Researchers observe an intermediate stage of hydrogen.
Hydrogen is the most-abundant element in the universe. It’s also the simplest—with only a single electron in each atom. But that simplicity is deceptive, because there is still so much we have to learn about hydrogen.
One of the biggest unknowns is its transformation under the extreme pressures and temperatures found in the interiors of stars and giant planets, where it is squeezed until it becomes liquid metal, capable of conducing electricity. New work published in Physical Review Letters by the University of Edinburgh’s Stewart McWilliams and Carnegie Mellon University's Alexander Goncharov measures the conditions under which hydrogen undergoes this transition in the lab and finds an intermediate state between gas and metal, which they’re calling dark hydrogen.
On the surface of giant planets like Jupiter, hydrogen is a gas. But between this gaseous surface and the liquid metal hydrogen in the planet’s core lies a layer of dark hydrogen, according to findings gleaned from the team’s lab mimicry.
Using a laser-heated diamond anvil cell to create the conditions likely to be found in gas giant planetary interiors, the team probed the physics of hydrogen under a range of pressures from 10,000 to 1.5 million times normal atmospheric pressure and up to 10,000 degrees Fahrenheit.
They discovered this unexpected intermediary phase, which does not reflect or transmit visible light, but does transmit infrared radiation.
“This observation would explain how heat can easily escape from gas giant planets like Saturn,” explained Goncharov.
They also found that this intermediary dark hydrogen is somewhat metallic, meaning it can conduct an electric current, albeit poorly. This means that it could play a role the process by which churning metallic hydrogen in gas giant planetary cores produces a magnetic field around these bodies, in the same way that the motion of liquid iron in Earth’s core created and sustained our own magnetic field.
“This dark hydrogen layer was unexpected and inconsistent with what modeling research had led us to believe about the change from hydrogen gas to metallic hydrogen inside of celestial objects,” Alexander Goncharov.
The results are detailed in a paper published in Physical Review Letters.
"In this paper, we measure the conditions where hydrogen becomes a metal inside planets, and observe an intermediate state – dark hydrogen – between the insulating gas and liquid metal. A dark hydrogen layer in giant planets separates the atmosphere and the metallic interior, and neither reflects nor transmits visible light, but does allow infrared radiation to pass. This indicates heat can easily escape from within giant planets. The dark hydrogen layer also weakly conducts electricity, allowing it to participate in the production of the planetary magnetic field." Stewart McWilliams, Centre for Science at Extreme Conditions, who took part in the study.
The team also included Carnegie’s Allen Dalton and Howard University’s Mohammad Mahmood.
Wilson Poon has been appointed to the Chair of Natural Philosophy, one of the oldest and most prestigious chairs in the University.
Prof. Poon is internationally known for his work using very well characterised, 'model' colloids to study phenomena that are ubiquitous across condensed matter and statistical physics, particularly the structure and dynamics of arrested states such as glasses and gels. Understanding such states is a grand challenge facing 21st century physics; at the same time, they occur widely in a very large range of industrial processes and products. To exploit the latter connections, he set up the Edinburgh Complex Fluids Partnership to coordinate industrial consultancy, and its clients now span many sectors, from food and confectionaries through personal care to specialty and agri-chemicals.
"My congratulations to Wilson Poon on winning this extremely prestigious Chair. I am very excited by the research programme that he has proposed to transform bacteria into Darwinian designers of new types of soft materials. This is a challenging vision but one that will develop new opportunities spanning both academic research and also links to industry." Prof. Arthur Trew, Head of the School of Physics & Astronomy, University of Edinburgh
Natural Philosophy at the University of Edinburgh
The Chair of Natural Philosophy was established in 1708 and over the past 300 years it has been held by such eminent scientists as Adam Ferguson, John Playfair FRS, James Forbes FRS, Peter Guthrie Tait, the Nobel Laureate Charles Barkla FRS, Norman Feather FRS, William Cochran FRS, FRSE, and, most recently, Michael Cates FRS.
Experiments that seek to recreate conditions found deep inside the Earth are enabling new insights into the evolution of the planet.
Scientists have carried out laboratory studies of iron at very high temperatures and pressures, like those found in the Earth’s core.
This is enabling them to better understand the history of Earth’s magnetic field, which is driven by the behaviour of its outer core – a reservoir of churning liquid iron beneath the planet’s rocky mantle.
Their experiments show that Earth’s magnetic field – which protects life on its surface from harmful radiation from space – might have existed since the planet’s formation. This would have accommodated the spread of primitive forms of life early in Earth’s history.
Researchers at the University of Edinburgh used specialist equipment – known as a laser heated diamond anvil cell – to mimic conditions in the Earth’s core. They examined how iron conducts heat at pressures up to 1.3 million times that of the atmosphere, and temperatures above 3000 Celsius.
They found that iron conducted relatively little heat at these conditions, which suggests that Earth’s molten iron core has been cooling very slowly since its formation. This means that Earth has had a magnetic field from the very distant past, when the planet’s interior conditions were much hotter than they are today.
Their findings agree with studies of old rocks that show Earth’s magnetic field has existed for almost the entire age of the planet.
“The magnetic field of Earth can only form under certain conditions, and until recently it was believed these might not have been present early in Earth’s history. We now know that the magnetic field could have existed even in this early era.” Stewart McWilliams, Centre for Science at Extreme Conditions, who took part in the study.
The study, published in Nature, was carried out in collaboration with the Carnegie Institution in Washington DC; the DESY Photon Science Laboratory in Hamburg; the Universidad de Los Andes in Bogotá; and the Chinese Academy of Sciences in Hefei.
The Edinburgh Soft Matter, Biological and Statistical Physics Group seeks to recruit four postdoctoral research associates (PDRAs) in Biological Physics, to work on a research programme that aims to understand how bacterial populations grow, assemble into spatially structured biofilms, and evolve to become resistant to antibiotics.
In particular the Group is interested in the interplay between resistance evolution and population spatial structure.
"Many of the most chronic and difficult to treat bacterial infections are in the form of biofilms: spatially structured layers of bacteria that form on surfaces such as medical implants. In this research programme we will investigate how the spatial structuring of a bacterial population affects how it responds to antibiotic treatment and how likely it is to generate mutant bacteria that are antibiotic-resistant. We are looking for highly motivated and talented researchers with expertise in experiments, theory or simulations to help us with this exciting research." Project leader Dr Rosalind Allen
The project, which is entitled 'The physics of antibiotic resistance evolution in spatially structured multicellular assemblies’ is funded by the European Research Council.
UK astronomers are celebrating funding to participate in the Large Synoptic Survey Telescope (LSST), which will create what is being called “the greatest movie ever made”.
When completed, the Large Synoptic Survey Telescope (LSST) will be the world’s largest digital camera. It will be able to take images of the sky that each cover over 40 times the area of the moon, building up a survey of the entire visible sky in just three nights.
That means that billions of galaxies, stars and solar system objects will be seen for the first time and monitored over ten years, with each patch of sky being observed more than 800 times in that period. UK astronomers will now play a key part after £17.7m of initial funding from the Science and Technology Facilities Council confirmed the UK’s participation.
Steven Kahn, the LSST Director, said: “I am delighted that STFC is supporting UK participation in LSST. It is great to see UK astronomers engaging in preparation for LSST, and we look forward to seeing our collaboration develop over the coming years. LSST will be one of the foremost astronomy projects in the next decades and the UK astronomical community will contribute strongly to its success.”
“This is great news for UK astronomy. LSST has long been the missing piece in UK astronomy’s future programme, and funding by STFC for UK participation in LSST will provide our researchers with unparalleled access to the suite of major international facilities that will be coming online in the next 5-10 years”. Bob Mann, LSST:UK Project Leader, University of Edinburgh
The telescope is being built in the Chilean Andes where conditions are some of the driest on Earth, making it the ideal position for observing. When it starts operating, the LSST will generate one of the largest scientific datasets in the world.
The LSST is a synoptic survey in several ways: billions of objects will be imaged in six colours in an unprecedented large volume of our universe. This survey over half of the sky also records the time evolution of these sources, creating the first motion picture of our universe.
The LSST:UK Project Scientist, Sarah Bridle from the University of Manchester, said: “What is unique about LSST is that each of its images covers a large area of sky to a depth that captures faint objects, and that it takes these images really quickly. That combination of area, depth and speed means that we can do lots of different science with the same dataset. Over its ten years of operations, LSST will build up a very detailed map of billions of galaxies, with approximate distances to each, from which we will learn about the mysterious dark energy that seems to be accelerating the expansion of the Universe. But, equally, it will look for changes in the sky from night to night; both moving objects, like asteroids, and new ones, like supernovae, that appear where nothing had been seen before.”
Big Data benefits
As well as providing unprecedented scientific data, the development of LSST will help train future scientists and bring advances in computing.
“Extracting scientific knowledge from LSST will pose major challenges in the management and analysis of data. These “Big Data” issues are seen across the commercial sector as well as in science, but astronomy provides the ideal testbed for addressing them, as our data is free from the ethical and commercial constraints found in other domains. Many from the generation of young researchers who develop their skills preparing for the LSST data deluge will end up applying their expertise in business or the public sector, so the impact of UK participation in LSST will be felt well beyond astrophysics," said Bob Mann.
Edinburgh researchers are at the forefront of addressing the computational challenges posed by LSST. They are developing the Data Access Centre through which UK astronomers will analyse LSST data. This builds upon several decades of expertise in survey astronomy at Edinburgh.
“The Wide-Field Astronomy Unit at Edinburgh has been curating the largest sky survey datasets for a long time, but LSST will be a step up for us. We have just published the latest data release for the VISTA Variables in the Via Lactea (VVV) survey, which contains over 50 billion rows of data and which we believe to be currently the largest public sky survey dataset in the world. However, that pales in comparison with LSST, whose first data release in 2023 will be about forty times bigger, and which will continue to grow over the following decade. The challenge is not storing the data – bigger databases already exist in the commercial sector – but providing astronomers with the flexible access mechanisms they need to extract astrophysical knowledge from the LSST dataset, with its spatial, spectral and temporal dimensions.” Bob Mann, LSST:UK Project Leader, University of Edinburgh
In addition to funding development of the Data Access Centre, STFC is also supporting a range of preparatory science being undertaken by a distributed team of researchers in six UK universities on behalf of the 36 institutions in the LSST:UK Consortium. This work is coordinated by LSST:UK Project Manager George Beckett, who is based at the University of Edinburgh.
"Many are talking about data-driven science, but LSST:UK is actually doing it. The preparatory phase in the lead-up to an operational telescope is a critical period. Acting on behalf of the whole consortium we have defined a programme of work, which the Edinburgh team will coordinate, that draws on the world-class expertise of the UK partner institutions . This will ensure that we are ready to exploit the LSST from Day 1." George Beckett, LSST:UK Project Manager, University of Edinburgh
CERN's Large Hadron Collider (LHC) and its experiments are back in action, and UK researchers and colleagues are now taking physics data for 2016 that will give us an improved understanding of fundamental physics.
UK particle physicists have been eagerly awaiting the move up to full energy so that they could get back to working on understanding the fundamental physics of the Universe. During the annual winter break of the LHC the accelerator complex and experiments have been fine-tuned using low-intensity beams and pilot proton collisions, and now the LHC and the experiments are ready to take an abundance of new data.
Following a short commissioning period, the LHC operators will now begin to increase the intensity of the beams so that the machine produces a larger number of collisions.
“For the UK team working on the ATLAS instrument at the LHC our focus now will be on using the larger number of even higher energy collisions to better understand the Higgs boson. Despite confirming its existence back in 2012, there is still a lot for us to learn about the Higgs boson to be able to fully test Peter Higgs' original theory." Dr Victoria Martin, University of Edinburgh Particle Physics Experiment group and a member of the ATLAS team at the LHC.
“The start of this new season of physics at the LHC means that the many UK researchers working both in CERN itself and back in the UK will have much more data to work with – much more of the information they need to start to answer some of the big questions that still remain in physics including why there is a lack of antimatter in the Universe, the nature of dark matter particles and whether Supersymmetry, the theory that predicts the existence of a whole other set of ‘super’ particles, is correct”Prof. John Womersley, particle physicist and Chief Executive of the UK’s Science and Technology Facilities Council (STFC).
The four largest LHC experimental collaborations, ALICE, ATLAS, CMS and LHCb, now start to collect and analyse the 2016 data. Their broad physics programme will be complemented by the measurements of three smaller experiments – TOTEM, LHCf and MoEDAL – which focus with enhanced sensitivity on specific features of proton collisions.
“The restart of the LHC always brings with it great emotion. With the 2016 data, the experiments will be able to perform improved measurements of the Higgs boson and other known particles and phenomena, and look for new physics with an increased discovery potential.” Fabiola Gianotti, CERN Director General and Honorary Professor in the School of Physics & Astronomy.
The Large Hadron Collider
This is the second year the LHC will run at a collision energy of 13 TeV. During the first phase of Run 2 in 2015, operators mastered steering the accelerator at this new higher energy by gradually increasing the intensity of the beams.
Beams are made of “trains” of bunches, each containing around 100 billion protons, moving at almost the speed of light around the 27-kilometre ring of the LHC. These bunch trains circulate in opposite directions and cross each other at the centre of experiments. Last year, operators increased the number of proton bunches up to 2244 per beam, spaced at intervals of 25 nanoseconds. These enabled the ATLAS and CMS collaborations to study data from about 400 million million proton–proton collisions. In 2016, operators will increase the number of particles circulating in the machine and the squeezing of the beams in the collision regions. The LHC will generate up to 1 billion collisions per second in the experiments.
The Higgs boson was the last piece of the puzzle for the Standard Model – a theory that offers us the best description of the known fundamental particles and the forces that govern them. In 2016, the ATLAS and CMS collaborations – who announced the discovery of the Higgs boson in 2012 – will study this boson in depth.
But there are still several questions that remain unanswered by the Standard Model, such as why nature prefers matter to antimatter, and what dark matter consists of, despite it potentially making up one quarter of our universe.
The huge amounts of data from the 2016 LHC run will enable physicists to challenge these and many other questions, to probe the Standard Model further and to possibly find clues about the physics that lies beyond it.
This new physics run with protons will last six months. The machine will then be set up for a four-week run colliding protons with lead ions.
There are four main experiments at the Large Hadron Collider at CERN: ALICE, LHCb, CMS and ATLAS. Each one has been undergoing major preparatory work for run 2, after the long shutdown during which important programmes for maintenance and improvements were achieved. They will now enter their final commissioning phase.
ALICE was built in a cavern 100m below ground near St Genis-Pouilly in France. ALICE is a heavy-ion detector designed to investigate the properties of the Strong Force that keeps particles inside the atomic nucleus together, and how this energy generates mass. It is the force that we know least about.
ALICE recreates conditions that existed only 0.00001 seconds after the Big Bang; temperatures 300,000 times hotter than the Sun and densities 50 times greater than in the core of a neutron star.
LHCb was built in a cavern 100m below ground near Ferney-Voltaire in France. It is investigating the subtle differences between matter and antimatter. One of the most fundamental questions is why is our Universe made of matter? It is widely thought that initially equal amounts of matter and antimatter were created, and currently there is no evidence opposing this.
LHCb studies the decay of particles containing b and anti-b quarks, collectively known as ‘B mesons’. Physicists believe that by comparing these decays, they may be able to gain useful clues as to why nature prefers matter over antimatter.
ATLAS is one of the four main experiments at the Large Hadron Collider at CERN. Like CMS, ATLAS is a general purpose detector designed to investigate a wide range of physics including supersymmetry, extra dimensions and particles that could make up dark matter. The scientific goals for the two experiments are the same, but they use different technical solutions. These similar science goals, but different designs allow the two experiments to cross-check results and confirm exciting discoveries such as a Higgs boson.
Like ATLAS, CMS is a general purpose detector designed to investigate a wide range of physics including supersymmetry, extra dimensions and particles that could make up dark matter. The scientific goals for the two experiments are the same, but they use different technical solutions. These similar science goals, but different designs allow the two experiments to cross-check results and confirm exciting discoveries such as a Higgs boson.
Congratulations to the School's Prof. James Dunlop, who has been elected to a Fellowship of the Royal Society.
"I am delighted that Jim Dunlop has been elected as a Fellow of the Royal Society for his outstanding investigations in observational astrophysics. This is a well-deserved accolade and follows his recent awards of the George Darwin Lectureship (2014), and the Herschel Medal (2016) from the Royal Astronomical Society. On behalf of the School I would like to express our congratulations." Prof. Arthur Trew, Head of the School of Physics & Astronomy
About the Fellowship
The Royal Society is a self-governing Fellowship made up of the most eminent scientists, engineers and technologists from the UK and the Commonwealth. Fellows and Foreign Members are elected for life through a peer review process on the basis of excellence in science.
There are approximately 1,600 Fellows and Foreign Members, including around 80 Nobel Laureates. Each year up to 52 Fellows and up to 10 Foreign Members are elected from a group of around 700 candidates who are proposed by the existing Fellowship.
"The scientists elected to the Fellowship are leaders who have advanced their fields through their ground breaking work. We are delighted to welcome them to the Royal Society.” Venki Ramakrishnan, President of the Royal Society
These prestigious 5-year awards support highly talented early career researchers from across the world to develop their careers.
The School invites applications in the following areas:
Food and Rheology: Soft condensed matter research and its impact through the Edinburgh Complex Fluids Partnership, particularly in the rheology of soft materials and in applications of physics to food and personal care products.
Computation/Big Data: Exploiting the link between particle physics simulations and the co-design of high-performance energy-efficient microprocessors.
Remote Sensing/Big Data: Data-driven astronomy and its link to wider data-science projects in remote sensing. Collaboration with the Alan Turing Institute and the Higgs Centre for Innovation will also create significant opportunities for cross-fertilization of algorithm research and exploitation of intellectual property.
About the Fellowships
Fellows will initially concentrate on research and innovation, with a start-up package in support, but will be trained in teaching and student development skills and be expected progressively to take up this core academic activity. It is anticipated that following a successful end of year 3 review the majority of Chancellors Fellows will transition to an open-ended lectureship.
Applicants must have a PhD in Physics and present clear evidence of their potential to undertake leading research in collaboration with industrial partners. Successful candidates will demonstrate scientific excellence, capacity to contribute to knowledge exchange, and a track record in obtaining external funding for such projects.
A commitment to excellence in undergraduate teaching is essential for all academic posts as Chancellor's Fellows will be expected to teach and to contribute to curriculum development at undergraduate and postgraduate level.
Holders of personal Fellowships are welcomed.
Follow the links below to see the particulars of each position.
Congratulations to Dr Jamie Cole and Professor Alex Murphy for their success in the 2016 Teaching Awards.
Jamie won the award for Best Personal Tutor and Alex was runner-up, which represents a clean sweep for the School in the Personal Tutor category.
“Personal Tutors in the School of Physics & Astronomy are dedicated to helping students realise their academic potential. The recognition Alex and I received – which belongs also to many equally deserving colleagues and to our excellent Student Support Team – will encourage the School in its desire to provide a high level of support to our students within a vibrant, challenging and hopefully rewarding learning environment.” Dr Jamie Cole
“We are incredibly pleased by this result, which shows our students’ recognition of the pastoral care that we give them. Over the past few years we have had more than our fair share of EUSA Teaching Awards, but this is the first time that we have won both the award and runner-up. My congratulations to both Dr Cole and Professor Murphy." Prof. Arthur Trew, Head of School
EUSA Teaching Awards
The EUSA Teaching Awards recognise excellence in teaching and student support. This year, there were over 2,200 nominations for courses, teaching staff, dissertation supervisors and professional and administrative staff.
Every student at the University has a Personal Tutor to help them make the most of their studies and to provide them with academic guidance and support throughout their degree.
Dr Jamie Cole (School of Physics & Astronomy, University of Edinburgh)
In March 2016, six undergraduate students from the College of Science & Engineering attended the Conference for Undergraduate Women in Physics held at the University of Oxford. Now in its second year, the Conference aims to help undergraduate women continue in physics by showcasing options for their educational and professional futures.
The Conference included academic and career panel sessions, skills workshops, a tour of facilities at the Rutherford Appleton Laboratory, talks from speakers including Prof Christine Davies, Prof Fay Dowker and Prof Daniela Bortoletto, and a number of social events. Year 3 student Emma Stam tells us about the event.
“Before attending the conference, I had been worried that all of the talks would be from women telling us all how hard being in a STEM field is for women working in the industry. However, the message seemed to be more about having confidence in your own abilities which seems to be something that women struggle with more than men.
“Throughout the conference, we were given information about various internships that were available with the companies that the speakers worked for or the laboratories that we toured and I applied to three summer internships in RAL that I wouldn’t have known about or considered before this conference. Also, during our visit to RAL, it was interesting to see people from a range of disciplines all working in one place. As I have an interest in biology, I got the chance learn about career opportunities that involved both physics and biology.
“My confidence in myself was definitely boosted after the Conference, by hearing stories that I could relate to both from the other girls that attended the Conference and the guest speakers.”
The Schools of Physics & Astronomy and Chemistry covered the cost for these students to travel to Oxford for the Conference.
“If funding hadn’t have been provided, I don’t think I would have been able to afford to attend the conference, so the fact that Edinburgh paid for travel for all of us is really appreciated! We were told that we were the largest group of girls from one single university that had ever attended the conference!”