Last night offered spectacular views of the Aurora Borealis (Northern Lights) all over Ireland. I took these amazing pictures, which are among the best I’ve seen, in Maynooth, County Kildare. I know that to the untrained eye they look like ordinary clouds, but an expert such as myself can clearly see dynamic patterns of brilliant green grey that appear as curtains, rays, spirals, and flickers covering the entire sky. It was a stunning, once-in-a-lifetime experience to witness this dramatic cosmic spectacle!
By sheer coincidence, the very same day that I posted a piece in which complained that the issue of PhD stipends for Irish postgraduates had apparently been “kicked into the long grass”, the consultation has at last opened.
You can contribute your submission or submit your contribution, whichever seems appropriate, here.
This week my social media timelines have been filled with pictures like this of British supermarket shelves bereft of salad vegetables, especially tomatoes. The UK Government has stated, through its mouthpiece the BBC, that this is due to unseasonably bad weather in Spain and Morocco, although I very much doubt this is the whole story.
There have been reports of similar shortages in Ireland but all I can do is report on my own experience. Because I live on my own in a small town with plenty of shops nearby I don’t do a big weekly trip to the supermarket but prefer to buy fresh things as and when I need them, usually on the way home from work. I therefore generally pop into Dunnes and/or Supervalu every day. On no occasion this week have I noticed any shortage of tomatoes or other salad ingredients in Maynooth, despite always going in the evening when you might expect the shelves to be depleted. I found plenty of nice tomatoes from both Spain and Morocco, though the ones I actually bought – of the cherry vine variety – are from Italy. People living elsewhere in Ireland may of course have experienced shortages, but I certainly haven’t.
A couple of papers were published recently that attracted quite a lot of media interest so I thought I’d mention the work here.
The researchers detail the theory in two papers, published in The Astrophysical Journaland The Astrophysical Journal Letters, with both laying out different aspects of the cosmological connection and providing the first “astrophysical explanation of dark energy”. The lead author of both papers is Duncan Farrah of the University of Hawaii. Both are available on the arXiv, where all papers worth reading in astrophysics can be found.
The first paper, available on the arXiv here, entitled Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z<2, and makes the argument that observations imply that supermassive black holes grow preferentially in elliptical galaxies:
The assembly of stellar and supermassive black hole (SMBH) mass in elliptical galaxies since z∼1 can help to diagnose the origins of locally-observed correlations between SMBH mass and stellar mass. We therefore construct three samples of elliptical galaxies, one at z∼0 and two at 0.7≲z≲2.5, and quantify their relative positions in the MBH−M∗ plane. Using a Bayesian analysis framework, we find evidence for translational offsets in both stellar mass and SMBH mass between the local sample and both higher redshift samples. The offsets in stellar mass are small, and consistent with measurement bias, but the offsets in SMBH mass are much larger, reaching a factor of seven between z∼1 and z∼0. The magnitude of the SMBH offset may also depend on redshift, reaching a factor of ∼20 at z∼2. The result is robust against variation in the high and low redshift samples and changes in the analysis approach. The magnitude and redshift evolution of the offset are challenging to explain in terms of selection and measurement biases. We conclude that either there is a physical mechanism that preferentially grows SMBHs in elliptical galaxies at z≲2, or that selection and measurement biases are both underestimated, and depend on redshift.
arXiv: 2212.06854
Note the important caveats at the end. I gather from people who work on this topic that it’s a rather controversial claim.
The second paper, entitled Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy and available on the arXiv here, discusses a mechanism by which it is claimed that the formation of black holes actually creates dark energy:
Observations have found black holes spanning ten orders of magnitude in mass across most of cosmic history. The Kerr black hole solution is however provisional as its behavior at infinity is incompatible with an expanding universe. Black hole models with realistic behavior at infinity predict that the gravitating mass of a black hole can increase with the expansion of the universe independently of accretion or mergers, in a manner that depends on the black hole’s interior solution. We test this prediction by considering the growth of supermassive black holes in elliptical galaxies over 0<z≲2.5. We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence. The redshift dependence of the mass growth implies that, at z≲7, black holes contribute an effectively constant cosmological energy density to Friedmann’s equations. The continuity equation then requires that black holes contribute cosmologically as vacuum energy. We further show that black hole production from the cosmic star formation history gives the value of ΩΛ measured by Planck while being consistent with constraints from massive compact halo objects. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the onset of accelerating expansion at z∼0.7.
arXiv:2302.07878
The first I saw of these papers was in a shockingly poor write-up in the Guardian which is so garbled that I dismissed the story out of hand. I recently saw it taken up in Physics World though so maybe there is something in it. Having scanned it quickly it doesn’t look trivially wrong as I had feared it would be.
I haven’t had much time to read papers over the last few weeks but I’ve decided to present the second paper – the more theoretical one – next time I do our cosmology journal club at Maynooth, which means I’ll have to read it! I’ll add my summary after I’ve done the Journal club on Monday afternoon.
In the meantime I was wondering what the general reaction in the cosmological community is to these papers, especially the second one. If anyone has strong views please feel free to put them in the comments box!
A while ago Government of Ireland announced a new scheme intended to recruit “high-level researchers” to PhD programmes in Ireland. This scheme, which is a public-private partnership of around €100 million, will fund around 400 PhD studentships with an annual stipend around €28K, which is substantially higher than the current rate for, e.g., ICR-funded students which is €18.5K. The justification for the higher €28K stipends is that they would be “in line with financial supports offered under similar global scholarships”. I take this as a statement that the Irish Government has acknowledged that the proper rate of pay for a PhD student is at this level, which seems to me to be about right. It seems to me to be logical that all PhD stipends should be increased to this level.
High levels of inflation are combining with spiraling rental costs to make it very difficult for a student to live on the current level of stipend (especially in the Greater Dublin area). This forces postgraduate students to undertake large amounts of tutoring or other work in order to get by financially. This situation is a direct result of the chronic underfunding of higher education in Ireland which means that there aren’t enough academic staff to cover the teaching required. Universities will argue that they don’t have any choice but to exploit PhD students to make up the shortfall, but that doesn’t make the situation is acceptable.
It is of course good for a research student to get some teaching experience during their PhD but this should be on a voluntary basis. A PhD student who chooses to teach will probably do a better job than one who is forced to do it in order to pay the rent. My basic point, though, is that a full-time research student should be funded to do research full time, and it is grossly unfair to pay them too little for this to be possible.
There needs to be a serious “levelling up” of PhD stipends across the entire third-level sector in Ireland. I hope in particular that my own institution, Maynooth University, will take the lead and increase its PhD studentships to the fair level of €28K per annum. This would be a good way to spend at least some of the surplus of €13.2M it ran up during the first year of the pandemic alone.
UPDATE: The Government has now opened a consultation on PhD supports to which you can contribute here.
I saw this doing the rounds on Twitter the other day. I even made a little joke about it which went viral (by my standards) with over a million views and almost 2000 retweets:
This is nonsense. My students sleep perfectly well during my early-morning lectures. pic.twitter.com/k3CIROnBei
— Peter Coles @telescoper@mastodon.social (@telescoper) February 21, 2023
There’s no accounting for taste.
Am I a meme now?
Anyway, I’m in the office quite early this morning ahead of my 9am Computational Physics lecture so thought I’d do a quick post. I realize that 9am is not early compared to practice in some institutions abroad where lectures can start at 7.30am or even earlier. Everything I say here is based on my own experience and is not claimed to be universal.
As a lecturer I don’t mind 9am lectures at all. I find itt’s nice to get something significant done before 10am as opposed to just trying to deal with emails. On the other hand, I live only about 20 minutes’ walk away from campus so I don’t have to get up especially early. As a matter of fact I get up at 7am on weekdays, so no real adjustment is necessary for a 9am start. If I had a two-hour commute it would no doubt be a different matter.
At conferences and so on, I don’t find myself sleeping in the morning sessions. I find the slots immediately after lunch the worst for staying awake. That’s the time we have our theoretical physics seminars at Maynooth, actually.
My own experiences of being an undergraduate student (at Cambridge) was that I had regular 9am lectures 6 days a week (Saturdays included) and didn’t mind those either. But Cambridge is relatively compact and, living in College, it didn’t take me long to get to the lecture theatres in town. I usually felt quite sharp at 9am, actually, probably less so later in the morning.
Of course the reality is different for many students, some of whom have lengthy journeys into campus on not-entirely reliable public transport, so find a 9am start a challenge (to say the least). It’s certainly not unknown for students to doze off, but I don’t mind that as long as they don’t snore too loudly. I try to break up these lectures with things for the students to do, and that sometimes wakes them up again. In terms of attendance it’s the early evening slots that are worse in my experience than early morning.
Anyway, here in Maynooth we teaching staff have no real say over timetabling so now I should head off to Hall C to set up.
UPDATE: I had a pretty full class but one student did doze (without snoring) for about 3 minutes.
About ten days ago I wrote a piece about authorship of scientific papers in which I pointed out that in astrophysics in cosmology it is often the case that many “authors” (i.e. people listed in the author list) of papers (largely those emanating from large consortia) often haven’t even read the paper they are claiming to have written.
I now draw your attention to a paper by Stuart Macdonald, with the abstract:
You can find the full paper here, but unfortunately it requires a subscription. Open Access hasn’t reached sociology yet.
The paper focuses on practices in medicine, but it would be very wrong to assume that the issues are confined to that discipline; others have already fallen into the mire. I draw your attention in particular to the sentence:
Many authors in medicine have made no meaningful contribution to the article that bears their names, and those who have contributed most are often not named as authors.
The first bit certainly also applies to astronomy, for example.
The paper does not just discuss authorship, but also citations. I won’t discuss the Journal Impact Factor further, as any sane person knows that it is daft. Citations are not just used to determine the JIF, however – citations at article level make more sense, but are also not immune from gaming, and although they undoubtedly contain some information, they do not tell the whole story. Nor will I discuss the alleged ineffectiveness of peer review in medicine (about which I know nothing). I will however end with one further quote from the abstract:
The problem is magnified by the academic publishing industry and by academic institutions….
So many problems are…
The underlying cause of all this is that the people in charge of academic institutions nowadays have no concept of the intrinsic value of research and scholarship. The only things that are meaningful in their world are metrics. Everything we do now is reduced to key performance indicators, such as publication and citation counts. This mindset is a corrupting influence encourages perverse behaviour among researchers as well as managers.
ESA’s Euclid mission is designed to explore the composition and evolution of the dark Universe. The space telescope will create a great map of the large-scale structure of the Universe across space and time by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky. Euclid will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and the nature of dark energy and dark matter.
Euclid is a fully European mission, built and operated by ESA, with contributions from NASA. The Euclid Consortium – consisting of more than 2000 scientists from 300 institutes in 13 European countries, the US, Canada and Japan – provided the scientific instruments and scientific data analysis. ESA selected Thales Alenia Space as prime contractor for the construction of the satellite and its Service Module, with Airbus Defence and Space chosen to develop the Payload Module, including the telescope. NASA provided the near-infrared detectors of the NISP instrument.
Today is Shrove Tuesday, Pancake Day, and Mardi Gras, which gives me three excuses to post an authentic New Orleans parade tune from way back in 1927.
Jazz began with the marching bands that performed in New Orleans but then largely moved into the bordellos of Storyville, the biggest (legal) red light district in the history of the United States. When Storyville was closed down in 1917 as a threat to the health of the US Navy most professional jazz musicians lost their only source of regular income. Fortunately the very lawmakers who condemned jazz for its association with vice and crime soon passed a law that unwittingly ensured the music’s survival, proposing the 18th Amendment to the Constitution of the United States, passed in 1919, which prohibited the manufacture, distribution and sale of alcohol for human consumption. This was soon followed by the Volstead Act, which gave federal government the powers to enforce the 18th amendment. This ushered in the era of Prohibition, which turned Chicago into a bootlegger’s paradise almost overnight and jazz musicians flocked there to perform in the numerous speakeasies. That’s why so many of the great New Orleans Jazz records of the 1920s were actually made in Chicago.
Although the exodus was substantial, not all Jazz musicians left New Orleans. Many stayed there and kept the roots of the music going while it branched out in Chicago and, later, New York. Most of the bands that stayed kept going through the depression but never really achieved great commercial success until the traditional Jazz revival of the 1940s and 1950s. This example is a record produced by the Victor Record Company who sent a recording unit to New Orleans in 1927 to record some of the musicians who had stayed behind, many of them still playing in the marching band tradition of Buddy Bolden.
The title is To-Wa-Bac-A-Wa. I don’t know what it means but it’s an old French creole version of a tune that has subsequently reappeared many times in different forms with different names, most notably Bucket’s Got A Hole In it. The band is Louis Dumaine’s Jazzola Eight. Besides the lead cornet of Louis Dumaine, who lived from 1889 to 1949, it’s worth mentioning the clarinet style of Willie Joseph, which is heavily influenced by that of the great Johnny Dodds.
Anyway, it’s the kind of jaunty march-like number that’s perfect as a Mardi Gras parade tune and it always puts a spring in my step every time I hear it! There are also some old photographs of Mardi Gras parades to get you in the mood.
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In the Dark 