Gravitational Waves Current Affairs - 2020

Scientists detect Gravitational waves for second time

Scientists for the second time have successfully detected gravitational waves created by the collision of two black holes 1.4 billion light years away.

These waves were detected using the twin Laser Interferometer Gravitational-wave Observatory (LIGO) interferometers in the US.

This second detection of gravitational waves once again confirms Einstein’s theory of general relativity and successfully tested LIGO’s ability to detect incredibly subtle gravitational signals.

Key Facts

  • The detection was made by the LIGO’s twin detectors in Louisiana and Washington on 26 December 2015 when the waves hit the observatory.
  • The second detection lasted for about a full second and was 5 times longer than the first one announced in February 2016.
  • Using advanced data analysis techniques, the team of researchers determined the waveform signalled a gravitational wave.
  • They also calculated that the gravitational wave arose from the collision of two black holes, 14.2 and 7.5 times the mass of the Sun.
  • The first detection reported on February 11, 2016 had lasted for 1.1 milliseconds and was very faint signal amid the surrounding noise. It had produced a clear peak in the data.
  • The second detection was far subtler, generating a shallower waveform that was almost buried in the data.

What are Gravitational Waves?

In physics, gravitational waves are ripples in the curvature of spacetime which propagate as waves, travelling outward from the source at the speed of light. They were first predicted in 1916 by Albert Einstein on the basis of his Theory of General Relativity. Gravitational waves transport energy as gravitational radiation and pass through matter without interacting with it.

India, US ink MoU for setting up LIGO observatory in India

India has signed a memorandum of Understanding (MoU) with the United States for setting up Laser Interferometer Gravitational-wave Observatory (LIGO) in India. LIGO is a large-scale physics experiment and observatory to detect gravitational waves.

The MoU was signed in the presence of Prime Minister Narendra Modi on the sidelines of the Nuclear Security Summit in Washington.

Key facts

  • The agreement was signed between the US’s National Science Foundation (NSF) and India’s Department of Atomic Energy (DAE) and Department of Science and Technology (DST).
  • As part of the agreement, the scientists of DAE, DST and NSF will form a Joint Oversight Group (JOG) for better coordination of the project.


Earlier in February 2016, the Union Cabinet had approved Rs 1200 crores for the LIGO India project. It will be third LIGO interferometer in the world and it is expected to be functional by 2023. It will significantly improve the ability of scientists to pinpoint the sources of gravitational waves and analyse the signals.

Presently there are twin LIGO Observatories at Hanford, Washington, and Livingston, Louisiana. They are funded by the US National Science Foundation (NSF) and were conceived, built, and are operated by Massachusetts Institute of Technology (MIT) and Caltech.

For more information: (i) Cabinet Approval (ii) Gravitational Waves