R.I.P. George F. Smoot (1945-2025)

Posted in Biographical, R.I.P., The Universe and Stuff with tags , , , , , , on September 26, 2025 by telescoper
George F. Smoot (1945-2025)

I’m very sad to have to report the death, at the age of 80, of eminent cosmologist George Smoot, who passed away at his home in Paris on 18th September. The news has been reported in France, where George had been living in recent years, but doesn’t seem to have been covered in the international media yet. I thought I would just record some personal relfections and reminiscences here, rather than try to pre-empt the official biographies.

George Smoot was an experimental astrophysicist who is best known for his research in observational cosmology, particularly on the cosmic microwave background. In 2006, jointly with John Mather, he was awarded the Nobel Prize for Physics for measurements made by the COBE satellite that, without exaggeration, ushered in a new era of cosmology. George led the paper Structure in the COBE Differential Microwave Radiometer First-Year Maps that reported the first detection of variations in temperature of the cosmic microwave background across the sky predicted by theories of cosmological structure formation.

I was fortunate enough to meet George many times over the years and to get to know him quite well. The first time was at a meeting in Durham for which this was the conference photo:

George is just to the left of centre in the front row with the red-and-white sweater.

What I remember about that meeting is that I gave a contributed talk there (a short one, because I was a mere postdoc at the time). Some time after that, George Smoot gave an invited talk during the course of which he mentioned (positively) the work I had spoken about. I was gobsmacked to have my little contribution recognized by someone so eminent, and it did wonders for my scientific self-confidence. I got the chance to have a conversation with George in person some time later at that meeting and found him very good value: he was both interesting and amusing to talk to. He was someone who took mentorship seriously, and didn’t confine it to those people he was working with directly.

Over the years I met George regularly at scientific meetings, including numerous times at the (then) Daniel Chalonge schools in Sicily and in Paris where we often chatted about science and other things over coffee breaks and dinner. I always found him hugely knowledgeable about many things, but he also had an almost child-like curiosity about things he didn’t previously know. He didn’t quite jump up and down with excitement when he learnt something interesting, but almost. He could also be very direct when disagreeing, which meant that some people found him a bit abrasive. He fell out with other members of the COBE time when he threw away the agreed protocol for the announcement of results in 1992. That caused a lot of bad feeling at the time, but it seems that by the time the Nobel Prize was awarded, some degree of reconciliation had been achieved. I was lucky enough to attend the Prize Ceremonies and at the ball afterwards chatted with both George and John Mather who seemed on very amiable terms then.

Anyway, in the early noughties George invited me to spend some time at the Lawrence Berkeley Laboratory, a visit that I enjoyed enormously. He was a very generous and thougtful host and I was looked after very well. One day at LBL he asked me if the hotel was OK. I replied that it was, but one thing I didn’t like about staying in a hotel was that I liked to cook and that was impossible in a hotel room. I thought nothing more of that conversation until the end of the day when George appeared and asked me if I wanted to “do dinner” at his house that evening. I answered in the affirmative so he drove me to his house, which was very fancy, set into the hillside overlooking Berkeley – like the sort of place I imagine a film star would live – and had a very large and well-provisioned kitchen.

It soon became clear that I’d misunderstood the invitation, in that “do dinner” didn’t mean “eat dinner” but “make dinner”. Although I was slightly taken aback I set about finding what he had in the refrigerator and on the shelves. There being a plentiful supply of spices, I decided to make a tandoori-style dish of chicken baked with yoghurt, with a couple of side dishes, none of which took long to cook. When everything was getting ready I wanted to add some lemon juice but couldn’t find any lemons in the fridge. I asked George if he had any lemons, at which point he showed me into the garden where he had several lemon trees in full fruit. I’ve never lived anywhere that this would be possible! I think he enjoyed the dinner because he paid me back a few days later with a dinner at Chez Panisse. He was quite the bon viveur.

(After that short visit, I was planning to spend a sabbatical year in Berkeley in 2005, but the United States Embassy in London put paid to that idea and I went to CITA in Toronto instead.)

The last encounters I had with George were online; he was in the audience when I gave talks in the Chalonge-de Vega series organized by Norma Sanchez in 2021 (here and here). I think he had already moved to Paris by that time. The first of these talks was about open access publishing in astrophysics; George subsequently co-authored a paper in the Open Journal of Astrophysics.

My favourite quote from George came during a discussion we had at Berkeley when I suggested that some methods used for studying the cosmic microwave background could be applied to the distribution of galaxies. His response was “Galaxies are shit”. To avoid offending my friends who work on galaxies, what he meant by that was that he thought galaxies were too messy for any statistical measurements to sufficiently reliable to compete with the CMB. I think he would have preferred a universe in which all galaxies were identical, like electrons.

I’m sure many others will have their own personal reflections on their interactions with George Smoot, but he also had a huge influence on many people who never met him personally, through his enormous contributions to astrophysics and cosmology. We will no doubt read many professionally-written official obituaries in days to come, but all I can say in a personal blog post is that he was a character, a very original thinker, a fine scientist, and a very nice man. Along with many others, I will miss him enormously.

Rest in Peace, George Fitzgerald Smoot III (1945-2025) .

Update: Here is an `In Memoriam’ piece from from the Berkeley Lab.

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That Magic Gene…

Posted in Biographical, Covid-19, History, LGBTQ+ with tags , , , , on September 25, 2025 by telescoper

While writing yesterday’s post about the evolution of languages, and the importance of genetic information in reconstructing the story thereof, I was reminded of a post I wrote a while ago about the peculiarities of my own genome, a listing of which I have on a CD-ROM at home. There’s not as much data involved as you might think: it’s effectively only about 800 MB.

Anyway, to cut a long story short, it turns out that I have the CCR5-Δ32 genetic mutation. Not only that, I have it twice over, in that I have two copies (homozygotes). I must therefore have inherited it from both parents. This mutation confers virtually complete immunity from HIV-1 infection.

The above graphic shows that more than 10% of the population in Northern Europe has this mutation in just one allele (i.e. they are heterozygotic). To get an estimate of how many have the form on two alleles (i.e. homozygotic) form you can just square that number, so around 1% or more.

It is thought that the CCR5-Δ32 mutation occurred in a single individual in Scandinavia around 1,000 years ago. When I wrote that post I tacitly assumed that it had propagated passively, i.e. without any particular selection, to the modern era. That it reached 10% of the population starting from just one individual surprised me, but I let it pass.

More recently, I came across a paper about how advances in genetics have impacted epidemiological studies. In the abstract it shows that my assumption was probably incorrect.

Algorithms of molecular evolutionary theory suggested that the CCR5-Δ32 mutation occurred but once in the last millennium and rose by strong selective pressure relatively recently to a ~10% allele frequency in Europeans. 

It goes on to say this:

Several lines of evidence support the hypothesis that CCR5-Δ32 was selected due to its protective influence to resist Yersinia pestis, the agent of the Black Death/bubonic plague of the 14th century.

I didn’t mention in yesterday’s post that evidence of the plague bacillus is found in a significant number of prehistoric human remains and this almost certainly played a role in the ebb and flow of populations. In the context of CCR5-∆32, however it seems that it may have been advantageous to carry it long before the arrival of HIV/AIDS. That might account for it reaching the relatively high level that it did.

Among the downsides, however, as the article explains, are an increased risk for encephalomyelitis and death when infected with the West Nile virus. Hopefully further cohort studies of people with this mutation will help elucidate its effect on other diseases.

By the way, in contrast to most people I know, I have still never had Covid-19…

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Proto, by Laura Spinney

Posted in History, Irish Language with tags , , , , , , , , on September 24, 2025 by telescoper

I interrupted the sequence of novels I’ve been reading recently to absorb a non-fiction book, Proto by Laura Spinney (left). I find linguistics a fascinating subject and when I saw a review of this recently and couldn’t resist. I’m glad I bought it because it’s absolutely fascinating. It is the story – or at least a very plausible account of the story of the lost ancestor of the Indo-European languages, the methods that have been used to reconstruct “Proto”, and why it was the spark that generated so many other languages across Europe, Eurasia and India.

The topic is very complex and I won’t attempt to describe it all in depth here; each chapter could be a book in itself because each family of languages within the Indo-European group – including lost ones such as Tocharian – has its own fascinating story. There are chapters focussing on the origins of language itself, the possibilities surround Proto (a language that was never written and probably exists in many dialects), Anatolian, Tocharian, Celtic, Germanic and Italic, the Indo-Iranian group (based on Sanskrit), Baltic and Slavic, and Albanian, Armenian and Greek. The last of these is fascinating because it used a method of writing borrowed from a  non-Indo-European source that became the origin of the European alphabet.

The story of which all these are subplots begins around the Black Sea shortly after end of the last Ice Age. In this area there lived mesolithic hunter-gatherers who had survived the ice who interacted with farmers moving up from the direction of modern day Syria. Their languages would have merged in some way to allow them to describe things that their neighbours had that they didn’t. Hunter-gatherers would not have words for, e.g., ploughing or barley while farmers would have fewer words for spears and other hunting equipment. Into this mix, the argument goes, came a third group, a fully nomadic culture called the Yamnaya people. These people and their successors subsequently underwent vast migrations from the steppes across the continent and were responsible for spreading the Proto-Indo-European languages. That’s a hypothesis, not a proven fact, but it is plausible and has a reasonable amount of evidence in its favour.

Recent progress in this field has been driven not only by linguists but also by archaeologists and geneticists, with each aspect of this triangulation vital. It was reading about archaeology in this book that prompted me to write a post about the Nebra Sky Disc. There are some fascinating snippets from palaeogenetics, too. Full DNA sequences are now known for about 10,000 individuals who lived in prehistoric times.

One extraordinary find involves two burials of individuals who both lived about 5,000 years ago. Their DNA profiles match so well that they were probably second cousins or first cousins once removed. The thing is that one of them was buried in the Don Valley, north-east of Rostov in modern-day Russian, while the other was found 3,000 km away in the Altai mountains. Assuming they were both buried where they died, the implications for the distance over which people could move in a lifetime are remarkable.

Another fascinating genetic snippet applies to Irish, a Celtic language. The Celtic languages derive from a proto-Celtic source that probably arose about 1000 BC. Around 2450 BC one of the cultures preceding the Celts arrived in Britain and Ireland, now called the Bell Beaker People because of their taste in pottery. The genetic record shows that the DNA of the Beaker folk replaced about 90% of the previous local gene pool, and all of the Y chromosomes; for some reason men of the earlier culture stopped fathering children. A similar change happened in Ireland, about 200 years later.One possible inference is that there was a violent conquest involving the erasure of the male population, but we don’t know for sure that it was sudden and catastrophic.

Whatever language the Beaker people brought with them was not Celtic (though it may have been Indo-European). The fascinating conundrum is that when Celtic languages arrived in Ireland whoever brought them left not a trace in the genetic record. This is unlike any of the similar changes in language use throughout European pre-history. Either the population responsible has not been identified or the language was spread through communication (e.g. for trade) rather than settlement. Irish may be a Celtic language, but there is little evidence of significant numbers of Celts settling here and bringing it with them.

Some time ago I wrote a post about the Celtic languages, which you might want to look at if you’re interested in this topic. A lot of that post I now realize to be very simplistic, but to add one other snippet I should mention that the name of Turkish football team Galatasaray translates to “Palace of the Celts” after the Celtic-speaking people who settled in Anatolia; these were the Galatians to whom Paul addressed his Epistle.

I thoroughly recommend this fascinating book. It made me want to find out more about so many things. It also gacve me additional motivation to pursue an idea I had a while ago to do a Masters in Linguistics wehn I retire from physics…

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And then there were three…

Posted in Politics with tags , , , , , , on September 24, 2025 by telescoper

Nominations of candidates for the next President of Ireland (Uachtarán na hÉireann) closed at 12 noon, and only three gathered enough support to be named on the ballot paper. These are Catherine Connolly (left), Jim Gavin (centre) and Heather Humphreys (right). The last time there were as few as three candidates was 1990, when Mary Robinson was elected. The last Presidential Election had six candidates.

A number of names were touted ahead of today’s deadline for nominations, some plausible and some bizarre, but most dropped out without ever getting started. That list includes Bob Geldof, Michael Flatley of Riverdance fame, Conor McGregor (a famous rapist), a man who runs a doggy-day-care business, and a lady, whose name escapes me, who used to read the weather forecast on the telly.

Last week businessperson Gareth Sheridan also dropped out, having failed to convince enought local authorities to nominate him. The threshold for this route to nomination is very low, just 4 out of 31 – 26 County Councils, three City Councils (Dublin, Galway and Cork) and two hybrids (Limerick and Waterford). Sheridan only secured two so dropped out. I never really understood why he was standing as his company is facing litigation in the USA for fraud and breach of contract, and that would have undergone relentless scrutiny during the election campaign, so I find it strange he was willing to risk that. Anyway, it doesn’t matter now; he’s a non-runner.

The last one to drop out was ultra-conservative Catholic anti-everything campaigner Maria Steen. She went for the route of nominations from members of the  Oireachtas (TDs and Senators). After frantically scraping the bottom of the barrel she came up two short of the 20 needed and dropped out just before the deadline. My worry with this reactionary person was not that Ireland would end up with her as President, but that the election campaign (which will last a month) would be dominated by her airing her bigoted views.

The three remaining candidates are: Catherine Connolly (an independent TD standing as a unified leftist) who has the support of Sinn Féin, Labour, the Social Democrats and People Before Profit. Jim Gavin is a former GAA player and football manager for Dublin and flying instructor in the Air Corps who was picked up by Fianna Fáil as their candidate (although I don’t think he was a member before the campaign started); and last;y we have the Fine Gael candidate Heather Humphreys. I normally react with an instant “no” to FG drones, but she is a Presbyterian, whose father was a member of an Orange Order, which would be interesting for North-South politics on the island.

Maria Steen would probably have fragmented the right-wing vote and thus favoured Connolly on first preferences, but now it’s basically a choice between one left and two right. Since FF and FG are basically equivalent, they will probably mainly transfer to each other, so if Connolly is going to win she will have to do it on first preferences.

Election day (24th October) is exactly a month away. Deciding who to vote for will be as easy as one-two-three.

PS. The bookies’ odds via Oddschecker are: Humphreys 11/10 fav; Gavin 15/8; Connolly 5/2.

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How to Fight Fraudulent Publishing

Posted in mathematics, Open Access with tags , , , , , , , on September 23, 2025 by telescoper
Photo by Tima Miroshnichenko on Pexels.com

There’s a short article on arXiv with the title How to Fight Fraudulent Publishing in the Mathematical Sciences: Joint Recommendations of the IMU and the ICIAM which is well worth reading. The abstract is not useful but the prelude reads:

Prelude. In November 2023, Clarivate announced that it had excluded the entire field of mathematics from the latest edition of its influential list of ‘highly cited researchers’. This prompted the IMU and the ICIAM to conduct a more thorough investigation into the problem of fraudulent publishing in the mathematical sciences (see [1]). Understanding the problem is one thing; finding a way out and regaining control is another. With the recommendations given below, we would like to start the discussion on how, as a global community, we can achieve this. We are all concerned. It affects the very core of the science we love so much. I.A.

arXiv:2509.09877

The paper correctly identifies predatory journals and citation cartels as two consequences of the effort to quantify and rank the quality of research through scientific ‘performance indicators’, in the form of bibliometric measures and suggests some possible remedies.

Many of the recommendations are already included in the San Francisco Declaration on Research Assessment (SFDORA). Many also apply beyond the mathematical sciences (which is why I dropped the Mathematical Sciences bit in the title of the paper from the title of this blog post) and it’s not a long paper so I suggest you read it.

In my view one of the most important steps to take is to ditch the reliance on such companies as Scopus and Clarivate, who have deliberately constructed a system that is so easy to game. All higher education institutes should follow the examples of the Sorbonne University in Paris and, more recently, Utrecht University in the Netherlands. The academic publishing racket is inherently fraudulent. Too many universities, and indeed researchers employed by them, are willing participants in the system.

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Euclid Flagship 2 Update

Posted in Euclid, The Universe and Stuff with tags , , , on September 22, 2025 by telescoper

I was thinking earlier today that it’s been a while since I last posted anything about the European Space Agency’s Euclid Mission but I’ve got an excuse to remedy that today because there is a brand new a press release about the Euclid Consortium’s Flagship 2 simulations, a (low-resolution) visual representation of one of which is shown above.

The news is that the largest ever synthetic galaxy catalogue is now public; a team of 8 institutions within the Euclid Consortium, led by the Institute of Space Sciences (ICE-CSIC) and the Port d’Informació Científica (PIC) in Barcelona have developed this `mock’ catalogue, which includes 3.4 billion galaxies, each with 400 modelled properties available for the scientific community. It was constructed to help analyse data from the Euclid mission, but has many other potential uses so is being shared otuside the Consortium.

You can read more about this catalogue, and also find out how the access the simulated catalogues, here. You could also read the scientific paper describing the flagship simulations here.

P.S. The first main data release from Euclid (known to its friends as DR1) will take please on October 21, 2026. That’s just 13 months away…

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Autumnal Equinox 2025

Posted in Biographical, Education, Maynooth, The Universe and Stuff with tags , on September 22, 2025 by telescoper

Just a note to say that the Autumnal Equinox (in the Northern hemisphere) takes place this evening (Monday 22nd September 2025)  at 19.20 Irish Summer Time (18.20 UTC).

Although  the term `equinox’  refers to a situation in which day and night are of equal length, which implies that it’s a day rather than a specific time, the astronomical equinox is more accurately defined by a specific event, i.e. when the plane defined by Earth’s equator passes through the centre of the Sun’s disk (or, if you prefer, when the centre of the Sun passes through the plane defined by Earth’s equator). Day and night are not necessarily exactly equal on the equinox, but they’re the closest they get. From now on days in the Northern hemisphere will be shorter than nights and they’ll get shorter still until the Winter Solstice on Sunday 21st December 2024 at 3.03 pm Irish Time.

Many people take the autumnal equinox to be the end of summer. There is a saying around these parts, however, that `Summer is Summer to Michaelmas Day’ (September 29th), which is not until next week. I must say, though, though it doesn’t feel particularly summery this morning as there is a chilly wind blowing from the North.

Anyway, make the most of the Equinox because there is a rumour circulating that The Rapture will occur tomorrow (Tuesday 23rd September).

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Back to Teaching and Coping with GenAI

Posted in Artificial Intelligence, Education, mathematics, Maynooth with tags , , , , on September 21, 2025 by telescoper

Summer is well and truly over: it’s a chilly day in Maynooth; the Autumnal Equinox takes place tomorrow; and tomorrow I return to teaching at Maynooth University. So begins my antepenultimate academic year as a university teacher.

I’ve often remarked how the academic year at Maynooth is largely defined by the astronomical phenomena of the equinoxes and solstices. This year demonstrates this perfectly: Semester 1 lectures for undergraduates begin tomorrow (22nd September), the day of the Autumnal equinox; they end on Friday 19th December with the Winter Solstice on 21st. The half-term study break coincides with Samhain, a cross-quarter day. It’s all refreshingly pagan.

This time last year, having been away on sabbatical the year before, I was preparing to teach two new modules. I have those two again this year so this year should be a bit easiest than last year. I still have to get everything sorted out, though, including setting up my Moodle pages and preparing the materials, which is what I’ve been doing today.

The timetable for my Engineering Mathematics (EE206 Differential Equations and Transform Methods) module has not changed, so my first lectures on that (a double session) are not until Tuesday. I’m also doing MP469 Differential Equations and Complex Analysis for 4th Year Mathematical Physics students again, but the lecture times for that have changed. That is because, as a consequence of the merger of the Departments of Theoretical Physics and Experimental Physics to form a single Department of Physics, times have been coordinated as far as possible to ensure that Physics students can have flexibility in their choice of theoretical or experimental-based modules. The Engineering Mathematics module has not changed because the times for those lectures are such as to fit with the needs of the Department of Engineering, rather than Physics.

The upshot of all this is that my first lecture of the new term is for MP469, tomorrow afternoon at 2pm and my second is also MP469, at 11am on Tuesday. This means that I have three hours of lectures on Tuesdays this term, but at least that makes it possible to have a day without teaching (Wednesday).

You will notice that both the modules I am teaching this term are mathematical in nature. I have been concerned about the integrity of the coursework element of these modules in the light of improvements in Generative AI. Only a couple of years ago GenAI could not solve the sort of problems I set for homework, but now it generally can – especially for EE206. I don’t altogether object to people applying artificial intelligence to solve mathematical problems, but the issue is that it does make mistakes. Moreover, instead of saying “sorry I can’t solve that problem” it will generally present a superficially plausible but incorrect solution. Although students will probably use GenAI for problem-solving, I think it is important that they learn to do such problems themselves, otherwise they won’t know whether the solution coughed up by the algorithm is correct or not. That way lies disaster.

The only way to learn mathematics is by doing it. If students get GenAI to do the mathematics for them, then they won’t learn it. In the past we have given marks for coursework (usually 20% of the module mark) mainly to encourage students to do them. Students who don’t bother to do these exercises generally do badly in the final exam (80%).

For these reasons I am moving the assessment from weekly homework sheets – which could be tackled with AI – to supervised in-class tests for which students can use notes on paper, but not laptops or phones, just like they would in the final examination. I will of course give examples for the students to have a go at themselves, and I will give feedback on their attempts, but they will not contribute to the module score. Another advantage of this approach is that students won’t have to do so much work against deadlines outside of class.

Anyway, that’s the approach I am going to try. I’d be interested to hear what others are doing to deal with GenAI. The Comments Box is at your disposal.

P.S. There is a rumour circulating that The Rapture will occur on Tuesday 23rd September, but it is as yet unclear whether this will happen before, during, or after the lectures I am due to give on that day.

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Weekly Update from the Open Journal of Astrophysics – 20/09/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , on September 20, 2025 by telescoper

It’s Saturday again, so it’s time for a summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published two new papers, which brings the number in Volume 8 (2025) up to 136, and the total so far published by OJAp up to 371.

The first paper to report this week is “The Moon as a possible source for Earth’s co-orbital bodies” by Rafael Sfair, L. C. Gomes, O. C. Winter & R. A. Moraes (São Paulo State University, Brazil), G. Borderes-Motta (Astronomical Institute of the Czech Academy of Sciences, Czech Republic) and C. M. Schäfer (Universität Tübingen, Germany). This paper was published on Monday 15th September, in the folder Earth and Planetary Astrophysics, and it presents a numerical exploration of the ejection velocities and launch locations necessary for lunar ejecta to evolve into Earth’s co-orbital bodies.

The overlay is here:

 

You can make this larger by clicking on it.  The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, published on Friday 19th September in the folder Solar and Stellar Astrophysics, is  “Jet-Driven Formation of Bipolar Rings in Planetary Nebulae: Numerical Simulations Inspired by NGC 1514” by Muhammad Akashi, Ealeal Bear, and Noam Soker (Technion, Haifa, Israel). This paper presents evidence from numerical simulations notion that jets play a substantial role in shaping planetary nebulae (PNe).

The corresponding overlay is here:

 

You can find the officially accepted version on arXiv here.

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The Nebra Sky Disc

Posted in Art, History, The Universe and Stuff with tags , , , , on September 19, 2025 by telescoper
By Frank Vincentz – Public Domain, https://commons.wikimedia.org/w/index.php?curid=117229202

This remarkable object is made of bronze, is around 30 cm diameter and weighs about 2.2 kg. It has a blue-green patina and is inlaid with gold symbols, usually interpreted as the full moon, a lunar crescent, and stars, including a cluster of seven stars, thought to represent the Pleiades. The gold arc on the right probably represents the Sun’s path between the solstices; the angle subtended by the arc (82°) is the correct angle sunrise at the summer and winter solstices and at the latitude of the discovery site (Mittelberg, near Nebra, in Germany); there was probably another such arc on the other side of the disk (now lost). Remarkably, the tin used in making the bronze from which it is formed has been traced by metallurgical analysis to Cornwall.

The Nebra disc has been dated to c. 1800–1600 BCE (Bronze Age) which makes it the oldest (certain) depiction of celestial phenomena known from anywhere in the world. In November 2021, a replica of the Nebra Sky Disc was taken by German astronaut Matthias Maurer to the International Space Station.

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