Weather patterns in a mysterious world beyond our solar system have been revealed for the first time, a study suggests.
Layers of clouds, made up of hot dust and droplets of molten iron, have been detected on a planet-like object found 75 light years from Earth, researchers say. Findings from the study could improve scientists’ ability to find out if conditions in far-off planets are capable of sustaining life.
University researchers used a telescope in Chile to study the weather systems in the distant world - known as PSO J318.5-22 - which is estimated to be around 20 million-years-old. They captured hundreds of infra-red images of the object as it rotated over a 5-hour period. By comparing the brightness of PSO J318.5-22 with neighbouring bodies, the team discovered that it is covered in multiple layers of thick and thin cloud.
The far-off world is around the same size as Jupiter - the largest planet in our solar system - but is roughly eight times more massive, the team says. Temperatures inside clouds on PSO J318.5-22 exceed 800°C, researchers say. The team was able to accurately measure changes in brightness on PSO J318.5-22 because it does not orbit a star. Stars like our sun emit huge amounts of light, which can complicate measurements made of the brightness of objects orbiting them, researchers say.
Such techniques may eventually be applicable to cooler, lower mass planets, which are more likely to be capable of supporting life.
The study, published in The Astrophysical Journal, was funded by the Science and Technology Facilities Council. The work also involved institutions in the US, Germany, France and Spain.
We're working on extending this technique to giant planets around young stars, and eventually we hope to detect weather in Earth-like exoplanets that may harbour life.
Dr Beth Biller, Chancellor's Fellow, School of Physics and Astronomy
Congratulations to Michal Michalowski, a researcher at the Institute for Astronomy, who was chosen in recognition of outstanding, individual accomplishments in the field of astronomy.
The full citation reads: "Dr Michalowski has made a significant contribution to our understanding of formation and evolution of dust in the Universe, and he is an independent and extraordinarily productive researcher. In particular, Dr Michalowski has found evidences that in the distant universe most of dust formed through grain growth in the interstellar medium, and was not directly produced by supernovae or asymptotic giant branch stars. Dr Michalowski has also proven that a large fraction of star formation activity in the Universe happened in the most luminous galaxies, which is a significant constraint on cosmological galaxy evolution models, and that these luminous galaxies have similar characteristics to their fainter counterparts. Moreover, Dr Michalowski found that most of stars in these luminous galaxies were formed before the current strong star-formation episode."
"I am honoured to receive this award. It was established in 1970 and since then has been awarded to many distinguished Polish astronomers. I am especially happy because now, together with the RAS award, the astronomical communities of the country where I am from and the country where I work have both recognised the importance of my research." Michal Michalowski, Institute for Astronomy
Neutrinos are fundamental particles which are created in radioactive decays, in fusion processes in stars, such as our Sun, and in cosmic ray interactions with the Earth’s atmosphere. Even though neutrinos are very abundant in nature and billions pass through our bodies each second, their very weak interaction make observation challenging.
Similar to other fundamental particle of the Standard Model, neutrinos come in three flavours: electron-, muon- and tau-neutrino.
The 2015 Nobel prize for Physics was jointly awarded to Prof. Arthur McDonald of the Sudbury Neutrino Observatory (SNO) in Canada and Professor Takaaki Kajita of the Super-Kamiokande (Super-K) collaboration in Japan. The experimental teams led by the laureates showed that neutrinos can switch (or oscillate) between the different flavours. This important observation implies that neutrinos have a small but non-zero mass.
The SNO experiment focused on studying neutrinos produced in our Sun. Previous measurements, for which Ray Davies was awarded the 2002 Nobel prize, indicated that there was a deficit in the electron-neutrinos produced compared to expectations from solar models. The measurements from SNO solve this discrepancy by showing that the electron neutrinos produced were oscillating into muon- or tau-neutrinos. The Super-K experiment is a large underground detector in Japan, consisting of a cylindrical stainless steel tank that is 41 m tall and 39 m in diameter holding 50,000 tons of ultra-pure water. It’s large size makes it ideal to detect and study neutrinos produced in the atmosphere and the experiment demonstrated the oscillation phenomenon applies also to muon-neutrinos, changing flavour into tau-neutrinos.
'The award of the Nobel prize for neutrino physics is fantastic news and well deserved. The fact that neutrinos oscillate and have mass was totally unexpected’. Dr Greig Cowan, University of Edinburgh
Scientists at the University of Edinburgh, including Greig, have recently joined the planned successor to the Super-K experiment, called Hyper-K. Hyper-K is also an underground detector located in Japan, filled with 1 million metric tons of ultrapure water, a volume approximately 20 times larger than that of Super-K. Start of science operation is foreseen from around 2025.
The behaviour of neutrinos could well surprise us in the future, in particular Hyper-K aims to study with unprecedented accuracy the differences in the switching properties for neutrinos and their anti-matter counterpart. During the Big Bang equal amounts of matter and anti-matter should have been produced. However, our Universe we see today is dominated by matter.
As Dr Cowan explained 'There must be new yet unknown physics processes that distinguish matter and anti-matter. One possibility is that neutrino oscillations are not the same for neutrinos and anti-neutrinos, which could help resolve the puzzle of the matter asymmetry of the Universe. If this is the case we will pin this down with Hyper-K in the coming years. The next years are going to be very exciting times for neutrino physics.'
The Scottish Universities Physics Alliance (SUPA) is offering PhD studentships for outstanding students from anywhere in the world.
These prestigious and competitive awards are intended to attract excellent students to study for a PhD in Scotland. SUPA opens a single front door into Physics PhDs in Scotland. When you apply for a SUPA Prize PhD Studentship you will also be considered for all other funded places available in physics departments in Scotland.
Major themes pursued by researchers in SUPA are:
Astronomy and Space Physics
Condensed Matter and Materials Physics
Physics and Life Sciences
Nuclear and Plasma Physics
SUPA Prize Students are registered for a PhD in physics at one of the participating universities:
University of the West of Scotland
An excellent training environment will be provided by the SUPA Graduate School, giving candidates access to a wide range of courses across Scotland.
Applications MUST be submitted by 23:59 GMT on Sunday 31st January 2016.
References MUST be uploaded by 23:59 GMT on Sunday 7th February 2016.
You will be informed of the result of your application by each institution. You must also apply to your chosen SUPA university to undertake a PhD and are obliged to meet the minimum requirements of that institution.
The soft matter physics group part of the Institute for Condensed Matter and Complex Systems took part in Doors Open Day, Edinburgh on 26th of September in the James Clerk Maxwell Building.
Eighteen researchers from the group showed demonstration experiments and guided visitors around the group’s laboratories. During the day 340 visitors made slime, punched corn starch and learned about the physics of bacteria. Researchers also chatted to lots of people visiting the department as part of the UCAS open day.
The demonstration experiments highlighted properties of non-Newtonian fluids whilst an interactive exhibition with microscopes and computer simulations allowed visitors to explore the groups’ research into active matter. In the labs visitors were able to see the rheometers (mechanical testing devices) and microscopes used to study these complex systems.
The School of Physics & Astronomy had a particularly strong line-up of speakers in this year's Orkney Science Festival, contributing to its outstanding public engagement record.
Peter Higgs' appearance attracted great interest and as expected "Peter Higgs in Conversation" at the Kirkwall Arts Theatre was a complete sell-out. His conversations with fellow particle physicist and science writer Frank Close were followed by the presentation "From Maxwell to Higgs - and Beyond?" by Alan Walker and Victoria Martin. Clive Greated's presentation "Sounds Around Us" at Pier Arts Centre in Stromness was also a sell-out.
The Particle Physics For Scottish Schools Exhibition (PP4SS) was present throughout the Festival, reaching a total audience of over 2000.
Physical Review Letters has published a paper on turbulence by PhD student Moritz Linkmann and Alexander Morozov, both of the School of Physics & Astronomy.
Chaotic flows of liquids or gases far away from any boundary, like many atmospheric and oceanic flows, are often viewed by scientists as real-life realisations of the so-called forced isotropic turbulence - a classical idealised description of turbulent motion that dates back to the beginning of the 20th century. In this framework turbulence is driven by a vigorous large-scale stirring and was thought to be featureless at smaller scales: if one would look at the flow through a magnifying glass, one should see the same picture independent of the degree of magnification. This is in contrast with turbulence between boundaries, like flow in a pipe, where recent research showed that the flow is organised by spatially regular, unstable structures.
Surprisingly, computer simulations performed in the Letter suggest that forced isotropic turbulence is not featureless and is much more similar to wall-bounded flows than was thought previously. We demonstrate that at moderate Reynolds number isotropic turbulence is always metastable and the probability of its sudden disappearance obeys an exponential law, previously found in experiments and simulations on pipe flows.
The similarities between the two systems suggest a universal scenario in which turbulence is always organized around unstable, spatially regular structures.
"It was very interesting to find that isotropic turbulence, which is an idealised system that allows the study of fundamental turbulent dynamics without having to consider external influences such as the geometry (and walls) of a container, is connected to real-world flows such as flow through a pipe." Moritz Linkmann, PhD student, School of Physics & Astronomy
Below, Moritz Linkmann explains the research behind the paper.
Dynamical systems and the transition to turbulence in parallel shear flows
In parallel wall-bounded shear flows (such as flow through a pipe or counter-rotating cylinders) the transition to turbulence does not occur due to a linear instability of the laminar profile. The state space of the system, where each point corresponds to a flow state, is organised by a complicated collection of unstable flow states and the linearly stable laminar profile. Turbulence is then characterised as the system revolving around these unstable flow states (so-called `exact coherent structures'). The important point is that the laminar profile and the turbulent states remain dynamically connected and a sudden `escape' from the turbulent region of state space can occur. Localised turbulence in a flow can therefore suddenly relaminarise and this has been observed in many experiments of parallel shear flows. This relaminarisation is a memoryless process, that is, it does not depend on the amount of time the system has spent in the turbulent region of the state space. A characteristic timescale can be associated with this process which increases with Reynolds number as a double exponential. This implies that there is always a finite probability of relaminarisation, even at high Reynolds numbers: Localised turbulence in wall-bounded shear flows is transient.
The transition to sustained turbulence then occurs due to a competing process,that is the splitting of a locally turbulent region into two. This process also has a characteristic timescale which now decreases with Reynolds number as a double exponential. The critical Reynolds number for sustained turbulence is then defined at the point where the two timescales are equal.
Collapse of isotropic turbulence
Isotropic turbulence and a parallel wall-bounded shear flow are a priori very different systems, isotropic turbulence being a simplified system studied in order to establish fundamental properties of turbulent flows. It is often thought of as high Reynolds number limit of wall-bounded flows, where the walls have negligible influence on the turbulent dynamics. It is traditionally studied in statistical terms and in numerical simulations, where the decay of turbulence due to viscous dissipation is balanced by an external energy input at the large scales. The emphasis in the simulations is usually on achieving high Reynolds numbers. The dynamics of forced isotropic turbulence has been thought to be as simpler than that of parallel shear flows. In particular, isotropic turbulence is not expected to show transitional behaviour and nothing is known about its phase space structure.
In this study we investigated the same system at low Reynolds numbers and observe a sudden collapse of turbulence in favour of a large-scale ordered flow. This can be seen in the figures, which show streamlines of the flow before and after the collapse of turbulence. A transition from a 'disordered' to an 'ordered' flow is clearly visible. This collapse of turbulence happens despite the continuous stirring of the flow at the large scales and had been observed in a previous study already. Our analysis, which is new in the sense that it is the first time that a dynamical systems approach has been applied to isotropic turbulence, now shows that this collapse has very similar features to relaminarisation events in pipe flow: It is a memoryless process with a characteristic timescale that increases with Reynolds number in much the same way as in wall-bounded shear flows. Furthermore, the base flow appears to be linearly stable. This shows that isotropic turbulence at low Reynolds numbers is transient and it suggests that the phase space dynamics of wall-bounded shear flows and isotropic turbulence may be very similar.
Outlook: the universality class of the transition to turbulence
Recent research suggests that the transition to turbulence in parallel shear flows constitutes a second-order nonequilibrium phase transition belonging to the Directed Percolation universality class. That is, the transition to turbulence in these flows behaves like, for example, the spread of diseases or wildfires. The similarities between relaminarisation in pipe flow and the collapse of isotropic turbulence reported here suggest that this behaviour may in fact be a universal feature of turbulence and plans are under way to investigate this further.
This work has made use of the resources provided by the Edinburgh Compute and Data Facility (http://www.ecdf.ed.ac.uk). Moritz Linkmann and Alexander Morozov acknowledge support from the UK Engineering and Physical Sciences Research Council (EP/K503034/1 and EP/I004262/1).
The School of Physics and Astronomy is opening its doors at the end of September.
Coordinated by the Cockburn Association, Doors Open Day is an annual opportunity for the public to visit buildings and institutions across the city that are not available during the rest of the year.
Take a guided tour of the Institute for Condensed Matter and Complex Systems (ICMCS) and go behind the scenes of soft matter research on Saturday 26 September at the James Clerk Maxwell Building on the King’s Building campus. You will have the opportunity to experiment with a variety of hands-on activities alongside staff and students, including having the chance to make and take away your own slime!
On Saturday 26 & Sunday 27 September, you will have the chance to talk to astronomers from the Institute for Astronomy about their work on galaxy evolution, planet formation and computer simulations of the Universe. There will be hands-on craft activities including making your own origami brown dwarf and the chance to try your hand at characterising light curves from stars to spot exoplanets. Relax on the sofa in the astronomers’ corner while discussing the big questions of the Universe and get an insight into the working life of an observatory. These events take place at the Royal Observatory Edinburgh.
Childhood memories of sticky hands from melting ice cream cones could soon become obsolete, thanks to a new food ingredient.
Scientists have discovered a naturally occurring protein that can be used to create ice cream that is more resistant to melting than conventional products. The protein binds together the air, fat and water in ice cream, creating a super-smooth consistency.
The new ingredient could enable ice creams to keep frozen for longer in hot weather. It could also prevent gritty ice crystals from forming, ensuring a fine, smooth texture like those of luxury ice creams. The development could allow products to be manufactured with lower levels of saturated fat – and fewer calories – than at present.
Researchers at the Universities of Edinburgh and Dundee developed a method of producing the new protein – which occurs naturally in some foods – in friendly bacteria. They estimate that ice cream made with the ingredient could be available within three to five years.
The protein works by adhering to fat droplets and air bubbles, making them more stable in a mixture. Using the ingredient could offer significant advantages for ice cream makers. It can be processed without loss of performance, and can be produced from sustainable raw materials.
Manufacturers could also benefit from a reduced need to deep freeze their product, as the ingredient would keep ice cream frozen for longer. The supply chain would also be eased by a reduced need to keep the product very cold throughout delivery and merchandising.
The protein, known as BslA, was developed with support from the Engineering and Physical Sciences Research Council and the Biotechnology and Biological Sciences Research Council.
Professor Cait MacPhee, of the University of Edinburgh’s School of Physics and Astronomy, who led the project, said: “We’re excited by the potential this new ingredient has for improving ice cream, both for consumers and for manufacturers.”
Dr Nicola Stanley-Wall, of the University of Dundee, said: “It has been fun working on the applied use of a protein that was initially identified due to its practical purpose in bacteria.”
Computer models of developing cancers reveal how tiny movements of cells can quickly transform the makeup of a tumour.
The models reinforce laboratory studies of how tumours evolve and spread, and why patients can respond well to therapy, only to relapse later.
Researchers used mathematical algorithms to create three-dimensional simulations of cancers developing over time. They studied how tumours begin with one rogue cell which multiplies to become a malignant mass containing many billions of cells.
Their models took into account changes that occur in cancerous cells as they move within the landscape of a tumour, and as they replicate or die. They also considered genetic variation, which makes some cells more suited to the environment of a tumour than others.
They found that movement and turnover of cells in a tumour allows those that are well suited to the environment to flourish. Any one of these can take over an existing tumour, replacing the original mass with new cells quickly - often within several months. This helps explain why tumours are comprised mostly of one type of cell, whereas healthy tissue tends to be made up of a mixture of cell types.
However, this mechanism does not entirely mix the cells inside the tumour, the team says. This can lead to parts of the tumour becoming immune to certain drugs, which enables them to resist chemotherapy treatment. Those cells that are not killed off by treatment can quickly flourish and repopulate the tumour as it regrows.
Researchers say treatments that target small movements of cancerous cells could help to slow progress of the disease.
The study, a collaboration between the University of Edinburgh, Harvard University and Johns Hopkins University, is published in the journal Nature. The research was supported by the Leverhulme Trust and The Royal Society of Edinburgh.
"Computer modelling of cancer enables us to gain valuable insight into how this complex disease develops over time and in three dimensions.” Dr Bartlomiej Waclaw, School of Physics and Astronomy