Latest news with #PriyamvadaNatarajan
Yahoo
7 days ago
- Science
- Yahoo
Monster Black Hole Merger Is Most Massive Ever Seen
Physicists have detected the biggest ever merger of colliding black holes. The discovery has major implications for researchers' understanding of how such bodies grow in the Universe. 'It's super exciting,' says Priyamvada Natarajan, a theoretical astrophysicist at Yale University in New Haven, Connecticut, who was not involved in the research. The merger was between black holes with masses too big for physicists to easily explain. 'We're seeing these forbidden high-mass black holes,' she says. The discovery was made by the Laser Interferometer Gravitational-Wave Observatory (LIGO), a facility involving two detectors in the United States. It comes at a time when US funding for gravitational-wave detection faces devastating cuts. The results, released as a preprint on the arXiv server1, were presented at the GR-Amaldi gravitational-waves meeting in Glasgow, UK, on 14 July. [Sign up for Today in Science, a free daily newsletter] LIGO detects gravitational waves by firing lasers down long, L-shaped arms. Minuscule changes in arm length reveal the passage of gravitational waves through the planet. The waves are ripples in space-time, caused by massive bodies accelerating, such as when two inspiralling black holes or neutron stars merge. Hundreds of these mergers have been observed using gravitational waves since LIGO's first detection in 2015. But this latest detection, made in November 2023, is the biggest yet. By modelling the signal detected by LIGO, scientists have calculated that the event, dubbed GW231123, was caused by two black holes with masses of about 100 and 140 times that of the Sun merging to form a final black hole weighing in at some 225 solar masses. 'It's the most massive [merger] so far,' says Mark Hannam, a physicist at Cardiff University, UK, and part of the LVK Collaboration, a wider network of gravitational-wave detectors that encompasses LIGO, Virgo in Italy and KAGRA in Japan. It's 'about 50% more than the previous record holder', he says. Most of the events captured by LIGO involve stellar mass black holes — those ranging from a few to 100 times the mass of the Sun — which are thought to form when massive stars end their lives as supernovae. However, the two black holes involved in GW231123 fall in or near a predicted range, of 60–130 solar masses, at which this process isn't expected to work, with theories instead predicting that the stars should be blown apart. 'So they probably didn't form by this normal mechanism,' says Hannam. Instead, the two black holes probably formed from earlier merger events — hierarchical mergers of massive bodies that led to the event detected by LIGO, which is estimated to have happened 0.7 to 4.1 billion parsecs away (2.3—13.4 billion light years). It's like 'four grandparents merging into two parents merging into one baby black hole', says Alan Weinstein, a physicist at the California Institute of Technology in Pasadena and also part of the LVK Collaboration. Models of the black holes also suggest that they were spinning exceedingly fast — about 40 times per second, which is near the limit of what Einstein's general theory of relativity predicts black holes can reach while remaining stable. 'They're spinning very close to the maximal spin allowable,' says Weinstein. Both the spin and the mass could provide clues to how black holes grow in the Universe. One of the biggest questions in astronomy is how the largest black holes, the supermassive black holes found at the centres of galaxies such as the Milky Way, grew in the early cosmos. Although there is plenty of evidence for the existence of stellar mass black holes and supermassive black holes — those of more than a million solar masses — intermediate mass black holes in the range of 100 to 100,000 solar masses have been harder to find. 'We don't see them,' says Natarajan. The latest detection might tell us that 'these intermediate-mass black holes of several hundred solar masses play a role in the evolution of galaxies', says Hannam, perhaps through hierarchical mergers, which could increase the spin speed, as well as the mass, of the resulting black holes. 'Little by little, we're building up a list of the kind of black holes that are out there,' he says. That growth in knowledge could be hampered by the administration of US President Donald Trump and its proposed cuts to the US National Science Foundation, which runs LIGO. Under the proposal, one of LIGO's two gravitational-wave observatories would be shut down. At the time of this detection in November 2023, Virgo and KAGRA were not operational. Without two detectors, scientists would not have been sure that they had made a real detection of two merging black holes, says Hannam. 'Because we had two detectors, we saw the same blip at the same time,' he says. The closure of one of the observatories would be 'catastrophic', says Natarajan. 'This discovery would not be possible if one arm was turned off.' Planned upgrades to LIGO in the coming years, and the addition of new detectors around the world, including one in India, could greatly increase physicists' capabilities in gravitational-wave research, an area of astronomy that is still in its infancy. 'We're going to be seeing thousands of black holes in the next few years,' says Hannam. 'There's this huge investment that's been done, and it's only just beginning to pay off.' This article is reproduced with permission and was first published on July 15, 2025.
Scientific American
15-07-2025
- Science
- Scientific American
Monster Black Hole Merger Is Most Massive Ever Seen
Physicists have detected the biggest ever merger of colliding black holes. The discovery has major implications for researchers' understanding of how such bodies grow in the Universe. 'It's super exciting,' says Priyamvada Natarajan, a theoretical astrophysicist at Yale University in New Haven, Connecticut, who was not involved in the research. The merger was between black holes with masses too big for physicists to easily explain. 'We're seeing these forbidden high-mass black holes,' she says. The discovery was made by the Laser Interferometer Gravitational-Wave Observatory (LIGO), a facility involving two detectors in the United States. It comes at a time when US funding for gravitational-wave detection faces devastating cuts. The results, released as a preprint on the arXiv server 1, were presented at the GR-Amaldi gravitational-waves meeting in Glasgow, UK, on 14 July. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Forbidden mass LIGO detects gravitational waves by firing lasers down long, L-shaped arms. Minuscule changes in arm length reveal the passage of gravitational waves through the planet. The waves are ripples in space-time, caused by massive bodies accelerating, such as when two inspiralling black holes or neutron stars merge. Hundreds of these mergers have been observed using gravitational waves since LIGO's first detection in 2015. But this latest detection, made in November 2023, is the biggest yet. By modelling the signal detected by LIGO, scientists have calculated that the event, dubbed GW231123, was caused by two black holes with masses of about 100 and 140 times that of the Sun merging to form a final black hole weighing in at some 225 solar masses. 'It's the most massive [merger] so far,' says Mark Hannam, a physicist at Cardiff University, UK, and part of the LVK Collaboration, a wider network of gravitational-wave detectors that encompasses LIGO, Virgo in Italy and KAGRA in Japan. It's 'about 50% more than the previous record holder', he says. Most of the events captured by LIGO involve stellar mass black holes — those ranging from a few to 100 times the mass of the Sun — which are thought to form when massive stars end their lives as supernovae. However, the two black holes involved in GW231123 fall in or near a predicted range, of 60–130 solar masses, at which this process isn't expected to work, with theories instead predicting that the stars should be blown apart. 'So they probably didn't form by this normal mechanism,' says Hannam. Instead, the two black holes probably formed from earlier merger events — hierarchical mergers of massive bodies that led to the event detected by LIGO, which is estimated to have happened 0.7 to 4.1 billion parsecs away (2.3—13.4 billion light years). It's like 'four grandparents merging into two parents merging into one baby black hole', says Alan Weinstein, a physicist at the California Institute of Technology in Pasadena and also part of the LVK Collaboration. Models of the black holes also suggest that they were spinning exceedingly fast — about 40 times per second, which is near the limit of what Einstein's general theory of relativity predicts black holes can reach while remaining stable. 'They're spinning very close to the maximal spin allowable,' says Weinstein. Both the spin and the mass could provide clues to how black holes grow in the Universe. One of the biggest questions in astronomy is how the largest black holes, the supermassive black holes found at the centres of galaxies such as the Milky Way, grew in the early cosmos. Although there is plenty of evidence for the existence of stellar mass black holes and supermassive black holes — those of more than a million solar masses — intermediate mass black holes in the range of 100 to 100,000 solar masses have been harder to find. 'We don't see them,' says Natarajan. The latest detection might tell us that 'these intermediate-mass black holes of several hundred solar masses play a role in the evolution of galaxies', says Hannam, perhaps through hierarchical mergers, which could increase the spin speed, as well as the mass, of the resulting black holes. 'Little by little, we're building up a list of the kind of black holes that are out there,' he says. Cuts ahead That growth in knowledge could be hampered by the administration of US President Donald Trump and its proposed cuts to the US National Science Foundation, which runs LIGO. Under the proposal, one of LIGO's two gravitational-wave observatories would be shut down. At the time of this detection in November 2023, Virgo and KAGRA were not operational. Without two detectors, scientists would not have been sure that they had made a real detection of two merging black holes, says Hannam. 'Because we had two detectors, we saw the same blip at the same time,' he says. The closure of one of the observatories would be 'catastrophic', says Natarajan. 'This discovery would not be possible if one arm was turned off.' Planned upgrades to LIGO in the coming years, and the addition of new detectors around the world, including one in India, could greatly increase physicists' capabilities in gravitational-wave research, an area of astronomy that is still in its infancy. 'We're going to be seeing thousands of black holes in the next few years,' says Hannam. 'There's this huge investment that's been done, and it's only just beginning to pay off.'
Yahoo
12-07-2025
- Science
- Yahoo
What's at the center of a black hole? Scientists have a sobering answer
They're the boogeymen of science fiction, a paradox of science and quite possibly a key to understanding the universe. Scientists have been scrambling to understand the mysterious forces of black holes for decades, but so far it seems they've found more existential questions than answers. We know a black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe, said Priyamvada Natarajan, a theoretical astrophysicist at Yale University. "A black hole is so concentrated that it causes a little deep puncture in space/time. At the end of the puncture you have a thing called a singularity where all known laws of nature break down. Nothing that we know of exists at that point." Nova explosion 'star' over Ohio? Why NASA is excited about T Coronae Borealis Understanding what science knows about black holes involves mysterious little red dots, the formation of galaxies, and spaghettification (the unpleasant thought experiment about what would happen to a person unlucky enough to be sucked into a black hole). First, the good news: Black holes aren't out to get us. They aren't whizzing around the universe looking for galaxies, suns and planets to devour. "They don't just sneak up to you in a dark alley," said Lloyd Knox, a professor of physics and astronomy at the University of California, Davis. But our understanding of the very fundamentals of the universe has been transformed over the past decade by new telescopes and sensors that are letting scientists see more black holes and at every stage of their lives. What to know about observatory: James Webb Space Telescope marks 3rd anniversary "Our understanding of the role black holes play, that they are an essential part of the formation of galaxies, is new," said Natarajan. Here what cosmic secrets are being revealed: The original understanding of how black holes formed was that when a sufficiently large sun (about 10 times or more massive than our Sun) reached the end of its life, it could explode into a supernova that then collapses back into a black hole. The matter can collapse down into something only a few miles across, becoming so dense that its gravity is strong enough that nothing, not even light, can escape. This is what is called a stellar mass black hole. But in the past two decades, new types of black holes have been seen and astronomers are beginning to understand how they form. Called supermassive black holes, they have been found at the center of pretty much every galaxy and are a hundred thousand to billion times the mass of our Sun. But how did they form? "The original idea was that small black holes formed and then they grew," said Natarajan. "But then there's a timing crunch to explain the monsters seen in the early universe. Even if they're gobbling down stellar gas, did they have the time to get so big? That was an open question even 20 years ago." In 2017, she theorized that these supermassive black holes from the early beginnings of the universe happened when galactic gas clouds collapsed directly in on themselves, skipping the star stage entirely and going straight from gas to a massive black hole seed, with a head start, that could then grow. "Then guess what? In 2023 the James Webb telescope found these objects," she said. "This is what a scientist lives for, to make a prediction and see it proven." Because they have such massive gravity, black holes gobble up stellar gases and anything else that gets too close to them. But it's not an endless process that ends up with the entire universe being sucked into them. People sometimes worry that black holes are these huge vacuum cleaners that draw in everything in sight. "It's not like a whirlpool dragging everything into it," said Knox. Black holes are really like any other concentration of mass, whether it's a sun or a planet. They have their own gravitational pull but it isn't infinite. "If you're far enough away, you'd just feel the gravitational force, just the way you'd feel it from a planet," said Brenna Mockler, a post-doctoral fellow at the Carnegie Observatories at the Carnegie Institution for Science in Pasadena, California. All matter causes a dip or pothole in space/time, said Natarajan. A black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe. "The bigger the mass, the bigger the pothole," she said. Where that puncture leads is unknown. "It's an open question," said Natarajan. "We don't think it could be another universe, because we don't know where in our universe it could go. But we don't know." So what if a human being fell into a black hole? Astrophysicists have a word for it – spaghettification. "If you were to fall head first into a black hole, the difference in gravity between your head and your toes would be so intense that you'd be stretched out and spaghettified," Natarajan said. There's no fear that our own Sun will become a black hole, said Knox. It's not big enough. "Lower mass stars burn through their hydrogen to make helium and then they'll start burning helium into carbon. And then at some point it ends up just pushing itself all apart," he said. "Our Sun will eventually expand and envelop the Earth and destroy it – but that's in 5 billion years, so you have some time to get ready. But it won't become a black hole." NASA's super powerful James Webb Space Telescope began its scientific mission in 2022 and almost immediately picked up something that so far no one can explain: small red objects that appear to be abundant in the cosmos. Dubbed "little red dots," these objects have perplexed astronomers. They could be very, very dense, highly star-forming galaxies. "Or they could be highly accreting supermassive black holes from the very early universe," said Mockler, who is an incoming professor at the University of California, Davis. This article originally appeared on USA TODAY: What is a black hole? Scientists scramble to untangle cosmic mystery
Yahoo
12-07-2025
- Science
- Yahoo
What's at the center of a black hole? Scientists have a sobering answer.
They're the boogeymen of science fiction, a paradox of science and quite possibly a key to understanding the universe. Scientists have been scrambling to understand the mysterious forces of black holes for decades, but so far it seems they've found more existential questions than answers. We know a black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe, said Priyamvada Natarajan, a theoretical astrophysicist at Yale University. "A black hole is so concentrated that it causes a little deep puncture in space/time. At the end of the puncture you have a thing called a singularity where all known laws of nature break down. Nothing that we know of exists at that point." Understanding what science knows about black holes involves mysterious little red dots, the formation of galaxies, and spaghettification (the unpleasant thought experiment about what would happen to a person unlucky enough to be sucked into a black hole). First, the good news: Black holes aren't out to get us. They aren't whizzing around the universe looking for galaxies, suns and planets to devour. "They don't just sneak up to you in a dark alley," said Lloyd Knox, a professor of physics and astronomy at the University of California, Davis. But our understanding of the very fundamentals of the universe has been transformed over the past decade by new telescopes and sensors that are letting scientists see more black holes and at every stage of their lives. "Our understanding of the role black holes play, that they are an essential part of the formation of galaxies, is new," said Natarajan. Here what cosmic secrets are being revealed: The original understanding of how black holes formed was that when a sufficiently large sun (about 10 times or more massive than our Sun) reached the end of its life, it could explode into a supernova that then collapses back into a black hole. The matter can collapse down into something only a few miles across, becoming so dense that its gravity is strong enough that nothing, not even light, can escape. This is what is called a stellar mass black hole. But in the past two decades, new types of black holes have been seen and astronomers are beginning to understand how they form. Called supermassive black holes, they have been found at the center of pretty much every galaxy and are a hundred thousand to billion times the mass of our Sun. But how did they form? "The original idea was that small black holes formed and then they grew," said Natarajan. "But then there's a timing crunch to explain the monsters seen in the early universe. Even if they're gobbling down stellar gas, did they have the time to get so big? That was an open question even 20 years ago." In 2017, she theorized that these supermassive black holes from the early beginnings of the universe happened when galactic gas clouds collapsed directly in on themselves, skipping the star stage entirely and going straight from gas to a massive black hole seed, with a head start, that could then grow. "Then guess what? In 2023 the James Webb telescope found these objects," she said. "This is what a scientist lives for, to make a prediction and see it proven." Because they have such massive gravity, black holes gobble up stellar gases and anything else that gets too close to them. But it's not an endless process that ends up with the entire universe being sucked into them. People sometimes worry that black holes are these huge vacuum cleaners that draw in everything in sight. "It's not like a whirlpool dragging everything into it," said Knox. Black holes are really like any other concentration of mass, whether it's a sun or a planet. They have their own gravitational pull but it isn't infinite. "If you're far enough away, you'd just feel the gravitational force, just the way you'd feel it from a planet," said Brenna Mockler, a post-doctoral fellow at the Carnegie Observatories at the Carnegie Institution for Science in Pasadena, California. All matter causes a dip or pothole in space/time, said Natarajan. A black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe. "The bigger the mass, the bigger the pothole," she said. "At the end of the puncture you have a thing called a singularity where all known laws of nature break down. Nothing that we know of exists at that point." Where that puncture leads is unknown. "It's an open question," said Natarajan. "We don't think it could be another universe, because we don't know where in our universe it could go. But we don't know." So what if a human being fell into a black hole? Astrophysicists have a word for it – spaghettification. "If you were to fall into head first into a black hole, the different in gravity between your head and your toes would be so intense that you'd be stretched out and spaghettified," Natarajan said. There's no fear that our own Sun will become a black hole, said Knox. It's not big enough. "Lower mass stars burn through their hydrogen to make helium and then they'll start burning helium into carbon. And then at some point it ends up just pushing itself all apart," he said. "Our Sun will eventually expand and envelop the Earth and destroy it – but that's in 5 billion years, so you have some time to get ready. But it won't become a black hole." NASA's super powerful James Webb Space Telescope began its scientific mission in 2022 and almost immediately picked up something that so far no one can explain: small red objects that appear to be abundant in the cosmos. Dubbed "little red dots," these objects have perplexed astronomers. They could be very, very dense, highly star-forming galaxies. "Or they could be highly accreting supermassive black holes from the very early universe," said Mockler, who is an incoming professor at the University of California, Davis. This article originally appeared on USA TODAY: What is a black hole? Scientists scramble to untangle cosmic mystery
USA Today
12-07-2025
- Science
- USA Today
What's at the center of a black hole? Scientists have a sobering answer.
First, the good news: Black holes aren't out to get us. But they do hold unfathomable mysteries. They're the boogeymen of science fiction, a paradox of science and quite possibly a key to understanding the universe. Scientists have been scrambling to understand the mysterious forces of black holes for decades, but so far it seems they've found more existential questions than answers. We know a black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe, said Priyamvada Natarajan, a theoretical astrophysicist at Yale University. "A black hole is so concentrated that it causes a little deep puncture in space/time. At the end of the puncture you have a thing called a singularity where all known laws of nature break down. Nothing that we know of exists at that point." Understanding what science knows about black holes involves mysterious little red dots, the formation of galaxies, and spaghettification (the unpleasant thought experiment about what would happen to a person unlucky enough to be sucked into a black hole). First, the good news: Black holes aren't out to get us. They aren't whizzing around the universe looking for galaxies, suns and planets to devour. "They don't just sneak up to you in a dark alley," said Lloyd Knox, a professor of physics and astronomy at the University of California, Davis. But our understanding of the very fundamentals of the universe has been transformed over the past decade by new telescopes and sensors that are letting scientists see more black holes and at every stage of their lives. "Our understanding of the role black holes play, that they are an essential part of the formation of galaxies, is new," said Natarajan. Here what cosmic secrets are being revealed: A new kind of black hole and a newly proven theory The original understanding of how black holes formed was that when a sufficiently large sun (about 10 times or more massive than our Sun) reached the end of its life, it could explode into a supernova that then collapses back into a black hole. The matter can collapse down into something only a few miles across, becoming so dense that its gravity is strong enough that nothing, not even light, can escape. This is what is called a stellar mass black hole. But in the past two decades, new types of black holes have been seen and astronomers are beginning to understand how they form. Called supermassive black holes, they have been found at the center of pretty much every galaxy and are a hundred thousand to billion times the mass of our Sun. But how did they form? "The original idea was that small black holes formed and then they grew," said Natarajan. "But then there's a timing crunch to explain the monsters seen in the early universe. Even if they're gobbling down stellar gas, did they have the time to get so big? That was an open question even 20 years ago." In 2017, she theorized that these supermassive black holes from the early beginnings of the universe happened when galactic gas clouds collapsed directly in on themselves, skipping the star stage entirely and going straight from gas to a massive black hole seed, with a head start, that could then grow. "Then guess what? In 2023 the James Webb telescope found these objects," she said. "This is what a scientist lives for, to make a prediction and see it proven." Black holes don't suck everything into them Because they have such massive gravity, black holes gobble up stellar gases and anything else that gets too close to them. But it's not an endless process that ends up with the entire universe being sucked into them. People sometimes worry that black holes are these huge vacuum cleaners that draw in everything in sight. "It's not like a whirlpool dragging everything into it," said Knox. Black holes are really like any other concentration of mass, whether it's a sun or a planet. They have their own gravitational pull but it isn't infinite. "If you're far enough away, you'd just feel the gravitational force, just the way you'd feel it from a planet," said Brenna Mockler, a post-doctoral fellow at the Carnegie Observatories at the Carnegie Institution for Science in Pasadena, California. If you fell into a black hole, you'd be 'spaghettified' All matter causes a dip or pothole in space/time, said Natarajan. A black hole is so heavy that its gravity creates a kind of divot in the geometry of the universe. "The bigger the mass, the bigger the pothole," she said. "At the end of the puncture you have a thing called a singularity where all known laws of nature break down. Nothing that we know of exists at that point." Where that puncture leads is unknown. "It's an open question," said Natarajan. "We don't think it could be another universe, because we don't know where in our universe it could go. But we don't know." So what if a human being fell into a black hole? Astrophysicists have a word for it – spaghettification. "If you were to fall into head first into a black hole, the different in gravity between your head and your toes would be so intense that you'd be stretched out and spaghettified," Natarajan said. Our Sun will never become a black hole There's no fear that our own Sun will become a black hole, said Knox. It's not big enough. "Lower mass stars burn through their hydrogen to make helium and then they'll start burning helium into carbon. And then at some point it ends up just pushing itself all apart," he said. "Our Sun will eventually expand and envelop the Earth and destroy it – but that's in 5 billion years, so you have some time to get ready. But it won't become a black hole." A still unanswered mystery – 'little red dots' NASA's super powerful James Webb Space Telescope began its scientific mission in 2022 and almost immediately picked up something that so far no one can explain: small red objects that appear to be abundant in the cosmos. Dubbed "little red dots," these objects have perplexed astronomers. They could be very, very dense, highly star-forming galaxies. "Or they could be highly accreting supermassive black holes from the very early universe," said Mockler, who is an incoming professor at the University of California, Davis.
