This episode of the Physics World Weekly podcast features George Efstathiou and Richard Bond, who share the 2025 Shaw Prize in Astronomy, “for their pioneering research in cosmology, in particular for their studies of fluctuations in the cosmic microwave background (CMB). Their predictions have been verified by an armada of ground-, balloon- and space-based instruments, leading to precise determinations of the age, geometry, and mass-energy content of the universe.”
Bond and Efstathiou talk about how the CMB emerged when the universe was just 380,000 years old and explain how the CMB is observed today. They explain why studying fluctuations in today’s CMB provides a window into the nature of the universe as it existed long ago, and how future studies could help physicists understand the nature of dark matter – which is one of the greatest mysteries in physics.
Efstathiou is emeritus professor of astrophysics at the University of Cambridge in the UK – and Richard Bond is a professor at the Canadian Institute for Theoretical Astrophysics (CITA) and university professor at the University of Toronto in Canada. Bond and Efstathiou share the 2025 Shaw Prize in Astronomy and its $1.2m prize money equally.
This podcast is sponsored by The Shaw Prize Foundation.
Quantum science is enjoying a renaissance as nascent quantum computers emerge from the lab and quantum sensors are being used for practical applications.
As the technologies we use become more quantum in nature, it follows that everyone should have a basic understanding of quantum physics. To explore how quantum physics can be taught to the masses, I am joined by Arjan Dhawan, Aleks Kissinger and Bob Coecke – who are all based in the UK.
Coecke is chief scientist at Quantinuum – which develops quantum computing hardware and software. Kissinger is associate professor of quantum computing at the University of Oxford; and Dhawan is studying mathematics at the University of Durham.
Kissinger and Coecke have developed a way of teaching quantum physics using diagrams. In 2023, Oxford and Quantinuum joined forces to use the method in a pilot summer programme for 15 to 17 year-olds. Dhawan was one of their students.
In this episode of the Physics World Weekly podcast I look at what’s new in the world of physics with the help of my colleagues Margaret Harris and Matin Durrani.
Then, we run time in reverse and go back to the German island of Helgoland, where in 1925 Werner Heisenberg laid the foundations of modern quantum mechanics. The island will soon host an event celebrating the centenary and Physics World will be there.
Many creative industries rely on cutting-edge digital technologies, so it is not surprising that this sector could easily become an early adopter of quantum computing.
In this episode of the Physics World Weekly podcast I am in conversation with James Wootton, who is chief scientific officer at Moth Quantum. Based in the UK and Switzerland, the company is developing quantum-software tools for the creative industries – focusing on artists, musicians and game developers.
Wootton joined Moth Quantum in September 2024 after working on quantum error correction at IBM. He also has long-standing interest in quantum gaming and creating tools that make quantum computing more accessible. If you enjoyed this interview with Wootton, check out this article that he wrote for Physics World in 2018: “Playing games with quantum computers“.
The UK-based company Delta.g has bagged the 2025 qBIG prize, which is awarded by the Institute of Physics (IOP). Initiated in 2023, qBIG celebrates and promotes the innovation and commercialization of quantum technologies in the UK and Ireland.
Based in Birmingham, Delta.g makes quantum sensors that measure the local gravity gradient. This is done using atom interferometry, whereby laser pulses are fired at a cloud of cold atoms that is freefalling under gravity.
On the Earth’s surface, this gradient is sensitive to the presence of buildings and underground voids such as tunnels. The technology was developed by physicists at the University of Birmingham and in 2022 they showed how it could be used to map out a tunnel below a road on campus. The system has also been deployed in a cave and on a ship to test its suitability for use in navigation.
Challenging to measure
“Gravity is a fundamental force, yet its full potential remains largely untapped because it is so challenging to measure,” explains Andrew Lamb who is co-founder and chief technology officer at Delta.g. “As the first to take quantum technology gravity gradiometry from the lab to the field, we have set a new benchmark for high-integrity, noise-resistant data transforming how we understand and navigate the subsurface.”
Awarded by the IOP, the qBIG prize is sponsored by Quantum Exponential, which is the UK’s first enterprise venture capital fund focused on quantum technology. The winner was announced today at the Economist’s Commercialising Quantum Global 2025 event in London. Delta.g receives a £10,000 unrestricted cash prize; 10 months of mentoring from Quantum Exponential; and business support from the IOP.
Louis Barson, the IOP’s director of science, innovation and skills says, “The IOP’s role as UK and Ireland coordinator of the International Year of Quantum 2025 gives us a unique opportunity to showcase the exciting developments in the quantum sector. Huge congratulations must go to the Delta.g team, whose incredible work stood out in a diverse and fast-moving field.”
Two runners-up were commended by the IOP. One is Glasgow-based Neuranics, which makes quantum sensors that detect tiny magnetic signals from the human body. This other is Southampton’s Smith Optical, which makes an augmented-reality display based on quantum technology.
The electrochemical reduction of carbon dioxide is used to produce a range of chemical and energy feedstocks including syngas (hydrogen and carbon monoxide), formic acid, methane and ethylene. As well as being an important industrial process, the large-scale reduction of carbon dioxide by electrolysis offers a practical way to capture and utilize carbon dioxide.
As a result, developing new and improved electrochemical processes for carbon-dioxide reduction is an important R&D activity. This work involves identifying which catalyst and electrolyte materials are optimal for efficient production. And when a promising electrochemical system is identified in the lab, the work is not over because the design must be then scaled up to create an efficient and practical industrial process.
Such R&D activities must overcome several challenges in operating and characterizing potential electrochemical systems. These include maintaining the correct humidification of carbon-dioxide gas during the electrolysis process and minimizing the production of carbonates – which can clog membranes and disrupt electrolysis.
While these challenges can be daunting, they can be overcome using the 670 Electrolysis Workstation from US-based Scribner. This is a general-purpose electrolysis system designed to test the materials used in the conversion of electrical energy to fuels and chemical feedstocks – and it is ideal for developing systems for carbon-dioxide reduction.
Turn-key and customizable
The workstation is a flexible system that is both turn-key and customizable. Liquid and gas reactants can be used on one or both of the workstation’s electrodes. Scribner has equipped the 670 Electrolysis Workstation with cells that feature gas diffusion electrodes and membranes from US-based Dioxide Materials. The company specializes in the development of technologies for converting carbon dioxide into fuels and chemicals, and it was chosen by Scribner because Dioxide Materials’ products are well documented in the scientific literature.
The gas diffusion electrodes are porous graphite cathodes through which carbon-dioxide gas flows between input and output ports. The gas can migrate from the graphite into a layer containing a metal catalyst. Membranes are used in electrolysis cells to ensure that only the desired ions are able to migrate across the cell, while blocking the movement of gases.
Fully integrated Scribner’s Jarrett Mansergh (left) and Luke Levin-Pompetzki of Hiden Analytical in Scribner’s lab after integrating the electrolysis and mass-spectrometry systems. (Courtesy: Scribner)
The system employs a multi-range ±20 A and 5 V potentiostat for high-accuracy operation over a wide range of reaction rates and cell sizes. The workstation is controlled by Scribner’s FlowCell™ software, which provides full control and monitoring of test cells and comes pre-loaded with a wide range of experimental protocols. This includes electrochemical impedance spectroscopy (EIS) capabilities up to 20 KHz and cyclic voltammetry protocols – both of which are used to characterize the health and performance of electrochemical systems. FlowCell™ also allows users to set up long duration experiments while providing safety monitoring with alarm settings for the purging of gases.
Humidified gas
The 670 Electrolysis Workstation features a gas handling unit that can supply humidified gas to test cells. Adding water vapour to the carbon-dioxide reactant is crucial because the water provides the protons that are needed to convert carbon dioxide to products such as methane and syngas. Humidifying gas is very difficult and getting it wrong leads to unwanted condensation in the system. The 670 Electrolysis Workstation uses temperature control to minimize condensation. The same degree of control can be difficult to achieve in homemade systems, leading to failure.
The workstation offers electrochemical cells with 5 cm2 and 25 cm2 active areas. These can be used to build carbon-dioxide reduction cells using a range of materials, catalysts and membranes – allowing the performance of these prototype cells to be thoroughly evaluated. By studying cells at these two different sizes, researchers can scale up their electrochemical systems from a preliminary experiment to something that is closer in size to an industrial system. This makes the 670 Electrolysis Workstation ideal for use across university labs, start-up companies and corporate R&D labs.
The workstation can handle, acids, bases and organic solutions. For carbon-dioxide reduction, the cell is operated with a liquid electrolyte on the positive electrode (anode) and gaseous carbon dioxide at the negative electrode (cathode). An electric potential is applied across the electrodes and the product gas comes off the cathode side.
The specific product is largely dependent on the catalyst used at the cathode. If a silver catalyst is used for example, the cell is likely to produce the syngas. If a tin catalyst is used, the product is more likely to be formic acid.
Mass spectrometry
The best way to ensure that the desired products are being made in the cell is to connect the gas output to a mass spectrometer. As a result, Scribner has joined forces with Hiden Analytical to integrate the UK-based company’s HPR-20 mass spectrometer for gas analysis. The Hiden system is specifically configured to perform continuous analysis of evolved gases and vapours from the 670 Electrolysis Workstation.
The Scribner CO2 Reduction Cell Fixture (Courtesy: Scribner)
If a cell is designed to create syngas, for example, the mass spectrometer will determine exactly how much carbon monoxide is being produced and how much hydrogen is being produced. At the same time, researchers can monitor the electrochemical properties of the cell. This allows researchers to study relationships between a system’s electrical performance and the chemical species that it produces.
Monitoring gas output is crucial for optimizing electrochemical processes that minimize negative effects such as the production of carbonates, which is a significant problem when doing carbon dioxide reduction.
In electrochemical cells, carbon dioxide is dissolved in a basic solution. This results in the precipitation of carbonate salts that clog up the membranes in cells, greatly reducing performance. This is a significant problem when scaling up cell designs for industrial use because commercial cells must be very long-lived.
Pulsed-mode operation
One strategy for dealing with carbonates is to operate electrochemical cells in pulsed mode, rather than in a steady state. The off time allows the carbonates to migrate away from electrodes, which minimizes clogging. The 670 Electrolysis Workstation allows users to explore the use of short, second-scale pulses. Another option that researchers can explore is the use of pulses of fresh water to flush carbonates away from the cathode area. These and other options are available in a set of pre-programmed experiments that allow users to explore the mitigation of salt formation in their electrochemical cells.
The gaseous products of these carbonate-mitigation modes can be monitored in real time using Hiden’s mass spectrometer. This allows researchers to identify any changes in cell performance that are related to pulsed operation. Currently, electrochemical and product characteristics can be observed on time scales as short as 100 ms. This allows researchers to fine-tune how pulses are applied to minimize carbonate production and maximize the production of desired gases.
Real-time monitoring of product gases is also important when using EIS to observe the degradation of the electrochemical performance of a cell over time. This provides researchers with a fuller picture of what is happening in a cell as it ages.
The integration of Hiden’s mass spectrometer to the 670 Electrolysis Workstation is the latest innovation from Scribner. Now, the company is working on improving the time resolution of the system so that even shorter pulse durations can be studied by users. The company is also working on boosting the maximum current of the 670 to 100 A.
This episode of the Physics World Weekly podcast comes from the Chicago metropolitan area – a scientific powerhouse that is home to two US national labs and some of the country’s leading universities.
Physics World’s Margaret Harris was there recently and met Nadya Mason. She is dean of the Pritzker School of Molecular Engineering at the University of Chicago, which focuses on quantum engineering; materials for sustainability; and immunoengineering. Mason explains how molecular-level science is making breakthroughs in these fields and she talks about her own research on the electronic properties of nanoscale and correlated systems.
Harris also spoke to Jeffrey Spangenberger who leads the Materials Recycling Group at Argonne National Laboratory, which is on the outskirts of Chicago. Spangenberger talks about the challenges of recycling batteries and how we could make it easier to recover materials from batteries of the future. Spangenberger leads the ReCell Center, a national collaboration of industry, academia and national laboratories that is advancing recycling technologies along the entire battery life-cycle.
On 13–14 May, The Economist is hosting Commercialising Quantum Global 2025 in London. The event is supported by the Institute of Physics – which brings you Physics World. Participants will join global leaders from business, science and policy for two days of real-world insights into quantum’s future. In London you will explore breakthroughs in quantum computing, communications and sensing, and discover how these technologies are shaping industries, economies and global regulation. Register now.
Finding fakes Illustration of how neutrons can pass easily through the metallic regions of an old coin, but are blocked by hydrogen-bearing compounds formed by corrosion. (Courtesy: S Kelley/NIST)
The presence of hydrogen in a sample is usually a bad thing in neutron scattering experiments, but now researchers in the US have turned the tables on the lightest element and used it to spot fake antique coins.
The scattering of relatively slow moving neutrons from materials provides a wide range of structural information. This is because these “cold” neutrons have wavelengths on par with the separations of atoms in a materials. However, materials that contain large amounts of hydrogen-1 nuclei (protons) can be difficult to study because hydrogen is very good at scattering neutrons in random directions – creating a noisy background signal. Indeed, biological samples containing lots of hydrogen are usually “deuterated” – replacing hydrogen with deuterium – before they are placed in a neutron beam.
However, there are some special cases where this incoherent scattering of hydrogen can be useful – measuring the water content of samples, for example.
Surfeit of hydrogen
Now, researchers in the US and South Korea have used a neutron beam to differentiate between genuine antique coins and fakes. The technique relies on the fact that the genuine coins have suffered corrosion that has resulted in the inclusion of hydrogen-bearing compounds within the coins.
Led by Youngju Kim and Daniel Hussey at the National Institute of Standards and Technology (NIST) in Colorado, the team fired a parallel beam of neutrons through individual coins (see figure). The particles travel with ease through a coin’s original metal, but tend to be scattered by the hydrogen-rich corrosion inclusions. This creates a 2D pattern of high and low intensity regions on a neutron-sensitive screen behind the coin. The coin can be rotated and a series of images taken. Then, the researchers used computed tomography to create a 3D image showing the corroded regions of a coin.
The team used this neutron tomography technique to examine an authentic 19th century coin that was recovered from a shipwreck, and on a coin that is known to be a replica. Although both coins had surface corrosion, the corrosion extended much deeper into the bulk of the authentic coin than it did in the replica.
The researchers also used a separate technique called neutron grating interferometry to characterize the pores in the surfaces of the coins. Pores are common on the surface of coins that have been buried or submerged. Authentic antique coins are often found buried or submerged, whereas replica coins will be buried or submerged to make them look more authentic.
Small-angle scattering
Neutron grating interferometry looks at the small-angle scattering of neutrons from a sample and focuses on structures that range in size from about 1 nm to 1 micron.
The team found that the authentic coin had many more tiny pores than the replica coin, which was dominated by much larger (millimetre scale) pores.
This observation was expected because when a coin is buried or submerged, chemical reactions cause metals to leach out of its surface, creating millimetre-sized pores. As time progresses, however, further chemical reactions cause corrosion by-products such as copper carbonates to fill in the pores. The result is that the pores in the older authentic coin are smaller than the pores in the newer replica coin.
The team now plans to expand its study to include more Korean coins and other metallic artefacts. The techniques could also be used to pinpoint corrosion damage in antique coins, allowing these areas to be protected using coatings.
As well as being important to coin collectors and dealers, the ability to verify the age of coins is of interest to historians and economists – who use the presence of coins in their research.
The study was done using neutrons from NIST’s research reactor in Maryland. That facility is scheduled to restart in 2026 so the team plans to continue its investigation using a neutron source in South Korea.
In a conversation with Physics World’s Tami Freeman Krausz talks about his research into using ultrashort-pulsed laser technology to develop a diagnostic tool for early disease detection. He also discusses his collaboration with Semmelweis University to establish the John von Neumann Institute for Data Science, and describes the Science4People initiative, a charity that he and his colleagues founded to provide education for children who have been displaced by the war in Ukraine.
On 13–14 May, The Economist is hosting Commercialising Quantum Global 2025 in London. The event is supported by the Institute of Physics – which brings you Physics World. Participants will join global leaders from business, science and policy for two days of real-world insights into quantum’s future. In London you will explore breakthroughs in quantum computing, communications and sensing, and discover how these technologies are shaping industries, economies and global regulation. Register now and use code QUANTUM20 to receive 20% off. This offer ends on 4 May.
In a conversation with Physics World’s Matin Durrani, Meredith talks about the importance of semiconductors in a hi-tech economy and why it is crucial for the UK to have a homegrown semiconductor industry.
Founded in 2020, CISM moved into a new, state-of-the-art £50m building in 2023 and is now in its first full year of operation. Meredith explains how technological innovation and skills training at CSIM is supporting chipmakers in the M4 hi-tech corridor, which begins in Swansea in South Wales and stretches eastward to London.
This podcast features Alonso Gutierrez, who is chief of medical physics at the Miami Cancer Institute in the US. In a wide-ranging conversation with Physics World’s Tami Freeman, Gutierrez talks about his experience using Elekta’s Leksell Gamma Knife for radiosurgery in a busy radiotherapy department.
This episode of the Physics World Weekly podcast features an interview with Panicos Kyriacou, who is chief scientist at the UK-based start-up Crainio. The company has developed a non-invasive way of using light to measure the pressure inside the skull. Knowing this intracranial pressure is crucial when diagnosing traumatic brain injury, which a leading cause of death and disability. Today, the only way to assess intracranial pressure is to insert a sensor into the patient’s brain, so Crainio’s non-invasive technique could revolutionize how brain injuries are diagnosed and treated.
Kyriacou tells Physics World’s Tami Freeman why it is important to assess a patient’s intracranial pressure as soon as possible after a head injury. He explains how Crainio’s optical sensor measures blood flow in the brain and then uses machine learning to deduce the intracranial pressure.
Kyriacou is also professor of engineering at City St George’s University of London, where the initial research for the sensor was done. He recalls how Crainio was spun out of the university and how it is currently in a second round of clinical trials.
As well as being non-invasive, Crainio’s technology could reduce the cost of determining intracranial pressure and make it possible to make measurements in the field, shortly after injuries occur.
This episode of the Physics World Weekly podcast features William Phillips, who shared the 1997 Nobel Prize for Physics for his work on cooling and trapping atoms using laser light.
In a wide-ranging conversation with Physics World’s Margaret Harris, Phillips talks about his long-time fascination with quantum physics – which began with an undergraduate project on electron spin resonance. Phillips chats about quirky quantum phenomena such as entanglement and superposition and explains how they are exploited in atomic clocks and quantum computing. He also looks to the future of quantum technologies and stresses the importance of curiosity-led research.
Phillips has spent much of his career at US’s National Institute for Standards and Technology (NIST) in Maryland and he also a professor of physics at the University of Maryland.
This podcast is supported by Atlas Technologies, specialists in custom aluminium and titanium vacuum chambers as well as bonded bimetal flanges and fittings used everywhere from physics labs to semiconductor fabs.
Researchers in the Netherlands, Austria, and France have created what they describe as the first operating system for networking quantum computers. Called QNodeOS, the system was developed by a team led by Stephanie Wehner at Delft University of Technology. The system has been tested using several different types of quantum processor and it could help boost the accessibility of quantum computing for people without an expert knowledge of the field.
In the 1960s, the development of early operating systems such as OS/360 and UNIX represented a major leap forward in computing. By providing a level of abstraction in its user interface, an operating system enables users to program and run applications, without having to worry about how to reconfigure the transistors in the computer processors. This advance laid the groundwork for the many of the digital technologies that have revolutionized our lives.
“If you needed to directly program the chip installed in your computer in order to use it, modern information technologies would not exist,” Wehner explains. “As such, the ability to program and run applications without needing to know what the chip even is has been key in making networks like the Internet actually useful.”
Quantum and classical
The users of nascent quantum computers would also benefit from an operating system that allows quantum (and classical) computers to be connected in networks. Not least because most people are not familiar with the intricacies of quantum information processing.
However, quantum computers are fundamentally different from their classical counterparts, and this means a host of new challenges faces those developing network operating systems.
“These include the need to execute hybrid classical–quantum programs, merging high-level classical processing (such as sending messages over a network) with quantum operations (such as executing gates or generating entanglement),” Wehner explains.
Within these hybrid programs, quantum computing resources would only be used when specifically required. Otherwise, routine computations would be offloaded to classical systems, making it significantly easier for developers to program and run their applications.
No standardized architecture
In addition, Wehner’s team considered that, unlike the transistor circuits used in classical systems, quantum operations currently lack a standardized architecture – and can be carried out using many different types of qubits.
Wehner’s team addressed these design challenges by creating a QNodeOS, which is a hybridized network operating system. It combines classical and quantum “blocks”, that provide users with a platform for performing quantum operations.
“We implemented this architecture in a software system, and demonstrated that it can work with different types of quantum hardware,” Wehner explains. The qubit-types used by the team included the electronic spin states of nitrogen–vacancy defects in diamond and the energy levels of individual trapped ions.
Multi-tasking operation
“We also showed how QNodeOS can perform advanced functions such as multi-tasking. This involved the concurrent execution of several programs at once, including compilers and scheduling algorithms.”
QNodeOS is still a long way from having the same impact as UNIX and other early operating systems. However, Wehner’s team is confident that QNodeOS will accelerate the development of future quantum networks.
“It will allow for easier software development, including the ability to develop new applications for a quantum Internet,” she says. “This could open the door to a new area of quantum computer science research.”
Last week I had the pleasure of attending the Global Physics Summit (GPS) in Anaheim California, where I rubbed shoulders with 15,0000 fellow physicists. The best part of being there was chatting with lots of different people, and in this podcast I share two of those conversations.
First up is Chetan Nayak, who is a senior researcher at Microsoft’s Station Q quantum computing research centre here in California. In February, Nayak and colleagues claimed a breakthrough in the development of topological quantum bits (qubits) based on Majorana zero modes. In principle, such qubits could enable the development of practical quantum computers, but not all physicists were convinced, and the announcement remains controversial – despite further results presented by Nayak in a packed session at the GPS.
I caught up with Nayak after his talk and asked him about the challenges of achieving Microsoft’s goal of a superconductor-based topological qubit. That conversation is the first segment of today’s podcast.
Distinctive jumping technique
Up next, I chat with Atharva Lele about the physics of manu jumping, which is a competitive aquatic sport that originates from the Māori and Pasifika peoples of New Zealand. Jumpers are judged by the height of their splash when they enter the water, and the best competitors use a very distinctive technique.
Lele is an undergraduate student at the Georgia Institute of Technology in the US, and is part of team that analysed manu techniques in a series of clever experiments that included plunging robots. He explains how to make a winning manu jump while avoiding the pain of a belly flop.
Connexion
