A COLLISION between two black holes was detected for the first time on 14 September 2015. It happened more than a billion years ago, but it generated ripples in the fabric of space-time, called gravitational waves, that were eventually detectable on Earth.
Researchers have since made countless discoveries about events in the universe using the Laser Interferometer Gravitational-Wave Observatory (LIGO), two widely separated gravitational-wave detectors based in the US. Now, they need your help to distinguish more signals from the noise.
Gravitational waves stretch and squeeze everything they pass through. These effects can be used to work out …