physicsworld--2020-09-30--Unprecedented ice loss is predicted for Greenland Ice Sheet - Physics World

Over the next eighty years global warming is set to melt enough ice from the Greenland Ice Sheet to reverse 4000 years of cumulative ice growth – with rates of ice-loss more than quadruple even the fastest melt rates during the past 12,000 years .
These stark conclusions come from new simulations which , for the first time , put current and projected future rates of ice-loss into context ; comparing them directly with historical rates of ice-loss .
These latest results are consistent with previous research that shows that if we continue our current high trajectory of greenhouse gas @ @ @ @ @ @ @ ice-free in as little as 1000 years .
A couple of weeks ago a massive chunk of ice – equivalent in size to the Caribbean island of Montserrat – broke away from north-east Greenland .
It serves as yet another indicator of the rapid pace of change in this region , with rising temperatures currently driving ice-loss at a rate of around 6100 billion tonnes per century .
But how unprecedented is this ?
How quickly did the Greenland Ice Sheet melt during warm periods in the past ?
The Greenland Ice Sheet @ @ @ @ @ @ @ geologists have used ice-core data to understand how it has waxed and waned in the past .
Until now , however , no-one had compared how ice-sheet activity in the past matched up with what scientists expect to see in the future .
Jason Briner , from the University at Buffalo in New York , and colleagues have made use of recent reconstructions of climate and ice-sheet thickness to simulate the evolution of a portion of ice-sheet in southwestern Greenland , running their simulations from 12,000 years ago , through to eighty years @ @ @ @ @ @ @ that the highest rates of ice melt during the Holocene ( the last 12,000 years ) occurred during a warm period between 10,000-7000 years ago when it was 3-5 °C warmer than today .
This resulted in ice being shed at a rate of around 6000 billion tonnes per century , which is similar to the loss rate seen over the last 20 years .
But as their simulation ventured into the future they discovered that the rate of ice-loss is likely to dwarf anything seen in the past .
Under a high-emissions @ @ @ @ @ @ @ and his colleagues show that ice loss could reach an eye-watering 35,900 billion tonnes per century by 2100 , whilst under a low-emissions scenario it is likely to rise to around 8800 billion tonnes per century .
“ It was a shocking to me to see that even with low emissions the pace of ice loss is going to be faster than it was during the warmest period in the past , ” says Briner , whose findings are published in Nature .
Under a low emissions scenario the global sea-level rise associated @ @ @ @ @ @ @ ice sheet is around 2 cm by 2100 , whilst under high emissions it adds around 10 cm .
Scaling this up to include the rest of the Greenland Ice Sheet suggests that Greenland ice-melt will produce at least 4-20 cm of sea level rise by 2100 .
“ The findings of this study are no surprise , but they highlight that we should do everything in our power to slow the rate of melt , ” says Timothy Lenton , Director of the Global Systems Institute at the University of Exeter .
@ @ @ @ @ @ @ ’ of the worlds coastlines and several major cities is a huge deal .
When we are talking about centuries of sea level rise , we are considering a timescale where the global human population could conceivably be declining ( as affluence leads couples to have fewer children , below ‘ replacement rate ’ ) .
That could make a realignment easier if it is further in the future .
Whereas with currently growing population and growing coastal megacities it could be a nightmare , ” he adds .
Previous research has suggested @ @ @ @ @ @ @ of no return for the Greenland Ice Sheet , with no hope of preventing a complete meltdown , but Briner and his colleagues are not convinced that this tipping point has passed .
“ It is clear that we are now committed to a lot of ice loss through this century , but our simulation shows that if we follow a low-emissions pathway the rate of ice-loss may slow as we approach 2100 .
It is possible to leave future generations with a healthy Greenland Ice Sheet , ” he says .
Lenton @ @ @ @ @ @ @ to act .
“ Even if tipping points have been passed , because the ice sheet dynamics are relatively slow , it is possible to ‘ overshoot ’ an ice sheet tipping point temporarily and still recover the situation .
That of course requires bringing greenhouse gas levels down , which is going to require deliberate greenhouse gas removal on top of stopping greenhouse gas emissions .
”

Fading fast The Greenland Ice Sheet. (Courtesy: Jason Briner)
Over the next eighty years global warming is set to melt enough ice from the Greenland Ice Sheet to reverse 4000 years of cumulative ice growth – with rates of ice-loss more than quadruple even the fastest melt rates during the past 12,000 years. These stark conclusions come from new simulations which, for the first time, put current and projected future rates of ice-loss into context; comparing them directly with historical rates of ice-loss. These latest results are consistent with previous research that shows that if we continue our current high trajectory of greenhouse gas emissions we can expect Greenland to become ice-free in as little as 1000 years.
A couple of weeks ago a massive chunk of ice – equivalent in size to the Caribbean island of Montserrat – broke away from north-east Greenland. It serves as yet another indicator of the rapid pace of change in this region, with rising temperatures currently driving ice-loss at a rate of around 6100 billion tonnes per century. But how unprecedented is this? How quickly did the Greenland Ice Sheet melt during warm periods in the past?
The Greenland Ice Sheet currently stretches across 1,710,000 square kilometres and geologists have used ice-core data to understand how it has waxed and waned in the past. Until now, however, no-one had compared how ice-sheet activity in the past matched up with what scientists expect to see in the future. Jason Briner, from the University at Buffalo in New York, and colleagues have made use of recent reconstructions of climate and ice-sheet thickness to simulate the evolution of a portion of ice-sheet in southwestern Greenland, running their simulations from 12,000 years ago, through to eighty years into the future.
“Shocking” pace of ice loss
The scientists found that the highest rates of ice melt during the Holocene (the last 12,000 years) occurred during a warm period between 10,000–7000 years ago when it was 3–5 °C warmer than today. This resulted in ice being shed at a rate of around 6000 billion tonnes per century, which is similar to the loss rate seen over the last 20 years.
But as their simulation ventured into the future they discovered that the rate of ice-loss is likely to dwarf anything seen in the past. Under a high-emissions “business as usual” scenario Briner and his colleagues show that ice loss could reach an eye-watering 35,900 billion tonnes per century by 2100, whilst under a low-emissions scenario it is likely to rise to around 8800 billion tonnes per century. “It was a shocking to me to see that even with low emissions the pace of ice loss is going to be faster than it was during the warmest period in the past,” says Briner, whose findings are published in Nature.
Under a low emissions scenario the global sea-level rise associated with the melt from this segment of ice sheet is around 2 cm by 2100, whilst under high emissions it adds around 10 cm. Scaling this up to include the rest of the Greenland Ice Sheet suggests that Greenland ice-melt will produce at least 4–20 cm of sea level rise by 2100.
“Centuries of sea level rise”
“The findings of this study are no surprise, but they highlight that we should do everything in our power to slow the rate of melt,” says Timothy Lenton, Director of the Global Systems Institute at the University of Exeter. “Buying time for ‘managed realignment’ of the worlds coastlines and several major cities is a huge deal. When we are talking about centuries of sea level rise, we are considering a timescale where the global human population could conceivably be declining (as affluence leads couples to have fewer children, below ‘replacement rate’). That could make a realignment easier if it is further in the future. Whereas with currently growing population and growing coastal megacities it could be a nightmare,” he adds.
Previous research has suggested that we have already passed the point of no return for the Greenland Ice Sheet, with no hope of preventing a complete meltdown, but Briner and his colleagues are not convinced that this tipping point has passed. “It is clear that we are now committed to a lot of ice loss through this century, but our simulation shows that if we follow a low-emissions pathway the rate of ice-loss may slow as we approach 2100. It is possible to leave future generations with a healthy Greenland Ice Sheet,” he says. Lenton concurs and thinks there is still time to act. “Even if tipping points have been passed, because the ice sheet dynamics are relatively slow, it is possible to ‘overshoot’ an ice sheet tipping point temporarily and still recover the situation. That of course requires bringing greenhouse gas levels down, which is going to require deliberate greenhouse gas removal on top of stopping greenhouse gas emissions.”


physicsworld--2020-10-01--Electrocaloric devices show potential for greener air conditioning - Physics World

Ever-growing in their use , air conditioning systems use refrigerants that are powerful greenhouse gases .
But independent teams in Europe and the US reckon they may have found a more environmentally friendly way to keep cool by using electricity to soak up heat by controlling the entropy of ceramic “ electrocaloric ” materials .
They have shown how to increase the cooling power of the technique and say it could become competitive with conventional vapour-compression cooling systems .
Air conditioning currently consumes about 10 % of the world ’ s electricity and could use far more in the future @ @ @ @ @ @ @ from 1.2 billion in 2018 to about 4.5 billion in 2050 , according to the Rocky Mountain Institute .
The hydrofluorocarbons often employed as the refrigerant in these systems are efficient and nonflammable , but they are also very potent greenhouse gases – trapping far more heat when released to the atmosphere than carbon dioxide .
Caloric materials can in principle do a similar job as these refrigerants while emitting no pollution .
The idea is to pump heat from a cool room to the hot outdoors , not by alternately compressing and @ @ @ @ @ @ @ and lowering the entropy of a material by controlling its elastic , magnetic or electrical properties .
In the latter case , this means using electric fields to control the polarization of dipole moments within a dielectric material .
Research on the electrocaloric effect in ceramics got off to a roaring start in the early 1990s when scientists at the Moscow Power Engineering Institute in Russia claimed they could support a temperature difference as high as 12.7 °C between heat source and heat bath .
Not relying on large compressors , pumps or @ @ @ @ @ @ @ of efficient , cheap and environmentally friendly air conditioners .
But transforming those results into practical devices has proved hard going , with material properties quite different in bulk components compared to the thin films used in labs .
New research from David Schwartz , Yunda Wang , and colleagues at PARC , part of Xerox in California , does not break any temperature records but does , they say , show how lab-scale devices could be scaled up .
They have used a large-volume fabrication technique often employed in the electronics industry @ @ @ @ @ @ @ ceramic capacitors .
The capacitors , each just a few millimetres across and made from lead scandium tantalite , were supplied by Japanese company Murata Manufacturing .
The heart of the PARC device has two layers of multi-layer capacitors lined up between copper rails and separated by insulators .
The upper layer contains five capacitors , while the lower one has four although it is capped by an aluminium heat sink at each end .
An actuator moves the top layer left and right so that four of its capacitors are always aligned @ @ @ @ @ @ @ one at either end comes into and out of thermal contact with the heat sink below it .
Schwartz and colleagues used their device to carry out many rounds of a thermodynamic Brayton cycle , with one of the heat sinks being progressively cooled while the other served as the external heat bath .
Cooling takes place in the first stage , with heat flowing from the four capacitors and the cold sink below to the five capacitors above .
Then in the second stage the top layer is moved , and the @ @ @ @ @ @ @ the dipoles and thereby reduces their entropy .
In compensation , however , the vibrational entropy of the material ’ s molecules goes up – resulting in an adiabatic temperature rise .
With the temperature of the upper layer now higher than that of the hot bath , the third stage sees the capacitor on the end dumping some of its heat into that sink .
Finally , the electric field is turned off and the temperature of the upper layer drops below that of the lower , again adiabatically .
The cycle @ @ @ @ @ @ @ that when they applied an electric field of just over 10 MV/m , the capacitors underwent an adiabatic temperature rise ( and fall ) of 2.5 °C per cycle .
With the cold sink slowly but steadily cooling over the course of about 100 cycles , they found that its temperature dropped by up 5.2 °C compared with the hot sink .
They also measured a heat flux of 135 mWcm-2 , which they say is more than four times higher than other electrocaloric cooling systems .
The researchers reckon that by adjusting @ @ @ @ @ @ @ and making other tweaks to their system , they should be able to raise the heat pumping efficiency to over 50 % .
And that , they say , would make it “ competitive with vapor compression cooling ” .
In fact , Emmanuel Defay , Alvar Torelló and colleagues at the Luxembourg Institute of Science and Technology in Luxembourg have achieved a much higher temperature differential of up to 13 °C in a slightly different system .
They also used multi-layer capacitors made from lead scandium tantalate supplied by Murata but achieved @ @ @ @ @ @ @ back and forth through the ( porous ) caloric solid .
Defay and colleagues argue that their temperature span “ breaks a crucial barrier and confirms that electrocaloric materials are promising candidates for cooling applications ” .
They also reckon that by reducing the thickness of their capacitors ( to 0.2 mm ) and using water rather than a dielectric they might achieve a span as high as 47.5 °C .
But their technology is still at a relatively early stage , and say that practical applications would require capacitors with higher breakdown @ @ @ @ @ @ @ .
The PARC results and the Luxembourg results are both reported in Science .

Staying cool: the new electrocaloric devices show potential for air conditioning. Courtesy: iStock/KMNPhoto)
Ever-growing in their use, air conditioning systems use refrigerants that are powerful greenhouse gases. But independent teams in Europe and the US reckon they may have found a more environmentally friendly way to keep cool by using electricity to soak up heat by controlling the entropy of ceramic “electrocaloric” materials. They have shown how to increase the cooling power of the technique and say it could become competitive with conventional vapour-compression cooling systems.
Air conditioning currently consumes about 10% of the world’s electricity and could use far more in the future – with cooling units projected to grow from 1.2 billion in 2018 to about 4.5 billion in 2050, according to the Rocky Mountain Institute. The hydrofluorocarbons often employed as the refrigerant in these systems are efficient and nonflammable, but they are also very potent greenhouse gases – trapping far more heat when released to the atmosphere than carbon dioxide.
Caloric materials can in principle do a similar job as these refrigerants while emitting no pollution. The idea is to pump heat from a cool room to the hot outdoors, not by alternately compressing and expanding a fluid but instead by raising and lowering the entropy of a material by controlling its elastic, magnetic or electrical properties. In the latter case, this means using electric fields to control the polarization of dipole moments within a dielectric material.
Promising start
Research on the electrocaloric effect in ceramics got off to a roaring start in the early 1990s when scientists at the Moscow Power Engineering Institute in Russia claimed they could support a temperature difference as high as 12.7 °C between heat source and heat bath. Not relying on large compressors, pumps or magnets, the work held the promise of efficient, cheap and environmentally friendly air conditioners. But transforming those results into practical devices has proved hard going, with material properties quite different in bulk components compared to the thin films used in labs.
New research from David Schwartz, Yunda Wang, and colleagues at PARC, part of Xerox in California, does not break any temperature records but does, they say, show how lab-scale devices could be scaled up. They have used a large-volume fabrication technique often employed in the electronics industry to produce a solid-state device from multi-layer ceramic capacitors. The capacitors, each just a few millimetres across and made from lead scandium tantalite, were supplied by Japanese company Murata Manufacturing.
The heart of the PARC device has two layers of multi-layer capacitors lined up between copper rails and separated by insulators. The upper layer contains five capacitors, while the lower one has four although it is capped by an aluminium heat sink at each end. An actuator moves the top layer left and right so that four of its capacitors are always aligned with those below, while the extra one at either end comes into and out of thermal contact with the heat sink below it.
The Brayton cycle
Schwartz and colleagues used their device to carry out many rounds of a thermodynamic Brayton cycle, with one of the heat sinks being progressively cooled while the other served as the external heat bath. Cooling takes place in the first stage, with heat flowing from the four capacitors and the cold sink below to the five capacitors above. Then in the second stage the top layer is moved, and the electric field applied, which lines up the dipoles and thereby reduces their entropy. In compensation, however, the vibrational entropy of the material’s molecules goes up – resulting in an adiabatic temperature rise.
With the temperature of the upper layer now higher than that of the hot bath, the third stage sees the capacitor on the end dumping some of its heat into that sink. Finally, the electric field is turned off and the temperature of the upper layer drops below that of the lower, again adiabatically. The cycle then repeats.
Schwartz and co-workers found that when they applied an electric field of just over 10 MV/m, the capacitors underwent an adiabatic temperature rise (and fall) of 2.5 °C per cycle. With the cold sink slowly but steadily cooling over the course of about 100 cycles, they found that its temperature dropped by up 5.2 °C compared with the hot sink. They also measured a heat flux of 135 mWcm-2, which they say is more than four times higher than other electrocaloric cooling systems.
The researchers reckon that by adjusting the size and shape of their capacitors and making other tweaks to their system, they should be able to raise the heat pumping efficiency to over 50%. And that, they say, would make it “competitive with vapor compression cooling”.
Much higher temperature differential
In fact, Emmanuel Defay, Alvar Torelló and colleagues at the Luxembourg Institute of Science and Technology in Luxembourg have achieved a much higher temperature differential of up to 13 °C in a slightly different system. They also used multi-layer capacitors made from lead scandium tantalate supplied by Murata but achieved greater cooling by sending a dielectric fluid back and forth through the (porous) caloric solid.
Defay and colleagues argue that their temperature span “breaks a crucial barrier and confirms that electrocaloric materials are promising candidates for cooling applications”. They also reckon that by reducing the thickness of their capacitors (to 0.2 mm) and using water rather than a dielectric they might achieve a span as high as 47.5 °C. But their technology is still at a relatively early stage, and say that practical applications would require capacitors with higher breakdown fields as well as better electrical insulation.
The PARC results and the Luxembourg results are both reported in Science.


physicsworld--2020-10-01--Online conferences, auxetic materials, and a new kind of rocket engine: the October 2020 issue of Ph

Online conferences, auxetic materials, and a new kind of rocket engine: the October 2020 issue of Physics World is now out - Physics World

When it comes to scientific conferences , we ’ ve all been affected by the restrictions from the COVID-19 pandemic .
But even when the pandemic is over , as it surely will be one day , I don ’ t think we ’ ll ever entirely go back to massive scientific conferences as we knew them .
Sending thousands of people halfway round the world at great expense to mix in stuffy rooms increasingly seems a thing of the past , not least on the grounds of cost and pollution .
What ’ s more , we can do @ @ @ @ @ @ @ it ’ ll take time to figure out what works best , but there are some intriguing developments already under way .
In the new issue of Physics World , for example , you can read about a recent online conference in attophysics that deliberately set out to create scientific “ battles ” .
More importantly , online conferences can make physics meetings more accessible and open .
If you ’ re a member of the Institute of Physics , you can read the whole of Physics World magazine every month via our @ @ @ @ @ @ @ 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 .
• US election focuses on science – From dealing with the COVID-19 pandemic to stimulating industries of the future , science policy will play a larger role than usual in next month ’ s US election , as Peter Gwynne reports • Redefining the scientific conference – Eleanor S Armstrong , @ @ @ @ @ @ @ argue that the COVID-19 pandemic offers an opportunity to start making scientific meetings more inclusive • Courting controversy online – Carla Figueira de Morisson Faria and Andrew Brown say that academic debate can still be fostered in an online-only world • Monumental mistake – Robert P Crease laments the disappearance of a landmark in US science history : the cooling tower at the Brookhaven National Laboratory • Green strings attached – Solving many of today ’ s environmental problems will require advanced technological solutions , says James McKenzie • Eliminating the boundary between @ @ @ @ @ @ @ vital to make access to space more affordable , but conventional rocket engines have their limits .
Oliver Nailard describes how UK firm Reaction Engines hopes to revolutionize space access with a new class of propulsion system , the Synergetic Air Breathing Rocket Engine ( SABRE ) • Stretching the limits – Most materials get thinner when stretched , but “ auxetics ” do the opposite and get thicker .
Helen Gleeson describes her group ’ s discovery of a material that is auxetic at the molecular level , which could be used @ @ @ @ @ @ @ glass • Optical microscopy – how small can it go ?
–For centuries diffraction limited the resolution of optical microscopy .
The past 50 years have , however , seen one limitation after another buckle under the ingenuity of a host of wide-ranging techniques , from lenses to tips , chips and doughnuts .
Anna Demming reports • Age of cosmic explosion – Tushna Commissariat reviews Look Up : Our Story with the Stars by Sarah Cruddas • Intrepid interstellar adventurers – Ian Randall reviews Spacefarers : How Humans Will Settle the Moon @ @ @ @ @ @ @ Wan • Path of least resistance – Graduate student Rosemary Teague and undergraduate Amber Yallop share their non-traditional degree pathways , some difficult choices they made along the way , and what a future in physics looks like for them now • Is anybody there ?
– Chris Holt on the physics of ghosts

The new issue of your favourite magazine examines the benefits of virtual meetings
Revolutionary rocket? The October 2020 issue of Physics World also looks at a new kind of engine.
When it comes to scientific conferences, we’ve all been affected by the restrictions from the COVID-19 pandemic. But even when the pandemic is over, as it surely will be one day, I don’t think we’ll ever entirely go back to massive scientific conferences as we knew them.
Sending thousands of people halfway round the world at great expense to mix in stuffy rooms increasingly seems a thing of the past, not least on the grounds of cost and pollution. What’s more, we can do so much more online.
Sure, it’ll take time to figure out what works best, but there are some intriguing developments already under way. In the new issue of Physics World, for example, you can read about a recent online conference in attophysics that deliberately set out to create scientific “battles”. More importantly, online conferences can make physics meetings more accessible and open.
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.
• US election focuses on science – from dealing with the COVID-19 pandemic to stimulating industries of the future, science policy will play a larger role than usual in next month’s US election, as Peter Gwynne reports
• Redefining the scientific conference – Eleanor S Armstrong, Divya M Persaud and Christopher A-L Jackson argue that the COVID-19 pandemic offers an opportunity to start making scientific meetings more inclusive
• Courting controversy online – Carla Figueira de Morisson Faria and Andrew Brown say that academic debate can still be fostered in an online-only world
• Monumental mistake – Robert P Crease laments the disappearance of a landmark in US science history: the cooling tower at the Brookhaven National Laboratory
• Green strings attached – solving many of today’s environmental problems will require advanced technological solutions, says James McKenzie
• Eliminating the boundary between sky and space – reusable vehicles are vital to make access to space more affordable, but conventional rocket engines have their limits. Oliver Nailard describes how UK firm Reaction Engines hopes to revolutionize space access with a new class of propulsion system, the Synergetic Air Breathing Rocket Engine (SABRE)
• Stretching the limits – most materials get thinner when stretched, but “auxetics” do the opposite and get thicker. Helen Gleeson describes her group’s discovery of a material that is auxetic at the molecular level, which could be used in everything from body armour to laminated glass
• Optical microscopy – how small can it go? For centuries diffraction limited the resolution of optical microscopy. The past 50 years have, however, seen one limitation after another buckle under the ingenuity of a host of wide-ranging techniques, from lenses to tips, chips and doughnuts. Anna Demming reports
• Age of cosmic explosion – Tushna Commissariat reviews Look Up: Our Story with the Stars by Sarah Cruddas
• Intrepid interstellar adventurers – Ian Randall reviews Spacefarers: How Humans Will Settle the Moon, Mars, and Beyond by Christopher Wan
• Path of least resistance – graduate student Rosemary Teague and undergraduate Amber Yallop share their non-traditional degree pathways, some difficult choices they made along the way, and what a future in physics looks like for them now
• Is anybody there? – Chris Holt on the physics of ghosts


physicsworld--2020-10-01--Why Google builds quantum computers, the LGBT+ experience in physics, CERN’s carbon footprint - Phys

Why Google builds quantum computers, the LGBT+ experience in physics, CERN’s carbon footprint - Physics World

In this episode of the Physics World Weekly podcast Google ’ s Sergio Boixo explains why the tech giant is @ @ @ @ @ .
Boixo will be a plenary speaker at the upcoming Quantum 2020 virtual conference , @ @ @ @ @ other plenary speakers in future episodes of the podcast .
Next up is Ramon Barthelemy @ @ @ @ @ University of Utah who has surveyed more than 300 LGBT+ physicists about their careers .
@ @ @ @ @ ’ s Matin Durrani about the survey and the issues faced by the LGBT+ physics @ @ @ @ @ described in a paper in the European Journal of Physics .
CERN is home to @ @ @ @ @ particle collider and several experiments that are the size of small office blocks .
So @ @ @ @ @ that the Geneva-based lab has a large carbon footprint .
What is surprising , however @ @ @ @ @ of CERN ’ s greenhouse gas emissions – as the science writer Kate Ravilious explains @ @ @ @ @ the podcast .

In this episode of the Physics World Weekly podcast Google’s Sergio Boixo explains why the tech giant is building its own quantum computers. Boixo will be a plenary speaker at the upcoming Quantum 2020 virtual conference, and we will be interviewing other plenary speakers in future episodes of the podcast.
Next up is Ramon Barthelemy – a physicist at the University of Utah who has surveyed more than 300 LGBT+ physicists about their careers. Barthelemy chats with Physics World’s Matin Durrani about the survey and the issues faced by the LGBT+ physics community, which are also described in a paper in the European Journal of Physics.
CERN is home to the world’s largest particle collider and several experiments that are the size of small office blocks. So, it is not unexpected that the Geneva-based lab has a large carbon footprint. What is surprising, however, is the main source of CERN’s greenhouse gas emissions – as the science writer Kate Ravilious explains in the final segment of the podcast.


physicsworld--2020-10-01--Overlooked for the Nobel: Nicola Cabibbo - Physics World

In 2008 three physicists bagged that year ’ s Nobel Prize for Physics for developing predictions and concepts on symmetry breaking that became the cornerstones of the Standard Model of Particle Physics .
Makoto Kobayashi of the KEK lab and Toshihide Maskawa from the University of Kyoto , both in Japan , shared one half of prize for their work in 1972 on the mechanism of broken symmetry , which led to the prediction of a new family of quarks .
Yoichiro Nambu of the University of Chicago in the US , who died in 2015 , bagged the other @ @ @ @ @ @ @ 1960 how to apply spontaneous symmetry breaking to particle physics .
Nambu ’ s work described how the vacuum is not the most symmetrical state , work that underpinned the mechanism for the Higgs field .
Symmetry breaking seeks to explain the subtle differences in physics that enables matter to tip the balance with antimatter in the universe .
Charge ( C ) symmetry involves particles behaving like their oppositely charged antiparticles , while “ parity ” ( P ) symmetry means events should be the same when the three spatial co-ordinates x @ @ @ @ @ @ @ In the 1950s , physicists discovered that charge symmetry breaks in the weak interaction , which governs radioactive beta decay .
This was followed a few years later by observations of parity breaking in the weak interaction .
A decade later and CP violation was shown to break during the decay of kaons .
It is the theory explaining CP violation that handed the 2008 Nobel prize to Kobayashi and Maskawa .
In 1972 , while at Nagoya University , the duo formulated a 3 × 3 matrix that describes how the strange @ @ @ @ @ @ @ can switch to and fro into their antiparticles and , in doing so , occasionally break CP symmetry .
Moreover , the mixing in the matrix implied the existence of new quarks – the charm , bottom and top – all of which were discovered over the following decades .
Kobayashi and Maskawa ’ s groundbreaking matrix was later named the CKM matrix after the initials of the physicists involved .
But the first initial , C , reveals the contribution of someone else : Nicola Cabibbo .
He was an Italian theorist @ @ @ @ @ @ @ who in 1963 developed a smaller 2 x 2 quark-mixing matrix that ultimately laid the groundwork for Kobayashi and Maskawa almost a decade later .
Unfortunately for Cabibbo , the statutes of the Nobel Foundation , set down in 1900 some three years after the reading of Alfred Nobel ’ s will , state that the prize can go to no more than three people every year .
While some mainained that Cabibbo could be honoured in another year , he died in 2010 at the age of 75 and another Nobel rule @ @ @ @ @ @ @ posthumously .
Some suggested that the committee could have given the prize in 2008 to Cabibbo , Kobayashi and Maskawa , leaving Nambu to be honoured in the future .
Indeed , Roberto Petronzio , president of Italy ’ s National Institute for Nuclear Physics , said at the time that he was “ filled with bitterness ” at Cabibbo missing out .
So , in an alternative universe , Cabibbo , Kobayashi and Maskawa would have shared the 2008 Nobel , leaving Nambu to be awarded the prize following the discovery of @ @ @ @ @ @ @ hindsight is a wonderful thing .

The 2020 Nobel Prize for Physics will be announced on Tuesday 6 October. In the run-up to the announcement, Physics World editors have picked some of the people who they think have been overlooked for a prize in the past
Missing out Should Nicola Cabibbo have shared the 2008 Nobel Prize for Physics (Courtesy: ICTP Photo Archive)
In 2008 three physicists bagged that year’s Nobel Prize for Physics for developing predictions and concepts on symmetry breaking that became the cornerstones of the Standard Model of Particle Physics.
Makoto Kobayashi of the KEK lab and Toshihide Maskawa from the University of Kyoto, both in Japan, shared one half of prize for their work in 1972 on the mechanism of broken symmetry, which led to the prediction of a new family of quarks. Yoichiro Nambu of the University of Chicago in the US, who died in 2015, bagged the other half of the prize for realizing in 1960 how to apply spontaneous symmetry breaking to particle physics. Nambu’s work described how the vacuum is not the most symmetrical state, work that underpinned the mechanism for the Higgs field.
Symmetry breaking seeks to explain the subtle differences in physics that enables matter to tip the balance with antimatter in the universe. Charge (C) symmetry involves particles behaving like their oppositely charged antiparticles, while “parity” (P) symmetry means events should be the same when the three spatial co-ordinates x, y and z are flipped. In the 1950s, physicists discovered that charge symmetry breaks in the weak interaction, which governs radioactive beta decay. This was followed a few years later by observations of parity breaking in the weak interaction. A decade later and CP violation was shown to break during the decay of kaons.
It is the theory explaining CP violation that handed the 2008 Nobel prize to Kobayashi and Maskawa. In 1972, while at Nagoya University, the duo formulated a 3 × 3 matrix that describes how the strange quark and down quark inside a kaon can switch to and fro into their antiparticles and, in doing so, occasionally break CP symmetry. Moreover, the mixing in the matrix implied the existence of new quarks – the charm, bottom and top – all of which were discovered over the following decades.
Missing link
Kobayashi and Maskawa’s groundbreaking matrix was later named the CKM matrix after the initials of the physicists involved. But the first initial, C, reveals the contribution of someone else: Nicola Cabibbo. He was an Italian theorist from the CERN particle-physics lab near Geneva who in 1963 developed a smaller 2 x 2 quark-mixing matrix that ultimately laid the groundwork for Kobayashi and Maskawa almost a decade later. Read more Overlooked for the Nobel: Jocelyn Bell Burnell
Unfortunately for Cabibbo, the statutes of the Nobel Foundation, set down in 1900 some three years after the reading of Alfred Nobel’s will, state that the prize can go to no more than three people every year. While some mainained that Cabibbo could be honoured in another year, he died in 2010 at the age of 75 and another Nobel rule stipulates that awards cannot be given posthumously.
Some suggested that the committee could have given the prize in 2008 to Cabibbo, Kobayashi and Maskawa, leaving Nambu to be honoured in the future. Indeed, Roberto Petronzio, president of Italy’s National Institute for Nuclear Physics, said at the time that he was “filled with bitterness” at Cabibbo missing out.
So, in an alternative universe, Cabibbo, Kobayashi and Maskawa would have shared the 2008 Nobel, leaving Nambu to be awarded the prize following the discovery of the Higgs boson in 2012. But hindsight is a wonderful thing.


physicsworld--2020-10-01--Redefining the scientific conference to be more inclusive - Physics World

The ongoing COVID-19 pandemic has led to the cancellation or postponement of many in-person scientific meetings that have historically been a key forum for scientists to present and share their ideas as well as to foster academic collaborations .
In response , scientists have moved their meetings online , which has been met with a mixed response , despite offering the possibility to dodge bad coffee , rubbish Wi-Fi and awkward poster sessions where you ’ re ignored in favour of warm beer .
Based on our experiences of organizing and participating in many conferences both before and during the @ @ @ @ @ @ @ the “ new normal ” could bring , particularly for those from under-represented groups .
Online conferences present an opportunity to challenge the problematic norms of existing conferences , which lead to the exclusion of already marginalized groups .
They can also eliminate the environment that facilitates sexual or other forms of harassment and , when appropriate care is taken , also improve access to disabled people .
The danger of scientific meetings going online only Many academics travel extensively for scientific meetings – to develop and sustain collaborative projects as well as @ @ @ @ @ @ @ travel presents barriers .
The opportunity to travel is not equally distributed and can be prohibitively expensive .
Most large conferences take place in the Global North and entering these countries from the Global South may require costly visas .
Potential delegates may be subject to countrywide travel bans and upon entry researchers of colour may experience racial aggressions .
Alongside the physical demands and inaccessibility of travel , unfamiliar locations may present challenges to disabled researchers and their carers .
Conferences held in countries with discriminatory laws and attitudes may be unsafe @ @ @ @ @ @ @ LGBTQ+ researchers .
Travel also contributes to the unnecessary release of CO .
Virtual conferences have the benefit of eliminating many of these barriers , making conferences more accessible to delegates who otherwise would be unable to attend .
For example , more early-career researchers from China , India and Latin America attended the 2020 Virtual Perovskite Conference than usual , and disabled academics took part in this year ’ s Space Science in Context meeting at a rate that reflected the 24 % of disabled people in the US and UK .
@ @ @ @ @ @ @ – provide an opportunity to showcase a more diverse range of speakers .
As questions can be asked anonymously and in advance , video-based talks have been shown to encourage questions from historically marginalized members of our communities such as early-career researchers or researchers of colour .
Online events also allow the value of different contributions to be reshaped .
Poster presentations are disproportionately delivered by early-career researchers and those of minoritized genders and people of colour .
Running them in the middle of the day rather than alongside other , typically alcohol-based @ @ @ @ @ @ @ higher value on this research .
Conferences have typically been hostile to disabled and neurodivergent people .
Combining pre-recorded and live events can improve accessibility for those who are disabled , chronically ill , neurodivergent and those with caregiving needs , who can access the material in their own time .
Having a choice of format – for example , text or audio – also lets people choose how they engage with the conference based on their needs and preferences .
Recorded meetings and having sessions repeat over the course of the conference @ @ @ @ @ @ @ zones .
Disabled people must now be involved in conference organizing , especially as online conferences do not present a one-size-fits-all approach to accessibility .
For example , lack of audio captioning , text that is not compatible with screen readers , video-based sessions without sign-language interpreters , and networking events conducted on inaccessible platforms will affect disabled researchers ’ ability to connect .
Evening events , meanwhile , may present barriers to attendees with caring or other responsibilities .
These are important considerations for conference committees .
While online conferences lessen the @ @ @ @ @ @ @ precarious positions , there will be additional costs linked to interpreters , captioning , Internet access and childcare .
But this could be prioritized over travel , location and conference-funded socializing .
Some have suggested that going online only could hinder how science is conducted in the long term and affect the “ culture ” of science .
Unsurprisingly , these commentaries are typically generated by scientists for whom the traditional conference format is not exclusionary .
Switching to an online conference can threaten meaningful networking , but tools and mechanisms do exist @ @ @ @ @ @ @ use of randomly allocated breakout “ coffee rooms ” , using virtual worlds , and different forms of “ virtual booths ” for networking based on shared interests .
Much like in-person events , ensuring a high-quality , rigorously enforced code of conduct is central to the success of online relationships .
Relationships that develop online can be just as strong as those formed offline .
In the face of COVID-19 we must be bold enough to redefine our norms .
Rather than trying to maintain business as usual in an online format @ @ @ @ @ @ @ not in the room where it happens .
We should ensure that we share knowledge and opportunity in an accessible and inclusive way .
Rather than representing an unmitigated disaster for the future of conferences and networking , COVID-19 is an opportunity to open up these spaces and make them welcoming to all .

Physics World, where it appeared under the headline "Redefining the scientific conference". Members of the Institute of Physics can enjoy the full issue Taken from the October 2020 issue of, where it appeared under the headline "Redefining the scientific conference". Members of the Institute of Physics can enjoy the full issue via the Physics World app
Eleanor S Armstrong, Divya M Persaud and Christopher A-L Jackson argue that the COVID-19 pandemic offers an opportunity to start making scientific meetings more welcoming for everyone
The ongoing COVID-19 pandemic has led to the cancellation or postponement of many in-person scientific meetings that have historically been a key forum for scientists to present and share their ideas as well as to foster academic collaborations. In response, scientists have moved their meetings online, which has been met with a mixed response, despite offering the possibility to dodge bad coffee, rubbish Wi-Fi and awkward poster sessions where you’re ignored in favour of warm beer.
Based on our experiences of organizing and participating in many conferences both before and during the pandemic, we see many advantages that the “new normal” could bring, particularly for those from under-represented groups. Online conferences present an opportunity to challenge the problematic norms of existing conferences, which lead to the exclusion of already marginalized groups. They can also eliminate the environment that facilitates sexual or other forms of harassment and, when appropriate care is taken, also improve access to disabled people.
Read more The danger of scientific meetings going online only
Many academics travel extensively for scientific meetings – to develop and sustain collaborative projects as well as undertake fieldwork. Although sometimes exhilarating, travel presents barriers. The opportunity to travel is not equally distributed and can be prohibitively expensive. Most large conferences take place in the Global North and entering these countries from the Global South may require costly visas. Potential delegates may be subject to countrywide travel bans and upon entry researchers of colour may experience racial aggressions. Alongside the physical demands and inaccessibility of travel, unfamiliar locations may present challenges to disabled researchers and their carers. Conferences held in countries with discriminatory laws and attitudes may be unsafe for people from marginalized groups such as LGBTQ+ researchers. Travel also contributes to the unnecessary release of CO 2 .
Virtual conferences have the benefit of eliminating many of these barriers, making conferences more accessible to delegates who otherwise would be unable to attend. For example, more early-career researchers from China, India and Latin America attended the 2020 Virtual Perovskite Conference than usual, and disabled academics took part in this year’s Space Science in Context meeting at a rate that reflected the 24% of disabled people in the US and UK.
Smile, you’re on camera
Video presentations – whether pre-recorded or live – provide an opportunity to showcase a more diverse range of speakers. As questions can be asked anonymously and in advance, video-based talks have been shown to encourage questions from historically marginalized members of our communities such as early-career researchers or researchers of colour. Online events also allow the value of different contributions to be reshaped. Poster presentations are disproportionately delivered by early-career researchers and those of minoritized genders and people of colour. Running them in the middle of the day rather than alongside other, typically alcohol-based “social” events, places a higher value on this research.
Conferences have typically been hostile to disabled and neurodivergent people. Combining pre-recorded and live events can improve accessibility for those who are disabled, chronically ill, neurodivergent and those with caregiving needs, who can access the material in their own time. Having a choice of format – for example, text or audio – also lets people choose how they engage with the conference based on their needs and preferences. Recorded meetings and having sessions repeat over the course of the conference can also overcome challenges related to time zones.
Disabled people must now be involved in conference organizing, especially as online conferences do not present a one-size-fits-all approach to accessibility. For example, lack of audio captioning, text that is not compatible with screen readers, video-based sessions without sign-language interpreters, and networking events conducted on inaccessible platforms will affect disabled researchers’ ability to connect. Evening events, meanwhile, may present barriers to attendees with caring or other responsibilities. These are important considerations for conference committees.
While online conferences lessen the burden for those in the most financially precarious positions, there will be additional costs linked to interpreters, captioning, Internet access and childcare. But this could be prioritized over travel, location and conference-funded socializing.
Some have suggested that going online only could hinder how science is conducted in the long term and affect the “culture” of science. Unsurprisingly, these commentaries are typically generated by scientists for whom the traditional conference format is not exclusionary. Switching to an online conference can threaten meaningful networking, but tools and mechanisms do exist to support such engagement, including the use of randomly allocated breakout “coffee rooms”, using virtual worlds, and different forms of “virtual booths” for networking based on shared interests. Much like in-person events, ensuring a high-quality, rigorously enforced code of conduct is central to the success of online relationships. Relationships that develop online can be just as strong as those formed offline.
In the face of COVID-19 we must be bold enough to redefine our norms. Rather than trying to maintain business as usual in an online format, we should ask ourselves who is not in the room where it happens. We should ensure that we share knowledge and opportunity in an accessible and inclusive way. Rather than representing an unmitigated disaster for the future of conferences and networking, COVID-19 is an opportunity to open up these spaces and make them welcoming to all.


physicsworld--2020-10-01--Fostering academic debate in an online world - Physics World

The past six months have seen scientists shift from working in the lab to conducting their research and collaborations online using tools such as Zoom .
Conferences , which had almost always been held in-person before the COVID-19 pandemic , have also had to switch to online-only .
This move has led some to warn of the long-term dangers for science , especially those fields in which there is “ much disagreement and passion ” .
Face-to-face meetings , they contend , are the “ only way to propel science forward ” .
We disagree .
We recently co-organized an @ @ @ @ @ @ @ Held in early July over three days , the Quantum Battles in Attoscience event had more than 300 registered participants from 34 countries .
Attoscience is a fairly new branch of physics and deals with some of the shortest times in nature ( 10–18 s ) .
At these time scales , researchers can image the real-time movements of electrons .
And since electrons carry energy in systems from biomolecules to nanostructures and metals , attoscience may impact many areas of science and even lead to “ optoelectronic ” computers .
Despite – @ @ @ @ @ @ @ , the attoscience community is very divided on almost all issues , siloed into factions without a co-ordinated effort toward constructive debate .
We have seen plenty of “ street fights ” at major international conferences and in journals , with not much respect being held between the different parties .
The idea of embracing , instead of avoiding , conflict emerged when we were writing a workshop proposal .
Privately , some of us had practised martial arts , where rigorous codes of conduct are enforced .
Breaking them will result in @ @ @ @ @ @ @ ’ s reputation .
In extreme cases , you may even have your belts revoked .
This approach is very different from academic street fights , so we asked : “ If people want to fight , why not go for the scientific equivalent of a martial-arts tournament ?
” We initially intended to host a “ battle ” event at University College London , but moved it online when the pandemic hit .
This posed several challenges , but also gave us plenty of opportunity to test this debating format with a @ @ @ @ @ @ @ especially for the event .
We invited early-career researchers – who we dubbed “ combatants ” – from opposing groups to participate in three “ battles ” on contentious topics .
Every combatant was promoted on the workshop website and on social-media platforms leading up to the conference .
They also became co-organizers of the conference , invested enormously in the planning of the battles and passed on the excitement to their groups .
The danger of scientific meetings going online only Bringing these people together to trust each other in a virtual @ @ @ @ @ @ @ was done via Zoom meetings and dedicated channels on Slack .
Two organizers – Bridgette Cooper and Andrew Maxwell – managed the interaction between participants .
Once the arguments had been agreed and prepared , we then carried out several mock battles .
Traditionally , panel discussions happen on the fly and involve leaders in the field , who would not have the time for such a lengthy preparation .
We heard from our combatants that as early-career researchers they wanted the practice as well as the reassurance that they would not be @ @ @ @ @ @ @ them to explore controversial points , let go of their impostor syndrome and step outside their comfort zones to discuss more “ fringe ” topics .
The mock battles helped to set boundaries and timing , ensuring that everyone was equally represented .
The battles were mediated by leading scientists in the field who were not affiliated with the panelists .
They met a few times to establish how the battles would be conducted .
Our conference still boasted big names but they were invited to give more traditional talks .
By focusing @ @ @ @ @ @ @ lot of politics and ego : the combatants were willing to invest in the process precisely because they had more to gain from it .
During the conference , it was also much easier to poll people online as anonymity helped to increase audience participation .
In a real conference we would only have the usual suspects asking or replying to questions .
Current conference culture is built to encourage the participation of principal investigators .
This needs to change – why do we need the same lectures every year from the same @ @ @ @ @ @ @ fresh faces and ideas , but this is a double-edged sword : a conference with no big names may not attract interest and may even look suspicious .
With this new initiative we wanted to change this mindset .
Furthermore , an onsite conference requires a huge investment in terms of local resource , sponsorship and infrastructure , both for the participants and the organizers .
This poses further barriers and favours those with privilege and time .
Online meetings avoid some of these issues .
The meeting was a huge success and @ @ @ @ @ @ @ hope to have shown that alternatives are possible .
Not only can debate happen in an online forum , but it can be done while maintaining respect for those involved .

Physics World, where it appeared under the headline "Courting controversy online". Members of the Institute of Physics can enjoy the full issue Taken from the October 2020 issue of, where it appeared under the headline "Courting controversy online". Members of the Institute of Physics can enjoy the full issue via the Physics World app
Carla Figueira de Morisson Faria and Andrew Brown say that academic disagreements can still be had in an online-only world
Fighting talk Quantum Battles in Attoscience was organized by (from top left, anticlockwise), Henry Bennie, Carla Faria, Andrew Maxwell, Bridgette Cooper, Sergey Yurchenko and Andrew Brown.
The past six months have seen scientists shift from working in the lab to conducting their research and collaborations online using tools such as Zoom. Conferences, which had almost always been held in-person before the COVID-19 pandemic, have also had to switch to online-only. This move has led some to warn of the long-term dangers for science, especially those fields in which there is “much disagreement and passion”. Face-to-face meetings, they contend, are the “only way to propel science forward”.
We disagree. We recently co-organized an online conference devoted entirely to controversy. Held in early July over three days, the Quantum Battles in Attoscience event had more than 300 registered participants from 34 countries. Attoscience is a fairly new branch of physics and deals with some of the shortest times in nature (10–18 s). At these time scales, researchers can image the real-time movements of electrons. And since electrons carry energy in systems from biomolecules to nanostructures and metals, attoscience may impact many areas of science and even lead to “optoelectronic” computers.
Despite – or perhaps because of – its vibrancy, the attoscience community is very divided on almost all issues, siloed into factions without a co-ordinated effort toward constructive debate. We have seen plenty of “street fights” at major international conferences and in journals, with not much respect being held between the different parties. The idea of embracing, instead of avoiding, conflict emerged when we were writing a workshop proposal. Privately, some of us had practised martial arts, where rigorous codes of conduct are enforced. Breaking them will result in your being expelled for tarnishing your school’s reputation. In extreme cases, you may even have your belts revoked. This approach is very different from academic street fights, so we asked: “If people want to fight, why not go for the scientific equivalent of a martial-arts tournament?”
If people want to fight, why not go for the scientific equivalent of a martial-arts tournament?
Mortal combat
We initially intended to host a “battle” event at University College London, but moved it online when the pandemic hit. This posed several challenges, but also gave us plenty of opportunity to test this debating format with a specific code of conduct that was developed especially for the event. We invited early-career researchers – who we dubbed “combatants” – from opposing groups to participate in three “battles” on contentious topics. Every combatant was promoted on the workshop website and on social-media platforms leading up to the conference. They also became co-organizers of the conference, invested enormously in the planning of the battles and passed on the excitement to their groups
Bringing these people together to trust each other in a virtual environment took around three months. This was done via Zoom meetings and dedicated channels on Slack. Two organizers – Bridgette Cooper and Andrew Maxwell – managed the interaction between participants. Once the arguments had been agreed and prepared, we then carried out several mock battles. Traditionally, panel discussions happen on the fly and involve leaders in the field, who would not have the time for such a lengthy preparation. We heard from our combatants that as early-career researchers they wanted the practice as well as the reassurance that they would not be caught off guard. The preparation allowed them to explore controversial points, let go of their impostor syndrome and step outside their comfort zones to discuss more “fringe” topics. The mock battles helped to set boundaries and timing, ensuring that everyone was equally represented. The battles were mediated by leading scientists in the field who were not affiliated with the panelists. They met a few times to establish how the battles would be conducted.
Our conference still boasted big names but they were invited to give more traditional talks. By focusing on early-career researchers we could avoid a lot of politics and ego: the combatants were willing to invest in the process precisely because they had more to gain from it. During the conference, it was also much easier to poll people online as anonymity helped to increase audience participation. In a real conference we would only have the usual suspects asking or replying to questions.
Culture change
Current conference culture is built to encourage the participation of principal investigators. This needs to change – why do we need the same lectures every year from the same people? We would like to see fresh faces and ideas, but this is a double-edged sword: a conference with no big names may not attract interest and may even look suspicious. With this new initiative we wanted to change this mindset. Furthermore, an onsite conference requires a huge investment in terms of local resource, sponsorship and infrastructure, both for the participants and the organizers. This poses further barriers and favours those with privilege and time. Online meetings avoid some of these issues.
The meeting was a huge success and by subverting a few paradigms, we hope to have shown that alternatives are possible. Not only can debate happen in an online forum, but it can be done while maintaining respect for those involved.


physicsworld--2020-10-01--White papers: Mad City Labs and Edinburgh Instruments - Physics World

The content highlighted in this article has been created and hosted by Physics World ’ s corporate partners .
It is free to read but you will be asked to share your contact details with the relevant partner first before being granted access immediately afterwards .
This time we are featuring two white papers from Mad City Labs and Edinburgh Instruments Single-molecule microscopy techniques allow researchers to directly study molecular mechanisms , enabling them to boost our understanding of , for example , how biological viruses assemble , disassemble and interact with their hosts .
In the new white paper @ @ @ @ @ @ @ Virus Mechanisms – One Particle At A Time , you can discover how Tijana Ivanovic from Brandeis University in the US has been using the company ’ s equipment to understand cell entry mechanisms and the relationship between the structure and organization of a virus particle and the early steps of infection .
With her lab having studied viruses ranging from those responsible for Ebola to COVID-19 , the white paper shows how these single-molecule techniques allow you to measure the “ trajectories ” of individual molecules in a population .
Semiconductor quantum @ @ @ @ @ @ @ which make them ideal for a range of important technological applications including solid-state lighting , displays , photovoltaics , and biomedical imaging .
Indium-phosphide quantum dots are of particular interest as an environmentally friendly and non-toxic alternative to traditional heavy metal-based quantum dots containing cadmium and lead .
Although indium-phosphide quantum dots do not emit light on their own , they can do this if coated with a layer of zinc sulphide .
In this latest white paper from Edinburgh Instruments , entitled Emission Tail of Indium Phosphide Quantum Dots Investigated using the @ @ @ @ @ @ @ how one of the company ’ s spectrofluorometers was used to characterize the absorbance , emission and lifetime of such indium-phosphide/zinc-selenide quantum dots , thereby helping to establish important structure–property relationships .

The content highlighted in this article has been created and hosted by Physics World’s corporate partners. It is free to read but you will be asked to share your contact details with the relevant partner first before being granted access immediately afterwards.
Welcome to the latest in a new series of sponsored articles showcasing some of the latest white papers and webinars from physics-based businesses around the world
Innovation in action: Virus have been studied using single-molecule microscopes from Mad City Labs (Courtesy: Ivanovic Lab, Brandeis University, Biochemistry Department); Indium-phosphide quantum dots, coated with zinc selenide, have been studied using Edinburgh Instruments’ spectrofluorometers (Courtesy: Edinburgh Instruments).
This time we are featuring two white papers from Mad City Labs and Edinburgh Instruments
Making sense of viruses
Single-molecule microscopy techniques allow researchers to directly study molecular mechanisms, enabling them to boost our understanding of, for example, how biological viruses assemble, disassemble and interact with their hosts. In the new white paper from Mad City Labs, entitled Understanding Virus Mechanisms – One Particle At A Time, you can discover how Tijana Ivanovic from Brandeis University in the US has been using the company’s equipment to understand cell entry mechanisms and the relationship between the structure and organization of a virus particle and the early steps of infection. With her lab having studied viruses ranging from those responsible for Ebola to COVID-19, the white paper shows how these single-molecule techniques allow you to measure the “trajectories” of individual molecules in a population.
Studying quantum dots
Semiconductor quantum dots have unique tuneable photoluminescence properties, which make them ideal for a range of important technological applications including solid-state lighting, displays, photovoltaics, and biomedical imaging. Indium-phosphide quantum dots are of particular interest as an environmentally friendly and non-toxic alternative to traditional heavy metal-based quantum dots containing cadmium and lead. Although indium-phosphide quantum dots do not emit light on their own, they can do this if coated with a layer of zinc sulphide. In this latest white paper from Edinburgh Instruments, entitled Emission Tail of Indium Phosphide Quantum Dots Investigated using the FS5 Spectrofluorometer, you can find out how one of the company’s spectrofluorometers was used to characterize the absorbance, emission and lifetime of such indium-phosphide/zinc-selenide quantum dots, thereby helping to establish important structure–property relationships.


physicsworld--2020-10-01--Ice-core mission in the Swiss Alps abandoned due to surprisingly hard glacier - Physics World

If you ’ re into home improvement , you may have experienced that sinking feeling of drilling into a wall and hitting something very hard .
Whether it ’ s a metal support or stubborn brickwork the result is the same : you can ’ t drill any deeper and you may have damaged your drill .
Last week , an Italian-Swiss group of climate scientists experienced a similar drilling defeat played out on a grand scale when they were forced to abandon attempts to drill ice cores from a glacier in the Swiss Alps .
The mission was part @ @ @ @ @ @ @ in which ice cores from several of the world ’ s threatened glaciers will be extracted and ultimately stored in an “ ice sanctuary ” in Antarctica .
The project ’ s main goal is to provide future scientists with access to this ice record before it vanishes due to climate change .
Tiny bubbles of gas , ancient pollen and possibly even microbes frozen within the ice can reveal information about Earth ’ s climate history .
“ The ice cores also certainly contain still other deposits and residues that could help @ @ @ @ @ @ @ , we don ’ t even know yet – in the future ” , said Margit Schwikowski , an environmental chemist at the Paul Scherrer Institute , who led the recent expedition .
Things began well for Schwikowski ’ s eight-person team .
On Monday 14 September the group set up base camp at an altitude of 4100 m on the Corbassière Glacier , on the Grand Combin mountain massif 90 km east of Geneva .
The mission was to extract three ice cores – each with a 7.5 cm diameter – which @ @ @ @ @ @ @ rock 80 m below .
But the group soon ran into difficulties .
In two closely separated drilling locations , the scientists encountered an unexpected transition at a depth of just 20 m , which halted progress and damaged the drill .
In early reports , the researchers suggest they may have encountered ice “ lenses ” – extremely resistant blocks of ice largely free from sediment .
Not to be deterred , the team managed to transport the equipment to the manufacturer ’ s lab in Bern to get it fixed .
@ @ @ @ @ @ @ weekend of 19–20 September , the scientists started drilling 10 m away from the previous holes , but progress was yet again halted at the same shallow depth .
With harsh weather conditions forecast , the team decided to leave the mountain and postpone the mission .
“ The water has complicated the whole operation .
We weren ’ t expecting to find the glacier like this , ” said Carlo Barbante , director of Italy ’ s Institute of Polar Sciences and researcher at Ca ’ Foscari University of Venice .
“ @ @ @ @ @ @ @ we drill the ice and hope it ’ s not too late to extract a full ice core from the Grand Combin.
” Although the scientists will be disappointed , it is not surprising to face setbacks when working in extreme mountain environments .
Harsh weather conditions also restricted the number of ice cores retrieved from earlier Ice Memory missions in Bolivia and Russia in 2017 and 2018 respectively .
However , both of those missions ultimately resulted in successful ice-core extractions , as did expeditions in the French Alps ( 2016 ) @ @ @ @ @ @ @ Mountains ( 2018 ) .
Barbante is also the co-ordinator of Beyond EPICA , which seeks to drill ice cores in Antarctica , providing a climate record for at least the past 1.5 million years .
That project is the follow-up to the European Project for Ice Coring in Antarctica ( EPICA ) , where researchers drilled 3270m deep into the Antarctic ice between 1996–2005 , which enabled them to reconstruct the climate history of the past 800,000 years .
So although this latest mission my have hit a metaphorical brick wall , @ @ @ @ @ @ @ to preserve the world ’ s ice record .
Undoubtedly there will be further challenges ahead , but climate scientists are depending on it .

Ice memory Corbassier glacier, Grand Combin mountain massif (Courtesy: Ca’ Foscari University of Venice/Ice Memory Project)
If you’re into home improvement, you may have experienced that sinking feeling of drilling into a wall and hitting something very hard. Whether it’s a metal support or stubborn brickwork the result is the same: you can’t drill any deeper and you may have damaged your drill. Last week, an Italian-Swiss group of climate scientists experienced a similar drilling defeat played out on a grand scale when they were forced to abandon attempts to drill ice cores from a glacier in the Swiss Alps.
The mission was part of Ice Memory, a UNESCO-backed project in which ice cores from several of the world’s threatened glaciers will be extracted and ultimately stored in an “ice sanctuary” in Antarctica. The project’s main goal is to provide future scientists with access to this ice record before it vanishes due to climate change. Tiny bubbles of gas, ancient pollen and possibly even microbes frozen within the ice can reveal information about Earth’s climate history.
“The ice cores also certainly contain still other deposits and residues that could help us answer scientific questions – which ones, we don’t even know yet – in the future”, said Margit Schwikowski, an environmental chemist at the Paul Scherrer Institute, who led the recent expedition.
Breaking the ice
Things began well for Schwikowski’s eight-person team. On Monday 14 September the group set up base camp at an altitude of 4100 m on the Corbassière Glacier, on the Grand Combin mountain massif 90 km east of Geneva. The mission was to extract three ice cores – each with a 7.5 cm diameter – which could extend as far as the underlying rock 80 m below.
But the group soon ran into difficulties. In two closely separated drilling locations, the scientists encountered an unexpected transition at a depth of just 20 m, which halted progress and damaged the drill. In early reports, the researchers suggest they may have encountered ice “lenses” – extremely resistant blocks of ice largely free from sediment.
Drill bit Researchers planned to drill three ice cores up to 80m in length (Courtesy: Ca’ Foscari University of Venice/Ice Memory Project)
Not to be deterred, the team managed to transport the equipment to the manufacturer’s lab in Bern to get it fixed. For the third attempt, during the weekend of 19–20 September, the scientists started drilling 10 m away from the previous holes, but progress was yet again halted at the same shallow depth. With harsh weather conditions forecast, the team decided to leave the mountain and postpone the mission.
“The water has complicated the whole operation. We weren’t expecting to find the glacier like this,” said Carlo Barbante, director of Italy’s Institute of Polar Sciences and researcher at Ca’ Foscari University of Venice. “We will need to change the way we drill the ice and hope it’s not too late to extract a full ice core from the Grand Combin.”
A challenging laboratory
Although the scientists will be disappointed, it is not surprising to face setbacks when working in extreme mountain environments. Harsh weather conditions also restricted the number of ice cores retrieved from earlier Ice Memory missions in Bolivia and Russia in 2017 and 2018 respectively. However, both of those missions ultimately resulted in successful ice-core extractions, as did expeditions in the French Alps (2016) and a Russian site in the Altai Mountains (2018).
Mountain challenges Harsh weather was a factor in deciding to abort the mission after one week (Courtesy: Ca’ Foscari University of Venice/Ice Memory Project)
Barbante is also the co-ordinator of Beyond EPICA, which seeks to drill ice cores in Antarctica, providing a climate record for at least the past 1.5 million years. That project is the follow-up to the European Project for Ice Coring in Antarctica (EPICA), where researchers drilled 3270m deep into the Antarctic ice between 1996–2005, which enabled them to reconstruct the climate history of the past 800,000 years.
So although this latest mission my have hit a metaphorical brick wall, it is part of a wider programme to preserve the world’s ice record. Undoubtedly there will be further challenges ahead, but climate scientists are depending on it.


physicsworld--2020-09-30--Lattice layabout in the park: an epitaxial guide to social distancing - Physics World

In these tough times of the COVID-19 pandemic , one of the safest ways of mixing with friends is to meet up in a local park .
But what 2D configuration , lattice or otherwise , offers the best way to maintain the appropriate social distance ?
Many years ago , I did a PhD on properties of 2D atomic lattices , so I thought I might have the answer to that question – how wrong I was .
My rather unsatisfactory answer is , “ it depends ” .
One criterion you might consider when advising people where to @ @ @ @ @ @ @ most folks are not familiar with crystallography and may not be able ( or indeed willing ) to create a 2D Bravais lattice in their local park .
So , perhaps it is best to go with a familiar square lattice .
But there are two problems here – one is that you only have four nearest neighbours to chat with , and if you extend your social circle out to next-nearest neighbours , there are just four of those as well .
The second problem is that a square lattice does not @ @ @ @ @ @ @ space – it delivers a 78 % efficiency when it comes to packing in personal bubbles of fixed diameter .
In contrast , a hexagonal lattice makes use of 91 % of available space – which is why this is called a “ close-packed ” arrangement .
The hexagonal lattice is also 50 % more social than a square lattice , because everyone has six nearest neighbours .
There ’ s also more room for the party to grow , because you also have six next-nearest neighbours .
A possible downside of this @ @ @ @ @ @ @ difficult for people to arrange themselves in a hexagonal lattice – ensuring that your six nearest neighbours are all at 60˚ from each other seems trickier than arranging your four nearest neighbours at right angles .
However , if everyone carried a metre-stick , then you could take advantage of the close-packed nature of the lattice by having people trace out a circle around them so that their circle touched on the circles of six other people .
Just as we have 2 m markers on the floor to tell us how to @ @ @ @ @ @ @ humans probably need a bit of help to crystallize in 2D .
I think social distancing in a park is best done as an epitaxial process , where someone from the parks department provides a suitable substrate by painting a lattice of close-packed circles on the grass before everyone arrives with their picnic baskets .
But human epitaxy has its challenges because interactions between individuals could cause something akin to a surface reconstruction .
This occurs when atoms deposited on a surface sit where they want , rather than adhering to the underlying @ @ @ @ @ @ @ to as “ relaxation ” , which is exactly the sort of thing you would expect to occur on a sunny Saturday afternoon in the park after the consumption of many gins-in-a-tin .
So , if you want to socially distance in an efficient way with 12 friends , then a hexagonal lattice is the winner .
But are there downsides to close packing ?
How would you , for example , join a group of friends in the middle of a busy park who have kindly left a space for you ?
@ @ @ @ @ @ @ , you might be able to hop like a highly correlated electron from one empty lattice site to the next .
I ’ m not sure if a partially full square or hexagonal lattice is the easiest to navigate in this way – I will leave that calculation to you – but one way of getting through a partially full park would be to rearrange people back and forth as you move through , much like those moving-tile puzzles of numbered squares that you find in Christmas crackers .
I don ’ t @ @ @ @ @ @ @ computed , but working out the best route and rearrangement of people on a 2D lattice is probably best addressed by a quantum annealer .
On a warm sunny afternoon , however , hopping like an electron through a crowded park is impossible .
The lattice is in the insulator state , and the only way to get to your friends is to defy the laws of physics , and social-distancing , and charge on through .
This is where the square lattice could offer an advantage because the lower packing density means @ @ @ @ @ @ @ from people than you could in a hexagonal lattice – but you would still break the 2 m rule .
So do any other 2D arrangements offer benefits ?
One problem with lattices is that people tend to line up along specific directions , which means that your near neighbours tend to block your line of sight to friends who are further away .
This could be a moot point because shouting across 4 m or more is not particularly sociable .
But if you wanted a direct line of sight to lots @ @ @ @ @ @ @ be a glass-like structure in which people are scattered about the park , at a minimum 2 m distance between individuals .
I suspect that this arrangement would naturally emerge in a park if people sat where they wished .
And perhaps there would be some sort of phase transition to a hexagonal lattice at a critical density ?
The finite nature of a park also comes to bear on social distancing .
Lattices , after all , are infinite constructs and a close-packed arrangement is not always the most efficient way to @ @ @ @ @ @ @ If a square garden only has room for 12 people , for example , a hexagonal arrangement works best – but a garden with room for 16 is best filled by a square lattice .
And between these two , the most efficient configurations are jumbled and do not have a lattice structure .
Park boundaries are a problem because they break a lattice ’ s translational symmetry – so why not choose a quasicrystal arrangement that does not have translational symmetry ?
I ’ ll leave that thought for the reader to @ @ @ @ @ @ @ the blazing sunshine .

Physics World, where it appeared under the headline "Lattice layabout in the park". Members of the Institute of Physics can enjoy the full issue Taken from the September 2020 issue of, where it appeared under the headline "Lattice layabout in the park". Members of the Institute of Physics can enjoy the full issue via the Physics World app
In this article (originally published in Lateral Thoughts, Physics World’s regular column of humorous and offbeat essays, puzzles, crosswords, quizzes and comics, which appears on the back page of the print edition), Hamish Johnston wonders how best to pack people into a park, while respecting COVID-19 social-distancing regulations
In these tough times of the COVID-19 pandemic, one of the safest ways of mixing with friends is to meet up in a local park. But what 2D configuration, lattice or otherwise, offers the best way to maintain the appropriate social distance? Many years ago, I did a PhD on properties of 2D atomic lattices, so I thought I might have the answer to that question – how wrong I was. My rather unsatisfactory answer is, “it depends”.
One criterion you might consider when advising people where to sit is simplicity – after all, most folks are not familiar with crystallography and may not be able (or indeed willing) to create a 2D Bravais lattice in their local park. So, perhaps it is best to go with a familiar square lattice. But there are two problems here – one is that you only have four nearest neighbours to chat with, and if you extend your social circle out to next-nearest neighbours, there are just four of those as well. The second problem is that a square lattice does not make efficient use of our precious green space – it delivers a 78% efficiency when it comes to packing in personal bubbles of fixed diameter.
In contrast, a hexagonal lattice makes use of 91% of available space – which is why this is called a “close-packed” arrangement. The hexagonal lattice is also 50% more social than a square lattice, because everyone has six nearest neighbours. There’s also more room for the party to grow, because you also have six next-nearest neighbours. A possible downside of this structure is that it could be more difficult for people to arrange themselves in a hexagonal lattice – ensuring that your six nearest neighbours are all at 60˚ from each other seems trickier than arranging your four nearest neighbours at right angles. However, if everyone carried a metre-stick, then you could take advantage of the close-packed nature of the lattice by having people trace out a circle around them so that their circle touched on the circles of six other people.
Just as we have 2 m markers on the floor to tell us how to space ourselves in a 1D queue, humans probably need a bit of help to crystallize in 2D
Just as we have 2 m markers on the floor to tell us how to space ourselves in a 1D queue, humans probably need a bit of help to crystallize in 2D. I think social distancing in a park is best done as an epitaxial process, where someone from the parks department provides a suitable substrate by painting a lattice of close-packed circles on the grass before everyone arrives with their picnic baskets. But human epitaxy has its challenges because interactions between individuals could cause something akin to a surface reconstruction. This occurs when atoms deposited on a surface sit where they want, rather than adhering to the underlying lattice structure. This process is referred to as “relaxation”, which is exactly the sort of thing you would expect to occur on a sunny Saturday afternoon in the park after the consumption of many gins-in-a-tin.
So, if you want to socially distance in an efficient way with 12 friends, then a hexagonal lattice is the winner. But are there downsides to close packing? How would you, for example, join a group of friends in the middle of a busy park who have kindly left a space for you? If the park is not too full, you might be able to hop like a highly correlated electron from one empty lattice site to the next. I’m not sure if a partially full square or hexagonal lattice is the easiest to navigate in this way – I will leave that calculation to you – but one way of getting through a partially full park would be to rearrange people back and forth as you move through, much like those moving-tile puzzles of numbered squares that you find in Christmas crackers. I don’t know if such a solution can be computed, but working out the best route and rearrangement of people on a 2D lattice is probably best addressed by a quantum annealer.
On a warm sunny afternoon, however, hopping like an electron through a crowded park is impossible. The lattice is in the insulator state, and the only way to get to your friends is to defy the laws of physics, and social-distancing, and charge on through. This is where the square lattice could offer an advantage because the lower packing density means you could manage to stay further away from people than you could in a hexagonal lattice – but you would still break the 2 m rule.
Glass on the grass
So do any other 2D arrangements offer benefits? One problem with lattices is that people tend to line up along specific directions, which means that your near neighbours tend to block your line of sight to friends who are further away. This could be a moot point because shouting across 4 m or more is not particularly sociable. But if you wanted a direct line of sight to lots of faraway neighbours, the solution could be a glass-like structure in which people are scattered about the park, at a minimum 2 m distance between individuals. I suspect that this arrangement would naturally emerge in a park if people sat where they wished. And perhaps there would be some sort of phase transition to a hexagonal lattice at a critical density?
The finite nature of a park also comes to bear on social distancing. Lattices, after all, are infinite constructs and a close-packed arrangement is not always the most efficient way to pack spheres within a confined space. If a square garden only has room for 12 people, for example, a hexagonal arrangement works best – but a garden with room for 16 is best filled by a square lattice. And between these two, the most efficient configurations are jumbled and do not have a lattice structure.
Park boundaries are a problem because they break a lattice’s translational symmetry – so why not choose a quasicrystal arrangement that does not have translational symmetry? I’ll leave that thought for the reader to ponder after a few cold ones in the blazing sunshine.


physicsworld--2020-10-02--Boron neutron capture therapy is back on the agenda - Physics World

Boron neutron capture therapy ( BNCT ) , a technique that deposits highly targeted radiation into tumour cells , was first investigated as a cancer treatment back in the 1950s .
But the field remains small , with only 1700 to 1800 patients treated to date worldwide .
This may be about to change .
“ The field of BNCT seems to be progressing rapidly at the moment , ” said Stuart Green , director of medical physics at University Hospital Birmingham .
“ The big difference compared with five or ten years ago is that the commercial interest from @ @ @ @ @ @ @ and this is driving the field.
” BNCT is a two-stage treatment .
First , a 10B-containing drug ( most commonly boronophenylalanine ) is infused into the patient ’ s bloodstream .
After a couple of hours , the drug accumulates preferentially in tumour cells and starts to wash out of healthy tissues .
At this point , the tumour target is irradiated with low-energy neutrons , which split the 10B atoms into alpha particles and 7Li ions – highly ionizing particles that are delivered directly into the cancer cells .
“ BNCT @ @ @ @ @ @ @ radiotherapy targeted at the cellular level , ” Green explained .
As neither the neutron beam nor the drug are toxic by themselves , damage to healthy tissue is minimized .
“ BNCT is relatively safe compared with administering radioactive drugs or chemotherapy , where toxicity may be experienced all around the body.
” Speaking at the Medical Physics & Engineering Conference ( MPEC ) , Green updated on the status of BNCT programmes worldwide , noting that clinical experience is continually increasing .
The US Food and Drug Administration has now approved @ @ @ @ @ @ @ But by far the majority of treatments , over 1150 to date , have taken place in Japan , initially using the Kyoto University Reactor in the early 2000s , and more recently using three Sumitomo accelerator systems in Kyoto , Fukushima and Osaka .
“ Very importantly , earlier this year we had the first ever medical device approval for BNCT , for treatment in Japan of recurrent head-and-neck cancer , ” said Green .
“ This is a significant marker for the entire field.
” Several BNCT clinical trials are now @ @ @ @ @ @ @ .
A work-in-progress study examining one-year survival in patients with recurrent malignant glioma is showing promising initial results .
Another trial , which formed the basis of the approval by the Japanese Medical Agency , examined three-month response rates of patients with unresectable local recurrent head-and-neck cancer .
This approval should enable the team to start treating patients on a routine basis .
In Finland , meanwhile , around 250 patients have been treated using neutrons from a research reactor .
This reactor closed in 2012 , but Helsinki University Hospital is currently @ @ @ @ @ @ @ from MIT ) to commission an accelerator-based BNCT facility .
Clinical trials at this facility were planned to begin late in 2020 ( now delayed due to the pandemic ) , initially examining recurrent head-and-neck cancer followed by glioblastoma and other indications .
The previous treatments in Finland included many patients with locally recurrent head-and-neck squamous cell carcinoma – a difficult-to-treat cancer that recurs in almost half of cases .
Green described a recent US-based study looking at conventional retreatments of this disease .
Patients retreated with intensity-modulated radiotherapy had an overall survival @ @ @ @ @ @ @ experiencing grade 5 toxicity ( death ) ; those receiving stereotactic body radiation therapy had 7.8 months overall survival with 0.5 % grade 5 toxicity .
In contrast , the ( so far unpublished ) Helsinki data showed that BNCT of similar cases conferred an overall survival of 25 months , with zero occurrences of grade 5 toxicity .
Elsewhere , Chinese company Neuboron is constructing a BNCT Centre at the Xiamen Humanity Hospital in China , with plans for other facilities in the future .
These facilities will be based around a @ @ @ @ @ @ @ US firm TAE Life Sciences .
Green also described recent developments in the UK , where the University of Birmingham has received a £9m award from the EPSRC funding agency to develop a high-power neutron source .
The source is slated mainly for testing and research into nuclear materials , but will also act as a user facility for other communities needing high-intensity neutron irradiation .
The source , which will be situated next to the university ’ s medical physics building , could be used to test new boron compounds in cells @ @ @ @ @ @ @ to perform dosimetry , beam characterization and imaging studies .
Green notes that builders arrived on site in the last few weeks , with accelerator delivery planned for August 2021 and full operation scheduled for February 2022 .
The other big news in the BNCT field , said Green , is the collaboration between oncology software specialist RaySearch and various BNCT companies , including Neutron Therapeutics , Sumitomo and TAE Life Sciences .
“ RaySearch has taken on BNCT and is producing treatment planning tools to help us bring it into our clinical @ @ @ @ @ @ @ For the first time , there ’ s a substantial and sustained effort in the commercial sector to drive this field forward , ” Green concluded .
“ We should keep an eye on BNCT over the next few years , there ’ s a lot happening , and hopefully our community can play a key role .
”

Boron neutron capture therapy, which targets cancer at the cellular level, is under development by several companies worldwide. (Courtesy: Hanna Koivonoro, Neutron Therapeutics)
Boron neutron capture therapy (BNCT), a technique that deposits highly targeted radiation into tumour cells, was first investigated as a cancer treatment back in the 1950s. But the field remains small, with only 1700 to 1800 patients treated to date worldwide. This may be about to change.
“The field of BNCT seems to be progressing rapidly at the moment,” said Stuart Green, director of medical physics at University Hospital Birmingham. “The big difference compared with five or ten years ago is that the commercial interest from a variety of companies is strong now and this is driving the field.”
BNCT is a two-stage treatment. First, a 10B-containing drug (most commonly boronophenylalanine) is infused into the patient’s bloodstream. After a couple of hours, the drug accumulates preferentially in tumour cells and starts to wash out of healthy tissues. At this point, the tumour target is irradiated with low-energy neutrons, which split the 10B atoms into alpha particles and 7Li ions – highly ionizing particles that are delivered directly into the cancer cells.
“BNCT is high-LET [linear energy transfer] radiotherapy targeted at the cellular level,” Green explained. As neither the neutron beam nor the drug are toxic by themselves, damage to healthy tissue is minimized. “BNCT is relatively safe compared with administering radioactive drugs or chemotherapy, where toxicity may be experienced all around the body.”
Speaking at the Medical Physics & Engineering Conference (MPEC), Green updated on the status of BNCT programmes worldwide, noting that clinical experience is continually increasing. The US Food and Drug Administration has now approved two boron drugs for clinical use. But by far the majority of treatments, over 1150 to date, have taken place in Japan, initially using the Kyoto University Reactor in the early 2000s, and more recently using three Sumitomo accelerator systems in Kyoto, Fukushima and Osaka.
“Very importantly, earlier this year we had the first ever medical device approval for BNCT, for treatment in Japan of recurrent head-and-neck cancer,” said Green. “This is a significant marker for the entire field.”
The Sumitomo BNCT system is the first approved accelerator-based BNCT system in the world. (Courtesy: Shin Masui, Sumitomo Heavy Industries)
Several BNCT clinical trials are now underway in Japan using these accelerator-based facilities. A work-in-progress study examining one-year survival in patients with recurrent malignant glioma is showing promising initial results. Another trial, which formed the basis of the approval by the Japanese Medical Agency, examined three-month response rates of patients with unresectable local recurrent head-and-neck cancer. This approval should enable the team to start treating patients on a routine basis.
In Finland, meanwhile, around 250 patients have been treated using neutrons from a research reactor. This reactor closed in 2012, but Helsinki University Hospital is currently working with Neutron Therapeutics (which originated from MIT) to commission an accelerator-based BNCT facility. Clinical trials at this facility were planned to begin late in 2020 (now delayed due to the pandemic), initially examining recurrent head-and-neck cancer followed by glioblastoma and other indications.
The previous treatments in Finland included many patients with locally recurrent head-and-neck squamous cell carcinoma – a difficult-to-treat cancer that recurs in almost half of cases. Green described a recent US-based study looking at conventional retreatments of this disease. Patients retreated with intensity-modulated radiotherapy had an overall survival of 13.3 months, with 1.8% experiencing grade 5 toxicity (death); those receiving stereotactic body radiation therapy had 7.8 months overall survival with 0.5% grade 5 toxicity. In contrast, the (so far unpublished) Helsinki data showed that BNCT of similar cases conferred an overall survival of 25 months, with zero occurrences of grade 5 toxicity.
Elsewhere, Chinese company Neuboron is constructing a BNCT Centre at the Xiamen Humanity Hospital in China, with plans for other facilities in the future. These facilities will be based around a relatively compact accelerator-based neutron source designed by US firm TAE Life Sciences.
Green also described recent developments in the UK, where the University of Birmingham has received a £9m award from the EPSRC funding agency to develop a high-power neutron source. The source is slated mainly for testing and research into nuclear materials, but will also act as a user facility for other communities needing high-intensity neutron irradiation.
The source, which will be situated next to the university’s medical physics building, could be used to test new boron compounds in cells, for example, as well as to perform dosimetry, beam characterization and imaging studies. Green notes that builders arrived on site in the last few weeks, with accelerator delivery planned for August 2021 and full operation scheduled for February 2022.
The other big news in the BNCT field, said Green, is the collaboration between oncology software specialist RaySearch and various BNCT companies, including Neutron Therapeutics, Sumitomo and TAE Life Sciences. “RaySearch has taken on BNCT and is producing treatment planning tools to help us bring it into our clinical work,” he said.
“For the first time, there’s a substantial and sustained effort in the commercial sector to drive this field forward,” Green concluded. “We should keep an eye on BNCT over the next few years, there’s a lot happening, and hopefully our community can play a key role.”