland – is Pancake Day, although I’m not sure what sort of penance it is to be forced to eat pancakes. Further afield the name for this day is a bit more glamorous. Mardi Gras, which I translated for the title of this post as Fat Tuesday using my schoolboy French, doesn’t make me think of pancakes but of carnivals. And being brought up in a house surrounded by Jazz, it makes me think of New Orleans and the wonderful marching bands that played not just during the Mardi Gras parades but at  just about every occasion for which they could find an excuse, including funerals.

The Mardi Gras parades gave rise to many of the great tunes of New Orleans Jazz, many of them named after the streets through which the parade would travel, mainly in  the famous French Quarter. Basin Street, South Rampart Street, and Bourbon Street are among the names redolent with history for Jazz fans and musicians around the world. The New Orleans Mardi Gras has on recent occasions sometimes got a bit out of hand, and you probably wouldn’t want to take kids into the French Quarter for fear they would see things they shouldn’t. Personally, though, I’d love the chance to savour the atmosphere and watch the parades.

Anyway, the clip I’ve chosen to mark the occasion of Fat Tuesday is Bourbon Street Parade. The one and only time I went to New Orleans I felt a real thrill walking along this Bourbon Street, just because I’ve heard the tune so many times on old records.  I didn’t go in Mardi Gras time, however, but in the middle of summer. The heat was sweltering and the humidity almost unbearable, but the air was filled with music as well as moisture. It was impossible to sleep in the heat, so I stayed up moving from bar to bar, drinking and listening to music until I was completely exhausted.

The tune was written by the late Paul Barbarin, who died in 1969 during a street parade in New Orleans. What a way to go! He also plays on the clip I included here. I picked this particular version because it features a much underrated British musician, Sammy Rimington. My Dad once played with Sammy Rimmngton and I remember the unqualified admiration with which he (my Dad) spoke of his (Sammy’s) playing.

P.S. This year Pancake Day coincides with both the Lunar New Year and the start of Ramadan. Best wishes to all who celebrate any of these!

The Trouble with Teaching Particle Physics…

Posted in Education, The Universe and Stuff with tags , on February 16, 2026 by telescoper

The trouble with teaching particle physics is that students start out thinking that the standard model looks like this

when it’s really more like this

I hope this clarifies the situation.

On the Blog

Posted in Biographical, Science Politics with tags , , , on February 15, 2026 by telescoper

This “shitty WordPress blog” (to use someone’s memorable phrase) has been going for over 17 years now. I have occasionally thought about breaking the habit but having gone this far I think I might as well keep going until I retire, by which time in it will have reached the grand old age of 20.

In recent years the traffic here has settled down to a level about 40% lower than it was in its heyday. There are about 2,000 people recceiving posts by email and a few hundred who read it on the fediverse; these are not counted in the web traffic statistics unless they click through to the website.

The most popular year ever for web traffic was 2012, in which In The Dark attracted 464k visitors, whereas for the last few years it has been more like 260k per annum. Part of the reason for the drop will have been my move to Ireland and not posting so much of relevance to people in the UK, which was my main audience. I prefer not to think that the decline is because I’m now older and my posts more boring, but that may well the case. Twitter used to be the source of a considerable number of clicks too, but the changes introduced by Elon Musk put a stop to that even before I left that platform. In any case the blog numbers are far higher than I thought I would attract when I started blogging way back in 2008.

Anyway, I have noticed that in recent weeks the levels of traffic have been closer to those of a decade or more ago, with several notifications like this popping up:

In the first two weeks of February, for example, there have been over 30k views, i.e. over 2000 per day. The drivers of this increase have been two posts about the STFC funding crisis, first mine at the end of January and then a Guest Post by George Efstathiou which has been shared very widely.

I suppose the recent increase in traffic is a new manifestation of the old adage that “bad news sells newspapers”…

Time After Time – Chet Baker

Posted in Jazz with tags , , on February 14, 2026 by telescoper

It seems an appropriate evening for a romantic love song. Lyrics by Sammy Cahn, music by Jule Styne, vocals and trumpet by Chet Baker. Baker’s singing is quite unlike most jazz singers, and many jazz fans don’t like it very much, but I think his intimate, tender, and somewhat melancholic vocal performance together with his spare yet lyrical trumpet playing combine make this a classic.

Weekly Update from the Open Journal of Astrophysics – 14/02/2026

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on February 14, 2026 by telescoper

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 30 and the total so far published by OJAp up to 478.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter (which nobody should be using); these announcements also show the DOI for each paper.

The first paper to report this week is “Faraday Depolarization Study of a Radio Galaxy Using LOFAR Two-metre Sky Survey: Data Release 2” by Samantha Sneha Paul and Abhik Ghosh (Banwarilal Bhalotia College, India). This was published on Tuesday February 10th in the folder Cosmology and Nongalactic Astrophysics. The paper analyzes the depolarization of radio galaxy ILTJ012215.21+254334.8 using LOFAR’s Sky Survey data, revealing a preferred three-component model and highlighting turbulence in the magneto-ionic medium.

The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Faraday Depolarization Study of a Radio Galaxy Using LOFAR Two-metre Sky Survey: Data Release 2" by Samantha Sneha Paul and Abhik Ghosh (Banwarilal Bhalotia College, India)

doi.org/10.33232/001c.157500

February 10, 2026, 6:25 am 0 boosts 1 favorites

The second paper is “Rapid cosmological inference with the two-loop matter power spectrum” by Thomas Bakx (Utrecht U., NL), Henrique Rubira (Ludwig-Maximilians-Universität, DE), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia). This was also published on Tuesday February 10th in the folder Cosmology and Nongalactic Astrophysics. This paper uses the COBRA method to compute the two-loop effective field theory power spectrum of dark matter density fluctuations, providing more precise cosmological constraints than the one-loop EFT.

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Rapid cosmological inference with the two-loop matter power spectrum" by Thomas Bakx (Utrecht U., NL), Henrique Rubira (Ludwig-Maximilians-Universität, DE), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia)

doi.org/10.33232/001c.157501

February 10, 2026, 6:41 am 0 boosts 0 favorites

Next, published on Wednesday 11th February in the folder Astrophysics of Galaxies, is “Interpreting nebular emission lines in the high-redshift Universe” by Aswin P. Vijayan (U. Sussex, UK) and 9 others based in the UK, Taiwan, China and The Netherlands. This article examines the reliability of diagnostics used to estimate star formation rate and gas-phase oxygen abundance in high-redshift galaxies. It finds that variations in stellar populations and star-dust geometry. The overlay is here:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Interpreting nebular emission lines in the high-redshift Universe" by Aswin P. Vijayan (U. Sussex, UK) and 9 others based in the UK, Taiwan, China and The Netherlands

doi.org/10.33232/001c.157554

February 11, 2026, 8:21 am 0 boosts 0 favorites

The fourth paper this week, also published on Wednesday 11th February, but in the folder Instrumentation and Methods for Astrophysics is “Derivative-Aligned Anticipation of Forbush Decreases from Entropy and Fractal Markers” by Juan D. Perez-Navarro & David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia). The paper presents a feature-based framework for predicting Forbush decreases, i.e. rapid, temporary drops in galactic cosmic ray (GCR) intensity (up to tens of percent) caused by solar wind disturbances, typically Coronal Mass Ejections (CMEs) or high-speed streams from coronal holes, in neutron-monitor records using various computational methods. The approach is reproducible, operates on native station units, and is stable.

Here is the overlay:

The official version can be found on arXiv here and the Fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Derivative-Aligned Anticipation of Forbush Decreases from Entropy and Fractal Markers" by Juan D. Perez-Navarro & David Sierra Porta (Universidad Tecnológica de Bolívar, Colombia)

doi.org/10.33232/001c.157585

February 11, 2026, 5:19 pm 0 boosts 0 favorites

The fifth paper, the penultimate for this week, is “Supermassive black hole growth from stellar binary encounters” by Aubrey L Jones and Benjamin C Bromley (University of Utah, USA). This paper explores the growth of supermassive black holes (SMBHs) through stellar accretion via the Hill’s mechanism, predicting capture rates and identifying potential growth drivers in 91 galaxies. It was published on Thursday 11th February 2026 in the folder Astrophysics of Galaxies.

The overlay is here:

The accepted version can be found on arXiv here, and the fediverse announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Supermassive black hole growth from stellar binary encounters" by Aubrey L Jones and Benjamin C Bromley (University of Utah, USA)

doi.org/10.33232/001c.157589

February 12, 2026, 7:31 am 1 boosts 2 favorites

Finally for this week we have “Dynamics in the Cores of Self-Interacting Dark Matter Halos: Reduced Stalling and Accelerated Core Collapse” by Frank C. van den Bosch and Shashank Dattathri (Yale University, USA). This study uses simulations to explore core dynamics in self-interacting dark matter (SIDM) halos. Findings suggest strong self-interactions prevent core stalling and buoyancy, leading to accelerated core collapse. This was published yesterday, on Friday 13th February 2026, in the folder Astrophysics of Galaxies.

The overlay is here:

You can find the published version of the article here, and the Mastodon announcement is here:

Open Journal of Astrophysics

New Publication at the Open Journal of Astrophysics: "Dynamics in the Cores of Self-Interacting Dark Matter Halos: Reduced Stalling and Accelerated Core Collapse" by Frank C. van den Bosch and Shashank Dattathri (Yale University, USA)

doi.org/10.33232/001c.157701

February 13, 2026, 8:27 am 1 boosts 2 favorites

And that concludes this week’s update. I will do another next Saturday.

The County Game

Posted in Cricket, GAA with tags , , , , on February 13, 2026 by telescoper

The National Hurling League – not to be confused with the All-Ireland Senior Hurling Championship (which follows it and ends in the All-Ireland Final) – started a couple of weeks ago so inter-county hurling has been on the telly recently once more. The League is organized in 5 divisions (1a, 1b, 2, 3 and 4) and the TV coverage usually focusses on higher-division teams . Last week for example, there was a televised game between Cork and Tipperary, last year’s Championship finalists, in Div 1a. Cork won a feisty contest in front of a crowd of over 40,000 that exploded into a huge brawl near half-time . Anyway, I was looking through the lower divisions on the web and did a bit of a double-take when I reached Division 4 as I thought I’d got muddled up with the cricket!

Yes, there are two English counties in the Hurling League. There’s also a team from London in Division 3. None of them are doing very well, but if you want to see some live hurling in England you could check out Lancashire GAA, Warwickshire GAA or London GAA.

The Rain Falls Down

Posted in Biographical, Maynooth on February 12, 2026 by telescoper

There’s been a lot of rain recently, combined with an unusual easterly wind; the usual prevailing wind in Ireland is from a westerly direction. I’ve managed to avoid the worst of the wet until today. On the way home from work this evening I got absolutely drenched. A lot of water had pooled on the paths and pavements on campus too; I hadn’t put sufficiently sturdy footwear on so my feet got wet too. It seems set to be similar weather tomorrow, so I’ll make sure I’m better prepared. Was it Billy Connolly who said that there’s not really such a thing as bad weather, just the wrong clothes?

We are approaching the end of Week 2 of Semester 2 at Maynooth. I’ve been busy with the usual start-of-term things as well as some other jobs of the sort that crop up from time to time. I started teaching Computational Physics again last week for the first time in a different computer lab, and there were numerous problems with logins, etc, which caused quite a lot of stress. The second cycle of labs started today and everything went much better. I hope this continues. My lecture course on Particle Physics seems to be going reasonably well too, although it’s early days. Hopefully things will settle down and I won’t feel so exhausted for the rest of term. Thursdays are busy for me this term, with a 9am lecture as well as a lab and, today, several other things in between. Combined with the drenching on the way home I feel in need of refreshment, so I think I’ll have a hot bath followed by a glass of brandy and an early night…

P.S. Anniversaries often give me ideas for blog posts but I forgot one yesterday, which was ten years to the day since the announcement of the discovery of gravitational waves. Here’s the blog I did on that day. Was it really a decade ago?

Snowdrops – Lillias Mitchell

Posted in Art with tags , on February 11, 2026 by telescoper

Snowdrops by Lillias Mitchell (1929, watercolour on paper, 29 x 34 cm, National Gallery of Ireland); painted when the artist, who lived from 1915 to 2000, was 14 years old.

Probabilistic inference in very large universes

Posted in The Universe and Stuff with tags , , , , on February 10, 2026 by telescoper

I came across a recent article on the arXiv with the title Probabilistic inference in very large universes by Feraz Azhar, Alan H. Guth, Mohammad Hossein Namjoo.

The paper discusses a conceptually challenging issue in cosmology, which I’ll put simply as follows. Suppose we have two cosmological theories: A, which describes a very large universe in only a tiny part of which low-energy physics turns out like ours; and B in which we have a possibly much smaller universe in which low-energy physics is like ours with a high probability. Can we determine whether A or B is the “better” theory, and if so how?

The abstract of the paper is below:

Some cosmological theories propose that the observable universe is a small part of a much larger universe in which parameters describing the low-energy laws of physics vary from region to region. How can we reasonably assess a theory that describes such a mostly unobservable universe? We propose a Bayesian method based on theory-generated probability distributions for our observations. We focus on basic principles, leaving aside concerns about practicality. (We also leave aside the measure problem, to discuss other issues.) We argue that cosmological theories can be tested by standard Bayesian updating, but we need to use theoretical predictions for “first-person” probabilities — i.e., probabilities for our observations, accounting for all relevant selection effects. These selection effects can depend on the observer, and on time, so in principle first-person probabilities are defined for each observer-instant — an observer at an instant of time. First-person probabilities should take into account everything the observer believes about herself and her surroundings — i.e., her “subjective state”. We advocate a “Principle of Self-Locating Indifference” (PSLI), asserting that any real observer should make predictions as if she were chosen randomly from the theoretically predicted observer-instants that share her subjective state. We believe the PSLI is intuitively very reasonable, but also argue that it maximizes the expected fraction of observers who will make correct predictions. Cosmological theories will in general predict a set of possible universes, each with a probability. To calculate first-person probabilities, we argue that each possible universe should be weighted by the number of observer-instants in the specified subjective state that it contains. We also discuss Boltzmann brains, the humans/Jovians parable of Hartle and Srednicki, and the use of “old evidence”.

arXiv:2602.02667

I haven’t had time to read the paper in detail yet, and I don’t think I’m going to agree with all of it when I do, but I found it sufficiently stimulating to share here in the hope that others will find it interesting.

Take Note!

Posted in Bad Statistics, Biographical, Education, Maynooth with tags , , , , on February 9, 2026 by telescoper

We’re a week into teaching term here at Maynooth University and I’m taking a short break from the task of preparing notes and problem sets for the modules  I’m teaching this term.  Yesterday I came across a paper with the title Typed Versus Handwritten Lecture Notes and College Student Achievement: A Meta-Analysis. I always cringe when I see the word “Meta-Analysis”, as this is a very problematic statistical approach. Nevertheless, that article reminded me of a post I did some time ago about  lecture notes which I thought I would rehash here. I won’t repeat the entire content of my earlier discussion, but one of the main points I made in that was that many students are simply not used to taking notes and find it difficult to do so effectively during lectures, so much so that the effort of copying things onto paper must surely prevent them absorbing the intellectual content of the lecture (assuming that there is any).

I dealt with the problem  of taking notes when I was an undergraduate by learning to write very quickly without looking at the paper as I did so. That way I didn’t waste time moving my head to and fro between paper and screen or blackboard. Of course, the notes I produced using this method weren’t exactly aesthetically pleasing, but my handwriting is awful at the best of times so that didn’t make much difference to me. I always wrote my notes up more neatly after the lecture anyway. But the great advantage was that I could write down everything in real time without this interfering with my ability to listen to what the lecturer was saying. An alternative to this approach is to learn shorthand, or invent your own form of abbreviated language. This approach is, however, unlikely to help you take down mathematical equations quickly.

My experience nowadays is that many students simply aren’t used to taking notes like this – I suppose because they get given so many powerpoint presentations or digital materials or other kinds of handout –  so they struggle to cope with the old-fashioned chalk-and-talk style of teaching that some lecturers still prefer (and which actually works very well in mathematically-based disciplines). That’s probably because they get much less practice at school than my generation did. Most of my school education was done via the blackboard..

Nowadays,  many lecturers  give copies of their presentations to students and others even give out complete sets of printed notes before, during, or after lectures. That’s all very well, I think, but what are the students supposed to be doing during the lecture if you do that? Listen, of course, but if there is to be a long-term benefit they should take notes too. In other words, entirely passive learning is unlikely to be effective.

Even if I hand out copies of slides or other notes, I always encourage my students to make their own independent set of notes, as completely as possible. I don’t mean by copying down what they see on the screen and what they may have on paper already, but by trying to write down what I say as I say it. I don’t think many take that advice, which means much of the spoken illustrations and explanations I give don’t find their way into any long term record of the lecture. And if the lecturer just reads out the printed notes, adding nothing by way of illustration or explanation, then the audience is bound to get bored very quickly.

My argument, then, is that regardless of what technology the lecturer uses, whether he/she gives out printed notes or not, then if the students can’t take notes accurately and efficiently then lecturing is a complete waste of time. 

As a further study aid, most lectures at my previous institutions (Sussex University and Cardiff University) were recorded and made available to students to view shortly after the event. At those institutions, we found – contrary to popular myth – no evidence that availability of recorded lectures lowers the attendance at in-person lectures. It appears that students use the recordings for revision and/or to clarify points raised in the notes they have taken, and if anything the recordings allow the students to get greater value from lectures rather than persuading them that there’s no need to attend them. Of course we had to use lecture recordings during the pandemic. Unfortunately Maynooth University decided not to invest in the technology needed to make this routine after we went back to classroom-based teaching, so we can’t offer lecture recordings in a systematic way. This is very regrettable,as many students live nowhere near campus and find it onerous to travel every day for one or two teaching sessions.

I do like lecturing, because I like talking about physics and astronomy, but as I’ve got older I’ve become less convinced that lectures play a useful role in actually teaching anything. I think we should use lectures more sparingly, relying more on problem-based learning to instil proper understanding. When we do give lectures, they should focus much more on stimulating interest by being entertaining and thought-provoking. They should not be for the routine transmission of information, which is far too often the default.

I’m not saying we should scrap lectures altogether. At the very least they have the advantage of giving the students a shared experience, which is good for networking and building a group identity. Some students probably get a lot out of lectures anyway, perhaps more than I did when I was their age. But different people benefit from different styles of teaching, so we need to move away from lecturing as the only option and ensure that a range of teaching methods is available.

I don’t think I ever learned very much about physics from lectures – I found problem-based learning far more effective – but I’m nevertheless glad I learned out how to take notes the way I did because I find it useful in all kinds of situations. Effective note-taking is definitely a transferable skill, but it’s also in danger of becoming a dying art. If we’re going to carry on using lectures, we old fogeys need to stop assuming that students learnt it the way we did and start teaching it as a skill.

Perhaps the biggest problem with the way physics is generally taught these days, however,  is not really about the mode of delivery but the compartmentalization that has crept in via the school system which encourages students to think of each `module’ as a bite-sized piece that can be retained until the examinations, regurgitated, and then forgotten. I’ve no doubt that a great many students pass the examinations we set by simply memorizing notes with little genuine understanding  needed or problem-solving ability demonstrated. We promote physics as a subject that nurtures these skills, but I don’t think many physics graduates – even those with good degrees – actually possess them at the end. We should be making much more of an effort in teaching students how to use their brains in other ways than as memory devices, and getting them engaged in more active teaching activities seems to me to be a very high priority. That said, I think we probably do much more of this in physics than in most other subjects!