An initial one-year run with a total of five detectors was unable to detect any gravitational waves, but the researchers see it as a great success nevertheless. Until now, the detectors, which consist of metal cylinders cooled to temperatures near Absolute Zero, were always used in stand-alone operation, which increases the risk of false alarms due to minimal seismic vibrations. The physicists reckon the likelihood of a false alarm occurring is about once in a million years of operation.
Gravitational waves are tiny deformities in space, that spread at the speed of light.
They may be triggered when neutron stars crash into each other, or when a star collapses to a black hole. The detector network's readings show that such events occur less than once a year in our Milky Way.