Archive for the The Universe and Stuff Category

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , on February 8, 2023 by telescoper

We’re on a bit of a roll at the Open Journal of Astrophysics and it’s time to announce yet another paper. We actually published this one yesterday (7th February 2023), which makes it two in two days. I don’t think we’ll keep up that rate but we have seen a big increase in submissions recently and these are working their way through the system very nicely. We aim to publish accepted papers within a day of the revised version appearing on arXiv.

The latest paper is the 6th paper in Volume 6 (2023) as well as the 71st in all. This one is another one for the folder marked Cosmology and Nongalactic Astrophysics. The title is “Almanac: Weak Lensing power spectra and map inference on the masked sphere”. The nub of the problem addressed by this paper is that the usual statistical analysis of data presented in projection on the sky involves spherical harmonics, which are orthogonal functions on the celestial sphere, but when the sky is not completely covered (i.e. part of it is masked), these functions are not orthogonal on what remains.

The authors of this paper are Arthur Loureiro (University of Edinburgh, UK), Lorne Whiteway (University College London, UK), Elena Selentin (Leiden University, NL), Javier Silva Lafaurie (Leiden University, NL), Andrew Jaffe (Imperial College London, UK) and Alan Heavens (Imperial College London, UK)

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

 

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.

How Euclid will scan the sky

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

A missive from Euclid High Command arrived yesterday confirming that ESA’s Euclid mission would be launched by SpaceX on a Falcon 9 rocket on a date between July 1st and July 30 (2023). It will soon be time to start getting nervous!

I also noticed that another video has appeared on the Euclid public website showing how the satellite will work. It’s not a traditional general-purpose observatory on which different users bid for time to observe different objects (as is the case for JWST, for example) but a dedicated mission that will compile a systematic survey with very specific science goals.

Euclid scans across the sky using a ‘step-and-stare’ method, combining separate measurements to form the largest cosmological survey ever conducted in the visible and near-infrared. Each time Euclid ‘stares’, its telescope points to a position in the sky, performing imaging and spectroscopic measurements on an area of approximately 0.5 deg² around this position. After each stare, the telescope steps to a new position.

This way the instruments will scan over a total of around 35% of the sky. This is the largest area over which one can guarantee a a complete detection of the galaxies necessary for Euclid’s cosmological studies. The rest of the sky is dominated by the high density of bright stars in our galaxy, and by the dust in the plane of our Solar System, both of which get in the way of the cosmology observations.

I hope this clarifies the situation.

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , on February 6, 2023 by telescoper

Well, it may be a Bank Holiday here in Ireland but there’s no break for the Open Journal of Astrophysics and it’s time to announce yet another paper hot off the press.

The latest paper is the 5th paper in Volume 6 (2023) as well as the 70th in all. This one is in the folder marked Instrumentation and Methods for Astrophysics. The title is “PSFs of coadded images”; for those of you not up with the lingo, “PSF” stands for point spread function.

The authors of this paper are Rachel Mandelbaum (1), Mike Jarvis (2), Robert H. Lupton (3), James Bosch (3), Arun Kannawadi (3), Michael D. Murphy (1) and Tianqing Zhang (1) and the LSST Dark Energy Science Collaboration. The affiliations of the individual authors are: (1) Carnegie Mellon University, Pittsburgh PA; (2) University of Pennsylvania, Philadelphia PA; (3) Princeton University, Princeton NJ; all in the USA of course.

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

 

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.

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , on February 3, 2023 by telescoper

The articles are coming in thick and fast at the Open Journal of Astrophysics. and why trying to get them refereed and published as quickly as we can. It’s time to announce yet another paper. This one was published officially yesterday (2nd February 2023) but I just found time to post about it here today before I go to my 9am tutorial.

The latest paper is the 4th paper in Volume 6 (2023) as well as the 69th in all. This one is in the Astrophysics of Galaxies folder.

The latest publication is entitled “Wide Binaries from GAIA EDR3: preference for GR over MOND?”.  The authors of this paper,  Charalambos Pittordis and Will Sutherland, are both based at Queen Mary, University of London. We published a related paper last month.

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 officially accepted version of the paper on the arXiv here.

The Euclid Public Website

Posted in Euclid, The Universe and Stuff with tags , , , , , on February 2, 2023 by telescoper

With the European Space Agency’s Euclid mission now scheduled for launch in the 3rd Quarter of 2023 a lot of work has been put in recently in developing the Euclid mission’s public website. For those of you not in the know, there is a summary on the new website:

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.

The public website is can be found here. Check it out. Many more stories, pictures and videos will be added over the forthcoming weeks but in the mean time here is a taster animated movie that shows various elements of the Euclid spacecraft, including the telescope, payload module and solar panels.

Even more information about the science to be done with Euclid can be found on the Euclid Consortium website, which is being revamped ahead of the launch.

Page Charges and Monthly Notices

Posted in Open Access, The Universe and Stuff with tags , , , , on January 31, 2023 by telescoper

Some time ago (in 2020) I reported here that the publishers of Monthly Notices of the Royal Astronomical Society (known as MNRAS for short) had decided to abandon the print edition and only have online articles. This is not surprising as demand for hard copies was falling drastically.

At the time I heard from a reliable source that MNRAS was also planning to introduce page charges – fees paid by authors to publish papers in the journal – and posted a comment to that effect here. This comment led to wild accusations of “serious academic misconduct” by me from a certain individual who shall remain nameless.

Well, the “rumour” I reported in 2020 is now confirmed to be the truth (as I knew it was). At a recent meeting of the national societies affiliated to the European Astronomical Society, Royal Astronomical Society President Mike Edmunds confirmed that, in the near future, all authors publishing in Monthly Notices of the Royal Astronomical Society will have to pay page charges. The timescale is “within a few years”.

This is part of a move to making all articles Open Access, largely forced by Plan S through which funding agencies require research outputs to be made freely available upon publication. Page charges are Article Processing Charges by another name.

Other notable journals, such as the Astrophysical Journal (ApJ) and Astronomy & Astrophysics (A&A), have levied page charges for as long as I can remember, though in the latter case it is complicated because there is a waiver for researchers in “member” countries. ApJ and other journals also have a waiver scheme for those who cannot afford to pay. For those who have to pay, the fee is usually about $100 per page. For a long time MNRAS was the exception and indeed the only feasible choice for people who don’t have access to funding to cover page charges, including many in the developing world. More recently, however, MNRAS introduced a charge for longer papers: £50 per page over 20 pages, so a paper of 21 pages costs £50 and one of 30 pages costs £500, etc. This will now be extended to all papers. I don’t have a figure for what MNRAS will charge in future or what waivers will be offered, but it seems likely to be similar to existing journals.

The introduction of page charges is an attempt to maintain the profitability of MNRAS after the loss of income from subscriptions, as readers will no longer be required to pay to read papers. It is therefore a transfer of cost from reader to author. I chose the ‘profitability’ because the prime purpose of MNRAS is no longer the dissemination of scientific results but the generation of income to fund other activities of the Royal Astronomical Society. Despite the move to the much cheaper digital-only publishing mode, the annual cost of an institutional subscription to this journal is currently over $10,000. Most of that is goes as profit to Oxford University Press (the actual publisher) and to the Royal Astronomical Society. Page charges are nothing to do with the actual cost of publication, but are intended to protect the publisher’s profit margins.

Much of what the RAS does with the revenue generated by journals is laudable, of course, but I don’t think it is fair to fleece researchers in order to fund its activities. I think authors can see this, and the attempt to transfer costs onto researchers will backfire. In particular, it’s a move that plays into the hands of The Open Journal of Astrophysics, which publishes papers (online only) in all the areas of Astrophysics covered by MNRAS, and more, but is entirely free both for authors and readers. If you don’t want to pay page charges, or make your library pay a subscription, then you could give it a try.

For myself, I abandoned the traditional journal system many years ago, as it is so clearly a racket.

The question for the Royal Astronomical Society, and other learned societies that fund their activities in a similar way, is whether they can find a sustainable funding model that takes proper account of the digital publishing revolution. If their revenue from publishing does fall, can they replace it? And, if not, in what form can they survive?

New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , on January 27, 2023 by telescoper

Time to announce another new paper at the Open Journal of Astrophysics. This one was published yesterday, 26th January 2023. The latest paper is the third paper in Volume 6 (2023) as well as the 68th in all. It’s yet another in the Cosmology and NonGalactic Astrophysics folder.

The latest publication is entitled “Palatini formulation for gauge theory: implications for slow-roll inflation” and the authors are Syksy Räsänen of the University of Helsinki in Finland and Yosef Verbin (The Open University of Israel, Ra’anana, Israel). The first author has  published a previous paper on the Palatini formulation in the Open Journal of Astrophysics.

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 officially accepted version of the paper on the arXiv here.

P.S. You may be wondering about the image shown in the overlay. This paper doesn’t contain any figures or images so I tried out the collection of stock photographs that comes free with the Scholastica platform by typing in “gauge”. The result was a quite amusing collection of pictures of various kinds of dials and other gauges. I quite liked the one above so used it just for show!

ChatGPT and Physics Education

Posted in Education, The Universe and Stuff with tags , , , on January 24, 2023 by telescoper

Following on the theme of ChatGPT, I see that Phil Moriarty has done a blog post about its use in Physics Education which many of my readers will find well worth reading in full. His findings are well in accord with mine, although I haven’t had as much time to play with it as he has. In particular, it is easily defeated by figures and pictures so if you want to make your assessment ChatGPT-proof all you need to do is unlike lots of graphics. More generally, ChatGPT is trained to produce waffle so avoid questions that require students to produce waffle. This shouldn’t pose too many problems, except for disciplines in which waffle is all there is.

Phil Moriarty also done a video in the Sixty Symbols series, on that YouTube thing that young people look at, which you can view here:

I start teaching Computational Physics next week and will be seeing how ChatGPT does at the Python coding exercises I was planning to set!

ChatGPT in the Swampland

Posted in Maynooth, Open Access, The Universe and Stuff with tags , , , , , on January 22, 2023 by telescoper

My inestimable PhD student Kay Lehnert has been having a look at the capabilities of the Artificial Intelligence platform ChatGPT at writing about string theoretical ideas, specifically the swampland conjectures. It’s remarkable what this does well but also notable what it doesn’t do well at all. What he found was so interesting he wrote it up as a little paper, which you can find on the arXiv here. The abstract is:

In this case study, we explore the capabilities and limitations of ChatGPT, a natural language processing model developed by OpenAI, in the field of string theoretical swampland conjectures. We find that it is effective at paraphrasing and explaining concepts in a variety of styles, but not at genuinely connecting concepts. It will provide false information with full confidence and make up statements when necessary. However, its ingenious use of language can be fruitful for identifying analogies and describing visual representations of abstract concepts.

It took arXiv a while to decide what to do with this paper as it doesn’t fit in any of the usual categories. The arXiv sections that usually cover string theory are General Relativity and Quantum Cosmology (gr-qc) and/or high-energy physics theory (hep-th), which was where it was originally submitted, but this isn’t really a string theory paper per se. After being held by the moderators for a while it eventually it appeared in Popular Physics (physics.pop-ph), cross-listed in Artificial Intelligence (cs.AI) & Computation and Language (cs.CL); the latter two are computer science categories, obviously.

Figure 2 of the paper, which you should read if you want to know what it represents!

The reclassification of this paper was perfectly reasonable. In fact with this, as with any other arXiv paper, the thing that matters most is that it it is freely available to anyone who wants to read it and is discoverable, i.e. can easily be found via search engines. In the era of Open Access, things will generate interest if they are interesting (and accessible).

We posted the following on the Maynooth University Theoretical Physics Department Twitter account, something we do whenever a new paper by someone in the Department comes out:

Judging by the number of views (101K) by this morning, this one certainly seems to be attracting interest! Hopefully this blog post will generate even more..

Finally, there might be people reading this blog who can suggest a journal that might consider publishing an article on this sort of subject? Whatever you think about ChatGPT I think it’s generating a lot of discussion right now, so the topic is… er… topical.

Please use the box below for any suggestions.

PhD Opportunity in Theoretical Astrophysics at Maynooth!

Posted in Maynooth, The Universe and Stuff with tags , , , on January 18, 2023 by telescoper

Posting this again because the deadline (31st January) is coming up fast….

The Department of Theoretical Physics at Maynooth University invites applications for a PhD in Theoretical Astrophysics starting in September 2023. The successful applicant will work in the group led by Dr. John Regan on a project examining the formation processes of massive black holes in the early Universe. Massive black holes populate the centres of all massive galaxies and are now also observed in both the centres and in off-centre locations in less massive dwarf galaxies.

For more details and instructions on how to apply, see here.