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Life in a carbon-neutral world

Green footprint — (Courtesy:iStock/Griffin24)

I live in the UK city of York and in March 2019 it declared a climate emergency, with the city’s council agreeing to become net carbon neutral by 2030. It was a bold declaration and an ambitious target. But York is far from alone in taking such a stand – more than 70 countries and hundreds of cities have now pledged to reduce carbon emissions to net zero by 2050 or sooner. Some countries, including the UK, have even turned this into a legally binding target. Right now, there is lots of discussion about how we might reach net zero, but what will it feel like to live in this clean, green world?

Like many others, in pre-COVID-19 times, I drove my car to the supermarket, went to work in a draughty office, heated my home with gas central heating, ate meat a couple of times each week, and liked to go somewhere warm for a holiday each year. Over the last few years I’ve made a few changes to my life to cut my own carbon footprint – taking the train instead of flying; trying to cycle more, instead of driving; eating less meat and dairy; and putting on another jumper instead of turning the thermostat up. But I’ve got a long way to go before I fully neutralize that footprint. However, if my hometown manages to keep its pledge, I’ll be living in a net-zero city in just 10 years’ time, and once my children are grown-up we’ll be living in a carbon-neutral country.

Currently, the UK government believes that we’ll have to use carbon-capture-and-storage technology to reach our targets. If we go down that route, then net-zero living may not feel too different to life today (see box below). But burying our emissions isn’t the only option. A forthcoming report from the Centre for Research into Energy Demand Solutions (CREDS) explores an alternative path based on radical reduction in energy demand. Meanwhile, Cambridgeshire County Council recently published Net Zero Cambridgeshire, which plots a more middle-of-the-road path by proposing both decreasing energy usage, and using carbon-capture-and-storage technology to reach net zero. Last November UK FIRES (a research collaboration between five UK universities) published Absolute Zero – a report detailing how the UK might completely eliminate all its greenhouse-gas emissions by 2050.

The technological fix

Peatland Wicken Fen UK — A natural solution: Wicken Fen in Cambridgeshire is a historic peatland that has been undergoing restoration since 1999. (Courtesy: Shutterstock/Andy333)

One way of slowing climate change is to take the offending greenhouse gases out of the air. Natural solutions include planting trees and restoring peatlands, while the main technological contender is carbon capture and storage (CCS) – gathering carbon dioxide from a power station, for example, and pumping it into an underground storage area. The UK is well placed to take advantage of CCS. “Our oil and gas industry has left us with many suitable reservoirs under the North Sea – enough to store 100 to 200 years’ worth of emissions for the UK,” says Stuart Haszeldine, a CCS expert at the University of Edinburgh. The carbon dioxide would remain locked underground for tens of thousands of years, buying us more time to bring emissions down.

If we do embrace this route to net zero, then Haszeldine envisages hydrogen being the fuel of choice for heating our homes (using the existing gas network), and electric and biofuels meeting many other energy needs. As for food, meat will stay on the menu, but might be lab-grown rather than from the farm. Life will feel a bit different, but not radically different from today.

However, Haszeldine is clear that CCS is not an excuse to slack off. “We still need to do everything we can to decrease emissions, but CCS is our insurance policy. It’s worth doing multiple actions in case some fail.”

Bringing it home

Like many other cities in the UK, a significant chunk of York’s greenhouse-gas emissions – around a third in fact – come from heating and powering our houses. Reducing energy use at home is going to be a crucial aspect of reaching net zero. “When it comes to homes we are going to have to phase out carbon-based heating,” says James Weber, a climate scientist at the University of Cambridge and one of the authors of Net Zero Cambridgeshire.

So that’s goodbye gas and hello low-carbon heat sources such as heat pumps, photovoltaics and smart energy-storage systems. But eco-energy alone won’t be enough; extensive improvements in energy efficiency are needed too. Indeed, the CREDS team calculates that we can halve our domestic energy demand so long as two-thirds of UK homes become super-insulated and have their gas boilers replaced within the next 15 years.

It’s goodbye gas and hello low-carbon heat sources. But eco-energy alone won’t be enough; extensive improvements in energy efficiency are needed too

It sounds like a serious undertaking, but some people have already embraced the challenge. Phil Bixby, a York-based architect, has retrofitted his end-of-terrace Victorian brick house to be super-energy efficient. “I didn’t do this to be an eco-warrior; I did it because it seemed the responsible thing to do and I wanted to show that you don’t have to forgo comfort to do this,” he says.

Superficially, the interior of Bixby’s house looks like any other home, but closer inspection reveals otherwise. Leading me over to the window during my visit in January, Bixby points out the additional 12 cm or so of insulation that has been added to the exterior walls. He chose high-performance polyurethene – a commonly used insulation material – over natural fibres such as sheep’s wool or hemp because it is more efficient, requiring less material, and hence wall thickness, for the same level of insulation. Looking around I also realize that there are no radiators; three electric towel rails and a small area of underfloor heating is the only additional warmth the house needs. To prevent condensation, a mechanical ventilation system extracts damp air and pulls in fresh air to all the living spaces. Meanwhile, in the dining room, positioned in pride of place, is a Tesla battery unit, which stores any excess electricity generated by the building’s solar panels and pulls electricity from the grid when extra is needed. Using weather-forecast data, it optimizes capturing solar energy on sunny days, and buys electricity when it is cheapest, helping to smooth the National Grid’s load.

The house doesn’t achieve official “Passivhaus” standards – where heat loss is reduced so much that the building hardly needs any heating at all – but it isn’t far off. “Our energy bills are around £700 per year now; approximately half of what they used to be,” says Bixby. And cheaper energy bills are not the only benefit. The filtered air helps prevent respiratory problems and the thick walls make it super quiet.

Energy-efficient home — Modernizing history: Whether it’s a Victorian terraced house (such as Phil Bixby’s home in York, above) or a former brewery (such as Resource Rows in Copenhagen, below), retrofitting existing buildings to become energy-efficient homes uses less carbon dioxide than building new houses. (Courtesy: Phil Bixby)

Resource Rows in Copenhagen — (Courtesy: Mikkel Strange)

Retrofits like Bixby’s don’t come cheap, but they could play a role in solving the UK’s housing crisis. The government’s target is to build 300,000 new homes every year by the mid-2020s, but the CREDS team says that repurposing empty homes could reduce the number of new-builds to under 200,000 every year, and breathe new life back into small towns, where many of the empty homes lie. “Building a new home can emit around 70 tonnes of carbon dioxide – approximately 15 return flights from the UK to Australia,” says John Barrett from the Sustainability Research Institute at the University of Leeds, UK, and co-ordinator of the forthcoming CREDS report. Around half the embedded energy in a building lies in the concrete and steel, so repurposing rather than demolishing can significantly reduce emissions.

Some architects are already embracing this philosophy. In the Danish city of Copenhagen, for example, architect Anders Lendager’s recent housing development, called Resource Rows, reused panels of brickwork from the demolition of a Carlsberg brewery building, halving carbon-dioxide emissions compared to conventional construction. And less flashy but equally impressive is the refurbished Minerva building in Leeds, which reused the existing concrete and steel frame of its 1970s predecessor to create a modern and energy-efficient office building.

Travelling with no footprint

So far, so good, but an eco-home can only get you so far. How do we tackle another huge source of emissions: transport? Where I live in York, vehicles are responsible for another third of the city’s greenhouse-gas emissions. It’s a similar picture across the rest of the country and a difficult one to fix. Electric vehicles will play a role, but they don’t solve congestion and still emit particulate matter from road, tyre and brake wear. Indeed, if everyone goes electric the demand for electricity will be huge. Switching to other modes of transport, and travelling less, are going to be important too.

In its report, Cambridgeshire County Council estimates that 10% of the distances we travel by car will have to be done using public transport, walking and cycling. The CREDS team goes even further than this and suggests that it’s plausible to halve the number of trips we take by car and reduce our number of car miles by 20%. For shorter journeys, walking and cycling will play a big role, making up 40% of our journeys (as compared to 25% now). UK FIRES presents the most radical change, with shipping significantly reduced and most airports closing this decade, leading to absolutely no shipping or air travel by 2050. But some don’t see this solution as wholly realistic. “I feel that this scenario fails to take into account the speed of social change and the potential damage associated with completely stopping world trade,” says Barrett.

For most of us, though, the biggest change we’ll notice will be the way we travel to work. “Commuting traffic generates the largest proportion of greenhouse-gas emissions but it is also the most difficult thing to change. We can’t rebuild our cities from scratch,” says Marc Barthelemy, an expert on spatial networks at the CEA Institute for Theoretical Physics in Saclay, France. Barthelemy has analysed traffic data from 25 major cities and showed that cities that combine high-density living with good access to public transport have the least traffic congestion and the lowest transport-related emissions. “In Tokyo, Seoul and Barcelona around 80% of the population live within 1 km of public transport and the percentage of people using their car in these cities is very low,” says Barthelemy. But counterintuitively not all public transport is a good thing. Barthelemy’s work has shown that public transport stations in outer suburbs can encourage car use and add to traffic congestion in the vicinity of the station. “Things like ‘park & ride’ are the wrong solution. They enable people to live further away from the city and encourage longer commutes,” he explains.

Things like ‘park & ride’ are the wrong solution. They enable people to live further away from the city and encourage longer commutes

Instead of focusing on extending subways and building “park & rides”, Barthelemy thinks that cities dominated by urban sprawl – such as Dallas and Los Angeles in the US – need to incentivize “urban villages”, where offices, homes and shops are mixed together. “You can already see this happening in cities like Dublin [Ireland], where big companies such as Google and Facebook have set themselves up outside of the city centre and are in the process of creating a nice living environment around them so that employees are encouraged to live their lives nearby,” says Barthelemy.

One city that has managed to bring about a fast change in people’s transport habits is Ghent in Belgium. The city transformed overnight on 3 April 2017, when it was divided into seven distinct transport zones – a car-free area in the historic centre with six zones radiating out from it like petals on a flower. “We made it impossible to go by car from one zone to another, but for pedestrians, cyclists, taxis and buses nothing changed,” explains Filip Watteeuw, the deputy mayor of Ghent, responsible for implementing the plan. “People started to question whether it was necessary to take the car and we quickly saw a big shift towards public transport and walking and cycling.”

In the three years since Ghent’s traffic plan was implemented, the number of traffic accidents has fallen by a third, the number of cars has dropped by a third, cycling has increased by 60%, carbon-dioxide emissions have been slashed by 1500 tonnes per year and there has been a significant improvement in air quality. Many people predicted that business would suffer, but in fact Ghent has seen a rise in start-ups and even a limited decrease in vacant shops. “The economy is good,” says Watteeuw. And because the plan simply repurposed existing roads, rather than building new infrastructure, it cost just €6m to implement – about the same cost as building one mile of motorway. But for Watteeuw it is the improvement in people’s quality of life that he is most proud of. “The most lovely compliment I had was from someone who said I was the best musical composer, because now they can hear the songs of the birds and before they could only hear the noise of cars,” he says. Birmingham – the UK’s second-biggest city – is already eyeing up a similar plan.

Work patterns will also need to change in order to accommodate reduced travel, and Barrett predicts greater flexibility from employers, with co-working hubs, home working and virtual meetings all becoming the norm. The COVID-19 virus has forced us to rapidly embrace many of these practices. But what kind of jobs will we be doing in a net-zero world? The fossil-fuel industry will become near-obsolete, but other opportunities will arise. “We anticipate a growth in renewable-energy industries and the IT sector, plus a rise in demand for people with engineering skills as we embrace a culture of recycling and repairing,” says Barrett. Builders and heating engineers will be run off their feet retrofitting everyone’s homes.

One important aspect of the CREDS scenario is a big reduction in the amount of stuff we buy, with throwaway fashion a thing of the past. The average lifetime of materials will increase by two years and changes in design standards will make products easier to repair. “The emphasis needs to change to value quality over quantity, and when something does break, we’ll be able to send it back to the manufacturer or take it to a repair cafe in the town centre,” says Barrett. Mundane shopping will be done online, out-of-town shopping malls will disappear, and a trip to the town centre will be a leisure experience, to have a coffee with friends or visit an attraction.

Eating in a net-zero world

So that’s transport, energy, work and leisure mapped out, but what about food? York hasn’t included food in its emissions tally, but the impact of agriculture is estimated to make up around 10% of global greenhouse emissions. Ruminants such as cows and sheep take much of the blame because they produce significant quantities of methane – a short-lived but very potent greenhouse gas. Will beef, lamb and dairy products still be on the menu in a carbon-neutral world?

Under the CREDS scenario, 40% of the UK population will be vegan (up from 3% today) and 40% will be vegetarian (up from 9% today). “We envisage a large shift in people’s diet. It will still meet all our nutritional requirements, but we’ll see a big reduction in the number of calories we consume,” says Barrett. One significant co-benefit of this shift is the improvement in people’s health, with obesity being eliminated (65% of people are classified as overweight or obese in the UK today).

However, Michelle Cain from the Environmental Change Institute at the University of Oxford, UK, suggests we might not need such a radical change in diet. Her work has shown that the short-term positive benefits of reducing methane levels are greater than often assumed and that even small changes could have tangible benefits. For example, the impact on climate of a cow herd occurs when it is first established, and remains steady over time if the herd remains the same size because the effect of methane is short lived. Cain’s calculations show that reducing methane emissions from a herd by 0.3% per year – either by decreasing herd size or by using feed additives and improved manure management – is enough to bring the emissions of the herd down to net zero. “Our calculations suggest that this reduction will have the same impact on climate as closing and stopping the carbon-dioxide emissions from an entire coal-fired power station,” says Cain.

Whichever route we choose – vegan, vegetarian or flexitarian – a walk in the countryside is going to feel very different in the decades to come. “Fewer fields of livestock will free up land and create opportunity to capture carbon by planting trees and restoring peatland,” says Barrett.

Both CREDS and Net Zero Cambridgeshire rely on trees in a big way. Weber and his colleagues calculate that even with all their proposed energy-reduction measures in place, Cambridgeshire will produce an excess 600,000 tonnes of carbon during the year 2050. Planting 0.5% of the county with trees now would be enough to mop up that much carbon between now and 2050, thereby ensuring Cambridgeshire hits the net-zero target in 2050, but it wouldn’t tackle the excess emissions produced between now and then, or those produced from 2051 onwards. If we want to hit net-zero by 2050 and maintain net-zero thereafter, they calculate that a whopping 10% of the county’s land area needs to be planted with trees now. As an added bonus, reforesting on this grand scale would also lock away around 10% of the county’s emissions in the lead-up to 2050, helping Cambridgeshire to reduce its contribution to global warming from the moment the trees are planted. But not just any old tree will do. “It is important that this isn’t a monoculture because that makes the trees vulnerable to disease and is bad for biodiversity,” says Weber. Instead the team concludes that most of the planting needs to be a mix of alder, aspen and sycamore, to maximize carbon sequestration, interspersed with a smattering of commercial forestry and traditional woodland.

Cambridgeshire will also need to restore peatland to turn it back into a carbon sink. “North Cambridgeshire has large areas of peatland that have been disturbed and used as farmland. If this peatland continues to degrade it will become a major source of emissions,” says Weber.

Making changes: Bo Asmus Kjeldgaard, former mayor of Copenhagen, believes that working collaboratively with stakeholders is key to the major projects required to achieve zero-carbon cities. (Courtesy: Greenovation)

Certainly, life is going to be very different in a net-zero world, but it’s far from the hair-shirt and lentil-eating existence that I might have imagined. And, if Copenhagen is anything to go by, net-zero living could be positively rosy. Back in 2009 the city set itself the goal of becoming carbon neutral by 2025. With five years to go, the city is pretty much on track, having reduced its emissions by 42% over the last 15 years, while growing its economy by 25%. Today two-thirds of trips in the city are made on foot, cycle or public transport, and more than half of the city’s heat and power is supplied by renewable energy. “We were motivated by wanting to improve the ‘liveability’ of the city, to combine sustainability and good quality of life,” says Bo Asmus Kjeldgaard, former mayor of the city and now chief executive of sustainable consultancy Greenovation.

But getting here has required tough decisions and significant investment. “Back in the 1990s we made it mandatory to connect to Copenhagen’s district heating system. Lots of people were against this but we knew we had to connect everyone to get the full benefit,” says Kjeldgaard. Ownership of utilities companies was also important, to ensure the city had control of its own power. However, it hasn’t all been top-down decision making, and Kjeldgaard is clear that working collaboratively with all stakeholders and gaining the trust of local people have been crucial too (see box below).

Kjeldgaard is also well aware that the city has not addressed the emissions associated with air travel, what people eat or what they choose to buy. “This wasn’t part of our calculation because we can’t control this, but we should be calculating these emissions and informing people about the choices they make,” he says. Kjeldgaard thinks there are still big challenges ahead for Copenhagen, but he is pleased that the city has demonstrated what can be achieved with good planning. “It hasn’t been like going back to the old times. We’ve shown that you can still be modern, use your computer, live in a nice home and eat inventive food, but also enjoy clean air and nature in the city,” he says. And if that is what is on offer, I’ll have a slice of that.

Governance for a carbon-neutral world

Ghent transport — Neutral transport: Ghent has achieved impressive reduction in car use since 2017. (Courtesy: CC BY 2.0/bvi4092)

Whichever the route, the journey to net zero it is a daunting challenge. So where do we begin? Beth Sawin, co-director of the US think-tank Climate Interactive, thinks that we need to start by implementing solutions that solve more than one problem – a technique she calls “multi-solving”. “For example, if we make walking and cycling safer, it helps to reduce air pollution and traffic congestion, and improve people’s health,” she explains.

But the convention of allocating budgets to specific government and council departments doesn’t favour multi-solving, with the transport department, say, spending money on cycle paths but failing to get the credit for the health savings, for example. “We need to connect decision-makers across different departments and allow them to take the whole system into account. Cities with mayors are often better able to do this,” says Sawin.

But that doesn’t mean we need to wait for a mayor to come along. Sawin has been involved in a number of successful multi-solving projects, where the wisdom and desires of the groups of people with most at stake are incorporated into the decision-making process. One such collaboration in the US city of Atlanta, known as the Just Growth Circle, brought together almost 70 people including representatives from government, business, philanthropy, conservation and local community groups. Over time the group members have come to trust each other, and worked together to shape an urban restoration plan, creating parks, walking trails and clean rivers, but also securing commitments to protect against gentrification of the neighbourhood. “Because these groups of people are already connected, they are able to seize opportunities when they arise, and steer towards outcomes like equity, climate protection and health,” says Sawin.

Europe seeks to harness power of AI in COVID-19 crisis

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Artificial intelligence (AI) may soon have a central role to play in the global battle against COVID-19. A European campaign is underway to develop a deep learning-based model for the automated detection of abnormalities on chest CT and for quantifying lung involvement.

“In these unprecedented circumstances, we must find ways of helping doctors in their fight against the virus,” noted Erik Ranschaert, president of the European Society of Medical Imaging Informatics (EuSoMII), who is leading the initiative with fellow radiologist Laurens Topff, from the Netherlands Cancer Institute (NKI) in Amsterdam. “The value of AI also comes into play, by reducing the burden on clinicians. While a manual read of a CT scan can take up to 15 minutes, AI can finish reading the image in 10 seconds.”

Around 30 partners have already expressed their willingness to share data and to support the plan to train the algorithm. These include academic and non-academic hospitals located in the most affected areas of Italy and Spain, and also in Germany, Belgium, the Netherlands and the UK.

European hospital collaboration — The map shows the European hospitals collaborating in the COVID-19 project, as of 20 March. (Courtesy: Erik Ranschaert)

Each hospital will transfer the data directly and securely to the servers of Quibim. Based in Valencia, Spain, it specializes in machine learning and image processing technologies for medical images, and it will provide a research platform for the development and deployment of the deep-learning model. For data preparation, annotation and algorithm training, the Robovision AI (RVAI) software will be used. The data will only be used for research purposes.

Automated image analysis with AI techniques can optimize the role of CT in the assessment of COVID-19 by supporting clinical decision-making, improving workflow efficiency, and allowing accurate and fast diagnosis of infection in a large number of patients, Ranschaert explained.

“We believe that it’s possible to train an accurate AI algorithm with the wealth of data already available since the outbreak of the virus in Europe, with the main aim of helping doctors to make this diagnosis in time,” he added.

A team from the NKI will assess and statistically analyse the performance of the deep-learning model, which will be made freely available as a research solution to participating hospitals.

Growing use of CT

The clinical presentation of patients with COVID-19 ranges from asymptomatic to severe pulmonary infection. The most specific method and reference standard to diagnose infection is the reverse transcription polymerase chain reaction (RT-PCR) test, but due to the varying levels of sensitivity of viral testing, shortage of viral testing kits and longer turnaround times to provide results, lung CT scans are attracting attention, Ranschaert said.

“COVID-19 causes a wide variety of findings on these scans, most typically ground-glass type of densities located on the outside of both lungs (see white areas in figure),” he continued. “The accuracy of chest CT to diagnose COVID-19 has been reported as high and can predate a positive classic serological RT-PCR test. Therefore, in endemic areas where the healthcare system is under pressure, hospitals with a high volume of admissions are using CT for rapid triage of patients.”

CT scan of a COVID-19 patient who was originally referred for CT angiography of the chest to exclude pulmonary embolism. (Courtesy: Erik Ranschaert)

There is a role for chest CT to assess COVID-19 infection in patients with severe and worsening respiratory disorders. Based on the images, doctors can evaluate how severely the lungs are affected and how the patient’s disease is evolving, which is helpful in making treatment decisions, according to Ranschaert.

Also, pulmonary abnormalities caused by COVID-19 can be found by chance in exams carried out for other reasons – for example, abdominal CT scans for bowel problems – in patients without respiratory complaints.

“Patients are coming in with different types of complaints and therefore sometimes get other examinations. Some radiologists are even proposing to do a standard CT chest with every CT abdomen,” he noted. “If a CT abdomen needs to be done because of nonspecific complaints, just scan higher to assess more lung tissue, leading to more nonspecific COVID-19 patients being detected.”

In areas of widespread coronavirus outbreak, many hospitals are installing special scanning units to enable efficient screening of the steadily growing number of victims. If CT is used for screening, there will be so many studies that radiologists will be overwhelmed and AI will be urgently needed.

CT traces disease progression in novel coronavirus

“The scans run full-time and the number of doctors to assess all these scans is sometimes insufficient, partly due to the fact that doctors are also more often exposed to infected patients and therefore themselves become victims of the virus,” Ranschaert pointed out, adding that 300 Chinese doctors had to be flown into Italy to cope with the growing number of patients.

The danger of cross-infection via the CT scanner is an important consideration.

“Some hospitals are very prudent and do a complete disinfection of the CT scan suite, taking about an hour,” he said. “Others only clean the contact surfaces of the scanner, while also protecting the radiographers of course with an adapted outfit – this on advice of their microbiologists. These hospitals usually have a dedicated scanning suite for COVID-19 scans. Some even have a mobile unit outside the hospital to provide these scans.”

A LinkedIn post last week was viewed more than 100,000 times with over 2000 likes. The website for the project is active now.

This article was originally published on AuntMinnieEurope.com ©2020 by AuntMinnieEurope.com. Any copying, republication or redistribution of AuntMinnieEurope.com content is expressly prohibited without the prior written consent of AuntMinnieEurope.com.

A Decade of Discovery Enabled by PeakForce Tapping

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PeakForce Tapping has been widely adopted in a broad range of research fields, outpacing all other recently developed AFM modes in research impact and productivity.

In December 2009, a new mode for atomic force microscopy was introduced – PeakForce Tapping. Since then, it has been widely adopted in a broad range of research fields, outpacing all other recently developed AFM modes in research impact and productivity. PeakForce Tapping and its associated modes ScanAsyst, PeakForce QNM, PeakForce TUNA, PeakForce KPFM, and PeakForce SECM, have been cited in more than 4000 peer-reviewed publications over the last 10 years, with more than 30% of these publications in the top 10% of journals. In this webinar, we will select from this vast repository of publications to review the impact of PeakForce Tapping on today’s science. In particular, we will examine how the measurement of mechanical and electrical properties at the nanoscale have led to new discoveries and insights into material behaviour.

PeakForce Tapping eliminates the need for contact mode in electrical modes, such as conductive and tunneling AFM (e.g. PeakForce TUNA), allowing high-resolution electrical property maps even on soft and fragile samples, and even in liquid (with PeakForce SECM). Battery work using the mode includes a recent Nature Communications article co-authored by Professor John Bannister Goodenough, the 2019 Chemistry Nobel laureate, where high-performance, dendrite-free metal lithium anodes were characterized. In energy research, PeakForce Tapping studies have resolved conductivity along individual lamellae in organic photovoltaics, revealed a nanocontact pinch-off that allows for improved solar fuel devices, and characterized the SEI layer in Li ion batteries in operando as well as ex situ.

Since PeakForce Tapping provides piconewton-level force control and sensitivity, it is ideal for mapping the nanomechanical properties of materials (enabling a mode called PeakForce QNM). Among the many firsts enabled by PeakForce QNM is work by Professor Konstantin Novoselov and Professor Andre Geim, the 2010 Physics Nobel laureates for the discovery of graphene, revealing a commensurate–incommensurate state transition in graphene on boron nitride, as shown in their Nature Physics article.

In biology, it has enabled new studies of ligand receptor interactions, of individual microvilli on live cells, and of variations in the DNA double helix structure, to name just a few. In studies of polymers and composites, it has become the mode of choice for quantifying properties at interfaces and in interphases, including in adhesives, where other AFM modes struggle.

Presenter:

Dr Bede Pittenger
Dr Bede Pittenger is a senior staff development scientist in the AFM Unit of Bruker’s Nano Surfaces business. He received his PhD in physics from the University of Washington (Seattle, WA) in 2000 and has worked with scanning probe microscopes for 25 years, building systems, developing techniques, and studying properties of materials at the nanoscale. His work includes more than 30 publications and four patents on various techniques and applications of scanning probe microscopy. Dr Pittenger’s interests span topics from interfacial melting of ice, to mechanobiology of cells and tissues, to the nanomechanics of polymers and composites.

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Physics in the pandemic: ‘My job is not amenable to working from home’

Photo of an optical setup bathed in purplish light — **Making lasers behave** As in most atomic physics experiments, the equipment in Hannah Williams’ lab requires regular attention and cannot be operated remotely. (Courtesy: Hannah Williams)

I moved to France with my partner just over five months ago, and we now live in a small flat in the centre of Paris. As an experimentalist, I usually spend most of my day in the lab, often coaxing the lasers into behaving. In my experiment, we trap individual atoms in an arbitrarily arrangeable array of optical tweezer traps. We can then excite these atoms into a Rydberg state and use the set-up to simulate quantum systems. There is no such thing as a normal day for me, as my tasks are dictated by the current state of the experiment. Over the course of a week I could be working on a laser, taking data, analysing and writing up results, or fixing machinery or other pieces of equipment. This hands-on variety is my favourite part of being a researcher.

Empty shops, empty lab

As with most people, the pandemic has had a huge impact on my daily life. The French government closed universities and research labs on 13 March, and since then it has introduced strict lockdown rules. My partner and I are expected to stay in our apartment, only leaving for food, medicine or exercise. We must remain within 1 km of our home, return within an hour and carry a note indicating the time we went out and the reason why. From my brief excursions it seems like people are adhering to these rules; the streets are empty and the shops and hotels have been boarded up, although the boulangeries remain open to provide the city with baguettes and croissants. This lockdown was initially set to last for 14 days, but it is likely to be extended.

The vast majority of my job is not amenable to working from home. Sadly, the experiment consists of many physical buttons and switches that need pressing in order to run, and it cannot be controlled remotely. Therefore, I have had to find new tasks that can be completed from the (relative) comfort of my dining table. I am currently focusing on building and running simulations of the experiment. This is a good task for me as I have wanted to do this for a while, but I find it too easy to get distracted by the goings-on in the lab.

Three mornings a week the lab has a group Skype where we discuss our work, catch up and check in on one another. Last week I also took part in a workshop that had been moved online. I had not registered for the “real-life” version, and had it not been for the global lockdown I would not have known about it. I also might never have got to experience being totally confused by a theory talk while sitting on my sofa, in my joggers.

A photo of the Pantheon, a large Classical building with columns and a dome with the French tricolour on top and an empty plaza out front — **Deserted** The Pantheon in Paris is normally a major tourist destination, both in its own right and because it has an uninterrupted view of the Eiffel tower. (Courtesy: Hannah Williams)

Blue skies above, anxiety below

Staying inside my flat has not been easy, as I like being outside and walking. I usually walk for over an hour each day just to get to my lab, but my Fitbit informs me that last week I walked 50 km less than normal. To make matters worse, the weather in Paris is suddenly beautiful, with blue skies every day and temperatures warm enough to eat ice-cream in the street. However, I understand the importance of staying inside and I know that I am in a position of privilege; I am healthy, I’m still getting paid, I live with my partner and French supermarkets are being kept very well stocked. I am enjoying the extra time I have because I’m no longer commuting; I am cooking more, doing yoga (almost) every day and running three or four times a week. I am also talking more to friends and families via group Skypes and virtual pub meet-ups in which we try to avoid talking about the virus, but inevitably circle back round to it.

Physics in the pandemic: ‘My job is not amenable to working from home’

I miss the lab, and I miss the work I was doing. After five months in my role, I finally really understood the experiment and was very excited about the data we were taking. Some days are harder than others and remaining productive can be a challenge. I feel anxious about the health of family and friends and down about the state of the world. It is difficult to escape from the barrage of statistics and endless lists of “How to be productive at home”, “Best workouts to do in your living room” and “Top TV shows to binge watch” – none of which make for interesting or uplifting reading. This is a time of uncertainty and disruption which many of us have never faced before, with no clear end in sight. So when I feel anxiety or stress, I take a break. I don’t try to make myself work. I do something else – and above all, I get off the Internet.

Nanoscale structures give some butterflies ‘ultra-black’ wings

Many male butterflies have exceptionally black wings with optical properties that have long-puzzled scientists. Now researchers in the US found that the wings of at least 10 species have nanoscale structures that increase light absorption and scattering that create the “ultra-black” appearance. These structures may have evolved to enhance the contrast of colour patches used in courtship displays, according to the researchers. Understanding why the wings are so dark could lead to the development of ultra-black synthetic materials.

Butterfly wings are made of scales that usually consist of two chitin layers. One layer is a smooth, flat plate. The other layer has ridges that are connected by cross ribs to form a honeycomb-like structure. The two layers are connected by pillars known as trabeculae.

It has been suggested that the size of the nanoscale holes in the honeycomb-like structure on the upper scales could be responsible for the extreme light-absorbing properties of some butterflies. But when Alex Davis at Duke University and colleagues examined the scales of 10 butterfly species that are exceptionally black, they found that that was not the case.

Extremely low directional reflectance

When the researchers shone light on specimens from museum and university collections, they found that the black scales had an extremely low directional reflectance. With the light source perpendicular to a wing’s surface, the ultra-black butterflies only reflected between 0.06 and 0.4% of light, they report in Nature Communications. In contrast, “control” butterflies that are brown or less black, had reflectance values of 1–3%.

Scanning electron microscopy on both the ultra-black and control butterflies found, however, that there was considerable variation in the shape and size of the holes in the upper wing scales – with them ranging from honeycombs and rectangles to a V-shaped pattern. The ultra-black specimens covered four different subfamilies of butterflies and there was little similarity between the hole structures. This led the researchers to conclude that hole shape or size is not linked to ultra-blackness.

Instead, Davis and colleagues found that other structures were very similar across the ultra-black specimens. The parallel ridges and trabeculae on their wing scales were much deeper and thicker than in the control butterflies, which had larger gaps between the ridges and either no or significantly reduced trabeculae.

Computer models

Next the team created computer models of different wing scales. Simulations of scales without either the ridged surface or interior pillars reflected up to 16 times more light, while those lacking both were up to 28 times more reflective.

Davis told Physics World that expanded trabeculae and ridges, the ultra-black butterflies have more surface area for absorbing and scattering light. This combined with the light absorbing pigment melanin, which is embedded in the structure, produces the low reflectance. Light enters the scales and bounces around, but very little bounces back.

This structure is so good at absorbing light that the ultra-black scales still appear black when coated with gold for scanning electron microscopy, the researchers report.

Brightly coloured areas

Ultra-black wing patches in butterflies often border brightly coloured areas. The researchers believe that the black patches have evolved to make those colours appear brighter during courtship. “Given that the males are much blacker than the females in most of these species, we suspect ultra-black scales have evolved to increase the contrast of signals used in mating,” Davies explains. “These butterflies tend to court one another in sunny areas where a typical black scale may look washed out.” Davies thinks there are probably many other ultra-black butterflies using the same structures.

Silvia Vignolini at the University of Cambridge, UK, who was not involved in the work, thinks there could be a more functional benefit to the enhanced light absorption. “They need to warm up the wings in order to fly,” she explains.

Vignolini adds that the study is interesting because it compares different butterfly species and families and shows how scale morphology can decrease reflection. She cautions, however, that while she sees no reason to doubt the results, the paper lacks detail on how the authors measured reflectance, and what they measured.

It is also not safe to assume that a single, ultrathin (2.5 μm) scale from one of these butterflies would show the same levels of reflectance, Vignolini says, as the researchers studied whole wings. “The wing is composed of more than one scale, and the scales are superimposed on top of each other,” she says. Adding that this means that “you have more scattering, because you have space between each scale”.

Beating COVID-19: the April 2020 issue of Physics World is now out

Physics World April 2020 cover — Life in the pandemic: how physics is helping us understand the virus behind COVID-19.

Like everyone else around the world, physicists have been caught up in the COVID-19 outbreak, which was declared a pandemic by the World Health Organization last month. Naturally, all of us will be concerned first and foremost for our own friends and family.

The disease is usually mild, but it can turn nasty – and with lots of people falling ill at once, there will be big pressures on medical systems around the world. It goes without saying that we should all look out for each other, especially older neighbours, colleagues and family members.

And with so many of us under lock-down, what better time to sit back with the latest issue of your favourite physics magazine, now out in print and via the Physics World digital apps for iOS, Android and Web browsers.

The cover feature is by science writer Jon Cartwright, who looks at how physics-based techniques are helping us to understand the virus behind COVID-19 – also available online here.

We’ve created a short video that summarizes the key points: bottom line, we can thank X-ray crystallography, cryo-electron microscopy and network theory for understanding the disease and how it spreads.

Remember that 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.

• Coronavirus puts physics in turmoil – COVID-19 has hit the international physics community hard, with meetings and conferences cancelled, including the showpiece events of the American Physical Society. Matin Durrani surveys the fall-out from the global pandemic.

• Moving forward together – In the run-up to a pivotal announcement on the future of particle physics in Europe, Tessa Charles urges backers of rival colliders to unite around whichever project gets the go-ahead.

• What would you do? – Robert P Crease examines his responsibility for not exploring one physicist’s treatment of women.

• Shipping carbon-free – Air travel is bad for the environment – but shipping is not that great either. James McKenzie wonders how best to decarbonize sea travel.

• Fighting a pandemic – The latest novel coronavirus, SARS-CoV-2, has reached pandemic status. While health workers and governments do their part, scientists are trying to understand the virus and develop vaccines and treatments. Jon Cartwright looks at how physics plays an important role in the fight.

• Life in a carbon-neutral world –Increasing numbers of cities and countries around the globe are pledging to become net carbon neutral within the next few decades. But what will day-to-day life look like in a “net-zero” world? Kate Ravilious looks at the changes that society will need to make.

• The diamond quantum revolution – Diamond is more than just a pretty gem – it has many attractive properties that stretch far beyond its aesthetic appeal. Matthew Markham and Daniel Twitchen from UK firm Element Six explain how this special form of carbon now has many practical quantum applications too.

• Can a machine think? – Susan Curtis reviews The Road to Conscious Machines: the Story of AI by Michael Wooldridge.

• Duck, duck, goose? – Ian Randall reviews At the Edge of Time: Exploring the Mysteries of Our Universe’s First Seconds by Dan Hooper.

• Half a life – Jess Wade reviews the film Radioactive, a biopic about Marie Curie directed by Marjane Satrapi, screenplay by Jack Thorne.

• Going with the flow – Early-career industry physicist Aidan White tells Joe McEntee about his work as a project engineer at TÜV SÜD National Engineering Laboratory, the UK’s designated institute for flow and density measurement.

• Ask me anything – In the latest in our new series of careers-advice articles, we feature Chad Orzel, who is an associate professor in the Department of Physics and Astronomy at Union, and author of four popular-science books.

• Physics on ice – Rhett Allain uses simple Newtonian mechanics to estimate how far an ice-hockey puck could travel on a low-friction icy surface.

Physics in the pandemic: ‘Watching a phenomenon of staggering scope unfold in real time, dictated by simple mathematics’

I suspect my experience with the outbreak of COVID-19 here in British Columbia differs little from that of millions of others. My wife and I both work at the University of Victoria, and it was relatively easy for us to shift our teaching, research and collegial interactions online. The simulated and historical data that comprise the grist of my climate research are still accessible, so that work goes on unhindered. We are both lucky in that respect, and also to have shielded our family from the tragedy thus far.

In the days before being sent home from the office, I combed the Internet for reliable sources of data on the spread and growth rate of the infection: a nightly hobby only another scientist could appreciate. One conclusion was immediate: each country’s cumulative cases closely followed an exponential curve, with only China exhibiting a flattening and subsequent decline. I downloaded the daily case totals and performed log-linear fits to the data, revealing differing growth rates across the world. And in my province, checked daily for signs of flattening. While undeniably tragic, it’s also fascinating to see a phenomenon of such staggering scope unfold in real time, dictated by simple mathematics. When my 14-year-old son’s home schooling starts next week, you can guess what applied math topic we’ll tackle first.

Once the government imposed physical distancing guidelines, a neighbour asked my opinion (“as a scientist”), and shared his own. The government measures were certainly overkill, he felt: his clients were shuttering their businesses, this was killing the economy, why are they even talking about months? I agreed it was sudden, and uncharted territory. But the exponential curve danced in my head: these were not bacteria multiplying in a dish, but sick human beings, in every corner of the world. If there is anything that would kill the economy, I opined, it’s something that forces people out of it. We agreed to disagree.

And lessons learned so far? Here on Vancouver Island, at the end of the Trans-Canada Highway and near the end of supply lines to western Canada, we are occasionally reminded that we live in an earthquake zone. There’s a better-than-even chance a megathrust quake will occur in the region during my kids’ lifetime, we’re told. The COVID-19 experience has already taught us that, even in a global crisis, people keep their heads, large populations adapt, and there is considerable resilience in the consumer supply chain. We can trust the advice proffered by government and scientists, provided it is evidence-based. And when we encounter those who may be more sceptical, as scientists we can share our perspectives on the natural laws that no amount of wishful thinking can supersede.

Physicists doing stupid things

When Physics World learned that an Australian astrophysicist had tried to invent a device to keep people from touching their faces during the coronavirus pandemic, only to wind up in hospital with four neodymium magnets stuck up his nose, our first thought was, “Is it April Fool’s Day in Australia already?”

Our second thought, though, was, “Yeah, that sounds like something a physicist would do.”

We write a lot about physicists. We’re regularly amazed and humbled by the creativity and cleverness they show in the face of daunting scientific challenges. But we also know that physicists have a rare talent for making absolute arses of themselves – and we have a giant red folder full of stories to prove it.

So this year, in lieu of an April Fool (and to reassure the above-mentioned Aussie, Daniel Reardon, that getting magnets stuck up your nose during a pandemic is not, in fact, the dumbest thing a physicist has ever done – although it’s close), we present five additional astonishing displays of idiocy by otherwise highly intelligent people. All are drawn from the Physics World archives and compiled by our emergency otolaryngology correspondent Ken Heartley-Wright, who is currently self-isolating at his country home in Borsetshire. Enjoy!

That’s not (n)ice

Like Reardon, Muhammad “Moe” Qureshi made a fool of himself while attempting to aid the battle against a terrible illness. In the “ice bucket challenge” of 2014, celebrities, politicians and ordinary folk lined up to pour buckets of ice over their heads to raise money for research on motor neurone disease. The late physicist Stephen Hawking, who lived with the condition for more than 50 years, was among the participants.

But Qureshi, who was then a nanotechnologist at the University of Toronto in Canada, decided to go one better than Hawking et al. “Instead of using ice water, we’re going to be using liquid nitrogen,” he announced to the camera as a collaborator filmed his don’t-try-this-at-home stunt. “This is extremely dangerous and not safe, but we’re going to do it anyway.” A few seconds later, the video shows Qureshi pouring a substantial quantity of steaming liquid nitrogen over his head.

Unlike Reardon, Qureshi did not require hospital treatment. However, the footage of him dancing around yelling “Oh my gosh, that’s cold!” while frantically trying to remove the 77 K liquid from his hair, T-shirt and shorts should nevertheless give would-be imitators pause.

Stranded tardigrades

Scientists have long wondered whether life exists outside the Earth. In April 2019, an Israeli space mission may have answered that question by accidentally populating the Moon with tardigrades. These creatures, also known as water bears, can survive in some of Earth’s most extreme environments, and they were flown to the Moon aboard the Beresheet spacecraft. During the landing process, however, a malfunction caused the craft’s engines to shut down, and it crashed to the lunar surface.

Beresheet’s crew of 10,000 tardigrades were shipped to the Moon in a dehydrated state, with a dramatically reduced metabolism. Tardigrades are, however, known to endure incredibly harsh conditions – including the vacuum of space. If they survived the crash, a little water might be enough to resurrect them. It’s a long shot, of course: tardigrades have poor tolerance to solar UV radiation, and the Moon (like some supermarkets during the current pandemic) has a distinct shortage of liquid water or food. But now we’ll always be wondering.

Legal troubles, part 1

In medieval and ancient times, alchemists sought to turn base metal into gold. In the late 2000s, Iain Fielden, a physicist at Sheffield Hallam University in the UK, managed to do the opposite by turning a £60 speeding ticket into court costs exceeding £20,000.

The affair began in mid-2006, when a speed camera clocked Fielden’s wife Vikki driving around a curved street in Huddersfield at 36 mph in a 30 mph zone. Fielden, who was sitting in the passenger seat at the time, insisted she was driving at 31±3 mph. He chose to fight the ticket because, he claimed, the speed camera was situated on a curve and would only work correctly for vehicles travelling in a straight line.

So far, so reasonable. But Fielden’s efforts quickly took on the character of a crusade. After a magistrate’s court handed down the £60 fine in 2007, he, his wife and two witnesses set out in the dead of night to measure the curvature of the road using a tape measure, rope and a laser. The results showed that the radius of the road was about 600 m – half the minimum value permitted in the camera manufacturer’s guidelines.

Fielden duly challenged the magistrate court’s ruling on the basis that the police were not using the radar in line with the guidelines. But despite spending 1000 hours researching the case (and, at one point, impersonating a lawyer for the Crown Prosecution Service during a phone conversation with a witness) he lost his appeal at Bradford Crown Court – one reason being that the limit of 1200 m for the curvature was, it seems, arbitrary.

By this time, Fielden’s legal costs had reached £15,000 – an amount he said would lead to “bankruptcy, probably”. But he didn’t stop there. Instead, he pursued the matter to the High Court, where, in mid-2009, one of the judges described the suit as “doomed to fail”, dismissed it and denied Fielden a further chance to appeal. This result cost him a further £5000 in legal fees. At that point, Fielden vowed to take his case to the European Court of Human Rights. While Physics World can find no record of his having done so, the protracted battle doesn’t seem to have diminished his interest in the law: he is now part of an expert witness programme at Sheffield Hallam’s Materials and Engineering Research Institute.

Legal troubles, part 2

Fielden’s problems with the law pale in comparison with those of Paul Frampton. A British-born theorist, Frampton made a name for himself within the field of particle physics. By 2012 he was a respected but decidedly un-famous professor at the University of North Carolina in the US.

All that changed when, at the age of 71, Frampton travelled to Bolivia in hopes of meeting the Czech-born lingerie model Denise Milani, with whom he had supposedly been corresponding over the Internet. When he arrived, Milani was nowhere to be seen, but someone did turn up with a request that he carry “her” suitcase to Buenos Aires, Argentina. This he duly did – only for airport officials to find 2 kg of cocaine tucked into its lining.

Exactly how much Frampton knew about this is a vexed question. While he has always maintained his innocence, text messages sent from him to “Milani” (in reality, a fraudster whose identity remains unknown) suggest that he may have been less naïve than he claims. According to a 2013 New York Times article, the texts included comments such as “This stuff is worth nothing in Bolivia, but millions in Europe” and “Monday arrival changed. You must not tell the coca-goons.”

At his trial, Frampton claimed the messages were “jokes”; later, he hired a forensic linguist to try to prove he hadn’t written them. Neither strategy did him much good. He was sentenced to 56 months in a Buenos Aires jail, and his former employer refused to reinstate him. Still, his experiences may yet have a silver lining of sorts. In 2013, Fox Searchlight asked officials from the US film-production company Film Rites to make a film based on his life. We can only assume that the pandemic must have held up production.

Acid attack

And finally, in our roll-call of dumbest things ever in physics, Physics World is delighted to bring you this cautionary tale of Irish physicist Kevin McGuigan during his time as a PhD student.

Seeking to dope some silicon ingots with copper, McGuigan decided to melt a glass tube containing his ingredients by heating them in a furnace at 1000 °C using an “oxygen-hydrogen welding station” in the corner of his lab. Upon opening the main valves to the gas cylinders, McGuigan noticed an ominous hissing noise that he wanted to “sort out” with a “small twist” of his spanner.

Physics World October 2002 — Cack-handed: a warning to all would-be Kevin McGuigans

Aware that hydrogen is dangerously flammable, McGuigan “panicked” and began turning the fittings on the cylinder “the wrong way”. The regulator refused to budge, prompting McGuigan to increase his “purchase” on the bottle, by wrapping his legs around the base “in an attempt to stop it spinning”.

Then, just as McGuigan was having visions of a Hindenburg-style disaster, his supervisor walked in. Upon seeing him wrapped around the hydrogen cylinder “wrestling with the regulator like a demented, pole-dancing plumber”, his boss calmly closed the cylinder’s main valve.

A nightmare was averted, but McGuigan’s day was about to take a turn for the worse.

After doping his samples, McGuigan placed them in a beaker of concentrated hydrochloric acid. While attempting to dissolve “the final traces of copper from the ingots”, he held the beaker up to the light “as you would with a fine wine”. Finally, he tried to inspect the samples’ surfaces by giving the beaker, as you do, “a good slosh”.

As luck would have it, the acid sloshed right out of the beaker and onto his groin. McGuigan jumped up, unbuckled his belt and trousers, and thrust them down by his ankles. Noticing the acid making its way onto his boxer shorts, he yanked them down too before “speed-shuffling over to a metal sink” and vigorously dousing his nether regions in water.

It was then that McGuigan’s supervisor, the head of department and a visiting female professor walked in – on an impromptu tour of the lab.

Although McGuigan was unscathed “apart from what looked like a pubic perm gone wrong”, his supervisor and the department head agreed that henceforth, McGuigan’s “theoretical and modelling skills should be enthusiastically encouraged”.

Tips for a rewarding career in physics

Most of the time science appears in the media – including in this podcast – the focus is on the scientific results. Rightly so, as scientific research consistently delivers inspiring breakthroughs. But this type of coverage can present an idealized version of science. Researchers are presented as dispassionate beings working together seamlessly to uncover the common truths of their discipline.

In reality, scientists are people with a range of personalities and backgrounds, displaying all the usual human traits – the good and the bad. In this episode of the Physics World Stories podcast, Andrew Glester meets a selection of successful researchers to discover what it is really like to carve out a career in physics. What motivates them? What are the big challenges lying ahead for early-career researchers? What are the rules they play by?