New Publication at the Open Journal of Astrophysics!

It’s nice to be able to announce that the Open Journal of Astrophysics has just published another paper. Here it is!

It’s by Darsh Kodwani, David Alonso and Pedro Ferreira from a combination of Oxford University and Cardiff University.

You can find the accepted version on the arXiv here. This version was accepted after modifications requested by the referee and editor.

This is another one for the `Cosmology and Nongalactic Astrophysics’ folder. We would be happy to get more submissions from other areas of astrophysics. Hint! Hint!

P.S. A few people have asked why the Open Journal of Astrophysics is not listed in the Directory of Open Access Journals. The answer to that is simple: to qualify for listing a journal must publish a minimum of five papers in a year. Since OJA underwent a failure long hiatus after publishing its first batch of papers we don’t yet qualify. However, so far in 2019 we have published four papers and have several others in the pipeline. We will reach the qualifying level soon and when we do I will put in the application!

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Einstein’s Legacy

Yesterday I braved the inclement weather and the perils of weekend travel on Southern Trains to visit Queen Mary College, in the East End of London, for the following event:

I used to work at  Queen Mary, but haven’t been back for a while. The college and environs have been smartened up quite a lot since I used to be there, as seems to be the case for the East End generally. I doubt if I could afford to live there now!

Owing to a little local difficulty which I won’t go into, I was running a bit late so I missed the morning session. I did, however, arrive in time to see my former colleague Bangalore Sathyaprakash from Cardiff talking about gravitational waves, Jim Hough from Glasgow talking about experimental gravity – including gravitational waves but also talking about the puzzling state of affairs over “Big G” – and Pedro Ferreira from Oxford whose talk on “Cosmology for the 21st Century” gave an enjoyable historical perspective on recent developments.

The talks were held in the Great Hall in the People’s Palace on Mile End Road, a large venue that was pretty full all afternoon. I’m not sure whether it was the District/Hammersmith & City Line or the Central Line (or both) that provided the atmospheric sound effects, especially when Jim Hough described the problems of dealing with seismic noise in gravitational experiments and a train rumbled underneath right on cue.

UPDATE: Thanks to Bryn’s comment (below) I looked at a map: the Central Line goes well to the North whereas the District and Hammersmith & City Line go directly under the main buildings adjacent to Mile End Road.

Anyway, the venue was even fuller for the evening session, kicked off by my former PhD supervisor, John Barrow:

This session was aimed at a more popular audience and was attended by more than a few A-level students. John’s talk was very nice, taking us through all the various cosmological models that have been developed based on Einstein’s theory of General Relativity.

Finally, topping the bill, was Sir Roger Penrose whose talk was engagingly lo-tech in terms of visual aids but aimed at quite a high level. His use of hand-drawn transparencies was very old-school, but a useful side-effect was that he conveyed very effectively how entropy always increases with time.

Penrose covered some really interesting material related to black holes and cosmology, especially to do with gravitational entropy, but my heart sank when he tried at the end to resurrect his discredited “Circles in the Sky” idea. I’m not sure how much the A-level students took from his talk, but I found it very entertaining.

The conference carries on today, but I couldn’t attend the Sunday session owing to pressure of work. Which I should be doing now!

P.S. I’ll say it before anyone else does: yes, all the speakers I heard were male, as indeed were the two I missed in the morning. I gather there was one cancellation  of a female speaker (Alessandra Buonanno), for whom Sathya stood in.  But still.

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The Week’s Ending

A later post than usual for a weekend. I’ve been feeling a bit fragile all day after a very late night last night “playing Bridge” (i.e. drinking and gossiping into the early hours of the morning, with the occasional hand of cards thrown in for good measure). My broadband connection has also been playing up nearly as badly as the connections in my brain, although I don’t think there’s a causal relationship between the two. Anyway, just time for a round-up of, and some reflections on, the events of the past seven days.

This has been the first week of term, so has naturally been extremely busy. I got my first week’s second-year lectures, examples sheets and handouts together last Sunday for a 9am start on Monday morning. There were 104 students on the register, and I was delighted to find that 100 of them actually showed up bright and early for the first session. The lecture wasn’t brilliant unfortunately – I misjudged how many worked examples I could fit into an hour and got a bit rushed as a consequence. Still, at least nobody threw anything at me, and I survived. At the end of the week the students were asked to hand in solutions to some problems, which most of them seem to have done. Unfortunately, however, I neglected to ask for the key to the box in which they are posted before the support staff went home at 5pm, so the scripts are still all in the box. At least that gives me an excuse for not having started to mark them yet.

I gave another lecture this week to the 4-th year Cardiff students taking the Quantum Field Theory lectures from Swansea, to try and fill in a bit of background our lot won’t have learned in other lectures on relativistic quantum mechanics, chiefly the Dirac equation. I really love that sort of stuff, so didn’t mind stepping up to do an impromptu class on it. They seemed to find it reasonably useful, although I went on a bit longer than I should.

Two other events this week in the School were a colloquium by Dr Anupam Mazumdar from Lancaster on Wednesday and a seminar by Prof. Pedro Ferreira from Oxford yesterday (Friday), both of which were related to alternative theories of gravity (i.e. modifications of Einstein’s theory of general relativity). Pedro has co-authored a comprehensive review article on such things if anyone is interested in following up the details. The basic point, however, is that standard cosmology almost all develops from the assumption that gravity and space-time are described by general relativity. That theory is well tested on solar-system scales, but independent tests on the much larger scales involved in cosmology are hard to come by. It’s clearly therefore an important goal to work towards testing alternative theories, as is the case in any scientific discipline.

As well as these specific events there was a steady stream of problems and irritations to do with the teaching timetable: rooms too small, clashes, and so on. This is part of my responsibility as Director of Teaching and Learning in the School of Physics and Astronomy, and I don’t mind telling you that it’s a royal pain in the derrière. However, I think all the bugs have been ironed out and we can hopefully now carry on with a settled teaching programme into the new year.

Looking back on the week I can see so many things I would not long ago have found unbearably stressful, even going to the pub after Friday’s seminar.  Such victories, however insignificant they may seem to others,  have given me the confidence to face the  greater challenges that I know the future has in store.

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