IoP meeting on Nuclear physics and r-process nucleosynthesis
We are pleased to announce an IoP-sponsored half-day meeting on “Nuclear Physics and R-process Nucleosynthesis”, which will take place on Friday May 15th at the University of Edinburgh.
This half-day meeting will bring together nuclear physicists, astronomers, and astrophysicists studying nucleosynthesis during rapid neutron-capture process. It will provide a venue to learn about exciting developments in the field, such as the observation of new elemental abundances in metal-poor stars, r-process models that include increasingly sophisticated treatment of the dynamical evolution of the astrophysical environment, and the opportunities for experiments with r-process isotopes with a new generation of radioactive ion beam laboratories and new equipment (eg the AIDA detector for beta-decays developed in the UK). The event will also be an opportunity to discuss future lines of research and ways to coordinate the efforts of our communities across disciplinary lines.
Invited speakers include: Norbert Christlieb (University of Heidelberg), Giuseppe Lorusso (National Physical Laboratory), Tomislav Marketin (University of Zagreb), and Nobuya Nishimura (Keele University).
Get involved
All members of the UK and international community are welcome to participate, and invited to register before May 5th.
Please register through the meeting website: https://indico.ph.ed.ac.uk/indico/event/iop2015
Those interested in giving a presentation are encouraged to submit a brief abstract by April 26th.
For further information, contact Alfredo Estrade (aestrade [at] ph.ed.ac.uk).
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The School is currently showing an exhibition on hydro power in Scotland
The School is currently showing an exhibition in Shetland on hydro power in Scotland together with artist Marianne Greated from Glasgow School of Art. It includes a short film which traces the heritage of small-scale hydro power in Scotland, starting with the horizontal water wheels used for powering small click mills, through to modern micro-hydro plants.
There is also an interactive model water-wheel. Shetland was noted for its horizontal wheels which powered small click mills used by farmers for grinding corn. It is estimated that in the early 19th century there were about 500 such water-powered click mills in Shetland alone and water power was the driving force behind the early Industrial Revolution. Today numerous micro-hydro plants are making a significant power input to the grid and there are still substantial untapped hydro resources in Scotland.
In collaboration with colleagues in Engineering, the School has a research programme that is developing new techniques for mapping untapped hydro resources.
The exhibition, called Revolutions, is sponsored by EPSRC and Historic Scotland.
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An Edinburgh Team led by Prof Graeme Ackland has discovered that at extreme shear rates, metals can melt: this "shear melting" is well known in colloids and soft solids, but almost unachievable in alloys. For pure titanium shear rates would be well beyond modern machining capability.
Titanium is hard to break. For applications, this is its big advantage, but for manufacturing it is a problem. In a lathe the waste material forms a long unbroken spiral chip which clogs the machine. The goal is to create an alloy that breaks easily in machining, but not in use.
An Edinburgh team led by Prof Graeme Ackland has discovered that at extreme shear rates, metals can melt: this "shear melting" is well known in colloids and soft solids, but almost unachievable in alloys. For pure titanium, shear rates would be well beyond modern machining capability.
To facilitate "shear melting", titanium could be mixed with an element which lowers the melting point. Typically, this would weaken the alloy, so the team chose something that does not dissolve: a rare earth metal (REM). REMs form small inclusions in the alloy under normal conditions, leaving its properties intact, but cutting breaks these inclusions releasing the REM into the alloy. In a feedback effect, cutting releases the rare REM, allowing shear melting which enables further fracture until the chip breaks.
The group of Carsten Siemers in Braunschweig has created the alloy, and in machining tests show that it does indeed break off in small pieces. The company GfE is now looking to develop it commercially.
The most likely applications for the alloy are where we can replace steels (which are heavy) or aluminium (which is soft). One company has already made a batch for use in trial applications in dental tool couplings and mouthpieces for brass instruments. In fact my collaborator in Braunschweig is a trombonist and has tested one of the mouthpieces.
Physical Review Letters paper
The work was supported by the EU "MAMINA" training network, and is reported this month in Physical Review Letters:
"Shear melting and high temperature embrittlement: theory and application to machining titanium". Con Healy, Sascha Koch, Carsten Siemers, Debashis Mukherji and Graeme J Ackland, Physical Review Letters, April 2015
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Scientists have furthered their understanding of dark matter, the elusive material that accounts for much of the mass of the Universe. They used NASA telescopes to study how dark matter behaved during cosmic crashes between galaxies in deep space. Each collision took hundreds of millions of years, and is captured as a freeze-frame from a single camera angle.
Their findings show that dark matter interacts with itself even less than was previously thought. It improves scientists’ understanding of the mysterious substance, and helps pinpoint what it might be made of.
“We expected to find that dark matter had minimal interaction with other objects, but we were surprised at how dark and elusive it seems to be." Andy Taylor, Professor of Astrophysics at the Institute for Astronomy, University of Edinburgh, who took part in the study.
Astronomers used observations from the NASA/ESA Hubble Space Telescope and NASA’s Chandra X-ray Observatory to examine 72 large cluster collisions. They studied what happened to their constituent stars, clouds of gas, and dark matter.
They saw that dark matter passed straight through the violent collisions, without slowing down, showing that it does not interact with visible particles, or with itself.
Narrowing down the properties of dark matter will help improve scientists’ models of the Universe.
Further research will examine whether dark matter particles bounce off each other, and will look at collisions between individual galaxies, which are much more common.
Download the Paper
The non-gravitational interactions of dark matter in colliding galaxy clusters
The study, published in the journal Science, was carried out by a collaboration co-led by
the University of Edinburgh and the École Polytechnique Fédérale de Lausanne.
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Congratulations to Charles Cockell and Andrew Liddle who have been appointed as Fellows of the Royal Society of Edinburgh, Scotland’s national academy.
"I'm very happy to be recognised by the Society and look forward to helping it in its many roles." Andrew Liddle, Professor of Theoretical Astrophysics at the Institute for Astronomy.
“It's exciting to be elected to the Society as it provides an opportunity to further contribute to both the work of the Society and science in general, particularly the interface between biology and space sciences.”
Prof. Charles Cockell, who leads the Astrobiology group within the Institute for Condensed Matter and Complex Systems
The Royal Society of Edinburgh (RSE)
Established in 1783, the RSE is an educational charity. Unlike similar organisations in the rest of the UK, the RSE’s 1500 Fellows includes people from a wide range of disciplines - science & technology, arts, humanities, social science, business and public service. This breadth of expertise makes the RSE unique in the UK.
Experiments by researchers in the School's Centre for Science at Extreme Conditions (CSEC) have revealed anomalous behaviour in the melting temperatures of high-pressure dense hydrogen.
As reported in the prestigious "Nature Materials”, the study provides evidence that at above 200 GPa (2,000,000 atm) surprisingly low temperatures (480 K) are required to reach a liquid phase.
As the simplest, lightest and most abundant element of the Universe, hydrogen is of fundamental interest in many fields of physics. At high pressure and low temperatures, hydrogen is predicted to transform to a new type of ordered quantum fluid possessing both superconducting and superfluid properties. The high temperature behaviour is crucial to planetary science as hydrogen is believed to be found in the centre of Jovian planets and to be the source of their exceptionally high magnetic fields. Reaching such conditions in the experimental laboratory, long enough to comprehensively study the material, has been a great challenge in the field of high pressure research. Even high compression at room temperature was thought to be beyond experimental capabilities until recently.
Through new technological breakthroughs in the containment of hot hydrogen in diamond anvil cell experiments, Ross Howie, Philip Dalladay-Simpson and Eugene Gregoryanz at the Centre for Science at Extreme Conditions, provide evidence that after a maximum in the melting curve, the melting temperatures of hydrogen rapidly decrease with pressure, dropping to 480 K at 255 GPa. This consequently results in the lowest melting temperature for any material at such pressures.
Tracking this transformation over a large pressure regime through Raman spectroscopy, the team also discovered a triple point between hydrogen’s solid molecular Phase I, the recently discovered solid mixed molecular-atomic phase IV and the liquid phase.
Remarkably, at pressures above 260 GPa the melting line flattens out, raising many questions about the high pressure, high temperature behaviour of hydrogen at even higher densities. If the melting curve were to increase at higher densities then the phase diagram would markedly resemble what is observed in the rest of the group I elements in the periodic table. Such behaviour questions the existence of the exotic states that hydrogen has been theoretically predicted to possess and at the very least pushes the transition pressures much higher than previously thought.
“It is remarkable to think that 4 years ago, researchers were unable to compress hydrogen above 180 GPa and 200 K, and now we are probing the melt line, far surpassing these conditions. Although this study is a major breakthrough in hydrogen research, it poses more questions about its high pressure behaviour and may even cast doubt on the existence of predicted exotic phases. Nevertheless it is very exciting to think what may occur at higher densities and will no doubt stimulate further research.” Ross Howie, Centre for Science at Extreme Conditions
Professor Peter Higgs has unveiled a blue plaque in his honour at the University. The installation marks the site where Nobel Laureate Professor Higgs first devised his seminal theory on the nature of mass more than 50 years ago.
The theoretical physicist was a researcher at the University in 1964 when he predicted a sub-atomic particle, now known as the Higgs boson, which enables other particles to acquire mass. His idea was borne out by experiments almost 50 years later, in 2012, at the European Organization for Nuclear Research (CERN) in Switzerland. Professor Higgs was awarded a Nobel Prize for Physics in 2013 for his work.
It is truly historic to celebrate such a seminal theory in physics with its author, Peter Higgs, in the building where he first wrote it more than 50 years ago, and in the company of some of his colleagues from that time.
Prof. Richard Kenway, Vice Principal, University of Edinburgh
Commemoration
The plaque, at Roxburgh Street in Edinburgh, is sponsored by the Institute of Physics and Edinburgh City Council. It notes that Professor Higgs ‘Wrote the papers which predicted the Higgs boson in this building in 1964’.
Professor Higgs unveiled the plaque following a ceremony at the University at which he was awarded an honorary degree by the University of North Carolina at Chapel Hill. He spent a sabbatical year at the US University from 1965-1966. During this time he wrote an academic paper that would form the basis of experiments at CERN.
Degree tribute
His honorary Doctor of Science degree was conferred by the University of North Carolina’s Chancellor, Professor Carol L Folt, for ‘outstanding accomplishment in the field of theoretical physics, especially his fundamental work on the origin of mass’. The event was hosted by the University of Edinburgh’s Vice Principal Professor Richard Kenway and attended by students from UNC who are currently studying at Edinburgh.
Nearly half a century ago, Professor Higgs found himself at the University of North Carolina at Chapel Hill conducting revolutionary work in physics and his work continues to inspire us. His research had a profound impact on the field of fundamental physics, and his example motivates our faculty and students to pursue their passions and make their own significant mark on their discipline.
Prof. Carol L Folt, Chancellor, University of North Carolina at Chapel Hill
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All University alumni are invited to become e-mentors for our 3rd, 4th and 5th-year undergraduates and all postgraduate students. The School's Judy Hardy explains how this innovative scheme works.
One of the best ways for students to gain an insight into what a particular job is really like is to talk to someone who is doing it. The choice of careers open to physics and astronomy graduates is vast. Career destinations reported by our recent alumni range from the scientific, technical, IT and financial sectors to the environmental industry, healthcare, teaching, retail, publishing and NGOs amongst others.
While some students have very clear career aims, others can be bewildered by the wide choice and find it difficult to know where to start, or may not even be aware of the full range of options open to them. Mentoring is an excellent way to help students explore and choose their career goals by talking to someone who is already doing a particular job.
Connect.ed
The Careers Service has recently launched an alumni e-mentoring scheme, Connect.ed, which links our alumni with current students or fellow alumni who are interested in a career in a similar area. By sharing experiences, offering suggestions or simply passing on information about their chosen field, e-mentors can help students to make informed career choices and to take their first steps towards achieving their aspirations.
There are also benefits for the e-mentor, with opportunities to consider and reflect on working practices, develop communication skills in a wider setting and build professional networks, as well as the personal satisfaction that comes from supporting others.
In outline, the scheme works as follows: e-mentors register their details, including a short career profile, via the secure MyEd Alumni Portal. Students can then browse the alumni profiles, again via MyEd, to identify and contact potential e-mentors. The e-mentor can then accept the relationship, which is conducted by email. The length of the relationship is flexible and can range from a simple one-off exchange of emails to a longer-term connection. The duration of the mentoring relationship, its scope and subject matter are agreed by e-mentor and e-mentee at the outset.
All University alumni are invited to become e-mentors. For e-mentees, the scheme is currently open to 3rd, 4th and 5th year undergraduates and all postgraduate students.
Why be an e-mentor?
- Share your experiences and insights into the realities of your job or career sector
- Help current students explore and decide on their career goals
- Reflect on your current role and working practice
- Enhance your interpersonal and communication skills
- Build links with other alumni, the School and the University.
Find out more about e-mentoring
To sign up as an e-mentor, or to find out more about the scheme, see the Connect.Ed website or Connected [at] ed.ac.uk (email the team). We are also happy to offer guidance and support for e-mentors.
The University Alumni Team
The Alumni Team provides opportunities for alumni to stay connected with the University and each other through events, reunions, clubs, networks and volunteering. It supports alumni by facilitating networking and professional development opportunities, and by providing a programme of benefits and services, including a range of publications. By highlighting and celebrating the achievements of our alumni, it aims to inspire the next generation of Edinburgh graduates.
Contact the Alumni Team
To find out more about how you can keep in touch or get involved, see the Alumni Services website or alumni [at] ed.ac.uk (email the team). You can also find them on:
This article also appeared in the School's newsletter, Enquire.
The Institute for Astronomy's Michal Michalowski has been awarded The Royal Astronomical Society's Winton Capital Award in astronomy.
Award citation
Dr Michałowski's main line of interest has been to study the origin of large dust masses in sub-millimetre galaxies, their evolution and their assembly into larger galaxies over time. This work has been documented in a remarkable output of well-cited publications. In another line of attack on the same problem of the evolution of the early universe, he has maintained his collaborative work on gamma ray bursts (GRBs) with researchers in Denmark, using GRBs to identify early galaxies and probe their properties. All this work has been carried out with numerous collaborators world-wide and a large range of cutting-edge observational facilities, spanning spectrum from the ultraviolet to the radio. It has been a dynamic start to a promising career.
Michal explains his work below.
I investigate the crucial component of the Universe, namely the cosmic dust residing in submm galaxies, gamma-ray bursts (GRB) host galaxies and quasars.
I found that submm galaxies contribute substantially (~20%) to the star-formation activity and the stellar mass density of the Universe, which justifies the need of understanding their nature. To reach this understanding I proved that they are not outlying galaxies in terms of star-formation properties. I also discovered that asymptotic giant branch (AGB) stars, or even supernovae are not efficient enough to form dust we see in these sources, hinting at grain growth in the interstellar medium as the main dust production mechanism. This is crucial in order to learn how dust formed in the early universe. I also tested the reliability of their stellar mass estimations - an important aspect of using them to constrain cosmological models. Finally, I found indications that GRBs trace cosmic star-formation, so they can be used as an excellent tool in cosmology.
I am honoured to receive this prestigious award! The list of previous award holders includes the best young astronomers in UK, so I am happy to be among them. This award gives me both the motivation for further research and shows the value and the recognition of my work, which is so important in the academic world. Michal Michalowski
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Marina Cortes, a Marie Curie Research Fellow in the School's Institute for Astronomy, has been jointly awarded the 2014 Buchalter Cosmology Prize, along with Lee Smolin of the Perimeter Institute (Canada), for their paper “The Universe as a Process of Unique Events” (arXiv:1307.6167).
The judging committee recognised the work as “a remarkable approach for introducing the irreversible flow of time into the foundations of physics.”
This is the first year that the prize, which is worth 10,000 US dollars, has been awarded. It was announced at the American Astronomical Society meeting in Seattle on the 6th of January 2015.
"It's a great, great honour to receive this award. It is of course always an honour to see our work recognized, but this particular work is very special. The ideas in it are very different to those that are commonly accepted in the field, and it took courage and determination in voicing our own views. To see these ideas recognized by our most esteemed peers, and valued in this prize, is a reward beyond imagination. It gives us a strong impetus for continuing to develop them." Marina Cortes, Institute for Astronomy, Edinburgh
Below, Marina summarises her work, which is the result of a collaboration with Lee Smolin.
Time comes first: the arrow of time in cosmology and quantum gravity
We begin from the hypothesis that time is both fundamental and irreversible: a bold assertion, given that most physicists see time as a property that “emerges” as a consequence of more fundamental physical laws. Time results directly from this irreversibility; the future is created continuously out of the present through the activity of time. Every instant of time has a unique “fingerprint”—the signature sum of the instants that preceded it and no others.
These fundamentals results in a universe that is as asymmetric in time as possible. We develop our theory analytically, and show how space-time and partial quantum mechanics can arise from them. We then illustrate this through numerical simulations of a simplified model of a universe in which space has only a single dimension.
The new framework holds significant key implications for fundamental physics. Indeed, we argue that the primacy of time, and its irreversibility, must be incorporated into contemporary physics in order to make progress on key questions that beset the field. We believe that, ultimately, it may point the way to a unification of quantum mechanics with relativity –the “Holy Grail” of contemporary theoretical physics.
