Jobs – Page 7 of 532 – CERN Courier

A thousand anomalies hiding in plain sight

The Hubble Space Telescope has been observing the cosmos for more than 35 years, amassing hundreds of thousands of observations. Each image was taken with a specific scientific goal, yet every exposure contains far more than its intended target: background galaxies, foreground objects and unexpected phenomena scattered across the field of view. Systematic human inspection of the millions of source cutouts in the Hubble Legacy Archive is impossible – but artificial intelligence has now uncovered more than a thousand astrophysical anomalies hiding in plain sight.

The challenge of identifying rare signals amid overwhelming backgrounds will resonate with CERN Courier readers. At the LHC, experiments increasingly deploy anomaly detection methods to search for new physics beyond the Standard Model without fully specifying the signal in advance. Both fields face a shared problem: isolating rare events from billions of observations with minimal prior assumptions about the target. “Semi-supervised” approaches that marry sparse expert knowledge with vast unlabelled datasets may prove as valuable for collider data as they have for astronomical archives.

A new semi-supervised machine-learning framework developed at the European Space Agency in December 2025 has identified 1339 unique astrophysical anomalies spanning 19 distinct morphological classes (see “Six out of 1339” figure). Approximately 65% of these – some 811 objects – had no prior reference in the scientific literature, despite residing in data that has been publicly available for years. Some of these newly discovered objects were excellent additions to existing catalogues of which examples are limited. These included collisional ring galaxies, galaxy mergers, jellyfish galaxies and gravitational lenses. Forty-three of the objects completely defied classification and remain unknown objects to this day.

Semi-supervised learning

At the heart of this work lies a fundamental tension in modern astronomy: datasets are growing far faster than our ability to label them. Traditional supervised machine learning requires large, annotated training sets, but expert labelling of millions of images is prohibitively expensive. Semi-supervised learning offers a way forward. In this approach, a model learns simultaneously from a small set of human-labelled examples and a vastly larger pool of unlabelled data, extracting patterns from the abundant unlabelled images to compensate for the scarcity of annotations.

The challenge of identifying rare signals amid overwhelming backgrounds will resonate with CERN Courier readers

The new code we have developed generates provisional “pseudo-labels” when the model’s confidence exceeds a threshold, then enforces consistent predictions with augmented versions of the same images. These augmentations take the form of cropping of the images, flipping them, inverting the pixel values, and so forth. This allows the model to leverage the statistical structure of millions of unlabelled cutouts without requiring a human to inspect each one. The algorithm then couples this semi-supervised backbone with human expertise. After each training cycle, the model ranks all images by anomaly score and a domain expert reviews the highest-ranked candidates, correcting misclassifications and confirming genuine anomalies. These newly labelled images feed the next training cycle. This human-in-the-loop design combines the pattern recognition capabilities of deep learning with the domain knowledge of an astronomer, achieving an efficiency that neither could match alone.

In our study, the entire process began with 128 standard astrophysical phenomena and three labelled anomalies where finding further examples would be valuable. The chosen examples were edge-on protoplanetary disks – young stellar objects with a proto-planetary disk around a host star that exhibits strong emission with a direct high-energy jet and secondary emission in a striking butterfly shape. Through successive iterations, the training set grew to 1400 images, at which point the model could flag anomaly types it had never been shown.

Community access

A search of this scale was made possible by ESA Datalabs, a collaborative science platform that provides researchers with direct access to ESA’s mission archives alongside computational resources – including GPU acceleration – through a browser-based environment. Rather than downloading terabytes of Hubble data, we brought our analysis code to where the data already resides. The full inference run across 99.6 million images completed in just 2.5 days on a single GPU, demonstrating that large-scale anomaly detection does not require vast computational resources, a consideration that matters as the community increasingly weighs the sustainability of data-intensive research.

The most abundant anomalies were galaxy mergers: 629 systems hosting tidal tails, bridges and other signatures of gravitational interactions that exist at the very limit of our detection power. We also found 140 candidate gravitational lenses and 39 gravitational arcs, where the warping of spacetime distorts background sources into characteristic rings. Mergers give us snapshots of hierarchical structure formation, while spacetime distortions provide direct tests of general relativity and enable dark-matter mapping on cosmological scales.

Even decades-old data can yield hundreds of new discoveries when the right tools are brought to bear

The model also independently recovered five previously catalogued quadruply lensed quasars in the Einstein cross configuration – a fourfold splitting of a distant quasar’s light by a foreground galaxy. That the model identified these without any lensed quasars in its training set validates its ability to generalise beyond the anomaly types it was explicitly taught. Fewer than 50 such systems are known, and each enables an independent “late universe” measurement of the Hubble constant; such measurements are invaluable given the persistent tension between values derived from the cosmic microwave background and the local distance ladder (CERN Courier March/April 2025 p28).

Among the genuinely new discoveries were two collisional ring galaxies – extreme systems that have undergone such an extreme galaxy interaction that a shockwave is moving through the galaxy, causing a burst of star formation through the galaxy. Thirty-five jellyfish galaxies shaped by ram pressure stripping in the intracluster medium also provide an excellent laboratory to understand the relationship between the galactic environment and the internal gas of the galaxy. Finally, 43 sources had morphologies that defied classification entirely – curved, distorted objects that fit none of the established categories and have been released to the community for further investigation.

With the Euclid space telescope now operational, and the Vera C. Rubin Observatory and Square Kilometre Array soon to follow, data volumes will dwarf Hubble’s archive by orders of magnitude. Our work shows that even decades-old data can yield hundreds of new discoveries when the right tools are brought to bear – and that AI-assisted discovery, guided by human expertise, is only just getting started.

Policymaking with data

In physics, as in life, it’s important to persevere in the face of setbacks. When James Robinson joined the ATLAS experiment at CERN in 2008, the Large Hadron Collider had just sputtered into life. “I remember the excitement of the initial startup and the disappointment when data taking was delayed for a year,” recalls Robinson.” Over the next decade, Robinson built a career in experimental particle physics, analysing jets and soft-QCD events, convening subgroups, tuning Monte Carlo generators and helping measure luminosity.

By 2018, Robinson was beginning to ponder his professional priorities. “I didn’t really want to spend another three years writing grants and not having much time to do physics,” he says. Constant relocation was another strain. “It was really nice having the freedom to travel, but in your mid-thirties you start thinking maybe it’s time to settle in one location.”

Real-world research

That’s when he spotted an opening at the Alan Turing Institute, the UK’s national centre for data science and AI. The Institute is a research-led organisation who hire experts and academics to find solutions to real-world challenges and to advise UK public policy. The role Robinson initially applied for focused on advanced computing and AI strategy, one that would apply his academic skills, and help develop his practical ones. “The Institute has a lot in common with CERN,” he says. “But I applied because of its larger focus on applications of research, rather than pure blue-sky work.”

Today, Robinson is the software engineering research lead in the Turing’s Environment and Sustainability programme, where teams of researchers, data scientists and engineers tackle urgent global challenges. “Right now we’re working with the Met Office on using AI to get faster and better weather predictions in the UK,” he explains. “For other projects, we also partner with African countries to improve forecasts in the global South, and model changes in Arctic and Antarctic sea ice, which is useful for everything from animal migrations to navigation.”

One of Robinson’s first projects was to model London’s air quality to inform the mayor’s office on pollution hot spots. “Traffic turned out to be the most important factor,” he says. “We could point to areas where we thought air quality was bad but under-measured, and the mayor’s office deployed mobile sensors to check. During COVID we even repurposed the project to monitor how busy London was coming out of lockdown. It felt really nice to see a project pivot quickly and directly feed into policy.”

Although the Turing Institute engages with government and public-sector partners, it isn’t a commercial consultancy. Each team decides which areas they would like to work in, and the problems they focus on improving. Once they identify a problem, the next stage is to find the best partner who will allow their models to make the most impact. “We’re not here to build a slightly better algorithm for its own sake,” says Robinson. “We want to apply AI to make change in the real world.”

The Institute’s mission echoes the one that first drew Robinson to physics. “One of the big similarities with CERN is the sense that what you’re doing is worthwhile and good for the world,” he says. “It’s still research, but more applied. Improving the weather forecast that everyone sees on their phone – that’s easy to explain to your grandparents.”

Robinson, who had previously been part of decades-long, large-scale research projects at ATLAS, felt it extremely satisfying to see the direct impact of his work. “At CERN you contribute a tiny part to a huge experiment,” he says. “Here I get to see a project from start to finish, and sometimes adapted straight into real-world decision making.”

Transferable skills

But was high-energy physics a good preparation for Robinson’s current career?

The answer is a resounding yes. Having done a PhD and two post docs, he was used to flexible and adaptable timelines. “I was often handed a problem without a clear solution,” he recalls. “Sometimes we have to pivot quickly away from one idea or plan and dive straight into another. That ability to rethink and improve has transferred directly to Turing.”

A lack of formal technical qualifications also need not be a problem. “Many of us were self-taught programmers at CERN,” he says. “The fact you’ve done research, adapted and developed those skills is what matters.”

Collaboration is another common thread. “Like CERN, Turing is a meeting place for people from many different institutions,” he says. “No one can just order work to happen. You negotiate, you build consensus.”

But Robinson notes that applying for non-academic roles requires a shift in mindset. While academic CVs and cover letters are often long and detailed, applications for industry, consultancy or somewhere in between like the Institute, may look different.

“Don’t go into the specifics of your ATLAS analysis because it won’t be directly relevant in industry,” says Robinson. “Show your research experience, but focus on the skills: problem-solving, collaboration, adaptability.”

But most importantly, make sure the values of the company you’re applying to align with your own. For Robinson, the Turning Institute was an obvious choice.

“I’m taking the same mindset I had at CERN and using it to make a difference you can see,” says Robinson. “That’s the rewarding part: turning data into something that genuinely helps people.”

The revolution ahead

**Michael S Turner** is an adjunct professor of physics and astronomy at UCLA and an emeritus professor at the University of Chicago. He recently co-chaired the US National Academies’ study of the future of US particle physics, *Elementary Particle Physics: The Higgs and Beyond*. Credit: M S Turner

Particle physics is the modern manifestation of the two-thousand-year quest to understand nature at the most fundamental level possible. That journey has not only deepened our understanding of the physical world but has also reaped enormous benefits for humanity, and is continuing to do so.

I have experienced two revolutions in this quest – the 1974 revolution in particle physics and the 1998 ΛCDM revolution that cemented the relationship between particle physics and cosmology. I am now anxiously awaiting a third. This one will deepen the connections between the quantum world of elementary particles and Einstein’s expanding universe by answering big questions about the origin of space, time and the universe as well as the unity of the particles and forces.

Powerful ideas, big surprises

In the early 1970s I was a graduate student at SLAC; it was an exciting and confusing time. Deep-inelastic scattering experiments at SLAC revealed free partons inside neutrons and protons, but they could not be knocked out. The SU(3) quark model successfully classified the elementary particles and predicted mass relations, but without any dynamics. There were powerful theoretical ideas – quantum field theory, the bootstrap, Regge trajectories, the eightfold way and scattering amplitudes – but no unifying picture.

In November 1974, the discovery of the J/ψ particle was announced. It seemed like overnight the Standard Model of particle physics, with its SU(3) of colour (not flavour) and the SU(2) × U(1) electroweak unification, was in place. All the pieces had been on the table earlier – Weinberg’s broken symmetry model of the weak and electromagnetic interactions, Gross–Wilczek–Politzer’s asymptotic freedom, the GIM mechanism, and evidence for quarks, but it was the discovery of the J/ψ that was needed to make it gel.

The 1980s and 1990s were exciting as new connections between the inner space of elementary particles and the outer space of cosmology were identified – some involving my own research. Inflation and particle dark matter in the form of slowly-moving particles – cold dark matter – led to an expansive theory about the early evolution of the universe along with strong predictions, including a flat, critical density universe, formation of structure from the bottom up, and scale-invariant density perturbations that arose from quantum fluctuations.

But, measurements of the matter density were coming up far short of the critical density, predictions for the large-scale distribution of matter didn’t fit the observations, and the age of the universe and Hubble constant measurements conflicted with a flat universe and possibly each other. Amidst all the confusion, some thought the bubble of enthusiasm would burst.

We are ready for another revolution that transforms our view of matter, energy, space and time, but when?

Then, in early 1998, two supernovae teams announced that the expansion of the universe is speeding up, not slowing down, and the missing piece of the puzzle had been found. ΛCDM quickly fell into place: a flat universe with cold dark matter accounting for a third of the critical density and the other two thirds in dark energy – something like a cosmological constant.

A bittersweet memory reminds me how fast things changed. My close friend and mentor, cosmologist David Schramm, was slated to debate whether the universe was flat with Jim Peebles in April 1998. David, who had the seemingly indefensible “flat” side of the debate, died tragically in a plane crash just weeks before the discovery of cosmic acceleration. When the debate took place and I subbed for David, the title had been changed to, “Cosmology solved?”

Here we are today. Two highly successful standard models which also raise profound questions about the fundamental nature of matter, energy, space and time. There are an abundance of powerful theoretical ideas not yet fully exploited or even completely understood.

There are plenty of clues. The 125 GeV Higgs – who ordered that? The dark-matter particle, dark energy and neutrino mass are not part of the Standard Model and hint at deeper connections between inner and outer space. Recent results from DESI indicate that dark energy may be evolving and is not a cosmological constant. And there is the Hubble tension, which could be telling us something is missing, both in cosmology and particle physics.

On the hunt

But sensitive searches for the dark-matter particle, at the LHC and other colliders, in deep underground experiments and space observatories, have come up short. The Higgs has yet to reveal its secrets. And there has yet to be experimental evidence for the predictions of the powerful theoretical ideas of supersymmetry, grand unification and string theory, which must play a role in moving forward.

We are ready for another revolution that transforms our view of matter, energy, space and time, but when? Take it from a cosmologist: predicting the past is hard and predicting the future is even harder. Nonetheless, just to illustrate, I mention two possibilities, based upon two speculative papers I have written.

The first, is the detection of gravitational waves from an unexpected cosmological phase transition at a temperature of 100 TeV or so by LIGO, and the second is the discovery that the observed CMB dipole is misaligned with that expected from large-scale structure and arises instead as a revealing relic of cosmic inflation. Either would shake things up, and lead to additions, discoveries and connections. Moreover, I am confident that the real triggering event will be even more impactful and exciting.

The discovery frontier today is very broad, from table-top experiments to colliders to telescopes on the ground and in space, and big ideas abound. The world is waiting and watching. Now is the time to double down and to believe that the next result will be the one that ushers in the coming revolution in our understanding of matter, energy, space and time.

Eiffel honour for women physicists

When the Eiffel Tower opened for the 1889 Exposition Universelle, its girders bore in gold lettering the names of scientists whom Gustave Eiffel said had honoured France since 1789. Every one of them was a man. 137 years later, on 26 January 2026, Anne Hidalgo, the mayor of Paris, accepted the nomination of 72 women scientists to join them.

The list spans nearly 250 years and multiple disciplinary domains. Many made important contributions to nuclear and particle physics, and several had close associations with strong partners to CERN such as the Centre national de la recherche scientifique (CNRS) and the Commissariat à l’énergie atomique et aux énergies alternatives (CEA).

Foremost among the women to be honoured is Polish–French physicist Marie Skłodowska Curie (1867–1934), who discovered polonium and radium, helping to establish radioactivity as an intrinsic property of atoms. She carried out systematic measurements of radioactive substances, determined radium’s atomic weight and developed methods to isolate radioactive elements from pitchblende. She shared the 1903 Nobel Prize in Physics and later won the 1911 Nobel Prize in Chemistry, becoming the first woman laureate and the only person to receive Nobel prizes in two different scientific fields.

A pioneer in X-ray spectroscopy, Yvette Cauchois (1908–1999) invented the Cauchois spectrometer, a curved-crystal spectrometer widely used for the analysis of X-rays and gamma rays. She introduced X-ray spectroscopy using synchrotron radiation to Europe and later studied the X-ray spectrum of the Sun.

A trailblazer for women physicists in Japan, nuclear physicist Toshiko Yuasa (1909–1980) studied the continuous spectrum of beta radiation emitted by artificial radioactive substances and developed her own double-focusing spectrometer. In 1955 she warned of the dangers of nuclear tests at Bikini Atoll. In the 1960s, promoted to senior research fellow at CNRS, she studied nuclear reactions using a synchrocyclotron.

Marie-Antoinette Tonnelat (1912–1980) worked on early unified theories that sought to connect gravity and electromagnetism. She served as director of research at CNRS.

Henriette Faraggi (1915–1985) introduced new techniques with photographic emulsions and directed the CEA Department of Nuclear Physics from 1972 to 1978. She also served as chair of the Nuclear Physics Commission of IUPAP and became the first woman elected president of the French Physical Society. Convinced early on of the importance of high-energy heavy-ion physics for studying quark–gluon plasma, she played a key role in the decision to build GANIL in Caen.

Cécile DeWitt-Morette (1922–2017) worked in quantum field theory and gravitation, and founded the Les Houches Summer School in 1951, which became a major international centre for theoretical physics training. She later contributed to path-integral methods in quantum theory.

Yvonne Choquet-Bruhat (1923–2025) placed Einstein’s field equations of general relativity on a firmer mathematical ground, showing how their behaviour follows from appropriate initial conditions. In 1979 she became the first woman elected as a full member of the Académie des Sciences.

A specialist in cosmic radiation, Lydie Koch (1931–2023) led stratospheric-balloon experiments to detect cosmic rays, contributed to the development of innovative germanium and silicon detectors for the HEAO-3 and COS-B satellites, and advanced X-ray and gamma-ray astronomy. She played a central role in the development of astrophysics at the CEA and was head of the Astrophysics Section from 1967 to 1979.

“It is time for this highly symbolic landmark to embrace the cause of equality between women and men, and to restore women to their rightful place on this monument dedicated to the glory of science and scientists,” said Hidalgo.

All that antimatters in the universe

**Intersections** The interdisciplinary antimatter workshop explored laboratory, astrophysical and cosmological probes of antimatter. Credit: CERN

Applying the Standard Model (SM) to early cosmological times leads to an uninhabitable universe, with tiny and equal amounts of matter and antimatter. Yet the universe is habitable and the local universe strongly matter-dominated. Observations of the diffuse gamma-ray background and cosmic microwave background show no evidence for the presence of antimatter on large scales and rule out a matter–antimatter symmetric universe.

From 19 to 22 January, 80 particle physicists, astronomers and cosmologists gathered at CERN for the first “All that Antimatters in the Universe” workshop to explore the frontier between the laboratory and astrophysical perspectives on the matter–antimatter asymmetry of the universe.

Broad panorama

Julia Harz (Mainz University) reviewed a broad panorama of baryogenesis models in which physics beyond the SM produces a homogeneous matter excess within the first seconds after the Big Bang, before light elements are synthesised. She highlighted their features and potential tests and constraints, including searches at colliders like the LHC and indirectly with experiments such as those looking for neutrinoless double-beta decays.

Questioning our assumptions about antimatter was a central thread of the workshop, with several presentations highlighting non-standard baryogenesis models that allow domains of antimatter to survive the Big Bang, as well as others in which antimatter is hidden in compact nuggets that could also constitute dark matter. A lively discussion explored how to hunt for these scenarios using astrophysical and cosmological observables. For example, spectral distortions of the cosmic microwave background could indicate energy injections from matter–antimatter annihilation in the early universe. Observations at 21 cm-wavelengths offer another probe: these signals trace neutral hydrogen during the cosmic-dawn epoch, when the first stars and galaxies formed, and could reveal anomalous heating or ionisation patterns characteristic of antimatter annihilation.

Questioning assumptions about antimatter was a central thread of the workshop

The discrete symmetries of charge conjugation (C), parity (P) and time reversal (T) have been central to particle physics since the discovery that nature violates them individually, yet their combined action (CPT) appears to be preserved in all standard interactions. In a particularly sharp presentation, Gabriela Barenboim (University of Valencia) stressed that while much attention is devoted to the search for differences in the interactions between particles and antiparticles through CP-symmetry violation, the more fundamental possibility of CPT violation remains largely unexplored. Unlike CP violation, which can occur within the Standard Model, any breakdown of CPT symmetry would signal new physics and could manifest as differences in the intrinsic properties of particles and antiparticles, including their masses and lifetimes.

Leading stress-tests of CPT symmetry are now carried out at CERN’s Antimatter Factory (AF), whose experiments presented an array of impressive results at the workshop. Eric Hunter (CERN) highlighted the potential of boosting the yield of antihydrogen formation at the AF experiments, showing how this could improve our knowledge of antimatter physics enormously. Improved yields of antimatter replicas of naturally occurring matter-based atoms would enable higher precision tests of key electromagnetic transitions and gravitational interactions of antimatter.

Much attention went to antimatter in cosmic rays. Primary cosmic rays are particles accelerated at astrophysical sources such as supernova remnants and injected into the galaxy, whereas secondary cosmic rays are produced when those primaries collide with gas and dust in the interstellar medium. In standard galactic cosmic-ray models, antimatter is purely a secondary product of the interactions of primary cosmic rays with the interstellar medium. However, the AMS-02 experiment operating on the International Space Station has firmly established a positron excess requiring a primary source, possibly pulsars. AMS-02 antiproton data also show some anomalies, but uncertainties in the propagation models and interaction cross-sections remain large.

Mind the GAPS

Complementary searches for cosmic-ray antimatter are also carried out by balloon-borne experiments. Principal investigator Chuck Hailey (Columbia University) described how the GAPS balloon experiment, uniquely suited to probe low-energy antiprotons, antideuterons and antihelium, reported its first data from a 25-day flight completed in early 2026. The specificity of GAPS is the exploitation of the characteristic X-ray emission produced by short-lived bound states between antimatter nuclei and ordinary atoms, which results in excellent particle-identification and background-rejection capabilities.

The atmosphere at the workshop was excellent, with participants curious to learn from other communities and expand their horizons everywhere that antimatter matters in the universe, from the cosmos to the lab, via astrophysical systems. While antimatter still holds many mysteries, All that Antimatters in the Universe brought us one step closer to answering them.

Antonino Zichichi 1929–2026

Antonino Zichichi, one of the most influential figures in high-energy physics and a towering presence in Italian scientific culture, passed away in Rome on 9 February 2026, at the age of 96.

Born in Trapani, Sicily, in 1929, into an ancient family from Erice, Zichichi graduated from the University of Palermo in the early 1950s. In 1955 he joined CERN, at the dawn of its experimental programme, and in 1965 he led the experiment at the Proton Synchrotron that culminated in the discovery of the antideuteron – an antinucleus composed of an antiproton and an antineutron that provided decisive confirmation of the existence of nuclear antimatter.

A professor of physics at the University of Bologna since 1960, he led the Bologna–CERN–Frascati collaboration, which carried out the first search for the tau lepton and established the experimental method through which its discovery would later be achieved at SLAC National Accelerator Laboratory. Beyond these early milestones, his results and discoveries were numerous and fundamental, including significant limits on free quark production in strong and weak interactions, the discovery of the effective energy in QCD and evidence for the first beauty baryon.

A master of invention

Equally important were his early inventions, among them the electronic circuit for time-of-flight measurements, the preshower for calorimetry and a new technology for high-precision polynomial magnetic fields. Later, by securing Italian funding for the LAA project at CERN, he launched an extensive R&D programme on innovative detection technologies. This notably allowed the development of microelectronics, which together with the design of silicon strip and pixel detectors, would become crucial for the LHC experiments and the development of the Multigap Resistive Plate Chamber (MRPC), a detector with record time resolution. The first large-scale implementation of MRPC technology was the ALICE experiment’s Time-of-Flight (TOF) system that Zichichi led for over two decades.

His scientific legacy cannot be separated from his profound and lasting contribution to the Italian National Institute for Nuclear Physics (INFN). Serving as its president from 1977 to 1982, he played a decisive role in strengthening the institute at a crucial stage of its development, consolidating its international standing and reinforcing Italy’s participation in the great global enterprises of particle physics. Under his leadership, INFN expanded its experimental commitments at CERN and in the US, while investing strategically in detector development and advanced technologies.

Zichichi was instrumental in establishing major research facilities and many large projects are tied to his name: from the LEP and LHC projects at CERN to the HERA project at DESY, and the Gran Sasso National Laboratories at INFN, that he conceived and strategically designed with its experimental halls pointing towards CERN. Today recognised as the world’s foremost underground laboratories for astroparticle physics, attracting thousands of scientists from leading institutions across the globe, the Gran Sasso National Laboratories stand as a monumental testament to Zichichi’s foresight. The idea that an international research centre such as the Gran Sasso Laboratories can serve as a crossroads for scientists from different backgrounds, cultures and institutions, collaborating in fundamental research, reflects the vision that Zichichi consistently pursued. A vision that sees science as a means of diplomacy, enabling dialogue among nations around a common goal.

Strongly convinced that scientific cooperation could be a concrete tool for diplomacy and peacebuilding, Zichichi founded the Ettore Majorana Foundation and Center for Scientific Culture in Erice, Sicily, in 1963, which became a hub for international scientific collaboration and a forum for discussion among researchers from around the world. From there, in 1982, he promoted the Erice Statement for Peace, an urgent appeal to the international scientific community to place its work in the service of peace rather than war, at a time of heightened risk of global nuclear conflict.

That same conviction informed his engagement in European and international scientific governance. Zichichi was among the founders of the European Physical Society (where he served as its president from 1978 to 1980), chaired the NATO Committee on Disarmament Technologies and represented the European Economic Community on the scientific committee of the International Science and Technology Center in Moscow. From 1986 onwards, as president of the World Lab and the World Federation of Scientists, he supported scientific development in emerging countries and focused attention on planetary emergencies.

He did not limit himself to building bridges between scientists, but also between science, culture and society. A highly skilled communicator and educator, he published widely read books and essays aimed at the broader public, and appeared frequently in the Italian media, inspiring young people across Italy and conveying to them his passion for, and belief in, the importance of scientific research. He helped shape scientific culture in Italy in the latter half of the 20th century, insisting that fundamental research is not merely a technical endeavour but a cornerstone of human progress.

Multiple honours

Over the course of his long career, Zichichi received more than 60 awards and honours in Italy and abroad, including the Knight Grand Cross of the Order of Merit of the Italian Republic and the Enrico Fermi Prize of the Italian Physical Society. He was also president of the Enrico Fermi Historical Museum and Research Centre, further testifying to his dedication to preserving and promoting Italy’s scientific heritage.

With his death, the global scientific community loses a visionary researcher, a formidable architect of international scientific collaborations, and a tireless advocate for science as a vehicle of dialogue and peace. What always struck those who shared with him the demanding and inspiring journey of research was his unfailing enthusiasm and deep passion for science, which he cultivated tirelessly until his final days. That same passion lives on not only in his discoveries and in the institutions he helped to create, but also in the generations of scientists who continue to build bridges across borders in the name of knowledge.

String pilgrimage to Santiago

**Modern methods** Researchers are converging on a common set of tools for string theory, holography and quantum gravity. Credit: IGFAE

One hundred researchers gathered in Santiago de Compostela from 21 to 23 January for Iberian Strings, the annual meeting of the vibrant Spanish and Portuguese string theory community. From the idea that black holes may test quantum gravity to the new, string-inspired ways of organising quantum field theories using symmetries and defects, the programme offered a broad overview of where string theory and holography currently sit. What stood out was the extent to which very different problems are now being tackled with a shared set of theoretical tools.

Black holes remain a clean laboratory for probing ideas about quantum gravity. Decades of work have shown they behave much like ordinary thermodynamic systems, with quantities such as temperature and entropy. A central question is how this simple large-scale behaviour arises from an underlying quantum description. Vijay Balasubramanian (University of Pennsylvania) emphasised that the challenge is not only reproducing the familiar area law – which links entropy to the area of the event horizon – but also understanding what different semiclassical calculations are really describing.

Calculations under control

One way to address this problem is to count the quantum states that give rise to a black hole’s entropy. To make progress, researchers often focus on settings where calculations are under better control. Gabriel Cardoso (IST Lisbon) discussed BPS black holes, highly symmetric solutions that allow precise calculations using holography. Stefano Trezzi (University of Barcelona) showed that near-extremal black holes, systems close to a zero-temperature limit, exhibit a universal near-horizon behaviour that provides a clean setting to study how quantum effects modify the semiclassical picture.

So much for static black holes; what about their evolution in time? Marija Tomašević (CERN) suggested that quantum effects can form a horizon where classical gravity would predict a naked singularity. Pablo A Cano (University of Murcia) and Marina David (KU Leuven) explored instead how black holes react when they are perturbed, emitting gravitational waves as they settle back to equilibrium through a process known as ringdown. Across these contributions, the focus was on separating what can be understood within controlled semiclassical calculations from what requires genuinely microscopic, quantum-gravitational input.

Some particle theories may have been gravity all along. And vice versa. These seemingly disparate worlds, with particle beams and colour confinement in one (particle physics) and curved spacetime in the other (gravity), may simply be two languages for the same physics. To translate between them, the particle side must live in one fewer dimension. Just as a hologram stores a 3D image on a 2D plate, a gravitational theory in D dimensions may be exactly equivalent to a non-gravitational quantum field theory in D–1 dimensions. This holographic correspondence is central to modern approaches to quantum gravity. The focus at the workshop was on its more applied uses, as a controlled way to learn about dynamics at strong coupling.

Elias Kiritsis (University of Crete) provided a concrete example. Using familiar spacetime physics, he studied how strongly interacting quantum systems respond to gentle deformations at low temperature, a standard probe of transport. In this setting, quantum effects can modify quantities such as the ratio of viscosity to entropy density beyond the semiclassical value.

To round the picture, Francesco Nitti (APC Paris), explored holographic models in which varying the curvature of spacetime can affect confinement, while Shota Komatsu (CERN) presented an overview of matrix-model methods in holography, emphasising how they can provide tractable descriptions of strong-coupling dynamics in specific regimes, such as large-N limits. Following ’t Hooft, theorists often treat the number of colours in an SU(N) gauge theory as a tunable parameter, providing a controlled simplification of strongly coupled dynamics.

Black holes remain a clean laboratory for probing ideas about quantum gravity

Working in simplified settings can be an effective way to make progress. In holography, a quantum field theory in two dimensions can map to a three-dimensional spacetime with a negative cosmological constant. Symmetries then constrain the gravity side, allowing us to pose – and sometimes answer – questions that would be far harder to tackle in higher dimensions or less symmetric settings. In this spirit, Stéphane Detournay (Université Libre de Bruxelles) showed how near-extremal black holes themselves can behave like two-dimensional systems, where effects due to thermodynamics, symmetry and quantum corrections can often be disentangled cleanly.

Rapid progress in understanding generalised symmetries and defects was a hot topic. Guillermo Arias-Tamargo (Imperial College London) described how recent work on non-invertible symmetries in non-linear sigma models pushes beyond the traditional picture of symmetries as simple group actions on local fields. In this modern framework, symmetries are realised through extended objects, such as defects or interfaces. Tracking how observables transform across these structures provides concrete constraints on the dynamics and phases of the theory.

A particularly sharp application came from José Calderón Infante (Caltech), who used defect-based arguments to rule out global shift symmetries in quantum gravity. Interfaces also featured prominently as physically meaningful probes, naturally connecting abstract symmetry ideas to concrete quantities such as boundary degrees of freedom and entropy-like measures – as discussed by Carlos Hoyos (Universidad de Oviedo).

The meeting covered a wide range of active topics, but controlled semiclassical arguments, low-dimensional holographic models and defect-based symmetry arguments resurfaced throughout the programme. In that sense, Iberian Strings provided an overview not only of open questions but also of modern methods.

HiLumi magnets face full-scale test

CERN has reached a crucial milestone in the advancement of the High-Luminosity Large Hadron Collider (HiLumi LHC) project with the start of the cryogenic cooldown to 1.9 K of its 95-metre-long test stand – a full-scale replica of the innovative equipment that will transform the LHC in the coming years. The test stand is designed to validate the novel magnet system (the inner triplet beam-focusing magnets) and its complex infrastructure, which is a key element in a major upgrade of the LHC that is set to enter operation in 2030.

This summer will mark the start of a four-year-long intensive work period to transform the LHC into the HiLumi LHC – a groundbreaking accelerator that will usher in a new era for high-energy physics. The HiLumi LHC will increase the number of particle collisions by a factor of 10, increasing the volume of physics data available for researchers. This leap forward will allow physicists to explore the behaviour of the Higgs boson and other elementary particles with unprecedented precision and to uncover rare new phenomena that might reveal themselves.

Exploring the unknown

“I don’t think it is possible to overstate the importance and excitement of the High-Luminosity LHC, which is the largest project undertaken by CERN for the past 20 years,” explains Mark Thomson, CERN Director-General. “Coupled with advanced new data tools and upgraded detectors, it will allow us to understand, for the first time, how the Higgs boson interacts with itself – a key measurement that will shed light on the first instants and possible fate of the universe. The HiLumi LHC will also explore uncharted territory and could reveal something completely new and unexpected. That’s the whole point of exploring the unknown: you don’t know what’s out there.”

Many of the technologies developed for the HiLumi LHC – such as superconducting crab cavities that tilt the particle beams before they collide, crystal collimators designed to remove errant particles and high-temperature superconducting electrical transfer lines to power the HiLumi magnets as efficiently as possible – have never been used in a proton accelerator before. Among these new key technologies, the inner triplet beam-focusing magnets are made of a superconducting compound based on niobium and tin (Nb₃Sn), enabling magnetic fields higher than those achieved with the current LHC niobium–titanium (NbTi) magnets (see “Superconductors for the energy frontier”). These new magnets will be deployed on both sides of the ATLAS and CMS experiments, alongside new cryogenic, powering, protection and alignment systems, and will operate at a temperature of 1.9 K, just like the LHC magnets.

The entire accelerator complex and associated experiments will benefit from the improvements

To ensure seamless integration, CERN has built, in an above-ground test hall, a full-scale test stand called the Inner Triplet String (IT String), which mirrors the underground configuration (CERN Courier March/April 2025 p8).

“All the systems have already been tested individually. The goal of the IT String is to validate their integration and their collective performance under operational conditions,” explains Oliver Brüning, CERN Director for Accelerators and Technology. “The connection and operation of all the equipment in the IT String give us a chance to optimise our procedures before the actual installation in the tunnel, so that we will be prepared and ready for an efficient and smooth installation.”

Harnessing potential

The large LHC experiments ATLAS and CMS will also undergo a major upgrade to enable them to harness the full scientific potential of the HiLumi LHC collisions – work that is being carried out in close coordination with hundreds of institutes worldwide. Additionally, the entire accelerator complex and associated experiments will benefit from improvements, says the lab, solidifying CERN’s leadership in high-energy physics.

The cooldown of the HiLumi LHC test string, which is achieved using a liquid-helium refrigeration and distribution system, is expected to take several weeks to complete.

Physics labs under the lens

Physics is beautiful in its ideas and in the people who pursue them across borders. What better, then, than for 16 laboratories across Asia, Europe and North America to throw open their doors for a photography competition, allowing the aesthetically inclined to immortalise on film the wonders within. The votes are now in.

The winning image of the 2025 Global Physics Photowalk, by photographer Marco Donghia, shows INFN National Laboratories of Frascati researcher Raffaella Donghia seated beside an open cryostat during installation of an ultracold experiment at COLD, the CryOgenic Laboratory for Detectors (see “First place” image). The apparatus houses an axion haloscope – a cryogenic antenna consisting of a microwave cavity resonating at about 9 GHz, immersed in a powerful 9 tesla magnetic field and connected to an ultra-low-noise amplification system designed to search for ultralight dark-matter candidates such as axions or dark photons (CERN Courier January/February 2026 p21). If ultralight dark matter circulates in a galactic halo, it could excite the resonant cavity at a frequency corresponding to the particle’s mass, appearing as a minute increase in electromagnetic power at that frequency. Cooling the system to 10 mK suppresses thermal noise to the point that quantum noise dominates.

“The image stood out for its clear visual storytelling and masterful use of light, which leads the eye through the scene and emphasises the moment of discovery,” said judge Tabea Rauscher, then creative lead at the European Molecular Biology Laboratory. “The researcher appears small in relation to the cryostat, highlighting the scale of the technology while keeping the human presence at the centre. The lighting creates a quiet, almost cinematic atmosphere that captures both the intensity and the solitude of scientific work.”

The photographs move between abstraction and lived experience

Fellow judge Dmitri Denisov, deputy associate laboratory director for high-energy physics at Brookhaven National Laboratory in the US, noted that while the judges chose Donghia’s photograph for its ability to convey the “deep connection between the apparatuses used in particle physics and the human developing them,” the second- and third-place photographs were chosen for their “deep looks into the inner workings of experiments and impressive display of colours.”

The judges awarded second place to Matteo Monzali for his photograph of a nuclear-physics experiment at INFN National Laboratories of Legnaro in Italy (see “Runner up” image) and third place to Hugo Pardinilla for a close-up image of a photomultiplier from the KM3NeT/ORCA experiment, a neutrino telescope currently being installed in the Mediterranean Sea at a depth of 2500 metres off the coast of Provence, France (see “Third place” image). Members of the public awarded first and second place to Yannig Van De Wouwer’s photographs of GANIL, the heavy-ion accelerator in Caen, France, featuring pipes and cables serving the SPIRAL2 linear accelerator and iridescent patterns in a beam pipe (see “Public preference” image). The public’s third choice went to Monzali’s snap of the AGATA–PRISMA setup in INFN Legnaro.

Deeply human

“Serving as a judge for the 2025 Global Physics Photowalk, I was struck by the range and sensitivity of the submissions,” concludes judge Will Warasila, a freelance photographer for the New York Times. “The photographs move between abstraction and lived experience – finding form, rhythm and quiet beauty in scientific spaces, while foregrounding the people whose labour and curiosity make this work possible. Across geographies and institutions, these images show how photography can slow us down, make complex systems legible and remind us that science is not only technical, but deeply human.”

The Global Physics Photowalk is organised by the Interactions Collaboration (interactions.org), an international network of particle-physics institutions including CERN and over 20 partner laboratories and research infrastructures around the world.

When accelerators turn into sweaters

**Accelerator materiality** Knitted from copper wire, the piece *When Accelerators Turn into Sweaters*, by artist Julijonas Urbonas, reduces accelerator infrastructure to garment scale. Credit: J Urbonas

What happens when an artist enters a particle-physics laboratory, not to explain its discoveries or visualise its equations, but simply to remain, observe and respond? In the Spaces Between, a sustained reflection on the long-running Arts at CERN programme, argues that what emerges is not illustration or explanation, but a shared space of inquiry – one that works with uncertainty rather than resolving it, echoing the statistical, instrument-mediated nature of contemporary physics.

Both art and particle physics push at the edges of what can be known, imagined and expressed. Through its programmes, Arts at CERN hosts artists for extended residencies at the laboratory, where they meet physicists and engineers, attend seminars, visit experimental sites and engage directly with ongoing research. The artists are not tasked with illustrating experiments or communicating results. Instead, they develop independent works – installations, performances, films, sculptures – shaped by sustained dialogue with the scientific community.

Creating coalitions

Edited by Mónica Bello, former head of Arts at CERN (CERN Courier March/April 2025 p41), the book brings together essays, images and reflective texts by artists, scientists and collaborators involved in the artist residency programme. Rather than presenting a catalogue of finished works, it focuses on the conditions that make exchange possible: how artists encounter scientific infrastructures, and how meaning begins to form in spaces where neither discipline fully sets the rules.

The book is organised around four broad themes: “quantum”, cosmology, experimentation and the unknown. These function less as explanatory frameworks than as loose points of orientation, allowing contributions to remain fragmentary and open-ended. The structure mirrors the reality of interdisciplinary work, which rarely unfolds in clean, linear ways, but instead through moments of partial understanding, misalignment and return.

For readers trained in physics, this approach may feel unexpectedly familiar. Scientific knowledge rarely emerges fully formed; it develops through iteration, uncertainty and interpretation. In a similar spirit, the contributions resist tidy conclusions and treat concepts not as definitions to be settled, but as materials for creative reworking. What matters is less resolution than the act of thinking itself, an openness that mirrors the exploratory character of research. At times this displacement can feel destabilising, yet it is precisely this imaginative expansion that gives the book much of its intellectual force.

This sensibility is vividly captured in Rohini Devasher’s Beyond the Standard Model. Spread across a dark, planetary surface, words such as “uncertainty”, “duality”, “observer”, “wonder” and “serendipity” – form a dense, drifting constellation. Some terms carry clear scientific weight; others belong to the emotional and imaginative registers that accompany research but rarely appear in formal papers. For Devasher, the interest lies precisely in language. By placing these words on the same visual plane, the piece loosens disciplinary hierarchies and allows concepts to float, cluster and collide. As the artist notes, the words are intended to read as a web. Rather than explaining physics, it evokes the conceptual environment in which physics thinking takes place.

Places and perspectives

On another page, language again becomes material in Cecilia Vicuña’s Ceque. The work draws on the ceq’e system of the Inca civilisation: a network of conceptual and ceremonial lines radiating outward from the city of Cusco, that are used to organise ritual practice, social relations and cosmological understanding. Rather than functioning as fixed geometrical paths, ceq’es describe relationships between places, perspectives and moments in time.

The page opens with the line “The ceq’e is not a line, it is an instant, a gaze.” Around it, words tilt, scatter and spiral – “a thought, radiating”, “another meridian”, “seen from above or from below”. Reading becomes a spatial act rather than a linear one. Meaning is not extracted or fixed; it unfolds uneasily alongside the order, diagrammatic structures through which Western science typically organises knowledge. The book offers little explicit explanation of the concept, allowing the work instead to function as an alternative way of organising knowledge: relational, situated and resistant to a single point of view.

Visual thinking also surfaces in drawings from Suzanne Treister’s project The Holographic Universe Theory of Art History (THUTOAH), including Alessandra Gnecchi’s Holographic Universe Principle. The work resembles a hand-drawn cosmology sketched in coloured pencil: strings, branes and horizons coexist with handwritten annotations and looping arrows. The emphasis is not on polished representation, but on the labour of thinking – the scribbles, approximations and half-formed connections that precede formalisation. Theory appears not as a final statement, but as something constantly under construction.

In the Spaces Between — Credit: dpr-barcelona

One of the more quietly striking works in the book is Julijonas Urbonas’s When Accelerators Turn into Sweaters: a translucent garment constructed from fine copper-stabilised superconducting fibres (see “Accelerator materiality” image). The title collapses the scale of accelerator infrastructure into a wearable object, shifting attention from machines as abstract systems to the materials from which they are built. As Urbonas puts it, the work aims to “bring a monumental, sealed infrastructure into the scale of the body, not just visually, but physically and imaginatively… a translation from the remote language of high-energy physics into something you can almost inhabit.”

In doing so, it foregrounds the material reality of high-energy physics – copper as thread and cable at once. Though made of copper, the sweater evokes the magnetic levitation of the Meissner effect, a reference to the cryogenic superconductivity of the LHC. As Urbonas observes, “the accelerator needs extreme cold to do its job, while a sweater’s whole purpose is warmth.” By keeping that gap open, the piece operates less as demonstration than as speculation: a domestic object positioned against an environment colder than outer space, inviting viewers to rethink how scientific infrastructure is imagined. Urbonas leaves the reader with a provocation: “What if physicists talked in the knitwork of the world instead?”

For accelerator physicists, this change of scale may register not simply as metaphor, but as a reminder that even the largest facilities depend on materials physically assembled, connected and maintained by hand. By reframing accelerator infrastructure at human scale, the piece foregrounds construction and material composition rather than the monumental image of the machine, aligning with the book’s broader emphasis on process over spectacle.

The contributions make clear that Arts at CERN is not a peripheral outreach activity, but a mature programme of sustained exchange

In the Spaces Between does not romanticise interdisciplinarity as a seamless merging of perspectives or a frictionless dialogue between equals. Several contributors openly acknowledge the asymmetries between artistic and scientific practice within a large research institution, where scientific priorities and infrastructures inevitably set the operating conditions. Rather than glossing over these tensions, the book treats them as productive constraints that actively shape how collaboration unfolds.

Taken together, the contributions make clear that Arts at CERN is a mature programme of sustained exchange. Its longevity has not led to conceptual closure; instead, the dialogue has deepened while remaining exploratory, evolving rather than resolving.

With its emphasis on process rather than outcomes, the book offers a rare window into how artistic inquiry operates inside a laboratory environment. It does not try to merge art and science, nor to reduce one to the language of the other. Instead, it traces the intellectual and imaginative terrain that lies between them, a space defined not by synthesis, but by ongoing negotiation.

Ultimately, In the Spaces Between suggests that experimentation runs deeply through both artistic and scientific practice, not only as a set of methods for testing ideas, but as a shared commitment to iteration, risk and revision. The sustained dialogue documented here does not aim at synthesis or resolution; rather, it creates conditions in which new forms of knowledge can emerge, forms that remain open-ended. The book will be of particular interest to those working at the intersections of art, science and research institutions, and to readers interested in what happens when disciplines meet without being forced into premature coherence.

Topics

Reset your password

Registration complete