Gravitational waves spotted again
June 15, 2016
Scientists from the LIGO and Virgo collaborations received an unexpected Christmas gift last year, it was revealed Wednesday, when LIGO detectors recorded a new gravitational wave signal, three months after they were first detected.
As with the first, “the signal came from the final ‘dance' of two black holes on the point of merging,” the National Center for Scientific Research (CNRS) reported.
Gravitational waves carry information about their origins and about the nature of gravity which is unable to be obtained otherwise. Physicists working with the LIGO and Virgo teams determined the final moments of a black hole merger generated the gravitational waves which were observed on December 26 last year.
Although weaker than the first signal, this second observation of gravitational waves confirms that such cataclysmic events are a relatively frequent phenomenon, meaning there is a high chance more will be detected in late 2016, when both the twin LIGO detectors and the Virgo collaboration resume data collection following upgrade works, the CNRS said.
Wednesday's news will “help scientists to better understand pairs of black holes, bodies that are so dense that neither light nor matter can escape from them,” the research center added.
Century-old theory
Albert Einstein posited the existence of gravitational waves a century ago in his Theory of Relativity. He described how waves were produced by disturbances in the fabric of space and time when a massive object - such as a black hole or a neutron star - moved through space-time.
Einstein theorized that gravitational waves would appear like ripples in a pond that formed when a stone was thrown into the water.
Until September last year, scientists had only been able to find indirect evidence of their existence, with gravitational waves being extremely hard to measure.