Euclid Update

Posted in Euclid, The Universe and Stuff with tags , , , , on October 7, 2023 by telescoper

Having settled in to my new apartment on the Gran Via I’ve got time for a another quick update on the European Space Agency’s Euclid mission. For full details about what follows you can see here. Everything I mention here is already in the public domain, so I am not disclosing any secrets!

The last update I posted contained some frustrating and potentially worrisome news: the Performance Verification (PV) phase of the mission had to be put on hold in order to troubleshoot an intermittent problem with the Fine Guidance Sensor (FGS), which is supposed to help to maintain correct pointing of the telescope. This wasn’t working correctly as demonstrated vividly by the following image:

Obviously the survey couldn’t proceed without accurate control of the pointing of the telescope so it was urgently necessary to find out what was going wrong and fix it. It turns out that the software was getting confused by the flashes caused by cosmic ray protons hitting the detectors, think they were the gude stars it was supposed to be steering by. After identifying the problem, new software was written and uploaded to the spacecraft.

I wasn’t sure how this had gone until I saw via an internal communication that the PV phase had restarted. That announcement would not have been made had the upgrade not worked and sure enough it has now been made public that all is well. Congratulations to the instrumentation and software teams for this success. They’ve been working phenomenally hard on this.

There was an additional problem with stray light in the telescope that I have also mentioned before. That was only an issue for specific orientations of the telescope and has been dealt with by simply redesigning the survey a little to minimize the occurrence of the effect.

So the gremlins have been dispelled, and we go on into the PV phase after a delay of about a month. The survey is due to last 6 year so this hiccup is not a big deal really. We can in fact anticipate some early science results from this phase in a month or so, although they will not be part of the full survey which will start after the PV phase is complete, after a few months.

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Apartament Nou

Posted in Barcelona, Biographical with tags , on October 6, 2023 by telescoper

Much to my surprise, my plan for relocating to Barcelona seems to be working out nicely. I booked a hotel initially while I looked around for an apartment for the bulk of my stay. I had a few disappointments with possible properties, and feared I might have to extend the hotel reservation, but then happened to be looking on one of the letting agency websites just as an ideal place in la Dreta de l’Eixample appeared. I got in touch with the agent straight away and had the chance to see the landlord the same day. We did the deal and so I have a place.

I had paid for 12 nights in the hotel (due to check out today), but my apartment was empty yesterday. The landlord was kind enough to allow me to leave some things there yesterday evening, before I returned to the hotel for my last night there. I checked out of the hotel and took the rest of my luggage to the apartment this morning. The apartment is only about 20 minutes away from the hotel, so it was easy to move my stuff.

A Room with a View

I did enjoy staying at the hotel -in particular it’s nice not having to get your own breakfast in the mornings – but it would be way to expensive there in the long term. Moreover, I like cooking and one can’t do that in a hotel room. The kitchen in my new place is small but fully equipped. The only problem is that the shelves are bare, for now, and I’ll need to buy quite a lot of ingredients before I can do anything complicated. My plan for the rest of today, therefore, is to cook something simple and relax with a bottle of the local wine to celebrate a mission accomplished.

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The Return of a Small Universe?

Posted in The Universe and Stuff with tags , , , , on October 5, 2023 by telescoper

Today I attended a cosmology discussion group where the paper being considered was by Jean-Luc Lehners and Jerome Quintin and was entitled A small Universe. Here is the abstract:

Many cosmological models assume or imply that the total size of the universe is very large, perhaps even infinite. Here we argue instead that the universe might be comparatively small, in fact not much larger than the currently observed size. A concrete implementation of this idea is provided by the no-boundary proposal, in combination with a plateau-shaped inflationary potential. In this model, opposing effects of the weighting of the wave function and of the criterion of allowability of the geometries conspire to favour small universes. We point out that a small size of the universe also fits well with swampland conjectures, and we comment on the relation with the dark dimension scenario.

arXiv:2309.03272

This paper is based on rather speculative arguments. I don’t have anything against those, but the discussion of this particular case reminded me that the idea that the Universe might be much smaller than we think is one that has come and gone many times during my lifetime. The point is that Einstein’s equations of general relativity are local in that they relate the geometric properties of space-time at specific coordinate position to the energy and momentum at the same position. When we make cosmological models based on these equations we usually assume a great deal of symmetry, i.e. that defined in a certain way the spatial sections which form surfaces of simultaneity have the same curvature everywhere, regardless of spatial position. The standard cosmology takes this curvature to be zero, in fact, so the spatial sections are Euclidean (flat), though the curvature could be positive or negative.

Usually when we assume the universe is flat we also assume that it is infinite, but it is possible in principle that a flat universe could be finite, for example in the case of a cube with opposite faces identified so that it has a sort of toroidal symmetry that has no physical edge. The size of the notional cube defines a topological scale which is independent of Einstein’s equations. That’ just a simple example: the topology does not have to be based on a cube; it could be, for example, a rhombic dodecahedron…

Likewise when we talk about a universe with negative spatial curvature we also assume it to be infinite, but that doesn’t have to be the case either: there are spaces with negative spatial curvature which are finite. A manifestation of this idea that I remember from way back in 1999 was a paper by Neil Cornish and David Spergel entitled A small universe after all?

Observing a small universe from the inside produces many interesting effects like a sort of cosmic hall of mirrors. For instance, if you can see far enough you will see the back of your own head. More realistically, the observed large-scale structure of the universe would repeat, and there would be correlated features in the cosmic microwave background. The idea is therefore amenable to observational test; the absence of any of the predicted correlations places constrains the topological scale to be comparable to the size of the observable universe or larger. Of course if it’s infinitely large then the small universe is not small at all…

(For a bit of gratuitous self-promotion, I refer you to a paper I wrote with Graca Rocha and Patrick Dineen back in 2004 using the WMAP observations of the CMB to constrain compact topologies. Given the wealth of new data we have acquired since then I’m sure the constraints are even stronger now.)

Anyway, my point is that speculative ideas are all very well but they don’t mean much if you can’t test them. This one at least has the virtue of making testable predictions.

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Towards a New Ecosystem for Scientific Publication

Posted in Open Access with tags , , , on October 4, 2023 by telescoper

A few days ago I posted an item about how the current system of scientific publication is under such intolerable strain that it is no longer fit for purpose. This is something I’ve felt for a while. Some time ago I wrote a post musing about what should replace it. That article included this:

I know I’m not alone in thinking that the current publishing ecosystem is doomed and will die a natural death soon enough. In my view the replacement should be a worldwide network of institutional and/or subject-based repositories that share research literature freely for the common good.

https://telescoper.blog/2023/09/12/lets-make-no-pay-open-access-real/

The Open Journal of Astrophysics was set up to demonstrate a way of achieving this kind of change in the field of Astrophysics. With this in mind I was delighted to to see a paper in PLOS Biology by Richard Sever (published just yesterday) with the following abstract:

Academic journals have been publishing the results of biomedical research for more than 350 years. Reviewing their history reveals that the ways in which journals vet submissions have changed over time, culminating in the relatively recent appearance of the current peer-review process. Journal brand and Impact Factor have meanwhile become quality proxies that are widely used to filter articles and evaluate scientists in a hypercompetitive prestige economy. The Web created the potential for a more decoupled publishing system in which articles are initially disseminated by preprint servers and then undergo evaluation elsewhere. To build this future, we must first understand the roles journals currently play and consider what types of content screening and review are necessary and for which papers. A new, open ecosystem involving preprint servers, journals, independent content-vetting initiatives, and curation services could provide more multidimensional signals for papers and avoid the current conflation of trust, quality, and impact. Academia should strive to avoid the alternative scenario, however, in which stratified publisher silos lock in submissions and simply perpetuate this conflation.

https://doi.org/10.1371/journal.pbio.3002234

(I added the emphasis). In case you were not aware, Richard Sever is a cofounder of the preprint servers bioRxiv and medRxiv.

I’m very glad to see similar thoughts to those I expressed about astrophysics being echoed in the field of biomedicine. I hope that more disciplines follow this path. The way it is realized will no doubt be domain-specific, but the benefits of such a new ecosystem will be for all science.

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Exploring the Cosmos at Maynooth

Posted in Maynooth, The Universe and Stuff with tags , , on October 4, 2023 by telescoper

Being away on sabbatical I almost forgot to post a reminder of the event I blogged about a few weeks ago at Maynooth University entitled Exploring the Cosmos. I’m told this has attracted a huge amount of interest, but the room for the event is very large and there may well be some space left.

Best wishes to everyone taking part and I hope it goes well!

On the 5th of October, at 6.30pm, in the TSI Building Maynooth University will host an all-ages event to explore the vastness of space. Using stunning visualisations Maynooth University Astrophysicists will examine star and planet formation, peer back in time with our physicists trying to image the very edges of our visible universe, and take a journey into the unknown as we trace the origin and evolution of black holes.

Programme:

18.30 Welcome

18.35: John Regan: “Black Holes in Our Universe”

Black Holes are among the most exotic objects in our Universe. In this talk John will discuss the basics of black hole formation, how we can detect them today and the future of black hole hunting using gravitational wave observatories that Maynooth University is a part of. John will also discuss some of the strange effects you might encounter near a black hole – like time slowing down!

18.55: Aoibhinn Gallagher: “The Dark Universe”

There is so much in our universe which is unknown to us, most of it in fact. What is dark matter, what is dark energy? We will go on a journey during this talk through the history of our universe and the history of cosmology (the study of the universe) itself to try and arrive at answers to these questions. Also I will talk about the real life science happening at Maynooth university on these very topics.

19.15: Tea & Coffee Break

19.45: Neil Trappe: “Seeing the Invisible Universe – Terahertz Astronomy”

When you look outside at the clear night sky you will see many thousands of stars overheard. The Moon, stars, planets, comets and galaxies can all be observed if you know where to look just using your eyes, binoculars or a telescope.

Astronomers spend many hours looking at the night sky with large automated telescopes from many exotic places around the world to add to our knowledge of the Universe and understand difficult questions like how did the Sun and our Solar System form, how are stars born and how do they die, is there life elsewhere in the Universe, and indeed how did the Universe come into existence at all?

In Maynooth University a team of researchers develop telescopes to see the Universe with different kinds of light, specifically far infrared or “terahertz” light. Why do we do this – we see the Universe differently and can learn lots more information ‘seeing’ with terahertz radiation that is invisible to our eyes.

20.05: Patrick Kavanagh: “The First Year of the James Webb Space Telescope”

The James Webb Space Telescope has made unexpected and groundbreaking discoveries almost routine in its first year. It has produced captivating images of our own Solar System, measured the content of atmospheres around other stars, viewed the stellar birth and death in amazing detail, revealed the skeletal structure of galaxies, and peered deep in to the cosmic past in search of the first stars and galaxies. In this talk Dr. Kavanagh will give an overview of Webb and present some of the highlights of the first year of this revolutionary telescope.

20.30: Finish

It should be a fun evening. If you’re around please come along. This event is free to attend but you need to register, which you can do here. Please feel free to share this with friends and colleagues.

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New Views of the Orion Nebula

Posted in The Universe and Stuff with tags , , on October 3, 2023 by telescoper

The Orion Nebula, a stellar nursery about 400 pc away from Earth, is a much-studied object that has yielded considerable insights into the processes of star formation. If you thought that there wasn’t much more to be learned about this object, though, you’d be very wrong. A set of JWST images has been released by the European Space Agency and they are amazing. You can see them all here, but here’s a taster in the form of a detail from one of the pictures. The following image is entitled “Explosion fingers from the BN-KL region in Orion” but to me it looks like demons rising up from the Underworld, like in the last act of Don Giovanni…

Here’s the blurb:

This cutout from the new NASA/ESA/CSA James Webb Space Telescope short-wavelength infrared image of the Orion Nebula shows bright ‘fingers’ of gas racing away from an explosion that occurred roughly 500 to 1000 years ago in the heart of a dense molecular cloud behind the nebula, perhaps as two young massive stars collided. The dense cloud is called Orion Molecular Cloud 1 and lies to the northwest of the visible Trapezium stars in Orion.

The fingers are predominantly red, indicating emission from molecular hydrogen gas that has been shocked by the immense energy pouring out from the explosion site. Near the tips of some of the fingers, the emission turns green due to hot iron gas and even white in some cases where the gas is at its hottest. Further down, the fingers seem mostly turbulent, but in some places, the flow appears laminar.

The Orion Nebula lies roughly 1300 light-years from Earth in the so-called ‘sword’ of the constellation of Orion the Hunter, and the image shows a region that is 4 by 2.75 light-years in size.

Image description: The image shows a series of red fingers of shocked molecular gas expanding from the bottom of the image towards the top and top right. Each of the fingers comprises a series of bright arcs of emission like bow waves, expanding behind tips, the latter often appearing green. There are many stars spread across the image with the characteristic eight spikes due to diffraction in the optics of Webb, and there is a foreground haze of wisp blue clouds due to the Orion Nebula, which lies in front of the fingers.

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Nobel Prize for Physics Speculation

Posted in Science Politics, The Universe and Stuff with tags , on October 2, 2023 by telescoper

Just  to mention that tomorrow morning (Tuesday, October 3rd 2023) will see the announcement of this year’s Nobel Prize for Physics. I must remember to make sure my mobile phone is fully charged so I can be easily reached.

Of course this is just one of the announcements. This morning, for example, there is the announcement of the Prize for Physiology or Medicine, and on Wednesday is the Prize for Chemistry: both of these sometimes go to physicists too. You can find links to all the announcements here.

I do, of course, already have a Nobel Prize Medal of my own already, dating from 2006, when I was lucky enough to attend the prize-giving ceremony and banquet.

I was, however, a guest of the Nobel Foundation rather than a prizewinner, so my medal is made of chocolate rather than gold. I think after 17 years the chocolate is now inedible, but it serves as a souvenir of a very nice weekend in Stockholm!

Regular readers of this blog, Sid and Doris Bonkers, may recall that I called it correctly last year when Alain Aspect, John F. Clauser and Anton Zeilinger won. I had however predicted them every year for many years until they won, and they won’t win it again, so I can’t follow my usual strategy. I’ll suggest that there’s an outside chance for Michael Berry and Yakir Aharonov for their work on the geometric phase, although if they were going to win they probably would have done so by now. Feel free to make your predictions through the comments box below.

To find out you’ll have to wait for the announcement, around about 10.45 (UK/Irish time) tomorrow morning. I’ll update this post when the wavefunction has collapsed.

UPDATE: The 2023 Nobel Prize for Physics goes to:

Pierre Agostini
The Ohio State University, Columbus, USA

Ferenc Krausz
Max Planck Institute of Quantum Optics, Garching and Ludwig-Maximilians-Universität München, Germany

Anne L’Huillier
Lund University, Sweden

“for experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter”

Congratulations to them! The full press release containing the citation can be found here.

Anyway, for the record, I’ll reiterate my opinion that while the Nobel Prize is flawed in many ways, particularly because it no longer really reflects how physics research is done, it does at least have the effect of getting people talking about physics. Surely that at least is a good thing?

P.S. My own claim for the 2023 Physics Nobel Prize is based on the discovery of the Coles Law.

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The Week in Barcelona

Posted in Barcelona, Biographical on October 1, 2023 by telescoper
The Arc de Triomf which can be loosely translated as “Arc de Triomphe”…

I was doing another tour of Barcelona today in the blazing sunshine, when it suddenly struck me that (a) I’ve been here for a week already and (b) it’s October! It certainly doesn’t feel like a normal October with not a cloud in the sky and the temperature at 27°C.

The tourist crowds were out in force. I always find it quite interesting listening for different languages as I go around. There are a few British and American, and of course Spanish, but the language I’ve come across most often among the tourists is French. That’s not surprising, of course, given the proximity to the border and, e.g., train services to and from France.

A bit of advice for people visiting. Many of the interesting locations (museums and art galleries, for example) are very busy and one can’t just turn up, buy a ticket and go in without a very long wait. The best way to do it is to buy a ticket online with a specific time on it, then you can bypass the queues and go straight in at the appointed hour.

The main that to have struck me while I’ve been here is that the cost of living is so much lower than Ireland. The grocery stores and supermarkets are stocked with a huge range of fresh food at prices much lower than back home. The choice of good quality wines for less than €10 per bottle is astonishing.

Eating in restaurants – even in the touristic areas – is generally inexpensive (although there are of course expensive places). In the area I am living in, every street corner seems to have a place where you can get something to eat and/or drink. I’ve sampled a few in my neighbourhood, and most have been very good indeed. There are, of course, some that aren’t so good.

Actually, I’m eating rather a lot less these days. I have a hearty breakfast but usually skip lunch and often only have a light snack or tapas in the evening. I think the temperature has reduced by appetite (at least for food….). That’s not bad, actually, because I could do with losing a bit of weight.

I’m still in my (very pleasant) hotel but will be moving to an apartment later next week, assuming nothing goes wrong with the contract.

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Gaudí and a Shorts Story

Posted in Architecture, Barcelona, Biographical with tags , , on September 30, 2023 by telescoper

It being a Saturday, and the weather forecast suggesting a temperature of around 30° C, I made an early start this morning to beat the tourist crowds and the heat as I walked around. I managed the latter but not the former. My aim was to visit the famous landmarks associated with architect Antoni Gaudí, the Casa Botlla and the still unfinished Sagrada Familia. Here are some pics I took on the way there and back.

Casa Batlló 
Crowded House
Approaching La Sagrada Familia
Closer view, with crowds
Entrance
Here’s another church they did earlier…

I didn’t actually go in either establishment because of the cost and the crowds. I’m told things will get a bit quieter later in the year so I might try again in November or so. Incidentally, if you’re interested in visiting the Sagrada Familia then be careful as it is quite difficult to get to: there are a lot of roadworks nearby associated with a new tram track so it’s best to walk there than try to get near it by car. It’s also quite expensive to get in – €34, no less. The other church (in the 6th pic) I passed on the way is, I think, this one.

The approach to the Sagrada Familia triggered some memories of my last visit there 30 years ago but the surrounding area has changed quite a bit. The fifth picture, entitled ‘Entrance’, was the best attempt I could make at recapturing an old view:

1993
2023

There is a busy main road now where there was a dirt track back in 1993 and I didn’t want to get run over by bus taking my picture so I couldn’t get close enough to reproduce the angle. Note also that the tower to the left in the old picture now has a new structure in front of it.

Anyway, I had a nice walk around, ending up by the harbour where there was a jazz-and-cocktails event going on but it was getting too hot by then so I went and ate an indoor pizza then retreated to my hotel for a siesta.

Last week, discovering how warm it is here, I decided to buy a new pair of shorts (Bermudas). That turned out to be trickier than expected. Many stores here are selling their autumn range rather than summer gear, but when I tried a nearby El Corte Inglés I found the remnants of the summer short range were on sale at half price. Sadly I was then flummoxed by the sizes and confounded by the lack of a signal so I could check using my phone. When I did find a conversion table from UK to Spanish sizes I found it was wildly inaccurate and had to try on three pairs of increasing size until I found a pair that fit.

Fancy that. Inaccurate information on the internet! Who would have though it?

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The Strain on Scientific Publishing

Posted in Open Access with tags , on September 29, 2023 by telescoper

It’s the end of my first week away but before I go home for a swim in the pool on my roof terrace I thought I’d share an interesting paper on the arXiv by Hanson et al. (4 authors) entitled The Strain on Scientific Publishing. The abstract is:

Scientists are increasingly overwhelmed by the volume of articles being published. Total articles indexed in Scopus and Web of Science have grown exponentially in recent years; in 2022 the article total was 47% higher than in 2016, which has outpaced the limited growth, if any, in the number of practising scientists. Thus, publication workload per scientist (writing, reviewing, editing) has increased dramatically. We define this problem as the strain on scientific publishing. To analyse this strain, we present five data-driven metrics showing publisher growth, processing times, and citation behaviours. We draw these data from web scrapes, requests for data from publishers, and material that is freely available through publisher websites. Our findings are based on millions of papers produced by leading academic publishers. We find specific groups have disproportionately grown in their articles published per year, contributing to this strain. Some publishers enabled this growth by adopting a strategy of hosting special issues, which publish articles with reduced turnaround times. Given pressures on researchers to publish or perish to be competitive for funding applications, this strain was likely amplified by these offers to publish more articles. We also observed widespread year-over-year inflation of journal impact factors coinciding with this strain, which risks confusing quality signals. Such exponential growth cannot be sustained. The metrics we define here should enable this evolving conversation to reach actionable solutions to address the strain on scientific publishing.

arXiv:2309.15884

Here’s a table with some figures taken from the article, from which is easy to identify the most extreme behaviour and see that it is associated with predatory publishers.

How did we end up with such an absurd system that encourages this sort of behaviour?

This of course just covers the big publishers. The Open Journal of Astrophysics is much smaller: it has only published about a hundred papers in the period covered by the Table. For comparison, the OJAp rejection rate is about 49% and our turnaround time is about three weeks, on average, though with a large dispersion.

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