The newly detected black holes were each around 30 to 35 times the mass of the sun, and they were spinning very slowly, said Maximiliano Isi, an assistant professor of astronomy at Columbia University and an astrophysicist at the Flatiron Institute\u2019s Center for Computational Astrophysics in New York City. Isi led a new study<\/a> for the LIGO-Virgo-KAGRA Collaboration on the GW250114 data, which published Wednesday in the journal Physical Review Letters.<\/p>\n \u201cThe black holes were about 1 billion light years away, and they were orbiting around each other in almost a perfect circle,\u201d Isi said. \u201cThe resulting black hole was around 63 times the mass of the sun, and it was spinning at 100 revolutions per second.\u201d<\/p>\n These characteristics make the merger an almost exact replica of that first, groundbreaking detection from 10 years ago, according to Isi. \u201cBut now, because the instruments have improved so much since then, we can see these two black holes with much greater clarity, as they approached each other and merged into a single one,\u201d he added.<\/p>\n Isi said the observation gives scientists a totally new view into \u201cthe dynamics of space and time.\u201d<\/p>\n Einstein and a two-toned ring<\/p>\n LIGO, which also has two smaller sister instruments \u2014 Virgo in Italy and KAGRA in Japan \u2014 is managed by a global scientific community<\/a> of about 1,600 researchers. It works by detecting tiny stretches in space caused by the gravitational waves that amount to \u201ca change in distance that is 1,000 times smaller than the radius of the nucleus of an atom,\u201d as Isi puts it. Scientists have used it to observe over 300 black hole mergers so far.<\/p>\n Earlier this year, the instrument detected the most massive black hole collision<\/a> to date between two black holes approximately 100 and 140 times the mass of the sun.<\/p>\n Since it debuted, some of LIGO\u2019s key components \u2014 including its lasers and mirrors \u2014 have been upgraded to increase accuracy and reduce background noise. This improved performance made its new observation over three times more precise than the inaugural one a decade ago.<\/p>\n That unprecedented clarity allowed astronomers to use GW250114 to confirm predictions about black holes made decades ago by prominent physicists.<\/p>\n The first prediction, devised by New Zealand mathematician Roy Kerr in 1963, builds upon Einstein\u2019s theory of general relativity, and states that black holes should be paradoxically simple objects, described by a single equation.<\/p>\n \u201cYes, black holes are very mysterious, complex and have important implications to the evolution of the universe,\u201d Isi said, \u201cbut mathematically we think they should be fully described by just two numbers. Everything there is to know about them should come from how big the black hole is \u2014 or what its mass is \u2014 and how fast it\u2019s rotating.\u201d<\/p>\n To test this theory, the researchers used a unique feature of black hole collisions: a \u201cringing\u201d or vibration \u2014 like a bell that\u2019s been struck \u2014 that the final black hole produces. \u201cIf you have a bell and you strike it with a hammer, it will ring,\u201d Isi noted. \u201cThe pitch and duration of the sound, the characteristics of the sound, tell you something about what the bell is made of. With black holes something similar happens \u2014 they ring in gravitational waves.\u201d<\/p>\n This ringing includes information about the structure of the black hole and the space around it, Isi added. Although the phenomenon was faintly observed before, GW250114 returned a signal with \u201ctwo modes \u2026 a fundamental mode and an overtone\u201d with much more clarity.<\/p>\n \u201cWe identified two components of this ringing, and that allowed us to test that this black hole really is consistent with being described by just two numbers, mass and rotation,\u201d he said. \u201cAnd this is fundamental to our understanding of how space and time works \u2014 that these black holes should be featureless, in some way. It\u2019s the first time we are able to see this so compellingly.\u201d<\/p>\n Hawking\u2019s surface area theorem<\/p>\n The second prediction confirmed by GW250114 is one made in 1971 by British physicist Stephen Hawking, which states that when two black holes merge, the resulting surface area must be equal to or greater than that of the original black holes.<\/p>\n \u201cIt\u2019s a profound, but very simple theorem that says the total surface area of a black hole can never decrease \u2014 it can only get bigger or stay the same,\u201d Isi said.<\/p>\n Although previous LIGO observations offered tentative confirmations<\/a> of the theorem, the clarity of this new signal gives researchers unparalleled confidence, Isi said.<\/p>\n \u201cBecause we\u2019re able to identify the portion of the signal that comes from the black holes early on, as they are separated from each other, we can infer their areas from that,\u201d he explained. \u201cThen we can look at the very final portion of the signal that comes from the final black hole, and measure its own area.\u201d<\/p>\n Just like Kerr\u2019s equation, Hawking\u2019s theorem also uses Einstein\u2019s work as its foundation: \u201cEinstein\u2019s theories are like the operating system for all of this,\u201d Isi explained.<\/p>\n Kip Thorne, one of the three recipients of the Nobel Prize for LIGO contributions, said Hawking called him as soon as he learned of the 2015 gravitational wave detection to ask if LIGO would be able to test his theorem. \u201cIf Hawking were alive, he would have reveled in seeing the area of the merged black holes increase,\u201d Thorne said of the esteemed physicist, who died in 2018, in a statement about the new findings.<\/p>\n It\u2019s remarkable how this seminal, theoretical work is being confirmed decades later with advanced instruments, Isi said. And confirming Hawking\u2019s equation, he added, could have implications for a very sought-after goal in physics \u2014 combining the seemingly incompatible theory of general relativity, which describes gravity, with quantum mechanics, which relates to the subatomic world.<\/p>\n \u201cLIGO has created an entire new branch of astronomy. It has revolutionized what we think about compact objects, black holes in particular,\u201d he said. \u201cBefore LIGO turned on, people weren\u2019t even sure that black holes could merge and crash and form in this way.\u201d<\/p>\n This chart plots discoveries made by the LIGO-Virgo-KAGRA (LVK) network since LIGO’s first detection, in 2015, of gravitational waves emanating from a pair of colliding black holes. – Caltech<\/p>\n A long-awaited milestone<\/p>\n Gravitational waves are very weak, and the titanic task of detecting them is often described as looking for a needle in a haystack, according to Emanuele Berti, a professor of physics and astronomy at Johns Hopkins University who was not involved with the study. He described the LIGO detectors as \u201chearing aids\u201d that help with this process.<\/p>\n \u201cA large group of scientists spent the last ten years improving those hearing aids, and now we can \u2018hear\u2019 the signals with much higher clarity,\u201d he said in an email. \u201cWe can now test fundamental principles of gravity that we could not test ten years ago.\u201d<\/p>\n Among these principles, he added, is the idea that black holes are the simplest macroscopic objects in the universe. The level of detail in the \u201cringing\u201d produced by the GW250114 collision means scientists can say with confidence that the final object is consistent with the black holes predicted by Einstein\u2019s general relativity, which Berti says is \u201cterribly exciting.\u201d<\/p>\n Leor Barack, a professor of mathematical physics at the University of Southampton in England who was also not part of the study, noted that among the more than 300 black-hole merger events recorded by LIGO, the latest one stands out as \u201cparticularly spectacular,\u201d and calls the new study a long-awaited analysis. Scientists were able to extract two of the \u201cpure tones\u201d of the remnant black hole as it settled into its final form, Barack added.<\/p>\n \u201cThis included, for the first time, a clear extraction of the first \u2018overtone,\u2019 a fainter harmonious sound of the ringing hole, in addition to the primary tone,\u201d he said. \u201cThis kind of test is the most precise to date, by a long margin.\u201d<\/p>\n The study represents a significant milestone in gravitational wave astronomy, said Macarena Lagos, an assistant professor at the Institute of Astrophysics of the Universidad Andr\u00e9s Bello in Chile. Lagos also was not involved with the work.<\/p>\n She agreed that the detection of a second tone in the \u201cringing\u201d black hole is particularly significant, adding that GW250114 demonstrates the success of LIGO\u2019s ongoing improvements and shows that gravitational wave detections can test fundamental physics in ways never before possible.<\/p>\n \u201cWhile current tests of gravity still have broad uncertainties, this work lays the groundwork for future detections\u201d of even better quality expected in the coming years, Lagos said in an email. \u201cThese future observations promise to provide more precise tests of our understanding of spacetime and gravity.\u201d<\/p>\n![\"This](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2025\/09\/af9d03696f0e91420a451111bf9bfd38.jpeg\"\/)
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