Archive for February, 2022

Two Years of Covid in Ireland

Posted in Biographical, Covid-19, Maynooth with tags , , on February 28, 2022 by telescoper

Trying to find something other than the conflict in Ukraine to write about, I thought I’d do a quick post to mark that we have reached the two year mark since the first “official” case of Covid-19 in Ireland was detected. It seems so long ago that I had forgotten that 2020 was a leap year and the date was 29th February, and the case was reported a day later on 1st March 2020.

It was to be another couple of weeks before we went into the first lockdown and I didn’t start keeping a log of all the cases and deaths until 27th March 2020, but you will find a complete record here (backdated to the date of the first case).

Here is the latest plot, with data complete up to today:

Today is the day that most Covid related restrictions are lifted. There is no longer a legal requirement to wear masks anywhere other than in healthcare settings, though at my University there is a recommendation to do so. I dropped into Dunnes this morning to buy a sandwich to have for lunch and I’d say a slight majority of shoppers (including myself) were still wearing masks, though all the staff I saw were unmasked (a fact which I found very disappointing).

I intend to carry on wearing a face covering in shops and, of course, in classrooms (and especially in labs) for the foreseeable future. I didn’t have any teaching this morning so I don’t know what the students are doing. We are told that if a student refuses to wear a mask then lecturers can’t make them, but peer pressure may do the job for us. We do have a significant number of students off and teaching staff unavailable due to Covid-19 infection but we just have to manage this as best we can.

The requirement to have a PCR test if you are symptomatic has also lapsed for most people in Ireland, but not for me. As I’m over the age of 55 I am still required to take a test if I have symptoms.

The drastic reduction in testing implied by the change in regulations will undoubtedly lead to a steep reduction in PCR-confirmed cases (currently running at a seven-day average of around 3500 per day) and in the light of this I’m not sure it’s worth carrying on plotting the data for much longer. I will persevere for the mean time though.

Holding your ground

Posted in Biographical, Brighton, Finance with tags , , , on February 26, 2022 by telescoper

Thinking about the brave defenders of Ukraine, especially in Kyiv, who include numerous civilians I suddenly remembered an old post about a friend I met in Brighton many years ago, a Jewish man of Austrian extraction who went by the name of Solly. He had been sent by his parents to live in England a few years before the start of World War 2 when he was still a teenager.

To cut a long story short, in 1940 Solly ended up joining the Local Defence Volunteers (the Home Guard) in Brighton. This is something he told me reminiscing abut those times. over dinner many years ago.

On 7th September 1940 the War Office issued the following communique:

Message to all UK units: codeword CROMWELL. Home Defence forces to highest degree of readiness. Invasion of mainland UK expected at any time.

After being informed of this signal Solly and his comrades turned up to be issued with the equipment with which they were expected to stop the imminent invasion. In his case it was an ancient pre-WW1 rifle, three rounds of ammunition, and two improvised grenades. With these meagre supplies, they were supposed to hold their positions until reinforced, possibly for up to 7 days.

As they walked to their posts, all the volunteers were certain that they had no chance and that none of them would survive the night. In such a grim situation they were understandably quiet, but what talk there was exclusively concerned the need to make all their shots count. If each of them could kill at least one invader before he himself was killed then the invasion might be thwarted.

After an agonizing wait, and several false alarms, dawn broke. The Germans never came.

Solly clearly found this recollection difficult. Few of us are ever faced with such a stark prospect of death. But I remember one thing he did say, which at the time I didn’t really understand, which is that it was in a way quite liberating – accepting that you are certain to die means that you no longer feel afraid. He had previously worried that he might lack the courage to fight if called upon to do so, but that doubt disappeared on 7th September 1940.

I think we’re already seeing this attitude in Ukrainian President Volodymyr Zelensky, who has emerged as a heroic figure . He must know that he is a marked man, and that his days are probably numbered, but he has refused offers to get him out to safety. The contrast between his courage and another so-called leader, who ran away from reporters to hid in a fridge, could not be greater.

Anyway, as the Russians enter the city of Kyiv, many civilians will be trying to summon up their courage right now. Received wisdom is that in urban fighting, the attacking force needs a numerical advantage of at least five to one and even more if the attackers are poorly trained conscripts, as seems to be the case in some parts of Ukraine. The defenders hold many cards, not least that it’s their land on which they’re fighting.

I fear that there is a bloodbath coming, but it seems to me very likely that the Russians will suffer worse. Not that Putin will be bothered. To him, his soldiers are mere cannon fodder.

To my Russian Friends

Posted in The Universe and Stuff on February 26, 2022 by telescoper

You can’t spend over 30 years working in theoretical physics without encountering Russian physicists and mathematicians. Over the years I’ve got to know a few quite well, through collaborations and discussions, and others by acquaintance. It occurred to me this morning that many of them might get caught up in the widespread condemnation of the Putin regime’s invasion of Ukraine. I don’t know any Russians (physicists or anything else) who support Putin or his oligarchs. I’m not saying that there are no such people, just that I don’t know any.

I think it’s important to say that my comments yesterday were not aimed at the many Russians around the world – including Russia itself – who want no part of the war and are horrified by the actions taken by the Russian leader.

As if to prove my point, there is an open letter from Russian scientists and science writers (in Russian here) which is already attracted a great many signatures.

On a related note this news, of Russian agency Roscosmos suspending all flights of the Soyuz spacecraft from the ESA launch facility in Kourou and withdrawing all Russian personnel from the site, seems to confirm what I thought yesterday, that the launch of Euclid will be postponed indefinitely. The alternative launcher, Ariane 6, has not yet had its first flight and at least two successful launches are required before it can be established as the vehicle for Euclid. On top of that the Euclid spacecraft itself will be need to be modified for the different vehicle. Details are yet to be confirmed, but it seems a lengthy delay is likely.

The Little Things

Posted in Biographical, Politics with tags , , , , on February 25, 2022 by telescoper

Yesterday morning I heard the news about Russia’s invasion of Ukraine via the radio as soon as it woke me up at 7am. It took me a while to summon up the energy to get out of bed and get ready for my 9am lecture. The routine things of life seem so trivial and futile compared to wars and other disasters over which one has no influence. But it does not help Ukraine (nor anyone else, including yourself) to be overwhelmed by despair. So I got up and did my lecture, as I did this morning with a 9am tutorial.

Somehow, it feels like a duty to persevere. I think that’s partly because the tyrants of this world want people to feel powerless. By persisting with the little things you are, in a very small way, defying those who want you to be terrified. The image of Vladimir Putin as some sort mastermind, a Karla-like bogeyman with strategic superpowers, has hypnotized too many. He’s just a sad old relic of the Cold War.

I try to resist looking at the news too often, my desire to stay informed tempered by a wish to remain sane. I’d like to believe that the Ukrainians can hold out, but they’re massively outnumbered and outgunned so the odds are heavily against them. But they’re fighting on their home soil for a just cause against an invader. That should count for something. The longer they can hold out wear down the Russian army the more chance there is that the tide will turn against Putin at home.

I doubt that sanctions from the West will have any impact on Putin’s murderous intentions, at least not in the short term. In any case they look weak to me. Russian teams are still playing in UEFA tournaments, and Russia will still be in Eurovision. Why is this tolerated?

I spent an hour yesterday on a zoom call related to the European Space Agency’s Euclid mission, which is due to be launched on a Russian Soyuz spacecraft in 2023. The latest batch of sanctions may lead to a delay in Euclid or even its cancellation. That would be a major problem for many scientists around the world. It’s a big thing for us, but it gets smaller when you compare it with what’s happening in the world. I bet a majority of us working in cosmology would prefer to see Euclid scrapped altogether than see further death and destruction unfold. I know I would.

It wouldn’t work that way, of course, but the question we have to ask ourselves is who are we happy to do business with? How could you sleep at night after giving money to or taking money from the Kremlin or its proxies? Maybe Putin will succeed only in giving the West a renewed sense of moral certainty.

For years the West has been corrupted by dirty money from Russia’s gangster oligarchs. Now Ukraine is paying the price. We’ve been far too slow to understand the true nature of who and what we’ve been dealing with. Now it’s time to get serious. “Business as usual” no longer applies, at least not with Russia…

A Dark Day #IStandWithUkraine

Posted in Politics with tags , on February 24, 2022 by telescoper

Just a reminder that Johnson’s UK Government has a huge majority in the House of Commons and could easily pass emergency laws to impose sanctions on Putin and his oligarch pals after Russia’s invasion of Ukraine, if it wanted to. It won’t, because the Conservative Party is awash with dirty Russian money and is fatally compromised.

February Storms

Posted in Talks and Reviews, The Universe and Stuff with tags , on February 23, 2022 by telescoper

We’ve had three major storms over the past week (Dudley, Eunice and Franklin). Today I was reminded that precisely five years ago today I was trying to make it from Cardiff to Lincoln to give a lecture, so I thought I’d reblog the post I wrote at the time. It took me nearly all day and I was an hour late, but, you know, the show must go on and so it did.

There’s obviously a thing about February and storms!

In the Dark

What a day!

This morning I set out from Cardiff to travel here to Lincoln for mypublic lecture. I took the9.45 train via Birmingham which, after a change of trains in Nottingham, should have got me into Lincoln at 14.23, with plenty of time to have a look around and chat to people before the scheduled start of my talk at 18.00 hours.

That was the plan, but it omitted an important factor:Storm Doris.Fallen trees, broken down trains and general disorganisation meant that it took ninehours to get to Lincoln, even including getting a taxi from Nottingham because I missed my connection.

The strangest thing was that I never actually saw any particularly bad weather. In fact there was quite a lot of sunshine en route. All the chaos was caused elsewhere, apparently.

Anyway I finally turned up almost an hour late for my talk…

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The art of building a smooth cosmic distance ladder in a perturbed universe

Posted in The Universe and Stuff with tags , , on February 22, 2022 by telescoper

Catching up on some literature on the inestimable arXiv I came across this paper by Obinna Umeh which I haven’t gone through in detail but which looks very interesting:

How does a smooth cosmic distance ladder emerge from observations made from a single location in a lumpy Universe? Distances to the Type Ia supernova (SN1A) in the Hubble flow are anchored on local distance measurements to sources that are very nearby. We described how this configuration could be built in a perturbed universe where lumpiness is described as small perturbations on top of a flat Friedmann-Lemaıtre Robertson-Walker (FLRW) spacetime. We show that there is a non-negligible modification (about 11%) to the background FLRW area distance due to the presence of inhomogeneities in the immediate neighbourhood of an observer. We find that the modification is sourced by the electric part of the Weyl tensor indicating a tidal deformation of the local spacetime of the observer. We show in detail how it could impact the calibration of the SN1A absolute magnitude in the Hubble flow. We show that it resolves the SN1A absolute magnitude and Hubble tensions simultaneously without the need for early or late dark energy.

The area distance here is what I usually call the angular-diameter distance; when one thinks of supernova measurements one usually thinks of the luminosity distance but these are related through the reciprocity relation discussed here which applies to each source regardless of whether the metric is of FLRW form or not. For a general discussion of cosmological distances see here.

A Time for Peace Piece

Posted in Jazz on February 22, 2022 by telescoper

With all that’s going on in the world right now it seems appropriate to repost this beautiful track by the great jazz pianist Bill Evans. I remember reading somewhere that Bill Evans recorded this right at the end of a session, in 1958. It was unrehearsed, entirely improvised and done in one take. It’s based on a simple two-chord progression that subsequently appeared in Flamenco Sketches, one of the tracks on the classic Miles Davis album Kind of Blue. To my ears, Peace Piece is more redolent of the composition style of Erik Satie than any other jazz musician I can think of. Although it starts out very simply it becomes more complex and fragmented as it develops, and makes effective use of dissonance in creating tension to contrast with the rather meditative atmosphere established at the beginning. Anyway, this is one of my all-time favourite tracks by one of my all-time favourite jazz musicians so I hope you don’t mind me sharing it on here.

Job Opportunity in Computer Science, Statistics or Applied Mathematics at Maynooth

Posted in mathematics, Maynooth with tags on February 21, 2022 by telescoper
This is the Library not the Hamilton Institute but you get the idea..

Just a quick post to pass on the news that my colleagues in the Hamilton Institute at Maynooth University have a vacancy for a permanent position at Professorial level.

You can find the full advert here. Please feel free to pass it on to anyone you think might be interested.

P. S. I’m looking forward to mentioning further announcements about a number of other permanent job opportunities at Maynooth in the not-too-distant future!

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , on February 21, 2022 by telescoper

It’s time yet again to announce a new publication in the Open Journal of Astrophysics! This one is the 3rd paper in Volume 5 (2022) and the 51st in all. We actually published this on Friday, byt I’ve only just got around to announcing it here now.

The latest publication is entitled Differentiable Predictions for Large Scale Structure with SHAMNet and is written by Andrew Hearin, Nesar Ramachandra and Matthew R. Becker of the Argonne National Laboratory and Joseph DeRose of the Lawrence Berkeley Laboratory (both institutions being in the USA).

Here is a screen grab of the overlay which includes the abstract:

You can click on the image to make it larger should you wish to do so. You can find the arXiv version of the paper here. This paper is in our popular Cosmology and Non-galactic Astrophysics section.

P. S. Here’s a bit of feedback from the author of this paper about the referees:

They reviewed the paper in conscientious detail, and every comment was thoughtful. We feel that our paper has materially improved in clarity as a result of their critique.”