That growth in knowledge could be hampered by the administration of US President Donald Trump and its proposed cuts to the US National Science Foundation, which runs LIGO. Under the proposal, one of LIGO’s two gravitational-wave observatories would be shut down.
At the time of this detection in November 2023, Virgo and KAGRA were not operational. Without two detectors, scientists would not have been sure that they had made a real detection of two merging black holes, says Hannam. “Because we had two detectors, we saw the same blip at the same time,” he says.
The closure of one of the observatories would be “catastrophic”, says Natarajan. “This discovery would not be possible if one arm was turned off.”
Planned upgrades to LIGO in the coming years, and the addition of new detectors around the world, including one in India, could greatly increase physicists’ capabilities in gravitational-wave research, an area of astronomy that is still in its infancy.
“We’re going to be seeing thousands of black holes in the next few years,” says Hannam. “There’s this huge investment that’s been done, and it’s only just beginning to pay off.”
This article is reproduced with permission and was first published on July 15, 2025. {read}