Q. Recently, Scientists observed the merger of giant blackholes’ billions of light-years away from the Earth. What is the significance of this observation?
- ‘Higgs boson particles’ were detected.
- ‘Gravitational waves’ were detected.
- Possibility of inter-galactic space travel through ‘wormhole’ was confirmed.
- It enabled the scientists to understand ‘singularity’.
Answer: (b) ‘Gravitational waves’ were detected.
Gravitational Waves
- Gravitational waves are waves of the intensity of gravity that are generated by the accelerated masses of binary stars and other motions of gravitating masses, and propagate as waves outward from their source at the speed of light.
- Albert Einstein predicted their existence in his general theory of Relativity in 1916.
- Production of Gravitational Waves:
- Cataclysmic Events: The strongest gravitational waves originate from colliding black holes, supernovae, and colliding neutron stars.
- Neutron Star Rotation: Gravitational waves can also be produced by the rotation of non-perfectly spherical neutron stars and possibly remnants of gravitational radiation from the Big Bang.
- Features and Detection
- Gravitational waves are challenging to detect due to their weak interaction with matter. Sensitive instruments like interferometers, such as the LIGO, are developed to detect gravitational waves by measuring tiny disturbances in space-time.
- The first direct observation of gravitational waves was made in 2015, when a signal generated by the merger of two black holes was received by the LIGO gravitational wave detectors in Livingston, Louisiana, and in Hanford, Washington.
- Why detect them?
- Gravitational waves provide a new way of observing the universe, allowing scientists to study and explore phenomena that were previously inaccessible.
- They provide valuable information about astrophysical events, such as the merger of black holes or neutron stars.
- They can offer insights into the nature of gravity, the properties of massive objects, and the early universe itself.
Giant Metrewave Radio Telescope (GMRT)
- GMRT is a low-frequency radio telescope that helps investigate various radio astrophysical problems ranging from nearby solar systems to the edge of the observable universe.
- Located at Khodad, 80 km north of Pune, the telescope is operated by the National Centre of Radio Astrophysics (NCRA).
- NCRA is a part of the Tata Institute of Fundamental Research (TIFR), Mumbai.
- GMRT is a project of the Department of Atomic Energy (DAE), operating under the Tata Institute of Fundamental Research (TIFR).
- It consists of 30 fully- steerable dish type antennas of 45-meter diameter each, spread over a 25-km region.
- GMRT is presently the world’s largest radio telescope operating at meter wavelength.
- GMRT is a very versatile instrument for investigating a variety of radio astrophysical problems. Two of its most important astrophysical objectives are:
- to detect the highly redshifted spectral line of neutral Hydrogen expected from protoclusters or protogalaxies before they condensed to form galaxies in the early phase of the Universe;
- Redshift represents the signal’s wavelength change depending on the object’s location and movement.
- to search for and study rapidly-rotating Pulsars in our galaxy.
- Pulsars are rapidly rotating neutron stars with extremely high densities.
- A pulsar is like a cosmic lighthouse as it emits radio beams that flashes by the Earth regularly akin to a harbour lighthouse.
- to detect the highly redshifted spectral line of neutral Hydrogen expected from protoclusters or protogalaxies before they condensed to form galaxies in the early phase of the Universe;