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Green jobs for physics graduates: decarbonizing energy sources

Ann Davies, chief operations officer, Lightsource BP

Taking advantage of new technologies will be essential if the world is to achieve its net-zero goals. Renewable energy sources are perhaps the most obvious of these, and the transition to them is already under way.

“I don’t think there’s ever been a more exciting time to join the energy sector,” says Ann Davies, who is chief operations officer at Lightsource BP, a firm that has been developing solar projects since 2010, and now employs nearly 600 people. She took up her current job after studying physics at the University of Oxford, UK, and gaining experience in several engineering roles after graduating.

Among the main reasons to choose a career in renewables, Davies cites the growth that the sector is experiencing due to the increased focus on climate change and demand for clean energy. “Along with the cost of solar and wind dropping significantly, that makes renewables a really sound economic proposition, which means that investment is at a record high,” she explains. “From a graduate perspective, that means there will be more and more opportunities as your career develops.”

Davies’ work involves leading teams of scientists and engineers working on the planning, implementation and operation of solar projects around the world. She notes that there are lots of problems for scientists to solve, from loading up the grid with renewables to managing intermittency issues.

When recruiting new scientists and engineers, Davies emphasizes the importance of technical grounding. “Physics teaches you how to break down complex problems into simple parts, and we need those skillsets,” she says. In the hiring process, she also values interpersonal skills. “It’s not one person who is going to solve this – it takes a team.”

Davies advises graduates who want to join these efforts to read widely and to connect with people in the industry. Since there are so many different areas of sustainability that physicists can contribute to, she believes it is important to find out what makes you tick as an individual, and how you want to apply your skills. For herself, she finds working in the energy sector rewarding, because it is so universal. “Energy touches everyone,” she says, “so being part of providing it in a responsible way really gets me going when I get up in the morning.”

Hari Chohan, nuclear radiation analyst, UK Atomic Energy Authority

While solar and wind energy might be the first clean-energy technologies that spring to mind, they are not the only low-carbon options. Another relevant area in which many physicists work is nuclear energy, both fission and fusion.

“I consider all nuclear energy to be green energy,” says Hari Chohan, who is a nuclear fusion radiation analyst at the UK Atomic Energy Authority (UKAEA). “My granddad was an engineer and worked on nuclear projects,” he adds, “so I’ve always been pro-nuclear energy.” Chohan developed a stronger interest in nuclear fusion while writing an article about it for one module of his physics degree at Imperial College London.

As a result of these two influences, Chohan decided to do a Master’s degree in physics and nuclear technology at the University of Birmingham, UK. He then did a nine-month internship at Fusion for Energy in Barcelona, a body that co-ordinates the EU’s contribution to ITER, which is the largest experimental fusion reactor under construction in the world.

During this internship, Chohan’s main area of work was neutronics, also known as neutron transport, which is the study of the motion of neutrons and how they interact with materials. This is not only important for developing appropriate shielding but also estimating the lifetimes of components. “Neutrons are produced in both fission and fusion,” he explains, “but they have a lot more energy in the case of fusion, so we need to ensure the materials and components we design can withstand them.”

Chohan continues to work on fusion neutronics in his current role at UKAEA, which involves programming, running simulations, analysing results and writing them up in reports. “As well as working on major international projects, we have a couple of fusion test machines at UKAEA, the Mega Amp Spherical Tokamak Upgrade (MAST-U) and EUROfusion’s Joint European Torus, and we’re designing a prototype fusion energy plant, the Spherical Tokamak for Energy Production, at the moment, so there’s a lot of active research going on,” he says.

Chohan believes accurate public communication about nuclear energy is essential. “In fusion, unlike fission, there will be no high-level nuclear waste generated by the reaction itself, but there will still be a lower level of nuclear waste generated by the interaction of the neutrons with the reactor components,” he says. “All technologies have advantages and disadvantages. To move away from fossil fuels, we will need a mixture of different energy sources, but we can’t do it without nuclear. And the prospect of nuclear fusion is truly exciting.”

Rhiann Canavan, scientific project manager, Crossfield Fusion

While fusion is a long-term goal with huge clean-energy potential once it’s achieved, we don’t have to wait until then to get something positive from the research going into it. There are many by-products along the way that can be useful more immediately, as Rhiann Canavan, who works at UK-based start-up Crossfield Fusion, has discovered.

While studying at the University of Birmingham, UK, Canavan was inspired by a nuclear-physics professor to go into nuclear power. “I knew I wanted to go into a job where I was delivering something useful,” she says, “and nuclear power seemed like it had the potential to change the world.”

After graduating with an MSci in physics, Canavan studied for a PhD in experimental nuclear physics with the University of Surrey, UK, and the National Physical Laboratory. Her project focused on understanding fast neutron-induced fission reactions, which can be done to make nuclear waste decay faster.

After finishing her PhD, Canavan did a summer placement with Crossfield Fusion, which she found through the South East Physics network (SEPnet) – an association of nine university physics departments that supports students in south-east England. “When I read the mission of the company, I really wanted to get involved,” she says. “The end goal is fusion, but there are also short- and mid-term goals, such as using the technology to produce radioisotopes for medical scans.”

Green jobs for physics graduates: finance and economics

After completing her internship, Canavan joined the company in a permanent role as scientific project manager. Crossfield Fusion is a start-up with just five employees, so her tasks vary widely. She began by helping to build the research reactor, and she now plans and carries out experiments with it. “Some days are lab days when everything has to be spot-cleaned because we’re installing components,” she says. “Other days I’m analysing data, computer programming or group brainstorming what to try next.”

Canavan says she feels a lot of ownership of the work, having seen the progress from the very early days. “Your heart is really in it and you want it to succeed,” she says. Since deuterium – a key ingredient in fusion reactions – is highly abundant and can be extracted from any type of water, Canavan also points out how much more environmentally friendly it would be to fuel a fusion reactor than to burn fossil fuels. “Instead of digging up coal,” she says, “we could just use sea water.”

‘CatGym’ algorithm predicts better catalysts

Designing efficient new catalysts is no easy task. In catalysts that contain more than one element, for example, researchers not only need to take into account all the possible elemental combinations, they must also add a number of other variables, such as particle size, shape and surface structure, as well as the degree of alloying or phase segregation. This ultimately leads to an overwhelmingly large number of potential candidates.

To address this challenge, scientists employ computational design techniques that focus on screening material components and alloy composition to optimize a catalyst’s activity for a given reaction and so reduce the overall number of prospective structures that would need to be tested and then developed. Such techniques require combinatorial approaches coupled with theory calculations, which can both be time-consuming and complex.

The best surface atom configurations

A team led by Zachary Ulissi of Carnegie Mellon University has now taken a different approach by developing a deep reinforcement learning (DRL) programme, dubbed CatGym, that iteratively changes the positions of atoms on the surface of a catalyst to find the best configurations from a given starting configuration.

The researchers showcased their technique by predicting the surface reconstruction pathways of a ternary Ni₃Pd₃Au₂(111) alloy catalyst. Their results show that the DRL programme can not only be used to explore more diverse surface compositions than conventional methods, but that it can also generate new pathways based on how energetically favourable they are.

The team also demonstrated that the kinetic pathways that lead to a stable surface composition (with a low minimum energy surface composition) and the associated transition state predicted by the DRL programme agree well with the minimum energy path predicted by traditional “nudged elastic band” calculations done “by hand”.

A lot of human input

There has been much excitement in recent years for when it comes to using machine learning methods to accelerate catalysis simulations, says Ulissi. Such an approach reduces the computational cost of each step in the simulation, but the downside is that it requires a lot of human input to run the calculation. This is because scientists need to define what structure is used from the outset, what mechanisms should be investigated and if there is a better path to take to go from reaction A to reaction B. All these questions require a trained expert many days or weeks to answer.

“The new work is very exciting for us because it proposes using DRL methods to tackle these strategic questions,” Ulissi tells Physics World. “With our system, we can let the computer autonomously explore a number of different possible pathways.”

Representation and action space

DRL requires three things, he explains. “The first is a representation – that is, how do we show an atomic structure of a catalyst to the computer in a way that it understands? In our system we use a common representation from the literature. The second is an “action space”: what are we going to let the computer do? In our approach, it can move an atom, find an energy minimum, find a transition state or run a short dynamic simulation. Finally, how do we decide what action to take next? In our case, we tried many DRL schemes to answer this question.”

“One aspect that made this project really interesting was that the final goal was not clear,” explains Ulissi. “In a video game, for example, it is obvious what you want you want the DRL to do – maximize the final score. We thus spent a lot of time defining and identifying the goal the DRL would work well with.”

Double-checking results

Ulissi says he previously studied catalyst surface reconstruction mechanisms by hand, which can be very tedious. “A tool to automate and accelerate this process not only allows us to ask much more interesting questions, it can also be used to double-check the results obtained by human experts.”

The researchers, who report their work in Machine Learning: Science and Technology, are now using the method they have developed to predict how stable hypothetical catalyst surfaces are. “We also hope to apply our approach to better understand the mechanisms at play on these surfaces,” adds Ulissi. “Doing this will help us think creatively about what might happen to a catalyst during real-world reactions.”

It will not all be plain sailing, however, he admits. One of the major limitations of the current technique is that, like most DRL applications, it requires a lot of data input and training episodes. “Accurate simulations are extremely demanding computationally,” he explains, “and the simulations we performed in our work are fast but rather coarse approximations.” The researchers are trying to solve this problem by also using machine learning models to make them not only faster but also more accurate.

Life beyond the Nobel: Russell Hulse’s path from binary pulsar discoverer to plasma physicist

In the summer of 1974, Russell Hulse was down in the weeds of collecting data for his PhD thesis when he noticed something odd. Together with his supervisor Joseph Taylor, Hulse was using the famed 305 m spherical reflector dish at the Arecibo Observatory in Puerto Rico to search for pulsars: compact and highly magnetized stars that broadcast bursts of radio waves across the galaxy as they rotate. Although the first pulsar had been spotted only six years earlier by another student-and-supervisor pair, Jocelyn Bell Burnell and Antony Hewish, these unusual stars were already a hot topic in astrophysics. Hulse hoped to make his mark by identifying more of them, but one of the 40 pulsars in his data was causing problems. Denoted PSR 19 13 + 16 in his notebook, it defied all his efforts to calculate its period of rotation.

Arecibo Observatory — The Arecibo radio telescope in Puerto Rico, which Russell Hulse used to observe the binary pulsar he discovered. (Courtesy: NAIC)

At the time, Hulse’s reaction was not “Eureka!” but instead, as he later recalled, “a rather annoyed ‘Nuts – what’s wrong now?’” Determined to get to the bottom of whatever technical glitch was causing the problem, Hulse focused his remaining observing time on this perplexing pulsar. By mid-September, he had his answer, and it was a doozy: PSR 19 13 + 16 was one half of a binary pair of stars, and its hard-to-calculate period was fluctuating under the gravitational influence of its companion.

For the next several months, Hulse worked as a self-described “pulsar data acquisition system” while Taylor performed orbit analysis calculations to test predictions of how this binary pulsar system should behave. Their findings were a stunning confirmation of Einstein’s general theory of relativity and, not incidentally, the first evidence of gravitational radiation. With these gold-plated results under his belt, the announcement that the 1974 Nobel Prize for Physics would honour the first pulsar discovery must have seemed, to Hulse, like a foretaste of the accolades that awaited him in his astronomy career.

By 1975, however, Hulse had a dilemma. Although he obtained a postdoctoral appointment at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, soon after finishing his PhD, it wasn’t a permanent job. “While I still enjoyed doing pulsar radio astronomy, from the moment I arrived at NRAO I was increasingly preoccupied with the lack of long-term career prospects in astronomy,” he later recalled. “While I had some confidence that I could find another position of some sort after NRAO, it was not at all clear to me when, where, and how I would be able to settle down with some reasonable expectation of stability in my career.” His concerns were sharpened by his personal circumstances. With his then-girlfriend (later wife) Jeanne Kuhlman doing graduate work in physics at the University of Pennsylvania and soon to embark on her own career, Hulse decided that “the potential for such repeated major dislocations in my personal life was more than I could quite tolerate”.

Photo of Russell Hulse — **Forking paths** Binary pulsar discoverer, computational plasma physicist and science educator Russell Hulse (Courtesy: University of Texas at Dallas).

When his NRAO appointment ended in 1977, therefore, Hulse left astronomy to take up a post at the Princeton Plasma Physics Laboratory (PPPL), located conveniently close to Jeanne in Philadelphia. He was able to switch fields in part because he did his PhD in physics rather than astronomy – a choice that reflected both his broad scientific interests and his desire to hedge his career bets – and in part because pulsar-hunting was already, in the mid-1970s, a highly computerized task. (In a lecture I attended in the early 2000s, Hulse joked that he spent so much time programming at Arecibo that he took to adding up his chequebook in hexadecimal.) At PPPL, his first task was to create new computer codes to model the behaviour of impurities in high-temperature plasmas. By 1993, when he and Taylor won the Nobel Prize for their binary pulsar discovery, he had carved out a niche as a developer and maintainer of codes for modelling thermonuclear fusion.

At this point, it is instructive to reflect on the Nobel committee’s differing treatment of Hulse and Bell Burnell. While Hulse and Taylor shared the 1993 prize equally, the pulsar half of the 1974 prize went solely to Bell Burnell’s supervisor Hewish (another astronomer, Martin Ryle, received the other half for unrelated work). While sexism surely played a role in this snub, Bell Burnell has long attributed it to her lowly student status; in 1974, she says, the Nobel committee had not yet realized that PhD students could and did make significant intellectual contributions. In this light, it is worth noting that in his Nobel lecture, Hulse paid tribute to Taylor for treating him and other students as “colleagues rather than subordinates”. Hence, the divergent Nobel fates of Hulse and Bell Burnell may be down to differing supervisory styles, as well as discrimination and shifting attitudes towards PhD students.

It is hard not to see Hulse’s career path as an indictment of how early-career research is funded and organized

In his official 1993 Nobel biography, Hulse comes across as sanguine about his career. “My interest in science has never been so much a matter of pursuing a career per se, but rather an expression of my personal fascination with knowing ‘how the world works,’” he wrote. Like other scientists who received the Nobel at a relatively young age (he was 42), Hulse found that the prize brought invitations to serve on advisory boards in academia, government and industry. In 2004, he accepted a visiting professorship at the University of Texas at Dallas with a focus on science education, and he remains on the faculty there, though the scope of his activities has been limited since 2012, when he was diagnosed with Parkinson’s disease. His wife Jeanne, for her part, retired in 2020 from a long career in the pharmaceutical industry.

Despite these achievements, though, it is hard not to see Hulse’s career path as an indictment of how early-career research is funded and organized. Forty-four years after a lack of job security forced this future Nobel laureate out of radio astronomy, academic career prospects remain highly uncertain. Researchers who are disinclined to change jobs (and sometimes countries or continents) every few years as postdocs still find their path to permanent positions blocked. And the same “two-body problem” that confronted Hulse and Kuhlman nearly half a century ago continues to force difficult choices onto scientific couples today, with consequences that affect all genders but disproportionately damage the careers of women. The Nobel committee’s attitude towards PhD students may well have changed since the mid-1970s. Too many other things have not.

Physics World‘s Nobel prize coverage is supported by Oxford Instruments Nanoscience, a leading supplier of research tools for the development of quantum technologies, advanced materials and nanoscale devices. Visit nanoscience.oxinst.com to find out more.

Green jobs for physics graduates: policy and behaviour change

Eunice Lo, researcher, University of Bristol, UK

In order to respond effectively to climate change, it’s important to understand its fundamental causes and effects. Eunice Lo is particularly interested in how climate change will affect extreme weather events, with a focus on heatwaves and their impact on human health.

Lo first became interested in this area while studying physics and astronomy at Durham University, UK, where her final-year project looked at how to calibrate telescopes to correct for atmospheric effects on the radiation they detect. “Climate change is also about radiation transfer through components of the atmosphere,” she explains, “with outgoing longwave radiation being trapped by greenhouse gases.”

To pursue this further, Lo did a PhD in atmosphere, oceans and climate at the University of Reading, UK. She found that her physics background helped her to hit the ground running, as she already had some understanding of atmospheric physics and had honed her computer programming skills during her undergraduate degree. Lo also did some Master’s courses in meteorology alongside the first year of her PhD. “That helped me transition from a pure physics background to applying my theoretical knowledge to the environment,” she recalls.

Lo now uses the programming languages Python and R to create climate models and study how global warming will affect the frequency and intensity of heatwaves. Since heatwaves can cause illnesses and even deaths, she then translates those possible future scenarios into projections of human health outcomes.

Crucially, Lo’s research is often included in reports such as the UK Climate Change Risk Assessment Report, which is published every five years, and which government officials use to make decisions about national mitigation and adaptation. She is also a contributing author to one chapter of the latest report published by the United Nations Intergovernmental Panel on Climate Change, and hopes this will prompt new policies on reducing emissions.

Mark Crouch, carbon management team lead, Mott MacDonald

Building a sustainable future is not just about action at a government level – businesses also need to make changes. Mark Crouch, who works at Mott MacDonald, an international engineering consultancy headquartered in the UK, is optimistic that companies are waking up to their responsibilities.

“The conversations with clients have become a lot more mature than they were when I first started in this field around 2010,” says Crouch. “Businesses no longer see sustainability as something they just have to consider to make themselves look good. They understand climate change as a real business risk.”

Crouch went into environmental engineering after studying physics with astrophysics at the University of Leeds, UK. While working on flood modelling and designing flood alleviation schemes, it struck home that global warming was having major impacts. “With something like flood risk, you can’t just keep building bigger dams,” he explains. “That’s what motivated me to get into mitigation and addressing the root causes.”

Crouch did a Master’s in sustainable energy at Imperial College London, which he found prepared him well for consultancy, and he now heads up the 100-strong and growing global carbon management practice at Mott MacDonald. His team in the UK works closely with bodies such as the Environment Agency and National Grid to understand the carbon impacts of major infrastructure projects such as HS2 on a full-life-cycle basis, and advises clients on how to reduce them. They also look at how emerging technologies fit in.

The full-life-cycle analysis is important because infrastructure often has a big carbon footprint not just when it is up and running but also when it is being built. Crouch notes that if cement manufacturing were a country, it would be the third biggest emitter of greenhouse gases, behind the US and China. “There’s a huge need for people to tackle that through developing new materials and approaches,” he says. “That’s another area of opportunity for people with science backgrounds, including physics.”

For graduates interested in sustainability, Crouch’s advice is to take all the opportunities you can for doing industrial placements, and to be proactive about building your network through webinars and industry forums. He also recommends reading widely across different subjects, as climate change is a highly multidisciplinary challenge.

The climate emergency requires immediate and sustained action, and the sector needs graduates who are passionate about making a difference
Mark Crouch

“It’s a really booming market,” Crouch says. “The climate emergency requires immediate and sustained action, and the sector needs graduates who are passionate about making a difference.” Among the skills that physicists can contribute, he notes the importance of understanding how to work with numbers and uncertainties, as well as the ability to think big. “Topics like cosmology and astrophysics really teach you to think on a different timescale, and outside of the day-to-day.”

Rosemary Pickering, senior sustainable business analyst, Farfetch

In addition to seeking advice from external consultants, many companies are putting together sustainability strategies and employing people in-house to drive progress towards their goals. Rosemary Pickering has combined her environmental values with her interest in fashion by working as a senior sustainable business analyst at Farfetch, a luxury fashion marketplace, which sells everything from handbags to activewear by high-end designers.

While studying courses in environmental and atmospheric physics as part of her physics degree, Pickering decided that she wanted to do a sustainability-related Master’s, so she enrolled in an MSc course on environmental technology and policy at Imperial College London. “That gave me a completely different perspective on sustainability and the environment,” she says. “Within that, I did a project looking at sustainable fashion.”

In her current role at Farfetch, Pickering focuses on the firm’s sustainability strategy, which has three main “pillars”. One is to encourage customers to switch to purchasing more sustainable options by providing information on the environmental and social impacts of different products. Another is to work towards net-zero carbon emissions by 2030, by minimizing the distance products have to travel, choosing the greenest transport methods and shipping each product in the smallest box possible. Finally, Farfetch has launched several circular services, whereby customers can resell products they are no longer using, or have items fixed or updated, instead of buying new ones.

Pickering’s role covers all three of the pillars, and involves reporting on trade performance and looking at which more sustainable products, such as items made of organic cotton, are selling. She also monitors which circular services customers are using, and Farfetch’s overall progress towards its sustainability goals.

“One of the projects I’ve really enjoyed working on was our Conscious Customer Report, which we published externally,” she says. “A lot of people in the [fashion] industry talk about changing trends and patterns, and you can actually see it coming through in the data, which is really exciting.”

Having a physics background has helped equip Pickering with the skills she needs for her job, as she has to be confident with calculating the statistics she is reporting, and also needs to use coding skills in Python for her day-to-day tasks.

For graduates looking for green jobs, Pickering emphasizes that there are more opportunities than you might think. “Many small businesses have a marketing or operations team where 50% of the role is focused on sustainability, because that’s embedded in the company’s mission,” she explains. “There are a lot more jobs out there than just the ones that have ‘sustainability’ in their titles.”

Green jobs for physics graduates: opportunities to help build a sustainable future

If the last few years of environmental coverage has taught us anything, it is that the climate crisis is a complex problem with no silver bullet. Effectively mitigating it will require a multifaceted approach that incorporates technological solutions as well as behaviour change at the governmental, corporate and individual levels. For physicists, the challenges of meeting our needs sustainably are already opening up lots of interesting and creative job opportunities.

In many of these roles, the skills and knowledge you gain from a physics degree are invaluable. As well as being numerate and having technical knowledge, you’ll have computer programming skills and practice of applying physical principles to solve real-world problems. To guide you through the myriad options, I spoke to nine physicists whose work relates to three main aspects of sustainability: policy and behaviour change; decarbonizing energy sources; and finance and economics. You can find links to those articles in the box below.

Green jobs case studies

Throughout this month we’re publishing a series of articles looking at three aspects of sustainability where physicists are key.

Policy and behaviour change

Eunice Lo, researcher, University of Bristol, UK

Mark Crouch, carbon management team lead, Mott MacDonald

Rosemary Pickering, senior sustainable business analyst, Farfetch

Decarbonizing energy sources

Ann Davies, chief operations officer, Lightsource BP

Hari Chohan, nuclear radiation analyst, UK Atomic Energy Authority

Rhiann Canavan, scientific project manager, Crossfield Fusion

Finance and economics

Rustam Majainah, senior pricing analyst, OVO

Flora Biggins, PhD student, University of Sheffield, UK

Lewis Ashworth, programme manager, Institutional Investors Group on Climate Change

Kitty Q teaches children about quantum mechanics, kitchen physics experiments, Emmy Noether takes on Baron Munchausen

Some parents would probably baulk at the idea of teaching their 11-year-old about quantum mechanics, but here at Physics World we believe that it’s never too early to ponder the weirdness of the quantum world. Indeed, children tend to have fewer preconceptions about the world around them, so starting young could make them “quantum native” and destined for a lucrative career in quantum technology.

If that’s the career path you have in mind for your little ones, you are in luck because physicists at the Würzburg-Dresden Cluster of Excellence for Complexity and Topology in Quantum Matter have created a mobile phone app that introduces quantum mechanics to children 11 and older. Called “Kitty Q — a quantum adventure” after Schrödinger’s famous cat, the app serves up 20 different puzzles that each teach something about quantum physics.

The researchers say that Kitty Q is aimed at children and young teens because this the age at which young people develop their views of science. In particular, the team hope that Kitty Q will help encourage girls to study physics and other sciences where they are currently underrepresented.

Kitty Q will be launched later this month, but you can get a preview here.

Staying on physics education, the Perimeter Institute for Theoretical Physics (PI) in Canada asked teachers to make videos about their favourite science demonstrations that you can do in your kitchen. The PI has put the eight submissions on its website and is asking the public to vote for their favourites.

The demos include a lesson on entropy using nuts and raisins, building your own hydrometer – demonstrated by a winemaker – and how to measure the acceleration due to gravity using a plastic bag and a mobile phone (as shown in the above video). You can watch all the videos and vote here.

Fantastical adventures

Baron Munchausen is a fictional character created in the 18th century by the German writer Rudolf Erich Raspe. The Baron is famous for his fantastical adventures such as riding a cannonball, travelling to the Moon and extracting himself and the horse he is sitting on from quicksand by pulling up on his own hair.

Now I’m guessing that the majority of 11-year-olds know that the latter is an impossible feat, but that hasn’t stopped Matthias Schmidt and Sophie Hermann from the University of Bayreuth in Germany from writing a paper that offers “a new and more comprehensive refutation” of Munchausen’s rescue.

The paper has been uploaded to the arXiv preprint server and their refutation involves the application of Noether’s theorem to statistical mechanics – something that is probably beyond the comprehension of most 11-year-olds.

Migration and the Nobel prize: more than one quarter of physics laureates are immigrants

For me, one of the joys of working in physics is that it is a truly global affair. Many university physics departments, for example, have large numbers of people who were born abroad – from students to senior professors. I believe that this diversity is crucial to the success of these institutions, which seek to attract the best physicists from around the world. Also, people from elsewhere bring with them a broad range of experiences that can enhance how research is done. And from a personal point of view, I suspect many physicists enjoy meeting and working with scientists from different cultures.

Europe Nobel laureate migration map — Continent in motion: the movement of laureates within Europe. The thickness of the lines is proportional to the number of laureates. (Courtesy: Paul Matson/ IOP Publishing)

It is no surprise, therefore, that many Nobel laureates are immigrants, as illustrated in these three infographics that we first produced in 2015 and have since updated. There are two maps that show the volume of international migration of physics Nobel laureates since the first prize was given – one showing the world outside of Europe and the other focussing on movements within Europe. The third is an “alluvial” infographic that provides more information about origins and destinations of individual laureates.

The biggest challenge in creating these infographics was deciding who is an immigrant. After much deliberation we came up with our own definition, which I admit is not perfect and may raise some hackles.

Our rather crude definition is that an immigrant laureate is someone who died or currently lives in a country other than that of their birth. Crucially, we are not interested in where a laureate did their award-winning work because we also want to include people who migrated after they bagged their prizes. We think that is important because some physicists made important scientific contributions in their adopted countries after they did their Nobel-winning work at home. An example is Enrico Fermi, who left his native Italy in the year he won his prize and went on to make important breakthroughs in nuclear physics in the US.

Flow infographic of Nobel laureates — Elite flow: alluvial infographic showing where migrant physics Nobel laureates were born (left) and where they died or live today. (Courtesy: Paul Matson/IOP Publishing)

So, who are the most recent additions to our list of immigrant laureates? There were none last year, with Roger Penrose, Andrea Ghez and Reinhard Genzel all currently living in the countries where they were born. It was a different story in 2019, with Canada-born James Peebles living in the US and Switzerland-born Didier Queloz living in the UK.

That means that out of a total of 215 physics Nobel laureates, 56 are immigrants – at least by our definition – or a little over one quarter. I think you would be hard pressed to find such a high percentage of immigrants at the pinnacle of any field outside of the sciences – with the possible exception of professional football.

If you are interested in how we created these infographics, I wrote a comprehensive blog in 2019 that describes many of the issues we struggled with when deciding who is and isn’t an immigrant. These included shifting borders in Europe after the two world wars as well as the partition of India and other acts of decolonization.

The blog also digs deep into the data, looking at which countries are the big winners when it comes to Nobel laureate migration, which countries are the losers – and which countries have managed to break even.

Physicists rise to the climate challenge: the October 2021 issue of Physics World

Image of a globe on a leaf — Global solutions: What physicists can do to tackle the climate crisis.

“A code red for humanity” is how António Guterres, the United Nations’ secretary general, described the latest report from the Intergovernmental Panel on Climate Change, which summarizes our current scientific understanding of the Earth’s climate and the potential impact that changes to it could have on the planet.

Without steep cuts in greenhouse-gas emissions, the report reminds us, the world will warm by over 2 °C this century – triggering more frequent heat waves, greater flooding, higher sea levels and more extreme heavy rainfall and droughts.

It’s easy to ignore such warnings as distant, vague and alarmist, something only of concern to policymakers and politicians at gatherings like next month’s COP26 climate summit in Glasgow. But the challenges of climate change shouldn’t be “other people’s problems”; they concern all of us.

Thankfully, plenty of physicists are already doing their bit to tackle the climate crisis, as we report in the October issue of Physics World magazine. The cover feature by James Dacey includes interviews with many of the climate scientists speaking at IOP Publishing’s forthcoming Environmental Research 2021 online conference. And don’t forget that the Institute of Physics is also hosting a week-long series of events on physics and the green economy.

If you’re a member of the Institute of Physics, you can read the whole of Physics World magazine every month via our digital apps for iOS, Android and Web browsers. Let us know what you think about the issue on Twitter, Facebook or by e-mailing us at pwld@ioppublishing.org.

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

• Do high-energy neutrinos lurk in SN1987A? The SN1987A supernova event might be the source of four particles detected in Japan and the US – and so possibly explain the origin of the most energetic cosmic rays, as Edwin Cartlidge reports

• A life in China – Italian astrophysicist Roberto Soria talks to Ling Xin about the opportunities and challenges of living in China and how that changed when the pandemic hit

• The challenge of change – James McKenzie believes the climate crisis offers opportunities to business – but warns that solutions will only be found with the help of governments and financial markets

• The nuclear fight – Robert P Crease talks to William D Magwood IV, director-general
of the Nuclear Energy Agency, about the battle to keep nuclear power on the agenda

• Why ‘net zero’ needs nuclear – Henry Preston and Saralyn Thomas say that nuclear energy must be part of the conversation during the COP26 climate talks in Glasgow next month

• Getting physical with the climate crisis – With world leaders set to gather in Glasgow next month for the United Nations’ COP26 climate summit, James Dacey examines four vital challenges where physicists can help the world to decarbonize and adapt to the reality of global warming

• Scanning the cosmos for signs of technology – Ever since planets beyond our solar system were first discovered, astronomers have been hunting life beyond our world. While biological signatures are crucial, the idea of scouring the skies for signs of technosignatures from advanced civilizations is gaining momentum, as David Appell discovers

• Towards proton arc therapy –Do we need proton arc therapy, and can we deliver it? At the recent European Society for Radiotherapy and Oncology (ESTRO) 2021 congress, Tami Freeman heard from researchers describing the latest developments with the technique and its potential to improve cancer treatments

• Frames of reference and objectivity – Immanuel Adewumi reviews The Disordered Cosmos: a Journey into Dark Matter, Spacetime, and Dreams Deferred by Chanda Prescod-Weinstein

• Between the lines: Environment special

• Green jobs for physics graduates – With their mix of technical knowledge and problem-solving skills, physics graduates are ideally placed to tackle the world’s environmental
challenges. Laura Hiscott speaks to a range of physicists who are doing their bit to build a greener, more sustainable future

• The climate-change outsider: Guy Callendar

Textile clinic: stretchable fabrics tailored with carbon nanotube electrodes monitor the heart

Museum collections across the world feature characteristic clothes from different time periods that showcase human history. Such garments can identify a wearer’s country, social status, approximate age and religion. Clothing also provides a historical link to the materials and textile technologies available at the time. Today, researchers envision that clothes’ functionalities could reach beyond fashion, protection and comfort to provide sophisticated biosensing and tracking capabilities.

Electronic clothing aims to combine flexible fabrics – that seamlessly morph with the body’s anatomy – with electronics that can capture signals such as the electrical activity of the heart in electrocardiograms (EKGs). For textile biosensing to succeed, however, the electronics must match the fabric’s flexibility and not affect the material’s thermal and moisture-transfer functions.

To achieve this, researchers in Matteo Pasquali’s laboratory at Rice University fabricated carbon nanotube-based conductive threads and sewed them into stretchable fabrics. Reporting their findings in Nano Letters, they demonstrate the durability and functionality of textile-based wearables as future health monitoring systems.

The researchers detail a non-invasive continuous monitoring strategy that uses the carbon nanotube electrodes to precisely record the heart’s electrical signals – even after 10 machine washes and 1000 stretching cycles.

“The major challenge with existing commercial hybrid electronic clothing is that the metal alloys used in these fabrics tend to have poor mechanical properties and cannot withstand repeated washing and wear,” explains lead author Lauren Taylor, a former graduate student in Pasquali’s laboratory. “This is where I feel our technology has demonstrated a major breakthrough. Our carbon-based conductive threads have the conductivity necessary for electronics but outstanding mechanical strength with the softness and flexibility of cotton.”

Textile nanomaterials

To form the carbon nanotube threads, Taylor and co-authors wove 21 cylindrical carbon nanotube filaments into a sewable thread, using a custom-built rope-making device. The resulting carbon threads have an electrical conductivity comparable to that of metals, and are soft and mechanically flexible.

The team then sewed 2, 15, 30 and 60 cm lengths of thread into elastic wrist straps, using a zigzag pattern to facilitate fabric stretching. Despite having a larger skin impedance than commercial electrodes, the all-carbon electrodes placed on the wrists could clearly capture the EKG signals used by physicians to assess heart conditions. Moreover, the wrist-mounted textile electrodes could also measure electrical signals generated during muscle activation cycles.

Weaving the fabric of health

Athletic clothing is designed with flexible fabrics that closely contact the skin and facilitate body motion during physical activities. To enable health monitoring using electronic textiles, the authors sewed five 15 cm carbon nanotube electrodes on an existing athletic shirt in a Holter configuration (the electrode placement pattern used in continuous EKG monitoring) to record a complete EKG while the wearer is running, jogging, walking and sitting.

Fitness tracking: Carbon nanotube threads in an athletic shirt could record EKG and heart rate data better than standard chest-strap monitors. (Courtesy: Jeff Fitlow/Rice University)

Additional carbon nanotube threads sewn through the shirt connect the electrodes to a Bluetooth monitor located in the back of the neck, which wirelessly transmits the recorded data to a nearby smartphone.

The authors asked three cardiologists to evaluate the quality of blinded EKG signals recorded by the carbon nanotube and commercial electrodes. All agreed that signals from the textile-based electrodes were “slightly better”, due to a better definition of the heart waves.

“When we made the EKG shirt, I had anticipated the advantages in wearability and washability – in essence, convenience. I had not expected that EKG quality would also be superior – that was a bit lucky,” senior author Matteo Pasquali tells Physics World.

Neutrons reveal secrets of self-assembly

**Emily Draper** The University of Glasgow chemist uses neutrons to develop self‑assembling materials. (Courtesy: University of Glasgow)

What materials do you study

My research group is looking at small organic molecules – normally based on dye molecules that we functionalize using amino acids. These molecules are designed to self-assemble in water to create a variety of structures. The molecules are conductive, and we are interested in how we can use different structures to make conductive devices for various applications.

What are some potential uses for these structures?

We are focused on three different types of applications. One involves chromic materials, which change colour upon either light stimulation or electrical stimulation. These materials can be used in smart windows such as those you see in modern aeroplanes – where the switch of a button darkens the windows. We are also looking at organic semiconductors, which are thin-film materials.

More recently, we have been making flexible thin-film devices that change their conductivity upon bending. These could be used to monitor muscle movement on the body with applications such as tocodynamometers, which monitor uterine contractions during pregnancy.

What are the benefits of using self-assembly to make devices?

Traditional devices are made from metals, which only assemble in a limited number of ways. Furthermore, the world is running out of metals, and they must be processed at high temperatures, which makes them expensive. Our self-assembly processes are done at room temperature in water, using simple molecules that can be easily made in large quantities. No dangerous chemicals or high temperatures are needed – it is very environmentally friendly.

You use small angle neutron scattering (SANS) to study these materials. How does that work?

SANS is done at a large-scale neutron facility such as the Institut Laue Langevin (ILL) in Grenoble, France. We put a sample into a neutron beam and then collect the neutrons that have scattered at small angles. This allows us to study the structure of a sample from the molecular length scale all the way up to the bulk scale.

SANS is important for my research because our materials are not appropriate for electron microscope studies – the organic molecules would be destroyed by the electron beam.

What are the pros and cons of using large neutron facilities?

An important benefit of using a large facility like ILL is that there are many experimental stations on the neutron beamline that you can use to do a variety of measurements. Also, the neutron flux is very high so you get really great data.

Another benefit is that the facility is used by a wide range of scientists – not just chemists – so the conversations you have over dinner can be very interesting. Working with the facility’s beamline scientists is also an important plus – they are experts in their fields who can give you loads of new research ideas.

One of the downsides is that you have to use your allotted beamtime 24 h a day. That means long, tiring nights – but that normally only lasts a few days. Also, the process of applying for beamtime can be laborious. If your application is successful, you may have to wait six months before you can start – so you need to be thinking ahead all the time of the experiments that you want to do.

A big plus for ILL visits is being in Grenoble. It’s really pretty and people can go skiing

Do you and your research group enjoy working at big facilities like ILL?

I was so excited when I was doing my postdoc and I got to go on my first beamline experiment. Being at a huge facility is completely different from working in a typical chemistry lab under a fume hood. It can be a bit scary at first with the safety protocols and the radiation dosimeters, but it’s quite cool and something that my team enjoys doing. And a big plus for ILL visits is being in Grenoble, which is in the middle of the mountains. It’s really pretty and people can go skiing.

Unfortunately, ILL has been closed for the lockdown and all our beamtime has been postponed or cancelled – so lots of my team haven’t been there yet. But recently I was able to send one of my PhD students to the ISIS neutron facility in Oxfordshire and she absolutely loved it.

Looking to the future, are there any new or planned neutron facilities that you are looking forward to using?

The European Spallation Source (ESS), which is being built in Sweden, looks interesting. I know that the ESS has been engaging with the neutron community to develop some exciting experimental stations. One technique that I am really interested in using is ultra-small-angle neutron scattering (USANS), so having new facilities for that would be great.

At current facilities, I enjoy working with beamline scientists to develop new experiments and instruments on existing beam lines. I love doing rheology, so developing experiments for that is something that I am interested in. The beamline scientists we work with at ILL trust me and team, so we can do all kinds of wacky experiments and I’m really appreciative of that.

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