Latest news with #EventHorizonTelescope
Yahoo
a day ago
- Science
- Yahoo
New technique promises clearer, more frequent views of black holes
When you buy through links on our articles, Future and its syndication partners may earn a commission. A powerful new technique is poised to revolutionize how astronomers observe black holes, by producing sharp, multicolored images that could reveal their dynamic evolution in real time. By compensating for Earth's turbulent atmosphere, the technique — called frequency phase transfer (FPT) — enables scientists using the global Event Horizon Telescope (EHT) array to see finer details and fainter features of cosmic objects (like black holes) than ever before. This method also improves the frequency of observations by expanding the EHT's limited observation window, allowing scientists to potentially create time-lapse "movies" of black hole activity. An international team of researchers have put this new technique to the test using three of the 12 telescopes belonging to the EHT array, including the IRAM 30-meter telescope atop Pico Veleta in Spain and the James Clerk Maxwell Telescope and Submillimeter Array observatories in Hawai'i, according to a statement from the Center for Astrophysics at Harvard & Smithsonian (CfA). The challenge of observing the cosmos with ground-based telescopes begins with Earth's atmosphere, which distorts radio waves coming from space, according to Sara Issaoun, lead author of the new study and an astronomer with the CfA. These distortions are especially problematic at higher frequencies like the 230 gigahertz (GHz) band — also known as the millimeter band, which the EHT currently uses — where signals are rapidly scrambled by atmospheric turbulence and water vapor. As a result, data can be collected only over short time spans, limiting sensitivity and making it harder to detect faint signals. The FPT technique works by taking advantage of the fact that atmospheric variations affect different frequencies in similar ways, creating a measurable correlation. By observing at a lower frequency, specifically 86 GHz, which experiences slower atmospheric fluctuations, scientists can use that data to correct for the faster, more disruptive variations at 230 GHz. This allows for much longer averaging periods at the higher frequency, significantly boosting signal clarity and sensitivity. This leap in performance could enable the EHT to detect dimmer black holes and finer details than ever before, Issaoun told The EHT is a global network of radio telescopes that uses a technique called Very Long Baseline Interferometry (VLBI) to digitally combine observations from around the world. Currently, the EHT is only operational for about 10 days each April, when weather conditions align across the widespread telescopes. With FPT, astronomers could greatly extend that window, opening up opportunities to observe black holes more regularly and flexibly, even under less-than-ideal weather conditions. That increased cadence is key to a major goal for the EHT: turning still images of black holes into movies that show how they change over time. Because most black holes evolve slowly, repeated observations are essential to track how matter swirls around them, how jets of material are launched, and how magnetic fields shift. By observing more frequently throughout the year, the EHT would be able to watch black holes change over time — potentially capturing phenomena in real time for the first time, Issaoun noted. To make this possible, telescopes in the EHT array are being upgraded to support simultaneous observations at multiple frequencies. This includes adding receivers for the 86 GHz band. However, not every telescope in the array needs to be outfitted with the new receiver for FPT to be effective. Even partial implementation can enhance the performance of the full network, since all telescopes work in tandem to build a complete picture of a cosmic target. While the required hardware upgrades are relatively minor, each telescope has unique technical constraints, posing challenges to implementation, according to Issaoun. RELATED STORIES — Event Horizon Telescope: A complete guide — Event Horizon Telescope spies jets erupting from nearby supermassive black hole — After snapping a photo of the Milky Way's monster black hole, scientists dream of videos In addition to boosting performance, this technique also adds a new layer of complexity to the images themselves. With multiple frequency bands, researchers can overlay data in different colors to reveal more detailed structures around a black hole. These multiband images will help disentangle features like swirling gas and magnetic fields, painting a more dynamic, multidimensional portrait of black hole environments. Ultimately, the FPT technique could enable the EHT to not only see black holes more clearly but also more often, unlocking a new era of black hole science. The team's initial findings were published on March 26 in The Astronomical Journal. The researchers continually work on developing the full potential of the EHT network and exploring even higher-frequency capabilities — such as 345 GHz — that can further complement multiband observations.
NDTV
2 days ago
- Science
- NDTV
Is Our Black Hole Defying Physics? New AI Study Challenges Theories
Astronomers, using AI and high-throughput computing from the University of Wisconsin-Madison's CHTC, have unlocked new insights into Sagittarius A* - the supermassive black hole at the heart of our galaxy. By training a neural network on millions of simulations, researchers found the black hole is spinning near its maximum speed, with its axis of rotation aimed toward Earth. The findings are based on data from the Event Horizon Telescope and offer fresh understanding of black hole behaviour. The AI also suggests that the emission near the black hole is primarily from extremely hot electrons in the accretion disk rather than a jet, and that the magnetic fields in the disk behave differently than previously thought. This research, published in Astronomy & Astrophysics, was made possible by high-throughput computing, a distributed computing method pioneered by Miron Livny, which allowed researchers to process a massive amount of data efficiently. "That we are defying the prevailing theory is, of course, exciting," says lead researcher Michael Janssen, of Radboud University Nijmegen, the Netherlands. "However, I see our AI and machine learning approach primarily as a first step. Next, we will improve and extend the associated models and simulations." "The ability to scale up to the millions of synthetic data files required to train the model is an impressive achievement," adds Chi-kwan Chan, an Associate Astronomer of Steward Observatory at the University of Arizona and a longtime PATh collaborator. "It requires dependable workflow automation and effective workload distribution across storage resources and processing capacity." "We are pleased to see EHT leveraging our throughput computing capabilities to bring the power of AI to their science," says Professor Anthony Gitter, a Morgridge Investigator and a PATh Co-PI. "Like in the case of other science domains, CHTC's capabilities allowed EHT researchers to assemble the quantity and quality of AI-ready data needed to train effective models that facilitate scientific discovery." The NSF-funded Open Science Pool, operated by PATh, offers computing capacity contributed by more than 80 institutions across the United States. The Event Horizon black hole project performed more than 12 million computing jobs in the past three years. "A workload that consists of millions of simulations is a perfect match for our throughput-oriented capabilities that were developed and refined over four decades", says Livny, director of the CHTC and lead investigator of PATh. "We love to collaborate with researchers who have workloads that challenge the scalability of our services."
Japan Forward
2 days ago
- Science
- Japan Forward
Black Holes: What They Are and What They're Not
このページを 日本語 で読む Almost everyone has heard the term "black hole" — it's one of the most recognizable concepts in modern science. But with that familiarity comes a lot of misunderstanding. While some misconceptions are too technical to unpack without advanced knowledge, this article focuses on several common ones about black holes that can be explained relatively clearly. People often describe a black hole as "a hole in space-time." Even experts sometimes use this phrase, but it's just a metaphor. In reality, a black hole has a surprisingly simple structure. It consists of only two parts: the singularity, where all the black hole's mass is compressed into a single point, and the event horizon that surrounds it. The event horizon isn't a physical substance like a membrane or mist. No matter how closely you look, there's nothing that resembles a surface. A black hole isn't literally a hole or a vortex, and it's not a traditional celestial object. It's better understood as a region of space-time with extreme properties. One of the most striking features is that beyond the event horizon, space behaves like time. It "flows" only inward toward the singularity, just as time only moves forward for us. This one-way flow is what gives the black hole its "hole-like" reputation. So, the metaphor of a "hole in space-time" likely comes from this defining feature: a region of severely distorted space-time from which nothing can return. If "observing a black hole" means directly detecting radiation from the singularity or the event horizon, then this idea is mostly correct. Hawking radiation, the thermodynamic radiation of black holes, is too weak to be detected for the foreseeable future, so it can be ignored in this discussion. In practice, though, observing a black hole usually means finding evidence of its presence through indirect methods. In that sense, there are several reliable ways to do it. The most common method is to observe electromagnetic radiation, such as strong X-rays or radio waves. The black hole itself does not emit radiation, but it pulls in a large amount of matter, usually gas or dust. As the material spirals inward, it heats up due to friction and compression, producing intense radiation. While other cosmic objects can also emit radiation, the extreme brightness and compactness of the source often point to a black hole. In the case of supermassive black holes, we can even map the surrounding radiation in enough detail to image the black hole's "shadow." The first image of this kind was captured by the Event Horizon Telescope (EHT), a global network of radio observatories. In April 2017, the EHT imaged the supermassive black hole at the center of the galaxy M87 in the Virgo constellation. The image was released to the public on April 10, 2019. To observe a black hole this way, there must be nearby matter to interact with. But since space is mostly empty, black holes with visible material around them are relatively rare. That's why many remain hidden from direct observation. Fortunately, newer indirect methods have made it possible to detect more of these hidden black holes. One is gravitational lensing, where a black hole bends the light from more distant stars. Another is the detection of gravitational waves, which are ripples in space-time produced when black holes collide. These techniques have opened exciting new paths in astrophysics, helping scientists better understand black holes and the structure of the universe. The idea that black holes are dangerous probably comes mainly from science fiction. However, in reality, black holes don't indiscriminately suck in or tear apart everything nearby. It's true that black holes have incredibly strong gravity, but that's mainly because their mass is packed into an extremely small space. In fact, their compactness allows matter, and even light, to get much closer to the center than with other objects of the same mass. Stars or planets have physical surfaces or atmospheres that prevent such close approach. (©Sankei) In fact, if the Sun were suddenly replaced by a black hole of the same mass, Earth and the other planets would continue orbiting just as they do now. We'd lose sunlight, which would be catastrophic for life, but Earth wouldn't be pulled in or torn apart. Whether something falls into a black hole depends on how close it is and whether it can change its speed or direction. As long as it stays outside the event horizon — the point of no return — it can still escape. That's why we can observe light and matter swirling just outside black holes. There's also a common idea that anything near a black hole gets stretched and ripped apart, a process nicknamed "spaghettification." This effect is real, but it mostly applies to smaller black holes. In those cases, tidal forces — differences in gravity across an object — become extreme just a few hundred kilometers from the center. A person or spacecraft getting too close would be torn apart long before reaching the event horizon. However, for supermassive black holes, which are millions of times the mass of the Sun, you wouldn't be torn apart or feel any discomfort even near the event horizon. In fact, you might not notice anything unusual at all as you cross that boundary. The reason for this big difference lies in the gravitational field around the black hole. For ordinary celestial bodies ike Earth, the difference in gravity over such a small distance is too weak to notice. In fact, even over a small distance, like from your toes to your head, there is a slight difference in gravitational strength. But near a black hole, where gravity grows stronger the closer you get to the center, the more significant this difference becomes. The varying strength of gravitational pull across an object can become so extreme that it stretches and tears the object apart. Again, the distance from the black hole at which these extreme forces occur depends on the black hole's mass. (©Laura A Whitlock, Kara C Granger & Jane D Mahon) The distance from the singularity to the event horizon, called the Schwarzschild radius, is also determined by the black hole's mass. The Schwarzschild radius grows much more rapidly than the distance at which extreme tidal forces begin to emerge. Because of this difference, the larger the black hole, the safer it is to approach — up to a point. Once you cross the event horizon, there's no coming back. And the deeper you go, the stronger the tidal forces become. Eventually, even in a supermassive black hole, those forces would tear you apart before you reached the center. Larger objects like stars don't fare any better. Even supermassive black holes can shred them before they reach the event horizon. So, if you're planning a trip near a black hole, leave the stars behind — and whatever you do, don't fall in. Because black holes are often described as objects in space, it's easy to picture them having a solid, dark surface. But as explained earlier, a black hole isn't really a celestial object. It's more accurate to think of it as a region of space-time with extreme properties. As mentioned before, you can actually get quite close to a large black hole without immediately being affected. But even up close, you wouldn't see a wall, a membrane, or a swirl of darkness. The event horizon — the point of no return — has no visible surface and gives no physical warning. If you crossed it, you wouldn't feel anything special. No bump, no jolt, no sudden shift. In fact, you might not realize you've passed it at all. But once you do, escape becomes impossible. You'd be on a one-way path toward the singularity. If black hole tourism ever becomes a thing, it's safe to assume there'd be clear warnings posted: "Do Not Enter: Black Hole Ahead ." The gravity would already be distorting your view of space around you, but without a visible marker, you wouldn't be able to tell where the event horizon actually is. The rumor that particle accelerators could create black holes and destroy the Earth began during the construction of CERN's Large Hadron Collider (LHC). The idea even shows up in some science fiction stories, so you may have heard it before. But given that Earth is still intact, we can safely say this fear is unfounded. A particle accelerator at CERN. (©Maximilien Brice) The concern arose because the LHC is capable of producing particle collisions at extremely high energies. Furthermore, some theoretical models also propose the existence of "extra dimensions" beyond the four we experience. If these extra dimensions exist and are larger than expected, it's theoretically possible — though extremely unlikely — that tiny black holes could form in these collisions. Furthermore, this scenario depends on several optimistic assumptions. First, we don't yet know if extra dimensions exist. And even if they do, the conditions needed to produce black holes are probably not met by the LHC. More importantly, if the LHC could create black holes, nature would already have done so. That's because cosmic rays, which are high-energy particles from space, routinely strike Earth's atmosphere with far more energy than the LHC can generate. These natural particle collisions have been happening for 4.6 billion years, all over the planet. If high-energy collisions could destroy Earth, it would have happened long ago. Even in the unlikely event that the LHC did create a tiny black hole, it wouldn't be dangerous. According to theory, it would vanish almost instantly due to a process called Hawking radiation. Even if Hawking radiation turned out not to occur, any black hole produced would be traveling so fast that it would escape Earth's gravity and fly off into space. And if, against all odds, such a black hole somehow stayed trapped by Earth's gravity, it would be smaller than an atom and would absorb almost nothing as it orbited through the planet. By the time it finally settled at Earth's core, millions or billions of years later, the Sun would have reached the end of its life, likely engulfing or incinerating the Earth long before any black hole could do serious harm. NASA Science Editorial Team. （Aug 13, 2019） "Shedding Light on Black Holes". NASA Sara Rigby. （Mar 30, 2021） "7 black hole 'facts' that aren't true". BBC Science Focus. Amanda Bauer & Christopher A Onken. "Black hole truths, myths and mysteries." Australian Academy of Science. Author: The Sankei Shimbun このページを 日本語 で読む
Yahoo
3 days ago
- Science
- Yahoo
'Artificial intelligence is not a miracle cure': Nobel laureate raises questions about AI-generated image of black hole spinning at the heart of our galaxy
When you buy through links on our articles, Future and its syndication partners may earn a commission. The monster black hole at the center of our galaxy is spinning at near "top speed," according to a new artificial intelligence (AI) model. The model, trained partially on complex telescope data that was previously considered too noisy to be useful, aims to create the most detailed black hole images ever. However, based on the questionable quality of the data, not all experts are convinced that the AI model is accurate. "I'm very sympathetic and interested in what they're doing," Reinhard Genzel, an astrophysicist at the Max Planck Institute for Extraterrestrial Physics in Germany and one of the winners of the 2020 Nobel Prize in physics, told Live Science. "But artificial intelligence is not a miracle cure." For decades, scientists have been trying to observe and characterize Sagittarius A*, the supermassive black hole at the heart of our galaxy. In May 2022, they unveiled the first-ever image of this enormous object, but there were still a number of questions, such as how it behaves. Now, an international team of scientists has attempted to harness the power of AI to glean more information about Sagittarius A* from data collected by the Event Horizon Telescope (EHT). Unlike some telescopes, the EHT doesn't reside in a single location. Rather, it is composed of several linked instruments scattered across the globe that work in tandem. The EHT uses long electromagnetic waves — up to a millimeter in length — to measure the radius of the photons surrounding a black hole. However, this technique, known as very long baseline interferometry, is very susceptible to interference from water vapor in Earth's atmosphere. This means it can be tough for researchers to make sense of the information the instruments collect. "It is very difficult to deal with data from the Event Horizon Telescope," Michael Janssen, an astrophysicist at Radboud University in the Netherlands and co-author of the study, told Live Science. "A neural network is ideally suited to solve this problem." Related: Astronomers discover most powerful cosmic explosions since the Big Bang Janssen and his team trained an AI model on EHT data that had been previously discarded for being too noisy. In other words, there was too much atmospheric static to decipher information using classical techniques. Through this AI technique, they generated a new image of Sagittarius A*'s structure, and their picture revealed some new features. For example, the black hole appears to be spinning at "almost top speed," the researchers said in a statement, and its rotational axis also seems to be pointing toward Earth. Their results were published this month in the journal Astronomy & Astrophysics. Pinpointing the rotational speed of Sagittarius A* would give scientists clues about how radiation behaves around supermassive black holes and offer insight into the stability of the disk of matter around it. RELATED STORIES —Monster black hole jet from the early universe is basking in the 'afterglow' of the Big Bang —Astronomers discover most powerful cosmic explosions since the Big Bang —Astronomers simulate a star's final moments as it's swallowed by a black hole: 'Breaks like an egg' However, not everyone is convinced that the new AI is totally accurate. According to Genzel, the relatively low quality of the data going into the model could have biased it in unexpected ways. As a result, the new image may be somewhat distorted, he said, and shouldn't be taken at face value. In the future, Janssen and his team plan to apply their technique to the latest EHT data and measure it against real-world results. They hope this analysis will help to refine the model and improve future simulations.
Yahoo
08-06-2025
- Science
- Yahoo
Monster black hole M87 is spinning at 80% of the cosmic speed limit — and pulling in matter even faster
When you buy through links on our articles, Future and its syndication partners may earn a commission. The monster black hole lurking at the center of galaxy M87 is an absolute beast. It is one of the largest in our vicinity and was the ideal first target for the Event Horizon Telescope. Scientists have taken a fresh look at the supermassive black hole using those iconic Event Horizon Telescope images and have now figured out just how fast this monster is spinning and how much material it's devouring. The results are pretty mind-blowing. This black hole, which weighs in at 6.5 billion times the mass of our Sun, is spinning at roughly 80% of the theoretical maximum speed possible in the universe. To put that in perspective, the inner edge of its accretion disk is whipping around at about 14% the speed of light - that's around 42 million meters per second. The team figured this out by studying the "bright spot" in the original black hole images. That asymmetric glow isn't just there for show - it's caused by something called relativistic Doppler beaming. The material on one side of the disk is moving toward us so fast that it appears much brighter than the material moving away from us. By measuring this brightness difference, the scientists could calculate the rotation speed. But here's where it gets really interesting. The researchers also looked at the magnetic field patterns around the black hole, which act like a roadmap for how material spirals inward. They discovered that matter is falling into the black hole at about 70 million meters per second - roughly 23% the speed of light. Using these measurements, they estimated that M87's black hole is consuming somewhere between 0.00004 to 0.4 solar masses worth of material every year. That might sound like a lot, but it's actually pretty modest for such a massive black hole - it's operating well below what scientists call the "Eddington limit," meaning it's in a relatively quiet phase. Related: Scientists just proved that 'monster' black hole M87 is spinning — confirming Einstein's relativity yet again Perhaps most importantly, the energy from all this in-falling material appears to perfectly match the power output of M87's famous jet - that spectacular beam of particles shooting out at near light-speed that extends for thousands of light-years. This supports the idea that these powerful jets are indeed powered by the black hole's feeding process. RELATED STORIES —Time-lapse of 1st black hole ever imaged reveals how matter swirls around it —Astronomers discover black hole ripping a star apart inside a galactic collision. 'It is a peculiar event' —Not 'Little Red Dots' or roaring quasars: James Webb telescope uncovers new kind of 'hidden' black hole never seen before The study represents a major step forward in understanding how supermassive black holes work. While previous estimates of M87's spin ranged anywhere from 0.1 to 0.98, this new method suggests it's definitely on the high end - at least 0.8 and possibly much closer to the theoretical maximum of 0.998. As we gear up for even more powerful telescopes and imaging techniques, M87's black hole will likely remain a cosmic laboratory for testing our understanding of gravity, spacetime, and the most extreme physics in the universe. Each new measurement brings us closer to answering fundamental questions about how these cosmic monsters shape entire galaxies and maybe even how they'll influence the ultimate fate of the cosmos itself. The original version of this article was published on Universe Today.
