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Europe’s science leaders speak out on Brexit

The inaugural Big Science Business Forum, which was held in Copenhagen this week, brought together 1000 scientists, engineers, business executives and government officials from 29 European nations to discuss the commercial opportunities for companies in big-science facilities across the continent. The European big-science market is big – it’s worth an estimated €12bn – but companies are often put off because each facility has its own complicated and time-consuming procurement rules and quality standards.

So the meeting was an attempt to create a more transparent and efficient big-science market in Europe by showing firms what opportunities are on offer and getting them talking to people form big-science facilities. But it left me wondering why the UK would want to quit the European Union (EU) when closer co-operation and freedom of movement of scientists are surely key to scientific and technological innovation in Europe of the kind espoused at the meeting.

My colleague Margaret Harris and I therefore put the following question to five of Europe’s top scientific leaders.

What are the threats to researchers and companies from Britain leaving the EU?

Carlos Moedas, EU commissioner for research, science and innovation

I think we will all be affected by that decision and that’s why we’re working so hard to find a solution for the future. I think the wish of all of us from the EU side and the UK side is that we find a solution for a future relationship. I cannot imagine that we will not find a solution so I am positive we are going through this phase of basically settling the accounts – what we call in our jargon the divorce bill. But then after that we will have to sit down and develop the relationship we want. And I hope that science and innovation will be part of that. But there’s nothing more I can tell you at the moment because there’s nothing more to tell.

John Womersley, director-general, European Spallation Source

There are two short-term issues. One concerns access to talent. A loss of freedom of movement, which until now has been a pre-requisite for membership of the EU’s Framework programmes, could make it harder for EU scientists to work in the UK and also for British researchers to study and work abroad.

The other concerns funding. The UK has been very good at winning grants, particularly from the European Research Council, and some universities have come to see it as a steady source of income that can make up for relatively flat funding from the research councils. If funding from the EU is cut off, that could damage UK research. The government has promised to more than make up for any potential shortfall from Europe by giving extra cast to UK Research and Innovation (UKRI) but much of that work is targeted at industrial and applied research so Brexit could mean less money for individual principal investigators doing basic research.

Longer term, Brexit could affect Britain’s ability to take part in decisions about future European projects and the overall direction of international projects. Many European scientific bodies, such as CERN, the ESS and the European Space Agency, are intergovernmental organisations and so in principle won’t be affected by Britain leaving the EU. But if the UK is “semi-detached” from international networks, science could suffer unless other networks are in place.

Brexit could affect Britain’s ability to take part in decisions about future European projects.
John Womersley, Director General, European Spallation Source

Many scientists in the rest of Europe are curious about the UK’s approach to Brexit because science has not been high on the agenda. Similarly, many UK scientists don’t look forward to the inevitable questions about Brexit because they don’t have any good answers. I’m really hoping we start to hear more from Mark Walport when he takes over as head of UKRI next month. This isn’t about lobbying for universities as a special interest group. Science and innovation are key to the future of everyone in Britain. It’s really important not to screw this up!

Xavier Barcons, director-general, European Southern Observatory

Brexit means no change for us. We are totally independent of the EU – I mean, we have close links, we try to work together with them and talk to each other and so on, but we are totally independent. So, I expect that there will be no changes in relation to UK companies and the government in terms of anything related to ESO.

Johann-Dietrich Wörner, director-general, European Space Agency

At a fundamental level, Brexit is no issue for us, because the UK remains an ESA member state. There are some issues concerning, for instance, working arrangements and working permissions for UK nationals at ESA, but I am sure these will be solved within a couple of months, because they have to be. Of course, we would like the UK to be part of other activities as well, and I am fighting like hell to get all of these solutions, but for us it’s not that big an issue.

I agree it is an issue [for the wider research community and companies], though. If you apply for EU funding to do research, it is an issue. Also, at ESA we have the Galileo programme and the Copernicus programme that are financed by the EU, and whenever we have a UK company in to do work on those projects, it will be a special problem in the future, because the EU may forbid that money from going to British companies. It is the EU saying that, not us; we at ESA would be fine with it, but if it’s EU money we might be not allowed to give it to a UK company. I hope that this will be clarified very soon by the discussion between UK and Brussels.

I am a convinced European. I am very unhappy about the developments we are seeing right now.
Johann-Dietrich Wörner, Director General, European Space Agency

I am a convinced European. I am very unhappy about the developments we are seeing right now, and the UK is just one example. Having a “United States of Europe” would be still my dream, but what I am doing is the “United Space of Europe”, and that means I try to cover all the different actors and collect them under the roof of ESA to work together. And it’s working. In ESA, the European spirit is 100% there.

Richard Cobben, head of ITER Delivery Department, Fusion for Energy

So far they [the UK] have communicated that they are still interested in participating in ITER. It’s fully under discussion but the first impression is that there won’t be a big change, let’s say closing down or not participating any more. They are willing to continue on this development. But again, discussions are ongoing. Initially it was some kind of a shock but people think the future looks reasonably stable and good so [the issue] has disappeared again. But nothing is decided yet but it does have an impact on British people working for us. It doesn’t have to have an impact but people are starting to wonder what does it mean for me.

Isotopes for precision medicine

The CERN-MEDICIS facility has produced its first radioisotopes for medical research, targeting novel diagnostic agents and treatments for diseases such as brain and pancreatic cancers.

The use of radioisotopes to treat cancer goes back to the late 19th century, with the first clinical trials taking place in France and the US at the beginning of the 20th century. Great strides have been made, and today radioisotopes are widely used by the medical community. Produced mostly in dedicated reactors, radioisotopes are used in precision medicine, both to diagnose cancers and other diseases, such as heart irregularities, as well as to deliver very small radiation doses exactly where they are needed to avoid destroying the surrounding healthy tissue.

However, many currently available isotopes do not combine the most appropriate physical and chemical properties and, in the case of certain tumours, a different type of radiation could be better suited. This is particularly true of the aggressive brain cancer glioblastoma multiforme and of pancreatic adenocarcinoma. Although external beam gamma radiation and chemotherapy can improve patient survival rates, there is a clear need for novel treatment modalities for these and other cancers.

On 12 December, a new facility at CERN called MEDICIS produced its first radioisotopes: a batch of terbium (¹⁵⁵Tb), which is part of the ^{149/152/155/161}Tb family considered a promising quadruplet suited for both diagnosis and treatment. MEDICIS is designed to produce unconventional radioisotopes with the right properties to enhance the precision of both patient imaging and treatment. It will expand the range of radioisotopes available – some of which can be produced only at CERN – and send them to hospitals and research centres in Switzerland and across Europe for further study.

Initiated in 2010 by CERN with contributions from the Knowledge Transfer Fund, private foundations and partner institutes, and also benefitting from a European Commission Marie Skłodowska-Curie training grant titled MEDICIS-Promed, MEDICIS is driven by CERN’s Isotope Mass Separator Online (ISOLDE) facility. ISOLDE has been running for 50 years, producing 1300 different isotopes from 73 chemicals for research in many areas including fundamental nuclear research, astrophysics and life sciences.

Although ISOLDE already produces isotopes for medical research, MEDICIS will more regularly produce isotopes with specific types of emission, tissue penetration and half-life – all purified based on expertise acquired at ISOLDE. This will allow CERN to provide radioisotopes meeting the requirements of the medical research community as a matter of course.

ISOLDE directs a high-intensity proton beam from the Proton Synchrotron Booster onto specially developed thick targets, yielding a large variety of atomic fragments. Different devices are used to ionise, extract and separate nuclei according to their masses, forming a low-energy beam that is delivered to various experimental stations. MEDICIS works by placing a second target behind ISOLDE’s: once the isotopes have been produced on the MEDICIS target, an automated conveyor belt carries them to a facility where the radioisotopes of interest are extracted via mass separation and implanted in a metallic foil. The final product is then delivered to local research facilities including the Paul Scherrer Institute, the University Hospital of Vaud and Geneva University Hospitals.

Clinical setting

Once in a medical-research environment, researchers dissolve the isotope and attach it to a molecule, such as a protein or sugar, which is chosen to target the tumour precisely. This makes the isotope injectable, and the molecule can then adhere to the tumour or organ that needs imaging or treating. Selected isotopes will first be tested in vitro, and in vivo by using mouse models of cancer. Researchers will test the isotopes for their direct effect on tumours and when they are coupled to peptides with tumour-homing capacities, and establish new delivery methods for brachytherapy using stereotactic or robotic-assisted surgery in large-animal models for their capacity to target glioblastoma or pancreatic adenocarcinoma or neuroendocrine tumour cells.

MEDICIS is not just a world-class facility for novel radioisotopes. It also marks the entrance of CERN into the growing field of theranostics, whereby physicians verify and quantify the presence of cellular and molecular targets in a given patient with a diagnostic radioisotope, before treating the disease with the therapeutic radioisotope. The prospect of a dedicated facility at CERN for the production of innovative isotopes, together with local leading institutes in life and medical sciences and a large network of laboratories, gives MEDICIS an exciting scientific programme in the years to come. It is also a prime example of the crossover between fundamental physics research and health applications, with accelerators set to play an increasing role in the production of life-changing medical isotopes.

• This article first appeared in the January/February 2018 issue of CERN Courier.

Holes reveal first fractional quantization

Advances in epitaxial growth of high-quality low-dimensional strained germanium semiconductor structures in recent years have opened up options for studies of these systems that previously were not possible. Maksym Myronov, who led these fabrication advances at Warwick University, Michael Pepper, and colleagues in the UK have seized the opportunity to study the transport behaviour of holes when loosely confined to one dimension (1D). To their great surprise they observed fractional quantized conductance for the first time ever in the absence of strong magnetic fields.

Quantum hole wire interview

“We’d been looking at electrons for a long time so we thought let’s see if there’s any difference between holes and electrons,” says Pepper, a researcher at University College London (UCL) who pioneered the study of low-dimensional electron gas systems and associated quantum effects. He had been studying electron transport in two-dimensional (2D) systems as they were gradually confined to 1D for several years with Sanjeev Kumar, also at UCL, before turning his attention to the transport of holes – corresponding positive charges where an electron is absent.

At the same time their colleague Maksym Myronov at Warwick University had been perfecting one of the epitaxial growth techniques to create high-quality epitaxial semiconductor materials, including germanium, which had previously been out of reach. Myronov was working with Stuart Holmes at Toshiba Research Europe at Cambridge Research Laboratory to examine the potential of holes in germanium for developing new spintronics systems.

As their interests aligned, Pepper, Kumar, Myronov and Holmes joined forces alongside Yilmaz Gul, who was studying for his PhD with Holmes and Pepper. “We thought we’d see the regular quantization, but we hadn’t expected to see any fractions, because they had not been seen before in any system, unless of course you apply a very strong magnetic field,” explains Pepper.

System architecture

The researchers studied epitaxial germanium grown on silicon, which makes it strained. They used split gates to confine the hole transport to 1D and gradually relaxed this confinement to allow some lateral drift so that a zig zag developed as opposed to a straight line of transport. With high confinement from the split gates, they measured hole conductance values in regular integers of the quantum unit 2e²/h – where e is the charge of an electron or hole, and h is Planck’s constant. This matched with the behaviour they had observed in studies of 1D electron conductance in other semiconductors such as GaAs. However, to their great surprise, as the confinement was weakened they found conductance values at 1/2, 1/4 and 1/32 of 2e²/h.

Transconductance showing fractional quantization

Quantized conductance – fractionalized

The first observations of fractional quantum conductance date back to 1982 with the fractional quantum Hall effect. However, this only occurs in the presence of a very high magnetic field, and there have been no observations of fractional quantum conductance besides this effect. In the experiments by Pepper and colleagues’ there is no large applied magnetic field, and the cause of the fractional quantization remains a mystery. The researchers are liaising with theorists to find an explanation.

“It is interesting to note, that so far, the fractional quantum Hall effect has been observed only in 2D systems made of semiconductor and oxide materials,” says Myronov. He adds, referring to work reported in one of his recent papers, “Just recently, in 2015, I and some colleagues observed this effect in superior quality strained germanium that I had grown epitaxially, which outlined the pathway to our latest discovery.”

As for explanations of the effect, Pepper describes some of the approaches to explore. “One is to look at extensions to the theory of the fractional quantum Hall effect, but without the magnetic field; others start from the formation of the zig zag and then seeing what happens when you add various interactions into that – but so far no explanation has emerged.”

Gul, for whom the observations formed the basis of his PhD thesis laughs at how in some ways it was an easy thesis to defend. “I didn’t have to learn any theories because there weren’t any.”

Applications and further work

The effect may find applications in quantum computing where the silicon substrate for the germanium hole wire may have advantages for integrating with silicon electronics processes and systems. Although to see the quantized conductance it is important that the germanium is high purity, as Holmes points out “The states that we observe are naturally protected from the environment, so things like disorder and impurity scattering may not be important. That would mean that you could have slightly impure materials that you might find more in industry – companies like Toshiba would be interested in developing that kind of technology.”

Myronov adds that although in the fractional quantum Hall effect there is no direct observation of a quarter charge, there is indirect evidence that it exists, and theory suggests that it can be very strongly coherent and difficult to decohere. This means that if it were carrying quantum information it would be much more difficult to corrupt than in other types of qubit. “There is of course a very long way to go but if this effect can be exploited in quantum information, then because it is a semiconductor it can be miniaturized with a very high density and germanium can be grown on silicon so the control circuitry can be integrated with the qubits,” says Myronov.

In addition, manipulating quibits with an applied electric field is more manageable than the large magnetic fields required for the fractional quantum Hall effect, although as Holmes emphasizes, it may be a little premature to talk of qubits before the state itself is properly understood.

Alongside discussions with theorists to try and explain the effects, the researchers’ next steps include looking to see if there are any more fractions of the conductance in germanium, studying the system at lower temperatures, and experiments to measure the actual charge itself. “It’s a completely new system,” says Pepper. “So we expect more surprises.”

Full details are reported in Journal of Condensed Matter Physics.

Composite polymer electrolyte helps improve Li-ion batteries

Solid-state electrolytes, such as those made from ceramic-polymer composites, are promising alternatives to liquid electrolytes for next-generation lithium-ion batteries that are safer and more stable. However, there is a problem in that these composites agglomerate at high weight ratios, which adversely affects their good ion conductivity properties. A new 3D interconnected framework consisting of ceramic nanofillers made using a nanostructured hydrogel template that does not aggregate could help overcome these problems.

“Ceramic-polymer composite electrolytes comprising ceramic nanofillers and a polymer matrix have improved mechanical and thermal stability as well as ionic conductivities that are better than pure polymer electrolytes,” explains Guihua Yu of the University of Texas at Austin, who led this study. “However, as these composites agglomerate at high weight ratios, the ion conductivity pathways in these materials becomes discontinuous. This is because the percolating network in the nanofiller deteriorates.

“In this new work, we fabricated 3D interconnected frameworks consisting of ceramic nanofillers using a simple nanostructured-hydrogel template technique. The framework provides a continuous ion conduction path that prevents nanofiller aggregation. It also provides excellent conductivity and electrochemical stability.”

Yu and colleagues made their percolating network of ceramic nanoparticles by nanoscale phase separation of a polymer (polyethylene oxide), water, and ceramic precursors (Li_0.35La_0.55TiO₃, or LLTO). The nanosized ceramic particles are interconnected to form a free-standing continuous, 3D porous structure.

“Once the self-supporting ceramic framework has formed, we fill the void pores with the polymer to prepare a polymer electrolyte,” Yu tells nanotechweb.org. “Unlike traditional composites in which particles are dispersed and separated in the polymer matrix, the nanostructured framework acts as a 3D nanofiller that can then form a continuous interphase between the polymer and the ceramic. The interaction between the filler and the polymer results in improved lithium ion conductivity, as mentioned, thanks to the formation of a continuous interphase, but also in sufficient mechanical integrity for use in a variety of flexible electronic devices.”

According to Yu, the interphase between the ceramic filler and the polymer is responsible for faster lithium ion conduction thanks to the high dielectric constant and the abundant surface defects in the LLTO.

The team, reporting its work in Angewandte Chemie DOI: 10.1002/anie.201710841, says that it would now like to apply its structural design strategy to other energy applications, such as composite electrodes. To this end, we need to better understand the interaction between the ceramic filler and the polymer matrix,” explains Yu.

Population grows in US floodplains

Maps that the US Federal Emergency Management Agency (FEMA) rely upon to determine flood risk underestimate the potentially affected population by a factor of three. A new model that covers the 48 contiguous states of the US (excluding Alaska and Hawaii) at 30-metre resolution places 41 million Americans in a 100-year floodplain, meaning the annual probability of flooding is 1%. FEMA's maps put that population figure at just 13 million.

The reason for the discrepancy, according to Oliver Wing of the University of Bristol, UK, is that FEMA's maps cover only about 60% of the land area, and "they tend to just focus on the primary large streams in those catchments".

Wing, who presented his findings at the American Geophysical Union's (AGU) Fall Meeting in New Orleans in December, said that FEMA "will tend to have not modeled the smaller headwater tributaries, and ... when you add those up across the country, that's a lot of risk that is therefore missed".

Wing and his colleagues combined data from their expanded floodplain maps with population and land-use projections from the US Environmental Protection Agency (EPA), to estimate how the affected population might grow this century. Currently, 13.3% of the US population lives in a 100-year floodplain, they found. By 2050, that will increase to around 15.7%, and by 2100, it could reach as high as 16.8%.

The researchers also evaluated the amount of developed land within flood zones. Currently about 150,000 sq. km, this could increase by anywhere from 37% to 72% by 2100, depending on the growth scenarios. In addition, the value of assets located on floodplains, currently $5.5 trillion, will double during the rest of the century.

"We're not even accounting for what climate change may do to flooding," Wing said at AGU. "We are simply looking at the intensification of floodplain development, and due to that alone, we see that risk is increasing quite dramatically."

Asked at a press conference whether FEMA would be making use of the data presented at the AGU meeting, Wing said his team would be happy to work with FEMA, if asked. He emphasized that the cutting-edge methodology employed in the study, involving "big data" and the enhanced computational power required to generate more detailed new maps, had only become available recently. He said he would be "very much surprised" if FEMA did not adopt the new methodology within the next five years.

The study included inputs from academia, the commercial world, the nonprofit sector, and government agencies, Wing said. At the time, the paper was under review for publication in Environmental Research Letters (ERL) – it has now gone live.

NPL launches Metrology for Medical Physics Centre

The National Physical Laboratory (NPL), the UK's National Measurement Institute, has launched the Metrology for Medical Physics Centre (MEMPHYS). The aim of MEMPHYS is to accelerate the development and implementation of innovative diagnostic and therapeutic technologies.

The Centre will provide a range of consultancy and research services, and offer quality assurance and commissioning tools that help get new equipment into routine use, and enable more efficient use of technologies already in the clinic. "MEMPHYS brings together all of the medical physics activities happening at NPL under a single banner and helps us to grow," explained Rebecca Nutbrown, NPL's head of metrology for medical physics. "NPL has been expanding its work in this area over the last year."

One area of medical physics in which NPL already has extensive experience is radiotherapy dosimetry, such as testing the calibration of linacs, for example. "We need to check that the patient treatment is delivered as expected," said Nutbrown, speaking at the MEMPHYS launch event. "So we devise phantoms that mimic the properties of the human body, embed dosimeters, and then treat them as we would a patient and check the radiation is delivered to the right place."

For example, as hypofractionated radiation treatments become increasingly prevalent, NPL - in collaboration with the Royal Surrey County Hospital and the Radiotherapy Trials QA (RTTQA) group - used a specialized CIRS head phantom (STEEV) to ensure that all centres using stereotactic radiosurgery (SRS) are treating patients in the same way, and treating accurately. Another development is a dosimetry audit for testing spinal stereotactic body radiotherapy (SBRT) - a treatment that necessitates exceptionally precise beam targeting.

NPL has also created a graphite calorimeter that measures radiation dose extremely accurately. The calorimeter is used to perform measurements on one of NPL's two linacs; then a hospital will send their instrument to NPL for comparison, thereby ensuring the accuracy of the instruments used for clinical dosimetry.

More recently, NPL has been working on a small portable calorimeter for reference dosimetry of proton therapy. The aim here is to standardize treatments across the UK's forthcoming proton therapy centres, and to ensure that proton therapy is delivered with the same level of accuracy as conventional radiotherapy.

Lab launch
MEMPHYS also sees the introduction of a new nuclear medicine laboratory. Last December, NPL installed a unique clinical SPECT/PET/CT camera that is directly calibrated against primary standards of radioactivity. As nuclear medicine continues to transition from qualitative to quantitative imaging, the goal is to provide primary standards for emerging quantitative approaches.

The camera will be used to image phantoms, which will then be taken to a clinic for imaging on its scanners. The two data sets, both of which will be processed by NPL to provide quantified measurement uncertainties, are then compared to assess scanner accuracy. To help tailor this process for specific applications, MEMPHYS has also set up a new Rapid Phantom Prototyping Laboratory to produce and optimize medical phantoms.

The lab applies 3D printing to rapidly develop complex phantoms. Examples include anthropomorphic phantoms for medical imaging and dosimetry, and mouse phantoms for calibrating equipment employed in small-animal and radiobiology experiments. The phantoms are fillable with radioactive solutions, though future approaches will involve integrating radioactivity directly into the printing material.

Device development
Finally, NPL's ultrasound group has developed a new scanner for breast imaging. Ultrasound can be employed as an adjunct to X-ray mammography, and generates more reliable images when breast tissue is dense. The team is developing a novel phase-insensitive ultrasound sensor, originally conceived for a measurement application, to create a system with potentially improved image quality and far fewer artefacts than a conventional ultrasound scanner.

The team has now built a prototype of the phase-insensitive ultrasound CT (piUCT) device. The system employs 14 parallel ultrasound emitter elements, plus one large sensor, all housed in a water tank. The elements can be can moved vertically to select the scan plane. During scanning, the patient lies prone and the breast is imaged without requiring compression, making the procedure much more comfortable than mammography.

Prototype phase-insensitive ultrasound CT device

The system is currently being evaluated at NPL using a breast phantom, and images will be compared in terms of quality and spatial resolution with X-ray CT and MRI scans. The next step is to test the system on a number of volunteers. For this, the piUCT will shortly be moved to Southmead Hospital in Bristol, for trials on 20-30 patients. Looking further ahead, NPL hopes to partner with a commercial manufacturer to translate this novel system into a clinical device.

Ultimately, MEMPHYS will function as an international centre for excellence, fostering interdisciplinary and inter-sector research to inspire cutting-edge innovations. MEMPHYS will work closely with the NHS, academia and industry to enable the rapid and widespread implementation of a host of new diagnostic and therapeutic technologies.

The March 2018 issue of Physics World is now out

Image of the cover of the March 2018 issue of Physics World — *Physics World* March 2018 is now out

I hope you’ve been enjoying the new-look Physics World website, which we launched earlier this week. I’m sure you’ll agree it’s a vast improvement on what went before.

And as if the excitement of the new site wasn’t enough, I’m pleased to say that that the March 2018 issue of Physics World is also now out.

As always, selected articles from the magazine will appear on this website over the course of the month, but if you’re a member of the Institute of Physics, which publishes Physics World, you can read the entire March issue right now in digital format.

In our cover story this month, one theoretical physicist tells of their ongoing battle with mental illness and how it affected their research career.

We also look at the career opportunities for physicists in environmental science, the research that goes on at US tape and adhesives giant 3M, as well as developments in technology that can help disabled people in everyday life.

The February 2018 issue of Physics World magazine is now out

Plus there are all the usual sections, including Reviews, Careers, Transactions and the ever-popular Lateral Thoughts.

Let us know what you think about the issue on Twitter, Facebook or by e-mailing us at pwld@iop.org .

For the record, here’s a run-down of what else is in the issue.

Revitalizing Japanese physics – Japan is trying to boost its declining international competitiveness in science by attracting top foreign researchers. But as Matin Durrani finds out, working in Japan can be challenging to outsiders
Science in a changing world – Japan has traditionally been strong in science and technology, but Tateo Arimoto calls for the country to reform if it wants to stay ahead
Lighting the way – In the second of his new columns about physics in industry, James McKenzie looks at the lessons we can learn from the humble light bulb
The pioneer princess – Robert P Crease celebrates a woman who transformed how learned societies should be run
My invisible battle – The stigma around mental illness is slowly crumbling, with society becoming increasingly aware of the problem that affects an estimated one in four adults, from any walk of life. But what about attitudes within the academic community? A theoretical physicist tells their story of battling mental illness while pursuing a research career, raising the question of whether the community does enough to help
The Cybathlon challenge – Science and engineering are vital for developing “assistive technology” to help disabled people perform everyday tasks. But as Rachel Brazil finds out, a sporting contest called the Cybathlon has proved invaluable for discovering if the devices are fit for purpose
A sticky wonderland – Adhesives are everywhere, from the aerospace industry to the simple but infamous Post-it Note. Alaina G Levine visits adhesive-giant 3M Company’s main US innovation centre to find out more about the physics involved
Race to space and beyond – Tim Gregory reviews Ad Astra: an Illustrated Guide to Leaving the Planet by Dallas Campbell
Tale of the atom tamers – Tushna Commissariat reviews the new documentary film Let There Be Light: the 100 Year Journey to Fusion, directed by Mila Aung-Thwin
From physics to environmental science: a natural evolution? – Physics and environmental research are more compatible than you might first think. Kate Ravilious talks to three leading physicists-turned-environmental researchers, to find out about their journey
In the pursuit of inspiration – Martijn Boerkamp from Dutch start-up firm Inkless on what triggered him into physics

And don’t forget, if you have any thoughts on the issue do let us know on Twitter, Facebook or by e-mailing us at physics.world@iop.org.

Ancient hydrogen reveals clues to dark matter’s identity

A potentially huge breakthrough in the study of dark matter has come from an unlikely source: radio emissions detected from hydrogen gas that existed just 180 million years after the Big Bang.

Dark matter makes up 26.8% of the total mass and energy in the universe, yet it continues to remain elusive. Astronomers have only been able to detect it through its gravity, while terrestrial experiments designed to identify dark matter particles have found nothing. However, new observations of the ancient universe suggest that the reason for this is that our experiments have been looking in the wrong place.

A team led by Judd Bowman of Arizona State University has used the EDGES all-sky radio antenna in western Australia to search for the faint signature of primordial hydrogen in the very early universe. When the first stars lit up, their ultraviolet radiation was absorbed by hydrogen atoms, which as the most common element is ubiquitous in the universe. This absorption caused the single electrons in hydrogen atoms to undergo a small jump between two hyperfine energy levels, releasing 21 cm/1420 MHz radio emission in the process.

Ancient history

EDGES was able to detect this emission, redshifted to a frequency of just 78 MHz by cosmic expansion. The redshift corresponds to an era just 180 million years after the Big Bang. However, there was a surprise. The amplitude of the signal was twice as large as had been predicted, and Bowman thinks this could be explained “if the gas in the early universe was colder than expected,” he tells Physics World.

The temperature of the gas 180 million years after the Big Bang had been expected to be about six degrees above absolute zero, but the strength of the signal detected by EDGES implied a temperature of just 3 K. The first implication of this observation is that it constrains when quasars switched on and began pouring out X-rays, since the X-rays would have heated the gas, but it is the second result, if confirmed, that could have the greatest repercussions for science.

Chilling effect

Rennan Barkana, of Tel Aviv University, suggests that dark matter is responsible for the hydrogen’s low temperature. At that point in time, the only matter that should have been colder than the hydrogen was dark matter, and if the dark matter particles and hydrogen atoms were scattering off one another, this would remove heat from the hydrogen atoms.

“If the dark matter interpretation of the new 21 cm signal is correct, then it is the first direct observational indication of a non-gravitational interaction,” says Barkana.

Although in the modern universe dark matter does not seem able to interact with ordinary matter through anything other than gravity, in the past this may have been different. The cold, low velocity conditions unique to that era may have permitted some interactions. For the scattering process to take place, the individual masses of the dark matter particles must be less than 4.3 GeV, which is equivalent to the mass of just a few protons. This is far removed from the expected region of 100 GeV, and could explain why experiments trying to directly detect dark matter particles are failing to find anything, because they are looking in the wrong energy range.

Dark matter did something

Although cautious about the results, Richard Massey of the UK's University of Durham, who was not involved in the research, says that, “If this interpretation is correct, it would be a breakthrough that transforms the field: the first time in 40 years that dark matter is seen as doing something rather than nothing.”

Independent confirmation could come soon. EDGES measured the hydrogen emission by taking an average across the entire sky, but the Hydrogen Epoch of Reionisation Array (HERA), and the upcoming Square Kilometre Array, both in South Africa, will be capable of taking more intricate measurements. Since the dark matter hypothesis predicts a very specific pattern in the radio waves, Barkana says “the real test will come from these more detailed measurements".

Beyond that, “people will think very hard now about the consequences of the dark matter interpretation and perhaps some new tests will be identified,” says Bowman. If Barkana and Bowman are proven correct, then it will mean that dark matter’s days of remaining hidden from us will be numbered.

The observations and theoretical calculations are described in two papers in Nature: Bowman et al and Barkana.

Welcome to a new look for Physics World

After months of activity behind the scenes, we are incredibly excited to reveal our stunning new website. We hope you like it as much as we do.

Our key motivation throughout the relaunch project has been to make it easier for you to discover the content of most interest to you. The striking new design can be enjoyed on any device you happen to be using, while improved navigation places renewed emphasis on the applied and interdisciplinary fields that are driving progress in such mission-critical areas as healthcare, the environment, and commercial and industrial development.

To help you explore our content, we have introduced 15 subject topics that span both core physics disciplines and emerging interdisciplinary fields. Whether your interest lies in condensed matter or biophysics and bioengineering, science careers or business innovation, you’ll find all the relevant news and commentary in a single place on our website.

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The ‘Big Science’ marketplace

What do a particle accelerator, a space agency, a free-electron laser lab and an experimental fusion reactor have in common?

The answer – or, at least, the most relevant answer for the inaugural Big Science Business Forum (BSBF) here in Copenhagen, Denmark – is the network of companies that supply them with equipment and services. Although the scientific goals of CERN, ESA, the European XFEL and the ITER fusion project are very different, when you get down to the nuts and bolts of everyday operations, the technologies required to probe the fundamental nature of the universe and to explore our little corner of it are strikingly similar. And if your company can make instruments that can withstand the harsh environment of space, then maybe you ought to consider building some that can operate in a fusion reactor, too.

That was one of the messages at the BSBF plenary session on “Big Science as a Market”, which featured speakers from several companies where big science is also big business. Among them was Gaizka Murga-Llano, astronomy business manager at the Bilbao-based engineering and construction firm IDOM. Their involvement in the big-science market dates back to 2005, when IDOM took part in a design contest for the dome of the Extremely Large Telescope. At the time, the instrument known as the E-ELT (it’s now just the ELT, in a rare example of an inverse relationship between acronym complexity and time) was intended to be 100 m in diameter, and a traditional dome was not considered feasible. Over the subsequent decade, however, both budget and technical constraints forced managers at the European Southern Observatory (ESO) to scale back their plans. Throughout that period, Murga-Llano explained that IDOM worked with the ESO to develop designs that met the instrument’s evolving needs; today, construction on a 39 m ELT is under way at the ESO site in Cerro Armazones, Chile, with first light expected in 2024.

The story of IDOM and the ELT nicely illustrates some of the challenges that companies – especially small and medium-sized enterprises (SMEs) – face in working with big-science facilities. “If you are in the development phase, and every three months, you have to tell your bosses or your shareholders that the interesting commercial returns will come in five years, it is not very easy,” said Kurt Ebbinghaus, who is now an industry liaison officer at Fusion 4 Energy (the umbrella organization for ITER) but was previously managing director at the industrial-services firm Bilfinger Noell. Another of the session’s speakers, Jens William Larsen, made a similar point, explaining that when his small coatings firm, Polyteknik AS, works with industrial customers, they measure timelines in hours, days and weeks. With their big-science customers, however, they have to talk about months, years and decades.

In some cases, there are cultural barriers, too. Big-science facilities are interested in scientific discoveries and grand challenges, Larsen observed, but “we are just practical guys who want to run a business, who want to make some products. How do we combine those perspectives?” Although the rewards of interacting are significant for both sides – contracts for the companies; expertise and a more robust supplier base for the scientific organization – the overwhelming message from the speakers is that these interactions don’t happen on their own.

“We are just practical guys who want to run a business, who want to make some products. How do we combine those perspectives?”
Jens William Larsen, Polyteknik AS

Toward the end of the session, one of the BSBF co-organizers, Juliette Forneris, offered some concrete suggestions for improving the state of the big-science market. Forneris is the Industrial Liaison Officer (ILO) for both CERN and the ESO in Denmark, where the national government set up an umbrella group several years ago to help Danish firms engage with all of the Big Science organizations mentioned above, plus the European Synchrotron Radiation Facility (ESRF) and the European Spallation Source under construction across the Øresund in Sweden. In her view, one of the biggest barriers, especially for small firms, is the maze of different procurement procedures in operation at the different scientific facilities. In many cases, these procedures are written into the facility’s founding documents, so changing them would be next to impossible. However, Forneris believes that facilities could do a better job of communicating their rules to companies – especially those that haven’t worked with big science organizations before, and need an entry point.

That last part is important, because as IDOM’s example shows, one big-science project often leads to another. Barely a decade after they submitted their first ELT design to the ESO, the firm now has a client portfolio that reads like a who’s who of major scientific facilities. “Our previous work on the astronomy field, and especially the ELT, made it easier to work on the ITER programme,” said Murga-Llano. “If you are thinking of doing something, my advice is, go for it. It’s fascinating.”

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