The largest funding body in the UK has announced a new open-access policy that will come into effect on 1 April 2022. UK Research and Innovation (UKRI) – the umbrella group for the UK’s seven research councils – will from that date mandate that all published papers written by researchers containing work carried out using UKRI cash must be free to read immediately upon publication. Yet the announcement has been met with concern by some publishers and researchers.
Open-access (OA) publishing has grown rapidly over the last two decades, especially in the UK, where 90% of articles published by researchers are now expected to be open access by the end of 2021. With an £8bn budget, UKRI is a supporter of the Europe-wide “Plan S” open-access initiative, which was unveiled in 2018 by 11 national research funding organizations, including UKRI. They say that all scientific publications resulting from research funded by them must be published in “compliant” open-access journals or on open-access platforms.
Traditionally, scholarly publishing has been free for authors, with publishers charging libraries journal subscription fees. The new UKRI policy mirrors Plan S’s aims, stating it will support researchers to publish either in “gold” open-access journals or in “hybrid” journals, in which “transformative agreements” with publishers allow universities to pay lump-sum fees to cover both subscription costs and to publish open access.
If no such agreement exists, UKRI will not pay the article-processing charge (APC) that is required to make the paper open access. Authors could publish in a traditional, non-open-access subscription journal but the author must then self-archive the accepted manuscript in an open repository under no embargo. Previous UKRI policy had permitted a six or 12-month embargo period before the paper could be submitted to such a repository.
IOP Publishing, which publishes Physics World, broadly welcomes the UKRI’s new open-access policy, which it says “aligns with our mission to expand physics globally”. However, it thinks that the requirement for researchers to deposit the final version of a manuscript in a repository under no embargo will be “harmful to the significant OA progress already made”. “This approach cannot form the basis for an economically viable publishing model for physics journals seeking to maintain the highest standards of peer review and publication.”
That view is echoed by the International Association of Scientific, Technical, and Medical Publishers (STM), which says it is “deeply concerned” that the UKRI policy gives equivalent status to the “subscription-tied accepted manuscript and the full OA publication of the version of record”. This, the STM says, could “jeopardize the continued progress of the open-access publishing transition by enabling an entirely unsustainable route”. The STM urges the UKRI board to “carefully consider these issues”.
John Harnad, director of the mathematical physics lab at the Centre de recherches mathématiques in Montreal, says that although the UKRI policy is well-intentioned, it fails to “provide a coherent strategy”, in particular when providing “any incentive or encouragement” for green open access. “UK scientific publishing does not operate in isolation, but as part of an international mix of authors, readers and subscribers,” he says, “Such a strategy seems solely to be a reaction to the continued rises in both subscription charges and article processing charges. But in fact, it would contribute nothing to counteracting the rising charges. And, given the international mix, it would not have sufficient impact to convince publishers of major journals to abandon their current policies and be ‘reborn’ as 100% OA journals.”
Meanwhile, the American Astronomical Society announced last week that from January 2022 all its journals will switch to being fully open access. Since 2017, the AAS journals, which are published by IOP Publishing, have provided a hybrid open access option, allowing authors the choice to publish their articles traditionally or open access. “We’ve seen that articles published open access in our journals are on average more widely cited than those that are paywalled,” says AAS chief publishing officer Julie Steffen. “The transition of all our journals from hybrid to fully open access in January will provide this same wide audience access to the entire cosmos.”
Q&A with IOP Publishing chief executive Antonia Seymour
How will the no-embargo aspect of the UK Research and Innovation’s new policy affect the move to OA?
Publication of articles costs money. Before any articles are even accepted for publication, journal editorial teams engage with their research communities to develop an appropriate scientific scope and direction for a journal, and to maintain an active, engaged and informed editorial board and network of peer reviewers. The editorial teams coordinate efficient and rigorous peer review in accordance with the latest standards for publication ethics and research integrity and use ever-evolving online editorial systems. These activities require trained, professional staff supported by increasingly complex technologies, as well as the necessary management, legal, financial and administrative overheads. It is therefore not economically viable for high-quality physics journals to provide entirely free and unrestricted distribution of accepted manuscripts, without any alternative and sustainable means of funding peer review and publication costs. Given the demonstrable progress towards full open access in the UK, I, along with many others have questioned the need to introduce this controversial component of the policy given it will undermine both subscription and open access business models. Why pay to subscribe to an article or to make it open access when a freely available substitute already exists?
What impact could the new policy have on researchers themselves – will they, for example, have sufficient funds to pay for it?
There’s a high risk of author confusion in trying to navigate the requirements imposed upon them by their funder and squaring those with what publishers offer. UKRI’s policy excludes the publication of funded research in journals where there is no transitional/transformative arrangement in place and where the publisher cannot support zero embargo publication of accepted manuscripts. That limits where authors who don’t have funds to pay the APC charges themselves can publish. IOP Publishing has a transitional agreement in place with JISC, but not all specialist and learned society publishers do.
What next steps will IOP Publishing be taking to respond to the new policy?
Learned societies, like the Institute of Physics, exist to ensure that physics delivers on its exceptional potential to benefit society. We recognise the important role of universal access to knowledge in achieving this goal and are therefore committed to making open access to physics research a reality. We welcome the increased policy momentum towards open publishing practices and are turning our attention to ensuring an effective implementation of the new UKRI policy – one that maximises funding for full open access publication of the “version of record” (gold), that will preserve the necessary choice physicists have in where to publish, and maintains the rigorous publication standards upon which researchers rely.
Twenty-three thousand. According to computer scientist Katie Bouman, that is how many people were involved in creating the first ever image of a black hole, taken by the Event Horizon Telescope (EHT) in 2019. Not all of these contributors are formally members of the EHT collaboration (whose numbers are in the hundreds) – the vast majority are those who write, maintain and support the free and open-source software tools that the researchers used in their work.
Bouman became the face of the EHT, after a photo of her delighted grin at seeing her work in action went viral. Code that she had written was part of the imaging software pipeline that extracted that famous photograph. But to Bouman, her contribution was only possible courtesy of software that was shared openly. “We would be getting nowhere if we didn’t have these kinds of tools that other people in the community have built up and have made free to use,” she told Physics World from her home in California, US. “We’re very, very thankful for everything that other people have done.”
Across the Atlantic, Suchita Kulkarni, a particle physicist at the University of Graz in Austria, who specializes in phenomenology of dark matter, agrees. “The reason phenomenology works, the reason people can look at exciting things at the Large Hadron Collider,” she says, “is because we have open-source software that is freely available under creative licences.”
Free and open-source software (FOSS) allows users to inspect the code, modify it and redistribute it with few or no restrictions. The “free” in FOSS thus refers to these freedoms, not to monetary cost. This makes FOSS particularly powerful in research, enabling collaboration between scientists working on code that they have modified, and today it is seen as an integral part of the wider open-science movement.
Code contributor
The term “software” can refer either to general user-facing tools and applications or to programs and analysis code used for specific tasks. Seen through this prism, there are at least four kinds of people who contribute to open-source software, with each group having its own motivations and reasons for doing so. First, you have the authors and maintainers – both paid and volunteer – of general-purpose software tools, including programming languages such as Python, Julia and R. Then there are those who write specialized software for certain domains of research, such as the Astropy library for astrophysics, or ROOT and Pythia for particle physics.
Third, you have scientists who write analysis code for their research that they then share openly, enabling others to learn from their work and apply the same code to different analyses. And finally, you have hobbyists, who contribute to open-source code on a one-off or regular basis, to develop their skills or to help maintainers of software they use. The boundaries between these are often fluid, and many maintainers of important software tools started out as hobbyist contributors.
Switzerland-based particle physicist turned software engineer Tim Head began using the open-source Python language as a physics student. According to him, a large part of the appeal of open-source tools is that they are usually distributed at no cost to the user. “The one thing everybody agrees with is that the easier it is for people to start using your software the better. With free and open-source software, you can just start using it today. You don’t have to ask your boss and then the purchasing department and then wait six months for them to negotiate a deal.”
After learning to programme in Python, Head began to use a greater number of open-source tools during his PhD, including “scikit-learn”, a Python library for machine-learning. Following a Twitter exchange with one of the developers of scikit-learn, he attended a workshop in Paris, aiming to make a contribution of his own. “I spent all afternoon fixing two typos in the documentation,” he laughs. But it sparked something in him.
Head got together with his fellow junior researchers on the LHCb collaboration at CERN to set up an open training programme to acquaint new members of the collaboration with some of the internal software tools used for performing physics analyses. Over time, he got involved with Mozilla Open Leadership, a mentorship programme for leading open-source projects, and started open-source projects of his own. Today, Head works as a senior engineer at Skribble, a digital signature platform. He is also a Distinguished Contributor to Project Jupyter, which provides some of the most popular tools for data analysis across domains of research.
How to make your next paper reproducible
(Courtesy: LIGO/Jupyter)
A reproducible paper is one in which a reader or a reviewer can remake every table and figure, from your data sets, using software on their own computer or using web-based tools. If you’d like to use a Jupyter notebook to write your next paper and make the entire document reproducible, here’s how to do it:
1. First, check to make sure the programming language you’ve chosen for your analysis is among those languages supported by Jupyter.
2. Create and launch a new Jupyter notebook.
3. Enter your text in a “text cell”. You can also use LaTeX for any equations you want to include.
4. Import your data in a “code cell”. You can store the data in the same folder as your notebook, or fetch data that was uploaded to CERN’s Zenodo open-source platform.
5. Instead of preparing your tables and figures separately and placing them in your paper, include the code for each in a “code cell”. Then, “run” each code cell to generate the table or figure.
6. When your paper is ready, upload the Jupyter notebook to a code-sharing platform like GitHub. Optionally, upload the file to Zenodo.
7. Follow the instructions for Binder to allow your paper to be recreated in the cloud.
8. Share the Binder link to your reproducible paper.
Jupyter notebooks are the most well-known product of Project Jupyter. They are interactive computational tools enabling “literate programming”, a concept in which one records descriptive prose in a human language, together with related snippets of code that perform bite-sized tasks. You can mix your narrative – what you did and why, what steps you took that led to dead-ends – with the actual code you used, along with the tables and plots it generated. You can then share the notebook with a colleague – or indeed with the wider research community. As long as they have sufficient computing resources and the same freely available open-source libraries installed, they can reproduce your research at the click of a button or change the parameters you chose and run a modified analysis (see box, above).
While it is one thing to share your analysis code with your collaborators, making your code available publicly is a different matter. After all, many scientists who write code do so without professional-level training in the best practices of software development. Some may therefore be reluctant to put their work out there for experts to scrutinize and criticize.
Collaborative contributions Katie Bouman (right) became the face of the Event Horizon Telescope’s black-hole-imaging team, but she points out that 23,000 people, including her colleague Andrew Chael (pictured), played a role in creating the black-hole photograph. (Courtesy: Lindy Blackburn)
That’s not just an abstract concern, as Bouman found to her cost. The EHT team released its imaging tools when it announced its observation of the black hole. After Bouman’s photo went viral, Internet trolls used this openness – which included information about individual contributions to the collaboration’s analysis – to disparage her input. Despite being a highly qualified engineer and computer scientist, Bouman found herself on the receiving end of harsh, often misogynistic comments about her coding skills. “It’s nerve-racking to put your code out there,” she says, “especially when people are inspecting it and going down deep into things that you did years and years ago.”
So what made the EHT researchers want to share their work so openly? “I think the main goals were transparency, reproducibility and having other people be able to test our methods and code,” Bouman remarks. “We wanted to be as transparent as possible with such an important result. We wanted our ideas to be improved on and we wanted people to use them in different applications.”
I think the main goals were transparency, reproducibility and having other people be able to test our methods and code. We wanted to be as transparent as possible with such an important result
The notion of sharing extends beyond software itself – indeed, it also embraces the services used to support the writing, dissemination and preservation of code-based tools. One such service is Zenodo, an open-source platform developed at CERN. “Zenodo is a platform to which anybody around the world can upload something that they consider a research object worth sharing,” explains Tim Smith, who leads the group in CERN’s IT department that is responsible for user-facing services. These objects could be a figure, a presentation, some data or even code. “The platform publishes it, issues a DOI [digital object identifier] with a guarantee to keep it forever, and makes it available for download to anybody who wants it.” With services like Zenodo, researchers can upload every version of their software libraries or analysis code, knowing that it will be available at the end of a DOI for the foreseeable future.
Another service that is gaining popularity is Binder, run by Project Jupyter. Binder allows you to take a static Jupyter notebook stored on the web, and make it interactive, without having to install any software on your computer. Everything runs in a web browser. In fact, you can even point Binder to properly configured Jupyter notebooks stored on Zenodo. Shortly after announcing the observation of gravitational waves, the LIGO team shared a Jupyter notebook containing a simplified version of their analysis. With a single click, anyone can, in principle, rerun the LIGO analysis in their browser (bit.ly/3iiqso3).
While Zenodo relies on the big-data storage facilities at CERN, Binder requires considerable cloud computing to function. Private cloud providers, such as Google Cloud Platform in the US and OVH in Europe, are the major donors of cloud services to Binder. Increasingly, however, research institutions such as the Alan Turing Institute have joined the fray, by sharing their own cloud infrastructure for Binder. “These institutes use the Binder software internally and also run a public instance of it,” Head explains. “You have to have benefactors like that. The more diverse and smaller the individual contributions are, the more resilient the project is.”
For Whitaker, who established the relationship between Turing and the Binder team, this desire to contribute internal infrastructure to external projects goes back to the idea of the commons. “If everyone plays a small part, you really can do huge and amazing things,” she says. “Where institutions like Turing come in is we just have to do it. By one person making it happen, it makes it more likely for others to do so.”
Citations as currency
Until recently, the role of code and those who write it has not been recognized within academic circles. Kulkarni, who both benefits from open-source software and contributes to it herself, is quite explicit about it. “Traditionally,” she says, “there have been very few positions in academia that have been given to software developers. It’s my opinion that we should have done a bit more to acknowledge the work of tool developers.”
Whitaker offers a simple solution to the problem of acknowledgement. “Cite the freaking software! If everybody recognized all of the shoulders that they were standing upon every time they were doing any part of their work, and they saw what has traditionally been invisible labour, we’d get there immediately.”
Open publication A paper published in the Journal of Open Source Software on ‘SunPy’, an open-source Python library used for data analysis and visualization in solar physics. (Courtesy: SunPy/JOSS)
Citing software is a relatively new idea and Whitaker acknowledges that authors of software must make it easy for their work to be cited. One way for software developers to do so, is to upload a given version of the code to a repository like Zenodo, and then display the DOI that is assigned to it. But scientists may wish to cite work that is peer-reviewed in some form. The Journal of Open Source Software (JOSS) was established precisely to address this, and conducts a fully open and transparent peer review of research software tools.
“JOSS is a hack on the system,” says Juanjo Bazán, an astrophysicist from the Center for Energy, Environmental and Technological Research in Madrid, Spain. “The founders of the journal noticed that in the research world the role of software developers is not really covered by academia’s credit system; they are not credited as authors of papers.” Anyone who writes a software library that is used in research can send a one- or two-page submission to JOSS, which peer reviews the quality of the software, determines whether it is well written and checks any performance claims made.
The entire process from submission to publication in JOSS happens publicly on GitHub, a web platform for sharing code and collaborating on its development. Submissions that are considered legitimate software papers are not consigned to the discard pile easily. Reviewers, who are not anonymous, openly leave their feedback to the software authors, with the objective of getting the authors to incorporate the suggestions and improve the software. Bazán, who is also a research software developer, was so enamoured by JOSS after submitting a paper to it that he now volunteers as an editor for astrophysics submissions. “JOSS has become popular among research developers,” he says. “We have just published our 1000th paper.”
Selective recognition
Tim Head does not believe that citations of software alone will solve the problem. He notes, first, that scientific software libraries are themselves often built upon existing tools or lower-level libraries – it’s software turtles all the way down. This raises the question of how many levels deep one must go. But on a more practical note, he remarks that having citations for a software paper does not mean recognition – and, more importantly, career progression – will be forthcoming. “A friend of mine is a core contributor to scikit-learn,” he says. “The team wrote a paper about it and it has a very large number of citations. But when he applied for some tenure-track jobs, he was told they would ignore this paper because it’s not ‘real’.”
Smith concurs that flaws in the system persist. “We have a reward system that is based on essentially a 300-year-old process. We have to change that reward system and get it to understand and acknowledge contributions in a digital age.” Those contributions, he explains, are diverse and encompass more than just the analysis process. “Many of our universities and research institutes are already changing their processes to start acknowledging these other contributions and how it all contributes to the advancement of science. All of those contributions should be valued.”
Token of appreciation GitHub asked NASA which libraries were used for the code of the Ingenuity Mars helicopter (top). Anyone who made a contribution to those libraries now has a small Mars helicopter badge on their GitHub profile (inset) and the libraries are listed on the GitHub Ingenuity page (below). (Courtesy: NASA; GitHub; Ariel Davis)
Indeed, the diversity of contributors to open-source software may mean that people seek diverse forms of recognition. Bazán notes that for hobbyists, a simple acknowledgement can be enough. “In April,” he explains, “GitHub talked with NASA and asked the agency to list all the libraries used for the code of the Ingenuity Mars helicopter. Anyone who made a contribution to those libraries now has a small Mars helicopter badge on their GitHub profile page. Maybe that’s enough for some.”
On the other hand, some forms of selective recognition within academia have issues of their own. Take the example of two software developers of the Pythia and Herwig Monte Carlo simulators used in particle physics, who received an award this year from the European Physical Society for their contributions on the software side. Although she appreciates the value in this, Kulkarni is nevertheless critical of what she believes to be the romanticized version of physics as a lone-wolf field, because the award recognized only two people out of dozens of developers.
“You want to have a leader,” Kulkarni says. “One person who is going to advance the field. You see it when people write recommendation letters; they don’t say someone is a great team member, they say they are a great leader. But we have a contradiction between recognizing the value of team work and benefiting from the value of team work.”
Fortunately, a cultural shift is in the making. Research is moving towards greater openness and transparency. With more and more researchers like Bouman, publicly acknowledging and thanking the developers of open-source software, the day may not be far off when software receives both recognition and increased institutional support for its foundational role in modern science.
Researchers in India and Australia have simulated the delivery of drugs used to treat pulmonary illnesses. Using a replica of the respiratory system, combined with fluid dynamics simulations, a team led by Suvash Saha at the University of Technology Sydney showed how smaller drug particles tend to reach smaller bronchi in the lungs more easily. The discovery could provide valuable guidance for clinicians in improving designs of both drugs and inhalers.
With levels of air pollution increasing in many cities – particularly in lower-income countries, lung diseases are a growing concern worldwide. Currently, among the most widely used methods to manage these diseases is through dry powder inhalers (DPIs): which disperse microscopic drug particles throughout a user’s lungs as they inhale through the device.
DPIs are particularly useful because they do not require a propellant, deliver more consistent doses, and enable a more widespread deposition of drugs within the bronchi of the lungs than other treatment devices. Yet despite these advantages, fewer than 30% of the drug particles delivered by DPIs actually settle within the lungs. Such a low efficiency is driving up the costs of drug doses, making treatments less accessible to the many millions of people who could benefit from inhalers.
Computational fluid dynamics
In previous studies, researchers have shown how this efficiency can be affected by the sizes of drug particles within the doses delivered by DPIs. To investigate this effect, Saha’s team developed a replica of the human respiratory tract, based on 3D images taken by computer tomography. By combining their model with computational fluid dynamics, they then simulated the deposition of different-sized drug particles onto different parts of the respiratory tract.
To recreate variations in human breathing, the researchers measured how depositions of the particles varied with different inhalation rates. They discovered that larger particles, as well as those those inhaled at faster speeds, were more likely to be deposited in the mouth. Since these particles carry higher inertial forces, they could less readily change direction at the sharp turn from the mouth into the trachea – causing more of them to settle before reaching the lungs.
In contrast, finer particles could more easily disperse into the bronchi: the passages in the lungs which branch out into ever finer structures, where gas exchange occurs. In addition, the simulations revealed that more particles were deposited in the bronchi of the right lung than the left – whose shape is distorted to accommodate the heart.
Based on their results, Saha and colleagues now propose that existing treatments for pulmonary diseases could improve through the use of smaller drug particles, which could more readily access the bronchi where breathing problems arise. They hope that their discoveries will help clinicians to design more effective drugs, and better devices for administering them.
The Paralympic Games in Tokyo will be wrapping up this weekend and to honour the hosts, this edition of the Red Folder is focussing on Japan.
World-class swimmers must work hard for even the smallest advantage in their sport. One physical reality that they are up against is that the resistive force pushing them back in the water is proportional to the cube of their swimming speed – which means that speeding up costs a lot of energy.
Swimmers increase their velocity by boosting their stroke frequency, but now researchers at the Faculty of Health and Sport Sciences at the University of Tsukuba have found that there is a maximum stroke frequency beyond which swimming speed for the front crawl is not increased.
Conflicting evidence
According to Tsukuba’s Hideki Takagi, this limit is “due to a change in the angle of attack of the hand that reduces its propulsive force”. They also found that the balance of forces at the hand were different at different swimming speeds – suggesting that different techniques could be optimal for short and long-distance swimming. Their study also found conflicting evidence for whether increased kicking frequency boosts speed – saying that there is much more work to be done to fully understand the subtleties of the front crawl.
Elsewhere at the University of Tsukuba, Shinichi Yamagiwa and colleagues have analysed video of judo throws from top-flight matches to try to determine the factors that contribute to good technique. The goals of the study were to improve the understanding of the biomechanics of judo and to improve coaching and training techniques. They report their findings in Sensors.
Soon, the world’s Paralympians will be packing up their medals and flying home. But should they be worried about radiation from solar flares that they could be exposed to when flying?
Ground level enhancements
A research team led by Yosuke Yamashiki at Kyoto University has addressed that question by looking at radiation doses experienced in aeroplanes flying eight different routes during five events called “ground level enhancements” (GLEs). These are periods of increased cosmic ray intensity measured at ground level and are normally associated with solar flares.
Yamashiki and colleagues found that there were increases in the detection of solar energetic particles (SEPs) on board the aircraft. However, they found that radiation levels were not high enough to justify current countermeasures such as flying at a lower altitude where radiation levels are lower during a GLE.
“There is no denying the potentially debilitating effects of radiation exposure,”says Yamashiki, “but the data suggest that current measures may be over-compensating for the actual risks”.
Astronomers in China have found that the Tibetan Plateau offers conditions that make it ideal for future gigantic optical-based telescopes. The researchers report that a mountain near the town of Lenghu (“cold lake”) in Qinghai Province has observing conditions similar to existing astronomy meccas in the Hawaiian mountains and Chilean deserts.
For years, astronomers had hoped to find a good observing site on the Tibetan Plateau — known as “the roof of the world” — due to its high altitude, dryness and minimal light pollution. However, the region’s harsh environment makes it extremely challenging to collect reliable and continuous observation data. Indeed, there was a general belief among astronomers that sandstorms ruled out Lenghu, while other nearby locations suffer from strong winds.
Lenghu site is indeed comparable in quality to the best established sites such as Chile, Hawaii, and the Canary Islands for large telescopes
Michael Ashley
Since March 2018, a team led by Licai Deng from the National Astronomical Observatories of China, Chinese Academy of Sciences, has been monitoring cloudiness, night-sky brightness, air temperature, humidity, wind speed and direction at “Summit C” on Saishiteng Mountain, which lies some 4200 m above sea level.
The team discovered that about 70% of the nights at the summit were clear enough for observation. As for “seeing” – a key parameter to describe the blurring of stars due to atmospheric turbulences along the light path – the median value was 0.75 arcseconds, or 1/4800 of a degree. The median night temperature variation was 2.4 °C when precipitable water vapour was lower than 2 mm for most of the night.
These parameters are like those of Mauna Kea in Hawaii, Cerro Paranal in Chile and La Palma in Spain, where the world’s most cutting-edge telescopes are located. In particular, the temperature fluctuations at the Lenghu site were much lower than the other sites, indicating very stable surface air.
In winter, temperatures on Saishiteng Mountain could drop to below –20 °C at night, which is favourable for infrared astronomy. Meanwhile, with little water vapour, Lenghu’s exceptional atmospheric transparency could open up a new window on terahertz astronomy to examine interstellar medium and better understand the origins of stars, galaxies, and the universe.
“The [work] provides convincing evidence that the Lenghu site is indeed comparable in quality to the best established sites such as Chile, Hawaii and the Canary Islands for large telescopes,” wrote astrophysicist Michael Ashley from the University of New South Wales in his reviewer comments for the paper. “The authors should be congratulated on completing this difficult task at such a remote location.”
That view is backed up by Paul Hickson from the University of British Columbia in Vancouver, Canada, who is not involved in the research, and calls the study extensive and thorough. “Three years of data is quite good, as it covers all seasons and provides some information on year-to-year variations,” he says.
Home for future telescopes
China’s astronomical aspirations have soared in recent years, but the reality remains that the country only has a couple of 2 m-level telescopes that work in the optical band – while the largest of its kind now under construction is about 40 m in diameter. The lack of an ideal observing site is a particular bottleneck, yet that could now change thanks to the discovery of favourable conditions on Saishiteng Mountain.
Indeed, Chinese astronomers have now proposed a line-up of telescopes for the mountain site. They include a 2.5 m-aperture optical telescope being built by the University of Science and Technology of China, which will have first light in 2023. It will be joined by a solar telescope and a telescope array called the Near Earth Object Hunter. The list could also include a 12 m-aperture telescope being proposed by the whole Chinese astronomy community to the government.
Deng believes, however, that Lenghu should not be just for China. With the rise of time-domain astronomy, it will serve as the only site in the eastern hemisphere to benefit the global observation of high-energy phenomena and transient events. Good astronomical sites are always in high demand – in particular given the construction deadlock at Mauna Kea – and Deng hopes that Lenghu could be home to international telescopes in the future.
Ashley, who has worked with Chinese astronomers at Antarctica’s Dome A, adds that the new site not only fills an observational gap in the eastern hemisphere but will be critical for China’s astronomical ambitions, including the chance to boost international collaboration. “My team would be more than happy to contribute part of a telescope to be put on Saishiteng Mountain on the Tibetan Plateau,” he adds.
The long road leading to Lenghu
Steep climb: Licai Deng from the National Astronomical Observatories of China, Chinese Academy of Sciences, and colleagues made dozens of hikes up Saishiteng Mountain to test conditions for astronomy at “Summit C”. (Courtesy: Cairang Tian)
Back in 2017, Licai Deng from the National Astronomical Observatories of China, Chinese Academy of Sciences, was having trouble with his 1 m-aperture telescope in Delingha, some 400 km east of Lenghu. As the Chinese node of the Stellar Observations Network Group (SONG) – a project which uses several telescopes around the world to observe stars and planetary systems — his observations were suffering due to light pollution caused by local economic development.
Just when Deng thought he needed a new site, officials from Lenghu invited him to check out conditions on Saishiteng Mountain. Lenghu used to be a major petroleum base in the country, with a population above 100,000, but as oil fields dried up it declined into a “ghost town” with a few hundred regular residents. The local government wanted to find a way out via astronomy-related tourism via Lenghu’s Mars-like landscape and beautiful night skies.
Deng signed a five-year contract – worth one million yuan per year – with the local government to collect scientific data and find out whether Saishiteng Mountain would make for a good astronomical site. At that point, no-one had ever set foot on the summit.
“The area still has a lot of sandy days,” says Deng. However, when they made it to the top of Saishiteng Mountain for the first time, they realized that all the sand and dust particulates were well below. The sky cleared up somewhere between 3800 and 4000 m, with the summit being another 200 m higher. “No-one could have known it without getting up there,” he says.
When the researchers first started the site survey, there were no roads or any other infrastructure they could use. The local government rented a helicopter to bring supplies to the site, including a 10 m-tall tower for mounting an instrument called differential image motion monitor.
Meanwhile, Deng and colleagues would hike two to three hours, carrying well over 10 kg of maintenance devices on their backs to the top of the mountain. During the 18 months without roads, everyone in Deng’s team hiked dozens of times. They managed to obtain continuous measurement and kept downtime under 3%. The road to Summit C was finally finished in 2019.
Deng expects China’s national grid to reach Saishiteng Mountain soon. He has also relocated his SONG telescope to the new site. To his delight, a night sky protection policy has been written into law by the local government, banning light pollution in the future over an area of 18,000 square kilometres.
The annual congress of the European Society for Radiation Oncology (ESTRO) sees physicists, clinicians, radiobiologists and radiation therapists come together to share their latest research developments, technical innovations and clinical studies. The best abstract submitted each year, selected by the scientific programme committee, is chosen to receive the Donal Hollywood Award.
At the ESTRO 2021 meeting – a hybrid meeting held online and live in Madrid, Spain – the winner was Brita Singers Sørensen from Aarhus University Hospital in Denmark, for her study on pencil-beam scanning proton FLASH.
FLASH radiotherapy delivers radiation at ultrahigh dose rates of 40 Gy/s or more, with treatments taking less than 0.5 s. Preclinical studies indicate that FLASH offers remarkable normal-tissue sparing without impacting tumour control. But according to Sørensen, there’s still a lot of information lacking.
“For example, we are still missing data on proton pencil-beam scanning and on normal tissue damage from full dose–response curves,” Sørensen explained. “We also need data from tumour control studies and finally there’s a huge need to understand the underlying mechanism for FLASH.” As such, she is working with her team in Aarhus to tackle some of these outstanding problems.
To investigate the effect of proton FLASH delivered with a scanning pencil beam, Sørensen, physicist Per Poulsen, and their colleagues designed an experiment to irradiate a mouse hind leg with protons at either conventional or FLASH dose rates. They placed the animal’s leg in a water bath, in the beam’s entrance plateau (to perform transmission FLASH rather than treating with the Bragg peak) and measured the delivered dose using an alanine pellet at the beam entrance and a scintillating crystal behind the target.
The researchers irradiated 154 mice with 244 MeV protons at a conventional dose rate (0.4 Gy/s), with doses ranging from 24.6 to 41.6 Gy. They also treated 144 mice with 250 MeV protons at a FLASH dose rate of 69–90 Gy/s. Here, they studied 12 dose levels of between 32.4 and 55.6 Gy. Mice in each dose group were scored daily for acute skin toxicity, from day 11 to day 28. The team then calculated the percentage of mice with a certain toxicity score in each dose group.
Comparing dose–response curves at five skin damage levels revealed a FLASH sparing factor of between 1.41 and 1.55. “The conclusion so far is that with pencil-beam scanning proton FLASH, we do see a normal tissue sparing effect on acute skin damage; we see 40 to 50% sparing,” said Sørensen.
But normal tissue damage is only half of the story when it comes to FLASH – the other half is investigating the impact on the tumour. With this aim, the team is currently conducting a parallel study looking at tumour control with proton FLASH, using the same set-up to irradiate mice with tumours implanted their hind legs.
Sørensen added that there are many other important factors to consider, such as investigating intermediate dose rates and the effect of beam pauses and fractionation. “Finally, we would very much like to look at FLASH in a spread-out Bragg peak instead of using a transmission beam as this would increase the clinical relevance,” she told the ESTRO delegates.
The award finalists
The four finalists for the Donal Hollywood Award presented their studies in a dedicated conference session. The three other finalists were:
Marie Louise Milo from Aarhus University. Milo presented a study investigating the risk of radiation-associated heart disease following radiotherapy for early-stage breast cancer. In a cohort of over 15,000 patients treated with CT-based radiotherapy, 204 were identified as having coronary artery disease following irradiation. Milo assessed the individual doses to the heart and cardiac substructures in these patients, as well as in matched controls from the cohort. The mean heart dose was 1.6 Gy in left-sided and 0.8 Gy in right-side irradiated patients, with the highest doses seen in different substructures for the two groups. But despite these differences in dose distribution, no difference was seen in the distribution of coronary artery disease. Milo also noted that no differences in the mean heart dose were seen between the heart disease cases and the controls. She concluded that, at a median follow up of 7.3 years, there was no dose–response relationship between the radiation dose and coronary artery disease.
Erica Bennett from Bon Secours Radiotherapy Cork. Bennett described her experience of implementing an oncology prehabilitation programme during the COVID-19 pandemic. Prehabilitation, she explained, occurs between a patient’s cancer diagnosis and their treatment. The process includes baseline physical and psychological assessments, and provides interventions to improve health and reduce the incidence of future impairments. Bennett designed a seven-week pilot programme incorporating exercise, diet and psychological support, with a combination of online and in-person interventions. The programme aimed to prepare patients for their treatment, educate them on physical health and wellbeing, and provide tools and support for lifestyle changes. All six patients enrolled in the pilot found the programme valuable and would recommend it to others. Bennett concluded that while the need for online counselling was not ideal, it was still possible to implement a successful prehabilitation programme during the pandemic.
Tobias Gauer from University Medical Center Hamburg. Gauer shared his findings on how 4D-CT imaging affects the outcome of stereotactic body-radiotherapy (SBRT) for lung and liver metastases. SBRT treatments are planned based on 4D-CT scans, but the reconstructed data often contain artefacts due to suboptimal imaging protocols or irregular patient breathing. A study of 373 SBRT cases revealed that while the mean breathing period was mostly predictable, breathing amplitude was random. Conventional 4D-CT can’t compensate for this unpredictability, resulting in artefacts. To assess the correlation between artefacts and clinical outcome, Gauer categorized 4D-CT planning data from 62 patients with 102 metastases as having severe or no/moderate artefacts. He found that local metastasis control was reduced from 90% to 70% if the SBRT planning data contained severe artefacts. He concluded that artefact-affected SBRT planning data impact the entire radiotherapy process and will likely influence clinical outcome. Such CT-related limitations could be overcome by employing breathing-adjusted imaging protocols.
In this episode of the Physics World Weekly podcast I chat with Erica Salazar of the Massachusetts Institute of Technology, who is developing high-temperature superconductor magnets for the next generation of fusion reactors. She explains why these materials could help make the dream of fusion power come true and why the magnets must be protected from a potentially damaging effect called quenching.
Also on hand is Physics World’s Michael Banks, who has just published this year’s Physics World China Briefing. He talks about the country’s rise to become a scientific superpower, especially when it comes to the exploration of space.
Describing how matter behaves at the quantum-mechanical level is notoriously hard, because the equations get so difficult to solve once there is more than a handful of particles involved. But a new experiment shows that the fine details might not matter too much – and that, if we “squint” at a many-particle quantum system to blur them, how the system changes over time can look surprisingly like the familiar classical process of diffusion.
Figuring out the exact trajectories of particles of ink in a glass of water as they are battered this way and that by water molecules is difficult. But you do not need to keep track of every molecule because. Fick’s law of diffusion says that the flow of material is simply proportional to its concentration gradient.
Fick’s law is an example of coarse-graining that is commonly used in hydrodynamics. For example, a fluid can be considered a collection of little “parcels”, each containing countless molecules, which move frictionally past one another.
Local blobs
Researchers have recently sought to describe quantum-mechanical many-particle systems using such an approach. Say you have a material containing a bunch of quantum spins that interact with one another, you create a local “blob” of oriented spins and calculate how it will then spread through the system.
“Hydrodynamics is generally the study of how a system goes from local equilibrium to global equilibrium,” says Joel Moore of the University of California at Berkeley. The equations of fluid mechanics, he says, assume that any detailed information about the initial state – where the particles are and how they are moving – is quickly lost once they have experienced just a few interactions (collisions) with others. “Then the fluid equations describe everything on longer time scales, from microseconds to years, very accurately.”
To study an analogous system of quantum spins, Moore has collaborated with Berkeley physicist Norman Yao and others. They examined a tiny single crystal of diamond containing two types of spins, both arising from the unpaired electrons of defects in the carbon-crystal lattice. One kind of defect, called a P1 centre and consisting of a nitrogen atom in place of a carbon, was dispersed randomly through the lattice at a concentration of 100 ppm. The other defect, called an NV centre, consists of a nitrogen substitution next to an empty space in the lattice, was dispersed at a concentration about two hundred times lower.
Spins with feelings
These spins can “feel” one another over long distances of many times the atomic separation. To see how the dynamics of the spins evolved, the researchers used the NV defects both to set up a perturbation and to probe the response. They could polarize these spins in one region using a laser pulse, and then transfer that localized disturbance to the more populous P1 spins by coupling the two using a magnetic field to bring them into resonance. Then they monitored how this perturbation spread through the P1 spins as the system moves towards its global equilibrium configuration.
“The lore is that if you take a uniform initial state and make a packet of excess energy or spin somewhere in the system, this packet will spread out according to some differential equation,” says Yao. For a quantum system, we might expect that to be the Schrödinger equation. But it would be very challenging to describe the process that way for all the interacting spins.
The measurements showed, however, that the overall dynamics were well described by a simpler equation that looked a lot like Fick’s diffusion. In other words, this strictly quantum process turns out to share much the same dynamics as a classical one. If you just measure the spin density at a slightly coarse-grained resolution, explains Yao, then “the differential equation that describes these dynamics can be much simpler than the Schrödinger equation, and instead like the diffusion equation”.
Not a perfect match
However, the behaviour of the spins was not a perfect match for diffusion. This, says Moore, is partly because the spins, unlike colliding particles, can feel one another over long distances. But it also seems to stem from the fact that the P1 defects are not quite all equivalent: the atoms around each defect might have slightly different local arrangements, producing some random disorder.
Yao says that other theoretical studies suggest that other processes of “quantum hydrodynamics” can take different forms, equivalent to other types of coarse-grained classical dynamics. For example, some systems in which spins interact in 1D chains are predicted to have similar dynamics to the so-called Kardar–Parisi–Zhang equation, which governs some kinds of surface growth processes and the way shock waves propagate.
What this suggests is that, at a coarse-grained level, dynamical processes on many-body systems might be rather insensitive to whether they are governed by quantum or classical physics. There is a kind of universality that depends more on the general interactions between the coarse-grained components than on their microscopic details – an echo, perhaps, of the universality seen in magnetic spin systems and classical fluids close to a critical phase transition.
Active field
“Understanding this emergence in detail is challenging for microscopic entities that are quantum, and equally so, in different ways, for microscopics that are classical,” says David Huse of Princeton University in New Jersey. This, he says, “is a long-standing enterprise in the fundamentals of statistical physics, that has become rather active recently for quantum microscopics because of the improved ability to explore it in the lab”.
The experimental work “is an impressive feat”, says Arijeet Pal of University College London. “The demonstration that there is a different hydrodynamic regime from conventional diffusion is an essential first step towards understanding the different dynamical universality classes allowed by quantum physics.”
While many activities here on Earth have slowed down or been put on hold due to the COVID-19 pandemic, that has not stopped China – and other countries – from forging ahead in space. China has managed several firsts this year, notably landing its first rover on Mars, starting construction of a fully-fledged space station, and successfully returning samples from the Moon.
In this year’s Physics World China Briefing, we report how that progress is only set to accelerate, with China’s space station set to be complete next year, giving it a permanent presence in Earth’s orbit for the next 10 years and more. The mid-2020s will also see China put a dedicated optical space telescope in orbit as well as launch further lunar craft. It may even start building a Moon base by the end of the decade – not to mention an asteroid and further missions to Mars.
We talk to some of the minds behind those missions, including Su Yan from the National Astronomical Observatories of China, Chinese Academy of Sciences, who has played a key role in China’s exploration of the Moon.
Back on Earth, China is also making a big push in materials science, which is set to play a large role in progress towards seven major research areas – including aerospace technology and quantum technology – that China has highlighted in its 14th five-year plan that began this year.
In this year’s briefing, we talk to Zhongfan Liu, founding president of Beijing Graphene Institute, about how it is pioneering the industrialization of new graphene materials as well as Weihua Wang, director of the Songshan Lake Materials Laboratory in Dongguan about a new joint venture with IOP Publishing, which publishes Physics World.
Early in my teaching career, I had a rather uncomfortable exchange with a retired physicist. He challenged me to defend the A-level physics curriculum, which he thought had been “dumbed down” and lacked any solid, mathematical rigour. I regret not putting my thoughts across better at the time, but – with the benefit of almost 15 years teaching experience behind me – I now feel more prepared to respond.
I should add that this physicist’s views were not a one-off. Since then, I have had many similar conversations with other university physics lecturers who mourn the lack of mathematical fluency in their first-year undergraduate students. I should point out that I am a huge advocate of mathematics in physics and believe that mathematics is in fact the more important subject, given that it is at the core of new discoveries.
I was surprised to discover that the inclusion of A-level maths content in physics specifications, or syllabuses, is a more recent affair than I had anticipated. It appears to have emerged in the mid-1980s in response to changes to the maths curriculum, which previously had not been standardized. Instead, there were small but significant variations between the A-level maths syllabuses offered by different exam boards. Unfortunately, attempts to remove the differences ended up having a knock-on effect for physics.
Back in the 1970s students benefited from studying some physics topics both in their maths A-level course and in their physics A-level. This gave students more opportunity to apply their learning as well as additional contact time with teachers to perfect these skills. Universities were therefore reluctant to accept physics students who had studied maths A-level courses that featured little or no physics. Admissions tutors instead preferred to accept students who had benefited from this “double study”.
But when maths A-levels were standardized, physics content was removed to make way for other topics, such as probability and statistics, that are important in the social sciences. The reduction of physics content from the maths curriculum now meant there was less overlap between A-level physics and A-level maths. With less opportunity for those taking physics to refine their skills, physics specifications appear to have coped by increasing the onus on the student to study the material independently. Students studying the two subjects were simply no longer getting the rounded experience that they previously had received.
The uptake of physics A-level dropped over the next decade and physics went from being the most popular science to the least popular. One of the reasons suggested for the low uptake was the perception that physics was disproportionately difficult, which is supported by an analysis of student grades. Bright students performed worse in physics than they did in other subjects, which is off-putting when a student needs to strategically consider their subject choices for applying to university.
A good compromise
We need to accept that there are many other reasons to take physics A-level, besides the desire to study the subject at university. The skills it provides are useful to many other fields, which can lead to engaged, scientifically literate citizens. So it is in our interest to be as inclusive as possible. At A-level, teachers cater for a wide range of career paths, not just those progressing on to a physics degree. We deliver the subject in a way that is attractive and useful to both sets of students and accept that not all A-level physics students will be studying A-level maths. One consequence of adjusting for this balance can be a loss in mathematical rigour, particularly when it comes to notation.
The skills A-level physics provides are useful to other fields, and can lead to engaged, scientifically literate citizens
Niki Bell
It does not help either that when students get to university, lecturers often use a vastly different mathematical notation from what students were taught at school. In fact, lecturers often do not adjust their presentation of mathematics at all to accommodate students’ varying experience. This can be incredibly intimidating, and I often wish that lecturers would adapt their teaching to be more inclusive.
Maths for physics
I believe that the solution lies in recombining A-level maths and physics, by redesigning maths A-level so that students can specialize in their second year. Students do not typically get much opportunity to choose their modules in A-level, which are decided by the exam board or school leaders. But if this were changed, then those wanting to do a physics degree could select “maths for physics” in their second year of maths A-level, allowing them to focus on concepts such as mechanics and applied calculus. Those wanting to specialize in other subject areas would be able to select more appropriate mathematics, such as probability and statistics. This would mean that those not studying maths can still do physics if they wish. Redesigning the maths course this way would reintroduce the overlap between the subjects and give students more opportunity to develop skills in class, not just for physics, but for every field.
I acknowledge that there are practical problems with this model, especially for small colleges that do not have the same staff numbers as larger ones, but I believe the potential benefits are worth it. I have taught on such a course and can attest to its success. Teaching physics to students on a specialized maths course was incredibly fulfilling. Their mathematical ability was excellent, the students were confident and had ample opportunity to hone their subject-specific skills, and those progressing on to study physics at university were well prepared for the mathematical content. Achieving this was not easy. Making the most of the overlap, and creating that experience, took careful management and negotiation between departments, but outcomes for students were worth it.
I believe this is the best way forward, not only for physics students, but maths students too.
