Climate intervention: a possible hope in the face of humanity’s biggest problem

29 Aug 2022 Hamish Johnston

Hamish Johnston reviews Pandora’s Toolbox: the Hopes and Hazards of Climate Intervention by Wake Smith

Unknown outcomes Climate-intervention methods could provide hope or hazards. (Courtesy: iStock/fergregory)

The rapid reduction of greenhouse-gas emissions to net zero is the only practical way to halt climate change. But thanks to two centuries of burning fossil fuels, we have created a warmer climate that will endure for generations. As a result, humanity will be faced with an important decision: do we live on a hot planet with all the problems that brings, or do we intervene to try to cool things down?

 

The power of photonics: from vertical farming to quantum computing

31 Aug 2022 James McKenzie

James McKenzie marvels at the wonders of photonics, which is so much more crucial to everyday life than it first appears

Lighting up the world Photonics has countless applications, including energy-efficient, pesticide-free “vertical farming”. (Courtesy: iStock/Supersmario)

Which industry employs twice as many people in the UK as pharmaceuticals and more than either the space or “fintech” sectors? The answer is photonics, according to the Photonics Leadership Group (PLG) – a trade association representing more than 120 members in the field.

 

Ultrafast switch takes a big step towards the terahertz regime

06 Sep 2022 Charly Leblanc

Fast switching: a pump signal creates a Bose-Einstein condensate of polaritons in a ZnO microcavity, which emits light. The control signal collapses the population of polaritons, turning off the microcavity emission. (Courtesy: Hui Li)

All-optical devices promise higher-frequency processing and faster information transfer, compared to their electronic counterparts. An elementary component of this circuitry is a switch fast enough to deal with optical frequencies. Now, Fei Chen at East China Normal University and his colleagues in China, have developed a room temperature ultrafast optoelectronic switch using a Bose-Einstein condensate (BEC) of polaritons. This device pushes the speed frontier of all-optical controlled polaritonic switches at room temperature towards the terahertz regime.

 

Twisted light could create solitons in Bose–Einstein condensates

31 Aug 2022

Sculpting matter: The image on the left illustrates twisted light with an angular momentum of two, which was used in the team’s calculations. The image on the right shows a BEC that has been impinged by the twisted light and has split into four solitons. (Courtesy: University of Strathclyde)

Researchers in the UK have done calculations that show how “twisted light” can be used to manipulate the ultracold atoms in an exotic state of matter called a Bose–Einstein condensate (BEC). Using theoretical models, Grant Henderson and colleagues at the UK’s University of Strathclyde discovered that light–matter solitons could be generated through the interaction between corkscrew-shaped wavefronts of light and BECs.

 

Ultrasound-powered implant treats brain cancer using electromagnetic fields

22 Aug 2022

Ultrasound-powered tumour treating device: (A) The implantable UP-TTD is excited by an external ultrasound source, producing adjustable alternating electric fields that inhibit brain tumour growth. (B) The device focuses on rapidly dividing tumour cells without affecting normal neural cells. (C) UP-TTD structure with key components labelled. (Courtesy: Y Yang et al Sci. Adv. 10.1126/sciadv.abm5023/CC BY-NC)

Successful treatment of brain tumours remains a challenge. Surgical removal is often the best option, but the inability to entirely remove all of the cancer cells can lead to recurrence and metastasis. Tumour treating fields (TTFs), which use alternating electric fields to interrupt cancer cells’ ability to divide, provide a potential new treatment option for brain tumours. For glioblastoma patients, TTFs are delivered following surgical resection and completion of chemotherapy and radiotherapy. Clinical trials have shown that the technique can notably extend survival for some patients.

 

Decision-making tool helps replan radiotherapy after a cyber attack

30 Aug 2022

Plan comparisons Radiotherapy treatment plan for a head-and-neck cancer patient, with the planning target volume (PTV) outlined in red. The graph shows the physical dose–volume histogram (DVH), the radiobiological DVH from EQD2VH and the point-dose calculation method, for the PTV and an organ-at-risk. (Courtesy: CC BY 4.0/J. Appl. Clin. Med. Phys. 10.1002/acm2.13716)

Cyber attacks on hospitals can have a devastating impact, especially for radiology and radiotherapy departments that are particularly reliant upon technology to function. A case in point is the nationwide cyber attack on Ireland’s public health services in May 2021, which interrupted scheduled radiotherapy treatments for some cancer patients for up to 12 days.

 

Squid teeth inspire stretchable 2D layered material

30 Aug 2022 Isabelle Dumé

Composite layered 2D materials that are resistant to breaking and extremely stretchable. (Courtesy: Dong Li, Nanyang Technological University)

Natural layered materials such as bone and mother-of-pearl have many functions. Alongside helping organisms protect and defend themselves, some, such as the shells of marine animals, can also sequester carbon by combining proteins and inorganic composites. Researchers at Pennsylvania State University in the US have now engineered artificial versions of these composites inspired by the ring teeth of squid. The new structures are tough and extremely stretchy, and they might find use in applications such as robotics and flexible electronics as well as in carbon sequestration.

 

Single atoms swim inside a graphene sandwich

01 Sep 2022 Isabelle Dumé

Atoms swimming in liquid thanks to graphene. Courtesy: The University of Manchester

A new technique makes it possible to capture videos of single atoms “swimming” at the interface between a solid and a liquid for the first time. The approach uses stacks of two-dimensional materials to trap the liquid, making it compatible with characterization techniques that usually require vacuum conditions. It could enable researchers to better understand how atoms behave at these interfaces, which play a crucial role in devices such as batteries, catalytic systems and separation membranes.

 

Magnets, magnets, magnets: we’ll need lots of them for a green economy

10 Aug 2022 James McKenzie

Taken from the August 2022 issue of Physics World, where it appeared under the headline "Magnetic economy". Members of the Institute of Physics can enjoy the full issue via the Physics World app.

James McKenzie realizes that we’re going to need lots of magnets if we want to turn the economy green

Green future Electric car motors on an assembly line. (Courtesy: iStock/Aranga87)

I was recently in Newcastle to attend PEMD2022 – the 11th international conference on power electronics, machines and drives. What struck me was not only the huge performance improvements that have been happening in electric motors and generators but just how far we still have to go to make transport fully carbon-free.

 

A spoonful of sugar makes the dendrites go down

05 Sep 2022 Isabelle Dumé

A sucrose-modified aqueous electrolyte increases the mobility of zinc ions in response to the electric field and successfully achieves dendrite-free zinc batteries. (Courtesy: Nano Research, Tsinghua University)

Aqueous zinc batteries are promising alternatives to their lithium-ion cousins, but they suffer from one of the same problems: the formation of dendrites. These needle-like structures form on the surface of the zinc anode and grow into the electrolyte, causing the battery to short or, in some cases, even ignite.

 

Wallpaper made of moth wings is an excellent absorber of sound

07 Jul 2022

Stealthy flier: the Antheraea pernyi moth is very good at absorbing ultrasound. (Courtesy: University of Bristol)

When moth wings are used to coat hard, artificial surfaces, they can significantly reduce the reflection of incoming ultrasound, researchers in the UK have shown. Without making any modifications to the wings’ scale structures, Marc Holderied and colleagues at the University of Bristol showed how the natural metamaterial performs remarkably well as natural soundproofing.

 

Liquid-metal experiment simulates astrophysical accretion discs

30 Aug 2022

Spin transfer Artist’s impression of an accretion disc surrounding a black hole. (Courtesy: Shutterstock/oorka)

Researchers in France have created a new experiment that could improve our understanding of the dynamics of stellar and black hole accretion discs. Designed by Marlone Vernet and colleagues at the Sorbonne University of Paris, the experiment uses a combination of radial electric fields and vertical magnetic fields to contain a rotating disc of liquid metal. This allowed the team to observe how angular momentum is transferred within the disc – something that could provide insights into planet formation and the regions around black holes.

 

Unconventional superconductor is even odder than expected

31 Aug 2022 Isabelle Dumé

A proof of odd-parity superconductivity. (Courtesy: © PRX)

Condensed-matter physicists knew that CeRh2As2 was an unconventional superconductor, but they didn’t appreciate just how unconventional it was until an international team of researchers took a closer look at how it behaves in high magnetic fields. According to the latest findings from researchers at the Max Planck Institute for Chemical Physics of Solids (MPI CPfS) in Dresden, Germany and colleagues, CeRh2As2 is one of only a few materials to boast an odd-parity superconducting state – that is, one that is stable to magnetic fields applied in certain directions.

 

How Betelgeuse blew its top and lost its rhythm

22 Aug 2022

Obscured by a cloud: the bottom panel shows a time series of the expected ~400-day pulsation in the brightness of Betelgeuse (blue dashes) as well as the measured brightness (orange line). The top panel shows corresponding illustrations of the ejection and the obscuring cloud. (Courtesy:NASA/ESA/Elizabeth Wheatley (STScI)

Further insights into the curious dimming of the star Betelgeuse have been unveiled by an international team of astronomers led by Andrea Dupree of the Harvard–Smithsonian Center for Astrophysics.

 

New device entangles free electrons with photons

03 Sep 2022

Entangled pairs: in this artistic representation of the experiment, a beam of free electrons (yellow) passes next to a ring-shaped microresonator (black). The evanescent interaction between an electron and the microresonator creates a photon (turquoise) that is entangled with the electron. (Courtesy: Ryan Allen/Second Bay Studios)

The quantum entanglement of a free electron with a photon has been achieved by researchers in Germany and Switzerland. The team, led by Armin Feist at the Max Planck Institute for Multidisciplinary Sciences, achieved the feat using a new experimental setup, which combines elements of photonics and electron microscopy.

 

High-resolution diamond sensor maps electrical currents in the heart

06 Sep 2022

Diamond detection A sensor based on NV centres has been used to measure electrical currents in the heart of a rat. (Courtesy: iStock/Gizmo)

A diamond-based sensor that maps out the subtle electrical currents inside the heart has been developed by researchers in Japan. Led by Takayuki Iwasaki at the Tokyo Institute of Technology, the team based its device on the fluorescence of nitrogen-vacancy (NV) centres in diamonds.

 

Slimmed-down terminal transmits quantum keys from space

02 Sep 2022

Secure transmission: Researchers experimentally demonstrated a space-to-ground quantum key distribution (QKD) network using a compact QKD terminal aboard the Chinese space lab Tiangong-2 and four ground stations. (Courtesy: Cheng-Zhi Peng, University of Science and Technology of China)

Researchers in China have achieved a major milestone in space-to-ground quantum key distribution (QKD) by demonstrating a functional QKD terminal with half the mass of a previous system.

 

earth's crust grew faster when our planet passed through the Milky Way’s spiral arms, study suggests

04 Sep 2022

Galactic voyage Artist’s impression of the Milky Way showing its spiral arms. (Courtesy: NASA/JPL-Caltech/ESO/R Hurt)

The rate at which Earth’s continental crust builds up goes through cycles, peaking around every 200 million years when the solar system travels through one of the Milky Way’s spiral arms. That is the conclusion of an international team of researchers, who argue that crustal production is boosted when more high-energy comets crash into the Earth. They say that these comets are dislodged from the Oort cloud by the influence of regions of space with dense interstellar clouds.