When you buy through links on our articles, Future and its syndication partners may earn a commission.(Main) An illustration of merging black holes. (Inset) Black hole masses in mergers detected in gravitational waves. | Credit: Robert Lea/LIGO-Kagra-VIRGO/Aaron Geller/NorthwesternAstronomers have struck “black gold” — a treasure trove of black hole mergers. And the discovery was made by analyzing ripples in the very fabric of space and time, or spacetime, called gravitational waves.This massive haul of mergers contained within the Gravitational Wave Transient Catalogue-5.0 (GWTC-5), released on Tuesday (May 26), could change our understanding of how black holes meet and collide. The latest catalog contains 161 new gravitational wave signals launched by merging black holes “heard” by iconic gravitational wave detectors LIGO (Laser Interferometer Gravitational-Wave Observatory), Virgo, and KAGRA (Kamioka Gravitational Wave Detector) between April 2024 and the end of January 2025.AdvertisementAdvertisementIt brings the total number of black hole mergers detected via gravitational waves up to 390.Highlights of GWTC-5 include the detection of “second generation mergers,” or collisions between two black holes that had formed in previous mergers, and the most precisely localized merger ever. While the former could help us better understand merger chains that allow black holes to grow to masses millions or even billions of times that of the sun, the latter could help develop a method of using such events and their gravitational wave signals to measure the rate at which the universe is expanding.”This bumper update has once again broadened and deepened our knowledge of the universe, and given us many more glimpses of its most elusive objects: colliding black holes,” Daniel Williams, a research fellow at the Institute for Gravitational Research, said in a statement. “We’re now detecting so many of these signals that we’re not just learning about individual collisions; it’s the astronomical equivalent of uncovering an ancient civilization.”Today’s new results are like finding a previously undiscovered hoard, revealing not just individual lives, but the structure of an entire lost world.”What are gravitational waves?Gravitational waves were first proposed in 1915 as part of Albert Einstein’s theory of gravity, known as general relativity. General relativity suggests that objects with mass cause spacetime (the four-dimensional unification of space and time) to warp. Gravity arises from this warping, meaning the larger the mass, the greater the curvature of spacetime and the stronger the gravitational influence.AdvertisementAdvertisementGeneral relativity goes beyond this, also suggesting that when objects accelerate in spacetime, they create ripples that radiate outward at the speed of light: gravitational waves. Though Einstein initially predicted this rippling of spacetime, he was wrong about one aspect of gravitational waves: he thought humanity would never detect them.LIGO made the first detection of gravitational waves in 2015; the signal came from the collision and merger of two massive black holes located around 1.3 billion light-years away. Since then, along with its fellow detectors Virgo and KAGRA, LIGO has detected gravitational waves from many mergers between pairs of black holes, pairs of ultra-dense neutron stars — and even mixed mergers between a black hole and a neutron star.Detected black hole masses organized on a diagram. | Credit: LIGO-Kagra-VIRGO/Aaron Geller/NorthwesternThe sensitivity of the gravitational wave detectors has only increased in recent years, with detections currently occurring as frequently as three to four times …
