Third gravitational wave merger detected


Observation of the merger of two black holes in January by scientists at LIGO confirms a pattern.


  • Named GW170104, this signal marks the third confirmed detection of gravitational waves coming from a binary black hole merger.
  • It is of great interest to the scientific community that the black holes, having masses nearly 31 times and 19 times the sun’s mass.
  • The Indian space-based ASTROSAT mission did a related sensitive search for short duration x-ray flashes associated with the event and did not detect any.
  • At LIGO, this time around, the detection has revealed not merely a black-hole merger but also the alignment of the spins of the black holes.
  • This can shed light on the way the black holes might have formed. In this event, the spins of the individual black holes making up the merger are probably not aligned along the same direction.
  • This supports the theory which says that black holes form independently in a star cluster, then sink to the centre of the cluster and eventually merge. the detection does not favor the competing theory according to which binary black holes form in pairs even at the start and eventually merge.

Einstein’s General Theory of Relativity

  • The observation also supports Einstein’s General Theory of Relativity.
  • Albert Einstein, in his theory of special relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels.
  • According to this theory, gravitational waves, unlike light waves, will not disperse as they travel through space. This, too, has been confirmed by the analysis of the latest signal.


The study had a major Indian contribution and the LIGO-India facility which is making immense progress will join the club in 2024.


The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool.


What are Gravitational waves?

Gravitational waves are ‘ripples’ in the fabric of space-time caused by some of the most violent and energetic processes in the Universe. The strongest gravitational waves are produced by catastrophic events such as colliding black holes, the collapse of stellar cores (supernovae), coalescing neutron stars or white dwarf stars and the remnants of gravitational radiation… Continue reading What are Gravitational waves?

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