Category: 7. Science

Simulations on TACC’s Stampede2, Stampede3 supercomputers explore accretion disc properties

The first black hole images stunned the world in 2019, with headlines announcing evidence of a glowing doughnut-shaped object from the center of galaxy Messier 87 (M87 —55 million light years from Earth. Supercomputer simulations are now helping scientists sharpen their understanding about the environment beyond a black hole’s ‘shadow,’ material just outside its event horizon.

“Ever since we made that first black hole image, there’s been a lot of work trying to understand the environment just around the black hole,” said Andrew Chael, an associate research scholar at Princeton University and a fellow of the Princeton Gravity Initiative.

Chael is part of the Event Horizon Telescope Collaboration (EHT), which connects telescopes from around the world to form a mega-telescope roughly the size of Earth. The EHT uses a technique called Very Long Baseline Interferometry, a type of astronomical interferometry used in radio astronomy that compares telescope signals to stitch together images that resolve the M87 black hole.

Shown in the black hole image is light from hot electrons that spiral around surrounding magnetic field lines and produce synchrotron radiation.

“We want to understand the nature of the particles of this plasma that the black hole is eating, and the details of the magnetic fields commingled with the plasma that in M87 launches huge, luminous jets of subatomic particles,” Chael said.

Like a beacon, the jets signal the possible presence of a black hole in center of the M87 galaxy as it spews particles thousands of light years from the source.

Using Supercomputers to Simulate Black Hole Plasma, Magnetism, and Gravity

Across the globe, scientists are harnessing the power of supercomputers to unravel one of the universe’s most extreme environments: the space around black holes.

Chael’s research group is among those using advanced simulations to model the dynamic interplay between high-energy plasma, powerful magnetic fields, and the overwhelming pull of gravity near these cosmic giants. These forces do not act in isolation—they interact in complex, feedback-driven ways that allow black holes to consume surrounding matter, launch jets across vast distances, and emit the glowing radiation captured by the Event Horizon Telescope.

Chael’s recent advancements in his simulation techniques are reported in his study published February 2025 in the Monthly Notices of the Astronomical Society. They go beyond typical simulations that treat the electrically charged particles of protons and electrons in the plasma surrounding the black hole like a single fluid.

“This paper is a first attempt of using a more advanced, more computationally expensive technique to directly model these separate particle species of electrons and protons to try to understand how they interact, and in particular, what the relative temperature of the two is,” he explained.

The relative temperature between the electrons and protons determines the brightness and other properties of the black hole image.

“What we found through simulations is the temperature of the electrons is much higher than is typically thought to be the case in M87. We’re not able to reproduce the low polarization, which is one of the main constraints in understanding what the temperature of the plasma is around the black hole,” Chael said.

The results highlight a fundamental tension between current models of electron heating in plasma physics and the observational constraints provided by the EHT.

“It seems like the black hole in M87 has electrons that are about 100 times cooler than the protons. This is an interesting direction to proceed,” Chael said.

Chael completed his black hole simulations on the Stampede2 and later the Stampede3 supercomputers at the Texas Advanced Computing Center (TACC), with allocations awarded by the National Science Foundation(NSF)-funded Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program.

“I’ve been using XSEDE, and now ACCESS resources at TACC since graduate school,” said Chael. “It’s been the primary academic supercomputing center that I’ve run simulations for my research.  These systems were both extremely easy to use with my code,” Chael said.

A series of 11 general relativistic magnetohydrodynamic simulations (GRMHDS) that cover a range of different black hole spins were completed on Stampede2 and Stampede3 for this study. Breaking that down, ‘general relativistic’ accounts for the strong gravity of the black hole spacetime. ‘Magnetohydrodynamic’ takes a fluid dynamics approach to the magnetic fields of the black hole.

More Research Ahead

There are several years of EHT data that hasn’t yet been imaged, and it hopes to make a movie that tracks its evolution over time.

In January 2025, Chael and his EHT collaborators published a study comparing the M87 black hole image captured by the EHT to a wide range of simulations. To support this work, he received computing allocations from ACCESS on the Stampede2 and Jetstream supercomputers, and he conducted simulations on the NSF-funded Frontera system at TACC.

High-resolution simulations revealed that while the black hole’s shadow remains remarkably consistent in size and general structure from year to year, it is far from static. Also, the brightest spot on the ring shifts over time, driven by turbulent mixing and dynamic flows of plasma near the event horizon. As different regions of gas heat up or cool down due to these chaotic processes, the black hole’s appearance subtly but measurably evolves.

“Black holes are extremely complicated environments,” Chael said. “The best available tools we have are supercomputing simulations. It’s amazing that we’ve been able to build these computers and codes that allow us to create accurate models of what’s going on in such a strange and complicated relationship. Simulations give us confidence that we are accounting for all these effects, which are all interacting in complicated and sometimes unpredictable ways.”

This article was originally published by TACC and is reprinted with permission.

When Kearse and his colleague Yoshihiro Kaneko at Kyoto University analyzed the video more carefully, they concluded that it had captured the first direct visual evidence of curved fault slip.

Earthquake geologists often observe curved slickenlines, the scrape marks created by blocks of rock moving past each other during faulting. But until now there has been no visual proof of the curved slip that might create these slickenlines.

The video confirmation of curved fault slip can help researchers create better dynamic models of how faults rupture, Kearse and Kaneko conclude in their paper published in The Seismic Record. (See video below.)

The video comes from a CCTV security camera recording along the trace of Myanmar’s Sagaing Fault, which ruptured 28 March in a magnitude 7.7 earthquake. The camera was placed about 20 meters to the east of the fault and was 120 kilometers away from the earthquake’s hypocenter.

The resulting video is astonishing. A fault in motion as never seen before — shaking followed by a visible northward slide of the land on the western side of the fault.

“I saw this on YouTube an hour or two after it was uploaded, and it sent chills down my spine straight away,” Kearse recalled. “It shows something that I think every earthquake scientist has been desperate to see, and it was just right there, so very exciting.”

Watching it over and over again, he noticed something else.

“Instead of things moving straight across the video screen, they moved along a curved path that has a convexity downwards, which instantly started bells ringing in my head,” Kearse said, “because some of my previous research has been specifically on curvature of fault slip, but from the geological record.”

Kearse had studied curved slickenlines associated with other earthquakes, such as the 2016 magnitude 7.8 Kaikoura earthquake in New Zealand, and their implications for understanding how faults rupture.

With the Myanmar video, “we set about to quantify the movement a bit more carefully, to extract objective quantitative information from the video rather than just pointing at it to say, look, it’s curved,” he said.

The researchers decided to track the movement of objects in the video by pixel cross correlation, frame by frame. The analysis helped them measure the rate and direction of fault motion during the earthquake.

They conclude that the fault slipped 2.5 meters for roughly 1.3 seconds, at a peak velocity of about 3.2 meters per second. This shows that the earthquake was pulse-like, which is a major discovery and confirms previous inferences made from seismic waveforms of other earthquakes. In addition, most of the fault motion is strike-slip, with a brief dip-slip component.

The slip curves rapidly at first, as it accelerates to top velocity, then remains linear as the slip slows down, the researchers found.

The pattern fits with what earthquake scientists had previously proposed about slip curvature, that it might occur in part because stresses on the fault near the ground surface are relatively low. “The dynamic stresses of the earthquake as it’s approaching and begins to rupture the fault near the ground surface are able to induce an obliquity to the fault movement,” said Kearse.

“These transient stresses push the fault off its intended course initially, and then it catches itself and does what it’s supposed to do, after that.”

The researchers previously concluded that the type of slip curvature — whether it curves in one direction, or in the other — is dependent on the direction that the rupture travels, and is consistent with the north to south rupture of the Myanmar earthquake. This means that slickenlines can record the dynamics of past earthquakes, which can be useful for understanding future seismic risks.

The Royal Society has announced plans that would make its journals open access next year.

A “subscribe to open” model is being adopted by the society, which is asking libraries to support the plan through their subscriptions.

If enough libraries sign up, the society said, its journals will be converted to open access for the year.

This would allow papers published in eight of its subscription titles, including the world’s oldest peer-reviewed journals, Philosophical Transactions A and B, to be freely available to read online, with author fees also removed. The society’s other journals, Open Biology and Royal Society Open Science, are already open access.

The journals will “become free to read and publish in for any author or reader, not just those associated with a subscribed library,” the society said.

It will repeat the offer in subsequent years as it works with libraries, institutions and consortia to establish “read and publish agreements” which it said would “provide a sustainable model of open access in the longer term”.

Rod Cookson, publishing director for the Royal Society, said the subscribe to open model “will help us transition more quickly and equitably, and is the right approach at this stage of our open access journey”.

“Most importantly, it will make the society’s journals stronger in the future, by reaching more readers and a wider range of researchers around the world.”

Mark Walport, vice president and chair of the Royal Society’s publishing board added that it had a “long history of transformative scientific publishing”.

“This proposal is a natural next step which, along with the society’s ongoing review on the ‘future of scientific publishing’, continues the tradition of innovation it has brought to scholarly communication since launching the world’s first scientific journal in 1665.”

tom.williams@timeshighereducation.com

The four crewmembers of NASA’s next moon mission are moving closer to their upcoming launch.

The Artemis 2 crew consists of NASA astronauts Reid Wiseman (commander), Victor Glover (pilot), Christina Koch (mission specialist) and the Canadian Space Agency’s Jeremy Hansen. After experiencing multiple delays, the quartet is scheduled to launch no earlier than April 2026 on their 10-day mission around the moon and back. With just months left before the historic launch, the Artemis crew is hard at work finishing their training and preparations. As part of that training, the whole crew suited up in their launch and entry suits to enter their Orion spacecraft together for the first time on July 31 at NASA’s Kennedy Space Center (KSC) in Florida during what is known as a suited crew test.

Researchers at the University of Southern California (USC) in the US turned to an often overlooked particle for storing and processing quantum information to overcome the fragility of quantum computers and make them more universal in the near future. Positioning one such particle in a quantum computer can help overcome errors in quantum computing, a university press release said. The age of quantum computing promises computations at speeds that will make even the fastest supercomputers of today appear like snails. These computers leverage quantum properties of materials to store information in quantum bits or ‘qubits’. Unlike binary bits that occupy either a 0 or 1 position, qubits can occupy a whole range of positions in between, allowing them to store and process more information. The hurdle with large-scale deployment of these systems is that they are extremely fragile and can be easily disrupted by their environment. These disruptions add errors to the computation, which accumulate faster in quantum systems, making them unreliable without error correction. Researchers have been working on various strategies for error correction, with topological quantum computing being one of the most promising approaches. In this approach, researchers work to secure quantum information by encoding it into the geometric properties of exotic particles called anyons. Predicted to exist in two dimensions, anyons are considered more resistant to noise and interference than other qubits, with Ising anyons leading the development of these quantum systems.

Full study : US researcher finds missing particle that makes quantum computing fully possible.

A new study has discovered that trees contain a rich and diverse microbiome inside their tree trunks, much like humans do in our bodies.

An average tree contains approximately one trillion microbe cells, according to data acquired from sampling the DNA of 150 trees and published today in the journal Nature.

It found that healthy trees contain distinct microbiomes specialized to different parts of the tree and rich in fungi, bacteria, and viruses. The authors believe these could play a vital role in tree health.

“Our study shows that each tree species hosts its own distinct microbial community that has evolved alongside the tree,” said study co-author Jon Gewirtzman at Yale University, US. 

Katie Field, a plant biologist at Sheffield University, UK, who was not involved in the research, said the study “helps redefine how we see trees — not just as standalone organisms, but as complex, integrated ecosystems that include a vast network of microbial life.” 

“In the same way that human microbiomes are important for our health, this work suggests we may need to start thinking similarly about trees. It opens a whole new frontier for environmental microbiology, forest science, and even biotechnology,” Field told DW.

One trillion microbes per tree

Microbes are an important part of plant life. The discovery of a ‘wood-wide web’ — a network that connects fungal filaments and tree roots in underground soil — led to the idea that other organisms aid plant growth and defense against pathogens. 

But little is known about the microbes living inside healthy wood. 

“The three trillion trees on Earth represent the world’s largest pool of biomass, much of which hosts unique ecosystems we’ve never studied,” said Gewirtzman.

The researchers set out to study the microbiomes of trees in the Yale-Myers Forest in Connecticut, US. They took multiple samples from 150 trees across 16 species, including oaks, maples, and pines.

Soil samples were also taken.

They then extracted DNA from the wood and soil and analyzed the data for evidence of DNA from bacteria, fungi, and viruses.

They found that trees contain huge numbers of different microbe species — roughly one microbe for every 20 plant cells. 

This translates to between 100 billion and one trillion microbial cells on average, which is still far fewer than the 39 trillion inside humans.

“This study provides some of the clearest evidence to date that the wood of living trees hosts distinct and adapted microbiomes, different to those of the surrounding soil, leaves, or tree roots,” said Field.

Wood microbiomes are specialized

Microbes weren’t equally distributed through the tree — specialized microbial communities existed in different parts of wood. 

The inner heartwood and outer sapwood contained completely different microbial communities. Denser heartwood was dominated by microbes that don’t need oxygen, while the sapwood contained more oxygen-requiring microbes.

Different microbiomes were also found in different tree species. Maple trees, for example, contained high abundance of microbes that are adept at breaking down sugars.

Further experiments showed that different communities changed gas concentrations inside these woods.

Do tree microbiomes affect forest health?

Whether these specialized microbiomes affect the health of their tree hosts is unclear. More studies are needed to understand how microbiomes affect wider forest health, but the authors believe there is a link.

“We know that certain microbes promote growth in certain model plants, including in major cereal crops and poplar trees, but there are thousands [of microbes] that we do not know the function of,” Gewirtzman told DW via email.

The study may also open new questions. For Field, this includes investigating the roles microbiomes play in tree aging, defence and decay.

“There is also clear potential to explore whether managing or modifying wood microbiomes could help improve forest resilience or carbon cycling,” said Field.

Gewirtzman suggests it could also answer big picture questions about how climate change impacts trees, or whether tree microbiomes could be deployed for other purposes.

“How will climate change affect these internal ecosystems and forest health? And can we harness these microbes for new forest management or biotechnology applications?”

But Michael Köhler, a botanist at Martin Luther University Halle-Wittenberg, Germany, told DW it’s far too early for Gewirtzman’s group to start monitoring tree microbiomes to measure climate impacts and forest health. 

“We’re investigating this at the moment — how climate change is affecting the microbiome of seeds and seedlings in grasslands,” he told DW.

Edited by: MW Agius

A full moon will rise this weekend — but, unlike most, there will be two opportunities to see it appear on the eastern horizon at dusk.

The Sturgeon Moon will officially reach its full moon phase at 3:55 a.m. ET on Saturday, Aug. 9, which will create opportunities for those in North America to see the full moon rise twice in successive evenings.

A new study has discovered that trees contain a rich and diverse microbiome inside their tree trunks, much like humans do in our bodies.

An average tree contains approximately 1 trillion microbe cells, according to data acquired from sampling the DNA of 150 trees which waspublished in the journal Nature.

It found that healthy trees contain distinct microbiomes specialized to different parts of the tree and are rich in fungi, bacteria, and viruses. The authors believe these could play a vital role in tree health.

“Our study shows that each tree species hosts its own distinct microbial community that has evolved alongside the tree,” said study co-author Jon Gewirtzman at Yale University, US.

Katie Field, a plant biologist at Sheffield University, UK, who was not involved in the research, said the study “helps redefine how we see trees — not just as standalone organisms, but as complex, integrated ecosystems that include a vast network of microbial life.”

“In the same way that human microbiomes are important for our health, this work suggests we may need to start thinking similarly about trees. It opens a whole new frontier for environmental microbiology, forest science, and even biotechnology,” Field told DW.

1 trillion microbes per tree

Microbes are an important part of plant life. The discovery of a ‘wood-wide web’ — a network that connects fungal filaments and tree roots in underground soil — led to the idea that other organisms aid plant growth and defense against pathogens.

But little is known about the microbes living inside healthy wood.

“The 3 trillion trees on Earth represent the world’s largest pool of biomass, much of which hosts unique ecosystems we’ve never studied,” said Gewirtzman.

The researchers set out to study the microbiomes of trees in the Yale-Myers Forest in Connecticut, US. They took multiple samples from 150 trees across 16 species, including oaks, maples, and pines.

Soil samples were also taken.

They then extracted DNA from the wood and soil and analyzed the data for evidence of DNA from bacteria, fungi, and viruses.

They found that trees contain huge numbers of different microbe species — roughly one microbe for every 20 plant cells.

This translates to between 100 billion and 1 trillion microbial cells on average, which is still far fewer than the 39 trillion inside humans.

“This study provides some of the clearest evidence to date that the wood of living trees hosts distinct and adapted microbiomes, different to those of the surrounding soil, leaves, or tree roots,” said Field.

Wood microbiomes are specialized

Microbes weren’t equally distributed through the tree — specialized microbial communities existed in different parts of wood.

The inner heartwood and outer sapwood contained completely different microbial communities. Denser heartwood was dominated by microbes that don’t need oxygen, while the sapwood contained more oxygen-requiring microbes.

Different microbiomes were also found in different tree species. Maple trees, for example, contained a high abundance of microbes that are adept at breaking down sugars.

Further experiments showed that different communities changed gas concentrations inside these woods.

Do tree microbiomes affect forest health?

Whether these specialized microbiomes affect the health of their tree hosts is unclear. More studies are needed to understand how microbiomes affect wider forest health, but the authors believe there is a link.

“We know that certain microbes promote growth in certain model plants, including in major cereal crops and poplar trees, but there are thousands [of microbes] that we do not know the function of,” Gewirtzman told DW via email.

The study may also open new questions. For Field, this includes investigating the roles microbiomes play in tree aging, defense and decay.

“There is also clear potential to explore whether managing or modifying wood microbiomes could help improve forest resilience or carbon cycling,” said Field.

Gewirtzman suggests it could also answer big picture questions about how climate change impacts trees, or whether tree microbiomes could be deployed for other purposes.

“How will climate change affect these internal ecosystems and forest health? And can we harness these microbes for new forest management or biotechnology applications?”

But Michael Köhler, a botanist at Martin Luther University Halle-Wittenberg, Germany, told DW it’s far too early for Gewirtzman’s group to start monitoring tree microbiomes to measure climate impacts and forest health.

“We’re investigating this at the moment — how climate change is affecting the microbiome of seeds and seedlings in grasslands,” he told DW.

Edited by: MW Agius