School of Physics and Astronomy

Fabiola Gianotti, former spokesperson of the Atlas collaboration who co-announced the discovery of the Higgs boson at CERN in July last year, has been appointed an Honorary Professor in the School of Physics & Astronomy.

"I am very honoured and pleased to be appointed Honorary Professor at this prestigious School, which has such great historical traditions and excellent theoretical and experimental groups. I look forward to collaborating with the Edinburgh physicists, in particular with the very strong and lively ATLAS group". Fabiola Gianotti

Fabiola will be associated with the School's Experimental Particle Physics Group, which carries out research at both the ATLAS and LHCb experiments at the LHC. She will work with Edinburgh staff and PhD students based at CERN and visit the School for specialist lectures. 

Fabiola is a member of the International Advisory Committee of the Higgs Centre for Theoretical Physics at the University of Edinburgh, and has been a colleague of Peter Higgs himself for some time.

"We are delighted that Fabiola is now an Honorary Professor in our research group. Fabiola is very enthusiastic and we look forward to seeing her here in Edinburgh in the autumn." Peter Clarke, Edinburgh Particle Physics Research Group

"We are very excited Fabiola will be joining our ATLAS research team as a visiting professor. Her vast knowledge of the ATLAS experiment will be a great asset to our research on the Higgs boson and in searching for any new phenomena the LHC may reveal." Victoria Martin, Edinburgh Particle Physics Research Group

Distinguished career

Fabiola has had a distinguished career in particle physics. She gained her PhD in 1989 from the University of Milan. As a post-doctoral researcher her first project was the R&D for what later became the ATLAS experiment at the Large Hadron Collider (LHC). In 1996 she joined the ALEPH experiment at the LEP-II (Large Electron Positron) collider where she worked upon the search for evidence of supersymmetric particles, which are candidates for dark matter.

She became a CERN Fellow and then a member of the CERN staff in 1996. After a period of detector development she became involved in the many physics preparation studies needed in advance of the first proton beams at the LHC as well as work on the liquid Argon calorimeter. She was elected “Physics Coordinator” of ATLAS from 1999-2003, Deputy Spokesperson from 2004-2009, and then in 2009 she was elected as the Spokesperson of ATLAS, a position she held until she stepped down in March 2013. This position is one of the most senior leadership positions in the field of experimental particle physics, where she was responsible for a collaboration of nearly 3000 physicists from over 170 international Institutions. Her role has of course been central to the most recent high point of the LHC programme, the discovery of the Higgs boson.

Prizes

In 2012 she was awarded the title of "Grande Ufficiale al merito della Repubblica" by the Italian President Giorgio Napolitano. She received the Special Fundamental Physics Prize (funded by the Milner Foundation), awarded jointly to the ATLAS and CMS Spokespersons for their leadership that led to the discovery of the Higgs Boson, and was elected as a member of the Italian “Accademia Nazionale dei Lincei” in 2012.

In 2013 Fabiola was awarded the Italian “Nonino Prize” and the Enrico Fermi prize of the Italian Physical Society.

Soft Matter journal has published a paper that details a School research team's investigations into the mechanical properties of emulsions that are stabilized by micron-sized particles.

The team, based in the School's Institute for Condensed Matter and Complex Systems (ICMCS) included two undergraduate students: Louison Maurice, an exchange student from Lyon who is currently teaching Physics and Chemistry in a secondary school in France, and Ryan Maguire from Edinburgh who is now a Nuclear Safety Consultant.

"It was very interesting for me to be part of this project, because, thanks to it, I found out all about the research process, from the idea and the experiment to the publication of a paper." Louison Maurice

Job Thijssen explains the research work described in the paper.

We have investigated the mechanical properties of emulsions stabilized by micron-sized particles. Emulsions consist of droplets of a liquid dispersed in an immiscible liquid, eg water in oil. Such materials are ubiquitous in the food, personal-care, agricultural, pharmaceutical and petrochemical industries. Typically, a third component is needed to stabilize an emulsion, eg mustard in a vinaigrette of vinegar and olive oil. Conventional stabilizers tend to be surfactant molecules, ie similar to those in washing-up liquids. However, recent years have seen an increasing interest in emulsions stabilized instead by particles, known as Pickering emulsions, mainly because they feature superior functionality and shelf-life.

Mechanical properties

The mechanical properties of emulsions are crucial to their processing and use. For example, food spreads should not flow off the knife, but should spread easily onto a sandwich. The mechanical properties of particle-stabilized emulsions are not yet fully understood, as they arise from a complex interplay between the elasticity of the liquid-liquid interface at the droplet surface and interactions between the particles on that surface. Notably, we have used particles that mutually interact as hard spheres in the continuous phase under ambient conditions, ie they only repel one another upon contact. This well-defined interaction has helped us model their contribution to the mechanical properties of the corresponding Pickering emulsions.

Increased understanding

In our study, we have compressed Pickering emulsions using a centrifuge with the aim of better understanding their behaviour in mechanical equilibrium; this is also important in interpreting flow experiments on similar samples. In addition, we have developed a transparent Pickering emulsion, allowing us to characterize the structure of our samples in 3D using microscopy (see image). Finally, we can explain our data using a quantitative model in which we have incorporated interdroplet liquid films with a thickness on the scale of the particles and repulsive interactions across these films. We suggest that this repulsion between droplets is due to the energy-expensive deformation of the liquid-liquid interface between particles on one droplet due to compression against a neighbouring droplet.

Applications in porous materials

Finally, we discuss the relevance of our results to the rational design of porous materials. Using centrifugation (see image), we can squeeze our emulsions into foam-like structures, which have been suggested as templates for porous materials with applications in separation techniques, catalysis, thermal insulators, metal foams and electrodes. We can control pore size via the droplet radius, and wall thickness via the particle size and/or centrifugation speed. Moreover, the mechanical properties of these structures are crucial to their use as materials templates. For example, we have shown that changing the interactions between the particles may result in significant post-centrifugation expansion, with obvious consequences for post-processing.

The paper appears in Soft Matter, 2013,9, 7757-7765; DOI: 10.1039/C3SM51046H

A Scottish research team that includes the School's Prof. Cait McPhee and Postdoctoral Research Fellow Keith Bromley has uncovered the workings of a 'bacterial raincoat' that helps to protect bacteria from the changing environment in which they live.

The findings of the team, led by Dr Nicola Stanley-Wall and Professor Daan van Aalten from the College of Life Sciences at Dundee, are published today in the journal Proceedings of the National Academy of Sciences.

"Myself and Keith Bromley were responsible for measuring the interfacial properties of the protein, showing that it formed a robust film very quickly at an oil/water interface. The film it forms crumples like cellophane, and we can change how it partitions to the interface by mutating the protein, which gives us a lot of control. Our findings have implications for antibiotic resistance, and proteins like this have also found uses in industrial applications."

Prof Cait McPhee, of the School's Institute for Condensed Matter and Complex Systems (ICMCS)

Read the University of Dundee press release.

Congratulations to Flaviu Cipcigan, who won the award for the best presentation at the International School of Physics "Enrico Fermi". Flaviu presented work by the research group in which he is studying and his own PhD results.

The research group is working on a simplified quantum mechanical model for the water molecule, while Flaviu's PhD focuses on the development of this model and exploring its properties.

One of the School's industry-supported graduate students, Flaviu works with The National Physical Laboratory (NPL) and IBM Research in the US. The research group is led by Prof. Jason Crain (Edinburgh/NPL) and Prof. Glenn Martyna (IBM), in collaboration with Dr Vlad Sokhan (NPL) and Dr Andrew Jones (Edinburgh/NPL).

Find out more

Scroll down to the bottom of this page for a summary of Flaviu's first year of research, his winning presentation and poster.

Attachments

Attachment	Size
A summary of Flaviu's first year of research, which focused on the liquid-vapour interface.	2.92 MB
Flaviu's presentation	2.31 MB
Flaviu's poster	9.73 MB

This month, a team of four UK scientists, including Claire Cousins from the UK Centre for Astrobiology (UKCA) based at the University of Edinburgh, went to Iceland to test a prototype of the Panoramic Camera (PanCam) instrument, which will form a major component of the European Space Agency’s 2018 ExoMars rover. 

Sending a robotic rover to explore the surface of Mars is a significant challenge, and an endeavour that requires many years of preparation, particularly of the various instruments that will become part of the rover payload.

Minerals on Mars

Dr Cousins, along with colleagues from Aberystwyth University, Birkbeck College, and University College London, spent two weeks working at the Krafla volcanic region of northern Iceland. Here, the terrain is characterised by basaltic rocks that have undergone extensive aqueous alteration, producing many of the same mineral assemblages that have been identified on Mars. Such terrains are evidence of environments that, at least on Earth, are home to thriving microbial communities. This makes this location an ideal site for testing instruments that will be on future astrobiology missions, such as the ExoMars mission, which will need to identify rocks and sediments that were produced in past habitable environments. Volcanic processes are particularly relevant to past Martian environments, as volcanism has been so prevalent throughout Martian history.

PanCam science

The PanCam instrument does more than just image the rover’s surroundings. Two wide-angle cameras set 50cm apart provide stereo vision, meaning the terrain can be imaged in 3D. It also has the ability to view the terrain at many different wavelengths, from the visible to the near-infrared (VNIR), providing information on the spatial distribution of particular mineral types. Finally, PanCam has a High Resolution Camera, which can provide detailed images of particular features on a distant rocky target. All together, these various data products enable planetary scientists to carry out geological investigations of the surrounding terrain, which is crucial for target selection (ie where to send the rover to investigate further) when exploring the Martian surface.

Ground-truthing

The aim of the Iceland fieldwork was to test PanCam at sites where the team could take samples (for laboratory analysis), and other in-situ data, in order to establish the scientific capabilities of the instrument. These samples will be analysed with XRD and Raman Spectroscopy to identify their mineralogy, and with VNIR reflectance spectroscopy to see how their spectral properties compare with PanCam multispectral data. Additionally, in-situ reflectance spectra were measured from PanCam targets using a field reflectance spectrometer loaned from the NERC Field Spectroscopy Facility, also based at the University of Edinburgh in the School of Geosciences. All this information will eventually feed into the PanCam data processing pipeline, ultimately fine-tuning the instrument and its software so it can be used confidently on the surface of Mars.

"Testing instruments on these types of terrains is the closest we can get to simulating the Martian surface geology. This was a very successful trip, not least due to the combined expertise of the team that included geology, remote sensing and engineering. I'm hopefull it'll lead to more Mars analogue field-testing of future instrument concepts." Claire Cousins, UK Centre for Astrobiology

Find out more

More details of this research, including an up-to-date web blog detailing the fieldwork itself, can be found at http://clairecousins.wordpress.com/category/fieldwork/iceland/.

This post by Jon Hill, Imperial College London first appeared on EPCC's blog.

I always jump at the chance to work with EPCC because the people there have a wealth of experience of making scientific code go even faster. Whilst this is extremely important to our research, we don't have the time to do both science and improve code performance.

The Applied Modelling and Computation Group (AMCG), which is part of the Earth Sciences and Engineering department at Imperial College London, carries out research in a number of scientific fields, from ocean modelling, through computational  fluid dynamics, to modelling nuclear reactors. For all this research we use one of three codes: Fluidity, Radiant or FEMDEM.

I work on Fluidity, the finite element framework that is used for simulating fluid dynamics, ocean modelling, tsunami modelling, landslides, and sedimentary systems.

We at AMCG have worked with EPCC on a number of projects. Most recently via its APOS-EU project and a HECToR dCSE (distributed Computational Science and Engineering) project. Both of these projects focused on how to make Fluidity go even faster and scale further on current cutting-edge hardware.

The idea was to restructure our memory accesses such that they performed well on NUMA (Non-Uniform Memory Access) machines, where data is placed close to the processing core that needs it. If data is stored on memory on a neighbouring core you get a performance hit as the data is fetched. We had ideas on how to do this, but we needed experienced software engineers to carry out and test our ideas. This is where EPCC comes in - not only can they provide the software engineers, they can help improve our initial ideas. In addition, the APOS-EU project was also looking to the future and how we are going to write code for future architectures (hint: you don't, you let the computer do it for you).

Performance increase

Both projects went very well, achieving what was set out. The only disappointment is that for every performance increase that was done, another bottleneck appeared, limiting the final performance improvement - but there was an improvement in the end. Carrying out this work means we can now run on more than 32,000 cores on HECToR and we gained up to a 20% decrease in runtime. Moreover, we understand our performance bottlenecks better now.

It was a pleasure to collaborate with my former colleagues and friends. Fluidity is that bit faster, smarter and better now. That saves me time every time I run a simulation, which in turn means I can get more science done.

An international team of astronomers may have found a new way to map quasars, the energetic and luminous central regions often found in distant galaxies. Team leader Prof. Andy Lawrence of the University of Edinburgh presents the new results on Monday 1 July at the RAS National Astronomy Meeting in St Andrews, Scotland.

If a star passes too close to a giant black hole found in the centre of a galaxy, it will be shredded by the strong gravitational field. This produces a flare-up in the brightness of an otherwise normal looking galaxy that then fades over a few months. In a large scale survey using the PanSTARRS telescope on Hawaii, Prof. Lawrence and his team studied millions of galaxies to search for this rare effect. They did find flare-ups but with very different behaviour to the ‘star shredding’ predictions.

Instead of seeing a fade over months, the objects they found look like ‘normal’ quasars, regions in the centre of galaxies where material is swirling around a giant black hole in a disk. But the quasars in the survey were not seen a decade ago, so must now be at least ten times brighter than before. Monitoring with the Liverpool Telescope on La Palma showed that they are also changing slowly, fading over a timescale of years rather than months.

The PanSTARRS telescope has a very wide field of view, so it can survey the sky repeatedly and look for things that change, as well as build up a deep picture of the sky over time. A variety of different science projects are being done with PanSTARRS, but my special interest is looking for Active Galactic Nuclei that vary dramatically. Together with Suvi Gezari in Maryland, we were looking for cases of a black hole shredding a star and then swallowing the gas. These are very rare, so we had to check millions of galaxies. We may have found some of those, but we also found these giant brightenings of background quasars." Prof. Andy Lawrence 

The biggest surprise however was that the quasars seemed to be at the wrong distance. Measuring the characteristic shift in lines found in the spectrum of the quasars allows astronomers to measure the speed at which they are moving away from the Earth. Knowing the way in which the universe is expanding enables scientists to deduce the distance to each object.

In the new survey, the quasars are typically around 10 billion light years away, whereas the galaxies that host them seem on average to be about 3 billion light years distant. The distances are rough estimates, so it could be that the estimated galaxy distances are completely wrong and that they are actually much further away. The black holes in their centres have then have flared up very dramatically, explaining why they seem so bright. But past studies of thousands of well known quasars have never shown events on this scale.

If however the estimated galaxy distances are right, then Prof. Lawrence and his team believe they are looking at a distant quasar through a foreground galaxy. Normally this has little effect on the light of the quasar, but if a single star in the foreground galaxy passes exactly in front of the quasar, it can produce a gravitational focusing of the light which makes the background quasar seem temporarily much brighter.

This "microlensing" phenomenon is well known inside our own Galaxy, producing a brightening when one star passes in front of another. (It is for example also now being used to detect exoplanets). Microlensing may also be the cause of low-level "flickering" seen in some quasars. But this is the first time it has been suggested to cause such giant brightening events.

Prof. Lawrence sees real potential in this newly-discovered effect. “This could give us a way to map out the internal structure of quasars in a way that is otherwise impossible, because quasars are so small. As the star moves across the face of the distant quasar, it is like scanning a magnifying glass across it, revealing details that would otherwise simply be impossible to detect.”

RAS National Astronomy Meeting (NAM 2013)

 Bringing together more than 600 astronomers and space scientists, the RAS National Astronomy Meeting (NAM 2013) will take place from 1-5 July 2013 at the University of St Andrews, Scotland. The conference is held in conjunction with the UK Solar Physics (UKSP: www.uksolphys.org) and Magnetosphere Ionosphere Solar Terrestrial (MIST: www.mist.ac.uk) meetings. NAM 2013 is principally sponsored by the RAS, STFC and the University of St Andrews and will form part of the ongoing programme to celebrate the University’s 600th anniversary.

Meeting arrangements and a full and up to date schedule of the scientific programme can be found on the official website at http://www.nam2013.co.uk

Royal Astronomical Society

The Royal Astronomical Society (RAS: www.ras.org.uk, Twitter: @royalastrosoc), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3500 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

Pan-STARRS

The Pan-STARRS Project is led by the University of Hawaii Institute for Astronomy, and exploits the unique combination of superb observing sites and technical and scientific expertise available in Hawaii. Funding for the development of the observing system has been provided by the United States Air Force Research Laboratory.

The Pan-STARRS1 Surveys (PS1) have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, and the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, and the University of Maryland.

Mathematical model shows two simple strategies can work together to allow large numbers of words to be learned almost as quickly as they are encountered.

Learning new words feels easy, and humans are prolific word learners: the average high-school graduate knows approximately 60,000 words, and even young children learn around ten words a day. But word learning should be really hard, since there are many things that any one word could mean. For instance, whenever a child hears the word “cup”, there will be lots of other objects in the room that “cup” could refer to (juice, spoon, table, chair, etc).

In a paper published in Physical Review Letters on 21st June 2013, a team of researchers based at the School of Physics & Astronomy and the School of Philosophy, Psychology and Language Sciences at the University of Edinburgh used a statistical physics approach to show that two very simple word-learning strategies can work together to allow large numbers of words to be learned almost as quickly as they are encountered.

Mathematical model

The mathematical model was developed by Rainer Reisenauer, a visiting undergraduate student from Ludwig-Maximilians-Universität Munich, along with physicist Richard Blythe and linguist Kenny Smith, both Edinburgh-based researchers. The model is grounded in small-scale laboratory experiments that reveal tricks children use to deal with uncertainty when learning the meaning of words. For instance, they might notice that cups tend to be around whenever the word "cup" is used, an approach called cross-situational learning. Children also seem to assume that words are mutually exclusive: that no object has two names.

The problem with experiments is that they are necessarily limited to very small numbers of words: there is no way to condense a lifetime of word learning into a single hour-long experiment. This is where statistical physics comes into play: it is a theory that allows the structure of large systems – traditionally, condensed matter systems comprising vast numbers of molecules – to be predicted from interactions between the microscopic components.

By treating each encounter with a word as the microscopic component in the statistical physics model, the researchers found that the simple combination of cross-situational learning and mutual exclusivity allows learners to acquire large numbers of words at a surprisingly rapid rate. In fact, when the level of uncertainty in each word’s meaning lies below a critical value (less than around fifteen potential alternative meanings to consider each time a word is used), the entire lexicon can be learned in the about same time it takes to hear the least common word. 

"What appears to be happening here is that the incorrect meanings of common words get eliminated quickly, so that when rare words are heard, there is essentially only one possible meaning remaining." Richard Blythe

This work shows that a small number of simple mechanisms may be enough for children to learn words to describe the complex world around them. Models of this type may also help shed some light on the nature of the developments that took place in early humans' brains as they developed their language ability.

Professor Peter Higgs, Belgian theoretical physicist François Englert and CERN laboratory have been jointly awarded the 2013 Prince of Asturias Award for Technical and Scientific Research, for the theoretical prediction and experimental detection of the Higgs boson.

“I am delighted and greatly honoured to be awarded the 2013 Prince of Asturias Award for Technical and Scientific Research, shared with François Englert and CERN. I too wish to pay tribute to the late Robert Brout who, with his colleague François Englert, initiated a programme of theoretical research, too often associated with my name alone”. Peter Higgs

Award citation

In 1964, the pioneering work of Higgs and of Englert and Brout (the latter died in 2011) established the theoretical basis for the existence of the so-called Higgs boson. This particle completes the Standard Model, which describes the fundamental components of Nature, and is responsible for certain elementary particles possessing mass. For nearly half a century, efforts to find the Higgs boson were unsuccessful due to the enormous experimental difficulties associated with its precise and unequivocal detection. The Higgs boson was finally identified in 2012 by the ATLAS and CMS detectors of the LHC particle accelerator at CERN, a milestone for the entire scientific community.

The discovery of the Higgs boson is a prime example of how Europe has led a collective effort to solve one of the deepest mysteries of physics.

An exciting range of interactive discussions, drawing on various fields of science, will be on offer during the Science Conversations @ Edinburgh event.

Science Conversations @ Edinburgh, an online public engagement initiative delivered by the University of Edinburgh, will enable enthusiastic amateur scientists to work alongside leading researchers.

Expertise in science is not required, but those taking part will have the chance to delve deeper into their chosen subject. Scientists from the Schools of Physics & Astronomy, Chemistry and Biological Sciences at the University of Edinburgh, who are behind the initiative, hope to encourage people of all ages and backgrounds to discover the world of science.

Activities

Activities are centred on modern drug discovery, the habitability of Mars, quantum chemistry and peer-learning approaches in physics teaching. Each conversation will comprise two online training and discussion sessions separated by a few days in which participants will engage in activities related to their topic.

Face-to-face sessions will take place in real time using online technology.

The event will incorporate an inspiring presentation and live discussion from Professor Peter Higgs and a select panel of his Edinburgh colleagues on the significance of the Higgs boson discovery.

The overall project will seek to raise awareness of distance-learning courses offered by the College of Science and Engineering. These include master’s programmes in Drug Discovery and Protein Biotechnology, Next Generation Drug Discovery and Research-Informed Science Education (RISE).  Further opportunities for online study in Chemistry are currently in the pipeline.

Science Conversations @ Edinburgh starts on Monday 17 June and runs for 2 weeks.

Find out more

Further information can be found on the event website. Spaces are limited for each conversation, so register now to avoid missing out!