physicsworld--2020-08-29--The power of authority: why we need to rely on experts - Physics World

Eons ago , we are told , the Flood nearly wiped out the human species , sparing only the tiny handful of people who had prepared themselves .
To my mind , COVID-19 is the 21st-century equivalent of the Flood .
It ’ s a global disaster that has killed hundreds of thousands of people , yet also a lesson about the need to prepare for future threats .
These days we face a wider variety of existential threats than in biblical times , including air and water pollution , climate change and rising seas .
We have more technologically @ @ @ @ @ @ @ such as medicines , vaccines and new energy sources .
We also generally assume the responsibility , for both practical and moral reasons , to employ these means to protect not just our immediate families but the entire human species as well .
Still , 21st-century humans face new and staggering challenges when it comes to using those means .
Noah had a direct communication channel with God and an unquestioned patriarchal authority , which let him convey the impending danger to his family without disbelief .
That divine link also let him @ @ @ @ @ @ @ build the boat that allowed him and his companions , literally , to weather the storm .
To cope with existential threats , we have to rely on the authority of people with special training – “ experts ” , we call them .
The 21st century has no Noah , and no God warning us of looming disasters .
To cope with existential threats , we have to rely on the authority of people with special training to identify , develop and apply the right tools – “ experts ” , we @ @ @ @ @ @ @ about the “ authority of science ” , we mean the will to defer to those experts about technical matters that we don ’ t understand in situations where we are vulnerable .
As I argued in my recent book The Workshop and the World , the authority of science is not something that comes naturally to humans , but has to be generated and maintained .
Such authority is fragile , and only happens in an atmosphere that has been carefully nurtured by three main things : political leadership , institutional consistency @ @ @ @ @ @ @ of COVID-19 is that the reaction to it illustrates by negative example why these three factors are important .
Let ’ s start with political leadership .
Fostering the authority of science requires leaders who demonstrate their commitment to defer to experts .
Donald Trump is a prime negative example .
The 45th US president has called the COVID-19 pandemic a hoax .
He ’ s said it will soon go away .
He ’ s looked for scapegoats , left counter-measures to others , and dismantled preparations that his predecessors had put @ @ @ @ @ @ @ advised using unsupported remedies or taking unproven ones – actions that not only may harm his health but also undermine the authority of expert advice that others need to stay healthy themselves .
The same is true of leaders who flout their own lockdown rules or don ’ t wear facemasks when required or advised .
Trump once retweeted a comment that wearing masks is a “ symbolic ” act , which dissolves what might be viewed as an act of commitment into mere theatrics .
He is still more proactive in sabotaging @ @ @ @ @ @ @ scientists , and appointing those without scientific credentials to oversee scientific activity .
Another basic element for maintaining scientific authority is to have reliable , consistent and transparent scientific institutions .
The credibility of scientific literature was hurt by retractions in The Lancet and the New England Journal of Medicine of papers reporting the results of coronavirus-related research .
The World Health Organization had to retract a claim about the incidence of asymptotic transmission of coronavirus .
The US Centers for Disease Control and Prevention botched coronavirus test kits , flip-flopped its evaluation @ @ @ @ @ @ @ results of certain tests .
In the UK , the government ’ s Scientific Advisory Group on Emergencies ( SAGE ) was criticized for lacking transparency .
True , the ability to change one ’ s conclusions based on new evidence or reanalysis is critical to the strength and reliability of science .
Yet doing so because of mistaken procedures or without transparency encourages suspicions that statements from scientific institutions are motivated by politics or incompetence .
Poor communication makes institutions appear opaque and their operations mysterious , making it easier for politicians @ @ @ @ @ @ @ “ I ’ m not a scientist ” or by blithely claiming “ I ’ m following ‘ the science ’ ” while doing nothing of the sort .
While the latter is somewhat more commendable , it also undermines scientific authority .
Finally , scientific authority can only flourish in communities that value health and welfare rather than , say , glory , wealth and self-advancement .
Such communities must also be willing to make rather than ignore decisions about how to justly allocate limited resources .
It is tempting to blame @ @ @ @ @ @ @ politicians , bad institutions or selfish people – or to think that such authority can be restored by fixing any one of these .
None of these three pillars by itself will generate scientific authority ; it is magical thinking to hope that , say , the next election will save us .
Each pillar affects the others .
Politicians who insult institutions or scientists hurt the authority of these and encourage community scepticism .
Institutions whose advice is inconsistent encourage individuals and politicians to discount their advice .
Desire for short-term gain @ @ @ @ @ @ @ for politicians and institutions to do the same .
I know this sounds religious , but think metaphorically of the pandemic as God ’ s lesson : “ Let me teach 21st-century humans by throwing a pandemic onto Earth and installing the people least able to handle it as our leaders .
Will humans get it ?
” The moral is that the inhabitants of a globalized and scientifically and technologically dependent world must cultivate an atmosphere in which scientific authority can exist or they will perish .
No more social distancing , @ @ @ @

Physics World, where it appeared under the headline "The power of authority". Members of the Institute of Physics can enjoy the full issue Taken from the August 2020 issue of, where it appeared under the headline "The power of authority". Members of the Institute of Physics can enjoy the full issue via the Physics World app
The COVID-19 pandemic has underlined why the authority of science is so important – and how it’s so easy to lose. Robert P Crease explains
Vital factors Authority in science needs political leadership, institutional consistency and trust. (Courtesy: iStock/Vaselena)
Eons ago, we are told, the Flood nearly wiped out the human species, sparing only the tiny handful of people who had prepared themselves. To my mind, COVID-19 is the 21st-century equivalent of the Flood. It’s a global disaster that has killed hundreds of thousands of people, yet also a lesson about the need to prepare for future threats.
These days we face a wider variety of existential threats than in biblical times, including air and water pollution, climate change and rising seas. We have more technologically advanced means to cope with them, such as medicines, vaccines and new energy sources. We also generally assume the responsibility, for both practical and moral reasons, to employ these means to protect not just our immediate families but the entire human species as well.
Still, 21st-century humans face new and staggering challenges when it comes to using those means. Noah had a direct communication channel with God and an unquestioned patriarchal authority, which let him convey the impending danger to his family without disbelief. That divine link also let him marshall and apply the resources needed to build the boat that allowed him and his companions, literally, to weather the storm.
To cope with existential threats, we have to rely on the authority of people with special training – “experts”, we call them.
The 21st century has no Noah, and no God warning us of looming disasters. To cope with existential threats, we have to rely on the authority of people with special training to identify, develop and apply the right tools – “experts”, we call them. And when we talk about the “authority of science”, we mean the will to defer to those experts about technical matters that we don’t understand in situations where we are vulnerable.
Flood control
As I argued in my recent book The Workshop and the World, the authority of science is not something that comes naturally to humans, but has to be generated and maintained. Such authority is fragile, and only happens in an atmosphere that has been carefully nurtured by three main things: political leadership, institutional consistency and communal trust. The silver lining of COVID-19 is that the reaction to it illustrates by negative example why these three factors are important.
Let’s start with political leadership. Fostering the authority of science requires leaders who demonstrate their commitment to defer to experts. Donald Trump is a prime negative example. The 45th US president has called the COVID-19 pandemic a hoax. He’s said it will soon go away. He’s looked for scapegoats, left counter-measures to others, and dismantled preparations that his predecessors had put in place. He’s even advised using unsupported remedies or taking unproven ones – actions that not only may harm his health but also undermine the authority of expert advice that others need to stay healthy themselves.
The same is true of leaders who flout their own lockdown rules or don’t wear facemasks when required or advised. Trump once retweeted a comment that wearing masks is a “symbolic” act, which dissolves what might be viewed as an act of commitment into mere theatrics. He is still more proactive in sabotaging scientific authority by insulting and even firing scientists, and appointing those without scientific credentials to oversee scientific activity.
Another basic element for maintaining scientific authority is to have reliable, consistent and transparent scientific institutions. The credibility of scientific literature was hurt by retractions in The Lancet and the New England Journal of Medicine of papers reporting the results of coronavirus-related research. The World Health Organization had to retract a claim about the incidence of asymptotic transmission of coronavirus. The US Centers for Disease Control and Prevention botched coronavirus test kits, flip-flopped its evaluation of mask-wearing, and mixed up the results of certain tests. In the UK, the government’s Scientific Advisory Group on Emergencies (SAGE) was criticized for lacking transparency.
True, the ability to change one’s conclusions based on new evidence or reanalysis is critical to the strength and reliability of science. Yet doing so because of mistaken procedures or without transparency encourages suspicions that statements from scientific institutions are motivated by politics or incompetence. Poor communication makes institutions appear opaque and their operations mysterious, making it easier for politicians to dismiss their advice either by saying “I’m not a scientist” or by blithely claiming “I’m following ‘the science’” while doing nothing of the sort. While the latter is somewhat more commendable, it also undermines scientific authority.
Finally, scientific authority can only flourish in communities that value health and welfare rather than, say, glory, wealth and self-advancement. Such communities must also be willing to make rather than ignore decisions about how to justly allocate limited resources.
It is tempting to blame the lack of scientific authority on shameless politicians, bad institutions or selfish people.
It is tempting to blame the lack of scientific authority on shameless politicians, bad institutions or selfish people – or to think that such authority can be restored by fixing any one of these. None of these three pillars by itself will generate scientific authority; it is magical thinking to hope that, say, the next election will save us. Each pillar affects the others. Politicians who insult institutions or scientists hurt the authority of these and encourage community scepticism. Institutions whose advice is inconsistent encourage individuals and politicians to discount their advice. Desire for short-term gain rather than long-term security provides the incentive for politicians and institutions to do the same.
The critical point
I know this sounds religious, but think metaphorically of the pandemic as God’s lesson: “Let me teach 21st-century humans by throwing a pandemic onto Earth and installing the people least able to handle it as our leaders. Will humans get it?” The moral is that the inhabitants of a globalized and scientifically and technologically dependent world must cultivate an atmosphere in which scientific authority can exist or they will perish. No more social distancing, extinction next time.


physicsworld--2020-08-31--Quantum computers may be heading underground to shield from cosmic rays - Physics World

Such is their sensitivity to environmental noise , quantum computers might in future be shielded by thick layers of lead and even operated deep underground .
So say physicists in the US , who have found that ionizing radiation significantly limits the coherence time of superconducting qubits .
Indeed , they say that minimizing radiation effects will be crucial if general-purpose quantum computers are to be made using superconducting technology .
Quantum computers can perform certain calculations much more quickly than classical computers by storing and processing information using quantum bits ( qubits ) .
Superconducting circuits are among the @ @ @ @ @ @ @ , generating superpositions of 0s and 1s from the ground and first excited states of an anharmonic oscillator formed from the combination of Josephson junctions and a capacitor .
Although they need to be cooled down to very low temperatures , such qubits are solid state and therefore hold the promise of being relatively easy to manufacture and integrate .
Indeed , last year John Martinis and colleagues at Google used a processor comprising 53 superconducting qubits to execute a very specific algorithm more than a billion times faster than they say would @ @ @ @ @ @ @ ’ s leading conventional supercomputers – although this billion-fold advantage has since been disputed .
Superconducting qubits can currently retain their delicate quantum states – their “ coherence ” – for more than 100 µs .
While this much better than the nanoseconds of two decades ago , coherence times will need to increase by several orders of magnitude before the qubits can be used in general-purpose fault-tolerant computers .
These devices would rely on error correction and can only work efficiently if the error rates on individual qubits and gates are already @ @ @ @ @ @ @ minimum coherence time .
Coherence is impeded by a wide range of noise sources .
On the timescale of tens or hundreds of microseconds , material defects , magnetic moments and trapped charges , among others , tend to cause the biggest headaches .
However , pushing coherence times up to and beyond a millisecond will require overcoming the problem of ionizing radiation .
Beta particles , gamma rays and cosmic rays create electron-hole pairs within devices , which lead to cascades of energy and the breakup of the Cooper pairs responsible for @ @ @ @ @ @ @ Earlier this year , physicists in Germany and Italy reported that environmental radioactivity can impair the performance of superconducting resonators .
The group , headed by Laura Cardani of the National Institute of Nuclear Physics in Rome and Ioan Pop of the Karlsruhe Institute of Technology , showed that cosmic rays and radioactive impurities can significantly increase the density of broken Cooper pairs , known as quasiparticles , within devices above ground .
Conversely , by using a radio-pure set-up within Italy ’ s Gran Sasso laboratory – located under 1400 m of @ @ @ @ @ @ @ the incidence of what are known as quasiparticle bursts by up to a factor of 50 .
Now , William Oliver and colleagues at at the Massachusetts Institute of Technology ( MIT ) and the Pacific Northwest National Laboratory have taken this research a step forward by measuring and modelling the effect of ionizing radiation on superconducting qubits themselves .
As they report in Nature , they did so using qubits made from aluminium mounted on a silicon substrate .
The team began by exposing two such qubits to a known source of @ @ @ @ @ @ @ copper-64 – and measured the rate at which qubits ’ decohere repeatedly over the course of several days ( the copper having a half-life of just over 12 h ) .
The idea was to establish how readily quasiparticles are generated in the qubits for a given flux of radiation .
The researchers then combined this information with measurements of the radiation present in the MIT lab , both from cosmic rays and naturally occurring radioactive isotopes – in the latter case , mainly from the lab ’ s concrete walls .
They @ @ @ @ @ @ @ radiation on the qubits would impose an upper limit to their coherence time of about 3-4 ms. To check this result with an independent experiment and establish how well such qubits might be shielded from ionizing radiation , the team surrounded seven such qubits ( or rather the cryostat used to keep them cool ) with 10 cm-thick lead bricks .
This is the kind of shielding often used in neutrino and dark-matter experiments .
By placing the shield on a scissor lift and periodically raising and lowering it , they were able @ @ @ @ @ @ @ radiation thereby confirming the coherence limit of about 4 ms .
They also found that the shield increased the coherence time by around 20 % .
Given the existence of stronger sources of decoherence , Oliver and colleagues say that this shielding only raised the qubits ’ overall coherence time by about 0.2 % .
But they have no doubt that such noise-reduction measures will be needed if quantum computing is really to take off .
“ Reducing or mitigating the impact of ionizing radiation will be critical for realizing fault-tolerant superconducting quantum @ @ @ @ @ @ @ option , at least in the medium-term , would be operate devices underground .
Oliver says that this would be a “ good direction to go for verification and research ” .
But he argues that for practical applications it would be better to design qubits that are less susceptible to quasiparticles .
“ That would allow us to keep superconducting quantum computers above ground , ” he says .

Deep qubits: practical quantum computers based on superconducting technologies may have to be located underground to protect against decoherence by ionizing radiation. (Courtesy: iStock/Devrimb)
Such is their sensitivity to environmental noise, quantum computers might in future be shielded by thick layers of lead and even operated deep underground. So say physicists in the US, who have found that ionizing radiation significantly limits the coherence time of superconducting qubits. Indeed, they say that minimizing radiation effects will be crucial if general-purpose quantum computers are to be made using superconducting technology.
Quantum computers can perform certain calculations much more quickly than classical computers by storing and processing information using quantum bits (qubits). Superconducting circuits are among the leading types of qubit currently under development, generating superpositions of 0s and 1s from the ground and first excited states of an anharmonic oscillator formed from the combination of Josephson junctions and a capacitor. Although they need to be cooled down to very low temperatures, such qubits are solid state and therefore hold the promise of being relatively easy to manufacture and integrate.
Indeed, last year John Martinis and colleagues at Google used a processor comprising 53 superconducting qubits to execute a very specific algorithm more than a billion times faster than they say would be possible using one of the world’s leading conventional supercomputers – although this billion-fold advantage has since been disputed.
Minimum coherence time
Superconducting qubits can currently retain their delicate quantum states – their “coherence” – for more than 100 µs. While this much better than the nanoseconds of two decades ago, coherence times will need to increase by several orders of magnitude before the qubits can be used in general-purpose fault-tolerant computers. These devices would rely on error correction and can only work efficiently if the error rates on individual qubits and gates are already below a certain threshold – implying a minimum coherence time.
Coherence is impeded by a wide range of noise sources. On the timescale of tens or hundreds of microseconds, material defects, magnetic moments and trapped charges, among others, tend to cause the biggest headaches. However, pushing coherence times up to and beyond a millisecond will require overcoming the problem of ionizing radiation. Beta particles, gamma rays and cosmic rays create electron-hole pairs within devices, which lead to cascades of energy and the breakup of the Cooper pairs responsible for the frictionless current in a superconductor.
Earlier this year, physicists in Germany and Italy reported that environmental radioactivity can impair the performance of superconducting resonators. The group, headed by Laura Cardani of the National Institute of Nuclear Physics in Rome and Ioan Pop of the Karlsruhe Institute of Technology, showed that cosmic rays and radioactive impurities can significantly increase the density of broken Cooper pairs, known as quasiparticles, within devices above ground. Conversely, by using a radio-pure set-up within Italy’s Gran Sasso laboratory – located under 1400 m of rock – it was able to reduce the incidence of what are known as quasiparticle bursts by up to a factor of 50.
Ionizing effects
Now, William Oliver and colleagues at at the Massachusetts Institute of Technology (MIT) and the Pacific Northwest National Laboratory have taken this research a step forward by measuring and modelling the effect of ionizing radiation on superconducting qubits themselves. As they report in Nature, they did so using qubits made from aluminium mounted on a silicon substrate.
The team began by exposing two such qubits to a known source of ionizing radiation – a thin disc of copper-64 – and measured the rate at which qubits’ decohere repeatedly over the course of several days (the copper having a half-life of just over 12 h). The idea was to establish how readily quasiparticles are generated in the qubits for a given flux of radiation.
The researchers then combined this information with measurements of the radiation present in the MIT lab, both from cosmic rays and naturally occurring radioactive isotopes – in the latter case, mainly from the lab’s concrete walls. They calculate that the decohering effects of this radiation on the qubits would impose an upper limit to their coherence time of about 3-4 ms.
Lead bricks for shielding
To check this result with an independent experiment and establish how well such qubits might be shielded from ionizing radiation, the team surrounded seven such qubits (or rather the cryostat used to keep them cool) with 10 cm-thick lead bricks. This is the kind of shielding often used in neutrino and dark-matter experiments. By placing the shield on a scissor lift and periodically raising and lowering it, they were able to establish the effect of the external radiation thereby confirming the coherence limit of about 4 ms. They also found that the shield increased the coherence time by around 20%.
Given the existence of stronger sources of decoherence, Oliver and colleagues say that this shielding only raised the qubits’ overall coherence time by about 0.2%. But they have no doubt that such noise-reduction measures will be needed if quantum computing is really to take off. “Reducing or mitigating the impact of ionizing radiation will be critical for realizing fault-tolerant superconducting quantum computers,” they write.
One option, at least in the medium-term, would be operate devices underground. Oliver says that this would be a “good direction to go for verification and research”. But he argues that for practical applications it would be better to design qubits that are less susceptible to quasiparticles. “That would allow us to keep superconducting quantum computers above ground,” he says.


physicsworld--2020-08-31--‘Proxima’ review: bonds beyond the bounds of Earth - Physics World

The bond between parent and child is undoubtedly a strong one , no matter the complexities involved .
Proxima , the latest film by French screenwriter and director Alice Winocour , follows the final weeks on Earth for Sarah ( Eva Green ) , an astronaut preparing for a 12-month stay on the International Space Station .
Stunningly shot in part on location in Star City – the cosmonaut training centre in Russia – and in collaboration with the European Space Agency ( ESA ) , the story transpires to be far more firmly rooted on Earth than it is @ @ @ @ @ @ @ strains , stresses and successes of the relationship between Sarah and her daughter Stella , as she prepares to leave for her long and dangerous journey .
This is a film about a mother who is an astronaut , and an astronaut who is a mother .
Green ’ s performance is exceptional , as her character treads the difficult line so many people must between being a good parent , while also excelling in their career .
It would be only fair to compare and contrast Proxima with two recent blockbuster sci-fi @ @ @ @ @ @ @ Interstellar ( 2014 ) and Ad Astra ( 2019 ) , which have a father–daughter and father–son bond respectively , as a key plot point .
But both those films ’ stories are juxtaposed against much larger , complex plots that philosophize about other “ big questions ” in the universe .
Proxima , on the other hand , is a fictional story set in a scientific field – and so in a sense could be thought of as science fiction – but focuses mainly on Sarah ’ s struggle to get through @ @ @ @ @ @ @ best astronaut she can , while also trying to support her daughter and maintain their very close relationship .
There are no warp drives or time travel to worry about , but for a space nerd like me , there is a real joy to be had from watching the scenes shot on location in iconic and historic locations such as the Baikonur Cosmodrome .
The direction and cinematography in Proxima provide a beautiful aesthetic that is worth catching on the big screen , if you can find one showing it and feel @ @ @ @ @ @ @ .
Another key theme in the film is that of separation .
Sarah is separated from Thomas , the father of her child , who is himself an ESA astrophysicist , played impeccably by Lars Eidinger .
As Sarah leaves for her training , Stella goes to live with her father , moving countries , joining a new school and most of all , missing her mother .
It is clear from early in the film that Thomas is an inattentive father , and Sarah has misgivings about leaving Stella with him .
@ @ @ @ @ @ @ her attempts to keep her strong connection with her daughter as she prepares to leave the planet , are at the heart of the film .
Proxima is indisputably a feminist film .
We are left with no doubt that life as an astronaut is made harder for a woman than it is for a man , especially if the woman is a parent .
Sarah must make decisions about whether to continue with her menstruation in space – the scene was reminiscent of the real-world story of NASA asking astronaut Sally Ride @ @ @ @ @ @ @ , whether 100 tampons would suffice for a week in space – and often has to grapple with equipment and space suits that are primarily designed for men .
If that were not bad enough , she is faced with boorish misogyny all too often , not least at the hands of mission commander , Mike Shannon , perfectly portrayed by Matt Dillon .
On first viewing , I was left with some misgivings about what exactly the film was trying to say , especially the finale .
It ’ s difficult to @ @ @ @ @ @ @ territory ( if that does not worry you , see the final question in my conversation with Winocour below ) but suffice to say that I watched Proxima with two other feminists , both of whom were frustrated by the difficult choices Sarah was forced to make throughout the film , and the lack of support she receives .
This film does not champion the ability to be a mother and an astronaut with ease .
Instead it realistically depicts the many hurdles along the way .
Indeed , Proxima portrays the struggles @ @ @ @ @ @ @ to excel , while battling with the pressures of a broken family and the rigours of preparing to go into space .
At the time of filming , the realities of a quarantine ( which all astronauts must go into before a mission , to avoid taking germs to the ISS ) were alien to most .
Since then , much of the global population has experienced some sort of lockdown .
Knowing what we now do , I wonder how many of us would be happy to quit the planet and spend @ @ @ @ @ @ @ others in space .
Leaving our family and loved ones behind is surely one of the most difficult things to imagine .
Proxima puts that idea centre stage and the result is a fascinating film that left me pondering our lives on Earth , more than our place in the universe .
It also left me with many questions , some of which I put to director and co-writer Winocour .
Be warned : there are spoilers in my final question .
What is the film about for you ?
I don ’ @ @ @ @ @ @ @ a message – but for me Proxima is about the relationship between a mother and daughter , and the idea of separation .
Because this mother is also an astronaut , she has to separate from her daughter and she also has to separate from the Earth .
To me there was a poetic parallel between those two things .
When you were initially writing the script , did you come at it more from the astronaut angle , or from the point of view of a mother ?
You never really know @ @ @ @ @ @ @ for me , the more I have to talk about something intimate , the more it has to be in another world .
In film , particularly in French cinema , people tend to tell autobiographical stories but I find I have to project myself into a distant , unknown world that I want to discover .
My first film was set in a psychiatric hospital in the 19th century , and my second was about soldiers returning from Afghanistan – so it can be very different types of things .
I am @ @ @ @ @ @ @ t know why .
When it comes to Proxima , I ’ ve always had a poetic fascination with space , but I didn ’ t know anything about that world .
So I decided to go to ESA and meet some people .
I told them we could do a film about a female astronaut , which was the first core idea to emerge .
Then I realized that the thing I wanted to talk about was this complex relationship between a mother and a daughter .
You never see superheroines in @ @ @ @ @ @ @ life , all the astronauts I ’ ve met do have children .
I wanted to change the perspective and to tell the story from this point of view .
There ’ s a realism to the film , as much of it was filmed on location in Star City and Baikonur .
Was that something of a coup ?
I really wanted to have an emotional story and a cinematic story .
I was not obsessed with the realistic look of things , but I wanted to film in those places , @ @ @ @ @ @ @ popular films had been shot there , yet when I went to Kazakhstan it was the place from which all passenger rockets leave the Earth .
Now there is SpaceX flying from the US , but at that time it was only Baikonur .
That made it a very emotional place and to shoot there was inspiring for the actors too .
There was something exhilarating about the whole adventure of making the movie .
We were like the astronauts , working with people from different countries .
We had a German crew @ @ @ @ @ @ @ crew and the Kazak crew .
I was really thankful to have ESA support .
I told them “ There are so many movies that show the work of NASA .
We need one to show your work , and that of the Russians .
When people think about space , thanks to movies , they only think of America .
In reality , there are all these other space agencies.
” Who did you work with at ESA ?
Everyone from the director of communications , to astronauts Samantha Cristoforetti and Thomas @ @ @ @ @ @ @ I met Tim Peake , who was training in Poland , several times .
I spent two years travelling between Star City , Cologne and Kazakhstan when I was writing the script .
Green and I met a lot of astronauts together , including Claudie Haigneré who was a kind of godmother for the film , as well as Canadian astronauts like Julie Payette – all those pictures of women you see at the end of the film .
Green was trained by the Russian trainers and they were very hard on her @ @ @ @ @ @ @ misogynistic way in which the mission commander Mike treats Sarah .
I ’ d like to think that that sort of behaviour would be beneath an astronaut in this day and age ?
I ’ m sorry to say that it is worse than you see in the film .
As women we are used to that kind of macho way of behaving .
Female astronauts experience the same , and there ’ s a kind of self-censorship that these women have to perform , in order to succeed in their careers .
@ @ @ @ @ @ @ the world , are women .
Most women don ’ t dare to dream that they could do that job or they think that , if they want children , they have to choose between the two .
Proxima shows how hard it is for women .
You have to do the same tasks as men , and then more beyond , to prove that you are capable and that you are credible .
But these women show they can do it .
Ultimately , for me , it is a story of @ @ @ @ @ @ @ , but when Sarah breaks out of the quarantine facility the night before they are meant to take off , to keep a promise to Stella , it is really shocking .
What was your thinking behind writing that ending ?
Quarantine for astronauts is not like a prison .
It ’ s more like something to keep journalists away .
To escape is…well , it ’ s very hard to not want to see your family .
While the scenes in the film were something I dreamt up , one of the @ @ @ @ @ @ @ the first mother in space , told me that she had escaped quarantine from Houston to go trick or treating at Halloween with her daughter .
She wanted to spend more time with her .
Another astronaut who left quarantine was Jean-François Clervoy , who went to see his son who was very ill at that time with cancer – Clervoy didn ’ t know if he would see him when he came back .
There is a risk of not coming back from a mission .
The day of launch is really @ @ @ @ @ @ @

Physics World. Members of the Institute of Physics can enjoy the full issue Taken from the September 2020 issue of. Members of the Institute of Physics can enjoy the full issue via the Physics World app
Andrew Glester reviews the film Proxima and interviews its writer-director Alice Winocour
Separation anxiety In new film Proxima Eva Green plays an astronaut who is worried about leaving Earth and her daughter. (Courtesy: Picturehouse Entertainment)
The bond between parent and child is undoubtedly a strong one, no matter the complexities involved. Proxima, the latest film by French screenwriter and director Alice Winocour, follows the final weeks on Earth for Sarah (Eva Green), an astronaut preparing for a 12-month stay on the International Space Station. Stunningly shot in part on location in Star City – the cosmonaut training centre in Russia – and in collaboration with the European Space Agency (ESA), the story transpires to be far more firmly rooted on Earth than it is about space.
Proxima explores the various strains, stresses and successes of the relationship between Sarah and her daughter Stella, as she prepares to leave for her long and dangerous journey. This is a film about a mother who is an astronaut, and an astronaut who is a mother. Green’s performance is exceptional, as her character treads the difficult line so many people must between being a good parent, while also excelling in their career.
It would be only fair to compare and contrast Proxima with two recent blockbuster sci-fi films that explore complicated parent-child relationships – Interstellar (2014) and Ad Astra (2019), which have a father–daughter and father–son bond respectively, as a key plot point. But both those films’ stories are juxtaposed against much larger, complex plots that philosophize about other “big questions” in the universe.
Proxima, on the other hand, is a fictional story set in a scientific field – and so in a sense could be thought of as science fiction – but focuses mainly on Sarah’s struggle to get through the gruelling astronaut training and be the best astronaut she can, while also trying to support her daughter and maintain their very close relationship. There are no warp drives or time travel to worry about, but for a space nerd like me, there is a real joy to be had from watching the scenes shot on location in iconic and historic locations such as the Baikonur Cosmodrome. The direction and cinematography in Proxima provide a beautiful aesthetic that is worth catching on the big screen, if you can find one showing it and feel comfortable with the COVID-19 protocols in place.
Another key theme in the film is that of separation. Sarah is separated from Thomas, the father of her child, who is himself an ESA astrophysicist, played impeccably by Lars Eidinger. As Sarah leaves for her training, Stella goes to live with her father, moving countries, joining a new school and most of all, missing her mother. It is clear from early in the film that Thomas is an inattentive father, and Sarah has misgivings about leaving Stella with him. Her struggle with this separation, and her attempts to keep her strong connection with her daughter as she prepares to leave the planet, are at the heart of the film.
Unknown worlds Screenwriter and director Alice Winocour likes to explore film settings far from her own experiences. (Courtesy: Aurélie Lamachère)
Proxima is indisputably a feminist film. We are left with no doubt that life as an astronaut is made harder for a woman than it is for a man, especially if the woman is a parent. Sarah must make decisions about whether to continue with her menstruation in space – the scene was reminiscent of the real-world story of NASA asking astronaut Sally Ride, the first US woman in space, whether 100 tampons would suffice for a week in space – and often has to grapple with equipment and space suits that are primarily designed for men. If that were not bad enough, she is faced with boorish misogyny all too often, not least at the hands of mission commander, Mike Shannon, perfectly portrayed by Matt Dillon.
On first viewing, I was left with some misgivings about what exactly the film was trying to say, especially the finale. It’s difficult to discuss it without straying far into spoiler territory (if that does not worry you, see the final question in my conversation with Winocour below) but suffice to say that I watched Proxima with two other feminists, both of whom were frustrated by the difficult choices Sarah was forced to make throughout the film, and the lack of support she receives. This film does not champion the ability to be a mother and an astronaut with ease. Instead it realistically depicts the many hurdles along the way. Indeed, Proxima portrays the struggles of a highly skilled woman, trying to excel, while battling with the pressures of a broken family and the rigours of preparing to go into space.
At the time of filming, the realities of a quarantine (which all astronauts must go into before a mission, to avoid taking germs to the ISS) were alien to most. Since then, much of the global population has experienced some sort of lockdown. Knowing what we now do, I wonder how many of us would be happy to quit the planet and spend a year with just a handful of others in space. Leaving our family and loved ones behind is surely one of the most difficult things to imagine. Proxima puts that idea centre stage and the result is a fascinating film that left me pondering our lives on Earth, more than our place in the universe.
It also left me with many questions, some of which I put to director and co-writer Winocour. Be warned: there are spoilers in my final question.
What is the film about for you?
I don’t think all films need to have a message – but for me Proxima is about the relationship between a mother and daughter, and the idea of separation. Because this mother is also an astronaut, she has to separate from her daughter and she also has to separate from the Earth. To me there was a poetic parallel between those two things.
When you were initially writing the script, did you come at it more from the astronaut angle, or from the point of view of a mother?
You never really know in the process of writing, but for me, the more I have to talk about something intimate, the more it has to be in another world. In film, particularly in French cinema, people tend to tell autobiographical stories but I find I have to project myself into a distant, unknown world that I want to discover. My first film was set in a psychiatric hospital in the 19th century, and my second was about soldiers returning from Afghanistan – so it can be very different types of things. I am drawn to that. I don’t know why.
When it comes to Proxima, I’ve always had a poetic fascination with space, but I didn’t know anything about that world. So I decided to go to ESA and meet some people. I told them we could do a film about a female astronaut, which was the first core idea to emerge. Then I realized that the thing I wanted to talk about was this complex relationship between a mother and a daughter. You never see superheroines in films with children, but in real life, all the astronauts I’ve met do have children. I wanted to change the perspective and to tell the story from this point of view.
There’s a realism to the film, as much of it was filmed on location in Star City and Baikonur. Was that something of a coup?
I really wanted to have an emotional story and a cinematic story. I was not obsessed with the realistic look of things, but I wanted to film in those places, which are kind of unknown. No popular films had been shot there, yet when I went to Kazakhstan it was the place from which all passenger rockets leave the Earth. Now there is SpaceX flying from the US, but at that time it was only Baikonur. That made it a very emotional place and to shoot there was inspiring for the actors too.
There was something exhilarating about the whole adventure of making the movie. We were like the astronauts, working with people from different countries. We had a German crew, a Russian crew, a French crew and the Kazak crew. I was really thankful to have ESA support. I told them “There are so many movies that show the work of NASA. We need one to show your work, and that of the Russians. When people think about space, thanks to movies, they only think of America. In reality, there are all these other space agencies.”
Who did you work with at ESA?
Everyone from the director of communications, to astronauts Samantha Cristoforetti and Thomas Pesquet – who trained Eva Green. I met Tim Peake, who was training in Poland, several times. I spent two years travelling between Star City, Cologne and Kazakhstan when I was writing the script.
Green and I met a lot of astronauts together, including Claudie Haigneré who was a kind of godmother for the film, as well as Canadian astronauts like Julie Payette – all those pictures of women you see at the end of the film. Green was trained by the Russian trainers and they were very hard on her.
Something that surprised me was the misogynistic way in which the mission commander Mike treats Sarah. I’d like to think that that sort of behaviour would be beneath an astronaut in this day and age?
I’m sorry to say that it is worse than you see in the film. As women we are used to that kind of macho way of behaving. Female astronauts experience the same, and there’s a kind of self-censorship that these women have to perform, in order to succeed in their careers. Only 10% of astronauts, in the world, are women. Most women don’t dare to dream that they could do that job or they think that, if they want children, they have to choose between the two.
Proxima shows how hard it is for women. You have to do the same tasks as men, and then more beyond, to prove that you are capable and that you are credible. But these women show they can do it. Ultimately, for me, it is a story of liberation.
This is a major spoiler, but when Sarah breaks out of the quarantine facility the night before they are meant to take off, to keep a promise to Stella, it is really shocking. What was your thinking behind writing that ending?
Quarantine for astronauts is not like a prison. It’s more like something to keep journalists away. To escape is…well, it’s very hard to not want to see your family. While the scenes in the film were something I dreamt up, one of the astronauts I met, Analie Fischer, the first mother in space, told me that she had escaped quarantine from Houston to go trick or treating at Halloween with her daughter. She wanted to spend more time with her. Another astronaut who left quarantine was Jean-François Clervoy, who went to see his son who was very ill at that time with cancer – Clervoy didn’t know if he would see him when he came back. There is a risk of not coming back from a mission. The day of launch is really scary, even for experienced astronauts.
2020 Dharamsala/ Darius Films 107 min


physicsworld--2020-09-01--Why bubbles burst in viscous liquids - Physics World

What causes a bubble to burst ?
For bubbles on the surface of viscous liquids such as paint or lava , the finger of blame has long pointed to gravity .
Now , however , researchers led by James Bird at Boston University in the US have turned this idea literally on its head , using an upside-down bubble-testing rig to show that surface tension , not gravity , is at fault .
Their result has implications for industrial processes such as glass manufacturing and spray painting and could even shed light on the break-up of respiratory aerosols – a @ @ @ @ @ @ @ due to the COVID-19 pandemic .
When a bubble rises to the surface of a liquid , it typically forms a thin , liquid , dome-shaped film supported by the gas trapped inside it .
Once this film develops a hole , surface tension causes the film to retract further , and the bubble bursts .
In runny , low-viscosity liquids , the bursting process is over in a matter of milliseconds .
In thicker , viscous fluid , it takes longer , yet the film collapses when the hole is barely open @ @ @ @ @ @ @ as the hole forms , trapped gas can escape from the bubble .
Without the support of this gas , the forces on the liquid film become unbalanced , causing the bubble to collapse and radial wrinkles to form around the bubble ’ s edge – rather like what happens in an elastic sheet , or a parachute .
Until now , scientists thought that the weight of the thin liquid film was responsible both for the bubble ’ s collapse and for the formation of the radial wrinkles – suggesting that gravity @ @ @ @ @ @ @ bursting .
Bird and colleagues set out to test this hypothesis by injecting an air bubble into a viscous silicone oil and filming the bubble ’ s collapse with a high-speed camera .
Their first experiments were aimed at replicating how viscous bubble collapse had been studied in the past .
Once they accomplished that , however , they did something different : they changed the orientation of the bubble relative to gravity .
This , Bird says , was possible because of the extreme viscosity of their test liquid .
“ We @ @ @ @ @ @ @ bubble in an upright position and then rapidly turning it upside down , quickly puncturing it before it could significantly readjust its shape , ” he explains .
In these upside-down experiments , the researchers varied the thickness of the films and the viscosity of the fluid , while also providing a way for the air inside a bubble to escape without rupturing the film .
Their results showed that gravity plays only a negligible role in bubble collapse .
Instead , it is surface tension and the dynamic stress of the liquid @ @ @ @ @ @ @ main drivers of viscous bubble behaviour – including the formation of unstable wrinkles .
This finding is exciting , Bird says , because it shows that such forces also play a role in situations where they might otherwise be overlooked – for example , at especially small scales and for multiple orientations of bubbles .
It is also important because it resolves a longstanding paradox : while surface tension normally smooths out wrinkles , in this case it also initiates them .
“ It is through a delicate interplay of capillary , viscous @ @ @ @ @ @ @ ” he tells Physics World .
“ Indeed , it took us a day to show that surface tension was responsible for the wrinkles and over a decade to adequately explain why.
” Bird and colleagues say that the results of their study have implications wherever curved viscous films are prevalent – either because the surrounding liquid is highly viscous ( as is the case for bubbles in molten glass or lava ) or because the bubble is small ( such as in bubbles that form on coated films ) .
Since the @ @ @ @ @ @ @ trap air , the transport of heat and mass at a liquid interface will be affected , too .
The retraction and collapse dynamics the researchers uncovered will also influence any breakup or aerosolization of the thin film .
“ A timely example of where our study could be applicable involves the mechanism by which respiratory aerosols form when we breathe and speak , ” says Bird .
“ These aerosols are believed to develop when thin , curved films repeatedly develop across small airways in the lungs and then rupture .
Since @ @ @ @ @ @ @ for the collapse and viscous buckling instability , it is possible that it is also relevant in these films.
” The team , which includes researchers in applied mathematics at the Massachusetts Institute of Technology and the Department of Mechanical and Aerospace Engineering at Princeton University , has developed a theoretical model to explain their observations .
They now hope to extend it to more complex liquids , such as viscoelastic fluids that have both liquid and solid-like behaviours .
“ For example , in respiratory tract fluids , elastic and dynamic surface @ @ @ @ @ @ @ the phenomenon in interesting and unexpected ways , ” says study lead author Alexandros Oratis .
The researchers also intend to explore the precise ways that a film ’ s thickness profile develops , and how this affects ( and is affected by ) the bubble collapse .
They detail their work in Science .

A viscous bubble film with sufficiently large viscosity will collapse under the force of surface tension. Credit: Oliver McRae
What causes a bubble to burst? For bubbles on the surface of viscous liquids such as paint or lava, the finger of blame has long pointed to gravity. Now, however, researchers led by James Bird at Boston University in the US have turned this idea literally on its head, using an upside-down bubble-testing rig to show that surface tension, not gravity, is at fault. Their result has implications for industrial processes such as glass manufacturing and spray painting and could even shed light on the break-up of respiratory aerosols – a phenomenon that has taken on extra significance due to the COVID-19 pandemic.
When a bubble rises to the surface of a liquid, it typically forms a thin, liquid, dome-shaped film supported by the gas trapped inside it. Once this film develops a hole, surface tension causes the film to retract further, and the bubble bursts.
In runny, low-viscosity liquids, the bursting process is over in a matter of milliseconds. In thicker, viscous fluid, it takes longer, yet the film collapses when the hole is barely open. The reason is that as soon as the hole forms, trapped gas can escape from the bubble. Without the support of this gas, the forces on the liquid film become unbalanced, causing the bubble to collapse and radial wrinkles to form around the bubble’s edge – rather like what happens in an elastic sheet, or a parachute.
Exploiting super-slow flow
Until now, scientists thought that the weight of the thin liquid film was responsible both for the bubble’s collapse and for the formation of the radial wrinkles – suggesting that gravity was the main factor behind viscous bubble bursting.
Bird and colleagues set out to test this hypothesis by injecting an air bubble into a viscous silicone oil and filming the bubble’s collapse with a high-speed camera. Their first experiments were aimed at replicating how viscous bubble collapse had been studied in the past. Once they accomplished that, however, they did something different: they changed the orientation of the bubble relative to gravity. This, Bird says, was possible because of the extreme viscosity of their test liquid. “We exploited this super-slow flow by preparing the bubble in an upright position and then rapidly turning it upside down, quickly puncturing it before it could significantly readjust its shape,” he explains.
In these upside-down experiments, the researchers varied the thickness of the films and the viscosity of the fluid, while also providing a way for the air inside a bubble to escape without rupturing the film. Their results showed that gravity plays only a negligible role in bubble collapse. Instead, it is surface tension and the dynamic stress of the liquid that forms the bubble that are the main drivers of viscous bubble behaviour – including the formation of unstable wrinkles.
A delicate interplay of forces
This finding is exciting, Bird says, because it shows that such forces also play a role in situations where they might otherwise be overlooked – for example, at especially small scales and for multiple orientations of bubbles. It is also important because it resolves a longstanding paradox: while surface tension normally smooths out wrinkles, in this case it also initiates them.
“It is through a delicate interplay of capillary, viscous and inertial forces that wrinkles develop,” he tells Physics World. “Indeed, it took us a day to show that surface tension was responsible for the wrinkles and over a decade to adequately explain why.”
A timely result
Bird and colleagues say that the results of their study have implications wherever curved viscous films are prevalent – either because the surrounding liquid is highly viscous (as is the case for bubbles in molten glass or lava) or because the bubble is small (such as in bubbles that form on coated films). Since the wrinkling and folding of liquid films can trap air, the transport of heat and mass at a liquid interface will be affected, too.
The retraction and collapse dynamics the researchers uncovered will also influence any breakup or aerosolization of the thin film. “A timely example of where our study could be applicable involves the mechanism by which respiratory aerosols form when we breathe and speak,” says Bird. “These aerosols are believed to develop when thin, curved films repeatedly develop across small airways in the lungs and then rupture. Since surface tension rather than gravity is important for the collapse and viscous buckling instability, it is possible that it is also relevant in these films.”
The team, which includes researchers in applied mathematics at the Massachusetts Institute of Technology and the Department of Mechanical and Aerospace Engineering at Princeton University, has developed a theoretical model to explain their observations. They now hope to extend it to more complex liquids, such as viscoelastic fluids that have both liquid and solid-like behaviours. “For example, in respiratory tract fluids, elastic and dynamic surface tension are present and these might modify the phenomenon in interesting and unexpected ways,” says study lead author Alexandros Oratis.
The researchers also intend to explore the precise ways that a film’s thickness profile develops, and how this affects (and is affected by) the bubble collapse. They detail their work in Science.


physicsworld--2020-09-01--Doomsday Clock, COVID-19 and modelling in medicine: the September 2020 issue of Physics World is now

Doomsday Clock, COVID-19 and modelling in medicine: the September 2020 issue of Physics World is now out - Physics World

Life has been turned upside-down since COVID-19 gripped the world earlier this year .
I wonder , though , what members of the Bulletin of the Atomic Scientists will make of the pandemic .
Every year they meet to decide the time on the Doomsday Clock – a notional device created by physicists shortly after the Second World War to surmise how close the world is to destruction .
In January the clock was set at 100 seconds to midnight – the furthest forward it ’ s ever been .
In the new issue of Physics World magazine , Rachel @ @ @ @ @ @ @ , which these days is no longer based solely on the risk from nuclear conflict , but also takes into account climate change , cyber security and biosecurity risks – including pandemics .
My bet is on Bulletin staff edging the clock even further towards midnight Elsewhere in the new issue , Sam Vennin shows how scientific modelling is increasingly critical to many aspects of medicine , including the spread of viruses , while Kate Ravilious finds out how lockdown and travel restrictions have led to air pollution plummeting , giving atmospheric scientists @ @ @ @ @ @ @ its impact on the weather and climate .
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 rundown of what else is in the issue .
• Tunnelling measured with ultracold atoms – Researchers have determined the @ @ @ @ @ @ @ through a laser beam , which could have implications for quantum technologies , as Philip Ball reports • Trio of probes launch to Mars – China , the UAE and the US have sent craft to Mars to study the planet in greater detail , with NASA set to conduct the first controlled flight on another planet , as Ling Xin , Michael Banks and Liz Kruesi report • A quantum revolution – Chaoyang Lu from the University of Science and Technology of China in Hefei talks to Michael Banks about planning Quantum @ @ @ @ @ @ @ and the future of quantum technologies • Hacking a path to innovation – Bonnie Tsim says “ hackathons ” are a great way for scientists to apply their skills to the commercial world • First-hand insights – With so much spin , jargon and fake news , it can be hard to know what businesses are really up to .
James McKenzie finds that hearing a company ’ s vision first hand is key to understanding its potential • It ’ s a material world – From wine and skis to clocks and @ @ @ @ @ @ @ passion for everyday materials , as he tells Robert P Crease • 100 seconds to midnight – For almost 75 years , the Doomsday Clock has monitored how close humankind is to global catastrophe .
With the clock now closer to midnight than ever before , Rachel Brazil talks to physicists who say we must step up our efforts to prevent disaster • Has the COVID-19 lockdown changed Earth ’ s climate ?
– The lockdown measures imposed by many nations due to the COVID-19 pandemic have led to air pollution falling dramatically @ @ @ @ @ @ @ to study its links with climate and weather .
But as Kate Ravillious discovers , it ’ s a complicated connection • How modelling is transforming medicine – Computational modelling has been brought under the spotlight during the COVID-19 pandemic , with scientists trying to predict how the SARS-CoV-2 virus will spread .
But epidemiology is not the only medical field in which modelling is sparking breakthroughs , as Sam Vennin explains • Build a bot – Ian Randall reviews How to Grow a Robot : Developing Human-Friendly , Social AI by Mark @ @ @ @ @ @ @ – Andrew Glester reviews the film Proxima directed by Alice Winocour • Closing the skills gap – Why do many science graduates lack the skills that industry is looking for ?
Sean Ryan and Veronica Benson of the South-East Physics Network explore the problem and discover that there is one straightforward way for universities and businesses to address this • Ask me anything – Nanophysicist Deji Akinwande from the University of Texas at Austin gives his tips for a rewarding career in physics • Lattice layabout in the park – Hamish Johnston muses @ @ @ @ @ @ @

The September 2020 issue of Physics World has a COVID-19 and Doomsday theme running through it
Time is ticking: why the Doomsday Clock is further forward than it’s ever been.
Life has been turned upside-down since COVID-19 gripped the world earlier this year. I wonder, though, what members of the Bulletin of the Atomic Scientists will make of the pandemic.
Every year they meet to decide the time on the Doomsday Clock – a notional device created by physicists shortly after the Second World War to surmise how close the world is to destruction. In January the clock was set at 100 seconds to midnight – the furthest forward it’s ever been.
In the new issue of Physics World magazine, Rachel Brazil describes how the clock gets set, which these days is no longer based solely on the risk from nuclear conflict, but also takes into account climate change, cyber security and biosecurity risks – including pandemics. My bet is on Bulletin staff edging the clock even further towards midnight
Elsewhere in the new issue, Sam Vennin shows how scientific modelling is increasingly critical to many aspects of medicine, including the spread of viruses, while Kate Ravilious finds out how lockdown and travel restrictions have led to air pollution plummeting, giving atmospheric scientists a unique and unexpected opportunity to study its impact on the weather and climate.
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 rundown of what else is in the issue.
• Tunnelling measured with ultracold atoms – Researchers have determined the time taken for an atom to tunnel through a laser beam, which could have implications for quantum technologies, as Philip Ball reports
• Trio of probes launch to Mars – China, the UAE and the US have sent craft to Mars to study the planet in greater detail, with NASA set to conduct the first controlled flight on another planet, as Ling Xin, Michael Banks and Liz Kruesi report
• A quantum revolution – Chaoyang Lu from the University of Science and Technology of China in Hefei talks to Michael Banks about planning Quantum 2020 – a major online conference – and the future of quantum technologies
• Hacking a path to innovation – Bonnie Tsim says “hackathons” are a great way for scientists to apply their skills to the commercial world
• First-hand insights – With so much spin, jargon and fake news, it can be hard to know what businesses are really up to. James McKenzie finds that hearing a company’s vision first hand is key to understanding its potential
• It’s a material world – From wine and skis to clocks and bone implants, Linn Hobbs has a passion for everyday materials, as he tells Robert P Crease
• 100 seconds to midnight – For almost 75 years, the Doomsday Clock has monitored how close humankind is to global catastrophe. With the clock now closer to midnight than ever before, Rachel Brazil talks to physicists who say we must step up our efforts to prevent disaster
• Has the COVID-19 lockdown changed Earth’s climate? – The lockdown measures imposed by many nations due to the COVID-19 pandemic have led to air pollution falling dramatically, thereby offering scientists a rare opportunity to study its links with climate and weather. But as Kate Ravillious discovers, it’s a complicated connection
• How modelling is transforming medicine – Computational modelling has been brought under the spotlight during the COVID-19 pandemic, with scientists trying to predict how the SARS-CoV-2 virus will spread. But epidemiology is not the only medical field in which modelling is sparking breakthroughs, as Sam Vennin explains
• Build a bot – Ian Randall reviews How to Grow a Robot: Developing Human-Friendly, Social AI by Mark Lee
• Beyond the bounds of Earth – Andrew Glester reviews the film Proxima and interviews its screenwriter-director Alice Winocour
• Closing the skills gap – Why do many science graduates lack the skills that industry is looking for? Sean Ryan and Veronica Benson of the South-East Physics Network explore the problem and discover that there is one straightforward way for universities and businesses to address this
• Ask me anything – Nanophysicist Deji Akinwande from the University of Texas at Austin gives his tips for a rewarding career in physics
• Lattice layabout in the park – Hamish Johnston muses on social distancing in public spaces.


physicsworld--2020-09-01--Focused X-ray beams provide personalized treatment for common eye disease - Physics World

A technique that improves the precision of radiotherapy used to treat wet ( neovascular ) age-related macular degeneration ( AMD ) is being developed at Stanford University School of Medicine .
Principal investigator Wu Liu and a multinational team of researchers are using polycapillary X-ray optics to deliver focused kilovoltage ( kV ) radiation .
The approach , described in Medical Physics , enables personalized conformal radiotherapy and spares critical structures in the eye , with potential to make AMD treatment more effective , less costly and more convenient for patients .
AMD is the leading cause of blindness in @ @ @ @ @ @ @ .
The International Agency for the Prevention of Blindness estimates that around 196 million people throughout the world currently have AMD , with steady increases projected as the global population ages .
The American Academy of Opthalmology estimates that 10–15 % of these AMD cases are wet AMD , which is caused by choroidal neovascularization ( CNV ) , the growth of abnormal blood vessels into the macula .
The standard treatment for wet AMD involves repeated intravitreal injections with anti-vascular endothelial growth factor ( VEGF ) drugs , which helps to control @ @ @ @ @ @ @ required every 30 to 60 days , are high in cost , and risk causing retinal detachment , injury , infection , bleeding and pain .
Radiotherapy could provide an appealing alternative , destroying abnormal vessels and potentially inhibiting associated inflammation and fibrosis not addressed by VEGF inhibitors .
A recent study of radiotherapy for neovascular AMD concluded that the role of stereotactic radiotherapy combined with anti-VEGF is currently uncertain , due primarily to a lack of clinical trial evidence .
But Liu and collaborators believe that a combination of radiotherapy with anti-VEGF @ @ @ @ @ @ @ to deliver stereotactic radiotherapy are improved .
Stereotactic radiotherapy involves targeting high doses of radiation onto a small area , minimizing exposure to surrounding healthy tissues .
Two clinical trials ( one completed and one with results expected in 2021 ) have investigated the use of stereotactic radiotherapy to treat wet AMD .
The first , the randomized phase II INTREPID trial of 230 individuals dependent on anti-VEGF therapy showed that a single 16 or 24 Gy radiation dose reduced injections by 25 % , compared with patients who did not receive radiotherapy @ @ @ @ @ @ @ STAR , builds on INTREPID ’ s findings , which showed that the best response was in patients who had an AMD lesion that was actively leaking at the time of radiotherapy and was smaller than 4 mm .
The STAR trial recruited 411 such patients to receive either a single 16 Gy dose or a sham treatment , supplemented by injections as needed over 24 months .
Both of these studies used a collimation-based kV radiotherapy device that delivers fixed 4 mm beams to the centre of macula .
This can , @ @ @ @ @ @ @ of various sizes and shapes .
To enable personalized treatment , Liu and colleagues are developing a system that uses polycapillary X-ray focusing lenses capable of withstanding continuous high-intensity radiation .
The polycapillary lens consists of a large number of hollow curved and tapered glass tubes .
A converging arrangement of hundreds of thousands of these small channels can produce an X-ray beam with a focus perpendicular to the beam direction of less than 0.2 mm , enabling high-accuracy targeting .
“ This ultrasmall beam focal spot enables spatially fractionated grid therapy , @ @ @ @ @ @ @ abnormal neovascular blood vessels versus normal ones , ” write the authors .
“ The grid dose delivery has the potential to control the CNV while sparing the retina and normal capillaries from the small possibility of radiation-induced retinopathy and capillary dropout associated with conventional radiotherapy.
” The researchers performed Geant4-based Monte Carlo simulations of conformal treatments of three clinical CNV cases , using 60-kVp focused X-ray beams .
To estimate possible dosimetric uncertainties to the target and critical organs , they introduced positioning errors that modelled setup errors and patient eye motion @ @ @ @ @ @ @ modulated dose delivery to the CNV lesion plus margin to demonstrate the potential of grid therapy .
“ The simulated treatments showed highly conformal delivery of dose to the lesion plus 0.75 mm margin with sharp dose fall-offs and controllable spatial modulation patterns , ” report the researchers .
“ The 90–10 % isodose penumbra is less than 0.5 mm .
With a prescription dose of 16 Gy to the lesions , critical structure doses are well below the tolerance.
” The team also noted that the proposed technique allowed adjustment of the @ @ @ @ @ @ @ the optic disc , to balance the benefits and risks .
The average CNV dose varied by no more than 10 % .
Liu and colleagues suggest that , because of the conformal nature and grid therapy potential of the technique , it may be possible to use focused X-rays alone to treat AMD .
The technique could also be used synergistically with anti-VEGF drugs , specifically for newly diagnosed wet AMD patients .
Here , patients would receive a single focused X-ray treatment within 14 days of the first anti-VEGF injection , @ @ @ @ @ @ @ subsequent ones as clinically determined .
“ Based on the promising computer simulation results , which show significant dosimetric improvement on wet AMD treatment compared with previously investigated devices , we plan to build a prototype focused kV X-ray platform with a Monte Carlo-based treatment planning system to enable subsequent pre-clinical translational laboratory and clinical research , ” Liu tells Physics World .
“ We hope this technique can be combined synergistically with anti-VEGF drugs to improve the treatment of wet AMD and substantially reduce the frequency of anti-VEGF injections .
After successful @ @ @ @ @ @ @ hope to conduct human clinical trials in the next few years .
”

Top row: fundus photos of large (a), medium (b) and small (c) choroidal neovascularization (CNV) lesions. Bottom row: dose coverage of the large (a), medium (c) and small (d) lesions using grid delivery; the solid contour delineates the CNV. (Courtesy: Med. Phys. 10.1002/mp.14404)
A technique that improves the precision of radiotherapy used to treat wet (neovascular) age-related macular degeneration (AMD) is being developed at Stanford University School of Medicine. Principal investigator Wu Liu and a multinational team of researchers are using polycapillary X-ray optics to deliver focused kilovoltage (kV) radiation. The approach, described in Medical Physics, enables personalized conformal radiotherapy and spares critical structures in the eye, with potential to make AMD treatment more effective, less costly and more convenient for patients.
AMD is the leading cause of blindness in people aged over 50 in developed nations. The International Agency for the Prevention of Blindness estimates that around 196 million people throughout the world currently have AMD, with steady increases projected as the global population ages. The American Academy of Opthalmology estimates that 10–15% of these AMD cases are wet AMD, which is caused by choroidal neovascularization (CNV), the growth of abnormal blood vessels into the macula.
The standard treatment for wet AMD involves repeated intravitreal injections with anti-vascular endothelial growth factor (VEGF) drugs, which helps to control the disease. However, injections are required every 30 to 60 days, are high in cost, and risk causing retinal detachment, injury, infection, bleeding and pain. Radiotherapy could provide an appealing alternative, destroying abnormal vessels and potentially inhibiting associated inflammation and fibrosis not addressed by VEGF inhibitors.
Principal investigator Wu Liu.
A recent study of radiotherapy for neovascular AMD concluded that the role of stereotactic radiotherapy combined with anti-VEGF is currently uncertain, due primarily to a lack of clinical trial evidence. But Liu and collaborators believe that a combination of radiotherapy with anti-VEGF treatment may be more effective if techniques to deliver stereotactic radiotherapy are improved.
Stereotactic radiotherapy involves targeting high doses of radiation onto a small area, minimizing exposure to surrounding healthy tissues. Two clinical trials (one completed and one with results expected in 2021) have investigated the use of stereotactic radiotherapy to treat wet AMD. The first, the randomized phase II INTREPID trial of 230 individuals dependent on anti-VEGF therapy showed that a single 16 or 24 Gy radiation dose reduced injections by 25%, compared with patients who did not receive radiotherapy.
A follow-up phase III trial, STAR, builds on INTREPID’s findings, which showed that the best response was in patients who had an AMD lesion that was actively leaking at the time of radiotherapy and was smaller than 4 mm. The STAR trial recruited 411 such patients to receive either a single 16 Gy dose or a sham treatment, supplemented by injections as needed over 24 months.
Both of these studies used a collimation-based kV radiotherapy device that delivers fixed 4 mm beams to the centre of macula. This can, however, over- or under-treat CNV lesions of various sizes and shapes.
To enable personalized treatment, Liu and colleagues are developing a system that uses polycapillary X-ray focusing lenses capable of withstanding continuous high-intensity radiation. The polycapillary lens consists of a large number of hollow curved and tapered glass tubes. A converging arrangement of hundreds of thousands of these small channels can produce an X-ray beam with a focus perpendicular to the beam direction of less than 0.2 mm, enabling high-accuracy targeting.
Schematic of a single focused X-ray beam using polycapillary optics in the AMD treatment simulation (not to scale). The X-ray source is placed at the input focus of the X-ray lens, the macula at the output focus. (Courtesy: Med. Phys. 10.1002/mp.14404)
“This ultrasmall beam focal spot enables spatially fractionated grid therapy, which has been shown to preferentially damage abnormal neovascular blood vessels versus normal ones,” write the authors. “The grid dose delivery has the potential to control the CNV while sparing the retina and normal capillaries from the small possibility of radiation-induced retinopathy and capillary dropout associated with conventional radiotherapy.”
The researchers performed Geant4-based Monte Carlo simulations of conformal treatments of three clinical CNV cases, using 60-kVp focused X-ray beams. To estimate possible dosimetric uncertainties to the target and critical organs, they introduced positioning errors that modelled setup errors and patient eye motion during treatment. They also simulated spatially modulated dose delivery to the CNV lesion plus margin to demonstrate the potential of grid therapy.
“The simulated treatments showed highly conformal delivery of dose to the lesion plus 0.75 mm margin with sharp dose fall-offs and controllable spatial modulation patterns,” report the researchers. “The 90–10% isodose penumbra is less than 0.5 mm. With a prescription dose of 16 Gy to the lesions, critical structure doses are well below the tolerance.”
The team also noted that the proposed technique allowed adjustment of the dose distribution based on the distance to the optic disc, to balance the benefits and risks. The average CNV dose varied by no more than 10%.
Liu and colleagues suggest that, because of the conformal nature and grid therapy potential of the technique, it may be possible to use focused X-rays alone to treat AMD. The technique could also be used synergistically with anti-VEGF drugs, specifically for newly diagnosed wet AMD patients. Here, patients would receive a single focused X-ray treatment within 14 days of the first anti-VEGF injection, followed by two additional monthly injections and subsequent ones as clinically determined.
“Based on the promising computer simulation results, which show significant dosimetric improvement on wet AMD treatment compared with previously investigated devices, we plan to build a prototype focused kV X-ray platform with a Monte Carlo-based treatment planning system to enable subsequent pre-clinical translational laboratory and clinical research,” Liu tells Physics World. “We hope this technique can be combined synergistically with anti-VEGF drugs to improve the treatment of wet AMD and substantially reduce the frequency of anti-VEGF injections. After successful prototype development and preclinical verifications, we hope to conduct human clinical trials in the next few years.”


physicsworld--2020-09-01--Secrets of spinning ‘blue whirl’ flames revealed by fluid simulations - Physics World

“ Blue whirls ” are small , spinning flames that were first spotted in 2016 .
Now computer simulations suggest that this soot-free mode of combustion involves three different flames .
Joseph Chung , Xiao Zhang , Carolyn Kaplan and Elaine Oran at the University of Maryland came to this conclusion by accounting for the distinct rates at which different types of laminar flame release heat .
Their discovery could make it far easier for researchers to stabilize and increase the size of blue whirl flames in the lab , which could lead the way to low-emission combustion .
Blue @ @ @ @ @ @ @ at Maryland by Oran , Michael Gollner and Huahua Xiao ; who were studying the behaviours of turbulent , sooty fire whirls .
They were surprised to see these inefficient sooty flames spontaneously evolve into small , stable blue whirls .
They found that these elegant new laminar flames could burn through a wide range of liquid hydrocarbon fuels without producing any soot – presenting a previously unknown route towards highly fuel-efficient combustion .
Subsequent simulations and experiments have revealed the conditions in which blue whirls can form .
So far , however @ @ @ @ @ @ @ the flame ’ s structure and dynamics in more detail .
In their study , Chung ’ s team explored these aspects using numerical simulations .
Their calculations were based around 3D time-dependent Navier-Stokes equations , which describe the motions of viscous fluids .
The researchers adjusted model parameters including the velocities and flow rates of fuel and air , until a blue whirl formed .
The simulation suggested the presence of three types of laminar flame , each of which releases heat at a different rate .
In diffusion flames , oxygen @ @ @ @ @ @ @ and the flame itself forms where they meet .
Oxygen and fuel can also be premixed , creating a moving flame front driven by thermal expansion .
Furthermore , these premixed flames can either be “ rich ” or “ lean ” in terms of the ratio of fuel to oxygen .
Chung and colleagues found that the purple “ crown ” of a blue whirl is a diffusion flame that is shaped like a large cone with an upward-facing point ( see figure ) .
This is surrounded by a premixed lean @ @ @ @ @ @ @ rich flame is shaped like a smaller , downward-pointing cone .
A “ triple flame ” appears as a bright , whirling blue ring where the three flames meet , in which a significant proportion of the whirl ’ s combustion occurs .
The team also discovered that the transition from turbulent fire whirls to blue whirls unfolds through the process of vortex breakdown – a fluid instability that can occur in swirling flows .
Through future simulations and experiments , the researchers now hope to explore how the blue whirl can be @ @ @ @ @ @ @ directly without transitioning through the dangerous turbulent whirl state .
With this future work , sophisticated new techniques could soon emerge for achieving large-scale and highly fuel-efficient combustion in the lab .
The simulations are described in Science Advances .
• Below is a video made by Elaine Oran and colleagues in 2016 , when they first discovered blue whirl flames .

Three in one: photograph of a blue whirl flame. (Courtesy: University of Maryland)
“Blue whirls” are small, spinning flames that were first spotted in 2016. Now computer simulations suggest that this soot-free mode of combustion involves three different flames. Joseph Chung, Xiao Zhang, Carolyn Kaplan and Elaine Oran at the University of Maryland came to this conclusion by accounting for the distinct rates at which different types of laminar flame release heat. Their discovery could make it far easier for researchers to stabilize and increase the size of blue whirl flames in the lab, which could lead the way to low-emission combustion.
Blue whirls were first characterized four years ago at Maryland by Oran, Michael Gollner and Huahua Xiao; who were studying the behaviours of turbulent, sooty fire whirls. They were surprised to see these inefficient sooty flames spontaneously evolve into small, stable blue whirls. They found that these elegant new laminar flames could burn through a wide range of liquid hydrocarbon fuels without producing any soot – presenting a previously unknown route towards highly fuel-efficient combustion.
Subsequent simulations and experiments have revealed the conditions in which blue whirls can form. So far, however, researchers have been unable to determine the flame’s structure and dynamics in more detail. In their study, Chung’s team explored these aspects using numerical simulations. Their calculations were based around 3D time-dependent Navier-Stokes equations, which describe the motions of viscous fluids.
Rich or lean
The researchers adjusted model parameters including the velocities and flow rates of fuel and air, until a blue whirl formed. The simulation suggested the presence of three types of laminar flame, each of which releases heat at a different rate. In diffusion flames, oxygen and fuel diffuse into each other, and the flame itself forms where they meet. Oxygen and fuel can also be premixed, creating a moving flame front driven by thermal expansion. Furthermore, these premixed flames can either be “rich” or “lean” in terms of the ratio of fuel to oxygen.
Chung and colleagues found that the purple “crown” of a blue whirl is a diffusion flame that is shaped like a large cone with an upward-facing point (see figure). This is surrounded by a premixed lean flame; while underneath, a premixed rich flame is shaped like a smaller, downward-pointing cone. A “triple flame” appears as a bright, whirling blue ring where the three flames meet, in which a significant proportion of the whirl’s combustion occurs.
The team also discovered that the transition from turbulent fire whirls to blue whirls unfolds through the process of vortex breakdown – a fluid instability that can occur in swirling flows. Through future simulations and experiments, the researchers now hope to explore how the blue whirl can be created on larger scales, and formed directly without transitioning through the dangerous turbulent whirl state. With this future work, sophisticated new techniques could soon emerge for achieving large-scale and highly fuel-efficient combustion in the lab.
The simulations are described in Science Advances.
Below is a video made by Elaine Oran and colleagues in 2016, when they first discovered blue whirl flames.


physicsworld--2020-09-02--Adapting electrochemical sensing to population-scale monitoring of SARS-CoV-2 infection spread - Phy

Adapting electrochemical sensing to population-scale monitoring of SARS-CoV-2 infection spread - Physics World

SARS-CoV-2 has infected more than 22 million people globally , leading to ~800 thousand deaths in just 10 months .
However , significant uncertainty still remains regarding the prevalence of asymptomatic and mild cases of COVID-19 , the disease caused by SARS-CoV-2 , as well as the magnitude , effectiveness , and duration of antibody responses .
Gaining a better understanding of population immunity is critical to improving predictive models of infection spread and safely reopening economies worldwide .
However , to fill knowledge gaps in these areas requires population-scale testing using low-cost , non-invasive , and highly specific and @ @ @ @ @ @ @ and serially to characterize antibody responses to SARS-CoV-2 .
Benchmark detection approaches are based on sandwich immunoassays relying on optical readouts of fluorescence emission or colour change to report antibody levels .
These technologies can be costly , often require centralized facilities with trained personnel and are , therefore , not amenable to at-home testing .
More affordable technologies , such as lateral flow assays have been found to be inaccurate or prone to user misinterpretation .
Motivated to circumvent such barriers , the Arroyo lab has undertaken a journey to develop an @ @ @ @ @ @ @ report the results of our initial , three-month effort to produce a portable immunoassay : Netzahualcóyotl Arroyo Currás ( Netz Arroyo ) is an assistant professor in the Department of Pharmacology and Molecular Sciences at Johns Hopkins University School of Medicine .
He obtained his PhD degree in analytical chemistry from the University of Texas at Austin , where he worked with Allen J Bard on electrochemical energy storage and studies of electrocatalysis employing scanning electrochemical microscopy .
He graduated in 2015 and moved to California to complete his postdoctoral training with Kevin @ @ @ @ @ @ @ Santa Barbara , where he developed electrochemical biosensing platforms supporting real-time measurements of specific molecular targets in the body .
His current research focuses on the development of electrochemical biosensors for pharmacological applications .

Available to watch now, The Electrochemical Society in partnership with BioLogic, presents the results of our initial, three-month effort to produce a portable immunoassay
Want to learn more on this subject? Watch now
SARS-CoV-2 has infected more than 22 million people globally, leading to ~800 thousand deaths in just 10 months. However, significant uncertainty still remains regarding the prevalence of asymptomatic and mild cases of COVID-19, the disease caused by SARS-CoV-2, as well as the magnitude, effectiveness, and duration of antibody responses. Gaining a better understanding of population immunity is critical to improving predictive models of infection spread and safely reopening economies worldwide. However, to fill knowledge gaps in these areas requires population-scale testing using low-cost, non-invasive, and highly specific and sensitive assays that can be deployed broadly and serially to characterize antibody responses to SARS-CoV-2.
Benchmark detection approaches are based on sandwich immunoassays relying on optical readouts of fluorescence emission or colour change to report antibody levels. These technologies can be costly, often require centralized facilities with trained personnel and are, therefore, not amenable to at-home testing.
More affordable technologies, such as lateral flow assays have been found to be inaccurate or prone to user misinterpretation. Motivated to circumvent such barriers, the Arroyo lab has undertaken a journey to develop an at-home electrochemical assay.
This presentation will report the results of our initial, three-month effort to produce a portable immunoassay:
Learn about SARS-CoV-2 immunoassays.
Discover how electrochemists help fight COVID-19.
Learn the challenges behind developing antibody-based sensors.
Want to learn more on this subject? Watch now
Netzahualcóyotl Arroyo Currás (Netz Arroyo) is an assistant professor in the Department of Pharmacology and Molecular Sciences at Johns Hopkins University School of Medicine. He obtained his PhD degree in analytical chemistry from the University of Texas at Austin, where he worked with Allen J Bard on electrochemical energy storage and studies of electrocatalysis employing scanning electrochemical microscopy. He graduated in 2015 and moved to California to complete his postdoctoral training with Kevin W Plaxco at the University of California Santa Barbara, where he developed electrochemical biosensing platforms supporting real-time measurements of specific molecular targets in the body. His current research focuses on the development of electrochemical biosensors for pharmacological applications.