Saturday, 30 January 2016

Mathematica on the Pi

I have recently dug out my raspberry pi computer, in order to make it act as a RAID array, and a ssh gateway, now that I live in a place of my own where I can select the network provider to one that allows incoming traffic.  When I went to the raspberry pi website to get the latest operating system, I discovered that the Mathematica software comes for free with the Rasperry Pi standard Linux distribution these days.  It remains a very expensive piece of software on other platforms.

Mathematica is a kind of programming language which is very high-level, in the lingo of such things.  This means that it abstracts from the user as much of the basic operations of computer processors as possibles, and allows one to concentrate on the concepts that one is interested in -- in this case symbolic mathematics, broadly speaking.  It gets used by mathematicians and physicists, amongst others, as a sophisticated tool, just in the way they use any other tool, be it a pencil, or calculus, to help them discover and understand new things.  I have used it a little bit in the past (when I was a PhD student), when I was at an institution in which there was a license for the software.  I never used it enough to really get to grips with it, but found it useful enough.  Since then, I've become a lot more competent with its rival software Maple, thanks to having access at Surrey, and also having taken an Open University module which made use of it.  

Today, thanks to my Raspberry Pi and the new licensing policy, I fired up Mathematica for the first time in ages.  Here's a snapshot of me getting used to using it again -- in this case to plot a simple graph.  I had Mathematica running on my Raspberry Pi, which sits under my sofa, with no monitor attached, while I was sitting in my office, on campus, taking a break from marking exam papers, using my office computer as a display.

Friday, 29 January 2016

Meetings in 2016

This seems to be the time of year when various announcements for meetings get sent round, with the usual selection of conferences and workshops, with extended deadlines to ensure that they get as many attendees as they would like.  As much for my own benefit as anything else, here's a selection of them, and some comments:

• 30/03–01/04: IoP Annual Nuclear Physics Conference 2016: This is, as the name reveals, a conference that takes place every year around Easter time.  Its organisation cycles round the nuclear physics groups in the UK and this year it's Liverpool's turn.   It's a national conference aimed at attracting most of the UK community along, though it's open to all, and some of the invited speakers are usually from overseas.  It's a place where UK PhD students get to cut their teeth with a talk.  I like going to it, and usually do go.  Haven't quite made up my mind about attending this year.  Around Easter I have to also fit in visits to our MPhys students on placement.   Abstract Deadline 23/02.

• 19/06–24/06: Nuclei in the Cosmos XIV: The fourteenth in the series of a conference dedicated to the role of nuclear physics in astrophysics and cosmology.  The remit is pretty wide -- covering things like dark matter and dark energy (presumably because of putative detection methods), to nucleosynthesis, neutron stars, and even the rather general "radioactive nuclei far from stability" (presumably because of relevance to the r-process).  I've never been to one of these conferences, and my research is not directly related to astrophysics (though it has implications in it).   The conference is in Niigata, where I have never been, but I don't intend to submit an abstract.  I received an email today telling me that the abstract deadline has been extended to 10/02.

• 11/07–15/07: DREB2016: The acronym stands for Direct Reactions with Exotic Beams -- so a rather specific topic.  Exotic beams means that the beam nucleus which is being fired at some target is radioactive, which typically (always?) means that it has been created as a product in some reaction in an accelerator facility and then is immediately taken to be used as the beam for a further reaction.  A direct reaction is one in which a fast single-step reaction takes places, such as a single nucleon (proton or neutron) gets knocked out or transferred between the colliding nuclei (as opposed to, say, fusion).  I don't really think of myself as part of the DREB community, but the theoretical technique I use is used to study the dynamics of transfer reactions.  Just not by me -- at least not very much.  Surrey once hosted a conference in the DREB series, in 2003, and I went along to a little bit of that, as I recall.  This one is in Halifax, Novo Scotia.  I'd quite like to go there, but I don't think it's terribly reasonable of me to try to spin any of my recent work as being really on-topic (not that that seems to inhibit many people at conferences).  They have also extended their abstract deadline, which now stands at 14/02.

• 24/07–29/07: Nuclear Structure 2016:  The first announcement for this arrived in my e-mail earlier this week.  "Nuclear Structure" means the structures and properties of nuclei -- sometimes used as opposed to nuclear reactions (being how nuclei interact with each other).  The structural properties of nuclei affect almost everything else, such as how they react, and one can imagine a wide range of talks, though they will presumably be concentrated on straightforward determination and understanding of structure of nuclei, with new results from the latest experiments pushing towards never-before-seen isotopes, and the latest theoretical developments.  It's in Knoxville, Tennessee.  I used to live there, so if I go (I might) then it would not be as an excuse to see a new part of the world. Nuclear Structure 1998 (also in Tennessee) was one of the first conferences I ever attended, when I was a PhD student, and living over there.  Abstract Deadline 01/04.

• 11/09–16/09: INPC2016:  This is a big conference, at least by nuclear physics standards.  Unusually for nuclear physics, these International Nuclear Physics Conferences are so big they take place in convention centres, with the capacity to have multiple parallel sessions.  I think it is still a smaller conference than in some other areas of physics, like the SPIE Photonics West conference that I accompanied my wife on when she was speaking at one.  I sometimes hear my colleagues describe INPC as "too big".  I went to my first INPC at its last outing, in Florence.  I used the fact that it was large, and with a correspondingly large scope, to attend sessions far from my area of expertise and so to learn some new things.  I enjoyed it, and am thinking seriously of submitting an abstract to attend this year, too.  It's in Adelaide.  I've never been to Australia, but I have to make a visit around this time of year to visit one of our students on placement, so it seems sensible to visit for a week instead of a day.  I'm not sure if they've announced an abstract deadline, but the first circular promises a second circular in February, which will no doubt give more details.  The picture with this post is of the Adelaide Convention Centre.

Sorry if I've omitted your conference or workshop.  I know there are others.  The NuPECC list is the most comprehensive one I am aware of.

Wednesday, 27 January 2016

Upcoming Guildford Talks

Dr Suzie Sheehy, coming to Guildford on 10th Feb
I organise the Institute of Physics South Central Branch talks which are hosted at the University of Surrey, Guildford.  

If you live within striking distance, and fancy attending some free evening physics talks, aimed at a general audience, then here are the upcoming ones that are organised.  They all take place in Lecture Theatre D at the University of Surrey.  Further details available on the IoP Branch Calendar, or for individual events via the Facebook event links below, where you can optionally register interest / start discussions.

• 10/02/2016: "Five Things you Should Never do with a Particle Accelerator" -- Suzie Sheehy (Oxford).  

Particle accelerators are some of the most advanced machines on the planet. They incorporate an impressive range of cutting-edge technology to do what seems like a simple job – to give subatomic particles energy. So what would happen if we tried to use them in unexpected ways? With the help of demonstrations, accelerator physicist Dr. Suzie Sheehy will discuss her top five things you should never do with a particle accelerator and a few things you definitely should. [ facebook event page ]

• 16/03/2016: "Gamma-rays: Imaging the Invisible" -- Laura Harkness-Brennan (Liverpool)

The ability to accurately detect and locate sources of gamma-rays has importance in the fields of medicine, the energy industry, security and environmental monitoring.  Examples include earlier detection of cancer, decommissioning nuclear power plants and monitoring uptake of radiation by plans, which is important in fallout areas such as near Fukushima.  This talk will outline the latest research being carried out by the University of Liverpool to develop new techniques for gamma-ray imaging. [ facebook event page ]

• 11/05/2016: "Mathematics and Reality" -- Mary Leng (York)

Blurb for this one to come, but Mary is a philosopher of Mathematics, who will talk about the nature of mathematics and its ability to represent an objective reality (or something like that.  I'll post her own words in advertisement when I have solicited it from her).

Tuesday, 19 January 2016

Papers from Dubna

I had an email this morning telling me that the conference proceedings from the conference I attended in Dubna are now online.  The papers are all open access and hence free to read (and from any IP address).  I expect I'll have a browse of some of the papers whose associated talks I remember finding interesting.  Of course, my paper has been up on the arXiv since around the time of the deadline of paper submission.  The extended deadline, I mean.  

Anyway, if you want to read through some recent papers on nuclear physics, they are there for all to see.

Monday, 11 January 2016

Star Man

With us all waking up today to the news that David Bowie has died, the Internet has been busy with tributes to him.  Let me add mine here by sharing this sweet song about having kids, from his album Hunky Dory:

Friday, 8 January 2016

Implications in Astrophysics

I'm at a conference called "Recent Trends in Nuclear Structure and its Implications in Astrophysics".  They invited me here to come and talk, and I have indeed come and talked.  I don't consider myself to be a nuclear astrophysicist, though my two most cited papers are on neutron stars and the constraints put on their properties but the nuclear interactions that determine their structure. 

I wanted to make sure my talk was on-topic, though, so I had a think about what the implications of my work for astrophysics were, as per the title of the conference.  Fortunately for me, some of the speakers (like Umesh Garg from Notre Dame) spoke before me and essentially covered why the measurement and theoretical calculation of giant resonances, for example, are important astrophysical input.

The Giant Monopole Resonance (GMR) is an excitation mode of the nucleus which is sometimes called the breathing mode as it can be likened to an oscillatory expansion and contraction of a nucleus, like the expansion and contractions of lungs as one breathes.  It's an excitation mode found in all nuclei and it tells us something about how the nuclear interaction provides a restoring force when the nucleus is squashed into higher density, or rarefied into lower density.  This understanding of the density-dependence of the nuclear interaction is vital for understanding how neutron stars form.  Neutron stars are large nuclei in which the core density is higher than in normal nuclei -- not by factors of 100s, but enough that we need to do something more than look at nuclear ground states to learn about it.  The GMR gives such a way.  To link the properties of the GMR to the neutron star, though, the best one can do is to develop a theory which consistently gives correct reproduction of GMR properties, and to then use to for neutron star calculations (which are then compared to observational data).  This is where my calculations come in.  Hopefully I managed to convey a bit of that in my talk.  I've had a few people come up to me after and say that they enjoyed my talk and thought it was very clear and understandable, which is nice.  This is sometimes accompanied by questions which appear to suggest my talk was not as understandable as it could have been.

The image attached is the from a dance show put on for the conference attendees before the dinner on Wednesday.  It is a traditional dance local to the state of Odisha, where the conference is taking place.  It was a pretty cool dance.  The colour of the picture has not been changed;  there was a pretty trippy psychedelic light show to accompany the dancing and the music.

Monday, 4 January 2016

Names for new elements on the way

A few days ago, the International Union of Pure and Applied Chemistry (IUPAC),  announced that they had approved the claims to discovery of elements 113, 115, 117 and 118.  This means that the groups that were awarded priority of claim can now go ahead and pick names for the elements.  Element 113 has gone to the group at RIKEN in Japan, which I had the pleasure to visit in April.  This will be the first time that the group there has had a chance to name an element.  My bet is that they will do something geographic -- nihonium or something like that, to add to the list of synthetic elements named after places significant to their discovery, or to the discoverer.  I guess the trend started with polonium, though plenty of naturally-occurring elements have been named after places where they were discovered, or isolated (e.g. hafnium, strontium, ytterbium ...)

The other three elements, 115, 117 and 118, have gone to a collaboration between JINR (Dubna, Russia), LLNL (California, USA) and ORNL (Tennessee, USA).  Perhaps they will divvy one element to each of the three groups to name.  LLNL is Lawrence Livermore National Laboratory.  There is already a lawrencium (element 103) and a livermorium (element 116), not to mention californium (98), so they will have to think of something else.  Moscovium might be on the cards, it being the oblast in which Dubna is sited, and a previously mooted suggestion.