First, we\u2019re more certain than ever that when black holes merge, the resulting black hole is wider than both parts combined. Second, we only need to know two metrics to describe gravitational disturbances in black holes: mass and spin.<\/p>\n
\u201cIt\u2019s a beautiful, landmark result,\u201d Arthur Kosowsky<\/a>, a theoretical physicist at the University of Pittsburgh who wasn\u2019t involved in the new work, told Gizmodo in an email. The latest results are \u201ca confirmation of both the fundamental nature of a spinning black hole and also a remarkable test of strong-field general relativity,\u201d he added.<\/p>\n The latest results come almost ten years after GW150914, the first gravitational wave signal ever detected, which LIGO observed in 2015. In 2021<\/a>, physicists used the 2015 signal to test Hawking\u2019s theorem. The team assessed a confidence level of 95% for this test, but with the new, cleaner result, that has jumped to an impressive 99.999%\u2014as close as one gets to the \u201ctruth\u201d in modern science.<\/p>\n \u201cA decade ago we couldn\u2019t be certain that black holes ever collide in our universe,\u201d Steve Fairhurst<\/a>, LIGO spokesperson and a physicist at Cardiff University in the United Kingdom, told Gizmodo. \u201cNow we observe several black hole mergers per week. With the 300 gravitational-wave candidates observed to date, we\u2019re beginning to provide a census of the population of black holes in the universe.\u201d<\/p>\n Black holes are ringing <\/p>\n Black holes lose a lot of mass during a merger. The violent conflagration can also speed up a black hole\u2019s spin, decreasing its area. Hawking and Jacob Bernstein\u2019s black hole area theorem posits that, despite these factors, the product of a merger will still generate a bigger black hole.<\/p>\n In the merger that produced GW250114, the initial black holes exhibited surface areas around 92,665 square miles (240,000 square kilometers), whereas the final black hole\u2019s surface area measured about 154,441 square miles (400,000 square kilometers). To put the final product in perspective, it weighs about 63 times the mass of our Sun and spins at 100 revolutions per second, according to the study.<\/p>\n \u201cMusical\u201d software developed by LIGO members\u2014including Gregorio Carullo<\/a>, an astrophysicist at the University of Birmingham in the United Kingdom\u2014enabled the team to make such precise measurements. The tool essentially let them \u201chear\u201d each black hole as it merged into a larger one, at sensitivity levels four times higher than a decade ago.<\/p>\n \u201cBlack holes are black, so it\u2019s very difficult to \u2018look\u2019 into them,\u201d Carullo told Gizmodo in a video call. Gravitational wave experiments offer an easy workaround, since everything controlled by gravity technically produces gravitational waves. Massive, cantankerous black holes are especially loud\u2014and we\u2019re getting better at tuning into these signals, he explained.<\/p>\n \u201cA decade ago we couldn\u2019t be certain that black holes ever collide in our universe. Now we observe several black hole mergers per week.\u201d<\/p>\n \u201cWhen black holes collide, they emit these characteristic sounds that are specific and peculiar to that black hole,\u201d Carullo said. \u201cIf we can hear these sounds, or notes, [that] depend on just the mass and the spin\u2026you can extract the mass and the spin of the black hole.\u201d<\/p>\n The fact that this is possible at all is what makes black holes so extraordinary, he added. \u201cPeople think of black holes as something scary, but actually, it\u2019s the simplest thing you can imagine.\u201d<\/p>\n A merger of knowledge <\/p>\n Excitingly, gravitational wave astronomy is still \u201cin its infancy,\u201d Fairhurst said. LIGO\u2019s Nobel-winning discovery was huge, no doubt, but no end goals exist for this project. If anything, the discovery of GW250114 marked the beginning<\/a> of a new chapter in astronomy.<\/p>\n \u201cIn the coming years, we will continue to see the sensitivity of the detectors improve, providing ever more and higher-fidelity observations,\u201d Fairhurst said. \u201cAt some stage, we are likely to observe something unexpected\u2014either a signal that is hard to explain astrophysically, one that doesn\u2019t exactly match the predictions of general relativity, or a signal from an unexpected source.\u201d<\/p>\n![\"Ligo](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/09\/LIGO-GW250114-Signal-Plot-comparison-1280x720.jpg\")
This plot shows gravitational-wave signals recorded by the LIGO almost ten years apart. The top shows data from GW150914, captured in 2015. The bottom shows the signal known as GW250114, captured in 2025. Both events involve colliding black holes about 1.3 billion light-years away with masses between 30 and 40 times that of our Sun. Credit: LIGO\/J. Tissino (GSSI)\/R. Hurt (Caltech-IPAC) <\/p>\n![\"Lvk](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/09\/LVK-LIGO-collaboration-black-hole-merger-chart-1280x720.jpg\")
This chart plots discoveries made by the LIGO-Virgo-KAGRA (LVK) network since LIGO\u2019s first detection, in 2015, of gravitational waves emanating from a pair of colliding black holes. Credit: LIGO\/Caltech\/MIT\/R. Hurt (IPAC) <\/p>\n