Archive for the Cardiff Category

Bernard Schutz FRS!

Posted in Cardiff, The Universe and Stuff with tags , , , , on May 6, 2021 by telescoper

I was idly wondering earlier this week when the annual list of new Fellows elected to the Royal Society would be published, as it is normally around this time of year. Today it finally emerged and can be found here.

I am particularly delighted to see that my erstwhile Cardiff colleague Bernard Schutz (with whom I worked in the Data Innovation Research Institute and the School of Physics & Astronomy) is now an FRS! In fact I have known Bernard for quite a long time – he chaired the Panel that awarded me an SERC Advanced Fellowship in the days before STFC, and even before PPARC, way back in 1993. It just goes to show that even the most eminent scientists do occasionally make mistakes…

Anyway, hearty congratulations to Bernard, whose elevation to the Royal Society follows the award, a couple of years ago, of the Eddington Medal of the Royal Astronomical Society about which I blogged here. The announcement from the Royal Society is rather brief:

Bernard Schutz is honoured for his work driving the field of gravitational wave searches, leading to their direct detection in 2015.

I thought I’d add a bit more detail by repeating what was included in the citation for Bernard’s Eddington Medal which focuses on his invention of a method of measuring the Hubble constant using coalescing binary neutron stars. The idea was first published in September 1986 in a Letter to Nature. Here is the first paragraph:

I report here how gravitational wave observations can be used to determine the Hubble constant, H 0. The nearly monochromatic gravitational waves emitted by the decaying orbit of an ultra–compact, two–neutron–star binary system just before the stars coalesce are very likely to be detected by the kilometre–sized interferometric gravitational wave antennas now being designed1–4. The signal is easily identified and contains enough information to determine the absolute distance to the binary, independently of any assumptions about the masses of the stars. Ten events out to 100 Mpc may suffice to measure the Hubble constant to 3% accuracy.

In this paper, Bernard points out that a binary coalescence — such as the merger of two neutron stars — is a self calibrating `standard candle’, which means that it is possible to infer directly the distance without using the cosmic distance ladder. The key insight is that the rate at which the binary’s frequency changes is directly related to the amplitude of the gravitational waves it produces, i.e. how `loud’ the GW signal is. Just as the observed brightness of a star depends on both its intrinsic luminosity and how far away it is, the strength of the gravitational waves received at LIGO depends on both the intrinsic loudness of the source and how far away it is. By observing the waves with detectors like LIGO and Virgo, we can determine both the intrinsic loudness of the gravitational waves as well as their loudness at the Earth. This allows us to directly determine distance to the source.

It may have taken 31 years to get a measurement, but hopefully it won’t be long before there are enough detections to provide greater precision – and hopefully accuracy! – than the current methods can manage!

Here is a short video of Bernard himself talking about his work:

Once again, congratulations to Bernard on a very well deserved election to a Fellowship of the Royal Society.

UPDATE: a more detailed biography of Bernard is now available on the Royal Society website.

The REF goes on

Posted in Biographical, Cardiff, Maynooth with tags , , , , on March 27, 2021 by telescoper

A few communications with former colleagues from the United Kingdom last week reminded me that, despite the Covid-19 pandemic, the deadline for submissions to the 2021 Research Excellence Framework is next week. It seems very strange to me to push ahead with this despite the Coronavirus disruption, but it’s yet another sign that academics have to serve the bureaucrats rather than the other way round.

I know quite a few people at quite a few institutions that are completely exhausted by the workload required to deal with the enormous exercise in paperwork that is intended to assess the quality and impact of research at UK universities.

With apologies for adding to the stack of memes based on recent events in the Suez Canal, it made me think of this:

One of the major plusses of being in Ireland is that there is no REF, so I’m able to avoid the enormous workload and stress generated by this exercise in bean-counting. That’s good because there are more than enough things on my plate right now, and more are being added every day.

My memories of the last REF in 2014 when I was Head of School at Sussex are quite painful, as it went badly for us then. I hope that the long-term investments we made then will pay off, though, and I hope things turn out better for Sussex this time especially for the Department of Physics & Astronomy for which the impact and environment components of the assessment dragged the overall score down.

Not being involved personally in the REF this time round I haven’t really paid much attention to the changes that have been adopted since 2014. One I knew about is that the rules make it harder for institutions to leave staff out of their REF return. Some universities played the system in 2014 by being very selective about whom they put in. Only staff with papers considered likely to be rated top-notch were submitted.

Having a quick glance at the documents I see two other significant differences.

One is that in 2014, with very few exceptions, all staff had to submit four research outputs (i.e. papers) to be graded. in 2021 the system is more flexible: the total number of outputs must equal 2.5 times the summed FTE (full-time equivalent) of the unit’s submitted staff, with no individual submitting more than 5 and none fewer than 1 (except in special cases related to Covid-19). Overall, then there will be fewer outputs than before, the multiplier of FTE being 2.5 (2021) instead of 4 (2014). There will still be a lot of papers, of course, not least because many Departments have grown since 2014, so the panels will have a great deal of reading to do. If that’s what they do with the papers. They’ll probably just look up citations…

The other difference relates to staff who have left an institution during the census period. In 2014 the institution to which a researcher moved got all the credit for the publications, while the institution they left got nothing. In 2021, institutions “may return the outputs of staff previously employed as eligible where the output was first made publicly available during the period of eligible employment, within the set number of outputs required.” I suppose this is to prevent the departure of a staff member causing too much damage to the institution they left and also to credit the institution where the work was done rather than specifically the individual who did it.

Thinking about the REF an amusing thought occurred to me about Research Assessment. My idea was to set up a sort of anti-REF (perhaps the Research Inferiority Framework) based not on the best outputs produced by an institutions researchers, but on the worst. The institutions producing the highest number of inferior papers could receive financial penalties and get relegated in the league tables for encouraging staff to write too many papers that nobody ever reads or are just plain wrong. My guess is that papers published in Nature might figure even more prominently in this…

Anyway, let me just take this opportunity to wish former colleagues at Cardiff and Sussex all the best for their REF submission on Wednesday 31st March. I hope it turns out well

Cosmology Talks: Marika Asgari on Kids 1000

Posted in Cardiff, Maynooth, The Universe and Stuff with tags , , , , on January 18, 2021 by telescoper

It’s time I shared another one of those interesting cosmology talks on the Youtube channel curated by Shaun Hotchkiss. This channel features technical talks rather than popular expositions so it won’t be everyone’s cup of tea but for those seriously interested in cosmology at a research level they should prove interesting. Since I haven’t posted any of these for a while I’ve got a few to catch up on – this one is from September 2020.

In this talk Marika Asgari tells us about the recent Kilo-Degree Survey (KiDS) cosmological results. These are the first results from KiDS after they have reached a sky coverage of 1000 square degrees. Marika first explains how they know that the results are “statistics dominated” and not “systematics dominated”, meaning that the dominant uncertainty comes from statistical errors, not systematic ones. She then presents the cosmological results, which primarily constrain the clumpiness of matter in the universe, and which therefore constrain Ωm and σ8. In the combined parameter “S8“, which is constrained almost independently from Ωm by their data they see a more than 3σ tension with the equivalent parameter one would infer from Planck.

P. S. The papers that accompany this talk can be found here and here.

Cosmology Talks: Eiichiro Komatsu & Yuto Minami on Parity Violation in the Cosmic Microwave Background

Posted in Cardiff, Maynooth, The Universe and Stuff with tags , , , , , , , , on December 2, 2020 by telescoper

It’s time I shared another one of those interesting cosmology talks on the Youtube channel curated by Shaun Hotchkiss. This channel features technical talks rather than popular expositions so it won’t be everyone’s cup of tea but for those seriously interested in cosmology at a research level they should prove interesting.

In this video, Eiichiro Komatsu and Yuto Minami talk about their recent work, first devising a way to extract a parity violating signature in the cosmic microwave background, as manifested by a form of birefringence. If the universe is birefringent then E-mode polarization would change into B-mode as electromagnetic radiation travels through space, so there would be a non-zero correlation between the two measured modes. They  try to measure this correlation using the Planck 2018 data, getting  a 2.4 sigma `hint’ of a result.

A problem with the measurement is that systematic errors, such as imperfectly calibrated detector angles,  could mimic the signal. Yuto and Eiichiro’s  idea was to measure the detector angle by looking at the E-B correlation in the foregrounds, where light hasn’t travelled far enough to be affected by any potential birefringence in the universe. They argue that this allows them to distinguish between the two types of measured E-B correlation. However, this is only the case if there is no intrinsic correlation between the E-mode and B-mode polarization in the foregrounds, which may not be the case, but which they are testing. The method can be applied to any of the plethora of CMB experiments currently underway so there will probably be more results soon that may shed further light on this issue.

Incidentally this reminds me of Cardiff days when work was going on about the same affect using the Quad instrument. I wasn’t involved with Quad but I do remember having interesting chats about the theory behind the measurement or upper limit as it was (which is reported here). Looking at the paper I realize that paper involved researchers from the Department of Experimental Physics at Maynooth University.

P. S. The paper that accompanies this talk can be found here.

Out of the REF

Posted in Biographical, Cardiff, Maynooth with tags , , , , on November 25, 2020 by telescoper

I was talking over Zoom with some former colleagues from the United Kingdom last week, and was surprised to learn that, despite the Covid-19 pandemic, the 2021 Research Excellence Framework is ploughing ahead next year, only slightly delayed. There’s no stopping bureaucratic juggernauts once they get going…

One of the major plusses of being in Ireland is that, outside the UK academic system, there is no REF. One can avoid the enormous workload and stress generated by this exercise in bean-counting My memories of the last REF in 2014 when I was Head of School at Sussex are quite painful, as it went badly for us then. I hope that the long-term investments we made then will pay off, though, and I hope things turn out better for Sussex this time especially for the Department of Physics & Astronomy for which the impact and environment components of the assessment dragged the overall score down.

The census period for the new REF is 1st August 2013 to 31st July 2020. Not being involved personally in the REF this time round I haven’t really paid much attention to the changes that have been adopted since 2014. One I knew about is that the rules make it harder for institutions to leave staff out of their REF return. Some universities played the system in 2014 by being very selective about whom they put in. Only staff with papers considered likely to be rated top-notch were submitted.

Having a quick glance at the documents I see two other significant differences.

One is that in 2014, with very few exceptions, all staff had to submit four research outputs (i.e. papers) to be graded. in 2021 the system is more flexible: the total number of outputs must equal 2.5 times the summed FTE (full-time equivalent) of the unit’s submitted staff, with no individual submitting more than 5 and none fewer than 1 (except in special cases related to Covid-19). Overall, then there will be fewer outputs than before, the multiplier of FTE being 2.5 (2021) instead of 4 (2014). There will still be a lot, of course, so the panels will have a great deal of reading to do. If that’s what they do with the papers. They’ll probably just look up citations…

The other difference relates to staff who have left an institution during the census period. In 2014 the institution to which a researcher moved got all the credit for the publications, while the institution they left got nothing. In 2021, institutions “may return the outputs of staff previously employed as eligible where the output was first made publicly available during the period of eligible employment, within the set number of outputs required.” I suppose this is to prevent the departure of a staff member causing too much damage to the institution they left.

I was wondering about this last point when chatting with friends the other day. I moved institutions twice during the relevant census period, from Sussex to Cardiff and then from Cardiff to Maynooth. In principle, therefore, both former employees could submit my outputs I published while I was there to the 2021 REF. I only published a dozen or so papers while I was at Sussex – the impact of being Head of School on my research productivity was considerable – and none of them are particularly highly cited so I don’t think that Sussex will want to submit any of them, but they could if they wanted to. They don’t have to ask my permission!

I doubt if Cardiff will be worried about my papers. Among other things they have a stack of gravitational wave papers that should all be 4*.

Anyway, thinking about the REF an amusing thought occurred to me about Research Assessment. My idea was to set up a sort of anti-REF (perhaps the Research Inferiority Framework) based not on the best outputs produced by an institutions researchers but on the worst. The institutions producing the highest number of inferior papers could receive financial penalties and get relegated in the league tables for encouraging staff to write too many papers that nobody ever reads or are just plain wrong. My guess is that papers published in Nature might figure even more prominently in this

Diversity in Physics – LGBTQ+ STEMDay

Posted in Biographical, Books, Talks and Reviews, Cardiff, LGBT with tags , , , , on November 14, 2020 by telescoper

The nice people involved with Physics at Cardiff University, Prism Exeter and the GW4 group generally have organized a (virtual) event to celebrate Diversity and Inclusion for LGBTQ+ STEM Day 2020 which is to take place on November 18th (that’s next Wednesday). I’m very honoured to have been invited to give a keynote talk at this event, the poster for which is below, and am looking forward to it.

There’s a blog post here that gives more information about the event, including how to register in order to receive the Zoom connection.

I won’t be able to stay for the whole event as I am teaching later that day. I’d have been particularly interested in the session on Open Science…

Astronomy Look-alikes No. 100

Posted in Astronomy Lookalikes, Cardiff, Television with tags , , , on September 16, 2020 by telescoper

I haven’t done any of these for a while, but last night I was surprised to see Professor Jane Greaves of Cardiff University on television for the second time in a week so I couldn’t resist. I wonder how while discovering phosphine in the atmosphere of Venus she finds the time to play Detective Chief Inspector Vera Stanhope in the popular detective series Vera?

Today’s Big Astronomy Announcement

Posted in Astrohype, Cardiff, The Universe and Stuff with tags , , on September 14, 2020 by telescoper

Rumours have been circulating for a few days about a big astronomical discovery. Here is a video of the announcement:

Sorry, that’s the wrong video.

The actual announcement will take place live at 4pm BST here:

Until a few minutes ago I didn’t have a clue what this was about, but now I do…

Phone ship surprisingly detected in atmosphere of Venus (9)

If you would like to read more about this discovery then you can read the paper in Nature here. Several of the authors are former Cardiff colleagues, including first author Jane Greaves, as well as Annabel Cartwright and my former office mate Emily Drabek-Maunder. Congratulations to them on an exciting result!

P.S. Emily reminded me last night that I was present at the discussion with Jane that started this project, over four years ago. I remember them talking about phosphine but had no idea that it would lead to this!

Eddington in Cardiff 100 years ago today: the first proposal that stars are powered by fusion

Posted in Cardiff, History, The Universe and Stuff with tags , , on August 24, 2020 by telescoper

Here’s a fascinating bit of astrophysics history by former Cardiff colleague Bernard Schutz: one hundred years ago today, Arthur Stanley Eddington gave a talk in Cardiff in which he, with great prescience, proposed the idea that stars might be powered by nuclear fusion.

The Rumbling Universe

One hundred years ago today, on 24 August 1920, with over 1000 people gathered in Cardiff for the annual meeting of the British Association, Arthur Eddington gave his address as the incoming president of the physical and mathematical sciences section. He elected to speak on the subject of the “Internal Constitution of the Stars”. When I first came across the text of the address last year (published in Nature in 1920), I was amazed to find as early as this such an insightful proposal that stars are powered by the synthesis of helium from hydrogen. But what really brought me up short was this sentence:

If, indeed, the sub-atomic energy in the stars is being freely used to maintain their great furnaces, it seems to bring a little nearer to fulfilment our dream of controlling this latent power for the well-being of the human race – or for…

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Weekend Weather and Travel Updates

Posted in Biographical, Cardiff with tags , , , on February 16, 2020 by telescoper

I got back from London to Dublin last night, rather later than planned courtesy of Storm Dennis. I made my way to Heathrow more in hope than expectation, as there seemed to be a significant probability that my flight would be cancelled (as several were), but in the end it was only delayed by about an hour. It was a bit wobbly coming in to land, but the weather in Dublin wasn’t all that bad last night so there wasn’t the level of drama I expected. I did miss the last Hopper bus, though, and had to take a taxi to Maynooth.

There was another bit of disruption earlier in the day when I discovered that there were no Piccadilly or District line trains between Hyde Park Corner and Acton Town (in either direction), which makes it impossible to get to Heathrow directly by Tube. That gave me an opportunity to explore the London Underground to find a way through. I had plenty of time so I thought it would be fun. In the end I chose the Central Line to Ealing Broadway then a quick couple of stops on the District Line to Acton Town where there were trains to Mornington Crescent Heathrow Airport.

Dublin is to leeward when bad weather comes in from the Atlantic, so doesn’t get the worst of it. This seems to have been the case for Storm Dennis. Wales hasn’t been so lucky and I’ve spent the morning following messages on social media from friends and former colleagues about flooding along the Rover Taff. At one point there were 85 active flood warnings in Wales:

When I bought my house in Pontcanna I signed up for Flood Alerts, and I got one of them too. Here are some pictures of the area taken this morning:

This grim scene is not far from my house, but it’s not as scary as it looks. The River Taff is flanked by steep embankments as it passes into Cardiff and these provide strong flood defences. There is also a tidal barrage across Cardiff Bay which prevents tidewater coming up the River Taff while floodwater is trying to come down it, which is the usual recipe for a flood. The whole system is designed so that before these are breached, water floods out further North over Pontcanna Fields (a wide flat area that is part of the natural flood plain of the Taff that doesn’t have houses on it). A huge amount of water can be `parked’ in this area until the spate subsides. This happened before when I lived in Cardiff in 2009 and it’s nothing to worry too much about. It’s not good for people wanting to play rugby on the playing fields though!

After the terrible floods of 1979 Cardiff built very strong flood defences, but the same is not true for smaller towns up in the Welsh valleys. It seems that Pontypridd has been particularly badly hit this time. There seems to be no political will to spend money protecting such places, which in my view would be far more worthwhile than building HS2.

This all reminds me of the time when I first moved in to my house in Pontcanna over a decade ago. Late one rainy evening the phone rang and it was an automated flood warning. I responded by doing everything the message told me not to do: I put on my coat and went to the river to see what was happening. It’s only a ten minute walk from my house to the embankment. When I got there, I found a crowd of about a dozen people watching. The river was only about a metre below the level of the embankment as it roared its way down to Cardiff Bay carrying along tree trunks, car tyres and various other items of rubbish. It was quite impressive, but I didn’t watch for long as it was very cold and wet.

I’m told that the worst part of the 1979 flood was not the surface water, but the fact that the drainage system couldn’t cope and sewage backed up into the houses and streets. That must have been horrible as well as causing a serious health hazard.

Update: I heard last night that the level of the Taff on Sunday was 80cm higher than it was during the 1979 floods.

Anyway, I was glad I did get back last night as today I am giving a talk at the Joint Congress of University Astronomical Societies. I’d better get on and write it!