After the historic announcement in February 2016 hailing the discovery of gravitational waves, it didn’t take long for skeptics to emerge. The detection of these feeble undulations in the fabric of space and time by the Laser Interferometer Gravitational-Wave Observatory (LIGO) was said to have opened a new ear on the cosmos. But the following year, a group of physicists at the Niels Bohr Institute in Copenhagen published a paper casting doubt on LIGO’s analysis.