Latest news with #LIGO
Scientific American
7 days ago
- Science
- Scientific American
We Just Discovered the Sounds of Spacetime. Let's Keep Listening
Long ago, in a galaxy far away, two black holes danced around each other, drawing ever closer until they ended in a cosmic collision that sent ripples through the fabric of spacetime. These gravitational waves traveled for over a billion years before reaching Earth. On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) heard their chirping signal, marking the first-ever detection of such a cosmic collision. Initially, scientists expected LIGO might detect just a few of these collisions. But now, nearing the first detection's 10th anniversary, we have already observed more than 300 gravitational-wave events, uncovering entirely unexpected populations of black holes. Just lately, on July 14, LIGO scientists announced the discovery of the most massive merger of two black holes ever seen. Gravitational-wave astronomy has become a global enterprise. Spearheaded by LIGO's two cutting-edge detectors in the U.S. and strengthened through collaboration with detectors in Italy (Virgo) and Japan (KAGRA), the field has become one of the most data-rich and exciting frontiers in astrophysics. It tests fundamental aspects of general relativity, measures the expansion of the universe and challenges our models of how stars live and die. 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. LIGO has also spurred the design and development of technologies beyond astronomy. For example advances in quantum technologies, which reduce the noise and thereby improve LIGO's detector sensitivity, have promising applications to both microelectronics and quantum computing. Given all this, it comes as no surprise that the Nobel Prize in Physics was awarded to LIGO's founders in 2017. Yet despite this extraordinary success story, the field now faces an existential threat. The Trump administration has proposed slashing the total National Science Foundation (NSF) budget by more than half: a move so severe that one of the two LIGO detectors would be forced to shut down. Constructing and upgrading the two LIGO detectors required a public investment of approximately $1.4 billion as of 2022, so abandoning half this project now would constitute a gigantic waste. A U.S. Senate committee in mid-July pushed back against hobbling LIGO, but Congress has lately folded against administration budget cut demands, leaving it still on the table. The proposed $19 million cut to the LIGO operations budget (a reduction from 2024 of some 40 percent) would be an act of stunning shortsightedness. With only one LIGO detector running, we will detect just 10 to 20 percent of the events we would have seen with both detectors operating. As a result, the U.S. will rapidly lose its leadership position in one of the most groundbreaking areas of modern science. Gravitational-wave astronomy, apart from being a technical success, is a fundamental shift in how we observe the universe. Walking away now would be like inventing the microscope, then tossing it aside before we had a good chance to look through the lens. Here's why losing one detector has such a devastating impact: The number of gravitational-wave events we expect to detect depends on how far our detectors can 'see.' Currently, they can spot a binary black hole merger (like the one detected in 2015) out to a distance of seven billion light-years! With just one of the two LIGO detectors operating, the volume we can probe is reduced to just 35 percent of its original size, slashing the expected detection rate by the same fraction. Moreover, distinguishing real gravitational-wave signals from noise is extremely challenging. Only when the same signal is observed in multiple detectors can we confidently identify it as a true gravitational-wave event, rather than, say, the vibrations of a passing truck. As a result, with just one detector operating, we can confirm only the most vanilla, unambiguous signals. This means we will miss extraordinary events like the one announced in mid-July. Accounting for both the reduced detection volume and the fact that we can only confirm the vanilla events, we get to the dreaded 10 to 20 percent of the expected gravitational wave detections. Lastly, we will also lose the ability to follow up on gravitational-wave events with traditional telescopes. Multiple detectors are necessary to triangulate an event's position in the sky. This triangulation was essential for the follow-up of the first detection of a binary neutron star merger. By pinpointing the merger's location in the sky, telescopes around the world could be called into action to capture an image of the explosion that accompanied the gravitational waves. This led to a cascade of new discoveries, including the realization in 2017 that such mergers comprise one of the main sources of gold in the universe. Beyond LIGO, the proposed budget also terminates U.S. support for the European-led space-based gravitational-wave mission LISA and all but guarantees the cancellation of the next-generation gravitational wave detector Cosmic Explorer. The U.S. is thus poised to lose its global leadership position. As Europe and China move forward with ambitious projects like the Einstein Telescope, LISA and TianQin, this could result not only in missing the next wave of breakthroughs but also in a significant brain drain. We cannot predict what discoveries still lie ahead. After all, when Heinrich Hertz first confirmed the existence of radio waves in 1887, no one could have imagined they would one day carry the Internet signal you used to load this article. This underscores a vital point: while cuts to science may appear to have only minor effects in the short term, systematic defunding of the fundamental sciences undermines the foundation of innovation and discovery that has long driven progress in the modern world and fueled our economies. The detection of gravitational waves is a breakthrough on par with the first detections of x-rays or radio waves, but even more profound. Unlike those forms of light, which are part of the electromagnetic spectrum, gravitational waves arise from an entirely different force of nature. In a way, we have unlocked a new sense for observing the cosmos. It is as if before, we could only see the universe. With gravitational waves, we can hear all the sounds that come with it. Choosing to stop listening now would be foolish.
Hindustan Times
22-07-2025
- Science
- Hindustan Times
Violent Collision of Two Black Holes Rippled Across the Universe
Astrophysicists have discovered the largest known merger of two black holes to form a larger single hole about 225 times the mass of the sun. The violent collision between the spinning objects, one about 100 times the mass of the sun and the other about 140 times that amount, produced a gravitational wave that rippled across the universe. Scientists detected the faint signal using the Laser Interferometer Gravitational-Wave Observatory (LIGO), a facility that uses 2.5-mile long, L-shaped instruments in Hanford, Wash., and Livingston, La., in unison to detect and measure cosmic gravitational waves. The signal, only 0.2 second long, was picked up in 2023 and announced July 13 at a conference in Glasgow. The findings have been posted ahead of peer review on the preprint server arXiv. A black hole is an astronomical object with a gravitational pull so strong that nothing, not even light, can escape. While scientists have predicted the existence of black holes since the 18th century, direct evidence has only turned up recently. In 2015, scientists used the LIGO to make the first-ever detection of a gravitational wave, a distortion in the fabric of space caused by the acceleration of massive objects such as black holes or neutron stars. Gravitational waves carry information about their origins and the nature of gravity itself. The effort won the researchers a Nobel Prize in 2017. In 2019, scientists released the first image of a black hole at the center of a galaxy roughly 55 million light years from Earth, showing a fuzzy ring of oranges and yellows surrounding a dark center, where light is trapped by the object's massive gravitational pull. Because the 2023 gravitational wave only produced a small amount of data, scientists don't know exactly how far away the object is. 'It's kind of ridiculous to say, but it's sort of between three or four billion light years away and 12 to 13 billion light years away,' said Mark Hannam, an astrophysicist at the University of Cardiff in the U.K., and a member of the scientific team that discovered the object, named GW231123 for 'gravitational wave' and the date it was discovered. Hannam said there is still a lot that scientists are learning and that the two black holes could have formed through earlier mergers of even smaller black holes. 'We don't know how many black holes were merged in this process,' Hannam said. The two black holes could also have formed from stars colliding and forming more massive, highly spinning stars which then collapsed to form black holes, according to Vicky Kalogera, professor of physics and astronomy at Northwestern University and a member of the team that analyzed the signal. Either way, this finding has opened up new lines of research using gravitational wave detectors, according to Alessandra Corsi, professor of physics and astronomy at Johns Hopkins University who wasn't involved in the paper. 'What excites me is finding different ways of studying the cosmos that are telling you, hey, there's surprising things that are going on,' she said. Write to Eric Niiler at
Yahoo
21-07-2025
- Science
- Yahoo
Scientists Found a Black Hole That Shouldn't Exist. Now Physics Has a Problem.
Here's what you'll learn when you read this story: Over the past decade, the LIGO-Virgo-KAGRA (LVK) network has detected hundreds of black hole mergers, but none quiet as large as GW231123. At 225 solar masses, the black hole resulting from the merger far exceeds previous record holder GW190521, which weighed in at 140 solar masses. This black holes involved in this merger were actually so large that they challenge some of our understanding of stellar evolution. The Laser Interferometer Gravitational-wave Observatory, or LIGO, made major headlines in 2015 when scientists confirmed the first ever detection of gravitational waves—ripples in spacetime caused by highly energetic deep space phenomena (think: black hole mergers, supernovae, and neutron star collisions). This particular detection originated from a black hole merger that created a new black hole 62 times the mass of our Sun. The LIGO-Virgo-KAGRA (LVK) network of gravitational wave detectors hasn't let off the gas in the decade since, and has made hundreds of confirmed gravitational-wave detections, including the first neutron star merger in 2017 and the largest black hole merger (clocking in at 140 solar masses) in 2021. Now, in a preprint uploaded to the arXiv server, LVK scientists have provided evidence that there's a new heavyweight champion—a merger that produced a new 255-solar-mass black hole. Designated GW231123 for the date it was discovered (November 23, 2023, during the fourth observing run of the LVK network), this black hole is actually too big, according to our current best understanding of physics. 'This is the most massive black hole binary we've observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,' Mark Hannam, a member of the LVK Collaboration from Cardiff University, said in a press statement. 'Black holes this massive are forbidden through standard stellar evolution models.' To form this black hole, the two black hole predecessors likely had to measure around 100 and 140 times the mass of the Sun, respectively. This means they potentially lie in what's known as the 'upper-mass gap'—a range of masses in which black holes aren't thought to form from stars directly (the resulting supernovae of these hugely massive stars should leave behind no stellar remnant at all). 'One possibility is that the two black holes in this binary formed through earlier mergers of smaller black holes." Hannam said. However, these black holes' masses aren't the only mystery, as both were spinning between 80 and 90 percent of their top speed limit. This makes them the highest spinning black holes ever recorded by LVK. 'The black holes appear to be spinning very rapidly—near the limit allowed by Einstein's theory of general relativity,' Charlie Hoy, another member of the LVK from the University of Portsmouth, said in a press statement. 'That makes the signal difficult to model and interpret. It's an excellent case study for pushing forward the development of our theoretical tools.' Because the detectors are sensitive to black holes of around 100 solar masses, detecting one more than double that size certainly pushes LIGO to its limits. According to Science News, the LVK network was only able to detect the smallest blip from this merger, with only around 0.1 seconds detected at the tail end of the collision. LIGO's decades-long mission to detect gravitational waves has given scientists a whole new understanding of the universe, and nearly a decade after its first detection, it shows no signs of stopping. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life? Solve the daily Crossword
CTV News
19-07-2025
- Science
- CTV News
‘Where do we come from?': U of M researchers help detect record-breaking black hole collision
CTV's Harrison Shin has more on the black hole discovery made by two University of Manitoba researchers. Two University of Manitoba researchers are exploring the cosmos with one philosophical question in mind. Dr. Samar Safi-Harb and postdoctoral fellow Nathan Steinle are part of a team using the Laser Interferometer Gravitational-Wave Observatory (LIGO), a facility capable of detecting gravitational waves. 'Not everything in the universe can be seen with light, and gravitational waves are a new way of looking at the universe. These are ripples in the fabric of space-time,' Safi-Harb said. LIGO recently detected a collision between two black holes — an event that stands out for its scale. 'It's the most massive black hole merger detected by LIGO. And by 'most massive,' I mean each of these black holes is more than 100 times the mass of the sun,' she said. Until now, black holes of this size had not been directly observed. LIGO's detection provides the first direct evidence of their existence, according to Safi-Harb. Steinle said the discovery raises fundamental questions. 'It's so important because we're not sure if there's an upper limit on the mass. Can it keep getting bigger and bigger until we all grow old?' he said. He added that the finding is just the beginning. 'It really gives you great hope. Once future detectors are built — and they'll have at least 10 times better sensitivity — we'll be able to do a lot more,' he said. For Safi-Harb, the discovery brings scientists one step closer to understanding the universe. 'Finding these extreme events — whether through light, gravitational waves or other cosmic messengers — really brings us a bit closer to understanding our cosmic origins,' she said.
The Hindu
18-07-2025
- Science
- The Hindu
New gravitational waves reveal black hole with ‘forbidden' mass
Scientists working with a network of observatories located around the world recently reported that they had detected a powerful and unusual burst of gravitational waves, which they called GW231123. The signal was traced back to two black holes colliding into each other on November 23, 2023. This isn't the first time the observatories have detected gravitational waves, but the event is special because of the extraordinary size of the black holes involved: they are much heavier than most seen before. More interesting is the fact that the heavier black hole appeared to have a 'forbidden' mass — a value inside a range called the pair instability mass gap — which challenges what physicists thought was possible for black holes created from dying stars. Imagine a massive star at the end of its life. Usually, very heavy stars explode in supernovae, leaving behind black holes. But theory predicts that no black holes should form with masses between about 60 and 130 times the mass of our sun. This is the pair instability mass gap: it's thought to exist because stars this large explode so violently that nothing remains, not even a black hole, just scattered gas. Above 130 solar masses, stars may skip the explosion and directly collapse to create supermassive black holes. So finding black holes in the mass gap raises important questions about how they got there. On November 23, 2023, the two Laser Interferometer Gravitational-wave Observatories (LIGO) in the U.S. detected a burst of gravitational waves, faint ripples in spacetime created by massive objects accelerating and colliding. The GW231123 event lasted only about one-tenth of a second and the signal was strong and clear. The collision happened about 2 billion lightyears away. Scientists at the LIGO as well as Virgo and KAGRA observatories in Italy and Japan, respectively, conducted a detailed analysis and determined the pre-merger mass of the two colliding black holes. The heavier one had 120-159 solar masses but likely centred at 137 solar masses. The lighter one weighed 51-123 solar masses but likely centred at 103 solar masses. The total mass involved in the collision was thus likely 190-265 solar masses, rendering GW231123 the most massive black hole merger ever seen with high confidence. The mass of the heavier black hole in the merger is right inside, or just above, the pair instability mass gap. The mass of the lighter one could also be in or near the gap, given the large uncertainty. According to theory, stars can't leave behind black holes in this range, so the scientists figure something else must be going on. They are already considering several explanations. One, for example, is called a hierarchical merger: smaller black holes could merge inside dense star clusters, then the resulting larger black holes merge again, building up over time and ending up inside the gap. This possibility finds some support from the fact that both black holes were spinning rapidly. Usually, black holes formed from individual stars aren't spinning this fast. Another possibility is a stellar merger. Sometimes, two stars might merge before they die, creating a much larger star that might collapse to form a black hole whose mass lands inside the gap. It's also possible these two black holes formed right after the Big Bang, by a process unrelated to stars, although this idea is in the realm of speculation. Yet other potential explanations include some stars losing less mass before exploding or hitherto entirely unknown processes. The main idea is that the detection of GW231123 suggests the universe can make black holes in the mass gap after all, and not just through the collapse of single stars. And that this fact means scientists' theories about the lives and deaths of massive stars need updating.
