Category: 7. Science

A new theory-guided framework could help scientists probe the properties of new semiconductors for next-generation microelectronic devices, or discover materials that boost the performance of quantum computers.

Research to develop new or better materials typically involves investigating properties that can be reliably measured with existing lab equipment, but this represents just a fraction of the properties that scientists could potentially probe in principle. Some properties remain effectively “invisible” because they are too difficult to capture directly with existing methods.

Take electron-phonon interaction — this property plays a critical role in a material’s electrical, thermal, optical, and superconducting properties, but directly capturing it using existing techniques is notoriously challenging.

Now, MIT researchers have proposed a theoretically justified approach that could turn this challenge into an opportunity. Their method reinterprets neutron scattering, an often-overlooked interference effect as a potential direct probe of electron-phonon coupling strength.

The procedure creates two interaction effects in the material. The researchers show that, by deliberately designing their experiment to leverage the interference between the two interactions, they can capture the strength of a material’s electron-phonon interaction.

The researchers’ theory-informed methodology could be used to shape the design of future experiments, opening the door to measuring new quantities that were previously out of reach.

“Rather than discovering new spectroscopy techniques by pure accident, we can use theory to justify and inform the design of our experiments and our physical equipment,” says Mingda Li, the Class of 1947 Career Development Professor and an associate professor of nuclear science and engineering, and senior author of a paper on this experimental method.

Li is joined on the paper by co-lead authors Chuliang Fu, an MIT postdoc; Phum Siriviboon and Artittaya Boonkird, both MIT graduate students; as well as others at MIT, the National Institute of Standards and Technology, the University of California at Riverside, Michigan State University, and Oak Ridge National Laboratory. The research appears this week in Materials Today Physics.

Investigating interference

Neutron scattering is a powerful measurement technique that involves aiming a beam of neutrons at a material and studying how the neutrons are scattered after they strike it. The method is ideal for measuring a material’s atomic structure and magnetic properties.

When neutrons collide with the material sample, they interact with it through two different mechanisms, creating a nuclear interaction and a magnetic interaction. These interactions can interfere with each other.

“The scientific community has known about this interference effect for a long time, but researchers tend to view it as a complication that can obscure measurement signals. So it hasn’t received much focused attention,” Fu says.

The team and their collaborators took a conceptual “leap of faith” and decided to explore this oft-overlooked interference effect more deeply.

They flipped the traditional materials research approach on its head by starting with a multifaceted theoretical analysis. They explored what happens inside a material when the nuclear interaction and magnetic interaction interfere with each other.

Their analysis revealed that this interference pattern is directly proportional to the strength of the material’s electron-phonon interaction.

“This makes the interference effect a probe we can use to detect this interaction,” explains Siriviboon.

Electron-phonon interactions play a role in a wide range of material properties. They affect how heat flows through a material, impact a material’s ability to absorb and emit light, and can even lead to superconductivity.

But the complexity of these interactions makes them hard to directly measure using existing experimental techniques. Instead, researchers often rely on less precise, indirect methods to capture electron-phonon interactions.

However, leveraging this interference effect enables direct measurement of the electron-phonon interaction, a major advantage over other approaches.

“Being able to directly measure the electron-phonon interaction opens the door to many new possibilities,” says Boonkird.

Rethinking materials research

Based on their theoretical insights, the researchers designed an experimental setup to demonstrate their approach.

Since the available equipment wasn’t powerful enough for this type of neutron scattering experiment, they were only able to capture a weak electron-phonon interaction signal — but the results were clear enough to support their theory.

“These results justify the need for a new facility where the equipment might be 100 to 1,000 times more powerful, enabling scientists to clearly resolve the signal and measure the interaction,” adds Landry.

With improved neutron scattering facilities, like those proposed for the upcoming Second Target Station at Oak Ridge National Laboratory, this experimental method could be an effective technique for measuring many crucial material properties.

For instance, by helping scientists identify and harness better semiconductors, this approach could enable more energy-efficient appliances, faster wireless communication devices, and more reliable medical equipment like pacemakers and MRI scanners.   

Ultimately, the team sees this work as a broader message about the need to rethink the materials research process.

“Using theoretical insights to design experimental setups in advance can help us redefine the properties we can measure,” Fu says.

To that end, the team and their collaborators are currently exploring other types of interactions they could leverage to investigate additional material properties.

“This is a very interesting paper,” says Jon Taylor, director of the neutron scattering division at Oak Ridge National Laboratory, who was not involved with this research. “It would be interesting to have a neutron scattering method that is directly sensitive to charge lattice interactions or more generally electronic effects that were not just magnetic moments. It seems that such an effect is expectedly rather small, so facilities like STS could really help develop that fundamental understanding of the interaction and also leverage such effects routinely for research.”

This work is funded, in part, by the U.S. Department of Energy and the National Science Foundation.

Astronomers at MIT, Columbia University, and elsewhere have used NASA’s James Webb Space Telescope (JWST) to peer through the dust of nearby galaxies and into the aftermath of a black hole’s stellar feast.

In a study appearing today in Astrophysical Journal Letters, the researchers report that for the first time, JWST has observed several tidal disruption events — instances when a galaxy’s central black hole draws in a nearby star and whips up tidal forces that tear the star to shreds, giving off an enormous burst of energy in the process.

Scientists have observed about 100 tidal disruption events (TDEs) since the 1990s, mostly as X-ray or optical light that flashes across relatively dust-free galaxies. But as MIT researchers recently reported, there may be many more star-shredding events in the universe that are “hiding” in dustier, gas-veiled galaxies.

In their previous work, the team found that most of the X-ray and optical light that a TDE gives off can be obscured by a galaxy’s dust, and therefore can go unseen by traditional X-ray and optical telescopes. But that same burst of light can heat up the surrounding dust and generate a new signal, in the form of infrared light.

Now, the same researchers have used JWST — the world’s most powerful infrared detector — to study signals from four dusty galaxies where they suspect tidal disruption events have occurred. Within the dust, JWST detected clear fingerprints of black hole accretion, a process by which material, such as stellar debris, circles and eventually falls into a black hole. The telescope also detected patterns that are strikingly different from the dust that surrounds active galaxies, where the central black hole is constantly pulling in surrounding material.

Together, the observations confirm that a tidal disruption event did indeed occur in each of the four galaxies. What’s more, the researchers conclude that the four events were products of not active black holes but rather dormant ones, which experienced little to no activity until a star happened to pass by.

The new results highlight JWST’s potential to study in detail otherwise hidden tidal disruption events. They are also helping scientists to reveal key differences in the environments around active versus dormant black holes.

“These are the first JWST observations of tidal disruption events, and they look nothing like what we’ve ever seen before,” says lead author Megan Masterson, a graduate student in MIT’s Kavli Institute for Astrophysics and Space Research. “We’ve learned these are indeed powered by black hole accretion, and they don’t look like environments around normal active black holes. The fact that we’re now able to study what that dormant black hole environment actually looks like is an exciting aspect.”

The study’s MIT authors include Christos Panagiotou, Erin Kara, Anna-Christina Eilers, along with Kishalay De of Columbia University and collaborators from multiple other institutions.

Seeing the light

The new study expands on the team’s previous work using another infrared detector — NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission. Using an algorithm developed by co-author Kishalay De of Columbia University, the team searched through a decade’s worth of data from the telescope, looking for infrared “transients,” or short peaks of infrared activity from otherwise quiet galaxies that could be signals of a black hole briefly waking up and feasting on a passing star. That search unearthed about a dozen signals that the group determined were likely produced by a tidal disruption event.

“With that study, we found these 12 sources that look just like TDEs,” Masterson says. “We made a lot of arguments about how the signals were very energetic, and the galaxies didn’t look like they were active before, so the signals must have been from a sudden TDE. But except for these little pieces, there was no direct evidence.”

With the much more sensitive capabilities of JWST, the researchers hoped to discern key “spectral lines,” or infrared light at specific wavelengths, that would be clear fingerprints of conditions associated with a tidal disruption event.

“With NEOWISE, it’s as if our eyes could only see red light or blue light, whereas with JWST, we’re seeing the full rainbow,” Masterson says.

A Bonafide signal

In their new work, the group looked specifically for a peak in infrared, that could only be produced by black hole accretion — a process by which material is drawn toward a black hole in a circulating disk of gas. This disk produces an enormous amount of radiation that is so intense that it can kick out electrons from individual atoms. In particular, such accretion processes can blast several electrons out from atoms of neon, and the resulting ion can transition, releasing infrared radiation at a very specific wavelength that JWST can detect. 

“There’s nothing else in the universe that can excite this gas to these energies, except for black hole accretion,” Masterson says.

The researchers searched for this smoking-gun signal in four of the 12 TDE candidates they previously identified. The four signals include: the closest tidal disruption event detected to date, located in a galaxy some 130 million light years away; a TDE that also exhibits a burst of X-ray light; a signal that may have been produced by gas circulating at incredibly high speeds around a central black hole; and a signal that also included an optical flash, which scientists had previously suspected to be a supernova, or the collapse of a dying star, rather than tidal disruption event.

“These four signals were as close as we could get to a sure thing,” Masterson says. “But the JWST data helped us say definitively these are bonafide TDEs.”

When the team pointed JWST toward the galaxies of each of the four signals, in a program designed by De, they observed that the telltale spectral lines showed up in all four sources. These measurements confirmed that black hole accretion occurred in all four galaxies. But the question remained: Was this accretion a temporary feature, triggered by a tidal disruption and a black hole that briefly woke up to feast on a passing star? Or was this accretion a more permanent trait of “active” black holes that are always on? In the case of the latter, it would be less likely that a tidal disruption event had occurred.

To differentiate between the two possibilities, the team used the JWST data to detect another wavelength of infrared light, which indicates the presence of silicates, or dust in the galaxy. They then mapped this dust in each of the four galaxies and compared the patterns to those of active galaxies, which are known to harbor clumpy, donut-shaped dust clouds around the central black hole. Masterson observed that all four sources showed very different patterns compared to typical active galaxies, suggesting that the black hole at the center of each of the galaxies is not normally active, but dormant. If an accretion disk formed around such a black hole, the researchers conclude that it must have been a result of a tidal disruption event.

“Together, these observations say the only thing these flares could be are TDEs,” Masterson says.

She and her collaborators plan to uncover many more previously hidden tidal disruption events, with NEOWISE, JWST, and other infrared telescopes. With enough detections, they say TDEs can serve as effective probes of black hole properties. For instance, how much of a star is shredded, and how fast its debris is accreted and consumed, can reveal fundamental properties of a black hole, such as how massive it is and how fast it spins.

“The actual process of a black hole gobbling down all that stellar material takes a long time,” Masterson says. “It’s not an instantaneous process. And hopefully we can start to probe how long that process takes and what that environment looks like. No one knows because we just started discovering and studying these events.”

This research was supported, in part, by NASA.

Now, researchers at the USC Viterbi School of Engineering have developed a revolutionary AI model that can simulate the behavior of billions of atoms simultaneously, opening new possibilities for materials design and discovery at unprecedented scales.

The current state of the world’s climate is a dire one. Brutal droughts, evaporating glaciers, and more disastrous hurricanes, rainstorms and wildfires devastate us each year. A major contributor to global warming is the constant emission of carbon dioxide into the atmosphere.

Aiichiro Nakano, a USC Viterbi professor of computer science, physics and astronomy, and quantitative and computational biology, was contemplating these issues after the January wildfires in Los Angeles. So, he reached out to longtime partner Ken-Ichi Nomura, a USC Viterbi professor of chemical engineering and materials science practice, with whom he’s collaborated for over 20 years.

Discussing these issues together helped spark their new project: Allegro-FM, an artificial intelligence-driven simulation model. Allegro-FM has made a startling theoretical discovery: it is possible to recapture carbon dioxide emitted in the process of making concrete and place it back into the concrete that it helped produce.

“You can just put the CO2 inside the concrete, and then that makes a carbon-neutral concrete,” Nakano said.

Nakano and Nomura, along with Priya Vashishta, a USC Viterbi professor of chemical engineering and materials science, and Rajiv Kalia, a USC professor of physics and astronomy, have been doing research on what they call “CO2 sequestration,” or the process of recapturing carbon dioxide and storing it, a challenging process.

By simulating billions of atoms simultaneously, Allegro-FM can test different concrete chemistries virtually before expensive real-world experiments. This could accelerate the development of concrete that acts as a carbon sink rather than just a carbon source — concrete production currently accounts for about 8% of global CO2 emissions.

The breakthrough lies in the model’s scalability. While existing molecular simulation methods are limited to systems with thousands or millions of atoms, Allegro-FM demonstrated 97.5% efficiency when simulating over four billion atoms on the Aurora supercomputer at Argonne National Laboratory.

This represents computational capabilities roughly 1,000 times larger than conventional approaches.

The model also covers 89 chemical elements and can predict molecular behavior for applications ranging from cement chemistry to carbon storage.

“Concrete is also a very complex material. It consists of many elements and different phases and interfaces. So, traditionally, we didn’t have a way to simulate phenomena involving concrete material. But now we can use this Allegro-FM to simulate mechanical properties [and] structural properties,” Nomura said.

Concrete is a fire-resistant material, making it an ideal building choice in the wake of the January wildfires. But concrete production is also a huge emitter of carbon dioxide, a particularly concerning environmental problem in a city like Los Angeles. In their simulations, Allegro-FM has been shown to be carbon neutral, making it a better choice than other concrete.

This breakthrough doesn’t only solve one problem. Modern concrete only lasts about 100 years on average, whereas ancient Roman concrete has lasted for over 2,000 years. But the recapture of CO2 can help this as well.

“If you put in the CO2, the so-called ‘carbonate layer,’ it becomes more robust,” Nakano said.

In other words, Allegro-FM can simulate a carbon-neutral concrete that could also last much longer than the 100 years concrete typically lasts nowadays. Now it’s just a matter of building it.

Behind the scenes

The professors led the development of Allegro-FM with an appreciation for how AI has been an accelerator of their complex work. Normally, to simulate the behavior of atoms, the professors would need a precise series of mathematical formulas — or, as Nomura called them, “profound, deep quantum mechanics phenomena.”

But the last two years have changed the way the two research.

“Now, because of this machine-learning AI breakthrough, instead of deriving all these quantum mechanics from scratch, researchers are taking [the] approach of generating a training set and then letting the machine learning model run,” Nomura said. This makes the professors’ process much faster as well as more efficient in its technology use.

Allegro-FM can accurately predict “interaction functions” between atoms — in other words, how atoms react and interact with each other. Normally, these interaction functions would require lots of individual simulations.

But this new model changes that. Originally, there were different equations for individual elements within the periodic table, with several unique functions for these elements. With the help of AI and machine-learning, though, we can now potentially simulate these interaction functions with nearly the entire periodic table at the same time, without the requirement for separate formulas.

“The traditional approach is to simulate a certain set of materials. So, you can simulate, let’s say, silica glass, but you cannot simulate [that] with, let’s say, a drug molecule,” Nomura said.

This new system is also a lot more efficient on the technology side, with AI models making lots of precise calculations that used to be done by a large supercomputer, simplifying tasks and freeing up that supercomputer’s resources for more advanced research.

“[The AI can] achieve quantum mechanical accuracy with much, much smaller computing resources,” Nakano said.

Nomura and Nakano say their work is far from over.

“We will certainly continue this concrete study research, making more complex geometries and surfaces,” Nomura said.

This research was published recently in The Journal of Physical Chemistry Letters and was featured as the journal’s cover image.

In March 2025, central Myanmar was struck by a powerful 7.7 magnitude earthquake—the strongest to hit the region in over a century and one of the deadliest in its modern history. What sets this seismic event apart is the capture of the fault’s sudden rupture in real time by a nearby CCTV camera, marking the first-ever video evidence of such rapid ground movement during an earthquake. The footage vividly shows the Earth’s surface splitting and slipping sideways by an impressive 2.5 meters in just 1.3 seconds. This rare visual record provides scientists with an unprecedented opportunity to study the detailed mechanics of earthquake fault slips, advancing our understanding of seismic behaviour and potentially transforming how future earthquakes are analysed and predicted.

Myanmar earthquake and rare real-time footage of 2.5 metre fault

On March 28, 2025, the Sagaing Fault near Mandalay, Myanmar’s second-largest city, ruptured in a strike-slip earthquake where two blocks of earth slid past each other horizontally. This earthquake was both powerful and deadly, shaking the region unlike any event in recent memory. What makes this event groundbreaking is the CCTV footage that captured the fault slipping in real time, a phenomenon never before recorded on video. Unlike previous studies relying on distant seismic sensors, this footage offers a direct visual record of the fault movement.

Detailed analysis reveals pulse-like rupture and curved slip path

Researchers from Kyoto University analyzed the footage using a pixel cross-correlation technique, measuring the fault’s rapid 2.5-meter slip at speeds up to 3.2 meters per second. The slip lasted only 1.3 seconds, confirming a pulse-like rupture — a short, intense burst of movement traveling along the fault, similar to a ripple across a rug. The study also showed the fault slip path was subtly curved, challenging earlier ideas of purely linear fault ruptures and aligning with geological observations worldwide.

New frontiers in earthquake science and future research

This first-of-its-kind video observation offers powerful new tools for seismologists to understand fault behavior and earthquake mechanics. Capturing such detailed fault movement in real time will improve earthquake models and help better predict the ground shaking in future events, which is crucial for disaster preparedness. The research team plans to further explore the factors controlling fault slip shape and speed through physics-based simulations, hoping to unlock deeper insights into earthquake dynamics globally.

The day before my thesis examination, my friend and radio astronomer Joe Callingham showed me an image we’d been awaiting for five long years – an infrared photo of two dying stars we’d requested from the Very Large Telescope in Chile.

I gasped – the stars were wreathed in a huge spiral of dust, like a snake eating its own tail.

We named it Apep, for the Egyptian serpent god of destruction. Now, our team has finally been lucky to use NASA’s James Webb Space Telescope (JWST) to look at Apep.

If anything could top the first shock of seeing its beautiful spiral nebula, it’s this breathtaking new image, with the JWST data now analysed in two papers on arXiv.

Violent star deaths

Right before they die as supernovae, the universe’s most massive stars violently shed their outer hydrogen layers, leaving their heavy cores exposed.

These are called Wolf-Rayet stars after their discoverers, who noticed powerful streams of gas blasting out from these objects, much stronger than the stellar wind from our Sun. The Wolf-Rayet stage lasts only millennia – a blink of the eye in cosmic time scales – before they violently explode.

Unlike our Sun, many stars in the universe exist in pairs known as binaries. This is especially true of the most massive stars, such as Wolf-Rayets.

When the fierce gales from a Wolf-Rayet star clash with their weaker companion’s wind, they compress each other. In the eye of this storm forms a dense, cool environment in which the carbon-rich winds can condense into dust. The earliest carbon dust in the cosmos – the first of the material making up our own bodies – was made this way.

The dust from the Wolf-Rayet is blown out in almost a straight line, and the orbital motion of the stars wraps it into a spiral-shaped nebula, appearing exactly like water from a sprinkler when viewed from above.

We expected Apep to look like one of these elegant pinwheel nebulas, discovered by our colleague and co-author Peter Tuthill. To our surprise, it did not.

Equal rivals

The new image was taken using JWST’s infrared camera, like the thermal cameras used by hunters or the military. It represents hot material as blue, and colder material in green through to red.

It turns out Apep isn’t just one powerful star blasting a weaker companion, but two Wolf-Rayet stars. The rivals have near-equal strength winds, and the dust is spread out in a very wide cone and wrapped into a wind-sock shape.

When we originally described Apep in 2018, we noted a third, more distant star, speculating whether it was also part of the system or a chance interloper along the line of sight.

The dust appeared to be moving much slower than the winds, which was hard to explain. We suggested the dust might be carried on a slow, thick wind from the equator of a fast-spinning star, rare today but common in the early universe.

The new, much more detailed data from JWST reveals three more dust shells zooming farther out, each cooler and fainter than the last and spaced perfectly evenly, against a background of swirling dust.

New data, new knowledge

The JWST data are now published and interpreted in a pair of papers, one led by Caltech astronomer Yinuo Han, and the other by Macquarie University Masters student Ryan White.

Han’s paper reveals how the nebula’s dust cools, links the background dust to the foreground stars, and suggests the stars are farther away from Earth than we thought. This implies they are extraordinarily bright, but weakens our original claim about the slow winds and rapid rotation.

In White’s paper, he develops a fast computer model for the shape of the nebula, and uses this to decode the orbit of the inner stars very precisely.

He also noticed there’s a “bite” taken out out of the dust shells, exactly where the wind of the third star would be chewing into them. This proves the Apep family isn’t just a pair of twins – they have a third sibling.

Understanding systems like Apep tells us more about star deaths and the origins of carbon dust, but these systems also have a fascinating beauty that emerges from their seemingly simple geometry.

The violence of stellar death carves puzzles that would make sense to Newton and Archimedes, and it is a scientific joy to solve them and share them.

Paleontologists have described a new genus and species of Triassic drepanosauromorph diapsid with striking integumentary appendages — which are neither feathers nor skin — based on two well-preserved skeletons and associated specimens. Their findings demonstrate that feathers or hair-like protrusions are not unique to birds and mammals.

Feathers and hair are examples of complex appendages on the outer bodies of vertebrate animals and have important functions such as forming insulation, aiding sensation, providing displays and contributing to flight.

Feathers and hair have their origins in stem lineages of birds and mammals, respectively.

However, the genetic toolkit for the development of these appendages is likely to have deeper roots among amniotes — the branch of animals that encompasses reptiles, birds and mammals.

A Triassic reptile species described by Dr. Stephan Spiekman from the Staatliches Museum für Naturkunde Stuttgart and his colleagues had a distinctive crest of appendages up to 15.3 cm (6 inches) long along its back.

Named Mirasaura grauvogeli, this strange creature lived in what is now Europe some 247 million years ago.

Although the species had a superficially bird-like skull, it belonged to a group of diapsids called Drepanosauromorpha.

Two well-preserved skeletons and 80 specimens with isolated appendages and preserved soft tissues of Mirasaura grauvogeli were found in northeastern France in the 1930s but remained unidentified until further preparation was undertaken in recent years.

“This allowed the crests and skeletal remains to be associated to each other,” the paleontologists explained.

“The tissues preserved within the appendages contain melanosomes (pigment-producing cells found in skin, hair and feathers) that are more similar to those seen in feathers than in reptilian skin or mammalian hair, although they lack the typical branching patterns seen in feathers.”

“These findings suggest that such complex appendages already evolved among reptiles before the origin of birds and their closest relatives, which may offer new insights into the origin of feathers and hair.”

“Considering the function of the appendages seen in Mirasaura grauvogeli, we ruled out roles in flight or camouflage and instead suggest a possible role in visual communication (signaling or predator deterrence).”

The team’s paper was published today in the journal Nature.

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S.N.F. Spiekman et al. Triassic diapsid shows early diversification of skin appendages in reptiles. Nature, published online July 23, 2025; doi: 10.1038/s41586-025-09167-9