School of Physics and Astronomy

Congratulations to Prof Jorge Peñarrubia who has become a member of the Spanish Royal Academy of Sciences.

Royal Academy of Sciences of Spain

The Real Academia de Ciencias Exactas, Físicas y Naturales de España (Royal Academy of Sciences of Spain), has made dark matter researcher Professor Jorge Peñarrubia a member.

The Spanish organisation dates back to 1847, and was created to ‘promote the study and research of the exact sciences, physical, chemical, geological and biological, and their applications, as well as to spread this knowledge’. Membership includes around 400 ‘academicos’, 88 of whom are based outside Spain, with several Nobel laureates among them. Historic members include Michael Faraday, Alexander von Humboldt, Lord Rayleigh, Albert Einstein, Arnold Sommmerfeld, Hendrik Lorentz, Ernest Rutherford, Erwin Schroedinger, Werber Heisenberg, to name a few.

The nature of dark matter

Professor Peñarrubia’s research focuses on the nature of dark matter. Scientists have mounting evidence that dark matter is the main component of the Universe, yet do not know what it is. Professor Peñarrubia investigates how visible objects, like stars, move in the gravitational field generated by dark matter particles. To do so, he uses statistical-dynamical models, which he then compares against observations of the Milky Way, our home galaxy.

Reflecting on this recognition, Professor Peñarrubia said:

Becoming a member of the Royal Academy of Sciences represents a great honour in many ways. At a personal level, it feels very rewarding to receive such an important recognition from the country where I was born. At a professional level, it is an opportunity to strengthen the scientific ties between the United Kingdom, Scotland in particular, and Spain. This task has become crucial after Brexit, which threatens long-existing, successful collaborations between the two countries - and worse - thwarts future ones.

We are delighted to announce that the University of Edinburgh has been rated as one of the top centres for Physics & Astronomy research in the UK.

Overall results

The School of Physics & Astronomy at the University of Edinburgh was ranked 4th in the UK and 1st in Scotland in the Research Excellence Framework (REF) 2021 listing for the quality, scale and breadth of its research by Times Higher Education. This is particularly impressive as the School submitted 119 staff for assessment (an increase of 78% from REF2014).

97% of the School’s research outputs were measured as world-leading/internationally excellent (with a score of 4*/3*) and nearly half (46%) of the research outputs were judged to be world-leading (4*).

+ 39 other higher education institutions

 * the Times Higher Education Research Power index values the influence of research by multiplying quality grading by the number of academic staff reported.

Within the top 5 physics departments in the UK, the School of Physics and Astronomy at the University of Edinburgh was ranked 3rd on quality of research.

These results confirm the exceptional performance of our staff, our excellent facilities, and our world-leading research.

Research excellence

The Research Excellence Framework (REF) is the UK’s system for assessing the quality of research in UK higher education institutions. Universities are evaluated on the standard of their research, the environment in which it is conducted, and the positive impact it has on the world.

Building on the results of the previous REF in 2014, the School of Physics & Astronomy has been rated even more highly in this latest REF2021 assessment exercise.

Our success is a ringing endorsement of our ability to expand our research base, while at the same time enhancing quality, by attracting and hiring many of the very best researchers from around the world.

Impact and breadth

Our impact ranges from the design of base stations on Mars, through the use of materials research to inform more sustainable food production, to the design of the next generation of computers.

We look forward to continued growth and the exciting research ahead in fields as diverse as cosmology, condensed matter, extrasolar planets, elementary particles and nuclei, and the physics of life.

Space urgently needs special legal protection similar to that given to land, sea and atmosphere to protect its fragile environment.

An influx of space debris in orbital space – around 100 kilometers above the earth’s surface – caused by the rapid growth of so-called satellite mega-constellations is endangering this precious ecosystem, researchers say.

The installation of these huge clusters of hardware, some with up to tens of thousands of satellites delivering broadband to Earth, are congesting space and rocket launches are also polluting the atmosphere. Pieces of broken satellites, which travel at enormous speeds through orbital space threaten working satellites in their path, the paper says. Furthermore, streaks from satellite flares, which cause light pollution, are increasingly disrupting research. The giant Vera C. Rubin Observatory in Chile, which aims to carry out a 10-year Legacy Survey of Space and Time, will be badly affected, for example.   

The paper, published in Nature Astronomy, argues that space is an important environment for all professional astronomers, amateur stargazers and indigenous peoples and the scientific, economic and cultural benefits of space should be carefully considered against these damaging environmental impacts. Addressing these issues requires a holistic approach that treats orbital space as part of the environment and worthy of environmental protection, at national and international levels, experts say. The researchers urge policy-makers to consider the environmental impacts of all aspects of satellite constellations – including their launch, operation and de-orbit – and to work collaboratively to create a shared, ethical, sustainable approach to space.

The research, led by the University of Edinburgh, is connected to a legal case currently before the US Court of Appeal, which will set an important precedent in the growing campaign for space environmentalism.

Professor Andy Lawrence, Regius Professor of Astronomy, University of Edinburgh Institute for Astronomy and lead author, said:

We are standing on a watershed in history. We can cheaply launch huge numbers of satellites and use them to the benefit of life on Earth – but this comes at a cost. As well as damaging stargazing, the space industry may be shooting itself in the foot.

Professor Lawrence brought these issues to popular attention in his book, Losing The Sky. The publication led to him writing an expert witness statement for a legal case currently before the US Court of Appeal which argued that US environmental regulations should apply to space launch licensing.

Professor Moriba Jah, co-author and Associate Professor of Aerospace Engineering and Engineering Mechanics at The University of Texas at Austin, said:

We believe that all things are interconnected and that we must embrace stewardship as if our lives depended on it. Traditional ecological knowledge holds a key to solving this wicked problem. The largest challenge we have is in recruiting empathy and compassion toward solving these environmental crises. If we can find innovative ways to enable the general public to project themselves into this dire condition, and feel concern to address it, the earth, and all of the lives she sustains, wins.

Professor Jah recently co-founded the start-up, Privateer Space together with Apple co-founder Steve Wozniak and CEO of Ripcord, Alex Fielding. The company takes a novel approach to mapping the objects in orbit accurately, in near real-time, to enable the sustainable use of space by a growing number of operators.

Dr Meredith Rawls, co-author and researcher at the University of Washington, said:

Rubin Observatory will be one of the most severely impacted astronomy facilities by large numbers of bright satellites due to its large mirror and wide field of view — the same characteristics that make it such a remarkable engine for discovery. I care a lot about how satellite streaks affect science, but the case for dark and quiet skies is much larger than that. We need all hands on deck to address the rapidly changing satellite situation if we can hope to co-create a future with dark and quiet skies for everyone.

Dr Rawls is a leading actor in the new International Astronomical Union (IAU) Centre for the Protection of the Dark and Quiet Skies from Satellite Constellation Interference which aims to bring together sky observer stakeholders to collaborate on quantifying, mitigating and disseminating the impacts of satellites.

Professors Marialuisa Aliotta and Sinead Farrington join the 80 names recognised as being some of the greatest thinkers, researchers and practitioners working in or with Scotland today.

The Royal Society of Edinburgh (RSE), Scotland’s National Academy, has announced its 2022 intake of Fellows, with 80 names from the arts, business, public service, civil society and academia, from Scotland and beyond.

They will be joining the RSE’s current Fellowship of around 1,700 Fellows, who are recognised as being some of the greatest thinkers, researchers and practitioners working in or with Scotland today.

Newly elected Fellows

Marialuisa is Professor of Experimental Nuclear Astrophysics. Her research interests focus on the investigation of nuclear reactions that occur in stars and govern stellar lifetimes and evolution. These reactions are also responsible for the creation of new chemical elements both in quiescent stars such as our sun and in explosive scenarios such as novae, supernovae, and X-ray bursts.

I’m delighted to be joining the Fellowship of the Royal Society of Edinburgh. I look forward to working with the society in support of its endeavours to help inspire future generations.

Sinead is an experimental particle physicist with interests across collider physics as a means of understanding the most fundamental particles and their interactions. She is currently leading the UK effort in the ATLAS collaboration at the LHC at CERN. She led ATLAS searches for the Higgs boson decaying to tau leptons and now searches for exotic particles. She collaborated in discoveries in the CDF collaboration at Fermilab, USA. Farrington serves on STFC’s Project Peer Review Panel and the European Committee on Future Accelerators. She was awarded the 2021 Physical Sciences Laureateship, Blavatnik UK New York Academy of Sciences prize.

Besides it being a great honour, what’s really special to me about being elected to the fellowship of the RSE is the way it links work over the centuries. In my research area that means linking the same quest to understand the most fundamental processes in nature - back to James Clerk Maxwell and the nature of light, up to the present day and the quest to understand the nature of how particles acquire mass which we tackle at the LHC.  The people change, the experimental methods change, but the fundamental quest for knowledge and understanding are the same. That’s at the same time grounding and inspiring. It links us to the past and to the future.  I’m looking forward to working with RSE colleagues across a huge range of expertise.

Commenting on the new fellows, Professor Sir John Ball, President of the Royal Society of Edinburgh, said:

It is a privilege to be able to welcome our new Fellows, and we are inspired by the breadth of talent and experience in our Fellowship. Every single individual elected this year has shown exceptional levels of expertise and insight in their chosen field, and their input helps RSE effect real and lasting change in Scotland’s society. We look forward to working with our diverse Fellowship who provide a crucial link between the world of academic research and practice with government, business and civil society.

The Royal Society of Edinburgh

The Royal Society of Edinburgh, Scotland's National Academy, is an educational charity established in 1783. Unlike similar organisations in the rest of the UK, the RSE’s strength lies in the breadth of disciplines represented by its Fellowship. Its membership stands at approximately 1700 Fellows from across the entire academic spectrum – science and technology, arts, humanities, social sciences, business, and public service. New Fellows are elected to the RSE each year through a rigorous five-stage nomination process.  This range of expertise enables the RSE to take part in a host of activities such as: providing independent and expert advice to Government and Parliament; supporting aspiring entrepreneurs through mentorship; facilitating education programmes for young people, and engaging the general public through educational events.

The Particle Physics Experiment group at the University of Edinburgh has been awarded £3.5M to carry out cutting edge physics research.

The award will allow the Edinburgh group to participate in major experimental efforts over the next 3 years at the European Organization for Nuclear Research (CERN) and other top labs around the world. These experiments aim to address key questions in physics, such as the dramatic imbalance between matter and antimatter in the visible Universe, the properties of fundamental particles like quarks and neutrinos, and the nature of Dark Matter.

The Edinburgh group are one of 18 UK universities to benefit from £60M funding from the Science and Technology Facilities Council (STFC). This funding will help keep the UK at the forefront of answering some of the biggest and most complex questions in science and supports the next generation of UK particle physicists.

Particle Physics Experiment group leaders, Professors Christos Leonidopoulos & Victoria Martin said:

The award will enable us to continue our strong involvement and leadership with the ATLAS and LHCb experiments at the Large Hadron Collider (LHC) and their upgrades for the high-luminosity phase. We continue to build our leading involvement in neutrino physics with participation in DUNE, MicroBooNE, SBND and AIT-WATCHMAN, covering design, construction and exploration. Our dark matter efforts build upon our strong contributions in LZ and now expand to include DarkSide. We are watching closely the evolution of plans for future colliders, and actively participate in research and development studies. We will also be delivering targeted outreach programmes and impact, particularly in silicon and photo-detectors and medical imaging.

Professor Phil Clark commented:

We are very grateful to have received this funding for our research work with the ATLAS experiment at CERN. This reflects well on the excellent international reputation of our team of academics, researchers, engineers and technicians. With the re-start at higher luminosity of the LHC this year, we are well placed to make a big impact in our Higgs and Exotics particle physics analysis programmes, as well as our work in simulation, trigger and the next silicon pixel detector of ATLAS.

Professor Franz Muheim said:

This is excellent news for the LHCb experiment that will commence data-taking with a new upgraded detector when the LHC restarts operation this year. The Edinburgh group played a leading role in the upgrade of the Ring Imaging Cherenkov (RICH) detectors for LHCb. This award will underpin the smooth operation and excellent performance of the RICH detectors and allow Edinburgh team members to make more exciting measurements in the area of flavour physics and beyond.

Astronomer Royal for Scotland, Professor Catherine Heymans, and black hole hunter Professor Martin Hendry are teaming up to celebrate James Clerk Maxwell – one of the greatest scientists of all time.

James Clerk Maxwell was born in Edinburgh and raised in Dumfries and Galloway. The 19^th century scientist and mathematician is credited with many achievements, including the theories that explain light and electromagnetism, being the father of electrical engineering and even creating the first colour image. Maxwell’s revolutionary understanding of energy paved the way for technology that is fundamental to life today, from bluetooth to broadband, from mobile phones to microwave ovens. He also laid the foundations for Einstein’s theory of relativity.

Professors Heymans and Hendry will share the life, work and legacy of James Clerk Maxwell at an online event on 10 March which is part of Big Bang, the Dumfries and Galloway festival of space and science. The event will be broadcasted from 14 India Street Edinburgh, the birthplace of James Clerk Maxwell, which is now home to a museum containing portraits, manuscripts and books associated with Maxwell, his family and scientific contemporaries. They will also lead a discussion about Maxwell on 11 April as part of the Edinburgh Science Festival, which will be held at the National Museum of Scotland.

Professor Heymans commented:

Martin and I are really looking forward to explaining James Clerk Maxwell’s amazing scientific discoveries, and what they mean for us today. And we'll be bringing things right up-to-date and showing people some of the latest discoveries in astronomy and astrophysics that have been made possible because of his amazing, influential work back in the late 1800s.

Find out about our MSc degrees in Physics and Astronomy and hear from our students and staff

The School of Physics & Astronomy will take part in the University of Edinburgh Postgraduate Virtual Open Days. Our academic and professional staff will be involved in online information sessions.

School of Physics and Astronomy events will run the following sessions:

• Tuesday 22 March: Introduction to MSc Theoretical Physics and Mathematical Physics 11:00-12:00 UK time
• Tuesday 22 March: Introduction to MSc Particle and Nuclear Physics  13:00-14:00 UK time
• Thursday 24 March: Q&A with Physics MSc students 13:00-14:00 UK time

To book a place visit the Virtual Postgraduate Open Days 2022 page on the University of Edinburgh website. 

High-speed winds in space blow biological particles into higher altitudes than previously thought.

For many decades large vertical winds have been observed at high altitudes of the Earth's atmosphere, in the mesosphere and thermosphere layers. These winds are not reproduced by weather models and the mechanism by which they are occurring is not fully understood.

Professor Arjun Berera and PhD student Daniel Brener, from the School’s Particle Physics Theory Group, have shown using theoretical estimates that particles similar in size to viruses could be projected by these strong vertical winds to higher altitudes than previously discovered.

Their studies found that biological particles could be carried more than 120km above the Earth’s surface by such high-speed vertical winds, and may even reach as high as 150km. This is much higher than the 77km altitude that bacteria spores have previously been discovered at.

If biological particles can be found at such high altitudes, it is also suggested that the hypervelocity space dust, which continuously impacts the atmosphere, can propel such particles into deep space. Over aeons, some of these micro-organisms may have landed on other planets, or may have travelled from other planets to Earth.

In their paper published in the Proceedings of the Royal Society A, the researchers discuss the numerous applications of these results in astrobiology and climate science. 

This work further advances the space dust interplanetary atmospheric exchange mechanism theory which was initially proposed by the Particle Physics Theory Group.

Researchers have used a combination of calculations and experimental techniques to prove that at high pressure oil can dissolve in water, but water cannot dissolve in oil.

Everyone knows that water and oil are chemically insoluble, they don’t mix. That's true at the molecular level, but it’s always possible to mix them, as in milk or French Dressing, as an emulsion of small droplets. Even in an emulsion, the droplets contain many millions of a single type of molecule. To determine whether a homogeneous sample is an emulsion or a solution requires information about which molecules are next to which.

Information about this can be obtained by neutron scattering - a method where a beam of neutron particles is deflected in characteristic ways by different atoms and their neighbours. But, for a molecular mixture, the neutrons scattered from the different atom types are all mixed together.  This is an example of a so-called "inverse problem", where the only way to proceed is to make a model for the system, and see if it fits the data. Although there isn't enough information in the data to solve the structure, there is enough data to reject most wrong models.

Even in an emulsion, molecules on the surface of a droplet are next to molecules on the other type e.g. in a cube made of one thousand small cubes almost half are on the surface. In real emulsion droplets it is less than a millionth. So the model structure must be made and analysed very carefully to distinguish between a fine emulsion and a true solution. We solved the problem of how to do this, and applied it to a mixture of methane (the simplest oil) and water, with remarkable results.

Under normal conditions, there is demixing - distinct water and methane droplets.  But as pressure increases, the methane dissolves in the water droplets, but the water does not dissolve in the methane. The model demonstrates that at the molecular level this can be understood in terms of chemical bonding. Water is held together by a network of hydrogen bonds, so each water molecule has only four nearest-neighbours. This forms an open network which can restructure to accommodate methane molecules creating a solution denser than either water on methane - high density is favoured at high pressure. By contrast, fluid methane forms many, weaker, bonds between molecules: there is no way to create space for dissolved water without breaking bonds.

Exploiting the behaviour of RNA viruses to help inspire new disinfection processes.

Many RNA viruses like flu are made through a process where their components spontaneously self-assemble. Upon infection they then disassemble again to release the RNA. This means that they live on the edge of thermodynamic stability, holding together just strongly enough to survive in the environment, but ready to fall apart once they make it into a host.

Recent work by colleagues based in the School’s Institute for Condensed Matter and Complex Systems suggests a way in which we might be able to exploit this to develop new cleaning or disinfecting processes.

In their Nature Communications paper, the team presents a theoretical model of the electrostatics of viruses near air-saline interfaces. The RNA within a virus is highly negatively charged, but salt ions in the solution usually act to screen the repulsion. When held at an air-water interface, there is no longer sufficient salt in the surroundings to screen the charges, and the increased electrostatic force destabilises the virus, and may cause it to fall apart. This result explains the decades-old observation that gently shaking a virus containing solution is enough to deactivate them, and could inspire new disinfectant formulations.