Science debate in action. I started to express a sense of skeptical curiosity when it appeared that LIGO was detecting several signals in a year or two. That would mean there are several black holes merging, maybe too many?

[newscientist.com]

Exclusive: Grave doubts over LIGO’s discovery of gravitational waves

The news we had finally found ripples in space-time reverberated around the world in 2015. Now it seems they might have been an illusion

THERE was never much doubt that we would observe gravitational waves sooner or later. This rhythmic squeezing and stretching of space and time is a natural consequence of one of science’s most well-established theories, Einstein’s general relativity. So when we built a machine capable of observing the waves, it seemed that it would be only a matter of time before a detection.

In point of fact, it took two days. The Laser Interferometer Gravitational-Wave Observatory collaboration, better known as LIGO, switched on its upgraded detectors on 12 September 2015. Within 48 hours, it had made its first detection. It took a few months before the researchers were confident enough in the signal to announce a discovery. Headlines around the world soon heralded one of the greatest scientific breakthroughs of the past century. In 2017, a Nobel prize followed. Five other waves have since been spotted.

Or have they? That’s the question asked by a group of physicists who have done their own analysis of the data. “We believe that LIGO has failed to make a convincing case for the detection of any gravitational wave event,” says Andrew Jackson, the group’s spokesperson. According to them, the breakthrough was nothing of the sort: it was all an illusion.

The big news of that first sighting broke on 11 February 2016. In a press conference, senior members of the collaboration announced that their detectors had picked up the signature of gravitational waves emitted as a pair of distant black holes spun into one another.

The misgivings of Jackson’s group, based at the Niels Bohr Institute in Copenhagen, Denmark, began with this press conference. The researchers were surprised at the confident language with which the discovery was proclaimed and decided to inspect things more closely.

Their claims are not vexatious, nor do they come from ill-informed troublemakers. Although the researchers don’t work on gravitational waves, they have expertise in signal analysis, and experience of working with large data sets such as the cosmic microwave background radiation, the afterglow of the big bang that is spread in a fine pattern across the sky. “These guys are credible scientists,” says Duncan Brown at Syracuse University in New York, a gravitational wave expert who recently left the LIGO collaboration.

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