The Escape Ladder – Joan Miró

Posted in Art with tags , , , on April 10, 2024 by telescoper
The Escape Ladder

by Joan Miró (1940, gouache, watercolor, and ink on paper, 38cm × 46 cm, The Museum of Modern Art, New York City )

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R.I.P. Peter Higgs (1929-2024)

Posted in Barcelona, Maynooth, R.I.P., The Universe and Stuff with tags , , , , , on April 9, 2024 by telescoper

I was very sad this afternoon to hear of the death of theoretical physicist Peter Higgs, on Monday 8th April 2024, at the age of 94. I never met Peter Higgs but I know how greatly liked and respected he was (see, e.g. here) and that he leaves an important legacy as a physicist, particularly the work that led to the award of the 2013 Nobel Prize for Physics (jointly with François Englert) . Condolences to his family, friends and colleagues.

You can read the very nice Guardian obituary here; there are many others published in media from elsewhere in the world (including Ireland and Barcelona).

I’ll add two extremely slight connections. One is that Peter Higgs visited Maynooth University in 2012, not long before his Nobel Prize was announced. The other is that he was born in the Elswick area of Newcastle upon Tyne, not far from Benwell, where I grew up.

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The Gates Foundation and Open Access

Posted in Open Access with tags , , , , , on April 9, 2024 by telescoper

There has been quite a lot of reaction (e.g. here) to the recent announcement of a new Open Access Policy by the Bill & Melinda Gates Foundation, which is one of the one of the world’s top funders of biomedical research. This mandates the distribution of research it funds as preprints and also states that it will not pay Article Processing Charges (APCs). The essentials of the policy, which comes into effect on 1st January 2025, are these:

  1. Funded Manuscripts Will Be Available. As soon as possible and to the extent feasible, Funded Manuscripts shall be published as a preprint in a preprint server recognized by the foundation or preapproved preprint server which applies a sufficient level of scrutiny to submissions. Accepted articles shall be deposited immediately upon publication in PubMed Central (PMC), or in another openly accessible repository, with proper metadata tagging identifying Gates funding. In addition, grantees shall disseminate Funded Manuscripts as described in their funding agreements with the foundation, including as described in any proposal or Global Access commitments.
  2. Dissemination of Funded Manuscripts Will Be On “Open Access” Terms. All Funded Manuscripts, including any subsequent updates to key conclusions, shall be available immediately, without any embargo, under the Creative Commons Attribution 4.0 International License (CC BY 4.0) or an equivalent license. This will permit all users to copy, redistribute, transform, and build on the material in any medium or format for any purpose (including commercial) without further permission or fees being required.
  3. Gates Grantees Will Retain Copyright. Grantees shall retain sufficient copyright in Funded Manuscripts to ensure such Funded Manuscripts are deposited into an open-access repository and published under the CC-BY 4.0 or equivalent license.
  4. Underlying Data Will Be Accessible Immediately. The Foundation requires that underlying data supporting the Funded Manuscripts shall be made accessible immediately and as open as possible upon availability of the Funded Manuscripts, subject to any applicable ethical, legal, or regulatory requirements or restrictions. All Funded Manuscripts must be accompanied by an Underlying Data Availability Statement that describes where any primary data, associated metadata, original software, and any additional relevant materials or information necessary to understand, assess, and replicate the Funded Manuscripts findings in totality can be found. Grantees are encouraged to adhere to the FAIR principles to improve the findability, accessibility, interoperability, and reuse of digital assets.
  5. The Foundation Will Not Pay Article Processing Charges (APC). Any publication fees are the responsibility of the grantees and their co-authors.
  6. Compliance Is A Requirement of Funding. This Open Access policy applies to all Funded Manuscripts, whether the funding is in whole or in part. Compliance will be continuously reviewed, and grantees and authors will be contacted when they are non-compliant.
    • As appropriate, Grantees should include the following acknowledgment and notice in Funded Manuscripts:
    • “This work was supported, in whole or in part, by the Bill & Melinda Gates Foundation [Grant number]. The conclusions and opinions expressed in this work are those of the author(s) alone and shall not be attributed to the Foundation. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. Please note works submitted as a preprint have not undergone a peer review process.”

Reactions to this new policy are generally positive, except (unsurprisingly) for the academic publishing industry.

For what it’s worth, my view is that it is a good policy, and I wish more funders went along this route, but it falls short of being truly excellent. As it stands, the policy seems to encourage authors to put the “final” version of their articles in traditional journals, without these articles being freely available through Open Access. That falls short of goal establishing a global worldwide network of institutional and/or subject-based repositories, linked to peer review mechanisms such as overlays, that share research literature freely for the common good. To help achieve that aim, the Gates’ Foundation should to encourage overlays rather than traditional journals as the way to carry out peer review. Perhaps this will be the next step?

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Presentation of the BAO DESI results at ICCUB Uni Barcelona – by Licia Verde & Héctor Gil Marin

Posted in The Universe and Stuff with tags , , , , on April 8, 2024 by telescoper

Last week, when I wrote about the new results from the Dark Energy Spectroscopic Instrument (DESI) I mentioned that there would be a seminar here at ICCUB about that very topic. Well, the seminar, by Licia Verde & Héctor Gil Marin, was recorded and here it is:

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Enjoy the Eclipse, but watch out for the cosmologists and druids!

Posted in Biographical, The Universe and Stuff with tags , , , , , on April 7, 2024 by telescoper

Ahead of tomorrow’s total eclipse of the Sun visible from a large part of the USA, I can’t resist sharing this excerpt from The Times warning about the consequences of a mass influx of people to Cornwall for the total eclipse of the Sun that was visible on August 11th 1999, almost 25 years ago. No doubt there are similar things going around about tomorrow’s eclipse:

I did write a letter to the Times complaining that, as a cosmologist, I felt this was very insulting… to druids. They didn’t publish it.

Anyway, I did get to see the total solar eclipse of 1999, not from Cornwall (where it was overcast and rainy) but from the island of Alderney (one of the Channel Islands). There was quite a lot of cloud cover in the morning of the big event so I was expecting to be disappointed. Indeed, the very start of the eclipse was hidden by cloud and there were groans from the large crowd assembled to watch it. A few seconds later, however, the clouds parted and we got a wonderful view. I remember very well that it seemed to get much colder during totality and an eery wind started to blow. Another thing is that all the birds thought it was night already and started to roost, although it was only around 11am.

You might think astronomers would be a bit indifferent to eclipses because they are well understood and totally predictable. But to experience an eclipse in person has a very powerful effect (or did on me anyway). We may be scientists but we don’t respond entirely rationally to everything. Nor should we.

Here’s a (not very good) scan of a (slightly damaged) picture from that eclipse:

Anyway, tomorrow (i.e. 8th April 2024) the total solar eclipse crosses North America with parts of 15 states able to view it: the eclipse will first appear along Mexico’s Pacific Coast at around 11:07 a.m. PDT, then travel across a swath of the U.S., from Texas to Maine, and into Canada. About 31.6 million people live in the path of totality. The path will range between 108 and 122 miles wide. An additional 150 million people live within 200 miles of the path of totality.

Do make the effort to see it if you can. It’s a remarkable experience that will live long in your memory. But watch out for the cosmologists and druids!

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Five New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , on April 6, 2024 by telescoper

As promised a couple of days ago, I am taking the opportunity today to announce the batch of papers at the Open Journal of Astrophysics that were paused slightly while we updated our system. This batch includes five papers, which I now present to you here. These five take the count in Volume 7 (2024) up to 25 and the total published by OJAp up to 140. We’re publishing roughly two papers a week these days so we expect publish about 100 this year.

In chronological order, the five papers, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.

This paper, by Yingtian Chen and Oleg Gnedin of the University of Michigan, is the 21st paper to be published in Volume 7 and the 136th altogether. It is a study of kinematic, chemical and age data of globular clusters from Gaia yielding clues to how the Milky Way Galaxy assembled. Here’s a screenshot of the overlay which includes the abstract. Note the new-style DOI at the bottom left.

You can read the article on arXiv directly here. This paper has a publication date of 20th March 2024, and is in the folder marked Astrophysics of Galaxies.

The second paper is “Generation of realistic input parameters for simulating atmospheric point-spread functions at astronomical observatories” by Claire-Alice Hébert (Stanford), Joshua E. Meyers (Stanford), My H. Do (Cal. State U, Pomona), Patricia R. Burchat (Stanford) and the LSST Dark Energy Science Collaboration. It explores the use of atmospheric modelling to generate realistic estimates of the point-spread function for observational work, especially for the Vera C. Rubin Observatory. This one is in the folder marked Instrumentation and Methods for Astrophysics and was published on 4th April 2024. Here is a screen grab of the overlay which includes the abstract:

 

You can find the officially accepted version of the paper on the arXiv here.

The third paper to announce is “Cosmic Dragons: A Two-Component Mixture Model of COSMOS Galaxies” by William K. Black and August E. Evrard of the University of Michigan (Ann Arbor, USA). This paper was also published on 4th April 2024,  is in the folder Astrophysics of Galaxies and you can see the overlay here:

 

The accepted version of this paper can be found on the arXiv here.

The next paper is “High mass function ellipsoidal variables in the Gaia Focused Product Release: searching for black hole candidates in the binary zoo” by Dominick M. Rowan, Todd A. Thompson,
Tharindu Jayasinghe, Christopher S. Kochanek and Krzysztof Z. Stanek of Ohio State University (USA). This paper, in the Solar and Stellar Astrophysics collection, describes a search for massive unseen stellar companions variable star systems found in Gaia data. This one was also published on 4th April 2024.

Here is the overlay:

 

 

You can find the full text for this one on the arXiv here.

Last in this batch, but by no means least, published yesterday (5th April 2024), we have a paper “Machine Learning the Dark Matter Halo Mass of Milky Way-Like Systems” by Elaheh Hayati & Peter Behroozi (University of Arizona, USA) and Ekta Patel (University of Utah, USA).  The primary classification for this one is once again Astrophysics of Galaxies and it presents a method for estimating the mass of a galaxy halo using neural networks that does not assume, for example,  dynamical equilibrium:

 

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

As you can see this is quite a diverse collection of papers. Given the increase in submissions in the area of galactic astrophysics we are very happy to welcome another expert in that area to our Editorial Board, in the form of Professor Walter Dehnen of the University of Heidelberg.

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Cosmology Talks: Cosmological Constraints from BAO

Posted in The Universe and Stuff, YouTube with tags , , , , , , , , , on April 5, 2024 by telescoper

Here’s another video in the Cosmology Talks series curated by Shaun Hotchkiss. This one very timely after yesterday’s announcement. Here is the description on the YouTube page:

The Dark Energy Spectroscopic Instrument (DESI) has produced cosmological constraints! And it is living up to its name. Two researchers from DESI, Seshadri Nadathur and Andreu Font-Ribera, tell us about DESI’s measurements of the Baryon Acoustic Oscillations (BAO) released today. These results use one full year of DESI data and are the first cosmological constraints from the telescope that have been released. Mostly, it is what you might expect: tighter constraints. However, in the realm of the equation of state of dark energy, they find, even with BAO alone, that there is a hint of evidence for evolving dark energy. When they combine their data with CMB and Supernovae, who both also find small hints of evolving dark energy on their own, the evidence for dark energy not being a cosmological constant jumps as high as 3.9σ with one combination of the datasets. It seems there still is “concordance cosmology”, it’s just not ΛCDM for these datasets. The fact that all three probes are tentatively favouring this is intriguing, as it makes it unlikely to be due to systematic errors in one measurement pipeline.

My own take is that the results are very interesting but I think we need to know a lot more about possible systematics before jumping to conclusions about time-varying dark energy. Am I getting conservative in my old age? These results from DESI do of course further underline the motivation for Euclid (another Stage IV survey), which may have an even better capability to identify departures from the standard model.

P.S. Here’s a nice graphic showing the cosmic web showing revealed by the DESI survey:

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DESI Year 1 Results: Baryon Acoustic Oscillations

Posted in Barcelona, Euclid, The Universe and Stuff with tags , , , , on April 4, 2024 by telescoper

There has been a lot of excitement around the ICCUB today – the press have been here and everything – ahead of the release of the Year 1 results from the Dark Energy Spectroscopic Instrument (DESI). The press release from the Lawrence Berkeley Laboratory in California can be found here.

The papers were just released at 5pm CEST and can be found here. The key results pertain to Baryon Acoustic Oscillations (BAOs) which can be used to track the expansion rate and geometry of the Universe. This is one of the techniques that will be used by Euclid.

There’s a lot of technical information to go through and I have to leave fairly soon. Fortunately we have seminar tomorrow that will explain everything at a level I can understand:

I will update this post with a bit more after the talk, but for the time being I direct you to the high-level cosmological implications are discussed in this paper (which is Paper VI from DESI).

If your main interest is in the Hubble Tension then I direct you to this Figure:

Depending on the other data sets included, the value obtained is around 68.5 ± 0.7 in the usual units, closer to the (lower) Planck CMB value than the (higher) Supernovae values but not exactly in agreement; the error bars are quite small too.

You might want to read my thoughts about distances estimated from angular diameters compared with distances measured using luminosity distances here.

If you’re wondering whether there is any evidence for departures from the standard cosmology, another pertinent comment is:

In summary, DESI data, both alone and in combination with other cosmological probes, do not show any evidence for a constant equation of state parameter different from −1 when a flat wCDM model is assumed.

DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations

More complicated models of time-varying dark energy might work, but there’s no strong evidence from the current data.

That’s all from me for now, but feel free to comment through the box below with any hot takes!

UPDATE: As expected there has been quite a lot of press coverage about this – see the examples below – mostly concentrating on the alleged evidence for “new physics”. Personally I think the old physics is fine!

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Open Journal of Astrophysics Update

Posted in OJAp Papers, Open Access with tags , , , , , on April 4, 2024 by telescoper

I’ve just noticed that my post earlier in the week about changes to the publication system at the Open Journal of Astrophysics is dated April 1st. I can assure you it wasn’t meant as a joke! Anyway, the integration with Crossref is now complete and I’ve started clearing the backlog of papers waiting to be published. I would say normal service has been resumed, but the idea is to make the process faster and more reliable than before so it’s hopefully a return but to better-than-normal service.

I want first of all to thank the people at Maynooth University Library, Crossref, and Scholastica for helping us figure out the issue and solve it. We would no doubt have got there faster were it not for the intervention of the Easter break, but in any case it has only required a pause of publication for a couple of weeks.

I’ll resume the regular weekly updates at the weekend. However, one paper got snarled up when we ran into a problem. Although published on 20th March, it was never properly registered with Crossref. The only way I could think of to sort out the issue with this one was to start it again, which I did this morning, and it is now published though I kept the publication date as 20th March.

This paper, by Yingtian Chen and Oleg Gnedin of the University of Michigan, is the 21st paper to be published in Volume 7 and the 136th altogether. It is a study of kinematic, chemical and age data of globular clusters from Gaia yielding clues to how the Milky Way Galaxy assembled. You can read the article on arXiv directly here.

You will note the new format of DOI on the overlay. Nothing else has changed that’s visible to the reader.

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Two Poems by Sir Thomas Wyatt

Posted in History, Poetry with tags , , , , , , , on April 3, 2024 by telescoper

Another character who appears in Hilary Mantel’s novel Wolf Hall is Sir Thomas Wyatt (1503-1542) who was a diplomat and member of the Court of Henry VIII, as well as being a fine poet. I thought I would post two of his famous poems.

The first is a sonnet, written some time in the 1530s, is ostensibly a (loose) translation of Petrarch’s Una Candida Cerva and thus one of the first examples of a Petrarchan Sonnet written in English. That makes it interesting in its own right, but many people think that it is actually about Anne Boleyn. The use of hunting as a metaphor for courtly love was widespread and, despite being married, Wyatt seems to have had his eye on Anne Boleyn. As far as is known, however, they didn’t have a sexual relationship. Wyatt wisely backed off when he realized he was competing with Henry VIII (thinly disguised as “Caesar”) in the penultimate line; Noli me tangere means “do not touch me” in Latin.

Whoso list to hunt, I know where is an hind,
But as for me, hélas, I may no more.
The vain travail hath wearied me so sore,
I am of them that farthest cometh behind.
Yet may I by no means my wearied mind
Draw from the deer, but as she fleeth afore
Fainting I follow. I leave off therefore,
Sithens in a net I seek to hold the wind.
Who list her hunt, I put him out of doubt,
As well as I may spend his time in vain.
And graven with diamonds in letters plain
There is written, her fair neck round about:
Noli me tangere, for Caesar’s I am,
And wild for to hold, though I seem tame.

Wyatt was in fact confined to the Tower of London in 1536 on suspicion of having committed adultery with Anne Boleyn; adultery with the King’s wife was considered treason, a capital offence. While in the Tower, where he witnessed executions, possibly including that of Anne Boleyn herself and others accused of treason with her, he wrote this other famous poem

Who list his wealth and ease retain,
Himself let him unknown contain.
Press not too fast in at that gate
Where the return stands by disdain,
For sure, circa Regna tonat.

The high mountains are blasted oft
When the low valley is mild and soft.
Fortune with Health stands at debate.
The fall is grievous from aloft.
And sure, circa Regna tonat.

These bloody days have broken my heart.
My lust, my youth did them depart,
And blind desire of estate.
Who hastes to climb seeks to revert.
Of truth, circa Regna tonat.

The bell tower showed me such sight
That in my head sticks day and night.
There did I learn out of a grate,
For all favour, glory, or might,
That yet circa Regna tonat.

By proof, I say, there did I learn:
Wit helpeth not defence too yerne,
Of innocency to plead or prate.
Bear low, therefore, give God the stern,
For sure, circa Regna tonat.

The repeated Latin phrase circa Regna tonat is usually translated “Thunder rolls around the Throne”, a reference to the dangerous temperament of the King.

Wyatt was not executed in 1536, but released after the intervention of none other than Thomas Cromwell. It seems he had a habit of sailing rather close to the wind, and was in and out of trouble with the King, being charged again with treason in 1541 and again released. He died, apparently of natural causes, in 1541, at the age of 39.

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