Earlier this year I met the Massachusetts-based steampunk artist Bruce Rosenbaum at the Global Physics Summit of the American Physical Society. He was exhibiting a beautiful sculpture of a “quantum engine” that was created in collaboration with physicists including NIST’s Nicole Yunger Halpern – who pioneered the scientific field of quantum steampunk.

I was so taken by the art and science of quantum steampunk that I promised Rosenbaum that I would chat with him and Yunger Halpern on the podcast – and here is that conversation. We begin by exploring the art of steampunk and how it is influenced by the technology of the 19th century. Then, we look at the physics of quantum steampunk, a field that weds modern concepts of quantum information with thermodynamics – which itself is a scientific triumph of the 19th century.

• Philip Ball reviews Yunger Halpern’s 2022 book Quantum Steampunk: the Physics of Yesterday’s Tomorrow

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What skills do you use every day in your job?

Obviously, I write: I wouldn’t be a very good science writer if I couldn’t. So communication skills are vital. Recently, for example, Qruise launched a new magnetic-resonance product for which I had to write a press release, create a new webpage and do social-media posts. That meant co-ordinating with lots of different people, finding out the key features to advertise, identifying the claims we wanted to make – and if we have the data to back those claims up. I’m not an expert in quantum computing or magnetic-resonance imagining or even marketing so I have to pick things up fast and then translate technically complex ideas from physics and software into simple messages for a broader audience. Thankfully, my colleagues are always happy to help. Science writing is a difficult task but I think I’m getting better at it.

What do you like best and least about your job?

I love the variety and the fact that I’m doing so many different things all the time. If there’s a day I feel I want something a little bit lighter, I can do some social media or the website, which is more creative. On the other hand, if I feel I could really focus in detail on something then I can write some documentation that is a little bit more technical. I also love the flexibility of remote working, but I do miss going to the office and socialising with my colleagues on a regular basis. You can’t get to know someone as well online, it’s nicer to have time with them in person.

What do you know today, that you wish you knew when you were starting out in your career?

That’s a hard one. It would be easy to say I wish I’d known earlier that I could combine science and writing and make a career out of that. On the other hand, if I’d known that, I might not have done my PhD – and if I’d gone into writing straight after my undergraduate degree, I perhaps wouldn’t be where I am now. My point is, it’s okay not to have a clear plan in life. As children, we’re always asked what we want to be – in my case, my dream from about the age of four was to be a vet. But then I did some work experience in a veterinary practice and I realized I’m really squeamish. It was only when I was 15 or 16 that I discovered I wanted to do physics because I liked it and was good at it. So just follow the things you love. You might end up doing something you never even thought was an option.

The post Ask me anything: Kirsty McGhee – ‘Follow what you love: you might end up doing something you never thought was an option’ appeared first on Physics World.

This episode of the Physics World Weekly podcast explores how quantum computing and artificial intelligence can be combined to help physicists search for rare interactions in data from an upgraded Large Hadron Collider.

My guest is Javier Toledo-Marín, and we spoke at the Perimeter Institute in Waterloo, Canada. As well as having an appointment at Perimeter, Toledo-Marín is also associated with the TRIUMF accelerator centre in Vancouver.

Toledo-Marín and colleagues have recently published a paper called “Conditioned quantum-assisted deep generative surrogate for particle–calorimeter interactions”.

The post Quantum computing and AI join forces for particle physics appeared first on Physics World.

Low-energy electrons escape from some materials via distinct “doorway” states, according to a study done by physicists at Austria’s Vienna Institute of Technology. The team studied graphene-based materials and found that the nature of the doorway states depended on the number of graphene layers in the sample.

Low-energy electron (LEE) emission from solids is used across a range of materials analysis and processing applications including scanning electron microscopy and electron-beam induced deposition. However, the precise physics of the emission process is not well understood.

Electrons are ejected from a material when a beam of electrons is fired at its surface. Some of these incident electrons will impart energy to electrons residing in the material, causing some resident electrons to be emitted from the surface. In the simplest model, the minimum energy needed for this LEE emission is the electron binding energy of the material.

Frog in a box

In this new study, however, researchers have shown that exceeding the binding energy is not enough for LEE emission from graphene-based materials. Not only does the electron need this minimum energy, it must also be in a specific doorway state or it is unlikely to escape. The team compare this phenomenon to the predicament of a frog in a cardboard box with a window. Not only must the frog hop a certain height to escape the box, it must also begin its hop from a position that will result in it travelling through the hole (see figure).

For most materials, the energy spectrum of LEE electrons is featureless. However, it was known that graphite’s spectrum has an “X state” at about 3.3 eV, where emission is enhanced. This state could be related to doorway states.

To search for doorway states, the Vienna team studied LEE emission from graphite as well as from single-layer and bi-layer graphene. Graphene is a sheet of carbon just one atom thick. Sheets can stick together via the relatively weak Van der Waals force to create multilayer graphene – and ultimately graphite, which comprises a large number of layers.

Because electrons are mostly confined within the graphene layers, the electronic states of single-layer, bi-layer and multi-layer graphene are broadly similar. As a result, it was expected that these materials would have similar LEE emission spectra . However, the Vienna team found a surprising difference.

Emission and reflection

The team made their discovery by firing a beam of relatively low energy electrons (173 eV) incident at 60° to the surface of single-layer and bi-layer graphene as well as graphite. The scattered electrons are then detected at the same angle of reflection. Meanwhile, a second detector is pointed normal to the surface to capture any emitted electrons. In quantum mechanics electrons are indistinguishable, so the modifiers scattered and emitted are illustrative, rather than precise.

The team looked for coincident signals in both detectors and plotted their results as a function of energy in 2D “heat maps”. These plots revealed that bi-layer graphene and graphite each had doorway states – but at different energies. However, single-layer graphene did not appear to have any doorway states. By combining experiments with calculations, the team showed that doorway states emerge above a certain number of layers. As a result the researchers showed that graphite’s X state can be attributed in part to a doorway state that appears at about five layers of graphene.

“For the first time, we’ve shown that the shape of the electron spectrum depends not only on the material itself, but crucially on whether and where such resonant doorway states exist,” explains Anna Niggas at the Vienna Institute of Technology.

As well as providing important insights in how the electronic properties of graphene morph into the properties of graphite, the team says that their research could also shed light on the properties of other layered materials.

The research is described in Physical Review Letters.

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This year’s Nobel Prize for Physics went to John Clarke, Michel Devoret and John Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantization in an electric circuit”.

That circuit was a superconducting device called a Josephson junction and their work in the 1980s led to the development of some of today’s most promising technologies for quantum computers.

To chat about this year’s laureates, and the wide-reaching scientific and technological consequences of their work I am joined by Ilana Wisby – who is a quantum physicist, deep tech entrepreneur and former CEO of UK-based Oxford Quantum Circuits. We chat about the trio’s breakthrough and its influence on today’s quantum science and technology.

The post From quantum curiosity to quantum computers: the 2025 Nobel Prize for Physics appeared first on Physics World.

John Clarke, Michel Devoret and John Martinis share the 2025 Nobel Prize for Physics “for the discovery of macroscopic quantum mechanical tunnelling and energy quantization in an electric circuit”. 

The award includes a SEK 11m prize ($1.2m), which is shared equally by the winners. The prize will be presented at a ceremony in Stockholm on 10 December.

The prize was announced this morning by members of the Royal Swedish Academy of Science. Olle Eriksson of Uppsala University and chair of the Nobel Committee for Physics commented, “There is no advanced technology today that does not rely on quantum mechanics.”

Göran Johansson of Chalmers University of Technology explained that the three laureates took quantum tunnelling from the microscopic world and onto superconducting chips, allowing physicists to study quantum physics and ultimately create quantum computers.

Speaking on the telephone, John Clarke said of his win, “To put it mildly, it was the surprise of my life,” adding “I am completely stunned. It had never occurred to me that this might be the basis of a Nobel prize.” On the significance of the trio’s research, Clarke said, “The basis of quantum computing relies to quite an extent on our discovery.”

As well as acknowledging the contributions of Devoret and Martinis, Clarke also said that their work was made possible by the work of Anthony Leggett and Brian Josephson – who laid the groundwork for their work on tunnelling in superconducting circuits. Leggett and Josephson are previous Nobel winners.

As well as having scientific significance, the trio’s work has led to the development of nascent commercial quantum computers that employ superconducting circuits. Physicist and tech entrepreneur Ilana Wisby, who co-founded Oxford Quantum Circuits, told Physics World, “It’s such a brilliant and well-deserved recognition for the community”.

A life in science

Clarke was born in 1942 in Cambridge, UK. He received his BA in physics from the University of Cambridge in 1964 before carrying out a PhD at Cambridge in 1968. He then moved to the University of California, Berkeley, to carry out a postdoc before joining the physics faculty in 1969 where he has remained since.

Devoret was born in Paris, France in 1953. He graduated from Ecole Nationale Superieure des Telecommunications in Paris in 1975 before earning a PhD from the University of Paris, Orsay, in 1982. He then moved to the University of California, Berkeley, to work in Clarke’s group collaborating with Martinis who was a graduate student at the time. In 1984 Devoret returned to France to start his own research group at the Commissariat à l’Energie Atomique in Saclay (CEA-Saclay) before heading to the US to Yale University in 2002. In 2024 he moved to the University of California, Santa Barbara, and also became chief scientist at Google Quantum AI.

Martinis was born in the US in 1958. He received a BS in physics in 1980 and a PhD in physics both from the University of California, Berkeley. He then carried out postdocs at CEA-Saclay, France, and the National Institute of Standards and Technology in Boulder, Colorado, before moving to the University of California, Santa Barbara, in 2004. In 2014 Martinis and his team joined Google with the aim of building the first useful quantum computer before he moved to Australia in 2020 to join the start-up Silicon Quantum Computing. In 2022 he co-founded the company Qolab, of which he is currently the chief technology officer.

The trio did its prizewinning work in the mid-1980s at the University of California, Berkeley. At the time Devoret was a postdoctoral fellow and Martinis was a graduate student – both working for Clarke. They were looking for evidence of macroscopic quantum tunnelling (MQT) in a device called a Josephson junction. This comprises two pieces of superconductor that are separated by an insulating barrier. In 1962 the British physicist Brian Josephson predicted how the Cooper pairs of electrons that carry current in a superconductor can tunnel across the barrier unscathed. This Josephson effect was confirmed experimentally in 1963.

Single wavefunction

The lowest-energy (ground) state of a superconductor is a macroscopic quantum state in which all Cooper pairs are described by a single quantum-mechanical wavefunction. In the late 1970s, the British–American physicist Anthony Leggett proposed that the tunnelling of this entire macroscopic state could be observed in a Josephson junction.

The idea is to put the system into a metastable state in which electrical current flows without resistance across the junction – resulting in zero voltage across the junction. If the system is indeed a macroscopic quantum state, then it should be able to occasionally tunnel out of this metastable state, resulting in a voltage across the junction.

This tunnelling can be observed by increasing the current through the junction and measuring the current at which a voltage occurs – obtaining an average value over many such measurements. As the temperature of the device is reduced, this average current increases – something that is expected regardless of whether the system is in a macroscopic quantum state.

However, at very low temperatures the average current becomes independent of temperature, which is the signature of macroscopic quantum tunnelling that Martinis, Devoret and Clarke were seeking. Their challenge was to reduce the noise in their experimental apparatus, because noise has a similar effect as tunnelling on their measurements.

Multilevel system

As well as observing the signature of tunnelling, they were also able to show that the macroscopic quantum state exists in several different energy states. Such a multilevel system is essentially a macroscopic version of an atom or nucleus, with its own spectroscopic structure.

The noise-control techniques developed by the trio to observe MQT and the fact that a Josephson junction can function as a macroscopic multilevel quantum system have led to the development of superconducting quantum bits (qubits) that form the basis of some nascent quantum computers.

The post John Clarke, Michel Devoret and John Martinis win the 2025 Nobel Prize for Physics appeared first on Physics World.

On Tuesday 7 October the winner(s) of the 2025 Nobel Prize for Physics will be announced. The process of choosing the winners is highly secretive, so looking for hints about who will be this year’s laureates is futile. Indeed, in the immediate run-up to announcement, only members of the Nobel Committee for Physics and the Class for Physics at the Royal Swedish Academy of Sciences know who will be minted as the latest Nobel laureates. What is more, recent prizes provide little guidance because the deliberations and nominations are kept secret for 50 years. So we really are in the dark when it comes to predicting who will be named next week.

If you would like to learn more about how the Nobel Prize for Physics is awarded, check out this profile of Lars Brink, who served on the Nobel Committee for Physics on eight occasions.

But this level of secrecy doesn’t stop people like me from speculating about this year’s winners. Before I explain the rather lovely infographic that illustrates this article – and how it could be used to predict future Nobel winners – I am going to share my first prediction for next week.

Inspired by last year’s physics Nobel prize, which went to two computer scientists for their work on artificial intelligence, I am predicting that the 2025 laureates will be honoured for their work on quantum information and algorithms. Much of the pioneering work in this field was done several decades ago, and has come to fruition in functioning quantum computers and cryptography systems. So the time seems right for an award and I have four people in mind. They are Peter Shor, Gilles Brassard, Charles Bennett and David Deutsch. However, only three can share the prize.

Moving on to our infographic, which gives a bit of pseudoscientific credibility to my next predictions! It charts the history of the physics Nobel prize in terms of field of endeavour. One thing that is apparent from the infographic is that since about 1990 there have been clear gaps between awards in certain fields. If you look at “atomic, molecular and optical physics”, for example, there are gaps between awards of about 5–10 years. One might conclude, therefore, that the Nobel committee considers the field of an award and tries to avoid bunching together awards in the same field.

Looking at the infographic, it looks like we are long overdue a prize in nuclear and particle physics – the last being 10 years ago. However, we haven’t had many big breakthroughs in this field lately. Two aspects of particle physics that have been very fruitful in the 21st century have been the study of the quark–gluon plasma formed when heavy nuclei collide; and the precise study of antimatter – observing how it behaves under gravity, for example. But I think it might be a bit too early for Nobels in these fields.

One possibility for a particle-physics Nobel is the development of the theory of cosmic inflation, which seeks to explain the observed nature of the current universe by invoking an exponential expansion of the universe in its very early history. If an award were given for inflation, it would most certainly go to Alan Guth and Andrei Linde. A natural for the third slot would have been Alexei Starobinsky, who sadly died in 2023 – and Nobels are not awarded posthumously. If there was a third winner for inflation, it would probably be Paul Steinhardt.

Invisibility cloaks

2016 was the last year when we had a Nobel prize in condensed-matter physics, so what work in that field would be worthy of an award this year? There has been a lot of very interesting research done in the field of metamaterials – materials that are engineered to have specific properties, particularly in terms of how they interact with light or sound.

A Nobel prize for metamaterials would surely go to the theorist John Pendry, who pioneered the concept of transformation optics. This simplifies our understanding of how light interacts with metamaterials and helps with the design of objects and devices with amazing properties. These include invisibility cloaks –the first of which was built in 2006 by the experimentalist David Smith, who I think is also a contender for this year’s Nobel prize. Smith’s cloak works at microwave frequencies, but my nomination for the third slot has done an amazing amount of work on developing metamaterials for practical applications in optics. If you follow this field, you know that I am thinking of the applied physicist Federico Capasso – who is also known for the invention of the quantum cascade laser.

The post Quantum information or metamaterials: our predictions for this year’s Nobel Prize for Physics appeared first on Physics World.

Next week, the winners of the 2025 Nobel Prize for Physics will be revealed. In the run-up to the announcement I’m joined in this podcast by my colleague Matin Durrani, who has surveyed the last quarter century of Nobel prizes and picked his top five physics prizes of the 21^st century – so far.

We also look back to two early Nobel prizes, which were given for very puzzling reasons. One was awarded in 1908 to Gabriel Lippmann for an impractical colour-photography technique that was quickly forgotten; and the other in 1912 to Gustaf Dalén for the development of several technologies used in lighthouses.

Our predictions

It’s a mug’s game, we know, but we couldn’t resist including a few predictions of who could win this year’s physics Nobel. Perhaps a prize for quantum algorithms could be announced on Tuesday, so stay tuned.

And finally, we round off this episode with a fun Nobel quiz. Do you know how old Lawrence Bragg was when he became the youngest person to win the physics prize?

Articles mentioned in this podcast:

“Nobel prizes you’ve never heard of: how a Swedish inventor was honoured for a technology that nearly killed him”

“Nobel prizes you’ve never heard of: how an obscure version of colour photography beat quantum theory to the most prestigious prize in physics”

“Inside the Nobels: Lars Brink reveals how the world’s top physics prize is awarded”

The post The curious history of Nobel prizes: from lighthouses to gravitational waves appeared first on Physics World.

In the past three decades astronomers have discovered more than 6000 exoplanets – planets that orbit stars other than the Sun. Many of these exoplanets are very unlike the eight planets of the solar system, making it clear that the cosmos contains a rich and varied array of alien worlds.

Weird and wonderful planets are also firmly entrenched in the world of science fiction, and the interplay between imagined and real planets is explored in the new book Amazing Worlds of Science Fiction and Science Fact. Its author Keith Cooper is my guest in this episode of the Physics World Weekly podcast and our conversation ranges from the amazing science of “hot Jupiter” exoplanets to how the plot of a popular Star Trek episode could inform our understanding of how life could exist on distant exoplanets.

• Keith Cooper has written a three-part feature article about the nature of dark matter for Physics World. The first instalment is “Cosmic combat: delving into the battle between dark matter and modified gravity“

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It is Peer Review Week and the theme for 2025 is “Rethinking Peer Review in the AI Era”. This is not surprising given the rapid rise in the use and capabilities of artificial intelligence. However, views on AI are deeply polarized for reasons that span its legality, efficacy and even its morality.

A recent survey done by IOP Publishing – the scientific publisher that brings you Physics World – reveals that physicists who do peer review are polarized regarding whether AI should be used in the process.

IOPP’s Laura Feetham-Walker is lead author of AI and Peer Review 2025, which describes the survey and analyses its results. She joins me in this episode of the Physics World Weekly podcast in a conversation that explores reviewers’ perceptions of AI and their views of how it should, or shouldn’t, be used in peer review.

The post Peer review in the age of artificial intelligence appeared first on Physics World.

“Imagine the day the aliens arrive.” So begins Do Aliens Speak Physics? by the US particle physicist Daniel Whiteson and the cartoonist and author Andy Warner. From that starting point, if you believe the plots of many works of science fiction, it wouldn’t be long before we’re communicating with emissaries of an extraterrestrial civilization. Quickly, we’d be marvelling at their advanced science and technology.

But is this a reasonable assumption? Would we really be able to communicate with aliens? Even if we could, would their way of doing science have any meaning to us? What if an advanced alien civilization had no science at all? These are some of the questions tackled by Whiteson and Warner in their entertaining and thought-provoking book.

While Do Aliens Speak Physics? focuses on the possible differences between human and alien science, it made me think about what science means to humans – and the role of science in our civilization. Indeed, when I spoke to Whiteson for a future episode of the Physics World Weekly podcast, he told me that his original plan for the book was to examine if physics is universal or shaped by human perspective.

But when he pitched the idea to his teenage son, Whiteson realized that approach was a bit boring and decided to spice things up using an alien landing. At the heart of the book is a new equation for estimating the number of alien civilizations that scientists could potentially communicate with – ideally, when the aliens arrive on Earth.

The authors aren’t the first people to do such a calculation. In 1961 the US astrophysicist Frank Drake famously did so by estimating how many habitable planets might exist and whether they could harbour life that’s evolved so far that it could communicate with us. Whiteson and Warner’s “extended Drake equation” adds four extra terms related to alien science.

The first is the probability that a civilization has developed science. The second is the likelihood that we would be able to communicate with the civilization, with the third being the probability that an alien civilization would ask scientific questions that are meaningful to us. The final term is whether human science would benefit from the answers to those questions.

One of Whiteson and Warner’s more interesting ideas is that aliens could perceive science and technology in very different ways to us. After all, an alien civilization could be completely focused on developing technology and not be at all interested in the underlying science. Technology without science might seem deeply foreign to us today, but for most of history humans have focused on how things work – not why.

Blacksmiths of the past, for example, developed impressive swords and other metal implements without any understanding of how the materials they worked with behaved at a microscopic level. So perhaps our alien visitors will come from a planet of blacksmiths rather than materials scientists.

Mind you, communicating with alien scientists could be a massive challenge given that we do so mainly using sound and visual symbols, whereas an alien might use smells or subatomic particles to get their point across. As the authors point out, it’s difficult even translating the Danish/Norwegian word hygge into English, despite the concept’s apparent popularity in the English-speaking world. Imagine how much harder things would be if we used a different form of communication altogether.

But could physics function as a kind of Rosetta Stone, offering a universal way of translating one language into another? We could then get the aliens to explain various physical processes – such as how a mass falls under the influence of gravity – and compare their reasoning to our understanding of the same phenomena.

Of course, an alien scientist’s questions might depend on how they perceive the universe. In a chapter titled “Can aliens taste electrons?”, the authors explore what might happen if aliens were so small that they experience quantum effects such as entanglement in their daily lives. What if an organism were so big that it feels the gravitational tug of dark matter? Or what if an intelligent alien could exist in an ultracold environment where everything moves so slowly that their perception of physics is completely different to ours?

The final term in the authors’ extended Drake equation looks at whether the answers to the questions of alien physics would be meaningful to humans. We naturally assume there are deep truths about nature that can be explored using experimental and mathematical tools. But what if there are no deep truths out there – and what if our alien friends are already aware of that fact?

When Drake proposed his equation, humans did not know of any planets beyond the solar system. Today, however, we have discovered nearly 6000 such exoplanets, and it is possible that there are billions of habitable, Earth-like exoplanets in the Milky Way. So it does not seem at all fanciful that we could soon be communicating with an alien civilization.

But when I asked Whiteson if he’s worried that visiting aliens could be hostile towards humans, he said he hoped for a “peaceful” visit. In fact, Whiteson is unable to think of a good reason why an advanced civilization would be hostile to Earth – pointing out that there is probably nothing of material value here for them. Fingers crossed, any visit will be driven by curiosity, peace and goodwill.

• 4 November 2025 WW Norton & Company 272pp £23.00 hb; £21.84 ebook

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