An international team of researchers from India and Belgium has developed portable particle detectors that could help scientists examine the interiors of mountains, tunnels and historical monuments without damaging them. The technology uses naturally occurring cosmic-ray particles to map variations in the density of objects, offering a potential approach to non-invasive imaging of large structures.

The detectors, developed using glass-based Resistive Plate Chambers (RPCs), achieved a particle-detection efficiency exceeding 95% during testing, according to a report published by Research Matters on October 24, 2026. The findings demonstrate the potential of compact detector systems to investigate dense materials and support future applications in geology, archaeology and infrastructure assessment.

The collaboration includes researchers from India’s National Institute of Science Education and Research (NISER), Bhubaneswar, and the Homi Bhabha National Institute (HBNI), alongside researchers from Belgian institutions, including Université catholique de Louvain and the Inter-University Institute for High Energies.

How cosmic rays reveal hidden structures

The technology uses muons, high-energy particles produced when cosmic rays interact with Earth’s atmosphere. These particles continuously reach the Earth’s surface and can penetrate substantial thicknesses of rock, concrete and other materials.

As muons travel through an object, some are absorbed or deflected depending on its density and thickness. By measuring the number and trajectories of particles passing through a structure, researchers can identify variations in internal density and reconstruct images of otherwise inaccessible areas.

The technique, known as muography, is comparable in principle to X-ray imaging, but uses naturally occurring particles instead of an artificial radiation source. It has previously been used to investigate geological formations, including volcanoes, and to explore archaeological structures.

However, conventional muon detectors can be bulky, difficult to transport and challenging to operate in remote locations. The new glass-based detectors aim to address some of these limitations through a compact design and sealed operation, reducing dependence on continuous gas supplies.

Testing the detector system

The researchers developed three glass RPC prototypes using thin glass electrodes separated by gas-filled gaps. When a muon passes through a chamber, it ionises the gas, generating an electrical signal that can be recorded to determine the particle’s position.

Electronic readout systems capture these signals and help reconstruct the trajectories of incoming particles. During testing, the detectors achieved an efficiency exceeding 95%, with a timing resolution of approximately 1.8 nanoseconds, according to the research report.

To examine the system’s ability to detect dense materials, the team conducted an absorption experiment using one prototype. During an open-sky measurement, researchers recorded nearly 55,000 muon tracks. After placing a lead block in the experimental setup, the recorded count fell to 30,894, demonstrating how dense material reduced the number of particles reaching the detector.

Representational image.Image credit:Pexels

The experiment provided proof of principle that the system could measure muon attenuation and support radiographic imaging. However, imaging complex structures such as mountains or monuments requires measurements from multiple directions and further computational reconstruction.

Applications and challenges ahead

Portable muon detectors could eventually help researchers investigate hidden cavities, examine geological formations, inspect tunnels and study the internal structures of historical monuments. Engineers could also explore their application in assessing infrastructure such as dams and bridges, although these uses would require additional testing and validation.

For cultural heritage conservation, muography could offer a valuable alternative where drilling or other invasive investigations risk damaging fragile structures. A 2025 review published in iScience highlighted the technique’s potential as a complementary, non-destructive method for studying cultural heritage objects, while noting that the relatively low flux of naturally occurring muons can require lengthy data-collection periods.

The technology is not yet a universal replacement for existing inspection methods. Its practical application will depend on factors such as spatial resolution, detector size, measurement duration and the complexity of the structure being examined.

The researchers have proposed further improvements, including lighter structural materials, larger detector areas and enhanced readout systems. These developments could make the detectors easier to deploy and improve the quality of reconstructed images.

Scientists have demonstrated a working nuclear clock based on thorium-229, an advance that could open new possibilities for precision timekeeping and the search for dark matter. Unlike conventional atomic clocks, which measure transitions involving electrons, the device uses an energy transition inside an atomic nucleus. The clock operates with thorium-229 nuclei embedded in a small crystal at room temperature, offering a potential route towards compact and highly sensitive timekeeping technology.

The findings, published in Nature demonstrate how a laser can be continuously stabilised using the nuclear transition itself. The researchers also used the device to investigate whether dark matter might produce detectable changes in fundamental physical quantities.

From atomic transitions to the atomic nucleus

Modern atomic clocks measure the frequency of radiation associated with transitions between energy levels in atoms or ions. Because these frequencies are highly stable, they provide precise standards for measuring time and testing physical theories.

The proposed nuclear clock uses thorium-229, an isotope with an unusually low-energy nuclear transition that can be excited using ultraviolet light. Researchers have explored this possibility for decades because nuclear transitions are expected to be less sensitive to some external disturbances than electronic transitions.

In the new experiment, the researchers embedded thorium-229 nuclei in a millimetre-sized calcium fluoride crystal. The device operated at approximately room temperature, around 294.7 kelvin. A laser emitting radiation at a wavelength of 148 nanometres was used to probe the nuclear transition.

A central feature of the experiment was its feedback system. The researchers measured how much laser light the nuclei absorbed and used the resulting signal to correct the laser frequency. This allowed the nuclear transition to serve as the reference for stabilising the laser, rather than relying entirely on an external reference.

A ytterbium optical lattice clock at NMIJ, National Metrology Institute of Japan used to measure International Atomic Time (TAI).Image credi:Wikimedia commons

The team also compared the nuclear clock with an established ytterbium-ion optical clock. This comparison helped researchers assess the new device’s frequency stability and look for possible changes in the thorium transition.

A new tool in the search for dark matter

Beyond timekeeping, the clock offers a way to investigate possible changes in fundamental constants of nature. Some theoretical models propose that ultralight dark matter could cause these constants to vary over time, producing small changes in the frequencies measured by precision clocks.

The researchers compared the thorium clock’s frequency with that of the ytterbium reference over approximately 23 hours. They searched for periodic fluctuations and gradual drifts that could indicate such changes.

The experiment found no statistically significant periodic signal within the range examined. Instead, the measurements placed new limits on certain interactions between ultralight dark matter and ordinary matter. The resulting constraints were competitive with leading atomic-clock measurements for some photon-related interactions and improved previous constraints involving the strong nuclear force.

These results do not establish the existence of dark matter, nor do they rule out all possible models. They demonstrate how a nuclear clock can be used to test predictions that might otherwise be difficult to investigate experimentally.

Challenges remain

The device is still a developing technology. Its performance is limited by factors including laser power, measurement noise and variations in the crystal’s nuclear transition frequency at different locations. The researchers also identified reproducibility between measurements taken on different days as an important limitation.

They suggest that stronger ultraviolet laser sources and improvements to the crystal material could substantially improve the clock’s stability and sensitivity. Their projections indicate that future versions could approach the performance of leading optical atomic clocks while retaining the practical advantages of a solid-state system.

The demonstration marks a significant step towards nuclear clocks that can operate as standalone devices. Further improvements will determine how effectively the technology can support precision timekeeping and searches for new physics.

Henri B. Kagan and Kenso Soai share the 2026 Nobel Prize in Chemistry for discovering how to make a chemical reaction favour one mirror-image molecule over its twin — a problem that had puzzled chemists since the 19th century.

The Royal Swedish Academy of Sciences announced on Wednesday that the 2026 Nobel Prize in Chemistry will be shared by Henri B. Kagan of Université Paris-Sud in France and Kenso Soai of Tokyo University of Science in Japan, honouring work that explains one of chemistry’s oldest unsolved riddles: why living things are built almost entirely from one version of certain molecules, when chemistry itself has no obvious reason to prefer it.

The Academy cited the pair “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis.”

2026 Nobel Prize in Chemistry: The Mystery of Left and Right

The puzzle at the heart of the prize concerns a property chemists call chirality. Many molecules essential to life — amino acids among them — exist in two forms that are mirror images of each other, much like a person’s left and right hands. The two versions contain exactly the same atoms, arranged in exactly the same way, except reversed. Yet biology is overwhelmingly one-handed: proteins in the human body are built almost exclusively from a single mirror-image form of amino acids, a property scientists call homochirality, from the Greek words for “same” and “hand.” Its mirror twin is almost absent from nature.

For most of the history of chemistry, that imbalance was impossible to reproduce in a laboratory. When chemists ran reactions designed to create chiral molecules, they got a near-perfect fifty-fifty mixture of both mirror forms every time — a far cry from the near-total one-sidedness found in living cells. That gap mattered well beyond academic curiosity: in medicine, where a drug’s two mirror-image forms can behave completely differently in the body, only one version typically produces the intended therapeutic effect, while the other can be useless or, in some cases, harmful. Producing a single mirror image cleanly, rather than a mixture, became one of the central technical challenges in modern pharmaceutical chemistry.

Kagan and Soai, working years apart, each supplied a piece of the solution.

In 1986, Kagan discovered a new way of steering asymmetric chemical reactions that allowed chemists to generate a far greater excess of one mirror-image molecule than had previously seemed achievable — a technique that reshaped how chemists thought about controlling chirality in the lab.

Soai built on that foundation from a different angle. In a landmark 1995 paper, he described the first chemical reaction with the theoretical potential to become fully homochiral — one mirror image reinforcing its own production through autocatalysis, a process in which a reaction’s product accelerates further reactions of the same kind. It took him until 2003 to actually demonstrate it: a reaction that produced only one of the two possible mirror-image molecules, with none of the other detectable at all. Outside of biology itself, nobody had managed that before.

“Henri Kagan and Kenso Soai have provided a solution to a chemical mystery that is over a century old: how homochirality can emerge spontaneously. The chemical reactions they have developed are spectacular,” said Heiner Linke, chair of the Nobel Committee for Chemistry, announcing the award.

The Academy said the discoveries have become decisive tools for chemists designing the reactions used to manufacture pharmaceuticals, where isolating a single mirror-image compound, rather than settling for a mixture, can determine whether a drug works safely at all.

Kagan and Soai will share the prize sum, along with the gold medal and diploma traditionally presented at the Nobel ceremony in Stockholm in December.