Latest news with #LIGO
Yahoo
2 days ago
- General
- Yahoo
US-led scientists discover new evidence on origins of intermediate-mass black holes
Black holes are generally grouped into three sizes: stellar-mass black holes, which are about five to 50 times the mass of the sun; supermassive black holes, with millions to billions of times the sun's mass; and intermediate-mass black holes, which fall somewhere in between. Four new studies have brought fresh insight into the mystery of intermediate-mass black holes. The research was led by Assistant Professor Karan Jani, founding director of the Vanderbilt Lunar Labs Initiative, with funding from the National Science Foundation and Vanderbilt University. The main study, titled "Properties of 'Lite' Intermediate-Mass Black Hole Candidates in LIGO-Virgo's Third Observing Run," was published in Astrophysical Journal Letters, with the team reexamining data from the LIGO detectors in the U.S. and the Virgo detector in Italy. They found that the detected gravitational waves came from mergers of black holes weighing between 100 and 300 times the mass of the sun, marking the largest black hole collisions ever recorded. According to Jani, black holes are like cosmic fossils that hold clues to the early universe. The newly identified group of black holes, revealed in this analysis, provides a unique opportunity to learn more about the very first stars that formed after the Big Bang. Earth-based detectors like LIGO can only catch a brief moment of the final collision of these 'lighter' intermediate-mass black holes, making it hard to understand how they form. To learn more, Jani's lab is focusing on the upcoming LISA mission—a space-based project by the European Space Agency and NASA set to launch in the late 2030s. Two additional studies published in the Astrophysical Journal demonstrated that the upcoming LISA mission can track intermediate-mass black holes years before they merge, providing new insights into their origins, evolution, and fate. The research also highlighted how detecting gravitational waves requires extreme precision—comparable to hearing a pin drop during a hurricane. The researchers noted that this work supports the idea that intermediate-mass black holes are among the most important sources for gravitational-wave detectors, both on Earth and in space. Each new detection helps scientists better understand where these black holes come from and why they exist within this unusual mass range. Looking ahead, the team plans to investigate how detectors on the moon could help observe intermediate-mass black holes in the future. Access to lower gravitational-wave frequencies from the lunar surface could help identify the environments where these black holes exist—something that Earth-based detectors cannot achieve. The scientist pointed out that this is an exciting time, not only for studying black holes but also for combining scientific research with the new era of space and lunar exploration. It presents a rare chance to train the next generation of students whose discoveries will be influenced by, and conducted from, the moon, Jani added.
Yahoo
2 days ago
- Business
- Yahoo
Trump science cuts may close WA LIGO observatory that confirmed theory of relativity
The Trump administration wants to close one of the nation's two cutting-edge observatories — one of them in the Tri-Cities — that made scientific history and launched a new way to study the universe. It's part of a $5.2 billion, or 57% cut, proposed Friday for the National Science Foundation and could result in the permanent closure of one of the special observatories, threatening the U.S.'s scientific leadership in such research. The National Science Foundation funds two Laser Interferometer Gravitational-wave Observatories, LIGO Hanford, which is about 10 miles from Richland on unused Hanford nuclear site land, and its twin, LIGO Livingston in Louisiana. In 2015 the two LIGOs detected gravitational waves from outer space passing through the Earth for the first time, nearly 100 years after Albert Einstein predicted their existence. The detection of matching vibrations at both sites confirmed that the infinitesimal movement detected was from gravitational waves reaching Earth from a violent event in space. In the first detection it was from the collision of two black holes 1.3 billion years ago. The finding led to a Nobel Prize in Physics for the work by three U.S. professors emeritus to design and build the two observatories. Since the two U.S. LIGOs came online, gravitational wave observatories have begun operating in Italy and Japan, but the United States remains the leader in the field with the most advanced and sensitive equipment. Fiscal 2026 budget documents released late Friday by the Trump administration proposed reducing the overall budget for the two LIGOs by 40% from $48 million in fiscal 2024 to $29 million in fiscal 2026. The current fiscal budget signed into law in March has not yet had program-specific spending plans released to compare to the fiscal 2026 proposal. The document released Friday is the Trump administration's recommendation for fiscal 2026, which Congress will use as a guide as it sets the budget amount. The Trump proposal calls for not only closing one of the two U.S. observatories in fiscal 2026 but also reducing LIGO spending for technology development. The two LIGOs were planned to be in an upgrade phase in 2026, with technology improvements being made to both. The Trump administration has not said which LIGO it would favor shutting down or why both would not be kept open with limited operations. If one of the two LIGOs were closed for a year, rehiring their highly specialized scientists to resume operating the next year could be very difficult, say officials. Louisiana Gov. Jeff Landry has been a frequent visitor to the White House in Trump's second term, as reported by the Shreveport Times, while Washington state is led by a Democrat governor and has filed numerous lawsuits against the Trump administration. On Wednesday, Washington state Attorney General Nick Brown joined a coalition of 15 other attorneys general to file a lawsuit against the Trump administrations attempts to cut National Science Foundation programs that it said helped maintain the United States' position as a global leader in science, technology, engineering and math. The 'National Science Foundation FY 2026 Budget Request to Congress' calls the LIGO system 'the most sensitive detector of gravitational waves ever built' and the leader in 'the worldwide effort to study the structure and evolution of the universe through gravitational radiation.' Since the initial detection of gravitational waves passing through Earth in 2015 through early spring of this year, the two LIGOs have detected 290 possible gravitational wave events from mergers of black holes and neutron stars, with more detections being made as scientific equipment has been upgraded and improved. The most recent improvements were made with the goal of improved detection and more advanced data analysis methods to allow scientists to extract more information from detections and increase their understanding of black holes and neutron stars. With improvements in sensitivity also comes new opportunities to detect signals from sources other than mergers, such as the continuous gravitational-wave signals that are generated by rapidly rotating neutron stars in our Galaxy, according to LIGO officials. At LIGO Hanford vacuum tubes extend for 2.5 miles at right angles across previously unused Hanford site shrub steppe land near the Tri-Cities. At the end of each tube, a mirror is suspended on glass fibers. A high-power laser beam is split to go down each tube, bouncing off the mirrors at each end. If the beam is undisturbed, it will bounce back and recombine perfectly. But if a gravitational wave is pulsing through the Earth, making one of the tubes repeatedly infinitesimally longer and the other infinitesimally shorter, the beam will not recombine as expected. LIGO Hanford and its Louisiana twin now can measure the stretching and the squeezing of the fabric of space-time on scales 10 thousand trillion times smaller than a human hair. Having multiple gravitational-wave observatories can allow scientist to localize the region of the sky from which the signal emerged and alert astronomers using more traditional telescopes, as well as neutrino detectors, to make observations. LIGO's most important finding to date may have been the detection of the fiery collision of two neutron stars in August 2017, opening up a new field of astronomy. The crash of the neutron stars — the collapsed cores of large stars — spewed material that radioactively decayed, creating heavy metals like gold and platinum. Unlike black holes, colliding neutron stars emit a flash of light in the form of gamma rays. It allows the event to be captured both by LIGO and by observatories that observe forms of light, including X-ray, ultraviolet, infrared and radiowaves. It was the first time that a cosmic event had been viewed in both gravitational waves and light, giving scientists a new way of learning about the universe through 'multi-messenger astronomy.' Within months, about a quarter of the world's professional astronomers have been involved in the follow-up of the initial discovery.
Yahoo
17-05-2025
- Science
- Yahoo
Black hole dance illuminates hidden math of the universe
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have made the most accurate predictions yet of the elusive space-time disturbances caused when two black holes fly closely past each other. The new findings, published Wednesday (May 14) in the journal Nature, show that abstract mathematical concepts from theoretical physics have practical use in modeling space-time ripples, paving the way for more precise models to interpret observational data. Gravitational waves are distortions in the fabric of space-time caused by the motion of massive objects like black holes or neutron stars. First predicted in Albert Einstein's theory of general relativity in 1915, they were directly detected for the first time a century later, in 2015. Since then, these waves have become a powerful observational tool for astronomers probing some of the universe's most violent and enigmatic events. To make sense of the signals picked up by sensitive detectors like LIGO (the Laser Interferometer Gravitational-Wave Observatory) and Virgo, scientists need extremely accurate models of what those waves are expected to look like, similar in spirit to forecasting space weather. Until now, researchers have relied on powerful supercomputers to simulate black hole interactions that require refining black hole trajectories step by step, a process that is effective but slow and computationally expensive. Now, a team led by Mathias Driesse of Humboldt University in Berlin has taken a different approach. Instead of studying mergers, the researchers focused on "scattering events" — instances in which two black holes swirl close to each other under their mutual gravitational pull and then continue on separate paths without merging. These encounters generate strong gravitational wave signals as the black holes accelerate past one another. To model these events precisely, the team turned to quantum field theory, which is a branch of physics typically used to describe interactions between elementary particles. Starting with simple approximations and systematically layering complexity, the researchers calculated key outcomes of black hole flybys: how much they are deflected, how much energy is radiated as gravitational waves and how much the behemoths recoil after the interaction. Their work incorporated five levels of complexity, reaching what physicists call the fifth post-Minkowskian order — the highest level of precision ever achieved in modeling these interactions. Reaching this level "is unprecedented, and represents the most precise solution to Einstein's equations produced to date," Gustav Mogull, a particle physicist at Queen Mary University of London and a co-author of the study, told The team's reaction to achieving the landmark precision was "mostly just astonishment that we managed to get the job done," Mogull recalled. Related stories: — What is the theory of general relativity? Understanding Einstein's space-time revolution — What are gravitational waves? — What is string theory? While calculating the energy radiated as gravitational waves, researchers found that intricate six-dimensional shapes known as Calabi–Yau manifolds appeared in the equations. These abstract geometrical structures — often visualized as higher-dimensional analogues of donut-like surfaces — have long been a staple of string theory, a framework attempting to unify quantum mechanics with gravity. Until now, they were believed to be purely mathematical constructs, with no directly testable role tied to observable phenomena. In the new study, however, these shapes appeared in calculations describing the energy radiated as gravitational waves when two black holes cruised past one another. This marks the first time they've appeared in a context that could, in principle, be tested through real-world experiments. Mogull likens their emergence to switching from a magnifying glass to a microscope, revealing features and patterns previously undetectable. "The appearance of such structures sheds new light on the sorts of mathematical objects that nature is built from," he said. These findings are expected to significantly enhance future theoretical models that aim to predict gravitational wave signatures. Such improvements will be crucial as next-generation gravitational wave detectors — including the planned Laser Interferometer Space Antenna (LISA) and the Einstein Telescope in Europe — come online in the years ahead. "The improvement in precision is necessary in order to keep up with the higher precision anticipated from these detectors," Mogull said.
Yahoo
15-05-2025
- Science
- Yahoo
Black Hole Mergers Show Strange Mathematical Link to String Theory
A decade ago astrophysicists at the Laser Interferometer Gravitational-Wave Observatory (LIGO), operated by the California Institute of Technology and the Massachusetts Institute of Technology, managed to detect subtle ripples in spacetime called gravitational waves, released by a pair of black holes spiraling into each other, for the first time. That impressive discovery—which earned the 2017 Nobel Prize in Physics—has since become commonplace, with researchers regularly detecting gravitational waves from myriad far-distant celestial sources. And as the numbers of gravitational-wave observations have increased, physicists' careful modeling is revealing new details about their mysterious origins. Some of the most intriguing gravitational-wave events, it turns out, could arise not from catastrophic collisions but rather from near misses. Furthermore, these cosmic close calls might be best understood using concepts derived from string theory—a notional theory of everything that posits that all of nature is fundamentally composed of countless, wriggling subatomic strings. This arguably marks the first linkage to date between a core mathematical aspect of the arcane theory and real-world astrophysics. At least, that's the conclusion of an international team of researchers that applied geometric structures inspired by particle physics and string theory to the behavior of black holes when the colossal objects closely pass and deflect each other. Such interactions between black holes or neutron stars (compact remnants of exploded massive stars) can be studied through the deflection angle, the energy released through the near miss and the momentum of the objects' recoil—all of which may be discerned in gravitational waves. The team's results were published in the journal Nature on Wednesday. [Sign up for Today in Science, a free daily newsletter] In their study, the researchers used an obscure class of abstract mathematical functions to solve the formidable equations involved in determining the radiated energy from a near miss. 'You need these new functions, which, in math and mathematical physics, have been studied intensively but, to date, have not appeared in any real physical observable. That's what makes it quite interesting,' says Jan Plefka, a theoretical physicist at the Humboldt University of Berlin and a co-author of the new study. Those obscure functions, known as six-dimensional Calabi-Yau manifolds, had never been shown as directly relevant to descriptions of real astrophysical phenomena before. In the years since LIGO's initial detection, two additional major gravitational-wave observatories, Europe's Virgo and Japan's Kamioka Gravitational-Wave Detector (KAGRA), have come online. Together, they form the international LIGO-Virgo-KAGRA collaboration and have amassed detections of nearly 300 gravitational-wave events over the past decade, mostly from colliding pairs of black holes. Also called black hole 'mergers,' such events are the cacophonous moment when these dense gravitational behemoths smash together to form a single, larger beast. Plefka and his colleagues are studying different interactions known as 'scattering' events, which occur when paired black holes slip by each other, usually in prelude to their eventual coalescence. During these close encounters, the clashing gravity of the black holes causes each to accelerate past the other, generating a significant gravitational-wave signal, but the objects are sufficiently separated to avoid merging. It's no coincidence that this resembles elementary particles deflecting each other. 'You can use the techniques developed for the scattering of microscopic objects to describe this scattering of macroscopic ones,' Plefka says. Considered from far enough away, well beyond the event horizon—that pivotal region within which neither matter nor light can escape—a black hole can be modeled as a particlelike point with mass and spin, albeit one that generates gravitational rather than electromagnetic waves. On that basis, Plefka and his colleagues applied techniques from quantum field theory that are more typically used to analyze the behavior of elementary particles. 'We're building on decades of work that has been done to make predictions for collider experiments,' says Gustav Mogull, a particle physicist at Queen Mary University of London and one of Plefka's co-authors. The team's goal was to bring its numerical approximations as close as possible to mirroring reality—which, of course, tends to be more messy. To do that, Mogull, Plefka and their team toiled to crank up the complexity of their calculations. In this work, the researchers incorporated five levels of that complexity—to what is known as the fifth post-Minkowskian order of precision—for describing the scattering angles of black hole pairs, their radiated energies and their recoils. This is where the Calabi-Yau geometric structures, normally associated with string theory, come in. In string theory, Calabi-Yau geometries involve the compactification of higher dimensions. Here, they are not merely abstractions but instead emerge from the researchers' calculations of black hole scattering. It's perhaps ironic that string theory, notoriously derided as untestable, has given rise to mathematical structures of relevance to measurable physics far from the rarefied realm of strings. Any mathematical function is associated with some kind of geometry, Mogull explains—and as the function increases in complexity, so, too, does its geometry. In the case of something basic, such as the sine or cosine functions used in trigonometry, that geometry is a simple circle. Elliptic functions, on the other hand, imply a doughnut-shaped geometry called a torus, which is also a Calabi-Yau onefold. It turns out that the functions Mogull, Plefka and their team developed for black hole scattering are associated with Calabi-Yau threefold structures, which involve six-dimensional surfaces. 'I don't think the appearance of Calabi-Yaus was that unexpected within our community. I would say this represents confirmation of something that people had suspected but was yet to be verified,' Mogull says. To demonstrate the utility of their approach in their study, Plefka, Mogull and their colleagues compare their approximations of black hole scattering angles to other, presumably more precise ones that were derived from numerical simulations. Such simulations can be time-consuming to run, even on state-of-the-art supercomputers—hence the search for accurate approximations. The team's highest-order approximation closely matches the results of supercomputer number crunching for cases of black holes that gently deflect each other across great distances. But when the black holes come closer to a head-on collision, the team's calculations begin diverging from the numerical simulations. Such work may seem to be a purely academic exercise, but in fact, the research could prove vital for making new discoveries. Signals from scattering black holes and neutron stars should be within reach of the next generation of gravitational-wave detectors that are set to come online in the late 2030s. These detectors, which will also need a new generation of models called waveform templates to discern true gravitational-wave signals from a sea of cosmic and terrestrial noise, include the proposed Einstein Telescope in Europe and Cosmic Explorer in the U.S. The latter, like LIGO, is supported by the National Science Foundation, and so far these kinds of gravitational-wave projects have avoided being directly targeted by the Trump administration's aggressive proposed cuts to federally funded science. The work's prospect for enhancing our understanding of gravitational-wave sources excites scientists who are gearing up for this new wave of detectors. They include Jocelyn Read, a physicist at California State University, Fullerton, who works with the Cosmic Explorer project. 'Next-generation facilities can measure nearby signals with exquisite fidelity,' she says. (Here 'nearby' means 'within a few billion light-years.') 'So having very accurate and precise predictions from our current theories is definitely needed to test them against those kinds of future observations,' Read adds. Yet she also urges caution when assessing the significance of Plefka, Mogull and their colleagues' work. 'If they're talking about implications for gravitational-wave astronomy, there are a few more steps that are needed,' she says. And their team has competitors, too, including some who have been deploying numerical simulations of their own. These kinds of approximate methods could eventually inform the waveform templates that are so crucial for filtering out noise in upcoming gravitational-wave detectors, Plefka says. Geraint Pratten, a LIGO physicist at the University of Birmingham in England, agrees. 'I think it's a heroic calculation by the group. It will provide a lot of insight into how we can structure next-generation waveform models,' he says. Pratten adds that more work will need to be done to move past the new study's limitations. For example, the paper focuses on black holes without spin and those that undergo 'unbound' scattering, which means that they deflect each other and never meet again. In reality, most, if not all, black holes are thought to spin, and usually scattering events precede an eventual merger. But in any case, he believes some gravitational waves from black hole and neutron star deflections will eventually be detectable, such as through observations of globular clusters, where these dense objects are packed together in a small space, cosmically speaking. For Plefka, Mogull and their peers, this macroscopic version of quantum field theory is still a young field, and there are many new types of astrophysically relevant calculations that they and others can do. These esoteric Calabi-Yau structures, formerly on the frontier of theoretical physics, could be just the beginning. 'You've had this whole new class of mathematical functions—these theoretical things that had appeared in string theory,' Mogull says. 'And we're saying, 'Look, this is tangible. This [radiated energy from scattering] is something you can try to detect, try to measure. This is real physics now.''
Scientific American
14-05-2025
- Science
- Scientific American
Deep Math from String Theory Appears in Clashing Black Holes
A decade ago astrophysicists at the Laser Interferometer Gravitational-Wave Observatory (LIGO), operated by the California Institute of Technology and the Massachusetts Institute of Technology, managed to detect subtle ripples in spacetime called gravitational waves, released by a pair of black holes spiraling into each other, for the first time. That impressive discovery—which earned the 2017 Nobel Prize in Physics—has since become commonplace, with researchers regularly detecting gravitational waves from myriad far-distant celestial sources. And as the numbers of gravitational-wave observations have increased, physicists' careful modeling is revealing new details about their mysterious origins. Some of the most intriguing gravitational-wave events, it turns out, could arise not from catastrophic collisions but rather from near misses. Furthermore, these cosmic close calls might be best understood using concepts derived from string theory—a notional theory of everything that posits that all of nature is fundamentally composed of countless, wriggling subatomic strings. This arguably marks the first linkage to date between a core mathematical aspect of the arcane theory and real-world astrophysics. At least, that's the conclusion of an international team of researchers that applied geometric structures inspired by particle physics and string theory to the behavior of black holes when the colossal objects closely pass and deflect each other. Such interactions between black holes or neutron stars (compact remnants of exploded massive stars) can be studied through the deflection angle, the energy released through the near miss and the momentum of the objects' recoil—all of which may be discerned in gravitational waves. The team's results were published in the journal Nature on Wednesday. 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. Black Holes as Particles In their study, the researchers used an obscure class of abstract mathematical functions to solve the formidable equations involved in determining the radiated energy from a near miss. 'You need these new functions, which, in math and mathematical physics, have been studied intensively but, to date, have not appeared in any real physical observable. That's what makes it quite interesting,' says Jan Plefka, a theoretical physicist at the Humboldt University of Berlin and a co-author of the new study. Those obscure functions, known as six-dimensional Calabi-Yau manifolds, had never been shown as directly relevant to descriptions of real astrophysical phenomena before. In the years since LIGO's initial detection, two additional major gravitational-wave observatories, Europe's Virgo and Japan's Kamioka Gravitational-Wave Detector (KAGRA), have come online. Together, they form the international LIGO-Virgo-KAGRA collaboration and have amassed detections of nearly 300 gravitational-wave events over the past decade, mostly from colliding pairs of black holes. Also called black hole 'mergers,' such events are the cacophonous moment when these dense gravitational behemoths smash together to form a single, larger beast. Plefka and his colleagues are studying different interactions known as 'scattering' events, which occur when paired black holes slip by each other, usually in prelude to their eventual coalescence. During these close encounters, the clashing gravity of the black holes causes each to accelerate past the other, generating a significant gravitational-wave signal, but the objects are sufficiently separated to avoid merging. It's no coincidence that this resembles elementary particles deflecting each other. 'You can use the techniques developed for the scattering of microscopic objects to describe this scattering of macroscopic ones,' Plefka says. Considered from far enough away, well beyond the event horizon—that pivotal region within which neither matter nor light can escape—a black hole can be modeled as a particlelike point with mass and spin, albeit one that generates gravitational rather than electromagnetic waves. On that basis, Plefka and his colleagues applied techniques from quantum field theory that are more typically used to analyze the behavior of elementary particles. 'We're building on decades of work that has been done to make predictions for collider experiments,' says Gustav Mogull, a particle physicist at Queen Mary University of London and one of Plefka's co-authors. Closer to Complex Realities The team's goal was to bring its numerical approximations as close as possible to mirroring reality—which, of course, tends to be more messy. To do that, Mogull, Plefka and their team toiled to crank up the complexity of their calculations. In this work, the researchers incorporated five levels of that complexity—to what is known as the fifth post-Minkowskian order of precision—for describing the scattering angles of black hole pairs, their radiated energies and their recoils. This is where the Calabi-Yau geometric structures, normally associated with string theory, come in. In string theory, Calabi-Yau geometries involve the compactification of higher dimensions. Here, they are not merely abstractions but instead emerge from the researchers' calculations of black hole scattering. It's perhaps ironic that string theory, notoriously derided as untestable, has given rise to mathematical structures of relevance to measurable physics far from the rarefied realm of strings. Any mathematical function is associated with some kind of geometry, Mogull explains—and as the function increases in complexity, so, too, does its geometry. In the case of something basic, such as the sine or cosine functions used in trigonometry, that geometry is a simple circle. Elliptic functions, on the other hand, imply a doughnut-shaped geometry called a torus, which is also a Calabi-Yau onefold. It turns out that the functions Mogull, Plefka and their team developed for black hole scattering are associated with Calabi-Yau threefold structures, which involve six-dimensional surfaces. 'I don't think the appearance of Calabi-Yaus was that unexpected within our community. I would say this represents confirmation of something that people had suspected but was yet to be verified,' Mogull says. To demonstrate the utility of their approach in their study, Plefka, Mogull and their colleagues compare their approximations of black hole scattering angles to other, presumably more precise ones that were derived from numerical simulations. Such simulations can be time-consuming to run, even on state-of-the-art supercomputers—hence the search for accurate approximations. The team's highest-order approximation closely matches the results of supercomputer number crunching for cases of black holes that gently deflect each other across great distances. But when the black holes come closer to a head-on collision, the team's calculations begin diverging from the numerical simulations. The Road Ahead Such work may seem to be a purely academic exercise, but in fact, the research could prove vital for making new discoveries. Signals from scattering black holes and neutron stars should be within reach of the next generation of gravitational-wave detectors that are set to come online in the late 2030s. These detectors, which will also need a new generation of models called waveform templates to discern true gravitational-wave signals from a sea of cosmic and terrestrial noise, include the proposed Einstein Telescope in Europe and Cosmic Explorer in the U.S. The latter, like LIGO, is supported by the National Science Foundation, and so far these kinds of gravitational-wave projects have avoided being directly targeted by the Trump administration's aggressive proposed cuts to federally funded science. The work's prospect for enhancing our understanding of gravitational-wave sources excites scientists who are gearing up for this new wave of detectors. They include Jocelyn Read, a physicist at California State University, Fullerton, who works with the Cosmic Explorer project. 'Next-generation facilities can measure nearby signals with exquisite fidelity,' she says. (Here 'nearby' means 'within a few billion light-years.') 'So having very accurate and precise predictions from our current theories is definitely needed to test them against those kinds of future observations,' Read adds. Yet she also urges caution when assessing the significance of Plefka, Mogull and their colleagues' work. 'If they're talking about implications for gravitational-wave astronomy, there are a few more steps that are needed,' she says. And their team has competitors, too, including some who have been deploying numerical simulations of their own. These kinds of approximate methods could eventually inform the waveform templates that are so crucial for filtering out noise in upcoming gravitational-wave detectors, Plefka says. Geraint Pratten, a LIGO physicist at the University of Birmingham in England, agrees. 'I think it's a heroic calculation by the group. It will provide a lot of insight into how we can structure next-generation waveform models,' he says. Pratten adds that more work will need to be done to move past the new study's limitations. For example, the paper focuses on black holes without spin and those that undergo 'unbound' scattering, which means that they deflect each other and never meet again. In reality, most, if not all, black holes are thought to spin, and usually scattering events precede an eventual merger. But in any case, he believes some gravitational waves from black hole and neutron star deflections will eventually be detectable, such as through observations of globular clusters, where these dense objects are packed together in a small space, cosmically speaking. For Plefka, Mogull and their peers, this macroscopic version of quantum field theory is still a young field, and there are many new types of astrophysically relevant calculations that they and others can do. These esoteric Calabi-Yau structures, formerly on the frontier of theoretical physics, could be just the beginning. 'You've had this whole new class of mathematical functions—these theoretical things that had appeared in string theory,' Mogull says. 'And we're saying, 'Look, this is tangible. This [radiated energy from scattering] is something you can try to detect, try to measure. This is real physics now.''
